Science.gov

Sample records for accelerated succession experiment

  1. Wetland reclamation by accelerating succession

    SciTech Connect

    Rushton, B.T.

    1988-01-01

    This research analyzed mechanisms and processes for accelerating natural succession in order to restore soils and forests on clay setting areas left from phosphate mining in central Florida. Field measurements of succession on unreclaimed clay ponds showed wet sites dominated by dense stands of small shrubby willows even after 60 years with succession arrested because of a shortage of seeds for later stage trees. For drier sites an orderly procession of pioneer wetland trees colonized when wetland seed sources were within 20 meters. The first woody species were willows, myrtles, and baccharis followed in 5 to 10 years by red maple and elm. Oaks colonized slightly drier elevations. Hackberry, cherry, and sweetgum were also found. Experiments in which 3000 seedlings of 11 species were planted in six clay settling areas demonstrated succession can be accelerated. After the first growing season, results suggest that mixed swamp vegetation typical of floodplains may be the most suitable forested wetland community for settling pond reclamation. Percent survival was best for Carolina ash, American elm, and red maple. Some alluvial floodplain species were intermediate in success with 74% survival for baldcypress, 61% for sweetgum, and 61% for laurel oak. Trees from bayheads had the least survival with 52% for swampbay and 41% for loblolly bay. Poorest survival for all species planted (39%) was swamp tupelo. Floodplain species which required fairly dry conditions had poor survival, i.e., southern magnolia (53%) and cabbage palm (43%). Planted tree seedlings were more cost effective than placing seeds on the ground and covering them with litter. A simulation model with hydrologic regimes and outside seeding was used to summarize the operation of the successional system. Simulation that suggested trends for a longer time period than those observed in the field trials are yet to be confirmed.

  2. High rates of carbon storage in old deciduous forests: Emerging mechanisms from the Forest Accelerated Succession ExperimenT (FASET)

    NASA Astrophysics Data System (ADS)

    Gough, C. M.; Nave, L. E.; Hardiman, B. S.; Bohrer, G.; Halperin, A.; Maurer, K.; Le Moine, J.; Nadelhoffer, K.; Vogel, C. S.; Curtis, P.; University Of Michigan Biological Station Forest Ecosystem Study (Umbs-Fest) Team

    2010-12-01

    Deciduous forests of the eastern US are broadly approaching an ecological threshold in which early successional dominant trees are senescing and giving way to later successional species, with unknown consequences for regional carbon (C) cycling. Though recent research demonstrates that forests may accumulate C for centuries, the mechanisms behind sustained rates of C storage in old, particularly deciduous, forests have not been identified. In a regionally representative forest at the University of Michigan Biological Station, we are combining observational and experimental C cycling studies to forecast how forest C storage responds to climate variation, disturbance, and succession. The Forest Accelerated Succession ExperimenT (FASET), in which >6,700 aspen and birch trees (~35 % LAI) were stem girdled within a 39 ha area, is testing the hypothesis that forest production will increase rather than decline with age, due to increases in nitrogen (N) availability, N allocation to the canopy, and the concurrent development of a more biologically and structurally complex canopy. Results thus far support our hypothesis that aging forests in the region may sustain high rates of C storage through shifts in N cycling and increased canopy complexity. Girdling-induced mortality of early successional species reduced soil respiration, accelerated fine root turnover, and prompted the redistribution of N from the foliage of early to later successional species. Nitrogen redistribution increased leaf area index (LAI) production by later successional species, offsetting declines in LAI from senescing early successional species. High rates of net primary production (NPP) were sustained in stands comprising a diverse assemblage of early and later successional species because later successional species, when already present in the canopy, rapidly compensated for declining growth of early successional species. Canopy structural complexity, which increased with forest age, was positively

  3. Principal Experiences of Succession

    ERIC Educational Resources Information Center

    Steele, Farla Gay

    2015-01-01

    This multiple case study explored the experiences of school principals and the usefulness of Peters' (2011) succession planning model. Ten purposefully selected principals from varying grade levels were interviewed; none reported a formal succession plan, and all had been assistant principals. The study concluded the assistant principal position…

  4. Nutrient Addition Dramatically Accelerates Microbial Community Succession

    PubMed Central

    Knelman, Joseph E.; Schmidt, Steven K.; Lynch, Ryan C.; Darcy, John L.; Castle, Sarah C.; Cleveland, Cory C.; Nemergut, Diana R.

    2014-01-01

    The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients – important drivers of plant succession – affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession. PMID:25050551

  5. Accelerated Baccalaureate Nursing Students: Perceptions of Success

    ERIC Educational Resources Information Center

    Blozen, Barbara B.

    2010-01-01

    Although there are a number of anecdotal reports on demographic characteristics and academic success of accelerated nursing students, few empirical studies have been undertaken to examine these students' success, despite this type of programs' existence for more than a decade, and only three studies have sought to examine the perspective of the…

  6. Non-accelerator experiments

    SciTech Connect

    Goldhaber, M.

    1986-01-01

    This report discusses several topics which can be investigated without the use of accelerators. Topics covered are: (1) proton decay, (2) atmospheric neutrinos, (3) neutrino detection, (4) muons from Cygnus X-3, and (5) the double-beta decay.

  7. Laboratory Reconnection Experiments - heating and particle acceleration

    NASA Astrophysics Data System (ADS)

    Ono, Yasushi

    Recent laboratory merging/ reconnection experiments have solved a number of key physics of magnetic reconnection: 1) reconnection heating/ acceleration, 2) fast reconnection mechanisms, 3) plasmoid reconnection, 4) non-steady reconnection and 5) non-thermal particle acceleration using new kinetic interpretations. Especially, significant ion temperatures 1.2keV were documented in the world-largest tokamak merging experiment: MAST after detailed 2D elucidation of ion and electron heating characteristics in TS-3 and 4 merging experiments. The measured 2D contours of ion and electron temperatures in TS-3, 4 and MAST reveal ion heating in the downstream by reconnection outflow and electron heating around the X-point by ohmic heating of current sheet. Their detailed heating mechanisms were further investigated by comparing those results with particle simulations developed by NIFS. The ion acceleration mechanism is mostly parallel acceleration by reconnection electric field and partly perpendicular acceleration by electrostatic potential. The fast shock and ion viscosity are the major dumping (heating) mechanisms for the accelerated ions. We successfully applied the reconnection heating - typically 10-50MW to the high-beta spherical tokamak formation and heating. This paper will review major progresses in those international and interdisciplinary merging tokamak experiments.

  8. FXR accelerator cavity impedance experiments

    SciTech Connect

    Avalle, C.A.

    1998-01-05

    One of the goals of the present Flash X-Ray (FXR) accelerator upgrade effort [1][2] at Lawrence Livermore National Laboratory (LLNL) is to reduce the cavity transverse impedance, since it has been shown that beam stability is significantly affected by this parameter [3]. Recently, we have evaluated various techniques and cell modifications to accomplish that, both through lab measurements and computer models. A spare cell, identical in every way to cells in the accelerator, was specially modified for the experiments. The impedance measurements were done without the beam, by applying twin-wire techniques. This report describes the results of these experiments and suggests possible cell modifications to improve their performance. The techniques and modifications which are suggested might also be applicable to AHF and DARHT-2 long-pulse accelerator development.

  9. Accelerator physics experiments at Aladdin

    SciTech Connect

    Chattopadhyay, S.; Cornacchia, M.; Jackson, A.; Zisman, M.S.

    1985-07-01

    The Aladdin accelerator is a 1 GeV synchrotron light source located at the University of Wisconsin. The results of experimental studies of the Aladdin accelerator are described. The primary purpose of the experiments reported was to investigate reported anomalies in the behavior of the linear lattice, particularly in the vertical plane. A second goal was to estimate the ring broadband impedance. Experimental observations and interpretation of the linear properties of the Aladdin ring are described, including the beta function and dispersion measurements. Two experiments are described to measure the ring impedance, the first a measurement of the parasitic mode loss, and the second a measurement of the beam transfer function. Measurements of the longitudinal and transverse emittance at 100 and 200 MeV are described and compared with predictions. 10 refs., 24 figs., 2 tabs. (LEW)

  10. Deuterium accelerator experiments for APT.

    SciTech Connect

    Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

  11. An Accelerated Collaboration Meets with Beaming Success

    SciTech Connect

    Hazi, A U

    2007-02-09

    Maintaining a smaller, aging U.S. nuclear weapons stockpile without underground nuclear testing requires the capability to verify and validate the complex computer calculations on which stockpile confidence is based. This capability, in turn, requires nonnuclear hydrodynamic tests (hydrotests) that can x-ray stages of the implosion process, providing freeze-frame photos of materials imploding at speeds of more than 16,000 kilometers per hour. The images will yield important information on shapes and densities of metals and other materials under the extreme pressures and temperatures generated by the detonation of high explosives. The Dual-Axis Radiographic Hydrodynamics Test (DARHT) Facility at Los Alamos national Laboratory is a two-arm x-ray imaging system that will provide such images, capturing the inner workings of a mock nuclear explosion with high resolution. Scientists compare the radiographic images with computer models, examine the differences, and refine the models to more accurately represent weapon behavior. One of DARHT's arms (now called DARHT-II) recently got a ''leg up'' through a collaboration of Lawrence Livermore and Los Alamos scientists, using a Livermore accelerator to test its subsystems and codes.

  12. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  13. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Roberts, W. T.

    1985-01-01

    The space experiments with particle accelerators (SEPAC) instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  14. Inverse Cerenkov laser acceleration experiment at ATF

    NASA Astrophysics Data System (ADS)

    Wang, X. J.; Pogorelsky, I.; Fernow, R.; Kusche, K. P.; Liu, Y.; Kimura, W. D.; Kim, G. H.; Romea, R. D.; Steinhauer, L. C.

    Inverse Cerenkov laser acceleration was demonstrated using an axicon optical system at the Brookhaven Accelerator Test Facility (ATF). The ATF S-band linac and a high power 10.6 MICROMETERSCO2 laser were used for the experiment. Experimental arrangement and the laser and the electron beams synchronization are discussed. The electrons were accelerated more than 0.7 MeV for a 34 MW CO2 laser power. More than 3.7 MeV acceleration was measured with 0.7 GW CO2 laser power, which is more than 20 times of the previous ICA experiment. The experimental results are compared with computer program TRANSPORT simulations.

  15. Successful Experiences in Teaching Metric.

    ERIC Educational Resources Information Center

    Odom, Jeffrey V., Ed.

    In this publication are presentations on specific experiences in teaching metrics, made at a National Bureau of Standards conference. Ideas of value to teachers and administrators are described in reports on: SI units of measure; principles and practices of teaching metric; metric and the school librarian; teaching metric through television and…

  16. Field experiments of success-breeds-success dynamics.

    PubMed

    van de Rijt, Arnout; Kang, Soong Moon; Restivo, Michael; Patil, Akshay

    2014-05-13

    Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive feedback operating on arbitrary initial advantages may increasingly set apart winners from losers, producing runaway inequality. To identify social feedback in human reward systems, we conducted randomized experiments by intervening in live social environments across the domains of funding, status, endorsement, and reputation. In each system we consistently found that early success bestowed upon arbitrarily selected recipients produced significant improvements in subsequent rates of success compared with the control group of nonrecipients. However, success exhibited decreasing marginal returns, with larger initial advantages failing to produce much further differentiation. These findings suggest a lesser degree of vulnerability of reward systems to incidental or fabricated advantages and a more modest role for cumulative advantage in the explanation of social inequality than previously thought. PMID:24778230

  17. Field experiments of success-breeds-success dynamics

    PubMed Central

    van de Rijt, Arnout; Kang, Soong Moon; Restivo, Michael; Patil, Akshay

    2014-01-01

    Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive feedback operating on arbitrary initial advantages may increasingly set apart winners from losers, producing runaway inequality. To identify social feedback in human reward systems, we conducted randomized experiments by intervening in live social environments across the domains of funding, status, endorsement, and reputation. In each system we consistently found that early success bestowed upon arbitrarily selected recipients produced significant improvements in subsequent rates of success compared with the control group of nonrecipients. However, success exhibited decreasing marginal returns, with larger initial advantages failing to produce much further differentiation. These findings suggest a lesser degree of vulnerability of reward systems to incidental or fabricated advantages and a more modest role for cumulative advantage in the explanation of social inequality than previously thought. PMID:24778230

  18. Success of myringoplasty: our experience.

    PubMed

    Kamath, M Panduranga; Sreedharan, Suja; Rao, A Raghavendra; Raj, Vinay; Raju, Krishnam

    2013-12-01

    The purpose of this study is to compare the efficacy of myringoplasty with or without cortical mastoidectomy in terms of freedom from discharge, graft take up and improvement in hearing. This is a Clinical prospective study of 120 patients from among a group of patients with chronic suppurative otitis media. A detailed history and examination was conducted including pure tone audiogram. Patients were randomly divided into two groups; group A would undergo myringoplasty only and group B would undergo cortical mastoidectomy with myringoplasty. Patients were reviewed after 3 weeks for inspection of the operated ear. Second post-operative review was at 3 months for clinicoaudiological assessment. Group B was found to have slightly more improvement as compared to the other group. No significant difference in the success rates of graft take-up in patients with unilateral or bilateral disease was found. Higher take up rates were seen in large (91.83 %) and medium perforations (90.69 %). In all our failed cases, post-operative ear discharge continued to be a persistent and troubling problem. The average audiological gain was 12.88 dB in group B, whereas it was 12.40 dB in group A. The reduction of air bone gap within each group was found to be significant. There is no statistical significant data indicating that tympanoplasty with mastoidectomy yields better results. When considering the addition of a mastoidectomy to a Tympanoplasty, the performing surgeon should consider not only the potential added benefit but also potential risks and costs to the patient. PMID:24427599

  19. The Transition Experiences of Successful Chinese Immigrants

    ERIC Educational Resources Information Center

    Amundson, Norman E.; Yeung, Thomas; Sun, Iris; Chan, Keith; Cheng, Johnny

    2011-01-01

    This article focused on the transition experiences of 20 successful Chinese immigrants, in particular their transition stories and how they accounted for their success (what facilitated and hindered their transition). An enhanced critical incident method was used for data analysis. Four major success categories emerged: having a positive attitude…

  20. Disturbance-mediated accelerated succession in two Michigan forest types

    USGS Publications Warehouse

    Abrams, Marc D.; Scott, Michael L.

    1989-01-01

    In northern lower Michigan, logging accelerated sugar maple (Acer saccharum) dominance in a northern white cedar (Thuja occidentals) community, and clear-cutting and burning quickly converted certain sites dominated by mature jack pine (Pinus banksiana) to early-succesional hardwoods, including Prunus, Populus, and Quercus. In both forest types the succeeding hardwoods should continue to increase in the future at the expense of the pioneer conifer species. In the cedar example, sugar maple was also increasing a an undisturbed, old-growth stand, but at a much reduced rate than in the logged stand. Traditionally, disturbance was through to set back succession to some earlier stage. However, out study sites and at least several other North American forest communities exhibited accelerated succession following a wide range of disturbances, including logging fire, ice storms, wind-throw, disease, insect attack, and herbicide spraying.

  1. Accelerator/Experiment Operations - FY 2010

    SciTech Connect

    Adamson, M.; Appel, J.A.; Casarsa, M.; Coleman, R.; Denisov, D.; Dixon, R.; Escobar, C.; Ginther, G.; Gruenendahl, S.; Harris, D.; Henderson, S.; /Fermilab

    2010-11-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2010. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2010 Run II at the Tevatron Collider, the MINOS and MINER?A experiments using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  2. Accelerator/Experiment Operations - FY 2011

    SciTech Connect

    Adamson, P.; Bernardi, G.; Casarsa, M.; Coleman, R.; Denisov, D.; Dixon, R.; Ginther, G.; Gruenendahl, S.; Hahn, S.; Harris, D.; Henderson, S.

    2011-11-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2011. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2011 Run II at the Tevatron Collider, the MINOS and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  3. Accelerator/Experiment operations - FY 2004

    SciTech Connect

    Bromberg, C.; Conrad, J.; Denisov, D.; Holmes, S.; Louis, W.; Meyer, A.; Moore, Craig D.; Raja, R.; Ramberg, E.; Roser, R.; /Fermilab

    2004-12-01

    This Technical Memorandum (TM) summarizes the accelerator and experiment operations for FY 2004. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2004 Run II at the Tevatron Collider, the MiniBooNE neutrino experiment, and SY 120 activities.

  4. Accelerated Application Development: The ORNL Titan Experience

    SciTech Connect

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; Philip, Bobby; Sankaran, Ramanan; Tharrington, Arnold N.; Turner, John A.

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this paper we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.

  5. Accelerated Application Development: The ORNL Titan Experience

    DOE PAGESBeta

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; et al

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

  6. Inverse Cerenkov laser acceleration experiment at ATF

    SciTech Connect

    Wang, X.J.; Pogorelsky, I.; Fernow, R.; Kusche, K.P.; Liu, Y.; Kimura, W.D.; Kim, G.H.; Romea, R.D.; Steinhauer, L.C.

    1994-09-01

    Inverse Cerenkov laser acceleration was demonstrated using an axicon optical system at the Brookhaven Accelerator Test Facility (ATF). The ATF S-band linac and a high power 10.6 {mu}m CO{sub 2} laser were used for the experiment. Experimental arrangement and the laser and the electron beams synchronization are discussed. The electrons were accelerated more than 0.7 MeV for a 34 MW CO{sub 2} laser power. More than 3.7 MeV acceleration was measured with 0.7 GW CO{sub 2} laser power, which is more than 20 times of the previous ICA experiment. The experimental results are compared with computer program TRANSPORT simulations.

  7. Space experiments with particle accelerators: SEPAC

    NASA Technical Reports Server (NTRS)

    Roberts, B.

    1986-01-01

    The SEPAC instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam-particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  8. The FRC Acceleration Space Thruster (FAST) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, Adam; Eskridge, Richard; Houts, Mike; Slough, John; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The objective of the FRC (Field Reversed Configuration) Acceleration Space Thruster (FAST) Experiment is to investigate the use of a repetitive FRC source as a thruster, specifically for an NEP (nuclear electric propulsion) system. The Field Reversed Configuration is a plasmoid with a closed poloidal field line structure, and has been extensively studied as a fusion reactor core. An FRC thruster works by repetitively producing FRCs and accelerating them to high velocity. An FRC thruster should be capable of I(sub sp)'s in the range of 5,000 - 25,000 seconds and efficiencies in the range of 60 - 80 %. In addition, they can have thrust densities as high as 10(exp 6) N/m2, and as they are inductively formed, they do not suffer from electrode erosion. The jet-power should be scalable from the low to the high power regime. The FAST experiment consists of a theta-pinch formation chamber, followed by an acceleration stage. Initially, we will produce and accelerate single FRCs. The initial focus of the experiment will be on the ionization, formation and acceleration of a single plasmoid, so as to determine the likely efficiency and I(sub sp). Subsequently, we will modify the device for repetitive burst-mode operation (5-10 shots). A variety of diagnostics are or will be available for this work, including a HeNe interferometer, high-speed cameras, and a Thomson-scattering system. The status of the experiment will be described.

  9. Accelerator/Experiment Operations - FY 2007

    SciTech Connect

    Brice, S.; Buchanan, N.; Coleman, R.; Convery, M.; Denisov, D.; Ginther, G.; Habig, A.; Holmes, S.; Kissel, W.; Lee, W.; Nakaya, T.; /Fermilab

    2007-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2007. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2007 Run II at the Tevatron Collider, the MiniBooNE and SciBooNE experiments running in the Booster Neutrino Beam (BNB), MINOS using the Main Injector Neutrino Beam (NuMI), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  10. Accelerator/Experiment Operations - FY 2008

    SciTech Connect

    Brice, Stephen J.; Buehler, M.; Casarsa, M.; Coleman, R.; Denisov, D.; Ginther, G.; Grinstein, S.; Habig, A.; Holmes, S.; Hylen, J.; Kissel, W.; /Fermilab

    2008-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2008. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2008 Run II at the Tevatron Collider, MINOS using the Main Injector Neutrino Beam (NuMI), the MiniBooNE and SciBooNE experiments running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  11. Accelerator/Experiment Operations - FY 2009

    SciTech Connect

    Andrews, M.N; Appel, J.A.; Brice, S.; Casarsa, M.; Coleman, R.; Denisov, d.; Ginther, G.; Gruenendahl, S.; Holmes, S.; Kissel, W.; Lee, W.M.; /Fermilab

    2009-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2009. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2009 Run II at the Tevatron Collider, MINOS using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  12. Accelerator/Experiment operations - FY 2006

    SciTech Connect

    Brice, S.; Conrad, J.; Denisov, D.; Ginther, G.; Holmes, S.; James, C.; Lee, W.; Louis, W.; Moore, C.; Plunkett, R.; Raja, R.; /Fermilab

    2006-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and experiment operations for FY 2006. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2006 Run II at the Tevatron Collider, the MiniBooNE experiments running in the Booster Neutrino Beam in neutrino and antineutrino modes, MINOS using the Main Injector Neutrino Beam (NuMI), and SY 120 activities.

  13. Diagnostics for advanced laser acceleration experiments

    SciTech Connect

    Misuri, Alessio

    2002-06-01

    The first proposal for plasma based accelerators was suggested by 1979 by Tajima and Dawson. Since then there has been a tremendous progress both theoretically and experimentally. The theoretical progress is particularly due to the growing interest in the subject and to the development of more accurate numerical codes for the plasma simulations (especially particle-in-cell codes). The experimental progress follows from the development of multi-terawatt laser systems based on the chirped-pulse amplification technique. These efforts have produced results in several experiments world-wide, with the detection of accelerated electrons of tens of MeV. The peculiarity of these advanced accelerators is their ability to sustain extremely large acceleration gradients. In the conventional radio frequency linear accelerators (RF linacs) the acceleration gradients are limited roughly to 100 MV/m; this is partially due to breakdown which occurs on the walls of the structure. The electrical breakdown is originated by the emission of the electrons from the walls of the cavity. The electrons cause an avalanche breakdown when they reach other metal parts of the RF linacs structure.

  14. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Obayashi, Tatsuzo

    1988-01-01

    The purpose of Space Experiments with Particle Accelerators (SEPAC) on the Atmospheric Laboratory for Applications and Science (ATLAS 1) mission, is to carry out active and interactive experiments on and in the earth's ionosphere, atmosphere, and magnetosphere. The instruments to be used are an electron beam accelerator (EBA), plasma contactor, and associated instruments the purpose of which is to perform diagnostic, monitoring, and general data taking functions. Four major classes of investigations are to be performed by SEPAC. They are: beam plasma physics, beam-atmosphere interactions, the use of modulated electron beams as transmitting antennas, and the use of electron beams for remote sensing of electric and magnetic fields. The first class consists mainly of onboard plasma physics experiments to measure the effects of phenomena in the vicinity of the shuttle. The last three are concerned with remote effects and are supported by other ATLAS 1 investigations as well as by ground-based observations.

  15. Accelerator/Experiment Operations - FY 2015

    SciTech Connect

    Czarapata, P.

    2015-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2015. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2015 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  16. Space experiments with particle accelerators. [Spacelab

    NASA Technical Reports Server (NTRS)

    Obayashi, T.

    1981-01-01

    The purpose of space experiments with particle accelerators (SEPAC) is to carry out active and interactive experiments on and in the Earth's ionosphere and magnetosphere. It is also intended to make an initial performance test for an overall program of Spacelab/SEPAC experiments. The instruments to be used are an electron beam accelerator, magnetoplasma dynamic arcjet, and associated diagnostic equipment. The accelerators are installed on the pallet, with monitoring and diagnostic observations being made by the gas plume release, beam-monitor TV, and particle-wave measuring instruments also mounted on the pallet. Command and display systems are installed in the module. Three major classes of investigations to be performed are vehicle charge neutralization, beam plasma physics, and beam atmosphere interactions. The first two are mainly onboard plasma physics experiments to measure the effect of phenomena in the vicinity of Spacelab. The last one is concerned with atmospheric modification and is supported by other Spacelab 1 investigations as well as by ground-based, remote sensing observations.

  17. Orbital Acceleration Research Experiment: Calibration Measurements

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.; Larman, Kevin T.

    1995-01-01

    The Orbital Acceleration Research Experiment (OARE), which has flown on STS-40, STS-50, and STS-58, contains a three-axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass, which can resolve accelerations to the 10(sub -9) g level. The experiment also contains a full calibration station to permit in situ bias and scale-factor calibration. This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accelerometers flown in the past on the Orbiter, and thus provides absolute acceleration measurement accuracy heretofore unachievable. This is the first time accelerometer scale-factor measurements have been performed on orbit. A detailed analysis of the calibration process is given, along with results of the calibration factors from the on-orbit OARE flight measurements on STS-58. In addition, the analysis of OARE flight-maneuver data used to validate the scale-factor measurements in the sensor's most sensitive range are also presented. Estimates on calibration uncertainties are discussed. These uncertainty estimates provides bounds on the STS-58 absolute acceleration measurements for future applications.

  18. Space Experiments with Particle Accelerators: SEPAC

    NASA Technical Reports Server (NTRS)

    Burch, J. L.; Roberts, W. T.; Taylor, W. W. L.; Kawashima, N.; Marshall, J. A.; Moses, S. L.; Neubert, T.; Mende, S. B.; Choueiri, E. Y.

    1994-01-01

    The Space Experiments with Particle Accelerators (SEPAC), which flew on the Atmospheric Laboratory for Applications and Science (ATLAS) 1 mission, used new techniques to study natural phenomena in the Earth's upper atmosphere, ionosphere and magnetosphere by introducing energetic perturbations into the system from a high power electron beam with known characteristics. Properties of auroras were studied by directing the electron beam into the upper atmosphere while making measurements of optical emissions. Studies were also performed of the critical ionization velocity phenomenon.

  19. Decay accelerating factor is essential for successful corneal engraftment

    PubMed Central

    Esposito, Andrew; Suedekum, Brandon; Liu, Jinbo; An, Fengqi; Lass, Jonathan; Strainic, Michael G; Lin, Feng; Heeger, Peter; Medof, M. Edward

    2012-01-01

    In contrast to immune restrictions that pertain for solid organ transplants, the tolerogenic milieu of the eye permits successful corneal transplantation without systemic immunosuppression, even across a fully MHC disparate barrier. Here we show that recipient and donor expression of decay accelerating factor (DAF or CD55), a cell surface C3/C5 convertase regulator recently shown to modulate T cell responses, is essential to sustain successful corneal engraftment. Whereas wild type (WT) corneas transplanted into multiple minor histocompatibility antigen (mH), or HY disparate WT recipients were accepted, DAF’s absence on either the donor cornea or in the recipient bed induced rapid rejection. Donor or recipient DAF deficiency led to expansion of donor-reactive IFN-γ producing CD4+ and CD8+ T cells, as well as inhibition of antigen induced IL-10 and TGF-β, together demonstrating that DAF deficiency precludes immune tolerance. In addition to demonstrating a requisite role for DAF in conferring ocular immune privilege, these results raise the possibility that augmenting DAF levels on corneal endothelium and/or the recipient bed could have therapeutic value for transplants that clinically are at high risk for rejection. PMID:20055803

  20. Accelerator-based neutrino oscillation experiments

    SciTech Connect

    Harris, Deborah A.; /Fermilab

    2007-12-01

    Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation experiments, and then describe very generally what the next accelerator-based steps are. In section 2 the article discusses how one uses an accelerator to make a neutrino beam, in particular, one made from decays in flight of charged pions. There are several different neutrino detection methods currently in use, or under development. In section 3 these are presented, with a description of the general concept, an example of such a detector, and then a brief discussion of the outstanding issues associated with this detection technique. Finally, section 4 describes how the measurements of oscillation probabilities are made. This includes a description of the near detector technique and how it can be used to make the most precise measurements of neutrino oscillations.

  1. Magnetically accelerated foils for shock wave experiments

    NASA Astrophysics Data System (ADS)

    Neff, Stephan; Ford, Jessica; Martinez, David; Plechaty, Christopher; Wright, Sandra; Presura, Radu

    2008-04-01

    The interaction of shock waves with inhomogeneous media is important in many astrophysical problems, e.g. the role of shock compression in star formation. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory, to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. Experiments with flyer-generated shock waves have been performed on the Z machine in Sandia. The Zebra accelerator at the Nevada Terawatt Facility (NTF) allows for complementary experiments with high repetition rate. First experiments on Zebra demonstrated flyer acceleration to sufficiently high velocities (around 2 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

  2. The LHCf experiment at the LHC accelerator

    SciTech Connect

    Bonechi, L.; Adriani, O.; Bongi, M.; D'Alessandro, R.; Papini, P.; Castellini, G.; Faus, A.; Velasco, J.; Haguenauer, M.; Itow, Y.; Mase, T.; Masuda, K.; Matsubara, Y.; Matsumoto, H.; Menjo, H.; Muraki, Y.; Sako, T.; Tanaka, K.; Watanabe, H.; Kasahara, K.

    2006-10-27

    The claimed discovery of atmospheric shower induced by cosmic-ray with energy beyond the GZK cutoff by the AGASA experiment in 1994-1995, although not confirmed by other important experiments like Fly's Eye and Hi-Res, together with the poor knowledge of the composition of cosmic rays around and beyond the Knee region, have highlighted the necessity of new experiments that should increase our present knowledge of HECR and UHECR. For this reason big efforts have been addressed to the development of new experiments, like Auger, TA and EUSO, for a systematic study of the UHE atmospheric showers with increased capabilities with respect to the previous experiments. Moreover complementary experiments should allow a precise calibration of the methods used for the reconstruction of cosmic-ray showers in atmosphere. Their aim is the measurement of quantities that are used in these procedures and that are not yet precisely known. Under this perspective the LHCf experiment is a compact experiment which has been proposed for the study of neutral pion and gamma production at high energy in proton-proton interaction in the very forward region of the LHC accelerator. It will help calibrating the algorithms that are used to reconstruct the atmospheric shower events for energy beyond the Knee. The LHCf apparatus and the results of the first beam test, held in 2004, are shortly discussed in this work.

  3. Choosing experiments to accelerate collective discovery

    SciTech Connect

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.; Evans, James A.

    2015-11-24

    Scientists perform a tiny subset of all possible experiments. What characterizes the experiments they choose? What are the consequences of those choices for the pace of scientific discovery? We model scientific knowledge as a network and science as a sequence of experiments designed to gradually uncover it. By analyzing millions of biomedical articles published over 30 y, we find that biomedical scientists pursue conservative research strategies exploring the local neighborhood of central, important molecules. Although such strategies probably serve scientific careers, we show that they slow scientific advance, especially in mature fields, where more risk and less redundant experimentation would accelerate discovery of the network. Lastly, we also consider institutional arrangements that could help science pursue these more efficient strategies.

  4. Choosing experiments to accelerate collective discovery

    DOE PAGESBeta

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.; Evans, James A.

    2015-11-24

    Scientists perform a tiny subset of all possible experiments. What characterizes the experiments they choose? What are the consequences of those choices for the pace of scientific discovery? We model scientific knowledge as a network and science as a sequence of experiments designed to gradually uncover it. By analyzing millions of biomedical articles published over 30 y, we find that biomedical scientists pursue conservative research strategies exploring the local neighborhood of central, important molecules. Although such strategies probably serve scientific careers, we show that they slow scientific advance, especially in mature fields, where more risk and less redundant experimentation wouldmore » accelerate discovery of the network. Lastly, we also consider institutional arrangements that could help science pursue these more efficient strategies.« less

  5. Designing a successful HMD-based experience

    NASA Technical Reports Server (NTRS)

    Pierce, J. S.; Pausch, R.; Sturgill, C. B.; Christiansen, K. D.; Kaiser, M. K. (Principal Investigator)

    1999-01-01

    For entertainment applications, a successful virtual experience based on a head-mounted display (HMD) needs to overcome some or all of the following problems: entering a virtual world is a jarring experience, people do not naturally turn their heads or talk to each other while wearing an HMD, putting on the equipment is hard, and people do not realize when the experience is over. In the Electric Garden at SIGGRAPH 97, we presented the Mad Hatter's Tea Party, a shared virtual environment experienced by more than 1,500 SIGGRAPH attendees. We addressed these HMD-related problems with a combination of back story, see-through HMDs, virtual characters, continuity of real and virtual objects, and the layout of the physical and virtual environments.

  6. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Obayashi, T.; Kawashima, N.; Kuriki, K.; Nagatomo, M.; Ninomiya, K.; Sasaki, S.; Ushirokawa, A.; Kudo, I.; Ejiri, M.; Roberts, W. T.

    1982-01-01

    Plans for SEPAC, an instrument array to be used on Spacelab 1 to study vehicle charging and neutralization, beam-plasma interaction in space, beam-atmospheric interaction exciting artificial aurora and airglow, and the electromagnetic-field configuration of the magnetosphere, are presented. The hardware, consisting of electron beam accelerator, magnetoplasma arcjet, neutral-gas plume generator, power supply, diagnostic package (photometer, plasma probes, particle analyzers, and plasma-wave package), TV monitor, and control and data-management unit, is described. The individual SEPAC experiments, the typical operational sequence, and the general outline of the SEPAC follow-on mission are discussed. Some of the experiments are to be joint ventures with AEPI (INS 003) and will be monitored by low-light-level TV.

  7. Magnetically accelerated foils for shock wave experiments

    NASA Astrophysics Data System (ADS)

    Neff, S.; Ford, J.; Wright, S.; Martinez, D.; Plechaty, C.; Presura, R.

    2009-08-01

    Many astrophysical phenomena involve the interaction of a shock wave with an inhomogeneous background medium. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. First experiments on Zebra at the Nevada Terawatt Facility (NTF) have demonstrated flyer acceleration to sufficiently high velocities (up to 5 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

  8. Successes and Experiences of the WIPP Project

    SciTech Connect

    CHU,MARGARET S. Y.; WEART,WENDELL D.

    2000-09-06

    In May 1998, the US Environmental Agency (EPA) certified the US Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP) as being in compliance with all of the applicable regulations governing the permanent disposal of spent nuclear fuel, high-level waste, and transuranic radioactive waste. The WIPP, a transuranic waste repository, is the first deep geologic repository in the US to have successfully demonstrated regulatory compliance with long-term radioactive waste disposal regulations and be certified to receive wastes. Many lessons were learned throughout the 25-year history of the WIPP--from site selection to the ultimate successful certification. The experiences and lessons learned from the WIPP may be of general interest to other repository programs in the world. The lessons learned include all facets of a repository program: programmatic, managerial, regulatory, technical, and social. This paper addresses critical issues that arose during the 25 years of WIPP history and how they influenced the program.

  9. Pulsed power accelerator for material physics experiments

    NASA Astrophysics Data System (ADS)

    Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Austin, K. N.; Waisman, E. M.; Hickman, R. J.; Davis, J.-P.; Haill, T. A.; Knudson, M. D.; Seagle, C. T.; Brown, J. L.; Goerz, D. A.; Spielman, R. B.; Goldlust, J. A.; Cravey, W. R.

    2015-09-01

    We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments.

  10. Worldwide experience shows horizontal well success

    SciTech Connect

    Karlsson, H.; Bitto, R.

    1989-03-01

    The convergence of technology and experience has made horizontal drilling an important tool in increasing production and solving a variety of completion problems. Since the early 1980s, horizontal drilling has been used to improve production on more than 700 oil and gas wells throughout the world. Approximately 200 horizontal wells were drilled in 1988 alone. Interest in horizontal drilling has been accelerating rapidly as service companies have developed and offered new technology for drilling and producing horizontal wells. Simultaneously, oil companies have developed better methods for evaluating reservoirs for potential horizontal applications, while their production departments have gained experience at completing and producing them. To date, most horizontal wells have been drilled in the United States. A major application is to complete naturally fractured formations, such as the Austin chalk in Texas, the Bakken shale in the Williston basin, the Spraberry in West Texas and the Devonian shale in the Eastern states. In addition, many horizontal wells have been drilled to produce the Niagaran reefs and the irregular Antrim shale reservoirs in Michigan.

  11. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travis, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.

    2006-11-27

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}z = 20 {mu}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {mu}m / OD = 325 {mu}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  12. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    NASA Astrophysics Data System (ADS)

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travis, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.

    2006-11-01

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., σz = 20 μm at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 μm / OD = 325 μm). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  13. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.; /LLNL, Livermore /UCLA /SLAC /Southern California U. /UC, Santa Barbara /Manhattan Coll., Riverdale

    2007-03-27

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  14. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Hogan, M; Ischebeck, R; Kirby, N; Siemann, R; Walz, D; Muggli, P; Scott, A; Yoder, R

    2006-08-04

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  15. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Taylor, William W. L.

    1994-01-01

    The scientific emphasis of this contract has been on the physics of beam ionosphere interactions, in particular, what are the plasma wave levels stimulated by the Space Experiments with Particle Accelerators (SEPAC) electron beam as it is ejected from the Electron Beam Accelerator (EBA) and passes into and through the ionosphere. There were two different phenomena expected. The first was generation of plasma waves by the interaction of the DC component of the beam with the plasma of the ionosphere, by wave particle interactions. The second was the generation of waves at the pulsing frequency of the beam (AC component). This is referred to as using the beam as a virtual antenna, because the beam of electrons is a coherent electrical current confined to move along the earth's magnetic field. As in a physical antenna, a conductor at a radio or TV station, the beam virtual antenna radiates electromagnetic waves at the frequency of the current variations. These two phenomena were investigated during the period of this contract.

  16. Disk Acceleration Experiment Utilizing Minimal Material (DAXUMM)

    NASA Astrophysics Data System (ADS)

    Biss, Matthew; Lorenz, Thomas; Sutherland, Gerrit

    2015-06-01

    A venture between the US Army Research Laboratory (ARL) and Lawrence Livermore National Laboratory (LLNL) is currently underway in an effort to characterize novel energetic material performance properties using a single, high-precision, gram-range charge. A nearly all-inclusive characterization experiment is proposed by combing LLNL's disk acceleration experiment (DAX) with the ARL explosive evaluation utilizing minimal material (AXEUMM) experiment. Spherical-cap charges fitted with a flat circular metal disk are centrally initiated using an exploding bridgewire detonator while photonic doppler velocimetry is used to probe the metal disk surface velocity and measure its temporal history. The metal disk's jump-off-velocity measurement is combined with conservation equations, material Hugoniots, and select empirical relationships to determine performance properties of the detonation wave (i.e., velocity, pressure, particle velocity, and density). Using the temporal velocity history with the numerical hydrocode CTH, a determination of the energetic material's equation of state and material expansion energy is possible. Initial experimental and computational results for the plastic-bonded energetic formulation PBXN-5 are presented.

  17. Isentropic Compression Experiments on the Z Accelerator

    NASA Astrophysics Data System (ADS)

    Asay, James

    1999-06-01

    Shock compression techniques are the only viable technique for making accurate EOS measurements in the multi-Mbar pressure regime. These experiments provide specific states of pressure, volume and internal energy on the Hugoniot. In many applications, it is necessary to know the off-Hugoniot isentropic loading response of materials to ultra-high pressures. Techniques for measuring isentropic response are challenging. At low pressures, ramp wave generators are used, while at high megabar pressures, graded density impactors are employed. In these latter experiments is a small amplitude shock results in the compression isentrope centered at some initial state. A new technique that is being developed shows promise for performing isentropic experiments with smooth loading to very high pressure. This approach uses the high current densities produced with fast pulsed power accelerators to create continuous magnetic loading to a few hundred kilobars over time intervals of 100-200 ns. The resulting ramp wave propagates through a planar specimen and are measured using time-resolved VISARS. Application of the differential equations of motion over the risetime of the waves determines pressure-volume states continuously. Experiments on copper and iron, have allowed determination of the isentropic compression curve in copper and the evaluation of the kinetic properties of the alpha-epsilon phase transition in iron. In this presentation, I will review previous studies of isentropic compression, discuss the new technique using Z and the results obtained on iron and copper. A perspective on the opportunities for isentropic compression experiments to multi-Mbar pressures, will be given. * Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL8500.

  18. Comparison of integrated numerical experiments with accelerator and FEL experiments

    SciTech Connect

    Thode, L.E.; Carlsten, B.E.; Chan, K.C.D.; Cooper, R.K.; Elliott, J.C.; Gitomer, S.J.; Goldstein, J.C.; Jones, M.E.; McVey, B.D.; Schmitt, M.J.; Takeda, H.; Tokar, R.L.; Wang, T.S.; Young, L.M.

    1991-01-01

    Even at the conceptual level the strong coupling between the laser subsystem elements, such as the accelerator, wiggler, optics, and control, greatly complicates the understanding and design of an FEL. Given the requirements for a high-performance FEL, the coupling between the laser subsystems must be included in the design approach. To address the subsystem coupling the concept of an integrated numerical experiment (INEX) has been implemented. Unique features of the INEX approach are consistency and numerical equivalence of experimental diagnostic. The equivalent numerical diagnostics mitigates the major problem of misinterpretation that often occurs when theoretical and experimental data are compared. A complete INEX model has been applied to the 10{mu}m high-extraction-efficiency experiment at Los Alamos and the 0.6-{mu}m Burst Mode experiment at Boeing Aerospace. In addition, various subsets of the INEX model have been compared with a number of other experiments. Overall, the agreement between INEX and the experiments is very good. With the INEX approach, it now appears possible to design high-performance FELS for numerous applications. The first full-scale test of the INEX approach is the Los Alamos HIBAF experiment. The INEX concept, implementation, and validation with experiments are discussed. 28 refs., 13 figs., 1 tab.

  19. Radiochemical Solar Neutrino Experiments - Successful and Otherwise.

    SciTech Connect

    Hahn,R.L.

    2008-05-25

    Over the years, several different radiochemical systems have been proposed as solar neutrino detectors. Of these, two achieved operating status and obtained important results that helped to define the current field of neutrino physics: the first solar-neutrino experiment, the Chlorine Detector ({sup 37}Cl) that was developed by chemist Raymond Davis and colleagues at the Homestake Mine, and the subsequent Gallium ({sup 71}Ga) Detectors that were operated by (a) the SAGE collaboration at the Baksan Laboratory and (b) the GALLEX/GNO collaborations at the Gran Sasso National Laboratory. These experiments have been extensively discussed in the literature and in many previous International Neutrino Conferences. In this paper, I present important updates to the results from SAGE and GALLEX/GNO. I also review the principles of the radiochemical detectors and briefly describe several different detectors that have been proposed. In light of the well-known successes that have been subsequently obtained by real-time neutrino detectors such as Kamiokande, Super-Kamiokande, SNO, and KamLAND, I do not anticipate that any new radiochemical neutrino detectors will be built. At present, only SAGE is still operating; the Chlorine and GNO radiochemical detectors have been decommissioned and dismantled.

  20. Energy deposition via magnetoplasmadynamic acceleration: I. Experiment

    NASA Astrophysics Data System (ADS)

    Gilland, James; Mikellides, Pavlos; Marriott, Darin

    2009-02-01

    The expansion of a high-temperature fusion plasma through an expanding magnetic field is a process common to most fusion propulsion concepts. The propulsive efficiency of this process has a strong bearing on the overall performance of fusion propulsion. In order to simulate the expansion of a fusion plasma, a concept has been developed in which a high velocity plasma is first stagnated in a converging magnetic field to high (100s of eV) temperatures, then expanded though a converging/diverging magnetic nozzle. As a first step in constructing this experiment, a gigawatt magnetoplasmadynamic plasma accelerator was constructed to generate the initial high velocity plasma and has been characterized. The source is powered by a 1.6 MJ, 1.6 ms pulse forming network. The device has been operated with currents up to 300 kA and power levels up to 200 MWe. These values are among the highest levels reached in an magnetoplasmadynamic thruster. The device operation has been characterized by quasi-steady voltage and current measurements for helium mass flow rates from 0.5 to 27 g s-1. Probe results for downstream plasma density and electron temperature are also presented. The source behavior is examined in terms of current theories for magnetoplasmadynamic thrusters.

  1. Argonne plasma wake-field acceleration experiments

    SciTech Connect

    Rosenzweig, J.B.; Cole, B.; Gai, W.; Konecny, R.; Norem, J.; Schoessow, P.; Simpson, J.

    1989-03-14

    Four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These wake-fields are of interest both in the laboratory, for acceleration and focusing of electrons and positrons in future linear colliders, and in nature as a possible cosmic ray acceleration mechanism. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory. Some of the topics discussed are: the Argonne Advanced Accelerator Test Facility; linear plasma wake-field theory; measurement of linear plasma wake-fields; review of nonlinear plasma wave theory; and experimental measurement of nonlinear plasma wake-fields. 25 refs., 11 figs.

  2. Real-Time Data from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The objective of the Orbital Acceleration Research Experiment (OARE) is to measure, with high accuracy, the low-frequency, low-magnitude acceleration levels onboard the space shuttle. The shuttle experiences acceleration from atmospheric drag, gravity gradient forces, shuttle rotations, crew activities, water/waste dumps, and shuttle attitude thrusters. The OARE instrument has successfully flown on five past shuttle missions and is scheduled for five upcoming microgravity science missions. The data collected by OARE will be utilized by microgravity scientists to better predict and analyze the influence and effects of the shuttle's on-orbit microgravity environment on experiments in materials, combustion, and fluids research.

  3. High Temperature μSR Experiments for Accelerator Developments

    NASA Astrophysics Data System (ADS)

    Ohmori, Chihiro; Koda, Akihiro; Miyake, Yasuhiro; Nishiyama, Kusuo; Shimomura, Koichiro; Schnase, Alexander; Ezura, Eiji; Hara, Keigo; Hasegawa, Katsushi; Nomura, Masahiro; Shimada, Taihei; Takata, Koji; Tamura, Fumihiko; Toda, Makoto; Yamamoto, Masanobu; Yoshii, Masahito

    High temperature μSR is a powerful technique to study magnetic materials. In J-PARC accelerator synchrotrons, the Rapid Cycling Synchrotron (RCS) and Main Ring (MR), a unique magnetic alloy-loaded cavity is used for the beam acceleration and much higher field gradient has been achieved. Such high field gradient cavities made a compact RCS possible by reducing the length for beam acceleration. Now, further upgrades of the J-PARC, RF cavities with higher RF voltage and less power loss in the magnetic core are needed for the MR. For the improvements of the magnetic property of magnetic alloy core, the high temperature μSR (muon Spin Rotation/Relaxation) was used to investigate the crystallization process of the material. Based on the measurement results, the test production of the large ring cores of a magnetic alloy, FT3L, was tried. The FT3L is the magnetic alloy which has two times better performance than the present one, FT3M. For the FT3L production, the magnetic annealing is needed to control the easy-magnetized axis of the crystalline. After the success of the test production, a mass production was started in the industry to replace all existing cavities in the MR. The first 5-cell FT3L cavity is assembled for the bench test before the installation in the accelerator tunnel. By the new cavities, the total RF voltage of J-PARC MR will be doubled to increase the beam power for neutrino experiment. In future, the cavities will be also used for the RCS to increase the beam power beyond 1 MW.

  4. Accelerating Latino Student Success at Texas Border Institutions: Possibilities and Challenges

    ERIC Educational Resources Information Center

    Santiago, Deborah A.

    2008-01-01

    This report examines enrollment and graduation trends at eight Texas institutions, highlights promising programs and strategies for serving Latino students, and offers policy recommendations for improving success rates for the state's Latino students. The analysis was prepared as part of Excelencia's Accelerating Latino Student Success (ALASS)…

  5. TeV/m Nano-Accelerator: Current Status of CNT-Channeling Acceleration Experiment

    SciTech Connect

    Shin, Young Min; Lumpkin, Alex H.; Thangaraj, Jayakar Charles; Thurman-Keup, Randy Michael; Shiltsev, Vladimir D.

    2014-09-17

    Crystal channeling technology has offered various opportunities in the accelerator community with a viability of ultrahigh gradient (TV/m) acceleration for future HEP collider. The major challenge of channeling acceleration is that ultimate acceleration gradients might require a high power driver in the hard x-ray regime (~ 40 keV). This x-ray energy exceeds those for x-rays as of today, although x-ray lasers can efficiently excite solid plasma and accelerate particles inside a crystal channel. Moreover, only disposable crystal accelerators are possible at such high externally excited fields which would exceed the ionization thresholds destroying the atomic structure, so acceleration will take place only in a short time before full dissociation of the lattice. Carbon-based nanostructures have great potential with a wide range of flexibility and superior physical strength, which can be applied to channeling acceleration. This paper presents a beam- driven channeling acceleration concept with CNTs and discusses feasible experiments with the Advanced Superconducting Test Accelerator (ASTA) in Fermilab.

  6. International Research Students' Experiences in Academic Success

    ERIC Educational Resources Information Center

    Yeoh, Joanne Sin Wei; Terry, Daniel R.

    2013-01-01

    The flow of international students to study in Australia increases each year. It is a challenge for students to study abroad in a different sociocultural environment, especially for postgraduate research students, as they experience numerous difficulties in an unfamiliar and vastly different study environment. A study aimed to investigate the…

  7. Pool Boiling Experiment Has Five Successful Flights

    NASA Technical Reports Server (NTRS)

    Chiaramonte, Fran

    1997-01-01

    The Pool Boiling Experiment (PBE) is designed to improve understanding of the fundamental mechanisms that constitute nucleate pool boiling. Nucleate pool boiling is a process wherein a stagnant pool of liquid is in contact with a surface that can supply heat to the liquid. If the liquid absorbs enough heat, a vapor bubble can be formed. This process occurs when a pot of water boils. On Earth, gravity tends to remove the vapor bubble from the heating surface because it is dominated by buoyant convection. In the orbiting space shuttle, however, buoyant convection has much less of an effect because the forces of gravity are very small. The Pool Boiling Experiment was initiated to provide insight into this nucleate boiling process, which has many earthbound applications in steamgeneration power plants, petroleum plants, and other chemical plants. In addition, by using the test fluid R-113, the Pool Boiling Experiment can provide some basic understanding of the boiling behavior of cryogenic fluids without the large cost of an experiment using an actual cryogen.

  8. Pool Boiling Experiment Has Successful Flights

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pool Boiling Experiment (PBE) is designed to improve understanding of the fundamental mechanisms that constitute nucleate pool boiling. Nucleate pool boiling is a process wherein a stagnant pool of liquid is in contact with a surface that can supply heat to the liquid. If the liquid absorbs enough heat, a vapor bubble can be formed. This process occurs when a pot of water boils. On Earth, gravity tends to remove the vapor bubble from the heating surface because it is dominated by buoyant convection. In the orbiting space shuttle, however, buoyant convection has much less of an effect because the forces of gravity are very small. The Pool Boiling Experiment was initiated to provide insight into this nucleate boiling process, which has many Earthbound applications, such as steam-generation power plants, petroleum, and other chemical plants. Also, by using the test fluid R-113, the Pool Boiling Experiment can provide some basic understanding of the boiling behavior of cryogenic fluids without the large cost of an experiment using an actual cryogen.

  9. The electron accelerator for the AWAKE experiment at CERN

    NASA Astrophysics Data System (ADS)

    Pepitone, K.; Doebert, S.; Burt, G.; Chevallay, E.; Chritin, N.; Delory, C.; Fedosseev, V.; Hessler, Ch.; McMonagle, G.; Mete, O.; Verzilov, V.; Apsimon, R.

    2016-09-01

    The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

  10. Estimates of effects of residual acceleration on USML-1 experiments

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J.

    1995-01-01

    The purpose of this study effort was to develop analytical models to describe the effects of residual accelerations on the experiments to be carried on the first U.S. Microgravity Lab mission (USML-1) and to test the accuracy of these models by comparing the pre-flight predicted effects with the post-flight measured effects. After surveying the experiments to be performed on USML-1, it became evident that the anticipated residual accelerations during the USML-1 mission were well below the threshold for most of the primary experiments and all of the secondary (Glovebox) experiments and that the only set of experiments that could provide quantifiable effects, and thus provide a definitive test of the analytical models, were the three melt growth experiments using the Bridgman-Stockbarger type Crystal Growth Furnace (CGF). This class of experiments is by far the most sensitive to low level quasi-steady accelerations that are unavoidable on space craft operating in low earth orbit. Because of this, they have been the drivers for the acceleration requirements imposed on the Space Station. Therefore, it is appropriate that the models on which these requirements are based are tested experimentally. Also, since solidification proceeds directionally over a long period of time, the solidified ingot provides a more or less continuous record of the effects from acceleration disturbances.

  11. From the Discovery of Radioactivity to the First Accelerator Experiments

    NASA Astrophysics Data System (ADS)

    Walter, Michael

    The chapter reviews the historical phases of cosmic ray research from the very beginning around 1900 until the 1940s when first particle accelerators replaced cosmic particles as source for elementary particle interactions. In opposite to the discovery of X-rays or the ionising α-, β- and γ-rays, it was an arduous path to the definite acceptance of the new radiation. The starting point was the explanation that air becomes conductive by the ionising radiation of radioactive elements in the surroundings. In the following years the penetration power of the radiation was studied with the result, that there seems be a component harder than the known γ-rays. Victor F. Hess did in 1912 the key experiment with a hydrogen balloon. He measured with three detectors an increase of ionisation up to altitudes of 5 300 m and discovered the extraterrestrial penetrating radiation. The next phase is characterised by W. Kolhörster's confirmation in 1914, doubts by R.A. Millikan and others as well as the spectacular re-discovery of cosmic rays by Millikan in 1926. With the invention of new detectors as the cloud chamber and the Geiger-Müller counter and of the coincidence method the properties of cosmic rays could be investigated. One of the striking results was the discovery that cosmic rays are of corpuscular nature. The broad research activities starting end of the 1920s were the begin of a scientific success story, which nobody of the early protagonists might have imagined. In 1932 C.D. Anderson discovered the antiparticle of the electron. It was the birth of elementary particle physics. Four years later the muon was discovered which was for many years wrongly assumed to be the carrier of the short range nuclear force predicted by H. Yukawa. One of the last high-lights before the particle accelerators took over this field of fundamental research was the discovery of the Yukawa particle. In photographic emulsions exposed by cosmic particles the pion was found in 1947. This

  12. Laser Wakefield Acceleration Experiments Using HERCULES Laser

    SciTech Connect

    Matsuoka, T.; McGuffey, C.; Dollar, F.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Horovitz, Y.

    2009-07-25

    Laser wakefield acceleration (LWFA) in a supersonic gas-jet using a self-guided laser pulse was studied by changing laser power and plasma electron density. The recently upgraded HERCULES laser facility equipped with wavefront correction enables a peak intensity of 6.1x10{sup 19} W/cm{sup 2} at laser power of 80 TW to be delivered to the gas-jet using F/10 focusing optics. We found that electron beam charge was increased significantly with an increase of laser power from 30 TW to 80 TW and showed density threshold behavior at a fixed laser power. We also studied the influence of laser focusing conditions by changing the f-number of the optics to F/15 and found an increase in density threshold for electron production compared to the F/10 configuration. The analysis of different phenomena such as betatron motion of electrons, side scattering of the laser pulse for different focusing conditions, the influence of plasma density down ramp on LWFA are shown.

  13. Isentropic compression experiments on the Sandia Z accelerator

    SciTech Connect

    HALL,CLINT A.

    2000-02-21

    A long-standing goal of the equation of state (EOS) community has been the development of a loading capability for direct measurement of material properties along an isentrope. Previous efforts on smooth bore launchers have been somewhat successful, but quite difficult to accurately reproduce, had pressure limitations, or tended to be a series of small shocks as opposed to a smoothly increasing pressure load. A technique has recently been developed on the Sandia National Laboratories Z accelerator which makes use of the high current densities and magnetic fields available to produce nearly isentropic compression of samples that are approximately 1 mm in thickness over approximately 120 ns. Velocity interferometry is used to measure the rear surface motion of these samples. The resulting time resolved velocity profiles from multiple sample thicknesses provide information about mechanical response under isentropic loading conditions and phase transition kinetics. Feasibility experiments have been performed to pressures of approximately 130 kbar in copper and 300 kbar in iron with effects of the {alpha}-{var_epsilon} phase change kinetics in iron clearly observed. Work is in progress to achieve 1--2% accuracy in P-v space along an isentrope, provide uniaxial strain, and to eliminate magnetic field and current diffusion within the sample of interest.

  14. Facilitating an accelerated experience-based co-design project.

    PubMed

    Tollyfield, Ruth

    This article describes an accelerated experience-based co-design (AEBCD) quality improvement project that was undertaken in an adult critical care setting and the facilitation of that process. In doing so the aim is to encourage other clinical settings to engage with their patients, carers and staff alike and undertake their own quality improvement project. Patient, carer and staff experience and its place in the quality sphere is outlined and the importance of capturing patient, carer and staff feedback established. Experience-based co-design (EBCD) is described along with the recently tested accelerated version of the process. An overview of the project and outline of the organisational tasks and activities undertaken by the facilitator are given. The facilitation of the process and key outcomes are discussed and reflected on. Recommendations for future undertakings of the accelerated process are given and conclusions drawn. PMID:24526020

  15. Ultrashort laser pulse driven inverse free electron laser accelerator experiment

    NASA Astrophysics Data System (ADS)

    Moody, J. T.; Anderson, S. G.; Anderson, G.; Betts, S.; Fisher, S.; Tremaine, A.; Musumeci, P.

    2016-02-01

    In this paper we discuss the ultrashort pulse high gradient inverse free electron laser accelerator experiment carried out at the Lawrence Livermore National Laboratory which demonstrated gradients exceeding 200 MV /m using a 4 TW 100 fs long 800 nm Ti :Sa laser pulse. Due to the short laser and electron pulse lengths, synchronization was determined to be one of the main challenges in this experiment. This made necessary the implementation of a single-shot, nondestructive, electro-optic sampling based diagnostics to enable time-stamping of each laser accelerator shot with <100 fs accuracy. The results of this experiment are expected to pave the way towards the development of future GeV-class IFEL accelerators.

  16. Choosing experiments to accelerate collective discovery

    PubMed Central

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.

