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Sample records for partial-depth spall repair

  1. Spall study in one dimension

    International Nuclear Information System (INIS)

    Glenn, H.D.

    1976-01-01

    A SOC one-dimensional calculation of an underground nuclear test is presented to exemplify the shock propagation and spall phenomenology commonly predicted. Then to examine the effects of spherical divergence on spall, a series of SOC calculations, at different radii of curvature, are conducted and prediction of depth and velocity for the first spall zone are compared with predictions from simple analytic theory. The excellent agreement in this comparison verifies that the SOC code accurately represents the physics of spalling. This study also indicates that the total spall depth is independent of divergence because of the compensating effect that subsequent convergence has on the reflected wave. The latter result implies that the total depth of spall calculated for each underground nuclear tests must be critically examined and evaluated. Finally, SOC calculations for nuclear detonations in tuff and granite are performed to demonstrate the significant effect that variations in material response under shock loading have on shock propagation and spall

  2. Counterforce applied to prevent spalling

    International Nuclear Information System (INIS)

    Glamheden, Rune; Bergkvist, Lars; Faelth, Billy; Jacobsson, Lars; Harrstroem, Johan; Berglund, Johan

    2010-04-01

    The field experiment within CAPS (Counterforce Applied to Prevent Spalling) was initiated to determine if the application of dry bentonite pellets is sufficient to suppress thermally-induced spalling in KBS-3 deposition holes. The experience gained from Aespoe Pillar Stability Experiment, conducted between 2002 and 2006, indicated that spalling could be controlled by the application of a small confining pressure in the deposition holes. The CAPS field experiment that included four pairs of boreholes with a diameter of approximately 0.5 m, was carried out as a series of demonstration experiments in the TASQ-tunnel. The first and second heating tests were performed in open holes, without any confining pressure on the borehole wall and the third and fourth heating tests with a confining pressure created by expanded clay pellets (LECA). The first heating test was initiated at the end of August 2008 and the final test was finished at the end of May 2009. The trials suggest that the small confining pressure offered by the LECA pellets was adequate to control spalling and prevent the formation of a highly conductive zone of fractured rock in the 500-mm-diameter holes. It is recommended that a full-scale test be carried out to assess if the findings are applicable to 1,750-mm-diameter deposition holes. Should the full scale tests support the findings from these initial trials, filling the gap between the bentonite blocks and rock wall with dry bentonite pellets will provide a viable engineered solution for controlling the effects of thermally induced spalling in the KBS-3 deposition holes

  3. Counterforce applied to prevent spalling

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Bergkvist, Lars (Golder Associates AB (Sweden)); Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jacobsson, Lars (SP Technical Research Institute of Sweden, Boraas (Sweden)); Harrstroem, Johan (Geosigma AB, Uppsala (Sweden)); Berglund, Johan (Vattenfall Power Consultant AB, Stockholm (Sweden))

    2010-04-15

    The field experiment within CAPS (Counterforce Applied to Prevent Spalling) was initiated to determine if the application of dry bentonite pellets is sufficient to suppress thermally-induced spalling in KBS-3 deposition holes. The experience gained from Aespoe Pillar Stability Experiment, conducted between 2002 and 2006, indicated that spalling could be controlled by the application of a small confining pressure in the deposition holes. The CAPS field experiment that included four pairs of boreholes with a diameter of approximately 0.5 m, was carried out as a series of demonstration experiments in the TASQ-tunnel. The first and second heating tests were performed in open holes, without any confining pressure on the borehole wall and the third and fourth heating tests with a confining pressure created by expanded clay pellets (LECA). The first heating test was initiated at the end of August 2008 and the final test was finished at the end of May 2009. The trials suggest that the small confining pressure offered by the LECA pellets was adequate to control spalling and prevent the formation of a highly conductive zone of fractured rock in the 500-mm-diameter holes. It is recommended that a full-scale test be carried out to assess if the findings are applicable to 1,750-mm-diameter deposition holes. Should the full scale tests support the findings from these initial trials, filling the gap between the bentonite blocks and rock wall with dry bentonite pellets will provide a viable engineered solution for controlling the effects of thermally induced spalling in the KBS-3 deposition holes

  4. Spall response of single-crystal copper

    Science.gov (United States)

    Turley, W. D.; Fensin, S. J.; Hixson, R. S.; Jones, D. R.; La Lone, B. M.; Stevens, G. D.; Thomas, S. A.; Veeser, L. R.

    2018-02-01

    We performed a series of systematic spall experiments on single-crystal copper in an effort to determine and isolate the effects of crystal orientation, peak stress, and unloading strain rate on the tensile spall strength. Strain rates ranging from 0.62 to 2.2 × 106 s-1 and peak shock stresses in the 5-14 GPa range, with one additional experiment near 50 GPa, were explored as part of this work. Gun-driven impactors, called flyer plates, generated flat top shocks followed by spall. This work highlights the effect of crystal anisotropy on the spall strength by showing that the spall strength decreases in the following order: [100], [110], and [111]. Over the range of stresses and strain rates explored, the spall strength of [100] copper depends strongly on both the strain rate and shock stress. Except at the very highest shock stress, the results for the [100] orientation show linear relationships between the spall strength and both the applied compressive stress and the strain rate. In addition, hydrodynamic computer code simulations of the spall experiments were performed to calculate the relationship between the strain rate near the spall plane in the target and the rate of free surface velocity release during the pullback. As expected, strain rates at the spall plane are much higher than the strain rates estimated from the free surface velocity release rate. We have begun soft recovery experiments and molecular dynamics calculations to understand the unusual recompression observed in the spall signature for [100] crystals.

  5. Spalling of concrete walls under blast load

    International Nuclear Information System (INIS)

    Kot, C.A.

    1977-01-01

    A common effect of the detonation of explosives in close proximity of concrete shield walls is the spalling (scabbing) of the back face of the wall. Spalling is caused by the free surface reflection of the shock wave induced in the wall by high pressure air blast and occurs whenever the dynamic tensile rupture strength is exceeded. While a complex process, reasonable analytical spall estimates can be obtained for brittle materials with low tensile strengths, such as concrete, by assuming elastic material behavior and instantaneous spall formation. Specifically, the spall thicknesses and velocities for both normal and oblique incidence of the shock wave on the back face of the wall are calculated. The complex exponential decay wave forms of the air blast are locally approximated by simple power law expressions. Variations of blast wave strength with distance to the wall, charge weight and angle of incidence are taken into consideration. The shock wave decay in the wall is also accounted for by assuming elastic wave propagation. For explosions close-in to the wall, where the reflected blast wave pressures are sufficiently high, multiple spall layers are formed. Successive spall layers are of increasing thickness, at the same time the spall velocities decrease. The spall predictions based on elastic theory are in overall agreement with experimntal results and provide a rapid means of estimating spalling trends of concrete walls subjected to air blast. (Auth.)

  6. Layer transfer by controlled spalling

    International Nuclear Information System (INIS)

    Bedell, Stephen W; Fogel, Keith; Lauro, Paul; Shahrjerdi, Davood; Ott, John A; Sadana, Devendra

    2013-01-01

    In this communication, we present what may be the simplest method yet devised for removing surface layers from brittle substrates. The process is called controlled spalling technology (CST) and works by depositing a tensile stressor layer on the surface of a substrate, introducing a crack near the edge of the substrate, and mechanically guiding the crack as a single fracture front across the surface. The entire process is performed at room-temperature using only common laboratory equipment. We present here, for the first time, the specific process conditions required for controlled spalling of Ge 〈0 0 1〉 substrates using Ni as the stressor layer. We also illustrate the versatility of CST by removing completed CMOS circuits from a Si wafer and demonstrate functionality of the flexible circuits. Raman spectroscopy of spalled circuits with the Ni stressor intact indicates a residual compressive Si strain of 0.0029, in good agreement with the calculated value of 0.0022. Therefore, CST also permits new opportunities for strain engineering of nanoscale devices. (fast track communication)

  7. Comparing Numerical Spall Simulations with a Nonlinear Spall Formation Model

    Science.gov (United States)

    Ong, L.; Melosh, H. J.

    2012-12-01

    Spallation accelerates lightly shocked ejecta fragments to speeds that can exceed the escape velocity of the parent body. We present high-resolution simulations of nonlinear shock interactions in the near surface. Initial results show the acceleration of near-surface material to velocities up to 1.8 times greater than the peak particle velocity in the detached shock, while experiencing little to no shock pressure. These simulations suggest a possible nonlinear spallation mechanism to produce the high-velocity, low show pressure meteorites from other planets. Here we pre-sent the numerical simulations that test the production of spall through nonlinear shock interactions in the near sur-face, and compare the results with a model proposed by Kamegai (1986 Lawrence Livermore National Laboratory Report). We simulate near-surface shock interactions using the SALES_2 hydrocode and the Murnaghan equation of state. We model the shock interactions in two geometries: rectangular and spherical. In the rectangular case, we model a planar shock approaching the surface at a constant angle phi. In the spherical case, the shock originates at a point below the surface of the domain and radiates spherically from that point. The angle of the shock front with the surface is dependent on the radial distance of the surface point from the shock origin. We model the target as a solid with a nonlinear Murnaghan equation of state. This idealized equation of state supports nonlinear shocks but is tem-perature independent. We track the maximum pressure and maximum velocity attained in every cell in our simula-tions and compare them to the Hugoniot equations that describe the material conditions in front of and behind the shock. Our simulations demonstrate that nonlinear shock interactions in the near surface produce lightly shocked high-velocity material for both planar and cylindrical shocks. The spall is the result of the free surface boundary condi-tion, which forces a pressure gradient

  8. Partial-depth modulation study of anions and neutrals in low pressure silane plasmas

    International Nuclear Information System (INIS)

    Cozurteille, C.; Dorier, J.L.; Hollenstein, C.; Sansonnens; Howling, A.A.

    1995-10-01

    Partial-depth modulation of the rf power in a capacitive discharge is used to investigate the relative importance of negative ions and neutral radicals for particle formation in low power, low pressure silane plasmas. For less than 85% modulation depth, anions are trapped indefinitely in the plasma and particle formation ensues, whereas the polymerised neutral flux magnitudes and dynamics are independent of the modulation depth and the powder formation. These observations suggest that negative ions could be the particle precursors in plasma conditions where powder appears many seconds after plasma ignition. Microwave interferometry and mass spectrometry were combined to infer an anion density of ≅7.10 9 cm -3 which is approximately twice the free electron density in these modulated plasmas. (author) 6 figs., tabs., refs

  9. Spall Strength Measurements in Transparent Epoxy Polymers

    Science.gov (United States)

    Pepper, Jonathan; Rahmat, Meysam; Petel, Oren

    2017-06-01

    Polymer nanocomposites are seeing more frequent use in transparent armour applications. The role of the microstructure on the performance of these materials under dynamic tensile loading conditions is of particular interest. In the present study, a series of plate impact experiments was conducted in order to evaluate the dynamic response of an epoxy (EPON 828) cured with two differed hardeners. The purpose was to compare the role of these hardeners on the dynamic performance of the resulting transparent epoxy. The material response was resolved with a multi-channel photonic Doppler velocimeter. This system was used to determine the shock Hugoniot and dynamic tensile (spall) strength of the materials. The experimental results are presented in reference to spall theory and are evaluated against results predicted by an analytical model of the impacts. While varying the hardener did not change the shock Hugoniot of the epoxy, it did have an effect on the measured spall strengths.

  10. The spalling mechanism of fire exposed concrete

    NARCIS (Netherlands)

    Lottman, B.B.G.

    2017-01-01

    --- ENGLISH VERSION --- The spalling damage observed to concrete structures after severe fire exposure has been the topic of scientific research for the past decades. This phenomenon is commonly characterised by the sudden and in some cases violent breaking off of concrete pieces from the

  11. Spalling of concrete as studied by NMR

    NARCIS (Netherlands)

    Pel, L.; Heijden, van der G.H.A.; Huinink, H.P.; Marchand, J.; Bissonnette, B.; Gagné, R.; Jolin, M.

    2006-01-01

    During the past twenty years concrete has developed in both strength and durability. A downside to these improvements is the increased risk of explosive spalling in case of fire. Different factors such as heating rate, applied loading, permeability, and moisture saturation play an important role in

  12. Low temperature spalling of silicon: A crack propagation study

    Energy Technology Data Exchange (ETDEWEB)

    Bertoni, Mariana; Uberg Naerland, Tine; Stoddard, Nathan; Guimera Coll, Pablo

    2017-06-08

    Spalling is a promising kerfless method for cutting thin silicon wafers while doubling the yield of a silicon ingot. The main obstacle in this technology is the high total thickness variation of the spalled wafers, often as high as 100% of the wafer thickness. It has been suggested before that a strong correlation exists between low crack velocities and a smooth surface, but this correlation has never been shown during a spalling process in silicon. The reason lies in the challenge associated to measuring such velocities. In this contribution, we present a new approach to assess, in real time, the crack velocity as it propagates during a low temperature spalling process. Understanding the relationship between crack velocity and surface roughness during spalling can pave the way to attain full control on the surface quality of the spalled wafer.

  13. Limits of Spalling of Fire-Exposed Concrete

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2003-01-01

    on the nature of spalling, add the latest findings from the research of the author, and derives limits within which spalling should not take place. Some guidelines are formulated based on experience from research and practise for reducing the spalling risk for constructions beyond the safe design limits....... The limits provided are those, which can be stated at present, but further research is in progress, identifying more precisely the range of materials susceptible to spalling and contributing to the full understanding of the phenomenon....

  14. Spalling of concrete subjected to blast loading

    Directory of Open Access Journals (Sweden)

    Foglar M.

    2013-09-01

    Full Text Available This paper presents outcomes of the blast field tests of FRC and reinforced concrete specimens, which were performed in cooperation with the Czech Army corps and Police of the Czech Republic in the military training area Boletice. The numerical evaluation of the experiments focused on the spalling of concrete subjected to blast loading started after the first set of the tests, took almost 3 years and required further small-scale experiments performed in the labs of the Czech Technical University.

  15. Shockless spalling damage of alumina ceramic

    Science.gov (United States)

    Erzar, B.; Buzaud, E.

    2012-05-01

    Ceramic materials are commonly used to build multi-layer armour. However reliable test data is needed to identify correctly models and to be able to perform accurate numerical simulation of the dynamic response of armour systems. In this work, isentropic loading waves have been applied to alumina samples to induce spalling damage. The technique employed allows assessing carefully the strain-rate at failure and the dynamic strength. Moreover, specimens have been recovered and analysed using SEM. In a damaged but unbroken specimen, interactions between cracks has been highlighted illustrating the fragmentation process.

  16. Spall behavior of cast iron with varying microstructures

    International Nuclear Information System (INIS)

    Plume, Gifford; Rousseau, Carl-Ernst

    2014-01-01

    The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

  17. Spall behavior of cast iron with varying microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Plume, Gifford; Rousseau, Carl-Ernst, E-mail: rousseau@uri.edu [Mechanical Engineering, University of Rhode Island, 92 Upper College Rd., Kingston, Rhode Island 02881 (United States)

    2014-07-21

    The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94–1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

  18. Spall behaviors of high purity copper under sweeping detonation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyanggroup@163.com [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhi-qiang, Peng; Xing-zhi, Chen [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Zhao-liang, Guo; Tie-gang, Tang; Hai-bo, Hu [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); Qing-ming, Zhang [National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

    2016-01-10

    Suites of sweeping detonation experiments were conducted to assess the spall behavior of high purity copper samples with different heat treatment histories. Incipient spall samples were obtained at different sweeping detonation condition. Metallographic and Electron Backscattered Diffraction (EBSD) analyses were performed on the soft-recovered samples. The effects of grain boundaries, grain size, crystal orientation and loading direction on the spall behaviors were discussed. Spall plane branching was found in the main spall plane of the damage samples. For similar microstructure, the area of voids increase with the increase of shock stress, and the coalescence of voids also become more obvious. Results from EBSD analysis show that the grain sizes were decreased and the grains were elongated along the direction of the plate width. Triple junctions composed of two or more general high angle boundaries are the preferred locations for intergranular damage. Voids prefer to nucleate in the grain boundaries composed of grain with high Taylor Factor (TF) than other grains. The damage areas in the grains with high TF are more severe. Boundaries close to perpendicular to the loading direction are more susceptible to void nucleation than the boundaries close to parallel to the loading direction, but the difference of voids nucleated in these two boundaries is less significant than the results obtained by plate impact experiment. It would be caused by the obliquity between the shock loading direction and the plate normal.

  19. Spall Strength Measurements of Concrete for Varying Aggregate Sizes

    International Nuclear Information System (INIS)

    Chhabildas, Lalit C.; Kipp, Marlin E.; Reinhart, William D.; Wilson, Leonard T.

    1999-01-01

    Controlled impact experiments have been performed to determine the spall strength of four different concrete compositions. The four concrete compositions are identified as, 'SAC-5, CSPC', (''3/4'') large, and (''3/8'') small, Aggregate. They differ primarily in aggregate size but with average densities varying by less than five percent. Wave profiles from sixteen experiments, with shock amplitudes of 0.07 to 0.55 GPa, concentrate primarily within the elastic regime. Free-surface particle velocity measurements indicate consistent pullback signals in the release profiles, denoting average span strength of approximately 40 MPa. It is the purpose of this paper to present spall measurements under uniaxial strain loading. Notwithstanding considerable wave structure that is a unique characteristic to the heterogeneous nature of the scaled concrete, the spall amplitudes appear reproducible and consistent over the pressure range reported in this study

  20. Spall behaviour of single crystal aluminium at three principal orientations

    Science.gov (United States)

    Owen, G. D.; Chapman, D. J.; Whiteman, G.; Stirk, S. M.; Millett, J. C. F.; Johnson, S.

    2017-10-01

    A series of plate impact experiments have been conducted to study the spall strength of the three principal crystallographic orientations of single crystal aluminium ([100], [110] and, [111]) and ultra-pure polycrystalline aluminium. The samples have been shock loaded at two impact stresses (4 GPa and 10 GPa). Significant differences have been observed in the elastic behaviour, the pullback velocities, and the general shape of the wave profiles, which can be accounted for by considerations of the microscale homogeneity, the dislocation density, and the absence of grain boundaries in the single crystal materials. The data have shown that there is a consistent order of spall strength measured for the four sample materials. The [111] orientation has the largest spall strength and elastic limit, followed closely by [110], [100], and then the polycrystalline material. This order is consistent with both quasi-static data and geometrical consideration of Schmid factors.

  1. Edge Effects at Spall Fracture for Titanium Alloys of Varying Oxygen Content

    National Research Council Canada - National Science Library

    Razorenov, Sergey

    1998-01-01

    ...% have been tested in about 50 shock-wave experiments. In the experiments performed the Hugoniot elastic limit, the spall strength, and the critical diameter for the spall element separation were measured...

  2. Ultrasonic detection of spall damage nucleation under low-velocity repeated impact

    Directory of Open Access Journals (Sweden)

    Watanabe T.

    2012-08-01

    Full Text Available Repeated plate impact testing with impact stress well below the threshold spall-stress (2.6 GPa on medium carbon steel was carried out to the identical target plate by impacting the flyer plate. Occurrence of spall damage under low-velocity repeated impact was evaluated nondestructively with a low frequency scanning acoustic microscope. We observed the spall damage distribution by the B- and C-scan images. In order to initiate the spall damage (voids in a ductile material or cracks in a brittle one the particular value of threshold spall-stress should be exceeded what already belongs to a commonly accepted knowledge. Generally, the spall damage development is dependent on the amplitude and the duration of the stress pulse. If the stress is high and duration is long enough to create tensile failure of material, the voids or cracks nucleate along the spall plane, and consequently, they form macrocracks. Therefore, the spall damage does not create when the first impact stress is less than the threshold spall-stress. However, after the fifth low-velocity repeated impact test, the generation of the spall damage was detected, even if the impact stress (1.1–1.7 GPa was lower than the threshold spall-stress (2.6 GPa.

  3. Evaluation of TBM tunnels with respect to stability against spalling

    Science.gov (United States)

    Shaalan, Heyam; Ismail, Mohd Ashraf Mohd; Azit, Romziah

    2017-10-01

    As the depth of tunnels and underground construction increases, instability occurs in the form of rock bursting or spalling because of the induced stresses. Spalling may appear as a strong compressive stress causing crack growth behind the excavated surface and buckling of the thin rock slabs. In this paper, we describe how to reduce the rock spalling failure to increase the underground safety and the tunnel stability. Thus, a parametric study is implemented using 2-D Elasto-plastic finite elements stress analysis software to investigate the parameters that can minimize the extent and depth of the failure zone. The critical section of Pahang Selangor Raw Water Transfer Tunnel under high overburden is analyzed. The effect of the shotcrete lining thickness, tunnel size and the removal of fallouts or scaled v-notch on the failure zone depth is investigated. The results demonstrate that the shotcrete lining thickness has less influence on the failure depth, while a small tunnel diameter minimizes the failure depth. In addition, the stability of the tunnel improves by removing the loose rock mass.

  4. Prediction of the spatial occurrence of fire induced spalling in concrete slabs using random fields

    Directory of Open Access Journals (Sweden)

    Van Coile R.

    2013-09-01

    Full Text Available As the loss of concrete cover can significantly influence the reliability of concrete elements during fire, spalling should be taken into account when performing reliability calculations. However, the occurrence and spatial variation of spalling are highly uncertain. A first step towards a probabilistic analysis of spalling is made by combining existing deterministic models with a stochastic representation of the concrete tensile strength and by using random fields to model the tensile strength spatial variation.

  5. Shock-induced spall in copper: the effects of anisotropy, temperature, loading pulse and defect

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shengnian [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; An, Qi [Los Alamos National Laboratory; Han, Li - Bo [USTC

    2009-07-28

    Shock-induced spall in Cu is investigated with molecular dynamics simulations. We examine spallation in initially perfect crystals and defective solids with grain boundaries (columnar bicrystals), stacking faults or vacancies, as well as the effect of temperature and loading pulses. Spall in single crystal Cu is anisotropic, and defects and high temperature may reduce the spall strength. Taylor-wave (triangular shock-release wave) loading is explored in comparison with square wave shock loading.

  6. Preventive effect on spalling of UFC using jute fiber at high temperature

    Directory of Open Access Journals (Sweden)

    Ozawa M.

    2013-09-01

    Full Text Available In this study, we examined the relationship between spalling behaviour and spalling ratio of UFC with three kinds of short fibers (jute, polypropylene, water-soluble polyvinyl alcohol at high temperature. The heating temperatures were 400 °C and 600 °C. Although the specimen with jute fiber dosage of 0.19% by volume was occurred explosive spalling, the damage of specimen was slightly small. It appears that the addition of jute fiber to UFC is effective for preventing spalling.

