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Sample records for residual damage gsi

  1. DNA-DSB in CHO-K1 cells induced by heavy-ions: Break rejoining and residual damage (GSI)

    NASA Technical Reports Server (NTRS)

    Taucher-Scholz, G.; Heilmann, J.; Becher, G.; Kraft, G.

    1994-01-01

    DNA double strand breaks (DSB's) are the critical lesions involved in cellular effects of ionizing radiation. Therefore, the evaluation of DSB induction in mammalian cells after heavy ion irradiation is an essential task for the assessment of high-LET radiation risk in space. Of particular interest has been the question of how the biological efficiency for the cellular inactivation endpoint relates to the initial lesions (DSBs) at varying LETs. For cell killing, an increased Relative Biological Efficiency (RBE) has been determined for highLET radiation around 100-200 keV/mu m. At higher LET, the RBE's decrease again to values below one for the very heavy particles. At GSI, DSB-induction was measured in CHO-K1 cells following irradiation with accelerated particles covering a wide LET range. The electrophoretic elution of fragmented DNA out of agarose plugs in a constant electrical field was applied for the detection of DSB's. The fraction of DNA retained was determined considering the relative intensities of ethidium bromide fluorescence in the well and in the gel lane. Dose-effect curves were established, from which the RBE for DSB induction was calculated at a fraction of 0.7 of DNA retained In summary, these rejoining studies are in line with an enhanced severity of the DNA DSB's at higher LET's, resulting in a decreased repairability of the induced lesions. However, no information concerning the fidelity of strand breaks rejoining is provided in these studies. To assess correct rejoining of DNA fragments an experimental system involving individual DNA hybridization bands has been set up. In preliminary experiments Sal I generated DNA fragments of 0.9 Mbp were irradiated with xrays and incubated for repair However, restitution of the original signals was not observed, probably due to the high radiation dose necessary for breakage of a fragment of this size. A banding pattern with NotI hybridization signals in a higher MW range (3Mbp) has been obtained by varying

  2. Prediction of residual strength of impact damaged aerospace composite structures

    SciTech Connect

    Garg, A.C.

    1993-12-31

    The importance of composites for aerospace structures is well known and therefore its increased use is being made for such structural components. However, these structures may be damaged as a result of various causes. One of the important causes is the impact damage either during manufacture or service. The amount of damage by impact created in the structure depends on several parameters such as impactor mass and velocity (impact energy), the structure material and support conditions. Since the magnitude of damage depends on impact energy, the residual strength may be expressed as a function of impact energy. Using a three parametric approach, a model is proposed to predict the residual strength behavior of impact damaged structure. The predicted behavior is shown to compare favorably with the available test data.

  3. Residual stresses and damage in unidirectional model composites

    SciTech Connect

    Chatterjee, A.; Moschler, J.W.; Mall, S.; Kerans, R.J.; Pagano, N.J.

    1989-10-01

    Unidirectional model composites were fabricated with SiC fibers and different borosilicate glasses to study the effect of residual stress states on the damage progression in these composites. A specially designed straining stage was employed to study the failure modes in these materials under stepwise loading. Although both fiber and matrix cracks were observed in all specimens, the mechanisms of failure were found to be different and strongly dependent on the residual stress state in these materials. 15 refs.

  4. Mechanical relaxation of localized residual stresses associatedwith foreign object damage

    SciTech Connect

    Boyce, B.L.; Chen, X.; Peters, J.O.; Hutchinson, J.H.; Ritchie,R.O.

    2002-05-01

    Foreign-object damage associated with the ingestion ofdebris into aircraft turbine engines can lead to a marked degradation inthe high-cycle fatigue life of turbine components. This degradation isgenerally considered to be associated with the premature initiation offatigue cracks at or near the damage sites; this is suspected to be dueto, at least in part, the impact-induced residual stress state, which canbe strongly tensile in these locations.

  5. Residual Strength Prediction of Fuselage Structures with Multiple Site Damage

    NASA Technical Reports Server (NTRS)

    Chen, Chuin-Shan; Wawrzynek, Paul A.; Ingraffea, Anthony R.

    1999-01-01

    This paper summarizes recent results on simulating full-scale pressure tests of wide body, lap-jointed fuselage panels with multiple site damage (MSD). The crack tip opening angle (CTOA) fracture criterion and the FRANC3D/STAGS software program were used to analyze stable crack growth under conditions of general yielding. The link-up of multiple cracks and residual strength of damaged structures were predicted. Elastic-plastic finite element analysis based on the von Mises yield criterion and incremental flow theory with small strain assumption was used. A global-local modeling procedure was employed in the numerical analyses. Stress distributions from the numerical simulations are compared with strain gage measurements. Analysis results show that accurate representation of the load transfer through the rivets is crucial for the model to predict the stress distribution accurately. Predicted crack growth and residual strength are compared with test data. Observed and predicted results both indicate that the occurrence of small MSD cracks substantially reduces the residual strength. Modeling fatigue closure is essential to capture the fracture behavior during the early stable crack growth. Breakage of a tear strap can have a major influence on residual strength prediction.

  6. FAIR project at GSI

    NASA Astrophysics Data System (ADS)

    Kester, Oliver; Spiller, Peter; Stoecker, Horst

    FAIR -- the Facility for Antiproton and Ion Research in Europe -- constructed at GSI Helmholtzzentrum für Schwerionenforschung GmbH in Darmstadt comprises an international centre of heavy ion accelerators that will drive heavy ion and antimatter research (FBTR, 2006). FAIR will provide worldwide unique accelerator and experimental facilities allowing a large variety of fore-front research in physics and applied science. FAIR will deliver antiproton and ion beams of unprecedented intensities and qualities. The main part of the FAIR facility is a sophisticated and cost efficient accelerator system, which delivers parallel beams to different experiments of the FAIR experimental collaborations -- APPA, NuSTAR, CBM and PANDA. The accelerated primary beams will then be employed to create new, often highly exotic particles in a series of parallel experimental programs. Experiments with exotic particles will explore fundamental processes which are expected to have taken place in the early phases and still happen in the on-going evolution of the Universe. These processes produced the basic constituents of matter and overall structure we observe today...

  7. FLAIR Project at GSI

    SciTech Connect

    Welsch, C. P.; Grieser, M.; Ullrich, J.; Wolf, A.

    2006-03-20

    The future Facility for Antiproton and Ion Research (FAIR) at Darmstadt will produce the highest flux of antiprotons in the world. Within the planned complex of storage rings, it will also be feasible to decelerate the antiprotons to about 30 MeV kinetic energy, opening up the unique possibility to create low energy antiprotons and thus, establish low-energy antiproton physics at GSI. In the Facility for Low-energy Antiproton and Ion Research (FLAIR) the antiprotons shall be slowed down by means of two cooler storage rings. In the second one, the Ultra-low energy electrostatic Storage Ring (USR), energies ranging from 300 keV to 20 keV will be available for various in-ring experiments as well as for efficient injection of antiprotons into traps. In the limit of such small beam energies, the realization of efficient electron cooling, employing electron energies of only a few eV is one of the new challenges. In this contribution, a review of the FLAIR facility is given and its deceleration and cooling scheme is elucidated in comparison to the present AD operation scheme. Special emphasis is placed on the problems related to electron cooling at ultra-low energies.

  8. A methodology to predict damage initiation, damage growth and residual strength in titanium matrix composites

    NASA Technical Reports Server (NTRS)

    Bakuckas, J. G., Jr.; Johnson, W. S.

    1994-01-01

    In this research, a methodology to predict damage initiation, damage growth, fatigue life, and residual strength in titanium matrix composites (TMC) is outlined. Emphasis was placed on micromechanics-based engineering approaches. Damage initiation was predicted using a local effective strain approach. A finite element analysis verified the prevailing assumptions made in the formulation of this model. Damage growth, namely, fiber-bridged matrix crack growth, was evaluated using a fiber bridging (FB) model which accounts for thermal residual stresses. This model combines continuum fracture mechanics and micromechanics analyses yielding stress-intensity factor solutions for fiber-bridged matrix cracks. It is assumed in the FB model that fibers in the wake of the matrix crack are idealized as a closure pressure, and an unknown constant frictional shear stress is assumed to act along the debond length of the bridging fibers. This frictional shear stress was used as a curve fitting parameter to the available experimental data. Fatigue life and post-fatigue residual strength were predicted based on the axial stress in the first intact 0 degree fiber calculated using the FB model and a three-dimensional finite element analysis.

  9. Stochastic Cooling Developments at GSI

    SciTech Connect

    Nolden, F.; Beckert, K.; Beller, P.; Dolinskii, A.; Franzke, B.; Jandewerth, U.; Nesmiyan, I.; Peschke, C.; Petri, P.; Steck, M.; Caspers, F.; Moehl, D.; Thorndahl, L.

    2006-03-20

    Stochastic Cooling is presently used at the existing storage ring ESR as a first stage of cooling for secondary heavy ion beams. In the frame of the FAIR project at GSI, stochastic cooling is planned to play a major role for the preparation of high quality antiproton and rare isotope beams. The paper describes the existing ESR system, the first stage cooling system at the planned Collector Ring, and will also cover first steps toward the design of an antiproton collection system at the planned RESR ring.

  10. Interpretation of body residues for natural resources damage assessment

    SciTech Connect

    Kubitz, J.A.; Markarian, R.K.; Lauren, D.J.; Dimitry, J.A.

    1995-12-31

    A 28-day caged mussel study using Corbicula sp. was conducted on Sugarland Run and the Potomac River following a spill of No. 2 fuel oil. In addition, resident Corbicula sp. from the Potomac River were sampled at the beginning and end of the study. The summed body residues of 39 polycyclic aromatic hydrocarbons (PAHs) ranged from 0.56 to 41 mg/kg dry weight within the study area. The summed body residues of the 18 PAHs that are routinely measured in the national oceanic and Atmospheric Administration Status and Trends Program (NST) ranged from 0.5 to 20 mg/kg dry weight for mussels in this study. These data were similar to summed PAH concentrations reported in the NST for mussels from a variety of US coastal waters, which ranged from 0.4 to 24.5 mg/kg dry weight. This paper will discuss interpretation of PAH residues in Corbicula sp. to determine the spatial extent of the area affected by the oil spill. The toxicological significance of the PAH residues in both resident and caged mussels will also be presented.

  11. Future Facility: FAIR at GSI

    NASA Astrophysics Data System (ADS)

    Rosner, Guenther

    2007-05-01

    The Facility for Antiproton and Ion Research, FAIR, is a new particle accelerator facility to be built at the GSI site in Germany. The research at FAIR will cover a wide range of topics in nuclear and hadron physics, high density plasma and atomic physics, and applications in condensed matter physics and biology. A 1.1 km circumference double ring of rapidly cycling 100 and 300 Tm synchrotrons, will be FAIR's central accelerator system. It will be used to produce, inter alia, high intensity secondary beams of antiprotons and short-lived radioactive nuclei. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experiments are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

  12. Progressive damage and residual strength of notched composite laminates: A new effective crack growth model

    SciTech Connect

    Ye, L.; Afaghi-Khatibi, A.; Mai, Y.W.

    1997-12-31

    The main objective of this study was to evaluate the residual strength of fiber reinforced metal laminates (FRMLs) and polymer matrix composite laminates (PMCLs) with a circular hole or sharp notch using an effective crack growth model (ECGM). Damage is assumed to initiate when the local normal stress at the hole edge/notch tip reaches the tensile strength or yield strength of the composite and metal layers, respectively. The damage in the constituent materials was modelled by fictitious cracks with cohesive stress acting on the crack surfaces, and the damage growth was simulated by extension of the fictitious cracks step by step and reduction of the cohesive stress with crack opening. The apparent fracture energy of composite layers and fracture toughness of metal layers were used to define the relationships between the tensile/yield strength and the critical crack opening. Based on the global equilibrium, an iterative technique was developed to evaluate the applied load required to produce the damage growth. The residual strength of notched composite laminates was defined by instability of the applied load and damage growth. The effect of hole/notch size on the residual strength was studied and the stress redistribution with damage growth was discussed. The residual strength simulated from ECGM correlated well with experimental data in the open literature.

  13. The FIRST experiment at GSI

    NASA Astrophysics Data System (ADS)

    Pleskac, R.; Abou-Haidar, Z.; Agodi, C.; Alvarez, M. A. G.; Aumann, T.; Battistoni, G.; Bocci, A.; Böhlen, T. T.; Boudard, A.; Brunetti, A.; Carpinelli, M.; Cirrone, G. A. P.; Cortes-Giraldo, M. A.; Cuttone, G.; De Napoli, M.; Durante, M.; Fernández-García, J. P.; Finck, C.; Golosio, B.; Gallardo, M. I.; Iarocci, E.; Iazzi, F.; Ickert, G.; Introzzi, R.; Juliani, D.; Krimmer, J.; Kurz, N.; Labalme, M.; Leifels, Y.; Le Fevre, A.; Leray, S.; Marchetto, F.; Monaco, V.; Morone, M. C.; Oliva, P.; Paoloni, A.; Piersanti, L.; Quesada, J. M.; Raciti, G.; Randazzo, N.; Romano, F.; Rossi, D.; Rousseau, M.; Sacchi, R.; Sala, P.; Sarti, A.; Scheidenberger, C.; Schuy, C.; Sciubba, A.; Sfienti, C.; Simon, H.; Sipala, V.; Spiriti, E.; Stuttge, L.; Tropea, S.; Younis, H.; Patera, V.

    2012-06-01

    The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at the SIS accelerator of GSI laboratory in Darmstadt has been designed for the measurement of ion fragmentation cross-sections at different angles and energies between 100 and 1000 MeV/nucleon. Nuclear fragmentation processes are relevant in several fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The start of the scientific program of the FIRST experiment was on summer 2011 and was focused on the measurement of 400 MeV/nucleon 12C beam fragmentation on thin (8 mm) graphite target. The detector is partly based on an already existing setup made of a dipole magnet (ALADiN), a time projection chamber (TP-MUSIC IV), a neutron detector (LAND) and a time of flight scintillator system (TOFWALL). This pre-existing setup has been integrated with newly designed detectors in the Interaction Region, around the carbon target placed in a sample changer. The new detectors are a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger scintillator system optimized for the detection of light fragments emitted at large angles. In this paper we review the experimental setup, then we present the simulation software, the data acquisition system and finally the trigger strategy of the experiment.

  14. Residual ultimate strength of a very large crude carrier considering probabilistic damage extents

    NASA Astrophysics Data System (ADS)

    Choung, Joonmo; Nam, Ji-Myung; Tayyar, Tansel

    2014-03-01

    This paper provides the prediction of ultimate longitudinal strengths of the hull girders of a very large crude carrier considering probabilistic damage extent due to collision and grounding accidents based on IMO Guidelines (2003). The probabilistic density functions of damage extent are expressed as a function of non-dimensional damage variables. The accumulated probabilistic levels of 10%, 30%, 50%, and 70% are taken into account for the estimation of damage extent. The ultimate strengths have been calculated using the in-house software called Ultimate Moment Analysis of Damaged Ships which is based on the progressive collapse method, with a new convergence criterion of force vector equilibrium. Damage indices are provided for several probable heeling angles from 0° (sagging) to 180° (hogging) due to collision- and grounding-induced structural failures and consequent flooding of compartments. This paper proves from the residual strength analyses that the second moment of area of a damage section can be a reliable index for the estimation of the residual ultimate strength. A simple polynomial formula is also proposed based on minimum residual ultimate strengths.

  15. A Progressive Damage Methodology for Residual Strength Predictions of Notched Composite Panels

    NASA Technical Reports Server (NTRS)

    Coats, Timothy W.; Harris, Charles E.

    1998-01-01

    The translaminate fracture behavior of carbon/epoxy structural laminates with through-penetration notches was investigated to develop a residual strength prediction methodology for composite structures. An experimental characterization of several composite materials systems revealed a fracture resistance behavior that was very similar to the R-curve behavior exhibited by ductile metals. Fractographic examinations led to the postulate that the damage growth resistance was primarily due to fractured fibers in the principal load-carrying plies being bridged by intact fibers of the adjacent plies. The load transfer associated with this bridging mechanism suggests that a progressive damage analysis methodology will be appropriate for predicting the residual strength of laminates with through-penetration notches. A progressive damage methodology developed by the authors was used to predict the initiation and growth of matrix cracks and fiber fracture. Most of the residual strength predictions for different panel widths, notch lengths, and material systems were within about 10% of the experimental failure loads.

  16. Response surface characterization of impact damage and residual strength degradation in composite sandwich panels

    NASA Astrophysics Data System (ADS)

    Samarah, Issam Khder

    2003-06-01

    The influence of material configuration and impact parameters on the damage tolerance characteristics of sandwich composites comprised of carbon-epoxy woven fabric facesheets and Nomex honeycomb cores was investigated using empirically based response surfaces. A series of carefully selected tests were used to isolate the coupled influence of various combinations of the number of facesheet plies, core density, core thickness, impact energy, impactor diameter, and impact velocity on the damage formation and residual strength degradation due to normal impact. The ranges of selected material parameters were typical of those found in common aircraft applications. The diameter of the planar damage area associated with Through Transmission Ultrasonic C-scan measurements and the peak residual facesheet indentation depth were used to describe the extent of internal and detectable surface damage, respectively. Standard analysis of variance techniques were used to assess the significance of the regression models, individual model terms, and model lack-of-fit. In addition, the inherent variability associated with given types of experimental measurements was evaluated. Response surface estimates of the size of the planar damage region and compressive residual strength as a continuous function of material system and impact parameters correlated reasonably well with experimentally determined values. For a fixed set of impact parameters, regression results suggest that impact damage development and residual strength degradation is highly material and lay-up configuration dependent. Increasing the number of facesheet plies and the thickness of the core material generally resulted in the greatest improvement in the damage tolerance characteristics. An increase in the impact energy can result in a significant decrease in the estimated residual strength, particularly for those sandwich panels with thicker facesheets. The effects of variable impact velocity on damage formation and loss

  17. Ultrasonic Method for Prediction of Residual Life of Creep Damaged Materials

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Yeol; Kim, Hak-Joon; Song, Sung-Jin; Kim, Bum-Joon; Lim, Byeong-Soo

    2009-03-01

    In the previous study, residual life time of creep damaged 9Cr-2W steel specimens were evaluated using attenuation of ultrasound and area fraction of precipitates. Since attenuation coefficients and area fraction of precipitates were increased as increasing their aging time. However, cause of increasing attenuation of ultrasound is not only increase in precipitates but also grain growth. So, in this study, we calculated attenuation coefficients for grain growth using the single scattering model in order to find effect grain growth in the creep damaged materials on attenuation. Then, we extract attenuation coefficients for precipitates from the measured ultrasonic attenuation of creep damaged specimens by subtracting attenuation coefficients for grain boundaries using the calculated attenuation. And, we predicted residual life time of the creep damaged specimens by using the attenuation for precipitates.

  18. Damage detection in elastic structures using vibratory residual forces and weighted sensitivity

    NASA Technical Reports Server (NTRS)

    Ricles, J. M.; Kosmatka, J. B.

    1992-01-01

    A methodology is presented for detecting structural damage in elastic structures by nondestructive means. Measured modal test data along with a correlated analytical structural model are used to locate potentially damaged regions using residual modal force vectors and to conduct a weighted sensitivity analysis to assess the extent of mass and/or stiffness variations, where damage is characterized as a stiffness reduction. The current approach is unique among other approaches in that it accounts for (1) variations in system mass, system stiffness, and mass center (locations), (2) perturbations of both the natural frequencies and modal vectors, and (3) statistical confidence factors for the structural parameters and potential experimental instrumentation error. Moreover, this procedure can be used with either full or reduced models. A wide variety of numerical examples are presented that show that the current method provides a precise indication of both the location and the extent of structural damage.

  19. On Using Residual Voltage to Estimate Electrode Model Parameters for Damage Detection

    PubMed Central

    Krishnan, Ashwati; Kelly, Shawn K.

    2016-01-01

    Current technology has enabled a significant increase in the number of electrodes for electrical stimulation. For large arrays of electrodes, it becomes increasingly difficult to monitor and detect failures at the stimulation site. In this paper, we propose the idea that the residual voltage from a biphasic electrical stimulation pulse can serve to recognize damage at the electrode-tissue interface. We use a simple switch circuit approach to estimate the relaxation time constant of the electrode model, which essentially models the residual voltage in biphasic electrical stimulation, and compare it with standard electrode characterization techniques. Out of 15 electrodes in a polyimide-based SIROF array, our approach highlights 3 damaged electrodes, consistent with measurements made using cyclic voltammetry and electrode impedance spectroscopy.

  20. A Progressive Damage Methodology for Residual Strength Predictions of Center-Crack Tension Composite Panels

    NASA Technical Reports Server (NTRS)

    Coats, Timothy William

    1996-01-01

    An investigation of translaminate fracture and a progressive damage methodology was conducted to evaluate and develop a residual strength prediction capability for laminated composites with through penetration notches. This is relevant to the damage tolerance of an aircraft fuselage that might suffer an in-flight accident such as an uncontained engine failure. An experimental characterization of several composite materials systems revealed an R-curve type of behavior. Fractographic examinations led to the postulate that this crack growth resistance could be due to fiber bridging, defined here as fractured fibers of one ply bridged by intact fibers of an adjacent ply. The progressive damage methodology is currently capable of predicting the initiation and growth of matrix cracks and fiber fracture. Using two difference fiber failure criteria, residual strength was predicted for different size panel widths and notch lengths. A ply discount fiber failure criterion yielded extremely conservative results while an elastic-perfectly plastic fiber failure criterion showed that the fiber bridging concept is valid for predicting residual strength for tensile dominated failure loads. Furthermore, the R-curves predicted by the model using the elastic-perfectly plastic fiber criterion compared very well with the experimental R-curves.

  1. Effects of stacking sequence on impact damage resistance and residual strength for quasi-isotropic laminates

    NASA Technical Reports Server (NTRS)

    Dost, Ernest F.; Ilcewicz, Larry B.; Avery, William B.; Coxon, Brian R.

    1991-01-01

    Residual strength of an impacted composite laminate is dependent on details of the damage state. Stacking sequence was varied to judge its effect on damage caused by low-velocity impact. This was done for quasi-isotropic layups of a toughened composite material. Experimental observations on changes in the impact damage state and postimpact compressive performance were presented for seven different laminate stacking sequences. The applicability and limitations of analysis compared to experimental results were also discussed. Postimpact compressive behavior was found to be a strong function of the laminate stacking sequence. This relationship was found to depend on thickness, stacking sequence, size, and location of sublaminates that comprise the impact damage state. The postimpact strength for specimens with a relatively symmetric distribution of damage through the laminate thickness was accurately predicted by models that accounted for sublaminate stability and in-plane stress redistribution. An asymmetric distribution of damage in some laminate stacking sequences tended to alter specimen stability. Geometrically nonlinear finite element analysis was used to predict this behavior.

  2. A damage-softening statistical constitutive model considering rock residual strength

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-liang; Li, Yong-chi; Wang, J. G.

    2007-01-01

    Under stress, the microcracks in rock evolve (initiation, growth and coalescence) from damage to fracture with a continuous process. In order to describe this continuous process, a damage-softening statistical constitutive model for rock was proposed based on the Weibull distribution of mesoscopic element strength. This model usually adopts the Drucker-Prager criterion as its distribution parameter of mesoscopic element strength, which may produce larger damage zone in numerical simulations. This paper mainly studies the effects of strength criteria and residual strength on the performance of this damage-softening statistical constitutive model of rock. Main works include following three aspects: Firstly, the mechanical behaviors of rock are comparatively studied when the Drucker-Prager and the Mohr-Coulomb criteria are employed, respectively, as the distribution parameter. Then, a coefficient is introduced to make this constitutive model be capable of describing the residual strength of rock. Finally, a user-defined subroutine is concisely developed for this model and checked through typical strain paths. The current work lays a good foundation for further application of this model in geotechnics and geosciences.

  3. Residual stress and damage-induced critical fracture on CO2 laser treated fused silica

    SciTech Connect

    Matthews, M; Stolken, J; Vignes, R; Norton, M

    2009-11-02

    Localized damage repair and polishing of silica-based optics using mid- and far-IR CO{sub 2} lasers has been shown to be an effective method for increasing optical damage threshold in the UV. However, it is known that CO{sub 2} laser heating of silicate surfaces can lead to a level of residual stress capable of causing critical fracture either during or after laser treatment. Sufficient control of the surface temperature as a function of time and position is therefore required to limit this residual stress to an acceptable level to avoid critical fracture. In this work they present the results of 351 nm, 3 ns Gaussian damage growth experiments within regions of varying residual stress caused by prior CO{sub 2} laser exposures. Thermally stressed regions were non-destructively characterized using polarimetry and confocal Raman microscopy to measure the stress induced birefringence and fictive temperature respectively. For 1 {approx} 40s square pulse CO{sub 2} laser exposures created over 0.5-1.25 kW/cm{sup 2} with a 1-3 mm 1/e{sup 2} diameter beam (T{sub max} {approx} 1500-3000 K), the critical damage site size leading to fracture increases weakly with peak temperature, but shows a stronger dependence on cooling rate, as predicted by finite element hydrodynamics simulations. Confocal micro-Raman was used to probe structural changes to the glass over different thermal histories and indicated a maximum fictive temperature of 1900K for T{sub max} {ge} 2000 K. The effect of cooling rate on fictive temperature caused by CO{sub 2} laser heating are consistent with finite element calculations based on a Tool-Narayanaswamy relaxation model.

  4. The NUSTAR Project at GSI and FAIR

    NASA Astrophysics Data System (ADS)

    Gerl, J.

    2015-11-01

    NUSTAR comprises the current nuclear structure, astrophysics and reactions programme at GSI and its proposed continuation and extension at FAIR. NUSTAR relies on the availability of exotic rare-isotope beams produced by fragmentation reactions and fission of relativistic heavy ions. The fragment separator FRS and a versatile set of instruments, including gamma arrays, particle spectrometers and a storage ring, enable unique experiments at GSI. The Super-FRS at the FAIR facility will provide several orders of magnitude stronger beams, providing access to the extremes of nuclear stability. To exploit these opportunities novel experimental set-ups are in preparation. R&D efforts have already resulted in improved detectors and enable the NUSTAR collaboration to steadily enhance the sensitivity and selectivity limits of their experiments. Current NUSTAR physics highlights, as well as development projects and activities, will be discussed.

  5. A Finite Element Analysis for Predicting the Residual Compressive Strength of Impact-Damaged Sandwich Panels

    NASA Technical Reports Server (NTRS)

    Ratcliffe, James G.; Jackson, Wade C.

    2008-01-01

    A simple analysis method has been developed for predicting the residual compressive strength of impact-damaged sandwich panels. The method is tailored for honeycomb core-based sandwich specimens that exhibit an indentation growth failure mode under axial compressive loading, which is driven largely by the crushing behavior of the core material. The analysis method is in the form of a finite element model, where the impact-damaged facesheet is represented using shell elements and the core material is represented using spring elements, aligned in the thickness direction of the core. The nonlinear crush response of the core material used in the analysis is based on data from flatwise compression tests. A comparison with a previous analysis method and some experimental data shows good agreement with results from this new approach.

  6. A Finite Element Analysis for Predicting the Residual Compression Strength of Impact-Damaged Sandwich Panels

    NASA Technical Reports Server (NTRS)

    Ratcliffe, James G.; Jackson, Wade C.

    2008-01-01

    A simple analysis method has been developed for predicting the residual compression strength of impact-damaged sandwich panels. The method is tailored for honeycomb core-based sandwich specimens that exhibit an indentation growth failure mode under axial compression loading, which is driven largely by the crushing behavior of the core material. The analysis method is in the form of a finite element model, where the impact-damaged facesheet is represented using shell elements and the core material is represented using spring elements, aligned in the thickness direction of the core. The nonlinear crush response of the core material used in the analysis is based on data from flatwise compression tests. A comparison with a previous analysis method and some experimental data shows good agreement with results from this new approach.

  7. Relevance of impacter shape to nonvisible damage and residual tensile strength of a thick graphite/epoxy laminate

    NASA Technical Reports Server (NTRS)

    Poe, Clarence C., Jr.

    1991-01-01

    A study was made to determine the relevance of impacter shape to nonvisible damage and tensile residual strength of a 36 mm thick graphite/epoxy motor case. The shapes of the impacters were as follows: 12.7 mm and 25.4 mm diameter hemispheres, a sharp corner, and a 6.3 mm diameter bolt-like rod. The investigation revealed that damage initiated when the contact pressure exceeded a critical level. However, the damage was not visible on the surface until an even higher pressure was exceeded. The impact energy to initiate damage or cause visible damage on the surface increased approximately with impacter diameter to the third power. The reduction in strength for nonvisible damage increased with increasing diameter, 9 and 30 percent for the 12.7 mm and 25.4 mm diameter hemispheres, respectively. The corner impacter made visible damage on the surface for even the smallest impact energy. The rod impacter acted like a punch and sliced through the composite. Even so, the critical level of pressure to initiate damage was the same for the rod and hemispherical impacters. Factors of safety for nonvisible damage increased with increasing kinetic energy of impact. The effects of impacter shape on impact force, damage size, damage visibility, and residual tensile strength were predicted quite well assuming Hertzian contact and using maximum stress criteria and a surface crack analysis.

  8. Residual skin damage in rats 1 year after exposure to x rays or accelerated heavy ions

    SciTech Connect

    Leith, J.T.; McDonald, M.; Howard, J.

    1982-01-01

    In conjunction with a study on the biological effects of accelerated heavy ions on rat spinal cord, we were able to assess the residual skin damage remaining 1 year postirradiation. In this study, rats were irradiated with 230-kVp fractionated doses of either X rays, carbon ions, or neon ions. Four radiation fractions were given at daily intervals. For the carbon and neon ion exposures, rats were irradiated in both the plateau and spread Bragg peak (4 cm) regions of ionization. Comparing doses that produced complete epilation with a slight suggestion of a residual radiation scar, it was found that the relative biological effectivesness (RBE) values 1 year postirradiation for the four fraction irradiations were: carbon ions (plateau ionization region), 1.06; carbon ions (spread Bragg peak ionization region), 1.88; neon ions (plateau region of ionization), 1.55; and neon ions (spread Bragg peak ionization region), 2.26. RBE values for production of paralysis after spinal cord irradiation (using the same X-ray total dose levels for comparison purposes) were in all cases higher than the RBE values obtained from assessment of residual skin injury.

  9. Composite sandwich construction with syntactic foam core - A practical assessment of post-impact damage and residual strength

    NASA Technical Reports Server (NTRS)

    Hiel, C.; Dittman, D.; Ishai, O.

    1993-01-01

    An account is given of an inspection method that has been successfully used to assess the postimpact damage and residual strength of syntactic (glass microspheres in epoxy matrix) foam-core sandwich panels with hybrid (carbon and glass fiber-reinforced) composite skins, which inherently possess high damage tolerance. SEM establishes that the crushing of the microspheres is responsible for the absorption of most of the impact energy. Damage tolerance is a function of the localization of damage by that high impact energy absorption.

  10. The influence of tensile fatigue damage on residual compressive strength of woven composites

    SciTech Connect

    Mitrovic, M.; Carman, G.P.

    1995-12-31

    The long term mechanical fatigue of a Celion G30-500/PMR-15 woven composite system is investigated to study the interrelationship between thermo-mechanical properties, namely the thermal expansion coefficient (TEC) and the compressive strength. Residual compressive strength measurements (IITRI fixture) conducted on specimens subjected to tension-tension fatigue cycling indicate that this material property is sensitive to cracks and delaminations which form during mechanical cycling. Measured compressive strength degradation are as large as 49% for this material undergoing mechanical fatigue cycling with TEC degradation as large as 61%. Experimental results show that a correlation exists between TEC measurements and compressive strength. This correlation suggests that TEC measurements may be used as a damage evaluation technique.

  11. Damage of composite structures: Detection technique, dynamic response and residual strength

    NASA Astrophysics Data System (ADS)

    Lestari, Wahyu

    2001-10-01

    Reliable and accurate health monitoring techniques can prevent catastrophic failures of structures. Conventional damage detection methods are based on visual or localized experimental methods and very often require prior information concerning the vicinity of the damage or defect. The structure must also be readily accessible for inspections. The techniques are also labor intensive. In comparison to these methods, health-monitoring techniques that are based on the structural dynamic response offers unique information on failure of structures. However, systematic relations between the experimental data and the defect are not available and frequently, the number of vibration modes needed for an accurate identification of defects is much higher than the number of modes that can be readily identified in the experiment. These motivated us to develop an experimental data based detection method with systematic relationships between the experimentally identified information and the analytical or mathematical model representing the defective structures. The developed technique use changes in vibrational curvature modes and natural frequencies. To avoid misinterpretation of the identified information, we also need to understand the effects of defects on the structural dynamic response prior to developing health-monitoring techniques. In this thesis work we focus on two type of defects in composite structures, namely delamination and edge notch like defect. Effects of nonlinearity due to the presence of defect and due to the axial stretching are studied for beams with delamination. Once defects are detected in a structure, next concern is determining the effects of the defects on the strength of the structure and its residual stiffness under dynamic loading. In this thesis, energy release rate due to dynamic loading in a delaminated structure is studied, which will be a foundation toward determining the residual strength of the structure.

  12. Impact damage resistance and residual property assessment of (0/+/-45/90)s SCS-6/Timetal 21S

    NASA Technical Reports Server (NTRS)

    Miller, Jennifer L.; Portanova, Marc A.; Johnson, W. Steven

    1995-01-01

    The impact damage resistance and residual mechanical properties of (0/ +/- 45/90)s SCS-6/Timetal 21S composites were evaluated. Both quasi-static indentation and drop-weight impact tests were used to investigate the impact behavior at two nominal energy levels (5.5 and 8.4 J) and determine the onset of internal damage. Through x-ray inspection, the extent of internal damage was characterized non-destructively. The composite strength and constant amplitude fatigue response were evaluated to assess the effects of the sustained damage. Scanning electron microscopy was used to characterize internal damage from impact in comparison to damage that occurs during mechanical loading alone. The effect of stacking sequence was examined by using specimens with the long dimension of the specimen both parallel (longitudinal) and perpendicular (transverse) to the 0 deg fiber direction. Damage in the form of longitudinal and transverse cracking occurred in all longitudinal specimens tested at energies greater than 6.3 J. Similar results occurred in the transverse specimens tested above 5.4 J. Initial load drop, characteristic of the onset of damage, occurred on average at 6.3 J in longitudinal specimens and at 5.0 J in transverse specimens. X-ray analysis showed broken fibers in the impacted region in specimens tested at the higher impact energies. At low impact energies, visible matrix cracking may occur, but broken fibers may not. Matrix cracking was noted along fiber swims and it appeared to depend on the surface quality of composite. At low impact energies, little damage has been incurred by the composite and the residual strength and residual life is not greatly reduced as compared to an undamaged composite. At higher impact energies, more damage occurred and a greater effect of the impact damage was observed.