    2015-01-01

    A scientist’s choice of research problem affects his or her personal career trajectory. Scientists’ combined choices affect the direction and efficiency of scientific discovery as a whole. In this paper, we infer preferences that shape problem selection from patterns of published findings and then quantify their efficiency. We represent research problems as links between scientific entities in a knowledge network. We then build a generative model of discovery informed by qualitative research on scientific problem selection. We map salient features from this literature to key network properties: an entity’s importance corresponds to its degree centrality, and a problem’s difficulty corresponds to the network distance it spans. Drawing on millions of papers and patents published over 30 years, we use this model to infer the typical research strategy used to explore chemical relationships in biomedicine. This strategy generates conservative research choices focused on building up knowledge around important molecules. These choices become more conservative over time. The observed strategy is efficient for initial exploration of the network and supports scientific careers that require steady output, but is inefficient for science as a whole. Through supercomputer experiments on a sample of the network, we study thousands of alternatives and identify strategies much more efficient at exploring mature knowledge networks. We find that increased risk-taking and the publication of experimental failures would substantially improve the speed of discovery. We consider institutional shifts in grant making, evaluation, and publication that would help realize these efficiencies. PMID:26554009

  17. Success Probability Analysis for Shuttle Based Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Liou, Ying-Hsin Andrew

    1996-01-01

    Presented in this report are the results of data analysis of shuttle-based microgravity flight experiments. Potential factors were identified in the previous grant period, and in this period 26 factors were selected for data analysis. In this project, the degree of success was developed and used as the performance measure. 293 of the 391 experiments in Lewis Research Center Microgravity Database were assigned degrees of success. The frequency analysis and the analysis of variance were conducted to determine the significance of the factors that effect the experiment success.

  18. Predictors of Success in Accelerated and Enrichment Summer Mathematics Courses for Academically Talented Adolescents

    ERIC Educational Resources Information Center

    Young, Adena E.; Worrell, Frank C.; Gabelko, Nina H.

    2011-01-01

    In this study, we used logistic regression to examine how well student background and prior achievement variables predicted success among students attending accelerated and enrichment mathematics courses at a summer program (N = 459). Socioeconomic status, grade point average (GPA), and mathematics diagnostic test scores significantly predicted…

  19. Space experiments with particle accelerators (SEPAC): Description of instrumentation

    NASA Technical Reports Server (NTRS)

    Taylor, W. W. L.; Roberts, W. T.; Reasoner, D. L.; Chappell, C. R.; Baker, B. B.; Burch, J. L.; Gibson, W. C.; Black, R. K.; Tomlinson, W. M.; Bounds, J. R.

    1987-01-01

    SEPAC (Space Experiments with Particle Accelerators) flew on Spacelab 1 (SL 1) in November and December 1983. SEPAC is a joint U.S.-Japan investigation of the interaction of electron, plasma, and neutral beams with the ionosphere, atmosphere and magnetosphere. It is scheduled to fly again on Atlas 1 in August 1990. On SL 1, SEPAC used an electron accelerator, a plasma accelerator, and neutral gas source as active elements and an array of diagnostics to investigate the interactions. For Atlas 1, the plasma accelerator will be replaced by a plasma contactor and charge collection devices to improve vehicle charging meutralization. This paper describes the SEPAC instrumentation in detail for the SL 1 and Atlas 1 flights and includes a bibliography of SEPAC papers.

  20. Directed abstraction: Encouraging broad, personal generalizations following a success experience.

    PubMed

    Zunick, Peter V; Fazio, Russell H; Vasey, Michael W

    2015-07-01

    People with negative self-views may fail to generalize appropriately from success experiences (e.g., Wood, Heimpel, Newby-Clark, & Ross, 2005). We drew on theories regarding self-views (Swann, Griffin, Predmore, & Gaines, 1987) and abstraction (Semin & Fiedler, 1991), as well as past linguistic framing work (e.g., Marigold, Holmes, & Ross, 2007, 2010; Salancik, 1974), to create a new technique to encourage people with negative self-views to generalize broadly from a success experience to the self-concept. We call this technique directed abstraction. In Experiment 1, participants with negative self-views who completed a directed abstraction writing task following success feedback regarding a novel laboratory task generalized more from that success, reporting higher ability levels and greater expectations of future success in the relevant domain. In Experiment 2, directed abstraction produced similar results (including more positive self-related affect, e.g., pride) after participants recalled a past public speaking success. In Experiment 3, participants high in fear of public speaking gave two speeches in a context designed to be challenging yet also to elicit successful performances. Directed abstraction helped these participants generalize from their success to beliefs about their abilities, expectations about the future, and confidence as a speaker. In Experiment 4, directed abstraction following success on a verbal task increased persistence in the face of failure on a subsequent verbal task. We discuss implications for understanding how and when people generalize from a success, compare directed abstraction to existing interventions, and suggest practical applications for this influence technique. PMID:25984786

  1. Approaches to Leadership Succession: What Comes with Experience?

    ERIC Educational Resources Information Center

    Macmillan, Robert B.

    This paper presents findings of a study that examined the ways in which principals' succession practices change as they gain greater experience with entry into different school settings. "Succession" refers to principal transfers to new schools. Data were collected from interviews conducted with five secondary school principals and some of their…

  2. A linear accelerator in the space: The beam experiment aboard rocket

    SciTech Connect

    O'Shea, P.G.; Butler, T.A.; Lynch, M.T.; McKenna, K.F.; Pongratz, M.B.

    1990-01-01

    On July 13, 1989 the BEAM experiment Aboard Rocket (BEAR) linear accelerator was successfully launched and operated in space. The flight demonstrated that a neutral hydrogen beam could be successfully propagated in an exoatmospheric environment. The accelerator, which was the result of an extensive collaboration between Los Alamos National Laboratory and industrial partners, was designed to produce a 10 mA (equivalent), 1 MeV neutral hydrogen beam in 50 {mu}s pulses at 5 Hz. The major components were a 30 keV H{sup {minus}} injector a 1 MeV radio frequency quadrupole, two 425 Mhz RF amplifiers, a gas cell neutralizer, beam optics, vacuum system and controls. The design was strongly constrained by the need for a lightweight rugged system that would survive the rigors of launch and operate autonomously. Following the flight the accelerator was recovered and operated again on the laboratory. 6 figs., 2 tabs.

  3. Micro-Bubble Experiments at the Van de Graaff Accelerator

    SciTech Connect

    Sun, Z. J.; Wardle, Kent E.; Quigley, K. J.; Gromov, Roman; Youker, A. J.; Makarashvili, Vakhtang; Bailey, James; Stepinski, D. C.; Chemerisov, S. D.; Vandegrift, G. F.

    2015-02-01

    In order to test and verify the experimental designs at the linear accelerator (LINAC), several micro-scale bubble ("micro-bubble") experiments were conducted with the 3-MeV Van de Graaff (VDG) electron accelerator. The experimental setups included a square quartz tube, sodium bisulfate solution with different concentrations, cooling coils, gas chromatography (GC) system, raster magnets, and two high-resolution cameras that were controlled by a LabVIEW program. Different beam currents were applied in the VDG irradiation. Bubble generation (radiolysis), thermal expansion, thermal convection, and radiation damage were observed in the experiments. Photographs, videos, and gas formation (O2 + H2) data were collected. The micro-bubble experiments at VDG indicate that the design of the full-scale bubble experiments at the LINAC is reasonable.

  4. Nuclear effects in atmospheric and accelerator neutrino experiments

    SciTech Connect

    Chauhan, S.; Athar, M. Sajjad; Singh, S. K.

    2010-11-24

    We have studied the nuclear medium effects in the neutrino (antineutrino) induced interactions in nuclei at intermediate energy region. We have applied this study to calculate the event rates for atmospheric and accelerator neutrino experiments. The study of the nuclear effects has been done for the quasielastic lepton production and the charged current incoherent and coherent pion production processes.

  5. The Student Course Experience among Online, Accelerated, and Traditional Courses

    ERIC Educational Resources Information Center

    Bielitz, Colleen L.

    2016-01-01

    The demand by the public for a wider variety of course formats has led to complexity in determining a course's optimal delivery format as many faculty members still believe that online and accelerated courses do not offer students an equivalent experience to traditional face to face instruction. The purpose of this quantitative, comparative study…

  6. Constant Acceleration: Experiments with a Fan-Driven Dynamics Cart.

    ERIC Educational Resources Information Center

    Morse, Robert A.

    1993-01-01

    Describes the rebuilding of a Project Physics fan cart on a PASCO dynamics cart chassis for achieving greatly reduced frictional forces. Suggests four experiments for the rebuilt cart: (1) acceleration on a level track, (2) initial negative velocity, (3) different masses and different forces, and (4) inclines. (MVL)

  7. Accelerator-based Experiments For Introductory-level Undergraduates

    SciTech Connect

    Sanders, Justin M.

    2009-03-10

    Although accelerator based experiments for undergraduates are often considered only for junior or senior physics majors, introductory students can also benefit from them. Rutherford backscattering and a {sup 12}C(p,p){sup 12}C elastic scattering resonance can be presented in ways that are well-suited for students who have taken only an introductory physics course.

  8. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  9. Results of the SINGAP Neutral Beam Accelerator Experiment at JAEA

    NASA Astrophysics Data System (ADS)

    de Esch, H. P. L.; Svensson, L.; Inoue, T.; Taniguchi, M.; Umeda, N.; Kashiwagi, M.; Fubiani, G.

    2009-03-01

    IRFM (CEA Cadarache) and JAEA Naka have entered into a collaboration in order to test a SINGAP [1] accelerator at the JAEA Megavolt Test Facility (MTF) at Naka, Japan. Whereas at the CEA testbed the acceleration current was limited to 0.1 A, at JAEA 0.5 A is available. This allows the acceleration of 15 H- beamlets in SINGAP to be tested and a direct comparison between SINGAP and MAMuG [2] to be made. High-voltage conditioning in the SINGAP configuration has been quite slow, with 581 kV in vacuum achieved after 140 hours of conditioning. With 0.1 Pa of H2 gas present in the accelerator 787 kV could be achieved. The conditioning curve for MAMuG is 200 kV higher. SINGAP beam optics appears in agreement with calculation results. A beamlet divergence better than 5 mrad was obtained. SINGAP accelerates electrons to a higher energy than MAMuG. Measurements of the power intercepted on one of the electron dumps have been compared with EAMCC code [3] calculations. Based on the experiments described here, electron production by a SINGAP accelerator scaled up to ITER size was estimated to be too high for comfort

  10. First results of the plasma wakefield acceleration experiment at PITZ

    NASA Astrophysics Data System (ADS)

    Lishilin, O.; Gross, M.; Brinkmann, R.; Engel, J.; Grüner, F.; Koss, G.; Krasilnikov, M.; Martinez de la Ossa, A.; Mehrling, T.; Osterhoff, J.; Pathak, G.; Philipp, S.; Renier, Y.; Richter, D.; Schroeder, C.; Schütze, R.; Stephan, F.

    2016-09-01

    The self-modulation instability of long particle beams was proposed as a new mechanism to produce driver beams for proton driven plasma wakefield acceleration (PWFA). The PWFA experiment at the Photo Injector Test facility at DESY, Zeuthen site (PITZ) was launched to experimentally demonstrate and study the self-modulation of long electron beams in plasma. Key aspects for the experiment are the very flexible photocathode laser system, a plasma cell and well-developed beam diagnostics. In this contribution we report about the plasma cell design, preparatory experiments and the results of the first PWFA experiment at PITZ.

  11. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R. J.; Colby, E. R.; McGuinness, C. M.; Noble, R.; Plettner, T.; Siemann, R. H.; Spencer, J. E.; Walz, D.; Ischebeck, R.; Sears, C. M. S.

    2009-01-22

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50 pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. We will describe the experimental plan and recent simulation studies of candidate fibers.

  12. The laser driven particle accelerator project: Theory and experiment

    SciTech Connect

    Plettner, T.; Byer, R.L. Smith, T.I.; Siemann, R.H. Huang, Y.C.

    1999-07-01

    A proof of principle experiment for laser driven electron acceleration from crossed laser beams in a dielectric loaded vacuum is being carried out at Stanford University. We seek to measure a maximum energy gain of about 250 keV for a 30{endash}35 MeV electron beam in one accelerator cell. We use laser pulses of a few picoseconds of duration from a regenerative Ti:sapphire laser amplifier at a wavelength of 800 nm in a laser-electron interaction distance of {approximately}1 mm. {copyright} {ital 1999 American Institute of Physics.}

  13. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R.J.; Colby, E.R.; Ischebeck, R.; McGuinness, C.M.; Noble, R.; Plettner, T.; Sears, C.M.S.; Siemann, R.H.; Spencer, J.E.; Walz, D.; /SLAC

    2011-11-21

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. They will describe the experimental plan and recent simulation studies of candidate fibers.

  14. Results from T2K and accelerator oscillation experiments

    NASA Astrophysics Data System (ADS)

    Bronner, C.

    2012-08-01

    Various experiments use secondary neutrino beams produced by accelerators to study neutrino oscillations. In this article, we will review oscillation results from a number of those experiments (MINOS, OPERA), and focus more on results from T2K. This long baseline off-axis experiment uses a beam of muon neutrinos produced in J-PARC in Japan to study muon neutrino disappearance in order to measure atmospheric parameters, as well as studying electron neutrino appearance to measure the 13 mixing angle. We will present in particular very recent results of those measurements obtained by MINOS and T2K.

  15. 78 FR 76410 - Request for Information on Strategies To Accelerate the Testing and Adoption of Pay for Success...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... Strategies to Accelerate the Testing and Adoption of Pay for Success (PFS) Financing Models (78 FR 60998... Request for Information on Strategies To Accelerate the Testing and Adoption of Pay for Success (PFS... information; reopening of comment period. SUMMARY: The Department of the Treasury is reopening the...

  16. Absolute acceleration measurements on STS-50 from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1994-01-01

    Orbital Acceleration Research Experiment (OARE) data on Space Transportation System (STS)-50 have been examined in detail during a 2-day time period. Absolute acceleration levels have been derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. During the interval, the tri-axial OARE raw telemetered acceleration measurements have been filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval have been analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z-axis sensitive range scale factors were determined in a separate process using orbiter maneuvers and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter center-of-gravity, which are the aerodynamic signals along each body axis. Results indicate that there is a force being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces have been reexamined, but none produces the observed effect. Thus, it is tentatively concluded that the orbiter is creating the environment observed. At least part of this force is thought to be due to the Flash Evaporator System.

  17. The Awful Truth About Zero-Gravity: Space Acceleration Measurement System; Orbital Acceleration Research Experiment

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Earth's gravity holds the Shuttle in orbit, as it does satellites and the Moon. The apparent weightlessness experienced by astronauts and experiments on the Shuttle is a balancing act, the result of free-fall, or continuously falling around Earth. An easy way to visualize what is happening is with a thought experiment that Sir Isaac Newton did in 1686. Newton envisioned a mountain extending above Earth's atmosphere so that friction with the air would be eliminated. He imagined a cannon atop the mountain and aimed parallel to the ground. Firing the cannon propels the cannonball forward. At the same time, Earth's gravity pulls the cannonball down to the surface and eventual impact. Newton visualized using enough powder to just balance gravity so the cannonball would circle the Earth. Like the cannonball, objects orbiting Earth are in continuous free-fall, and it appears that gravity has been eliminated. Yet, that appearance is deceiving. Activities aboard the Shuttle generate a range of accelerations that have effects similar to those of gravity. The crew works and exercises. The main data relay antenna quivers 17 times per second to prevent 'stiction,' where parts stick then release with a jerk. Cooling pumps, air fans, and other systems add vibration. And traces of Earth's atmosphere, even 200 miles up, drag on the Shuttle. While imperceptible to us, these vibrations can have a profound impact on the commercial research and scientific experiments aboard the Shuttle. Measuring these forces is necessary so that researchers and scientists can see what may have affected their experiments when analyzing data. On STS-107 this service is provided by the Space Acceleration Measurement System for Free Flyers (SAMS-FF) and the Orbital Acceleration Research Experiment (OARE). Precision data from these two instruments will help scientists analyze data from their experiments and eliminate outside influences from the phenomena they are studying during the mission.

  18. TRIDAQ systems in HEP experiments at LHC accelerator

    NASA Astrophysics Data System (ADS)

    Zagozdzińska, Agnieszka; Romaniuk, Ryszard S.; Poźniak, Krzysztof T.; Zalewski, Piotr

    2013-01-01

    The paper describes Trigger and Data Acquisition (TRIDAQ) systems of accelerator experiments for High Energy Physics. The background for physics research comprises assumptions of the Standard Model theory with basic extensions. On this basis, a structure of particle detector system is described, with emphasis on the following functional blocks: Front-End Electronics, Trigger and DAQ systems. The described solutions are used in the LHC experiments: ATLAS, ALICE, CMS and LHCb. They are also used in other accelerator experiments. Data storage and processing functionality is divided into two hardware systems: Trigger and Data Acquisition, that are dependent on each other. High input data rate impose relevant choices for the architecture and parameters of both systems. The key parameters include detailed system structure and its overall latency. Trigger structure is defined by the physics requirements and the storage capability of DAQ system. Both systems are designed to achieve the highest possible space and time resolution for particle detection. Trigger references are reviewed [1-43] as well as chosen accelerator research efforts origination in this country [44-83].

  19. Pedagogical Technology Experiences of Successful Late-Career Faculty

    ERIC Educational Resources Information Center

    Blakely, Barbara J.

    2015-01-01

    A small-scale phenomenological study reveals interesting and suggestive insights into the pedagogical technology experiences of late-career faculty with institutional recognition as successful instructors. Referred to in much of the literature as "resistant" and assumed to lack training in pedagogical technology and/or to adhere to…

  20. Introducing Development Education in Technical Universities: Successful Experiences in Spain

    ERIC Educational Resources Information Center

    Boni, A.; Perez-Foguet, A.

    2008-01-01

    This paper presents and analyses the main characteristics of successful experiences of Development Education (DE) introduced in two major Spanish Technical Universities (Technical University of Catalonia, TUC, and Technical University of Valencia, TUV) during the nineties and the beginning of the twenty-first century. In this paper, after a brief…

  1. Cryogenic supply for accelerators and experiments at FAIR

    SciTech Connect

    Kauschke, M.; Xiang, Y.; Schroeder, C. H.; Streicher, B.; Kollmus, H.

    2014-01-29

    In the coming years the new international accelerator facility FAIR (Facility for Antiproton and Ion Research), one of the largest research projects worldwide, will be built at GSI. In the final construction FAIR consists of synchrotrons and storage rings with up to 1,100 meters in circumference, two linear accelerators and about 3.5 kilometers beam transfer lines. The existing GSI accelerators serve as pre-accelerators. Partly the new machines will consist of superconducting magnets and therefore require a reliable supply with liquid helium. As the requirements for the magnets is depending on the machine and have a high variety, the cooling system is different for each machine; two phase cooling, forced flow cooling and bath cooling respectively. In addition the cold mass of the individual magnets varies between less than 1t up to 80t and some magnets will cause a dynamic heat load due to ramping that is higher than the static loads. The full cryogenic system will be operated above atmospheric pressure. The refrigeration and liquefaction power will be provided by two main cryogenic plants of 8 and 25 kW at 4K and two smaller plants next to the experiments.

  2. Dielectric Wakefield Accelerator Experiments at the SABER Facility

    SciTech Connect

    Kanareykin, A.; Thompson, M.C.; Berry, M.K.; Blumenfeld, I.; Decker, F.J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Siemann, Robert H.; Walz, D.R.; Badakov, H.; Cook, A.M.; Rosenzweig, J.B.; Tikhoplav, R.; Travish, G.; Muggli, P.; /Southern California U.

    2008-01-28

    Electron bunches with the unparalleled combination of high charge, low emittances, and short time duration, as first produced at the SLAC Final Focus Test Beam (FFTB), are foreseen to be produced at the SABER facility. These types of bunches have enabled wakefield driven accelerating schemes of multi-GV/m in plasmas. In the context of the Dielectric Wakefield Accelerators (DWA) such beams, having rms bunch length as short as 20 um, have been used to drive 100 um and 200 um ID hollow tubes above 20 GV/m surface fields. These FFTB tests enabled the measurement of a breakdown threshold in fused silica (with full data analysis still ongoing) [1]. With the construction and commissioning of the SABER facility at SLAC, new experiments would be made possible to test further aspects of DWAs including materials, tube geometrical variations, direct measurements of the Cerenkov fields, and proof of acceleration in tubes >10 cm in length. This collaboration will investigate breakdown thresholds and accelerating fields in new materials including CVD diamond. Here we describe the experimental plans, beam parameters, simulations, and progress to date as well as future prospects for machines based of DWA structures.

  3. Inverse Cerenkov laser accelerator experiment annual report. 1990 Annual report

    SciTech Connect

    Not Available

    1991-03-29

    During the past year further progress was made on preparations for the Spectra Technology, Inc. (STI) inverse Cerenkov acceleration (ICA) experiment to be performed on the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. Major progress was made in the design and fabrication of the experimental apparatus. This includes the gas cell, where the ICA process occurs, and the optical system that converts the CO{sub 2} laser beam into a radially polarized beam. In terms of progress on theoretical work, the authors finished optimizing the ATF ICA design parameters using their Monte Carlo computer simulation. The optimized design predicts for the ATF conditions that over 50% energy gain should be observed. They published a paper on an improved method of performing ICA by operating near the resonance of a gas. They also began analysis of a method of accelerating particles in a vacuum using a radially polarized beam and axicon focusing. Although this new method can no longer be considered ICA, it has the potential of high acceleration gradients without the drawbacks of gas scattering and gas breakdown. Three papers were published and two conference papers were presented during 1990.

  4. Structure Loaded Vacuum Laser-Driven Particle Acceleration Experiments at SLAC

    SciTech Connect

    Plettner, T.; Byer, R.L.; Colby, E.R.; Cowan, B.M.; Ischebeck, R.; McGuinness, C.; Lincoln, M.R.; Sears, C.M.; Siemann, R.H.; Spencer, J.E.; /SLAC /Stanford U., Phys. Dept.

    2007-04-09

    We present an overview of the future laser-driven particle acceleration experiments. These will be carried out at the E163 facility at SLAC. Our objectives include a reconfirmation of the proof-of-principle experiment, a staged buncher laser-accelerator experiment, and longer-term future experiments that employ dielectric laser-accelerator microstructures.

  5. An inverse free electron laser accelerator: Experiment and theoretical interpretation

    SciTech Connect

    Fang, Jyan-Min

    1997-06-01

    Experimental and numerical studies of the Inverse Free Electron Laser using a GW-level 10.6 {mu}m CO{sub 2} laser have been carried out at Brookhaven`s Accelerator Test Facility. An energy gain of 2.5 % ({Delta}E/E) on a 40 MeV electron beam has been observed E which compares well with theory. The effects on IFEL acceleration with respect to the variation of the laser electric field, the input electron beam energy, and the wiggler magnetic field strength were studied, and show the importance of matching the resonance condition in the IFEL. The numerical simulations were performed under various conditions and the importance of the electron bunching in the IFEL is shown. The numerical interpretation of our IFEL experimental results was examined. Although good numerical agreement with the experimental results was obtained, there is a discrepancy between the level of the laser power measured in the experiment and used in the simulation, possibly due to the non-Gaussian profile of the input high power laser beam. The electron energy distribution was studied numerically and a smoothing of the energy spectrum by the space charge effect at the location of the spectrometer was found, compared with the spectrum at the exit of the wiggler. The electron bunching by the IFEL and the possibility of using the IFEL as an electron prebuncher for another laser-driven accelerator were studied numerically. We found that bunching of the electrons at 1 meter downstream from the wiggler can be achieved using the existing facility. The simulation shows that there is a fundamental difference between the operating conditions for using the IFEL as a high gradient accelerator, and as a prebuncher for another accelerator.

  6. Guenter Tulip Filter Retrieval Experience: Predictors of Successful Retrieval

    SciTech Connect

    Turba, Ulku Cenk Arslan, Bulent Meuse, Michael Sabri, Saher; Macik, Barbara Gail

    2010-08-15

    We report our experience with Guenter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Guenter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Guenter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.

  7. Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

    PubMed Central

    Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

    2014-01-01

    Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments. PMID:24805129

  8. Successfully recruiting a multicultural population: the DASH-Sodium experience.

    PubMed

    Kennedy, Betty M; Conlin, Paul R; Ernst, Denise; Reams, Patrice; Charleston, Jeanne B; Appel, Lawrence J

    2005-01-01

    Recruiting practices employed by the four clinical centers participating in the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial were examined to assess the most successful method of obtaining participants and to describe pertinent learning experiences gained as a result of the trial. The primary recruitment strategies employed by each center were mass mailing brochures (direct, coupon packs, or other) and mass media (advertisements in newspapers, radio, and television spots). Of 412 randomized participants, 265 (64%) were from mass distribution of brochures, 62 (15%) mass media, and 85 (21%) were prior study participants, referred by word-of-mouth, or reported coming from screening events and presentations. Although the most successful method of recruitment was mass mailing brochures, three times as many brochures were distributed to obtain similar success as in the initial DASH trial. PMID:15720059

  9. Hypervelocity macroparticle accelerator experiments at CEM-UT

    NASA Astrophysics Data System (ADS)

    Weeks, D. A.; Weldon, W. F.; Zowarka, R. C., Jr.

    1991-01-01

    Railgun experiments designed to accelerate projectile masses of 2 to 5 g to velocities greater than 6 km/s were performed. Two parallel rail-type accelerators with 12.7-mm square bores were used for the experiments. One gun is 2 m long and has Mo rails and Al2O3 insulators. The other is 1 m long and has Mo rails and granite insulators. The greatest velocity achieved was 5.1 km/s. The following ideas to enhance performance were tested: stiff-gun structures to reduce plasma leakage and rail movement, refractory bore materials to reduce ablation and frictional losses, and prefilling the gun bore with gases to eliminate precursor arcs. After three experiments with the 2-m-long launcher at peak currents 660-780 kA, a gun barrel with 96 percent Al2O3 insulators and 99.9 percent Mo rails (hydraulically contained and preloaded) has survived with minimal damage and no degradation of seals. This launcher configuration is capable of maintaining 0.4 torr rough vacuum for over 1 h after disconnecting the roughing pump used to evacuate the gun.

  10. Recent Developments on ALICE (Accelerators and Lasers In Combined Experiments) at Daresbury Laboratory

    SciTech Connect

    Saveliev, Y M; Buckley, R K; Buckley, S R; Clarke, J A; Corlett, P A; Dunning, D J; Goulden, A R; Hill, S F; Jackson, F; Jamison, S P; Jones, J K; Jones, L B; Leonard, S; McIntosh, P A; McKenzie, J W; Middleman, K J; Militsyn, B L; Moss, A J; Muratori, B D; Orrett, J F; Pattalwar, S M; Phillips, P J; Scott, D J; Seddon, E A; Shepherd, B.J.A.; Smith, S L; Thompson, N; Wheelhouse, A E; Williams, P H; Harrison, P; Holder, D J; Holder, G M; Schofield, A L; Weightman, P; Williams, R L; Laundry, D; Powers, T; Priebe, G; Surman, M

    2010-05-01

    Progress made in ALICE (Accelerators and Lasers In Combined Experiments) commissioning and a summary of the latest experimental results are presented in this paper. After an extensive work on beam loading effects in SC RF linac (booster) and linac cavities conditioning, ALICE can now operate in full energy recovery mode at the bunch charge of 40pC, the beam energy of 30MeV and train lengths of up to 100us. This improved operation of the machine resulted in generation of coherently enhanced broadband THz radiation with the energy of several tens of uJ per pulse and in successful demonstration of the Compton Backscattering x-ray source experiment. The next steps in the ALICE scientific programme are commissioning of the IR FEL and start of the research on the first non-scaling FFAG accelerator EMMA. Results from both projects will be also reported.

  11. Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL

    SciTech Connect

    Nakamura, K.; Esarey, E.; Leemans, W. P.; Gonsalves, A. J.; Panasenko, D.; Toth, Cs.; Geddes, C. G. R.; Schroeder, C. B.; Lin, C.

    2009-01-22

    Laser wakefield acceleration experiments were carried out by using a hydrogen-filled capillary discharge waveguide. For a 15 mm long, 200 {mu}m diameter capillary, quasi-monoenergetic e-beams up to 300 MeV were observed. By de-tuning discharge delay from optimum guiding performance, self-trapping was found to be stabilized. For a 33 mm long, 300 {mu}m capillary, a parameter regime with high energy electron beams, up to 1 GeV, was found. In this regime, the electron beam peak energy was correlated with the amount of trapped electrons.

  12. Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL

    SciTech Connect

    Advanced Light Source; Nakamura, Kei; Gonsalves, Anthony; Panasenko, Dmitriy; Lin, Chen; Toth, Csaba; Geddes, Cameron; Schroeder, Carl; Esarey, Eric; Leemans, Wim

    2008-09-29

    Laser wakefield acceleration experiments were carried out by using a hydrogen-filledcapillary discharge waveguide. For a 15 mm long, 200 mu m diameter capillary, quasi-monoenergetic e-beams up to 300 MeV were observed. By de-tuning discharge delay from optimum guiding performance, self-trapping was found to be stabilized. For a 33 mm long, 300 mu m capillary, a parameter regime with high energy electron beams, up to 1 GeV, was found. In this regime, the electron beam peak energy was correlated with the amount of trapped electrons.

  13. Subpanel on accelerator-based neutrino oscillation experiments

    SciTech Connect

    1995-09-01

    Neutrinos are among nature`s fundamental constituents, and they are also the ones about which we know least. Their role in the universe is widespread, ranging from the radioactive decay of a single atom to the explosions of supernovae and the formation of ordinary matter. Neutrinos might exhibit a striking property that has not yet been observed. Like the back-and-forth swing of a pendulum, neutrinos can oscillate to-and-from among their three types (or flavors) if nature provides certain conditions. These conditions include neutrinos having mass and a property called {open_quotes}mixing.{close_quotes} The phenomenon is referred to as neutrino oscillations. The questions of the origin of neutrino mass and mixing among the neutrino flavors are unsolved problems for which the Standard Model of particle physics holds few clues. It is likely that the next critical step in answering these questions will result from the experimental observation of neutrino oscillations. The High Energy Physics Advisory Panel (HEPAP) Subpanel on Accelerator-Based Neutrino Oscillation Experiments was charged to review the status and discovery potential of ongoing and proposed accelerator experiments on neutrino oscillations, to evaluate the opportunities for the U.S. in this area of physics, and to recommend a cost-effective plan for pursuing this physics, as appropriate. The complete charge is provided in Appendix A. The Subpanel studied these issues over several months and reviewed all the relevant and available information on the subject. In particular, the Subpanel reviewed the two proposed neutrino oscillation programs at Fermi National Accelerator Laboratory (Fermilab) and at Brookhaven National Laboratory (BNL). The conclusions of this review are enumerated in detail in Chapter 7 of this report. The recommendations given in Chapter 7 are also reproduced in this summary.

  14. Hyper-velocity impact experiments with electrostatic dust accelerators

    NASA Astrophysics Data System (ADS)

    Mocker, Anna; Aust, Thomas; Bugiel, Sebastian; Hillier, Jonathan; Hornung, Klaus; Li, Yan-Wei; Strack, Heiko; Ralf, Srama

    2015-06-01

    Hypervelocity impacts (HVI) of micrometer-sized particles play an important role in a variety of fields such as the investigation of matter at extreme pressures and temperatures, shock waves in solid bodies, planetology and cosmic dust. The physical phenomena occurring upon impact are fragmentation and cratering, shock waves, the production of neutral and ionized gas, and light flashes. Advanced analysis techniques promise new insights into short time-scale high-pressure states of matter, requiring the production of high speed projectiles. Electrostatic accelerators act as a source of micrometer and sub-micrometer particles as projectiles for HVI experiments. This paper describes an HVI facility, capable of accelerating particles to over 100 km/s, currently located at the Max Planck Institute for Nuclear Physics in Heidelberg, together with planned improvements. The facility is about to be relocated to the University of Stuttgart. This is an opportunity to enhance the facility to meet the requirements of future experimental campaigns, necessary to better understand the micrometeoroid hypervelocity impact process and develop new in situ dust experiments. We will present the design of the new facility and the planned enhancements, including new diagnostic apparatus.

  15. Imaging system QA of a medical accelerator, Novalis Tx, for IGRT per TG 142: our 1 year experience.

    PubMed

    Chang, Zheng; Bowsher, James; Cai, Jing; Yoo, Sua; Wang, Zhiheng; Adamson, Justus; Ren, Lei; Yin, Fang-Fang

    2012-01-01

    American Association of Physicists in Medicine (AAPM) task group (TG) 142 has recently published a report to update recommendations of the AAPM TG 40 report and add new recommendations concerning medical accelerators in the era of image-guided radiation therapy (IGRT). The recommendations of AAPM TG 142 on IGRT are timely. In our institute, we established a comprehensive imaging QA program on a medical accelerator based on AAPM TG 142 and implemented it successfully. In this paper, we share our one-year experience and performance evaluation of an OBI capable linear accelerator, Novalis Tx, per TG 142 guidelines. PMID:22766946

  16. Advancing Successful Physics Majors - The Physics First Year Seminar Experience

    NASA Astrophysics Data System (ADS)

    Deibel, Jason; Petkie, Douglas

    In 2012, the Wright State University physics curriculum introduced a new year-long seminar course required for all new physics majors. The goal of this course is to improve student retention and success via building a community of physics majors and provide them with the skills, mindset, and advising necessary to successfully complete a degree and transition to the next part of their careers. This new course sequence assembles a new cohort of majors annually. To prepare each cohort, students engage in a variety of activities that span from student success skills to more specific physics content while building an entrepreneurial mindset. Students participate in activities including study skills, career night, course planning, campus services, and a department social function. More importantly, students gain exposure to programming, literature searches, data analysis, technical writing, elevator pitches, and experimental design via hands-on projects. This includes the students proposing, designing, and conducting their own experiments. Preliminary evidence indicates increased retention, student success, and an enhanced sense of community among physics undergraduate students, The overall number of majors and students eventually completing their physics degrees has nearly tripled. Associate Professor, Department of Physics.

  17. Preliminary Results from the UCLA/SLAC Ultra-High Gradient CerenkovWakefield Accelerator Experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.; /Manhattan Coll., Riverdale

    2008-02-06

    The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. This experiment takes advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam has been successfully focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam was varied in the range 20 {micro}m < {sigma}{sub z} < 100 {micro}m which produced a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain more information about the strength of the accelerating fields.

  18. Accelerated Aging Experiments for Capacitor Health Monitoring and Prognostics

    NASA Technical Reports Server (NTRS)

    Kulkarni, Chetan S.; Celaya, Jose Ramon; Biswas, Gautam; Goebel, Kai

    2012-01-01

    This paper discusses experimental setups for health monitoring and prognostics of electrolytic capacitors under nominal operation and accelerated aging conditions. Electrolytic capacitors have higher failure rates than other components in electronic systems like power drives, power converters etc. Our current work focuses on developing first-principles-based degradation models for electrolytic capacitors under varying electrical and thermal stress conditions. Prognostics and health management for electronic systems aims to predict the onset of faults, study causes for system degradation, and accurately compute remaining useful life. Accelerated life test methods are often used in prognostics research as a way to model multiple causes and assess the effects of the degradation process through time. It also allows for the identification and study of different failure mechanisms and their relationships under different operating conditions. Experiments are designed for aging of the capacitors such that the degradation pattern induced by the aging can be monitored and analyzed. Experimental setups and data collection methods are presented to demonstrate this approach.

  19. Wakefield Simulations for the Laser Acceleration Experiment at SLAC

    SciTech Connect

    Ng, Johnny

    2012-04-18

    Laser-driven acceleration in dielectric photonic band gap structures can provide gradients on the order of GeV/m. The small transverse dimension of the structure, on the order of the laser wavelength, presents interesting wakefield-related issues. Higher order modes can seriously degrade beam quality, and a detailed understanding is needed to mitigate such effects. On the other hand, wakefields also provide a direct way to probe the interaction of a relativistic bunch with the synchronous modes supported by the structure. Simulation studies have been carried out as part of the effort to understand the impact on beam dynamics, and to compare with data from beam experiments designed to characterize candidate structures. In this paper, we present simulation results of wakefields excited by a sub-wavelength bunch in optical photonic band gap structures.

  20. Accelerating multidimensional NMR and MRI experiments using iterated maps

    NASA Astrophysics Data System (ADS)

    Barrett, Sean; Frey, Merideth; Sethna, Zachary; Manley, Gregory; Sengupta, Suvrajit; Zilm, Kurt; Loria, J. Patrick

    2014-03-01

    Techniques that accelerate data acquisition without sacrificing the advantages of fast Fourier transform (FFT) reconstruction could benefit a wide variety of magnetic resonance experiments. Here we discuss an approach for reconstructing multidimensional nuclear magnetic resonance (NMR) spectra and MR images from sparsely-sampled time domain data, by way of iterated maps. This method exploits the computational speed of the FFT algorithm and is done in a deterministic way, by reformulating any a priori knowledge or constraints into projections, and then iterating. In this paper we explain the motivation behind this approach, the formulation of the specific projections, the benefits of using a `QUasi-Even Sampling, plus jiTter' (QUEST) sampling schedule, and various methods for handling noise. Applying the iterated maps method to real 2D NMR and 3D MRI of solids data, we show that it is flexible and robust enough to handle large data sets with significant noise and artifacts.

  1. Accelerating multidimensional NMR and MRI experiments using iterated maps

    NASA Astrophysics Data System (ADS)

    Frey, Merideth A.; Sethna, Zachary M.; Manley, Gregory A.; Sengupta, Suvrajit; Zilm, Kurt W.; Loria, J. Patrick; Barrett, Sean E.

    2013-12-01

    Techniques that accelerate data acquisition without sacrificing the advantages of fast Fourier transform (FFT) reconstruction could benefit a wide variety of magnetic resonance experiments. Here we discuss an approach for reconstructing multidimensional nuclear magnetic resonance (NMR) spectra and MR images from sparsely-sampled time domain data, by way of iterated maps. This method exploits the computational speed of the FFT algorithm and is done in a deterministic way, by reformulating any a priori knowledge or constraints into projections, and then iterating. In this paper we explain the motivation behind this approach, the formulation of the specific projections, the benefits of using a ‘QUasi-Even Sampling, plus jiTter' (QUEST) sampling schedule, and various methods for handling noise. Applying the iterated maps method to real 2D NMR and 3D MRI of solids data, we show that it is flexible and robust enough to handle large data sets with significant noise and artifacts.

  2. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    NASA Astrophysics Data System (ADS)

    Rosenzweig, J. B.; Andonian, G.; Muggli, P.; Niknejadi, P.; Travish, G.; Williams, O.; Xuan, K.; Yakimenko, V.

    2010-11-01

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation (CCR) production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of the FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in ˜33 cm DWA tubes. In the nearer term before FACET's commissioning, we are performing measurements at the BNL ATF, in which we drive ˜50-200 MV/m fields with single pulses or pulse trains, and observe resonantly driven CCR as well as deflection modes. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for high efficiency operation with pulse trains, and explore transverse modes for the first time.

  3. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    SciTech Connect

    Rosenzweig, J. B.; Andonian, G.; Niknejadi, P.; Travish, G.; Williams, O.; Xuan, K.; Muggli, P.; Yakimenko, V.

    2010-11-04

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation (CCR) production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of the FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are performing measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains, and observe resonantly driven CCR as well as deflection modes. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for high efficiency operation with pulse trains, and explore transverse modes for the first time.

  4. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    SciTech Connect

    Rosenzweig, James; Travish, Gil; Hogan, Mark; Muggli, Patric; /Southern California U.

    2012-07-05

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are planning measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for efficient operation with pulse trains.

  5. Operational experience on the Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect

    Batchelor, K.; Babzien, M.; Ben-Zvi, I.

    1994-09-01

    Brookhaven National Laboratory Accelerator Test Facility is a laser-electron linear accelerator complex designed to provide high brightness beams for testing of advanced acceleration concepts and high power pulsed photon sources. Results of electron beam parameters attained during the commissioning of the nominally 45 MeV energy machine are presented.

  6. Proof-of-principle experiments of laser Wakefield acceleration

    SciTech Connect

    Nakajima, K.; Kawakubo, T.; Nakanishi, H.

    1994-04-01

    Recently there has been a great interest in laser-plasma accelerators as possible next-generation particle accelerators because of their potential for ultra high accelerating gradients and compact size compared with conventional accelerators. It is known that the laser pulse is capable of exciting a plasma wave propagating at a phase velocity close to the velocity of light by means of beating two-frequency lasers or an ultra short laser pulse. These schemes came to be known as the Beat Wave Accelerator (BWA) for beating lasers or as the Laser Wakefield Accelerator (LWFA) for a short pulse laser. In this paper, the principle of laser wakefield particle acceleration has been tested by the Nd:glass laser system providing a short pulse with a power of 10 TW and a duration of 1 ps. Electrons accelerated up to 18 MeV/c have been observed by injecting 1 MeV/c electrons emitted from a solid target by an intense laser impact. The accelerating field gradient of 30 GeV/m is inferred.

  7. STS-40 orbital acceleration research experiment flight results during a typical sleep period

    NASA Technical Reports Server (NTRS)

    Blanchard, R. C.; Nicholson, J. Y.; Ritter, J. R.

    1992-01-01

    The Orbital Acceleration Research Experiment (OARE), an electrostatic accelerometer package with complete on-orbit calibration capabilities, was flown for the first time aboard the Space Shuttle on STS-40. This is also the first time an accelerometer package with nano-g sensitivity and a calibration facility has flown aboard the Space Shuttle. The instrument is designed to measure and record the Space Shuttle aerodynamic acceleration environment from the free molecule flow regime through the rarified flow transition into the hypersonic continuum regime. Because of its sensitivity, the OARE instrument defects aerodynamic behavior of the Space Shuttle while in low-earth orbit. A 2-hour orbital time period on day seven of the mission, when the crew was asleep and other spacecraft activities were at a minimum, was examined. During the flight, a 'trimmed-mean' filter was used to produce high quality, low frequency data which was successfully stored aboard the Space Shuttle in the OARE data storage system. Initial review of the data indicated that, although the expected precision was achieved, some equipment problems occurred resulting in uncertain accuracy. An acceleration model which includes aerodynamic, gravity-gradient, and rotational effects was constructed and compared with flight data. Examination of the model with the flight data shows the instrument to be sensitive to all major expected low frequency acceleration phenomena; however, some erratic instrument bias behavior persists in two axes. In these axes, the OARE data can be made to match a comprehensive atmospheric-aerodynamic model by making bias adjustments and slight linear corrections for drift. The other axis does not exhibit these difficulties and gives good agreement with the acceleration model.

  8. Accelerated growth of calcium silicate hydrates: Experiments and simulations

    SciTech Connect

    Nicoleau, Luc

    2011-12-15

    Despite the usefulness of isothermal calorimetry in cement analytics, without any further computations this brings only little information on the nucleation and growth of hydrates. A model originally developed by Garrault et al. is used in this study in order to simulate hydration curves of cement obtained by calorimetry with different known hardening accelerators. The limited basis set of parameters used in this model, having a physical or chemical significance, is valuable for a better understanding of mechanisms underlying in the acceleration of C-S-H precipitation. Alite hydration in presence of four different types of hardening accelerators was investigated. It is evidenced that each accelerator type plays a specific role on one or several growth parameters and that the model may support the development of new accelerators. Those simulations supported by experimental observations enable us to follow the formation of the C-S-H layer around grains and to extract interesting information on its apparent permeability.

  9. Effects of Internship Predictors on Successful Field Experience.

    ERIC Educational Resources Information Center

    Beard, Fred; Morton, Linda

    1999-01-01

    Finds that a majority of advertising and public-relations interns found their internships successful. Indicates that successful internships depend on predictors given the least attention by school programs: quality of supervision was the most important single predictor variable, followed in importance by organizational practices/policies, positive…

  10. Participation in the definition, conduct, and analysis of particle accelerator experiments for the first Spacelab Mission

    NASA Technical Reports Server (NTRS)

    Burch, J. L.

    1994-01-01

    The Space Experiments with Particle Accelerators (SEPAC) is a joint endeavor between NASA and the Institute of Space and Aeronautical Sciences (ISAS) in Japan. Its objectives are to use energetic electron beams to investigate beam-atmosphere interactions and beam-plasma interactions in the earth's upper atmosphere and ionosphere using the shuttle Spacelab. Two flights of SEPAC have occurred to date (Spacelab 1 on STS-9 in Nov.-Dec. 1983 and ATLAS 1 on STS-45 in Mar.-Apr. 1992). The SEPAC instrumentation is available for future missions, and the scientific results of the first two missions justify further investigations; however, at present there are no identifiable future flight opportunities. As specified in the contract, the primary purpose of this report is to review the scientific accomplishments of the ATLAS 1 SEPAC experiments, which have been documented in the published literature, with only a brief review of the earlier Spacelab 1 results. One of the main results of the Spacelab 1 SEPAC experiments was that the ejection of plasma from the magnetoplasmadynamic (MPD) arcjet was effective in maintaining vehicle charge neutralization during electron beam firings, but only for a brief period of 10 ms or so. Therefore, a xenon plasma contactor, which can provide continuous vehicle charge neutralization, was developed for the ATLAS 1 SEPAC experiments. Because of the successful operation of the plasma contactor on ATLAS 1, it was possible to perform experiments on beam-plasma interactions and beam-atmosphere interactions at the highest beam power levels of SEPAC. In addition, the ability of the plasma contactor to eject neutral xenon led to a successful experiment on the critical ionization velocity (CIV) phenomena on ATLAS 1.

  11. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  12. Statistical analysis of microgravity experiment performance using the degrees of success scale

    NASA Technical Reports Server (NTRS)

    Upshaw, Bernadette; Liou, Ying-Hsin Andrew; Morilak, Daniel P.

    1994-01-01

    This paper describes an approach to identify factors that significantly influence microgravity experiment performance. Investigators developed the 'degrees of success' scale to provide a numerical representation of success. A degree of success was assigned to 293 microgravity experiments. Experiment information including the degree of success rankings and factors for analysis was compiled into a database. Through an analysis of variance, nine significant factors in microgravity experiment performance were identified. The frequencies of these factors are presented along with the average degree of success at each level. A preliminary discussion of the relationship between the significant factors and the degree of success is presented.

  13. Acceleration units for the Induction Linac Systems Experiment (ILSE)

    SciTech Connect

    Faltens, A.; Brady, V.; Brodzik, D.; Hansen, L.; Laslett, L.J.; Mukherjee, S.; Bubp, D.; Ravenscroft, D.; Reginato, L.

    1989-03-01

    The design of a high current heavy ion induction linac driver for inertial confinement fusion is optimized by adjusting the acceleration units along the length of the accelerator to match the beam current, energy, and pulse duration at any location. At the low energy end of the machine the optimum is a large number of electrostatically focused parallel beamlets, whereas at higher energies the optimum is a smaller number of magnetically focused beams. ILSE parallels this strategy by using 16 electrostatically focused beamlets at the low end followed by 4 magnetically focused beams after beam combining. 3 refs., 2 figs.

  14. Two-Channel Rectangular Dielectric Wake Field Accelerator Structure Experiment

    SciTech Connect

    Sotnikov, G. V.; Marshall, T. C.; Shchelkunov, S. V.; Didenko, A.; Hirshfield, J. L.

    2009-01-22

    A design is presented for a two-channel 30-GHz rectangular dielectric wake field accelerator structure being built for experimental tests at Argonne National Laboratory (ANL). This structure allows for a transformer ratio T much greater than two, and permits continuous coupling of energy from drive bunches to accelerated bunches. It consists of three planar slabs of cordierite ceramic ({epsilon} = 4.7) supported within a rectangular copper block, forming a drive channel 12 mmx6 mm, and an accelerator channel 2 mmx6 mm. When driven by a 50 nC, 14 MeV single bunch available at ANL, theory predicts an acceleration field of 6 MeV/m, and T = 12.6. Inherent transverse wake forces introduce deflections and some distortion of bunch profiles during transit through the structure that are estimated to be tolerable. Additionally, a cylindrical two-channel DWFA is introduced which shares many advantages of the rectangular structure including high T, and the added virtue of axisymmetry that eliminates lowest-order transverse deflecting forces.

  15. RF ACCELERATING STRUCTURE FOR THE MUON COOLING EXPERIMENT.

    SciTech Connect

    CORLETT,J.; GREEN,M.; LI,D.; HOLTKAMP,N.; MORETTI,A.; KIRK,H.G.; PALMER,R.B.; ZHAO,Y.; SUMMERS,D.

    1999-03-29

    The ionization cooling of muons requires longitudinal acceleration of the muons after scattering in a hydrogen target. In order to maximize the accelerating voltage, we propose using linear accelerating structures with cells bounded by thin beryllium metal foils. This produces an on-axis field equivalent to the maximum surface field, whereas with beam-pipes the accelerating field is approximately half that of the peak surface field in the cavity. The muons interact only weakly with the thin foils. A {pi}/2 interleaved cavity structure has been chosen, with alternate cells coupled together externally, and the two groups of cells fed in quadrature. At present they are considering an operating temperature of 77K to gain a factor of at least two in Q-value over room temperature. The authors describe the design of the {pi}/2 interleaved cavity structure, design of an alternative {pi}-mode open structure, preliminary experimental results from a low-power test cavity, and plans for high-power testing.

  16. Present and future high-energy accelerators for neutrino experiments

    SciTech Connect

    Kourbanis, I.; /Fermilab

    2007-06-01

    There is an active neutrino program making use of the high-energy (larger than 50 GeV) accelerators both in USA at Fermilab with NuMI and at CERN in Europe with CNGS. In this paper we will review the prospects for high intensity high energy beams in those two locations during the next decade.

  17. The 7-gap-resonator-accelerator for the REX-ISOLDE-experiment at CERN

    NASA Astrophysics Data System (ADS)

    Podlech, H.; Grieser, M.; von Hahn, R.; Papureanu, S.; Repnow, R.; Schwalm, D.

    1998-04-01

    The Radioactive Beam Experiment at ISOLDE (REX-ISOLDE-Experiment) which presently is being developed and under construction at CERN serves to investigate exotic, very neutron rich, radioactive nuclei [1](Radioactive beam EXperiment at ISOLDE: Coloumb Excitation and Neutron Transfer Reactions of Exotic Nuclei, Proposal to the ISOLDE commitee, CERNSIC94-25). A linear accelerator delivers radioactive ions which are produced by the isotope separator ISOLDE with energies between 0.85 and 2.2 MeV/u. The Linac will consist of a RFQ-accelerator, an interdigital H-Structure (IH) and three 7-gap-resonators with variable energy. While the LMU Munich is responsible for the frontpart of the accelerator, the backpart is being built by the MPI [2](H. Podlech, Master Thesis, MPI-H-V21-1997, Heidelburg, 1997). After estimation of the voltage of one resonator to 1.75 MV at 90 kW, the design velocities were fixed to 5.4%, 6.0% and 6.6% of the velocity of light. Three downscaled models (1:2.5) were built in order to optimize the shuntimpedance and the field-distribution at the operation frequency of the amplifiers of 101.28 MHz. The optimization of all low power resonators is now successfully finished. Extensive beam dynamic calculations were made in order to optimize the transmission of the beam up to the target. It turned out that final energies between 0.85 and 2.2 MeV/u with nearly 100% transmission can be achieved. The acceptance in the x-plane is 1.2π mm mrad (norm.) and in the y-plane 3.0π mm mrad (norm.). The bunchlength of the fully accelerated beam (2.2 MeV/u) is 2.4 ns at the target. The development of the resonators was accompanied by extensive MAFIA calculations. It could be demonstrated that spiral-resonators like 7-gap-resonators can be calculated with MAFIA with an accuracy of 1% in comparison with experimental results. Presently, the tanks and the half shells of the power type resonators are manufactured in the workshops of the MPI.

  18. Accelerating the connection between experiments and models: The FACE-MDS experience

    NASA Astrophysics Data System (ADS)

    Norby, R. J.; Medlyn, B. E.; De Kauwe, M. G.; Zaehle, S.; Walker, A. P.

    2014-12-01

    The mandate is clear for improving communication between models and experiments to better evaluate terrestrial responses to atmospheric and climatic change. Unfortunately, progress in linking experimental and modeling approaches has been slow and sometimes frustrating. Recent successes in linking results from the Duke and Oak Ridge free-air CO2 enrichment (FACE) experiments with ecosystem and land surface models - the FACE Model-Data Synthesis (FACE-MDS) project - came only after a period of slow progress, but the experience points the way to future model-experiment interactions. As the FACE experiments were approaching their termination, the FACE research community made an explicit attempt to work together with the modeling community to synthesize and deliver experimental data to benchmark models and to use models to supply appropriate context for the experimental results. Initial problems that impeded progress were: measurement protocols were not consistent across different experiments; data were not well organized for model input; and parameterizing and spinning up models that were not designed for simulating a specific site was difficult. Once these problems were worked out, the FACE-MDS project has been very successful in using data from the Duke and ORNL FACE experiment to test critical assumptions in the models. The project showed, for example, that the stomatal conductance model most widely used in models was supported by experimental data, but models did not capture important responses such as increased leaf mass per unit area in elevated CO2, and did not appropriately represent foliar nitrogen allocation. We now have an opportunity to learn from this experience. New FACE experiments that have recently been initiated, or are about to be initiated, include a eucalyptus forest in Australia; the AmazonFACE experiment in a primary, tropical forest in Brazil; and a mature oak woodland in England. Cross-site science questions are being developed that will have a

  19. Assisting Your Preservice Teacher to Be Successful during Field Experiences

    ERIC Educational Resources Information Center

    Brett, Christine

    2006-01-01

    Field experience (junior practicum and student teaching) is considered by many to be the most influential part of a teacher preparation program (Cruickshank & Aramalin, 1986; Tannehill & Zakrajsek, 1988). During field experiences, preservice teachers (hereafter referred to as PSTs) are guided by a cooperating teacher (hereafter referred to as a…

  20. Road to Success: Service Learning Enhances Tech Ed Experience

    ERIC Educational Resources Information Center

    Howell, Robert T.

    2008-01-01

    Service learning, a form of experiential learning, is not a new idea. Students learn through participation in thoughtfully organized service experiences that meet real community needs are are coordinated in collaboration with schools/faculty and community organizations. the service experiences are integrated into the students' academic curriculum,…

  1. The Keller Plan: A Successful Experiment in Engineering Education.

    ERIC Educational Resources Information Center

    Koen, Billy; And Others

    1985-01-01

    Discusses the Keller Plan or personalized system of instruction (PSI), a mastery-oriented, self-paced, modular teaching strategy using student/peer proctors. Success for PSI in chemical engineering, operations research, electrical engineering, and nuclear engineering courses is explained. (DH)

  2. Assessing the Chances of Success: Naive Statistics versus Kind Experience

    ERIC Educational Resources Information Center

    Hogarth, Robin M.; Mukherjee, Kanchan; Soyer, Emre

    2013-01-01

    Additive integration of information is ubiquitous in judgment and has been shown to be effective even when multiplicative rules of probability theory are prescribed. We explore the generality of these findings in the context of estimating probabilities of success in contests. We first define a normative model of these probabilities that takes…

  3. Methoprene and protein supplements accelerate reproductive development and improve mating success of male tephritid flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have been studying the physiological mechanisms responsible for coordination of reproductive maturity and sex pheromone communication in males of tephritid flies in order to develop methods for acceleration of reproductive maturity among sterilized males. Our studies revealed that the juvenile ho...

  4. Smoking Cessation 1 Year or More: Experiences of Successful Quitters.

    PubMed

    DiPiazza, Jennifer T; Naegle, Madeline

    2016-01-01

    There is a paucity of research focused on the experience of maintaining cessation for a year or longer, and recidivism rates for smoking cessation are estimated at 50% to 97%. As cigarette smoking is one of the leading causes of death worldwide, there is a critical need for more knowledge about maintaining smoking cessation. Therefore, this study was undertaken to explore the lived experience of maintaining cigarette smoking cessation for a year or more. Using Streubert's nurse-developed descriptive phenomenological method, seven adults who sustained cessation for 1.5 to 18 years, after repeated relapses, were interviewed about their experience of sustaining cessation. Data collection included interviews, field notes, and a reflexive journal. Phenomenological analysis involved dwelling intensely with the data, extracting parts of the transcript, and identifying codes and themes, defined by Streubert as essences, common to all participants' descriptions of the experience of sustained cessation. Through this inductive process, the investigator ascertained relationships among the essences, forming the basis for a formalized, exhaustive description of the experience. Six essences captured participants' experiences of maintaining cigarette smoking cessation: (a) breaking free, (b) developing an olfactory aversion, (c) reframing, (d) learning through relapse, (e) reclaiming acceptance, and (f) self-transformation. The findings suggest that maintaining cessation for a year or more is shaped by biological, psychological, and social conditions, as reflected in the essences. The essences coalesced to a tipping point of motivation and conditions leading to sustained behavior change, allowing participants to maintain cessation. PMID:27580193

  5. Space Experiments with Particle Accelerators: SEPAC - SEPAC program for First Spacelab Mission

    NASA Astrophysics Data System (ADS)

    Obayashi, T.

    The Space Shuttle/Spacelab Mission Space Experiment with Particle Accelerators (SEPAC) will carry out interactive experiments on, and in, the earth ionosphere and magnetosphere, and comprises an electron beam accelerator, MPD arcjet, and associated diagnostic equipment. The mission Payload Specialist will be responsible for (1) manual control of scientific instruments, (2) monitoring of experiment displays, (3) restructuring of experiment sequence by means of display system keyboard, (4) safety and emergency operations, and (5) voice communications. Attention is given to the configurational and sequential organization of the SEPAC experiments.

  6. Experience in using FlexCtrl SCADA for accelerator automation

    NASA Astrophysics Data System (ADS)

    Nikiforov, A.; Aleinikov, V.; Sychev, A.; Borina, I.; Rukavishnikov, A.