  7. Spall damage of a mild carbon steel: Effects of peak stress, strain rate and pulse duration

    International Nuclear Information System (INIS)

    Li, C.; Li, B.; Huang, J.Y.; Ma, H.H.; Zhu, M.H.; Zhu, J.; Luo, S.N.

    2016-01-01

    We investigate spall damage of a mild carbon steel under high strain-rate loading, regarding the effects of peak stress, strain rate, and pulse duration on spall strength and damage, as well as related microstructure features, using gas gun plate impact, laser velocimetry, and electron backscatter diffraction analysis. Our experiments demonstrate strong dependences of spall strength on peak stress and strain rate, and its weak dependence on pulse duration. We establish numerical relations between damage and peak stress or pulse duration. Brittle and ductile spall fracture modes are observed at different loading conditions. Damage nucleates at grain boundaries and triple junctions, either as transgranular cleavage cracks or voids.

  8. Spall damage of a mild carbon steel: Effects of peak stress, strain rate and pulse duration

    Energy Technology Data Exchange (ETDEWEB)

    Li, C. [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Li, B.; Huang, J.Y. [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Ma, H.H. [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); Zhu, M.H. [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhu, J., E-mail: zhujun01@163.com [College of Physical Science and Technology, Sichuan University, Chengdu, Sichuan 610064 (China); Luo, S.N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610031 (China); Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2016-04-13

    We investigate spall damage of a mild carbon steel under high strain-rate loading, regarding the effects of peak stress, strain rate, and pulse duration on spall strength and damage, as well as related microstructure features, using gas gun plate impact, laser velocimetry, and electron backscatter diffraction analysis. Our experiments demonstrate strong dependences of spall strength on peak stress and strain rate, and its weak dependence on pulse duration. We establish numerical relations between damage and peak stress or pulse duration. Brittle and ductile spall fracture modes are observed at different loading conditions. Damage nucleates at grain boundaries and triple junctions, either as transgranular cleavage cracks or voids.

  9. Test Method for Spalling of Fire Exposed Concrete

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt

    2005-01-01

    A new material test method is presented for determining whether or not an actual concrete may suffer from explosive spalling at a specified moisture level. The method takes into account the effect of stresses from hindered thermal expansion at the fire-exposed surface. Cylinders are used, which...... in many countries serve as standard specimens for testing the compressive strength. Consequently, the method is quick, cheap and easy to use in comparison to the alternative of testing full-scale or semi full-scale structures with correct humidity, load and boundary conditions. A number of concretes have...

  10. The shock and spall response of AA 7010-T7651

    Science.gov (United States)

    Hazell, Paul; Appleby-Thomas, Gareth; Wood, David; Painter, Jonathan

    2013-06-01

    Aluminium alloys are used extensively in armour. Their use as armour materials is primarily due to their relatively low densities and their high strength characteristics. The aerospace-grade 7000-series alloy Al7010-T7651 is one possible contender for armour. In this study a series of plate-impact experiments were undertaken to investigate the behaviour of this alloy under shock. Manganin stress gauges and a heterodyne velocimeter system were used to interrogate both strength and dynamic tensile failure (spall) respectively; with microscopic analysis of recovered samples providing insight into the development of failure in the material.

  11. Development of Laboratory Testing Criteria for Evaluating Cementitious, Rapid-Setting Pavement Repair Materials

    Science.gov (United States)

    2011-04-01

    Squadron, Engineer (RED HORSE) squadrons, and Prime BEEF (Base Engineer Emergency Force) units. Additional users of this report include Army, Navy...approved AFRL 10 2007 PavePatch 3000 Conspec Co. Fail Not approved AFRL 11 2007 Premium Patch 200 Pre-Blend Products, Inc. Fail Expeditionary spall...damaged pavement. A small patch is not limited to spall repair as it may replace pavement damaged within a slab, such as a small utility cut . Large

  12. Explosive Spalling of Fire Exposed Resource Saving Concrete Structures

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Hertz, Kristian Dahl; Kristiansen, Finn Harken

    2003-01-01

    The paper describes briefly a new test facility, which has been developed within the project “Resource Saving Concrete Structures”, also called “Green Concrete” and some test results from the project. A full report is available from the home page of the Department of Civil Engineering Kristiansen......, Hertz, Sørensen [1]. The main idea was to establish a test method by means of which it should be possible to assess whether a particular concrete has an increased risk of spalling compared to traditional concretes as defined in Hertz [2] and only using ordinary standard cylinders as test specimens....... The method has been applied on the green concretes of the project and later also as a first indicator in other projects. The method appears to be a valuable tool for the first investigation of new concretes...

  13. The virtual fields method applied to spalling tests on concrete

    Directory of Open Access Journals (Sweden)

    Forquin P.

    2012-08-01

    Full Text Available For one decade spalling techniques based on the use of a metallic Hopkinson bar put in contact with a concrete sample have been widely employed to characterize the dynamic tensile strength of concrete at strain-rates ranging from a few tens to two hundreds of s−1. However, the processing method mainly based on the use of the velocity profile measured on the rear free surface of the sample (Novikov formula remains quite basic and an identification of the whole softening behaviour of the concrete is out of reach. In the present paper a new processing method is proposed based on the use of the Virtual Fields Method (VFM. First, a digital high speed camera is used to record the pictures of a grid glued on the specimen. Next, full-field measurements are used to obtain the axial displacement field at the surface of the specimen. Finally, a specific virtual field has been defined in the VFM equation to use the acceleration map as an alternative ‘load cell’. This method applied to three spalling tests allowed to identify Young’s modulus during the test. It was shown that this modulus is constant during the initial compressive part of the test and decreases in the tensile part when micro-damage exists. It was also shown that in such a simple inertial test, it was possible to reconstruct average axial stress profiles using only the acceleration data. Then, it was possible to construct local stress-strain curves and derive a tensile strength value.

  14. Extension of the principles of the kinetic conception of strength to the process of spalling fracture

    International Nuclear Information System (INIS)

    Molodets, A.M.; Dremin, A.N.

    1983-01-01

    The universality and graphical physical meaning of the characteristic relationship for thermal activation processes and time stimulate attempts for its utilization to describe the time dependence of the spall strength. The involvement of this relationship to describe spall requires a definite model of the spall process first. It is also necessary to to consider the question of the relationship between the applied and local stresses and the selection of a definite connection between these variables. The phenomenological model of spall in which the analogue of the cumulative rudimentary discontinuity is isolated has already been proposed. In this paper, a model is proposed within the framework of this previously described model, taking into account the thermal activation processes and the mean level of the stresses. Comparisons of this model with experimental data on the spall in copper show good agreement. In the spall domain the overstress factor is approximately one third its limit value. This means that higher values of the applied stresses than those found under quasistatic conditions correspond to the identical local stress level. It is possible that the thermal activation stage proceeds during spall in metals exactly as under quasistatic conditions, namely; rudimentary discontinuities are submicrocracks of dimensions less than 10 -7 microns

  15. Influence of rock spalling on concrete lining in shaft sinking at the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Tsusaka, Kimikazu; Inagaki, Daisuke; Nago, Makito; Koike, Masashi; Matsubara, Makoto; Sugawara, Kentaro

    2013-01-01

    A shaft is the shortest way to access the deep underground. In shaft sinking through large-scale faults or under low competence factor, spalling of shaft walls is likely to occur. Although earlier studies indicated that rock spalling is an undesirable phenomenon that threatens safety in excavation work and causes delay in construction schedule, there have been few studies which discussed damage to concrete lining induced by spalling. Japan Atomic Energy Agency has been constructing three shafts (one for ventilation and the others for access) to a depth of 500 m in the Horonobe Underground Research Laboratory. During the construction of the Ventilation Shaft (4.5 m diameter) below a depth of 250 m, rock spalling occurred at several depths and an open crack developed in the concrete lining installed just above the location of the rock spalling. In this study, the geometry of the shaft wall was measured using a three-dimensional laser scanner. Numerical analysis was also conducted to estimate changes in stress distribution and deformation induced by rock spalling in both the concrete lining and the surrounding rock. As a result, it was clarified that rock spalling induced a vertical tensile stress in the concrete lining. Especially, the tensile stress in a concrete lining was likely to exceed the tensile strength of the concrete lining when it developed more than 100 cm into the wall rock. (author)

  16. Microstructure Effects on Spall Strength of Titanium-based Bulk Metallic Glass Composites

    Science.gov (United States)

    Diaz, Rene; Hofmann, Douglas; Thadhani, Naresh; Georgia Tech Team; GT-JPL Collaboration

    2017-06-01

    The spall strength of Ti-based metallic glass composites is investigated as a function of varying volume fractions (0-80%) of in-situ formed crystalline dendrites. With increasing dendrite content, the topology changes such that neither the harder glass nor the softer dendrites dominate the microstructure. Plate-impact experiments were performed using the 80-mm single-stage gas gun over impact stresses up to 18 GPa. VISAR interferometry was used to obtain rear free-surface velocity profiles revealing the velocity pullback spall failure signals. The spall strengths were higher than for Ti-6Al-4V alloy, and remained high up to impact stress. The influence of microstructure on the spall strength is indicated by the constants of the power law fit with the decompression strain rate. Differences in fracture behavior reveal void nucleation as a dominant mechanism affecting the spall strength. The microstructure with neither 100% glass nor with very high crystalline content, provides the most tortuous path for fracture and therefore highest spall strength. The results allow projection of spall strength predictions for design of in-situ formed metallic glass composites. ARO Grant # W911NF-09 ``1-0403 NASA JPL Contract # 1492033 ``Prime # NNN12AA01C; NSF GRFP Grant #DGE-1148903; and NDSE & G.

  17. Failure Modes in Concrete Repair Systems due to Ongoing Corrosion

    NARCIS (Netherlands)

    Lukovic, M.; Šavija, B.; Ye, G.; Schlangen, H.E.J.G.; van Breugel, K.

    2017-01-01

    Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. It can result in cracking and spalling of the concrete cover. After the damaged cover is repaired, reinforcement corrosion might continue and even accelerate. While the development of the corrosion

  18. Assessment of the potential for rock spalling in the technical rooms of the ONKALO

    International Nuclear Information System (INIS)

    Siren, T.; Martinelli, D.; Uotinen, L.

    2011-06-01

    It is important to be able to predict the rock spalling in the ONKALO while the excavation advances deeper. When stresses at the excavation boundary reach the rock mass spalling strength, a brittle failure occurs that is often called 'spalling'. The spalling phenomenon occurs as a strong compressive stress induces crack growth behind the excavated surface. Spalling is, expressly, an event that can create problems in the ONKALO, not so much for the overall stability of all of the excavations, but rather in particular areas that can cause unnecessary and unintended over-excavations and hazards. For rock engineering and layout design purposes, the knowledge of the predicted spalling in the excavation surface is crucial. Optimization of the design is mainly done by directing the tunnels parallel to the major principal stress direction. However, due to the complex forms and crossing tunnels, especially at the shaft access drift area, sophisticated methods are required in order to minimize spalling and to support the unavoidable spalling that occurs. The complex tunnels require three-dimensional analysis. The software used for the main calculation has been MIDAS/GTS, a geotechnical 3-D FEM that is able to calculate complex geometries rather easily. Most of the models have also been verified with Rocscience Examine3D, which returns the results with a high precision at boundary. The area to model is large, and due to the computational limits, it is divided into six blocks. This analysis, carried out step by step for each block, permitted to draw a map of the spalling depth prevision in the whole tunnel contract 5 (TU5) area. The dominating rock types in the area are migmatitic gneiss and pegmatitic granite. The strength of these rocks has been broadly tested with point load and uniaxial compressive strength tests. The test results show a deviation of the UCS as well as other parameters. Due to this large deviation, a Monte Carlo has been used as an auxiliary analysis

  19. New data on the kinetics and governing factors of the spall fracture of metals

    Science.gov (United States)

    Kanel, G. I.; Razorenov, S. V.; Garkushin, G. V.; Savinykh, A. S.

    2018-01-01

    This paper presents two examples of significant departures from usual trends of varying the resistance to spall fracture (spall strength) with changing loading history, load duration and peak shock stress. In experiments with vanadium single crystals we observed an important decrease of spall strength when increasing the shock stress. This was interpreted in terms of disruption of the matter homogeneity as a result of its twinning at shock compression. In experiments with 12Kh18N10T austenitic stainless steel we observed a sharp increase of recorded spall strength value when short load pulses of a triangular profile were replaced by shock pulses of long duration having a trapezoidal shape. This anomaly is associated with formation of the deformation-induced martensitic phase.

  20. Experimental and numerical study of the micro-spalling of metallic targets subjected to laser shock

    International Nuclear Information System (INIS)

    Loison, D.

    2012-01-01

    Micro-spalling is a failure phenomenon consisting in dynamic fragmentation of a material after partial or full melting under intense shock wave loading. High power pulsed lasers are used as shock wave generators in laboratory for scientific and industrial purposes, such as research on inertial confinement fusion. In this context, the production of high velocity fragments can damage the facilities where shock experiments are conducted. This thesis, realized in collaboration with different teams from CEA, aims at understanding and modeling the different processes involved in micro-spalling phenomenon. Experiments to study micro-spalling of laser shock-loaded tin and aluminum targets have been performed. Various and complementary diagnostics (photonic Doppler velocimetry, soft recovery of debris and microtomography) have been used to characterize the ballistic properties (size distributions and velocities) of droplets constituting the micro-spalling cloud. In parallel, phase transition and fragmentation models have been adapted to simulate micro-spalling. These models have been implemented in a code to predict the sizes and velocities of debris. The combination of experimental and numerical results allows characterizing the successive stages of micro-spalling from laser-matter interaction to the ejection of droplets. (author)

  1. A physics-based algorithm for the estimation of bearing spall width using vibrations

    Science.gov (United States)

    Kogan, G.; Klein, R.; Bortman, J.

    2018-05-01

    Evaluation of the damage severity in a mechanical system is required for the assessment of its remaining useful life. In rotating machines, bearings are crucial components. Hence, the estimation of the size of spalls in bearings is important for prognostics of the remaining useful life. Recently, this topic has been extensively studied and many of the methods used for the estimation of spall size are based on the analysis of vibrations. A new tool is proposed in the current study for the estimation of the spall width on the outer ring raceway of a rolling element bearing. The understanding and analysis of the dynamics of the rolling element-spall interaction enabled the development of a generic and autonomous algorithm. The algorithm is generic in the sense that it does not require any human interference to make adjustments for each case. All of the algorithm's parameters are defined by analytical expressions describing the dynamics of the system. The required conditions, such as sampling rate, spall width and depth, defining the feasible region of such algorithms, are analyzed in the paper. The algorithm performance was demonstrated with experimental data for different spall widths.

  2. Role of spall in microstructure evolution during laser-shock-driven rapid undercooling and resolidification

    International Nuclear Information System (INIS)

    Colvin, Jeffrey D.; Jankowski, Alan F.; Kumar, Mukul; MoberlyChan, Warren J.; Reed, Bryan W.; Paisley, Dennis L.; Tierney, Thomas E.

    2009-01-01

    We previously reported [Colvin et al., J. Appl. Phys. 101, 084906 (2007)] on the microstructure morphology of pure Bi metal subjected to rapid laser-shock-driven melting and subsequent resolidification upon release of pressure, where the estimated effective undercooling rates were of the order of 10 9 -10 10 K/s. More recently, we repeated these experiments, but with a Bi/Zn alloy (Zn atomic fraction of 2%-4%) instead of elemental Bi and with a change in target design to suppress spall in the Bi/Zn samples. We observed a similar microstructure morphology in the two sets of experiments, with initially columnar grains recrystallizing to larger equiaxed grains. The Bi samples, however, exhibited micron-scale dendrites on the spall surfaces, whereas there were no dendritic structures anywhere in the nonspalled Bi/Zn, even down to the nanometer scale as observed by transmission electron microscopy. We present the simulations and the interferometry data that show that the samples in the two sets of experiments followed nearly identical hydrodynamic and thermodynamic paths apart from the presence of (probably partially liquid) spall in pure Bi. Simulations also show that the spall occurs right at the moving phase front and, hence, the spall itself cuts off the principal direction for latent heat dissipation across the phase boundary. We suggest that it is the liquid spall itself that creates the conditions for dendrite formation

  3. DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.

    Energy Technology Data Exchange (ETDEWEB)

    Gilkey, Amy P. (GRAM Inc., Albuquerque, NM); Hansen, Clifford W.; Schatz, John F. (John F. Schatz Research & Consulting, Inc., Del Mar, CA); Rudeen, David Keith (GRAM Inc., Albuquerque, NM); Lord, David L.

    2006-02-01

    This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface

  4. Preliminary assessment of potential underground stability (wedge and spalling) at Forsmark, Simpevarp and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Derek [Univ. of Alberta, Edmonton (Canada). Geotechnical Engineering

    2005-12-15

    In SKB's Underground Design Premises the objective in the early design phase is to estimate if there is sufficient space for the repository at a site. One of the conditions that could limit the space available is stability of the underground openings, i.e., deposition tunnels and deposition boreholes. The purpose of this report is to provide a preliminary assessment of the potential for wedge instability and spalling that may be encountered at the Forsmark, Simpevarp and Laxemar sites based on information from the site investigations program up to July 30, 2004. The rock mass spalling strength was defined using the in-situ results from SKB's Aespoe Pillar Stability Experiment and AECL's Mine-by Experiment. These experiments suggest that the rock mass spalling strength for crystalline rocks can be estimated as 0.57 of the mean laboratory uniaxial compressive strength. A probability-based methodology utilizing this in-situ rock mass spalling strength has been developed for assessing the risk for spalling in a repository at the Forsmark, Simpevarp and Laxemar sites. The in-situ stresses and the uniaxial compressive strength data from these sites were used as the bases for the analyses. Preliminary findings from all sites suggest that, generally, the risk for spalling increases as the depth of the repository increases, simply because the stress magnitudes increase with depth. The depth at which the risk for spalling is significant, depends on the individual sites which are discussed below. The greatest uncertainty in the spalling analyses for Forsmark is related to the uncertainty in the horizontal stress magnitudes and associated stress gradients with depth. The confidence in these analyses can only be increased by increasing the confidence in the stress and geology model for the site. From the analyses completed it appears that spalling in the deposition tunnels can be controlled by orienting the tunnels approximately parallel to the maximum horizontal

  5. Influence of nano-size inclusions on spall fracture of copper single crystals

    International Nuclear Information System (INIS)

    Razorenov, S. V.; Ivanchihina, G. E.; Kanel, G. I.; Herrmann, B.; Zaretsky, E. B.

    2007-01-01

    Spall experiments have been carried out for copper in different structural states. The samples were copper single crystals, crystals of Cu+0.1% Si, copper crystals with silica particles of 180 nm average size, and polycrystalline copper. In experiments, the free surface velocity histories were recorded with the VISAR. The recovered samples were studied using optical microscopy and SEM. Solid solution Cu+0.1% Si demonstrates slower spall process than pure copper crystals. At longer pulse durations its spall strength is slightly less than that of pure crystals but approaches the latter with decreasing pulse duration. Fracture of copper with silica inclusions is completed much faster. The spall strength of this material is close to that of Cu+0.1% Si crystals at longer pulse duration and approaches the strength of polycrystalline copper with decreasing the load duration. Fractography of the spall surfaces correlates with the free surface velocity histories. The main fracture surface of the Cu+0.1% Si grains consists of net of dimples ∼4 μm to 40 μm mean diameter. The fracture surfaces of copper with silica inclusions is covered by a net of dimples of 1 μm to 5 μm size

  6. The influence of microstructure on the shock and spall behaviour of the magnesium alloy, Elektron 675

    International Nuclear Information System (INIS)

    Hazell, P.J.; Appleby-Thomas, G.J.; Wielewski, E.; Stennett, C.; Siviour, C.

    2012-01-01

    Alloying elements such as aluminium, zinc and rare earth metals allow precipitation hardening of magnesium (Mg). The low densities of such strengthened Mg alloys have led to their adoption as aerospace materials and (more recently) they are being considered as armour materials. Consequently, understanding their response to high strain-rate loading is becoming increasingly important. Here, the plate-impact technique was employed to measure stress evolution in an armour-grade wrought Mg alloy (Elektron 675) under one-dimensional shock loading. The effects of sample orientation and heat treatment were examined. The spall behaviour was interrogated using a heterodyne velocimeter system, with an estimate made of the material’s spall strength and Hugoniot elastic limit (HEL) for both aged and unaged materials. In particular, it is shown that the HEL and spall strength values are higher along the extrusion direction. It is thought that this is caused by striations of relatively small grains that run along the extrusion direction.

  7. A study on spalling in soft rock under low confining stress

    International Nuclear Information System (INIS)

    Tomita, Atsunori; Ebina, Takahito; Toida, Masaru; Shirasagi, Suguru; Kishida, Kiyoshi; Adachi, Toshihisa

    2007-01-01

    The aim of this paper is to study spalling in soft rock excavation. During the test cavern excavation of the radioactive waste disposal project, spalling occurred. Therefore, it has been estimated performing the stress path simulation test and measuring the induced stress. In the stress path simulation test, the splitting failure has been confirmed under low confining stress. In the induced stress measurements, the rock mass around the cavern has shifted to the low radial confinement. Hence, spalling in soft rock was interpreted by the splitting failure caused by the induced stress under low confinement. Furthermore, the failure zone was proved by the numerical analysis applying the criterion based on the results of the above triaxial test. (author)

  8. Spalling stress in oxidized thermal barrier coatings evaluated by X-ray diffraction method

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K. [Faculty of Education and Human Sciences, Niigata Univ., Niigata (Japan); Tanaka, K. [Dept. of Mechanical Engineering, Nagoya Univ., Furoh-cho, Chikusa-ku, Nagoya (Japan)

    2005-07-01

    The spallation of thermal barrier coatings (TBCs) is promoted by thermally grown oxide (TGO). To improve TBCs, it is very important to understand the influence of TGO on the spalling stress. In this study 'the TBCs were oxidized at 1373 K for four different periods: 0, 500,1000 and 2000 h. The distribution of the in-plane stress in oxidized TBCs, {sigma}{sub 1}, was obtained by repeating the X-ray stress measurement with low energy X-rays after successive removal of the surface layer. The distribution of the out-of-plane stress, {sigma}{sub 1} - {sigma}{sub 3}, was measured with hard synchrotron X-rays, because high energy X-rays have a large penetration depth. From the results by the low and high energy X-rays, the spalling stress in the oxidized TBCs, {sigma}{sub 3}, was evaluated. The evaluated value of the spalling stress for the oxidized TBC was a small tension beneath the surface, but steeply increased near the interface between the top and bond coating. This large tensile stress near the interface is responsible for the spalling of the top coating. (orig.)