  13. S1219 residue of 53BP1 is phosphorylated by ATM kinase upon DNA damage and required for proper execution of DNA damage response

    SciTech Connect

    Lee, Haemi; Kwak, Hee-Jin; Cho, Il-taeg; Park, Seok Hee; Lee, Chang-Hun

    2009-01-02

    53BP1 is phosphorylated by the protein kinase ATM upon DNA damage. Even though several ATM phosphorylation sites in 53BP1 have been reported, those sites have little functional implications in the DNA damage response. Here, we show that ATM phosphorylates the S1219 residue of 53BP1 in vitro and that the residue is phosphorylated in cells exposed to ionizing radiation (IR). Transfection with siRNA targeting ATM abolished IR-induced phosphorylation at this residue, supporting the theory that this process is mediated by the kinase. To determine the functional relevance of this phosphorylation event, a U2OS cell line expressing S1219A mutant 53BP1 was established. IR-induced foci formation of MDC1 and {gamma}H2AX, DNA damage signaling molecules, was reduced in this cell line, implying that S1219 phosphorylation is required for recruitment of these molecules to DNA damage sites. Furthermore, overexpression of the mutant protein impeded IR-induced G2 arrest. In conclusion, we have shown that S1219 phosphorylation by ATM is required for proper execution of DNA damage response.

  14. Experimental Investigations on Fatigue Damage and Residual Properties of Interacting Notched Woven E-Glass/Epoxy Composite

    NASA Astrophysics Data System (ADS)

    Bhaskara Rao, Pathakokila; Rama Krishna, Avasarala; Ramji, Koona; Satya Devi, Ambadipudi

    2015-10-01

    The interacting notched laminates of plain weave E-glass fiber reinforced with epoxy were fatigued at predetermined frequency in tension-tension to investigate the fatigue damage and residual properties. The results from stress-life curves summarize that damage growing around the notches due to stress concentration is the underlying cause for the variation in fatigue strengths among the geometrically different specimens considered. The residual strength and modulus decay with respect to cycle number at 50 % of the ultimate tensile strength were investigated. It is evident from the experimental data that the residual strength decreases with cycle number and increases due to redistribution of stress around the notches. The detailed study of the damage development under cyclic loads also explains the causes of modulus reduction for all the laminate geometries.

  15. Relevance of impacter shape to nonvisible damage and residual tensile strength of a thick graphite/epoxy laminate

    NASA Technical Reports Server (NTRS)

    Poe, C. C., Jr.

    1990-01-01

    A study was made to determine the relevance of impacter shape to nonvisible damage and tensile residual strength of a 36 mm (1.4 in.) thick graphite/epoxy motor case. The shapes of the impacters were as follows: 12.7 mm (0.5 in.) and 25.4 mm (1.0 in.) diameter hemispheres, a sharp corner, and a 6.3 mm (0.25 in.) diameter bolt-like rod. The investigation revealed that damage initiated when the contact pressure exceeded a critical level. However, the damage was not visible on the surface until an even higher pressure was exceeded. The damage on the surface consisted of a crater shaped like the impacter, and the damage below the surface consisted of broken fibers. The impact energy to initiate damage or cause visible damage on the surface increased approximately with impacter diameter to the third power. The reduction in strength for nonvisible damage increased with increasing diameter, 9 and 30 percent for the 12.7 mm (0.5 in.) and 25.4 mm (1.0 in.) diameter hemispheres, respectively. The corner impacter made visible damage on the surface for even the smallest impact energy. The rod impacter acted like a punch and sliced through the composite. Even so, the critical level of pressure to initiate damage was the same for the rod and hemispherical impacters. Factors of safety for nonvisible damage increased with increasing kinetic energy of impact. The effects of impacter shape on impact force, damage size, damage visibility, and residual tensile strength were predicted quite well assuming Hertzian contact and using maximum stress criteria and a surface crack analysis.

  16. Evaluation of residual stand damage following whole-tree partial cutting in northern forest types

    SciTech Connect

    Cline, M.L. ); Hoffman, B. . Coll. of Forest Resources); Cyr, M. )

    1990-06-01

    A market for low-quality wood chips for biomass boilers in recent years has evoked mixed reactions from both the public and the forestry community. The increased demand for rough, rotten, and cull trees for fuelwood presents opportunities to improve timber stand quality in the Northeast forest. In the past, only the best trees were harvested in the past leaving the poorer quality ones to develop into the next forest, a practice called high-grading. The new market for low-quality wood offers an opportunity to reverse the adverse impacts of high-grading. The present study was designed to quantify the amount of residual stand damage that occurs when whole-trees are harvested during thinning or partial cut operations, and to correlate the extend of damage with several important variables of silvicultural management. A total of 18 hardwood or mixed wood study sites were selected in Maine, New Hampshire, and Vermont that were harvested within the last five years using wheeled, drive-to-bunch harvesting machines.

  17. Vacuum arc ion source development at GSI

    SciTech Connect

    Spaedtke, P.; Emig, H.; Wolf, B.H.

    1996-08-01

    Ion beams produced by the Mevva ion source are well suited for the injection into a synchrotron accelerator due to the low repetition rate (0.2 ... 5 Hz, the higher repetition rate is for the optimization of the linear accelerator only) and the short pulse length (up to 0.5ms). From the beginning of the authors experience with the Mevva ion source at GSI they tried to improve the reliability of pulse-to-pulse reproducibility and to minimize the noise on the extracted ion beam. For accelerator application this is highly necessary, otherwise the accelerator tuning and optimization becomes very difficult or even impossible. Already the beam transport becomes difficult for a noisy beam, because space charge compensation can be destroyed (at least partially). Furthermore a noisy dc-beam results in some rf-buckets which might be even empty.

  18. The ASY-EOS Experiment at GSI

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Chartier, M.; Cozma, M. D.; De Filippo, E.; Le Fèvre, A.; Gannon, S.; Gašparić, I.; Kiš, M.; Kupny, S.; Leifels, Y.; Lemmon, R. C.; Li, Q.; Łukasik, J.; Marini, P.; Pawłowski, P.; Trautmann, W.; Acosta, L.; Adamczyk, M.; Al-Ajlan, A.; Al-Garawi, M.; Al-Homaidhi, S.; Amorini, F.; Auditore, L.; Aumann, T.; Ayyad, Y.; Baran, V.; Basrak, Z.; Bassini, R.; Benlliure, J.; Boiano, C.; Boisjoli, M.; Boretzky, K.; Brzychczyk, J.; Budzanowski, A.; Cardella, G.; Cammarata, P.; Chajecki, Z.; Chbihi, A.; Colonna, M.; Czech, B.; Di Toro, M.; Famiano, M.; Greco, V.; Grassi, L.; Guazzoni, C.; Guazzoni, P.; Heil, M.; Heilborn, L.; Introzzi, R.; Isobe, T.; Kezzar, K.; Krasznahorkay, A.; Kurz, N.; La Guidara, E.; Lanzalone, G.; Lasko, P.; Lombardo, I.; Lynch, W. G.; Matthews, Z.; May, L.; Minniti, T.; Mostazo, M.; Pagano, A.; Papa, M.; Pirrone, S.; Pleskac, R.; Politi, G.; Porto, F.; Reifarth, R.; Reisdorf, W.; Riccio, F.; Rizzo, F.; Rosato, E.; Rossi, D.; Santoro, S.; Simon, H.; Skwirczynska, I.; Sosin, Z.; Stuhl, L.; Trifirò, A.; Trimarchi, M.; Tsang, M. B.; Verde, G.; Veselsky, M.; Vigilante, M.; Wieloch, A.; Wigg, P.; Wolter, H. H.; Wu, P.; Yennello, S.; Zambon, P.; Zetta, L.; Zoric, M.

    2016-05-01

    The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. In the ASY-EOS experiment at the GSI laboratory, flows of neutrons and light charged particles were measured for 197Au+197Au collisions at 400 MeV/nucleon. Flow results obtained for the Au+Au system, in comparison with predictions of the UrQMD transport model, confirm the moderately soft to linear density dependence of the symmetry energy deduced from the earlier FOPI-LAND data.

  19. Experience with carbon ion radiotherapy at GSI

    NASA Astrophysics Data System (ADS)

    Jäkel, O.; Schulz-Ertner, D.; Karger, C. P.; Heeg, P.; Debus, J.

    2005-12-01

    At GSI, a radiotherapy facility was established using beam scanning and active energy variation. Between December 1997 and April 2004, 220 patients have been treated at this facility with carbon ions. Most patients are treated for chordoma and chondrosarcoma of the base of skull, using a dose of 60 Gye (Gray equivalent) in 20 fractions. Carbon ion therapy is also offered in a combination with conventional radiotherapy for a number of other tumors (adenoidcystic carcinoma, chordoma of the cervical spine and sacrum, atypical menningeoma). The patients treated for skull base tumors showed an overall local control rate after two years of 90%. The overall treatment toxicity was mild. This shows that carbon ion radiotherapy can safely be applied using a scanned beam and encouraged the Heidelberg university hospital to build a hospital based facility for ion therapy.

  20. ASY-EOS experiment at GSI

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Acosta, L.; Adamczyk, M.; Al-Ajlan, A.; Al-Garawi, M.; Al-Homaidhi, S.; Amorini, F.; Auditore, L.; Aumann, T.; Ayyad, Y.; Baran, V.; Basrak, Z.; Benlliure, J.; Boiano, C.; Boisjoli, C.; Boretzky, K.; Brzychczyk, J.; Budzanowski, A.; Cardella, G.; Cammarata, P.; Cavallaro, S.; Chajecki, Z.; Chartier, M.; Chbihi, A.; Colonna, M.; Czech, B.; De Filippo, E.; Di Toro, M.; Famiano, M.; Le Fevre, A.; Gašsparić, A.; Geraci, E.; Grassi, L.; Greco, V.; Guazzoni, C.; Guazzoni, P.; Heil, M.; Heilborn, L.; Introzzi, R.; Isobe, T.; Kezzar, K.; Kiš, M.; Kupny, S.; Kurz, N.; La Guidara, E.; Lanzalone, G.; Lasko, P.; Leifels, Y.; Lemmon, R.; Li, Q.; Lombardo, I.; Loria, D.; Lukasik, J.; Lynch, W. G.; Marini, P.; Matthews, Z.; May, L.; Minniti, T.; Mostazo, M.; Pagano, A.; Papa, M.; Pawlowski, P.; Petrovici, M.; Pirrone, S.; Politi, G.; Porto, F.; Reifarth, R.; Reisdorf, W.; Riccio, F.; Rizzo, F.; Rosato, E.; Rossi, D.; Santoro, S.; Simon, H.; Skwirczynska, I.; Sosin, Z.; Trautmann, W.; Trifirò, A.; Trimarchi, M.; Tsang, B.; Veselsky, M.; Verde, G.; Vigilante, M.; Wieloch, A.; Wigg, P.; Wilczynski, J.; Wolter, H. H.; Wu, P.; Yennello, S.; Zambon, P.; Zetta, L.; Zoric, M.

    2012-07-01

    The elliptic-flow ratio of neutrons with respect to protons in reactions of neutron rich Heavy-Ion at intermediate energies has been recently proposed as an observable sensitive to the strength of the symmetry term in the nuclear equation of state (EOS) at supra-saturation densities. The recent results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate of the symmetry term of the EOS but suffer from a considerable statistical uncertainty. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration in May 2011.

  1. Impact damage resistance and residual property assessment of [0/{+-}45/90]{sub s} SCS-6/TIMETAL 21S

    SciTech Connect

    Miller, J.L.; Portanova, M.A.; Johnson, W.S.

    1997-12-31

    Titanium-matrix composites (TMCs) are candidate materials for high-temperature structural applications, such as gas turbine engines, where their high specific strength at elevated temperatures and good general corrosion resistance are beneficial. Here, the impact damage resistance and residual mechanical properties of [0/{+-}45/90]{sub s} SCS-6/TIMETAL 21S composites were evaluated.Both quasi-static indentation and drop-weight impact tests were used to investigate the impact behavior at two nominal energy levels and to determine the onset of internal damage. Through X-ray inspection, the extent of internal damage was characterized nondestructively. The composite strength and constant-amplitude fatigue response were evaluated to assess the effects of the sustained damage. SEM was used to characterize internal damage from impact in comparison to damage that occurs during mechanical loading alone. The effect of stacking sequence was examined by using specimens with the long dimension of the specimen both parallel and perpendicular to the 0{degree} fiber direction. Damage in the form of longitudinal and transverse cracking occurred in all longitudinal specimens tested at energies greater than 6.3 J. Similar results occurred in the transverse specimens tested above 5.4 J. Initial load drop, characteristic of the onset of damage, occurred on average at 6.3 J in longitudinal specimens and at 5.0 J in transverse specimens. X-ray analysis showed broken fibers in the impacted region in specimens tested at the higher impact energies. At low impact energies, visible matrix cracking may occur, but broken fibers may not. Matrix cracking was noted along fiber swims, and it appeared to depend on the surface quality of the composite. At low impact energies, little damage had been incurred by the composite and the residual strength and residual life was not greatly reduced as compared to an undamaged composite.

  2. Site reactivity in the free radicals induced damage to leucine residues: a theoretical study.

    PubMed

    Medina, M E; Galano, A; Alvarez-Idaboy, J R

    2015-02-21

    Several recent computational studies have tried to explain the observed selectivity in radical damage to proteins. In this work we use Density Functional Theory and Transition State Theory including tunnelling corrections, reaction path degeneracy, the effect of diffusion, and the role of free radicals to get further insights into this important topic. The reaction between a leucine derivative and free radicals of biological significance, in aqueous and lipid media, has been investigated. Both thermochemical and kinetic analyses, in both hydrophilic and hydrophobic environments, have been carried out. DPPH, ˙OOH, ˙OOCH3, ˙OOCH2Cl, ˙OOCHCl2 and ˙OOCHCH2 radicals do not react with the target molecule. The reactions are proposed to be kinetically controlled. The leucine gamma site was the most reactive for the reactions with ˙N3, ˙OOCCl3, ˙OCH3, ˙OCH2Cl, and ˙OCHCl2 radicals, with rate constants equal to 1.97 × 10(5), 3.24 × 10(4), 6.68 × 10(5), 5.98 × 10(6) and 8.87 × 10(8) M(-1) s(-1), respectively, in aqueous solution. The ˙Cl, ˙OH and ˙OCCl3 radicals react with leucine at the beta, gamma, and delta positions at rates close to the diffusion limit with the alpha position which is the slowest path and the most thermodynamically favored. The presented results confirm that the Bell-Evans-Polanyi principle does not apply for the reactions between amino acid residues and free radicals. Regarding the influence of the environment on the reactivity of the studied series of free radicals towards leucine residues, it is concluded that hydrophilic media slightly lower the reactivity of the studied radicals, compared to hydrophobic ones, albeit the trends in reactivity are very similar. PMID:25592549

  3. Two glycosylase families diffusively scan DNA using a wedge residue to probe for and identify oxidatively damaged bases

    PubMed Central

    Nelson, Shane R.; Dunn, Andrew R.; Kathe, Scott D.; Warshaw, David M.; Wallace, Susan S.

    2014-01-01

    DNA glycosylases are enzymes that perform the initial steps of base excision repair, the principal repair mechanism that identifies and removes endogenous damages that occur in an organism’s DNA. We characterized the motion of single molecules of three bacterial glycosylases that recognize oxidized bases, Fpg, Nei, and Nth, as they scan for damages on tightropes of λ DNA. We find that all three enzymes use a key “wedge residue” to scan for damage because mutation of this residue to an alanine results in faster diffusion. Moreover, all three enzymes bind longer and diffuse more slowly on DNA that contains the damages they recognize and remove. Using a sliding window approach to measure diffusion constants and a simple chemomechanical simulation, we demonstrate that these enzymes diffuse along DNA, pausing momentarily to interrogate random bases, and when a damaged base is recognized, they stop to evert and excise it. PMID:24799677

  4. Residual strength and crack propagation tests on C-130 airplane center wings with service-imposed fatigue damage

    NASA Technical Reports Server (NTRS)

    Snider, H. L.; Reeder, F. L.; Dirkin, W. J.

    1972-01-01

    Fourteen C-130 airplane center wings, each containing service-imposed fatigue damage resulting from 4000 to 13,000 accumulated flight hours, were tested to determine their fatigue crack propagation and static residual strength characteristics. Eight wings were subjected to a two-step constant amplitude fatigue test prior to static testing. Cracks up to 30 inches long were generated in these tests. Residual static strengths of these wings ranged from 56 to 87 percent of limit load. The remaining six wings containing cracks up to 4 inches long were statically tested as received from field service. Residual static strengths of these wings ranged from 98 to 117 percent of limit load. Damage-tolerant structural design features such as fastener holes, stringers, doublers around door cutouts, and spanwise panel splices proved to be effective in retarding crack propagation.

  5. Binding of the UvrB dimer to non-damaged and damaged DNA: residues Y92 and Y93 influence the stability of both subunits.

    PubMed

    Moolenaar, Geri F; Schut, Menno; Goosen, Nora

    2005-06-01

    UvrB is the ultimate damage-binding protein in bacterial nucleotide excision repair. Previous AFM experiments have indicated that UvrB binds to a damage as a dimer. In this paper we visualize for the first time a UvrB dimer in a gel retardation assay, with the second subunit (B2) more loosely bound than the subunit (B1) that interacts with the damage. A beta-hairpin motif in UvrB plays an important role in damage specific binding. Alanine substitutions of Y92 or Y93 in the beta-hairpin result in proteins that kill E. coli cells as a consequence of incision in non-damaged DNA. Apparently, both residues are needed to prevent binding of UvrB to non-damaged DNA. The lethality of Y93A results from UvrC-mediated incisions, whereas that of Y92A is due to incisions by Cho. This difference could be ascribed to a difference in stability of the B2 subunit in the mutant UvrB-DNA complexes. We show that for 3' incision UvrC needs to displace this second UvrB subunit from the complex, whereas Cho seems capable to incise the dimer-complex. Footprint analysis of the contacts of UvrB with damaged DNA revealed that the B2 subunit interacts with the flanking DNA at the 3' side of the lesion. The B2 subunit of mutant Y92A appeared to be more firmly associated with the DNA, indicating that even when B1 is bound to a lesion, the B2 subunit probes the adjacent DNA for presence of damage. We propose this to be a reflection of the process that the UvrB dimer uses to find lesions in the DNA. In addition to preventing binding to non-damaged DNA, the Y92 and Y93 residues appear also important for making specific contacts (of B1) with the damaged site. We show that the concerted action of the two tyrosines lead to a conformational change in the DNA surrounding the lesion, which is required for the 3' incision reaction. PMID:15886069

  6. Conceptualizing a Genomics Software Institute (GSI)

    PubMed Central

    Gilbert, Jack A.; Catlett, Charlie; Desai, Narayan; Knight, Rob; White, Owen; Robbins, Robert; Sankaran, Rajesh; Sansone, Susanna-Assunta; Field, Dawn; Meyer, Folker

    2012-01-01

    Microbial ecology has been enhanced greatly by the ongoing ‘omics revolution, bringing half the world's biomass and most of its biodiversity into analytical view for the first time; indeed, it feels almost like the invention of the microscope and the discovery of the new world at the same time. With major microbial ecology research efforts accumulating prodigious quantities of sequence, protein, and metabolite data, we are now poised to address environmental microbial research at macro scales, and to begin to characterize and understand the dimensions of microbial biodiversity on the planet. What is currently impeding progress is the need for a framework within which the research community can develop, exchange and discuss predictive ecosystem models that describe the biodiversity and functional interactions. Such a framework must encompass data and metadata transparency and interoperation; data and results validation, curation, and search; application programming interfaces for modeling and analysis tools; and human and technical processes and services necessary to ensure broad adoption. Here we discuss the need for focused community interaction to augment and deepen established community efforts, beginning with the Genomic Standards Consortium (GSC), to create a science-driven strategic plan for a Genomic Software Institute (GSI). PMID:22675605

  7. Proton microscopy at GSI and FAIR

    SciTech Connect

    Merrill, Frank E; Mariam, Fesseha G; Golubev, A A; Turtikov, V I; Varentsov, D

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and facilities have been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international collaboration was formed to develop a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located at Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt, Germany. This new Proton microscope for FAIR (PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. These dynamic experiments will be driven with many energy sources including heavy ions, high explosives and lasers. The design of the proton microscope and expected radiographic performance is presented.

  8. Damage assessment and residual compression strength of thick composite plates with through-the-thickness reinforcements

    NASA Technical Reports Server (NTRS)

    Smith, Barry T.; Farley, Gary L.; Maiden, Janice; Coogan, Dreux; Moore, Judith G.

    1991-01-01

    Damage in composite materials was studied with through-the-thickness reinforcements. As a first step it was necessary to develop new ultrasonic imaging technology to better assess internal damage of the composite. A useful ultrasonic imaging technique was successfully developed to assess the internal damage of composite panels. The ultrasonic technique accurately determines the size of the internal damage. It was found that the ultrasonic imaging technique was better able to assess the damage in composite panel with through-the-thickness reinforcements than by destructively sectioning the specimen and visual inspection under a microscope. Five composite compression-after-impact panels were tested. The compression-after-impact strength of the panels with the through-the-thickness reinforcements was almost twice that of the comparable panel without through-the-thickness reinforcement.

  9. Damage assessment and residual compression strength of thick composite plates with through-the-thickness reinforcements

    NASA Technical Reports Server (NTRS)

    Smith, Barry T.

    1990-01-01

    Damage in composite materials was studied with through-the-thickness reinforcements. As a first step it was necessary to develop new ultrasonic imaging technology to better assess internal damage of the composite. A useful ultrasonic imaging technique was successfully developed to assess the internal damage of composite panels. The ultrasonic technique accurately determines the size of the internal damage. It was found that the ultrasonic imaging technique was better able to assess the damage in a composite panel with through-the-thickness reinforcements than by destructively sectioning the specimen and visual inspection under a microscope. Five composite compression-after-impact panels were tested. The compression-after-impact strength of the panels with the through-the-thickness reinforcements was almost twice that of the comparable panel without through-the-thickness reinforcement.

  10. Evaluation of residual strength in the basalt fiber reinforced composites under impact damage

    NASA Astrophysics Data System (ADS)

    Kim, Yun-Hae; Lee, Jin-Woo; Moon, Kyung-Man; Yoon, Sung-Won; Baek, Tae-Sil; Hwang, Kwang-Il

    2015-03-01

    Composites are vulnerable to the impact damage by the collision as to the thickness direction, because composites are being manufactured by laminating the fiber. The understanding about the retained strength after the impact damage of the material is essential in order to secure the reliability of the structure design using the composites. In this paper, we have tried to evaluate the motion of the material according to the kinetic energy and potential energy and the retained strength after impact damage by testing the free fall test of the basalt fiber reinforced composite in the limelight as the environment friendly characteristic.

  11. Ultrasonic method to evaluate the residual properties of thermally damaged sandstone based on time-frequency analysis

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Xu, Jin-yu; Liu, Shi

    2015-01-01

    Evaluation of the residual properties of thermally damaged rocks is of vital importance for rock engineering. For this study, uniaxial compression experiments and ultrasonic tests were conducted on sandstone specimens which experienced temperature treatments of different levels, including 25, 100, 200, 400, 600, 800 and 1000°C. Time-frequency analysis methods were applied to evaluate the deformation and strength properties of sandstone after being exposed to high temperature, confirming the effectiveness of the ultrasonic evaluation method. Linear correlations between the peak stress, deformation modulus and the longitudinal wave velocity confirm the effectiveness of ultrasonic time-domain properties in estimating the deformation behaviour of the thermally damaged sandstone. Synchronisation in the change of the peak stress and the kurtosis of frequency spectrum as temperature rises, defined in this paper to describe the spectrum distribution, as well as the centroid frequency, demonstrates the feasibility of ultrasonic frequency-domain properties in estimating the residual strength of the thermally damaged sandstone. The results have certain guiding significance for rock engineering in a high-temperature environment.

  12. Involvement of phylogenetically conserved acidic amino acid residues in catalysis by an oxidative DNA damage enzyme formamidopyrimidine glycosylase.

    PubMed

    Lavrukhin, O V; Lloyd, R S

    2000-12-12

    Formamidopyrimidine glycosylase (Fpg) is an important bacterial base excision repair enzyme, which initiates removal of damaged purines such as the highly mutagenic 8-oxoguanine. Similar to other glycosylase/AP lyases, catalysis by Fpg is known to proceed by a nucleophilic attack by an amino group (the secondary amine of its N-terminal proline) on C1' of the deoxyribose sugar at a damaged base, which results in the departure of the base from the DNA and removal of the sugar ring by beta/delta-elimination. However, in contrast to other enzymes in this class, in which acidic amino acids have been shown to be essential for glycosyl and phosphodiester bond scission, the catalytically essential acidic residues have not been documented for Fpg. Multiple sequence alignments of conserved acidic residues in all known bacterial Fpg-like proteins revealed six conserved glutamic and aspartic acid residues. Site-directed mutagenesis was used to change glutamic and aspartic acid residues to glutamines and asparagines, respectively. While the Asp to Asn mutants had no effect on the incision activity on 8-oxoguanine-containing DNA, several of the substitutions at glutamates reduced Fpg activity on the 8-oxoguanosine DNA, with the E3Q and E174Q mutants being essentially devoid of activity. The AP lyase activity of all of the glutamic acid mutants was slightly reduced as compared to the wild-type enzyme. Sodium borohydride trapping of wild-type Fpg and its E3Q and E174Q mutants on 8-oxoguanosine or AP site containing DNA correlated with the relative activity of the mutants on either of these substrates. PMID:11106507

  13. Evaluation of relationships between cable logging system parameters and damage to residual mixed conifer stands

    SciTech Connect

    Miles, J.; Burk, J.

    1984-01-01

    Cable logging practices were observed on a production logging operation. Using a marked leave tree stand, damage at each phase of the operation was quantified. Log stability, motion and sweep area were also observed for each turn. These variables were evaluated in relation to the system geometry, terrain and logging practices. The results identify variables which influence log stability, motion and sweep area. Logging damage was closely related to operator log control, both for felling and for yarding. Good control could usually be maintained on slopes of less than 35% but special techniques and equipment were required on slopes of more than 35%. Silvicultural prescription, marking quality, planning and layout also affected the level of logging damage.

  14. Antibacterial and leishmanicidal activities of temporin-SHd, a 17-residue long membrane-damaging peptide.

    PubMed

    Abbassi, Feten; Raja, Zahid; Oury, Bruno; Gazanion, Elodie; Piesse, Christophe; Sereno, Denis; Nicolas, Pierre; Foulon, Thierry; Ladram, Ali

    2013-02-01

    Temporins are a family of short antimicrobial peptides (8-17 residues) that mostly show potent activity against Gram-positive bacteria. Herein, we demonstrate that temporin-SHd, a 17-residue peptide with a net charge of +2 (FLPAALAGIGGILGKLF(amide)), expressed a broad spectrum of antimicrobial activity. This peptide displayed potent antibacterial activities against Gram-negative and Gram-positive bacteria, including multi-drug resistant Staphylococcus aureus strains, as well as antiparasitic activity against promastigote and the intracellular stage (amastigote) of Leishmania infantum, at concentration not toxic for the macrophages. Temporin-SHd that is structured in a non-amphipathic α-helix in anionic membrane-mimetic environments, strongly and selectively perturbs anionic bilayer membranes by interacting with the polar head groups and acyl region of the phospholipids, with formation of regions of two coexisting phases: one phase rich in peptide and the other lipid-rich. The disruption of lipid packing within the bilayer may lead to the formation of transient pores and membrane permeation/disruption once a threshold peptide accumulation is reached. To our knowledge, Temporin-SHd represents the first known 17-residue long temporin expressing such broad spectrum of antimicrobial activity including members of the trypanosomatidae family. Additionally, since only a few shorter members (13 residues) of the temporin family are known to display antileishmanial activity (temporins-TA, -TB and -SHa), SHd is an interesting tool to analyze the antiparasitic mechanism of action of temporins. PMID:23116712

  15. Search for Two-Proton Emitters at FRS-GSI

    SciTech Connect

    Pfuetzner, M.

    2000-12-31

    A project of studying proton drip-line nuclei in vicinity of {sup 48}Ni, running at GSI Darmstadt, is shortly reviewed. Prospects for spectroscopy studies on {sup 45}Fe, presently identified as the best candidate for the 2p radioactivity, are briefly discussed.

  16. Proton Emission Studies at GSI in the 1980s

    SciTech Connect

    Hofmann, Sigurd

    2000-12-31

    This article describes the experiments that were performed during the first decade of the operation of UNILAC, GSI-Darmstadt, at the recoil separator SHIP and the on-line mass separator. The measurements resulted in the discovery of the first radioactive ground state proton emitters, {sup 151}Lu and {sup 147}Tm.

  17. Girls' Science Investigations (GSI) New Haven: Evaluating the Impact

    NASA Astrophysics Data System (ADS)

    Knodell, Claire; Fleming, Bonnie

    2009-05-01

    Girls' Science Investigations (GSI) New Haven seeks to empower the girls of today to shape the science of tomorrow. Funded by the NSF and Yale University and held at Yale, this program was designed to motivate, empower, and interest middle school girls in developing the skills required to pursue a career in science during a day-long investigation of the session's featured topic in science. Yale students and female professors act as mentors and guide younger girls through an environment for understanding and exploring various disciplines of science through hands-on activities in a laboratory setting. GSI strives to close the gap between males and females one action-packed Saturday at a time. This paper evaluates the success of the program. Student participant evaluations over the past 2 years coupled with student testimony and GSI coordinator, instructors', and volunteers' interviews allowed for an analysis of GSI's ability to inspire girls to pursue careers in science. The data indicates that a majority of girls who attended the program were more inclined to continue their study of science. The positive results are detailed in the following paper which points to the hands-on activities and enthusiasm of instructors as integral to the program's success.

  18. Mapping residual stresses after foreign object damage using the contour method

    SciTech Connect

    Prime, M. B.; Martineau, R. L.

    2002-01-01

    A 51-mm thick plate of High-Strength Low-Alloy (HSLA-100) steel was impacted by a 6.4 mm diameter tungsten carbide sphere traveling at 2.2 km/sec. The projectile penetration left a 10 mm diameter and 12 mm deep crater. A residual stress map over a cross-section through the crater was measured by the contour method. The predominant feature of the stress map was a peak compressive stress of 900 MPa, or 1.3 times the yield strength, centered about 1.5 crater radii below the crater floor. The results were compared with an explicit finite element simulation of the impact event. The model has good agreement with the measured residual stresses. As part of the study, residual stresses in the as-received HSLA-100 plate were also measured and found to be a typical quenching stress distribution with peak compressive stress of about 165 MPa a few mm below the surface and tensile stress of 200 MPa in the center of the plate thickness.

  19. Towards the Handing of Cloud-Affected Infrared Radiances in the GSI

    NASA Technical Reports Server (NTRS)

    McCarty, William

    2012-01-01

    In the gridpoint statistical interpolation (GSI) data assimilation algorithm, only thermal infrared measurements determined to be uncontaminated by clouds are assimilated. Using this approach, typically only 19-29% of footprints are deemed to have no cloud affects through the measured spectra. This study will discuss the efforts underway at the Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center, in conjunction with the Joint Center for Satellite Data Assimilation (JCSDA), to actively assimilate these morecomplicated observations by using a graybody assumption. In the GSI, cloud top pressure and effective cloud amount are retrieved concurrently using a minimum residual method. This study will address the limitations and advantages of the technique and the modifications underway to the assimilation system to incorporate those two parameters into the radiative transfer forward operators and TL/AD calculations. Furthermore, it will explain the efforts underway to incorporate these parameters into the control vector so that they can be altered variationally as part of the minimization.

  20. Detection of DNA damage: effect of thymidine glycol residues on the thermodynamic, substrate and interfacial acoustic properties of oligonucleotide duplexes.

    PubMed

    Yang, F; Romanova, E; Kubareva, E; Dolinnaya, N; Gajdos, V; Burenina, O; Fedotova, E; Ellis, J S; Oretskaya, T; Hianik, T; Thompson, M

    2009-01-01

    Thymidine glycol residues in DNA are biologically active oxidative molecular damage sites caused by ionizing radiation and other factors. One or two thymidine glycol residues were incorporated in 19- to 31-mer DNA fragments during automatic oligonucleotide synthesis. These oligonucleotide models were used to estimate the effect of oxidized thymidines on the thermodynamic, substrate and interfacial acoustic properties of DNA. UV-monitoring melting data revealed that modified residues in place of thymidines destabilize the DNA double helix by 8-22 degrees C, depending on the number of lesions, the length of oligonucleotide duplexes and their GC-content. The diminished hybridizing capacity of modified oligonucleotides is presumably due to the loss of aromaticity and elevated hydrophilicity of thymine glycol in comparison to the thymine base. According to circular dichroism (CD) data, the modified DNA duplexes retain B-form geometry, and the thymidine glycol residue introduces only local perturbations limited to the lesion site. The rate of DNA hydrolysis by restriction endonucleases R.MvaI, R.Bst2UI, R.MspR9I and R.Bme1390I is significantly decreased as the thymidine glycol is located in the central position of the double-stranded recognition sequences 5'-CC / WGG-3' (W = A, T) or 5'-CC / NGG-3' (N = A, T, G, C) adjacent to the cleavage site. On the other hand, the catalytic properties of enzymes R.Psp6I and R.BstSCI recognizing the similar sequence are not changed dramatically, since their cleavage site is separated from the point of modification by several base-pairs. Data obtained by gel-electrophoretic analysis of radioactive DNA substrates were confirmed by direct spectrophotometric assay developed by the authors. The effect of thymidine glycol was also observed on DNA hybridization at the surface of a thickness-shear mode acoustic wave device. A 1.9-fold decrease in the rate of duplex formation was noted for oligonucleotides carrying one or two thymidine glycol

  1. Nonlinear Response and Residual Strength of Damaged Stiffened Shells Subjected to Combined Loads

    NASA Technical Reports Server (NTRS)

    Starnes, James H., Jr.; Britt, Vicki O.; Rose, Cheryl A.; Rankin, Charles C.