    2012-07-01

    The programmed component of the automatic control of accelerators on the basis of licensed software packages (FlexCtrl SCADA, Photon Application Builder, and Cogent DataHub) and an additionally developed library of classes (related to visual programming with regard to functional capabilities and which all together represent an integrated media for producing the automation system) is described in the article. The number of features of the media components and the number of the components themselves can be increased since the developed media is characterized as open.

  7. Second-order state estimation experiments using acceleration measurements

    NASA Technical Reports Server (NTRS)

    Belvin, W. K.

    1992-01-01

    The estimation of dynamic states for feedback control of structural systems using second-order differential equations and acceleration measurements is described. The formulation of the observer model, and the design of the observer gains is discussed in detail. It is shown the second-order observer is highly stable because the stability constraints on the observer gains are model independent. The limitation of the proposed observer is the need for 'nearly' collocated actuators and accelerometers. Experimental results using a control-structure interaction testbed are presented that show the second-order observer provided more stability than a Kalman filter estimator without decreasing closed-loop performance.

  8. The First-Year Experiences of Successful Superintendents

    ERIC Educational Resources Information Center

    Roberts, Kerry; Hanna, Shellie L.; Womack, Sid T.

    2012-01-01

    These qualitative case studies give the prospective superintendent a real-life look at life on the other side of the district CEO's desk. Two dozen superintendents reflect upon their first challenges and growth opportunities that arose during that all-important first year. They tell it like it is, no sugar-coating. The experiences they listed, in…

  9. School Leader Succession: A Description of Transitional Experiences

    ERIC Educational Resources Information Center

    Zimmerman, Judith A.

    2007-01-01

    This qualitative case study describes the transitional experiences (first 4 1/2 months) of four school leaders. The "life cycle" of leaders is often short, necessitating job changes with resulting transitions, when new leaders must simultaneously learn their positions and make changes to improve schools. Using previous leadership…

  10. Profiles in Success: Reflections on the Community College Experience.

    ERIC Educational Resources Information Center

    Bahruth, Robert E., Ed.; Venditti, Phillip N., Ed.

    In September 1989, letters were sent to the presidents and public information officers of each member college of the American Association of Community and Junior Colleges (Washington, D.C.) asking them to identify outstanding graduates who might be interested in composing short essays describing their community college experience. More than 190…

  11. Numerical and Experimental Investigation of the Effects of Acceleration Disturbances on Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Ramachandran, Narayanan

    2000-01-01

    Normal vibrational modes on large spacecraft are excited by crew activity, operating machinery, and other mechanical disturbances. Periodic engine burns for maintaining vehicle attitude and random impulse type disturbances also contribute to the acceleration environment of a Spacecraft. Accelerations from these vibrations (often referred to as g-jitter) are several orders of magnitude larger than the residual accelerations from atmospheric drag and gravity gradient effects. Naturally, the effects of such accelerations have been a concern to prospective experimenters wishing to take advantage of the microgravity environment offered by spacecraft operating in low Earth orbit and the topic has been studied extensively, both numerically and analytically. However, these studies have not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter could use to assess how his/her experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling thereby providing comparative theoretical and experimental data. The modeling, it is hoped will provide a predictive tool that can be used for assessing experiment response to Spacecraft vibrations.

  12. Successes and lessons learned: How to accelerate the base closure process

    SciTech Connect

    Larkin, V.C.; Stoll, R.

    1994-12-31

    Naval Station Puget Sound, Seattle, was nominated for closure by the Base Closure Commission in 1991 (BRAC II) and will be transferred in September of 1995. Historic activities have resulted in petroleum-related environmental issues. Unlike many bases being closed, the politically sensitive issues are not the economics of job losses. Because homeless housing is expected to be included in the selected reuse plan, the primary concerns of the public are reduced real estate values and public safety. In addition to a reuse plan adopted by the Seattle City Council, the Muckleshoot Indian tribe has also submitted an alternative reuse plan to the Navy. Acceleration methods described in this paper include methods for beginning the environmental impact statement (EIS) process before reuse plans are finalized; tracking development of engineering alternatives in parallel with environmental investigations; using field screening data to begin developing plans and specifications for remediation, instead of waiting 6 weeks for analytical results and data validation; using efficient communication techniques to facilitate accelerated review of technical documents by the BCT; expediting removal actions and performing ``cleanups incidental to investigation``; and effectively facilitating members of the Restoration Advisory Board with divergent points of view. This paper will describe acceleration methods that proved to be effective and methods that could be modified to be more effective at other sites.

  13. Laser wakefield acceleration experiments at the University of Michigan

    SciTech Connect

    Matsuoka, T.; McGuffey, C.; Horovitz, Y.; Dollar, F.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Reed, S.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Huntington, C. M.; Drake, R. P.; Levin, M.; Zigler, A.

    2009-01-22

    Laser wakefield acceleration (LWFA) in a supersonic gas-jet using a self-guided laser pulse was studied by changing the laser power and electron density. The recently upgraded HERCULES laser facility equipped with wavefront correction enables a peak intensity of 8x10{sup 19} W/cm{sup 2} at laser power of 100 TW to be delivered to the gas-jet using f/10 focusing optics. We found that electron beam charge was increased significantly with an increase of the laser power from 30 TW to 80 TW and showed density threshold behavior at a fixed laser power. Betatron motion of electrons was also observed depending on laser power and electron density.

  14. Accelerator Challenges and Opportunities for Future Neutrino Experiments

    SciTech Connect

    Zisman, Michael S

    2010-12-24

    There are three types of future neutrino facilities currently under study, one based on decays of stored beta-unstable ion beams (?Beta Beams?), one based on decays of stored muon beams (?Neutrino Factory?), and one based on the decays of an intense pion beam (?Superbeam?). In this paper we discuss the challenges each design team must face and the R&D being carried out to turn those challenges into technical opportunities. A new program, the Muon Accelerator Program, has begun in the U.S. to carry out the R&D for muon-based facilities, including both the Neutrino Factory and, as its ultimate goal, a Muon Collider. The goals of this program will be briefly described.

  15. Operational experience from a large EPICS-based accelerator facility

    SciTech Connect

    Ciarlette, D.J.; Gerig, R.

    1995-12-31

    The Advanced Photon Source (APS) at Argonne National Laboratory is a third-generation x-ray light source which uses the Experimental Physics and Industrial Control System (EPICS) to operate its linear accelerator, positron accumulator ring, booster synchrotron, and storage ring equipment. EPICS has been used at the APS since the beginning of installation and commissioning. Currently, EPICS controls approximately 100 VME crates containing over 100,000 process variables. With this complexity, the APS has had to review some of the methods originally employed and make changes as necessary. In addition, due to commissioning and operational needs, higher-level operator software needed to be created. EPICS has been flexible enough to allow this.

  16. Elements of Successful and Safe Fusion Experiment Operations

    SciTech Connect

    K. Rule, L. Cadwallader, Y. Takase, T. Norimatsu, O. Kaneko, M. Sato, and R. Savercool

    2009-02-03

    A group of fusion safety professionals contribute to a Joint Working Group (JWG) that performs occupational safety walkthroughs of US and Japanese fusion experiments on a routine basis to enhance the safety of visiting researchers. The most recent walkthrough was completed in Japan in March 2008 by the US Safety Monitor team. This paper gives the general conclusions on fusion facility personnel safety that can be drawn from the series of walkthroughs.

  17. A call for virtual experiments: accelerating the scientific process.

    PubMed

    Cooper, Jonathan; Vik, Jon Olav; Waltemath, Dagmar

    2015-01-01

    Experimentation is fundamental to the scientific method, whether for exploration, description or explanation. We argue that promoting the reuse of virtual experiments (the in silico analogues of wet-lab or field experiments) would vastly improve the usefulness and relevance of computational models, encouraging critical scrutiny of models and serving as a common language between modellers and experimentalists. We review the benefits of reusable virtual experiments: in specifying, assaying, and comparing the behavioural repertoires of models; as prerequisites for reproducible research; to guide model reuse and composition; and for quality assurance in the translational application of models. A key step towards achieving this is that models and experimental protocols should be represented separately, but annotated so as to facilitate the linking of models to experiments and data. Lastly, we outline how the rigorous, streamlined confrontation between experimental datasets and candidate models would enable a "continuous integration" of biological knowledge, transforming our approach to systems biology. PMID:25433232

  18. Physics study of the TRADE : TRIGA accelerator driven experiment.

    SciTech Connect

    Naberejnev, D.; Imel, G.; Palmiotti, G.; Salvatores, M.

    2004-01-13

    This report deals with the validation of an ADS dynamic behavior through the TRADE program. We first describe the motivations behind the TRADE project. This includes the types of ADS experiments to be performed and their necessity, beam trips issues, representativity of the experiment, and steps to be taken in the validation procedure. Then we perform the characterization of the TRADE core using deterministic methods. The general core description is given. A number of results related to the core criticality and modeling with different geometries are presented. Finally we report the experimental results of the recent critical measurements including the control rod calibration, determination of the critical configurations and fluxes in the core.

  19. Parasitic success without sex – the nematode experience.

    PubMed

    Castagnone-Sereno, P; Danchin, E G J

    2014-07-01

    Asexual reproduction is usually considered as an evolutionary dead end, and difficulties for asexual lineages to adapt to a fluctuating environment are anticipated due to the lack of sufficient genetic plasticity. Yet, unlike their sexual congeners, mitotic parthenogenetic root-knot nematode species, Meloidogyne spp., are remarkably widespread and polyphagous, with the ability to parasitize most flowering plants. Although this may reflect in part the short-term stability of agricultural environments, the extreme parasitic success of these clonal species points them as an outstanding evolutionary paradox regarding current theories on the benefits of sex. The discovery that most of the genome of the clonal species M. incognita is composed of pairs of homologous but divergent segments that have presumably been evolving independently in the absence of sexual recombination has shed new light on this evolutionary paradox. Together with recent studies on other biological systems, including the closely related sexual species M. hapla and the ancient asexual bdelloid rotifers, this observation suggests that functional innovation could emerge from such a peculiar genome architecture, which may in turn account for the extreme adaptive capacities of these asexual parasites. Additionally, the higher proportion of transposable elements in M. incognita compared to M. hapla and other nematodes may also be responsible in part for genome plasticity in the absence of sexual reproduction. We foresee that ongoing sequencing efforts should lead soon to a genomic framework involving genetically diverse Meloidogyne species with various different reproductive modes. This will undoubtedly promote the entire genus as a unique and valuable model system to help deciphering the evolution of asexual reproduction in eukaryotes. PMID:25105196

  20. Control of malaria: a successful experience from Viet Nam.

    PubMed Central

    Hung, Le Q.; Vries, Peter J. de; Giao, Phan T.; Nam, Nguyen V.; Binh, Tran Q.; Chong, M. T.; Quoc, N. T. T. A.; Thanh, T. N.; Hung, L. N.; Kager, P. A.

    2002-01-01

    OBJECTIVE: To follow malaria prospectively in an ethnic minority commune in the south of Viet Nam with high malaria transmission and seasonal fluctuation, during malaria control interventions using insecticide-treated bednets (ITBNs) and early diagnosis and treatment (EDT) of symptomatic patients. METHODS: From 1994 onwards the following interventions were used: distribution of ITBNs to all households with biannual reimpregnation; construction of a health post and appointment of staff trained in microscopic diagnosis and treatment of malaria; regular supply of materials and drugs; annual cross-sectional malaria surveys with treatment of all parasitaemic subjects, and a programme of community involvement and health education. Surveys were held yearly at the end of the rainy season. During the surveys, demographic data were updated. Diagnosis and treatment of malaria were free of charge. Plasmodium falciparum infection was treated with artesunate and P. vivax infection with chloroquine plus primaquine. FINDINGS: The baseline survey in 1994 recorded 716 inhabitants. Of the children under 2 years of age, 37% were parasitaemic; 56% of children aged 2-10 years, and 35% of the remaining population were parasitaemic. P. falciparum accounted for 73-79% of these infections. The respective splenomegaly rates for the above-mentioned age groups were 20%, 56%, and 32%. In 1999, the proportion of parasitaemic subjects was 4%, 7% and 1%, respectively, of which P.falciparum contributed 56%. The splenomegaly rate was 0%, 5% and 2%, respectively. CONCLUSIONS: A combination of ITBNs and EDT, provided free of charge, complemented by annual diagnosis and treatment during malaria surveys and community involvement with health education successfully brought malaria under control. This approach could be applied to other regions in the south of Viet Nam and provides a sound basis for further studies in other areas with different epidemiological patterns of malaria. PMID:12219158

  1. Brisk Attitude and Optimism: Top Workers' Childhood Experiences Forming the Basis of Success at Work

    ERIC Educational Resources Information Center

    Uusiautti, Satu; Määttä, Kaarina

    2013-01-01

    This study focused on the phenomenon of success at work asking whether it would be possible to find factors from top workers' children and school experiences that would explain their later success. This study was a part of a larger research in which Finnish top workers, employees of the year, who have been selected as successful professionals of…

  2. Subjective Acceleration of Time Experience in Everyday Life across Adulthood

    ERIC Educational Resources Information Center

    John, Dennis; Lang, Frieder R.

    2015-01-01

    Most people believe that time seems to pass more quickly as they age. Building on assumptions of socioemotional selectivity theory, we investigated whether awareness that one's future lifetime is limited is associated with one's experience of time during everyday activities across adulthood in 3 studies. In the first 2 studies (Study 1: N = 608;…

  3. Joining Forces: How Student Success Centers Are Accelerating Statewide Community College Improvement Efforts

    ERIC Educational Resources Information Center

    Couturier, Lara K.

    2013-01-01

    There's an emerging trend in the national college completion movement. A group of small but powerful Student Success Centers is creating statewide impact in states traditionally devoid of a strong centralized tradition of community college governance. Growing directly out of a decade of hard work to dramatically boost student completion rates in…

  4. GPU acceleration experience with RRTMG long wave radiation model

    NASA Astrophysics Data System (ADS)

    Price, Erik; Mielikainen, Jarno; Huang, Bormin; Huang, HungLung A.; Lee, Tsengdar

    2013-10-01

    in many weather forecast and climate models. RRTMG_LW is in operational use in ECMWF weather forecast system, the NCEP global forecast system, the ECHAM5 climate model, Community Earth System Model (CESM) and the weather and forecasting (WRF) model. RRTMG_LW has also been evaluated for use in GFDL climate model. In this paper, we examine the feasibility of using graphics processing units (GPUs) to accelerate the RRTMG_LW as used by the WRF. GPUs can provide a substantial improvement in RRTMG speed by supporting the parallel computation of large numbers of independent radiative calculations. Furthermore, using commodity GPUs for accelerating RRTMG_LW allows getting a much higher computational performance at lower price point than traditional CPUs. Furthermore, power and cooling costs are significantly reduced by using GPUs. A GPU-compatible version of RRTMG was implemented and thorough testing was performed to ensure that the original level of accuracy is retained. Our results show that GPUs can provide significant speedup over conventional CPUs. In particular, Nvidia's GTX 680 GPU card can provide a speedup of 69x for the compared to its single-threaded Fortran counterpart running on Intel Xeon E5-2603 CPU.

  5. Kaonic atoms measurements at the DAFNE accelerator: the SIDDHARTA experiment

    NASA Astrophysics Data System (ADS)

    Rizzo, A.; Bazzi, M.; Beer, G.; Berucci, C.; Bombelli, L.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu (Petrascu, C.; Corradi, G.; dUffizi, A.; Fiorini, C.; Frizzi, T.; Ghio, F.; Guaraldo, C.; Hayano, R. S.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Kienle, P.; Levi Sandri, P.; Longoni, A.; Lucherini, V.; Marton, J.; Okada, S.; Pietreanu, D.; Ponta, T.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Tudorache, A.; Tudorache, V.; Vazquez Doce, O.; Widmann, E.; Wunschek, B.; Zmeskal, J.

    2012-03-01

    Kaonic Hydrogen and Helium X-ray measurements play nowadays a fundamental role in testing the reliability of the Chiral Perturbation Theory as a realisation of the Quantum Chromodynamics at low energies. Dictated by both electromagnetic and strong interaction, X-ray transitions at lower energy levels of these complex bound systems offer indeed the unique opportunity to perform a threshold measurements of zero-energy meson-nucleon scattering. Nowadays the SIDDHARTA experiment at DAFNE collider is the only apparatus which can provide such kind of measurements with the high precision needed to disentangle different theoretical calculation scenarios. In this work we present the SIDDHARTA experiment performances and results, with a focus on the main topics of light kaonic atom physics.

  6. Space Experiments with Particle Accelerators (SEPAC), status review, 23 September 1980

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The development responsibilities of SEPAC include: accelerator systems, diagnostic systems, power systems, dedicated experiment processor, interface unit, control panel, and all flight software. The operations of SEPAC, including automated experiments under DEP command control and SEPAC manual operations, are outlined. A diagram of the system configuration is presented.

  7. Space radiation accelerator experiments - The role of neutrons and light ions

    NASA Astrophysics Data System (ADS)

    Norbury, John W.; Slaba, Tony C.

    2014-10-01

    The importance of neutrons and light ions is considered when astronauts spend considerable time in thickly shielded regions of a spacecraft. This may be relevant for space missions both in and beyond low Earth orbit (LEO). In addition to heavy ion experiments at accelerators, it is suggested that an increased emphasis on experiments with lighter ions may be useful in reducing biological uncertainties.

  8. 3D Simulations for a Micron-Scale, Dielectric-Based Acceleration Experiment

    SciTech Connect

    Yoder, R. B.; Travish, G.; Xu Jin; Rosenzweig, J. B.

    2009-01-22

    An experimental program to demonstrate a dielectric, slab-symmetric accelerator structure has been underway for the past two years. These resonant devices are driven by a side-coupled 800-nm laser and can be configured to maintain the field profile necessary for synchronous acceleration and focusing of relativistic or nonrelativistic particles. We present 3D simulations of various versions of the structure geometry, including a metal-walled structure relevant to ongoing cold tests on resonant properties, and an all-dielectric structure to be constructed for a proof-of-principle acceleration experiment.

  9. The LILIA experiment: Energy selection and post-acceleration of laser generated protons

    NASA Astrophysics Data System (ADS)

    Turchetti, Giorgio; Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Sumini, Marco; Giove, Dario; De Martinis, Carlo

    2012-12-01

    The LILIA experiment is planned at the SPARCLAB facility of the Frascati INFN laboratories. We have simulated the laser acceleration of protons, the transport and energy selection with collimators and a pulsed solenoid and the post-acceleration with a compact high field linac. For the highest achievable intensity corresponding to a = 30 over 108 protons at 30 MeV with a 3% spread are selected, and at least107 protons are post-accelerated up to 60 MeV. If a 10 Hz repetition rated can be achieved the delivered dose would be suitable for the treatment of small superficial tumors.

  10. The LILIA experiment: Energy selection and post-acceleration of laser generated protons

    SciTech Connect

    Turchetti, Giorgio; Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Sumini, Marco; Giove, Dario; De Martinis, Carlo

    2012-12-21

    The LILIA experiment is planned at the SPARCLAB facility of the Frascati INFN laboratories. We have simulated the laser acceleration of protons, the transport and energy selection with collimators and a pulsed solenoid and the post-acceleration with a compact high field linac. For the highest achievable intensity corresponding to a= 30 over 10{sup 8} protons at 30 MeV with a 3% spread are selected, and at least10{sup 7} protons are post-accelerated up to 60 MeV. If a 10 Hz repetition rated can be achieved the delivered dose would be suitable for the treatment of small superficial tumors.

  11. Physical conditions for conducting radiobiological experiments in beams of accelerated particles with high linear energy transfer

    NASA Technical Reports Server (NTRS)

    Kudryashov, Y. I.; Marennyy, A. M.; Popov, V. I.; Aykhorn, K.; Ertsgreber, G.

    1974-01-01

    The design and construction of an accelerator to conduct radiobiological experiments is reported that uses aluminum filters to control the accelerated ion beam while preserving its stability, and a vacuum chamber to conduct the ion beam with the help of a collector through a lavsan exit port to the target. Depth distribution of the absorbed dose from a monodirectional ion beam is practically completely represented by the change in the energy spectrum of the biological object.

  12. Remediation of the Melton Valley Watershed at Oak Ridge National Lab: An Accelerated Closure Success Story

    SciTech Connect

    Johnson, Ch.; Cange, J.; Skinner, R.; Adams, V.

    2008-07-01

    The Melton Valley (MV) Watershed at the U. S. Department of Energy's (DOE's) Oak Ridge National Laboratory (ORNL) encompasses approximately 430 hectares (1062 acres). Historic operations at ORNL produced a diverse legacy of contaminated facilities and waste disposal areas in the valley. In addition, from 1955 to 1963, ORNL served as a major disposal site for wastes from over 50 off-site government-sponsored installations, research institutions, and other isotope users. Contaminated areas in the watershed included burial grounds, landfills, underground tanks, surface impoundments, liquid disposal pits/trenches, hydro-fracture wells, leak and spill sites, inactive surface structures, and contaminated soil and sediment. Remediation of the watershed in accordance with the requirements specified in the Melton Valley Record of Decision (ROD) for Interim Actions in Melton Valley, which estimated that remedial actions specified in the ROD would occur over a period of 14 years, with completion by FY 2014. Under the terms of the Accelerated Closure Contract between DOE and its contractor, Bechtel Jacobs Company, LLC, the work was subdivided into 14 separate sub-projects which were completed between August 2001 and September 2006, 8 years ahead of the original schedule. (authors)

  13. A self-injection acceleration test experiment for the FLAME laser

    NASA Astrophysics Data System (ADS)

    Labate, L.; Anelli, F.; Bacci, A.; Batani, D.; Bellaveglia, M.; Benedetti, C.; Benocci, R.; Cacciotti, L.; Cecchetti, C. A.; Ciricosta, O.; Clozza, A.; Cultrera, L.; Di Pirro, G.; Drenska, N.; Faccini, R.; Ferrario, M.; Filippetto, D.; Gallo, S.; Fioravanti, S.; Gamucci, A.; Gatti, G.; Ghigo, A.; Giulietti, A.; Giulietti, D.; Köster, P.; Levato, T.; Lollo, V.; Pace, E.; Pathak, N.; Rossi, A.; Serafini, L.; Turchetti, G.; Vaccarezza, C.; Valente, P.; Vicario, C.; Gizzi, L. A.

    2010-10-01

    A 250-TW laser system (FLAME - Frascati laser for acceleration and multidisciplinary experiments) is now in its commissioning phase in a new laboratory at LNF-INFN in the framework of the PLASMONX (Plasma acceleration and monochromatic X-ray generation) project. The laser will deliver<25 fs duration pulses with an energy up to 6 J, at a 10 Hz repetition rate. An ad hoc target area has also been designed and is currently being set up, allowing the first test experiments of electron laser wakefield acceleration to be carried out over the next few months in a safe, radiation-protected environment. An overview of the main features of the laser system and target area is given, along with a survey of the design and set-up of the self-injection test experiment, which is expected to reach the production of sub-GeV electron bunches.

  14. Shielding Benchmark Experiments Through Concrete and Iron with High-Energy Proton and Heavy Ion Accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Sasaki, M.; Nunomiya, T.; Nakao, N.; Kim, E.; Kurosawa, T.; Taniguchi, S.; Iwase, H.; Uwamino, Y.; Shibata, T.; Ito, S.; Fukumura, A.; Perry, D. R.; Wright, P.

    The deep penetration of neutrons through thick shield has become a very serious problem in the shielding design of high-energy, high-intensity accelerator facility. In the design calculation, the Monte Carlo transport calculation through thick shields has large statistical errors and the basic nuclear data and model used in the existing Monte Carlo codes are not well evaluated because of very few experimental data. It is therefore strongly needed to do the deep penetration experiment as shielding benchmark for investigating the calculation accuracy. Under this circumference, we performed the following two shielding experiments through concrete and iron, one with a 800 MeV proton accelerator of the Rutherford Appleton Laboratory (RAL), England and the other with a high energy heavy iron accelerator of the National Institute of Radiological Sciences (NIRS), Japan. Here these two shielding benchmark experiments are outlined.

  15. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    DOE PAGESBeta

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-17

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detectormore » front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.« less

  16. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    SciTech Connect

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-17

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detector front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.

  17. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    NASA Astrophysics Data System (ADS)

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-01

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detector front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on the development of a technique for testing analog to digital converters for radiation effects, in particular for single event effects. A total of seventeen commercial ADCs were evaluated for ionizing dose tolerance and extensive SEU measurements performed on a twelve and fourteen bit ADCs. Mitigation strategies for single event effects (SEE) are discussed for their use in the large hadron collider environment.

  18. Predicting Community College Student Success by Participation in a First-Year Experience Course

    ERIC Educational Resources Information Center

    Gardner, Andy Franklin

    2013-01-01

    A first-year experience is a collaborative effort of many initiatives, with varying names that have the greatest impact on student success during the first year of college. A first-year experience course, a feature of the first-year experience, is an intervention program designed to increase student academic performance and integration (Braxton…

  19. An investigation into the effectiveness of smartphone experiments on students’ conceptual knowledge about acceleration

    NASA Astrophysics Data System (ADS)

    Mazzella, Alessandra; Testa, Italo

    2016-09-01

    This study is a first attempt to investigate effectiveness of smartphone-based activities on students’ conceptual understanding of acceleration. 143 secondary school students (15–16 years old) were involved in two types of activities: smartphone- and non-smartphone activities. The latter consisted in data logging and ‘cookbook’ activities. For the sake of comparison, all activities featured the same phenomena, i.e., the motion on an inclined plane and pendulum oscillations. A pre-post design was adopted, using open questionnaires as probes. Results show only weak statistical differences between the smartphone and non-smartphone groups. Students who followed smartphone activities were more able to design an experiment to measure acceleration and to correctly describe acceleration in a free fall motion. However, students of both groups had many difficulties in drawing acceleration vector along the trajectory of the studied motion. Results suggest that smartphone-based activities may be effective substitutes of traditional experimental settings and represent a valuable aid for teachers who want to implement laboratory activities at secondary school level. However, to achieve a deeper conceptual understanding of acceleration, some issues need to be addressed: what is the reference system of the built-in smartphone sensor; relationships between smartphone acceleration graphs and experimental setup; vector representation of the measured acceleration.

  20. Modeling laser wakefield accelerator experiments with ultrafast particle-in-cell simulations in boosted frames

    SciTech Connect

    Martins, S. F.; Fonseca, R. A.; Vieira, J.; Silva, L. O.

    2010-05-15

    The development of new laser systems at the 10 Petawatt range will push laser wakefield accelerators to novel regimes, for which theoretical scalings predict the possibility to accelerate electron bunches up to tens of GeVs in meter-scale plasmas. Numerical simulations will play a crucial role in testing, probing, and optimizing the physical parameters and the setup of future experiments. Fully kinetic simulations are computationally very demanding, pushing the limits of today's supercomputers. In this paper, the recent developments in the OSIRIS framework [R. A. Fonseca et al., Lect. Notes Comput. Sci. 2331, 342 (2002)] are described, in particular the boosted frame scheme, which leads to a dramatic change in the computational resources required to model laser wakefield accelerators. Results from one-to-one modeling of the next generation of laser systems are discussed, including the confirmation of electron bunch acceleration to the energy frontier.

  1. Artificially accelerating the reversal of desertification: cyanobacterial inoculation facilitates the succession of vegetation communities.

    PubMed

    Lan, Shubin; Zhang, Qingyi; Wu, Li; Liu, Yongding; Zhang, Delu; Hu, Chunxiang

    2014-01-01

    Desertification has been recognized as a global environmental problem, and one region experiencing ongoing desertification is the eastern edge of Qubqi Desert (Inner Mongolia). To investigate the facilitating effects of cyanobacterial inoculation technology on the desertification control along this steppe-desert transition region, artificial cyanobacterial crusts were constructed with two filamentous cyanobacteria 3 and 8 years ago combined with Salix planting. The results showed that no crusts formed after 3 years of fixation only with Salix planting, whereas after cyanobacterial inoculation, the crusts formed quickly and gradually succeed to moss crusts. During that course, topsoil environments were gradually improved, providing the necessary material basis for the regeneration of vascular plants. In this investigation, total 27 species of vascular plants had regenerated in the experimental region, mainly belonging to Asteraceae, Poaceae, Chenopodiaceae and Leguminosae. Using space time substitution, the dominant species along with the application of cyanobacterial inoculation technology succeeded from Agriophyllum squarrosum ultimately to Leymus chinensis. In addition, it was found that the shady side of the dunes is more conducive to crust development and succession of vegetation communities. Conclusively, our results indicate artificial cyanobacterial inoculation technology is an effective and desirable path for desertification control. PMID:24303976

  2. Laser-based acceleration for nuclear physics experiments at ELI-NP

    NASA Astrophysics Data System (ADS)

    Tesileanu, O.; Asavei, Th.; Dancus, I.; Gales, S.; Negoita, F.; Turcu, I. C. E.; Ursescu, D.; Zamfir, N. V.

    2016-05-01

    As part of the Extreme Light pan-European research infrastructure, Extreme Light Infrastructure - Nuclear Physics (ELI-NP) in Romania will focus on topics in Nuclear Physics, fundamental Physics and applications, based on very intense photon beams. Laser-based acceleration of electrons, protons and heavy ions is a prerequisite for a multitude of laser-driven nuclear physics experiments already proposed by the international research community. A total of six outputs of the dual-amplification chain laser system, two of 100TW, two of 1PW and two of 10PW will be employed in 5 experimental areas, with the possibility to use long and short focal lengths, gas and solid targets, reaching the whole range of laser acceleration processes. We describe the main techniques and expectations regarding the acceleration of electrons, protons and heavy nuclei at ELI-NP, and some physics cases for which these techniques play an important role in the experiments.

  3. Acceleration of heavy and light particles in turbulence: Comparison between experiments and direct numerical simulations

    NASA Astrophysics Data System (ADS)

    Volk, R.; Calzavarini, E.; Verhille, G.; Lohse, D.; Mordant, N.; Pinton, J.-F.; Toschi, F.

    2008-08-01

    We compare experimental data and numerical simulations for the dynamics of inertial particles with finite density in turbulence. In the experiment, bubbles and solid particles are optically tracked in a turbulent flow of water using an Extended Laser Doppler Velocimetry technique. The probability density functions (PDF) of particle accelerations and their auto-correlation in time are computed. Numerical results are obtained from a direct numerical simulation in which a suspension of passive pointwise particles is tracked, with the same finite density and the same response time as in the experiment. We observe a good agreement for both the variance of acceleration and the autocorrelation time scale of the dynamics; small discrepancies on the shape of the acceleration PDF are observed. We discuss the effects induced by the finite size of the particles, not taken into account in the present numerical simulations.

  4. A Phenomenological Investigation of the Lived Experiences of Successful First Generation Hispanic College Students

    ERIC Educational Resources Information Center

    Puente, Christina C.

    2013-01-01

    This qualitative phenomenological research study investigated the lived experiences of five successful first generation Hispanic college students. Participants' interviews were analyzed using Creswell's (2007) six steps for analyzing phenomenological studies. Findings from this study affirm the factors for student success in college regarding…

  5. "I Was Overcome with Joy at that Moment": Successful Experiences of School Counsellors

    ERIC Educational Resources Information Center

    Gilat, Itzhak; Rosenau, Sarah

    2012-01-01

    Inspired by positive psychology, the present research explores the manner in which school counsellors perceive the meaning of success in their work. Data were collected by means of a narrative questionnaire in which 66 school counsellors were requested to write a detailed description of a well-remembered successful experience and to answer two…

  6. Mathematically Successful Sons: The Roles Perceptions, and Experiences of African American Parents

    ERIC Educational Resources Information Center

    Berry, Robert Q., III.

    2008-01-01

    The stories of four mathematically successful middle schools African American boys are used to describe the roles, perceptions, and experiences of their parents. The parents of played multiple roles for their sons: (a) guardians of opportunities, (b) standard setters, (c) resources for mathematical knowledge, and (d) models of success. As…

  7. The Shared Experiences: Facilitating Successful Transfer of Women and Underrepresented Minorities in STEM Fields

    ERIC Educational Resources Information Center

    Jackson, Dimitra Lynette; Starobin, Soko S.; Laanan, Frankie Santos

    2013-01-01

    This chapter addresses critical issues related to the transfer success of women and underrepresented minorities (URMs) in STEM disciplines and will highlight implications for fostering a successful transfer experience for these populations. For the purposes of this chapter, URMs is defined by the National Science Foundation to include African…

  8. An Examination of the Lived Experiences of Successful African American Men Attending a Historically Black University

    ERIC Educational Resources Information Center

    Powell, Clark R.

    2013-01-01

    This phenomenological research explored the lived experiences of successful African American men attending a Historically Black College and University (HBCU) in the Midwest. The guiding questions for the study were (a) What positive characteristics do successful African American men demonstrate at HBCUs that offset major problems, concerns, and…

  9. Linear Accelerator and Gamma Knife-Based Stereotactic Cranial Radiosurgery: Challenges and Successes of Existing Quality Assurance Guidelines and Paradigms

    SciTech Connect

    Goetsch, Steven J.

    2008-05-01

    Intracranial stereotactic radiosurgery has been practiced since 1951. The technique has expanded from a single dedicated unit in Stockholm in 1968 to hundreds of centers performing an estimated 100,000 Gamma Knife and linear accelerator cases in 2005. The radiation dosimetry of small photon fields used in this technique has been well explored in the past 15 years. Quality assurance recommendations have been promulgated in refereed reports and by several national and international professional societies since 1991. The field has survived several reported treatment errors and incidents, generally reacting by strengthening standards and precautions. An increasing number of computer-controlled and robotic-dedicated treatment units are expanding the field and putting patients at risk of unforeseen errors. Revisions and updates to previously published quality assurance documents, and especially to radiation dosimetry protocols, are now needed to ensure continued successful procedures that minimize the risk of serious errors.

  10. Examining Nontraditional Graduate Students' Academic Writing Experiences in an Accelerated Adult Program

    ERIC Educational Resources Information Center

    Crite, Charles E., Jr.

    2013-01-01

    The academic writing competencies of nontraditional graduate students enrolled in accelerated graduate programs have become a growing concern for many higher learning educators in those programs. The purpose of this nonexperimental quantitative study was to examine the writing experiences that impacted nontraditional graduate students enrolled in…

  11. School Counselors' Perceptions and Experience with Acceleration as a Program Option for Gifted and Talented Students

    ERIC Educational Resources Information Center

    Wood, Susannah; Portman, Tarrell Awe Agahe; Cigrand, Dawnette L.; Colangelo, Nicholas

    2010-01-01

    This article presents findings from a national survey of 149 practicing school counselors who are members of the American School Counselor Association. The survey gathered information on school counselors' perceptions of and experiences with acceleration as a program option for gifted students. Results indicate that, although school counselors'…

  12. The Gift of Time: Today's Academic Acceleration Case Study Voices of Experience

    ERIC Educational Resources Information Center

    Scheibel, Susan Riley

    2010-01-01

    The purpose of this qualitative case study was to examine today's academic acceleration from the lived experience and perspectives of two young adults whose education was shortened, thereby allowing them the gift of time. Through personal interviews, parent interviews, and physical artifacts, the researcher gained a complex, holistic understanding…

  13. Recent results from polarization experiments at the LHEP-JINR Accelerator

    SciTech Connect

    Ladygin, V. P.; Azhgirey, L. S.; Gurchin, Yu. V.; Isupov, A. Yu.; Krasnov, V. A.; Khrenov, A. N.; Kiselev, A. S.; Kizka, V. A.; Kurilkin, A. K.; Kurilkin, P. K.; Livanov, A. N.; Ladygina, N. B.; Malakhov, A. I.; Piyadin, S. M.; Reznikov, S. G.; Shikhalev, M. A.; Vasiliev, T. A.; Uesaka, T.; Kawabata, T.; Sakaguchi, S.

    2008-10-13

    The review of recent results from polarization experiments performed at LHEP-JINR Accelerator Complex in a GeV range is given. The current status of the spin program at Nuclotron as well as its further continuation with new high intensity polarized deuterons ion source is discussed.

  14. First experiments on neutron detection on the accelerator-based source for boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. S.; Malyshkin, G. N.; Makarov, A. N.; Sorokin, I. N.; Sulyaev, Yu. S.; Taskaev, S. Yu.

    2009-04-01

    A pilot accelerator-based source of epithermal neutrons, which is intended for wide application in clinics for boron neutron capture therapy, has been constructed at the Budker Institute of Nuclear Physics (Novosibirsk). A stationary proton beam has been obtained and near-threshold neutron generation regime has been realized. Results of the first experiments on neutron generation using the proposed source are described.

  15. Starting Where the Student Is: An Experiment in Accelerated Graduate Social Work Education

    ERIC Educational Resources Information Center

    Eades, Joe C.

    1976-01-01

    A description and interim evaluation of an experimental accelerated master's degree program is presented. The program is designed for students whose undergraduate preparation, work experience, and performance on a qualifying examination suggest that they can benefit from a curriculum that builds directly upon their previous educational and work…

  16. Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations

    NASA Astrophysics Data System (ADS)

    Carlos Castro-Palacio, Juan; Velázquez-Abad, Luisberis; Giménez, Marcos H.; Monsoriu, Juan A.

    2013-06-01

    We have used a mobile phone acceleration sensor, and the Accelerometer Monitor application for Android, to collect data in physics experiments on free and damped oscillations. Results for the period, frequency, spring constant, and damping constant agree very well with measurements obtained by other methods. These widely available sensors are likely to find increased use in instructional laboratories.

  17. After-event reviews: drawing lessons from successful and failed experience.

    PubMed

    Ellis, Shmuel; Davidi, Inbar

    2005-09-01

    The claim that appropriate after-event review might decrease the relative advantage of drawing lessons from failures over drawing lessons from successes was examined in a quasi-field experiment. The results show that performance of soldiers doing successive navigation exercises improved significantly when they were debriefed on their failures and successes after each training day, compared with others who reviewed their failed events only. The findings also show that, before the manipulation, in both groups, learners' mental models of failed events were richer in constructs and links than were their mental models of successful events. This gap closed gradually in subsequent measurements. PMID:16162059

  18. Accelerate!

    PubMed

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves. PMID:23155997

  19. Exploring the Impact of Work Experience on Part-Time Students' Academic Success in Malaysian Polytechnics

    ERIC Educational Resources Information Center

    Ibrahim, Norhayati; Freeman, Steven A.; Shelley, Mack C.

    2012-01-01

    The study explored the influence of work experience on adult part-time students' academic success as defined by their cumulative grade point average. The sample consisted of 614 part-time students from four polytechnic institutions in Malaysia. The study identified six factors to measure the perceived influence of work experiences--positive…

  20. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2012-12-01

    We simulated the slip of a fault-patch during a large earthquake by rapidly loading an experimental, ring-shaped fault with energy stored in a spinning flywheel. The flywheel abruptly delivers a finite amount of energy by spinning the fault-patch that spontaneously dissipates the energy without operator intervention. We conducted 42 experiments on Sierra White granite (SWG) samples, and 24 experiments on Kasota dolomite (KD) samples. Each experiment starts by spinning a 225 kg disk-shaped flywheel to a prescribed angular velocity. We refer to this experiment as an "earthquake-like slip-event" (ELSE). The strength-evolution in ELSE experiments is similar to the strength-evolution proposed for earthquake models and observed in stick-slip experiments. Further, we found that ELSE experiments are similar to earthquakes in at least three ways: (1) slip driven by the release of a finite amount of stored energy; (2) pattern of fault strength evolution; and (3) seismically observed values, such as average slip, peak-velocity and rise-time. By assuming that the measured slip, D, in ELSE experiments is equivalent to the average slip during an earthquake, we found that ELSE experiments (D = 0.003-4.6 m) correspond to earthquakes in moment-magnitude range of Mw = 4-8. In ELSE experiments, the critical-slip-distance, dc, has mean values of 2.7 cm and 1.2 cm for SWG and KD, that are much shorter than the 1-10 m in steady-state classical experiments in rotary shear systems. We attribute these dc values, to ELSE loading in which the fault-patch is abruptly loaded by impact with a spinning flywheel. Under this loading, the friction-velocity relations are strikingly different from those under steady-state loading on the same rock samples with the same shear system (Reches and Lockner, Nature, 2010). We further note that the slip acceleration in ELSE evolves systematically with fault strength and wear-rate, and that the dynamic weakening is restricted to the period of intense

  1. Experiments in sensing transient rotational acceleration cues on a flight simulator

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.

    1979-01-01

    Results are presented for two transient motion sensing experiments which were motivated by the identification of an anomalous roll cue (a 'jerk' attributed to an acceleration spike) in a prior investigation of realistic fighter motion simulation. The experimental results suggest the consideration of several issues for motion washout and challenge current sensory system modeling efforts. Although no sensory modeling effort is made it is argued that such models must incorporate the ability to handle transient inputs of short duration (some of which are less than the accepted latency times for sensing), and must represent separate channels for rotational acceleration and velocity sensing.

  2. Vibration isolation technology: Sensitivity of selected classes of experiments to residual accelerations

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.

    1990-01-01

    The solution was sought of a 2-D axisymmetric moving boundary problem for the sensitivity of isothermal and nonisothermal liquid columns and the sensitivity of thermo-capillary flows to buoyancy driven convection caused by residual accelerations. The sensitivity of a variety of space experiments to residual accelerations are examined. In all the cases discussed, the sensitivity is related to the dynamic response of a fluid. In some cases the sensitivity can be defined by the magnitude of the response of the velocity field. This response may involve motion of the fluid associated with internal density gradients, or the motion of a free liquid surface. For fluids with internal density gradients, the type of acceleration to which the experiment is sensitive will depend on whether buoyancy driven convection must be small in comparison to other types of fluid motion (such as thermocapillary flow), or fluid motion must be suppressed or eliminated (such as in diffusion studies, or directional solidification experiments). The effect of the velocity on the composition and temperature field must be considered, particularly in the vicinity of the melt crystal interface. As far as the response to transient disturbances is concerned the sensitivity is determined by both the magnitude and frequency the acceleration and the characteristic momentum and solute diffusion times.

  3. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    SciTech Connect

    Wender, S.A.; Venneri, F.; Bowman, C.D.; Arthur, E.D.; Heighway, E.A.; Beard, C.A.; Bracht, R.R.; Buksa, J.J.; Chavez, W.; DeVolder, B.G.

    1994-10-01

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MW{sub t}.

  4. STS-40 orbital acceleration research experiment flight results during a typical sleep period

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1992-01-01

    The Orbital Acceleration Research Experiment (OARE), an electrostatic accelerometer package with complete on-orbit calibration capabilities was flown aboard Shuttle on STS-40. The instrument is designed to measure and record the Shuttle aerodynamic acceleration environment from the free molecule flow regime through the rarefied flow transition into the hypersonic continuum regime. Because of its sensitivity, the OARE instrument detects aerodynamic behavior of the Shuttle while in low-earth orbit. A 2-h orbital time period on day seven of the mission, when the crew was asleep and other spacecraft activities were at a minimum, was examined. Examination of the model with the flight data shows the instrument to be sensitive to all major expected low-frequency acceleration phenomena; however, some erratic instrument bias behavior persists in two axes. In these axes, the OARE data can be made to match a comprehensive atmospheric-aerodynamic model by making bias adjustments and slight liner corrections for drift.

  5. The ANL experiment for a wake field accelerator using an rf structure

    SciTech Connect

    Ruggiero, A.G.; Schoessow, P.; Simpson, J.

    1986-08-27

    Experiments are planned at ANL to study a new accelerating concept that has been developed during the last few years named the WAKEATRON. This requires a very special, simple configuration of the beams and of the rf structure involved. The basic concepts are explained. Like most proposed experimental work, this too was initiated by a considerable amount of computational work, both analytical and numerical, on which we would like to report. We will then describe details of the planned experiments we will carry out at ANL to check some of our predictions for this concept. These experiments concentrate on beam and cavity geometry applicable to the Wakeatron.

  6. Your College Experience: Strategies for Success. The Freshman Year Experience Series.

    ERIC Educational Resources Information Center

    Gardner, John N., Ed.; Jewler, A. Jerome, Ed.

    This textbook is designed to prepare college freshmen for their undergraduate career. Organized in 15 chapters the course introduces basic academic and study skills as well as suggestions for thinking about a career choice, and responding to the social challenges of campus life. Chapter One, "Keys to Success," discusses setting goals and the value…

  7. The LACARA Vacuum Laser Accelerator Experiment: Beam Positioning and Alignment in a Strong Magnetic Field

    SciTech Connect

    Shchelkunov, Sergey V.; Marshall, T. C.; Hirshfield, J. L.; Wang, Changbiao; LaPointe, M. A.

    2006-11-27

    LACARA (laser cyclotron auto-resonance accelerator) is a vacuum laser accelerator of electrons that is under construction at the Accelerator Test Facility (ATF), Brookhaven National Laboratory. It is expected that the experiment will be assembled by September 2006; this paper presents progress towards this goal. According to numerical studies, as an electron bunch moves along the LACARA solenoidal magnetic field ({approx}5.2 T, length {approx}1 m), it will be accelerated from 50 to {approx}75 MeV by interacting with a 0.8 TW Gaussian-mode circularly polarized optical pulse provided by the ATF CO2 10.6{mu}m laser system. The LACARA laser transport optics must handle 10 J and be capable of forming a Gaussian beam inside the solenoid with a 1.4 mm waist and a Rayleigh range of 60 cm. The electron optics must transport a bunch having input emittance of 0.015 mm-mrad and 100 {mu}m waist through the magnet. Precision alignment between the electron beam and the solenoid magnetic axis is required, and a method to achieve this is described in detail. Emittance- filtering may be necessary to yield an accelerated bunch having a narrow ({approx}1%) energy-spread.

  8. Helicon Plasma Injector and Ion Cyclotron Acceleration Development in the VASIMR Experiment

    NASA Technical Reports Server (NTRS)

    Squire, Jared P.; Chang, Franklin R.; Jacobson, Verlin T.; McCaskill, Greg E.; Bengtson, Roger D.; Goulding, Richard H.

    2000-01-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) radio frequency (rf) waves both produce the plasma and then accelerate the ions. The plasma production is done by action of helicon waves. These waves are circular polarized waves in the direction of the electron gyromotion. The ion acceleration is performed by ion cyclotron resonant frequency (ICRF) acceleration. The Advanced Space Propulsion Laboratory (ASPL) is actively developing efficient helicon plasma production and ICRF acceleration. The VASIMR experimental device at the ASPL is called VX-10. It is configured to demonstrate the plasma production and acceleration at the 10kW level to support a space flight demonstration design. The VX-10 consists of three electromagnets integrated into a vacuum chamber that produce magnetic fields up to 0.5 Tesla. Magnetic field shaping is achieved by independent magnet current control and placement of the magnets. We have generated both helium and hydrogen high density (>10(exp 18) cu m) discharges with the helicon source. ICRF experiments are underway. This paper describes the VX-10 device, presents recent results and discusses future plans.

  9. Motivation for proposed experimentation in the realm of accelerated E. M. systems: A preliminary design for an experiment

    NASA Technical Reports Server (NTRS)

    Post, E. J.

    1970-01-01

    An experiment, designed to determine the difference between fields-magnetic and electric-surrounding a uniformly moving charge as contrasted with the fields surrounding an accelerated charge, is presented. A thought experiment is presented to illustrate the process.

  10. Responses to Success: Seeking Pleasant Experiences before a Task Is Complete?

    PubMed Central

    Schall, Marina; Goetz, Thomas; Martiny, Sarah E.; Maymon, Rebecca

    2015-01-01

    Although engaging in pleasant experiences following successful performance may be hedonically rewarding, in the present research we proposed that individuals might forego pleasant experiences when they have not yet completed a task. In Study 1 (N = 100), participants reported the extent to which they would like to engage in pleasant experiences in a hypothetical situation where their performance outcome on a task (successful vs. average) and task completion (task in progress vs. completed) were manipulated. In Study 2 (N = 115), participants were in a real situation in which they achieved either a successful or average performance outcome. Task completion was manipulated (task in progress vs. completed) and motivation to engage in a pleasant experience was assessed by a behavioral measure. Results of both studies provided support for our prediction by showing individuals to have a lower desire to engage in pleasant experiences following successful, but not average, performance when the task was in progress than when it was complete. These findings are discussed in light of the underlying mechanisms and consequences of the tendency to forego pleasant experiences. PMID:26295350

  11. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    USGS Publications Warehouse

    Chang, Jefferson C.; Lockner, David A.; Reches, Z.

    2012-01-01

    After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

  12. Rapid Acceleration Leads to Rapid Weakening in Earthquake-Like Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2012-10-01

    After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

  13. Applied-B ion diode experiments on the Particle Beam Fusion Accelerator-I

    NASA Astrophysics Data System (ADS)

    Dreike, P. L.; Burns, E. J. T.; Slutz, S. A.; Crow, J. T.; Johnson, D. J.; Johnson, P. R.; Leeper, R. J.; Miller, P. A.; Mix, L. P.; Seidel, D. B.; Wenger, D. F.

    1986-08-01

    A series of experiments was performed with an Applied-B ion diode on the Particle Beam Fusion Accelerator-I, with peak voltage, current, and power of approximately 1.8 MV, 6 MA, and 6 TW, respectively. The purpose of these experiments was to explore issues of scaling of Applied-B diode operation from the sub-TW level on single module accelerators to the multi-TW level on a low impedance, self-magnetically insulated, multimodule accelerator. This is an essential step in the development of the 100-TW level light ion beam driver required for inertial confinement fusion. The accelerator and the diode are viewed as a whole because the power pulse delivered by the 36 imperfectly synchronized magnetically insulated transmission lines to the single diode affects module addition, diode operation, and ion beam focusability. We studied electrical coupling between the accelerator and the diode, power flow symmetry, the ionic composition of the beam, and the focusability of the proton component of the beam. Scaling of the diode impedance behavior and beam quality with electrical drive power is obtained from comparison with lower-power experiments. The diode impedance lifetime was about 10 ns, several times shorter than for lower-power experiments. Azimuthal and top-to-bottom variations of the diode and ion currents were found to be approximately ±10%, compared with an estimated requirement of 5%-7% uniformity to avoid focal blurring by self-magnetic field effects. The ion production efficiency was 80%-90%. However, only 50%±10% of the ion current was carried by protons; the balance was carried by multiply charged carbon and oxygen ions. Activation measurements showed a proton beam energy of approximately 50 kJ. A gas cell filled with 5 Torr of argon was used for beam transport. The macroscopic divergence was 15±10 mrad and the microscopic divergence was 20±15 mrad, values that are similar to those from lower-power experiments. A model of beam focusing is formulated that

  14. Accelerators for society: succession of European infrastructural projects: CARE, EuCARD, TIARA, EuCARD2

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2013-10-01

    Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the realization of CARE (Coordinated Accelerator R&D), EuCARD (European Coordination of Accelerator R&D) and during the national annual review meeting of the TIARA - Test Infrastructure of European Research Area in Accelerator R&D. The European projects on accelerator technology started in 2003 with CARE. TIARA is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparatory phase) is an European infrastructural project run by this Consortium and realized inside EU-FP7. The paper presents a general overview of CARE, EuCARD and especially TIARA activities, with an introduction containing a portrait of contemporary accelerator technology and a digest of its applications in modern society. CARE, EuCARD and TIARA activities integrated the European accelerator community in a very effective way. These projects are expected very much to be continued.

  15. Informed Practice: Students' Clinical Experiences in the Undergraduate Phase of an Accelerated Physician Assistant Program.

    PubMed

    Dereczyk, Amy; DeWitt, Rachel

    2016-06-01

    This qualitative study explored the clinical experiences of students in an accelerated physician assistant (PA) program. The participants were either certified nursing assistants (CNAs) or emergency medical technicians-basic (EMTs-B). The study was designed to elicit (1) how the participants perceived their older patients and (2) how the participants' experiences might affect their own future communications, bedside manner, and clinical preparedness as PAs. This study used a focus group to explore students' clinical experiences before the graduate phase of their accelerated PA program. Five female and 2 male PA students (N = 7) participated in the study. All participants were 23 years old and worked as either a CNA or an EMT-B. Results fell into 2 basic themes: informing practice and forming relationships. Regarding the first theme, participants felt that their experience as entry-level health care providers allowed them to improve their communication skills and bedside manner and to provide greater comfort to patients. Regarding the second theme, participants gained appreciation for older people and began to recognize the knowledge deficits and learning needs of their patients. The results suggested that a student's clinical experience as a CNA or an EMT-B before entering a PA program has a positive effect on the student's personal and professional development. The participants acquired greater appreciation and respect for older patients and members of the health care team. PMID:27123599

  16. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    SciTech Connect

    Kafka, Gene

    2015-05-01

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with signi cant exibility in mind, but without compromising cost e ciency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of di erent variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of- ight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  17. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Kafka, Gene

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with significant flexibility in mind, but without compromising cost efficiency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of different variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of-flight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  18. Voices of Experience: Understanding and Enhancing Successful Conflict Management by Community College Presidents

    ERIC Educational Resources Information Center

    Zanjani, Mellissia M.

    2012-01-01

    The purpose of this research study was to enhance understanding of successful conflict management by community college Presidents through highlighting and describing conflict experiences with the faculty union or the board of trustees in a community college context. The following questions guided the research: (a) How do community college…

  19. Are Success and Failure Experiences Equally Motivational? An Investigation of Regulatory Focus and Feedback

    ERIC Educational Resources Information Center

    Shu, Tse-Mei; Lam, Shui-fong

    2011-01-01

    The present study extended regulatory focus theory (Idson & Higgins, 2000) to an educational setting and attempted to identify individuals with high motivation after both success and failure feedback. College students in Hong Kong (N = 180) participated in an experiment with a 2 promotion focus (high vs. low) x 2 prevention focus (high vs. low) x…

  20. Lessons from Success: The Experiences of Women Who Completed an Associate Degree while Parenting Children

    ERIC Educational Resources Information Center

    Vander Hooven, James L.

    2009-01-01

    This study presents the experiences of success of 11 women who have completed an associate degree while parenting children. Women parenting children are a population at especially high risk of non-completion. In much of the research, however, women parenting children are only mentioned peripherally as a subpopulation of nontraditional students;…

  1. The Study Experiences of the High Achievers in a Competitive Academic Environment: A Cost of Success?

    ERIC Educational Resources Information Center

    Nordmo, Ivar; Samara, Akylina

    2009-01-01

    The present paper is a case study that explores the study experiences and possible costs of success for the students accepted into the professional program in psychology at the University of Bergen in Norway. In this highly competitive environment, between 500 and 1000 students compete for 36 places during the introduction year. The study is based…

  2. The latest results from ELM-simulation experiments in plasma accelerators

    NASA Astrophysics Data System (ADS)

    Garkusha, I. E.; Arkhipov, N. I.; Klimov, N. S.; Makhlaj, V. A.; Safronov, V. M.; Landman, I.; Tereshin, V. I.

    2009-12-01

    Recent results of ELM-simulation experiments with quasi-stationary plasma accelerators (QSPAs) Kh-50 (Kharkov, Ukraine) and QSPA-T (Troitsk, Russia) as well as experiments in the pulsed plasma gun MK-200UG (Troitsk, Russia) are discussed. Primary attention in Troitsk experiments has been focused on investigating the carbon-fibre composite (CFC) and tungsten erosion mechanisms, their onset conditions and the contribution of various erosion mechanisms (including droplet splashing) to the resultant surface damage at varying plasma heat flux. The obtained results are used for validating the numerical codes PEGASUS and MEMOS developed in FZK. Crack patterns and residual stresses in tungsten targets under repetitive edge localized mode (ELM)-like plasma pulses are studied in simulation experiments with QSPA Kh-50. Statistical processing of the experimental results on crack patterns after different numbers of QSPA Kh-50 exposures as well as those on the dependence of cracking on the heat load and surface temperature is performed.

  3. Beryllium liner implosion experiments on the Z accelerator in preparation for magnetized liner inertial fusiona)

    NASA Astrophysics Data System (ADS)

    McBride, R. D.; Martin, M. R.; Lemke, R. W.; Greenly, J. B.; Jennings, C. A.; Rovang, D. C.; Sinars, D. B.; Cuneo, M. E.; Herrmann, M. C.; Slutz, S. A.; Nakhleh, C. W.; Ryutov, D. D.; Davis, J.-P.; Flicker, D. G.; Blue, B. E.; Tomlinson, K.; Schroen, D.; Stamm, R. M.; Smith, G. E.; Moore, J. K.; Rogers, T. J.; Robertson, G. K.; Kamm, R. J.; Smith, I. C.; Savage, M.; Stygar, W. A.; Rochau, G. A.; Jones, M.; Lopez, M. R.; Porter, J. L.; Matzen, M. K.

    2013-05-01

    Multiple experimental campaigns have been executed to study the implosions of initially solid beryllium (Be) liners (tubes) on the Z pulsed-power accelerator. The implosions were driven by current pulses that rose from 0 to 20 MA in either 100 or 200 ns (200 ns for pulse shaping experiments). These studies were conducted in support of the recently proposed Magnetized Liner Inertial Fusion concept [Slutz et al., Phys. Plasmas 17, 056303 (2010)], as well as for exploring novel equation-of-state measurement techniques. The experiments used thick-walled liners that had an aspect ratio (initial outer radius divided by initial wall thickness) of either 3.2, 4, or 6. From these studies, we present three new primary results. First, we present radiographic images of imploding Be liners, where each liner contained a thin aluminum sleeve for enhancing the contrast and visibility of the liner's inner surface in the images. These images allow us to assess the stability of the liner's inner surface more accurately and more directly than was previously possible. Second, we present radiographic images taken early in the implosion (prior to any motion of the liner's inner surface) of a shockwave propagating radially inward through the liner wall. Radial mass density profiles from these shock compression experiments are contrasted with profiles from experiments where the Z accelerator's pulse shaping capabilities were used to achieve shockless ("quasi-isentropic") liner compression. Third, we present "micro-Ḃ" measurements of azimuthal magnetic field penetration into the initially vacuum-filled interior of a shocked liner. Our measurements and simulations reveal that the penetration commences shortly after the shockwave breaks out from the liner's inner surface. The field then accelerates this low-density "precursor" plasma to the axis of symmetry.