  9. Effect of fire exposure on cracking, spalling and residual strength of fly ash geopolymer concrete

    International Nuclear Information System (INIS)

    Sarker, Prabir Kumar; Kelly, Sean; Yao, Zhitong

    2014-01-01

    Highlights: • Fire endurance of fly ash geopolymer concrete has been studied. • No spalling in geopolymer concrete cylinders up to 1000 °C fire. • Less cracking and better fire endurance of geopolymer concrete than OPC concrete. • Geopolymer microstructure remained stable up to 1000 °C fire. - Abstract: Fly ash based geopolymer is an emerging alternative binder to cement for making concrete. The cracking, spalling and residual strength behaviours of geopolymer concrete were studied in order to understand its fire endurance, which is essential for its use as a building material. Fly ash based geopolymer and ordinary portland cement (OPC) concrete cylinder specimens were exposed to fires at different temperatures up to 1000 °C, with a heating rate of that given in the International Standards Organization (ISO) 834 standard. Compressive strength of the concretes varied in the range of 39–58 MPa. After the fire exposures, the geopolymer concrete specimens were found to suffer less damage in terms of cracking than the OPC concrete specimens. The OPC concrete cylinders suffered severe spalling for 800 and 1000 °C exposures, while there was no spalling in the geopolymer concrete specimens. The geopolymer concrete specimens generally retained higher strength than the OPC concrete specimens. The Scanning Electron Microscope (SEM) images of geopolymer concrete showed continued densification of the microstructure with the increase of fire temperature. The strength loss in the geopolymer concrete specimens was mainly because of the difference between the thermal expansions of geopolymer matrix and the aggregates

  10. Analytic model for surface ground motion with spall induced by underground nuclear tests

    International Nuclear Information System (INIS)

    MacQueen, D.H.

    1982-04-01

    This report provides a detailed presentation and critique of a model used to characterize the surface ground motion following a contained, spalling underground nuclear explosion intended for calculation of the resulting atmospheric acoustic pulse. Some examples of its use are included. Some discussion of the general approach of ground motion model parameter extraction, not dependent on the specific model, is also presented

  11. Meso-Scale Modeling of Spall in a Heterogeneous Two-Phase Material

    Energy Technology Data Exchange (ETDEWEB)

    Springer, Harry Keo [Univ. of California, Davis, CA (United States)

    2008-07-11

    The influence of the heterogeneous second-phase particle structure and applied loading conditions on the ductile spall response of a model two-phase material was investigated. Quantitative metallography, three-dimensional (3D) meso-scale simulations (MSS), and small-scale spall experiments provided the foundation for this study. Nodular ductile iron (NDI) was selected as the model two-phase material for this study because it contains a large and readily identifiable second- phase particle population. Second-phase particles serve as the primary void nucleation sites in NDI and are, therefore, central to its ductile spall response. A mathematical model was developed for the NDI second-phase volume fraction that accounted for the non-uniform particle size and spacing distributions within the framework of a length-scale dependent Gaussian probability distribution function (PDF). This model was based on novel multiscale sampling measurements. A methodology was also developed for the computer generation of representative particle structures based on their mathematical description, enabling 3D MSS. MSS were used to investigate the effects of second-phase particle volume fraction and particle size, loading conditions, and physical domain size of simulation on the ductile spall response of a model two-phase material. MSS results reinforce existing model predictions, where the spall strength metric (SSM) logarithmically decreases with increasing particle volume fraction. While SSM predictions are nearly independent of applied load conditions at lower loading rates, which is consistent with previous studies, loading dependencies are observed at higher loading rates. There is also a logarithmic decrease in SSM for increasing (initial) void size, as well. A model was developed to account for the effects of loading rate, particle size, matrix sound-speed, and, in the NDI-specific case, the probabilistic particle volume fraction model. Small-scale spall experiments were designed

  12. Rock stress orientation measurements using induced thermal spalling in slim boreholes

    International Nuclear Information System (INIS)

    Hakami, Eva

    2011-05-01

    In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

  13. Rock stress orientation measurements using induced thermal spalling in slim boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Hakami, Eva [Geosigma AB, Uppsala (Sweden)

    2011-05-15

    In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

  14. In Situ Observation of Rock Spalling in the Deep Tunnels of the China Jinping Underground Laboratory (2400 m Depth)

    Science.gov (United States)

    Feng, Xia-Ting; Xu, Hong; Qiu, Shi-Li; Li, Shao-Jun; Yang, Cheng-Xiang; Guo, Hao-Sen; Cheng, Yuan; Gao, Yao-Hui

    2018-04-01

    To study rock spalling in deep tunnels at China Jinping Underground Laboratory Phase II (CJPL-II), photogrammetry method and digital borehole camera were used to quantify key features of rock spalling including orientation, thickness of slabs and the depth of spalling. The failure mechanism was analysed through scanning electron microscope and numerical simulation based on FLAC3D. Observation results clearly showed the process of rock spalling failure: a typical spalling pattern around D-shaped tunnels after top-heading and bottom bench were discovered. The orientation and thickness of the slabs were obtained. The slabs were parallel to the excavated surfaces of the tunnel and were related to the shape of the tunnel surface and orientation of the principal stress. The slabs were alternately thick and thin, and they gradually increased in thickness from the sidewall inwards. The form and mechanism of spalling at different locations in the tunnels, as influenced by stress state and excavation, were analysed. The result of this study was helpful to those rethinking the engineering design, including the excavation and support of tunnels, or caverns, at high risk of spalling.

  15. Improving the behavior of concrete exposed to fire by using an air entraining agent (AEA: Assessment of spalling

    Directory of Open Access Journals (Sweden)

    D'Aloia L.

    2013-09-01

    Full Text Available Several concrete mixes have been designed to evaluate the influence of an air entraining agent (AEA on spalling. Tests have been performed under the ISO curve (occasionally under the HCinc curve on specimens of various sizes and shapes to assess spalling. Results were somehow erratic on the smallest specimens whereas the beneficial effect of the air-bubble network could be emphasized on slabs.

  16. Variability in dynamic properties of tantalum : spall, attenuation and load/unload.

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Reinhart, William Dodd; Trott, Wayne Merle; Vogler, Tracy John; Chhabildas, Lalit Chandra

    2005-07-01

    A suite of impact experiments was conducted to assess spatial and shot-to-shot variability in dynamic properties of tantalum. Samples had a uniform refined {approx}20 micron grain structure with a strong axisymmetric [111] crystallographic texture. Two experiments performed with sapphire windows (stresses of approximately 7 and 12 GPa) clearly showed elastic-plastic loading and slightly hysteretic unloading behavior. An HEL amplitude of 2.8 GPa (corresponding to Y 1.5 GPa) was observed. Free-surface spall experiments showed clear wave attenuation and spallation phenomena. Here, loading stresses were {approx} 12.5 GPa and various ratios of impactor to target thicknesses were used. Spatial and shot-to-shot variability of the spall strength was {+-} 20%, and of the HEL, {+-} 10%. Experiments conducted with smaller diameter flyer plates clearly showed edge effects in the line and point VISAR records, indicating lateral release speeds of roughly 5 km/s.

  17. Spall wave-profile and shock-recovery experiments on depleted uranium

    International Nuclear Information System (INIS)

    Hixson, R.S.; Vorthman, J.E.; Gustavsen, R.L.; Zurek, A.K.; Thissell, W.R.; Tonks, D.L.

    1998-01-01

    Depleted Uranium of two different purity levels has been studied to determine spall strength under shock wave loading. A high purity material with approximately 30 ppm of carbon impurities was shock compressed to two different stress levels, 37 and 53 kbar. The second material studied was uranium with about 300 ppm of carbon impurities. This material was shock loaded to three different final stress level, 37, 53, and 81 kbar. Two experimental techniques were used in this work. First, time-resolved free surface particle velocity measurements were done using a VISAR velocity interferometer. The second experimental technique used was soft recovery of samples after shock loading. These two experimental techniques will be briefly described here and VISAR results will be shown. Results of the spall recovery experiments and subsequent metallurgical analyses are described in another paper in these proceedings. copyright 1998 American Institute of Physics

  18. Review on the prevailing methods for the prediction of potential rock burst / rock spalling in tunnels

    OpenAIRE

    Panthi, Krishna Kanta

    2017-01-01

    Rock burst / rock spalling is among the prevailing stability challenges, which can be met while tunneling through hard rock mass. Especially, this is very relevant for the mountainous country like Norway where hard rock is dominating and many road, railway and hydropower tunnels have to be aligned deep into the mountain with steep valley slope topography. Tunnels passing beneath deep rock cover (overburden), in general, are subjected to high in-situ stresses. If the rock mass is relatively un...

  19. Modeling Dynamic Anisotropic Behaviour and Spall Failure in Commercial Aluminium Alloys AA7010

    Science.gov (United States)

    Mohd Nor, M. K.; Ma'at, N.; Ho, C. S.

    2018-04-01

    This paper presents a finite strain constitutive model to predict a complex elastoplastic deformation behaviour involves very high pressures and shockwaves in orthotropic materials of aluminium alloys. The previous published constitutive model is used as a reference to start the development in this work. The proposed formulation that used a new definition of Mandel stress tensor to define Hill's yield criterion and a new shock equation of state (EOS) of the generalised orthotropic pressure is further enhanced with Grady spall failure model to closely predict shockwave propagation and spall failure in the chosen commercial aluminium alloy. This hyperelastic-plastic constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM's version, named Material Type 92 (Mat92). The implementations of a new EOS of the generalised orthotropic pressure including the spall failure are also discussed in this paper. The capability of the proposed constitutive model to capture the complex behaviour of the selected material is validated against range of Plate Impact Test data at 234, 450 and 895 ms-1 impact velocities.

  20. Spall strength and ejecta production of gold under explosively driven shock wave compression

    International Nuclear Information System (INIS)

    La Lone, B. M.; Stevens, G. D.; Turley, W. D.; Veeser, L. R.; Holtkamp, D. B.

    2013-01-01

    Explosively driven shock wave experiments were conducted to characterize the spall strength and ejecta production of high-purity cast gold samples. The samples were from 0.75 to 1.84 mm thick and 30 mm in diameter. Peak stresses up to 44 GPa in gold were generated using PBX-9501 high explosive. Sample free surface and ejecta velocities were recorded using photonic Doppler velocimetry techniques. Lithium niobate pins were used to quantify the time dependence of the ejecta density and the total ejected mass. An optical framing camera for time-resolved imaging and a single-image x-ray radiograph were used for additional characterization. Free surface velocities exhibited a range of spall strengths from 1.7 to 2.4 GPa (mean: 2.0 ±0.3 GPa). The pullback signals were faint, minimal ringing was observed in the velocity records, and the spall layer continued to decelerate after first pull back. These results suggest finite tensile strength was present for some time after the initial void formation. Ejecta were observed for every sample with a roughened free surface, and the ejecta density increased with increased surface roughness, which was different in every experiment. The total ejected mass is consistent with the missing mass model.

  1. Modelling Dynamic Behaviour and Spall Failure of Aluminium Alloy AA7010

    Science.gov (United States)

    Ma'at, N.; Nor, M. K. Mohd; Ismail, A. E.; Kamarudin, K. A.; Jamian, S.; Ibrahim, M. N.; Awang, M. K.

    2017-10-01

    A finite strain constitutive model to predict the dynamic deformation behaviour of Aluminium Alloy 7010 including shockwaves and spall failure is developed in this work. The important feature of this newly hyperelastic-plastic constitutive formulation is a new Mandel stress tensor formulated using new generalized orthotropic pressure. This tensor is combined with a shock equation of state (EOS) and Grady spall failure. The Hill’s yield criterion is adopted to characterize plastic orthotropy by means of the evolving structural tensors that is defined in the isoclinic configuration. This material model was developed and integration into elastic and plastic parts. The elastic anisotropy is taken into account through the newly stress tensor decomposition of a generalized orthotropic pressure. Plastic anisotropy is considered through yield surface and an isotropic hardening defined in a unique alignment of deviatoric plane within the stress space. To test its ability to describe shockwave propagation and spall failure, the new material model was implemented into the LLNL-DYNA3D code of UTHM’s. The capability of this newly constitutive model were compared against published experimental data of Plate Impact Test at 234m/s, 450m/s and 895m/s impact velocities. A good agreement is obtained between experimental and simulation in each test.

  2. The characteristics of void distribution in spalled high purity copper cylinder under sweeping detonation

    Science.gov (United States)

    Yang, Yang; Jiang, Zhi; Chen, Jixinog; Guo, Zhaoliang; Tang, Tiegang; Hu, Haibo

    2018-03-01

    The effects of different peak compression stresses (2-5 GPa) on the spallation behaviour of high purity copper cylinder during sweeping detonation were examined by Electron Backscatter Diffraction Microscopy, Doppler Pins System and Optical Microscopy techniques. The velocity history of inner surface and the characteristics of void distributions in spalled copper cylinder were investigated. The results indicated that the spall strength of copper in these experiments was less than that revealed in previous reports concerning plate impact loading. The geometry of cylindrical copper and the obliquity of incident shock during sweeping detonation may be the main reasons. Different loading stresses seemed to be responsible for the characteristics of the resultant damage fields, and the maximum damage degree increased with increasing shock stress. Spall planes in different cross-sections of sample loaded with the same shock stress of 3.29 GPa were found, and the distance from the initiation end has little effect on the maximum damage degree (the maximum damage range from 12 to 14%), which means that the spallation behaviour was stable along the direction parallel to the detonation propagation direction under the same shock stress.

  3. Failure Modes in Concrete Repair Systems due to Ongoing Corrosion

    Directory of Open Access Journals (Sweden)

    Mladena Luković

    2017-01-01

    Full Text Available Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. It can result in cracking and spalling of the concrete cover. After the damaged cover is repaired, reinforcement corrosion might continue and even accelerate. While the development of the corrosion cell is difficult to control, the damage can be possibly delayed and controlled by use of a suitable repair material. The lattice fracture model is used in this paper to investigate the performance of strain hardening cementitious composite (SHCC in concrete repair systems exposed to ongoing corrosion. Numerical results were verified by experimental tests when SHCC, nonreinforced material (repair mortar, and commercial repair mortar are used as repair materials. In experiments, reinforcement bars (surrounded by a repair material were exposed to accelerated corrosion tests. The influence of the substrate surface preparation, the type of repair material, the interface, and the substrate strength on the resulting damage and failure mode of repair systems are discussed. In general, SHCC repair enables distributed cracking with small crack widths, up to several times smaller compared to repair mortar. Furthermore, more warning signs prior to the final failure are present in the SHCC repair system.

  4. Spalling fracture of metals and alloys under intense x-radiation

    International Nuclear Information System (INIS)

    Molitvin, A.M.

    2001-01-01

    Creation of different power and irradiating installations assisted in studying mechanical properties of structural materials under the effect of high-power radiation fluxes: laser, electron, X-ray, ion beam etc. There are being widely investigated such phenomena as surface and deep hardening of metals and alloys under irradiation, generation of elastic and shock waves, materials failure under thermal shock etc.In the paper there are discussed the results of long researches of spalling fracture of materials and alloys under intense X-radiation. Model assemblies with consequently arranged samples (foils) of metals and alloys under investigation underwent pulse X-radiation. The energy flux of X-radiation was weakened to the needed value by dose filters intensively absorbing soft spectrum of X-radiation. At carrying out the researches the foils of copper, nickel, titanium, brass, bronze, molybdenum, tungsten, tantalum, cadmium, lead, zinc, silver and steels 0.005-1 mm thick were used as objects under investigation. The samples diameter (10-16 mm) was chosen to be quite large as compared to their thickness so that the side load does not affect the central part of the samples and the front (looking the source of X-radiation) and back (shadow) surfaces of the samples are free what makes it possible to consider the processes of spalling fracture in one-dimensional approximation. Within the frames of kinetic approach to the problem of solid states spalling fracture under pulse loading that considers fracture as progressing in time process there were found spalling fracture time dependencies of lead, cadmium, zinc, silver, copper, brass, bronze, nickel, titanium, molybdenum, tungsten, tantalum and steels under thermal shock initiated by X-radiation. It was demonstrated that longevity of metals and alloys under thermal shock exponentially decreases with the growth of rupture stresses amplitude and can be described in terms of kinetic concept of strength.Within the frames of

  5. Microstructural Effects on the Spall Properties of ECAE-Processed AZ31B Magnesium Alloy

    Science.gov (United States)

    2016-10-01

    stresses using 51 mm and 105 mm bore gas guns . The Hugoniot Elastic Limit (HEL) was measured to be approximately 181 ± 3 MPa. The spall strengths...MD 21218, USA b Institute of Shock Physics, Imperial College London, London SW7 2AZ, UK c U.S. Army Research Laboratory, Aberdeen Proving Ground, MD...21005, USA d Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA A R T I C L E I N F O Article history: Received

  6. A survey of high explosive-induced damage and spall in selected metals using proton radiography

    International Nuclear Information System (INIS)

    Holtkamp, D.B.; Clark, D.A.; Ferm, E.N.; Gallegos, R.A.; Hammon, D.; Hemsing, W.F.; Hogan, G.E.; Holmes, V.H.; King, N.S.P.; Lopez, R.P.; Merrill, F.E.; Morris, C.L.; Morley, K.B.; Murray, M.M.; Pazuchanics, P.D.; Prestridge, K.P.; Quintana, J.P.; Saunders, A.; Shinas, M.A.; Stacy, H.L.

    2004-01-01

    Multiple spall and damage layers can be created in metal when the free surface reflects a Taylor wave generated by high explosives. These phenomena have been explored in different thicknesses of several metals (tantalum, copper, 6061 T6-aluminum, and tin) using high-energy proton radiography. Multiple images (up to 21) can be produced of the dynamic evolution of damaged material on the microsecond time scale with a <50 ns 'shutter' time. Movies and multiframe still images of areal and (Abel inverted) volume densities are presented. An example of material that is likely melted on release (tin) is also presented

  7. Study of flow stress and spall strength of additively manufactured Ti-6-4 alloy

    Science.gov (United States)

    Cohen, Amitay; Paris, Vitaly; Yosef-Hai, Arnon; Gudinetsky, Eli; Tiferet, Eitan

    2017-06-01

    The use of additive manufacturing (AM) by Electron Beam Melting (EBM) or Selective Laser Melting (SLM) has extensively grown in the past few years. A major goal in AM is to manufacture materials with mechanical properties at least as good as traditionally manufactured materials. In this work we present results of planar impact tests and Split Hopkinson Pressure Bar tests (SHPB) on Ti-6-4 manufactured by EBM and SLM processes. Results of planar impact tests on SLM samples display slightly higher spall strength compared to EBM while the stress at Hugoniot elastic limit (HEL) is practically the same. Stress strain curves based on SHPB measurements at two different strain rates present similar plastic flow stresses for SLM and EBM processed Ti-6-4 alloy, while the flow stress is about 20% higher than reported for commercial reference material. The strain to failure of both materials shows considerable strain rate sensitivity. The results of post-mortem analysis of spall fracture will also be presented.

  8. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Martini, R., E-mail: roberto.martini@imec.be [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Kepa, J.; Stesmans, A. [Department of Physics, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven (Belgium); Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Poortmans, J. [Department of Electrical Engineering, KU Leuven, Kasteelpark 10, 3001 Leuven (Belgium); imec, Kapeldreef 75, 3001 Leuven (Belgium); Universiteit Hasselt, Martelarenlaan 42, B-3500 Hasselt (Belgium)

    2014-10-27

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  9. Thin silicon foils produced by epoxy-induced spalling of silicon for high efficiency solar cells

    International Nuclear Information System (INIS)

    Martini, R.; Kepa, J.; Stesmans, A.; Debucquoy, M.; Depauw, V.; Gonzalez, M.; Gordon, I.; Poortmans, J.

    2014-01-01

    We report on the drastic improvement of the quality of thin silicon foils produced by epoxy-induced spalling. In the past, researchers have proposed to fabricate silicon foils by spalling silicon substrates with different stress-inducing materials to manufacture thin silicon solar cells. However, the reported values of effective minority carrier lifetime of the fabricated foils remained always limited to ∼100 μs or below. In this work, we investigate epoxy-induced exfoliated foils by electron spin resonance to analyze the limiting factors of the minority carrier lifetime. These measurements highlight the presence of disordered dangling bonds and dislocation-like defects generated by the exfoliation process. A solution to remove these defects compatible with the process flow to fabricate solar cells is proposed. After etching off less than 1 μm of material, the lifetime of the foil increases by more than a factor of 4.5, reaching a value of 461 μs. This corresponds to a lower limit of the diffusion length of more than 7 times the foil thickness. Regions with different lifetime correlate well with the roughness of the crack surface which suggests that the lifetime is now limited by the quality of the passivation of rough surfaces. The reported values of the minority carrier lifetime show a potential for high efficiency (>22%) thin silicon solar cells.

  10. DNA repair

    International Nuclear Information System (INIS)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals

  11. DRSPALL: Impact of the Modification of the Numerical Spallings Model on Waste Isolation Pilot Plant Performance Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Kicker, Dwayne Curtis [Stoller Newport News Nuclear, Inc., Carlsbad, NM (United States); Herrick, Courtney G. [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Zeitler, Todd [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Malama, Bwalya [Sandia National Lab. (SNL-NM), Carlsbad, NM (United States); Rudeen, David Keith [GRAM Inc., Albuquerque, NM (United States); Gilkey, Amy P. [GRAM Inc., Albuquerque, NM (United States)

    2016-01-01

    The numerical code DRSPALL (from direct release spallings) is written to calculate the volume of Waste Isolation Pilot Plant (WIPP) solid waste subject to material failure and transport to the surface as a result of a hypothetical future inadvertent drilling intrusion. An error in the implementation of the DRSPALL finite difference equations was discovered as documented in Software Problem Report (SPR) 13-001. The modifications to DRSPALL to correct the finite difference equations are detailed, and verification and validation testing has been completed for the modified DRSPALL code. The complementary cumulative distribution function (CCDF) of spallings releases obtained using the modified DRSPALL is higher compared to that found in previous WIPP performance assessment (PA) calculations. Compared to previous PAs, there was an increase in the number of vectors that result in a nonzero spallings volume, which generally translates to an increase in spallings releases. The overall mean CCDFs for total releases using the modified DRSPALL are virtually unchanged, thus the modification to DRSPALL did not impact WIPP PA calculation results.

  12. The impact of the amount of polypropylene fibres on spalling behaviour and residual mechanical properties of Reactive Powder Concretes

    Directory of Open Access Journals (Sweden)

    Hager I.

    2013-09-01

    Full Text Available In this paper, an experimental study on the spalling behaviour and mechanical properties of Reactive Powder Concretes (RPCs in high temperature are presented. The research program was established to evaluate the impact of low melting temperature polypropylene fibres PP on mechanical properties evolution with temperature but also to verify the effectiveness of their addition to prevent spalling. Three sets of RPC specimens were prepared for this study with different amount of PP fibres (no fibres, 1.0 kg/m3 and 2.0 kg/m3. The addition of PP fibres reduces the initial compressive strength of the RPC material by approx. 14% no significant influence on modulus of elasticity was observed. Addition of 1 kg/m3 of PP fibres in RPC, seem not to give a sufficient protection against occurrence of spalling phenomenon. By adding 2 kg/m3 of PP fibres the risk of spalling is significantly reduced.