    1996-01-01

    The results of an analytical study of the nonlinear response of stiffened fuselage shells with long cracks are presented. The shells are modeled with a hierarchical modeling strategy and analyzed with a nonlinear shell analysis code that maintains the shell in a nonlinear equilibrium state while the crack is grown. The analysis accurately accounts for global and local structural response phenomena. Fuselage skins, frames stringers and failsafe straps are included in the models. Results are presented for various combinations of internal pressure and mechanical bending, vertical shear and torsion loads, and the effects of crack orientation and location on the shell response are described. These results indicate that the nonlinear interaction between the in-plane stress resultants and the out-of-plane displacements near a crack can significantly affect the structural response of the shell, and the stress-intensity factors associated with a crack that are used to predict residual strength. The effects of representative combined loading conditions on the stress-intensity factors associated with a crack are presented. The effects of varying structural parameters on the stress-intensity factors associated with a crack, and on self-similar and non-self-similar crack-growth are also presented.

  2. Characterization of complex rock masses by combined borehole GSI and sonic logging

    NASA Astrophysics Data System (ADS)

    Sapigni, Michele; Agliardi, Federico; Crosta, Giovanni B.

    2015-04-01

    Reliable assessment of the strength and hydraulic properties of rock masses at depth is key to a number of geological, engineering and geohazard applications, including tunnelling, reservoir characterization and slope stability analysis. Rock mass investigations usually exploit direct geomechanical core logging and indirect geophysical techniques. A cost-effective and reliable characterisation of rock mass quality by direct investigation is often hampered by extremely variable lithological and structural conditions. On the other hand, available indirect methods correlating rock mass properties with geophysical investigation results apply to near-surface (upper few tens of meters in depth) and rely on rock mass descriptors poorly suitable for complex rocks (including deformed, weathered, or damaged rocks). Thus, there is a need to set up: 1) robust and versatile approaches to quantify (direct) rock mass descriptors suitable for complex geological conditions from drillcores; 2) statistically-sound relationships between such descriptors and rock mass properties obtained by (indirect) geophysical methods. We focus on the analysis of relationships between sonic P-wave velocity and rock mass quality described by the Geological Strength Index (GSI), both quantified in deep boreholes. The GSI is a suitable descriptor of rock mass structure and weathering, suitable for application to nearly all kind of rock types and geological conditions. We used site investigation data gathered to design a 9.2 km long headrace tunnel in a crystalline core complex of the central italian Alps. We analysed three boreholes up to 400 m deep in gneiss and meta-sedimentary rocks (including gypsum-anhydrite, marbles, decomposed carbonates) from which high quality HQ drillcores were extracted, allowing high-resolution geological and geomechanical logging. In the same boreholes, geophysical logging was performed using a "full-wave" sonic tool (transmitter operating at 27 kHz, receivers recording up

  3. Girls' Science Investigations (GSI) New Haven Curriculum and Educational Method

    NASA Astrophysics Data System (ADS)

    Hilton, Sheena; Fleming, Bonnie

    2009-05-01

    Girls' Science Investigations (GSI) New Haven is a program which aims at encouraging middle school girls to pursue careers in science. To accomplish this goal, each day at GSI features a different area of science; ``the material world,'' ``the chemical world,'' and ``the electromagnetic world'' are examples of the sessions held during the past two years. Every session features a short explanation of the science topic given by a volunteer and a variety of hands-on activities, which allow the girls to experiment with and absorb the concepts presented in the short presentations. Activities are selected based on their ability to visualize the concepts under study. The education philosophy of GSI is that if the students have the opportunity to perform science experiments themselves, rather than just watching others do it, and enjoy performing these experiments, then the students will be more confident in their ability to succeed in a scientific field. Thus, in addition to encouraging girls to learn as much science as they can, the volunteers work to ensure that the girls enjoy the program as well. By giving the girls the opportunity to explore science in a fun and exciting way, the girls begin to see themselves as capable of becoming scientists and are more inclined to pursue science in the future.

  4. TREATMENT OF HYDROCARBON, ORGANIC RESIDUE AND PRODUCTION CHEMICAL DAMAGE MECHANISMS THROUGH THE APPLICATION OF CARBON DIOXIDE IN NATURAL GAS STORAGE WELLS

    SciTech Connect

    Lawrence J. Pekot; Ron Himes

    2004-05-31

    Core specimens and several material samples were collected from two natural gas storage reservoirs. Laboratory studies were performed to characterize the samples that were believed to be representative of a reservoir damage mechanism previously identified as arising from the presence of hydrocarbons, organic residues or production chemicals. A series of laboratory experiments were performed to identify the sample materials, use these materials to damage the flow capacity of the core specimens and then attempt to remove or reduce the induced damage using either carbon dioxide or a mixture of carbon dioxide and other chemicals. Results of the experiments showed that pure carbon dioxide was effective in restoring flow capacity to the core specimens in several different settings. However, in settings involving asphaltines as the damage mechanism, both pure carbon dioxide and mixtures of carbon dioxide and other chemicals provided little effectiveness in damage removal.

  5. Assimilation of GPM GMI Rainfall Product with WRF GSI

    NASA Technical Reports Server (NTRS)

    Li, Xuanli; Mecikalski, John; Zavodsky, Bradley

    2015-01-01

    The Global Precipitation Measurement (GPM) is an international mission to provide next-generation observations of rain and snow worldwide. The GPM built on Tropical Rainfall Measuring Mission (TRMM) legacy, while the core observatory will extend the observations to higher latitudes. The GPM observations can help advance our understanding of precipitation microphysics and storm structures. Launched on February 27th, 2014, the GPM core observatory is carrying advanced instruments that can be used to quantify when, where, and how much it rains or snows around the world. Therefore, the use of GPM data in numerical modeling work is a new area and will have a broad impact in both research and operational communities. The goal of this research is to examine the methodology of assimilation of the GPM retrieved products. The data assimilation system used in this study is the community Gridpoint Statistical Interpolation (GSI) system for the Weather Research and Forecasting (WRF) model developed by the Development Testbed Center (DTC). The community GSI system runs in independently environment, yet works functionally equivalent to operational centers. With collaboration with the NASA Short-term Prediction Research and Transition (SPoRT) Center, this research explores regional assimilation of the GPM products with case studies. Our presentation will highlight our recent effort on the assimilation of the GPM product 2AGPROFGMI, the retrieved Microwave Imager (GMI) rainfall rate data for initializing a real convective storm. WRF model simulations and storm scale data assimilation experiments will be examined, emphasizing both model initialization and short-term forecast of precipitation fields and processes. In addition, discussion will be provided on the development of enhanced assimilation procedures in the GSI system with respect to other GPM products. Further details of the methodology of data assimilation, preliminary result and test on the impact of GPM data and the

  6. Assimilation of Dual-Polarimetric Radar Observations with WRF GSI

    NASA Technical Reports Server (NTRS)

    Li, Xuanli; Mecikalski, John; Fehnel, Traci; Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Dual-polarimetric (dual-pol) radar typically transmits both horizontally and vertically polarized radio wave pulses. From the two different reflected power returns, more accurate estimate of liquid and solid cloud and precipitation can be provided. The upgrade of the traditional NWS WSR-88D radar to include dual-pol capabilities will soon be completed for the entire NEXRAD network. Therefore, the use of dual-pol radar network will have a broad impact in both research and operational communities. The assimilation of dual-pol radar data is especially challenging as few guidelines have been provided by previous research. It is our goal to examine how to best use dual-pol radar data to improve forecast of severe storm and forecast initialization. In recent years, the Development Testbed Center (DTC) has released the community Gridpoint Statistical Interpolation (GSI) DA system for the Weather Research and Forecasting (WRF) model. The community GSI system runs in independently environment, yet works functionally equivalent to operational centers. With collaboration with the NASA Short-term Prediction Research and Transition (SPoRT) Center, this study explores regional assimilation of the dual-pol radar variables from the WSR-88D radars for real case storms. Our presentation will highlight our recent effort on incorporating the horizontal reflectivity (ZH), differential reflectivity (ZDR), specific differential phase (KDP), and radial velocity (VR) data for initializing convective storms, with a significant focus being on an improved representation of hydrometeor fields. In addition, discussion will be provided on the development of enhanced assimilation procedures in the GSI system with respect to dual-pol variables. Beyond the dual-pol variable assimilation procedure developing within a GSI framework, highresolution (=1 km) WRF model simulations and storm scale data assimilation experiments will be examined, emphasizing both model initialization and short-term forecast

  7. Effects of overlap and pass number in CO2 laser skin resurfacing: preliminary results of residual thermal damage, cell death, and wound healing

    NASA Astrophysics Data System (ADS)

    Ross, E. V.; Glatter, Robert D.; Duke, Daniella; Grevelink, Joop M.

    1997-05-01

    Newer carbon-dioxide laser systems incorporating short pulse and scanning technology have been used effectively to resurface the skin. Although scarring is rare, as the number of resurfacing cases has increased, some hypertrophic scarring has been observed. Previous dermabrasion and continuous wave (cw) carbon-dioxide studies suggest that depth of injury and/or thermal damage are important predictors of scarring for a given anatomic region. To determine if overlapping laser pulses/scans significantly altered wound healing, we examined residual thermal damage, cell death, and histologic and clinical wound healing in a farm pig. The Ultrapulse and SilkTouch systems were used with various radiant exposures, degrees of overlap, and numbers of passes. Thermal damage was assessed by histology, and dermal cell viability was measured with nitrotetrazolium blue staining. Presence or absence of clinical scarring was determined by noting textural change and loss of skin markings. We observed that thermal damage and cell death depth did not increase significantly with pass number; however, by double-pulsing or double-scanning sites, residual thermal damage and cell death depth were increased as much as 100% over areas without immediate overlap of laser impacts. Also, scarring was increased focally in areas with overlap. We conclude that immediate overlapping of carbon- dioxide laser pulses/scans is a significant risk factor in increasing thermal damage, cell death, and scarring.

  8. TRB for HADES and FAIR experiments at GSI

    NASA Astrophysics Data System (ADS)

    Fröhlich, I.; Schrader, C.; Stroeble, H.; Stroth, J.; Tarantrola, A.; Kajetanowicz, M.; Korcyl, K.; Krzemień, W.; Palka, M.; Salabura, P.; TrȨBACZ, R.; Skott, P.; Traxler, M.

    2008-06-01

    TRB module is a multi-purpose Trigger and Readout Board with on-board DAQ functionality developed for the upgrade of the HADES experiment. It contains single computer chip (Etrax) running Linux and the 100 Mbit/s Ethernet interface. It has been orginally designed as the 128-channel Time to Digital Converter based on the HPTDC chip from CERN. The new version of TRB contains 2 Gbit/s optical link and interface connector (15 Gbit/s) implementing the add-on card concept and making the board more flexible. Moreover, FPGA chip (Xilinx, Virtex 4 LX 40) and TigerSharc DSP provide new computing resources which can be used to run on-line analysis algorithms. The TRB is proposed as a prototype of base readout module for the planned detector systems PANDA and CBM at the future FAIR facility at GSI-Darmstadt.

  9. GSI promotes vincristine-induced apoptosis by enhancing multi-polar spindle formation.

    PubMed

    Singh, Akannsha; Zapata, Mariana C; Choi, Yong Sung; Yoon, Sun-Ok

    2014-01-01

    Gamma secretase inhibitors (GSI), cell-permeable small-molecule inhibitors of gamma secretase activity, had been originally developed for the treatment of Alzheimer disease. In recent years, it has been exploited in cancer research to inhibit Notch signaling that is aberrantly activated in various cancers. We previously found that GSI could synergize with anti-microtubule agent, vincristine (VCR) in a Notch-independent manner. Here, we delineate the underlying cell cycle-related mechanism using HeLa cells, which have strong mitotic checkpoints. GSI enhanced VCR-induced cell death, although GSI alone did not affect cell viability at all. GSI augmented VCR-induced mitotic arrest in a dose-dependent manner, which was preceded by apoptotic cell death, as shown by an increase in Annexin V-positive and caspase-positive cell population. Furthermore, GSI amplified multi-polar spindle formation triggered by VCR. Altogether, we show the evidence that GSI enhances VCR-induced apoptosis in HeLa cells via multi-polar mitotic spindle formation, independent of Notch signaling. These data suggest that one or more GS substrates, yet to be identified, in a post-GS processed form, may play a role in maintaining functional centrosomes/mitotic spindles. More significantly, the synergistic effect of GSI in combination with VCR could be exploited in clinical setting to improve the efficacy of VCR. PMID:24200971

  10. TREATMENT OF HYDROCARBON, ORGANIC RESIDUE AND PRODUCTION CHEMICAL DAMAGE MECHANISMS THROUGH THE APPLICATION OF CARBON DIOXIDE IN NATURAL GAS STORAGE WELLS

    SciTech Connect

    Lawrence J. Pekot

    2004-06-30

    Two gas storage fields were studied for this project. Overisel field, operated by Consumer's Energy, is located near the town of Holland, Michigan. Huntsman Storage Unit, operated by Kinder Morgan, is located in Cheyenne County, Nebraska near the town of Sidney. Wells in both fields experienced declining performance over several years of their annual injection/production cycle. In both fields, the presence of hydrocarbons, organic materials or production chemicals was suspected as the cause of progressive formation damage leading to the performance decline. Core specimens and several material samples were collected from these two natural gas storage reservoirs. Laboratory studies were performed to characterize the samples that were believed to be representative of a reservoir damage mechanism previously identified as arising from the presence of hydrocarbons, organic residues or production chemicals. A series of laboratory experiments were performed to identify the sample materials, use these materials to damage the flow capacity of the core specimens and then attempt to remove or reduce the induced damage using either carbon dioxide or a mixture of carbon dioxide and other chemicals. Results of the experiments showed that pure carbon dioxide was effective in restoring flow capacity to the core specimens in several different settings. However, in settings involving asphaltines as the damage mechanism, both pure carbon dioxide and mixtures of carbon dioxide and other chemicals provided little effectiveness in damage removal.

  11. Community Service and User Support for the Gridpoint Statistical Interpolation (GSI) Data Assimilation and Analysis System

    NASA Astrophysics Data System (ADS)

    Shao, H.; Hu, M.; Stark, D.; Newman, K.; Zhou, C.; Derber, J.; Lueken, M.

    2013-12-01

    The Gridpoint Statistical Interpolation (GSI) system is a unified variational data assimilation and analysis system for both global and regional applications. It is currently used as a data assimilation system by various operational centers, including the National Oceanic and Atmospheric Administration (NOAA) (e.g., Global Forecasting System (GFS), North American Mesoscale (NAM) system, the Hurricane WRF (HWRF), and the RAPid Refresh (RAP) system), the National Aeronautics and Space Administration (NASA) (Goddard Earth Observing System (GEOS) Model), and the Air Force Weather Agency (AFWA). This analysis system is also used to generate certain analysis products, such as output from NOAA's GFS reanalysis and the Real-Time Mesoscale Analysis (RTMA) (e.g., 2m temperature, 10m winds gust, surface pressure and surface visibility). GSI can also be used to generate analyses for climate studies (e.g., ozone and sea surface temperature (SST) analyses) or assimilate non-'traditional' fields (e.g., aerosol data assimilation) for air quality studies (e.g., dust storms). Lately, an effort was initiated to use GSI for data assimilation throughout the entire atmosphere. One example of such an effort is the development of a data assimilation system for the Whole Atmosphere Model (WAM) at NCEP. Over the past few years, GSI has been transitioned to a community resource through a joint effort led by the Developmental Testbed Center (DTC), in collaboration with the National Centers for Environmental Prediction (NCEP) Environmental Modeling Center (EMC) and other GSI partners. The DTC is a distributed facility with a goal of serving as a bridge between the research and operational communities by transitioning the operational capability to a community resource and committing the contributions from the research community to the operational repository. The DTC has hosted four Community GSI tutorials and released five versions of the community GSI system with a corresponding User's Guide

  12. Role of the Bacillus subtilis gsiA gene in regulation of early sporulation gene expression.

    PubMed Central

    Mueller, J P; Sonenshein, A L

    1992-01-01

    The Bacillus subtilis gsiA operon was induced rapidly, but transiently, as cells entered the stationary phase in nutrient broth medium. A mutation at the gsiC locus caused sporulation to be defective and expression of gsiA to be elevated and prolonged. The sporulation defect in this strain was apparently due to persistent expression of gsiA, since a gsiA null mutation restored sporulation to wild-type levels. Detailed mapping experiments revealed that the gsiC82 mutation lies within the kinA gene, which encodes the histidine protein kinase member of a two-component regulatory system. Since mutations in this gene caused a substantial blockage in expression of spoIIA, spoIIG, and spoIID genes, it seems that accumulation of a product of the gsiA operon interferes with sporulation by blocking the completion of stage II. It apparently does so by inhibiting or counteracting the activity of KinA. PMID:1624431

  13. Damage to DNA thymine residues in CHO cells by hydrogen peroxide and copper, ascorbate and copper, hypochlorite, or other oxidants: Protection by low MW polyethylene glycol

    SciTech Connect

    Schellenberg, K.A.; Shaeffer, J. )

    1991-03-11

    Polyethylene glycol (PEG) MW 200-600, has been shown to protect animals against oxidant and radiation damage. In order to study the mechanism the authors examined the effect of PEG on damage to thymine residues in the DNA of living Chinese hamster ovary (CHO) cells. After growing to confluence in the presence of (methyl{sup 3}H)thymidine, the cells were treated, usually for 1 hr, with various combinations of H{sub 2}O{sub 2}, Cu{sup ++}, Fe{sup ++}, Ocl{sup {minus}}, ascorbate UV or X-irradiation, and PEG MW 300. The oxidants H{sub 2}O{sub 2}/Cu{sup ++}, and OCL{sup {minus}} released {sup 3}H into the medium from DNA thymine, and also formed thymine glycol residues in the DNA that were assayed by alkaline borohydride. The presence of 10% PEG during treatment significantly reduced the release of {sup 3}H into the medium but did not prevent formation of thymine glycol residues bound to the DNA. PEG at 10% had no effect on the cloning efficiency of CHO cells.

  14. Heavy Ion High Intensity Upgrade of the GSI UNILAC

    SciTech Connect

    Barth, W.; Dahl, L.; Galonska, M.; Glatz, J.; Groening, L.; Hollinger, R.; Richter, S.; Yaramyshev, S.

    2005-06-08

    For the future Facility for Antiproton and Ion Research (FAIR) at Darmstadt the present GSI-accelerator complex, consisting of the linear accelerator UNILAC and the heavy ion synchrotron SIS 18, is foreseen to serve as U28+-injector for up to 1012 particles/s. After a new High Current Injector (HSI) was installed, many different ion species were accelerated in the UNILAC for physics experiments. In 2001 a high energy physics experiment used up to 2{center_dot}109 uranium ions per SIS 18-spill (U73+) while a MEVVA ion source was in routine operation for the first time. In the past two years, different hardware measures and careful fine tuning in all sections of the UNILAC resulted in an increase of the beam intensity to 9.5{center_dot}1010 U27+-ions per 100 {mu}s or 1.5{center_dot}1010 U73+-ions per 100 {mu}s. The contribution reports results of beam measurements during the high current operation with argon and uranium beams (pulse beam power up to 0.5 MW). One of the major tasks was to optimize the beam matching to the Alvarez-DTL. In addition further upgrades, including improved beam diagnostics, are described, which allow to fill the SIS 18 up to its space charge limit (SCL) of 2.7{center_dot}1011 U28+-ions per cycle.

  15. Summary of a study to determine low-velocity impact damage and residual tension strength for a thick graphite/epoxy motor case

    NASA Technical Reports Server (NTRS)

    Poe, C. C., Jr.

    1990-01-01

    Impacters of various shapes and masses were dropped from various heights onto 36 mm (1.4 in.) thick graphite/epoxy cylinders, which represented filament wound cases (FWC) for the booster motors of the Space Shuttle. Insert solid propellant was cast into some of the cylinders. The cylinders were impacted numerous times around the circumference and then cut into 51 mm (2.0 in.) wide tension specimens, each containing an impact site. Four indenters were used: a sharp corner, two hemispheres, and a bolt-like rod. The diameters of the hemispheres were 12.7 mm mm (0.5 in.) and 25.4 mm (1.0 in.), and the diameter of the rod was 6.3 mm (0.25 in.). Impacts with the rod were simulated by pressing the rod against the face of specimens. For the hemispheres, the damage initiated beneath the surface at a critical contact pressure and was not visible on the surface until an even larger pressure was exceeded. The damage consisted of matrix cracking and broken fiber. The rod an corner made visible surface damage in all tests. For the hemispheres, the tension strength was reduced considerably before the damage was visible on the surface, 30 percent for the 25.4 mm (1.0 in.) diameter hemisphere and 10 percent for the 12.7 mm (0.5 in.) diameter hemisphere. Analytical methods were used to predict the damage and residual tension strength. A factor of safety to account for nonvisible damage was determined.

  16. Bilinear and biquadratic interlayer exchange coupling in sputtered Co/Cu multilayers damaged with residual gas impurities

    NASA Astrophysics Data System (ADS)

    Marrows, C. H.; Hickey, B. J.

    1999-01-01

    The oscillatory indirect exchange coupling exhibited by magnetic/nonmagnetic metal multilayers is known to be highly sensitive to structural defects. We have measured the effects on coupling of residual gas atoms in sputtered Co/Cu multilayers. We have used a simple technique to selectively probe particular parts of the multilayer stack. A large reduction in the giant magnetoresistance has been observed when gas impurity atoms are introduced into the middle of the Cu spacer layers, with a corresponding increase in the remanence of the sample. These changes are shown to be consistent with overwhelmingly strong biquadratic coupling between the Co layers. This leads to the moments in adjacent layers being no longer collinear in zero applied field, which we have confirmed by other measurements. We discuss the applicability of the various theoretical models of biquadratic coupling to our observations.

  17. An Evaluation of the Use of X-ray Residual Stress Determination as a Means of Characterizing Oxidation Damage of Nickel-Based, Cr2O3-Forming Superalloys Subjected to Various Oxidizing Condition

    SciTech Connect

    Barnard, Bryan R; Watkins, Thomas R; Liaw, Peter K

    2010-01-01

    The use of X-ray residual stress determination as a technique for evaluating the damage incurred by nickel-based, Cr2O3-forming superalloy materials under various service conditions (isothermal heating, thermal cycling, applied stress, stressed and cycled) was investigated. Large and small compressive residual stresses were observed for the oxides and the near surface substrates, respectively. It was expected that the applied stresses and thermal cycling would cause an enhanced degree of oxidation damage that would translate into appreciable differences in residual stress values. Differences in the magnitude of residual stress values were not appreciable condition-to-condition, however. An increase in the severity of the oxidizing conditions in the form of longer oxidation times, higher oxidizing temperatures, and a much greater frequency of thermal cycling is suggested for future studies.

  18. Influence of Source/Drain Residual Implant Lattice Damage Traps on Silicon Carbide Metal Semiconductor Field-Effect Transistor Drain I-V Characteristics

    NASA Astrophysics Data System (ADS)

    Adjaye, J.; Mazzola, M. S.

    4H-SiC n-channel power metal semiconductor field-effect transistors (MESFETs) with nitrogen n+-implanted source/drain ohmic contact regions, with and without p-buffer layer fabricated on semi-insulating substrates exhibited hysteresis in the drain I-V characteristics of both types of devices at 300 K and 480 K due to traps. However, thermal spectroscopic measurements could detect the traps only in the devices without p-buffer. Device simulation and optical admittance spectroscopy (OAS) are used to resolve the discrepancy in the initial experimental characterization results. Device simulations and OAS suggest that, in addition to the semi-insulating (SI) substrate traps, acceptor traps due to source/drain residual implant lattice damage contribute to the hysteresis observed in the drain I-V characteristics of the devices. Simulations suggest these traps are contained in the lateral straggle of the implanted source and drain regions since the drain current largely flows between the un-gated edges of the source and drain through the volume of lateral straggle traps. Since hysteresis in I-V curves is a manifestation of the presence of defects in devices and since defects degrade carrier mobility and hence device performance, efforts should be made to minimize the source/drain lateral straggle implant damage.

  19. Comparison of two freshwater turtle species as monitors of radionuclide and chemical contamination: DNA damage and residue analysis

    SciTech Connect

    Meyers-Schoene, L. ); Shugart, L.R.; Beauchamp, J.J.; Walton, B.T. )

    1993-08-01

    Two species of turtles that occupy different ecological niches were compared for their usefulness as monitors of freshwater ecosystems where both low-level radioactive and nonradioactive contaminants are present. The pond slider (Trachemys scripta) and common snapping turtle (Chelydra serpentina) were analyzed for the presence of [sup 90]Sr, [sup 137]Cs, [sup 60]Co, and Hg, radionuclides and chemicals known to be present at the contaminated site, and single-strand breaks in liver DNA. The integrity of the DNA was examined by the alkaline unwinding assay, a technique that detects strand breaks as a biological marker of possible exposure to genotoxic agents. This measure of DNA damage was significantly increased in both species of turtles at the contaminated site compared with turtles of the same species at a reference site, and shows that contaminant-exposed populations were under more severe genotoxic stress than those at the reference site. The level of strand breaks observed at the contaminated site was high and in the range reported for other aquatic species exposed to deleterious concentrations of genotoxic agents such as chemicals and ionizing radiation. Statistically significantly higher concentrations of radionuclides and Hg were detected in the turtles from the contaminated area. Mercury concentrations were significantly higher in the more carnivorous snapping turtle compared with the slider; however, both species were effective monitors of the contaminants.

  20. Vectra GSI, Inc. low-level waste melter testing Phase 1 test report

    SciTech Connect

    Stegen, G.E.; Wilson, C.N.

    1996-02-21

    A multiphase program was initiated in 1994 to test commercially available melter technologies for the vitrification of the low-level waste (LLW) stream from defense wastes stored in underground tanks at the Hanford Site in southeastern Washington State. Vectra GSI, Inc. was one of seven vendors selected for Phase 1 of the melter demonstration tests using simulated LLW that were completed during fiscal year 1995. The attached report prepared by Vectra GSI, Inc. describes results of melter testing using slurry feed and dried feeds. Results of feed drying and prereaction tests using a fluid bed calciner and rotary dryer also are described.

  1. Development and Implementation of Dynamic Scripts to Execute Cycled GSI/WRF Forecasts

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Berndt, Emily; Li, Xuanli; Watson, Leela

    2014-01-01

    The Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model and Gridpoint Statistical Interpolation (GSI) data assimilation (DA) are the operational systems that make up the North American Mesoscale (NAM) model and the NAM Data Assimilation System (NDAS) analysis used by National Weather Service forecasters. The Developmental Testbed Center (DTC) manages and distributes the code for the WRF and GSI, but it is up to individual researchers to link the systems together and write scripts to run the systems, which can take considerable time for those not familiar with the code. The objective of this project is to develop and disseminate a set of dynamic scripts that mimic the unique cycling configuration of the operational NAM to enable researchers to develop new modeling and data assimilation techniques that can be easily transferred to operations. The current version of the SPoRT GSI/WRF Scripts (v3.0.1) is compatible with WRF v3.3 and GSI v3.0.

  2. Transcriptional regulation of Bacillus subtilis glucose starvation-inducible genes: control of gsiA by the ComP-ComA signal transduction system.

    PubMed Central

    Mueller, J P; Bukusoglu, G; Sonenshein, A L

    1992-01-01

    The Bacillus subtilis glucose starvation-inducible transcription units, gsiA and gsiB, were characterized by DNA sequencing, transcriptional mapping, mutational analysis, and expression in response to changes in environmental conditions. The gsiA operon was shown to consist of two genes, gsiAA and gsiAB, predicted to encode 44.9- and 4.8-kDa polypeptides, respectively. The gsiB locus contains a single cistron which encodes a protein of unusual structure; most of its amino acids are arranged in five highly conserved, tandemly repeated units of 20 amino acids. The 5' ends of gsiA and gsiB mRNAs were located by primer extension analysis; their locations suggest that both are transcribed by RNA polymerase containing sigma A. Expression of both gsiA and gsiB was induced by starvation for glucose or phosphate or by addition of decoyinine, but only gsiA was induced by exhaustion of nutrient broth or by amino acid starvation. Regulation of gsiA expression was shown to be dependent upon the two-component signal transduction system ComP-ComA, which also controls expression of genetic competence genes. Mutations in mecA bypassed the dependency of gsiA expression on ComA. Disruption of gsiA relieved glucose repression of sporulation but did not otherwise interfere with sporulation, development of competence, motility, or glucose starvation survival. We propose that gsiA and gsiB are members of an adaptive pathway of genes whose products are involved in responses to nutrient deprivation other than sporulation. Images PMID:1378051

  3. GSI experiments on the synthesis of superheavy elements

    SciTech Connect

    Hessberger, F. P.; Hofmann, S.; Ninov, V.; Armbruster, P.; Folger, H.; Muenzenberg, G.; Stodel, Ch.; Lavrentev, A.; Popeko, A. G.; Yeremin, A. N.; Leino, M. E.; Saro, S.

    1998-02-15

    Evaporation residue production was investigated at SHIP in cold fusion reactions of Pb- and Bi-target nuclei with projectiles of elements between Ti (Z=22) and Se (Z=34) leading to compound nuclei Z{sub CN}=104-116. The isotopes {sup 269}110, {sup 271}110, {sup 272}111, and {sup 277}112 of the elements Z=110, Z=111 and Z=112 were unambiguously identified for the first time in bombardments of {sup 208}Pb, {sup 209}Bi with {sup 62,64}Ni and {sup 70}Zn. Excitation functions for {sup 50}Ti+{sup 208}Pb and {sup 58}Fe+{sup 208}Pb were measured with high precision, three new spontaneous fission (sf) activities {sup 253}104, {sup 254}104, {sup 258}106 were identified. A small {alpha}-decay branch of the even-even nucleus {sup 256}104 (b{sub {alpha}}{approx_equal}0.003) was confirmed, allowing to estimate mass excesses {delta}mc{sup 2} for N-Z=48 nuclei up to {sup 264}Hs (Z=108). An analysis of the {alpha}-decay chains observed in a bombardment of {sup 209}Bi with {sup 58}Fe projectiles showed evidence for an isomeric state in {sup 266}Mt (Z=109). We further report on an attempt to produce element 116 and a second isotope of element 112 by the reactions {sup 82}Se+{sup 208}Pb and {sup 68}Zn+{sup 208}Pb, respectively.

  4. Digital geological information delivery in the Geological Survey of Ireland (GSI)

    NASA Astrophysics Data System (ADS)

    Carter, Mary

    2014-05-01

    Digital information is delivered though a web portal with other spatial data from the Department of Communications Energy and Natural Resources. Individual viewers specific to major GSI topics can be access for a central web page on the GSI website. Most data is available to download from our data download site the Interactive Web Data Delivery System (IWDDS) which is interactively linked to our main viewers. More recent viewers include 3D viewers able to show the topography of a selected area, as well as dynamic legends for some layers and the ability to choose from a selection of basemaps and choose the transparency of each basemap. The hardware infrastructure for web delivery is based on virtual server technology and SAN technology, this maximises uptime and ease of administration as well as providing a flexible scaling of architecture as the need arises.

  5. Mechanism of 'GSI oscillations' in electron capture by highly charged hydrogen-like atomic ions

    SciTech Connect

    Krainov, V. P.

    2012-07-15

    We suggest a qualitative explanation of oscillations in electron capture decays of hydrogen-like {sup 140}Pr and {sup 142}Pm ions observed recently in an ion experimental storage ring (ESR) of Gesellschaft fuer Schwerionenforschung (GSI) mbH, Darmstadt, Germany. This explanation is based on the electron multiphoton Rabi oscillations between two Zeeman states of the hyperfine ground level with the total angular momentum F = 1/2. The Zeeman splitting is produced by a constant magnetic field in the ESR. Transitions between these states are produced by the second, sufficiently strong alternating magnetic field that approximates realistic fields in the GSI ESR. The Zeeman splitting amounts to only about 10{sup -5} eV. This allows explaining the observed quantum beats with the period 7 s.

  6. Assimilation of NUCAPS Retrieved Profiles in GSI for Unique Forecasting Applications

    NASA Technical Reports Server (NTRS)

    Berndt, Emily Beth; Zavodsky, Bradley; Srikishen, Jayanthi; Blankenship, Clay

    2015-01-01

    Hyperspectral IR profiles can be assimilated in GSI as a separate observation other than radiosondes with only changes to tables in the fix directory. Assimilation of profiles does produce changes to analysis fields and evidenced by: Innovations larger than +/-2.0 K are present and represent where individual profiles impact the final temperature analysis.The updated temperature analysis is colder behind the cold front and warmer in the warm sector. The updated moisture analysis is modified more in the low levels and tends to be drier than the original model background Analysis of model output shows: Differences relative to 13-km RAP analyses are smaller when profiles are assimilated with NUCAPS errors. CAPE is under-forecasted when assimilating NUCAPS profiles, which could be problematic for severe weather forecasting Refining the assimilation technique to incorporate an error covariance matrix and creating a separate GSI module to assimilate satellite profiles may improve results.

  7. Real-time Aerosol Forecasting over North America using RAP-Chem and the GSI.

    NASA Astrophysics Data System (ADS)

    Pagowski, M.

    2015-12-01

    RAP-Chem is an implementation of WRF-Chem meteorology-chemistry model that is run daily at NOAA/ESRL over continental domain for air-quality forecasting. The chemical forecasts are combined with observations of species using three-dimensional variational data assimilation procedure implemented in the Gridpoint Statistical Interpolation (GSI). In the presentation we detail the method of the assimilation and show verification statistics of the model performance.

  8. Nuclear astrophysics experiments with stored, highly-charged ions at FRS-ESR at GSI

    SciTech Connect

    Scheidenberger, Christoph

    2010-08-12

    At the FRS-ESR complex of GSI a nuclear physics program with exotic nuclei has been established in last 18 years, which also addresses key questions and nuclear properties relevant in nuclear astrophysics. The paper summarizes production of exotic nuclei, lifetime studies of highly-charged ions, direct mass measurements and reactions at internal targets. A few comments on the analysis of two-body weak decays are given.