  4. Beryllium liner implosion experiments on the Z accelerator in preparation for magnetized liner inertial fusion

    SciTech Connect

    McBride, R. D.; Martin, M. R.; Lemke, R. W.; Jennings, C. A.; Rovang, D. C.; Sinars, D. B.; Cuneo, M. E.; Herrmann, M. C.; Slutz, S. A.; Nakhleh, C. W.; Davis, J.-P.; Flicker, D. G.; Rogers, T. J.; Robertson, G. K.; Kamm, R. J.; Smith, I. C.; Savage, M.; Stygar, W. A.; Rochau, G. A.; Jones, M.; and others

    2013-05-15

    Multiple experimental campaigns have been executed to study the implosions of initially solid beryllium (Be) liners (tubes) on the Z pulsed-power accelerator. The implosions were driven by current pulses that rose from 0 to 20 MA in either 100 or 200 ns (200 ns for pulse shaping experiments). These studies were conducted in support of the recently proposed Magnetized Liner Inertial Fusion concept [Slutz et al., Phys. Plasmas 17, 056303 (2010)], as well as for exploring novel equation-of-state measurement techniques. The experiments used thick-walled liners that had an aspect ratio (initial outer radius divided by initial wall thickness) of either 3.2, 4, or 6. From these studies, we present three new primary results. First, we present radiographic images of imploding Be liners, where each liner contained a thin aluminum sleeve for enhancing the contrast and visibility of the liner's inner surface in the images. These images allow us to assess the stability of the liner's inner surface more accurately and more directly than was previously possible. Second, we present radiographic images taken early in the implosion (prior to any motion of the liner's inner surface) of a shockwave propagating radially inward through the liner wall. Radial mass density profiles from these shock compression experiments are contrasted with profiles from experiments where the Z accelerator's pulse shaping capabilities were used to achieve shockless (“quasi-isentropic”) liner compression. Third, we present “micro-B-dot ” measurements of azimuthal magnetic field penetration into the initially vacuum-filled interior of a shocked liner. Our measurements and simulations reveal that the penetration commences shortly after the shockwave breaks out from the liner's inner surface. The field then accelerates this low-density “precursor” plasma to the axis of symmetry.

  5. Design and fabrication of plasma accelerator for space micro-debris simulation and preliminary experiment

    NASA Astrophysics Data System (ADS)

    Han, J.; Zhang, Z.; Huang, J.; Li, X.; Chen, Z.; Quan, R.

    A simulation facility for hypervelocity impact of space micro-debris is designed and fabricated Just after the assembly of the facility some preliminary debugging experiments have conducted A plasma accelerator is the core component of the facility which composed of a coaxial discharge electrode an electromagnetic compressing coil and a nozzle The coaxial electrode is discharged synchronously by pulse injected gas from a delicate fabricated electromagnetic valve and pulse voltage from a capacitance bank The time periods for the pulse gas valve to turn on and to feed gas are 400 and 900 microseconds respectively As to the capacitance bank the maximum capacity is 512 mu F and can be charged as high as 30kV Therefore the maximum energy storage for the capacitance and discharge is 230KJ A custom designed control circuit ignites the pulse valve and discharge switch in turn Then a block of plasma is produced and accelerated into the electromagnetic coil where the plasma is compressed denser Eventually a plasma flow with high pressure and temperature is sprayed out the nozzle which pushes a cluster of micro-particles attached closely to the nozzle exit to hypervelocity During the preliminary debugging experiment 128 mu F capacitance is charged to 15kV and 400kA discharge current is generated then glass spheres with 100 mu m diameter is accelerated to 4 3km s Now the debug for the facility is still in progress in the near future it can accelerate micro-particles to higher velocity

  6. Experiences Associated with Intervening with Homeless, Substance-abusing Mothers: The Importance of Success

    PubMed Central

    Slesnick, Natasha; Glassman, Michael; Katafiasz, Heather; Collins, Jennifer C.

    2015-01-01

    This article documents the experiences of providing housing and supportive services, or ecologically based treatment, to shelter-recruited, substance-abusing homeless women with young children in their care. Among clients, observed experiences related to housing, substance abuse, and health and mental health care are discussed. Among therapists, experiences related to managing the chaotic nature of the client's lives, wanting to manage the client's lives, and frustration with client's life trajectories are reviewed. Observations related to the therapeutic process include the client's relationship to the therapist, balancing the client's independence and need for assistance, and unrealistic expectations among the clients. Recommendations for successfully approaching these clinical situations and experiences are offered. The purpose of this article is to document these therapy experiences to facilitate the work of future teams seeking to intervene in the lives of homeless families through homeless shelters or other settings. PMID:23285834

  7. Electromagnetic Safety of Spacecraft During Active Experiments with the Use of Plasma Accelerators and Ion Injectors

    NASA Astrophysics Data System (ADS)

    Plokhikh, Andrey; Popov, Garri; Shishkin, Gennady; Antropov, Nikolay; Vazhenin, Nikolay; Soganova, Galina

    Works under the development and application of stationary and pulsed plasma accelerators of charged particles conducted at the Moscow Aviation Institute and Research Institute of Applied Mechanics and Electrodynamics during over 40 years, active experiments on board meteorological rockets, artificial Earth satellites and "Mir" orbital station including [1], allowed to obtain data on the influence of pulsed and continuous plasma injection with the given parameters on the drop of energetic particles out of the radiation belts, efficiency of artificial excitation and propagation of electromagnetic waves in ELF and VLF ranges, and evolution of artificial plasma formations in different regions of ionosphere. Variation of the near-spacecraft electromagnetic environment related to the operation of plasma injectors was registered during active experiments along with the global electrodynamic processes. The measured electromagnetic fields are of rather high intensity and occupy frequency spectrum from some Hz to tens of GHz that may be of definite danger for the operation of spacecraft and its onboard systems. Analysis for the known test data is presented in the paper and methods are discussed for the diagnostics and modeling under laboratory conditions of radiative processes proceeding at the operation of plasma accelerators and ion injectors used while making active space experiments. Great attention is paid to the methodological and metrological bases for making radio measurements in vacuum chambers, design concept and hardware configuration of ground special-purpose instrumentation scientific complexes [2]. Basic requirements are formulated for the measurements and analysis of electromagnetic fields originating during the operation of plasma accelerators, including the radiative induced and conductive components inside the spacecraft, as well as the wave emission and excitation outside the spacecraft, in the ionosphere including. Measurement results for the intrinsic

  8. Measurements of fusion neutrons from Magnetized Liner Inertial Fusion Experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E. C.; Awe, T. J.; Torres, J. A.; Jones, B.; Bur, J. A.; Cooper, G. W.; Styron, J. D.; Glebov, V. Yu.

    2015-11-01

    Strong evidence of thermonuclear neutron production has been observed during Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z accelerator. So far, these experiments have utilized deuterium fuel and produced primary DD fusion neutron yields up to 2e12 with electron and ion stagnation temperatures in the 2-3 keV range. We present MagLIF neutron measurements and compare to other data and implosion simulations. In addition to primary DD and secondary DT yields and ion temperatures, other complex physics regarding the degree of fuel magnetization and liner density are elucidated by the neutron measurements. Neutron diagnostic development for deuterium and future deuterium-tritium fuel experiments are also discussed. Sandia is sponsored by the U.S. DOE's NNSA under contract DE-AC04-94AL85000.

  9. An Ultra-High Gradient Cherenkov Wakefield Acceleration Experiment at SLAC FFTB

    SciTech Connect

    Rosenzweig, J.B.; Hoover, S.; Hogan, M.J.; Muggli, P.; Thompson, M.; Travish, G.; Yoder, R.; /UCLA /SLAC /Southern California U.

    2005-08-02

    The creation of ultra-high current, ultra-short pulse beams Q=3 nC, {sigma}{sub z} = 20{micro}m at the SLAC FFTB has opened the way for very high gradient plasma wakefield acceleration experiments. We study here the use of these beams in a proposed Cherenkov wakefield experiment, where one may excite electromagnetic wakes in a simple dielectric tube with inner diameter of few 100 microns that exceed the GV/m level. We discuss the scaling of the fields with design geometric design parameters, and choice of dielectric. We also examine measurable aspects of the experiment, such as the total coherent Cerenkov radiation energy one may collect, and the expected aspects of dielectric breakdown at high fields.

  10. Investigation of neutrino oscillations in the T2k long-baseline accelerator experiment

    SciTech Connect

    Izmaylov, A. O. Yershov, N. V.; Kudenko, Yu. G.; Matveev, V. A.; Mineev, O. V.; Musienko, Yu. V.; Khabibulliun, M. M.; Khotjantsev, A. N.; Shaykhiev, A. T.

    2012-02-15

    High-sensitivity searches for transitions of muon neutrinos to electron neutrinos are the main task of the T2K (Tokai-to-Kamioka) second-generation long-baseline accelerator neutrino experiment. The present article is devoted to describing basic principles of T2K, surveying experimental apparatuses that it includes, and considering in detail the muon-range detector (SMRD) designed and manufactured by a group of physicists from the Institute of Nuclear Research (Russian Academy of Sciences, Moscow). The results of the first measurements with a neutrino beam are presented, and plans for the near future are discussed.

  11. Turbulent Magnetohydrodynamic Acceleration Processes: Theory SSX Experiments and Connections to Space and Astrophysics

    SciTech Connect

    W Matthaeus; M Brown

    2006-07-15

    This is the final technical report for a funded program to provide theoretical support to the Swarthmore Spheromak Experiment. We examined mhd relaxation, reconnecton between two spheromaks, particle acceleration by these processes, and collisonless effects, e.g., Hall effect near the reconnection zone,. Throughout the project, applications to space plasma physics and astrophysics were included. Towards the end ofthe project we were examining a more fully turbulent relaxation associated with unconstrained dynamics in SSX. We employed experimental, spacecraft observations, analytical and numerical methods.

  12. Vibration isolation technology: Sensitivity of selected classes of space experiments to residual accelerations

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.; Zhang, Y. Q.; Adebiyi, Adebimpe

    1989-01-01

    Progress performed on each task is described. Order of magnitude analyses related to liquid zone sensitivity and thermo-capillary flow sensitivity are covered. Progress with numerical models of the sensitivity of isothermal liquid zones is described. Progress towards a numerical model of coupled buoyancy-driven and thermo-capillary convection experiments is also described. Interaction with NASA personnel is covered. Results to date are summarized and they are discussed in terms of the predicted space station acceleration environment. Work planned for the second year is also discussed.

  13. The UCLA/SLAC Ultra-High Gradient Cerenkov Wakefield Accelerator Experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebec, R.; Siemann, R.; Walz, D.; Scott, A.; Yoder, R.; /Manhattan Coll., Riverdale

    2006-01-25

    An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC/USC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {delta}{sub z} = 20 {micro}m at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields.

  14. Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

    NASA Astrophysics Data System (ADS)

    Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

    2015-04-01

    We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J ×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH2 with 2.8% H2 served as the discharge medium. H2 was chosen in order to observe the broadening of the Hβ emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 1016 cm-3 . Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

  15. Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

    SciTech Connect

    Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

    2015-04-15

    We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH{sub 2} with 2.8% H{sub 2} served as the discharge medium. H{sub 2} was chosen in order to observe the broadening of the H{sub β} emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 10{sup 16} cm{sup −3}. Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

  16. Effects of Experiment Location and Orbiter Attitude on the Residual Acceleration On-Board STS-73 (USML-2)

    NASA Technical Reports Server (NTRS)

    Hakimzadeh, Roshanak; McPherson, Kevin M.; Matisak, Brian P.; Wagar, William O.

    1997-01-01

    A knowledge of the quasi-steady acceleration environment on the NASA Space Shuttle Orbiter is of particular importance for materials processing experiments which are limited by slow diffusive processes. The quasi-steady (less than 1 HZ) acceleration environment on STS-73 (USML-2) was measured using the Orbital Acceleration Research Experiment (OARE) accelerometer. One of the facilities flown on USML-2 was the Crystal Growth Furnace (CGF), which was used by several Principal Investigators (PIS) to grow crystals. In this paper the OARE data mapped to the sample melt location within this furnace is presented. The ratio of the axial to radial components of the quasi-steady acceleration at the melt site is presented. Effects of Orbiter attitude on the acceleration data is discussed.

  17. Test particle acceleration in a numerical MHD experiment of an anemone jet

    NASA Astrophysics Data System (ADS)

    Rosdahl, K. J.; Galsgaard, K.

    2010-02-01

    Aims: To use a 3D numerical MHD experiment representing magnetic flux emerging into an open field region as a background field for tracing charged particles. The interaction between the two flux systems generates a localised current sheet where MHD reconnection takes place. We investigate how efficiently the reconnection region accelerates charged particles and what kind of energy distribution they acquire. Methods: The particle tracing is done numerically using the Guiding Center Approximation on individual data sets from the numerical MHD experiment. Results: We derive particle and implied photon distribution functions having power law forms, and look at the impact patterns of particles hitting the photosphere. We find that particles reach energies far in excess of those seen in observations of solar flares. However the structure of the impact region in the photosphere gives a good representation of the topological structure of the magnetic field. Three movies are only available in electronic form at http://www.aanda.org

  18. Recent accelerator experiments updates in Shielding INtegral Benchmark Archive Database (SINBAD)

    NASA Astrophysics Data System (ADS)

    Kodeli, I.; Sartori, E.; Kirk, B.

    2006-06-01

    SINBAD is an internationally established set of radiation shielding and dosimetry data relative to experiments relevant in reactor shielding, fusion blanket neutronics and accelerator shielding. In addition to the characterization of the radiation source, it describes shielding materials and instrumentation and the relevant detectors. The experimental results, be it dose, reaction rates or unfolded spectra are presented in tabular ASCII form that can easily be exported to different computer environments for further use. Most sets in SINBAD also contain the computer model used for the interpretation of the experiment and, where available, results from uncertainty analysis. The set of primary documents used for the benchmark compilation and evaluation are provided in computer readable form. SINBAD is available free of charge from RSICC and from the NEA Data Bank.

  19. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Torres, J. A.; Bur, J. A.; Cuneo, M. E.; Glebov, V. Yu; Harvey-Thompson, A. J.; Herrman, M. C.; Hess, M. H.; Johns, O.; Jones, B.; Lamppa, D. C.; Lash, J. S.; Martin, M. R.; McBride, R. D.; Peterson, K. J.; Porter, J. L.; Reneker, J.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Smith, I. C.; Styron, J. D.; Vesey, R. A.

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ∼2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner∼1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Plans to improve and expand the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.

  20. Application of an electromagnetic accelerator to ultra-high-speed plastic deformation experiments

    NASA Astrophysics Data System (ADS)

    Okada, A.; Kiritani, M.

    2002-01-01

    An electromagnetic accelerator (railgun) is briefly introduced, and several examples of experimental results obtained from test runs of this facility are shown and merits of the application of the railgun to high-speed deformation experiments are emphasized. On applying this facility to high-speed deformation experiments, several specific adapters should be designed, such as a jig for applying a designed amount of deformation to a specimen, A specimen cooling system is also important, as a measure against severe temperature rise occurring during extraordinarily rapid deformation. Although application of the railgun involves many difficulties, the railgun is expected to be a very attractive tool for ultra-high-speed deformation research. The railgun can realize the ultra-high-speed deformation via the collision of a projectile and a target material at a speed comparable to the sonic wave velocity Such high speeds cannot be obtainable by other methods.

  1. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    NASA Astrophysics Data System (ADS)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  2. Successes and Challenges in the SAGE (Summer of Applied Geophysical Experience) REU Program

    NASA Astrophysics Data System (ADS)

    Braile, L. W.; Baldridge, W. S.; Pellerin, L.; Ferguson, J. F.; Bedrosian, P.; Biehler, S.; Jiracek, G. R.; Snelson, C. M.; Kelley, S.; McPhee, D.

    2014-12-01

    The SAGE program was initiated in 1983 to provide an applied geophysics research and education experience for students. Since 1983, 820 students have completed the SAGE summer program. Beginning in 1992, with funding from the NSF, SAGE has included an REU (Research Experience for Undergraduates) experience for selected undergraduate students from U.S. colleges and universities. Since 1992, 380 undergraduate REU students have completed the SAGE program. The four week, intensive, summer program is based in Santa Fe, New Mexico, and involves students in learning geophysical theory and applications; collection of geophysical field data in the northern Rio Grande Rift area; data processing, modeling and interpretation; and presentation (oral and written) of results of each student's research results. Students (undergraduates, graduates and professionals) and faculty are together on a school campus for the summer program. Successful strategies (developed over the years) of the program include teamwork experience, mentoring of REUs (by faculty and more senior students), cultural interchange due to students from many campuses across the U.S. and international graduate students, including industry visitors who work with the students and provide networking, a capstone experience of the summer program that includes all students making a "professional-meeting" style presentation of their research and submitting a written report, a follow-up workshop for the REU students to enhance and broaden their experience, and providing professional development for the REUs through oral or poster presentations and attendance at a professional meeting. Program challenges include obtaining funding from multiple sources; significant time investment in program management, reporting, and maintaining contact with our many funding sources and industry affiliates; and, despite significant efforts, limited success in recruiting racial and ethnic minority students to the program.

  3. Juvenile social experience affects pairing success at adulthood: congruence with the loser effect?

    PubMed

    Mariette, Mylene M; Cathaud, Charlène; Chambon, Rémi; Vignal, Clémentine

    2013-09-22

    Social interactions with adults are often critical for the development of mating behaviours. However, the potential role of other primary social partners such as juvenile counterparts is rarely considered. Most interestingly, it is not known whether interactions with juvenile females improve males' courtship and whether, similar to the winner and loser effects in a fighting context--outcome of these interactions shapes males' behaviour in future encounters. We investigated the combined effects of male quality and juvenile social experience on pairing success at adulthood in zebra finches (Taeniopygia guttata). We manipulated brood size to alter male quality and then placed males in either same- or mixed-sex juvenile dyads until adulthood. We found that males from reduced broods obtained more copulations and males from mixed-sex dyads had more complete courtships. Furthermore, independent of their quality, males that failed to pair with juvenile females, but not juvenile males, had a lower pairing success at adulthood. Our study shows that negative social experience with peers during adolescence may be a potent determinant of pairing success that can override the effects of early environmental conditions on male attractiveness and thereby supports the occurrence of an analogous process to the loser effect in a mating context. PMID:23902911

  4. Food supply and seasonal variation in breeding success: an experiment in the European coot

    PubMed Central

    Brinkhof, M. W. G.; Cave, A. J.

    1997-01-01

    We investigated experimentally the seasonal role of food supply in brood survival of the European coot Fulica atra. For two breeding seasons, individual pairs were offered supplemental food the first ten days after their young hatched. Under natural conditions this period was largely responsible for the seasonal variation in brood survival. Our experiment tested three hypotheses: (1) food supply is not involved in breeding success at any date (other factors hypothesis), (2) food supply limits success independently of date (elevation hypothesis), and (3) food supply affects success seasonally and is responsible for the natural seasonal trend in success (date hypothesis). Experimental pairs with supplemental food raised heavier, larger and more chicks than control pairs. Consistent with the date hypothesis, food supplementation abolished seasonal variation in chick survival. Chick growth under supplemental food was in agreement with the elevation hypothesis. This discrepancy was probably due to the limited supply of additional food. We conclude that seasonal variation in offspring production was in essence the result of seasonal variation in food availability.

  5. PROPOSAL FOR A PRE-BUNCHED LASER WAKEFIELD ACCELERATION EXPERIMENT AT THE BNL DUV FEL FACILITY.

    SciTech Connect

    WANG,X.J.SHEEHY,B.WU,Z.GAI,W.TING,A.

    2003-05-12

    We propose a pre-bunched Laser Wakefield Acceleration (LWFA) experiment in a plasma channel at the BNL DUV-FEL Facility. BNL DUV-FEL facility is uniquely qualified to carry out the proposed experiment because of the high-brightness' electron beam and RF synchronized TW Ti:Sapphire laser system. The DUV-FEL is a 200 MeV linac facility equipped with a photocathode RF gun injector, a 100 fs Ti:Sapphire laser system and a magnetic bunch compressor. The proposed LWFA will inject a 150 MeV, 10 fs electron bunch into a centimeters long plasma channel. Simulation and preliminary experiment showed that, high-brightness 10 fs electron bunch with 20 pC charge could be produced using the technique of longitudinal emittance compensation. The initial experiment will be performed using the existing Ti:Sapphire laser system (50mJ, 100 fs) with 30 {micro}m spot and 4 cm channel, the maximum energy gain will be about 15 MeV. We propose to upgrade the existing SDL laser output to 500 mJ with a shorter pulse length (50 fs). For an electron beam spot size of 20 um, the expected energy gain is about 100 MeV for a 5 TW, 50 fs laser pulse.

  6. Statistical comparison between experiments and numerical simulations of shock-accelerated gas cylinders

    SciTech Connect

    Rider, William; Kamm, J. R.; Zoldi, C. A.; Tomkins, C. D.

    2002-01-01

    We present detailed spatial analysis comparing experimental data and numerical simulation results for Richtmyer-Meshkov instability experiments of Prestridge et al. and Tomkins et al. These experiments consist, respectively, of one and two diffuse cylinders of sulphur hexafluoride (SF{sub 6}) impulsively accelerated by a Mach 1.2 shockwave in air. The subsequent fluid evolution and mixing is driven by the deposition of baroclinic vorticity at the interface between the two fluids. Numerical simulations of these experiments are performed with three different versions of high resolution finite volume Godunov methods, including a new weighted adaptive Runge-Kutta (WARK) scheme. We quantify the nature of the mixing using using integral measures as well as fractal analysis and continuous wavelet transforms. Our investigation of the gas cylinder configurations follows the path of our earlier studies of the geometrically and dynamically more complex gas 'curtain' experiment. In those studies, we found significant discrepancies in the details of the experimentally measured mixing and the details of the numerical simulations. Here we evaluate the effects of these hydrodynamic integration techniques on the diffuse gas cylinder simulations, which we quantitatively compare with experimental data.

  7. Coseismic Damage Generation in Fault Zones by Successive High Strain Rate Loading Experiments

    NASA Astrophysics Data System (ADS)

    Aben, F. M.; Doan, M. L.; Renard, F.; Toussaint, R.; Reuschlé, T.; Gratier, J. P.

    2014-12-01

    Damage zones of active faults control both resistance to rupture and transport properties of the fault. Hence, knowing the rock damage's origin is important to constrain its properties. Here we study experimentally the damage generated by a succession of dynamic loadings, a process mimicking the stress history of a rock sample located next to an active fault. A propagating rupture generates high frequency stress perturbations next to its tip. This dynamic loading creates pervasive damage (pulverization), as multiple fractures initiate and grow simultaneously. Previous single loading experiments have shown a strain rate threshold for pulverization. Here, we focus on conditions below this threshold and the dynamic peak stress to constrain: 1) if there is dynamic fracturing at these conditions and 2) if successive loadings (cumulative seismic events) result in pervasive fracturing, effectively reducing the pulverization threshold to milder conditions. Monzonite samples were dynamically loaded (strain rate > 50 s-1) several times below the dynamic peak strength, using a Split Hopkinson Pressure Bar apparatus. Several quasi-static experiments were conducted as well (strain rate < 10-5-s). Samples loaded up to stresses above the quasi-static uniaxial compressive strength (qsUCS) systematically fragmented or pulverized after four successive loadings. We measured several damage proxies (P-wave velocity, porosity), that show a systematic increase in damage with each load. In addition, micro-computed tomography acquisition on several damage samples revealed the growth of a pervasive fracture network between ensuing loadings. Samples loaded dynamically below the qsUCS failed along one fracture after a variable amount of loadings and damage proxies do not show any a systematic trend. Our conclusions is that milder dynamic loading conditions, below the dynamic peak strength, result in pervasive dynamic fracturing. Also, successive loadings effectively lower the pulverization

  8. Accelerated Learning Options: Moving the Needle on Access and Success. A Study of State and Institutional Policies and Practices

    ERIC Educational Resources Information Center

    Western Interstate Commission for Higher Education, 2006

    2006-01-01

    This document was designed to inform members of the policy, education, and research communities about existing state and institutional policies and practices associated with four accelerated learning programs: Advanced Placement (AP), dual/concurrent enrollment, the International Baccalaureate (IB) Diploma Program, and Tech-Prep. This effort was…

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  10. Laboratory Experiments with the Concordia College High-Speed Dust Particle Accelerator

    NASA Astrophysics Data System (ADS)

    Manning, H. L.

    2011-12-01

    During the Apollo Era, NASA's Goddard Space Flight Center built a 2MeV high-speed, dust particle accelerator. This facility was used to test and calibrate the LEAM instrument which was flown to the lunar surface by Apollo 17. As the Apollo project wound down, NASA no longer had need of the dust particle accelerator, and in 1975, it was move to Concordia College in Moorhead, MN. Through the years, it has been maintained and some modifications and improvements have been made to it. In the past decade, the facility has been revived and used by several collaborating institutions to study dust detector instrumentation as well as the effects of dust impacts on various materials. We have tested a prototype, space-flight dust particle detector. Also, piezoelectric pins which can be used as dust detectors were studied to learn the pin's response to single particle impacts of different energies and momenta, and then those measured responses were compared with theoretical models. The effects of high speed impacts on ultra-high temperature ceramics, aerogel, and several different thin films have also been studied at our facility. The results of these experiments will be presented.

  11. Electron Acceleration and Ionization Production in High-Power Heating Experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Mishin, E. V.; Pedersen, T.

    2012-12-01

    Recent ionospheric modification experiments with the 3.6 MW transmitter at the High Frequency Active Auroral Research Program (HAARP) facility in Alaska led to discovery of artificial ionization descending from the nominal interaction altitude in the background F-region ionosphere by ~60-80 km. Artificial ionization production is indicated by significant 427.8 nm emissions from the 1st negative band of N2+ and the appearance of transmitter-induced bottomside traces in ionosonde data during the periods of most intense optical emissions. However, the exact mechanisms producing the artificial plasmas remain to be determined. Yet the only existing theoretical models explain the development of artificial plasma as an ionizing wavefront moving downward due to ionization by electrons accelerated by HF-excited strong Langmuir turbulence (SLT) generated near the plasma resonance, where the pump frequency matches the plasma frequency. However, the observations suggest also the significance of interactions with upper hybrid and electron Bernstein waves near multiples of the electron gyrofrequency. We describe recent observations and discuss suitable acceleration mechanisms.

  12. Acceleration of Dense Flowing Plasmas using ICRF Power in the VASIMR Experiment

    SciTech Connect

    Squire, Jared P.

    2005-09-26

    ICRF power in the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) concept energizes ions (> 100 eV) in a diverging magnetic field to accelerate a dense ({approx} 1019 m-3) flowing plasma to velocities useful for space propulsion ({approx}100 km/s). Theory predicts that an ICRF slow wave launched from the high field side of the resonance will propagate in the magnetic beach to absorb nearly all of the power at the resonance, thus efficiently converting the RF power to ion kinetic energy. The plasma flows through the resonance only once, so the ions are accelerated in a single pass. This process has proven efficient ({approx} 70%) with an ICRF power level of 1.5 kW at about 3.6 MHz in the VASIMR experiment, VX-30, using deuterium plasma created by a helicon operating in flowing mode. We have measured ICRF plasma loading up to 2 ohms, consistent with computational predictions made using Oak Ridge National Laboratory's EMIR code. Recent helicon power upgrades (20 kW at 13.56 MHz) have enabled a 5 cm diameter target plasma for ICRF with an ion flux of over 3x10 20 s-1 and a high degree of ionization. This paper summarizes our ICRF results and presents the latest helicon developments in VX-30.

  13. Students' Perceptions of Factors That Contribute to Risk and Success in Accelerated High School Courses

    ERIC Educational Resources Information Center

    Shaunessy-Dedrick, Elizabeth; Suldo, Shannon M.; Roth, Rachel A.; Fefer, Sarah A.

    2015-01-01

    In this qualitative study, we investigated 15 successful and 15 struggling high school students, perceived stressors, coping strategies, and intrapersonal and environmental factors that students perceive to influence their success in college-level courses. We found that students' primary sources of stress involved meeting numerous academic…

  14. Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons

    SciTech Connect

    Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans,Wim P.; Nakamura, Kei; Panasenko, Dmitriy; Schroeder, Carl B.; Bruhwiler,D.; Cary, J.R.

    2007-06-25

    An optical injection scheme for a laser-plasma basedaccelerator which employs a non-collinear counter-propagating laser beamto push background electrons in the focusing and acceleration phase viaponderomotive beat with the trailing part of the wakefield driver pulseis discussed. Preliminary experiments were performed using a drive beamof a_0 = 2.6 and colliding beam of a_1 = 0.8 both focused on the middleof a 200 mu m slit jet backed with 20 bar, which provided ~; 260 mu mlong gas plume. The enhancement in the total charge by the collidingpulse was observed with sharp dependence on the delay time of thecolliding beam. Enhancement of the neutron yield was also measured, whichsuggests a generation of electrons above 10 MeV.

  15. Do US Black Women Experience Stress-Related Accelerated Biological Aging?

    PubMed Central

    Hicken, Margaret T.; Pearson, Jay A.; Seashols, Sarah J.; Brown, Kelly L.; Cruz, Tracey Dawson

    2010-01-01

    We hypothesize that black women experience accelerated biological aging in response to repeated or prolonged adaptation to subjective and objective stressors. Drawing on stress physiology and ethnographic, social science, and public health literature, we lay out the rationale for this hypothesis. We also perform a first population-based test of its plausibility, focusing on telomere length, a biomeasure of aging that may be shortened by stressors. Analyzing data from the Study of Women's Health Across the Nation (SWAN), we estimate that at ages 49–55, black women are 7.5 years biologically “older” than white women. Indicators of perceived stress and poverty account for 27% of this difference. Data limitations preclude assessing objective stressors and also result in imprecise estimates, limiting our ability to draw firm inferences. Further investigation of black-white differences in telomere length using large-population-based samples of broad age range and with detailed measures of environmental stressors is merited. PMID:20436780

  16. Major Successes of Theory-and-Experiment-Combined Studies in Surface Chemistry and Heterogeneous Catalysis.

    SciTech Connect

    Somorjai, Gabor A.; Li, Yimin

    2009-11-21

    Experimental discoveries followed by theoretical interpretations that pave the way of further advances by experimentalists is a developing pattern in modern surface chemistry and catalysis. The revolution of modern surface science started with the development of surface-sensitive techniques such as LEED, XPS, AES, ISS and SIMS, in which the close collaboration between experimentalists and theorists led to the quantitative determination of surface structure and composition. The experimental discovery of the chemical activity of surface defects and the trends in the reactivity of transitional metals followed by the explanations from the theoretical studies led to the molecular level understanding of active sites in catalysis. The molecular level knowledge, in turn, provided a guide for experiments to search for new generation of catalysts. These and many other examples of successes in experiment-and-theory-combined studies demonstrate the importance of the collaboration between experimentalists and theorists in the development of modern surface science.

  17. Optimization of accelerator target and detector for portal imaging using Monte Carlo simulation and experiment

    NASA Astrophysics Data System (ADS)

    Flampouri, S.; Evans, P. M.; Verhaegen, F.; Nahum, A. E.; Spezi, E.; Partridge, M.

    2002-09-01

    Megavoltage portal images suffer from poor quality compared to those produced with kilovoltage x-rays. Several authors have shown that the image quality can be improved by modifying the linear accelerator to generate more low-energy photons. This work addresses the problem of using Monte Carlo simulation and experiment to optimize the beam and detector combination to maximize image quality for a given patient thickness. A simple model of the whole imaging chain was developed for investigation of the effect of the target parameters on the quality of the image. The optimum targets (6 mm thick aluminium and 1.6 mm copper) were installed in an Elekta SL25 accelerator. The first beam will be referred to as Al6 and the second as Cu1.6. A tissue-equivalent contrast phantom was imaged with the 6 MV standard photon beam and the experimental beams with standard radiotherapy and mammography film/screen systems. The arrangement with a thin Al target/mammography system improved the contrast from 1.4 cm bone in 5 cm water to 19% compared with 2% for the standard arrangement of a thick, high-Z target/radiotherapy verification system. The linac/phantom/detector system was simulated with the BEAM/EGS4 Monte Carlo code. Contrast calculated from the predicted images was in good agreement with the experiment (to within 2.5%). The use of MC techniques to predict images accurately, taking into account the whole imaging system, is a powerful new method for portal imaging system design optimization.

  18. Systematic Study of Spin Effects at SPASCHARM Experiment at 70-GeV Accelerator in Protvino

    NASA Astrophysics Data System (ADS)

    Mochalov, V. V.; Abramov, V. V.; Bazhanov, N. A.; Borisov, N. S.; Derevschikov, A. A.; Evdokimova, A. S.; Meshchanin, A. P.; Minaev, N. G.; Morozov, D. A.; Nurushev, S. B.; Ryzhikov, S. V.; Semenov, P. A.; Ryazantsev, A. V.; Strikhanov, M. N.; Rykov, V. L.; Usov, Y. A.; Vasiliev, A. N.

    2016-02-01

    A new experiment SPASCHARM for systematic study of polarization phenomena in the inclusive and exclusive hadronic reactions in the energy range of IHEP accelerator U-70 (12-50GeV) is currently under development. The universal experimental setup will detect dozens of various resonances and stable particles produced in collisions of unpolarized beams with the polarized target, and at the next stage, using polarized proton and antiproton beams. At the beginning, the final states consisting of light quarks (u, d, s) will be reconstructed, and later on the charmonium states will be studied. Measurements are planned for a variety of beams: π±,K±,p, antiprotons. Hyperon polarization and spin density matrix elements of the vector mesons will be measured along with the single-spin asymmetry (SSA). The 2π-acceptance in azimuth, which is extremely useful for reduction of systematic errors in measurements of spin observables, will be implemented in the experiment. The solid angle acceptance of the setup, Δθ ≈ 250 mrad vertically and 350 mrad horizontally in the beam fragmentation region, covers a wide range of kinematic variables pT and xF. This provides the opportunity for separating dependences on these two variables which is usually not possible in the setups with a small solid angle acceptance. Unlike some previous polarization experiments, the SPASCHARM will be able to simultaneously accumulate and record data on the both, charged and neutral particle production.

  19. ATTO SECOND ELECTRON BEAMS GENERATION AND CHARACTERIZATION EXPERIMENT AT THE ACCELERATOR TEST FACILITY.

    SciTech Connect

    ZOLOTOREV, M.; ZHOLENTS, A.; WANG, X.J.; BABZIEN, M.; SKARITKA, J.; RAKOWSKY, G.; YAKIMENKO, V.

    2002-02-01

    We are proposing an Atto-second electron beam generation and diagnostics experiment at the Brookhaven Accelerator Test facility (ATF) using 1 {micro}m Inverse Free Electron Laser (IFEL). The proposed experiment will be carried out by an BNL/LBNL collaboration, and it will be installed at the ATF beam line II. The proposed experiment will employ a one-meter long undulator with 1.8 cm period (VISA undulator). The electron beam energy will be 63 MeV with emittance less than 2 mm-mrad and energy spread less than 0.05%. The ATF photocathode injector driving laser will be used for energy modulation by Inverse Free Electron Laser (IFEL). With 10 MW laser peak power, about 2% total energy modulation is expected. The energy modulated electron beam will be further bunched through either a drift space or a three magnet chicane into atto-second electron bunches. The attosecond electron beam bunches will be analyzed using the coherent transition radiation (CTR).

  20. Synergy Between Experiments and Simulations in Laser and Beam-Driven Plasma Acceleration and Light Sources

    NASA Astrophysics Data System (ADS)

    Mori, Warren B.

    2015-11-01

    Computer simulations have been an integral part of plasma physics research since the early 1960s. Initially, they provided the ability to confirm and test linear and nonlinear theories in one-dimension. As simulation capabilities and computational power improved, then simulations were also used to test new ideas and applications of plasmas in multi-dimensions. As progress continued, simulations were also used to model experiments. Today computer simulations of plasmas are ubiquitously used to test new theories, understand complicated nonlinear phenomenon, model the full temporal and spatial scale of experiments, simulate parameters beyond the reach of current experiments, and test the performance of new devices before large capital expenditures are made to build them. In this talk I review the progress in simulations in a particular area of plasma physics: plasma based acceleration (PBA). In PBA a short laser pulse or particle beam propagates through long regions of plasma creating plasma wave wakefields on which electrons or positrons surf to high energies. In some cases the wakefields are highly nonlinear, involve three-dimensional effects, and the trajectories of plasma particles cross making it essential that fully kinetic and three-dimensional models are used. I will show how particle-in-cell (PIC) simulations were initially used to propose the basic idea of PBA in one dimension. I will review some of the dramatic progress in the experimental demonstration of PBA and show how this progress was dramatically helped by a synergy between experiments and full-scale multi-dimensional PIC simulations. This will include a review of how the capability of PIC simulation tools has improved. I will also touch on some recent progress on improvements to PIC simulations of PBA and discuss how these improvements may push the synergy further towards real time steering of experiments and start to end modeling of key components of a future linear collider or XFEL based on PBA

  1. The Characteristics and Experiences of Successful Undergraduate Latina Students Who Persist in Engineering

    NASA Astrophysics Data System (ADS)

    Robinson, Carrie

    Females and underrepresented ethnic minorities earn a small percentage of engineering and computer science bachelor's degrees awarded in the United States, earn an even smaller proportion of master's and doctoral degrees, and are underrepresented in the engineering workforce (Engineering Workforce Commission, [2006], as cited in National Science Foundation, 2012; United States Department of Education, [2006], as cited in National Science Foundation, 2009a; United States Department of Education, [2006], as cited in National Science Foundation, 2009b). Considerable research has examined the perceptions, culture, curriculum, and pedagogy in engineering that inhibits the achievement of women and underrepresented ethnic minorities. This action research study used a qualitative approach to examine the characteristics and experiences of Latina students who pursued a bachelor's degree in the Ira A. Fulton Schools of Engineering at Arizona State University (ASU) as part of the 2008 first-time full-time freshman cohort. The researcher conducted two semi-structured individual interviews with seven undergraduate Latina students who successfully persisted to their fourth (senior) year in engineering. The researcher aimed to understand what characteristics made these students successful and how their experiences affected their persistence in an engineering major. The data collected showed that the Latina participants were motivated to persist in their engineering degree program due to their parents' expectations for success and high academic achievement; their desire to overcome the discrimination, stereotyping, and naysayers that they encountered; and their aspiration to become a role model for their family and other students interested in pursuing engineering. From the data collected, the researcher provided suggestions to implement and adapt educational activities and support systems within the Ira A. Fulton Schools of Engineering to improve the retention and graduation rates

  2. ESA successfully conducts experiment in Advanced Space Robotics on Japanese satellite

    NASA Astrophysics Data System (ADS)

    1999-04-01

    performed even without the artificial markers which are typically used to guide telemanipulation. This is an important capability for robotically servicing "non-cooperative" targets. The success of these experiments is an important step towards the development of a number of ESA space robot systems which will be launched and installed on the International Space Station in the next few years. Looking beyond the ISS, the functional demonstration of satellite capture by robotic means could also inspire novel applications for space robotics on free-flying servicing vehicles. Development work for the ESA experiments was funded by Belgium under the ESA Technology Demonstration Programme (TDP) and the ESA General Support Technology Programme (GSTP). After competitive tendering, the contract was awarded to a team led by TRASYS Space and including as sub-contractors SAS and two institutes at the Catholic University (KUL) in Louvain, Belgium. ETS-VII was launched in November 1997. It operates in a circular orbit at an altitude of 550 km and is controlled from the Tsukuba Space Centre via NASA's Tracking and Data Relay Satellite. In the course of 1998, NASDA successfully performed a range of experiments in space robotics and rendez-vous and docking. In an effort to strengthen international cooperation NASDA offered ESA an opportunity to participate in the ETS-VII experiments. ESA responded positively with several proposals and in 1997 an ESA/NASDA Memorandum of Understanding was concluded concerning the joint robot experiment. Information on this and the other experiments on ETS-VII can be viewed on http://oss1.tksc.nasda.go.jp/ets-7index_e.html More information on ESA at http://www.esa.int

  3. Optimal feedback control successfully explains changes in neural modulations during experiments with brain-machine interfaces

    PubMed Central

    Benyamini, Miri; Zacksenhouse, Miriam

    2015-01-01

    Recent experiments with brain-machine-interfaces (BMIs) indicate that the extent of neural modulations increased abruptly upon starting to operate the interface, and especially after the monkey stopped moving its hand. In contrast, neural modulations that are correlated with the kinematics of the movement remained relatively unchanged. Here we demonstrate that similar changes are produced by simulated neurons that encode the relevant signals generated by an optimal feedback controller during simulated BMI experiments. The optimal feedback controller relies on state estimation that integrates both visual and proprioceptive feedback with prior estimations from an internal model. The processing required for optimal state estimation and control were conducted in the state-space, and neural recording was simulated by modeling two populations of neurons that encode either only the estimated state or also the control signal. Spike counts were generated as realizations of doubly stochastic Poisson processes with linear tuning curves. The model successfully reconstructs the main features of the kinematics and neural activity during regular reaching movements. Most importantly, the activity of the simulated neurons successfully reproduces the observed changes in neural modulations upon switching to brain control. Further theoretical analysis and simulations indicate that increasing the process noise during normal reaching movement results in similar changes in neural modulations. Thus, we conclude that the observed changes in neural modulations during BMI experiments can be attributed to increasing process noise associated with the imperfect BMI filter, and, more directly, to the resulting increase in the variance of the encoded signals associated with state estimation and the required control signal. PMID:26042002

  4. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    DOE PAGESBeta

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; et al

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ~2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner ~ 1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Furthermore, plans to improve and expandmore » the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.« less

  5. Beam-wall interaction measurements in LLNL induction accelerator bend experiment

    NASA Astrophysics Data System (ADS)

    Molvik, A. W.; Friedman, A.; Kamin, G. W.; Sangster, T. C.; Eylon, S.; Hopkins, H. S.

    1997-11-01

    Ion-induced desorption coefficients are determined from measurements of pressure rises when an ion beam strikes a surface. These measurements are made after the first bend of 9^circ by deflecting the beam onto the stainless steel beam tube, and within a pill-box where the beam strikes a stainless steel target at an angle that can be varied from 90^circ to ~10^circ. The beam consists of 2 mA of singly-charged potassium ions at 80 keV with pulse lengths of several microsec. Data near 10^circ are relevant to near-term experiments where beam halo could strike the wall at angles of a few degrees. Data near 90^circ are relevant to ions resulting from charge exchange with a reactor driver class beam which has a space potential of the order of 100 kV. These data will aid in assessing the adequacy of the existing vacuum system when the bend experiment is upgraded to a recirculator induction accelerator.

  6. Vibrotactile masking experiments reveal accelerated somatosensory processing in congenitally blind Braille readers

    PubMed Central

    Bhattacharjee, Arindam; Ye, Amanda J.; Lisak, Joy A.; Vargas, Maria G.; Goldreich, Daniel

    2010-01-01

    Braille reading is a demanding task that requires the identification of rapidly varying tactile patterns. During proficient reading, neighboring characters impact the fingertip at about 100-ms intervals, and adjacent raised dots within a character at 50-ms intervals. Because the brain requires time to interpret afferent sensorineural activity, among other reasons, tactile stimuli separated by such short temporal intervals pose a challenge to perception. How, then, do proficient Braille readers successfully interpret inputs arising from their fingertips at such rapid rates? We hypothesized that somatosensory perceptual consolidation occurs more rapidly in proficient Braille readers. If so, Braille readers should outperform sighted participants on masking tasks, which demand rapid perceptual processing, but would not necessarily outperform the sighted on tests of simple vibrotactile sensitivity. To investigate, we conducted two-interval forced-choice vibrotactile detection, amplitude discrimination, and masking tasks on the index fingertips of 89 sighted and 57 profoundly blind humans. Sighted and blind participants had similar unmasked detection (25-ms target tap) and amplitude discrimination (compared to 100-micron reference tap) thresholds, but congenitally blind Braille readers, the fastest readers among the blind participants, exhibited significantly less masking than the sighted (masker: 50-Hz, 50-micron; target-masker delays ±50 and ±100 ms). Indeed, Braille reading speed correlated significantly and specifically with masking task performance, and in particular with the backward masking decay time constant. We conclude that vibrotactile sensitivity is unchanged, but that perceptual processing is accelerated in congenitally blind Braille readers. PMID:20980584

  7. Maximizing Undergraduate Success By Combining Research Experiences with Outreach, Peer Mentoring and Professional Development

    NASA Astrophysics Data System (ADS)

    Bruno, B. C.

    2014-12-01

    The C-MORE Scholars Program provides hands-on, closely mentored research experiences to University of Hawaii (UH) undergraduates during the academic year. Students majoring in the geosciences, especially underrepresented students, from all campuses are encouraged to apply. The academic-year research is complemented by outreach, professional development and summer internships. Combined, these experiences help students develop the skills, confidence and passion that are essential to success in a geoscience career. Research. All students enter the program as trainees, where they learn lab and field research methods, computer skills and science principles. After one year, they are encouraged to reapply as interns, where they work on their own research project. Students who have successfully completed their intern year can reapply as fellows, where they conduct an independent research project such as an honors thesis. Students present their research at a Symposium through posters (trainees) or talks (interns and fellows). Interns and fellows help organize program activities and serve as peer mentors to trainees.Multi-tiered programs that build a pathway toward graduation have been shown to increase student retention and graduation success. Outreach. Undergraduate researchers rarely feel like experts when working with graduate students and faculty. For students to develop their identity as scientists, it is essential that they be given the opportunity to assume the role as expert. Engaging students in outreach is a win-win situation. Students gain valuable skills and confidence in sharing their research with their local community, and the public gets to learn about exciting research happening at UH. Professional Development. Each month, the Scholars meet to develop their professional skills on a particular topic, such as outreach, scientific presentations, interviewing, networking, and preparing application materials for jobs, scholarships and summer REUs. Students are

  8. Accelerated aging and human immunodeficiency virus infection: emerging challenges of growing older in the era of successful antiretroviral therapy.

    PubMed

    Bhatia, Ramona; Ryscavage, Patrick; Taiwo, Babafemi

    2012-08-01

    HIV-infected patients are living longer as a result of potent antiretroviral therapy. Immuno-inflammatory phenomena implicated in the normal aging process, including immune senescence, depreciation of the adaptive immune system, and heightened systemic inflammation are also pathophysiologic sequelae of HIV infection, suggesting HIV infection can potentiate the biological mechanisms of aging. Aging HIV-infected patients manifest many comorbidities at earlier ages, and sometimes with more aggressive phenotypes compared to seronegative counterparts. In this review, we describe relevant biologic changes shared by normal aging and HIV infection and explore the growing spectrum of clinical manifestations associated with the accelerated aging phenotype in HIV-infected individuals. PMID:22205585

  9. Proof-Of-Principle Experiment for Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum

    SciTech Connect

    Plettner, T.; Byer, R.L.; Colby, E.; Cowan, B.; Sears, C.M.S.; Spencer, J.E.; Siemann, R.H.; /SLAC

    2006-03-01

    We recently achieved the first experimental observation of laser-driven particle acceleration of relativistic electrons from a single Gaussian near-infrared laser beam in a semi-infinite vacuum. This article presents an in-depth account of key aspects of the experiment. An analysis of the transverse and longitudinal forces acting on the electron beam is included. A comparison of the observed data to the acceleration viewed as an inverse transition radiation process is presented. This is followed by a detailed description of the components of the experiment and a discussion of future measurements.

  10. High-Current Experiments for Accelerator-Based Neutron Capture Therapy Applications

    SciTech Connect

    Gierga, D.P.; Klinkowstein, R.E.; Hughey, B.H.; Shefer, R.E.; Yanch, J.C.; Blackburn, B.W.

    1999-06-06

    Several accelerator-based neutron capture therapy applications are under development. These applications include boron neutron capture therapy for glioblastoma multiform and boron neutron capture synovectomy (BNCS) for rheumatoid arthritis. These modalities use accelerator-based charged-particle reactions to create a suitable neutron source. Neutrons are produced using a high-current, 2-MV terminal tandem accelerator. For these applications to be feasible, high accelerator beam currents must be routinely achievable. An effort was undertaken to explore the operating regime of the accelerator in the milliampere range. In preparation for high-current operation of the accelerator, computer simulations of charged-particle beam optics were performed to establish high-current operating conditions. Herein we describe high beam current simulations and high beam current operation of the accelerator.

  11. The physics of sub-critical lattices in accelerator driven hybrid systems: The MUSE experiments in the MASURCA facility

    SciTech Connect

    Chauvin, J. P.; Lebrat, J. F.; Soule, R.; Martini, M.; Jacqmin, R.; Imel, G. R.; Salvatores, M.

    1999-06-10

    Since 1991, the CEA has studied the physics of hybrid systems, involving a sub-critical reactor coupled with an accelerator. These studies have provided information on the potential of hybrid systems to transmute actinides and, long lived fission products. The potential of such a system remains to be proven, specifically in terms of the physical understanding of the different phenomena involved and their modelling, as well as in terms of experimental validation of coupled systems, sub-critical environment/accelerator. This validation must be achieved through mock-up studies of the sub-critical environments coupled to a source of external neutrons. The MUSE-4 mock-up experiment is planed at the MASURCA facility and will use an accelerator coupled to a tritium target. The great step between the generator used in the past and the accelerator will allow to increase the knowledge in hybrid physic and to decrease the experimental biases and the measurement uncertainties.

  12. Sprint Accelerations to First Base Among Major League Baseball Players With Different Years of Career Experience.

    PubMed

    Coleman, A Eugene; Amonette, William E

    2015-07-01

    The purpose of this article was to compare times to first base in Major League Baseball games to determine whether running velocity decreases to the foul line and first base among players with differing years of playing experience. From 1998 to 2012, 1,185 sprint times to first base were analyzed: 469 outfielders, 601 infielders, and 115 catchers. The players were divided into differing experience categories depending on their years of service in Major League Baseball: 1-5, 6-10, 11-15, and 16-20+ years. Velocity at the foul line and first base was compared and interval accelerations were reported. Comparisons were completed by playing position, and within left- and right-handed batters. Left-handed outfielders exhibited reduced velocities at 6-10 (p = 0.04), 11-15 (p = 0.004), and 16-20 years (p < 0.001) compared with 1-5 years; there were no statistical differences in velocity at the foul line. Right-handed outfielders exhibited significantly reduced velocities at first base in 6-10 (p = 0.002) and 11-15 years (p = 0.001); they also had a reduced velocities at the foul line in 6-10 (p = 0.004) and 11-15 years (p = 0.009). Right-handed infielders had reduced velocities at first base in 11-15 years (p < 0.001). No other differences were observed within infielders at first base or the foul line. There were no differences within the compared variables for catchers. Decreases in running velocity to first base with experience are seen in outfielders but are less prominent in infielders and catchers. Although physical capabilities for sprinting may decline with age, it is possible that through repetition more experienced players perfect the skill-related component of running to first base, thus preserving speed. PMID:25353082

  13. A Case Study of Factors Leading to Student Success in an Accelerated Licensed Practical Nurse to Associate Degree Nursing Program

    ERIC Educational Resources Information Center

    Taylor, Sherry T.

    2012-01-01

    This case study attempted to discover and comprehend the relationship of students and contributing factors of success, of one Licensed Practical Nurse (LPN) to Associate Degree in Nursing (ADN) program, to formulate an understanding of which contributing factors are most beneficial to enable students to persist to graduation and/or successfully…

  14. Alloparenting experience affects future parental behavior and reproductive success in prairie voles (Microtus ochrogaster).

    PubMed

    Stone, Anita Iyengar; Mathieu, Denise; Griffin, Luana; Bales, Karen Lisa

    2010-01-01

    Various hypotheses have been proposed to explain the function of alloparental behavior in cooperatively breeding species. We examined whether alloparental experience as juveniles enhanced later parental care and reproductive success in the prairie vole (Microtus ochrogaster), a cooperatively breeding rodent. Juveniles cared for one litter of siblings (1EX), two litters of siblings (2EX) or no siblings (0EX). As adults, these individuals were mated to other 0EX, 1EX or 2EX voles, yielding seven different pair combinations, and we recorded measures of parental behaviors, reproductive success, and pup development. As juveniles, individuals caring for siblings for the first time were more alloparental; and as adults, 0EX females paired with 0EX males spent more time in the nest with their pups. Taken together, these results suggest that inexperienced animals spend more time in infant care. As parents, 1EX males spent more time licking their pups than 2EX and 0EX males. Pups with either a 1EX or 2EX parent gained weight faster than pups with 0EX parents during certain developmental periods. While inexperienced animals may spend more time in pup care, long-term benefits of alloparenting may become apparent in the display of certain, particularly important parental behaviors such as licking pups, and in faster weight gain of offspring. PMID:19732810

  15. Model experiment of cosmic ray acceleration due to an incoherent wakefield induced by an intense laser pulse

    SciTech Connect

    Kuramitsu, Y.; Sakawa, Y.; Takeda, K.; Tampo, M.; Takabe, H.; Nakanii, N.; Kondo, K.; Tsuji, K.; Kimura, K.; Fukumochi, S.; Kashihara, M.; Tanimoto, T.; Nakamura, H.; Ishikura, T.; Kodama, R.; Mima, K.; Tanaka, K. A.; Mori, Y.; Miura, E.; Kitagawa, Y.

    2011-01-15

    The first report on a model experiment of cosmic ray acceleration by using intense laser pulses is presented. Large amplitude light waves are considered to be excited in the upstream regions of relativistic astrophysical shocks and the wakefield acceleration of cosmic rays can take place. By substituting an intense laser pulse for the large amplitude light waves, such shock environments were modeled in a laboratory plasma. A plasma tube, which is created by imploding a hollow polystyrene cylinder, was irradiated by an intense laser pulse. Nonthermal electrons were generated by the wakefield acceleration and the energy distribution functions of the electrons have a power-law component with an index of {approx}2. The maximum attainable energy of the electrons in the experiment is discussed by a simple analytic model. In the incoherent wakefield the maximum energy can be much larger than one in the coherent field due to the momentum space diffusion or the energy diffusion of electrons.

  16. Qualitative research study of high-achieving females' life experiences impacting success

    NASA Astrophysics Data System (ADS)

    Butcher, Ann Patrice

    2003-07-01

    This qualitative study investigated the life experiences of five academically gifted female students in math and science in reflection of their elementary learning prior to enrollment at a prestigious science and mathematics high school. The elite high school limits admission to the state of Illinois' top students. The purpose of this study is to unfold the story of five academically gifted females in attendance at the elite high school reflecting on their life experiences in elementary school that contributed to their current academic success. Twelve female students, who at the time of this study were currently in their senior year (12th grade) of high school, were solicited from the top academic groups who are regarded by their teachers as highly successful in class. Students were selected as part of the study based on academic status, survey completion and interest in study, Caucasian and Asian ethnicity, locale of elementary school with preference given to the variety of school demographics---urban, suburban, and rural---further defined the group to the core group of five. All female participants were personally interviewed and communicated via Internet with the researcher. Parents and teachers completing surveys as well met the methodological requirements of triangulation. An emergent theme of paternal influence came from the research. Implications supported in the research drawn from this study to increase achievement of academically gifted females include: (a) proper early identification of learner strengths plays a role; (b) learning with appropriate intellectual peers is more important than learning with their age group; (c) teachers are the greatest force for excellent instruction; (d) effective teaching strategies include cooperative learning, multi-sensory learning, problem-based learning, and hands-on science; (e) rigor in math is important; (f) gender and stereotypes need not be barriers; (g) outside interests and activities are important for self

  17. Two Channel Dielectric-Lined Rectangular High Transformer Ratio Accelerator Structure Experiment

    SciTech Connect

    Shchelkunov, S. V.; LaPointe, M. A.; Hirshfield, J. L.; Marshall, T. C.; Sotnikov, G.; Gai, Wei; Conde, M.; Power, J.; Mihalcea, D.

    2010-11-04

    Current status of a two-channel cm-scale rectangular dielectric lined wakefield accelerator structure is described. This structure is installed at the Argonne Wakefield Accelerator facility (AWA), and is presently being evaluated. The device has a transformer ratio of {approx}12.5:1. When driven by a {approx}50 nC single drive bunch it is expected to obtain {approx}6 MV/m acceleration gradient. Related issues are discussed.

  18. The Colorado Student Space Weather Experiment: A successful student-run scientific spacecraft mission

    NASA Astrophysics Data System (ADS)

    Schiller, Q.; Li, X.; Palo, S. E.; Blum, L. W.; Gerhardt, D.

    2015-12-01

    The Colorado Student Space Weather Experiment is a spacecraft mission developed and operated by students at the University of Colorado, Boulder. The 3U CubeSat was launched from Vandenberg Air Force Base in September 2012. The massively successful mission far outlived its 4 month estimated lifetime and stopped transmitting data after over two years in orbit in December 2014. CSSWE has contributed to 15 scientific or engineering peer-reviewed journal publications. During the course of the project, over 65 undergraduate and graduate students from CU's Computer Science, Aerospace, and Mechanical Engineering Departments, as well as the Astrophysical and Planetary Sciences Department participated. The students were responsible for the design, development, build, integration, testing, and operations from component- to system-level. The variety of backgrounds on this unique project gave the students valuable experience in their own focus area, but also cross-discipline and system-level involvement. However, though the perseverance of the students brought the mission to fruition, it was only possible through the mentoring and support of professionals in the Aerospace Engineering Sciences Department and CU's Laboratory for Atmospheric and Space Physics.

  19. Critical Components of a Successful Undergraduate Research Experience in the Geosciences for Minority Students

    NASA Astrophysics Data System (ADS)

    Liou-Mark, J.; Blake, R.; Chukuigwe, C.