  13. ZrCuAl Bulk Metallic Glass spall induced by laser shock

    Science.gov (United States)

    Jodar, Benjamin; Loison, Didier; Yokoyama, Yoshihiko; Lescoute, Emilien; Berthe, Laurent; Sangleboeuf, Jean-Christophe

    2017-06-01

    To face High Velocity Impacts, the aerospace industry is always seeking for innovative materials usable as debris shielding components. Bulk Metallic Glasses (BMG) revealed interesting mechanical properties in case of static and quasi-static loading conditions: high elasticity, high tenacity, low density and high fracture threshold... The department of Mechanics and Glass of the Institut of Physics Rennes conducted on the ELFIE facility, laser shock experiments to study the behavior of a ternary ZrCuAl BMG under high strain rate, up-to fragmentation process. On the one hand, in-situ diagnostics were used to measure ejection velocities with PDV and debris morphologies were observed by Shadowgraphy. On the other hand, spalled areas (dimensions and features) were characterized through post-mortem analysis (optical observations, profilometry and SEM). These results are compared to experimental and numerical data on the crystalline forms of the ZrCuAl basic compounds.

  14. Modeling of thermal spalling during electrical discharge machining of titanium diboride

    International Nuclear Information System (INIS)

    Gadalla, A.M.; Bozkurt, B.; Faulk, N.M.

    1991-01-01

    Erosion in electrical discharge machining has been described as occurring by melting and flushing the liquid formed. Recently, however, thermal spalling was reported as the mechanism for machining refractory materials with low thermal conductivity and high thermal expansion. The process is described in this paper by a model based on a ceramic surface exposed to a constant circular heating source which supplied a constant flux over the pulse duration. The calculations were based on TiB 2 mechanical properties along a and c directions. Theoretical predictions were verified by machining hexagonal TiB 2 . Large flakes of TiB 2 with sizes close to grain size and maximum thickness close to the predicted values were collected, together with spherical particles of Cu and Zn eroded from cutting wire. The cutting surfaces consist of cleavage planes sometimes contaminated with Cu, Zn, and impurities from the dielectric fluid

  15. Twin boundary spacing effects on shock response and spall behaviors of hierarchically nanotwinned fcc metals

    International Nuclear Information System (INIS)

    Yuan, Fuping; Chen, Liu; Jiang, Ping; Wu, Xiaolei

    2014-01-01

    Atomistic deformation mechanisms of hierarchically nano-twinned (NT) Ag under shock conditions have been investigated using a series of large-scale molecular dynamics simulations. For the same grain size d and the same spacing of primary twins λ 1 , the average flow stress behind the shock front in hierarchically NT Ag first increases with decreasing spacing of secondary twins λ 2 , achieving a maximum at a critical λ 2 , and then drops as λ 2 decreases further. Above the critical λ 2 , the deformation mechanisms are dominated by three type strengthening mechanisms: (a) partial dislocations emitted from grain boundaries (GBs) travel across other boundaries; (b) partial dislocations emitted from twin boundaries (TBs) travel across other TBs; (c) formation of tertiary twins. Below the critical λ 2 , the deformation mechanism are dominated by two softening mechanisms: (a) detwinning of secondary twins; (b) formation of new grains by cross slip of partial dislocations. Moreover, the twin-free nanocrystalline (NC) Ag is found to have lower average flow stress behind the shock front than those of all hierarchically NT Ag samples except the one with the smallest λ 2 of 0.71 nm. No apparent correlation between the spall strength and λ 2 is observed in hierarchically NT Ag, since voids always nucleate at both GBs and boundaries of the primary twins. However, twin-free NC Ag is found to have higher spall strength than hierarchically NT Ag. Voids can only nucleate from GBs for twin-free NC Ag, therefore, twin-free NC Ag has less nucleation sources along the shock direction when compared to hierarchically NT Ag, which requiring higher tensile stress to create spallation. These findings should contribute to the understandings of deformation mechanisms of hierarchically NT fcc metals under extreme deformation conditions

  16. On the mechanism of polypropylene fibres in preventing fire spalling in self-compacting and high-performance cement paste

    International Nuclear Information System (INIS)

    Liu, X.; Ye, G.; De Schutter, G.; Yuan, Y.; Taerwe, L.

    2008-01-01

    With the increasing application of self-compacting concrete (SCC) in construction and infrastructure, the fire spalling behavior of SCC has been attracting due attention. In high performance concrete (HPC), addition of polypropylene fibers (PP fibers) is widely used as an effective method to prevent explosive spalling. Hence, it would be useful to investigate whether the PP fibers are also efficient in SCC to avoid explosive spalling. However, no universal agreement exists concerning the fundamental mechanism of reducing the spalling risk by adding PP fiber. For SCC, the reduction of flowability should be considered when adding a significant amount of fibres. In this investigation, both the micro-level and macro-level properties of pastes with different fiber contents were studied in order to investigate the role of PP fiber at elevated temperature in self-compacting cement paste samples. The micro properties were studied by backscattering electron microscopy (BSE) and mercury intrusion porosimetry (MIP) tests. The modification of the pore structure at elevated temperature was investigated as well as the morphology of the PP fibers. Some macro properties were measured, such as the gas permeability of self-compacting cement paste after heating at different temperatures. The factors influencing gas permeability were analyzed. It is shown that with the melting of PP fiber, no significant increase in total pore volume is obtained. However, the connectivity of isolated pores increases, leading to an increase of gas permeability. With the increase of temperature, the addition of PP fibers reduces the damage of cement pastes, as seen from the total pore volume and the threshold pore diameter changes. From this investigation, it is concluded that the connectivity of pores as well as the creation of micro cracks are the major factors which determine the gas permeability after exposure to high temperatures. Furthermore, the connectivity of the pores acts as a dominant factor

  17. Review and perspectives on spallings release models in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Knowles, M.K.; Hansen, F.D.; Thompson, T.W.; Schatz, J.F.; Gross, M.

    2000-01-01

    The Waste Isolation Pilot Plant was licensed for disposal of transuranic wastes generated by the US Department of Energy. The facility consists of a repository mined in a bedded salt formation, approximately 650 m below the surface. Regulations promulgated by the US Environmental Protection Agency require that performance assessment calculations for the repository include the possibility that an exploratory drilling operation could penetrate the waste disposal areas at some time in the future. Release of contaminated solids could reach the surface during a drilling intrusion. One of the mechanisms for release, known as spallings, can occur if gas pressures in the repository exceed the hydrostatic pressure of a column of drilling mud. Calculation of solids releases for spallings depends critically on the conceptual models for the waste, for the spallings process, and assumptions regarding driller parameters and practices. This paper presents a review of the evolution of these models during the regulatory review of the Compliance Certification Application for the repository. A summary and perspectives on the implementation of conservative assumptions in model development are also provided

  18. Review and perspectives on spallings release models in the 1996 performance assessment for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Knowles, M.K; Hansen, F.D.; Thompson, T.W.; Schatz, J.F.; Gross, M.

    2000-01-01

    The Waste Isolation Pilot Plant was licensed for disposal of transuranic wastes generated by the US Department of Energy. The facility consists of a repository mined in a bedded salt formation, approximately 650 m below the surface. Regulations promulgated by the US Environmental Protection Agency require that performance assessment calculations for the repository include the possibility that an exploratory drilling operation could penetrate the waste disposal areas at some time in the future. Release of contaminated solids could reach the surface during a drilling intrusion. One of the mechanisms for release, known as spallings, can occur if gas pressures in the repository exceed the hydrostatic pressure of a column of drilling mud. Calculation of solids releases for spallings depends critically on the conceptual models for the waste, for the spallings process, and assumptions regarding driller parameters and practices. The paper presents a review of the evolution of these models during regulatory review of the Compliance Certification Application for the repository. A summary and perspectives on the implementation of conservative assumptions in model development are also provided

  19. Description and evaluation of a mechanistically based conceptual model for spall

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, F.D.; Knowles, M.K.; Thompson, T.W. [and others

    1997-08-01

    A mechanistically based model for a possible spall event at the WIPP site is developed and evaluated in this report. Release of waste material to the surface during an inadvertent borehole intrusion is possible if future states of the repository include high gas pressure and waste material consisting of fine particulates having low mechanical strength. The conceptual model incorporates the physics of wellbore hydraulics coupled to transient gas flow to the intrusion borehole, and mechanical response of the waste. Degraded waste properties using of the model. The evaluations include both numerical and analytical implementations of the conceptual model. A tensile failure criterion is assumed appropriate for calculation of volumes of waste experiencing fragmentation. Calculations show that for repository gas pressures less than 12 MPa, no tensile failure occurs. Minimal volumes of material experience failure below gas pressure of 14 MPa. Repository conditions dictate that the probability of gas pressures exceeding 14 MPa is approximately 1%. For these conditions, a maximum failed volume of 0.25 m{sup 3} is calculated.

  20. Spall strength, dynamic elastic limit and fracture of ittrya dopped tetragonal zirconia

    Science.gov (United States)

    Milyavskiy, Vladimir; Savinykh, Andrey; Schlothauer, Thomas; Lukin, Evgeny; Akopov, Felix

    2013-06-01

    Specimens of the ceramics based on zirconia partially stabilized by yttrium oxide of the composition of 97 mol % ZrO2 + 3 mol % Y2O3 were prepared. The densities of the specimens were 5.79 and 6.01 g/cc. The ceramics mainly have the tetragonal structure (93-98 wt. % of t-ZrO2) . The mechanical action on the ceramic activates the transformation of the tetragonal phase into the monoclinic one: at the abrasive cutting or at the fracture by hammer shock, the content of the monoclinic phase is increasing. The same trend was observed in the specimens, recovered after stepwise shock compression up to 36, 52 and 99 GPa. It was found that shock compression do not initiates tetragonal-monoclinic phase transition directly, and this transition is caused by the destruction. Recovered specimens do not reveal any traces of the phase change which was observed by Mashimo et al. under the pressures 30-35 GPa (J. Appl. Phys. 1995. V. 77. P. 5069). Recording of the profiles of the free surface velocity of the specimens during single-stage shock compression allowed us to determine the dynamic elastic limit, as well as spall strength of the material versus maximal shock stress. In addition, the ceramics were subjected to the action of low temperatures. There were no significant changes in the specimens recovered after storage in liquid nitrogen and helium. The work was supported by The State Atomic Energy Corporation ROSATOM.

  1. Description and evaluation of a mechanistically based conceptual model for spall

    International Nuclear Information System (INIS)

    Hansen, F.D.; Knowles, M.K.; Thompson, T.W.

    1997-08-01

    A mechanistically based model for a possible spall event at the WIPP site is developed and evaluated in this report. Release of waste material to the surface during an inadvertent borehole intrusion is possible if future states of the repository include high gas pressure and waste material consisting of fine particulates having low mechanical strength. The conceptual model incorporates the physics of wellbore hydraulics coupled to transient gas flow to the intrusion borehole, and mechanical response of the waste. Degraded waste properties using of the model. The evaluations include both numerical and analytical implementations of the conceptual model. A tensile failure criterion is assumed appropriate for calculation of volumes of waste experiencing fragmentation. Calculations show that for repository gas pressures less than 12 MPa, no tensile failure occurs. Minimal volumes of material experience failure below gas pressure of 14 MPa. Repository conditions dictate that the probability of gas pressures exceeding 14 MPa is approximately 1%. For these conditions, a maximum failed volume of 0.25 m 3 is calculated

  2. Prevalent material parameters governing spalling of a slag-impregnated refractory

    Energy Technology Data Exchange (ETDEWEB)

    Blond, E.; Schmitt, N.; Arnould, O.; Hild, F. [LMT-Cachan (ENS de Cachan / CNRS-UMR 8535 / Univ. Paris 6), Cachan (France); Blumenfeld, P. [CRDM / ARCELOR Grande Synthe, Dunkerque (France); Poirier, J. [CRDM / ARCELOR Grande Synthe, Dunkerque (France); CRMHT-CNRS, Orleans (France)

    2004-07-01

    In steel ladle linings, bauxite refractories in contact with iron and steel slag are subjected to complex loadings. To identify the causes of degradation in different reactor linings, a coupling diagram made up of three poles is established: namely, slag impregnation (I), Thermomechanics (TM) and phase transformations (P). The variation of the microstructure and the gradient of the chemical composition resulting from the (I-P) coupling are characterized by microprobe analyses; a natural impregnation tracer is identified. The (I-T) coupling is studied by modeling the refractory lining behavior subjected to a cyclic thermal loading within the framework of the mechanics of porous continua. Parameters governing the location and amplitude of the maximum pore pressure are obtained and their influences are studied. The analysis of the (TM) pole leads to the identification of a thermo-elasto-viscoplastic model for bauxite in various states of slag impregnation. Numerical simulations show that the stress state developed during the heating stages can induce spalling, probably generated by a localized over-pressure of slag. (orig.)

  3. Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

    Directory of Open Access Journals (Sweden)

    Yaw ChiaHwan

    2014-01-01

    Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

  4. Multibillion-atom Molecular Dynamics Simulations of Plasticity, Spall, and Ejecta

    Science.gov (United States)

    Germann, Timothy C.

    2007-06-01

    Modern supercomputing platforms, such as the IBM BlueGene/L at Lawrence Livermore National Laboratory and the Roadrunner hybrid supercomputer being built at Los Alamos National Laboratory, are enabling large-scale classical molecular dynamics simulations of phenomena that were unthinkable just a few years ago. Using either the embedded atom method (EAM) description of simple (close-packed) metals, or modified EAM (MEAM) models of more complex solids and alloys with mixed covalent and metallic character, simulations containing billions to trillions of atoms are now practical, reaching volumes in excess of a cubic micron. In order to obtain any new physical insights, however, it is equally important that the analysis of such systems be tractable. This is in fact possible, in large part due to our highly efficient parallel visualization code, which enables the rendering of atomic spheres, Eulerian cells, and other geometric objects in a matter of minutes, even for tens of thousands of processors and billions of atoms. After briefly describing the BlueGene/L and Roadrunner architectures, and the code optimization strategies that were employed, results obtained thus far on BlueGene/L will be reviewed, including: (1) shock compression and release of a defective EAM Cu sample, illustrating the plastic deformation accompanying void collapse as well as the subsequent void growth and linkup upon release; (2) solid-solid martensitic phase transition in shock-compressed MEAM Ga; and (3) Rayleigh-Taylor fluid instability modeled using large-scale direct simulation Monte Carlo (DSMC) simulations. I will also describe our initial experiences utilizing Cell Broadband Engine processors (developed for the Sony PlayStation 3), and planned simulation studies of ejecta and spall failure in polycrystalline metals that will be carried out when the full Petaflop Opteron/Cell Roadrunner supercomputer is assembled in mid-2008.

  5. Localized atomic segregation in the spalled area of a Zr50Cu40Al10 bulk metallic glasses induced by laser-shock experiment

    Science.gov (United States)

    Jodar, B.; Loison, D.; Yokoyama, Y.; Lescoute, E.; Nivard, M.; Berthe, L.; Sangleboeuf, J.-C.

    2018-02-01

    Laser-shock experiments were performed on a ternary {Zr50{Cu}40{Al}10} bulk metallic glass. A spalling process was studied through post-mortem analyses conducted on a recovered sample and spall. Scanning electron microscopy magnification of fracture surfaces revealed the presence of a peculiar feature known as cup-cone. Cups are found on sample fracture surface while cones are observed on spall. Two distinct regions can be observed on cups and cones: a smooth viscous-like region in the center and a flat one with large vein-pattern in the periphery. Energy dispersive spectroscopy measurements conducted on these features emphasized atomic distribution discrepancies both on the sample and spall. We propose a mechanism for the initiation and the growth of these features but also a process for atomic segregation during spallation. Cup and cones would originate from cracks arising from shear bands formation (softened paths). These shear bands result from a quadrupolar-shaped atomic disorder engendered around an initiation site by shock wave propagation. This disorder turns into a shear band when tensile front reaches spallation plane. During the separation process, temperature gain induced by shock waves and shear bands generation decreases material viscosity leading to higher atomic mobility. Once in a liquid-like form, atomic clusters migrate and segregate due to inertial effects originating from particle velocity variation (interaction of release waves). As a result, a high rate of copper is found in sample cups and high zirconium concentration is found on spall cones.

  6. Meningocele repair

    Science.gov (United States)

    ... is surgery to repair birth defects of the spine and spinal membranes. Meningocele and myelomeningocele ... is covered by a sterile dressing. Your child may then be transferred to a neonatal intensive ...

  7. Spalling behavior and residual resistance of fibre reinforced Ultra-High performance concrete after exposure to high temperatures

    Directory of Open Access Journals (Sweden)

    Xiong, Ming-Xiang

    2015-12-01

    Full Text Available Experimental results of spalling and residual mechanical properties of ultra-high performance concrete after exposure to high temperatures are presented in this paper. The compressive strength of the ultra-high performance concrete ranged from 160 MPa~185 MPa. This study aimed to discover the effective way to prevent spalling for the ultra-high performance concrete and gauge its mechanical properties after it was subjected to fire. The effects of fiber type, fiber dosage, heating rate and curing condition were investigated. Test results showed that the compressive strength and elastic modulus of the ultra-high performance concrete declined slower than those of normal strength concrete after elevated temperatures. Polypropylene fiber rather than steel fiber was found effective to prevent spalling but affected workability. The effective fiber type and dosage were recommended to prevent spalling and ensure sufficient workability for casting and pumping of the ultra-high performance concrete.En este trabajo se presentan los resultados más relevantes del trabajo experimental realizado para valorar la laminación y las propiedades mecánicas residuales de hormigón de ultra-altas prestaciones tras su exposición a altas temperaturas. La resistencia a la compresión del hormigón de ultra-altas prestaciones osciló entre 160 MPa~185 MPa. El objetivo de este estudio fue descubrir una manera eficaz de prevenir desprendimientos y/o laminaciones en este hormigón y medir sus propiedades mecánicas después de ser sometido al fuego. Las variables estudiadas fueron la presencia y dosificación de fibras, velocidad de calentamiento y condiciones de curado. Los resultados mostraron, tras la exposición a altas temperaturas, que la resistencia a compresión y el módulo de elasticidad del hormigón de ultra-altas prestaciones disminuían más lento que las de un hormigón con resistencia normal. La fibra de polipropileno resultó más eficaz para prevenir

  8. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: cuttings, cavings and spallings

    International Nuclear Information System (INIS)

    Berglund, J.W.; Garner, J.W.; Helton, J.C.; Johnson, J.D.; Smith, L.N.

    2000-01-01

    The following topics related to the treatment of cuttings, cavings and spallings releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (i) mathematical description of models; (ii) uncertainty and sensitivity analysis results arising from subjective (i.e. epistemic) uncertainty for individual releases; (iii) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e. aleatory) uncertainty; and (iv) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that direct releases due to cuttings, cavings and spallings do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for cuttings, cavings and spallings releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency's standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

  9. Direct releases to the surface and associated complementary cumulative distribution functions in the 1996 performance assessment for the Waste Isolation Pilot Plant: Cuttings, cavings and spallings

    International Nuclear Information System (INIS)

    Berglund, J.W.; Garner, J.W.; Helton, Jon Craig; Johnson, J.D.; Smith, L.N.; Anderson, R.P.

    2000-01-01

    The following topics related to the treatment of cuttings, cavings and spallings releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (1) mathematical description of models. (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that direct releases due to cuttings, cavings and spallings do not constitute a serious threat to the effectiveness of the WIPP as a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for cuttings, cavings and spallings releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194)

  10. DNA repair

    International Nuclear Information System (INIS)

    Van Zeeland, A.A.

    1984-01-01

    In this chapter a series of DNA repair pathways are discussed which are available to the cell to cope with the problem of DNA damaged by chemical or physical agents. In the case of microorganisms our knowledge about the precise mechanism of each DNA repair pathway and the regulation of it has been improved considerably when mutants deficient in these repair mechanisms became available. In the case of mammalian cells in culture, until recently there were very little repair deficient mutants available, because in almost all mammalian cells in culture at least the diploid number of chromosomes is present. Therefore the frequency of repair deficient mutants in such populations is very low. Nevertheless because replica plating techniques are improving some mutants from Chinese hamsters ovary cells and L5178Y mouse lymphoma cells are now available. In the case of human cells, cultures obtained from patients with certain genetic diseases are available. A number of cells appear to be sensitive to some chemical or physical mutagens. These include cells from patients suffering from xeroderma pigmentosum, Ataxia telangiectasia, Fanconi's anemia, Cockayne's syndrome. However, only in the case of xeroderma pigmentosum cells, has the sensitivity to ultraviolet light been clearly correlated with a deficiency in excision repair of pyrimidine dimers. Furthermore the work with strains obtained from biopsies from man is difficult because these cells generally have low cloning efficiencies and also have a limited lifespan in vitro. It is therefore very important that more repair deficient mutants will become available from established cell lines from human or animal origin

  11. The scale constituents and spalling characteristics of Ni-Fe(O-60%) alloys oxidized in air at 800-12000C

    International Nuclear Information System (INIS)

    Tomlinson, W.J.; Gardner, M.J.; Kowalski, R.J.

    1977-01-01

    The spalling behaviour of scales on Ni-Fe alloys containing 0, 2, 10, 20, 30, 40, 50 and 60% Fe oxidized in air at 900, 1000, 1100 and 1200 0 C for periods up to 165 h have been investigated. The phases present and their relative amounts in the scales formed at 1200 0 C have been determined. Spalling was most severe in the Ni-30% Fe alloy, which had a scale consisting of 30% Nisub(x)Fesub(3-x)O 4 and 70% Nisub(1-x)Fesub(x)O. (author)

  12. Repair process and a repaired component

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, III, Herbert Chidsey; Simpson, Stanley F.

    2018-02-20

    Matrix composite component repair processes are disclosed. The matrix composite repair process includes applying a repair material to a matrix composite component, securing the repair material to the matrix composite component with an external securing mechanism and curing the repair material to bond the repair material to the matrix composite component during the securing by the external securing mechanism. The matrix composite component is selected from the group consisting of a ceramic matrix composite, a polymer matrix composite, and a metal matrix composite. In another embodiment, the repair process includes applying a partially-cured repair material to a matrix composite component, and curing the repair material to bond the repair material to the matrix composite component, an external securing mechanism securing the repair material throughout a curing period, In another embodiment, the external securing mechanism is consumed or decomposed during the repair process.