  9. Development and Implementation of Dynamic Scripts to Execute Cycled WRF/GSI Forecasts

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi; Berndt, Emily; Li, Quanli; Watson, Leela

    2014-01-01

    Automating the coupling of data assimilation (DA) and modeling systems is a unique challenge in the numerical weather prediction (NWP) research community. In recent years, the Development Testbed Center (DTC) has released well-documented tools such as the Weather Research and Forecasting (WRF) model and the Gridpoint Statistical Interpolation (GSI) DA system that can be easily downloaded, installed, and run by researchers on their local systems. However, developing a coupled system in which the various preprocessing, DA, model, and postprocessing capabilities are all integrated can be labor-intensive if one has little experience with any of these individual systems. Additionally, operational modeling entities generally have specific coupling methodologies that can take time to understand and develop code to implement properly. To better enable collaborating researchers to perform modeling and DA experiments with GSI, the Short-term Prediction Research and Transition (SPoRT) Center has developed a set of Perl scripts that couple GSI and WRF in a cycling methodology consistent with the use of real-time, regional observation data from the National Centers for Environmental Prediction (NCEP)/Environmental Modeling Center (EMC). Because Perl is open source, the code can be easily downloaded and executed regardless of the user's native shell environment. This paper will provide a description of this open-source code and descriptions of a number of the use cases that have been performed by SPoRT collaborators using the scripts on different computing systems.

  10. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Radiances from hyperspectral sounders such as the Atmospheric Infrared Sounder (AIRS) are routinely assimilated both globally and regionally in operational numerical weather prediction (NWP) systems using the Gridpoint Statistical Interpolation (GSI) data assimilation system. However, only thinned, cloud-free radiances from a 281-channel subset are used, so the overall percentage of these observations that are assimilated is somewhere on the order of 5%. Cloud checks are performed within GSI to determine which channels peak above cloud top; inaccuracies may lead to less assimilated radiances or introduction of biases from cloud-contaminated radiances.Relatively large footprint from AIRS may not optimally represent small-scale cloud features that might be better resolved by higher-resolution imagers like the Moderate Resolution Imaging Spectroradiometer (MODIS). Objective of this project is to "swap" the MODIS-derived cloud top pressure (CTP) for that designated by the AIRS-only quality control within GSI to test the hypothesis that better representation of cloud features will result in higher assimilated radiance yields and improved forecasts.

  11. Grid Computing at GSI for ALICE and FAIR - present and future

    NASA Astrophysics Data System (ADS)

    Schwarz, Kilian; Uhlig, Florian; Karabowicz, Radoslaw; Montiel-Gonzalez, Almudena; Zynovyev, Mykhaylo; Preuss, Carsten

    2012-12-01

    The future FAIR experiments CBM and PANDA have computing requirements that fall in a category that could currently not be satisfied by one single computing centre. One needs a larger, distributed computing infrastructure to cope with the amount of data to be simulated and analysed. Since 2002, GSI operates a tier2 center for ALICE@CERN. The central component of the GSI computing facility and hence the core of the ALICE tier2 centre is a LSF/SGE batch farm, currently split into three subclusters with a total of 15000 CPU cores shared by the participating experiments, and accessible both locally and soon also completely via Grid. In terms of data storage, a 5.5 PB Lustre file system, directly accessible from all worker nodes is maintained, as well as a 300 TB xrootd-based Grid storage element. Based on this existing expertise, and utilising ALICE's middleware ‘AliEn’, the Grid infrastructure for PANDA and CBM is being built. Besides a tier0 centre at GSI, the computing Grids of the two FAIR collaborations encompass now more than 17 sites in 11 countries and are constantly expanding. The operation of the distributed FAIR computing infrastructure benefits significantly from the experience gained with the ALICE tier2 centre. A close collaboration between ALICE Offline and FAIR provides mutual advantages. The employment of a common Grid middleware as well as compatible simulation and analysis software frameworks ensure significant synergy effects.

  12. Upgrading the GSI beamline microscope with a confocal fluorescence lifetime scanner to monitor charged particle induced chromatin decondensation in living cells

    NASA Astrophysics Data System (ADS)

    Abdollahi, Elham; Taucher-Scholz, Gisela; Durante, Marco; Jakob, Burkhard

    2015-12-01

    We report the upgrade of the GSI beamline microscope coupled to the linear accelerator UNILAC by a confocal FLIM scanner utilizing time correlated single photon counting technique (TCSPC). The system can now be used to address the radiation induced chromatin decondensation in more detail and with higher sensitivity compared to intensity based methods. This decondensation of heterochromatic areas is one of the early DNA damage responses observed after charged particle irradiation and might facilitate the further processing of the induced lesions. We describe here the establishment of different DNA dyes as chromatin compaction probes usable for quantification of the DNA condensation status in living cells utilizing lifetime imaging. In addition, we find an evidence of heterochromatic chromatin decondensation in ion irradiated murine chromocenters detected after subsequent fixation using FLIM measurements.

  13. Multiple positive and negative elements involved in the regulation of expression of GSY1 in Saccharomyces cerevisiae.

    PubMed

    Unnikrishnan, Indira; Miller, Steven; Meinke, Marilyn; LaPorte, David C

    2003-07-18

    GSY1 is one of the two genes encoding glycogen synthase in Saccharomyces cerevisiae. Both the GSY1 message and the protein levels increased as cells approached stationary phase. A combination of deletion analysis and site-directed mutagenesis revealed a complex promoter containing multiple positive and negative regulatory elements. Expression of GSY1 was dependent upon the presence of a TATA box and two stress response elements (STREs). Expression was repressed by Mig1, which mediates responses to glucose, and Rox1, which mediates responses to oxygen. Characterization of the GSY1 promoter also revealed a novel negative element. This element, N1, can repress expression driven by either an STRE or a heterologous element, the UAS of CYC1. Repression by N1 is dependent on the number of these elements that are present, but is independent of their orientation. N1 repressed expression when placed either upstream or downstream of the UAS, although the latter position is more effective. Gel shift analysis detected a factor that appears to bind to the N1 element. The complexity of the GSY1 promoter, which includes two STREs and three distinct negative elements, was surprising. This complexity may allow GSY1 to respond to a wide range of environmental stresses. PMID:12697770

  14. A regional GSI-based EnKF system for the Rapid Refresh configuration: Tests for Satellite Radiance Observation

    NASA Astrophysics Data System (ADS)

    Zhu, Kefeng; Xue, Ming

    2015-04-01

    A regional ensemble Kalman filter data assimilation (EnKF) system based on the NCEP operational Grid-point Statistical Interpolation (GSI) system has been established for the target Rapid Refresh (RAP) applications. The EnKF system borrows the data processing and observation operators from the GSI system, and pre-calculates observation priors using the GSI. The filter is based on the serial ensemble square-root Kalman filter (EnSRF) and updates both the state vector and observation priors and its distributed memory parallelization is carried out at the state vector level. In this study, the impact of satellite radiance including AMSU, AIRS, MHS and HIRS within the established EnKF-RAP framework was examined. Testing is performed at the ~40 km grid spacing, and its performance is compared to the GSI system which uses three dimensional variation method. The performance is evaluated in terms of short-range (up to 18 hours) forecast errors verified again soundings. The assimilation of AMSU-A data improved the forecast accuracy for all the verified variables especially for the wind components; the assimilation of AIRS data greatly improved the forecast accuracy of relative humidity; when all the radiance data were assimilated, the forecast is the best. The forecast started from EnKF analysis is consistently better than from GSI analysis though the relative improvement is smaller than GSI. In additional, the configurations like bias correction and thinning for radiance assimilation within ENKF-RAP will be presented and discussed.

  15. Notch3-specific inhibition using siRNA knockdown or GSI sensitizes paclitaxel-resistant ovarian cancer cells.

    PubMed

    Kang, Haeyoun; Jeong, Ju-Yeon; Song, Ji-Ye; Kim, Tae Heon; Kim, Gwangil; Huh, Jin Hyung; Kwon, Ah-Young; Jung, Sang Geun; An, Hee Jung

    2016-07-01

    Notch signaling plays an important role in ovarian cancer chemoresistance, which is responsible for recurrence. Gamma-secretase inhibitor (GSI) is a broad-spectrum Notch inhibitor, but it has serious side effects. The efficacy of Notch3-specific inhibition in paclitaxel-resistant ovarian cancers was assessed in this study, which has not yet been evaluated relative to GSI. To analyze the effect of Notch3-specific inhibition on paclitaxel-resistant ovarian cancers, we compared cell viability, apoptosis, cell migration, angiogenesis, cell cycle, and spheroid formation after treatment with either Notch3 siRNA or GSI in paclitaxel-resistant SKpac cells and parental SKOV3 cells. Expression levels of survival, cell cycle, and apoptosis-related proteins were measured and compared between groups. Notch3 was significantly overexpressed in chemoresistant cancer tissues and cell lines relative to chemosensitive group. In paclitaxel-resistant cancer cells, Notch inhibition significantly reduced viability, migration, and angiogenesis and increased apoptosis, thereby boosting sensitivity to paclitaxel. Spheroid formation was also significantly reduced. Both Notch3 siRNA-treated cells and GSI-treated cells arrested in the G2/M phase of the cell cycle. Proteins of cell survival, cyclin D1 and cyclin D3 were reduced, whereas p21 and p27 were elevated. Both GSI and Notch3 siRNA treatment reduced expression of anti-apoptotic proteins (BCL-W, BCL2, and BCL-XL) and increased expression of pro-apoptotic proteins (Bad, Bak, Bim, Bid, and Bax). These results indicate that Notch3-specific inhibition sensitizes paclitaxel-resistant cancer cells to paclitaxel treatment, with an efficacy comparable to that of GSI. This approach would be likely to avoid the side effects of broad-spectrum GSI treatment. © 2015 Wiley Periodicals, Inc. PMID:26207830

  16. PET imaging for treatment verification of ion therapy: Implementation and experience at GSI Darmstadt and MGH Boston

    NASA Astrophysics Data System (ADS)

    Parodi, Katia; Bortfeld, Thomas; Enghardt, Wolfgang; Fiedler, Fine; Knopf, Antje; Paganetti, Harald; Pawelke, Jörg; Shakirin, Georgy; Shih, Helen

    2008-06-01

    Ion beams offer the possibility of improved conformation of the dose delivered to the tumor with better sparing of surrounding tissue and critical structures in comparison to conventional photon and electron external radiation treatment modalities. Full clinical exploitation of this advantage can benefit from in vivo confirmation of the actual beam delivery and, in particular, of the ion range in the patient. During irradiation, positron emitters like 15O (half-life T1/2≈2 min) and 11C ( T1/2≈20 min) are formed in nuclear interactions between the ions and the tissue. Detection of this transient radioactivity via positron emission tomography (PET) and comparison with the expectation based on the prescribed beam application may serve as an in vivo, non-invasive range validation method of the whole treatment planning and delivery chain. For technical implementation, PET imaging during irradiation (in-beam) requires the development of customized, limited angle detectors with data acquisition synchronized with the beam delivery. Alternatively, commercial PET or PET/CT scanners in close proximity to the treatment site enable detection of the residual activation from long-lived emitters shortly after treatment (offline). This paper reviews two clinical examples using a dedicated in-beam PET scanner for verification of carbon ion therapy at GSI Darmstadt, Germany, as well as a commercial offline PET/CT tomograph for post-radiation imaging of proton treatments at Massachusetts General Hospital, Boston, USA. Challenges as well as pros and cons of the two imaging approaches in dependence of the different ion type and beam delivery system are discussed.

  17. Production of high current proton beams using complex H-rich molecules at GSI.

    PubMed

    Adonin, A; Barth, W; Heymach, F; Hollinger, R; Vormann, H; Yakushev, A

    2016-02-01

    In this contribution, the concept of production of intense proton beams using molecular heavy ion beams from an ion source is described, as well as the indisputable advantages of this technique for operation of the GSI linear accelerator. The results of experimental investigations, including mass-spectra analysis and beam emittance measurements, with different ion beams (CH3(+),C2H4(+),C3H7(+)) using various gaseous and liquid substances (methane, ethane, propane, isobutane, and iodoethane) at the ion source are summarized. Further steps to improve the ion source and injector performance with molecular beams are depicted. PMID:26932072

  18. RECENT TEST RESULTS OF THE FAST-PULSED 4 T COS DIPOLE GSI 001.

    SciTech Connect

    MORITZ, G.; KAUGERTS, J.; ESCALLIER, J.; GANETIS, G.; JAIN, A.; MARONE, A.; MURATORE, J.; THOMAS, R.; WANDERER, P.; ET AL.

    2005-05-26

    For the FAIR-project at GSI a model dipole was built at BNL with the nominal field of 4 T and a nominal ramp rate of 1 T/S. The magnet design was similar to the RHIC dipole, with some changes for loss reduction and better cooling. The magnet was already successfully tested in a vertical cryostat, with good training behavior. Cryogenic losses were measured and first results of field harmonics were published. However, for a better understanding of the cooling process, quench currents at several ramp rates were investigated. Detailed measurements of the field harmonics at 2 T/S between 0 and 4 T were performed.

  19. Production of high current proton beams using complex H-rich molecules at GSI

    NASA Astrophysics Data System (ADS)

    Adonin, A.; Barth, W.; Heymach, F.; Hollinger, R.; Vormann, H.; Yakushev, A.

    2016-02-01

    In this contribution, the concept of production of intense proton beams using molecular heavy ion beams from an ion source is described, as well as the indisputable advantages of this technique for operation of the GSI linear accelerator. The results of experimental investigations, including mass-spectra analysis and beam emittance measurements, with different ion beams (CH3+,C2H4+,C3H7+) using various gaseous and liquid substances (methane, ethane, propane, isobutane, and iodoethane) at the ion source are summarized. Further steps to improve the ion source and injector performance with molecular beams are depicted.

  20. Use of MODIS Cloud Top Pressure to Improve Assimilation Yields of AIRS Radiances in GSI

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley; Srikishen, Jayanthi

    2014-01-01

    Improvements to global and regional numerical weather prediction have been demonstrated through assimilation of data from NASA's Atmospheric Infrared Sounder (AIRS). Current operational data assimilation systems use AIRS radiances, but impact on regional forecasts has been much smaller than for global forecasts. Previously, it has been shown that cloud top designation associated with quality control procedures within the Gridpoint Statistical Interpolation (GSI) system used operationally by a number of Joint Center for Satellite Data Assimilation (JCSDA) partners may not provide the best representation of cloud top pressure (CTP). Because this designated CTP determines which channels are cloud-free and, thus, available for assimilation, ensuring the most accurate representation of this value is imperative to obtaining the greatest impact from satellite radiances. This paper examines the assimilation of hyperspectral sounder data used in operational numerical weather prediction by comparing analysis increments and numerical forecasts generated using operational techniques with a research technique that swaps CTP from the Moderate-resolution Imaging Spectroradiometer (MODIS) for the value of CTP calculated from the radiances within GSI.

  1. Facility for Antiproton and Ion Research, FAIR, at the GSI site

    SciTech Connect

    Rosner, Guenther

    2006-11-17

    FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

  2. Feasibility of OTR imaging of non-relativistic ions at GSI

    SciTech Connect

    Lumpkin, A.H.; /Fermilab

    2011-03-01

    The feasibility of using the optical transition radiation (OTR) generated as a 11.4- to 300-MeV/u ion beam passes through a single metal conducting plane for a minimally intercepting beam profile monitor for GSI/Darmstadt has been evaluated for the first time. Although these are non-relativistic beams, their beta and gamma values are similar to the 80-keV electron-beam imaging studies previously done on the CTF3 injector. With anticipated beam intensities of 10{sup 9} to 10{sup 11} particles per pulse and the predicted charge-squared dependence of OTR, the ion charge state becomes a critical factor for photon production. The OTR signal from the ion charge integrated over the video field time should be comparable to or larger than the CTF3 electron case. These signal strengths will allow a series of experiments to be done that should further elucidate the working regime of this technique.

  3. Bacillus subtilis GSY 1057 assay for aflatoxin B activation by rainbow trout (Salmo gairdneri).

    PubMed

    Schoenhard, G L; Bishop, P E; Lee, D J; Sinnhuber, R O

    1975-09-01

    A rapid and sensitive microbial assay was developed to detect lethal products of aflatoxin B metabolism by rainbow trout (Salmon gairdneri) Mt. Shasta strain. Bacillus subtilis GSY 1057 (hisA1, uvr-1, metB4), a DNA repair deficient strain, was incubated for 20 min in the 20,000 times g supernate from trout liver homogenates which had been preincubated for 10 min with various levels of aflatoxin B. Serial dilutions of the incubation mixture were plated in triplicate on tryptose blood agar base plates and colonies were counted after 12 hr at 37 degrees C. One mumole aflatoxin B in 3.2 ml incubation mixture reduced viability 60%. PMID:808527

  4. Is the GSI anomaly due to neutrino oscillations? A real time perspective

    SciTech Connect

    Wu Jun; Boyanovsky, Daniel; Hutasoit, Jimmy A.; Holman, Richard

    2010-08-15

    We study a model for the 'GSI anomaly' in which we obtain the time evolution of the population of parent and daughter particles directly in real time, considering explicitly the quantum entanglement between the daughter particle and neutrino mass eigenstates in the two-body decay. We confirm that the decay rate of the parent particle and the growth rate of the daughter particle do not feature a time modulation from interference of neutrino mass eigenstates. The lack of interference is a consequence of the orthogonality of the mass eigenstates. This result also follows from the density matrix obtained by tracing out the unobserved neutrino states. We confirm this result by providing a complementary explanation based on Cutkosky rules applied to the Feynman diagram that describes the self energy of the parent particle.

  5. The ASY-EOS experiment at GSI: investigating symmetry energy at supra-saturation densities

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Chartier, M.; Cozma, M. D.; De Filippo, E.; Le Fèvre, A.; Gannon, S.; Gašparić, I.; Kiš, M.; Kupny, S.; Leifels, Y.; Lemmon, R. C.; Li, Q.; Łukasik, J.; Marini, P.; Pawłowski, P.; Santoro, S.; Trautmann, W.; Veselsky, M.; Acosta, L.; Adamczyk, M.; Al-Ajlan, A.; Al-Garawi, M.; Al-Homaidhi, S.; Amorini, F.; Auditore, L.; Aumann, T.; Ayyad, Y.; Baran, V.; Basrak, Z.; Bassini, R.; Benlliure, J.; Boiano, C.; Boisjoli, M.; Boretzky, K.; Brzychczyk, J.; Budzanowski, A.; Cardella, G.; Cammarata, P.; Chajecki, Z.; Chbihi, A.; Colonna, M.; Czech, B.; Di Toro, M.; Famiano, M.; Greco, V.; Grassi, L.; Guazzoni, C.; Guazzoni, P.; Heil, M.; Heilborn, L.; Introzzi, R.; Isobe, T.; Kezzar, K.; Krasznahorkay, A.; Kurz, N.; La Guidara, E.; Lanzalone, G.; Lasko, P.; Lombardo, I.; Lynch, W. G.; Matthews, Z.; May, L.; Minniti, T.; Mostazo, M.; Pagano, A.; Papa, M.; Pirrone, S.; Pleskac, R.; Politi, G.; Porto, F.; Reifarth, R.; Reisdorf, W.; Riccio, F.; Rizzo, F.; Rosato, E.; Rossi, D.; Simon, H.; Skwirczynska, I.; Sosin, Z.; Stuhl, L.; Trifirò, A.; Trimarchi, M.; Tsang, M. B.; Verde, G.; Vigilante, M.; Wieloch, A.; Wigg, P.; Wolter, H. H.; Wu, P.; Yennello, S.; Zambon, P.; Zetta, L.; Zoric, M.

    2014-03-01

    The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of heavy-ions at pre-relativistic energies has been proposed as an observable sensitive to the strength of the symmetry term of the nuclear equation of state at supra-saturation densities. The results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model simulations favoured a moderately soft symmetry term, but suffer from a considerable statistical uncertainty. These results have been confirmed by an independent analysis based on the Tübingen QMD simulations. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration. The present status of the data analysis is reported

  6. The ASY-EOS experiment at GSI: investigating the symmetry energy at supra-saturation densities

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Chartier, M.; De Filippo, E.; Le Fèvre, A.; Gannon, S.; Gašparić, I.; Kiš, M.; Kupny, S.; Leifels, Y.; Lemmon, R. C.; Łukasik, J.; Marini, P.; Pagano, A.; Pawłowski, P.; Santoro, S.; Trautmann, W.; Veselsky, M.; Acosta, L.; Adamczyk, M.; Al-Ajlan, A.; Al-Garawi, M.; Al-Homaidhi, S.; Amorini, F.; Auditore, L.; Aumann, T.; Ayyad, Y.; Baran, V.; Basrak, Z.; Benlliure, J.; Boiano, C.; Boisjoli, M.; Boretzky, K.; Brzychczyk, J.; Budzanowski, A.; Cardella, G.; Cammarata, P.; Chajecki, Z.; Chbihi, A.; Colonna, M.; Cozma, D.; Czech, B.; Di Toro, M.; Famiano, M.; Geraci, E.; Greco, V.; Grassi, L.; Guazzoni, C.; Guazzoni, P.; Heil, M.; Heilborn, L.; Introzzi, R.; Isobe, T.; Kezzar, K.; Krasznahorkay, A.; Kurz, N.; La Guidara, E.; Lanzalone, G.; Lasko, P.; Li, Q.; Lombardo, I.; Lynch, W. G.; Matthews, Z.; May, L.; Minniti, T.; Mostazo, M.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Reifarth, R.; Reisdorf, W.; Riccio, F.; Rizzo, F.; Rosato, E.; Rossi, D.; Simon, H.; Skwirczynska, I.; Sosin, Z.; Stuhl, L.; Trifirò, A.; Trimarchi, M.; Tsang, M. B.; Verde, G.; Vigilante, M.; Wieloch, A.; Wigg, P.; Wolter, H. H.; Wu, P.; Yennello, S.; Zambon, P.; Zetta, L.; Zoric, M.

    2013-03-01

    The elliptic-flow ratio of neutrons with respect to protons in reactions of neutron rich heavy-ions systems at intermediate energies has been proposed as an observable sensitive to the strength of the symmetry term in the nuclear Equation Of State (EOS) at supra-saturation densities. The recent results obtained from the existing FOPI/LAND data for 197Au+197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model allowed a first estimate of the symmetry term of the EOS but suffer from a considerable statistical uncertainty. In order to obtain an improved data set for Au+Au collisions and to extend the study to other systems, a new experiment was carried out at the GSI laboratory by the ASY-EOS collaboration in May 2011.

  7. Lognormal Assimilation of Water Vapor in a WRF-GSI Cycled System

    NASA Astrophysics Data System (ADS)

    Fletcher, S. J.; Kliewer, A.; Jones, A. S.; Forsythe, J. M.

    2015-12-01

    Recent publications have shown the viability of both detecting a lognormally-distributed signal for water vapor mixing ratio and the improved quality of satellite retrievals in a 1DVAR mixed lognormal-Gaussian assimilation scheme over a Gaussian-only system. This mixed scheme is incorporated into the Gridpoint Statistical Interpolation (GSI) assimilation scheme with the goal of improving forecasts from the Weather Research and Forecasting (WRF) Model in a cycled system. Results are presented of the impact of treating water vapor as a lognormal random variable. Included in the analysis are: 1) the evolution of Tropical Storm Chris from 2006, and 2) an analysis of a "Pineapple Express" water vapor event from 2005 where a lognormal signal has been previously detected.

  8. Generic Safety Issue (GSI) 171 -- Engineered Safety Feature (ESF) failure from a loop subsequent to LOCA: Assessment of plant vulnerability and CDF contributions

    SciTech Connect

    Martinez-Guridi, G.; Samanta, P.; Chu, L.; Yang, J.

    1998-03-01

    Generic Safety Issue 171 (GSI-171), Engineered Safety Feature (ESF) from a Loss Of Offsite Power (LOOP) subsequent to a Loss Of Coolant Accident (LOCA), deals with an accident sequence in which a LOCA is followed by a LOOP. This issue was later broadened to include a LOOP followed by a LOCA. Plants are designed to handle a simultaneous LOCA and LOOP. In this paper, the authors address the unique issues that are involved i LOCA with delayed LOOP (LOCA/LOOP) and LOOP with delayed LOCA (LOOP/LOCA) accident sequences. LOCA/LOOP accidents are analyzed further by developing event-tree/fault-tree models to quantify their contributions to core-damage frequency (CDF) in a pressurized water reactor and a boiling water reactor (PWR and a BWR). Engineering evaluation and judgments are used during quantification to estimate the unique conditions that arise in a LOCA/LOOP accident. The results show that the CDF contribution of such an accident can be a dominant contributor to plant risk, although BWRs are less vulnerable than PWRs.

  9. MEASURED AND CALCULATED LOSSES IN A MODEL DIPOLE FOR GSI'S HEAVY ION SYNCHROTRON.

    SciTech Connect

    WANDERER,P.; ANERELLA,M.; GANETIS,G.; GHOSH,A.K.; JOSHI,P.; MARONE,A.; MURATORE,J.; ET AL.

    2003-06-15

    The new heavy ion synchrotron facility proposed by GSI will have two superconducting magnet rings in the same tunnel, with rigidities of 300T{center_dot}m and 10OT{center_dot}m. Fast ramp times are needed. These can cause problems of ac loss and field distortion in the magnets. For the high energy ring, a lm model dipole magnet has been built, based on the RHIC dipole design. This magnet was tested under boiling liquid helium in a vertical dewar. The quench current showed very little dependence on ramp rate. The ac losses, measured by an electrical method, were fitted to straight line plots of loss/cycle versus ramp rate, thereby separating the eddy current and hysteresis components. These results were compared with calculated values, using parameters which had previously been measured on short samples of cable. Reasonably good agreement between theory and experiment was found, although the measured hysteresis loss is higher than expected in ramps to the highest field levels.

  10. Production and Decay of Element 114 Isotopes with the BGS (LBNL) and TASCA (GSI)

    NASA Astrophysics Data System (ADS)

    Gates, Jacklyn

    2010-11-01

    During the last 10 years, the Dubna Gas Filled Recoil Separator (DGFRS) group has published numerous reports of the production and decay of superheavy elements (SHE) with Z=112-118 in ^48Ca irradiations of actinide targets. Recently the production of element 114 in the ^242Pu(^48Ca,3-4n) reaction was verified at the Lawrence Berkeley National Laboratory using the Berkeley Gas-filled Separator (BGS). Later experiments at the BGS successfully extended the region of known SHE nuclides along the neutron-deficient side using the ^242Pu(^48Ca,5n)^285114 reaction. Almost concurrently with the BGS, the TransActinide Separator and Chemistry Apparatus at the GSI Helmholtzzentrum fúr Schwerionenforschung investigated the ^244Pu(^48Ca,3-4n) reaction and observed cross sections on the order of 10 pb for the production of element 114 when the more neutron-rich ^244Pu target was used. An alpha-decay branch in ^281Ds was also discovered, leading to the new nucleus ^277Hs. Cross sections, decay modes and decay properties all agree with those published by the DGFRS group. Implications of these results on the field of heavy elements will be discussed.

  11. Electrophysiological effects of 12C on patients undergoing heavy ions therapy at GSI: a pilot study

    NASA Astrophysics Data System (ADS)

    Sannita, W. G.; Narici, L.; Debus, J.; Carozzo, S.; Saturno, M.; Schardt, D.; Schulz-Ertner, D.

    Phosphenes light flashes observed in space have been attributed to heavy ions interfering with the retina photoreceptors However their generating mechanisms are still undefined and neurons of the retina and non-ocular visual structures are as sensitive to ionizing agents as retinal photoreceptors Multiple sources are therefore possible that could question safety in manned space travel Patients undergoing 12C ion therapy of skull tumors also involving the anterior optic pathway often report phosphenes similar to those described by astronauts and volunteers in accelerator experiments In a pilot study their occurrence either within each beam pulse or shortly after it in case of very short pulses correlated with the beam position and local dose deposited near the optic nerve or eye during irradiation Further research is in progress at the GSI Biophysics facilities in Darmstadt FRG Purposes of the study are 1- to identify electrophysiological cortical concomitants of phosphenes 2- to correlate phosphenes with irradiated portions of the anterior visual pathways and with known basic mechanisms of vision and 3- to obtain information to be used in the understanding of phosphenes observed in space We will present preliminary results from the first measurements

  12. Measurements of 12 C ion fragmentation on thin carbon target from the FIRST collaboration at GSI

    NASA Astrophysics Data System (ADS)

    Toppi, M.; FIRST Collaboration

    2015-04-01

    The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at GSI laboratory took data in summer 2011, studying the collisions of a 12C ion beam with Carbon and Au thin targets. The experiment main purpose is the double differential cross section measurement of the carbon ion fragmentation at energies that are relevant both for tumor therapy and space radiation protection applications (100-1000 MeV/u). The FIRST dataset contains carbon ions collisions on a 3.43 g·Cin-2 carbon target (about 24 M events) and on a 0.96 g·cm-2 Au target (about 4.5 M events). The SIS (heavy ion synchrotron) was used to accelerate the 12C ions at the energy of 400 MeV/u. The preliminary results of differential cross sections measurements as a function of angle and energy for carbon target, in the small angle region (θ ≤ 5°), are presented.

  13. Monte Carlo simulations for the shielding of the future high-intensity accelerator facility FAIR at GSI.

    PubMed

    Radon, T; Gutermuth, F; Fehrenbacher, G

    2005-01-01

    The Gesellschaft für Schwerionenforschung (GSI) is planning a significant expansion of its accelerator facilities. Compared to the present GSI facility, a factor of 100 in primary beam intensities and up to a factor of 10,000 in secondary radioactive beam intensities are key technical goals of the proposal. The second branch of the so-called Facility for Antiproton and Ion Research (FAIR) is the production of antiprotons and their storage in rings and traps. The facility will provide beam energies a factor of approximately 15 higher than presently available at the GSI for all ions, from protons to uranium. The shielding design of the synchrotron SIS 100/300 is shown exemplarily by using Monte Carlo calculations with the FLUKA code. The experimental area serving the investigation of compressed baryonic matter is analysed in the same way. In addition, a dose comparison is made for an experimental area operated with medium energy heavy-ion beams. Here, Monte Carlo calculations are performed by using either heavy-ion primary particles or proton beams with intensities scaled by the mass number of the corresponding heavy-ion beam. PMID:16381714

  14. Current Status of the Development of a Transportable and Compact VLBI System by NICT and GSI

    NASA Technical Reports Server (NTRS)

    Ishii, Atsutoshi; Ichikawa, Ryuichi; Takiguchi, Hiroshi; Takefuji, Kazuhiro; Ujihara, Hideki; Koyama, Yasuhiro; Kondo, Tetsuro; Kurihara, Shinobu; Miura, Yuji; Matsuzaka, Shigeru; Tanimoto, Daisuke

    2010-01-01

    MARBLE (Multiple Antenna Radio-interferometer for Baseline Length Evaluation) is under development by NICT and GSI. The main part of MARBLE is a transportable VLBI system with a compact antenna. The aim of this system is to provide precise baseline length over about 10 km for calibrating baselines. The calibration baselines are used to check and validate surveying instruments such as GPS receiver and EDM (Electro-optical Distance Meter). It is necessary to examine the calibration baselines regularly to keep the quality of the validation. The VLBI technique can examine and evaluate the calibration baselines. On the other hand, the following roles are expected of a compact VLBI antenna in the VLBI2010 project. In order to achieve the challenging measurement precision of VLBI2010, it is well known that it is necessary to deal with the problem of thermal and gravitational deformation of the antenna. One promising approach may be connected-element interferometry between a compact antenna and a VLBI2010 antenna. By measuring repeatedly the baseline between the small stable antenna and the VLBI2010 antenna, the deformation of the primary antenna can be measured and the thermal and gravitational models of the primary antenna will be able to be constructed. We made two prototypes of a transportable and compact VLBI system from 2007 to 2009. We performed VLBI experiments using theses prototypes and got a baseline length between the two prototypes. The formal error of the measured baseline length was 2.7 mm. We expect that the baseline length error will be reduced by using a high-speed A/D sampler.

  15. Optimizing expression and purification of an ATP-binding gene gsiA from Escherichia coli k-12 by using GFP fusion

    PubMed Central

    Wang, Zhongshan; Xiang, Quanju; Wang, Guangjun; Wang, Haiyan; Zhang, Yizheng

    2011-01-01

    The cloning, expression and purification of the glutathione (sulfur) import system ATP-binding protein (gsiA) was carried out. The coding sequence of Escherichia coli gsiA, which encodes the ATP-binding protein of a glutathione importer, was amplified by PCR, and then inserted into a prokaryotic expression vector pWaldo-GFPe harboring green fluorescent protein (GFP) reporter gene. The resulting recombinant plasmid pWaldo-GFP-GsiA was transformed into various E. coli strains, and expression conditions were optimized. The effect of five E. coli expression strains on the production of the recombinant gsiA protein was evaluated. E. coli BL21 (DE3) was found to be the most productive strain for GsiA-GFP fusion-protein expression, most of which was insoluble fraction. However, results from in-gel and Western blot analysis suggested that expression of recombinant GsiA in Rosetta (DE3) provides an efficient source in soluble form. By using GFP as reporter, the most suitable host strain was conveniently obtained, whereby optimizing conditions for overexpression and purification of the proteins for further functional and structural studies, became, not only less laborious, but also time-saving. PMID:22215971

  16. Composite heat damage assessment

    SciTech Connect

    Janke, C.J.; Wachter, E.A.; Philpot, H.E.; Powell, G.L.

    1993-12-31

    The effects of heat damage were determined on the residual mechanical, physical, and chemical properties of IM6/3501-6 laminates, and potential nondestructive techniques to detect and assess material heat damage were evaluated. About one thousand preconditioned specimens were exposed to elevated temperatures, then cooled to room temperature and tested in compression, flexure, interlaminar shear, shore-D hardness, weight loss, and change in thickness. Specimens experienced significant and irreversible reduction in their residual properties when exposed to temperatures exceeding the material upper service temperature of this material (350{degrees}F). The Diffuse Reflectance Infrared Fourier Transform and Laser-Pumped Fluorescence techniques were found to be capable of rapid, in-service, nondestructive detection and quantitation of heat damage in IM6/3501- 6. These techniques also have the potential applicability to detect and assess heat damage effects in other polymer matrix composites.