    2013-12-01

    For the past five years, the New York City College of Technology has administered a successful National Science Foundation (NSF) Research Experience for Undergraduates (REU) program. The program provides rich, substantive, academic and life-transformative STEM educational experiences for students who would otherwise not pursue STEM education altogether or would not pursue STEM education through to the graduate school level. The REU Scholars are provided with an opportunity to conduct intensive satellite and ground-based remote sensing research at the National Oceanic and Atmospheric Administration Cooperative Remote Sensing Science and Technology Center (NOAA-CREST). Candidates for the program are recruited from the City University of New York's twenty-three separate campuses. These students engage in a research experience that spans the summer and the fall and spring semesters. Eighty-four percent (84%) of the program participants are underrepresented minorities in STEM, and they are involved in a plethora of undergraduate research best practice activities that include: training courses in MATLAB programming, Geographic Information Systems, and Remote Sensing; workshops in Research Ethics, Scientific Writing, and Oral and Poster Research Presentations; national, regional, and local conference presentations; graduate school support; and geoscience exposure events at national laboratories, agencies, and research facilities. To enhance their success in the program, the REU Scholars are also provided with a comprehensive series of safety nets that include a multi-tiered mentoring design specifically to address critical issues faced by this diverse population. Since the inception of the REU program in 2008, a total of 61 undergraduate students have finished or are continuing with their research or are pursuing their STEM endeavors. All the REU Scholars conducted individual satellite and ground-based remote sensing research projects that ranged from the study of

  20. Shock experiments and numerical simulations on low energy portable electrically exploding foil accelerators

    NASA Astrophysics Data System (ADS)

    Saxena, A. K.; Kaushik, T. C.; Gupta, Satish C.

    2010-03-01

    Two low energy (1.6 and 8 kJ) portable electrically exploding foil accelerators are developed for moderately high pressure shock studies at small laboratory scale. Projectile velocities up to 4.0 km/s have been measured on Kapton flyers of thickness 125 μm and diameter 8 mm, using an in-house developed Fabry-Pérot velocimeter. An asymmetric tilt of typically few milliradians has been measured in flyers using fiber optic technique. High pressure impact experiments have been carried out on tantalum, and aluminum targets up to pressures of 27 and 18 GPa, respectively. Peak particle velocities at the target-glass interface as measured by Fabry-Pérot velocimeter have been found in good agreement with the reported equation of state data. A one-dimensional hydrodynamic code based on realistic models of equation of state and electrical resistivity has been developed to numerically simulate the flyer velocity profiles. The developed numerical scheme is validated against experimental and simulation data reported in literature on such systems. Numerically computed flyer velocity profiles and final flyer velocities have been found in close agreement with the previously reported experimental results with a significant improvement over reported magnetohydrodynamic simulations. Numerical modeling of low energy systems reported here predicts flyer velocity profiles higher than experimental values, indicating possibility of further improvement to achieve higher shock pressures.

  1. Nike Experiments on Acceleration of Planar Targets Stabilized with a Short Spike Pulse^1

    NASA Astrophysics Data System (ADS)

    Weaver, J. L.; Velikovich, A. L.; Metzler, N.; Aglitskiy, Y.; Oh, J.; Mostovych, A. N.; Gardner, J. H.

    2005-10-01

    Theoretical work has shown that a low energy spike pulse in front of the drive laser pulse can help mitigate the growth of hydrodynamic instabilities in targets for inertial confinement fusion.[1]^ While other experiments [2] used higher spike pulse energies, this study reports the influence of a lower energy spike and longer spike-main pulse delay on the acceleration of planar CH targets. Time evolution of preimposed sinusoidal ripples on the target surface was observed using a monochromatic x-ray imaging system. Delayed onset and/or suppression of mode growth was found for the spike prepulse shots compared to those with a low intensity foot, in good agreement with predictions from FAST2D simulations. The propagation velocity of the decaying shock wave from the spike pulse was measured with VISAR and was also in good agreement with an analytical prediction.[3] [1] Metzler et al., Phys. Plasmas 6, 3283 (1999); 9, 5050 (2002); 10, 1897 (2003);Goncharov et al., Phys. Plasmas 10, 1906 (2003) ;Betti et al., Phys Plamas 12, 042703 (2005) ;[2]Knauer et al., Phys. Plasmas 12, 056306 (2005) ; [3]Velikovich et al., Phys. Plasmas 10, 3270 (2003). ^1Work supported by U. S. Department of Energy

  2. Accelerated Aging Experiments for Prognostics of Damage Growth in Composite Materials

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Goebel, Kai Frank; Larrosa, Cecilia C.; Janapati, Vishnuvardhan; Roy, Surajit; Chang, Fu-Kuo

    2011-01-01

    Composite structures are gaining importance for use in the aerospace industry. Compared to metallic structures their behavior is less well understood. This lack of understanding may pose constraints on their use. One possible way to deal with some of the risks associated with potential failure is to perform in-situ monitoring to detect precursors of failures. Prognostic algorithms can be used to predict impending failures. They require large amounts of training data to build and tune damage model for making useful predictions. One of the key aspects is to get confirmatory feedback from data as damage progresses. These kinds of data are rarely available from actual systems. The next possible resource to collect such data is an accelerated aging platform. To that end this paper describes a fatigue cycling experiment with the goal to stress carbon-carbon composite coupons with various layups. Piezoelectric disc sensors were used to periodically interrogate the system. Analysis showed distinct differences in the signatures of growing failures between data collected at conditions. Periodic X-radiographs were taken to assess the damage ground truth. Results after signal processing showed clear trends of damage growth that were correlated to damage assessed from the X-ray images.

  3. Numerical simulations of recent proton acceleration experiments with sub-100 TW laser systems

    NASA Astrophysics Data System (ADS)

    Sinigardi, Stefano

    2016-09-01

    Recent experiments carried out at the Italian National Research Center, National Optics Institute Department in Pisa, are showing interesting results regarding maximum proton energies achievable with sub-100 TW laser systems. While laser systems are being continuously upgraded in laboratories around the world, at the same time a new trend on stabilizing and making ion acceleration results reproducible is growing in importance. Almost all applications require a beam with fixed performance, so that the energy spectrum and the total charge exhibit moderate shot to shot variations. This result is surely far from being achieved, but many paths are being explored in order to reach it. Some of the reasons for this variability come from fluctuations in laser intensity and focusing, due to optics instability. Other variation sources come from small differences in the target structure. The target structure can vary substantially, when it is impacted by the main pulse, due to the prepulse duration and intensity, the shape of the main pulse and the total energy deposited. In order to qualitatively describe the prepulse effect, we will present a two dimensional parametric scan of its relevant parameters. A single case is also analyzed with a full three dimensional simulation, obtaining reasonable agreement between the numerical and the experimental energy spectrum.

  4. Accelerating phylogenetics computing on the desktop: experiments with executing UPGMA in programmable logic.

    PubMed

    Davis, J P; Akella, S; Waddell, P H

    2004-01-01

    Having greater computational power on the desktop for processing taxa data sets has been a dream of biologists/statisticians involved in phylogenetics data analysis. Many existing algorithms have been highly optimized-one example being Felsenstein's PHYLIP code, written in C, for UPGMA and neighbor joining algorithms. However, the ability to process more than a few tens of taxa in a reasonable amount of time using conventional computers has not yielded a satisfactory speedup in data processing, making it difficult for phylogenetics practitioners to quickly explore data sets-such as might be done from a laptop computer. We discuss the application of custom computing techniques to phylogenetics. In particular, we apply this technology to speed up UPGMA algorithm execution by a factor of a hundred, against that of PHYLIP code running on the same PC. We report on these experiments and discuss how custom computing techniques can be used to not only accelerate phylogenetics algorithm performance on the desktop, but also on larger, high-performance computing engines, thus enabling the high-speed processing of data sets involving thousands of taxa. PMID:17270875

  5. Absolute reactivity calibration of accelerator-driven systems after RACE-T experiments

    SciTech Connect

    Jammes, C. C.; Geslot, B.

    2006-07-01

    The RACE-T experiments that were held in november 2005 in the ENEA-Casaccia research center near Rome allowed us to improve our knowledge of the experimental techniques for absolute reactivity calibration at either startup or shutdown phases of accelerator-driven systems. Various experimental techniques for assessing a subcritical level were inter-compared through three different subcritical configurations SC0, SC2 and SC3, about -0.5, -3 and -6 dollars, respectively. The area-ratio method based of the use of a pulsed neutron source appears as the most performing. When the reactivity estimate is expressed in dollar unit, the uncertainties obtained with the area-ratio method were less than 1% for any subcritical configuration. The sensitivity to measurement location was about slightly more than 1% and always less than 4%. Finally, it is noteworthy that the source jerk technique using a transient caused by the pulsed neutron source shutdown provides results in good agreement with those obtained from the area-ratio technique. (authors)

  6. Ice Target and Gas Target Experiments in the IMPACT Dust Accelerator

    NASA Astrophysics Data System (ADS)

    Munsat, T. L.; Collette, A.; Dee, R.; Gruen, E.; Horanyi, M.; James, D.; Janches, D.; Kempf, S.; Plane, J. M. C.; Shu, A. J.; Simolka, J.; Sternovsky, Z.; Thomas, E.

    2014-12-01

    The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) is presently implementing two major target upgrades: a cryogenic ice target and a high-pressure gas target. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system as well as a movable freezer/holder for a pre-mixed liquid cartridge. Planned experiments include the bombardment of a variety of frozen targets and simulated ice/regolith mixtures, and the assessment of all impact products (solid ejecta, gas, plasma) as well as spectroscopy of both the impact-produced light flashes and the reflected spectra (UV, visible, IR). Such measurements are highly relevant to both physical and chemical surface modification of airless bodies due to micrometeoroid impacts. The gas target consists of a differentially pumped chamber kept at moderate background pressures, such that high-velocity (~10 km/s) micrometeoroids are completely ablated within 10's of cm (i.e. within the measurement chamber). The chamber is configured with segmented electrodes to perform a spatially-resolved measurement of charge production during ablation, and localized light-collection optics enable an assessment of the light production (luminous efficiency). Such studies are critical to the understanding of past and future ground-based measurements of meteor ablation in Earth's atmosphere, which in turn can potentially provide the best estimates of the interplanetary dust particle flux.

  7. Diazotroph community succession during the VAHINE mesocosms experiment (New Caledonia Lagoon)

    NASA Astrophysics Data System (ADS)

    Turk-Kubo, K. A.; Frank, I. E.; Hogan, M. E.; Desnues, A.; Bonnet, S.; Zehr, J. P.

    2015-06-01

    The VAHINE mesocosm experiment, conducted in the low-nutrient low-chlorophyll waters of the Noumea Lagoon (coastal New Caledonia) was designed to trace the incorporation of nitrogen (N) fixed by diazotrophs into the food web, using large volume (50 m3) mesocosms. This experiment provided a unique opportunity to study the succession of different N2-fixing microorganisms (diazotrophs) and calculate in situ net growth and loss rates in response to fertilization with dissolved inorganic phosphate (DIP) over a 23 day period, using quantitative polymerase chain reaction (qPCR) assays. Inside the mesocosms, the diazotroph community assemblage was dominated by the heterocyst-forming Richelia associated with Rhizosolenia (Het-1) in the first half of the experiment, and unicellularcyanobacterial Group C (UCYN-C) became the dominant diazotroph in the second half of the experiment. Decreasing DIP concentrations following the fertilization event and increasing temperatures were significantly correlated with increasing abundances of UCYN-C. Maximum net growth rates for UCYN-C were calculated to be between 1.23 ± 0.07 and 2.16 ± 0.07 d-1 which are among the highest growth rates reported for diazotrophs. Outside the mesocosms in the Noumea Lagoon, UCYN-C abundances remained low, despite increasing temperatures, suggesting that the microbial community response to the DIP fertilization created conditions favorable for UCYN-C growth inside the mesocosms. Maximum net growth and loss rates for nine diazotroph phylotypes throughout the 23 day experiment were variable between mesocosms, and repeated fluctuations between periods of net growth and loss were commonly observed. The field population of diazotrophs in the Noumea Lagoon, was dominated by Het-1 over the course of the study period. However, eight additional diazotroph phylotypes were present in the lagoon at lower abundances, indicating a diverse field population of diazotrophs. Two ecotypes of the Braarudosphaera bigelowii

  8. Diazotroph community succession during the VAHINE mesocosm experiment (New Caledonia lagoon)

    NASA Astrophysics Data System (ADS)

    Turk-Kubo, K. A.; Frank, I. E.; Hogan, M. E.; Desnues, A.; Bonnet, S.; Zehr, J. P.

    2015-12-01

    The VAHINE mesocosm experiment, conducted in the low-nutrient low-chlorophyll waters of the Noumea lagoon (coastal New Caledonia) was designed to trace the incorporation of nitrogen (N) fixed by diazotrophs into the food web, using large volume (50 m3) mesocosms. This experiment provided a unique opportunity to study the succession of different N2-fixing microorganisms (diazotrophs) and calculate in situ net growth and mortality rates in response to fertilization with dissolved inorganic phosphate (DIP) over a 23-day period, using quantitative polymerase chain reaction (qPCR) assays targeting widely distributed marine diazotroph lineages. Inside the mesocosms, the most abundant diazotroph was the heterocyst-forming Richelia associated with Rhizosolenia (Het-1) in the first half of the experiment, while unicellular cyanobacterial Group C (UCYN-C) became abundant during the second half of the experiment. Decreasing DIP concentrations following the fertilization event and increasing temperatures were significantly correlated with increasing abundances of UCYN-C. Maximum net growth rates for UCYN-C were calculated to range between 1.23 ± 0.07 and 2.16 ± 0.07 d-1 in the mesocosms, which are among the highest growth rates reported for diazotrophs. Outside the mesocosms in the New Caledonia lagoon, UCYN-C abundances remained low, despite increasing temperatures, suggesting that the microbial community response to the DIP fertilization created conditions favorable for UCYN-C growth inside the mesocosms. Diazotroph community composition analysis using PCR targeting a component of the nitrogenase gene (nifH) verified that diazotrophs targeted in qPCR assays were collectively among the major lineages in the lagoon and mesocosm samples, with the exception of Crocosphaera-like phylotypes, where sequence types not typically seen in the oligotrophic ocean grew in the mesocosms. Maximum net growth and mortality rates for nine diazotroph phylotypes throughout the 23-day

  9. The Boeing photocathode accelerator magnetic pulse compression and energy recovery experiment

    SciTech Connect

    Dowell, D.H.; Adamski, J.L.; Hayward, T.D.

    1995-12-31

    An 18 MeV, photocathode accelerator operating at 433 MHz is being commissioned for FEL applications. The accelerator consists of a two-cell RF photocathode imjector followed by four new multicell cavities. The two cell injector has previously been operated at a micropulse repetition frequency of 27 MHz, a micropulse charge of 5 nC and 25% duty factor.

  10. Students' Perceptions of Their Experiences from within Acceleration Programs in Mathematics

    ERIC Educational Resources Information Center

    Rawlins, Peter

    2004-01-01

    This article reports on the findings of a research project examining participant students' points of view on accelerated programs in mathematics from four state secondary schools in New Zealand. The four participant schools in this research offered a variety of different acceleration designs and philosophies and were different in size location,…

  11. "DIANA" - A New, Deep-Underground Accelerator Facility for Astrophysics Experiments

    SciTech Connect

    Leitner, M.; Leitner, D.; Lemut, A.; Vetter, P.; Wiescher, M.

    2009-05-28

    The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory to build a nuclear astrophysics accelerator facility 1.4 km below ground. DIANA is part of the US proposal DUSEL (Deep Underground Science and Engineering Laboratory) to establish a cross-disciplinary underground laboratory in the former gold mine of Homestake in South Dakota, USA. DIANA would consist of two high-current accelerators, a 30 to 400 kV variable, high-voltage platform, and a second, dynamitron accelerator with a voltage range of 350 kV to 3 MV. As a unique feature, both accelerators are planned to be equipped with either high-current microwave ion sources or multi-charged ECR ion sources producing ions from protons to oxygen. Electrostatic quadrupole transport elements will be incorporated in the dynamitron high voltage column. Compared to current astrophysics facilities, DIANA could increase the available beam densities on target by magnitudes: up to 100 mA on the low energy accelerator and several mA on the high energy accelerator. An integral part of the DIANA project is the development of a high-density super-sonic gas-jet target which can handle these anticipated beam powers. The paper will explain the main components of the DIANA accelerators and their beam transport lines and will discuss related technical challenges.

  12. Successfully accelerating translational research at an academic medical center: The University of Michigan-Coulter Translational Research Partnership Program.

    PubMed Central

    Pienta, Kenneth J.

    2010-01-01

    Translational research encompasses the effective movement of new knowledge and discoveries into new approaches for prevention, diagnosis, and treatment of disease. There are many roadblocks to successful bench to bedside research, but few have received as much recent attention as the “valley of death”. The valley of death refers to the lack of funding and support for research that moves basic science discoveries into diagnostics, devices, and treatments in humans, and is ascribed to be the result of companies unwilling to fund research development that may not result in a drug or device that will be utilized in the clinic and conversely, the fact that researchers have no access to the funding needed to carry out preclinical and early clinical development to demonstrate potential efficacy in humans. The valley of death also exists because bridging the translational gap is dependent on successfully managing an additional four risks: Scientific, Intellectual Property, Market, and Regulatory. The University of Michigan (UM) has partnered with the Wallace H. Coulter Foundation (CF) to create a model providing an infrastructure to overcome these risks. This model is easily adoptable to other academic medical centers. PMID:21167009

  13. Successfully accelerating translational research at an academic medical center: the University of Michigan-Coulter translational research partnership program.

    PubMed

    Pienta, Kenneth J

    2010-12-01

    Translational research encompasses the effective movement of new knowledge and discoveries into new approaches for prevention, diagnosis, and treatment of disease. There are many roadblocks to successful bench to bedside research, but few have received as much recent attention as the "valley of death". The valley of death refers to the lack of funding and support for research that moves basic science discoveries into diagnostics, devices, and treatments in humans, and is ascribed to be the result of companies unwilling to fund research development that may not result in a drug or device that will be utilized in the clinic and conversely, the fact that researchers have no access to the funding needed to carry out preclinical and early clinical development to demonstrate potential efficacy in humans. The valley of death also exists because bridging the translational gap is dependent on successfully managing an additional four risks: scientific, intellectual property, market, and regulatory. The University of Michigan (UM) has partnered with the Wallace H. Coulter Foundation (CF) to create a model providing an infrastructure to overcome these risks. This model is easily adoptable to other academic medical centers (AMCs). PMID:21167009

  14. Connecting with Communities of Learners and Speakers: Integrative Ideals, Experiences, and Motivations of Successful Black Second Language Learners

    ERIC Educational Resources Information Center

    Anya, Uju

    2011-01-01

    Utilizing data from the language learning autobiographies of six black college students, this pilot study investigates the experiences and motivations of blacks who do and do not achieve advanced-level second language acquisition (SLA). It hypothesizes that successful black second language (L2) learners (1) have positive formative experiences of…

  15. Exploring the Experiences of Successful Completers of a System of Care for Children and Their Families through Case Narratives

    ERIC Educational Resources Information Center

    Anderson, Jeffrey A.; McIntyre, Janet S.; Somers, John W.

    2004-01-01

    This paper explores the experiences of three young people with emotional and behavioral challenges and their families as they entered, participated in, and completed a community-based system of care. Using a case narrative approach, the characteristics and experiences of the children and families who successfully completed the Dawn Project system…

  16. Investing in success: student experiences in a structured, decelerated preclinical medical school curriculum

    PubMed Central

    Arvidson, Cindy G.; Green, Wrenetta D.; Allen, Renoulte; Reznich, Christopher; Mavis, Brian; Osuch, Janet R.; Lipscomb, Wanda; O'Donnell, John; Brewer, Patricia

    2015-01-01

    Purpose Many students in the Michigan State University College of Human Medicine (CHM) are non-traditional with unique needs and experiences. To meet these needs, in 1988 CHM developed a structured Extended Curriculum Program (ECP), which allows students to take longer than 2 years to complete the preclinical curriculum. This work examined the reasons why students extended their programs, their perceptions of that experience, and the outcome with respect to satisfaction and success in their careers after graduation. Methods The analysis used data from the college database, follow-up surveys of residency directors and graduates, surveys of graduates who extended, and the AMA Physician Masterfile. Results Graduates who responded to the survey were evenly split between those who extended for academic reasons and those who extended for other reasons. Although feelings about extending were mixed at the time of extension, nearly all respondents agreed that extending was the right decision in the long run. Extended students continued to face academic challenges having lower basic science averages, lower USMLE Step 1 and 2 first attempt pass rates, and more instances of repeated clerkships compared to those who did not extend, however, most were able to secure a residency in the specialty they desired and had comparable career satisfaction ratings. Conclusions The ECP allows some students to complete medical school who otherwise may not have been able to do so. This analysis has provided valuable information that was used to improve the program, allowing CHM to continue its mission of training a diverse set of students to be exemplary physicians. PMID:26381089

  17. Experiments of interest to nuclear astrophysics using 17F, 18F and 56NI beams from the ATLAS accelerator

    SciTech Connect

    Rehm, K.E.

    1997-12-31

    First experiments with radioactive beams of 17F, 18F and 56Ni have been performed at the superconducting accelerator ATLAS at Argonne National laboratory. The experiments address several questions related to the hot CNO cycle and the breakout into the rp process, in particular the production of 19Ne via the 18F(p,gamma) and of 17F via the 14O(4He,p) reactions. The beams were produced by using either the two-accelerator method (18F, 56Ni) or (for 17F) by bombarding a hydrogen (deuterium) target with 17O or 16O, respectively. Special high-efficiency detection techniques were developed to perform experiments with low beam intensities and sometimes considerable isobar impurities. Planned measurements with other radioactive ion beams will be discussed.

  18. Early Experiences and Predictors of Recruitment Success for the National Children's Study

    PubMed Central

    Andrews, Howard F.; Goranson, Christopher; Li, Wenhui; Barrow, Elise C.; VanderBeek, Suzette B.; McCrary, Brittany; Allen, Suzannah B.; Gallagher, Kathleen D.; Rundle, Andrew; Quinn, James; Brenner, Barbara

    2011-01-01

    OBJECTIVES: We aimed to describe 17 months of experience with household recruitment of live births for the National Children's Study in Queens, a highly urban, diverse borough of New York City (NYC), and to assess predictors of recruitment success. METHODS: Recruitment data (enumeration, pregnancy screening of age-eligible women, identification of pregnancies, and consent) for the period of January 2009 through May 2010 were calculated. Geographic information systems were used to create 11 community-level variables for each of the 18 study segments where recruitment occurred, using US Census, NYC Office of Vital Statistics, NYC Department of City Planning, and NYC Police Department data. Recruitment yields were analyzed with respect to these variables at the segment level. RESULTS: Enumeration identified 4889 eligible women, of whom 4333 (88.6%) completed the pregnancy screener. At least 115 births were lost because of an inability of the pregnancy screener to identify pregnant women, whereas another 115 could be expected to be lost because of missed enumerations and pregnancy screeners. The consent rate was 60.3%. Segments with higher percentages of low birth weight had higher enumeration, pregnancy screening, and consent rates. CONCLUSIONS: In a highly immigrant, urban setting, households could be approached for recruitment of women to participate in the National Children's Study with consent rates equal to those experienced in clinical settings. Refinement of the pregnancy screener and other recruitment materials presents an opportunity to optimize recruitment, improve the representativeness of study participants, and improve the cost-effectiveness of study execution. PMID:21262893

  19. The foundations of reusability: Successful experience and important conclusions from planning and scheduling of space operations

    NASA Technical Reports Server (NTRS)

    Hornstein, Rhoda Shaller; Willoughby, J. K.

    1995-01-01

    NASA's Office of Space Communications is sponsoring a combined technical and management initiative to dramatically decrease the cost of preparing for and conducting space operations. The authors present their successful experience and important conclusions from producing generalized and readily reusable solutions and systems for planning and scheduling applications. While generality by itself should enable reuse, generality alone may not produce the desired cost savings. Generality achieved by accumulating numerous special cases within a software system often increases the complexity of the software to the extent that maintenance costs overtake development savings. Because of this phenomenon, the authors have insisted on simplicity, as well as generality, to achieve cost-effective operation reusability. Simplicity and generality can be accomplished simultaneously when the basic 'Building Blocks' for a problem domain, in this paper, planning and scheduling, are discovered and implemented with reuse in mind. The Building Blocks for planning and scheduling are described. The authors also present examples of how these Building Blocks have accommodated various scenarios that were previously treated as mission-peculiar. Two case histories are presented to demonstrate operational reusability and cost effectiveness.

  20. State experiences implementing youth sports concussion laws: challenges, successes, and lessons for evaluating impact.

    PubMed

    Lowrey, Kerri McGowan; Morain, Stephanie R

    2014-01-01

    While provisions of youth sports concussion laws are very similar, little is known as to how they are being implemented, factors that promote or impede implementation, or the level of compliance in each jurisdiction. We aimed to describe state experiences with implementation in order to inform ongoing efforts to reduce the harm of sports-related traumatic brain injury and to guide future evaluations of the laws' impacts and the development of future public health laws. We conducted key-informant interviews in 35 states with recently enacted concussion legislation. States varied considerably in their readiness and capacity for implementation. Factors facilitating implementation included existing partnerships, procedures, and resources; centralized implementation authority; prior related efforts; and involvement in the policymaking process by those now charged with implementation. Inhibitors included ambiguous statutory language, unclear delegation of authority, and compliance difficulties. Ongoing challenges persist, including primary prevention; determining which providers are qualified to make return-to-play assessments and contents of those assessments; compliance difficulties in rural and under-served areas; and unclear responsibility for enforcement. Despite the similarity of youth sports concussion laws, early evidence suggests there is considerable variation in their implementation. These findings are critical for ongoing empirical investigations to accurately evaluate the laws' provisions and to identify successful legal approaches to protecting young athletes. PMID:25264087

  1. Planned High-gradient Flat-beam-driven Dielectric Wakefield Experiments at the Fermilab’s Advanced Superconducting Test Accelerator

    SciTech Connect

    Lemery, Francois; Mihalcea, Daniel; Piot, Philippe; Zhu, Jun

    2014-07-01

    In beam driven dielectric wakefield acceleration (DWA), high-gradient short-wavelength accelerating fields are generally achieved by employing dielectric-lined waveguides (DLWs)  with small aperture which constraints the beam sizes. In this paper we investigate the possibility of using a low-energy (50-MeV) flat beams to induce high-gradient wakes in a slab-symmetric DLW. We demonstrate via numerical simulations the possibility to produce axial electric field with peak amplitude close to 0.5 GV/m. Our studies are carried out using the Fermilab's Advanced Superconducting Test Accelerator (ASTA) photoinjector beamline. We finally discuss a possible experiment that could be performed in the ASTA photoinjector and eventually at higher energies.  

  2. Optimization of magnetically accelerated, ultra-high velocity aluminum flyer plates for use in plate impact, shock wave experiments.

    SciTech Connect

    Cochrane, Kyle Robert; Knudson, Marcus D.; Slutz, Stephen A.; Lemke, Raymond William; Davis, J. P.; Harjes, Henry Charles III; Giunta, Anthony Andrew; Bliss, David Emery

    2005-05-01

    The intense magnetic field produced by the 20 MA Z accelerator is used as an impulsive pressure source to accelerate metal flyer plates to high velocity for the purpose of performing plate impact, shock wave experiments. This capability has been significantly enhanced by the recently developed pulse shaping capability of Z, which enables tailoring the rise time to peak current for a specific material and drive pressure to avoid shock formation within the flyer plate during acceleration. Consequently, full advantage can be taken of the available current to achieve the maximum possible magnetic drive pressure. In this way, peak magnetic drive pressures up to 490 GPa have been produced, which shocklessly accelerated 850 {micro}m aluminum (6061-T6) flyer plates to peak velocities of 34 km/s. We discuss magnetohydrodynamic (MHD) simulations that are used to optimize the magnetic pressure for a given flyer load and to determine the shape of the current rise time that precludes shock formation within the flyer during acceleration to peak velocity. In addition, we present results pertaining to plate impact, shock wave experiments in which the aluminum flyer plates were magnetically accelerated across a vacuum gap and impacted z-cut, {alpha}-quartz targets. Accurate measurements of resulting quartz shock velocities are presented and analyzed through high-fidelity MHD simulations enhanced using optimization techniques. Results show that a fraction of the flyer remains at solid density at impact, that the fraction of material at solid density decreases with increasing magnetic pressure, and that the observed abrupt decrease in the quartz shock velocity is well correlated with the melt transition in the aluminum flyer.

  3. Magnetic Insulation for Electrostatic Accelerators

    SciTech Connect

    Grisham, L. R.

    2011-09-26

    The voltage gradient which can be sustained between electrodes without electrical breakdowns is usually one of the most important parameters in determining the performance which can be obtained in an electrostatic accelerator. We have recently proposed a technique which might permit reliable operation of electrostatic accelerators at higher electric field gradients, perhaps also with less time required for the conditioning process in such accelerators. The idea is to run an electric current through each accelerator stage so as to produce a magnetic field which envelopes each electrode and its electrically conducting support structures. Having the magnetic field everywhere parallel to the conducting surfaces in the accelerator should impede the emission of electrons, and inhibit their ability to acquire energy from the electric field, thus reducing the chance that local electron emission will initiate an arc. A relatively simple experiment to assess this technique is being planned. If successful, this technique might eventually find applicability in electrostatic accelerators for fusion and other applications.

  4. Neutrino factory and beta beam: accelerator options for future neutrino experiments

    SciTech Connect

    Zisman, Michael S.

    2012-06-03

    Two accelerator options for producing intense neutrino beams a Neutrino Factory based on stored muon beams and a Beta Beam facility based on stored beams of beta unstable ions are described. Technical challenges for each are described and current R&D efforts aimed at mitigating these challenges are indicated. Progress is being made in the design of both types of facility, each of which would extend the state-of-the-art in accelerator science.

  5. Early operating experience with the Brookhaven National Laboratory radio frequency quadrupole accelerator

    SciTech Connect

    Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M.; Warner, P.

    1984-05-01

    The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and high power rf testing will be reported together with initial results of operation in the polarized H/sup -/ beam line.

  6. Acceleration ground test program to verify GAS payload No. 559 structure/support avionics and experiment structural integrity

    NASA Technical Reports Server (NTRS)

    Cassanto, John M.; Cassanto, Valerie A.

    1988-01-01

    Acceleration ground tests were conducted on the Get Away Special (GAS) payload 559 to verify the structural integrity of the structure/support avionics and two of the planned three flight experiments. The ITA (Integrated Test Area) Standardized Experiment Module (ISEM) structure was modified to accommodate the experiments for payload 559. The ISEM avionics consisted of a heavy duty sliver zinc power supply, three orthogonal-mounted low range microgravity accelerometers, a tri-axis high range accelerometer, a solid state recorder/programmer sequencer, and pressure and temperature sensors. The tests were conducted using the Gravitational Plant Physiology Laboratory Centrifuge of the University City Science Center in Philadelphia, PA. The launch-powered flight steady state acceleration profile of the shuttle was simulated from lift-off through jettison of the External Tank (3.0 g's). Additional tests were conducted at twice the nominal powered flight acceleration levels (6 g's) and an over-test condition of four times the powered flight loads to 12.6 g's. The present test program has demonstrated the value of conducting ground tests to verify GAS payload experiment integrity and operation before flying on the shuttle.

  7. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    SciTech Connect

    Leonard, Charles E.; Tallhamer, Michael M.S.; Johnson, Tim; Hunter, Kari C.M.D.; Howell, Kathryn; Kercher, Jane; Widener, Jodi; Kaske, Terese; Paul, Devchand; Sedlacek, Scot; Carter, Dennis L.

    2010-02-01

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  8. Supernova / Acceleration Probe: a Satellite Experiment to Study the Nature of the Dark Energy

    SciTech Connect

    Aldering, G.; Althouse, W.; Amanullah, R.; Annis, J.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, S.; Bebek, C.; Bergstrom, L.; Bernstein, G.; Bester, M.; Bigelow, B.; Blandford, R.; Bohlin, R.; Bonissent, A.; Bower, C.; Brown, M.; Campbell, M.; Carithers, W.; Commins, E.; /LBL, Berkeley /SLAC /Stockholm U. /Fermilab /Paris U., VI-VII /Yale U. /Pennsylvania U. /UC, Berkeley /Michigan U. /Baltimore, Space Telescope Sci. /Marseille, CPPM /Indiana U. /American Astron. Society /Caltech /Case Western Reserve U. /Cambridge U. /Saclay /Lyon, IPN

    2005-08-15

    The Supernova/Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled astrophysical measurements. We here describe a self-consistent reference mission design that can accomplish this goal with the two leading measurement approaches being the Type Ia supernova Hubble diagram and a wide-area weak gravitational lensing survey. This design has been optimized to first order and is now under study for further modification and optimization. A 2-m three-mirror anastigmat wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The instrumentation suite provides simultaneous discovery and light-curve measurements of supernovae and then can target individual objects for detailed spectral characterization. The SNAP mission will discover thousands of Type Ia supernovae out to z = 3 and will obtain high-signal-to-noise calibrated light-curves and spectra for a subset of > 2000 supernovae at redshifts between z = 0.1 and 1.7 in a northern field and in a southern field. A wide-field survey covering one thousand square degrees in both northern and southern fields resolves {approx} 100 galaxies per square arcminute, or a total of more than 300 million galaxies. With the PSF stability afforded by a space observatory, SNAP will provide precise and accurate measurements of gravitational lensing. The high-quality data available in space, combined with the large sample of supernovae, will enable stringent control of systematic uncertainties. The resulting data set will be used to determine the energy density of dark energy and parameters that describe its dynamical behavior. The data also provide a direct test of theoretical models for the dark energy

  9. Supernova/Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

    SciTech Connect

    Aldering, G.; Althouse, W.; Amanullah, R.; Annis, J.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, E.; Bebek, C.; Bergstrom, L.; Bernstein, G.; Bester, M.; Bigelow, C.; Blandford, R.; Bohlin, R.; Bonissent, A.; Bower, C.; Brown, M.; Campbell, M.; Carithers, W.; Commins, E.; Craig, W.; Day, C.; DeJongh, F.; Deustua, S.; Diehl, T.; Dodelson, S.; Ealet, A.; Ellis, R.; Emmet, W.; Fouchez, D.; Frieman, J.; Fruchter, A.; Gerdes, D.; Gladney, L.; Goldhaber, G.; Goobar, A.; Groom, D.; Heetderks, H.; Hoff, M.; Holland, S.; Huffer, M.; Hui, L.; Huterer, D.; Jain, B.; Jelinsky, P.; Karcher, A.; Kent, S.; Kahn, S.; Kim, A.; Kolbe, W.; Krieger, B.; Kushner, G.; Kuznetsova, N.; Lafever, R.; Lamoureux, J.; Lampton, M.; Le Fevre, O.; Levi, M.; Limon, P.; Lin, H.; Linder, E.; Loken, S.; Lorenzon, W.; Malina, R.; Marriner, J.; Marshall, P.; Massey, R.; Mazure, A.; McKay, T.; McKee, S.; Miquel, R.; Morgan, N.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Peoples, J.; Perlmutter, S.; Prieto, E.; Rabinowitz, D.; Refregier, A.; Rhodes, J.; Roe, N.; Rusin, D.; Scarpine, V.; Schubnell, M.; Sholl, M.; Samdja, G.; Smith, R.M.; Smoot, G.; Snyder, J.; Spadafora, A.; Stebbine, A.; Stoughton, C.; Szymkowiak, A.; Tarle, G.; Taylor, K.; Tilquin, A.; Tomasch, A.; Tucker, D.; Vincent, D.; von der Lippe, H.; Walder, J-P.; Wang, G.; Wester, W.

    2004-05-12

    The Supernova/Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universes expansion by performing a series of complementary systematics-controlled astrophysical measurements. We here describe a self-consistent reference mission design that can accomplish this goal with the two leading measurement approaches being the Type Ia supernova Hubble diagram and a wide-area weak gravitational lensing survey. This design has been optimized to first order and is now under study for further modification and optimization. A 2-m three-mirror anastigmat wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high efficiency low-resolution integral field spectrograph. The instrumentation suite provides simultaneous discovery and light-curve measurements of supernovae and then can target individual objects for detailed spectral characterization. The SNAP mission will discover thousands of Type Ia supernovae out to z = 3 and will obtain high-signal-to-noise calibrated light-curves and spectra for a subset of > 2000 supernovae at redshifts between z = 0.1 and 1.7 in a northern field and in a southern field. A wide-field survey covering one thousand square degrees in both northern and southern fields resolves {approx} 100 galaxies per square arcminute, or a total of more than 300 million galaxies. With the PSF stability afforded by a space observatory, SNAP will provide precise and accurate measurements of gravitational lensing. The high-quality data available in space, combined with the large sample of supernovae, will enable stringent control of systematic uncertainties. The resulting data set will be used to determine the energy density of dark energy and parameters that describe its dynamical behavior. The data also provide a direct test of theoretical models for the dark energy

  10. Succession within the prokaryotic communities during the VAHINE mesocosms experiment in the New Caledonia lagoon

    NASA Astrophysics Data System (ADS)

    Pfreundt, U.; Van Wambeke, F.; Bonnet, S.; Hess, W. R.

    2015-12-01

    N2 fixation fuels ~ 50 % of new primary production in the oligotrophic South Pacific Ocean. The VAHINE experiment has been designed to track the fate of diazotroph derived nitrogen (DDN) and carbon within a coastal lagoon ecosystem in a comprehensive way. For this, large-volume (~ 50 m3) mesocosms were deployed in the New Caledonia lagoon and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. This study examined the temporal dynamics of the prokaryotic community together with the evolution of biogeochemical parameters for 23 consecutive days in one of these mesocosms (M1) and in the Nouméa lagoon using MiSeq 16S rRNA gene sequencing. We observed clear successions within M1, some of which were not mirrored in the lagoon. The dominating classes in M1 were alpha- and gammaproteobacteria, cyanobacteria (mainly Synechococcus), eukaryotic microalgae, on days 10 and 14 Marine Group II euryarchaea, on days 12-23 also Flavobacteriia. Enclosure led to significant changes in the M1 microbial community, probably initiated by the early decay of Synechococcus and diatoms. However, we did not detect a pronounced bottle effect with a copiotroph-dominated community. The fertilization with ~ 0.8 μM DIP on day 4 did not have directly observable effects on the overall community within M1, as the data samples obtained from before and four days after fertilization clustered together, but likely influenced the development of individual populations later on, like Defluviicoccus-related bacteria and UCYN-C type diazotrophic cyanobacteria. Growth of UCYN-C led to among the highest N2 fixation rates ever measured in this region and enhanced growth of nearly all abundant heterotrophic groups in M1. We further show that different Rhodobacteraceae were the most efficient heterotrophs in the investigated system and we observed niche partitioning within the SAR86 clade. Whereas the location in- or outside the mesocosm had a significant effect on

  11. Succession within the prokaryotic communities during the VAHINE mesocosms experiment in the New Caledonia lagoon

    NASA Astrophysics Data System (ADS)

    Pfreundt, Ulrike; Van Wambeke, France; Caffin, Mathieu; Bonnet, Sophie; Hess, Wolfgang R.

    2016-04-01

    N2 fixation fuels ˜ 50 % of new primary production in the oligotrophic South Pacific Ocean. The VAHINE experiment has been designed to track the fate of diazotroph-derived nitrogen (DDN) and carbon within a coastal lagoon ecosystem in a comprehensive way. For this, large-volume ( ˜ 50 m3) mesocosms were deployed in the New Caledonian lagoon and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. This study examined the temporal dynamics of the prokaryotic community together with the evolution of biogeochemical parameters for 23 consecutive days in one of these mesocosms (M1) and in the Nouméa lagoon using MiSeq 16S rRNA gene sequencing and flow cytometry. Combining these methods allowed for inference of absolute cell numbers from 16S data. We observed clear successions within M1, some of which were not mirrored in the lagoon. The dominating classes in M1 were Alpha- and Gammaproteobacteria, Cyanobacteria, eukaryotic microalgae, Marine Group II Euryarchaeota, Flavobacteriia, and Acidimicrobia. Enclosure led to significant changes in the M1 microbial community, probably initiated by the early decay of Synechococcus and diatoms. However, we did not detect a pronounced bottle effect with a copiotroph-dominated community. The fertilization with ˜ 0.8 µM DIP on day 4 did not have directly observable effects on the overall community within M1, as the data samples obtained from before and 4 days after fertilization clustered together, but likely influenced the development of individual populations later on, like Defluviicoccus-related bacteria and UCYN-C-type diazotrophic cyanobacteria (Cyanothece). Growth of UCYN-C led to among the highest N2-fixation rates ever measured in this region and enhanced growth of nearly all abundant heterotrophic groups in M1. We further show that different Rhodobacteraceae were the most efficient heterotrophs in the investigated system and we observed niche partitioning within the SAR86 clade

  12. A Framework for Successful Research Experiences in the Classroom: Combining the Power of Technology and Mentors

    NASA Technical Reports Server (NTRS)

    Graff, Paige Valderrama; Stefanov, William L.; Willis, Kim; Runco, Susan; McCollum, Tim; Lindgren, Charles F.; Baker, Marshalyn; Mailhot, Michele

    2011-01-01

    Authentic research opportunities in the classroom are most impactful when they are student-driven and inquiry-based. These experiences are even more powerful when they involve technology and meaningful connections with scientists. In today's classrooms, activities are driven by state required skills, education standards, and state mandated testing. Therefore, programs that incorporate authentic research must address the needs of teachers. NASA's Expedition Earth and Beyond (EEAB) Program has developed a framework that addresses teacher needs and incorporates the use of technology and access to mentors to promote and enhance authentic research in the classroom. EEAB is a student involvement program that facilitates student investigations of Earth or planetary comparisons using NASA data. To promote student-led research, EEAB provides standards-aligned, inquiry-based curricular resources, an implementation structure to facilitate research, educator professional development, and ongoing support. This framework also provides teachers with the option to incorporate the use of technology and connect students with a mentor, both of which can enrich student research experiences. The framework is structured by a modeled 9-step process of science which helps students organize their research. With more schools gaining increased access to technology, EEAB has created an option to help schools take advantage of students' interest and comfort with technology by leveraging the use of available technologies to enhance student research. The use of technology not only allows students to collaborate and share their research, it also provides a mechanism for them to work with a mentor. This framework was tested during the 2010/2011 school year. Team workspaces hosted on Wikispaces for Educators allow students to initiate their research and refine their research question initially without external input. This allows teams to work independently and rely on the skills and interests of

  13. A Framework for Successful Research Experiences in the Classroom: Combining the Power of Technology and Mentors

    NASA Astrophysics Data System (ADS)

    Graff, P. V.; Stefanov, W. L.; Willis, K.; Runco, S.; McCollum, T.; Lindgren, C. F.; Baker, M.; Mailhot, M.

    2011-12-01

    Authentic research opportunities in the classroom are most impactful when they are student-driven and inquiry-based. These experiences are even more powerful when they involve technology and meaningful connections with scientists. In today's classrooms, activities are driven by state required skills, education standards, and state mandated testing. Therefore, programs that incorporate authentic research must address the needs of teachers. NASA's Expedition Earth and Beyond (EEAB) Program has developed a framework that addresses teacher needs and incorporates the use of technology and access to mentors to promote and enhance authentic research in the classroom. EEAB is a student involvement program that facilitates student investigations of Earth or planetary comparisons using NASA data. To promote student-led research, EEAB provides standards-aligned, inquiry-based curricular resources, an implementation structure to facilitate research, educator professional development, and ongoing support. This framework also provides teachers with the option to incorporate the use of technology and connect students with a mentor, both of which can enrich student research experiences. The framework is structured by a modeled 9-step process of science which helps students organize their research. With more schools gaining increased access to technology, EEAB has created an option to help schools take advantage of students' interest and comfort with technology by leveraging the use of available technologies to enhance student research. The use of technology not only allows students to collaborate and share their research, it also provides a mechanism for them to work with a mentor. This framework was tested during the 2010/2011 school year. Team workspaces hosted on Wikispaces for Educators allow students to initiate their research and refine their research question initially without external input. This allows teams to work independently and rely on the skills and interests of

  14. Generation and propagation of an electromagnetic pulse in the Trigger experiment and its possible role in electron acceleration

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.; Kintner, P. M.; Kudeki, E.; Holmgren, G.; Bostrom, R.; Fahleson, U. V.

    1980-01-01

    Instruments onboard the Trigger payload detected a large-amplitude, low-frequency, electric field pulse which was observed with a time delay consistent only with an electromagnetic wave. A model for this perturbation is constructed, and the associated field-aligned current is calculated as a function of altitude. This experiment may simulate the acceleration mechanism which results in the formation of auroral arcs, and possibly even other events in cosmic plasmas.

  15. From experiment to design -- Fault characterization and detection in parallel computer systems using computational accelerators

    NASA Astrophysics Data System (ADS)

    Yim, Keun Soo

    This dissertation summarizes experimental validation and co-design studies conducted to optimize the fault detection capabilities and overheads in hybrid computer systems (e.g., using CPUs and Graphics Processing Units, or GPUs), and consequently to improve the scalability of parallel computer systems using computational accelerators. The experimental validation studies were conducted to help us understand the failure characteristics of CPU-GPU hybrid computer systems under various types of hardware faults. The main characterization targets were faults that are difficult to detect and/or recover from, e.g., faults that cause long latency failures (Ch. 3), faults in dynamically allocated resources (Ch. 4), faults in GPUs (Ch. 5), faults in MPI programs (Ch. 6), and microarchitecture-level faults with specific timing features (Ch. 7). The co-design studies were based on the characterization results. One of the co-designed systems has a set of source-to-source translators that customize and strategically place error detectors in the source code of target GPU programs (Ch. 5). Another co-designed system uses an extension card to learn the normal behavioral and semantic execution patterns of message-passing processes executing on CPUs, and to detect abnormal behaviors of those parallel processes (Ch. 6). The third co-designed system is a co-processor that has a set of new instructions in order to support software-implemented fault detection techniques (Ch. 7). The work described in this dissertation gains more importance because heterogeneous processors have become an essential component of state-of-the-art supercomputers. GPUs were used in three of the five fastest supercomputers that were operating in 2011. Our work included comprehensive fault characterization studies in CPU-GPU hybrid computers. In CPUs, we monitored the target systems for a long period of time after injecting faults (a temporally comprehensive experiment), and injected faults into various types of

  16. The Breckenridge Experience: Reframing the Conversation about Student Success. A Discussion Paper.

    ERIC Educational Resources Information Center

    American Association of Community Colleges, Washington, DC. National Council of Instructional Administrators.

    The paper addresses the following controversial issues between colleges and their external stakeholders: defining and measuring student success, developmental education, and accountability. Given a variety of educational goals by individual learners, community colleges need to create a system of multiple measures to define student success. An…

  17. Transforming First-Year Learning Experiences to Enhance Success for At-Risk Undergraduates

    ERIC Educational Resources Information Center

    Zander, Douglas; Mack, Nakia; Aviles, Jose; Corkery, Caleb; Shettel, Jennifer; Prabhu,Vilas; Shibley, Lisa

    2013-01-01

    The Millersville Scholars Program at Millersville University of Pennsylvania, located in the Southeastern Pennsylvania metropolitan area, provides a compelling best practice for transition programs that address the specific needs of underprepared students so their success mirrors success rates of well-prepared students.

  18. Cell inactivation, repair and mutation induction in bacteria after heavy ion exposure: results from experiments at accelerators and in space.

    PubMed

    Horneck, G; Schafer, M; Baltschukat, K; Weisbrod, U; Micke, U; Facius, R; Bucker, H

    1989-01-01

    To understand the mechanisms of accelerated heavy ions on biological matter, the responses of spores of B. subtilis to this structured high LET radiation was investigated applying two different approaches. 1) By the use of the Biostack concept, the inactivation probability as a function of radial distance to single particles' trajectory (i.e. impact parameter) was determined in space experiments as well as at accelerators using low fluences of heavy ions. It was found that spores can survive even a central hit and that the effective range of inactivation extends far beyond impact parameters where inactivation by delta-ray dose would be effective. Concerning the space experiment, the inactivation cross section exceeds those from comparable accelerator experiments by roughly a factor of 20. 2) From fluence effect curves, cross sections for inactivation and mutation induction, and the efficiency of repair processes were determined. They are influenced by the ions characteristics in a complex manner. According to dependence on LET, at least 3 LET ranges can be differentiated: A low LET range (app. < 200 keV/micrometers), where cross sections for inactivation and mutation induction follow a common curve for different ions and where repair processes are effective; an intermediate LET range of the so-called saturation cross section with negligible mutagenic and repair efficiency; and a high LET range (>1000 keV/micrometers) where the biological endpoints are majorly dependent on atomic mass and energy of the ion under consideration. PMID:11537282

  19. Design of a 5-MA 100-ns linear-transformer-driver accelerator for wire array Z-pinch experiments

    NASA Astrophysics Data System (ADS)

    Zhou, Lin; Li, Zhenghong; Wang, Zhen; Liang, Chuan; Li, Mingjia; Qi, Jianmin; Chu, Yanyun

    2016-03-01

    The linear-transformer-driver (LTD) is a recently developed pulsed-power technology that shows great promise for a number of applications. These include a Z -pinch-driven fission-fusion-hybrid reactor that is being developed by the Chinese Academy of Engineering Physics. In support of the reactor development effort, we are planning to build an LTD-based accelerator that is optimized for driving wire-array Z -pinch loads. The accelerator comprises six modules in parallel, each of which has eight series 0.8-MA LTD cavities in a voltage-adder configuration. Vacuum transmission lines are used from the interior of the adder to the central vacuum chamber where the load is placed. Thus the traditional stack-flashover problem is eliminated. The machine is 3.2 m tall and 12 m in outer diameter including supports. A prototype cavity was built and tested for more than 6000 shots intermittently at a repetition rate of 0.1 Hz. A novel trigger, in which only one input trigger pulse is needed by utilizing an internal trigger brick, was developed and successfully verified in these shots. A full circuit modeling was conducted for the accelerator. The simulation result shows that a current pulse rising to 5.2 MA in 91 ns (10%-90%) can be delivered to the wire-array load, which is 1.5 cm in height, 1.2 cm in initial radius, and 1 mg in mass. The maximum implosion velocity of the load is 32 cm /μ s when compressed to 0.1 of the initial radius. The maximum kinetic energy is 78 kJ, which is 11.7% of the electric energy stored in the capacitors. This accelerator is supposed to enable a radiation energy efficiency of 20%-30%, providing a high efficient facility for research on the fast Z pinch and technologies for repetition-rate-operated accelerators.

  20. Planned High-brightness Channeling Radiation Experiment at Fermilab's Advanced Superconducting Test Accelerator

    SciTech Connect

    Blomberg, Ben; Mihalcea, Daniel; Panuganti, Harsha; Piot, Philippe; Brau, Charles; Choi, Bo; Gabella, William; Ivanov, Borislav; Mendenhall, Marcus; Lynn, Christopher; Sen, Tanaji; Wagner, Wolfgang

    2014-07-01

    In this contribution we describe the technical details and experimental setup of our study aimed at producing high-brightness channeling radiation (CR) at Fermilab’s new user facility the Advanced Superconducting Test Accelerator (ASTA). In the ASTA photoinjector area electrons are accelerated up to 40-MeV and focused to a sub-micron spot on a ~40 micron thick carbon diamond, the electrons channel through the crystal and emit CR up to 80-KeV. Our study utilizes ASTA’s long pulse train capabilities and ability to preserve ultra-low emittance, to produce the desired high average brightness.

  1. Construction, commissioning and operational experience of the Advanced Photon Source (APS) linear accelerator

    SciTech Connect

    White, M.; Arnold, N.; Berg, W.

    1996-10-01

    The Advanced Photon Source linear accelerator system consists of a 200 MeV, 2856 MHz S-Band electron linac and a 2-radiation-thick tungsten target followed by a 450 MeV positron linac. The linac system has operated 24 hours per day for the past year to support accelerator commissioning and beam studies and to provide beam for the user experimental program. It achieves the design goal for positron current of 8 mA and produces electron energies up to 650 MeV without the target in place. The linac is described and its operation and performance are discussed.

  2. Mimicking pestcide percolation dynamics in ditches bed by successive column infltration experiment

    NASA Astrophysics Data System (ADS)

    Dages, Cecile; Samouelian, Anatja; Storck, Veronika; Negro, Sandrine; Huttel, Olivier; Voltz, Marc

    2014-05-01

    Soil layers underlying ditch beds acquire specific characteristics due to ii) hydrological and erosion/deposition processes occurring within the ditch and ii) management practices (burning, dredging, mowing, …). For example, organic matter contents of the ditch beds can be larger than those in neighboring fields, since ditches act as buffer zones. Besides, in Mediterranean catchments, farmed ditches are known to be zones of groundwater recharge and thereby may contribute to groundwater pollution. The role of farmed ditches in groundwater contamination needs therefore to be clarified. The purpose of this study was to determine the dynamic of pesticide percolation in infiltrating farmed ditches bed during a sequence of flood events. A complementary aim was to determine to which extent pesticide percolation from the ditches is correlated to surface flow water contamination. A succession of 9 flood simulations were performed on an undisturbed soil column sampled in the a ditch of the Roujan catchment (Hérault, France), which belongs to the long term Mediterranean hydrological observatory OMERE (Voltz and Albergel, 2002). The soil column was 15 cm long with a 15 cm inner-diameter. For the first 5 flood simulations, injected water was doped with 14C-diuron, an herbicide used in vineyards; uncontaminated water was injected for the last 4 simulations. Free drainage was imposed at the bottom of the column. Diuron concentration was kept constant during a simulated infiltration experiment, but it was progressively decreased from 1000 to 0 µg/L along the succession of the 9 events to mimic the observed seasonal variation of mean diuron concentration in surface flow at the study site (Louchart et al., 2001). Additionally, the first flood simulation was performed with tritium water to assess references on conservative transport within the soil column. For each simulation, the inflow and outflow hydrogram and chemogram were monitored. Extractable (water and solvent) and non

  3. Simulations of laser-wakefield acceleration with external electron-bunch injection for REGAE experiments at DESY

    SciTech Connect

    Grebenyuk, Julia; Mehrling, Timon; Tsung, Frank S.; Floettman, Klaus; Osterhoff, Jens

    2012-12-21

    We present particle-in-cell simulations for future laser-plasma wakefield experiments with external bunch injection at the REGAE accelerator facility at DESY, Hamburg, Germany. Two effects have been studied in detail: emittance evolution of electron bunches externally injected into a wake, and longitudinal bunch compression inside the wakefield. Results show significant transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This might introduce the necessity to include beam-matching sections upstream of each plasma-accelerator section with fundamental implications on the design of staged laser wakefield accelerators. When externally injected at the zero-field crossing of the laser-driven wake, the electron bunch may undergo significant compression in longitudinal direction and be accelerated simultaneously due to the gradient in the acting force. The mechanism would allow for production of single high-energy, ultra-short (on the order of one femtosecond) bunches at REGAE. The optimal conditions for maximal bunch compression are discussed in the presented studies.

  4. Accelerating Opportunity: A Portrait of Students and Their Program Experiences from the 2014 Student Survey

    ERIC Educational Resources Information Center

    Spaulding, Shayne; Martin-Caughey, Ananda

    2015-01-01

    This report presents findings from a survey of students enrolled in Accelerating Opportunity (AO) career pathways in spring 2014. AO provides grants to help community colleges create career pathway programs to enroll students with low basic skills into for-credit career and technical education courses to improve educational and employment…

  5. Highly accelerated cardiac MRI using iterative SENSE reconstruction: initial clinical experience.

    PubMed

    Allen, Bradley D; Carr, Maria; Botelho, Marcos P F; Rahsepar, Amir Ali; Markl, Michael; Zenge, Michael O; Schmidt, Michaela; Nadar, Mariappan S; Spottiswoode, Bruce; Collins, Jeremy D; Carr, James C

    2016-06-01

    To evaluate the qualitative and quantitative performance of an accelerated cardiovascular MRI (CMR) protocol that features iterative SENSE reconstruction and spatio-temporal L1-regularization (IS SENSE). Twenty consecutively recruited patients and 9 healthy volunteers were included. 2D steady state free precession cine images including 3-chamber, 4-chamber, and short axis slices were acquired using standard parallel imaging (GRAPPA, acceleration factor = 2), spatio-temporal undersampled TSENSE (acceleration factor = 4), and IS SENSE techniques (acceleration factor = 4). Acquisition times, quantitative cardiac functional parameters, wall motion abnormalities (WMA), and qualitative performance (scale: 1-poor to 5-excellent for overall image quality, noise, and artifact) were compared. Breath-hold times for IS SENSE (3.0 ± 0.6 s) and TSENSE (3.3 ± 0.6) were both reduced relative to GRAPPA (8.4 ± 1.7 s, p < 0.001). No difference in quantitative cardiac function was present between the three techniques (p = 0.89 for ejection fraction). GRAPPA and IS SENSE had similar image quality (4.7 ± 0.4 vs. 4.5 ± 0.6, p = 0.09) while, both techniques were superior to TSENSE (quality: 4.1 ± 0.7, p < 0.001). GRAPPA WMA agreement with IS SENSE was good (κ > 0.60, p < 0.001), while agreement with TSENSE was poor (κ < 0.40, p < 0.001). IS SENSE is a viable clinical CMR acceleration approach to reduce acquisition times while maintaining satisfactory qualitative and quantitative performance. PMID:26894256

  6. Experiments with Orbit-Spin Coupling Accelerations in a Mars General Circulation Model

    NASA Astrophysics Data System (ADS)

    Mischna, M. A.; Shirley, J. H.; Newman, C. E.