  13. Motorcycle Repair.

    Science.gov (United States)

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  14. Turbine repair process, repaired coating, and repaired turbine component

    Science.gov (United States)

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  15. Computational model of spalling and effective fibers on toughening in fiber reinforced composites at an early stage of crack formation

    Directory of Open Access Journals (Sweden)

    Chong Wang

    Full Text Available This work suggests a computational model that takes account of effective fibers on toughening in FRC at an early stage of crack formation. We derived the distribution of pressure provoked by a random inclined fiber in the matrix and calculated stresses through integrating the pressure and tangent stress along the fiber/matrix interface with the Kelvin's fundamental solution and the Mindlin's complementary solution. The evolution of spalling in the matrix was traced. The percentages of effective fibers were evaluated with variations in strength, interface resistance, diameter and elasticity modulus. The main conclusion is that low elasticity modulus combined high strength of fibers raises dramatically the effective fibers, which would benefit toughening.

  16. Influence of deposited nanoparticles on the spall strength of metals under the action of picosecond pulses of shock compression

    Science.gov (United States)

    Ebel, A. A.; Mayer, A. E.

    2018-01-01

    Molecular dynamic simulations of the generation and propagation of shock pulses of picosecond duration initiated by nanoscale impactors, and their interaction with the rear surface is carried out for aluminum and copper. It is shown that the presence of deposited nanoparticles on the rear surface increases the threshold value of the impact intensity leading to the rear spallation. The interaction of a shock wave with nanoparticles leads to severe plastic deformation in the surface layer of the metal including nanoparticles. A part of the compression pulse energy is expended on the plastic deformation, which suppresses the spall fracture. Spallation threshold substantially increases at large diameters of deposited nanoparticles, but instability develops on the rear surface of the target, which is accompanied by ejection of droplets. The instability disrupts the integrity of the rear surface, though the loss of integrity occurs through the ejection of mass, rather than a spallation.

  17. Effect of fibre orientations on the mechanical properties of kenaf–aramid hybrid composites for spall-liner application

    Institute of Scientific and Technical Information of China (English)

    R. YAHAYA; S.M. SAPUAN; M. JAWAID; Z. LEMAN; E.S. ZAINUDIN

    2016-01-01

    This paper presents the effect of kenaf fibre orientation on the mechanical properties of kenaf–aramid hybrid composites for military vehicle's spall liner application. It was observed that the tensile strength of woven kenaf hybrid composite is almost 20.78%and 43.55%higher than that of UD and mat samples respectively. Charpy impact strength of woven kenaf composites is 19.78%and 52.07%higher than that of UD and mat kenaf hybrid composites respectively. Morphological examinations were carried out using scanning electron microscopy. The results of this study indicate that using kenaf in the form of woven structure could produce a hybrid composite material with high tensile strength and impact resistance properties.

  18. Contribution to the explanation of the spalling of small specimen without any mechanical restraint exposed to high temperature

    International Nuclear Information System (INIS)

    Morais, Marcus V.G. de; Pliya, Prosper; Noumowe, Albert; Beaucour, Anne-Lise; Ortola, Sophie

    2010-01-01

    The behaviour of concrete subjected to high temperature is studied. The aim of the study is to explain the spalling or bursting phenomenon observed during experimental studies in the laboratory. Mechanical computations are carried out with the finite element code CAST3M developed at the French Atomic Energy Agency (CEA). Heat gradient and water vapour pressure inside the concrete element are determined by using a thermo-hydrous model. Then, the mechanical stresses generated in the studied concrete element are calculated according to two behaviour assumptions: the linear isotropic elastic law and an elastoplastic model. Numerical simulations show that, during the heating cycles, tension stresses are developed in the central part and compression stresses at the surface of the cylindrical concrete element. The highest stresses appear when the surface temperature of the concrete element is about 300 o C. The tension stresses in the specimens then exceed the concrete tensile strength.

  19. Contribution to the explanation of the spalling of small specimen without any mechanical restraint exposed to high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Marcus V.G. de, E-mail: mvmorais@unb.b [Cergy-Pontoise University - L2MGC, 5 mail Gay-Lussac Neuville sur Oise, 95031 Cergy-Pontoise Cedex (France); Pliya, Prosper [Cergy-Pontoise University - L2MGC, 5 mail Gay-Lussac Neuville sur Oise, 95031 Cergy-Pontoise Cedex (France); Noumowe, Albert, E-mail: Albert.Noumowe@u-cergy.f [Cergy-Pontoise University - L2MGC, 5 mail Gay-Lussac Neuville sur Oise, 95031 Cergy-Pontoise Cedex (France); Beaucour, Anne-Lise; Ortola, Sophie [Cergy-Pontoise University - L2MGC, 5 mail Gay-Lussac Neuville sur Oise, 95031 Cergy-Pontoise Cedex (France)

    2010-10-15

    The behaviour of concrete subjected to high temperature is studied. The aim of the study is to explain the spalling or bursting phenomenon observed during experimental studies in the laboratory. Mechanical computations are carried out with the finite element code CAST3M developed at the French Atomic Energy Agency (CEA). Heat gradient and water vapour pressure inside the concrete element are determined by using a thermo-hydrous model. Then, the mechanical stresses generated in the studied concrete element are calculated according to two behaviour assumptions: the linear isotropic elastic law and an elastoplastic model. Numerical simulations show that, during the heating cycles, tension stresses are developed in the central part and compression stresses at the surface of the cylindrical concrete element. The highest stresses appear when the surface temperature of the concrete element is about 300 {sup o}C. The tension stresses in the specimens then exceed the concrete tensile strength.

  20. Delineation of spall zone from pre/post shot reflections studies: Preliminary results from BEXAR. Los Alamos Source Region Project

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.R.; Cogbill, A.H.; Weaver, T.A. [Los Alamos National Lab., NM (United States); Miller, R.; Steeples, D. [Kansas Univ., Lawrence, KS (United States)

    1992-12-31

    In order to delineate the lateral and depth extent of spall from a buried nuclear explosion, we have performed a high-resolution pre- and post-shot seismic reflection survey from BEXAR. Although the data quality were marginal due to poor wave propagation through the volcanic tuffs of Pahute Mesa, a number of interesting differences are observed on the pre- and post-shot surveys. On the pre-shot survey, a reflector (reflector `` 1 ``) is observed at 250 ms (or about 150 m depth) using a stacking velocity of 1300 m/s. On the post-shot survey two reflectors are observed and a stacking velocity of 1150 m/s was used representing a 12% reduction in compressional velocity. With this stacking velocity, reflector `` 1 `` is recorded at 290 ms (still at about 150 m depth) and a new reflector ``2`` is observed at 210 ms (or about 100 m depth). These stacking velocities correspond well with available uphole travel times collected in U19ba and nearby U19ax (BEXAR and KEARSARGE emplacement holes, respectively). The cause for the differences observed in the pre- and post-shot surveys may be due to one of two reasons. First, it is possible that the near-surface rocks were damaged as part of the spallation process (thus reducing the in situ velocities) and reflector ``2`` represents a spall detachment surface. However, analysis of acceleration data collected close to the reflection line suggests that the ground motions were probably inadequate to damage the tuffs. Also, no evidence of actual spallation was actually observed. The second hypothesis is that the near-surface velocities of the tuffs were altered by the change in saturation state due to extensive rains occurring between the pre- and postshot surveys. Although the dependence of seismic velocity on saturation state is controlled by a number of complex factors, it cannot be ruled out.

  1. Brain aneurysm repair

    Science.gov (United States)

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  2. Shock-induced mechanical response and spall fracture behavior of an extra-low interstitial grade Ti–6Al–4V alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yu; Wang, Fuchi [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Tan, Chengwen, E-mail: tanchengwen@126.com [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Wang, Shuyou [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Yu, Xiaodong [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China); Jiang, Jianwei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Ma, Honglei [China Astronaut Research and Training Center, Beijing 100094 (China); Cai, Hongnian [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); National Key Laboratory of Science and Technology on Materials Under Shock and Impact, Beijing Institute of Technology, Beijing 100081 (China)

    2013-08-20

    The mechanical response and spall fracture behavior of an extra-low interstitial (ELI) grade Ti–6Al–4V alloy are systemically investigated during one-dimensional shock loading. The effects of oxygen content on the shock response and dynamic failure characteristic of Ti–6Al–4V are also shown through the comparison of the obtained results with those for commercial Ti–6Al–4V. The measured Hugoniot elastic limit (HEL) of Ti–6Al–4V ELI is lower than that of commercial Ti–6Al–4V. While the fitted shock parameters and the measured Hugoniot in the stress-particle velocity space of Ti–6Al–4V ELI are found to be almost identical to those of commercial Ti–6Al–4V. These results indicate that the oxygen content can significantly affect the HEL of Ti–6Al–4V, but has little or no influence on the shock response of this alloy beyond the HEL. The postshock Ti–6Al–4V ELI does not display shock-induced strengthening during quasistatic and dynamic compression tests. Transmission electron microscopy (TEM) analyses reveal that the lack of high density dislocations or dislocation cells limits the shock-induced strengthening effect, although dislocation multiplication and tangles lead to increased yield strength and strain hardening rate of the reloaded material. Finally, Ti–6Al–4V ELI is demonstrated to spall in a ductile manner, and has similar spall strengths to those of commercial Ti–6Al–4V under different shock loading conditions. The oxygen content exerts no effect on the spall fracture manner of Ti–6Al–4V, although reducing the oxygen content enables this alloy to endure more micro-damages.

  3. Shock-induced mechanical response and spall fracture behavior of an extra-low interstitial grade Ti–6Al–4V alloy

    International Nuclear Information System (INIS)

    Ren, Yu; Wang, Fuchi; Tan, Chengwen; Wang, Shuyou; Yu, Xiaodong; Jiang, Jianwei; Ma, Honglei; Cai, Hongnian

    2013-01-01

    The mechanical response and spall fracture behavior of an extra-low interstitial (ELI) grade Ti–6Al–4V alloy are systemically investigated during one-dimensional shock loading. The effects of oxygen content on the shock response and dynamic failure characteristic of Ti–6Al–4V are also shown through the comparison of the obtained results with those for commercial Ti–6Al–4V. The measured Hugoniot elastic limit (HEL) of Ti–6Al–4V ELI is lower than that of commercial Ti–6Al–4V. While the fitted shock parameters and the measured Hugoniot in the stress-particle velocity space of Ti–6Al–4V ELI are found to be almost identical to those of commercial Ti–6Al–4V. These results indicate that the oxygen content can significantly affect the HEL of Ti–6Al–4V, but has little or no influence on the shock response of this alloy beyond the HEL. The postshock Ti–6Al–4V ELI does not display shock-induced strengthening during quasistatic and dynamic compression tests. Transmission electron microscopy (TEM) analyses reveal that the lack of high density dislocations or dislocation cells limits the shock-induced strengthening effect, although dislocation multiplication and tangles lead to increased yield strength and strain hardening rate of the reloaded material. Finally, Ti–6Al–4V ELI is demonstrated to spall in a ductile manner, and has similar spall strengths to those of commercial Ti–6Al–4V under different shock loading conditions. The oxygen content exerts no effect on the spall fracture manner of Ti–6Al–4V, although reducing the oxygen content enables this alloy to endure more micro-damages

  4. DNA repair , cell repair and radiosensitivity

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.

    1983-01-01

    Data obtained in laboratory of radiation cytology and literature data testifying to a considerable role of DNA repair in cell sensitivity to radiation and chemical DNA-tropic agents have been considered. Data pointing to the probability of contribution of inducible repair of DNA into plant cells sensitivity to X-rays are obtained. Certain violations of DNA repair do not result in the increase of radiosensitivity. It is assumed that in the cases unknown mechanisms of DNA repair operate

  5. Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material

    Directory of Open Access Journals (Sweden)

    Tanvir Manzur

    2016-01-01

    Full Text Available Carbon nanotubes (CNTs are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques are currently available to enhance the integrity and durability of concrete structures with cracks and spalling, but applicability and/or reliability is/are often limited. Therefore, there is always a need for innovative high performing concrete repair materials with good mechanical, rheological, and durability properties. Considering the mechanical properties of carbon nanotubes (CNTs and the test results of CNT reinforced cement composites, it is apparent that such composites could be used conveniently as concrete repair material. With this end in view, the applicability of multiwalled carbon nanotube (MWNT reinforced cement composites as concrete repair material has been evaluated in this study in terms of setting time, bleeding, and bonding strength (slant shear tests. It has been found that MWNT reinforced cement mortar has good prospective as concrete repair material since such composites exhibited desirable behavior in setting time, bleeding, and slant shear.

  6. Rapid road repair vehicle

    Science.gov (United States)

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  7. Experimental study and field application of calcium sulfoaluminate cement for rapid repair of concrete pavements

    Institute of Scientific and Technical Information of China (English)

    Yanhua GUAN; Ying GAO; Renjuan SUN; Moon C.WON; Zhi GE

    2017-01-01

    The fast-track repair of deteriorated concrete pavement requires materials that can be placed,cured,and opened to the traffic in a short period.Type Ⅲ cement and Calcium Sulfoaluminate (CSA) cement are the most commonly used fast-setting hydraulic cement (FSHC).In this study,the properties of Type Ⅲ and CSA cement concrete,including compressive strength,coefficient of thermal expansion (CTE) and shrinkage were evaluated.The test results indicate that compressive strength of FSHC concrete increased rapidly at the early age.CSA cement concrete had higher early-age and long term strength.The shrinkage of CSA cement concrete was lower than that of Type Ⅲ cement concrete.Both CSA and Type Ⅲ cement concrete had similar CTE values.Based on the laboratory results,the CSA cement was selected as the partial-depth rapid repair material for a distressed continuously reinforced concrete pavement.The data collected during and after the repair show that the CSA cement concrete had good short-term and long-term performances and,therefore,was suitable for the rapid repair of concrete pavement.

  8. Collision Repair Campaign

    Science.gov (United States)

    The Collision Repair Campaign targets meaningful risk reduction in the Collision Repair source category to reduce air toxic emissions in their communities. The Campaign also helps shops to work towards early compliance with the Auto Body Rule.

  9. Retinal detachment repair

    Science.gov (United States)

    ... medicines Problems breathing You may not recover full vision. ... detachments can be repaired. Failure to repair the retina always results in loss of vision to some degree. After surgery, the quality of ...

  10. Massive spalling of Cu-Zn and Cu-Al intermetallic compounds at the interface between solders and Cu substrate during liquid state reaction

    Science.gov (United States)

    Kotadia, H. R.; Panneerselvam, A.; Mokhtari, O.; Green, M. A.; Mannan, S. H.

    2012-04-01

    The interfacial intermetallic compound (IMC) formation between Cu substrate and Sn-3.8Ag-0.7Cu-X (wt.%) solder alloys has been studied, where X consists of 0-5% Zn or 0-2% Al. The study has focused on the effect of solder volume as well as the Zn or Al concentration. With low solder volume, when the Zn and Al concentrations in the solder are also low, the initial Cu-Zn and Al-Cu IMC layers, which form at the solder/substrate interface, are not stable and spall off, displaced by a Cu6Sn5 IMC layer. As the total Zn or Al content in the system increases by increasing solder volume, stable CuZn or Al2Cu IMCs form on the substrate and are not displaced. Increasing concentration of Zn has a similar effect of stabilizing the Cu-Zn IMC layer and also of forming a stable Cu5Zn8 layer, but increasing Al concentration alone does not prevent spalling of Al2Cu. These results are explained using a combination of thermodynamic- and kinetics-based arguments.

  11. 'Regular' and 'emergency' repair

    International Nuclear Information System (INIS)

    Luchnik, N.V.

    1975-01-01

    Experiments on the combined action of radiation and a DNA inhibitor using Crepis roots and on split-dose irradiation of human lymphocytes lead to the conclusion that there are two types of repair. The 'regular' repair takes place twice in each mitotic cycle and ensures the maintenance of genetic stability. The 'emergency' repair is induced at all stages of the mitotic cycle by high levels of injury. (author)

  12. Repair kinetics in tissues

    International Nuclear Information System (INIS)

    Thames, H.D.

    1989-01-01

    Monoexponential repair kinetics is based on the assumption of a single, dose-independent rate of repair of sublethal injury in the target cells for tissue injury after exposure to ionizing radiation. Descriptions of the available data based on this assumption have proved fairly successful for both acutely responding (skin, lip mucosa, gut) and late-responding (lung, spinal cord) normal tissues. There are indications of biphasic exponential repair in both categories, however. Unfortunately, the data usually lack sufficient resolution to permit unambiguous determination of the repair rates. There are also indications that repair kinetics may depend on the size of the dose. The data are conflicting on this account, however, with suggestions of both faster and slower repair after larger doses. Indeed, experiments that have been explicitly designed to test this hypothesis show either no effect (gut, spinal cord), faster repair after higher doses (lung, kidney), or slower repair after higher doses (skin). Monoexponential repair appears to be a fairly accurate description that provides an approximation to a more complicated picture, the elucidation of whose details will, however, require very careful and extensive experimental study. (author). 30 refs.; 1 fig

  13. Snowmobile Repair. Teacher Edition.

    Science.gov (United States)

    Hennessy, Stephen S.; Conrad, Rex

    This teacher's guide contains 14 units on snowmobile repair: (1) introduction to snowmobile repair; (2) skis, front suspension, and steering; (3) drive clutch; (4) drive belts; (5) driven clutch; (6) chain drives; (7) jackshafts and axles; (8) rear suspension; (9) tracks; (10) shock absorbers; (11) brakes; (12) engines; (13) ignition and…

  14. DNA repair genes

    International Nuclear Information System (INIS)

    Morimyo, Mitsuoki

    1995-01-01

    Fission yeast S. pombe is assumed to be a good model for cloning of human DNA repair genes, because human gene is normally expressed in S. pombe and has a very similar protein sequence to yeast protein. We have tried to elucidate the DNA repair mechanisms of S. pombe as a model system for those of mammals. (J.P.N.)

  15. DNA repair protocols

    DEFF Research Database (Denmark)

    Bjergbæk, Lotte

    In its 3rd edition, this Methods in Molecular Biology(TM) book covers the eukaryotic response to genomic insult including advanced protocols and standard techniques in the field of DNA repair. Offers expert guidance for DNA repair, recombination, and replication. Current knowledge of the mechanisms...... that regulate DNA repair has grown significantly over the past years with technology advances such as RNA interference, advanced proteomics and microscopy as well as high throughput screens. The third edition of DNA Repair Protocols covers various aspects of the eukaryotic response to genomic insult including...... recent advanced protocols as well as standard techniques used in the field of DNA repair. Both mammalian and non-mammalian model organisms are covered in the book, and many of the techniques can be applied with only minor modifications to other systems than the one described. Written in the highly...

  16. Repairing fuel for reinsertion

    International Nuclear Information System (INIS)

    Krukshenk, A.

    1986-01-01

    Eqiupment for nuclear reactor fuel assembly repairing produced by Westinghouse and Brawn Bovery companies is described. Repair of failed fuel assemblies replacement of defect fuel elements gives a noticeable economical effect. Thus if the cost of a new fuel assembly is 450-500 thousand dollars, the replacement of one fuel element in it costs approximately 40-60 thousand dollars. In simple cases repairing includes either removal of failed fuel elements from a fuel assembly and its reinsertion with the rest of fuel elements into the reactor core (reactor refueling), or replacement of unfailed fuel elements from one fuel assembly to a new one (fuel assembly overhaul and reconditioning)

  17. DNA Repair Systems

    Indian Academy of Sciences (India)

    DNA molecule which makes it ideal for storage and propagation of genetic information. ... of these errors are broadly referred to as DNA repair. DNA can ... changes occur in the human genome per day. ..... nails, frequent physical and mental.

  18. Brain aneurysm repair - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000123.htm Brain aneurysm repair - discharge To use the sharing features ... this page, please enable JavaScript. You had a brain aneurysm . An aneurysm is a weak area in ...

  19. Ventral hernia repair

    Science.gov (United States)

    ... incarcerated) in the hernia and become impossible to push back in. This is usually painful. The blood supply ... you are lying down or that you cannot push back in. Risks The risks of ventral hernia repair ...

  20. Omphalocele repair - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100033.htm Omphalocele repair - series—Normal anatomy To use the sharing ... Go to slide 4 out of 4 Overview Omphalocele is an abdominal wall defect at the base ...

  1. Celebrating DNA's Repair Crew.

    Science.gov (United States)

    Kunkel, Thomas A

    2015-12-03

    This year, the Nobel Prize in Chemistry has been awarded to Tomas Lindahl, Aziz Sancar, and Paul Modrich for their seminal studies of the mechanisms by which cells from bacteria to man repair DNA damage that is generated by normal cellular metabolism and stress from the environment. These studies beautifully illustrate the remarkable power of DNA repair to influence life from evolution through disease susceptibility. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Use of acoustic emission technique to study the spalling behaviour of oxide scales on Ni-10Cr-8Al containing sulphur and/or yttrium impurity

    International Nuclear Information System (INIS)

    Khanna, A.S.; Quadakkers, W.J.; Jonas, H.

    1989-01-01

    It is now well established that the presence of small amounts of sulphur impurity in a NiCrAl-based alloy causes a deleterious effect on their high temperature oxidation behaviour. It is, however, not clear whether the adverse effect is due to a decrease in the spalling resistance of the oxide scale or due to an enhanced scale growth. In order to confirm which of the factors is dominating, two independent experimental techniques were used in the investigation of the oxidation behaviour of Ni-10Cr-8Al containing sulphur- and/or yttrium additions: conventional thermogravimetry, to study the scale growth rates and acoustic emission analysis to study the scale adherence. The results indicated that the dominant factor responsible for the deleterious effect of sulphur impurity on the oxidation of a Ni-10Cr-8Al alloy, was a significant change in the growth rate and the composition of the scale. Addition of yttrium improved the oxidation behaviour, not only by increasing the scale adherence, but also by reducing the scale growth due to gettering of sulphur. (orig.) [de

  3. Radiobiological significance of DNA repair

    International Nuclear Information System (INIS)

    Kuzin, A.M.

    1978-01-01

    A short outline is given on the history of the problem relating to the repair of radiation injuries, specifically its molecular mechanisms. The most urgent problems which currently confront the researchers are noted. This is a further study on the role of DNA repair in post-radiation recovery, search for ways to activate and suppress DNA repair, investigations into the activity balance of various repair enzymes as well as the problem of errors in the structure of repairing DNA. An important role is attached to the investigations of DNA repair in solving a number of practical problems

  4. Recombinational repair: workshop summary

    International Nuclear Information System (INIS)

    Howard-Flanders, P.