  17. NASA SPoRT Modeling and Data Assimilation Research and Transition Activities Using WRF, LIS and GSI

    NASA Technical Reports Server (NTRS)

    Case, Jonathan L.; Blankenship, Clay B.; Zavodsky, Bradley T.; Srikishen, Jayanthi; Berndt, Emily B.

    2014-01-01

    weather research and forecasting ===== The NASA Short-term Prediction Research and Transition (SPoRT) program has numerous modeling and data assimilation (DA) activities in which the WRF model is a key component. SPoRT generates realtime, research satellite products from the MODIS and VIIRS instruments, making the data available to NOAA/NWS partners running the WRF/EMS, including: (1) 2-km northwestern-hemispheric SST composite, (2) daily, MODIS green vegetation fraction (GVF) over CONUS, and (3) NASA Land Information System (LIS) runs of the Noah LSM over the southeastern CONUS. Each of these datasets have been utilized by specific SPoRT partners in local EMS model runs, with select offices evaluating the impacts using a set of automated scripts developed by SPoRT that manage data acquisition and run the NCAR Model Evaluation Tools verification package. SPoRT is engaged in DA research with the Gridpoint Statistical Interpolation (GSI) and Ensemble Kalman Filter in LIS for soil moisture DA. Ongoing DA projects using GSI include comparing the impacts of assimilating Atmospheric Infrared Sounder (AIRS) radiances versus retrieved profiles, and an analysis of extra-tropical cyclones with intense non-convective winds. As part of its Early Adopter activities for the NASA Soil Moisture Active Passive (SMAP) mission, SPoRT is conducting bias correction and soil moisture DA within LIS to improve simulations using the NASA Unified-WRF (NU-WRF) for both the European Space Agency's Soil Moisture Ocean Salinity and upcoming SMAP mission data. SPoRT has also incorporated real-time global GVF data into LIS and WRF from the VIIRS product being developed by NOAA/NESDIS. This poster will highlight the research and transition activities SPoRT conducts using WRF, NU-WRF, EMS, LIS, and GSI.

  18. Time Modulation of the K-Shell Electron Capture Decay Rates of H-like Heavy Ions at GSI Experiments

    SciTech Connect

    Ivanov, A. N.; Kienle, P.

    2009-08-07

    According to experimental data at GSI, the rates of the number of daughter ions, produced by the nuclear K shell electron capture decays of the H-like heavy ions with one electron in the K shell, such as {sup 140}Pr{sup 58+}, {sup 142}Pm{sup 60+}, and {sup 122}I{sup 52+}, are modulated in time with periods T{sub EC} of the order of a few seconds, obeying an A scaling T{sub EC}=A/20 s, where A is the mass number of the mother nuclei, and with amplitudes a{sub d}{sup EC}approx0.21. We show that these data can be explained in terms of the interference of two massive neutrino mass eigenstates. The appearance of the interference term is due to overlap of massive neutrino mass eigenstate energies and of the wave functions of the daughter ions in two-body decay channels, caused by the energy and momentum uncertainties introduced by time differential detection of the daughter ions in GSI experiments.

  19. Nonuniform radiation damage in permanent magnet quadrupoles

    SciTech Connect

    Danly, C. R.; Merrill, F. E.; Barlow, D.; Mariam, F. G.

    2014-08-15

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL’s pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

  20. Nonuniform radiation damage in permanent magnet quadrupoles.

    PubMed

    Danly, C R; Merrill, F E; Barlow, D; Mariam, F G

    2014-08-01

    We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components. PMID:25173260

  1. SURVIVAL EFFICACY OF THE PEGYLATED G-CSFS MAXY-G34 AND NEULASTA IN A MOUSE MODEL OF LETHAL H-ARS, AND RESIDUAL BONE MARROW DAMAGE IN TREATED SURVIVORS

    PubMed Central

    Chua, Hui Lin; Plett, P. Artur; Sampson, Carol H.; Katz, Barry P.; Carnathan, Gilbert W.; MacVittie, Thomas J.; Lenden, Keith; Orschell, Christie M.

    2013-01-01

    In an effort to expand the worldwide pool of available medical countermeasures (MCM) against radiation, the PEGylated G-CSF (PEG-G-CSF) molecules Neulasta and Maxy-G34, a novel PEG-G-CSF designed for increased half-life and enhanced activity compared to Neulasta, were examined in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS), along with the lead MCM for licensure and stockpiling, G-CSF. Both PEG-G-CSFs were shown to retain significant survival efficacy when administered as a single dose 24hr post-exposure, compared to the 16 daily doses of G-CSF required for survival efficacy. Furthermore, 0.1 mg kg−1 of either PEG-G-CSF effected survival of lethally-irradiated mice that was similar to a 10-fold higher dose. The one dose/low dose administration schedules are attractive attributes of radiation MCM given the logistical challenges of medical care in a mass casualty event. Maxy-G34-treated mice that survived H-ARS were examined for residual bone marrow damage (RBMD) up to 9mo post-exposure. Despite differences in Sca-1 expression and cell cycle position in some hematopoietic progenitor phenotypes, Maxy-G34-treated mice exhibited the same degree of hematopoietic stem cell (HSC) insufficiency as vehicle treated H-ARS survivors in competitive transplantation assays of 150 purified Sca-1+cKit+lin-CD150+ cells. These data suggest that Maxy-G34, at the dose, schedule, and time frame examined, did not mitigate RBMD, but significantly increased survival from H-ARS at one-tenth the dose previously tested, providing strong support for advanced development of Maxy-G34, as well as Neulasta, as MCM against radiation. PMID:24276547

  2. Survival efficacy of the PEGylated G-CSFs Maxy-G34 and neulasta in a mouse model of lethal H-ARS, and residual bone marrow damage in treated survivors.

    PubMed

    Chua, Hui Lin; Plett, P Artur; Sampson, Carol H; Katz, Barry P; Carnathan, Gilbert W; MacVittie, Thomas J; Lenden, Keith; Orschell, Christie M

    2014-01-01

    In an effort to expand the worldwide pool of available medical countermeasures (MCM) against radiation, the PEGylated G-CSF (PEG-G-CSF) molecules Neulasta and Maxy-G34, a novel PEG-G-CSF designed for increased half-life and enhanced activity compared to Neulasta, were examined in a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS), along with the lead MCM for licensure and stockpiling, G-CSF. Both PEG-G-CSFs were shown to retain significant survival efficacy when administered as a single dose 24 h post-exposure, compared to the 16 daily doses of G-CSF required for survival efficacy. Furthermore, 0.1 mg kg of either PEG-G-CSF affected survival of lethally-irradiated mice that was similar to a 10-fold higher dose. The one dose/low dose administration schedules are attractive attributes of radiation MCM given the logistical challenges of medical care in a mass casualty event. Maxy-G34-treated mice that survived H-ARS were examined for residual bone marrow damage (RBMD) up to 9 mo post-exposure. Despite differences in Sca-1 expression and cell cycle position in some hematopoietic progenitor phenotypes, Maxy-G34-treated mice exhibited the same degree of hematopoietic stem cell (HSC) insufficiency as vehicle-treated H-ARS survivors in competitive transplantation assays of 150 purified Sca-1+cKit+lin-CD150+cells. These data suggest that Maxy-G34, at the dose, schedule, and time frame examined, did not mitigate RBMD but significantly increased survival from H-ARS at one-tenth the dose previously tested, providing strong support for advanced development of Maxy-G34, as well as Neulasta, as MCM against radiation. PMID:24276547

  3. A new data acquisition system for Schottky signals in atomic physics experiments at GSI's and FAIR's storage rings

    NASA Astrophysics Data System (ADS)

    Trageser, C.; Brandau, C.; Kozhuharov, C.; Litvinov, Yu A.; Müller, A.; Nolden, F.; Sanjari, S.; Stöhlker, T.

    2015-11-01

    A new continuous and broadband data acquisition system for measurements of Schottky-signals of ions revolving in a storage ring has been implemented. This set-up is capable of recording the radio frequency (RF) signal of the ions that circulate in the storage ring with a sustained acquisition rate of more than 3.5× {10}7 IQ-samples per second. This allows several harmonics of the full momentum acceptance of a storage ring to be measured at the same time. The RF signal analyzer modules are complemented by further electronic modules such as counters, precision clocks and synchronization modules that facilitate a seamless integration with main experimental data acquisitions for atomic and nuclear physics. In this contribution, the setup and first results from a test run at the experimental storage ring at GSI, Darmstadt, Germany, are presented.

  4. Data-flow coupling and data-acquisition triggers for the PreSPEC-AGATA campaign at GSI

    NASA Astrophysics Data System (ADS)

    Ralet, D.; Pietri, S.; Aubert, Y.; Bellato, M.; Bortolato, D.; Brambilla, S.; Camera, F.; Dosme, N.; Gadea, A.; Gerl, J.; Golubev, P.; Grave, X.; Johansson, H. T.; Karkour, N.; Korichi, A.; Kurz, N.; Lafay, X.; Legay, E.; Linget, D.; Pietralla, N.; Rudolph, D.; Schaffner, H.; Stezowski, O.; Travers, B.; Wieland, O.

    2015-06-01

    The PreSPEC setup for high-resolution γ-ray spectroscopy using radioactive ion beams was employed for experimental campaigns in 2012 and 2014. The setup consisted of the state of the art Advanced GAmma Tracking Array (AGATA) and the High Energy γ deteCTOR (HECTOR+) positioned around a secondary target at the final focal plane of the GSI FRagment Separator (FRS) to perform in-beam γ-ray spectroscopy of exotic nuclei. The Lund York Cologne CAlorimeter (LYCCA) was used to identify the reaction products. In this paper we report on the trigger scheme used during the campaigns. The data-flow coupling between the Multi-Branch System (MBS) based Data AcQuisition (DAQ) used for FRS-LYCCA and the "Nouvelle Acquisition temps Réel Version 1.2 Avec Linux" (NARVAL) based acquisition system used for AGATA are also described.

  5. Stacking of 3 GeV Antiprotons with a Moving Barrier Bucket Method at the GSI-RESR

    SciTech Connect

    Katayama, T.; Beller, P.; Franzke, B.; Nesmiyan, I.; Nolden, F.; Steck, M.; Moehl, D.; Kikuchi, T.

    2006-03-20

    At the FAIR project at GSI, 3GeV pbar beams are to be accumulated in the RESR ring up to the intensity of 1.0e11. Every 5 seconds a new batch of 1.0e8 pbars is transferred from a Collector Ring (CR) where the pbar beams are pre-cooled to the momentum spread of 0.1% with stochastic cooling. The main task of the RESR is the accumulation of 1000 batches from the CR. In the classical way established at CERN's AA/AC, a new batch is injected on the injection orbit and is stacked in the radially separated stacking region. In the present paper, an alternative way, azimuthal separation with barrier bucket is proposed. The process is simulated up to 1000 injections and the emittance growth and the intra-beam scattering effects are evaluated.

  6. Residual microstructure and damage geometry associated with high speed impact crater in Al{sub 2}O{sub 3} and TiB{sub 2} particles reinforced 2024 Al composite

    SciTech Connect

    Guo, Q.; Sun, D.L. Jiang, L.T.; Wu, G.H.; Chen, G.Q.

    2012-04-15

    The resistance of Al{sub 2}O{sub 3} + TiB{sub 2}/2024Al composite to hypervelocity impact was tested by a two-stage light gas gun. The impact damage behaviors of the Al{sub 2}O{sub 3} + TiB{sub 2}/2024Al composite by different-sized Al projectiles with a velocity of 2.49 km/s and the residual microstructures associated with the crater impacted by a 1.2 mm aluminum projectile were investigated by transmission electron microscopy and high-resolution transmission electron microscopy. Both the diameters of craters at front face and spalling areas at back face increased with the aluminum projectile diameter. The diameter of perforation on the 2 mm thick Al{sub 2}O{sub 3} + TiB{sub 2}/Al composite target was zero when impacted by 1.2 mm aluminum projectile and it increased to 2.4 mm when the projectile diameter was 1.5 mm, indicating that the critical perforation diameter of the aluminum projectile was between 1.2 mm and 1.5 mm when the 2 mm thick Al{sub 2}O{sub 3} + TiB{sub 2}/Al composite target was impacted by 2.49 km/s aluminum projectiles. The diameter of perforation increases with the diameter of Al projectile. In addition, under each impact condition, the diameters of craters at front face were smaller than that of spalling areas at back face. Microstructure observations by transmission electron microscopy demonstrated four characteristics: stacking faults around TiB{sub 2} particle and dislocations within the TiB{sub 2} particle; twins in the Al{sub 2}O{sub 3} particle; recrystal grains in 2024 Al matrix; and mixture of amorphous microstructure and nanograins in the matrix. - Highlights: Black-Right-Pointing-Pointer Stacking faults were produced around the edge of TiB{sub 2} particle after impact. Black-Right-Pointing-Pointer Twins with the twin plane of (2{sup Macron }112) were observed in Al{sub 2}O{sub 3} particle after impact. Black-Right-Pointing-Pointer Recrystal grains with size of 100 nm were formed in aluminum matrix after impact. Black

  7. STRE- and cAMP-independent transcriptional induction of Saccharomyces cerevisiae GSY2 encoding glycogen synthase during diauxic growth on glucose.

    PubMed

    Parrou, J L; Enjalbert, B; François, J

    1999-10-01

    It has been shown that the so-called stationary phase GSY2 gene encoding glycogen synthase was induced as the cells left the exponential phase of growth, while glucose and all other nutrients were still plentiful in the medium (Parrou et al., 1999). Since this effect was essentially controlled at the transcriptional level, we looked for the cis- and trans-acting elements required for this specific growth-related genetic event. We demonstrated that mutations of the HAP2/3/4 binding site and of the two STress-Responsive cis-Elements (STRE) did not abolish the early induction of GSY2, although the latter mutation led to a 20-fold drop in the transcriptional activity of the promoter, as determined from lacZ gene fusions. Insertion of a DNA fragment (from -390 to -167 bp, relative to the ATG) of the promoter lacking the two STREs, upstream to the TATA box of a CYC1-lacZ fusion gene, allowed this reporter gene to be induced with a kinetic similar to that of GSY2-lacZ. Mutations in BCY1, which results in a hyperactive protein kinase A, did not alleviate the early induction, while causing a five- to 10-fold reduction in the transcriptional activity of GSY2. In addition, the repressive effect of protein kinase A was quantitatively conserved when both STREs were mutated in GSY2 promoter, indicating that the negative control of gene expression by the RAS-cAMP signalling pathway does not act solely through STREs. Taken together, these results are indicative of an active process that couples growth control to dynamic glucose consumption. PMID:10514565

  8. GSI-I (Z-LLNle-CHO) inhibits γ-secretase and the proteosome to trigger cell death in precursor-B acute lymphoblastic leukemia.

    PubMed

    Meng, X; Matlawska-Wasowska, K; Girodon, F; Mazel, T; Willman, C L; Atlas, S; Chen, I-M; Harvey, R C; Hunger, S P; Ness, S A; Winter, S S; Wilson, B S

    2011-07-01

    Gamma secretase inhibitors (GSIs) comprise a growing class of compounds that interfere with the membrane-bound Notch signaling protein and its downstream intra-nuclear transcriptional targets. As GSI-I (Z-LLNle-CHO) is also a derivative of a widely used proteosome inhibitor MG-132, we hypothesized that this compound might be active in precursor-B acute lymphoblastic leukemia (ALL) cell lines and patient samples. We found that GSI-I treatment of precursor-B ALL blasts induced apoptotic cell death within 18-24 h. With confirmation using RNA and protein analyses, GSI-I blocked nuclear accumulation of cleaved Notch1 and Notch2, and inhibited Notch targets Hey2 and Myc. Microarray analyses of 207 children with high-risk precursor-B ALL demonstrate that Notch pathway expression is a common feature of these neoplasms. However, microarray studies also implicated additional transcriptional targets in GSI-I-dependent cell death, including genes in the unfolded protein response, nuclear factor-κB and p53 pathways. Z-LLNle-CHO blocks both γ-secretase and proteosome activity, inducing more robust cell death in precursor-B ALL cells than either proteosome-selective or γ-secretase-selective inhibitors alone. Using Z-LLNle-CHO in a nonobese diabetes/severe combined immunodeficiency (NOD/SCID) precursor-B ALL xenograft model, we found that GSI-I alone delayed or prevented engraftment of B-lymphoblasts in 50% of the animals comprising the experimental group, suggesting that this compound is worthy of additional testing. PMID:21494254

  9. The capture and dissemination of integrated 3D geospatial knowledge at the British Geological Survey using GSI3D software and methodology

    NASA Astrophysics Data System (ADS)

    Kessler, Holger; Mathers, Steve; Sobisch, Hans-Georg

    2009-06-01

    The Geological Surveying and Investigation in 3 Dimensions (GSI3D) software tool and methodology has been developed over the last 15 years. Since 2001 this has been in cooperation with the British Geological Survey (BGS). To-date over a hundred BGS geologists have learned to use the software that is now routinely deployed in building systematic and commercial 3D geological models. The success of the GSI3D methodology and software is based on its intuitive design and the fact that it utilises exactly the same data and methods, albeit in digital forms, that geologists have been using for two centuries in order to make geological maps and cross-sections. The geologist constructs models based on a career of observation of geological phenomena, thereby incorporating tacit knowledge into the model. This knowledge capture is a key element to the GSI3D approach. In BGS GSI3D is part of a much wider set of systems and work processes that together make up the cyberinfrastructure of a modern geological survey. The GSI3D software is not yet designed to cope with bedrock structures in which individual stratigraphic surfaces are repeated or inverted, but the software is currently being extended by BGS to encompass these more complex geological scenarios. A further challenge for BGS is to enable its 3D geological models to become part of the semantic Web using GML application schema like GeoSciML. The biggest benefits of widely available systematic geological models will be an enhanced public understanding of the sub-surface in 3D, and the teaching of geoscience students.

  10. Crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues [e.g., corn (Zea mays) stover and small grain straw] are sometimes excluded when discussing cellulosic energy crops per se, but because of the vast area upon which they are grown and their current role in the development of cellulosic energy systems. This chapter focuses on current cor...

  11. Radiation impact caused by activation of air from the future GSI accelerator facility fair.

    PubMed

    Gutermuth, F; Wildermuth, H; Radon, T; Fehrenbacher, G

    2005-01-01

    The Gesellschaft für Schwerionenforschung in Darmstadt is planning a new accelerator Facility for Antiproton and Ion Research (FAIR). Two future experimental areas are regarded to be the most decisive points concerning the activation of air. One is the area for the production of antiprotons. A second crucial experimental area is the so-called Super Fragment Separator. The production of radioactive isotopes in air is calculated using the residual nuclei option of the Monte Carlo program FLUKA. The results are compared with the data for the activation of air given by Sullivan and in IAEA report 283. The resulting effective dose is calculated using a program package from the German Federal Office for Radiation Protection, the Bundesamt für Stranlenschutz. The results demonstrate that a direct emission of the total radioactivity produced into the air will probably conflict with the limits of the German Radiation Protection Ordinance. Special measures have to be planned in order to reduce the amount of radioactivity released into the air. PMID:16381762

  12. Combinatorial control by the protein kinases PKA, PHO85 and SNF1 of transcriptional induction of the Saccharomyces cerevisiae GSY2 gene at the diauxic shift.

    PubMed

    Enjalbert, B; Parrou, J L; Teste, M A; François, J

    2004-07-01

    Genes involved in storage carbohydrate metabolism are coordinately induced when yeast cells are subjected to conditions of stress, or when they exit the exponential growth phase on glucose. We show that the STress Responsive Elements (STREs) present in the promoter of GSY2 are essential for gene activation under conditions of stress, but dispensable for gene induction and glycogen accumulation at the diauxic shift on glucose. Using serial promoter deletion, we found that the latter induction could not be attributed to a single cis -regulatory sequence, and present evidence that this mechanism depends on combinatorial transcriptional control by signalling pathways involving the protein kinases Pho85, Snf1 and PKA. Two contiguous regions upstream of the GSY2 coding region are necessary for negative control by the cyclin-dependent protein kinase Pho85, one of which is a 14-bp G/C-rich sequence. Positive control by Snf1 is mediated by Mig1p, which acts indirectly on the distal part of the GSY2 promoter. The PKA pathway has the most pronounced effect on GSY2, since transcription of this gene is almost completely abolished in an ira1ira2 mutant strain in which PKA is hyperactive. The potent negative effect of PKA is dependent upon a branched pathway involving the transcription factors Msn2/Msn4p and Sok2p. The SOK2 branch was found to be effective only under conditions of high PKA activity, as in a ira1ira2 mutant, and this effect was independent of Msn2/4p. The Msn2/4p branch, on the other hand, positively controls GSY2 expression directly through the STREs, and indirectly via a factor that still remains to be discovered. In summary, this study shows that the transcription of GSY2 is regulated by several different signalling pathways which reflect the numerous factors that influence glycogen synthesis in yeast, and suggests that the PKA pathway must be deactivated to allow gene induction at the diauxic shift. PMID:15221454

  13. X-ray spectroscopy of warm and hot electron components in the CAPRICE source plasma at EIS testbench at GSI

    SciTech Connect

    Mascali, D. Celona, L.; Castro, G.; Torrisi, G.; Neri, L.; Gammino, S.; Ciavola, G.; Maimone, F.; Maeder, J.; Tinschert, K.; Spaedtke, K. P.; Rossbach, J.; Lang, R.; Romano, F. P.; Musumarra, A.; Altana, C.; Caliri, C.

    2014-02-15

    An experimental campaign aiming to detect X radiation emitted by the plasma of the CAPRICE source – operating at GSI, Darmstadt – has been carried out. Two different detectors (a SDD – Silicon Drift Detector and a HpGe – hyper-pure Germanium detector) have been used to characterize the warm (2–30 keV) and hot (30–500 keV) electrons in the plasma, collecting the emission intensity and the energy spectra for different pumping wave frequencies and then correlating them with the CSD of the extracted beam measured by means of a bending magnet. A plasma emissivity model has been used to extract the plasma density along the cone of sight of the SDD and HpGe detectors, which have been placed beyond specific collimators developed on purpose. Results show that the tuning of the pumping frequency considerably modifies the plasma density especially in the warm electron population domain, which is the component responsible for ionization processes: a strong variation of the plasma density near axis region has been detected. Potential correlations with the charge state distribution in the plasma are explored.

  14. The TransActinide Separator and Chemistry Apparatus (TASCA) at GSI Optimization of ion-optical structures and magnet designs

    NASA Astrophysics Data System (ADS)

    Semchenkov, A.; Brüchle, W.; Jäger, E.; Schimpf, E.; Schädel, M.; Mühle, C.; Klos, F.; Türler, A.; Yakushev, A.; Belov, A.; Belyakova, T.; Kaparkova, M.; Kukhtin, V.; Lamzin, E.; Sytchevsky, S.

    2008-10-01

    The new, highly efficient gas-filled TransActinide Separator and Chemistry Apparatus (TASCA) was designed and built at GSI with the aim to study chemical and physical properties of superheavy elements with atomic numbers 104 and higher produced in heavy-ion reactions with actinide targets. To reach the highest possible transmission, while exploiting an existing dipole magnet and two quadrupoles of a previously used gas-filled separator, an optimization of the ion-optical structure of TASCA was performed with the program TRANSPORT. Two modes of TASCA operation, the "High Transmission Mode" and the "Small Image-size Mode" were selected. Magnetic field measurements were carried out with the dipole and were compared with KOMPOT model calculations. Magnetic field model calculations of the dipole and the quadrupoles, including a duct and a large exit valve, were performed to optimize the pole pieces of the dipole and the ducts. This increased the efficiency up to 50%. Both modes of operation were successfully tested in first commissioning experiments.

  15. A Non-Normal Incidence Pumped Ni-Like Zr XRL for Spectroscopy of Li-Like Heavy Ions at GSI/FAIR

    NASA Astrophysics Data System (ADS)

    Kühl, T.; Ursescu, D.; Bagnoud, V.; Javorkova, D.; Rosmej, O.; Zimmer, D.; Cassou, K.; Kazamias, S.; Klisnick, A.; Ros, D.; Zielbauer, B.; Janulewicz, K.; Nickles, P.; Pert, G.; Neumayer, P.; Dunn, J.

    One of the unique features of the PHELIX laser installation is the combination of the ultra-high intensity laser with the heavy-ion accelerator facility at GSI and its planned extension FAIR. Due to this combination, PHELIX will allow novel investigations in the fields of plasma physics, atomic physics, nuclear physics, and accelerator studies. An important issue within the scientific program is the generation of high quality x-ray laser beams for x-ray laser spectroscopy of highly-charged ions. The long range perspective is the study of nuclear properties of radioactive isotopes within the FAIR [1] project. A novel single mirror focusing scheme for the TCE XRL has been successfully implemented by the LIXAM/MBI/GSI collaboration under different pump geometries. Intense and stable laser operation with Ni-like Zr and Ni-like Ag was demonstrated at pump energies between 2 J and 5 J from the PHELIX pre-amplifier section.

  16. Residual Cap

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 May 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a summertime view of the south polar residual cap of Mars. In this image, mesas composed largely of solid carbon dioxide are separated from one another by irregularly-shaped depressions. The variation in brightness across this scene is a function of several factors including, but not limited to, varying proportions of dust and solid carbon dioxide, undulating topography, and differences in the roughness of the slopes versus the flat surfaces.

    Location near: 86.7oS, 343.3oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  17. Crop residue and residue management effects on Armadillidium vulgare (Isopoda: Armadillidiidae) populations and soybean stand densities.

    PubMed

    Johnson, W A; Alfaress, S; Whitworth, R J; McCornack, B P

    2012-10-01

    In general, Armadillidium vulgare (Latreille) are considered nonpests of soybean [Glycine max (L.) Merrill], but changes in soil conservation practices have shifted the pest status of this organism from an opportunistic to a perennial, early-season pest in parts of central Kansas. As a result, soybean producers that rotate with corn (Zea mays L.) under conservation tillage practices have resorted to removing excess corn residue by using controlled burns. In a 2-yr field study (2009-2010), we demonstrated that residue removal in burned compared with unburned plots (measured as previous crop residue weights) had minimal impact on numbers of live and dead A. vulgare, soybean seedling emergence, and isopod feeding damage over time. Specifically, removal of residue by burning did not result in higher emergence rates for soybean stands or less feeding damage by A. vulgare. In a separate study, we found that number of live A. vulgare and residue weights had no consistent relationship with seedling emergence or feeding damage. Furthermore, seedling emergence was not impacted by higher numbers ofA. vulgare in unburned plots, indicating that emergence in this study may have been influenced by factors other than A. vulgare densities. These studies demonstrate that removing residue through controlled burning did not impact seedling emergence in presence of A. vulgare and that residue and feeding damage to seedlings did not consistently relate to A. vulgare densities. Other factors that may have influenced a relationship between residue and live isopod numbers, such as variable moisture levels, are discussed. PMID:23156159

  18. Aflatoxin B1 metabolism to aflatoxicol and derivatives lethal to Bacillus subtilis GSY 1057 by rainbow trout (Salmo gairdneri) liver.

    PubMed

    Schoenhard, G L; Lee, D J; Howell, S E; Pawlowski, N E; Libbey, L M; Sinnhuber, R O

    1976-06-01

    Aflatoxicol, R0, was isolated from Mt. Shasta strain rainbow trout (Salmo gairdneri), and liver homogenates were incubated with aflatoxin B1. Its identity was confirmed by mass, infrared, and ultraviolet spectrometry. The structure was identical to one of the diastereomers prepared by chemical reduction of aflatoxin B1. Aflatoxicol was apparently formed by a reduced nicotinamide adenine dinucleotide phosphate-dependent soluble enzyme of the 105,000 x g supernatant from rainbow trout. Aflatoxicol was not lethal in phosphate buffer to Bacillus subtilis GSY 1057 (metB4, hisA1, uvr-1) nor were aflatoxins B1, Q1, and B2. In the presence of reduced nicotinamide adenine dinucleotide phosphate and trout liver microsomes, aflatoxicol reduced the viability of B. subtilis. Aflatoxin B2, which lacks the vinyl ether present in the other compounds, could not be activated. The product of aflatoxin B1 activation by trout liver microsomes was sought after incubation of 14C-labeled aflatoxin B1. The radioactivity was found in unaltered aflatoxin B1 and in three extremely polar metabolites. The quantity of the new metabolites and the level of microbial lethality was reduced by addition of cytosine and cysteine to the incubation medium. The vinyl ether configuration was a structural requirement for activation, and this finding and the nature of the enzymatic reaction were consistent with the hypothesis that the compounds were metabolized to highly reactive and unstable electrophilic products which bound to nucleophiles such as cytosine and were lethal to B. subtilis. The formation of aflatoxicol as the major product of trout liver metabolism is of great significance considering that it could be activated to a lethal compound and that rainbow trout are one of the most sensitive species to aflatoxin B1-induced carcinoma. PMID:5190

  19. Protein damage, radiation sensitivity and aging.

    PubMed

    Radman, Miroslav

    2016-08-01

    This paper promotes a concept that protein damage determines radiation resistance and underlies aging and age-related diseases. The first bottleneck in cell recovery from radiation damage is functional (proteome) rather than informational (DNA), since prokaryotic and eukaryotic cell death correlates with incurred protein, but not DNA, damage. Proteome protection against oxidative damage determines survival after ionizing or UV irradiation, since sufficient residual proteome activity is required to turn on the DNA damage response activating DNA repair and protein renewal processes. Extreme radiation and desiccation resistance of rare bacterial and animal species is accounted for by exceptional constitutive proteome protection against oxidative damage. After excessive radiation their well-protected proteome faithfully reconstitutes a transcription-competent genome from hundreds of DNA fragments. The observation that oxidative damage targeted selectively to cellular proteins results in aging-like phenotypes suggests that aging and age-related diseases could be phenotypic consequences of proteome damage patterns progressing with age. PMID:27264559

  20. Damage Tolerance of Composite Laminates from an Empirical Perspective

    NASA Technical Reports Server (NTRS)

    Nettles, Alan T.

    2009-01-01

    Damage tolerance consists of analysis and experimentation working together. Impact damage is usually of most concern for laminated composites. Once impacted, the residual compression strength is usually of most interest. Other properties may be of more interest than compression (application dependent). A damage tolerance program is application specific (not everyone is building aircraft). The "Building Block Approach" is suggested for damage tolerance. Advantage can be taken of the excellent fatigue resistance of damaged laminates to save time and costs.

  1. Right Hemisphere Brain Damage

    MedlinePlus

    ... Language and Swallowing / Disorders and Diseases Right Hemisphere Brain Damage [ en Español ] What is right hemisphere brain ... right hemisphere brain damage ? What is right hemisphere brain damage? Right hemisphere brain damage (RHD) is damage ...

  2. Studies on fission with ALADIN. Precise and simultaneous measurement of fission yields, total kinetic energy and total prompt neutron multiplicity at GSI

    NASA Astrophysics Data System (ADS)

    Martin, Julie-Fiona; Taieb, Julien; Chatillon, Audrey; Bélier, Gilbert; Boutoux, Guillaume; Ebran, Adeline; Gorbinet, Thomas; Grente, Lucie; Laurent, Benoit; Pellereau, Eric; Alvarez-Pol, Héctor; Audouin, Laurent; Aumann, Thomas; Ayyad, Yassid; Benlliure, Jose; Casarejos, Enrique; Cortina Gil, Dolores; Caamaño, Manuel; Farget, Fanny; Fernández Domínguez, Beatriz; Heinz, Andreas; Jurado, Beatriz; Kelić-Heil, Aleksandra; Kurz, Nikolaus; Nociforo, Chiara; Paradela, Carlos; Pietri, Stéphane; Ramos, Diego; Rodríguez-Sànchez, Jose-Luis; Rodríguez-Tajes, Carme; Rossi, Dominic; Schmidt, Karl-Heinz; Simon, Haik; Tassan-Got, Laurent; Vargas, Jossitt; Voss, Bernd; Weick, Helmut

    2015-12-01

    A novel technique for fission studies, based on the inverse kinematics approach, is presented. Following pioneering work in the nineties, the SOFIA Collaboration has designed and built an experimental set-up dedicated to the simultaneous measurement of isotopic yields, total kinetic energies and total prompt neutron multiplicities, by fully identifying both fission fragments in coincidence, for the very first time. This experiment, performed at GSI, permits to study the fission of a wide variety of fissioning systems, ranging from mercury to neptunium, possibly far from the valley of stability. A first experiment, performed in 2012, has provided a large array of unprecedented data regarding the nuclear fission process. An excerpt of the results is presented. With this solid starter, further improvements of the experimental set-up are considered, which are consistent with the expected developments at the GSI facility, in order to measure more fission observables in coincidence. The completeness reached in the SOFIA data, permits to scrutinize the correlations between the interesting features of fission, offering a very detailed insight in this still unraveled mechanism.

  3. Comment on 'Time modulation of K-shell electron capture decay rates of H-like heavy ions at GSI experiments.'

    SciTech Connect

    Lipkin, H. J.; Physics; Weizmann Inst. of Science; Tel Aviv Univ.

    2010-04-16

    A Comment on the Letter by A.N. Ivanov and P. Kienle, Physical Review Letters volume 103, Issue 6, 062502 (2009). The authors of the Letter offer a Reply to experimental data at GSI, the rates of the number of daughter ions, produced by the nuclear K shell electron capture decays of the H-like heavy ions with one electron in the K shell, such as {sup 140}Pr{sup 58+}, {sup 142}Pm{sup 60+}, and {sup 122}I{sup 52+}, are modulated in time with periods T{sub EC} of the order of a few seconds, obeying an A scaling T{sub EX}=A/20 s, where A is the mass number of the mother nuclei, and with amplitudes a{sub d {sup EC}}{approx}0.21. We show that these data can be explained in terms of the interference of two massive neutrino mass eigenstates. The appearance of the interference term is due to overlap of massive neutrino mass eigenstate energies and of the wave functions of the daughter ions in two-body decay channels, caused by the energy and momentum uncertainties introduced by time differential detection of the daughter ions in GSI experiments.