    2014-12-01

    We explore the hypothesis that year-to-year differences in the orbital angular momentum of Mars [Shirley, this meeting] can contribute to the interannual variability of the Mars climate. For much of the year, the seasonal cycle of the atmospheric circulation is highly repeatable, being driven by global insolation patterns; however, during southern summer (the 'dust storm season'), the atmosphere is more highly variable from year-to-year. The processes underlying this variability are not yet clear. As a means of addressing this uncertainty, we explore the possibility that the root cause may be extrinsic to the atmospheric system itself. Recent work has uncovered a mechanism for a coupling of Mars' orbital and rotational motions that yields heretofore-unsuspected accelerations on the martian atmosphere. These accelerations, while instantaneously small (on the order of 10-5 ms-2), may cumulatively yield wind velocity changes of several 10s of ms-1 on seasonal timescales. Here, we use the MarsWRF general circulation model to examine the effect of these newly identified coupling term accelerations (CTAs) on Mars' atmospheric circulation. The accelerations vary significantly with time, and exhibit variable phasing with respect to Mars' annual cycle. We have run MarsWRF with the inclusion of the additional accelerations for a range of years from MY -16 (1924) to MY 34 (2018). We find that interannual variability in the model output derives largely from differences in the sign and magnitude of the CTAs, confirming one of the predictions of the physical hypothesis. During certain seasons the overall circulation is strengthened by the CTAs, while at other times the CTAs disappear. Resultant surface wind stresses, which are a function of the near-surface winds, are enhanced during periods when the CTAs attain maximum values. We have begun to explore the relationship between the CTAs and the martian dust cycle through its influence on these surface stresses.

  7. On the Successful Use of Inquiry-Driven Experiments in the Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Mohrig, Jerry R.; Hammond, Christina Noring; Colby, David A.

    2007-01-01

    The mix of guided-inquiry and design based experiments is feasible to do in introductory organic chemistry lab courses. It can provide students with experience in two parts of experimental chemistry such as the significance and careful analysis of experimental data and the design of experiments.

  8. Interest, Enjoyment and Pride after Failure Experiences? Predictors of Students' State-Emotions after Success and Failure during Learning in Mathematics

    ERIC Educational Resources Information Center

    Tulis, Maria; Ainley, Mary

    2011-01-01

    The current investigation was designed to identify emotion states students experience during mathematics activities, and in particular to distinguish emotions contingent on experiences of success and experiences of failure. Students' task-related emotional responses were recorded following experiences of success and failure while working with an…

  9. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    SciTech Connect

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  10. Predicting Community College Transfer Student Success: The Role of Community College Academic Experiences on Post-Transfer Adjustment

    ERIC Educational Resources Information Center

    Woods, Kristin LeAnne

    2013-01-01

    Community college students who transfer to four-year universities face a variety of academic, social, and psychological challenges as they adjust to new postsecondary institutions (Laanan, 2001; Townsend, 2008). Student success through the transfer process is positively influenced by accumulated knowledge, skills, and experiences from the…

  11. General and Special Educators' Predictions of Student Success as a Function of Learner Characteristics and Teacher Experience

    ERIC Educational Resources Information Center

    Podell, David M.; Tournaki, Nelly

    2007-01-01

    This study compared the influence of teacher and learner characteristics on general and special educators' predictions of student success. Two groups of teachers, 384 general educators and 384 special educators, reported year of experience and responded to case studies describing a student for whom gender, reading achievement, social behavior, and…

  12. Undergraduate African American females in the sciences: A qualitative study of student experiences affecting academic success and persistence

    NASA Astrophysics Data System (ADS)

    Essien-Wood, Idara R.

    Given the lack of literature on Undergraduate African American females in the sciences (UAAFS), this study sought to explicate their experiences at one large, predominantly White, Research I institution in the southwestern United States. In particular, the purpose of this study was to identify factors that affect the academic success and persistence of Black females in the natural and physical sciences. Data was collected via in-depth, semi-structured interviews with 15 Black female science majors. Findings from this study identified several supportive mechanisms for academic success: family, religion, teaching assistants and friends. Also identified were seven barriers to academic success: employment, lack of diversity, cultural dissonance, unwelcoming Research I environment, faculty, advisors, classmates, and lab groups. Further, an analysis of students' responses revealed numerous instances of racial and gender micro-aggressions. Recommendations are provided to address factors identified as affecting student academic success and persistence as well as a culture of micro-aggressive behavior.

  13. Summer Learning: Accelerating Student Success

    ERIC Educational Resources Information Center

    Pitcock, Sarah; Seidel, Bob

    2015-01-01

    As numerous studies from 1906 on have confirmed, children lose ground in learning if they lack opportunities for building skills over the summer. Nonetheless, summer learning loss comes up but rarely in the national discussion of education reform. By the end of summer, students perform on average one month behind where they left off in the spring.…

  14. X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment

    SciTech Connect

    Marsh, Roark A.; Shapiro, Michael A.; Temkin, Richard J.; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC

    2012-06-11

    In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  15. Neutron dosimetry in linear electron accelerator during radiotherapy treatment: simulation and experiment

    NASA Astrophysics Data System (ADS)

    Manfredotti, Claudio; Nastasi, U.; Ongaro, C.; Stasi, E.; Zanini, Alessandro

    1995-03-01

    In the electron linear accelerators used for radiotherapy by high energy electrons or gamma rays, there is a non negligible production of neutrons by photodisintegration or electrodisintegration reactions on the high Z components of the head machine (target, flattening filter, collimators). At the Experimental Physics Department of Torino University, Torino, Italy an experimental and theoretical evaluation has been performed on the undesired neutron production in the MD Class Mevatron Siemens accelerator used at the Radiotherapy Department of S. Giovanni Battista A.S. Hospital for cancer therapy by a 15 MV gamma ray beam. A simulation of the total process has been carried out, using EGS4 MonteCarlo computer code for the evaluation of photoneutron spectra and MCNP code for the neutron transport in the patient's body. The geometrical description both of the accelerator head in EGS4 and of the anthropomorphous phantom in MCNP have been highly optimized. Experimental measurements have been carried out by bubble detectors BD 100R appropriately allocated inside a new phantom in polyetylene and plexiglass, especially designed for this purpose.

  16. The Effect of Selected Preschool Activities on the Success of Reading Comprehension: A Turkish Experience.

    ERIC Educational Resources Information Center

    Celenk, Suleyman

    2003-01-01

    Considers how reading and writing experiences gained during the preschool period have enormous effect on children's first learning to read and write. Initiates a cross-cultural dimension to the subject matter from an empirical paradigm. Provides some evidence that emergent literacy is extensible to experiences regardless of linguistic forms. (SG)

  17. Undertaking the Journey Together: Peer Learning for a Successful and Enjoyable PhD Experience

    ERIC Educational Resources Information Center

    Stracke, Elke

    2010-01-01

    This paper deals with the challenge of supervising PhD students. Any supervision is likely to constitute a challenging experience for the supervisor, even more so when they are a new academic staff member with little experience in PhD supervision in the Australasian context. This paper shows how one supervisor addressed the challenge by fostering…

  18. Experiences Associated with Intervening with Homeless, Substance-Abusing Mothers: The Importance of Success

    ERIC Educational Resources Information Center

    Slesnick, Natasha; Glassman, Michael; Katafiasz, Heather; Collins, Jennifer C.

    2012-01-01

    This article documents the experiences of providing housing and supportive services, or ecologically based treatment, to shelter-recruited, substance-abusing homeless women with young children in their care. Among clients, observed experiences related to housing, substance abuse, and health and mental health care are discussed. Among therapists,…

  19. Assessment Is Essential for Implementing Successful First-Year Experience Programs

    ERIC Educational Resources Information Center

    Dolinsky, Beverly; Matthews, Roberta S.; Greenfield, Gerald M.; Curtis-Tweed, Phyllis; Evenbeck, Scott E.

    2007-01-01

    Creating a climate of assessment is critical for fostering institutional change. This article discusses the authors' work in the Foundations of Excellence in the First College Year project, which has confirmed (across very different campuses) the centrality of assessment in the development and implementation of successful programs to strengthen…

  20. Exploring the Experiences of Successful First-Generation College Students at Selected Community Colleges

    ERIC Educational Resources Information Center

    Waters, Jennifer Ann

    2012-01-01

    The purpose of this study was to examine how successful FGCS in community colleges addressed challenges they face in order to complete their degree programs. This study was based upon Titno's (1993) Model of Student Departure and explored what methods and programs were most beneficial in helping FGCS overcome the challenges they faced as they…

  1. Organizing for Student Success: The University College Model. The First Year Experience Monograph Series No. 53

    ERIC Educational Resources Information Center

    Evenbeck, Scott E.; Jackson, Barbara; Smith, Maggy; Ward, Dorothy

    2010-01-01

    Organizing for Student Success draws on data from more than 50 institutions to provide insight into how university colleges are organized, the initiatives they house, and the practices in place to ensure their effectiveness. Twenty case studies from 15 different campuses offer an in-depth understanding of institutional practice. Ultimately,…

  2. The Impact of Network Relationships, Prison Experiences, and Internal Transformation on Women's Success after Prison Release

    ERIC Educational Resources Information Center

    Bui, Hoan N.; Morash, Merry

    2010-01-01

    Using data obtained from retrospective, in-depth interviews with 20 successful female parolees, the present study examines the effects of women offenders' relationships with people in their social networks (i.e., their network relationships) before, during, and after incarceration on their postrelease desistence from crime. Because women's social…

  3. Conceptual design of a 1013 -W pulsed-power accelerator for megajoule-class dynamic-material-physics experiments

    NASA Astrophysics Data System (ADS)

    Stygar, W. A.; Reisman, D. B.; Stoltzfus, B. S.; Austin, K. N.; Ao, T.; Benage, J. F.; Breden, E. W.; Cooper, R. A.; Cuneo, M. E.; Davis, J.-P.; Ennis, J. B.; Gard, P. D.; Greiser, G. W.; Gruner, F. R.; Haill, T. A.; Hutsel, B. T.; Jones, P. A.; LeChien, K. R.; Leckbee, J. J.; Lewis, S. A.; Lucero, D. J.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Root, S.; Savage, M. E.; Sceiford, M. E.; Spielman, R. B.; Waisman, E. M.; Wisher, M. L.

    2016-07-01

    We have developed a conceptual design of a next-generation pulsed-power accelerator that is optimized for megajoule-class dynamic-material-physics experiments. Sufficient electrical energy is delivered by the accelerator to a physics load to achieve—within centimeter-scale samples—material pressures as high as 1 TPa. The accelerator design is based on an architecture that is founded on three concepts: single-stage electrical-pulse compression, impedance matching, and transit-time-isolated drive circuits. The prime power source of the accelerator consists of 600 independent impedance-matched Marx generators. Each Marx comprises eight 5.8-GW bricks connected electrically in series, and generates a 100-ns 46-GW electrical-power pulse. A 450-ns-long water-insulated coaxial-transmission-line impedance transformer transports the power generated by each Marx to a system of twelve 2.5-m-radius water-insulated conical transmission lines. The conical lines are connected electrically in parallel at a 66-cm radius by a water-insulated 45-post sextuple-post-hole convolute. The convolute sums the electrical currents at the outputs of the conical lines, and delivers the combined current to a single solid-dielectric-insulated radial transmission line. The radial line in turn transmits the combined current to the load. Since much of the accelerator is water insulated, we refer to it as Neptune. Neptune is 40 m in diameter, stores 4.8 MJ of electrical energy in its Marx capacitors, and generates 28 TW of peak electrical power. Since the Marxes are transit-time isolated from each other for 900 ns, they can be triggered at different times to construct-over an interval as long as 1 μ s -the specific load-current time history required for a given experiment. Neptune delivers 1 MJ and 20 MA in a 380-ns current pulse to an 18 -m Ω load; hence Neptune is a megajoule-class 20-MA arbitrary waveform generator. Neptune will allow the international scientific community to conduct dynamic

  4. Progress on plasma accelerators

    SciTech Connect

    Chen, P.

    1986-05-01

    Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

  5. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    NASA Astrophysics Data System (ADS)

    Stygar, W. A.; Awe, T. J.; Bailey, J. E.; Bennett, N. L.; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; Genoni, T. C.; Gomez, M. R.; Greiser, G. W.; Gruner, F. R.; Herrmann, M. C.; Hutsel, B. T.; Jennings, C. A.; Jobe, D. O.; Jones, B. M.; Jones, M. C.; Jones, P. A.; Knapp, P. F.; Lash, J. S.; LeChien, K. R.; Leckbee, J. J.; Leeper, R. J.; Lewis, S. A.; Long, F. W.; Lucero, D. J.; Madrid, E. A.; Martin, M. R.; Matzen, M. K.; Mazarakis, M. G.; McBride, R. D.; McKee, G. R.; Miller, C. L.; Moore, J. K.; Mostrom, C. B.; Mulville, T. D.; Peterson, K. J.; Porter, J. L.; Reisman, D. B.; Rochau, G. A.; Rochau, G. E.; Rose, D. V.; Rovang, D. C.; Savage, M. E.; Sceiford, M. E.; Schmit, P. F.; Schneider, R. F.; Schwarz, J.; Sefkow, A. B.; Sinars, D. B.; Slutz, S. A.; Spielman, R. B.; Stoltzfus, B. S.; Thoma, C.; Vesey, R. A.; Wakeland, P. E.; Welch, D. R.; Wisher, M. L.; Woodworth, J. R.

    2015-11-01

    suggest Z 300 will deliver 4.3 MJ to the liner, and achieve a yield on the order of 18 MJ. Z 800 is 52 m in diameter and stores 130 MJ. This accelerator generates 890 TW at the output of its LTD system, and delivers 65 MA in 113 ns to a MagLIF target. The peak electrical power at the MagLIF liner is 2500 TW. The principal goal of Z 800 is to achieve high-yield thermonuclear fusion; i.e., a yield that exceeds the energy initially stored by the accelerator's capacitors. 2D MHD simulations suggest Z 800 will deliver 8.0 MJ to the liner, and achieve a yield on the order of 440 MJ. Z 300 and Z 800, or variations of these accelerators, will allow the international high-energy-density-physics community to conduct advanced inertial-confinement-fusion, radiation-physics, material-physics, and laboratory-astrophysics experiments over heretofore-inaccessible parameter regimes.

  6. Breeding Experience, Alternative Reproductive Strategies and Reproductive Success in a Captive Colony of Zebra Finches (Taeniopygia guttata)

    PubMed Central

    Baran, Nicole M.; Adkins-Regan, Elizabeth

    2014-01-01

    Birds exhibit a remarkable diversity of different reproductive strategies both between and within species. Species such as the zebra finch (Taeniopygia guttata) may evolve the flexible use of alternative reproductive strategies, as well as benefit from prior breeding experience, which allows them to adaptively respond to unpredictable environments. In birds, the flexible use of alternative reproductive strategies, such as extra-pair mating, has been reported to be associated with fast reproduction, high mortality and environmental variability. However, little is known about the role of previous breeding experience in the adaptive use of alternative reproductive strategies. Here we performed an in-depth study of reproductive outcomes in a population of domesticated zebra finches, testing the impact of prior breeding experience on the use of alternative reproductive strategies and reproductive success. We provide evidence that older females with prior breeding experience are quicker to initiate a clutch with a new partner and have increased success in chick rearing, even in a captive colony of zebra finches with minimal foraging demands. We also find evidence that the breeding experience of other females in the same social group influences reproductive investment by female zebra finches. Furthermore, we demonstrate that the use of alternative reproductive strategies in female zebra finches is associated with previous failed breeding attempts with the same pair partner. The results provide evidence that age and breeding experience play important roles in the flexible use of both facultative and adaptive reproductive strategies in female zebra finches. PMID:24587051

  7. Reactor physics studies for the Advanced Fuel Cycle Initiative (AFCI) Reactor-Accelerator Coupling Experiments (RACE) Project

    NASA Astrophysics Data System (ADS)

    Stankovskiy, Evgeny Yuryevich

    In the recently completed RACE Project of the AFCI, accelerator-driven subcritical systems (ADS) experiments were conducted to develop technology of coupling accelerators to nuclear reactors. In these experiments electron accelerators induced photon-neutron reactions in heavy-metal targets to initiate fission reactions in ADS. Although the Idaho State University (ISU) RACE ADS was constructed only to develop measurement techniques for advanced experiments, many reactor kinetics experiments were conducted there. In the research reported in this dissertation, a method was developed to calculate kinetics parameters for measurement and calculation of the reactivity of ADS, a safety parameter that is necessary for control and monitoring of power production. Reactivity is measured in units of fraction of delayed versus prompt neutron from fission, a quantity that cannot be directly measured in far-subcritical reactors such as the ISU RACE configuration. A new technique is reported herein to calculate it accurately and to predict kinetic behavior of a far-subcritical ADS. Experiments conducted at ISU are first described and experimental data are presented before development of the kinetic theory used in the new computational method. Because of the complexity of the ISU ADS, the Monte-Carlo method as applied in the MCNP code is most suitable for modeling reactor kinetics. However, the standard method of calculating the delayed neutron fraction produces inaccurate values. A new method was developed and used herein to evaluate actual experiments. An advantage of this method is that its efficiency is independent of the fission yield of delayed neutrons, which makes it suitable for fuel with a minor actinide component (e.g. transmutation fuels). The implementation of this method is based on a correlated sampling technique which allows the accurate evaluation of delayed and prompt neutrons. The validity of the obtained results is indicated by good agreement between experimental

  8. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  9. POLAR 5 - An electron accelerator experiment within an aurora. III - Evidence for significant spacecraft charging by an electron accelerator at ionospheric altitudes

    NASA Technical Reports Server (NTRS)

    Jacobsen, T. A.; Maynard, N. C.

    1980-01-01

    The POLAR 5 rocket experiment carried an electron accelerator on a 'daughter' payload which injected a 0.1 A beam of 10 keV electrons in a pulsed mode every 410 ms. With spin and precession, injections were made over a wide range of pitch angles. Measurements from a double probe electric field instrument and from particle detectors on the 'mother' payload and from a crude RPA on the 'daughter' payload are interpreted to indicate that the 'daughter' charges to a potential between several hundred volts and 1 kV. The neutralizing return current to the 'daughter' is shown to be asymmetrically distributed with the majority being collected from the direction of the beam. The additional electrons necessary to neutralize the daughter are thought to be produced and heated through beam-plasma interactions postulated by Maehlum et al. (1980) and Grandal et al. (1980) to explain the particle and optical measurements. Significant electric fields emanating from the charged 'daughter' and the beam are seen at distances exceeding 100 m at the 'mother' payload.

  10. Polar 5 - An electron accelerator experiment within an aurora. I - Instrumentation and geophysical conditions

    NASA Technical Reports Server (NTRS)

    Maehlum, B. N.; Grandal, B.; Jacobsen, T. A.; Maseide, K.; Egeland, A.; Holtet, J.; Soraas, F.; Aarsnes, K.; Stadsnes, J.; Maynard, N. C.

    1980-01-01

    A mother-daughter rocket was launched over two auroral structures, which included a 10 keV electron accelerator and a series of diagnostic instruments for monitoring optical and wave effects generated through beam-atmospheric interactions and production of secondary electrons. The instrumentation, the ground and rocket background measurements obtained, and some of the beam effects on various geophysical parameters are presented. Attention is given to the rocket geometry, capacitance probe, particle counters, photometers, and the bremsstrahlung X-ray detector. Observations on the plasma environment, auroral particle precipitation, d.c. electric field, optical emissions, and auroral background HF and VLF emissions are also discussed.

  11. From Idea to Innovation: The Role of LDRD Investments in Sandia's Recent Successful B61 Experiments.

    SciTech Connect

    Arrowsmith, Marie Danielle

    2015-11-01

    The Laboratory Directed Research and Development (LDRD) program, authorized by U.S. Congress in 1991, enables Department of Energy (DOE) laboratories to devote a small portion of their research funding to high-risk and potentially high-payoff research. Because it is high-risk, LDRD-supported research may not lead to immediate mission impacts; however, many successes at DOE labs can be traced back to investments in LDRD. LDRD investments have a history of enabling significant payoffs for long-running DOE and NNSA missions and for providing anticipatory new technologies that ultimately become critical to future missions. Many of Sandia National Laboratories’ successes can be traced back to investments in LDRD. Capabilities from three LDRDs were critical to recent tests of the B61-12 gravity bomb—tests that would previously have only been performed experimentally.

  12. Situating Second-Year Success: Understanding Second-Year STEM Experiences at a Liberal Arts College

    PubMed Central

    Gregg-Jolly, Leslie; Swartz, Jim; Iverson, Ellen; Stern, Joyce; Brown, Narren; Lopatto, David

    2016-01-01

    Challenges particular to second-year students have been identified that can impact persistence in science, technology, engineering, and mathematics (STEM) fields. We implemented a program to improve student success in intermediate-level science courses by helping students to feel they belonged and could succeed in STEM. We used survey measures of perceptions and attitudes and then qualitative measures to characterize the impact of support strategies, including peer mentoring, a second-year science student retreat, learning and advising support resources, and department-specific activities. Analysis of registration and transcript information revealed underperformance by students of color (SOC) and first-generation (FG) students in 200-level science courses. Comparison of these data before and during programming revealed significant improvement in success rates of these students in 200-level biology and chemistry courses, but success rates of SOC and FG students remain lower than the overall rate for 200-level science courses. Contemporaneous with the program, qualitative and quantitative measures of student attitudes revealed a high level of belongingness and support. The results suggest that a focus on students’ metacognition about their own abilities and strategic knowledge of how to succeed may be a fruitful direction for future research. PMID:27587855

  13. Situating Second-Year Success: Understanding Second-Year STEM Experiences at a Liberal Arts College.

    PubMed

    Gregg-Jolly, Leslie; Swartz, Jim; Iverson, Ellen; Stern, Joyce; Brown, Narren; Lopatto, David

    2016-01-01

    Challenges particular to second-year students have been identified that can impact persistence in science, technology, engineering, and mathematics (STEM) fields. We implemented a program to improve student success in intermediate-level science courses by helping students to feel they belonged and could succeed in STEM. We used survey measures of perceptions and attitudes and then qualitative measures to characterize the impact of support strategies, including peer mentoring, a second-year science student retreat, learning and advising support resources, and department-specific activities. Analysis of registration and transcript information revealed underperformance by students of color (SOC) and first-generation (FG) students in 200-level science courses. Comparison of these data before and during programming revealed significant improvement in success rates of these students in 200-level biology and chemistry courses, but success rates of SOC and FG students remain lower than the overall rate for 200-level science courses. Contemporaneous with the program, qualitative and quantitative measures of student attitudes revealed a high level of belongingness and support. The results suggest that a focus on students' metacognition about their own abilities and strategic knowledge of how to succeed may be a fruitful direction for future research. PMID:27587855

  14. Accelerated Helium and Hydrogen Production in Fe-54 Doped Alloys - Measurements and Calculations for the FIST Experiment

    SciTech Connect

    Greenwood, Lawrence R.; Oliver, Brian M.; Ohnuki, S.; Shiba, K.; Kohno, Y.; Kohyama, A.; Robertson, J. P.; Meadows, J. W.; Gelles, David S.

    2000-09-01

    Helium and hydrogen measurements for F-82H alloys enriched up to 96% in 54Fe demonstrate accelerated gas production due to differences in the isotopic cross sections. The samples were irradiated in the JP-17 and JP-22 experiments in HFIR. Results are compared to calculations using isotopic helium production cross sections from ENDF/B-VI or the computer code, GNASH, for the radioactive isotope 55Fe. Helium measurements demonstrated an accelerated helium (appm)/dpa ratio of 2.3 after a 1.25-year irradiation, an increase of a factor of 4.3 over natural iron, due to higher helium production cross sections for 54Fe and 55Fe. Alloys doped with 55Fe could achieve helium/dpa ratios up to about 20, well above the fusion reactor ratio of 10. Calculations predict that hydrogen production is accelerated by about a factor of 13 over natural iron. However, measurements show that most of this hydrogen is not retained in the samples.

  15. High Transformer ratios in collinear wakefield accelerators.

    SciTech Connect

    Power, J. G.; Conde, M.; Yusof, Z.; Gai, W.; Jing, C.; Kanreykin, A.; Schoessow, P.; High Energy Physics; Euclid Techlabs, LLC

    2008-01-01

    Based on our previous experiment that successfully demonstrated wakefield transformer ratio enhancement in a 13.625 GHz dielectric-loaded collinear wakefield accelerator using the ramped bunch train technique, we present here a redesigned experimental scheme for even higher enhancement of the efficiency of this accelerator. Design of a collinear wakefield device with a transformer ratio R2, is presented. Using a ramped bunch train (RBT) rather than a single drive bunch, the enhanced transformer ratio (ETR) technique is able to increase the transformer ratio R above the ordinary limit of 2. To match the wavelength of the fundamental mode of the wakefield with the bunch length (sigmaz=2 mm) of the new Argonne wakefield accelerator (AWA) drive gun (where the experiment will be performed), a 26.625 GHz dielectric based accelerating structure is required. This transformer ratio enhancement technique based on our dielectric-loaded waveguide design will result in a compact, high efficiency accelerating structures for future wakefield accelerators.

  16. Accelerators for critical experiments involving single-particle upset in solid-state microcircuits

    NASA Technical Reports Server (NTRS)

    Zoutendyk, J. A.

    1985-01-01

    Charged-particle interactions in microelectronic circuit chips (integrated circuits) present a particularly insidious problem for solid-state electronic systems due to the generation of soft errors or single-particle event upset (SEU) by either cosmic rays or other radiation sources. Particle accelerators are used to provide both light and heavy ions in order to assess the propensity of integrated circuit chips for SEU. Critical aspects of this assessment involve the ability to analytically model SEU for the prediction of error rates in known radiation environments. In order to accurately model SEU, the measurement and prediction of energy deposition in the form of an electron-hole plasma generated along an ion track is of paramount importance. This requires the use of accelerators which allow for ease in both energy control (change of energy) and change of ion species. This and other aspects of ion-beam control and diagnostics (e.g., uniformity and flux) are of critical concern for the experimental verification of theoretical SEU models.

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

    SciTech Connect

    Ni, P. A.; Alexander, N.; Barnard, J. J.; Lund, S. M.

    2014-05-15

    We present a summary of recent experiments on focusing of laser target-normal-sheath-accelerated (TNSA) proton beam with a stack of thin conducting foils. The experiments were performed using the Phelix laser (GSI-Darmstadt) and the Titan laser, Lawrence Livermore National Laboratory. The phenomena consistent with self-collimation (or weak self-focusing) of TNSA protons were experimentally observed for the first time at the Phelix laser user facility, in a specially engineered structure ('lens') consisting of a stack of 300 thin aluminum foils separated by 50 μm vacuum gaps. Follow up experiments using the Titan laser obtained results consistent with the collimation/focusing observed in the initial experiments using the Phelix. The Titan experiments employed improved, 25 μm- and 50 μm-gap targets and the new fine mesh diagnostic. All the experiments were carried out in a “passive environment,” i.e., no external fields were applied, and no neutralization plasma or injection of secondary charged particles was imposed. A plausible interpretation of the observed phenomena is that the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the conducting foils inhibits radial expansion of the beam.

  18. Predictive power of individual factors and clinical learning experience on academic success: findings from a longitudinal study.

    PubMed

    Dante, Angelo; Fabris, Stefano; Palese, Alvisa

    2015-01-01

    Academic failure is the inability of a nursing student to graduate or to complete the nursing degree on time. This longitudinal cohort study, involving 2 Italian universities, documents the effects of selected individual variables and the quality of the clinical learning experience as perceived by students on academic success. Factors related to the clinical learning experience were the quality of the supervisory relationship, pedagogical atmosphere, and commitment of the ward related to the level of personalized nursing care delivered and clarity of nursing documentation. PMID:25643319

  19. Development of an online nursing management course: successful experience between Brazil and Portugal.

    PubMed

    Tronchin, Daisy Maria Rizatto; Peres, Heloisa Helena Ciqueto; Lima, Antônio Fernandes Costa; Alavarce, Débora Cristina; Prata, Ana Paula; Santos, Margarida Reis; Aroldi, Juscilynne Barros da Costa

    2015-12-01

    Objective To describe the experience of planning and developing online refresher courses in nursing management for nurses in the contexts of Brazil and Portugal. Method The instructional design was based on meaningful learning theory, andragogy, and dialectical methodology, so it valued interaction between the actors, emphasizing the scenarios of practice and applying the concepts covered. The course structure is divided into nine theoretical units, four case studies, and an essay exam. Results The course was positively evaluated by the participants, who reported opportunities for acquisition of new knowledge, interaction and exchange of experiences, motivation to study the topics, and self-learning. Conclusion It is expected that description of this experience will stimulate proposals for new courses and programs in distance education modalities, improving the processes of teaching and learning so as to give support to future analyses of their impact on the development and enhancement of management skills in nursing. PMID:26959169

  20. Simultaneous modulated accelerated radiation therapy in the treatment of nasopharyngeal cancer: A local center's experience

    SciTech Connect

    Wu Shixiu . E-mail: wushixiu@medmail.com.cn; Xie Congying; Jin Xiance; Zhang Ping

    2006-11-15

    Purpose: To evaluate the feasibility, toxicity, and clinical efficacy of simultaneous modulated accelerated radiation therapy boost technique for nasopharyngeal carcinoma. Method and Materials: Seventy-five patients with nasopharyngeal carcinoma were treated with simultaneous modulated accelerated radiation therapy boost technique. Daily fraction of 2.5 Gy and 2.0 Gy were prescribed to the gross tumor volume (GTV) and clinical tumor volume (CTV) to a total dose of 70 Gy and 56 Gy, respectively, in 38 days. In 24 of these patients, GTV was boosted to 80 Gy. Quantitative {sup 99m}Tc-pertechnetate salivary scintigraphy was performed by assessing excretion uptake and excretion index of parotid glands. Results: In dosimetry, the mean doses delivered to the GTV, CTV1, and CTV2 were 68.1 Gy, 58.7 Gy, and 54.3 Gy, respectively. An average of 1% of the GTV and 3% of the CTV received less than 90% and 95% of the prescribed dose, respectively, whereas the mean doses delivered to the organ at risk were kept below tolerance limits. The mean doses to the ipsilateral and contralateral parotids were 31.1 Gy and 21.9 Gy, respectively. {sup 99m}Tc-pertechnetate salivary scintigraphy showed excretion index and uptake index decreased by 44.6% and 28.3%, respectively, in ipsilateral parotid (p < 0.05), whereas no significant decline in contralateral parotid was observed. Acute toxicities were well tolerated, except for the relatively high incidence of severe mucositis. No Grade 4 side effect occurred. With a median follow-up of 23.8 months (range, 10-39 months), the 2-year local progression-free, local-regional progression-free, and distant metastasis-free survival were 97.26%, 87.21%, and 82.03%, respectively. The 2-year overall survival was 86.81%. Conclusions: Simultaneous modulated accelerated radiation therapy yielded superior dose distribution over conventional radiotherapy in nasopharyngeal carcinoma and could be delivered with acceptable toxicity and risky organ sparing. Dose

  1. Enhancing Children's Success in Science Learning: An Experience of Science Teaching in Teacher Primary School Training

    ERIC Educational Resources Information Center

    Ferreira, Maria Eduarda; Porteiro, Ana Cláudia; Pitarma, Rui

    2015-01-01

    The Environmental Studies curricular area, taught at primary school level in Portugal, is a challenging context for curricular interdisciplinarity and the achievement of small-scale research and creative and innovative experiences, inside and outside the classroom. From that assumption, we present, under the master course of primary teacher…

  2. Career-Related Success-Learning Experiences of Academically Underachieving Urban Middle School Students

    ERIC Educational Resources Information Center

    Jackson, Margo A.; Perolini, Claudia M.; Fietzer, Alexander W.; Altschuler, Elizabeth; Woerner, Scott; Hashimoto, Naoko

    2011-01-01

    Evidence has supported the effectiveness of educational and psychosocial interventions that include strengths and promote the competence enhancement of schoolchildren. Nevertheless, students in low-income, culturally diverse urban schools who are academically underachieving may be the least likely but most in need to experience feedback about…

  3. Integrating IS Curriculum Knowledge through a Cluster-Computing Project--A Successful Experiment

    ERIC Educational Resources Information Center

    Kitchens, Fred L.; Sharma, Sushil K.; Harris, Thomas

    2004-01-01

    MIS curricula in business schools are challenged to provide MIS courses that give students a strong practical understanding of the basic technologies, while also providing enough hands-on experience to solve real life problems. As an experimental capstone MIS course, the authors developed a cluster-computing project to expose business students to…

  4. Success and Failure in Adult Education: The Immigrant Experience 1914-1924.

    ERIC Educational Resources Information Center

    Seller, Maxine S.

    The educational experience of adult immigrants to the United States between 1914-24 is discussed. Attempts of educators and Americanization agencies to reach adult immigrants are described and reasons for the failure of these attempts are given, including inadequate funding, narrowness in subject matter and methods, and insensitivity to ethnic…

  5. Returning from the Field: Did Recent, Relevant, and Successful Teaching Experience Make a Difference?

    ERIC Educational Resources Information Center

    Russell, Tom

    This paper is a personal interpretation of how two half-year daily teaching assignments in grade 12 physics influenced the career of a science teacher educator at Queen's University (Kingston, Ontario, Canada). The teacher educator felt that this experience helped him speak to his preservice teachers more realistically and convincingly about the…

  6. Success with ELLs: A Decade of ESOL Experience in about a Thousand Words

    ERIC Educational Resources Information Center

    Dailey, Alex

    2009-01-01

    In this article, the author shares her experience and the lessons learned in teaching English to Speakers of Other Languages (ESOL) for a decade. After thousands of lessons, uncountable revisions to those lessons, numerous hours of professional development, access to dozens of talented colleagues, and an abundance of thoughts and insights from…

  7. Getting My Feet Wet: A Student Educator's Perspective on a Successful Learning Experience. Perspectives.

    ERIC Educational Resources Information Center

    Gifford, Diane

    1997-01-01

    A graduate student in a nontraditional experiential program in environmental education at the Audubon Expedition Institute (Belfast, Maine) reflects on an experience in which she and her peers faced an ethical decision about whether to pay a fee to paper companies in order to hike in the North Woods. Describes the processes that allowed the group…

  8. Beyond Instructional Leadership: The Lived Experiences of Principals in Successful Urban Schools

    ERIC Educational Resources Information Center

    White-Smith, Kimberly A.

    2012-01-01

    Despite national statistics that suggest declining African American and Latino student achievement, few schools accept the challenge of educating the neediest students, and even fewer succeed. This phenomenological study examined the experiences of and strategies employed by three principals of urban schools that effectively educate traditionally…

  9. Surprise, Sensemaking, and Success in the First College Year: Black Undergraduate Men's Academic Adjustment Experiences

    ERIC Educational Resources Information Center

    Harper, Shaun R.; Newman, Christopher B.

    2016-01-01

    Background: Much has been written about Black undergraduate men's out-of-class engagement and social experiences, identity development, participation in intercollegiate athletics, and college enrollment and completion rates. Too little is known about their academic readiness and first-year college adjustment. Purpose: The purpose of this study was…

  10. A YOUNG SCIENTIST'S GUIDE TO GAINFUL EMPLOYMENT: RECENT GRADUATES' EXPERIENCES AND SUCCESSFUL STRATEGIES

    EPA Science Inventory

    Securing a job after completing a graduate degree is among a graduate student's most rewarding (and most stressful) experiences. The job hunting process, from submitting an application to signing a contract, varies greatly among individuals. It is difficult for any applicant to a...

  11. Successful Latina Scientists and Engineers: Their Lived Mentoring Experiences and Career Development

    ERIC Educational Resources Information Center

    San Miguel, Anitza M.; Kim, Mikyong Minsun

    2015-01-01

    Utilizing a phenomenological perspective and method, this study aimed to reveal the lived career mentoring experiences of Latinas in science and engineering and to understand how selected Latina scientists and engineers achieved high-level positions. Our in-depth interviews revealed that (a) it is important to have multiple mentors for Latinas'…

  12. Mobile Students' Appraisals of Keys to a Successful Stay Abroad Experience: Hints from the IEREST Project

    ERIC Educational Resources Information Center

    Van Maele, Jan; Vassilicos, Basil; Borghetti, Claudia

    2016-01-01

    In order to provide better support for students in higher education throughout a mobility experience, it is important to understand their point of view regarding stay abroad. This paper analyzes the responses of pre-departure, while-abroad, and upon-return students of different academic backgrounds (N = 990) to an open question that asked them to…

  13. Stories of Success: Experiences of American Indian Students in a Peer-Mentoring Retention Program

    ERIC Educational Resources Information Center

    Shotton, Heather J.; Oosahwe, E. Star L.; Cintron, Rosa

    2007-01-01

    The postsecondary attrition rate for American Indian students is higher than of any other racial or ethnic group. It is therefore imperative to identify factors that encourage their persistence in higher education. Employing a phenomenological approach, this study explored the experiences of American Indian college students in a peer-mentoring…

  14. Successful Isothermal Dendritic Growth Experiment (IDGE) Proves Current Theories of Dendritic Solidification are Flawed

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The scientific objective of the Isothermal Dendritic Growth Experiment (IDGE) is to test fundamental assumptions about dendritic solidification of molten materials. "Dendrites"-- from the ancient Greek word for tree--are tiny branching structures that form inside molten metal alloys when they solidify during manufacturing. The size, shape, and orientation of the dendrites have a major effect on the strength, ductility (ability to be molded or shaped), and usefulness of an alloy. Nearly all of the cast metal alloys used in everyday products (such as automobiles and airplanes) are composed of thousands to millions of tiny dendrites. Gravity, present on Earth, causes convection currents in molten alloys that disturb dendritic solidification and make its precise study impossible. In space, gravity is negated by the orbiting of the space shuttle. Consequently, IDGE (which was conducted on the space shuttle) gathered the first precise data regarding undisturbed dendritic solidification. IDGE is a microgravity materials science experiment that uses an apparatus which was designed, built, tested, and operated by people from the NASA Lewis Research Center. This experiment was conceived by the principal investigator, Professor Martin E. Glicksman, from Rensselaer Polytechnic Institute in Troy, New York. The experiment was a team effort of Lewis civil servants, contractors from Aerospace Design & Fabrication Inc. (ADF), and personnel at Rensselaer.

  15. Silkworms, Schedules, and Mummy Spices: Experiences That Are a Success with Student Teachers.

    ERIC Educational Resources Information Center

    Montgomery, Jill

    1994-01-01

    Contends that the student teaching assignment can be viewed either as the single most important event in teaching or a six-month long nightmare. Discusses the student teaching experience and provides advice on interaction with the supervising teacher, relationships with students, and instructional methods. (CFR)

  16. Underserved, Underrepresented, Unprepared: Experiences of African American Females in Community College with Barriers to Academic Success

    ERIC Educational Resources Information Center

    Jobe, LaWanda D.

    2013-01-01

    African American women are enrolling and returning to college in large numbers across many community college campuses, especially those women who would be characterized as nontraditional students. This qualitative study examined and analyzed the experiences, stresses, and coping mechanisms of first generation, nontraditional, single parent,…

  17. Research experience in Maine leads to teacher and student success in Texas

    NASA Astrophysics Data System (ADS)

    Slade-Redden, D.; Incze, L.; Census Of Marine Life-Maine

    2010-12-01

    As a High School science teacher it is my responsibility to present curriculum, to create enthusiasm for science, and to instill a passion and love for science in my students. Through a research experience as an ARMADA master teacher my passion and enthusiasm for the ocean was rekindled in the Gulf of Maine. Topics I had taught for years came alive in front of my eyes, and I was able to experience science to its fullest. I brought home many photographs, valuable information, and new enthusiasm to my students. I began a program called S.A.N.D. (Students As Nature Directors). In this program my students teach 3rd graders about the oceans and its many wonders. Also, I have incorporated hands-on research based projects. The research experience has enabled my students to become more scientifically literate and capable of sharing scientific knowledge with others. This presentation will show how research/teacher partnerships benefit students as well as teachers and how my students and district have benefited from my experience as an ARMADA master teacher. Author: Debra Slade-Redden Author #2: Lew Incze

  18. A Successful Experiment in Collaboration: U.S. Science Agencies Forge Major Joint IPY Outreach Efforts

    NASA Astrophysics Data System (ADS)

    Cole, S.; Goldman, J.; West, P.

    2008-12-01

    The International Polar Year (IPY) provided U.S. agencies involved in polar research with a major outreach challenge: how to portray a unified view of the wealth of federal activity through a communications network dominated by agency-focused channels. To meet this challenge, 16 federal agencies joined together in an ongoing interagency working group, lead by the National Science Foundation's Office of Polar Programs, resulting in a series of successful media and public outreach endeavors. These included a unique interagency U.S. IPY web site (www.ipy.gov) that allowed participating agencies to independently upload relevant information every day; a major IPY kickoff event at the National Academies of Science; and a joint NASA/NSF/USGS televised press conference unveiling a new satellite map of Antarctica. Key to these successes was the interagency working group, which facilitated in-depth and sustained interaction between the agencies in coordinating development of outreach strategies both at the agency and federal level.

  19. Factors affecting student success in a first-year mathematics course: a South African experience

    NASA Astrophysics Data System (ADS)

    Kizito, Rita; Munyakazi, Justin; Basuayi, Clement

    2016-01-01

    In spite of sustained efforts tertiary institutions implement to try and improve student academic performance, the number of students succeeding in first-year mathematics courses remains disturbingly low. For most students, the gap between their mathematical capability and the competencies they are expected and need to develop to function effectively in these courses persists even after course instruction. In this study, an instrument for identifying and examining factors affecting student performance and success in a first-year Mathematics university course was developed and administered to 86 students. The overall Cronbach's Alpha coefficient for the questionnaire was found to be 0.916. Having identified variables from prior research known to affect student performance, factor analysis was used to identify variables exhibiting the greatest impact on student performance. The variables included prior academic knowledge, workload, student approaches to learning, assessment, student support teaching quality, methods and resources. From the analysis, students' perceptions of their workload emerged as the factor having the greatest impact on student's performance, followed by the matriculation examination score. The findings are discussed and strategies that can be used to improve teaching and contribute to student success in a first-year mathematics course in a South African context are presented.

  20. Partnered Research Experiences for Junior Faculty at Minority-Serving Institutions Enhance Professional Success

    PubMed Central

    Campbell, Andrew G.; Leibowitz, Michael J.; Murray, Sandra A.; Burgess, David; Denetclaw, Wilfred F.; Carrero-Martinez, Franklin A.; Asai, David J.

    2013-01-01

    Scientific workforce diversity is critical to ensuring the realization of our national research goals and minority-serving institutions play a vital role in preparing undergraduate students for science careers. This paper summarizes the outcomes of supporting career training and research practices by faculty from teaching-intensive, minority-serving institutions. Support of these faculty members is predicted to lead to: 1) increases in the numbers of refereed publications, 2) increases in federal grant funding, and 3) a positive impact on professional activities and curricular practices at their home institutions that support student training. The results presented show increased productivity is evident as early as 1 yr following completion of the program, with participants being more independently productive than their matched peers in key areas that serve as measures of academic success. These outcomes are consistent with the goals of the Visiting Professorship Program to enhance scientific practices impacting undergraduate student training. Furthermore, the outcomes demonstrate the benefits of training support for research activities at minority-serving institutions that can lead to increased engagement of students from diverse backgrounds. The practices and results presented demonstrate a successful generalizable approach for stimulating junior faculty development and can serve as a basis for long-term faculty career development strategies that support scientific workforce diversity. PMID:24006388

  1. E-referral Solutions: Successful Experiences, Key Features and Challenges- a Systematic Review

    PubMed Central

    Naseriasl, Mansour; Adham, Davoud; Janati, Ali

    2015-01-01

    Background: around the world health systems constantly face increasing pressures which arise from many factors, such as an ageing population, patients and providers demands for equipment’s and services. In order to respond these challenges and reduction of health system’s transactional costs, referral solutions are considered as a key factor. This study was carried out to identify referral solutions that have had successes. Methods: relevant studies identified using keywords of referrals, consultation, referral system, referral model, referral project, electronic referral, electronic booking, health system, healthcare, health service and medical care. These searches were conducted using PubMed, ProQuest, Google Scholar, Scopus, Emerald, Web of Knowledge, Springer, Science direct, Mosby’s index, SID, Medlib and Iran Doc data bases. 4306 initial articles were obtained and refined step by step. Finally, 27 articles met the inclusion criteria. Results: we identified seventeen e-referral systems developed in UK, Norway, Finland, Netherlands, Denmark, Scotland, New Zealand, Canada, Australia, and U.S. Implemented solutions had variant degrees of successes such as improved access to specialist care, reduced wait times, timeliness and quality of referral communication, accurate health information transfer and integration of health centers and services. Conclusion: each one of referral solutions has both positive and changeable aspects that should be addressed according to sociotechnical conditions. These solutions are mainly formed in a small and localized manner. PMID:26236167

  2. Successful living donor intestinal transplantation in cross-match positive recipients: Initial experience

    PubMed Central

    Garcia-Roca, Raquel; Tzvetanov, Ivo G; Jeon, Hoonbae; Hetterman, Elisabeth; Oberholzer, Jose; Benedetti, Enrico

    2016-01-01

    Sensitized patients tend to have longer waiting times on the deceased donor list and are at increased risk of graft loss from acute or chronic rejection compared to non-sensitized candidates. Desensitization protocols are utilized to decrease the levels of alloantibodies and to convert an initial positive cross-match to prospective donors into a negative crossmatch. These procedures are mostly available in the setting of living donation. Due to the elective nature of the procedure, desensitization protocols can be extended until the desire result is obtained prior to transplantation. We present two cases of successful desensitization protocol applied to living donor intestinal transplant candidates that converted to negative cross-match to their donors. We present two cases of intestinal transplant candidates with a potential living donor to whom they are sensitized. Both cases underwent successful transplantation after desensitization protocol. No evidence of humoral rejection has occurred in either recipient. Living donor intestinal transplantation in sensitized recipients against the prospective donors provides the ability to implement a desensitization protocol to convert to negative cross-match. PMID:26843919

  3. Connections in the Field and Beyond: A Case Study of Successful Teacher Research Experiences at the Poles

    NASA Astrophysics Data System (ADS)

    Rosenberger, D.

    2007-12-01

    Successful and lasting partnerships between scientists and teachers can be established through Teacher Research Experiences (TRE). The documented benefits of the TRE include increased teacher retention in addition to renewed instructional practices in veteran teachers. The reality and excitement of field science is very difficult to convey to students if the teacher has never personally experienced it, and a TRE can transfer this interest into the classroom. With the field research experience as the centerpiece of the TRE relationship, much should be done before, during, and after the TRE to ensure a positive and lasting connection that meets the needs of both the teacher and researcher. This presentation focuses, from a teacher's first-hand perspective, on the critical issues that scientists must consider to ensure successful collaborations with teachers in the field. I have participated in two TRE's and have learned a great deal from both. In 2001, through the National Science Foundation sponsored program Teachers Experiencing Antarctica and the Arctic (TEA) I was able to participate in biochemical oceanographic science on-board the Icebreaker Oden in the Arctic Ocean. In 2005, I did biogeochemical research at Pony Lake/McMurdo Station in Antarctica as a participant in Teachers and Researchers Exploring and Collaborating (TREC), a program of the Arctic Research Consortium of the United States (ARCUS). On both research experiences, I was a working member of the science team. I was responsible for numerous teaching and outreach activities including: uploading daily journals and photos to a website, answering email from students and the public, and managing live communications with schools. Both research experiences were very successful and have resulted in lasting relationships with scientists and other teachers interested in polar science. My participation in these experiences also influenced my teaching by increasing student enthusiasm in the classroom and

  4. High brightness cathode experiments on the experimental test accelerator (ETA). Final report

    SciTech Connect

    Schlitt, L.; Proulx, G.

    1984-01-01

    The experiments performed on the ETA during the months of September through October of 1984 were intended to accomplish two objectives; to discover or develop a source capable of producing an electron beam whose brightness is substantially higher than that of previous sources, and to determine, if possible, the mechanisms which limit the source brightness so that further enhancements might be obtained. The results of the experiments met these objectives to a limited degree. A cathode material (velvet) and a diode geometry were identified which resulted in more than a factor of two improvements in brightness over that obtained with previous flashboard cathodes. Experiments were performed which have yielded information about mechanisms which may limit beam brightness, and have suggested approaches for further work to improve brightness. However, the desired brightness of 10/sup 5/ A/(cm/sup 2/-rad/sup 2/) was not achieved in these experiments. This report contains a discussion of the cathodes used, the diode geometries employed, the diagnostics, the typical characteristics of a single beam experiment, and the characteristics of the collimator used to measure the brightness. The entire ensemble of brightness data is presented and broken down into classes of experiments. In addition, the results of an EBQ calculation of one diode geometry are discussed, and differences between the results of similar experiments on ETA and ATA are noted. Finally, conclusions and recommendations are presented.

  5. Experience-based Learning in Acadia National Park: a Successful, Long-running, Model Field Course

    NASA Astrophysics Data System (ADS)

    Connaughton, M.

    2015-12-01

    This two-week field course has been offered alternate summers since 2000 in Acadia National Park on Mount Desert Island, Maine and addresses the geological history, physical and biological oceanography and principles of community ecology applicable to terrestrial and/or marine communities of coastal Maine. The course is often transformative and deeply meaningful to the students, many of whom have limited travel experience. The essential components of experience-based learning are well represented in this class with multiple opportunities for abstract conceptualization, active experimentation, concrete hands-on experiences and reflective observation built into the course. Each day begins with a lecture introducing concepts, which are then made concrete though daily field trips (4-8 hours in duration) into the park that include rigorous hiking, some kayaking and one commercial nature cruise. Field trips include hands-on experience with lecture concepts, on-site lessons in field methods, and data collection for independent projects. Each field trip is tied to a specific independent project, which are generated by the instructor, but self-selected by the students. Every student is actively involved in data collection during each field trip, with one student in charge of the collection each day. Daily guided journaling in three parts (scientific, personal and creative) and evening discussions provide ample opportunity for the student to reflect on the scientific content of the course, examine their personal reactions to what they have experienced and to be creative, sharing prior experiences, prior learning and their personalities. The course includes two exams, each following a week of lecture and field experiences. Independent research projects include the production of a manuscript-formatted report complete with statistical analysis of the data and a literature-based discussion of the conclusions. The combination of experiential reinforcement of concepts, abundant

  6. Experience in using workstations as hosts in an accelerator control environment

    SciTech Connect

    Abola, A.; Casella, R.; Clifford, T.; Hoff, L.; Katz, R.; Kennell, S.; Mandell, S.; McBreen, E.; Weygand, D.P.

    1987-03-01

    A new control system has been used for light ion acceleration at the Alternating Gradient Synchrotron (AGS). The control system uses Apollo workstations in the dual role of console hardware computer and controls system host. It has been found that having a powerful dedicated CPU with a demand paging virtual memory OS featuring strong interprocess communication, mapped memory shared files, shared code, and multi-window capabilities, allows us to provide an efficient operation environment in which users may view and manage several control processes simultaneously. The same features which make workstations good console computers also provide an outstanding platform for code development. The software for the system, consisting of about 30K lines of ''C'' code, was developed on schedule, ready for light ion commissioning. System development is continuing with work being done on applications programs.

  7. Physico-Mechanical Characteristics of Freeze-Thaw Weathered Gneiss based on Accelerated Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Um, J. G.

    2014-12-01

    An experimental study of physical weathering was performed on fresh and slightly weathered gneiss samples from the Wonju area of South Korea. The study investigated changes in the physico-mechanical properties of these samples during accelerated laboratory-based weathering, including analyses of microfracture formation. The deteriorated samples used in the study were subjected to 100-150 freeze-thaw cycles, with index properties and microfracture geometries measured between each cycle. Each complete freeze-thaw cycle lasted 24 hours, and consisted of 2 hours of saturation in a vacuum chamber, 8 hours of freezing at -21°C ±1°C, and 14 hours of thawing at room temperature. Specific gravity and seismic velocity values were negatively correlated with the number of freeze-thaw cycles, whereas absorption values tended to increase. The amount of deterioration of the rock samples was dependent on the degree of weathering of the rock prior to the start of the analysis. Absorption, specific gravity, and seismic velocity values can be used to infer the amount of physical weathering experienced by a gneiss in the study area. The sizes and density of microfracture in the rock specimens varied with the number of freeze-thaw cycles. It was found that box fractal dimensions can be used to quantify the formation and propagation of microfracture in the samples. In addition, these box fractal dimensions can be used as a weathering index for the mid- and long-term prediction of rock weathering. The present results indicate that accelerated-weathering analysis can provide a detailed overview of the weathering characteristics of deteriorated rocks.

  8. Operational experience for coupled operation of the Holifield tandem electrostatic accelerator and isochronous cyclotron

    SciTech Connect

    Martin, J.A.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Jones, C.M.; Juras, R.C.; Lane, S.S.; Ludemann, C.A.; Meigs, M.J.; Milner, W.T.

    1986-10-01

    Coupled operation of the 25 MV tandem accelerator and the Oak Ridge Isochronous Cyclotron of the Holifield Heavy Ion Research Facility began in January 1981. Since that time the use of the cyclotron in this mode has become routine. Thirty-six different ion species in the range from /sup 9/Be to /sup 150/Nd have been accelerated; 106 separate beam setups have been provided. Since the beginning of coupled operation, significant improvement of cyclotron systems, and setup and operating techniques, have been made. The graphite electrostatic deflector septum formerly used for high-current light ion beams has been replaced by a thin molybdenum septum. Extraction system positioning mechanisms have been refined and recalibrated and more precise and reliable position readouts have been provided. The computer-based control system has been improved. The frequency range of the rf system has been increased to eliminate an energy dead-band. Cyclotron setup calculations have been improved and standardized methods have been developed to consistently achieve well-centered orbits, correct beam extraction system positions, and electrostatic and magnetic strengths. A totally new beam bunching system has been installed. The improvements in the phase-lock system of the beam buncher have been especially effective. A large number of obsolete and unreliable power supplies have been replaced. Beam extraction efficiency has been increased from approx.50% to approx.70%. Accuracy of obtaining the desired energy without fine tuning is now approx.1% compared to 2 to 3% in early coupled operation. Beam setup time (tuning) has been reduced by approx.20%. Unscheduled maintenance has been reduced by a factor of two.

  9. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    SciTech Connect

    G. Youinou; M. Salvatores; M. Paul; R. Pardo; G. Palmiotti; F. Kondev; G. Imel

    2010-04-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  10. Design and characterization of the DC acceleration and transport system required for the IMW Free Electron Master experiment

    SciTech Connect

    Caplan, M.; Van Der Geer, C.; Valentini, M.; Urbanus, W.

    1995-08-01

    A Free Electron Maser (FEM) has been constructed and is soon to be tested at the FOM Institute (Rijnhuizen) Netherlands with the ultimate goal of producing 1 MW long pulse to CW microwave output in the range 130 GHz to 250 GHz. The DC acceleration and beam transport systems is eventually to be used in a depressed collector configuration requiring 99.8% beam transmission in order that the High Voltage 2MV supply be required only to supply 20 milliamps of body current. A relativistic version of the Herrmann optical theory originally developed for microwave tube beams is used to take in account thermal electrons far out on the gaussian distribution tail which can translate into beam current well outside the ideal beam edge. This theory is applied to the FOM beamline design and predicts that the beam envelope containing 99.8% of the current can be successfully transported to the undulator for a wide range of assume d emittance values.

  11. Isentropic Compression Experiments Performed By LLNL On Energetic Material Samples Using The Z Accelerator

    SciTech Connect

    Vandersall, K S; Reisman, D B; Forbes, J W; Hare, D E; Garcia, F; Uphaus, T M; Elsholz, A J; Tarver, C M; Eggert, J H

    2007-10-25

    Several experiments have been conducted by LLNL researchers using isentropic compression experiments (ICE) on energetic materials as samples from Fiscal Year 2001 (FY01) to Fiscal Year 2005 (FY05). Over this span of time, advancements of the experimental techniques and modeling of the results have evolved to produce improved results. This report documents the experiments that have been performed, provides details of the results generated, and modeling and analysis advances to fully understand the results. Publications on the topics by the various principal investigators (PI's) are detailed in the Appendices for quick reference for the work as it progressed.

  12. Blunt cardiac rupture with prehospital pulseless electrical activity: a rare successful experience.

    PubMed

    Lu, Li-Hua; Choi, Wai-Mau; Wu, Hsueh-Ru; Liu, Hung-Chang; Chiu, Wen-Ta; Tsai, Shin-Han

    2005-12-01

    Blunt cardiac rupture is highly associated with mortality. In the recent literature, the reported mortality rates of cardiac rupture ranged from 59.7% to 100%. The probability of survival for those with prehospital pulseless electrical activity was extremely low. This case report describes a rare example of survival of a female patient with life-threatening cardiac rupture and cardiac tamponade after a major car accident. The victim developed pulseless electrical activity at admission. She recovered from the accident, however, without developing any signs of neurologic deficits. This case study emphasizes the value of the primary survey of patients and prompt and accurate interventions, including focused abdominal sonography for trauma, pericardiocentesis, and an urgent thoracotomy in the operating room for primary repair of cardiac rupture without applying a cardiopulmonary bypass system. The study showed that early diagnosis and aggressive interventions are crucial factors to the successful outcome of patient's survival. PMID:16394928

  13. Metrics for the effectiveness and success of an Education and Public Outreach Program; the HST experience

    NASA Astrophysics Data System (ADS)

    Griffin, I. P.; Eisenhammer, B.; Kakadelis, S.; Stanley, M.; Stoke, J.; Teays, T.; Villard, R.; Voit, G. M.

    2002-05-01

    The Office of Public Outreach (OPO) at the STScI was created to share the amazing discoveries of the Hubble Space Telescope with the American public. During the last five years we have developed a multitude of products and programs that have capitalized on the intense interest in Hubble to inform and inspire millions of Americans and many others around the globe. Our Education and Public outreach program has five complementary strands that broadly define the communities we serve. These are News, Formal Education, Informal Science Education, Online Outreach, Origins Forum In this paper we present and discuss some of the metrics for effectiveness and success that we have developed and use in each area of our outreach program.