    1983-01-01

    Recombinational repair may or may not be synonymous with postreplication repair. Considerable progress has been made in the study of the relevant enzymes, particularly those from bacteria. In this workshop we focus on the recombination enzyme RecA protein. What structural changes take place in the protein and in DNA during repair. How does homologous pairing take place. How is ATP hydrolysis coupled to the stand exchange reaction and the formation of heteroduplx DNA. Turning to another enzyme needed for certain kinds of bacterial recombination, we will ask whether the purified recB protein and recC protein complement each other and are sufficient for exonuclease V activity. In higher cells, we would like to know whether sister exchanges, which occur in bacteria after uv irradiation, are also seen in animal cells

  5. Meniscal repair devices.

    Science.gov (United States)

    Barber, F A; Herbert, M A

    2000-09-01

    Meniscal repair devices not requiring accessory incisions are attractive. Many factors contribute to their clinical effectiveness including their biomechanical characteristics. This study compared several new meniscal repair devices with standard meniscal suture techniques. Using a porcine model, axis-of-insertion loads were applied to various meniscal sutures and repair devices. A single device or stitch was placed in a created meniscal tear and a load applied. Both loads and modes of failure were recorded. The load-to-failure data show stratification into 4 distinct statistical groups. Group A, 113 N for a double vertical stitch; group B, 80 N for a single vertical stitch; group C, 57 N for the BioStinger, 56 N for a horizontal mattress stitch, and 50 N for the T-Fix stitch; and group D, 33 N for the Meniscus Arrow (inserted by hand or gun), 32 N for the Clearfix screw, 31 N for the SDsorb staple, 30 N for the Mitek meniscal repair system, and 27 N for the Biomet staple. The failure mechanism varied. Sutures broke away from the knot. The Meniscus Arrow and BioStinger pulled through the inner rim with the crossbar intact. The Clearfix screw failed by multiple mechanisms, whereas 1 leg of the SDsorb staple always pulled out of the outer rim. The Mitek device usually failed by pullout from the inner rim. The Biomet staple always broke at the crosshead or just below it. Although the surgeon should be aware of the material properties of the repair technique chosen for a meniscal repair, this information is only an indication of device performance and may not correlate with clinical healing results.

  6. DNA repair and cancer

    International Nuclear Information System (INIS)

    Rathore, Shakuntla; Joshi, Pankaj Kumar; Gaur, Sudha

    2012-01-01

    DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecule that encode it's genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many one million individual molecular lesions per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions include potentially harmful mutation in cell's genome which affect the survival of it's daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. Inherited mutation that affect DNA repair genes are strongly associated with high cancer risks in humans. Hereditary non polyposis colorectal cancer (HNPCC) is strongly associated with specific mutation in the DNA mismatch repair pathway. BRCA1, BRCA2 two famous mutation conferring a hugely increased risk of breast cancer on carrier, are both associated with a large number of DNA repair pathway, especially NHEJ and homologous recombination. Cancer therapy procedures such as chemotherapy and radiotherapy work by overwhelming the capacity of the cell to repair DNA damage, resulting in cell death. Cells that are most rapidly dividing most typically cancer cells are preferentially affected. The side effect is that other non-cancerous but rapidly dividing cells such as stem cells in the bone marrow are also affected. Modern cancer treatment attempt to localize the DNA damage to cells and tissue only associated with cancer, either by physical means (concentrating the therapeutic agent in the region of the tumor) or by biochemical means (exploiting a feature unique to cancer cells in the body). (author)

  7. Biological radiolesions and repair

    International Nuclear Information System (INIS)

    Laskowski, W.

    1981-01-01

    In 7 chapters, the book answers the following questions: 1) What reactions are induced in biological matter by absorption of radiation energy. 2) In what parts of the cell do the radiation-induced reactions with detectable biological effects occur. 3) In which way are these cell components changed by different qualities of radiation. 4) What are the cell mechanisms by which radiation-induced changes can be repaired. 5) What is the importance of these repair processes for man, his life and evolution. At the end of each chapter, there is a bibliography of relevant publications in this field. (orig./MG) [de

  8. Composite Repair System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — GTL has developed an innovative composite repair methodology known as the Composite Repair System (CRS). In this phase I effort, CRS is being developed for the...

  9. About the Collision Repair Campaign

    Science.gov (United States)

    EPA developed the Collision Repair Campaign to focus on meaningful risk reduction in the Collision Repair source sector to complement ongoing community air toxics work and attain reductions at a faster rate.

  10. Vesicovaginal Fistula Repair During Pregnancy

    African Journals Online (AJOL)

    Vesicovaginal Fistula Repair During Pregnancy: A Case Report ... Abstract. We report a repair of Vesicovaginal fistula during pregnancy that was aimed at preventing another spontaneous ... practices that encourage teenage marriage and girl.

  11. Ship Repair Workflow Cost Model

    National Research Council Canada - National Science Library

    McDevitt, Mike

    2003-01-01

    The effects of intermittent work patterns and funding on the costs of ship repair and maintenance were modeled for the San Diego region in 2002 for Supervisor of Shipbuilding and Repair (SUPSHIP) San Diego...

  12. Social repair of relationships

    DEFF Research Database (Denmark)

    Fahnøe, Kristian Relsted

    2017-01-01

    organisations, friends and family, and communities. These social relations are viewed as the foundation of citizenship as experienced and practised. Focusing on how two dimensions of lived citizenship, namely rights-responsibilities and belonging, are affected by the social repairs, the chapter shows how...

  13. Comprehensive Small Engine Repair.

    Science.gov (United States)

    Hires, Bill; And Others

    This curriculum guide contains the basic information needed to repair all two- and four-stroke cycle engines. The curriculum covers four areas, each consisting of one or more units of instruction that include performance objectives, suggested activities for teacher and students, information sheets, assignment sheets, job sheets, visual aids,…

  14. Patent urachus repair - slideshow

    Science.gov (United States)

    ... Drugs & Supplements Videos & Tools About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Patent urachus repair - series—Normal anatomy URL of this ...

  15. Patent urachus repair

    Science.gov (United States)

    ... Drugs & Supplements Videos & Tools About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Patent urachus repair URL of this page: //medlineplus.gov/ ...

  16. DNA Repair Systems

    Indian Academy of Sciences (India)

    Thanks to the pioneering research work of Lindahl, Sancar, Modrich and their colleagues, we now have an holistic awareness of how DNA damage occurs and how the damage is rectified in bacteria as well as in higher organisms including human beings. A comprehensive understanding of DNA repair has proven crucial ...

  17. Aircraft Propeller Hub Repair

    Energy Technology Data Exchange (ETDEWEB)

    Muth, Thomas R [ORNL; Peter, William H [ORNL

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  18. Role of DNA repair in repair of cytogenetic damages. Slowly repaired DNA injuries involved in cytogenetic damages repair

    International Nuclear Information System (INIS)

    Zaichkina, S.I.; Rozanova, O.M.; Aptikaev, G.F.; Ganassi, E.Eh.

    1989-01-01

    Caffeine was used to study the kinetics of cytogenetic damages repair in Chinese hamster fibroblasts. Its half-time (90 min) was shown to correlate with that of repair of slowly repaired DNA damages. The caffeine-induced increase in the number of irreparable DNA damages, attributed to inhibition of double-strand break repair, is in a quantitative correlation with the effect of the cytogenetic damage modification

  19. Cleft lip and palate repair

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002979.htm Cleft lip and palate repair To use the sharing features on this ... Cheiloplasty; Cleft rhinoplasty; Palatoplasty; Tip rhinoplasty Patient Instructions Cleft lip and palate repair - discharge Images Cleft lip repair - series References ...

  20. DNA repair in human cells

    International Nuclear Information System (INIS)

    Regan, J.D.; Carrier, W.L.; Kusano, I.; Furuno-Fukushi, I.; Dunn, W.C. Jr.; Francis, A.A.; Lee, W.H.

    1982-01-01

    Our primary objective is to elucidate the molecular events in human cells when cellular macromolecules such as DNA are damaged by radiation or chemical agents. We study and characterize (i) the sequence of DNA repair events, (ii) the various modalities of repair, (iii) the genetic inhibition of repair due to mutation, (iv) the physiological inhibition of repair due to mutation, (v) the physiological inhibition of repair due to biochemical inhibitors, and (vi) the genetic basis of repair. Our ultimate goals are to (i) isolate and analyze the repair component of the mutagenic and/or carcinogenic event in human cells, and (ii) elucidate the magnitude and significance of this repair component as it impinges on the practical problems of human irradiation or exposure to actual or potential chemical mutagens and carcinogens. The significance of these studies lies in (i) the ubiquitousness of repair (most organisms, including man, have several complex repair systems), (ii) the belief that mutagenic and carcinogenic events may arise only from residual (nonrepaired) lesions or that error-prone repair systems may be the major induction mechanisms of the mutagenic or carcinogenic event, and (iii) the clear association of repair defects and highly carcinogenic disease states in man [xeroderma pigmentosum (XP)

  1. The journey of DNA repair.

    Science.gov (United States)

    Saini, Natalie

    2015-12-01

    21 years ago, the DNA Repair Enzyme was declared "Molecule of the Year". Today, we are celebrating another "year of repair", with the 2015 Nobel Prize in Chemistry being awarded to Aziz Sancar, Tomas Lindahl and Paul Modrich for their collective work on the different DNA repair pathways.

  2. Repair mechanisms and exposure standards

    International Nuclear Information System (INIS)

    Mills, W.A.

    1978-01-01

    The following topics are discussed; public policy for setting radiation standards; use of linear, nonthreshold theory in setting radiation standards; dose-rate dependence; occupational exposure to radiation; radon inhalation from radium in the soil in the vicinity of the phosphate industry; relation of repair mechanisms for cell survival to cancer induction; application of information on genetic repair to humans and to cancer induction; importance of repair processes in radiation protection standards; corrective factors for repair processes; relation of repair processes to age, sex, and other factors; and population distribution in radiosensitivity

  3. DNA repair deficiency in neurodegeneration

    DEFF Research Database (Denmark)

    Jeppesen, Dennis Kjølhede; Bohr, Vilhelm A; Stevnsner, Tinna V.

    2011-01-01

    Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive...... neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative...... base lesions is base excision repair, and such repair is crucial for neurons given their high rates of oxygen metabolism. Mismatch repair corrects base mispairs generated during replication and evidence indicates that oxidative DNA damage can cause this pathway to expand trinucleotide repeats, thereby...

  4. Handbook of Equipment Repair.

    Science.gov (United States)

    1981-05-14

    state of leapin- fn’rw.rd. Tn recent years, many mechanical repair workers often write and ask us to reprint the book. In our consideration, however...ast 4iron 1. .-eat _--OSIS-RTS 5.5 . . 4-5 t4- cast -3.01 -6 ~.0 ’ ɘ.᝱ 5,,:e j?24 2 * 10- 5 aron C l 50 S lcon : Ielt rSSIS-RQTS-s;.4 u a 2.47 5at- .0

  5. Specific features of the occurrence, development, and re-compaction of spall and shear fractures in spherically-convergent shells made of unalloyed iron and some steels under their spherical explosive loading

    International Nuclear Information System (INIS)

    Kozlov, E.A.; Brichikov, S.A.; Gorbachev, D.M.; Brodova, I.G.; Yablonskikh, T.I.

    2007-01-01

    Results of comparative metallographic examination of recovered shells exposed to explosive loading in two modes (with and without a heavy casing confining explosion products scatter) are presented. The shells were made of high-purity and technical-grade unalloyed iron with the initial grain size 250 and 125 μm, steel 30KhGSA in delivery state and quenched up to HR C 35...40, austenitic stainless steel 12Kh18N10T. The heavy casing used in experiments is demonstrated to ensure a rather compact convergence of shells destroyed at high radii. In the described comparative experiments, one managed to compile the 12Kh18N10T steel shell, after it was spalled at high radii and exposed to shear fracture and spallation layer fragmentation at medium radii, into a compact sphere but failed to do the same with the 30KhGSA quenched steel shell after it was fractured according to spall and shear mechanisms at high and medium radii. Polar zones of this steel shell have obvious undercompressed areas due to significant dissipative losses to overcome the shear strength. Occurrence, development, and re-compaction of spall and shear fractures in spherically-convergent shells made of materials, which were already carefully investigated in 1D- and 2D-geometry experiments, were systematically studied in order to verify and validate new physical models of dynamic fractures, as well as up-to-date used in 1D-, 2D- and 3D-numerical algorithms [ru

  6. Improving Aviation Depot Level Repairable (AVDLR) Inventory and Repair Management

    National Research Council Canada - National Science Library

    Baird, Dennis

    1997-01-01

    .... Additionally, research was conducted to document the management process for determining repair requirements at the Naval Inventory Control Point Philadelphia and how those requirements are accepted...

  7. When is cartilage repair successful?

    International Nuclear Information System (INIS)

    Raudner, M.; Roehrich, S.; Zalaudek, M.; Trattnig, S.; Schreiner, M.M.

    2017-01-01

    Focal cartilage lesions are a cause of long-term disability and morbidity. After cartilage repair, it is crucial to evaluate long-term progression or failure in a reproducible, standardized manner. This article provides an overview of the different cartilage repair procedures and important characteristics to look for in cartilage repair imaging. Specifics and pitfalls are pointed out alongside general aspects. After successful cartilage repair, a complete, but not hypertrophic filling of the defect is the primary criterion of treatment success. The repair tissue should also be completely integrated to the surrounding native cartilage. After some months, the transplants signal should be isointense compared to native cartilage. Complications like osteophytes, subchondral defects, cysts, adhesion and chronic bone marrow edema or joint effusion are common and have to be observed via follow-up. Radiological evaluation and interpretation of postoperative changes should always take the repair method into account. (orig.) [de

  8. Engineered Heart Repair.

    Science.gov (United States)

    Fujita, B; Zimmermann, W-H

    2017-08-01

    There is a pressing need for the development of advanced heart failure therapeutics. Current state-of-the-art is protection from neurohumoral overstimulation, which fails to address the underlying cause of heart failure, namely loss of cardiomyocytes. Implantation of stem cell-derived cardiomyocytes via tissue-engineered myocardium is being advanced to realize the remuscularization of the failing heart. Here, we discuss pharmacological challenges pertaining to the clinical translation of tissue-engineered heart repair with a focus on engineered heart muscle (EHM). © 2017 American Society for Clinical Pharmacology and Therapeutics.

  9. Promoting peripheral myelin repair.

    Science.gov (United States)

    Zhou, Ye; Notterpek, Lucia

    2016-09-01

    Compared to the central nervous system (CNS), peripheral nerves have a remarkable ability to regenerate and remyelinate. This regenerative capacity to a large extent is dependent on and supported by Schwann cells, the myelin-forming glial cells of the peripheral nervous system (PNS). In a variety of paradigms, Schwann cells are critical in the removal of the degenerated tissue, which is followed by remyelination of newly-regenerated axons. This unique plasticity of Schwann cells has been the target of myelin repair strategies in acute injuries and chronic diseases, such as hereditary demyelinating neuropathies. In one approach, the endogenous regenerative capacity of Schwann cells is enhanced through interventions such as exercise, electrical stimulation or pharmacological means. Alternatively, Schwann cells derived from healthy nerves, or engineered from different tissue sources have been transplanted into the PNS to support remyelination. These transplant approaches can then be further enhanced by exercise and/or electrical stimulation, as well as by the inclusion of biomaterial engineered to support glial cell viability and neurite extension. Advances in our basic understanding of peripheral nerve biology, as well as biomaterial engineering, will further improve the functional repair of myelinated peripheral nerves. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Mapping of repair genes

    International Nuclear Information System (INIS)

    Hori, Tadaaki

    1985-01-01

    Chromosome mapping of repair genes involved in U.V. sensitivity is reported. Twenty-three of 25 hybrid cells were resistant to U.V. light. Survival curves of 2 U.V.-resistant cell strains, which possessed mouse chromosomes and human chromosome No.7 - 16, were similar to those of wild strain (L5178Y). On the other hand, survival curves of U.V.-sensitive hybrid cells was analogous to those of Q31. There was a definitive difference in the frequency of inducible chromosome aberrations between U.V. resistant and sensitive mouse-human hybrid cells. U.V.-resistant cell strains possessed the ability of excision repair. Analysis of karyotype in hybrid cells showed that the difference in U.V. sensitivity is dependent upon whether or not human chromosome No.13 is present. Synteny test on esterase D-determining locus confirmed that there is an agreement between the presence of chromosome No.13 and the presence of human esterase D activity. These results led to a conclusion that human genes which compensate recessive character of U.V.-sensitive mutant strain, Q31, with mouse-human hybrid cells are located on the locus of chromosome No.13. (Namekawa, K.)

  11. Spall Strength of Tungsten Carbide

    Science.gov (United States)

    2004-09-01

    1 PCS GROUP CAVENDISH LABORATORY W G PROUD MADINGLEY RD CAMBRIDGE UNITED KINGDOM 1 CENTRE D ETUDES DE GRAMAT J Y TRANCHET...46500 GRAMAT FRANCE 1 MINISTERE DE LA DEFENSE DR G BRAULT DGA DSP STTC 4 RUE DE LA PORTE DISSY 75015 PARIS FRANCE 1 SPART

  12. Handbook of adhesive bonded structural repair

    CERN Document Server

    Wegman, Raymond F

    1992-01-01

    Provides repair methods for adhesive bonded and composite structures; identifies suitable materials and equipment for repairs; describes damage evaluation criteria and techniques, and methods of inspection before and after repair.

  13. [Constitutional mismatch repair deficiency syndrome

    NARCIS (Netherlands)

    Jongmans, M.C.J.; Gidding, C.E.M.; Loeffen, J.; Wesseling, P.; Mensenkamp, A.; Hoogerbrugge, N.

    2015-01-01

    BACKGROUND: Constitutional mismatch repair deficiency (CMMR-D) syndrome is characterised by a significantly increased risk for developing cancer in childhood. It arises when both parents have a mutation in the same mismatch repair gene and pass it on to their child. CASE DESCRIPTION: An 8-year-old

  14. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  15. Nucleotide excision repair in yeast

    NARCIS (Netherlands)

    Eijk, Patrick van

    2012-01-01

    Nucleotide Excision Repair (NER) is a conserved DNA repair pathway capable of removing a broad spectrum of DNA damage. In human cells a defect in NER leads to the disorder Xeroderma pigmentosum (XP). The yeast Saccharomyces cerevisiae is an excellent model organism to study the mechanism of NER. The

  16. My journey to DNA repair.

    Science.gov (United States)

    Lindahl, Tomas

    2013-02-01

    I completed my medical studies at the Karolinska Institute in Stockholm but have always been devoted to basic research. My longstanding interest is to understand fundamental DNA repair mechanisms in the fields of cancer therapy, inherited human genetic disorders and ancient DNA. I initially measured DNA decay, including rates of base loss and cytosine deamination. I have discovered several important DNA repair proteins and determined their mechanisms of action. The discovery of uracil-DNA glycosylase defined a new category of repair enzymes with each specialized for different types of DNA damage. The base excision repair pathway was first reconstituted with human proteins in my group. Cell-free analysis for mammalian nucleotide excision repair of DNA was also developed in my laboratory. I found multiple distinct DNA ligases in mammalian cells, and led the first genetic and biochemical work on DNA ligases I, III and IV. I discovered the mammalian exonucleases DNase III (TREX1) and IV (FEN1). Interestingly, expression of TREX1 was altered in some human autoimmune diseases. I also showed that the mutagenic DNA adduct O(6)-methylguanine (O(6)mG) is repaired without removing the guanine from DNA, identifying a surprising mechanism by which the methyl group is transferred to a residue in the repair protein itself. A further novel process of DNA repair discovered by my research group is the action of AlkB as an iron-dependent enzyme carrying out oxidative demethylation. Copyright © 2013. Production and hosting by Elsevier Ltd.

  17. The journey of DNA repair

    OpenAIRE

    Saini, Natalie

    2015-01-01

    21 years ago, the DNA Repair Enzyme was declared “Molecule of the Year”. Today, we are celebrating another “year of repair”, with the 2015 Nobel Prize in Chemistry being awarded to Aziz Sancar, Tomas Lindahl and Paul Modrich for their collective work on the different DNA repair pathways.

  18. Procedures for maintenance and repairs

    International Nuclear Information System (INIS)

    Pickel, E.

    1981-01-01

    After a general review of the operation experience in the history of more than 12 operating years, the organization in the plant will be shown with special aspect to quality assurance, capacity of the workshops and connected groups as radiation protection, chemical laboratories etc. The number, time intervals and manpower effort for the repeating tests will be discussed. Reasons and examples for back-fitting activities in the plant are given. Besides special repair and maintenance procedures as repair of the steam generators, in-service inspection of the reactor pressure vessel, repair of a feed-water pipe and repair of the core structure in the pressure vessel, the general system to handle maintenance and repair-work in the KWO-plant will be shown. This includes also the detailed planning of the annual refueling and revision of the plant. (orig./RW)

  19. Wound repair in Pocillopora

    Science.gov (United States)

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry M.; Calderon-Aguileraa, Luis Eduardo

    2016-01-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40 days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40 d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals.

  20. Repairing Nanoparticle Surface Defects.

    Science.gov (United States)

    Marino, Emanuele; Kodger, Thomas E; Crisp, Ryan W; Timmerman, Dolf; MacArthur, Katherine E; Heggen, Marc; Schall, Peter

    2017-10-23

    Solar devices based on semiconductor nanoparticles require the use of conductive ligands; however, replacing the native, insulating ligands with conductive metal chalcogenide complexes introduces structural defects within the crystalline nanostructure that act as traps for charge carriers. We utilized atomically thin semiconductor nanoplatelets as a convenient platform for studying, both microscopically and spectroscopically, the development of defects during ligand exchange with the conductive ligands Na 4 SnS 4 and (NH 4 ) 4 Sn 2 S 6 . These defects can be repaired via mild chemical or thermal routes, through the addition of L-type ligands or wet annealing, respectively. This results in a higher-quality, conductive, colloidally stable nanomaterial that may be used as the active film in optoelectronic devices. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  1. Reward optimization of a repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Castro, I.T. [Departamento de Matematicas, Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad, s/n. 10071 Caceres (Spain)]. E-mail: inmatorres@unex.es; Perez-Ocon, R. [Departamento de Estadistica e Investigacion Operativa, Facultad de Ciencias, Universidad de Granada, Avenida de Severo Ochoa, s/n. 18071 Granada (Spain)]. E-mail: rperezo@ugr.es

    2006-03-15

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures.

  2. Reward optimization of a repairable system

    International Nuclear Information System (INIS)

    Castro, I.T.; Perez-Ocon, R.

    2006-01-01

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures

  3. Tissue repair capacity and repair kinetics deduced from multifractionated or continuous irradiation regimens with incomplete repair

    International Nuclear Information System (INIS)

    Thames, H.D. Jr.; Peters, L.J.