  4. Studies of heavy ion-induced high-energy density states in matter at the GSI Darmstadt SIS-18 and future FAIR facility

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Adonin, A.; Deutsch, C.; Fortov, V. E.; Grandjouan, N.; Geil, B.; Grayaznov, V.; Hoffmann, D. H. H.; Kulish, M.; Lomonosov, I. V.; Mintsev, V.; Ni, P.; Nikolaev, D.; Piriz, A. R.; Shilkin, N.; Spiller, P.; Shutov, A.; Temporal, M.; Ternovoi, V.; Udrea, S.; Varentsov, D.

    2005-05-01

    This paper presents numerical simulation results of heating and compression of matter using intense beams of energetic heavy ions. In this study we consider different beam parameters that include those which are currently available at the heavy ion synchrotron, SIS18 at the Gesellschaft für Schwerionenforschung (GSI), Darmstadt and those which will be available in the near future as a result of the upgraded facility. In addition to this, we carried out detailed calculations considering parameters of high-intensity beam which will be generated at the GSI future Facility for Antiprotons and Ion Research (FAIR facility) that has been approved by the German Government. These simulations show that by using the above ion beam parameter range, it will be possible to carry out very useful studies on the thermophysical properties of high-energy density (HED) states in matter. This scheme would make it possible to investigate those regions of the phase diagram that are either very difficult to access or even are unaccessible using the traditional methods of shock waves. Moreover, employing a hollow ion beam which has an annular (ring shaped) focal spot, it would be possible to achieve a low entropy compression of a test material like hydrogen, which is enclosed in a cylindrical shell of a high-density material such as lead or gold. These experiments will enable one to study the interiors of Giant planets, Jupiter and Saturn as well as to investigate the problem of hydrogen metallization.

  5. Compressive residual strength of graphite/epoxy laminates after impact

    NASA Technical Reports Server (NTRS)

    Guy, Teresa A.; Lagace, Paul A.

    1992-01-01

    The issue of damage tolerance after impact, in terms of the compressive residual strength, was experimentally examined in graphite/epoxy laminates using Hercules AS4/3501-6 in a (+ or - 45/0)(sub 2S) configuration. Three different impactor masses were used at various velocities and the resultant damage measured via a number of nondestructive and destructive techniques. Specimens were then tested to failure under uniaxial compression. The results clearly show that a minimum compressive residual strength exists which is below the open hole strength for a hole of the same diameter as the impactor. Increases in velocity beyond the point of minimum strength cause a difference in the damage produced and cause a resultant increase in the compressive residual strength which asymptotes to the open hole strength value. Furthermore, the results show that this minimum compressive residual strength value is independent of the impactor mass used and is only dependent upon the damage present in the impacted specimen which is the same for the three impactor mass cases. A full 3-D representation of the damage is obtained through the various techniques. Only this 3-D representation can properly characterize the damage state that causes the resultant residual strength. Assessment of the state-of-the-art in predictive analysis capabilities shows a need to further develop techniques based on the 3-D damage state that exists. In addition, the need for damage 'metrics' is clearly indicated.

  6. Resist residue removal using UV ozone treatment

    NASA Astrophysics Data System (ADS)

    Chen, Shu-Fang; Chang, Ching-Yu; Ku, Yao-Ching

    2010-04-01

    In a conventional lithography process, the resist pattern is removed by dry strip or wet chemical etch. The wet chemical etch includes sulfuric peroxide etch and solvent etch. The wet chemical etch process is always combined with the dry strip process to meet the residue process spec. However, in some applications, only the wet-etch process can be used to avoid substrate damage during the plasma step. However, organic residue can be found from particle surface scan and TGA/DSC after normal solvent strip. In this paper, we investigate polymer residue stripping using only solvent as well as solvent in combination with UV treatment. For solvents only, some solvents different from the conventional PGMEA/PGME mixture in polarity, also exhibited stripping ability but the efficiency is not as good as PGME/PGMEA mixture. When supplemented with UV treatment, the organic residue can be further decomposed and removed completely. The UV we used contains 185nm and 254nm wavelengths. Ozone is generated during UV exposure and acts as oxidant. The organic residue is thus decomposed and removed. It has been proven as an effective method to cleave the C-C bond without damaging the wafer substrate. The organic residue on the wafer surface can be easily stripped away under UV-ozone exposure. Its defect performance is also discussed in this paper.

  7. Numerical analysis of impact-damaged sandwich composites

    NASA Astrophysics Data System (ADS)

    Hwang, Youngkeun

    Sandwich structures are used in a wide variety of structural applications due to their relative advantages over other conventional structural materials in terms of improved stability, weight savings, and ease of manufacture and repair. Foreign object impact damage in sandwich composites can result in localized damage to the facings, core, and core-facing interface. Such damage may result in drastic reductions in composite strength, elastic moduli, and durability and damage tolerance characteristics. In this study, physically-motivated numerical models have been developed for predicting the residual strength of impact-damaged sandwich composites comprised of woven-fabric graphite-epoxy facesheets and Nomex honeycomb cores subjected to compression-after-impact loading. Results from non-destructive inspection and destructive sectioning of damaged sandwich panels were used to establish initial conditions for damage (residual facesheet indentation, core crush dimension, etc.) in the numerical analysis. Honeycomb core crush test results were used to establish the nonlinear constitutive behavior for the Nomex core. The influence of initial facesheet property degradation and progressive loss of facesheet structural integrity on the residual strength of impact-damaged sandwich panels was examined. The influence of damage of various types and sizes, specimen geometry, support boundary conditions, and variable material properties on the estimated residual strength is discussed. Facesheet strains from material and geometric nonlinear finite element analyses correlated relatively well with experimentally determined values. Moreover, numerical predictions of residual strength are consistent with experimental observations. Using a methodology similar to that presented in this work, it may be possible to develop robust residual strength estimates for complex sandwich composite structural components with varying levels of in-service damage. Such studies may facilitate sandwich

  8. β-decay and β-delayed Neutron Emission Measurements at GSI-FRS Beyond N=126, for r-process Nucleosynthesis

    SciTech Connect

    Caballero-Folch, R.; Domingo-Pardo, C.; Cortès, G.; Taín, J.L.; Agramunt, J.; Algora, A.; Ameil, F.; Ayyad, Y.; Benlliure, J.; Bowry, M.; Calviño, F.; Cano-Ott, D.; Davinson, T.; and others

    2014-06-15

    New measurements of very exotic nuclei in the neutron-rich region beyond N=126 have been performed at the GSI facility with the fragment separator (FRS). The aim of the experiment is to determine half-lives and β-delayed neutron emission branching ratios of isotopes of Hg, Tl and Pb in this region. This contribution summarizes final counting statistics for identification and for implantation, as well as the present status of the data analysis of the half-lives. In summary, isotopes of Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn and Fr were clearly identified and several of them ({sup 208-211}Hg, {sup 211-215}Tl, {sup 214-218}Pb) were implanted with enough statistics to determine their half-lives. About half of them are expected to be neutron emitters, in such cases it will become possible to obtain the neutron emission probabilities, Pn.

  9. Effects of Kamdhenu Ark and Active Immunization by Gonadotropin Releasing Hormone Conjugate (GnRH-BSA) on Gonadosomatic Indices (GSI) and Sperm Parameters in Male Mus musculus

    PubMed Central

    Ganaie, Javid Ahmad; Gautam, Varsha; Shrivastava, Vinoy Kumar

    2011-01-01

    Background Active immunization against GnRH decreases the secretion of gonadotropins and causes cessation of gonadal function, thereby, inducing infertility. Based on the immunoenhancing activity of Kamdhenu ark (distilled cow urine), this study was performed to evaluate its effects on the gonadosomatic indices (GSI) and sperm parameters in male mice receiving a GnRH contraceptive vaccine. Methods Sixty adult male mice of Parke's strain were divided into three groups of twenty. Group I served as the controls, while group II was immunized by GnRH-BSA conjugate (50/0.2/35 µg/ml/g BW) by four intraperitoneal injections at different intervals on days 1, 30, 60 and 90. However, group III was supplemented daily by oral Kamdhenu ark (100 ppm) along with GnRH-BSA immunizations. The animals were sacrificed after 30, 60, 90 and 120 days and their testis and epididymis were dissected out weighed and semen analysis was performed. Results GSI values, sperm motility, sperm count and sperm morphology in male Mus musculus were decreased significantly in all the experimental groups as compared to the control group (p<0.01). Kamdhenu ark significantly enhanced the effect of GnRH vaccine on the aforesaid parameters especially in 90 and 120 days treated groups (p<0.05). Conclusion The changes witnessed in sperm parameters suggested that the GnRH-BSA immunization suppressed the activities of gonadotropins and testosterone directly through hypothalamo-hypophysial-gonadal axis and indirectly by acting on the testes which may modulate the sperm morphology, sperm count and motility. However, Kamdhenu ark seems to have enhanced these effects because of its immune-modulatory properties too. PMID:23926493

  10. Damage of hybrid composite laminates

    NASA Astrophysics Data System (ADS)

    Haery, Haleh A.; Kim, Ho Sung

    2013-08-01

    Hybrid laminates consisting of woven glass fabric/epoxy composite plies and woven carbon fabric/epoxy composite plies are studied for fatigue damage and residual strength. A theoretical framework based on the systems approach is proposed as a guide to deal with the complexity involving uncertainties and a large number of variables in the hybrid composite system. A relative damage sensitivity factor expression was developed for quantitative comparisons between non-hybrid and hybrid composites. Hypotheses derived from the theoretical framework were tested and verified. The first hypothesis was that the difference between two different sets of properties produces shear stress in interface between carbon fibre reinforced plastics (CRP) and glass fibre reinforced plastics (GRP), and eventually become a source for CRP/GRP interfacial delamination or longitudinal cracking. The second hypothesis was that inter-fibre bundle delamination occurs more severely to CRP sub-system than GRP sub-system.

  11. Impacts of AMSU-A, MHS and IASI data assimilation on temperature and humidity forecasts with GSI-WRF over the western United States

    NASA Astrophysics Data System (ADS)

    Bao, Y.; Xu, J.; Powell, A. M., Jr.; Shao, M.; Min, J.; Pan, Y.

    2015-10-01

    Using NOAA's Gridpoint Statistical Interpolation (GSI) data assimilation system and NCAR's Advanced Research WRF (Weather Research and Forecasting) (ARW-WRF) regional model, six experiments are designed by (1) a control experiment (CTRL) and five data assimilation (DA) experiments with different data sets, including (2) conventional data only (CON); (3) microwave data (AMSU-A + MHS) only (MW); (4) infrared data (IASI) only (IR); (5) a combination of microwave and infrared data (MWIR); and (6) a combination of conventional, microwave and infrared observation data (ALL). One-month experiments in July 2012 and the impacts of the DA on temperature and moisture forecasts at the surface and four vertical layers over the western United States have been investigated. The four layers include lower troposphere (LT) from 800 to 1000 hPa, middle troposphere (MT) from 400 to 800 hPa, upper troposphere (UT) from 200 to 400 hPa, and lower stratosphere (LS) from 50 to 200 hPa. The results show that the regional GSI-WRF system is underestimating the observed temperature in the LT and overestimating in the UT and LS. The MW DA reduced the forecast bias from the MT to the LS within 30 h forecasts, and the CON DA kept a smaller forecast bias in the LT for 2-day forecasts. The largest root mean square error (RMSE) is observed in the LT and at the surface (SFC). Compared to the CTRL, the MW DA produced the most positive contribution in the UT and LS, and the CON DA mainly improved the temperature forecasts at the SFC. However, the IR DA gave a negative contribution in the LT. Most of the observed humidity in the different vertical layers is overestimated in the humidity forecasts except in the UT. The smallest bias in the humidity forecast occurred at the SFC and in the UT. The DA experiments apparently reduced the bias from the LT to UT, especially for the IR DA experiment, but the RMSEs are not reduced in the humidity forecasts. Compared to the CTRL, the IR DA experiment has a larger

  12. New results from isochronous mass measurements of neutron-rich uranium fission fragments with the FRS-ESR-facility at GSI

    NASA Astrophysics Data System (ADS)

    Knöbel, R.; Diwisch, M.; Geissel, H.; Litvinov, Yu. A.; Patyk, Z.; Plaß, W. R.; Scheidenberger, C.; Sun, B.; Weick, H.; Bosch, F.; Boutin, D.; Chen, L.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Hausmann, M.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S. A.; Matoš, M.; Mazzocco, M.; Münzenberg, G.; Nakajima, S.; Nociforo, C.; Nolden, F.; Ohtsubo, T.; Ozawa, A.; Stadlmann, J.; Steck, M.; Suzuki, T.; Walker, P. M.; Winkler, M.; Yamaguchi, T.

    2016-05-01

    Masses of uranium fission fragments have been measured with the FRagment Separator (FRS) combined with the Experimental Storage Ring (ESR) at GSI. A 410-415 MeV/u 238U projectile beam was fast extracted from the synchrotron SIS-18 with an average intensity of 109/spill. The projectiles were focused on a 1g/cm2 beryllium target at the entrance of the FRS to create neutron-rich isotopes via abrasion-fission. The fission fragments were spatially separated with the FRS and injected into the isochronous storage ring ESR for fast mass measurements without applying cooling. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B ρ-tagging at the high-resolution dispersive central focal plane of the FRS. The evaluation has been done for the combined data sets from both experiments with a new method of data analysis. The use of a correlation matrix has provided experimental mass values for 23 different neutron-rich isotopes for the first time and 6 masses with improved values. The new masses were obtained for nuclides in the element range from Se to Ce. The applied analysis has given access even to rare isotopes detected with an intensity of a few atoms per week. The novel data analysis and systematic error determination are described and the results are compared with extrapolations of experimental values and theoretical models.

  13. Modeling event building architecture for the triggerless data acquisition system for PANDA experiment at the HESR facility at FAIR/GSI

    NASA Astrophysics Data System (ADS)

    Korcyl, K.; Konorov, I.; Kühn, W.; Schmitt, L.

    2012-12-01

    A novel architecture is being proposed for the data acquisition and trigger system of the PANDA experiment at the HESR facility at FAIR/GSI. The experiment will run without hardware trigger signal using timestamps to correlate detector data from a given time window. The broad physics program in combination with the high rate of 2 * 107 interactions per second requires very selective filtering algorithms accessing information from many detectors. Therefore the effective filtering will happen later than in today's systems ie. after the event building. To assess that, the complete architecture will be built of two stages: the data concentrator stage providing event building and the rate reduction stage. For the former stage, which requires a throughput of 100 GB/s to perform event building, we propose two layers of ATCA crates filled with Compute Nodes - modules designed at IHEP and University of Giessen for trigger and data acquisition systems. Currently each board is equipped with 5 Virtex4 FX60 FPGAs and high bandwidth connectivity is provided by 8 front panel RocketIO ports and 12 backplane ports for the inter-module communication. We designed simplified models of the components of the architecture and using the SystemC library as support for the discrete event simulations, demonstrate the expected throughput of the full-size system. We also show impact of some architectural choices and key parameters on the architecture's performance.

  14. Feasibility Study of Using Gemstone Spectral Imaging (GSI) and Adaptive Statistical Iterative Reconstruction (ASIR) for Reducing Radiation and Iodine Contrast Dose in Abdominal CT Patients with High BMI Values

    PubMed Central

    Zhu, Zheng; Zhao, Xin-ming; Zhao, Yan-feng; Wang, Xiao-yi; Zhou, Chun-wu

    2015-01-01

    Purpose To prospectively investigate the effect of using Gemstone Spectral Imaging (GSI) and adaptive statistical iterative reconstruction (ASIR) for reducing radiation and iodine contrast dose in abdominal CT patients with high BMI values. Materials and Methods 26 patients (weight > 65kg and BMI ≥ 22) underwent abdominal CT using GSI mode with 300mgI/kg contrast material as study group (group A). Another 21 patients (weight ≤ 65kg and BMI ≥ 22) were scanned with a conventional 120 kVp tube voltage for noise index (NI) of 11 with 450mgI/kg contrast material as control group (group B). GSI images were reconstructed at 60keV with 50%ASIR and the conventional 120kVp images were reconstructed with FBP reconstruction. The CT values, standard deviation (SD), signal-noise-ratio (SNR), contrast-noise-ratio (CNR) of 26 landmarks were quantitatively measured and image quality qualitatively assessed using statistical analysis. Results As for the quantitative analysis, the difference of CNR between groups A and B was all significant except for the mesenteric vein. The SNR in group A was higher than B except the mesenteric artery and splenic artery. As for the qualitative analysis, all images had diagnostic quality and the agreement for image quality assessment between the reviewers was substantial (kappa = 0.684). CT dose index (CTDI) values for non-enhanced, arterial phase and portal phase in group A were decreased by 49.04%, 40.51% and 40.54% compared with group B (P = 0.000), respectively. The total dose and the injection rate for the contrast material were reduced by 14.40% and 14.95% in A compared with B. Conclusion The use of GSI and ASIR provides similar enhancement in vessels and image quality with reduced radiation dose and contrast dose, compared with the use of conventional scan protocol. PMID:26079259

  15. Experimental investigations into composite fuselage impact damage resistance and post-impact compression behavior

    NASA Technical Reports Server (NTRS)

    Dost, E. F.; Finn, S. R.; Stevens, J. J.; Lin, K. Y.; Fitch, C. E.

    1992-01-01

    Impact damage resistance and residual strength of laminated composite transport aircraft fuselage structure was studied experimentally. Techniques to quantify impact damage discretely and non-discretely are described. Experimental techniques to three-dimensionally map matrix damage and determine the sublaminate structure are illustrated. Impact damage was also quantified non-discretely, using characteristics of flexural wave propagation. Strain distributions in compressively loaded impact damaged laminates were experimentally measured.

  16. Dynamic response of damaged angleplied fiber composites

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.; Lark, R. F.

    1979-01-01

    An investigation was conducted to determine the effects of low level damage induced by monotonic load, cyclic load and/or residual stresses on the vibration frequencies and damping factors of fiber composite angleplied laminates. Two different composite systems were studied - low modulus fiber and ultra high modulus fiber composites. The results obtained showed that the frequencies and damping factors of angleplied laminates made from low modulus fiber composites are sensitive to low level damage while those made from ultra high modulus composites are not. Also, vibration tests may not be sufficiently sensitive to assess concentrated local damage in angleplied laminates. And furthermore, dynamic response determined from low-velocity impact coupled with the Fast Fourier Transform and packaged in a minicomputer can be a convenient procedure for assessing low-level damage in fiber composite angleplied laminates.

  17. Surrogate Modeling of High-Fidelity Fracture Simulations for Real-Time Residual Strength Predictions

    NASA Technical Reports Server (NTRS)

    Spear, Ashley D.; Priest, Amanda R.; Veilleux, Michael G.; Ingraffea, Anthony R.; Hochhalter, Jacob D.

    2011-01-01

    A surrogate model methodology is described for predicting in real time the residual strength of flight structures with discrete-source damage. Starting with design of experiment, an artificial neural network is developed that takes as input discrete-source damage parameters and outputs a prediction of the structural residual strength. Target residual strength values used to train the artificial neural network are derived from 3D finite element-based fracture simulations. A residual strength test of a metallic, integrally-stiffened panel is simulated to show that crack growth and residual strength are determined more accurately in discrete-source damage cases by using an elastic-plastic fracture framework rather than a linear-elastic fracture mechanics-based method. Improving accuracy of the residual strength training data would, in turn, improve accuracy of the surrogate model. When combined, the surrogate model methodology and high-fidelity fracture simulation framework provide useful tools for adaptive flight technology.

  18. Quantitative Assessment of Radon-222 Degassing Phenomenon from the Investigation of Groundwater/Surface water Interaction (GSI) processes in Shallow Turbulent Rivers in Campania region, Southern Italy.

    NASA Astrophysics Data System (ADS)

    Cuomo, A.; Guadagnolo, D.; Guida, D.; Guida, M.; Paschke, A.; Schubert, M.; Siervo, V.

    2012-04-01

    In the investigation of Groundwater/Surface water Interaction (GSI) processes in different water bodies typologies, the use of Environmental Tracers, like Naturally Occurring Radionuclides, have been proven to be an extremely reliable and powerful tool. In particular, among them the (short-lived) radionuclide Radon-222 (referred to as Radon), occurring in the gaseous phase in normal conditions of temperature and pressure, has the advantages to be almost chemically inert, easily detectable on site and its physical signal is not disturbed by any kind of anthropically produced "noise". Therefore, differently from other tracers of artificial nature, it can be safely and successfully employed especially in natural environments, like Natural Parks and Wildlife Protected Areas, because it does not contaminate the surrounding environments being a Naturally Occurring Radioactive Material. Radon, produced in every mineral matrix through the spontaneous decay of Radium, turns out to be rather soluble in water, even though depending on the temperature of the water body, and, therefore, it occurs ubiquitously in all kinds of natural waters. In particular, Radon activity concentrations values, measured in groundwater, are typically some (from three to four) orders of magnitude higher than those ones detected, instead, in surface waters. For such reasons Radon turns out to be a remarkable tool for the Groundwater/Surface water Interaction (GSI) processes and a good indicator for the localization and the semi-quantitative assessment of groundwater discharges into different kinds of water bodies like lakes, rivers and sea. This work summarizes some outcomes from a series of experimental measurements campaigns performed in relevant river basins of Campania region, southern Italy, where interdisciplinary investigations about Groundwater-River Interactions have been carried on using Radon as a Natural Tracer. The experimental measurement campaigns have been performed using the Radon

  19. Interfacial residual thermal strain

    NASA Astrophysics Data System (ADS)

    Kasen, M.; Santoyo, R.

    A method has been developed for assessing the influence of polymer chemical composition and of processing parameters on the magnitude of residual stress developed in glass-fibre-reinforced composites subjected to various cure cycles and subsequently cooled to cryogenic temperatures. The test method was applied to nine resin types, including epoxy, vinyl ester, polyester, cyanate ester and phenolic formulations. Results suggest that polyester resin develops substantially less overall residual strain than do the other resin systems.

  20. Development of a viscoelastic continuum damage model for cyclic loading

    NASA Astrophysics Data System (ADS)

    Sullivan, R. W.

    2008-12-01

    A previously developed spectrum model for linear viscoelastic behavior of solids is used to describe the rate-dependent damage growth of a time dependent material under cyclic loading. Through the use of the iterative solution of a special Volterra integral equation, the cyclic strain history is described. The spectrum-based model is generalized for any strain rate and any uniaxial load history to formulate the damage function. Damage evolution in the body is described through the use of a rate-type evolution law which uses a pseudo strain to express the viscoelastic constitutive equation with damage. The resulting damage function is used to formulate a residual strength model. The methodology presented is demonstrated by comparing the peak values of the computed cyclic strain history as well as the residual strength model predictions to the experimental data of a polymer matrix composite.

  1. Numerical simulation of damage progression in unidirectional composites

    NASA Astrophysics Data System (ADS)

    Chung, Michael

    1997-11-01

    The damage growth in unidirectional composite materials is a complex evolutionary process. The initiation, growth and interaction of these damage mechanisms are strongly influenced by the properties of the constituent materials. In addition, thermal residual stresses are usually induced in composite material during the curing process. Therefore it is essential to consider the effect of the properties of the constituent materials and thermal residual stresses on the fracture behavior of composite materials. In this study, a computational methodology that employs a hybrid micromechanical-anisotropic continuum model developed previously to simulate the damage growth on the constituent level of composite materials has been modified and extended to include the effect of temperature change. The unique features of this methodology is that multiple modes of damage can be simulated simultaneously, and the direction of damage growth, in the form of a crack path, needs not be pre-selected. More specifically, the methodology uses a special purpose finite element program, PSEUDO, with a node splitting and nodal force relaxation algorithm that is capable of generating new crack surfaces to simulate damage initiation and growth in unidirectional fiber reinforced composites. An incremental elastic-plastic algorithm with Jsb2 flow theory and isotropic hardening is incorporated to account for matrix plastic deformation when analyzing damage growth in metal matrix composites. Damage progression in two types of metal matrix composites, namely, the as-received boron/aluminum-5.6/6061-AR and the solution aged and treated boron/aluminum-5.6/6061-T6 metal matrix composites, with thermal residual stresses, have been analyzed. The results show that the thermal residual stresses do have significant effects on the damage initiation, damage progression and the notch strengths of the composite materials.

  2. Femoral nerve damage (image)

    MedlinePlus

    The femoral nerve is located in the leg and supplies the muscles that assist help straighten the leg. It supplies sensation ... leg. One risk of damage to the femoral nerve is pelvic fracture. Symptoms of femoral nerve damage ...

  3. New elements produced at GSI

    NASA Astrophysics Data System (ADS)

    Hofmann, Sigurd

    1998-12-01

    In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using lead or bismuth targets and 1n-deexcitation channels. The isotopes were unambiguously identified by means of α-α correlations. Not fission, but alpha decay is the dominant decay mode. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical SuperHeavy Elements (SHE) could be achieved by fusion reactions using 208Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. The likelihood of broadening the energy window by investigation of radiative capture reactions, use of neutron deficient projectile isotopes and use of actinide targets is discussed.

  4. New elements produced at GSI

    SciTech Connect

    Hofmann, Sigurd

    1998-12-21

    In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using lead or bismuth targets and 1n-deexcitation channels. The isotopes were unambiguously identified by means of {alpha}-{alpha} correlations. Not fission, but alpha decay is the dominant decay mode. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical SuperHeavy Elements (SHE) could be achieved by fusion reactions using {sup 208}Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. The likelihood of broadening the energy window by investigation of radiative capture reactions, use of neutron deficient projectile isotopes and use of actinide targets is discussed.

  5. Fault damage zones

    NASA Astrophysics Data System (ADS)

    Kim, Young-Seog; Peacock, David C. P.; Sanderson, David J.

    2004-03-01

    Damage zones show very similar geometries across a wide range of scales and fault types, including strike-slip, normal and thrust faults. We use a geometric classification of damage zones into tip-, wall-, and linking-damage zones, based on their location around faults. These classes can be sub-divided in terms of fault and fracture patterns within the damage zone. A variety of damage zone structures can occur at mode II tips of strike-slip faults, including wing cracks, horsetail fractures, antithetic faults, and synthetic branch faults. Wall damage zones result from the propagation of mode II and mode III fault tips through a rock, or from damage associated with the increase in slip on a fault. Wall damage zone structures include extension fractures, antithetic faults, synthetic faults, and rotated blocks with associated triangular openings. The damage formed at the mode III tips of strike-slip faults (e.g. observed in cliff sections) are classified as wall damage zones, because the damage zone structures are distributed along a fault trace in map view. Mixed-mode tips are likely to show characteristics of both mode II and mode III tips. Linking damage zones are developed at steps between two sub-parallel faults, and the structures developed depend on whether the step is extensional or contractional. Extension fractures and pull-aparts typically develop in extensional steps, whilst solution seams, antithetic faults and synthetic faults commonly develop in contractional steps. Rotated blocks, isolated lenses or strike-slip duplexes may occur in both extensional and contractional steps. Damage zone geometries and structures are strongly controlled by the location around a fault, the slip mode at a fault tip, and by the evolutionary stage of the fault. Although other factors control the nature of damage zones (e.g. lithology, rheology and stress system), the three-dimensional fault geometry and slip mode at each tip must be considered to gain an understanding of

  6. Close proximity gunshot residues.

    PubMed

    Thornton, J I

    1986-04-01

    Intuitively, a hand held in close proximity to a firearm at the instant of discharge will intercept a significant amount of gunshot residue, even though the hand did not actually come into contact with the weapon. There is, however, little information specifically described in the forensic science literature concerning the residue levels which might be encountered in such an instance. The present work confirms that antimony levels consistent with an individual having fired or handled a firearm may be intercepted by a hand held in close proximity. PMID:3711843

  7. Size Effects in Impact Damage of Composite Sandwich Panels

    NASA Technical Reports Server (NTRS)

    Dobyns, Alan; Jackson, Wade

    2003-01-01

    Panel size has a large effect on the impact response and resultant damage level of honeycomb sandwich panels. It has been observed during impact testing that panels of the same design but different panel sizes will show large differences in damage when impacted with the same impact energy. To study this effect, a test program was conducted with instrumented impact testing of three different sizes of sandwich panels to obtain data on panel response and residual damage. In concert with the test program. a closed form analysis method was developed that incorporates the effects of damage on the impact response. This analysis method will predict both the impact response and the residual damage of a simply-supported sandwich panel impacted at any position on the panel. The damage is incorporated by the use of an experimental load-indentation curve obtained for the face-sheet/honeycomb and indentor combination under study. This curve inherently includes the damage response and can be obtained quasi-statically from a rigidly-backed specimen or a specimen with any support conditions. Good correlation has been obtained between the test data and the analysis results for the maximum force and residual indentation. The predictions can be improved by using a dynamic indentation curve. Analyses have also been done using the MSC/DYTRAN finite element code.

  8. CHARACTERIZATION OF DAMAGED MATERIALS

    SciTech Connect

    Hsu, P C; Dehaven, M; McClelland, M; Chidester, S; Maienschein, J L

    2006-06-23

    Thermal damage experiments were conducted on LX-04, LX-10, and LX-17 at high temperatures. Both pristine and damaged samples were characterized for their material properties. A pycnometer was used to determine sample true density and porosity. Gas permeability was measured in a newly procured system (diffusion permeameter). Burn rate was measured in the LLNL strand burner. Weight losses upon thermal exposure were insignificant. Damaged pressed parts expanded, resulting in a reduction of bulk density by up to 10%. Both gas permeabilities and burn rates of the damaged samples increased by several orders of magnitude due to higher porosity and lower density. Moduli of the damaged materials decreased significantly, an indication that the materials became weaker mechanically. Damaged materials were more sensitive to shock initiation at high temperatures. No significant sensitization was observed when the damaged samples were tested at room temperature.

  9. A Coupled Approach for Structural Damage Detection with Incomplete Measurements

    NASA Technical Reports Server (NTRS)

    James, George; Cao, Timothy; Kaouk, Mo; Zimmerman, David

    2013-01-01

    This historical work couples model order reduction, damage detection, dynamic residual/mode shape expansion, and damage extent estimation to overcome the incomplete measurements problem by using an appropriate undamaged structural model. A contribution of this work is the development of a process to estimate the full dynamic residuals using the columns of a spring connectivity matrix obtained by disassembling the structural stiffness matrix. Another contribution is the extension of an eigenvector filtering procedure to produce full-order mode shapes that more closely match the measured active partition of the mode shapes using a set of modified Ritz vectors. The full dynamic residuals and full mode shapes are used as inputs to the minimum rank perturbation theory to provide an estimate of damage location and extent. The issues associated with this process are also discussed as drivers of near-term development activities to understand and improve this approach.

  10. Surrogate Modeling of High-Fidelity Fracture Simulations for Real-Time Residual Strength Predictions

    NASA Technical Reports Server (NTRS)

    Spear, Ashley D.; Priest, Amanda R.; Veilleux, Michael G.; Ingraffea, Anthony R.; Hochhalter, Jacob D.

    2011-01-01

    A surrogate model methodology is described for predicting, during flight, the residual strength of aircraft structures that sustain discrete-source damage. Starting with design of experiment, an artificial neural network is developed that takes as input discrete-source damage parameters and outputs a prediction of the structural residual strength. Target residual strength values used to train the artificial neural network are derived from 3D finite element-based fracture simulations. Two ductile fracture simulations are presented to show that crack growth and residual strength are determined more accurately in discrete-source damage cases by using an elastic-plastic fracture framework rather than a linear-elastic fracture mechanics-based method. Improving accuracy of the residual strength training data does, in turn, improve accuracy of the surrogate model. When combined, the surrogate model methodology and high fidelity fracture simulation framework provide useful tools for adaptive flight technology.

  11. Widespread fatigue damage monitoring: Issues and concerns

    NASA Technical Reports Server (NTRS)

    Swift, T.

    1994-01-01

    This paper is intended to illustrate the considerable effect that small in-service undetectable multi-site-damage (MSD) can have on the residual strength capability of aging aircraft structures. In general, very few people in the industry believe that tiny cracks of undetectable size are a problem because they know that many aircraft have been able to survive much larger damage. In fact they have been certified for this large damage capability. However, this is not the issue. The real issue is the effect the tiny cracks, at multiple sites, have on the large damage capability which the industry has become accustomed to expect and which the aircraft have been certified to sustain. The concern is that this message does not appear to be fully understood by many people outside the fracture community. The prime purpose of this paper, therefore, has been to convey this message by describing in simple terms the net section yielding phenomenon in ductile materials which causes loss in lead crack residual strength in the presence of MSD. The explanation continues with a number of examples on complex stiffened structures, using the results of previous finite element analyses, which illustrate that the effect of MSD is extremely sensitive to structural configuration. It is hoped that those members of the aviation community who believe that tiny cracks are not a problem will read this paper very carefully.

  12. CROP-RESIDUE MANAGEMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our agricultural production system is under increasing pressure to provide low cost, high quality food, fiber and biofuels while maintaining and preserving the environment. Increased interest in crop residues for production system sustainability is related to the recognition that the soil, water and...

  13. ARX model-based damage sensitive features for structural damage localization using output-only measurements

    NASA Astrophysics Data System (ADS)

    Roy, Koushik; Bhattacharya, Bishakh; Ray-Chaudhuri, Samit

    2015-08-01

    The study proposes a set of four ARX model (autoregressive model with exogenous input) based damage sensitive features (DSFs) for structural damage detection and localization using the dynamic responses of structures, where the information regarding the input excitation may not be available. In the proposed framework, one of the output responses of a multi-degree-of-freedom system is assumed as the input and the rest are considered as the output. The features are based on ARX model coefficients, Kolmogorov-Smirnov (KS) test statistical distance, and the model residual error. At first, a mathematical formulation is provided to establish the relation between the change in ARX model coefficients and the normalized stiffness of a structure. KS test parameters are then described to show the sensitivity of statistical distance of ARX model residual error with the damage location. The efficiency of the proposed set of DSFs is evaluated by conducting numerical studies involving a shear building and a steel moment-resisting frame. To simulate the damage scenarios in these structures, stiffness degradation of different elements is considered. It is observed from this study that the proposed set of DSFs is good indicator for damage location even in the presence of damping, multiple damages, noise, and parametric uncertainties. The performance of these DSFs is compared with mode shape curvature-based approach for damage localization. An experimental study has also been conducted on a three-dimensional six-storey steel moment frame to understand the performance of these DSFs under real measurement conditions. It has been observed that the proposed set of DSFs can satisfactorily localize damage in the structure.