  14. Widening Paths to Success, Improving the Environment, and Moving Toward Lessons Learned from the Experiences of Powre and Cbl Awardees

    NASA Astrophysics Data System (ADS)

    Rosser, Sue V.; Daniels, Jane Z.

    To better understand the barriers and discouragements encountered by female faculty members in science and engineering, this article compares the experience of National Science Foundation - funded Professional Opportunities for Women in Research and Education (POWRE) awardees and Clare Boothe Luce (CBL) Professorship recipients. Because most POWRE awardees work at research institutions, and many CBL professors teach at small liberal arts colleges, this study helps in understanding the experiences of female faculty members across a broad spectrum of academic settings. Their experiences suggest positive changes in institutional policies or practices to increase the satisfaction, retention, and success of female faculty members infields in which they are the least well represented. The retention of female faculty members becomes critical for attracting undergraduate students as they consider the wisdom of choosing careers in academia.

  15. Investigating young people's experiences of successful or helpful psychological interventions for tic disorders: An Interpretative Phenomenological Analysis study.

    PubMed

    Smith, Heather; Fox, John Re; Hedderly, Tammy; Murphy, Tara; Trayner, Penny

    2016-08-01

    There is emerging evidence for talking therapies in the treatment of tic disorders. This study explored experiences of young people who self-identified as having had a successful or helpful talking therapy, in order to understand the phenomenology, value and meaning of outcomes. The experiences of seven participants aged 10-17 years were described in semi-structured interviews and analysed using Interpretative Phenomenological Analysis. Themes included the challenging battle with tics and process of re-defining self-identity, making sense of and managing experiences, the value of control, and spectrum of positive change. The results highlighted valued outcomes that could be incorporated into clinical practice and future evaluation. PMID:25649427

  16. Succession change of microorganisms on plant waste decomposition in simulation modelling field experiment

    NASA Astrophysics Data System (ADS)

    Vinogradova, Julia; Perminova, Evgenia; Khabibullina, Fluza; Kovaleva, Vera; Lapteva, Elena

    2016-04-01

    Plant waste decomposition processes are closely associated with living activity of soil microbiota in aboveground ecosystems. Functional activity of microorganisms and soil invertebrates determines plant material transformation rate whereby changes in plant material chemical composition during destruction - succession change of soil biota. The purpose of the work was revealing the mechanism of microorganisms succession change during plant waste decomposition in middle-taiga green-moss spruce forests and coniferous-deciduous secondary stands formed after earlier cut bilberry spruce forests. The study materials were undisturbed bilberry spruce forest (Sample Plot 1 - SP1) and coniferous-deciduous secondary stands which were formed after tree cutting activities of 2001-2002 (SP2) and 1969 and 1970 (SP3). Plant material decomposition intensity was determined in microcosms isolated into kapron bags with cell size of 1 mm. At SP1 and SP2, test material was living mosses and at SP3 - fallen birch and aspen leaves. Every test material was exposed for 2 years. Destruction rate was calculated as a weight loss for a particular time period. Composition of micromycetes which participated in plant material decomposition was assessed by the method of inoculation of soil extract to Getchinson's medium and acidified Czapek's medium (pH=4.5). Microbe number and biomass was analyzed by the method of luminescent microscopy. Chemical analysis of plant material was done in the certified Ecoanalytical Laboratory of the Institute of Biology Komi SC UrD RAS. Finally, plant material destruction intensity was similar for study plots and comprised 40-44 % weight loss for 2 years. The strongest differences in plant material decomposition rate between undisturbed spruce forests and secondary after-cut stands were observed at first stages of destruction process. In the first exposition year, mineralizing processes were most active in undisturbed spruce forest. Decomposition rate in cuts at that

  17. Coastal Downscaling Experiments: Can CESM Fields Successfully Force Regional Coastal Ocean Simulations with Strong Freshwater Forcing?

    NASA Astrophysics Data System (ADS)

    MacCready, P.; Bryan, F.; Tseng, Y. H.; Whitney, M. M.

    2014-12-01

    The coastal ocean accounts for about half of the global fish harvest, but is poorly resolved in global climate models (a one-degree grid barely sees the continental shelf). Moreover, coastal ocean circulation is strongly modified by river freshwater sources, often coming from estuarine systems that are completely unresolved in the coarse grid. River freshwater input in CESM is added in a practical but ad hoc way, by imposing a surface salinity sink over a region of the ocean approximating the plume area of a given river. Here we present results from a series of model experiments using a high-resolution (1.5 km) ROMS model of the NE Pacific, including the Columbia River and the inland waters of Puget Sound. The base model does multi-year hindcasts using the best available sources of atmospheric (MM5/WRF), ocean (NCOM), river (USGS), and tidal forcing. It has been heavily validated against observations of all sorts, and performs well, so it is an ideal test bed for downscaling experiments. The model framework also does biogeochemistry, including oxygen, and carbon chemistry is being added to make forecasts of Ocean Acidification.This high-resolution ROMS model is systematically run in downscaling experiments for the year 2005 with combinations of CESM forcing (CAM, POP, and rivers) swapped in. Skill is calculated using observations. It is found that the runs with CESM forcing generally retain much of the skill of the base model. A compact metric of response to freshwater forcing is used, which is the mechanical energy required to destratify a shallow coastal volume. This, along with the average temperature and salinity of the volume, are used to characterize and compare runs, including the original CESM-POP fields. Finally the model is run with projected CESM simulation forcing at the end of 21st century based on a set of RCP scenarios, and the compact metrics are used to quantify differences from 2005.

  18. Early Regulatory Engagement for Successful Site Remediation: the UK Experience - 13173

    SciTech Connect

    Maitland, R.P.; Senior, D.

    2013-07-01

    The Office for Nuclear Regulation (ONR) is an independent safety, security and transport regulator of the UK nuclear industry. ONR regulates all civil nuclear reactor power stations, fuel manufacture, enrichment, spent fuel reprocessing, most defence sites and installations that store and process legacy spent fuel and radioactive waste. The responsibility for funding and strategic direction of decommissioning and radioactive waste management of state owned legacy sites has rested solely with the Nuclear Decommissioning Authority (NDA) since 2005. A key component of NDA's mandate was to encourage new strategic approaches and innovation to dealing with the UK's waste legacy and which deliver value-for-money to the UK taxpayer. ONR, as an agency of the Health and Safety Executive, is entirely independent of NDA and regulates all prescribed activities on NDA's sites. NDA's competition of site management and closure contracts has attracted significant international interest and the formation of consortia comprised of major British, US, French and Swedish organizations bidding for those contracts. The prominence of US organizations in each of those consortia reflects the scale and breadth of existing waste management and D and D projects in the US. This paper will articulate, in broad terms, the challenges faced by international organizations seeking to employ 'off-the-shelf' technology and D and D techniques, successfully employed elsewhere, into the UK regulatory context. The predominantly 'goal-setting' regulatory framework in the UK does not generally prescribe a minimum standard to which a licensee must adhere. The legal onus on licensees in the UK is to demonstrate, whatever technology is selected, that in its applications, risks are reduced 'So Far As Is Reasonably Practicable' or 'SFAIRP'. By the nature of its role, ONR adopts a conservative approach to regulation; however ONR also recognises that in the decommissioning (and ultimately the site closure) domain

  19. Novel pulsed particle accelerator for energy dependent positron re-emission experiments.

    PubMed

    Grill, Niklas; Piochacz, Christian; Zimnik, Samantha; Hugenschmidt, Christoph

    2016-05-01

    We report on a novel device for particle acceleration based on elevation of the potential energy of beam pulses. This so-called energy elevator is particularly beneficial if both the particle source and the sample have to be near ground potential due to experimental constraints. We applied this new technique to enable depth dependent measurements of re-emitted positrons using the surface spectrometer at the NEPOMUC positron beam facility. First, a two-stage bunching system is used to generate positron pulses with a repetition rate of 5 MHz and a duration of 1.663(5) ns before their energy is raised to several keV. The whole system was shown to work with an exceptional efficiency of 88%. We demonstrated the usability of our setup by investigating the positron re-emission spectra of Ni and Pd as function of positron implantation energy. For Ni the positron work function could be determined to be ΦNi (+)=-1.4(2)eV. In addition, as predicted by theory, our experimental findings imply a positive positron work function for Pd. PMID:27250411

  20. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    SciTech Connect

    Stygar, W. A.; Awe, T. J.; Bennett, N L; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; Genoni, T. C.; Gomez, M. R.; Greiser, G. W.; Gruner, F. R.; Herrmann, M. C.; Hutsel, B. T.; Jennings, C. A.; Jobe, D. O.; Jones, B. M.; Jones, M. C.; Jones, P. A.; Knapp, P. F.; Lash, J. S.; LeChien, K. R.; Leckbee, J. J.; Leeper, R. J.; Lewis, S. A.; Long, F. W.; Lucero, D. J.; Madrid, E. A.; Martin, M. R.; Matzen, M. K.; Mazarakis, M. G.; McBride, R. D.; McKee, G. R.; Miller, C. L.; Moore, J. K.; Mostrom, C. B.; Mulville, T. D.; Peterson, K. J.; Porter, J. L.; Reisman, D. B.; Rochau, G. A.; Rochau, G. E.; Rose, D. V.; Savage, M. E.; Sceiford, M. E.; Schmit, P. F.; Schneider, R. F.; Schwarz, J.; Sefkow, A. B.; Sinars, D. B.; Slutz, S. A.; Spielman, R. B.; Stoltzfus, B. S.; Thoma, C.; Vesey, R. A.; Wakeland, P. E.; Welch, D. R.; Wisher, M. L.; Woodworth, J. R.; Bailey, J. E.; Rovang, D. C.

    2015-11-30

    ) simulations suggest Z 300 will deliver 4.3 MJ to the liner, and achieve a yield on the order of 18 MJ. Z 800 is 52 m in diameter and stores 130 MJ. This accelerator generates 890 TW at the output of its LTD system, and delivers 65 MA in 113 ns to a MagLIF target. The peak electrical power at the MagLIF liner is 2500 TW. The principal goal of Z 800 is to achieve high-yield thermonuclear fusion; i.e., a yield that exceeds the energy initially stored by the accelerator’s capacitors. 2D MHD simulations suggest Z 800 will deliver 8.0 MJ to the liner, and achieve a yield on the order of 440 MJ. Z 300 and Z 800, or variations of these accelerators, will allow the international high-energy-density-physics community to conduct advanced inertial-confinement-fusion, radiation-physics, material-physics, and laboratory-astrophysics experiments over heretofore-inaccessible parameter regimes.

  1. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    DOE PAGESBeta

    Stygar, W. A.; Awe, T. J.; Bennett, N L; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; et al

    2015-11-30

    ) simulations suggest Z 300 will deliver 4.3 MJ to the liner, and achieve a yield on the order of 18 MJ. Z 800 is 52 m in diameter and stores 130 MJ. This accelerator generates 890 TW at the output of its LTD system, and delivers 65 MA in 113 ns to a MagLIF target. The peak electrical power at the MagLIF liner is 2500 TW. The principal goal of Z 800 is to achieve high-yield thermonuclear fusion; i.e., a yield that exceeds the energy initially stored by the accelerator’s capacitors. 2D MHD simulations suggest Z 800 will deliver 8.0 MJ to the liner, and achieve a yield on the order of 440 MJ. Z 300 and Z 800, or variations of these accelerators, will allow the international high-energy-density-physics community to conduct advanced inertial-confinement-fusion, radiation-physics, material-physics, and laboratory-astrophysics experiments over heretofore-inaccessible parameter regimes.« less

  2. The Energetic Particles Acceleration, Composition, and Transport (EPACT) experiment on the ISTP/wind spacecraft

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Von Rosenvinge, T. T.; Ramaty, R.; Mason, G. M.; Hamilton, D. C.; Forman, M. A.; Webber, W. R.

    1990-01-01

    The EPACT experiment will measure abundances, spectra, and angular distributions of particles from 20 keV/amu to 500 MeV/amu. At high energies, isotopes will be resolved up through Z = 26, at intermediate energies elements with Z between 1 and 82 will be observed, and at low energies element abundances above Z = 2 will be resolved for the first time.

  3. The Energetic Particles Acceleration, Composition, and Transport (EPACT) experiment on the ISTP/wind spacecraft

    NASA Astrophysics Data System (ADS)

    Reames, D. V.; von Rosenvinge, T. T.; Ramaty, R.; Mason, G. M.; Hamilton, D. C.; Forman, M. A.; Webber, W. R.

    1990-03-01

    The EPACT experiment will measure abundances, spectra, and angular distributions of particles from 20 keV/amu to 500 MeV/amu. At high energies, isotopes will be resolved up through Z = 26, at intermediate energies elements with Z between 1 and 82 will be observed, and at low energies element abundances above Z = 2 will be resolved for the first time.

  4. Successful partnerships with third sector organisations to enhance the healthcare student experience: a partnership evaluation.

    PubMed

    Bell, Katie; Tanner, Judith; Rutty, Jane; Astley-Pepper, Maxine; Hall, Richard

    2015-03-01

    There is limited research surrounding academic partnerships and more research is needed to educate universities, and the private, public and third sectors about the benefits and limitations of such partnerships. The aim of this study was to outline the unique partnership between Macmillan Cancer Support and De Montfort University and to evaluate the progress of this partnership. A qualitative approach was employed which involved interviews with nine members of the partnership's steering group. Interviews were transcribed and analysed using thematic analysis. The results showed that a partnership between a university and a third sector charity can have mutual benefits for all those involved, particularly for students and those affected by cancer. Furthermore, the module to develop volunteering among families affected cancer, created through this partnership is now being considered by other universities as a way of providing holistic and non-traditional lecture based learning experiences. Recommendations are made for future partnerships between third sector charities and universities. PMID:25575475

  5. Coralline algae disease reduces survival and settlement success of coral planulae in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Quéré, Gaëlle; Nugues, Maggy M.

    2015-09-01

    Disease outbreaks have been involved in the deterioration of coral reefs worldwide and have been particularly striking among crustose coralline algae (CCA). Although CCA represent important cues for coral settlement, the impact of CCA diseases on the survival and settlement of coral planulae is unknown. Exposing coral larvae to healthy, diseased, and recently dead crusts from three important CCA species, we show a negative effect of disease in the inductive CCA species Hydrolithon boergesenii on larval survivorship of Orbicella faveolata and settlement of O. faveolata and Diploria labyrinthiformis on the CCA surface. No effect was found with the less inductive CCA species Neogoniolithon mamillare and Paragoniolithon accretum. Additionally, a majority of planulae that settled on top of diseased H. boergesenii crusts were on healthy rather than diseased/dying tissue. Our experiments suggest that CCA diseases have the potential to reduce the survivorship and settlement of coral planulae on coral reefs.

  6. Seismic velocities within the sedimentary succession of the Canada Basin and southern Alpha-Mendeleev Ridge, Arctic Ocean: evidence for accelerated porosity reduction?

    NASA Astrophysics Data System (ADS)

    Shimeld, John; Li, Qingmou; Chian, Deping; Lebedeva-Ivanova, Nina; Jackson, Ruth; Mosher, David; Hutchinson, Deborah

    2016-01-01

    borehole data for Miocene turbidites in the eastern Gulf of Mexico. The station-specific results also indicate that Quaternary sediments coarsen towards the Beaufort-Mackenzie and Banks Island margins in a manner that is consistent with the variable history of Laurentide Ice Sheet advance documented for these margins. Lithological factors do not fully account for the elevated velocity-depth trends that are associated with the southwestern Canada Basin and the Alpha-Mendeleev magnetic domain. Accelerated porosity reduction due to elevated palaeo-heat flow is inferred for these regions, which may be related to the underlying crustal types or possibly volcanic intrusion of the sedimentary succession. Beyond exploring the variation of an important physical property in the Arctic Ocean basin, this study provides comparative reference for global studies of seismic velocity, burial history, sedimentary compaction, seismic inversion and overpressure prediction, particularly in mudrock-dominated successions.

  7. Providing Research Experiences to Minority Undergraduates: The Pathway to Success in Graduate Education?

    NASA Astrophysics Data System (ADS)

    Andronicos, C. L.; Miller, K. C.; Langford, R. P.; Carrick, T. L.

    2004-12-01

    UTEP is an Hispanic Serving Institution located along the U.S.-Mexico border with tremendous access to a diverse student population. The Pathways Research Experience Program (PREP) at UTEP is designed to provide students from underrepresented groups access to research under the supervision of a faculty mentor. Students are selected for the program based on GPA, letters of recommendation, and a research proposal. Since 2002, 16 students have worked on a variety of research projects under the auspices of PREP. This group has included 12 women and 10 Hispanics. Of these students 6 have graduated and 4 have continued onto graduate programs at other institutions. A key part of this project is the research stipend which enables students to focus on their undergraduate studies without having to seek outside employment. Student research topics have been diverse and have included projects in paleontology, structural geology, hydrogeology, environmental geology, and geomicrobiology. Student research projects have been presented at national meetings including the Geological Society of America and Society for the Advancement of Chicanos and Native Americans in the Sciences, as well as research expos at UTEP. In addition to providing access to research projects the students participate in workshops on applying to graduate schools, obtaining financial aid, and good study habits. Our overall goals for this project have been to mentor students through an undergraduate degree in geology and prepare them for graduate education in the Earth Sciences. Although our project is just beginning, our preliminary results suggest that this type of research experience increases the likelihood that minority students will continue onto graduate school.

  8. The care continuum in acromegaly: how patients, nurses, and physicians can collaborate for successful treatment experiences

    PubMed Central

    Plunkett, Cynthia; Barkan, Ariel L

    2015-01-01

    Patients with acromegaly (a condition of chronic growth hormone hypersecretion by a pituitary adenoma) often require pharmacological treatment. Somatostatin analogs (SSAs) such as pasireotide, lanreotide, and octreotide are frequently used as first-line medical therapy. As SSAs are delivered by regular subcutaneous or intramuscular injections, they can result in injection-related pain or anxiety and can be challenging to fit into patients’ lifestyles. When combined with the prolonged, debilitating psychological complications associated with acromegaly, these administration challenges can negatively impact compliance, adherence, and quality of life. Proactively managing patients’ expectations and providing appropriate, timely guidance are crucial for maximizing adherence, and ultimately, optimizing the treatment experience. As part of ongoing clinical research since 1997, our team at the University of Michigan has used SSAs to treat 30 patients with acromegaly. Based on our clinical experiences with multiple SSA administration regimens (long-acting intramuscular, long-acting deep subcutaneous, and twice-daily subcutaneous), we generated a dialog map that guides health care professionals through the many sensitive and complex patient communication issues surrounding this treatment process. Beginning with diagnosis, the dialog map includes discussion of treatment options, instruction on proper drug administration technique, and ensuring of appropriate follow-up care. At each step, we provide talking points that address the following: the patients’ clinical situation; their geographic, economic, and psychological concerns; and their inclination to communicate with clinicians. We have found that involving patients, nurses, and physicians as equal partners in the treatment process optimizes treatment initiation, adherence, and persistence in acromegaly. By encouraging collaboration across the care continuum, this dialog map can facilitate identification of the

  9. Salt reduction in the United Kingdom: a successful experiment in public health.

    PubMed

    He, F J; Brinsden, H C; MacGregor, G A

    2014-06-01

    The United Kingdom has successfully implemented a salt reduction programme. We carried out a comprehensive analysis of the programme with an aim of providing a step-by-step guide of developing and implementing a national salt reduction strategy, which other countries could follow. The key components include (1) setting up an action group with strong leadership and scientific credibility; (2) determining salt intake by measuring 24-h urinary sodium, identifying the sources of salt by dietary record; (3) setting a target for population salt intake and developing a salt reduction strategy; (4) setting progressively lower salt targets for different categories of food, with a clear time frame for the industry to achieve; (5) working with the industry to reformulate food with less salt; (6) engaging and recruiting of ministerial support and potential threat of regulation by the Department of Health (DH); (7) clear nutritional labelling; (8) consumer awareness campaign; and (9) monitoring progress by (a) frequent surveys and media publicity of salt content in food, including naming and shaming, (b) repeated 24-h urinary sodium at 3-5 year intervals. Since the salt reduction programme started in 2003/2004, significant progress has been made as demonstrated by the reductions in salt content in many processed food and a 15% reduction in 24-h urinary sodium over 7 years (from 9.5 to 8.1 g per day, P<0.05). The UK salt reduction programme reduced the population's salt intake by gradual reformulation on a voluntary basis. Several countries are following the United Kingdom's lead. The challenge now is to engage other countries with appropriate local modifications. A reduction in salt intake worldwide will result in major public health improvements and cost savings. PMID:24172290

  10. Can cognitive activities during breaks in repetitive manual work accelerate recovery from fatigue? A controlled experiment.

    PubMed

    Mathiassen, Svend Erik; Hallman, David M; Lyskov, Eugene; Hygge, Staffan

    2014-01-01

    Neurophysiologic theory and some empirical evidence suggest that fatigue caused by physical work may be more effectively recovered during "diverting" periods of cognitive activity than during passive rest; a phenomenon of great interest in working life. We investigated the extent to which development and recovery of fatigue during repeated bouts of an occupationally relevant reaching task was influenced by the difficulty of a cognitive activity between these bouts. Eighteen male volunteers performed three experimental sessions, consisting of six 7-min bouts of reaching alternating with 3 minutes of a memory test differing in difficulty between sessions. Throughout each session, recordings were made of upper trapezius muscle activity using electromyography (EMG), heart rate and heart rate variability (HRV) using electrocardiography, arterial blood pressure, and perceived fatigue (Borg CR10 scale and SOFI). A test battery before, immediately after and 1 hour after the work period included measurements of maximal shoulder elevation strength (MVC), pressure pain threshold (PPT) over the trapezius muscles, and a submaximal isometric contraction. As expected, perceived fatigue and EMG amplitude increased during the physical work bouts. Recovery did occur between the bouts, but fatigue accumulated throughout the work period. Neither EMG changes nor recovery of perceived fatigue during breaks were influenced by cognitive task difficulty, while heart rate and HRV recovered the most during breaks with the most difficult task. Recovery of perceived fatigue after the 1 hour work period was also most pronounced for the most difficult cognitive condition, while MVC and PPT showed ambiguous patterns, and EMG recovered similarly after all three cognitive protocols. Thus, we could confirm that cognitive tasks between bouts of fatiguing physical work can, indeed, accelerate recovery of some factors associated with fatigue, even if benefits may be moderate and some responses may be

  11. The Coronal Physics Investigator (cpi) Experiment For Iss: A New Vision For Understanding Solar Wind Acceleration

    NASA Astrophysics Data System (ADS)

    Raymond, John C.; Janzen, P. H.; Kohl, J. L.; Reisenfeld, D. B.; Chandran, B. D. G.; Cranmer, S. R.; Forbes, T. G.; Isenberg, P. A.; Panasyuk, A. V.; van Ballegooijen, A. A.

    2011-05-01

    We propose an Explorer Mission of Opportunity program to develop and operate a large-aperture ultraviolet coronagraph spectrometer called the Coronal Physics Investigator (CPI) as an attached International Space Station (ISS) payload. The primary goal of this program is to identify and characterize the physical processes that heat and accelerate the primary and secondary components of the fast and slow solar wind. Also, CPI can make key measurements needed to understand CMEs. CPI is dedicated to high spectral resolution measurements of the off-limb extended corona with far better stray light suppression than can be achieved by a conventional instrument. UVCS/SOHO allowed us to identify what additional measurements need to be made to answer the fundamental questions about how solar wind streams are produced, and CPI's next-generation capabilities were designed specifically to make those measurements. Compared to previous instruments, CPI provides unprecedented sensitivity, a wavelength range extending from 25.7 to 126 nm, higher temporal resolution, and the capability to measure line profiles of He II, N V, Ne VII, Ne VIII, Si VIII, S IX, Ar VIII, Ca IX, and Fe X, never before seen in coronal holes above 1.3 solar radii. CPI will constrain the properties and effects of coronal MHD waves by (1) observing many ions over a large range of charge and mass,(2) providing simultaneous measurements of proton and electron temperatures to probe turbulent dissipation mechanisms, and (3) measuring amplitudes of low-frequency compressive fluctuations. CPI is an internally occulted ultraviolet coronagraph that provides the required high sensitivity without the need for a deployable boom, and with all technically mature hardware including an ICCD detector. A highly experienced Explorer and ISS contractor, L-3 Com Integrated Optical Systems and Com Systems East will provide the tracking and pointing system as well as the instrument, and the integration to the ISS.

  12. Can Cognitive Activities during Breaks in Repetitive Manual Work Accelerate Recovery from Fatigue? A Controlled Experiment

    PubMed Central

    Mathiassen, Svend Erik; Hallman, David M.; Lyskov, Eugene; Hygge, Staffan

    2014-01-01

    Neurophysiologic theory and some empirical evidence suggest that fatigue caused by physical work may be more effectively recovered during “diverting” periods of cognitive activity than during passive rest; a phenomenon of great interest in working life. We investigated the extent to which development and recovery of fatigue during repeated bouts of an occupationally relevant reaching task was influenced by the difficulty of a cognitive activity between these bouts. Eighteen male volunteers performed three experimental sessions, consisting of six 7-min bouts of reaching alternating with 3 minutes of a memory test differing in difficulty between sessions. Throughout each session, recordings were made of upper trapezius muscle activity using electromyography (EMG), heart rate and heart rate variability (HRV) using electrocardiography, arterial blood pressure, and perceived fatigue (Borg CR10 scale and SOFI). A test battery before, immediately after and 1 hour after the work period included measurements of maximal shoulder elevation strength (MVC), pressure pain threshold (PPT) over the trapezius muscles, and a submaximal isometric contraction. As expected, perceived fatigue and EMG amplitude increased during the physical work bouts. Recovery did occur between the bouts, but fatigue accumulated throughout the work period. Neither EMG changes nor recovery of perceived fatigue during breaks were influenced by cognitive task difficulty, while heart rate and HRV recovered the most during breaks with the most difficult task. Recovery of perceived fatigue after the 1 hour work period was also most pronounced for the most difficult cognitive condition, while MVC and PPT showed ambiguous patterns, and EMG recovered similarly after all three cognitive protocols. Thus, we could confirm that cognitive tasks between bouts of fatiguing physical work can, indeed, accelerate recovery of some factors associated with fatigue, even if benefits may be moderate and some responses may

  13. The development and succession of microbial communities in 90-day Bioregenerative Life Support Experiment in the Lunar Palace 1

    NASA Astrophysics Data System (ADS)

    Sun, Yi; Liu, Hong; Fu, Yuming; Liu, Bojie; Su, Qiang; Xie, Beizhen; Qin, Youcai; Dong, Chen; Liu, Guanghui

    Lunar Palace 1, as an integrative experiment facility for permanent astrobase life-support artificial closed ecosystem, is an artificial ecosystem which consists of plant cultivation, animal breeding and waste treatment units. It has been used to carry out a 90-day bioregenerative life support experiment with three crew members. Apparently, it’s hard to prevent the growth of microorganisms in such closed ecosystem for their strong adaptive capacity. Original microorganisms in the cabin, microbes in the course of loads delivery and the autologous microorganism by crew members and animals themselves are all the main source of the interior microorganisms, which may grow and regenerate in air, water and plants. Therefore, if these microorganisms could not be effectively monitored and controlled, it may cause microbial contamination and even lead to the unsteadiness of the whole closed ecosystem. In this study, the development and succession of the microbial communities of air, water system, plant system, and key facilities surfaces in Lunar Palace 1 were continuously monitored and analyzed by using plate counting method and molecular biological method during the 90-day experiment. The results were quite useful for the controlling of internal microorganisms and the safe operation of the whole system, and could also reveal the succession rules of microorganisms in an artificial closed ecosystem.

  14. SMS versus voice messaging to deliver MNCH communication in rural Malawi: assessment of delivery success and user experience

    PubMed Central

    Crawford, Jessica; Larsen-Cooper, Erin; Jezman, Zachariah; Cunningham, Stacey C; Bancroft, Emily

    2014-01-01

    Objective: To determine the difference in delivery success of health messages delivered through pushed SMS, pushed voice messages sent to personal phones, and voice messages retrieved from a community phone (“retrieved voice messaging”), as well as the difference in quality of the user experience. Methods: We analyzed the project's electronic monitoring data between September 2011 and June 2013, including demographics, enrollment data, and messages sent and successfully delivered. We also collected and analyzed information from quarterly phone-based surveys with users to assess quality of the user experience, including acceptability, comprehension, new information learned, and reported behavior change. Results: More than half of subscribers enrolled in the retrieved voice messaging service while nearly one-third enrolled in the pushed SMS service and less than 10% in pushed voice messaging. Message delivery success was highest among pushed SMS subscribers and lowest among retrieved voice subscribers. Overall, 99% of survey respondents reported trusting messages they received, and about 75% of respondents recalled the last message they received and learned something new. Almost 75% of respondents reported that they had already changed or intended to change their behavior based on received messages. Intended or actual behavior change was significantly higher among pushed SMS enrollees than among pushed or retrieved voice messaging enrollees (P = .01). Conclusion: All message modalities led to high levels of satisfaction, comprehension, and new information learned. Due to lower cost, higher delivery success, and higher levels of intended or actual behavior change, SMS is the preferred delivery modality. However, the majority of users included in this study did not have access to a personal phone, and retrieved voice messages provided an opportunity to access a population that otherwise could not be served. Providing multiple methods by which users could access

  15. Acceleration modules in linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Wang, Shao-Heng; Deng, Jian-Jun

    2014-05-01

    The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

  16. Effects of numerical methods on comparisons between experiments and simulations of shock-accelerated mixing.

    SciTech Connect

    Rider, William; Kamm, J. R.; Tomkins, C. D.; Zoldi, C. A.; Prestridge, K. P.; Marr-Lyon, M.; Rightley, P. M.; Benjamin, R. F.

    2002-01-01

    We consider the detailed structures of mixing flows for Richtmyer-Meshkov experiments of Prestridge et al. [PRE 00] and Tomkins et al. [TOM 01] and examine the most recent measurements from the experimental apparatus. Numerical simulations of these experiments are performed with three different versions of high resolution finite volume Godunov methods. We compare experimental data with simulations for configurations of one and two diffuse cylinders of SF{sub 6} in air using integral measures as well as fractal analysis and continuous wavelet transforms. The details of the initial conditions have a significant effect on the computed results, especially in the case of the double cylinder. Additionally, these comparisons reveal sensitive dependence of the computed solution on the numerical method.

  17. A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments.

    PubMed

    Sears, Christopher M S; Cuevas, Sofia Benavides; Schramm, Ulrich; Schmid, Karl; Buck, Alexander; Habs, Dieter; Krausz, Ferenc; Veisz, Laszlo

    2010-07-01

    Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accuracy are limited by the convolved transverse spot size and pointing jitter of the beam. In this paper we present an electron energy spectrometer consisting of two magnets designed specifically for laser wakefield experiments. In the primary magnet the field is produced by permanent magnets. A second optional electromagnet can be used to obtain better resolution for electron energies above 75 MeV. The spectrometer has an acceptance of 2.5-400 MeV (E(max)/E(min)>100) with a resolution of better than 1% rms for electron energies above 25 MeV. This high resolution is achieved by refocusing electrons in the energy plane and without any postprocessing image deconvolution. Finally, the spectrometer employs two complimentary detection mechanisms: (1) absolutely calibrated scintillation screens imaged by cameras outside the vacuum chamber and (2) an array of scintillating fibers coupled to a low-noise charge-coupled device. PMID:20687714

  18. A high resolution, broad energy acceptance spectrometer for laser wakefield acceleration experiments

    SciTech Connect

    Sears, Christopher M. S.; Cuevas, Sofia Benavides; Veisz, Laszlo; Schramm, Ulrich; Schmid, Karl; Buck, Alexander; Habs, Dieter; Krausz, Ferenc

    2010-07-15

    Laser wakefield experiments present a unique challenge in measuring the resulting electron energy properties due to the large energy range of interest, typically several 100 MeV, and the large electron beam divergence and pointing jitter >1 mrad. In many experiments the energy resolution and accuracy are limited by the convolved transverse spot size and pointing jitter of the beam. In this paper we present an electron energy spectrometer consisting of two magnets designed specifically for laser wakefield experiments. In the primary magnet the field is produced by permanent magnets. A second optional electromagnet can be used to obtain better resolution for electron energies above 75 MeV. The spectrometer has an acceptance of 2.5-400 MeV (E{sub max}/E{sub min}>100) with a resolution of better than 1% rms for electron energies above 25 MeV. This high resolution is achieved by refocusing electrons in the energy plane and without any postprocessing image deconvolution. Finally, the spectrometer employs two complimentary detection mechanisms: (1) absolutely calibrated scintillation screens imaged by cameras outside the vacuum chamber and (2) an array of scintillating fibers coupled to a low-noise charge-coupled device.

  19. First Protein Crystallization Experiments on The International Space Station: Sweet Success in Space With Thaumatin

    NASA Technical Reports Server (NTRS)

    Kundrot, Craig E.; Barnes, Cindy L.; Snell, Eddie H.; Achari, Aniruddha; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We determined the room temperature 1.2 A structure of thaumatin using a crystal grown in the first protein crystallization experiment conducted aboard the International Space Station (ISS). The crystals were grown in the Enhanced Gaseous Nitrogen Dewar (EGN) developed by Alexander McPherson and co-workers. EGN transports frozen solutions contained in tygon tubing in a liquid nitrogen Dewar to ISS where the tubes then thaw. Batch, free interface diffusion (FID), or vapor diffusion crystallization occurs after thawing. EGN was flown to the ISS on STS-106 on September 8, 2000. This was a "risk mitigation" flight that tested EGN performance and the process of conducting experiments on ISS. We focused on how to map a hanging drop crystallization recipe to the EGN FID method. Thaumatin was chosen as the test system. Three series of crystallization recipes were set-up. Each series tested different volume ratios of protein-rich solution to precipitant-rich solution. The series differed from each other by fixing either the protein concentration or the amount of protein in the solutions. Upon return of the samples to Earth on October 24 by STS-92, bubbles that spanned the diameter of the tubing were observed in all tubes. Such bubbles interrupt liquid-liquid diffusion and force vapor diffusion equilibration to occur instead. Nonetheless, crystals grew in 9 of 30 tubes. Many large crystals were grown, the largest being 2.0 x 1.1 x 1.0 cubic mm. The largest crystal was used to collect data at room temperature on beamline 7-1 of the Stanford Synchrotron Radiation Source to a maximum resolution of 1.2 A. The structure was refined anisotropically using SHELX with a data to parameter ratio of 4.5 to give an R(sub factor) of 15.8% (R(sub free) = 18.2%) for ail reflections without generated hydrogens. This refinement is proceeding. Comparisons of this 1.2 A microgravity structure to previous reports of the thaumatin structure at 1.75 A and to ground control crystals will be

  20. Experiences of Self-Monitoring: Successes and Struggles during Treatment for Weight Loss

    PubMed Central

    Burke, Lora E.; Swigart, Valerie; Turk, Melanie Warziski; Derro, Nicole; Ewing, Linda J.

    2009-01-01

    We interviewed 15 individuals who completed a behavioral weight loss treatment study with the aim of exploring participants’ reflections on their feelings, attitudes and behaviors while using a paper diary to self-monitor their diet. Constant comparative and matrix analysis procedures were used to analyze interview data; the qualitative results were then interfaced with descriptive numerical data on individuals’ adherence to self-monitoring and weight loss. Three categories of self-monitoring experience were identified (a) Well-Disciplined – those who had high adherence to self-monitoring, high weight loss and a “can do” positive approach, (b) Missing the Connection – those who had moderate adherence, moderate to low weight loss, and an “it’s an assignment” approach without integrating self-monitoring into every day life, and (c) Diminished Support – those who had poor adherence, poor weight control, and were adversely affected by co-existing negative factors. Given the variations in how individuals integrated the process of self-monitoring, we need to consider individualizing self-monitoring strategies to improve adherence. PMID:19365099

  1. [Fighting cholera in shanty-town. Successful experience of a Quebec project adapted to Peru].

    PubMed

    Fréchette, L; Peralta, M

    1994-12-01

    Originally designed in Quebec, the MOI project was a collaboration between two professors of social work from Quebec and two members of the Peruvian NGO called SUR in Villa de Salvador, one of poorest slum areas on the outskirts of Lima. The approach is founded on the notion that the body is the primary instrument through which a person can interact with the world around him or her, and that the physical and mental health of an individual exists within the context of healthy conditions of life that must include at least a basic social and health infrastructure as well as healthy hygiene practices on the part of individuals, families and the local community. Preschool children (ages 4-6), study a different part of the body and its proper care each week through classroom observation games. Parents' help is requested to modify unhealthy conditions, at the same time to enrich the children's experience and to mobilize the community to improve health conditions. During the 1991 cholera epidemic, not a single case was counted in the experimental district, despite its clearly socio-economically impoverished status, and despite the fact that the Ministry of Health recorded 86,650 cases in the Lima-Callao district, accounting for about 40% of the total number of cases in the Peru. The prior work made it easier to explain how cholera is spread and what special new measures needed to be taken in addition to the hygiene habits already taught.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7820377

  2. Three Accelerated Developmental Education Programs: Features, Student Outcomes, and Implications

    ERIC Educational Resources Information Center

    Jaggars, Shanna Smith; Hodara, Michelle; Cho, Sung-Woo; Xu, Di

    2015-01-01

    To support the long-term success of underprepared students, many community colleges are experimenting with accelerated developmental education models, which allow students to complete remediation and enroll in college-level math and English within a shorter time frame. This study examines three developmental acceleration programs, including two in…

  3. Accelerator experiments on the contribution of secondary particles to the production of cosmogenic nuclides in meteorites

    NASA Technical Reports Server (NTRS)

    Dragovitsch, P.; Englert, P.

    1985-01-01

    Through the interaction of galactic cosmic particle radiation (GCR) a wide variety of cosmogenic nuclides is produced in meteorites. They provide historical information about the cosmic radiation and the bombarded meteorites. An important way to understand the production mechanisms of cosmogenic nuclides in meteorites is to gather information about the depth and size dependence of the build-up of Galactic Rays Cosmic-secondary particles within meteorites of different sizes and chemical compositions. Simulation experiments with meteorite models offer an alternative to direct observation providing a data basis to describe the development and action of the secondary cascade induced by the GCR in meteorites.

  4. Multi-processor developments in the United States for future high energy physics experiments and accelerators

    SciTech Connect

    Gaines, I.

    1988-03-01

    The use of multi-processors for analysis and high-level triggering in High Energy Physics experiments, pioneered by the early emulator systems, has reached maturity, in particular with the multiple microprocessor systems in use at Fermilab. It is widely acknowledged that such systems will fulfill the major portion of the computing needs of future large experiments. Recent developments at Fermilab's Advanced Computer Program will make such systems even more powerful, cost-effective, and easier to use than they are at present. The next generation of microprocessors, already available, will provide CPU power of about one VAX 780 equivalent/$300, while supporting most VMS FORTRAN extensions and large (>8MB) amounts of memory. Low cost high density mass storage devices (based on video tape cartridge technology) will allow parallel I/O to remove potential I/O bottlenecks in systems of over 1000 VAX equipment processors. New interconnection schemes and system software will allow more flexible topologies and extremely high data bandwidth, especially for on-line systems. This talk will summarize the work at the Advanced Computer Program and the rest of the US in this field. 3 refs., 4 figs.

  5. Searching for Physics beyond the Standard Model with Accelerator Neutrino Experiments

    SciTech Connect

    Louis, William C

    2008-01-01

    The MiniBooNE experiment at Fermilab was designed to test the LSND evidence for {bar {nu}}{sub {mu}} {yields} {bar {nu}}{sub e} oscillations . The first MiniBooNE oscillation result in neutrino mode shows no significant excess of events at higher energies (E{sub {nu}} > 475 MeV), although a sizeable excess is observed at lower energies (E{sub {nu}}< 475 MeV). The lack of a significant excess at higher energies allows MiniBooNE to rule out simple 2 - {nu} oscillations as an explanation of the LSND signal. However, the low-energy excess is presently unexplained. Additional antineutrino data and NuMI data may allow the collaboration to determine whether the excess is due, for example, to a neutrino neutral-current radiative interaction or to neutrino oscillations involving sterile neutrinos. If the excess is consistent with being due to sterile neutrinos, then future experiments at FNAL (BooNE) or ORNL (OscSNS) could prove their existence.

  6. Magnetic flux compression experiments on the Z pulsed-power accelerator

    NASA Astrophysics Data System (ADS)

    McBride, R. D.; Gomez, M. R.; Hansen, S. B.; Jennings, C. A.; Bliss, D. E.; Knapp, P. F.; Schmit, P. F.; Awe, T. J.; Martin, M. R.; Sinars, D. B.; Greenly, J. B.; Intrator, T. P.; Weber, T. E.

    2014-10-01

    We report on the progress made to date for diagnosing magnetic flux compression on Z. Each experiment consisted of an initially solid Be or Al liner (cylindrical tube), which was imploded using Z's drive current (0-20 MA in 100 ns). The imploding liner compresses a 10-T axial seed field, Bz(0), supplied by an independently driven Helmholtz coil pair. Assuming perfect flux conservation, the axial field amplification should be well described by Bz (t) =Bz (0) × [ R (0) / R (t) ]2 , where R is the liner's inner surface radius. With perfect flux conservation, Bz and dBz/dt values exceeding 104 T and 1012 T/s, respectively, are expected. These large values, the diminishing liner volume, and the harsh environment on Z, make it particularly challenging to measure these fields. We report our latest efforts to do so using three primary techniques: (1) micro B-dot probes, (2) streaked visible Zeeman spectroscopy, and (3) fiber-based Faraday rotation. We will also briefly highlight some recent developments using neutron diagnostics (ratio of secondary DT to primary DD neutrons and secondary DT neutron energy spectra) to assess the degree of magnetization in fully integrated magnetized liner inertial fusion (MagLIF) experiments on Z. This project was funded in part by Sandia's LDRD program and US DOE-NNSA Contract DE-AC04-94AL85000.

  7. Pathways to success in science: A phenomenological study, examining the life experiences of African-American women in higher education

    NASA Astrophysics Data System (ADS)

    Giscombe, Claudette Leanora

    This study is a qualitative investigation in which five African American women science faculty, in higher education, within the age range of 45--60, were the participants. The data that was collected, over twelve months, was primarily obtained from the in-depth phenomenological interviewing method (Seidman, 1991). The interpretation of the data was the result of ongoing cross analysis of the participants' life experiences, perceptions, and beliefs of the how they navigated and negotiated pathways to careers in the natural sciences, and the meanings they attach to these experiences. The software Ethnograph (V5.0) was used to organize the participants' responses into patterns and emergent themes. The Black women in this study articulated several themes that were critical determinants of their successes and achievements in science careers. From the analysis of the data set, four major findings were identified: (1) "Black Intentional Communities" acted as social agencies for the positive development of the participants; (2) "My World Reality" which was described by the participants as their acceptance of their segregated worlds, not being victims of inequities and injustices, but being resilient and determined to forge on to early academic successes. Early academic successes were identified as precursors and external motivational stimuli to their interests and achievements in science; (3) Their experiences of "Tensions and Double Consciousness" from race and gender negative images and career stereotypes, required the women to make "intra-cultural deviations" from stereotypic career roles and to develop "pragmatic coping strategies" to achieve in science careers and; (4) "Meaning-making"---Significant to the meaning of their journey was the fact that the participants grounded their experiences in a social context rather than in a scientific context and that they ended their journey with expressions of personal satisfactions about their journey and their unique drive and

  8. The IGSN Experience: Successes and Challenges of Implementing Persistent Identifiers for Samples

    NASA Astrophysics Data System (ADS)

    Lehnert, Kerstin; Arko, Robert

    2016-04-01

    Physical samples collected and studied in the Earth sciences represent both a research resource and a research product in the Earth Sciences. As such they need to be properly managed, curated, documented, and cited to ensure re-usability and utility for future science, reproducibility of the data generated by their study, and credit for funding agencies and researchers who invested substantial resources and intellectual effort into their collection and curation. Use of persistent and unique identifiers and deposition of metadata in a persistent registry are therefore as important for physical samples as they are for digital data. The International Geo Sample Number (IGSN) is a persistent, globally unique identifier. Its adoption by individual investigators, repository curators, publishers, and data managers is rapidly growing world-wide. This presentation will provide an analysis of the development and implementation path of the IGSN and relevant insights and experiences gained along its way. Development of the IGSN started in 2004 as part of a US NSF-funded project to establish a registry for sample metadata, the System for Earth Sample Registration (SESAR). The initial system provided a centralized solution for users to submit information about their samples and obtain IGSNs and bar codes. Challenges encountered during this initial phase related to defining the scope of the registry, granularity of registered objects, responsibilities of relevant actors, and workflows, and designing the registry's metadata schema, its user interfaces, and the identifier itself, including its syntax. The most challenging task though was to make the IGSN an integral part of personal and institutional sample management, digital management of sample-based data, and data publication on a global scale. Besides convincing individual researchers, curators, editors and publishers, as well as data managers in US and non-US academia, state and federal agencies, the PIs of the SESAR project

  9. Simultaneous processing of photographic and accelerator array data from sled impact experiment

    NASA Astrophysics Data System (ADS)

    Ash, M. E.

    1982-12-01

    A Quaternion-Kalman filter model is derived to simultaneously analyze accelerometer array and photographic data from sled impact experiments. Formulas are given for the quaternion representation of rotations, the propagation of dynamical states and their partial derivatives, the observables and their partial derivatives, and the Kalman filter update of the state given the observables. The observables are accelerometer and tachometer velocity data of the sled relative to the track, linear accelerometer array and photographic data of the subject relative to the sled, and ideal angular accelerometer data. The quaternion constraints enter through perfect constraint observations and normalization after a state update. Lateral and fore-aft impact tests are analyzed with FORTRAN IV software written using the formulas of this report.

  10. Data quality management system (DQMS) for BAC detector in the ZEUS experiment at the HERA accelerator

    NASA Astrophysics Data System (ADS)

    Luszczak, Zbigniew; Jezynski, Tomasz; Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Kuthan, Marcin; Bigos, Grzegorz; Gierej, Artur

    2003-10-01

    The paper presents functional structure of database system of data measurement quality for BAC detector in ZEUS experiment. The system collects diagnostic and experimental data. Diagnostic data are: work parameters of the detector and electronics/photonics, tests of electronic/photonic blocks. These data are archived for certain period of time. The quality of current data collection process is estimated using these archived data. The result of such estimation is generated in a form of status map of the detector. Such maps, describing status of the hardware, are fundamental for elementary particle analysis by the calorimeter. The DAQ system, collecting data to the database, estimates data quality on-line during transmission and writing. This mechanism of fast on-line data quality management leads to early discoveries of detector work irregularities and faults.

  11. Commnity Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect

    Spentzouris, Panagiotis; Cary, John; Mcinnes, Lois Curfman; Mori, Warren; Ng, Cho; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2008-07-01

    The design and performance optimization of particle accelerators is essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC1 Accelerator Science and Technology project, the SciDAC2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modeling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multi-physics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  12. Community petascale project for accelerator science and simulation : Advancing computational science for future accelerators and accelerator technologies.

    SciTech Connect

    Spentzouris, P.; Cary, J.; McInnes, L. C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.

    2008-01-01

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R & D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  13. Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

    SciTech Connect

    Spentzouris, Panagiotis; Cary, John; Mcinnes, Lois Curfman; Mori, Warren; Ng, Cho; Ng, Esmond; Ryne, Robert; /LBL, Berkeley

    2011-10-21

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors.

  14. Modeling of Nike Experiments on Acceleration of Planar Targets Stabilized with a Short Spike

    NASA Astrophysics Data System (ADS)

    Metzler, N.; Velikovich, A. L.; Gardner, J. H.

    2005-10-01

    A short sub-ns laser pulse (spike) produces a decelerating shock wave and a rarefaction wave immediately behind it, shaping a density gradient in the target. The following main pulse ``rides'' this graded density profile. We have demonstrated how the deceleration of the ablation front following the shock wave suppresses laser imprint and delays perturbation growth in the target [1]. We report the results of 2D numerical modeling of experiments on Nike laser at NRL, with its recently developed short-pulse capability, for a low-energy spike which does not affect the target adiabat. We studied the effect of spike on laser imprint on smooth planar targets and on the growth of perturbations imposed as single-mode ripples on the irradiated surface of the targets. For all cases, delay of the onset and/or suppression of the rate of the mass perturbation growth due to the spike are robust and significant enough to be observable on Nike. [1] N. Metzler et al., Phys. Plasmas 6, 3283 (1999); 9, 5050 (2002); 10, 1897 (2003).

  15. Accelerated Capacity Development in Water Resources Education: the experiences of the Ethiopian Institute of Water Resources

    NASA Astrophysics Data System (ADS)

    Alamirew, T.; Mekonnen, G.; Viglione, A.

    2012-04-01

    Ethiopia recently recognises that the water resources development is the major entry point in poverty alleviation and sustainable development. Water in Ethiopia plays a key role in the Water-Energy-Food-nexus. Over 98% of the electricity in the country is generated using hydropower and yet about 2000 MW has been developed. Out of the 3.5 Mha potentially irrigable land, only 0.25 Mha has been developed to date. Access to drinking water supply coverage is among the lowest in the world. One of the limiting factors in harnessing the resource base is the absence of water professionals to face the fast growing demand in education, research, development in the water sector. Recognising this, in collaboration with University of Connecticut of the United States, Addis Ababa University launched the Ethiopian Institute of Water Resources (EIWR) by enrolling 18 PhD and 24 MSc students. The program is unique in that much of the course instructors are coming from US and European Universities, but deliver courses together with Ethiopian collaborators. This is supposed to facilitate knowledge and experience transfer from the US/EU scientist to Ethiopian counterparts. The theses/dissertations are designed to focus on Ethiopia's immediate hydrological problems on selected basins, and will be coordinated by three advisors for each PhD - one from US/EU, one from Ethiopian Universities, and one water professional from the sector. We report here the lessons learned in setting up the EIWR institute and the education program.

  16. Group Dynamics as a Critical Component of Successful Space Exploration: Conceptual Theory and Insights from the Biosphere 2 Closure Experiment

    NASA Astrophysics Data System (ADS)

    Nelson, Mark; Allen, John P.

    As space exploration and eventually habitation achieves longer durations, successfully managing group dynamics of small, physically isolated groups will become vital. The paper summarizes important underlying research and conceptual theory and how these manifested in a well-documented example: the closure experiments of Biosphere 2. Key research breakthroughs in discerning the operation of small human groups comes from the pioneering work of W.R. Bion. He discovered two competing modalities of behavior. The first is the “task-oriented” or work group governed by shared acceptance of goals, reality-thinking in relation to time, resources and rational, and intelligent management of challenges presented. The opposing, usually unconscious, modality is what Bion called the “basic-assumption” group and alternates between three “group animal” groups: dependency/kill the leader; fight/flight and pairing. If not dealt with, these dynamics work to undermine and defeat the conscious task group’s goal achievement. The paper discusses crew training and selection, various approaches to structuring the work and hierarchy of the group, the importance of contact with a larger population through electronic communication and dealing with the “us-them” syndrome frequently observed between crew and Mission Control. The experience of the first two year closure of Biosphere 2 is drawn on in new ways to illustrate vicissitudes and management of group dynamics especially as both the inside team of biospherians and key members of Mission Control had training in working with group dynamics. Insights from that experience may help mission planning so that future groups in space cope successfully with inherent group dynamics challenges that arise.

  17. Preliminary experiments on the production of high photon energy continuum radiation from a Z-pinch at the Z accelerator

    NASA Astrophysics Data System (ADS)

    Coverdale, C. A.; Deeney, C.; Harper-Slaboscewica, V. J.; Lepell, P. D.; Velikovich, A. L.; Davis, J.; Oreshkin, V. I.

    2003-10-01

    Traditionally, the generation of multi-keV x-ray radiation from Z-pinch plasmas has focused on K-shell emissions from moderate Z materials. While this approach has worked well, it requires increasingly higher energies be coupled to each ion to produce substantial output as the photon energy increases. An alternate approach to generating multi-keV radiation, proposed in Ref. 1, utilizes lower Z materials than are necessary to generate the appropriate K-shell lines, but tailors the Z-pinch load to overheat the plasma in order to enhance the recombination radiation that is generated. Initial experiments have been performed at the Z Accelerator to evaluate the level of recombination radiation that can be generated through the tailoring of initial load radius and mass with Aluminum and Titanium wire arrays. In this paper, the results of these experiments will be presented. Measurements of yield were made for several photon energy ranges and spectra were collected to evaluate the high energy continuum. These results will be compared with simulations and theoretical predictions to evaluate the feasibility of an overheated plasma for generating higher photon energy emissions. This work is supported by the Defense Threat Reduction Agency and the Department of Energy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AI85000. *Ktech Corporation [1] A.L. Velikovich, et. al., Phys. Plasmas 8, 4509 (2001).

  18. Beam dynamics simulations of the transverse-to-longitudinal emittance exchange proof-of-principle experiment at the Argonne Wakefield Accelerator

    SciTech Connect

    Rihaoui, M.; Gai, W.; Kim, K.J.; Piot, Philippe; Power, John Gorham; Sun, Y.E.; /Fermilab

    2009-01-01

    Transverse-to-longitudinal emittance exchange has promising applications in various advanced acceleration and light source concepts. A proof-of-principle experiment to demonstrate this phase space manipulation method is currently being planned at the Argonne Wakefield Accelerator. The experiment focuses on exchanging a low longitudinal emittance with a high transverse horizontal emittance and also incorporates room for possible parametric studies e.g. using an incoming flat beam with tunable horizontal emittance. In this paper, we present realistic start-to-end beam dynamics simulation of the scheme, explore the limitations of this phase space exchange.

  19. Beam dynamics simulations of the transverse-to-longitudinal emittance exchange proof-of-principle experiment at the Argonne Wakefield Accelerator.

    SciTech Connect

    Gao, F.; Gai, W.; Power, J. G.; Kim, K. J.; Sun, Y. E.; Piot, P.; Rihaoui, M.; High Energy Physics; Northern Illinois Univ.; FNAL

    2009-01-01

    Transverse-to-longitudinal emittance exchange has promising applications in various advanced acceleration and light source concepts. A proof-of-principle experiment to demonstrate this phase space manipulation method is currently being planned at the Argonne Wakefield Accelerator. The experiment focuses on exchanging a low longitudinal emittance with a high transverse horizontal emittance and also incorporates room for possible parametric studies e.g. using an incoming flat beam with tunable horizontal emittance. In this paper, we present realistic start-to-end beam dynamics simulation of the scheme, explore the limitations of this phase space exchange.

  20. Beam dynamics simulations of the transverse-to-longitudinal emittance exchange proof-of-principle experiment at the Argonne Wakefield Accelerator

    SciTech Connect

    Rihaoui, M.; Gai, W.; Kim, K.-J.; Power, J. G.; Piot, P.; Sun, Y.-E.

    2009-01-22

    Transverse-to-longitudinal emittance exchange has promising applications in various advanced acceleration and light source concepts. A proof-of-principle experiment to demonstrate this phase space manipulation method is currently being planned at the Argonne Wakefield Accelerator. The experiment focuses on exchanging a low longitudinal emittance with a high transverse horizontal emittance and also incorporates room for possible parametric studies e.g. using an incoming flat beam with tunable horizontal emittance. In this paper, we present realistic start-to-end beam dynamics simulation of the scheme, explore the limitations of this phase space exchange.

  1. A Co-Investigator Proposal for the Cornell University CAPER Rocket: Cleft Accelerated Plasma Experiment Rocket

    NASA Technical Reports Server (NTRS)

    Arnoldy, Roger L.

    2001-01-01

    The objectives are: 1) To support the Cornell wave instruments in a study of dayside ion outflow. 2) In conjunction with the U. of Alaska ground optical data, a prime objective was to measure the topside Cusp ion spectra responsible for dayside proton aurora. If such a correlative measurement could be made, then monitoring of this cusp precipitation from the ground could be routinely achieved. The nature of Cusp ions has and will continue to provide information about dayside magnetic reconnection. 3) A third objective was to study the dayside microburst electron precipitation from the BPS/CPS population. The Scifer rocket flight showed a bursty electron population at 1000 km altitude correlated closely with pulsation ground aurora on closed field lines. The frequency of this pulsating aurora is about 1 Hz. Ground pulsation measurements have recorded dayside bursts of Pc1 waves which could very well be the source of the electrons responsible for the pulsating aurora. In support of the Caper flight, UNH provided ground induction antennas to measure the equatorial Pc1 waves that might be dumping trapped electrons from the Central Plasma Sheet population. The Caper flight was launched on the last day of the window and all the Cornell and UNH instrumentation worked perfectly. Unfortunately the rocket trajectory flew very far to the west of the ground site at Longyearbyen missing conjugacy by several hundred kilometers. This meant the intended aurora was not crossed and all the ground experiments were far from being near the foot print of the rocket ruling out correlative science. The "miss" was primarily due to a decision during the countdown by the Andoya Rocket Range to move the azimuth of the rocket to the west to avoid Norwegian fishing boats at the splash point of the first two stages, and to make matters worse, the dispersion of the fourth stage of the rocket added entirely in this direction. Although no publications have resulted from the UNH data up to this

  2. Successful Experience of Laparoscopic Pancreaticoduodenectomy and Digestive Tract Reconstruction With Minimized Complications Rate by 14 Case Reports

    PubMed Central

    Fan, Yong; Zhao, Yanhui; Pang, Lan; Kang, Yingxing; Kang, Boxiong; Liu, Yongyong; Fu, Jie; Xia, Bowei; Wang, Chen; Zhang, Youcheng

    2016-01-01

    Abstract Laparoscopic pancreatic surgery is one of the most sophisticated and advanced applications of laparoscopy in the current surgical practice. The adoption of laparoscopic pancreaticoduodenectomy (LPD) has been relatively slow due to the technical challenges. The aim of this study is to review and characterize our successful LPD experiences in patients with distal bile duct carcinoma, periampullary adenocarcinoma, pancreas head cancer, and duodenal cancer and evaluate the clinical outcomes of LPD for its potential in oncologic surgery applications. We retrospectively analyzed the clinical data from 14 patients who underwent LPD from August 2013 to February 2015 in our institute. We presented our LPD experience with no cases converted to open surgery in all 14 cases, which included 10 cases of laparoscopic digestive tract reconstruction and 4 cases of open digestive tract reconstructions. There were no deaths during the perioperative period and no case of gastric emptying disorder or postoperative bleeding. The other clinical indexes were comparable to or better than open surgery. Based on our experience, LPD could be potentially safe and feasible for the treatment of early pancreas head cancer, distal bile duct carcinoma, periampullary adenocarcinoma, and duodenal cancer. The master of LPD procedure requires technical expertise but it can be accomplished with a short learning curve. PMID:27124014

  3. Successful Experience of Laparoscopic Pancreaticoduodenectomy and Digestive Tract Reconstruction With Minimized Complications Rate by 14 Case Reports.