    1984-01-01

    A model is proposed for cell survival after multiple doses, when the interfraction interval is insufficient for complete Elkind repair. In the limit of ever-increasing number of ever-smaller fractional doses, the model transforms into the accumulation model of survival after continuous irradiation. When adapted to describe tissue responses to isoeffective multifractionated regimens, wherein repair is incomplete, a generalization of the usually linear plot of reciprocal total dose versus dose per fraction is obtained, in which downward curvature is evident. There is an advantage in studying tissue responses to multifractionated regimens with incomplete repair in the interfraction intervals, or continuous exposures at various dose rates since, in addition to determination of repair capacity, there is an estimate of repair kinetics. Results of analyses of previously published data are presented as illustration. Estimated from the response of three acutely responding normal tissues in the mouse (jejunum, colon and bone marrow), repair halftimes ranged from 0.3-0.9 h and values of β/delta were approximately 0.1 Gy -1 . From the response of mouse lung (LD50 for pneumonitis) to multifractionated regimens with incomplete repair, the repair halftime was estimated at 1.5 h and β/delta was 0.27 Gy -1 . In the rat spinal cord β/delta was 0.7 Gy -1 and Tsub(1/2) was 1.5 h. (U.K.)

  4. Residual stress by repair welds

    International Nuclear Information System (INIS)

    Mochizuki, Masahito; Toyoda, Masao

    2003-01-01

    Residual stress by repair welds is computed using the thermal elastic-plastic analysis with phase-transformation effect. Coupling phenomena of temperature, microstructure, and stress-strain fields are simulated in the finite-element analysis. Weld bond of a plate butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. Microstructure is considered by using CCT diagram and the transformation behavior in the repair weld is also simulated. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress. (author)

  5. Monogenic diseases of DNA repair

    DEFF Research Database (Denmark)

    Keijzers, Guido; Bakula, Daniela; Scheibye-Knudsen, Morten

    2017-01-01

    Maintaining the stability of the genome is essential for all organisms, and it is not surprising that damage to DNA has been proposed as an explanation for multiple chronic diseases.1-5 Conserving a pristine genome is therefore of central importance to our health. To overcome the genotoxic stress...... of a growing number of human diseases. Notably, many of these monogenic DNA-repair disorders display features of accelerated aging, supporting the notion that genome maintenance is a key factor for organismal longevity. This review focuses on the physiological consequences of loss of DNA repair, particularly...... in the context of monogenic DNA-repair diseases....

  6. Repairing and Upgrading Your PC

    CERN Document Server

    Thompson, Robert

    2009-01-01

    Repairing and Upgrading Your PC delivers start-to-finish instructions, simple enough for even the most inexperienced PC owner, for troubleshooting, repairing, and upgrading your computer. Written by hardware experts Robert Bruce Thompson and Barbara Fritchman Thompson, this book covers it all: how to troubleshoot a troublesome PC, how to identify which components make sense for an upgrade, and how to tear it all down and put it back together. This book shows how to repair and upgrade all of your PC's essential components.

  7. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Science.gov (United States)

    2010-07-01

    ... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.” (a... killing or growth inhibition of repair deficient bacteria in a set of repair proficient and deficient...

  8. Innovative repair of subsidence damage

    International Nuclear Information System (INIS)

    Marino, G.G.

    1992-01-01

    In order to improve handling of subsidence damages the Illinois Mine Subsidence Insurance Fund supported the development of novel cost-effective methods of repair. The research in developing the repairs was directed towards the most common and costly damages that had been observed. As a result repair techniques were designed for structurally cracked foundations in the tension zone; structurally cracked foundations in the compression zone; and damaged or undamaged tilted foundations. When appropriate the postulated methods would result in: 1. significant cost savings (over conventional procedures); 2. a structural capacity greater than when the foundation was uncracked; and 3. an aesthetic appeal. All the postulated repair methodologies were laboratory and/or field tested. This paper will summarize the essentials of each technique developed and the test results

  9. Umbilical hernia repair - series (image)

    Science.gov (United States)

    ... treatment. The indications for umbilical hernia repair include: incarcerated (strangulated) umbilical hernia defects not spontaneously closed by 4 to 5 years of age children under 2 with very large defects unacceptable to ...

  10. Mammalian DNA Repair. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Richard D.

    2003-01-24

    The Gordon Research Conference (GRC) on Mammalian DNA Repair was held at Harbortown Resort, Ventura Beach, CA. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  11. Canadian company innovates dam repair

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    Successful repair without any downtime, of the Sabana Yegua power and irrigation structure in the western Dominican Republic by Aquatic Sciences Ltd., a St. Catherine, Ontario-based underwater specialist company, is discussed. The structure was damaged by Hurricane George last when when rising water levels damaged a major valve in the control gate chamber. The repair strategy designed by Aquatic Sciences used a remotely operated vehicle with a mechanical arm for minor tasks which placed a specially-made plug into the inlet pipe. The work was completed in one week, saving the utility company a great deal of money by making it possible to make the repairs remotely in the gate chamber without having to drain the tunnel, as would have been necessary had the repair been completed manually. The remotely operated vehicles use a scanning sonar as well as light to find their way. They are particularly well adapted to work underwater under low-visibility conditions

  12. Betonreparationers holdbarhed (Durability of Concrete Repairs)

    DEFF Research Database (Denmark)

    Brimnes, Eydbjørn; Dali, Bogi í; Larsen, Erik Stoklund

    1999-01-01

    Concrete repairs on 11 pillars on bridges built in the sixties and repaired 8 to 9 years ago have been examined. Especially the chloride penetration in the repair concrete have been measured. Chloride penetration in the repair concrete is much lower than in the original concrete....

  13. 40 CFR 63.1005 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1005 Section 63.1005... Standards for Equipment Leaks-Control Level 1 § 63.1005 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected no later than 15 calendar days after it is detected, except as...

  14. 40 CFR 63.1024 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Leak repair. 63.1024 Section 63.1024... Standards for Equipment Leaks-Control Level 2 Standards § 63.1024 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical, but not later than 15 calendar...

  15. 40 CFR 65.105 - Leak repair.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Leak repair. 65.105 Section 65.105... FEDERAL AIR RULE Equipment Leaks § 65.105 Leak repair. (a) Leak repair schedule. The owner or operator shall repair each leak detected as soon as practical but not later than 15 calendar days after it is...

  16. Laparoscopic Repair of Inguinal Hernias

    OpenAIRE

    Carter, Jonathan; Duh, Quan-Yang

    2011-01-01

    For patients with recurrent inguinal hernia, or bilateral inguinal hernia, or for women, laparoscopic repair offers significant advantages over open techniques with regard to recurrence risk, pain, and recovery. For unilateral first-time hernias, either laparoscopic or open repair with mesh can offer excellent results. The major drawback of laparoscopy is that the technique requires a significant number of cases to master. For surgeons in group practice, it makes sense to have one surgeon in ...

  17. Repair Types, Procedures - Part 1

    Science.gov (United States)

    2010-05-01

    Affordable Combat Aircraft, AGARD - CP -600, 1997. [17] Helbling J, Grover R and Ratwani M. M “Analysis and Structural Test of Composite Reinforcement to...considered suitable for the composite patch repair of aluminum structure. Ductile adhesives such as FM- 73 are preferred over brittle adhesives Repair Types...zone. A proper cure cycle is followed as prescribed by the adhesive manufacturer. For FM- 73 adhesive cure at 2500F (1210C) for 120 minutes is

  18. Laparoscopic repair of postoperative perineal hernia.

    LENUS (Irish Health Repository)

    Ryan, Stephen

    2010-01-01

    Perineal hernias are infrequent complications following abdominoperineal operations. Various approaches have been described for repair of perineal hernias including open transabdominal, transperineal or combined abdominoperineal repairs. The use of laparoscopic transabdominal repair of perineal hernias is not well-described. We present a case report demonstrating the benefits of laparoscopic repair of perineal hernia following previous laparoscopic abdominoperineal resection (APR) using a nonabsorbable mesh to repair the defect. We have demonstrated that the use of laparoscopy with repair of the pelvic floor defect using a non absorbable synthetic mesh offers an excellent alternative with many potential advantages over open transabdominal and transperineal repairs.

  19. Overlapping sphincteroplasty and posterior repair.

    Science.gov (United States)

    Crane, Andrea K; Myers, Erinn M; Lippmann, Quinn K; Matthews, Catherine A

    2014-12-01

    Knowledge of how to anatomically reconstruct extensive posterior-compartment defects is variable among gynecologists. The objective of this video is to demonstrate an effective technique of overlapping sphincteroplasty and posterior repair. In this video, a scripted storyboard was constructed that outlines the key surgical steps of a comprehensive posterior compartment repair: (1) surgical incision that permits access to posterior compartment and perineal body, (2) dissection of the rectovaginal space up to the level of the cervix, (3) plication of the rectovaginal muscularis, (4) repair of internal and external anal sphincters, and (5) reconstruction of the perineal body. Using a combination of graphic illustrations and live video footage, tips on repair are highlighted. The goals at the end of repair are to: (1) have improved vaginal caliber, (2) increase rectal tone along the entire posterior vaginal wall, (3) have the posterior vaginal wall at a perpendicular plane to the perineal body, (4) reform the hymenal ring, and (5) not have an overly elongated perineal body. This video provides a step-by-step guide on how to perform an overlapping sphincteroplasty and posterior repair.

  20. Scarf Repair of Composite Laminates

    Directory of Open Access Journals (Sweden)

    Xie Zonghong

    2016-01-01

    Full Text Available The use of composite materials, such as carbon-fiber reinforced plastic (CFRP composites, aero-structures has led to an increased need of advanced assembly joining and repair technologies. Adhesive bonded repairs as an alternative to recover full or part of initial strength were investigated. Tests were conducted with the objective of evaluating the effectiveness of techniques used for repairing damage fiber reinforced laminated composites. Failure loads and failure modes were generated and compared with the following parameters: scarf angles, roughness of grind tool and number of external plies. Results showed that scarf angle was the critical parameter and the largest tensile strength was observed with the smallest scarf angle. Besides, the use of external plies at the outer surface could not increase the repairs efficiency for large scarf angle. Preparing the repair surfaces by sanding them with a sander ranging from 60 to 100 grit number had significant effect on the failure load. These results allowed the proposal of design principles for repairing CFRP structures.

  1. Aging and DNA repair capability. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Tice, R R

    1977-01-01

    A review of the literature on DNA repair processes in relation to aging is presented under the following headings: DNA repair processes; age-related occurrence of unrepaired DNA lesions; DNA repair capability as a function of age; tissue-specific DNA repair capability; acceleration of the aging process by exposure to DNA damaging agents; human genetic syndromes; and longevity and DNA repair processes. (HLW)

  2. 49 CFR 1242.42 - Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired...

    Science.gov (United States)

    2010-10-01

    ... repair, equipment damaged, dismantling retired property, fringe benefits, other casualties and insurance, lease rentals, joint facility rents, other rents, depreciation, joint facility, repairs billed to others... maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits, other...

  3. Evaluation of compatible mortars to repair 19th century natural cement cast stone from the French Rhône-Alpes region

    Directory of Open Access Journals (Sweden)

    Myriam Bouichou

    2008-01-01

    Full Text Available In France, natural cements were extensively produced in the middle of the 19th century. In the French Alps, due to their ochre color, these cements were massively used, notably to produce cast stone, to simulate natural freestone. A preliminary survey revealed an overall good state of preservation of the buildings of this period. Two kinds of decays mechanisms were however identified : erosion affecting the surface of the majority of the buildings, inducing a gradual disappearance of the initial "fake-stone aspect", and a spalling phenomenon often combined with salts crystallization, observed only on a few buildings. Today, due to a lack of appropriate repair materials, the rehabilitation of these buildings mainly consists in the use of gray Portland-cement-based-mortars combined with a painting finishing, which is not satisfactory considering the conservation deontology, as the original appearance is lost. Therefore, the aim of this project was to develop and to test compatible repair materials to restore the culture heritage of this region. Based on the preliminary characterization of a set of representative ancient buildings, combined to a literature review, specifications concerning the composition and the main properties of repair materials, which could assure a compatibility with the ancient concrete of the region were established. Then, three Prompt-cement and one Portland-cement based mortars were selected, two of them being specifically formulated. Firstly, the appearance, the workability and the mechanical and physical properties of those mortars were characterized. Secondly, to evaluate the compatibility of the selected mortars with ancient concrete, Prompt-cement-based slabs were cast using a 19th century concrete formula, and were artificially eroded. After applying the 4 mortars on the slabs, visual observations and pull-out tests will be carried out before and after artificial aging. Finally, the repair mortar presenting the best

  4. Imaging of cartilage repair procedures

    International Nuclear Information System (INIS)

    Sanghvi, Darshana; Munshi, Mihir; Pardiwala, Dinshaw

    2014-01-01

    The rationale for cartilage repair is to prevent precocious osteoarthritis in untreated focal cartilage injuries in the young and middle-aged population. The gamut of surgical techniques, normal postoperative radiological appearances, and possible complications have been described. An objective method of recording the quality of repair tissue is with the magnetic resonance observation of cartilage repair tissue (MOCART) score. This scoring system evaluates nine parameters that include the extent of defect filling, border zone integration, signal intensity, quality of structure and surface, subchondral bone, subchondral lamina, and records presence or absence of synovitis and adhesions. The five common techniques of cartilage repair currently offered include bone marrow stimulation (microfracture or drilling), mosaicplasty, synthetic resorbable scaffold grafts, osteochondral allograft transplants, and autologous chondrocyte implantation (ACI). Complications of cartilage repair procedures that may be demonstrated on magnetic resonance imaging (MRI) include plug loosening, graft protuberance, graft depression, and collapse in mosaicplasty, graft hypertrophy in ACI, and immune response leading to graft rejection, which is more common with synthetic grafts and cadaveric allografts

  5. Reprogramming Cells for Brain Repair

    Directory of Open Access Journals (Sweden)

    Randall D. McKinnon

    2013-08-01

    Full Text Available At present there are no clinical therapies that can repair traumatic brain injury, spinal cord injury or degenerative brain disease. While redundancy and rewiring of surviving circuits can recover some lost function, the brain and spinal column lack sufficient endogenous stem cells to replace lost neurons or their supporting glia. In contrast, pre-clinical studies have demonstrated that exogenous transplants can have remarkable efficacy for brain repair in animal models. Mesenchymal stromal cells (MSCs can provide paracrine factors that repair damage caused by ischemic injury, and oligodendrocyte progenitor cell (OPC grafts give dramatic functional recovery from spinal cord injury. These studies have progressed to clinical trials, including human embryonic stem cell (hESC-derived OPCs for spinal cord repair. However, ESC-derived allografts are less than optimal, and we need to identify a more appropriate donor graft population. The cell reprogramming field has developed the ability to trans-differentiate somatic cells into distinct cell types, a technology that has the potential to generate autologous neurons and glia which address the histocompatibility concerns of allografts and the tumorigenicity concerns of ESC-derived grafts. Further clarifying how cell reprogramming works may lead to more efficient direct reprogram approaches, and possibly in vivo reprogramming, in order to promote brain and spinal cord repair.

  6. DNA repair in PHA stimulated human lymphocytes

    International Nuclear Information System (INIS)

    Catena, C.; Mattoni, A.

    1984-01-01

    Damage an repair of radiation induced DNA strand breaks were measured by alkaline lysis and hydroxyapatite chromatography. PHA stimulated human lymphocytes show that the rejoining process is complete within the first 50 min., afterwords secondary DNA damage and chromatid aberration. DNA repair, in synchronized culture, allows to evaluate individual repair capacity and this in turn can contribute to the discovery of individual who, although they do not demonstrate apparent clinical signs, are carriers of DNA repair deficiency. Being evident that a correlation exists between DNA repair capacity and carcinogenesis, the possibility of evaluating the existent relationship between DNA repair and survival in tumor cells comes therefore into discussion

  7. Role of DNA repair in repair of cytogenetic damages. Contribution of repair of single-strand DNA breaks to cytogenetic damages repair

    International Nuclear Information System (INIS)

    Rozanova, O.M.; Zaichkina, S.I.; Aptikaev, G.F.; Ganassi, E.Eh.

    1989-01-01

    The comparison was made between the results of the effect of poly(ADP-ribosylation) ingibitors (e.g. nicotinamide and 3-aminobenzamide) and a chromatin proteinase ingibitor, phenylmethylsulfonylfluoride, on the cytogenetic damages repair, by a micronuclear test, and DNA repair in Chinese hamster fibroblasts. The values of the repair half-periods (5-7 min for the cytogenetic damages and 5 min for the rapidly repaired DNA damages) and a similar modyfying effect with regard to radiation cytogenetic damages and kynetics of DNA damages repair were found to be close. This confirms the contribution of repair of DNA single-strand breaks in the initiation of structural damages to chromosomes

  8. Incore inspection and repairing device

    International Nuclear Information System (INIS)

    Ito, Arata; Kimura, Motohiko

    1998-01-01

    The present invention provides a device for inspecting and repairing the inside of a reactor container even if it is narrow, with no trouble by using a swimming-type operation robot. Namely, the device of the present invention conducts inspection and repairing operations for the inside of the reactor by introducing a swimming type operation robot into the reactor container. The swimming-type operation robot comprises a robot main body having a propeller, a balancer operably disposed to the robot main body and an inspection and repairing unit attached detachable to the balancer. In the device of the present invention, since the inspection and preparing unit is attached detachably to the swimming robot, a robot which transports tools is formed as a standard product. As a result, the production cost can be reduced, and the reliability of products can be improved. Appropriate operations can be conducted by using best tools. (I.S.)

  9. Mitochondrial DNA repair and aging

    International Nuclear Information System (INIS)

    Mandavilli, Bhaskar S.; Santos, Janine H.; Van Houten, Bennett

    2002-01-01

    The mitochondrial electron transport chain plays an important role in energy production in aerobic organisms and is also a significant source of reactive oxygen species that damage DNA, RNA and proteins in the cell. Oxidative damage to the mitochondrial DNA is implicated in various degenerative diseases, cancer and aging. The importance of mitochondrial ROS in age-related degenerative diseases is further strengthened by studies using animal models, Caenorhabditis elegans, Drosophila and yeast. Research in the last several years shows that mitochondrial DNA is more susceptible to various carcinogens and ROS when compared to nuclear DNA. DNA damage in mammalian mitochondria is repaired by base excision repair (BER). Studies have shown that mitochondria contain all the enzymes required for BER. Mitochondrial DNA damage, if not repaired, leads to disruption of electron transport chain and production of more ROS. This vicious cycle of ROS production and mtDNA damage ultimately leads to energy depletion in the cell and apoptosis

  10. Mitochondrial DNA repair and aging

    Energy Technology Data Exchange (ETDEWEB)

    Mandavilli, Bhaskar S.; Santos, Janine H.; Van Houten, Bennett

    2002-11-30

    The mitochondrial electron transport chain plays an important role in energy production in aerobic organisms and is also a significant source of reactive oxygen species that damage DNA, RNA and proteins in the cell. Oxidative damage to the mitochondrial DNA is implicated in various degenerative diseases, cancer and aging. The importance of mitochondrial ROS in age-related degenerative diseases is further strengthened by studies using animal models, Caenorhabditis elegans, Drosophila and yeast. Research in the last several years shows that mitochondrial DNA is more susceptible to various carcinogens and ROS when compared to nuclear DNA. DNA damage in mammalian mitochondria is repaired by base excision repair (BER). Studies have shown that mitochondria contain all the enzymes required for BER. Mitochondrial DNA damage, if not repaired, leads to disruption of electron transport chain and production of more ROS. This vicious cycle of ROS production and mtDNA damage ultimately leads to energy depletion in the cell and apoptosis.

  11. Primary unilateral cleft lip repair

    OpenAIRE

    Adenwalla, H. S.; Narayanan, P. V.

    2009-01-01

    The unilateral cleft lip is a complex deformity. Surgical correction has evolved from a straight repair through triangular and quadrilateral repairs to the Rotation Advancement Technique of Millard. The latter is the technique followed at our centre for all unilateral cleft lip patients. We operate on these at five to six months of age, do not use pre-surgical orthodontics, and follow a protocol to produce a notch-free vermillion. This is easy to follow even for trainees. We also perform clos...

  12. Outreach Materials for the Collision Repair Campaign

    Science.gov (United States)

    The Collision Repair Campaign offers outreach materials to help collision repair shops reduce toxic air exposure. Materials include a DVD, poster, training video, and materials in Spanish (materiales del outreach en español).

  13. Intern's Experiences with Episiotomy and its Repair

    African Journals Online (AJOL)

    repair is inadequately done, it may leave the woman suffering from perineal pain and other long term conditions with serious impact on the .... The maternity section had an average of ... with the job of performing episiotomy repair necessitating.

  14. Nucleotide excision repair in the test tube.

    NARCIS (Netherlands)

    N.G.J. Jaspers (Nicolaas); J.H.J. Hoeijmakers (Jan)

    1995-01-01

    textabstractThe eukaryotic nucleotide excision-repair pathway has been reconstituted in vitro, an achievement that should hasten the full enzymological characterization of this highly complex DNA-repair pathway.

  15. Regression Models for Repairable Systems

    Czech Academy of Sciences Publication Activity Database

    Novák, Petr

    2015-01-01

    Roč. 17, č. 4 (2015), s. 963-972 ISSN 1387-5841 Institutional support: RVO:67985556 Keywords : Reliability analysis * Repair models * Regression Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.782, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/novak-0450902.pdf

  16. Microwave Oven Repair. Teacher Edition.

    Science.gov (United States)

    Smreker, Eugene

    This competency-based curriculum guide for teachers addresses the skills a technician will need to service microwave ovens and to provide customer relations to help retain the customer's confidence in the product and trust in the service company that performs the repair. The guide begins with a task analysis, listing 20 cognitive tasks and 5…

  17. Cloning human DNA repair genes

    International Nuclear Information System (INIS)

    Jeggo, P.A.; Carr, A.M.; Lehmann, A.R.

    1994-01-01

    Many human genes involved in the repair of UV damage have been cloned using different procedures and they have been of great value in assisting the understanding of the mechanism of nucleotide excision-repair. Genes involved in repair of ionizing radiation damage have proved more difficult to isolate. Positional cloning has localized the XRCC5 gene to a small region of chromosome 2q33-35, and a series of yeast artificial chromosomes covering this region have been isolated. Very recent work has shown that the XRCC5 gene encodes the 80 kDa subunit of the Ku DNA-binding protein. The Ku80 gene also maps to this region. Studies with fission yeast have shown that radiation sensitivity can result not only from defective DNA repair but also from abnormal cell cycle control following DNA damage. Several genes involved in this 'check-point' control in fission yeast have been isolated and characterized in detail. It is likely that a similar checkpoint control mechanism exists in human cells. (author)

  18. Pure robotic retrocaval ureter repair

    Directory of Open Access Journals (Sweden)

    Ashok k. Hemal

    2008-12-01

    Full Text Available PURPOSE: To demonstrate the feasibility of pure robotic retrocaval ureter repair. MATERIALS AND METHODS: A 33 year old female presented with right loin pain and obstruction on intravenous urography with the classical "fish-hook" appearance. She was counseled on the various methods of repair and elected to have a robot assisted repair. The following steps are performed during a pure robotic retrocaval ureter repair. The patient is placed in a modified flank position, pneumoperitoneum created and ports inserted. The colon is mobilized to expose the retroperitoneal structures: inferior vena cava, right gonadal vein, right ureter, and duodenum. The renal pelvis and ureter are mobilized and the renal pelvis transected. The ureter is transposed anterior to the inferior vena cava and a pyelopyelostomy is performed over a JJ stent. RESULTS: This patient was discharged on postoperative day 3. The catheter and drain tube were removed on day 1. Her JJ stent was removed at 6 weeks postoperatively. The postoperative intravenous urography at 3 months confirmed normal drainage of contrast medium. CONCLUSION: Pure robotic retrocaval ureter is a feasible procedure; however, there does not appear to be any great advantage over pure laparoscopy, apart from the ergonomic ease for the surgeon as well the simpler intracorporeal suturing.