  14. The oxidative environment and protein damage.

    PubMed

    Davies, Michael J

    2005-01-17

    Proteins are a major target for oxidants as a result of their abundance in biological systems, and their high rate constants for reaction. Kinetic data for a number of radicals and non-radical oxidants (e.g. singlet oxygen and hypochlorous acid) are consistent with proteins consuming the majority of these species generated within cells. Oxidation can occur at both the protein backbone and on the amino acid side-chains, with the ratio of attack dependent on a number of factors. With some oxidants, damage is limited and specific to certain residues, whereas other species, such as the hydroxyl radical, give rise to widespread, relatively non-specific damage. Some of the major oxidation pathways, and products formed, are reviewed. The latter include reactive species, such as peroxides, which can induce further oxidation and chain reactions (within proteins, and via damage transfer to other molecules) and stable products. Particular emphasis is given to the oxidation of methionine residues, as this species is readily oxidised by a wide range of oxidants. Some side-chain oxidation products, including methionine sulfoxide, can be employed as sensitive, specific, markers of oxidative damage. The product profile can, in some cases, provide valuable information on the species involved; selected examples of this approach are discussed. Most protein damage is non-repairable, and has deleterious consequences on protein structure and function; methionine sulfoxide formation can however be reversed in some circumstances. The major fate of oxidised proteins is catabolism by proteosomal and lysosomal pathways, but some materials appear to be poorly degraded and accumulate within cells. The accumulation of such damaged material may contribute to a range of human pathologies. PMID:15680218

  15. Experimental investigation of the residues produced in the {sup 136}Xe+Pb and {sup 124}Xe+Pb fragmentation reactions at 1A GeV

    SciTech Connect

    Henzlova, D.; Schmidt, K.-H.; Ricciardi, M. V.; Kelic, A.; Henzl, V.; Pleskac, R.; Yordanov, O.; Napolitani, P.; Benlliure, J.; Casarejos, E.; Kurtukian, T.; Ordonez, M. F.; Pereira, J.; Boudard, A.; Ducret, J. E.; Leray, S.; Villagrasa, C.

    2008-10-15

    The nuclide cross sections and longitudinal velocity distributions of residues produced in the reactions of {sup 136}Xe and {sup 124}Xe at 1A GeV in a lead target were measured at the high-resolution magnetic spectrometer, the fragment separator (FRS) of GSI. The data cover a broad range of isotopes of the elements between Z=3 and Z=56 for {sup 136}Xe and between Z=5 and Z=55 for {sup 124}Xe, reaching down to cross sections of a few microbarns. The velocity distributions exhibit a Gaussian shape for masses above A=20, while more complex behavior is observed for lighter masses. The isotopic distributions for both reactions preserve a memory on the projectile N/Z ratio over the whole residue mass range.

  16. Hypervelocity impact damage tolerance of fused silica glass

    NASA Technical Reports Server (NTRS)

    Edelstein, K. S.

    1992-01-01

    A test program was conducted at the NASA/Johnson Space Center (JSC) concerning hypervelocity impact damage in fused silica glass. The objectives of this test program were: to expand the penetration equation data base in the velocity range between 2 and 8 km/s; to determine how much strength remains in a glass pane that has sustained known impact damage; and to develop a relationship between crater measurements and residual strength predictions that can be utilized in the Space Shuttle and Space Station programs. The results and conclusions of the residual strength testing are discussed below. Detailed discussion of the penetration equation studies will follow in future presentations.

  17. Developments in impact damage modeling for laminated composite structures

    NASA Technical Reports Server (NTRS)

    Dost, Ernest F.; Avery, William B.; Swanson, Gary D.; Lin, Kuen Y.

    1991-01-01

    Damage tolerance is the most critical technical issue for composite fuselage structures studied in the Advanced Technology Composite Aircraft Structures (ATCAS) program. The objective here is to understand both the impact damage resistance and residual strength of the laminated composite fuselage structure. An understanding of the different damage mechanisms which occur during an impact event will support the selection of materials and structural configurations used in different fuselage quadrants and guide the development of analysis tools for predicting the residual strength of impacted laminates. Prediction of the damage state along with the knowledge of post-impact response to applied loads will allow for engineered stacking sequencies and structural configurations; intelligent decisions on repair requirements will also result.

  18. Damage Tolerance of Composites

    NASA Technical Reports Server (NTRS)

    Hodge, Andy

    2007-01-01

    Fracture control requirements have been developed to address damage tolerance of composites for manned space flight hardware. The requirements provide the framework for critical and noncritical hardware assessment and testing. The need for damage threat assessments, impact damage protection plans, and nondestructive evaluation are also addressed. Hardware intended to be damage tolerant have extensive coupon, sub-element, and full-scale testing requirements in-line with the Building Block Approach concept from the MIL-HDBK-17, Department of Defense Composite Materials Handbook.

  19. Residual stresses in material processing

    SciTech Connect

    Kozaczek, K.J.; Watkins, T.R.; Hubbard, C.R.; Wang, Xun-Li; Spooner, S.

    1994-09-01

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then adresses the direct, nondestructive methods of residual stress measurement by X-ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  20. Disorder and residual helicity alter p53-Mdm2 binding affinity and signaling in cells.

    PubMed

    Borcherds, Wade; Theillet, François-Xavier; Katzer, Andrea; Finzel, Ana; Mishall, Katie M; Powell, Anne T; Wu, Hongwei; Manieri, Wanda; Dieterich, Christoph; Selenko, Philipp; Loewer, Alexander; Daughdrill, Gary W

    2014-12-01

    Levels of residual structure in disordered interaction domains determine in vitro binding affinities, but whether they exert similar roles in cells is not known. Here, we show that increasing residual p53 helicity results in stronger Mdm2 binding, altered p53 dynamics, impaired target gene expression and failure to induce cell cycle arrest upon DNA damage. These results establish that residual structure is an important determinant of signaling fidelity in cells. PMID:25362358

  1. SRC Residual fuel oils

    DOEpatents

    Tewari, Krishna C.; Foster, Edward P.

    1985-01-01

    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  2. Residual Neuromuscular Blockade.

    PubMed

    Plummer-Roberts, Anna L; Trost, Christina; Collins, Shawn; Hewer, Ian

    2016-02-01

    This article provides an update on residual neuromuscular blockade for nurse anesthetists. The neuromuscular junction, pharmacology for producing and reversing neuromuscular blockade, monitoring sites and methods, and patient implications relating to incomplete reversal of neuromuscular blockade are reviewed. Overall recommendations include using multiple settings when employing a peripheral nerve stimulator for monitoring return of neuromuscular function and administering pharmacologic reversal when the train-of-four ratio is below 0.9. PMID:26939390

  3. Energy from rice residues

    SciTech Connect

    Mahin, D.B.

    1990-03-01

    Developing countries produce millions of tons of rice husks and straw as a byproduct of harvesting rice. Although some of these rice residues are used for fuel or other purposes, most are burned for disposal or just dumped. However, since the mid- 1980's, industrial plants for rice residue utilization have been installed in several countries and are planned in a number of others. The report provides information on systems to produce energy from rice residues that are commercially available in the United States, Europe, and various developing countries, with an emphasis on those currently used or sold on an international level. Specifically reviewed are the use of rice husks to produce: (1) industrial process heat either directly from furnaces or by generating low pressure steam in boilers; (2) mechanical and electrical power for rice milling via steam engine systems, steam turbine/generator systems, and gasifier/engine systems; and (3) electric power for the grid. The outlook for producing energy from rice straw is also assessed. In addition, the prospects for the use of energy from husks or straw in the processing of rice bran are reviewed.

  4. Decays of the Three Top Contributors to the Reactor ν[over ¯]_{e} High-Energy Spectrum, ^{92}Rb, ^{96gs}Y, and ^{142}Cs, Studied with Total Absorption Spectroscopy.

    PubMed

    Rasco, B C; Wolińska-Cichocka, M; Fijałkowska, A; Rykaczewski, K P; Karny, M; Grzywacz, R K; Goetz, K C; Gross, C J; Stracener, D W; Zganjar, E F; Batchelder, J C; Blackmon, J C; Brewer, N T; Go, S; Heffron, B; King, T; Matta, J T; Miernik, K; Nesaraja, C D; Paulauskas, S V; Rajabali, M M; Wang, E H; Winger, J A; Xiao, Y; Zachary, C J

    2016-08-26

    We report total absorption spectroscopy measurements of ^{92}Rb, ^{96gs}Y, and ^{142}Cs β decays, which are the most important contributors to the high energy ν[over ¯]_{e} spectral shape in nuclear reactors. These three β decays contribute 43% of the ν[over ¯]_{e} flux near 5.5 MeV emitted by nuclear reactors. This ν[over ¯]_{e} energy is particularly interesting due to spectral features recently observed in several experiments including the Daya Bay, Double Chooz, and RENO Collaborations. Measurements were conducted at Oak Ridge National Laboratory by means of proton-induced fission of ^{238}U with on-line mass separation of fission fragments and the Modular Total Absorption Spectrometer. We observe a β-decay pattern that is similar to recent measurements of ^{92}Rb, with a ground-state to ground-state β feeding of 91(3)%. We verify the ^{96gs}Y ground-state to ground-state β feeding of 95.5(20)%. Our measurements substantially modify the β-decay feedings of ^{142}Cs, reducing the β feeding to ^{142}Ba states below 2 MeV by 32% when compared with the latest evaluations. Our results increase the discrepancy between the observed and the expected reactor ν[over ¯]_{e} flux between 5 and 7 MeV, the maximum excess increases from ∼10% to ∼12%. PMID:27610847

  5. Nonlinear damage analysis: Postulate and evaluation

    NASA Technical Reports Server (NTRS)

    Leis, B. N.; Forte, T. P.

    1983-01-01

    The objective of this program is to assess the viability of a damage postulate which asserts that the fatigue resistance curve of a metal is history dependent due to inelastic action. The study focusses on OFE copper because this simple model material accentuates the inelastic action central to the damage postulate. Data relevant to damage evolution and crack initiation are developed via a study of surface topography. The effects of surface layer residual stresses are explored via comparative testing as were the effects in initial prestraining. The results of the study very clearly show the deformation history dependence of the fatigue resistance of OFE copper. Furthermore the concept of deformation history dependence is shown to qualitatively explain the fatigue resistance of all histories considered. Likewise quantitative predictions for block cycle histories are found to accurately track the observed results. In this respect the assertion that damage per cycle for a given level of the damage parameter is deformation history dependent appears to be physically justified.

  6. Endobronchial Ultrasound Bronchoscope Damage.

    PubMed

    Patil, Monali; Harris, Kassem; Krishnan, Amita; Alraiyes, Abdul H; Dhillon, Samjot S

    2016-07-01

    Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration is an effective, safe, and cost-effective diagnostic bronchoscopy technique for the work-up of mediastinal lymphadenopathy. Concern has been raised, however, about the high cost of convex-probe EBUS bronchoscope repairs. The damage is usually due to breakage of the insertion tube (the flexible part that is advanced into the airways), moisture invasion and damages to the working channel, image guide bundle, or umbilical cord. Understanding the root cause of EBUS scope damage is important for its prevention. We describe 2 unusual cases of EBUS scope damage. In the first case, the distal black rubber covering of the EBUS scope insertion tube was damaged due to friction with the edge of an endotracheal tube and in the second case, the EBUS scope insertion tube was angulating laterally instead of vertically during the flexion maneuver, probably due to scope manipulation while wedged tightly in a segmental bronchus. PMID:27077640

  7. Guest Editorial: Laser Damage

    SciTech Connect

    Vitaly Gruzdev, Michelle D. Shinn

    2012-12-01

    Laser damage of optical materials, first reported in 1964, continues to limit the output energy and power of pulsed and continuous-wave laser systems. In spite of some 48 years of research in this area, interest from the international laser community to laser damage issues remains at a very high level and does not show any sign of decreasing. Moreover, it grows with the development of novel laser systems, for example, ultrafast and short-wavelength lasers that involve new damage effects and specific mechanisms not studied before. This interest is evident from the high level of attendance and presentations at the annual SPIE Laser Damage Symposium (aka, Boulder Damage Symposium) that has been held in Boulder, Colorado, since 1969. This special section of Optical Engineering is the first one devoted to the entire field of laser damage rather than to a specific part. It is prepared in response to growing interest from the international laser-damage community. Some papers in this special section were presented at the Laser Damage Symposium; others were submitted in response to the general call for papers for this special section. The 18 papers compiled into this special section represent many sides of the broad field of laser-damage research. They consider theoretical studies of the fundamental mechanisms of laser damage including laser-driven electron dynamics in solids (O. Brenk and B. Rethfeld; A. Nikiforov, A. Epifanov, and S. Garnov; T. Apostolova et al.), modeling of propagation effects for ultrashort high-intensity laser pulses (J. Gulley), an overview of mechanisms of inclusion-induced damage (M. Koldunov and A. Manenkov), the formation of specific periodic ripples on a metal surface by femtosecond laser pulses (M. Ahsan and M. Lee), and the laser-plasma effects on damage in glass (Y. Li et al). Material characterization is represented by the papers devoted to accurate and reliable measurements of absorption with special emphasis on thin films (C. Mühlig and S

  8. A damage mechanics based approach to structural deterioration and reliability

    SciTech Connect

    Bhattcharya, B.; Ellingwood, B.

    1998-02-01

    Structural deterioration often occurs without perceptible manifestation. Continuum damage mechanics defines structural damage in terms of the material microstructure, and relates the damage variable to the macroscopic strength or stiffness of the structure. This enables one to predict the state of damage prior to the initiation of a macroscopic flaw, and allows one to estimate residual strength/service life of an existing structure. The accumulation of damage is a dissipative process that is governed by the laws of thermodynamics. Partial differential equations for damage growth in terms of the Helmholtz free energy are derived from fundamental thermodynamical conditions. Closed-form solutions to the equations are obtained under uniaxial loading for ductile deformation damage as a function of plastic strain, for creep damage as a function of time, and for fatigue damage as function of number of cycles. The proposed damage growth model is extended into the stochastic domain by considering fluctuations in the free energy, and closed-form solutions of the resulting stochastic differential equation are obtained in each of the three cases mentioned above. A reliability analysis of a ring-stiffened cylindrical steel shell subjected to corrosion, accidental pressure, and temperature is performed.

  9. Metabolite Damage and Metabolite Damage Control in Plants.

    PubMed

    Hanson, Andrew D; Henry, Christopher S; Fiehn, Oliver; de Crécy-Lagard, Valérie

    2016-04-29

    It is increasingly clear that (a) many metabolites undergo spontaneous or enzyme-catalyzed side reactions in vivo, (b) the damaged metabolites formed by these reactions can be harmful, and (c) organisms have biochemical systems that limit the buildup of damaged metabolites. These damage-control systems either return a damaged molecule to its pristine state (metabolite repair) or convert harmful molecules to harmless ones (damage preemption). Because all organisms share a core set of metabolites that suffer the same chemical and enzymatic damage reactions, certain damage-control systems are widely conserved across the kingdoms of life. Relatively few damage reactions and damage-control systems are well known. Uncovering new damage reactions and identifying the corresponding damaged metabolites, damage-control genes, and enzymes demands a coordinated mix of chemistry, metabolomics, cheminformatics, biochemistry, and comparative genomics. This review illustrates the above points using examples from plants, which are at least as prone to metabolite damage as other organisms. PMID:26667673

  10. Fracture and damage; Winter Annual Meeting of the American Society of Mechanical Engineers, Anaheim, CA, Nov. 8-13, 1992

    NASA Technical Reports Server (NTRS)

    Nagar, Arvind (Editor)

    1992-01-01

    The latest developments in the area of fracture and damage at high temperatures are discussed, in particular: modeling; analysis and experimental techniques for interface damage in composites including the effects of residual stresses and temperatures; and crack growth, inelastic deformation and fracture parameters for isotropic materials. Also included are damage modeling and experiments at elevated temperatures.

  11. Cumulative fatigue damage models

    NASA Technical Reports Server (NTRS)

    Mcgaw, Michael A.

    1988-01-01

    The problem of calculating expected component life under fatigue loading conditions is complicated by the fact that component loading histories contain, in many cases, cyclic loads of widely varying amplitudes. In such a case a cumulative damage model is required, in addition to a fatigue damage criterion, or life relationship, in order to compute the expected fatigue life. The traditional cumulative damage model used in design is the linear damage rule. This model, while being simple to use, can yield grossly unconservative results under certain loading conditions. Research at the NASA Lewis Research Center has led to the development of a nonlinear cumulative damage model, named the double damage curve approach (DDCA), that has greatly improved predictive capability. This model, which considers the life (or loading) level dependence of damage evolution, was applied successfully to two polycrystalline materials, 316 stainless steel and Haynes 188. The cumulative fatigue behavior of the PWA 1480 single-crystal material is currently being measured to determine the applicability of the DDCA for this material.

  12. Laser Damage Lab

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Optical Damage Threshold Testing Instrumentation at NASA Langley Research Center. This work was sanctioned and funded by Code Q, R, & AE to develop a new standard for damage testing various types of optical materials and coatings. Laser Induced Damage Threshold (LIDT) testing is a destructive test procedure to determine the minimum applied laser energy level that will result in damage and is referred to as the damage threshold. The damage threshold is often the critical limitation in the section of optical materials for use in high-energy laser systems.The test station consists of diagnostic equipment, beam conditioning optical elements, an inspection microscope and three lasers: a high energy pulsed ND: Yag, which develops 650mJ at 10 hz and outputs three wavelengths which include 1.06m, 532nm and 355 nm; a Ti:sapphire laser which produces a continuum of laser output from 790nm to 900nm; and a alignment HeNe, which looks yellow when mixed with the 2nd harmonic ND:Yag laser. Laser sources are used to perform damage threshold testing at the specific wavelength of interest.

  13. Quantification of residual stress from photonic signatures of fused silica

    NASA Astrophysics Data System (ADS)

    Cramer, K. Elliott; Hayward, Maurice; Yost, William T.

    2014-02-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 ± 0.54 × 10-12 Pa-1. Fused silica specimens containing impacts artificially made at NASA's Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented.

  14. War Damage Assessment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    During and after the Persian Gulf war, hundreds of "oil lakes" were created in Kuwait by oil released from damaged wells. The lakes are a hazard to the Kuwait atmosphere, soil and ground water and must be carefully monitored. Boston University Center for Remote Sensing, assisted by other organizations, has accurately mapped the lakes using Landsat and Spot imagery. The war damage included the formation of over 300 oil lakes, oil pollution and sand dune movement. Total damage area is over 5,400 square kilometers - 30 percent of Kuwait's total surface area.

  15. DNA Damage Response

    PubMed Central

    Giglia-Mari, Giuseppina; Zotter, Angelika; Vermeulen, Wim

    2011-01-01

    Structural changes to DNA severely affect its functions, such as replication and transcription, and play a major role in age-related diseases and cancer. A complicated and entangled network of DNA damage response (DDR) mechanisms, including multiple DNA repair pathways, damage tolerance processes, and cell-cycle checkpoints safeguard genomic integrity. Like transcription and replication, DDR is a chromatin-associated process that is generally tightly controlled in time and space. As DNA damage can occur at any time on any genomic location, a specialized spatio-temporal orchestration of this defense apparatus is required. PMID:20980439

  16. The residual caries dilemma.

    PubMed

    Weerheijm, K L; Groen, H J

    1999-12-01

    Restorative dentistry is based on the assumption that bacterial infection of demineralized dentine should prompt operative intervention. One of the concepts of practical dentistry is to create a favourable environment for caries arrest with minimal operative intervention. The progress of remaining primary caries is key to any discussion of this concept. This discussion is important for the atraumatic restorative treatment (ART) approach, since the removal of all carious dentine is sometimes difficult using hand instruments only. In this paper the results of possible measures to guard against the effects of residual carious and its consequences are reviewed, in order to obtain an impression of the justification for (in)complete excavation of occlusal dentinal caries. Three types of measure are considered: isolating the caries process from the oral environment, excavating the carious dentine, and using a cariostatic filling material. Each of these measures contributes to the arrest of the caries process. However, none of these measures can arrest this process by itself. A combination of all three seems necessary. It is concluded that although residual caries does not seem to be the criterion for rerestoration, one has to strive for as complete caries removal as possible. If this cannot be fulfilled the sealing capacities of the filling material seem to be more important than its cariostatic properties. PMID:10600078

  17. Characterization and damage evaluation of advanced materials

    NASA Astrophysics Data System (ADS)

    Mitrovic, Milan

    Mechanical characterization of advanced materials, namely magnetostrictive and graphite/epoxy composite materials, is studied in this dissertation, with an emphasis on damage evaluation of composite materials. Consequently, the work in this dissertation is divided into two parts, with the first part focusing on characterization of the magneto-elastic response of magnetostrictlve materials, while the second part of this dissertation describes methods for evaluating the fatigue damage in composite materials. The objective of the first part of this dissertation is to evaluate a nonlinear constitutive relation which more closely depict the magneto-elastic response of magnetostrictive materials. Correlation between experimental and theoretical values indicate that the model adequately predicts the nonlinear strain/field relations in specific regimes, and that the currently employed linear approaches are inappropriate for modeling the response of this material in a structure. The objective of the second part of this dissertation is to unravel the complexities associated with damage events associated with polymeric composite materials. The intent is to characterize and understand the influence of impact and fatigue induced damage on the residual thermo-mechanical properties and compressive strength of composite systems. The influence of fatigue generated matrix cracking and micro-delaminations on thermal expansion coefficient (TEC) and compressive strength is investigated for woven graphite/epoxy composite system. Experimental results indicate that a strong correlation exists between TEC and compressive strength measurements, indicating that TEC measurements can be used as a damage metric for this material systems. The influence of delaminations on the natural frequencies and mode shapes of a composite laminate is also investigated. Based on the changes of these parameters as a function of damage, a methodology for determining the size and location of damage is suggested

  18. LSD and Genetic Damage

    ERIC Educational Resources Information Center

    Dishotsky, Norman I.; And Others

    1971-01-01

    Reviews studies of the effects of lysergic acid diethylamide (LSD) on man and other organisms. Concludes that pure LSD injected in moderate doses does not cause chromosome or detectable genetic damage and is not a teratogen or carcinogen. (JM)

  19. Composites Damage Tolerance Workshop

    NASA Technical Reports Server (NTRS)

    Gregg, Wayne

    2006-01-01

    The Composite Damage Tolerance Workshop included participants from NASA, academia, and private industry. The objectives of the workshop were to begin dialogue in order to establish a working group within the Agency, create awareness of damage tolerance requirements for Constellation, and discuss potential composite hardware for the Crew Launch Vehicle (CLV) Upper Stage (US) and Crew Module. It was proposed that a composites damage tolerance working group be created that acts within the framework of the existing NASA Fracture Control Methodology Panel. The working group charter would be to identify damage tolerance gaps and obstacles for implementation of composite structures into manned space flight systems and to develop strategies and recommendations to overcome these obstacles.

  20. Diabetes and nerve damage

    MedlinePlus

    ... hot or cold When the nerves that control digestion are affected, you may have trouble digesting food. ... harder to control. Damage to nerves that control digestion almost always occurs in people with severe nerve ...

  1. Residual strength of thin panels with cracks

    NASA Technical Reports Server (NTRS)

    Madenci, Erdogan

    1994-01-01

    The previous design philosophies involving safe life, fail-safe and damage tolerance concepts become inadequate for assuring the safety of aging aircraft structures. For example, the failure mechanism for the Aloha Airline accident involved the coalescence of undetected small cracks at the rivet holes causing a section of the fuselage to peel open during flight. Therefore, the fuselage structure should be designed to have sufficient residual strength under worst case crack configurations and in-flight load conditions. Residual strength is interpreted as the maximum load carrying capacity prior to unstable crack growth. Internal pressure and bending moment constitute the two major components of the external loads on the fuselage section during flight. Although the stiffeners in the form of stringers, frames and tear straps sustain part of the external loads, the significant portion of the load is taken up by the skin. In the presence of a large crack in the skin, the crack lips bulge out with considerable yielding; thus, the geometric and material nonlinearities must be included in the analysis for predicting residual strength. Also, these nonlinearities do not permit the decoupling of in-plane and out-of-plane bending deformations. The failure criterion combining the concepts of absorbed specific energy and strain energy density addresses the aforementioned concerns. The critical absorbed specific energy (local toughness) for the material is determined from the global specimen response and deformation geometry based on the uniaxial tensile test data and detailed finite element modeling of the specimen response. The use of the local toughness and stress-strain response at the continuum level eliminates the size effect. With this critical parameter and stress-strain response, the finite element analysis of the component by using STAGS along with the application of this failure criterion provides the stable crack growth calculations for residual strength predictions.

  2. Reducing systems protecting the bacterial cell envelope from oxidative damage.

    PubMed

    Arts, Isabelle S; Gennaris, Alexandra; Collet, Jean-François

    2015-06-22

    Exposure of cells to elevated levels of reactive oxygen species (ROS) damages DNA, membrane lipids and proteins, which can potentially lead to cell death. In proteins, the sulfur-containing residues cysteine and methionine are particularly sensitive to oxidation, forming sulfenic acids and methionine sulfoxides, respectively. The presence of protection mechanisms to scavenge ROS and repair damaged cellular components is therefore essential for cell survival. The bacterial cell envelope, which constitutes the first protection barrier from the extracellular environment, is particularly exposed to the oxidizing molecules generated by the host cells to kill invading microorganisms. Therefore, the presence of oxidative stress defense mechanisms in that compartment is crucial for cell survival. Here, we review recent findings that led to the identification of several reducing pathways protecting the cell envelope from oxidative damage. We focus in particular on the mechanisms that repair envelope proteins with oxidized cysteine and methionine residues and we discuss the major questions that remain to be solved. PMID:25957772

  3. Evaluation of damaged tank car structural integrity

    SciTech Connect

    Reuter, W.G.; Mudlin, J.D.; Harris, B.L.; Haggag, F.M.; Epstein, J.S.; Server, W.L.

    1987-06-01

    To assess the safety of moving a damaged tank car, it is necessary to know the sizes and shapes of cracks, the stresses associated with moving the tank car, and the fracture toughness of the material used to fabricate the tank car. This report provides the results and recommendations for the research related to the examination of nondestructive evaluation techniques and measurements of the mechanical properties of deformed steel plate; Evaluation of computer codes to identify those capable of performing a large displacement inelastic analysis; Two 1/5-scale-model tank cars, representing damaged tank cars that were hydroburst to failure; and Preliminary tests conducted using more interferometry for determining residual stresses of rail components. 24 refs., 37 figs., 4 tabs.

  4. Residual gas analyzer calibration

    NASA Technical Reports Server (NTRS)

    Lilienkamp, R. H.

    1972-01-01

    A technique which employs known gas mixtures to calibrate the residual gas analyzer (RGA) is described. The mass spectra from the RGA are recorded for each gas mixture. This mass spectra data and the mixture composition data each form a matrix. From the two matrices the calibration matrix may be computed. The matrix mathematics requires the number of calibration gas mixtures be equal to or greater than the number of gases included in the calibration. This technique was evaluated using a mathematical model of an RGA to generate the mass spectra. This model included shot noise errors in the mass spectra. Errors in the gas concentrations were also included in the valuation. The effects of these errors was studied by varying their magnitudes and comparing the resulting calibrations. Several methods of evaluating an actual calibration are presented. The effects of the number of gases in then, the composition of the calibration mixture, and the number of mixtures used are discussed.

  5. Impact damage in filament wound composite bottles

    NASA Technical Reports Server (NTRS)

    Highsmith, Alton L.

    1993-01-01

    Increasingly, composite materials are being used in advanced structural applications because of the significant weight savings they offer when compared to more traditional engineering materials. The higher cost of composites must be offset by the increased performance that results from reduced structural weight if these new materials are to be used effectively. At present, there is considerable interest in fabricating solid rocket motor cases out of composite materials, and capitalizing on the reduced structural weight to increase rocket performance. However, one of the difficulties that arises when composite materials are used is that composites can develop significant amounts of internal damage during low velocity impacts. Such low velocity impacts may be encountered in routine handling of a structural component like a rocket motor case. The ability to assess the reduction in structural integrity of composite motor cases that experience accidental impacts is essential if composite rocket motor cases are to be certified for manned flight. While experimental studies of the post-impact performance of filament wound composite motor cases haven been proven performed (2,3), scaling impact data from small specimens to full scale structures has proven difficult. If such a scaling methodology is to be achieved, an increased understanding of the damage processes which influence residual strength is required. The study described herein was part of an ongoing investigation of damage development and reduction of tensile strength in filament wound composites subjected to low velocity impacts. The present study, which focused on documenting the damage that develops in filament wound composites as a result of such impacts, included two distinct tasks. The first task was to experimentally assess impact damage in small, filament wound pressure bottles using x-ray radiography. The second task was to study the feasibility of using digital image processing techniques to assist in

  6. 75 FR 793 - Damage Tolerance and Fatigue Evaluation of Composite Rotorcraft Structures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-06

    ...This proposal would revise airworthiness standards for type certification requirements of normal and transport category rotorcraft. The amendment would require evaluation of fatigue and residual static strength of composite rotorcraft structures using a damage tolerance evaluation, or a fatigue evaluation, if the applicant establishes that a damage tolerance evaluation is impractical. The......

  7. Effect of scanned quasi-cw CO2 laser irradiation on tissue thermal damage

    NASA Astrophysics Data System (ADS)

    Domankevitz, Yacov; Bua, Dominic; Chung, Jina; Hanel, Edward; Silver, Geoffrey; Nishioka, Norman S.

    1994-08-01

    Residual thermal damage produced by a scanned quasi cw CO2 laser was measured in pig skin. The effects of scan speed on thermal damage distribution for laser dwell times ranging between 1 and 150 msec were examined. Significantly larger thermal damage zones were produced along the crater wall for laser dwell times longer than 50 msec. Thermal damage along the crater base was constant independent of dwell time. The preliminary experimental results suggest that quasi cw CO2 can consistently produce less than 200 micrometers zones of thermal damage if laser parameters are carefully chosen.

  8. Surface state reconstruction in ion-damaged SmB6

    DOE PAGESBeta

    Wakeham, N.; Wang, Y. Q.; Fisk, Z.; Ronning, F.; Thompson, J. D.

    2015-02-12

    We have used ion-irradiation to damage the (001) surfaces of SmB₆ single crystals to varying depths, and have measured the resistivity as a function of temperature for each depth of damage. We observe a reduction in the residual resistivity with increasing depth of damage. Our data are consistent with a model in which the surface state is not destroyed by the ion-irradiation, however instead the damaged layer is poorly conducting and the initial surface state is reconstructed below the damage. This behavior is consistent with a surface state that is topologically protected.

  9. Assessing Tropical Cyclone Damage

    NASA Astrophysics Data System (ADS)

    Done, J.; Czajkowski, J.

    2012-12-01

    Landfalling tropical cyclones impact large coastal and inland areas causing direct damage due to winds, storm-surge flooding, tornadoes, and precipitation; as well as causing substantial indirect damage such as electrical outages and business interruption. The likely climate change impact of increased tropical cyclone intensity, combined with increases in exposure, bring the possibility of increased damage in the future. A considerable amount of research has focused on modeling economic damage due to tropical cyclones, and a series of indices have been developed to assess damages under climate change. We highlight a number of ways this research can be improved through a series of case study analyses. First, historical loss estimates are revisited to properly account for; time, impacted regions, the source of damage by type, and whether the damage was direct/indirect and insured/uninsured. Second, the drivers of loss from both the socio-economic and physical side are examined. A case is made to move beyond the use of maximum wind speed to more stable metrics and the use of other characteristics of the wind field such as direction, degree of gustiness, and duration is explored. A novel approach presented here is the potential to model losses directly as a function of climate variables such as sea surface temperature, greenhouse gases, and aerosols. This work is the first stage in the development of a tropical cyclone loss model to enable projections of losses under scenarios of both socio-economic change (such as population migration or altered policy) and physical change (such as shifts in tropical cyclone activity one from basin to another or within the same basin).

  10. First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the {sup 244}Pu({sup 48}Ca,3-4n) reaction

    SciTech Connect

    Gates, J. M.; Duellmann, Ch. E.; Schaedel, M.; Ackermann, D.; Block, M.; Bruechle, W.; Essel, H. G.; Hartmann, W.; Hessberger, F. P.; Huebner, A.; Jaeger, E.; Khuyagbaatar, J.; Kindler, B.; Krier, J.; Kurz, N.; Lommel, B.; Schaffner, H.; Schausten, B.; Schimpf, E.; Steiner, J.

    2011-05-15

    Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of {sup 48}Ca to irradiate targets of {sup 206-208}Pb, which led to the production of {sup 252-254}No isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ({sup 288-291}114) were produced in irradiations of {sup 244}Pu targets with {sup 48}Ca beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of {sup 288-291}114. A new {alpha}-decay branch in {sup 281}Ds was observed, leading to the new nucleus {sup 277}Hs.

  11. Effects of oil and oil burn residues on seabird feathers.

    PubMed

    Fritt-Rasmussen, Janne; Linnebjerg, Jannie Fries; Sørensen, Martin X; Brogaard, Nicholas L; Rigét, Frank F; Kristensen, Paneeraq; Jomaas, Grunde; Boertmann, David M; Wegeberg, Susse; Gustavson, Kim

    2016-08-15

    It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified. To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil. PMID:27234369

  12. Materials recovery from shredder residues

    SciTech Connect

    Daniels, E. J.; Jody, B. J.; Pomykala, J., Jr.

    2000-07-24

    Each year, about five (5) million ton of shredder residues are landfilled in the US. Similar quantities are landfilled in Europe and the Pacific Rim. Landfilling of these residues results in a cost to the existing recycling industry and also represents a loss of material resources that are otherwise recyclable. In this paper, the authors outline the resources recoverable from typical shredder residues and describe technology that they have developed to recover these resources.

  13. Microwave emission and crop residues

    NASA Technical Reports Server (NTRS)

    Jackson, Thomas J.; O'Neill, Peggy E.

    1991-01-01

    A series of controlled experiments were conducted to determine the significance of crop residues or stubble in estimating the emission of the underlying soil. Observations using truck-mounted L and C band passive microwave radiometers showed that for dry wheat and soybeans the dry residue caused negligible attenuation of the background emission. Green residues, with water contents typical of standing crops, did have a significant effect on the background emission. Results for these green residues also indicated that extremes in plant structure, as created using parallel and perpendicular stalk orientations, can cause very large differences in the degree of attenuation.