    PubMed

    Fan, Yong; Zhao, Yanhui; Pang, Lan; Kang, Yingxing; Kang, Boxiong; Liu, Yongyong; Fu, Jie; Xia, Bowei; Wang, Chen; Zhang, Youcheng

    2016-04-01

    Laparoscopic pancreatic surgery is one of the most sophisticated and advanced applications of laparoscopy in the current surgical practice. The adoption of laparoscopic pancreaticoduodenectomy (LPD) has been relatively slow due to the technical challenges. The aim of this study is to review and characterize our successful LPD experiences in patients with distal bile duct carcinoma, periampullary adenocarcinoma, pancreas head cancer, and duodenal cancer and evaluate the clinical outcomes of LPD for its potential in oncologic surgery applications.We retrospectively analyzed the clinical data from 14 patients who underwent LPD from August 2013 to February 2015 in our institute.We presented our LPD experience with no cases converted to open surgery in all 14 cases, which included 10 cases of laparoscopic digestive tract reconstruction and 4 cases of open digestive tract reconstructions. There were no deaths during the perioperative period and no case of gastric emptying disorder or postoperative bleeding. The other clinical indexes were comparable to or better than open surgery.Based on our experience, LPD could be potentially safe and feasible for the treatment of early pancreas head cancer, distal bile duct carcinoma, periampullary adenocarcinoma, and duodenal cancer. The master of LPD procedure requires technical expertise but it can be accomplished with a short learning curve. PMID:27124014

  4. Portraits of Success: A Mixed-Method Study of the Enrollment, Persistence, and Success Experiences of Female Graduate Engineering Students at a Hispanic Serving Institution

    ERIC Educational Resources Information Center

    Aguirre-Covarrubias, Sandra

    2013-01-01

    The current study addresses the underrepresentation of female graduate engineering students. Specifically, its purpose was to gain insight on how enrollment, persistence, and success factors are experienced by female graduate engineering students at a Hispanic Serving Institution located on the U.S.-Mexico border. The topic of underrepresentation…

  5. Accelerating Particles with Plasma

    SciTech Connect

    Litos, Michael; Hogan, Mark

    2014-11-05

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  6. Assessing the Impact of the Cambridge International Acceleration Program on U.S. University Determinants of Success: A Multi-Level Modeling Approach

    ERIC Educational Resources Information Center

    Shaw, Stuart; Warren, Jayne; Gill, Tim

    2014-01-01

    This article focuses on the research being conducted by Cambridge International Examinations (Cambridge) to ensure that its international assessments prepare students as well as other acceleration programs for continued study in U.S. colleges and universities. The study, which builds on previous freshman GPA data modeling work using data supplied…

  7. From Distance Learning to Research Experience: a Successful Model for Best Practices in Research-Based Science Education

    NASA Astrophysics Data System (ADS)

    Walker, C. E.; Pompea, S. M.; Croft, S.; Lockwood, J.; Rector, T.; Howell, S.; Accetta, R. A.

    2004-12-01

    Teacher Leaders in Research Based Science Education (TLRBSE) is an NSF-funded Teacher Enhancement Program hosted by the National Optical Astronomy Observatory (NOAO) in Tucson, AZ. Consistent with national priorities in education, TLRBSE seeks to retain and renew middle and high school science teachers. Within the exciting context of astronomy, TLRBSE integrates the best pedagogical practices of Research Based Science Education with the process of mentoring. The main means by which participants are provided training in astronomy content, research pedagogy, image processing and leadership skills is through a 15-week distance-learning course and an in-residence, two-week summer institute at Kitt Peak National Observatory and the National Solar Observatory. At the observatories, teachers are the researchers on one of four research projects. In preparation for the research experience on Kitt Peak, the distance-learning course addresses the transition of the educational environment into an authentic research center and describes how best to prepare teachers to become part of scientific research teams. The DL course achieves this by successfully modeling best practices in research-based science education in three investigations. Subsequently the teachers' experience and knowledge gained through the distance-learning course and the summer institute are transferred to the classroom, where students learn science by doing science and mentees are mentored. Staff support by astronomers and education specialists continues with efforts to sustain a professional learning community that outlives the research experience. Further observing experience is available during the academic year. Students submit research papers to the RBSE on-line journal. Teachers and their mentees present at national NSTA meetings. During the AGU presentation, the focus will be on aspects of the distance-learning course, outcomes, lessons learned and future directions.

  8. Analyzing radial acceleration with a smartphone acceleration sensor

    NASA Astrophysics Data System (ADS)

    Vogt, Patrik; Kuhn, Jochen

    2013-03-01

    This paper continues the sequence of experiments using the acceleration sensor of smartphones (for description of the function and the use of the acceleration sensor, see Ref. 1) within this column, in this case for analyzing the radial acceleration.

  9. FIX-COUNT: A Program for Computing the Error-Success Transitions in Fixed-Trial Two-Stage Markov Learning Experiments.

    ERIC Educational Resources Information Center

    Kingma, Johannes; Van Den Bos, Kees P.

    1987-01-01

    A FORTRAN 77 program is described that computes both the different response success-error patterns and their summary statistics for learning and forgetting in fixed trial experiments using a two-stage Markov model. (Author/GDC)

  10. Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect

    Spentzouris, P.; Cary, J.; McInnes, L.C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.; /LBL, Berkeley

    2011-11-14

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization

  11. Experience-dependent enhancement of pitch-specific responses in the auditory cortex is limited to acceleration rates in normal voice range.

    PubMed

    Krishnan, A; Gandour, J T; Suresh, C H

    2015-09-10

    The aim of this study is to determine how pitch acceleration rates within and outside the normal pitch range may influence latency and amplitude of cortical pitch-specific responses (CPR) as a function of language experience (Chinese, English). Responses were elicited from a set of four pitch stimuli chosen to represent a range of acceleration rates (two each inside and outside the normal voice range) imposed on the high rising Mandarin Tone 2. Pitch-relevant neural activity, as reflected in the latency and amplitude of scalp-recorded CPR components, varied depending on language-experience and pitch acceleration of dynamic, time-varying pitch contours. Peak latencies of CPR components were shorter in the Chinese than the English group across stimuli. Chinese participants showed greater amplitude than English for CPR components at both frontocentral and temporal electrode sites in response to pitch contours with acceleration rates inside the normal voice pitch range as compared to pitch contours with acceleration rates that exceed the normal range. As indexed by CPR amplitude at the temporal sites, a rightward asymmetry was observed for the Chinese group only. Only over the right temporal site was amplitude greater in the Chinese group relative to the English. These findings may suggest that the neural mechanism(s) underlying processing of pitch in the right auditory cortex reflect experience-dependent modulation of sensitivity to acceleration in just those rising pitch contours that fall within the bounds of one's native language. More broadly, enhancement of native pitch stimuli and stronger rightward asymmetry of CPR components in the Chinese group is consistent with the notion that long-term experience shapes adaptive, distributed hierarchical pitch processing in the auditory cortex, and reflects an interaction with higher order, extrasensory processes beyond the sensory memory trace. PMID:26166727

  12. Experience-dependent enhancement of pitch-specific responses in the auditory cortex is limited to acceleration rates in normal voice range

    PubMed Central

    Krishnan, Ananthanarayan; Gandour, Jackson T.; Suresh, Chandan H.

    2015-01-01

    The aim of this study is to determine how pitch acceleration rates within and outside the normal pitch range may influence latency and amplitude of cortical pitch-specific responses (CPR) as a function of language experience (Chinese, English). Responses were elicited from a set of four pitch stimuli chosen to represent a range of acceleration rates (two each inside and outside the normal voice range) imposed on the high rising Mandarin Tone 2. Pitch-relevant neural activity, as reflected in the latency and amplitude of scalp-recorded CPR components, varied depending on language-experience and pitch acceleration of dynamic, time-varying pitch contours. Peak latencies of CPR components were shorter in the Chinese than the English group across stimuli. Chinese participants showed greater amplitude than English for CPR components at both frontocentral and temporal electrode sites in response to pitch contours with acceleration rates inside the normal voice pitch range as compared to pitch contours with acceleration rates that exceed the normal range. As indexed by CPR amplitude at the temporal sites, a rightward asymmetry was observed for the Chinese group only. Only over the right temporal site was amplitude greater in the Chinese group relative to the English. These findings may suggest that the neural mechanism(s) underlying processing of pitch in the right auditory cortex reflect experience-dependent modulation of sensitivity to acceleration in just those rising pitch contours that fall within the bounds of one’s native language. More broadly, enhancement of native pitch stimuli and stronger rightward asymmetry of CPR components in the Chinese group is consistent with the notion that long-term experience shapes adaptive, distributed hierarchical pitch processing in the auditory cortex, and reflects an interaction with higher-order, extrasensory processes beyond the sensory memory trace. PMID:26166727

  13. Beam dynamics of the Neutralized Drift Compression Experiment-II (NDCX-II),a novel pulse-compressing ion accelerator

    SciTech Connect

    Friedman, A.; Barnard, J.J.; Cohen, R.H.; Grote, D.P.; Lund, S.M.; Sharp, W.M.; Faltens, A.; Henestroza, E.; Jung, J.-Y.; Kwan, J.W.; Lee, E.P.; Leitner, M.A.; Logan, B.G.; Vay, J.-L.; Waldron, W.L.; Davidson, R.C.; Dorf, M.; Gilson, E.P.; Kaganovich, I.D.

    2009-12-19

    Intense beams of heavy ions are well suited for heating matter to regimes of emerging interest. A new facility, NDCX-II, will enable studies of warm dense matter at {approx}1 eV and near-solid density, and of heavy-ion inertial fusion target physics relevant to electric power production. For these applications the beam must deposit its energy rapidly, before the target can expand significantly. To form such pulses, ion beams are temporally compressed in neutralizing plasma; current amplification factors of {approx}50-100 are routinely obtained on the Neutralized Drift Compression Experiment (NDCX) at LBNL. In the NDCX-II physics design, an initial non-neutralized compression renders the pulse short enough that existing high-voltage pulsed power can be employed. This compression is first halted and then reversed by the beam's longitudinal space-charge field. Downstream induction cells provide acceleration and impose the head-to-tail velocity gradient that leads to the final neutralized compression onto the target. This paper describes the discrete-particle simulation models (1-D, 2-D, and 3-D) employed and the space-charge-dominated beam dynamics being realized.

  14. Beam dynamics of the Neutralized Drift Compression Experiment-II (NDCX-II), a novel pulse-compressing ion accelerator

    SciTech Connect

    Friedman, A; Barnard, J J; Cohen, R H; Grote, D P; Lund, S M; Sharp, W M; Faltens, A; Henestroza, E; Jung, J; Kwan, J W; Lee, E P; Leitner, M A; Logan, B G; Vay, J; Waldron, W L; Davidson, R C; Dorf, M; Gilson, E P; Kaganovich, I

    2009-11-19

    Intense beams of heavy ions are well suited for heating matter to regimes of emerging interest. A new facility, NDCX-II, will enable studies of warm dense matter at {approx}1 eV and near-solid density, and of heavy-ion inertial fusion target physics relevant to electric power production. For these applications the beam must deposit its energy rapidly, before the target can expand significantly. To form such pulses, ion beams are temporally compressed in neutralizing plasma; current amplification factors of {approx}50-100 are routinely obtained on the Neutralized Drift Compression Experiment (NDCX) at LBNL. In the NDCX-II physics design, an initial non-neutralized compression renders the pulse short enough that existing high-voltage pulsed power can be employed. This compression is first halted and then reversed by the beam's longitudinal space-charge field. Downstream induction cells provide acceleration and impose the head-to-tail velocity gradient that leads to the final neutralized compression onto the target. This paper describes the discrete-particle simulation models (1-D, 2-D, and 3-D) employed and the space-charge-dominated beam dynamics being realized.

  15. Demonstration of space-resolved x-ray Thomson scattering capability for warm dense matter experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Ao, T.; Harding, E. C.; Bailey, J. E.; Lemke, R. W.; Desjarlais, M. P.; Hansen, S. B.; Smith, I. C.; Geissel, M.; Maurer, A.; Reneker, J.; Romero, D.; Sinars, D. B.; Rochau, G. A.; Benage, J. F.

    2016-03-01

    Experiments on the Sandia Z pulsed-power accelerator have demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size, which are ideal for investigations of fundamental WDM properties. For the first time, space-resolved x-ray Thomson scattering (XRTS) spectra from shocked carbon foams were recorded on Z. The large (>20 MA) electrical current produced by Z was used to launch Al flyer plates up to 25 km/s. The impact of the flyer plate on a CH2 foam target produced a shocked state with an estimated pressure of 0.75 Mbar, density of 0.52 g/cm3, and temperature of 4.3 eV. Both unshocked and shocked portions of the foam target were probed with 6.2 keV x-rays produced by focusing the Z-Beamlet laser onto a nearby Mn foil. The data are composed of three spatially distinct spectra that were simultaneously captured with a single spectrometer with high spectral (4.8 eV) and spatial (190 μm) resolutions. Detailed spectral information from three target locations is provided simultaneously: the incident x-ray source, the scattered signal from unshocked foam, and the scattered signal from shocked foam.

  16. Demonstration of space-resolved x-ray Thomson scattering capability for warm dense matter experiments on the Z accelerator

    DOE PAGESBeta

    Ao, T.; Harding, E. C.; Bailey, J. E.; Lemke, R. W.; Desjarlais, M. P.; Hansen, S. B.; Smith, I. C.; Geissel, M.; Maurer, A.; Reneker, J.; et al

    2016-01-13

    Experiments on the Sandia Z pulsed-power accelerator demonstrated the ability to produce warm dense matter (WDM) states with unprecedented uniformity, duration, and size, which are ideal for investigations of fundamental WDM properties. For the first time, space-resolved x-ray Thomson scattering (XRTS) spectra from shocked carbon foams were recorded on Z. The large (> 20 MA) electrical current produced by Z was used to launch Al flyer plates up to 25 km/s. The impact of the flyer plate on a CH2 foam target produced a shocked state with an estimated pressure of 0.75 Mbar, density of 0.52 g/cm3, and temperature ofmore » 4.3 eV. Both unshocked and shocked portions of the foam target were probed with 6.2 keV x-rays produced by focusing the Z-Beamlet laser onto a nearby Mn foil. The data is composed of three spatially distinct spectra that were simultaneously captured with a single spectrometer with high spectral (4.8 eV) and spatial (190 μm) resolutions. Furthermore, these spectra provide detailed information on three target locations: the laser spot, the unshocked foam, and the shocked foam.« less

  17. Polymer gel dosimetry for neutron beam in the Neutron Exposure Accelerator System for Biological Effect Experiments (NASBEE)

    NASA Astrophysics Data System (ADS)

    Kawamura, H.; Sato, H.; Hamano, T.; Suda, M.; Yoshii, H.

    2015-01-01

    This study aimed to investigate whether gel dosimetry could be used to measure neutron beams. We irradiated a BANG3-type polymer gel dosimeter using neutron beams in the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) at the National Institute of Radiological Sciences (NIRS) in Japan. First, the polymer gels were irradiated from 0 to 7.0 Gy to investigate the dose-R2 responses. Irradiated gels were evaluated using 1.5-T magnetic resonance R2 images. Second, the polymer gels were irradiated to 1.0, 3.0, and 5.0 Gy to acquire a depth-R2 response curve. The dose-R2 response curve was linear up to approximately 7 Gy, with a slope of 1.25 Gy-1·s-1. Additionally, compared with the photon- irradiated gels, the neutron-irradiated gels had lower R2 values. The acquired depth-R2 curves of the central axis from the 3.0- and 5.0-Gy neutron dose-irradiated gels exhibited an initial build-up. Although, a detailed investigation is needed, polymer gel dosimetry is effective for measuring the dose-related R2 linearity and depth-R2 relationships of neutron beams.

  18. Calibration and monitoring of the MEG experiment by a proton beam from a Cockcroft-Walton accelerator

    NASA Astrophysics Data System (ADS)

    Adam, J.; Bai, X.; Baldini, A.; Baracchini, E.; Bemporad, C.; Boca, G.; Cattaneo, P. W.; Cavoto, G.; Cei, F.; Cerri, C.; Corbo, M.; Curalli, N.; de Bari, A.; De Gerone, M.; Doke, T.; Dussoni, S.; Egger, J.; Fratini, K.; Fujii, Y.; Galli, L.; Gallucci, G.; Gatti, F.; Golden, B.; Grassi, M.; Grigoriev, D. N.; Haruyama, T.; Hildebrandt, M.; Ignatov, F.; Iwamoto, T.; Kettle, P.-R.; Khazin, B. I.; Kiselev, O.; Korenchenko, A.; Kravchuk, N.; Maki, A.; Mihara, S.; Molzon, W.; Mori, T.; Mzavia, D.; Natori, H.; Nicolò, D.; Nishiguchi, H.; Nishimura, Y.; Ootani, W.; Panareo, M.; Papa, A.; Pazzi, R.; Piredda, G.; Popov, A.; Renga, F.; Ritt, S.; Rossella, M.; Sawada, R.; Sergiampietri, F.; Signorelli, G.; Tenchini, F.; Topchyan, C.; Uchiyama, Y.; Valle, R.; Voena, C.; Xiao, F.; Yamamoto, A.; Yudin, Yu. V.; Zanello, D.; MEG Collaboration

    2011-06-01

    The MEG experiment at PSI searches for the decay μ→eγ at a level of ≈10-13 on the branching ratio BR(μ→eγ/μ→tot), well beyond the present experimental limit ( BR≤1.2×10-11) and is sensitive to the predictions of SUSY-GUT theories. To reach this goal the experiment uses one of the most intense continuous surface muon beams available ( ≈108 μ/s) and relies on advanced technology (LXe calorimetry, a gradient-field superconducting spectrometer as well as flexible and powerful trigger and acquisition systems). In order to maintain the highest possible energy, time and spatial resolutions for such detector, frequent calibration and monitoring, using a Cockcroft-Walton proton accelerator, are required. The proton beam is brought to the centre of MEG by a special bellows insertion system and travels in a direction opposite to the one of the normal μ-beam. Protons interact with a lithium tetraborate (Li 2B 4O 7) nuclear target and produce one γ (17.6 MeV) from the reaction Li(p,γ)37Be48 or two coincident γs (11.67 and 4.4 MeV) from the reaction B(p,γ1)511C*612. The 17.6 MeV γ is used for calibrating and monitoring the LXe calorimeter ( σ/Eγ=3.85±0.15% at 17.6 MeV) while the coincident 11.67 and 4.4 MeV γs are used to measure the relative timing of the calorimeter and the spectrometer timing counters ( σ=0.450±0.015 ns).

  19. Successful establishment of patient-derived tumor xenografts from gastrointestinal stromal tumor-a single center experience

    PubMed Central

    Jiang, Quan; Tong, Han-Xing; Zhang, Yong; Hou, Ying-Yong; Li, Jing-Lei; Wang, Jiong-Yuan; Zhou, Yu-Hong; Lu, Wei-Qi

    2016-01-01

    Patient-derived tumor xenografts (PDTX) generally represent a kind of more reliable model of human disease, by which a potential drugs’ preclinical efficacy could be evaluated. To date, no stable gastrointestinal stromal tumor (GIST) PDTX models have been reported. In this study, we aimed to establish stable GIST PDTX models and to evaluate whether these models accurately reflected the histological feature of the corresponding patient tumors and create a reliable GIST PDTX models for our future experiment. By engrafting fresh patient GIST tissues into immune-compromised mice (BALB/c athymic mice), 4 PDTX models were established. Histological features were assessed by a qualified pathologist based on H&E staining, CD117 and DOG-1. We also conduct whole exome sequencing(WES) for the 4 established GIST PDTX models to test if the model still harbored the same mutation detected in corresponding patient tumors and get a more intensive vision for the genetic profile of the models we have established, which will help a lot for our future experiment. To explore the tumorigenesis mechanism for GIST, we also have a statistical analysis for the genes detected as nonsynchronous-mutated simultaneously in 4 samples. All 4 GIST PDTX models retained the histological features of the corresponding human tumors, with original morphology type and positive stains for CD117 and DOG-1. Between the GIST PDTX models and their parental tumors, a same mutation site was detected, which confirmed the genetic consistency. The stability of molecular profiles observed within the GIST PDTX models provides confidence in the utility and translational significance of these models for in vivo testing of personalized therapies. To date, we conducted the first study to successfully establish a GIST PDTX model whose genetic profiles were revealed by whole exome sequencing. Our experience could be of great use. PMID:27186422

  20. Beryllium liner implosion experiments on the Z accelerator in preparation for Magnetized Liner Inertial Fusion (MagLIF)*

    NASA Astrophysics Data System (ADS)

    McBride, Ryan D.

    2012-10-01

    Magnetized Liner Inertial Fusion (MagLIF) [1] is a concept that involves using a pulsed electrical current to implode an initially-solid, cylindrical metal tube (liner) filled with preheated and magnetized fusion fuel. One- and two-dimensional simulations predict that if sufficient liner integrity can be maintained throughout the implosion, then significant fusion yield (>100 kJ) is possible on the 25-MA, 100-ns Z accelerator. The greatest threat to the liner integrity is the Magneto-Rayleigh-Taylor (MRT) instability, which first develops on the outer liner surface, and then works its way inward toward the inner surface throughout the implosion. Two-dimensional simulations predict that a thick liner, with Router/δR=6, should be robust enough to keep the MRT instability from overly disrupting the fusion burn at stagnation. This talk will present the first experiments designed to study a thick, MagLIF-relevant liner implosion through to stagnation on Z [2]. The use of beryllium for the liner material enabled us to obtain penetrating monochromatic (6151±0.5 eV) radiographs that reveal information about the entire volume of the imploding liner. This talk will also discuss experiments that investigated Z's pulse-shaping capabilities to either shock- or shocklessly-compress the imploding liners [3], as well as our most recent experiments that used 2-micron-thick aluminum sleeves to provide high-contrast tracers for the positions and states of the inner surfaces of the imploding beryllium liners. The radiography data to be presented provide stringent constraints on the simulation tools used by the broader high energy density physics and inertial confinement fusion communities, where quantitative areal density measurements, particularly of convergent fusion targets, are relatively scarce. We will also present power-flow tests of the MagLIF load hardware as well as new micro-B-dot measurements of the azimuthal drive magnetic field that penetrates the initially vacuum

  1. Fulfilling the Promise of the Community College: Increasing First-Year Student Engagement and Success. The First-Year Experience Monograph Series Number 56

    ERIC Educational Resources Information Center

    Brown, Thomas, Ed.; King, Margaret C., Ed.; Stanley, Patricia, Ed.

    2011-01-01

    For the past three decades, American higher education has paid increasing attention to the beginning college experience--to ensuring that entering students make a successful transition to college. Yet, much of the extant research and practice literature focuses on the experience of first-year students entering four-year colleges and universities.…

  2. Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility

    SciTech Connect

    Spata, Michael F.

    2014-12-01

    Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.

  3. Commissioning and early experience with a new-generation low-energy linear accelerator with advanced delivery and imaging functionalities

    PubMed Central

    2011-01-01

    Background A new-generation low-energy linear accelerator (UNIQUE) was introduced in the clinical arena during 2009 by Varian Medical Systems. The world's first UNIQUE was installed at Oncology Institute of Southern Switzerland and put into clinical operation in June 2010. The aim of the present contribution was to report experience about its commissioning and first year results from clinical operation. Methods Commissioning data, beam characteristics and the modeling into the treatment planning system were summarized. Imaging system of UNIQUE included a 2D-2D matching capability and tests were performed to identify system repositioning capability. Finally, since the system is capable of delivering volumetric modulated arc therapy with RapidArc, a summary of the tests performed for such modality to assess its performance in preclinical settings and during clinical usage was included. Results Isocenter virtual diameter was measured as less than 0.2 mm. Observed accuracy of isocenter determination and repositioning for 2D-2D matching procedures in image guidance was <1.2 mm. Concerning reproducibility and stability over a period of 1 year, deviations from reference were found <0.3 ± 0.2% for linac output, <0.1% for homogeneity, similarly to symmetry. Rotational accuracy of the entire gantry-portal imager system showed a maximum deviation from nominal 0.0 of <1.2 mm. Pre treatment quality assurance of RapidArc plans resulted with a Gamma Agreement Index (fraction of points passing the gamma criteria) of 97.0 ± 1.6% on the first 182 arcs verified. Conclusions The results of the commissioning tests and of the first period of clinical operation, resulted meeting specifications and having good margins respect to tolerances. UNIQUE was put into operation for all delivery techniques; in particular, as shown by the pre-treatment quality assurance results, it enabled accurate and safe delivery of RapidArc plans. PMID:21961830

  4. Simulations of an accelerator-based shielding experiment using the particle and heavy-ion transport code system PHITS.

    PubMed

    Sato, T; Sihver, L; Iwase, H; Nakashima, H; Niita, K

    2005-01-01

    In order to estimate the biological effects of HZE particles, an accurate knowledge of the physics of interaction of HZE particles is necessary. Since the heavy ion transport problem is a complex one, there is a need for both experimental and theoretical studies to develop accurate transport models. RIST and JAERI (Japan), GSI (Germany) and Chalmers (Sweden) are therefore currently developing and bench marking the General-Purpose Particle and Heavy-Ion Transport code System (PHITS), which is based on the NMTC and MCNP for nucleon/meson and neutron transport respectively, and the JAM hadron cascade model. PHITS uses JAERI Quantum Molecular Dynamics (JQMD) and the Generalized Evaporation Model (GEM) for calculations of fission and evaporation processes, a model developed at NASA Langley for calculation of total reaction cross sections, and the SPAR model for stopping power calculations. The future development of PHITS includes better parameterization in the JQMD model used for the nucleus-nucleus reactions, and improvement of the models used for calculating total reaction cross sections, and addition of routines for calculating elastic scattering of heavy ions, and inclusion of radioactivity and burn up processes. As a part of an extensive bench marking of PHITS, we have compared energy spectra of secondary neutrons created by reactions of HZE particles with different targets, with thicknesses ranging from <1 to 200 cm. We have also compared simulated and measured spatial, fluence and depth-dose distributions from different high energy heavy ion reactions. In this paper, we report simulations of an accelerator-based shielding experiment, in which a beam of 1 GeV/n Fe-ions has passed through thin slabs of polyethylene, Al, and Pb at an acceptance angle up to 4 degrees. PMID:15934196

  5. Simulations of an accelerator-based shielding experiment using the particle and heavy-ion transport code system PHITS

    NASA Astrophysics Data System (ADS)

    Sato, T.; Sihver, L.; Iwase, H.; Nakashima, H.; Niita, K.

    In order to estimate the biological effects of HZE particles, an accurate knowledge of the physics of interaction of HZE particles is necessary. Since the heavy ion transport problem is a complex one, there is a need for both experimental and theoretical studies to develop accurate transport models. RIST and JAERI (Japan), GSI (Germany) and Chalmers (Sweden) are therefore currently developing and bench marking the General-Purpose Particle and Heavy-Ion Transport code System (PHITS), which is based on the NMTC and MCNP for nucleon/meson and neutron transport respectively, and the JAM hadron cascade model. PHITS uses JAERI Quantum Molecular Dynamics (JQMD) and the Generalized Evaporation Model (GEM) for calculations of fission and evaporation processes, a model developed at NASA Langley for calculation of total reaction cross sections, and the SPAR model for stopping power calculations. The future development of PHITS includes better parameterization in the JQMD model used for the nucleus-nucleus reactions, and improvement of the models used for calculating total reaction cross sections, and addition of routines for calculating elastic scattering of heavy ions, and inclusion of radioactivity and burn up processes. As a part of an extensive bench marking of PHITS, we have compared energy spectra of secondary neutrons created by reactions of HZE particles with different targets, with thicknesses ranging from <1 to 200 cm. We have also compared simulated and measured spatial, fluence and depth-dose distributions from different high energy heavy ion reactions. In this paper, we report simulations of an accelerator-based shielding experiment, in which a beam of 1 GeV/n Fe-ions has passed through thin slabs of polyethylene, Al, and Pb at an acceptance angle up to 4°.

  6. The National Coalition for Sustained Optimal Iodine intake (NSOI): a case study of a successful experience from India.

    PubMed

    Yadav, Kapil; Chakrabarty, Arijit; Rah, Jee Hyun; Kumar, Rakesh; Aguayo, Victor; Ansari, Mohammad Anas; Sankar, Rajan; Karmarkar, Madhu Ganesh; Pandav, Chandrakant S

    2014-01-01

    Iodine deficiency disorders (IDD) constitute the single most important preventable cause of mental handicap at global level. Recognizing the importance of coordination and synergy of the activities of wide range of universal salt iodisation (USI) stakeholders, WHO/ Unicef/ ICCIDD has prescribed a national multi-sectoral coalition as one of the ten indicators essential for attaining sustainable elimination of IDD at national level. Challenge for coordination among different stakeholders of IDD/USI is even greater in democratic and diverse country like India. In the present article we present successful experience from India regarding formation of a national coalition and contributions made by the coalition towards promoting USI in India. The activities of the national coalition in India are classified into three phases; 1) Phase 1- year 2006 to 2009- the inception; 2) Phase 2- year 2009 to 2012- consolidation; 3) Phase 3- year 2013 and ongoing- expansion. The National coalition for Sustained Optimal Iodine Intake (NSOI) has been instrumental in ensuring greater coordination and synergy amongst IDD and USI stakeholders in India and partially responsible for the current 71 percentage household level coverage of adequately iodised salt. The most significant contribution of the national coalition has been to act as a high level advocacy channel and provide a platform for regular dialogue for all partners of the coalition. With "mission" approach and allocation of optimal resource, India can achieve and should achieve USI by 2015, an apt culmination of a decade of existence of the national coalition. PMID:25384725

  7. Acceleration induced depriming and capillary rewetting of external artery heat pipes - Comparison with SHARE-II flight experiment

    NASA Technical Reports Server (NTRS)

    Ochterbeck, J. M.; Peterson, G. P.; Ungar, E. K.

    1993-01-01

    A combined analytical and numerical model for the analysis of the deprime and reprime/rewetting characteristics of two high-capacity external artery heat pipe designs undergoing externally induced accelerations was developed using several previously derived analytical expressions. Three distinct phases of the deprime and reprime/rewetting process were analyzed: (1) the effect of longitudinal accelerations on the depriming, (2) the time required for repriming of the liquid artery once the longitudinal acceleration has been terminated, and (3) the rewetting characteristics of the circumferential wall grooves. Combining the three processes, a technique was developed allowing the prediction of the effect of external acceleration on the characteristics of the external artery heat pipes. The predictions made with this technique agreed well with the microgravity flight results.

  8. Perceived benefits and challenges of repeated exposure to high fidelity simulation experiences of first degree accelerated bachelor nursing students.

    PubMed

    Kaddoura, Mahmoud; Vandyke, Olga; Smallwood, Christopher; Gonzalez, Kristen Mathieu

    2016-01-01

    This study explored perceptions of first-degree entry-level accelerated bachelor nursing students regarding benefits and challenges of exposure to multiple high fidelity simulation (HFS) scenarios, which has not been studied to date. These perceptions conformed to some research findings among Associate Degree, traditional non-accelerated, and second-degree accelerated Bachelor of Science in Nursing (BSN) students faced with one to two simulations. However, first-degree accelerated BSN students faced with multiple complex simulations perceived improvements on all outcomes, including critical thinking, confidence, competence, and theory-practice integration. On the negative side, some reported feeling overwhelmed by the multiple HFS scenarios. Evidence from this study supports HFS as an effective teaching and learning method for nursing students, along with valuable implications for many other fields. PMID:26260522

  9. Experiences of successful action programmes for occupational health, safety, and ergonomics promotion in small scale enterprises in Thailand.

    PubMed

    Tandhanskul, N; Duangsa-Ad, S; Pongpanich, C; Pungok, A; Punpeng, T; Juengprasert, W; Kawakami, T

    1995-06-01

    Small-scale enterprises are playing a vital role for the national economy in Thailand, creating employment in both urban and rural areas. The improvement of working conditions and occupational safety and health, together with improved productivity has long been a priority. How we could practically provide owners and workers of small-scale enterprises with opportunities for improvement action has been our concern. In the present project, we have adopted a new programme of action which emphasizes participation, a positive approach and locally made solutions. The project site was in Samutprakarn province, an industrial zone near Bangkok. Four local small-scale enterprises participated in the action programme. They were a lead smelting, a dry-cell battery plant, a wet-cell battery plant and a pesticides factory. The programme consisted of the following steps. 1) A demonstration training session was conducted to motivate the enterprises' representatives to take action. Locally invented improvement examples were presented and small group discussion was organized for facilitating their action. 2) The participants were encouraged to use a checklist for assessing safety, health and ergonomic risks in their own workplaces. Concrete action plans were established based on their checklist results. 3) The improvement action started, in which step-by-step approaches were emphasized. Advisory and supporting roles of expert teams comprising the authors and other professionals were important to accelerate and sustain the action at these enterprises. On the basis of this self-help action, the participants were enabled to make many improvements at their workplaces. These improvements developed by their own initiative were multi-factorial. They included 1) machine and electrical safety device, 2) workstation redesign, 3) materials handling improvement, 4) establishing new welfare facilities such as canteens or bathrooms and 5) work environment improvement such as better lighting or

  10. Ingredients of a Successful Summer Learning Program: A Case Study of the Building Educated Leaders for Life (BELL) Accelerated Learning Summer Program

    ERIC Educational Resources Information Center

    Capizzano, Jeffrey; Bischoff, Kendra; Woodroffe, Nicola; Chaplin, Duncan

    2007-01-01

    Based on positive results from a previous evaluation of a summer learning intervention, the current report describes the specific elements of the successful program so it can be replicated, and investigates potential barriers to implementation and replication. The study estimated impacts of the program overall; the authors could not identify which…

  11. Telepresence field research experience for undergraduate and graduate students: An R/V Okeanos Explorer/AUV Sentry success story

    NASA Astrophysics Data System (ADS)

    Van Dover, C. L.; German, C. R.; Yoerger, D. R.; Kaiser, C. L.; Brothers, L.

    2012-12-01

    Telepresence and ocean exploration are generally perceived as rich visual experiences informed by streaming video of ocean environments from ship to shore. In an NSF/NOAA-funded partnership, our team of engineers, scientists, and students pushed the boundary of what it means to engage in a telepresence research experience. Instead of using a tethered ROV as our data-gathering platform, we used the autonomous underwater vehicle Sentry on science missions to explore the Blake Ridge and Cape Fear Diapirs off the Carolina coast. The shore-based team included one senior engineer, two senior scientists, the talented support staff of the Inner Space Center at the University of Rhode Island, three PhD students, four undergraduate interns, and one MFA graduate student. The ship-based team included an engineer, a scientist, and extremely capable NOAA personnel. Sentry was deployed nightly on science missions designed from shore with input from shipboard science and engineering. The vehicle was recovered and data was downloaded and sent to shore each morning, where the data was 'attacked' by student teams. Within three days of the start of the field program, the student teams had developed their research questions under the mentorship of the senior scientists and identified the priority data streams required from Sentry. Students initially were audience to science mission planning discussions, but less than halfway through the 11-mission program, student teams were providing key data to inform planning decisions. Their entrepreneurial engagement with the research was so complete that the last two missions were designed by the students in collaboration with the engineers who programmed each mission. This scientific maturation of the students was markedly swift by usual standards and is attributed in large part to the data-sharing and data-processing capacity of the Inner Space Center. Post-cruise analysis of the data by students continued with the same avidity, resulting in

  12. Successive sheep grazing reduces population density of Brandt's voles in steppe grassland by altering food resources: a large manipulative experiment.

    PubMed

    Li, Guoliang; Yin, Baofa; Wan, Xinrong; Wei, Wanhong; Wang, Guiming; Krebs, Charles J; Zhang, Zhibin

    2016-01-01

    Livestock grazing has shaped grassland ecosystems around the world. Previous studies indicated grazing showed various impacts on small rodents; however, most studies were conducted over 1-2 years without controlling for confounding factors such as immigration/emigration and predation in rodents. Brandt's voles (Lasiopodomys brandtii) are generally recognized as pests because of food overlap with domestic herbivores, but are also important for biodiversity conservation because they provide nests or food to many birds. Fully understanding the ecological relationship between domestic herbivores and small mammals is essential to making ecosystem management decisions. To address these needs, we carried out a field experiment during the period 2010-2013 to assess the effects of sheep grazing on vegetation and the population density of Brandt's voles along a gradient of three grazing intensities by using 12 large-scale enclosures. Responses of Brandt's voles to livestock grazing varied with grazing intensity and year. As compared to the control group, sheep grazing had no effect on vole abundance in the first year but an overall negative effect on vole abundance in the following 3 years. Successive grazing caused decreases in survival and male body mass of voles, but had no significant effect on fecundity. Negative effects of grazing were associated with a grazing-induced deterioration in both food quantity (reflected by biomass and cover of less-preferred plants), and food quality (measured by tannin and total phenol content). Our findings highlight the urgent need for more flexible management of yearly rotational grazing to optimize livestock production while maintaining species diversity and ecosystem health. PMID:26446568

  13. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  14. Linear Accelerators

    SciTech Connect

    Sidorin, Anatoly

    2010-01-05

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  15. Dosimetric experience with 2 commercially available multilumen balloon-based brachytherapy to deliver accelerated partial-breast irradiation

    SciTech Connect

    Fu, Weihua Kim, Jong Oh; Chen, Alex S.J.; Mehta, Kiran; Pucci, Pietro; Huq, M. Saiful

    2015-10-01

    The purpose of this work was to report dosimetric experience with 2 kinds of multilumen balloon (MLB), 5-lumen Contura MLB (C-MLB) and 4-lumen MammoSite MLB (MS-MLB), to deliver accelerated partial-breast irradiation, and compare the ability to achieve target coverage and control skin and rib doses between 2 groups of patients treated with C-MLB and MS-MLB brachytherapy. C-MLB has 5 lumens, the 4 equal-spaced peripheral lumens are 5 mm away from the central lumen. MS-MLB has 4 lumens, the 3 equal-spaced peripheral lumens are 3 mm away from the central lumen. In total, 43 patients were treated, 23 with C-MLB, and 20 with MS-MLB. For C-MLB group, 8 patients were treated with a skin spacing < 7 mm and 12 patients with rib spacing < 7 mm. For MS-MLB group, 2 patients were treated with a skin spacing < 7 mm and 5 patients with rib spacing < 7 mm. The dosimetric goals were (1) ≥ 95% of the prescription dose (PD) covering ≥ 95% of the target volume (V{sub 95%} ≥ 95%), (2) maximum skin dose ≤ 125% of the PD, (3) maximum rib dose ≤ 145% of the PD (if possible), and (4) the V{sub 150%} ≤ 50 cm{sup 3} and V{sub 200%} ≤ 10 cm{sup 3}. All dosimetric criteria were met concurrently in 82.6% of C-MLB patients, in 80.0% of MS-MLB patients, and in 81.4% of all 43 patients. For each dosimetric parameter, t-test of these 2 groups showed p > 0.05. Although the geometric design of C-MLB is different from that of MS-MLB, both applicators have the ability to shape the dose distribution and to provide good target coverage, while limiting the dose to skin and rib. No significant difference was observed between the 2 patient groups in terms of target dose coverage and dose to organs at risk.

  16. Women, Poverty, and Educational Success: A Critical Exploration of Low-Income Women's Experience in Community Colleges

    ERIC Educational Resources Information Center

    Barry, Kate R.

    2012-01-01

    The purpose of this study is to critically explore low-income women's experience as they negotiate post secondary education in community colleges. Three research questions explore the context through which low-income women have entered the college experience, what that experience is like for them, and how the community college experience has…

  17. Another Wrinkle in the Debate about Successful Aging: The Undervalued Concept of Resilience and the Lived Experience of Dementia

    ERIC Educational Resources Information Center

    Harris, Phyllis Braudy

    2008-01-01

    The concept of "successful aging" is a contested discourse in gerontology. Two conflicting paradigms dominate the discussion: a health promotion activity model, and a model critical of the concept of successful aging. However, this study takes a different perspective and proposes that perhaps we have been striving for the wrong goal. The true…

  18. Understanding the Lived Experiences of At-Risk Black Males as It Relates to Their Academic Success

    ERIC Educational Resources Information Center

    Orrock, Jason Southall

    2012-01-01

    Through an ecological systems perspective, this study explores factors that influence successful academic achievement for at-risk African American males. The purpose of this qualitative study was to examine factors that contribute to the successful achievement and advancement to higher education for African American males from at-risk populations.…

  19. Social Success Skills: Black Male High School Students' Perspectives on Society and Their Media Experiences

    ERIC Educational Resources Information Center

    Degand, Darnel

    2013-01-01

    This dissertation's purpose was to better understand how messages received through different cultural mediums influences the development of social success skills. Black male students were chosen as the focal participants for this year-long study because they are included among the groups whose social success skills development are thought to…

  20. A multi-sample changer coupled to an electron cyclotron resonance source for accelerator mass spectrometry experiments

    NASA Astrophysics Data System (ADS)

    Vondrasek, R.; Palchan, T.; Pardo, R.; Peters, C.; Power, M.; Scott, R.

    2014-02-01

    A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving between samples in 1 min. The sample changer is part of a project using Accelerator Mass Spectrometry (AMS) at the Argonne Tandem Linac Accelerator System (ATLAS) facility to measure neutron capture rates on a wide range of actinides in a reactor environment. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly charged positive ions in an electron cyclotron resonance ion source followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation chosen to limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples.

  1. Space Acceleration Measurement System

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This training video, presented by the Lewis Research Center's Space Experiments Division, gives a background and detailed instructions for preparing the space acceleration measurement system (SAMS) for use. The SAMS measures, conditions, and records forces of low gravity accelerations, and is used to determine the effect of these forces on various experiments performed in microgravity. Inertial sensors are used to measure positive and negative acceleration over a specified frequency range. The video documents the SAMS' uses in different configurations during shuttle missions.

  2. Accelerators Beyond The Tevatron?

    SciTech Connect

    Lach, Joseph

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  3. Start with the End in Mind: Experiences of Accelerated Course Completion by Pre-Service Teachers and Educators

    ERIC Educational Resources Information Center

    Collins, Anita; Hay, Iain; Heiner, Irmgard

    2013-01-01

    In response to changes government funding and policies over the past five years, the Australian tertiary sector has entered an increasingly competitive climate. This has forced many universities to become more strategic in attracting increased numbers of PSTs. Providing accelerated learning opportunities for PSTs is viewed as one way to gain…

  4. HOME for STEPS. Homemaking Opportunity Modules for Education for Use with Surviving Today's Experiences and Problems Successfully. Compiled from Competency Based Modules Based on V-TECS Catalogs.

    ERIC Educational Resources Information Center

    Marshall Univ., Huntington, WV. Dept. of Home Economics.

    Designed to accompany Surviving Today's Experiences and Problems Successfully (STEPS) for 9th and 10th grade home economics courses, this volume consists of individualized learning packages dealing with four areas: management/family economics, human development, housing, and foods/nutrition. The book is divided into four parts. First, the…

  5. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  6. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

  7. Electron Lenses for Experiments on Nonlinear Dynamics with Wide Stable Tune Spreads in the Fermilab Integrable Optics Test Accelerator

    SciTech Connect

    Stancari, G.; Carlson, K.; McGee, M. W.; Nobrega, L. E.; Romanov, A. L.; Ruan, J.; Valishev, A.; Noll, D.

    2015-06-01

    Recent developments in the study of integrable Hamiltonian systems have led to nonlinear accelerator lattice designs with two transverse invariants. These lattices may drastically improve the performance of high-power machines, providing wide tune spreads and Landau damping to protect the beam from instabilities, while preserving dynamic aperture. To test the feasibility of these concepts, the Integrable Optics Test Accelerator (IOTA) is being designed and built at Fermilab. One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The parameters of the required device are similar to the ones of existing electron lenses. We present theory, numerical simulations, and first design studies of electron lenses for nonlinear integrable optics.

  8. Quasi-Steady Acceleration Direction Indicator in Three Dimensions

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Nelson, Emily S.; Jules, Kenol

    2000-01-01

    Many materials processing and fluids physics experiments conducted in a microgravity environment require knowledge of the orientation of the low-frequency acceleration vector. This need becomes especially acute for space experiments such as directional solidification of a molten semiconductor, which is extremely sensitive to orientation and may involve tens of hours of operations of a materials furnace. These low-frequency acceleration data have been measured for many Shuttle missions with the Orbital Acceleration Research Experiment. Previous attempts at using fluid chambers for acceleration measurements have met with limited success due to pointing and vehicle attitude complications. An acceleration direction indicator is described, which is comprised of two orthogonal short cylinders of fluid, each with a small bubble. The motion and the position of the bubble within the chamber will indicate the direction of the acceleration experienced at the sensor location. The direction of the acceleration vector may then be calculated from these data. The frequency response of such an instrument may be tailored for particular experiments with the proper selection of fluid and gas parameters, surface type, and geometry. A three-dimensional system for sensing and displaying the low-frequency acceleration direction via an innovative technique described in this paper has advantages in terms of size, mass, and power compared with electronic instrumentation systems.

  9. Success, Difficulty, and Instructional Strategy to Enact an Argument-Based Inquiry Approach: Experiences of Elementary Teachers

    ERIC Educational Resources Information Center

    Choi, Aeran; Klein, Vanessa; Hershberger, Susan

    2015-01-01

    This study aimed to investigate the successes and difficulties that teachers perceived as they enacted an argument-based inquiry approach; and instructional strategies that teachers used within an argument-based inquiry approach. Nineteen elementary teachers from 14 Midwestern elementary schools were enrolled in an intensive 2-week professional…

  10. Student Experience and Academic Success: Comparing a Student-Centred and a Lecture-Based Course Programme

    ERIC Educational Resources Information Center

    Severiens, Sabine; Meeuwisse, Marieke; Born, Marise

    2015-01-01

    Past research has shown that, under certain conditions, student-centred and small-scale course programmes result in more academic success. The present study investigates these conditions in further detail. It is examined whether, in comparison to a course programme that is relatively more lecture-based, a student-centred course programme promotes…

  11. Accelerating reproductive and child health programme impact with community-based services: the Navrongo experiment in Ghana.

    PubMed Central

    Phillips, James F.; Bawah, Ayaga A.; Binka, Fred N.

    2006-01-01

    OBJECTIVE: To determine the demographic and health impact of deploying health service nurses and volunteers to village locations with a view to scaling up results. METHODS: A four-celled plausibility trial was used for testing the impact of aligning community health services with the traditional social institutions that organize village life. Data from the Navrongo Demographic Surveillance System that tracks fertility and mortality events over time were used to estimate impact on fertility and mortality. RESULTS: Assigning nurses to community locations reduced childhood mortality rates by over half in 3 years and accelerated the time taken for attainment of the child survival Millennium Development Goal (MDG) in the study areas to 8 years. Fertility was also reduced by 15%, representing a decline of one birth in the total fertility rate. Programme costs added 1.92 US Dollar per capita to the 6.80 US Dollar per capita primary health care budget. CONCLUSION: Assigning nurses to community locations where they provide basic curative and preventive care substantially reduces childhood mortality and accelerates progress towards attainment of the child survival MDG. Approaches using community volunteers, however, have no impact on mortality. The results also demonstrate that increasing access to contraceptive supplies alone fails to address the social costs of fertility regulation. Effective deployment of volunteers and community mobilization strategies offsets the social constraints on the adoption of contraception. The research in Navrongo thus demonstrates that affordable and sustainable means of combining nurse services with volunteer action can accelerate attainment of both the International Conference on Population and Development agenda and the MDGs. PMID:17242830

  12. [Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center]. Progress report, calendar year 1993

    SciTech Connect

    Hertzbach, S.S.; Kofler, R.R.

    1993-12-31

    The High Energy Physics group at the University of Massachusetts has continued its` program of experimental studies of electron-positron interactions at the Stanford Linear Accelerator Center (SLAC). The group activities have included: analysis of data taken between 1982 and 1990 with the TPC detector at the PEP facility, continuing data collection and data analysis using the SLC/SLD facility, planning for the newly approved B-factory at SLAC, and participation in design studies for future high energy linear colliders. This report will briefly summarize these activities.

  13. The pleasures of success: game-related efficacy experiences as a mediator between player performance and game enjoyment.

    PubMed

    Trepte, Sabine; Reinecke, Leonard

    2011-09-01

    In the present study, the interplay of player performance, game-related self-efficacy experiences, and the resulting effects on game enjoyment are investigated. We hypothesized that a player's performance stimulates enjoyment via its potential to stimulate game-related self-efficacy experiences. In a laboratory setting, participants (N = 213) played a jump 'n' run game. Their performance during game play was recorded by log-file software, and efficacy and enjoyment were assessed with questionnaires. As predicted, both player performance and game-related self-efficacy experience were significant predictors of enjoyment. Furthermore, the results demonstrate that game-related self-efficacy experience significantly mediates the relationship between player performance and game enjoyment. PMID:21342012

  14. Digit ratio (2D:4D) predicts sporting success among female fencers independent from physical, experience, and personality factors.

    PubMed

    Voracek, M; Reimer, B; Dressler, S G

    2010-12-01

    Research particularly focusing on male athletes and popular sports (running and soccer) suggests associations of lower (masculinized) second-to-fourth digit ratio (2D:4D), a putative marker of prenatal androgen action, with better sports performance. Studies focusing on women, non-mainstream sports, or controlling for covariates relevant for sporting success are still sparse. This study examined associations between 2D:4D and performance of both male and female athletes active in fencing (a non-mainstream sport dominated by male participants), while controlling for covariates. National fencing rankings and 2D:4D of 58 male and 41 female Austrian tournament fencers (mean age 24 years) were correlated. Among female, but not male, fencers, lower 2D:4D was related to better national fencing rankings. 2D:4D still accounted for incremental variance (12%) in fencing success, when the effects of salient performance factors (age, body mass index, years of fencing, training intensity, and the personality variables achievement, control, harm avoidance, and social potency) were controlled for (totaling 35% attributable variance). Athletes active in the most aggressive form (the sabre) had lower 2D:4D than those active in the other forms (épée and foil fencing). Sporting success in adult life might be partly prenatally programmed via long-lasting extragenital effects of testosterone. PMID:19843265

  15. Five years' experience in a (really) rural teleradiology practice. Was it worth it? The successes and the failures

    NASA Astrophysics Data System (ADS)

    Telepak, Robert J.; Freede, Emily; Jaramillo, Richard E.; Alverson, Dale C.

    1998-07-01

    During the past 5 years (1992 - 1997) the Department of Radiology of the University of New Mexico Health Sciences Center has developed an active teleradiology program. Contracts are in place to provide both routine and emergency image interpretations 24 hours per day, every day of the year. Several rural hospitals are served as well as the Navajo Indian Health Service. Areas of success: include significantly improved radiologic service to the rural sites, specialty consultations to general radiologists, successful teaching of teleradiology practice to radiology residents and staff, good diagnostic quality images, a small but real profit, improved quality assurance for the rural sites, and no significant medical-legal problems. Failures include: significant telecommunications problems, lack of acceptance and utilization by some of the rural sites, poor QA compliance by some sites, a long period of disappointing technical support by equipment vendors, and slow acceptance of DICOM by equipment manufacturers. The successes outweigh the failures. We would do it again -- but somewhat differently. We offer advice to institutions developing a new rural teleradiology operation.

  16. The MESA accelerator

    SciTech Connect

    Aulenbacher, Kurt

    2013-11-07

    The MESA accelerator will operate for particle and nuclear physics experiments in two different modes. A first option is conventional c.w. acceleration yielding 150-200MeV spin-polarized external beam. Second, MESA will be operated as a superconducting multi-turn energy recovery linac (ERL), opening the opportunity to perform experiments with a windowless target with beam current of up to 10 mA. The perspectives for innovative experiments with such a machine are discussed together with a sketch of the accelerator physics issues that have to be solved.

  17. Detecting Energy Modulation in a Dielectric Laser Accelerator

    SciTech Connect

    Lukaczyk, Louis

    2015-08-21

    The Dielectric Laser Acceleration group at SLAC uses micro-fabricated dielectric grating structures and conventional infrared lasers to accelerator electrons. These structures have been estimated to produce an accelerating gradient up to 2 orders of magnitude greater than that produced by conventional RF accelerators. The success of the experiment depends on both the laser damage threshold of the structure and the timing overlap of femtosecond duration laser pulses with the electron bunch. In recent dielectric laser acceleration experiments, the laser pulse was shorter both temporally and spatially than the electron bunch. As a result, the laser is theorized to have interacted with only a small portion of the electron bunch. The detection of this phenomenon, referred to as partial population modulation, required a new approach to the data analysis of the electron energy spectra. A fitting function was designed to separate the accelerated electron population from the un-accelerated electron population. The approach was unsuccessful in detecting acceleration in the partial population modulation data. However, the fitting functions provide an excellent figure of merit for previous data known to contain signatures of acceleration.

  18. Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    PubMed

    Wilson, Peter J; Williams, Janet R; Smee, Robert I

    2014-09-01

    Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series. PMID:24825407

  19. Supratentorial primitive neuroectodermal tumors (S-PNET) in children: A prospective experience with adjuvant intensive chemotherapy and hyperfractionated accelerated radiotherapy

    SciTech Connect

    Massimino, Maura . E-mail: maura.massimino@istitutotumori.mi.it; Gandola, Lorenza; Spreafico, Filippo; Luksch, Roberto; Collini, Paola; Giangaspero, Felice; Simonetti, Fabio; Casanova, Michela; Cefalo, Graziella; Pignoli, Emanuele; Ferrari, Andrea; Terenziani, Monica; Podda, Marta; Meazza, Cristina; Polastri, Daniela; Poggi, Geraldina; Ravagnani, Fernando; Fossati-Bellani, Franca

    2006-03-15

    Purpose: Supratentorial primitive neuroectodermal tumors (S-PNET) are rare and have a grim prognosis, frequently taking an aggressive course with local relapse and metastatic spread. We report the results of a mono-institutional therapeutic trial. Methods and Materials: We enrolled 15 consecutive patients to preradiation chemotherapy (CT) consisting of high-dose methotrexate, high-dose etoposide, high-dose cyclophosphamide, and high-dose carboplatin, craniospinal irradiation (CSI) with hyperfractionated accelerated radiotherapy (HART) plus focal boost, maintenance with vincristine/lomustine or consolidation with high-dose thiotepa followed by autologous stem-cell rescue. Results: Median age was 9 years; 7 were male, 8 female. Site of disease was pineal in 3, elsewhere in 12. Six patients were had no evidence of disease after surgery (NED). Of those with evidence of disease after surgery (ED), 2 had central nervous system spread. Of the 9 ED patients, 2 had complete response (CR) and 2 partial response (PR) after CT, 4 stable disease, and 1 progressive disease. Of the 7 ED patients before radiotherapy, 1 had CR, 4 PR, and 2 minor response, thus obtaining a 44% CR + PR after CT and 71% after HART. Because of rapid progression in 2 of the first 5 patients, high-dose thiotepa was systematically adopted after HART in the subsequent 10 patients. Six of 15 patients relapsed (4 locally, 1 locally with dissemination, 1 with dissemination) a mean of 6 months after starting CT, 2 developed second tumors; 5 of 6 relapsers died at a median of 13 months. Three-year progression-free survival, event-free survival, and overall survival were 54%, 34%, and 61%, respectively. Conclusion: Hyperfractionated accelerated RT was the main tool in obtaining responses in S-PNET; introducing the myeloablative phase improved the prognosis (3/10 vs. 3/5 relapses), though the outcome remained unsatisfactory despite the adoption of this intensive treatment.

  20. Nonlinear optimisation techniques for accelerator performance improvement on-line: recent trials and experiment for the CERN antiproton accumulator

    NASA Astrophysics Data System (ADS)

    Chohan, Vinod

    1986-06-01

    The use of function minimisation techniques for optimum design according to given performance criteria is well-known. Given a well-defined criterion and a means of evaluating it precisely, the problem reduces to choosing the best optimisation procedure to suit the problem. Direct search techniques which do not generally rely on the computation of derivatives of the error function are ideal for on-line improvement of the global accelerator performance since the error function is not known analytically, e.g. the number of antiprotons stored in the antiproton accumulator ring on a pulse-to-pulse basis as a function of all the antiproton production and stochastic cooling system parameters. The user-friendliness of the NODAL interpreter at the man-machine interaction level, its capability to easily control and manipulate equipment as well as its capability to synchronise with respect to time events on a cycle-to-cycle basis makes it suitable for an on-line accelerator performance optimisation type of application. A modular procedure, based on the Simplex technique [1] has been implemented recently which allows function minimisation depending on the error function definition module. This enables an easy manipulation of variables and synchronization with machine events. For the antiproton accumulator (AA), while the circulating beam current transformer lacks the resolution to measure the exact number of antiprotons stored on a pulse-to-pulse basis, there are a large number of electrons produced in the production process [2] and a signal emanating from these can be adapted to provide the performance criterion and appropriate parameters used as function variables in the optimisation process. First trials based on optimisation of injection of antiprotons in the AA look promising, but further work is necessary in the direct definition of the error functions.