  14. Methodologies for measuring residual stress distributions in epitaxial thin films

    NASA Astrophysics Data System (ADS)

    Liu, M.; Ruan, H. H.; Zhang, L. C.

    2013-01-01

    Residual stresses in a thin film deposited on a dissimilar substrate can bring about various interface or subsurface damages, such as delamination, dislocation, twinning and cracking. In high performance integrated circuits and MEMS, a too high residual stress can significantly alter their electronic properties. A proper residual stress characterization needs the description of full stress tensors and their variations with thickness. The problem is that film thickness measurement requires different means, and that direct measurement techniques to fulfill the tasks are not straightforward. This paper provides a simple method using X-ray diffraction (XRD) and Raman scattering for the measurement of residual stresses and their thickness dependence. Using the epitaxial silicon film on a sapphire substrate as an example, this paper demonstrates that the improved XRD technique can make use of multiple diffraction peaks to give rise to a highly accurate stress tensor. The co-existence of silicon and sapphire peaks in a Raman spectrum then allows a simultaneous measurement of film thickness from the peak intensity ratio and the residual stress from the peak shift. The paper also concludes the relation between film thickness and residual stresses.

  15. Crumpling Damaged Graphene.

    PubMed

    Giordanelli, I; Mendoza, M; Andrade, J S; Gomes, M A F; Herrmann, H J

    2016-01-01

    Through molecular mechanics we find that non-covalent interactions modify the fractality of crumpled damaged graphene. Pristine graphene membranes are damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled membranes exhibit a fractal dimension of 2.71 ± 0.02 when all interactions between carbon atoms are considered, and 2.30 ± 0.05 when non-covalent interactions are suppressed. The transition between these two values, obtained by switching on/off the non-covalent interactions of equilibrium configurations, is shown to be reversible and independent on thermalisation. In order to explain this transition, we propose a theoretical model that is compatible with our numerical findings. Finally, we also compare damaged graphene membranes with other crumpled structures, as for instance polymerised membranes and paper sheets, that share similar scaling properties. PMID:27173442

  16. Damage Tolerance Assessment Branch

    NASA Technical Reports Server (NTRS)

    Walker, James L.

    2013-01-01

    The Damage Tolerance Assessment Branch evaluates the ability of a structure to perform reliably throughout its service life in the presence of a defect, crack, or other form of damage. Such assessment is fundamental to the use of structural materials and requires an integral blend of materials engineering, fracture testing and analysis, and nondestructive evaluation. The vision of the Branch is to increase the safety of manned space flight by improving the fracture control and the associated nondestructive evaluation processes through development and application of standards, guidelines, advanced test and analytical methods. The Branch also strives to assist and solve non-aerospace related NDE and damage tolerance problems, providing consultation, prototyping and inspection services.

  17. Crumpling Damaged Graphene

    NASA Astrophysics Data System (ADS)

    Giordanelli, I.; Mendoza, M.; Andrade, J. S., Jr.; Gomes, M. A. F.; Herrmann, H. J.

    2016-05-01

    Through molecular mechanics we find that non-covalent interactions modify the fractality of crumpled damaged graphene. Pristine graphene membranes are damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled membranes exhibit a fractal dimension of 2.71 ± 0.02 when all interactions between carbon atoms are considered, and 2.30 ± 0.05 when non-covalent interactions are suppressed. The transition between these two values, obtained by switching on/off the non-covalent interactions of equilibrium configurations, is shown to be reversible and independent on thermalisation. In order to explain this transition, we propose a theoretical model that is compatible with our numerical findings. Finally, we also compare damaged graphene membranes with other crumpled structures, as for instance polymerised membranes and paper sheets, that share similar scaling properties.

  18. Crumpling Damaged Graphene

    PubMed Central

    Giordanelli, I.; Mendoza, M.; Andrade Jr., J. S.; Gomes, M. A. F.; Herrmann, H. J.

    2016-01-01

    Through molecular mechanics we find that non-covalent interactions modify the fractality of crumpled damaged graphene. Pristine graphene membranes are damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled membranes exhibit a fractal dimension of 2.71 ± 0.02 when all interactions between carbon atoms are considered, and 2.30 ± 0.05 when non-covalent interactions are suppressed. The transition between these two values, obtained by switching on/off the non-covalent interactions of equilibrium configurations, is shown to be reversible and independent on thermalisation. In order to explain this transition, we propose a theoretical model that is compatible with our numerical findings. Finally, we also compare damaged graphene membranes with other crumpled structures, as for instance polymerised membranes and paper sheets, that share similar scaling properties. PMID:27173442

  19. Subrupture Tendon Fatigue Damage

    PubMed Central

    Laudier, Damien M.; Shine, Jean H.; Basta-Pljakic, Jelena; Jepsen, Karl J.; Schaffler, Mitchell B.; Flatow, Evan L.

    2016-01-01

    The mechanical and microstructural bases of tendon fatigue, by which damage accumulates and contributes to degradation, are poorly understood. To investigate the tendon fatigue process, rat flexor digitorum longus tendons were cyclically loaded (1–16 N) until reaching one of three levels of fatigue damage, defined as peak clamp-to-clamp strain magnitudes representing key intervals in the fatigue life: i) Low (6.0%–7.0%); ii) Moderate (8.5%–9.5%); and iii) High (11.0%–12.0%). Stiffness, hysteresis, and clamp-to-clamp strain were assessed diagnostically (by cyclic loading at 1–8 N) before and after fatigue loading and following an unloaded recovery period to identify mechanical parameters as measures of damage. Results showed that tendon clamp-to-clamp strain increased from pre- to post-fatigue loading significantly and progressively with the fatigue damage level (p≤0.010). In contrast, changes in both stiffness and hysteresis were significant only at the High fatigue level (p≤0.043). Correlative microstructural analyses showed that Low level of fatigue was characterized by isolated, transverse patterns of kinked fiber deformations. At higher fatigue levels, tendons exhibited fiber dissociation and localized ruptures of the fibers. Histomorphometric analysis showed that damage area fraction increased significantly with fatigue level (p≤0.048). The current findings characterized the sequential, microstructural events that underlie the tendon fatigue process and indicate that tendon deformation can be used to accurately assess the progression of damage accumulation in tendons. PMID:18683881

  20. Spectrometry researches on interaction and sonodynamic damage of riboflavin (RF) to bovine serum albumin (BSA)

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqiu; Li, Jushi; Wang, Jun; Zou, Mingming; Wang, Siyu; Li, Ying; Kong, Yumei; Xia, Lixin

    2012-02-01

    In this paper, the riboflavin (RF) was used to study the interaction and sonodynamic damage to bovine serum albumin (BSA) by fluorescence and UV-vis spectroscopy. The results showed that the RF could efficiently bind to BSA in aqueous solution. Under ultrasonic irradiation, the RF could obviously damage the BSA. In addition, synchronous fluorescence spectroscopy revealed that the RF showed more accessible to tryptophan (Trp) residues than to tyrosine (Tyr) residues. Also, it damaged Trp residues more seriously than Tyr residues under ultrasonic irradiation. At last, the generation of reactive oxygen species (ROS) in sonodynamic process was estimated by the method of Oxidation-Extraction Spectrometry (OES). And then, several radical scavengers were used to determine the kind of ROS. It was found that at least the singlet oxygen ( 1O 2) and hydroxyl radicals ( rad OH) were generated.

  1. On tide-induced lagrangian residual current and residual transport: 1. Lagrangian residual current

    USGS Publications Warehouse

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi

    1986-01-01

    Residual currents in tidal estuaries and coastal embayments have been recognized as fundamental factors which affect the long-term transport processes. It has been pointed out by previous studies that it is more relevant to use a Lagrangian mean velocity than an Eulerian mean velocity to determine the movements of water masses. Under weakly nonlinear approximation, the parameter k, which is the ratio of the net displacement of a labeled water mass in one tidal cycle to the tidal excursion, is assumed to be small. Solutions for tides, tidal current, and residual current have been considered for two-dimensional, barotropic estuaries and coastal seas. Particular attention has been paid to the distinction between the Lagrangian and Eulerian residual currents. When k is small, the first-order Lagrangian residual is shown to be the sum of the Eulerian residual current and the Stokes drift. The Lagrangian residual drift velocity or the second-order Lagrangian residual current has been shown to be dependent on the phase of tidal current. The Lagrangian drift velocity is induced by nonlinear interactions between tides, tidal currents, and the first-order residual currents, and it takes the form of an ellipse on a hodograph plane. Several examples are given to further demonstrate the unique properties of the Lagrangian residual current.

  2. Bioinformatic prediction and in vivo validation of residue-residue interactions in human proteins

    NASA Astrophysics Data System (ADS)

    Jordan, Daniel; Davis, Erica; Katsanis, Nicholas; Sunyaev, Shamil

    2014-03-01

    Identifying residue-residue interactions in protein molecules is important for understanding both protein structure and function in the context of evolutionary dynamics and medical genetics. Such interactions can be difficult to predict using existing empirical or physical potentials, especially when residues are far from each other in sequence space. Using a multiple sequence alignment of 46 diverse vertebrate species we explore the space of allowed sequences for orthologous protein families. Amino acid changes that are known to damage protein function allow us to identify specific changes that are likely to have interacting partners. We fit the parameters of the continuous-time Markov process used in the alignment to conclude that these interactions are primarily pairwise, rather than higher order. Candidates for sites under pairwise epistasis are predicted, which can then be tested by experiment. We report the results of an initial round of in vivo experiments in a zebrafish model that verify the presence of multiple pairwise interactions predicted by our model. These experimentally validated interactions are novel, distant in sequence, and are not readily explained by known biochemical or biophysical features.

  3. Coping with brain damage

    NASA Technical Reports Server (NTRS)

    Waring, W.

    1974-01-01

    Two neurological disorders, cerebral palsy, and traumatic brain damage as from an accident, are considered. The discussion covers the incidence of disabilities, their characteristics, and what is now being done to deal with them, particularly in reference to areas in which the capabilities of the engineer can be effectively applied.

  4. Repairing damaged platforms

    SciTech Connect

    Moore, R.E.; Kwok, P.H.; Wang, S.S.

    1995-10-01

    This paper introduces a unique method for strengthening of platforms and replacing damaged members. Extending the life of existing infrastructure is approved means of decreasing cash expenditures for new platforms and facilities. Platforms can be affected by corrosion, overloading and fatigue. The renovation and repair of existing offshore installations is an important part of offshore engineering. The basis behind this paper is an April, 1993 incident in the Arabian Gulf. A vessel broke loose from its moorings in a severe storm and collided with a wellhead platform. The collision severely damaged the platform buckling seven major support members and cracking joints throughout the structure. In view of the significant damage, there was an urgent need to repair the structure to avoid any further damage from potentially sever winter storm conditions. Various means of repair and their associated costs were evaluated: traditional dry hyperbaric welding, adjacent platforms, grouted clamped connections, and mechanical pipe connectors. The repair was completed using an innovative combination of clamps and wet welding to attach external braces to the structure.

  5. Courtside: A Damaging Lesson

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2004-01-01

    This case presents a costly lesson for teachers and for districts that include a liquidated, or stipulated, damages clause in their teacher employment contracts. Although the court enforced the clause in this case, in this well-reasoned recent decision and in most of the much older, canvassed case law from other jurisdictions, the answer to the…

  6. Loss and damage

    NASA Astrophysics Data System (ADS)

    Huq, Saleemul; Roberts, Erin; Fenton, Adrian

    2013-11-01

    Loss and damage is a relative newcomer to the climate change agenda. It has the potential to reinvigorate existing mitigation and adaptation efforts, but this will ultimately require leadership from developed countries and enhanced understanding of several key issues, such as limits to adaptation.

  7. Laryngeal nerve damage

    MedlinePlus

    Laryngeal nerve damage is injury to one or both of the nerves that are attached to the voice box. ... Injury to the laryngeal nerves is uncommon. When it does occur, it can be from: A complication of neck or chest surgery (especially thyroid, lung, ...

  8. Modifying Radiation Damage

    PubMed Central

    Kim, Kwanghee; McBride, William H.

    2011-01-01

    Radiation leaves a fairly characteristic footprint in biological materials, but this is rapidly all but obliterated by the canonical biological responses to the radiation damage. The innate immune recognition systems that sense “danger” through direct radiation damage and through associated collateral damage set in motion a chain of events that, in a tissue compromised by radiation, often unwittingly result in oscillating waves of molecular and cellular responses as tissues attempt to heal. Understanding “nature’s whispers” that inform on these processes will lead to novel forms of intervention targeted more precisely towards modifying them in an appropriate and timely fashion so as to improve the healing process and prevent or mitigate the development of acute and late effects of normal tissue radiation damage, whether it be accidental, as a result of a terrorist incident, or of therapeutic treatment of cancer. Here we attempt to discuss some of the non-free radical scavenging mechanisms that modify radiation responses and comment on where we see them within a conceptual framework of an evolving radiation-induced lesion. PMID:20583981

  9. Oxidative DNA damage accumulation in gastric carcinogenesis

    PubMed Central

    Farinati, F; Cardin, R; Degan, P; Rugge, M; Di, M; Bonvicini, P; Naccarato, R

    1998-01-01

    Background—Gastric carcinogenesis is a multifactorial, multistep process, in which chronic inflammation plays a major role. 
Aims—In order to ascertain whether free radical mediated oxidative DNA damage is involved in such a process, concentrations of 8-hydroxydeoxyguanosine (8OHdG), a mutagenic/carcinogenic adduct, and thiobarbituric acid reactive substances (TBARS), as an indirect measure of free radical mediated damage, were determined in biopsy specimens from patients undergoing endoscopy. 
Patients—Eighty eight patients were divided into histological subgroups as follows: 27 with chronic non-atrophic gastritis, 41 with atrophic gastritis, six with gastric cancer, and 14 unaffected controls. 
Methods—Intestinal metaplasia, Helicobacter pylori infection, and disease activity were semiquantitatively scored. 8OHdG concentrations were assessed by HPLC with electrochemical detection, and TBARS concentrations were fluorimetrically assayed. 
Results—8OHdG concentrations (mean number of adducts/105 dG residues) were significantly higher in chronic atrophic gastritis (p=0.0009). Significantly higher concentrations were also detected in the presence of severe disease activity (p=0.02), intestinal metaplasia (p=0.035), and H pylori infection (p=0.001). TBARS concentrations were also higher in atrophic gastritis, though not significantly so. In a multiple logistic regression analysis, 8OHdG concentrations correlated best with the presence and severity of H pylori infection (r=0.53, p=0.002). 
Conclusions—Chronic gastritis is characterised by the accumulation of oxidative DNA damage with mutagenic and carcinogenic potential. H pylori infection is the major determinant for DNA adduct formation. 

 Keywords: free radicals; oxidative DNA damage; gastric carcinogenesis; precancerous changes; peroxidative damage PMID:9577340

  10. Quantification of Residual Stress from Photonic Signatures of Fused Silica

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott; Hayward, Maurice; Yost, William E.

    2013-01-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 +/- 0.54 x 10(exp -12)/Pa. Fused silica specimens containing impacts artificially made at NASA's Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented. Keywords: Glass, fused silica, photoelasticity, residual stress

  11. Prediction of residual tensile strength of transversely impacted composite laminates

    NASA Technical Reports Server (NTRS)

    Lal, K. M.

    1982-01-01

    The response to low velocity impact of graphite-epoxy T300/5208 composite laminates is discussed. Steel balls of 3/8 inch, 5/8 inch, and 1 inch diameter were the projectiles. Impact energy was limited to 1.2 joules. Impacted specimens were ultrasonically C scanned to determine the impact damaged region. The threshold value of impact energy for impact damage was found to be approximately 0.3 joules. A model was developed to predict the tensile residual strength of impact damaged specimens from fracture mechanics concepts. Impacted specimens were tested in tension to provide a fracture data base. The experimental results agreed well with the predictions from fracture mechanics. In this study, the maximum impact velocity used to simulate the low velocity transverse impact from common objects like tool drops was 10 m/s.

  12. Universality in Protein Residue Networks

    PubMed Central

    Estrada, Ernesto

    2010-01-01

    Abstract Residue networks representing 595 nonhomologous proteins are studied. These networks exhibit universal topological characteristics as they belong to the topological class of modular networks formed by several highly interconnected clusters separated by topological cavities. There are some networks that tend to deviate from this universality. These networks represent small-size proteins having <200 residues. This article explains such differences in terms of the domain structure of these proteins. On the other hand, the topological cavities characterizing proteins residue networks match very well with protein binding sites. This study investigates the effect of the cutoff value used in building the residue network. For small cutoff values, <5 Å, the cavities found are very large corresponding almost to the whole protein surface. On the contrary, for large cutoff value, >10.0 Å, only very large cavities are detected and the networks look very homogeneous. These findings are useful for practical purposes as well as for identifying protein-like complex networks. Finally, this article shows that the main topological class of residue networks is not reproduced by random networks growing according to Erdös-Rényi model or the preferential attachment method of Barabási-Albert. However, the Watts-Strogatz model reproduces very well the topological class as well as other topological properties of residue network. A more biologically appealing modification of the Watts-Strogatz model to describe residue networks is proposed. PMID:20197043

  13. Damage mechanics in engineering materials

    SciTech Connect

    Voyiadjis, G.Z.; Woody Ju, J.W.; Chaboche, J.L.

    1998-12-31

    This book contains thirty peer-reviewed papers that are based on the presentations made at the symposium on Damage Mechanics in Engineering Materials on the occasion of the Joint ASME/ASCE/SES Mechanics Conference (McNU97), held in Evanston, Illinois, June 28--July 2, 1997. The key area of discussion was on the constitutive modeling of damage mechanics in engineering materials encompassing the following topics: macromechanics/micromechanical constitutive modeling, experimental procedures, numerical modeling, inelastic behavior, interfaces, damage, fracture, failure, computational methods. The book is divided into six parts: study of damage mechanics; localization and damage; damage in brittle materials; damage in metals and metal matrix composites; computational aspects of damage models; damage in polymers and elastomers.

  14. Glycosylases utilize ``stop and go'' motion to locate DNA damage

    NASA Astrophysics Data System (ADS)

    Nelson, Shane

    2015-03-01

    Oxidative damage to DNA results in alterations that are mutagenic or even cytotoxic. Base excision repair is a mechanism that functions to identify and correct these lesions, and is present in organisms ranging from bacteria to humans. DNA glycosylases are the first enzymes in this pathway and function to locate and remove oxidatively damaged bases, and do so utilizing only thermal energy. However, the question remains of how these enzymes locate and recognize a damaged base among millions of undamaged bases. Utilizing fluorescence video microscopy with high spatial and temporal resolution, we have observed a number of different fluorescently labeled glycosylases (including bacterial FPG, NEI, and NTH as well as mammalian MutyH and OGG). These enzymes diffuse along DNA tightropes at approximately 0.01 +/- 0.005 μm2/s with binding lifetimes ranging from one second to several minutes. Chemically induced damage to the DNA substrate causes a ~ 50% reduction in diffusion coefficients and a ~ 400% increase in binding lifetimes, while mutation of the key ``wedge residue'' - which has been shown to be responsible for damage detection - results in a 200% increase in the diffusion coefficient. Utilizing a sliding window approach to measure diffusion coefficients within individual trajectories, we observe that distributions of diffusion coefficients are bimodal, consistent with periods of diffusive motion interspersed with immobile periods. Utilizing a unique chemo-mechanical simulation approach, we demonstrate that the motion of these glycosylases can be explained as free diffusion along the helical pitch of the DNA, punctuated with two different types of pauses: 1) rapid, short-lived pauses as the enzyme rapidly probes DNA bases to interrogate for damage and, 2) less frequent, longer lived pauses that reflect the enzyme bound to and catalytically removing a damaged base. These simulations also indicate that the wedge residue is critical for interrogation and recognition of

  15. Damage tolerance of a composite sandwich with interleaved foam core

    NASA Technical Reports Server (NTRS)

    Ishai, Ori; Hiel, Clement

    1992-01-01

    A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

  16. Safety assessment of drug residues

    SciTech Connect

    Jackson, B.A.

    1980-05-15

    The safety assessment of drug residues is part of the process for defining the conditions for the safe use of drugs in food-producing animals. The information needed to assess the safety of drug residues is provided by chemical and toxicity tests. Toxicity tests are conducted to identify the type of effect produced and to determine the exposure concentrations that would be expected not to produce the effect. These tests include acute, subacute, and chronic toxicity tests, as well as reproduction studies and other special tests. The results are used to find an acceptable daily intake for drug residues that can be used to set a tolerance.

  17. Influence of Impactor Mass on the Damage Characteristics and Failure Strength of Laminated Composite Plates

    NASA Technical Reports Server (NTRS)

    Ambur, Damodar R.; Kemmerly, Heather L.

    1998-01-01

    The results of an experimental study of the effect of impactor mass on the low-speed impact response of laminated flat composite plates is presented. Dropped weight impact response, damage characteristics, and residual strengths of quasi-isotropic flat plates are presented for a range of energy levels by systematically varying the mass of the impactor. Measured contact forces and damage areas are also presented. The results indicate that the contact force and damage area are nonlinear functions of the impactor mass and vary considerably over the entire range of energy levels considered. The different damage levels induced in a plate specimen when impacted at a given energy level with impactors of different masses significantly influence its compressive residual strength. The results provide clear and consistent trends in contact force, damage area, and compression-after-impact strength when the data are expressed as a function of the impactor momentum.

  18. Polarimetric sensors for damage detection of aluminum materials

    NASA Astrophysics Data System (ADS)

    Chang, Wee M.; Ng, Poh K.; Sng, Su-fern S.; Ma, Jianjun; Asundi, Anand K.; Puttappa, Jayanth

    2001-06-01

    A PFOS for monitoring and detecting damages in aluminum specimen has been demonstrated. It has been shown that PFOS can be used to monitor the development of cracks and predict residual load on aluminum structures. The experimental result obtained is very consistent and the sensor is immune to temperature changes and electromagnetic interference, as it does not require a reference are more accurate for damage detection. Some of the features such as low cost, durable, light weight and real-time applications of PFOS have been highlighted.

  19. Hypertension and cerebrovascular damage.

    PubMed

    Veglio, Franco; Paglieri, Cristina; Rabbia, Franco; Bisbocci, Daniela; Bergui, Mauro; Cerrato, Paolo

    2009-08-01

    Hypertension is the most important modifiable factor for cerebrovascular disease. Stroke and dementia are growing health problems that have considerable social and economical consequences. Hypertension causes brain lesions by several mechanisms predisposing to lacunar infarctions, leucoaraiosis, and white matter changes as well as to intracerebral haemorrhages. These parenchymal damages determine evident or silent neurological alterations that often precede the onset of cognitive decline. It is important to recognize cerebrovascular disease and, above all, to correlate typical lesions to hypertension. Antihypertensive therapy has shown clinical benefits in primary and secondary prevention of stroke. These drugs represent important instruments against cerebrovascular disease but their effects on cognition are still matter of debate. Cerebral parenchymal and functional damages have to be considered together to make medical intervention more incisive. PMID:19100549

  20. DNA damage tolerance.

    PubMed

    Branzei, Dana; Psakhye, Ivan

    2016-06-01

    Accurate chromosomal DNA replication is fundamental for optimal cellular function and genome integrity. Replication perturbations activate DNA damage tolerance pathways, which are crucial to complete genome duplication as well as to prevent formation of deleterious double strand breaks. Cells use two general strategies to tolerate lesions: recombination to a homologous template, and trans-lesion synthesis with specialized polymerases. While key players of these processes have been outlined, much less is known on their choreography and regulation. Recent advances have uncovered principles by which DNA damage tolerance is regulated locally and temporally - in relation to replication timing and cell cycle stage -, and are beginning to elucidate the DNA dynamics that mediate lesion tolerance and influence chromosome structure during replication. PMID:27060551

  1. Tornado damage risk assessment

    SciTech Connect

    Reinhold, T.A.; Ellingwood, B.

    1982-09-01

    Several proposed models were evaluated for predicting tornado wind speed probabilities at nuclear plant sites as part of a program to develop statistical data on tornadoes needed for probability-based load combination analysis. A unified model was developed which synthesized the desired aspects of tornado occurrence and damage potential. The sensitivity of wind speed probability estimates to various tornado modeling assumptions are examined, and the probability distributions of tornado wind speed that are needed for load combination studies are presented.

  2. The distribution of subsurface damage in fused silica

    SciTech Connect

    Miller, P E; Suratwala, T I; Wong, L L; Feit, M D; Menapace, J A; Davis, P J; Steele, R A

    2005-11-21

    Managing subsurface damage during the shaping process and removing subsurface damage during the polishing process is essential in the production of low damage density optical components, such as those required for use on high peak power lasers. Removal of subsurface damage, during the polishing process, requires polishing to a depth which is greater than the depth of the residual cracks present following the shaping process. To successfully manage, and ultimately remove subsurface damage, understanding the distribution and character of fractures in the subsurface region introduced during fabrication process is important. We have characterized the depth and morphology of subsurface fractures present following fixed abrasive and loose abrasive grinding processes. At shallow depths lateral cracks and an overlapping series of trailing indentation fractures were found to be present. At greater depths, subsurface damage consists of a series of trailing indentation fractures. The area density of trailing fractures changes as a function of depth, however the length and shape of individual cracks remain nearly constant for a given grinding process. We have developed and applied a model to interpret the depth and crack length distributions of subsurface surface damage in terms of key variables including abrasive size and load.

  3. Americium recovery from reduction residues

    DOEpatents

    Conner, W.V.; Proctor, S.G.

    1973-12-25

    A process for separation and recovery of americium values from container or bomb'' reduction residues comprising dissolving the residues in a suitable acid, adjusting the hydrogen ion concentration to a desired level by adding a base, precipitating the americium as americium oxalate by adding oxalic acid, digesting the solution, separating the precipitate, and thereafter calcining the americium oxalate precipitate to form americium oxide. (Official Gazette)

  4. Damage tolerance of candidate thermoset composites for use on single stage to orbit vehicles

    NASA Technical Reports Server (NTRS)

    Nettles, A. T.; Lance, D.; Hodge, A.

    1994-01-01

    Four fiber/resin systems were compared for resistance to damage and damage tolerance. One toughened epoxy and three toughened bismaleimide (BMI) resins were used, all with IM7 carbon fiber reinforcement. A statistical design of experiments technique was used to evaluate the effects of impact energy, specimen thickness, and impactor diameter on the damage area, as computed by C-scans, and residual compression-after-impact (CAI) strength. Results showed that two of the BMI systems sustained relatively large damage zones yet had an excellent retention of CAI strength.

  5. DISSOLUTION OF NEPTUNIUM OXIDE RESIDUES

    SciTech Connect

    Kyser, E

    2009-01-12

    This report describes the development of a dissolution flowsheet for neptunium (Np) oxide (NpO{sub 2}) residues (i.e., various NpO{sub 2} sources, HB-Line glovebox sweepings, and Savannah River National Laboratory (SRNL) thermogravimetric analysis samples). Samples of each type of materials proposed for processing were dissolved in a closed laboratory apparatus and the rate and total quantity of off-gas were measured. Samples of the off-gas were also analyzed. The quantity and type of solids remaining (when visible) were determined after post-dissolution filtration of the solution. Recommended conditions for dissolution of the NpO{sub 2} residues are: Solution Matrix and Loading: {approx}50 g Np/L (750 g Np in 15 L of dissolver solution), using 8 M nitric acid (HNO{sub 3}), 0.025 M potassium fluoride (KF) at greater than 100 C for at least 3 hours. Off-gas: Analysis of the off-gas indicated nitric oxide (NO), nitrogen dioxide (NO{sub 2}) and nitrous oxide (N{sub 2}O) as the only identified components. No hydrogen (H{sub 2}) was detected. The molar ratio of off-gas produced per mole of Np dissolved ranged from 0.25 to 0.4 moles of gas per mole of Np dissolved. A peak off-gas rate of {approx}0.1 scfm/kg bulk oxide was observed. Residual Solids: Pure NpO{sub 2} dissolved with little or no residue with the proposed flowsheet but the NpCo and both sweepings samples left visible solid residue after dissolution. For the NpCo and Part II Sweepings samples the residue amounted to {approx}1% of the initial material, but for the Part I Sweepings sample, the residue amounted to {approx}8 % of the initial material. These residues contained primarily aluminum (Al) and silicon (Si) compounds that did not completely dissolve under the flowsheet conditions. The residues from both sweepings samples contained minor amounts of plutonium (Pu) particles. Overall, the undissolved Np and Pu particles in the residues were a very small fraction of the total solids.

  6. Residual fatigue life of metallic materials with a long service life

    SciTech Connect

    Koupak, V.I.

    1986-01-01

    The concept of residual life is discussed as most widely used in assessing the additional resource of materials of power station structural elements after they have exceeded their calculated life. No methods have been developed which provide a highly reliable solution of numerical problems involved in determining the residual life of materials damaged in operation of steam-piping straight sections or their bends. Stuctural state of a material can not be predicted in time. The possibility of the use of the equation of linear summation for the evaluation of residual life is considered and presented.

  7. Crack Growth Simulation and Residual Strength Prediction in Airplane Fuselages

    NASA Technical Reports Server (NTRS)

    Chen, Chuin-Shan; Wawrzynek, Paul A.; Ingraffea, Anthony R.

    1999-01-01

    The objectives were to create a capability to simulate curvilinear crack growth and ductile tearing in aircraft fuselages subjected to widespread fatigue damage and to validate with tests. Analysis methodology and software program (FRANC3D/STAGS) developed herein allows engineers to maintain aging aircraft economically, while insuring continuous airworthiness, and to design more damage-tolerant aircraft for the next generation. Simulations of crack growth in fuselages were described. The crack tip opening angle (CTOA) fracture criterion, obtained from laboratory tests, was used to predict fracture behavior of fuselage panel tests. Geometrically nonlinear, elastic-plastic, thin shell finite element crack growth analyses were conducted. Comparisons of stress distributions, multiple stable crack growth history, and residual strength between measured and predicted results were made to assess the validity of the methodology. Incorporation of residual plastic deformations and tear strap failure was essential for accurate residual strength predictions. Issue related to predicting crack trajectory in fuselages were also discussed. A directional criterion, including T-stress and fracture toughness orthotropy, was developed. Curvilinear crack growth was simulated in coupon and fuselage panel tests. Both T-stress and fracture toughness orthotropy were essential to predict the observed crack paths. Flapping of fuselages were predicted. Measured and predicted results agreed reasonable well.

  8. Residual stresses in welded plates

    NASA Technical Reports Server (NTRS)

    Bernstein, Edward L.

    1994-01-01

    The purpose of this project was to develop a simple model which could be used to study residual stress. The mechanism that results in residual stresses in the welding process starts with the deposition of molten weld metal which heats the immediately adjacent material. After solidification of weld material, normal thermal shrinkage is resisted by the adjacent, cooler material. When the thermal strain exceeds the elastic strain corresponding to the yield point stress, the stress level is limited by this value, which decreases with increasing temperature. Cooling then causes elastic unloading which is restrained by the adjoining material. Permanent plastic strain occurs, and tension is caused in the region immediately adjacent to the weld material. Compression arises in the metal farther from the weld in order to maintain overall static equilibrium. Subsequent repair welds may add to the level of residual stresses. The level of residual stress is related to the onset of fracture during welding. Thus, it is of great importance to be able to predict the level of residual stresses remaining after a weld procedure, and to determine the factors, such as weld speed, temperature, direction, and number of passes, which may affect the magnitude of remaining residual stress. It was hoped to use traditional analytical modeling techniques so that it would be easier to comprehend the effect of these variables on the resulting stress. This approach was chosen in place of finite element methods so as to facilitate the understanding of the physical processes. The accuracy of the results was checked with some existing experimental studies giving residual stress levels found from x-ray diffraction measurements.

  9. Residual deformations in ocular tissues

    PubMed Central

    Wang, Ruoya; Raykin, Julia; Gleason, Rudolph L.; Ethier, C. Ross

    2015-01-01

    Residual deformations strongly influence the local biomechanical environment in a number of connective tissues. The sclera is known to be biomechanically important in healthy and diseased eyes, such as in glaucoma. Here, we study the residual deformations of the sclera, as well as the adjacent choroid and retina. Using freshly harvested porcine eyes, we developed two approaches of quantifying residual deformations in the spherically shaped tissues of interest. The first consisted of punching discs from the posterior wall of the eye and quantifying the changes in the area and eccentricity of these samples. The second consisted of cutting a ring from the equatorial sclera and making stress-relieving cuts in it. Measurements of curvature were made before and after the stress-relieving cuts. Using the first approach, we observed a 42% areal contraction of the choroid, but only modest contractions of the sclera and retina. The observed contractions were asymmetric. In the second approach, we observed an opening of the scleral rings (approx. 10% decrease in curvature). We conclude that residual bending deformations are present in the sclera, which we speculate may be due to radially heterogeneous growth and remodelling of the tissue during normal development. Further, residual areal deformations present in the choroid may be due to the network of elastic fibres in this tissue and residual deformations in the constituent vascular bed. Future studies of ocular biomechanics should attempt to include effects of these residual deformations into mechanical models in order to gain a better understanding of the biomechanics of the ocular wall. PMID:25740853

  10. Condition and residual life assessment of seamless steam pipe bends

    SciTech Connect

    Dufour, L.B.

    1995-12-01

    The majority of steam pipe bends in Dutch power plants are seamless. Reliable assessment of the condition of seamless bends after {approximately}100,000 hours of operation and beyond is a very complex and sometime frustrating procedure. Complex because external pipe forces can influence the damage and/or strain distribution in the bend. Besides, metallurgical, wall thickness and ovality variations are present anyhow, making the damage distribution in fact unknown. In accordance with a Dutch authority rule, a seamless bend is tested using a magnetic particles and investigated metallurgically with the aid of five surface replicas. Sometime more replicas are investigated and wall thickness and diameter measurements are performed as well. Occasionally, strain measurements are executed by applying capacitive strain gauges and the speckle correlation technique. In rare cases samples are taken from the first bend near the boiler outlet in order to perform isostress creep tests, allowing the determination of the condition and the residual life of other bends in the pipe systems. Based on years of experience the authors have learned that there is no single method or technique capable of assessing the condition and residual life of seamless steam pipe bends. Some experiences will be highlighted, together with recent developments in the field of quantified creep (void) damage--in order to determine inspection intervals--and the field of the speckle correlation technique.