  19. Discrete time analysis of a repairable machine

    OpenAIRE

    Alfa, Attahiru Sule; Castro, I. T.

    2002-01-01

    We consider, in discrete time, a single machine system that operates for a period of time represented by a general distribution. This machine is subject to failures during operations and the occurrence of these failures depends on how many times the machine has previously failed. Some failures are repairable and the repair times may or may not depend on the number of times the machine was previously repaired. Repair times also have a general distribution. The operating times...

  20. Molecular biological mechanisms I. DNA repair

    International Nuclear Information System (INIS)

    Friedl, A.A.

    2000-01-01

    Cells of all living systems possess a variety of mechanisms that allow to repair spontaneous and exogeneously induced DNA damage. DNA repair deficiencies may invoke enhanced sensitivity towards DNA-damaging agents such as ionizing radiation. They may also enhance the risk of cancer development, both spontaneously or after induction. This article reviews several DNA repair mechanisms, especially those dealing with DNA double-strand breaks, and describes hereditary diseases associated with DNA repair defects. (orig.) [de

  1. Repair of steam turbines by welding

    International Nuclear Information System (INIS)

    Bohnstedt, H.J.; Loebert, P.

    1987-01-01

    In some cases, turbine parts can be repaired by welding, even rotating parts such as the shaft or the blades. Practical examples of successful repair work are explained, as for instance: welding of the last web of the turbine wheel of two MD-rotors, repair of erosion damage on turbine blades, of solid-matter erosion on a medium-pressure blading, or welding repair of a high-pressure turbine casing. (DG) [de

  2. Recent advances in DNA repair and recombination.

    Science.gov (United States)

    Iwanejko, L A; Jones, N J

    1998-09-11

    The subjects of the talks at this 1-day DNA Repair Network meeting, held at City University, London on December 15, 1997, encompassed a range of topics and reflected some of the current areas of research in the United Kingdom. Topics included DNA double-strand break repair, V(D)J recombination, DNA ligases, the RecQ family of helicases and Bloom's syndrome, UVB and immunosuppression, the repair of oxidative damage and mismatch repair mechanisms.

  3. Use of Drosophila to study DNA repair

    International Nuclear Information System (INIS)

    Boyd, J.B.; Harris, P.V.; Sakaguchi, K.

    1988-01-01

    This paper discusses Drosophila, the premier metazoan organism for analyzing many fundamental features of eukaryotic gene regulation. The authors present adaptations of several approaches for studying DNA repair to an analysis of repair-defective mutants in Drosophila. A current understanding of Drosophila DNA repair is described

  4. 30 CFR 56.6801 - Vehicle repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Vehicle repair. 56.6801 Section 56.6801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Vehicle repair. Vehicles containing explosive material and oxidizers shall not be taken into a repair...

  5. The two faces of plan repair

    NARCIS (Netherlands)

    Van der Krogt, R.P.J.; De Weerdt, M.M.

    2004-01-01

    Plan repair has two faces. Alternately, a plan repair method looks like a planning method, or looks like a method that does exactly the opposite, i.e., removing actions from a plan. We propose a general framework for plan repair that shows the relation between these two alternating steps. Any plan

  6. 30 CFR 57.14104 - Tire repairs.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tire repairs. 57.14104 Section 57.14104 Mineral... Devices and Maintenance Requirements § 57.14104 Tire repairs. (a) Before a tire is removed from a vehicle for tire repair, the valve core shall be partially removed to allow for gradual deflation and then...

  7. 30 CFR 56.14104 - Tire repairs.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tire repairs. 56.14104 Section 56.14104 Mineral... Devices and Maintenance Requirements § 56.14104 Tire repairs. (a) Before a tire is removed from a vehicle for tire repair, the valve core shall be partially removed to allow for gradual deflation and then...

  8. Is laparoscopic inguinal hernia repair more effective than open repair

    International Nuclear Information System (INIS)

    Aly, O.; Green, A.; Joy, M.; Wong, C.H.; Malik, M

    2011-01-01

    To systematically review randomized controlled trials, (RCT) evidence comparing Lichtenstein to total extraperitoneal (TEP) hernia repair in terms of clinical and cost effectiveness. Study Design: Case series. Place and Duration of Study: The study was conducted at University of Abderdeen, U.K. Methodology: A comprehensive online literature search was undertaken using databases such as MEDLINE, PubMed, EMBASE and Springerlink. Studies were then short listed according to the selection criteria (RCT with over 100 subject and English language publications from 1995 onwards) and appraised using the SIGN Methodology Checklist. A meta analysis of the data was also performed using RevMan software. Results: Analysis of reported data shows that TEP has less postoperative pain and return to work than Lichtenstein method. Operation time is shown to be longer in the TEP but this difference is shortened with increasing surgeon experience. The meta-analysis of the data on complications shows that there are no significant differences between the two types of procedures. TEP causes more short-term recurrences which are attributed to the learning curve effect. Long term recurrence rates on the other hand show no significant differences. At present TEP is slightly more expensive than Lichtenstein repair. Conclusion: Both TEP and Lichtenstein repair are clinically effective procedures. The choice between them should be made on a case-by-case basis; which depends on the patient's preference and characteristics such as age, work and health status. (author)

  9. Metabolic modulation of mammalian DNA excision repair

    Energy Technology Data Exchange (ETDEWEB)

    Schrader, T.J.

    1988-01-01

    First, ultraviolet light (UVL)- and dimethylsulfate (DMS)-induced excision repair was examined in quiescent and lectin-stimulated bovine lymphocytes. Upon mitogenic stimulation, UVL-induced repair increased by a factor of 2 to 3, and reached this maximum 2 days before the onset of DNA replication. However, DMS-induced repair increased sevenfold in parallel with DNA replication. Repair patch sizes were smaller for DMS-induced damage reflecting patches of 7 nucleotides in quiescent lymphocytes compared to 20 nucleotides induced by UVL. The patch size increased during lymphocyte stimulation until one day prior to the peak of DNA replication when patch sizes of 45 and 35 nucleotides were produced in response to UVL- and DMS-induced damage, respectively. At the peak of DNA replication, the patch sizes were equal for both damaging agents at 34 nucleotides. In the second study, a small amount of repair replication was observed in undamaged quiescent and concanavalin A-stimulated bovine lymphocytes as well as in human T98G glioblastoma cells. Repair incorporation doubled in the presence of hydroxyurea. Thirdly, the enhanced repair replication induced by the poly (ADP-ribose) polymerase inhibitor, 3-aminobenzamide, (3-AB), could not be correlated either with an increased rate of repair in the presence of 3-AB or with the use of hydroxyurea in the repair protocol. Finally, treatment of unstimulated lymphocytes with hyperthermia was accompanied by decreased repair replication while the repair patches remained constant at 20 nucleotides.

  10. Complex networks under dynamic repair model

    Science.gov (United States)

    Chaoqi, Fu; Ying, Wang; Kun, Zhao; Yangjun, Gao

    2018-01-01

    Invulnerability is not the only factor of importance when considering complex networks' security. It is also critical to have an effective and reasonable repair strategy. Existing research on network repair is confined to the static model. The dynamic model makes better use of the redundant capacity of repaired nodes and repairs the damaged network more efficiently than the static model; however, the dynamic repair model is complex and polytropic. In this paper, we construct a dynamic repair model and systematically describe the energy-transfer relationships between nodes in the repair process of the failure network. Nodes are divided into three types, corresponding to three structures. We find that the strong coupling structure is responsible for secondary failure of the repaired nodes and propose an algorithm that can select the most suitable targets (nodes or links) to repair the failure network with minimal cost. Two types of repair strategies are identified, with different effects under the two energy-transfer rules. The research results enable a more flexible approach to network repair.

  11. Current Biomechanical Concepts for Rotator Cuff Repair

    Science.gov (United States)

    2013-01-01

    For the past few decades, the repair of rotator cuff tears has evolved significantly with advances in arthroscopy techniques, suture anchors and instrumentation. From the biomechanical perspective, the focus in arthroscopic repair has been on increasing fixation strength and restoration of the footprint contact characteristics to provide early rehabilitation and improve healing. To accomplish these objectives, various repair strategies and construct configurations have been developed for rotator cuff repair with the understanding that many factors contribute to the structural integrity of the repaired construct. These include repaired rotator cuff tendon-footprint motion, increased tendon-footprint contact area and pressure, and tissue quality of tendon and bone. In addition, the healing response may be compromised by intrinsic factors such as decreased vascularity, hypoxia, and fibrocartilaginous changes or aforementioned extrinsic compression factors. Furthermore, it is well documented that torn rotator cuff muscles have a tendency to atrophy and become subject to fatty infiltration which may affect the longevity of the repair. Despite all the aforementioned factors, initial fixation strength is an essential consideration in optimizing rotator cuff repair. Therefore, numerous biomechanical studies have focused on elucidating the strongest devices, knots, and repair configurations to improve contact characteristics for rotator cuff repair. In this review, the biomechanical concepts behind current rotator cuff repair techniques will be reviewed and discussed. PMID:23730471

  12. [Constitutional mismatch repair deficiency syndrome].

    Science.gov (United States)

    Jongmans, Marjolijn C; Gidding, Corrie E; Loeffen, Jan; Wesseling, Pieter; Mensenkamp, Arjen; Hoogerbrugge, Nicoline

    2015-01-01

    Constitutional mismatch repair deficiency (CMMR-D) syndrome is characterised by a significantly increased risk for developing cancer in childhood. It arises when both parents have a mutation in the same mismatch repair gene and pass it on to their child. An 8-year-old girl was diagnosed with CMMR-D syndrome after she developed a brain tumour at the age of 4 and a T-cell non-Hodgkin lymphoma at the age of 6. She had multiple hyperpigmented skin lesions and died of myelodysplastic syndrome at the age of 11. In children with cancer CMMR-D syndrome can be recognized particularly if there are multiple primary malignancies and skin hyperpigmentations and hypopigmentations. The parents of these children are at high risk for colorectal and endometrial cancer (Lynch syndrome), amongst others.

  13. Mitochondrial base excision repair assays

    DEFF Research Database (Denmark)

    Maynard, Scott; de Souza-Pinto, Nadja C; Scheibye-Knudsen, Morten

    2010-01-01

    The main source of mitochondrial DNA (mtDNA) damage is reactive oxygen species (ROS) generated during normal cellular metabolism. The main mtDNA lesions generated by ROS are base modifications, such as the ubiquitous 8-oxoguanine (8-oxoG) lesion; however, base loss and strand breaks may also occur....... Many human diseases are associated with mtDNA mutations and thus maintaining mtDNA integrity is critical. All of these lesions are repaired primarily by the base excision repair (BER) pathway. It is now known that mammalian mitochondria have BER, which, similarly to nuclear BER, is catalyzed by DNA...... glycosylases, AP endonuclease, DNA polymerase (POLgamma in mitochondria) and DNA ligase. This article outlines procedures for measuring oxidative damage formation and BER in mitochondria, including isolation of mitochondria from tissues and cells, protocols for measuring BER enzyme activities, gene...

  14. Repair welding and online radiography

    International Nuclear Information System (INIS)

    Nuding, W.; Grimm, R.; Link, R.; Schroeder, P.; Schroeder, G.

    1990-01-01

    The status of a joint project is reported, which is to develop a computerized testing and welding system for repair work in turbine blades. An X-ray radiographic testing device consisting of microfocus tube, manipulator and image processing system, is modified for this purpose so as to offer a greater number of image points scanned for image processing, and to thus achieve a better resolution for reliable detection of even very small defects. The consistency of the X-ray tube performance, which is a pre-requisite for automation, is to be achieved by a wa tercooled, high-duty tube head. The recording of defect coordinates in the repair zone is done for input into a welding robot to be developed by other partners in the project, so as to allow automated welding work. (orig.) [de

  15. Primary unilateral cleft lip repair.

    Science.gov (United States)

    Adenwalla, H S; Narayanan, P V

    2009-10-01

    The unilateral cleft lip is a complex deformity. Surgical correction has evolved from a straight repair through triangular and quadrilateral repairs to the Rotation Advancement Technique of Millard. The latter is the technique followed at our centre for all unilateral cleft lip patients. We operate on these at five to six months of age, do not use pre-surgical orthodontics, and follow a protocol to produce a notch-free vermillion. This is easy to follow even for trainees. We also perform closed alar dissection and extensive primary septoplasty in all these patients. This has improved the overall result and has no long-term deleterious effect on the growth of the nose or of the maxilla. Other refinements have been used for prevention of a high-riding nostril, and correction of the vestibular web.

  16. Primary unilateral cleft lip repair

    Directory of Open Access Journals (Sweden)

    Adenwalla H

    2009-10-01

    Full Text Available The unilateral cleft lip is a complex deformity. Surgical correction has evolved from a straight repair through triangular and quadrilateral repairs to the Rotation Advancement Technique of Millard. The latter is the technique followed at our centre for all unilateral cleft lip patients. We operate on these at five to six months of age, do not use pre-surgical orthodontics, and follow a protocol to produce a notch-free vermillion. This is easy to follow even for trainees. We also perform closed alar dissection and extensive primary septoplasty in all these patients. This has improved the overall result and has no long-term deleterious effect on the growth of the nose or of the maxilla. Other refinements have been used for prevention of a high-riding nostril, and correction of the vestibular web.

  17. Large Extremity Peripheral Nerve Repair

    Science.gov (United States)

    2016-12-01

    These antimicrobial peptides are implicated in the resistance of epithelial surfaces to microbial colonisation and have been shown to be upregulated...be equivalent to standard autograft repair in rodent models. Outcomes have now been validated in a large animal (swine) model with 5 cm ulnar nerve...Goals of the Project Task 1– Determine mechanical properties, seal strength and resistance to biodegradation of candidate photochemical nerve wrap

  18. Repair of EL4 leaks

    International Nuclear Information System (INIS)

    1985-03-01

    The reactor shutdown was decided on the 15th of November 1984, because the evolution of the carbon dioxide quantity in the helium blanket of the heavy water. Leaks have been localized on three different channels. Repairs have been made in hard conditions taking into account the reactor state (materials strongly irradiated). The restart has been authorized on the 24th of January 1985 [fr

  19. Mutagenic DNA repair in enterobacteria

    International Nuclear Information System (INIS)

    Sedgwick, S.G.; Chao Ho; Woodgate, R.

    1991-01-01

    Sixteen species of enterobacteria have been screened for mutagenic DNA repair activity. In Escherichia coli, mutagenic DNA repair is encoded by the umuDC operon. Synthesis of UmuD and UmuC proteins is induced as part of the SOS response to DNA damage, and after induction, the UmuD protein undergoes an autocatalytic cleavage to produce the carboxy-terminal UmuD' fragment needed for induced mutagenesis. The presence of a similar system in other species was examined by using a combined approach of inducible-mutagenesis assays, cross-reactivity to E. coli UmuD and UmuD' antibodies to test for induction and cleavage of UmuD-like proteins, and hybridization with E. coli and Salmonella typhimurium u mu DNA probes to map umu-like genes. The results indicate a more widespread distribution of mutagenic DNA repair in other species than was previously thought. They also show that umu loci can be more complex in other species than in E. coli. Differences in UV-induced mutability of more than 200-fold were seen between different species of enteric bacteria and even between multiple natural isolates of E. coli, and yet some of the species which display a poorly mutable phenotype still have umu-like genes and proteins. It is suggested that umuDC genes can be curtailed in their mutagenic activities but that they may still participate in some other, unknown process which provides the continued stimulus for their retention

  20. Comparing Biomechanical Properties, Repair Times, and Value of Common Core Flexor Tendon Repairs.

    Science.gov (United States)

    Chauhan, Aakash; Schimoler, Patrick; Miller, Mark C; Kharlamov, Alexander; Merrell, Gregory A; Palmer, Bradley A

    2018-05-01

    The aim of the study was to compare biomechanical strength, repair times, and repair values for zone II core flexor tendon repairs. A total of 75 fresh-frozen human cadaveric flexor tendons were harvested from the index through small finger and randomized into one of 5 repair groups: 4-stranded cross-stitch cruciate (4-0 polyester and 4-0 braided suture), 4-stranded double Pennington (2-0 knotless barbed suture), 4-stranded Pennington (4-0 double-stranded braided suture), and 6-stranded modified Lim-Tsai (4-0 looped braided suture). Repairs were measured in situ and their repair times were measured. Tendons were linearly loaded to failure and multiple biomechanical values were measured. The repair value was calculated based on operating room costs, repair times, and suture costs. Analysis of variance (ANOVA) and Tukey post hoc statistical analysis were used to compare repair data. The braided cruciate was the strongest repair ( P > .05) but the slowest ( P > .05), and the 4-stranded Pennington using double-stranded suture was the fastest ( P > .05) to perform. The total repair value was the highest for braided cruciate ( P > .05) compared with all other repairs. Barbed suture did not outperform any repairs in any categories. The braided cruciate was the strongest of the tested flexor tendon repairs. The 2-mm gapping and maximum load to failure for this repair approached similar historical strength of other 6- and 8-stranded repairs. In this study, suture cost was negligible in the overall repair cost and should be not a determining factor in choosing a repair.

  1. DNA repair in Mycobacterium tuberculosis revisited.

    Science.gov (United States)

    Dos Vultos, Tiago; Mestre, Olga; Tonjum, Tone; Gicquel, Brigitte

    2009-05-01

    Our understanding of Mycobacterium tuberculosis DNA repair mechanisms is still poor compared with that of other bacterial organisms. However, the publication of the first complete M. tuberculosis genome sequence 10 years ago boosted the study of DNA repair systems in this organism. A first step in the elucidation of M. tuberculosis DNA repair mechanisms was taken by Mizrahi and Andersen, who identified homologs of genes involved in the reversal or repair of DNA damage in Escherichia coli and related organisms. Genes required for nucleotide excision repair, base excision repair, recombination, and SOS repair and mutagenesis were identified. Notably, no homologs of genes involved in mismatch repair were identified. Novel characteristics of the M. tuberculosis DNA repair machinery have been found over the last decade, such as nonhomologous end joining, the presence of Mpg, ERCC3 and Hlr - proteins previously presumed to be produced exclusively in mammalian cells - and the recently discovered bifunctional dCTP deaminase:dUTPase. The study of these systems is important to develop therapeutic agents that can counteract M. tuberculosis evolutionary changes and to prevent adaptive events resulting in antibiotic resistance. This review summarizes our current understanding of the M. tuberculosis DNA repair system.

  2. Treatment and Controversies in Paraesophageal Hernia Repair

    Directory of Open Access Journals (Sweden)

    P. Marco eFisichella

    2015-04-01

    Full Text Available Background: Historically all paraesophageal hernias were repaired surgically, today intervention is reserved for symptomatic paraesophageal hernias. In this review, we describe the indications for repair and explore the controversies in paraesophageal hernia repair, which include a comparison of open to laparoscopic paraesophageal hernia repair, the necessity of complete sac excision, the routine performance of fundoplication, and the use of mesh for hernia repair.Methods: We searched Pubmed for papers published between 1980 and 2015 using the following keywords: hiatal hernias, paraesophageal hernias, regurgitation, dysphagia, gastroesophageal reflux disease, aspiration, GERD, endoscopy, manometry, pH monitoring, proton pump inhibitors, anemia, iron deficiency anemia, Nissen fundoplication, sac excision, mesh, mesh repair. Results: Indications for paraesophageal hernia repair have changed, and currently symptomatic paraesophageal hernias are recommended for repair. In addition, it is important not to overlook iron-deficiency anemia and pulmonary complaints, which tend to improve with repair. Current practice favors a laparoscopic approach, complete sac excision, primary crural repair with or without use of mesh, and a routine fundoplication.

  3. Ultrasound determination of rotator cuff tear repairability

    Science.gov (United States)

    Tse, Andrew K; Lam, Patrick H; Walton, Judie R; Hackett, Lisa

    2015-01-01

    Background Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability. Methods The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability. Results Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p tear size (p tear size ≥4 cm2 or anteroposterior tear length ≥25 mm indicated an irreparable rotator cuff tear. Conclusions Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability. PMID:27582996

  4. A study of everyday repair: informing interaction design

    OpenAIRE

    Maestri, Leah Adriana

    2012-01-01

    Repair is typically seen in design as the restoration of broken objects to their original state. Repair by non-experts, or everyday repair, can often lead to novel forms of repair resulting in the creative repurposing of objects that are often unforeseen by designers. Using a grounded theory approach, this study describes key aspects of repair including: the techniques non-experts employ for repairing their objects; the motivations that prompt acts of repair; and the outcomes that result fr...

  5. Influence of repair length on residual stress in the repair weld of a clad plate

    International Nuclear Information System (INIS)

    Jiang Wenchun; Xu, X.P.; Gong, J.M.; Tu, S.T.

    2012-01-01

    Highlights: ► Residual stress in the repair weld of a stainless steel clad plate is investigated. ► The effect of repair length on residual stress has been studied. ► Large tensile residual stress is generated in the repair weld and heat affected zone. ► With the increase of repair length, transverse stress is decreased. ► Repair length has little effect on longitudinal stress. - Abstract: A 3-D sequential coupling finite element simulation is performed to investigate the temperature field and residual stress in the repair weld of a stainless steel clad plate. The effect of repair length on residual stress has been studied, aiming to provide a reference for repairing the cracked clad plate. The results show that large tensile residual stresses are generated in the repair weld and heat affected zone (HAZ), and then decrease gradually away from the weld and HAZ. The residual stresses through thickness in the clad layer are relative uniform, while they are non-uniform in the base metal. A discontinuous stress distribution is generated across the interface between weld metal and base metal. The repair length has a great effect on transverse stress. With the increase of repair length, the transverse stress is decreased. When the repair length is increased to 14 cm, the peak of transverse stress has been decreased below yield strength, and the transverse stress in the weld and HAZ has also been greatly decreased. But the repair length has little effect on longitudinal stress.

  6. Laparoscopic repair for vesicouterine fistulae

    Directory of Open Access Journals (Sweden)

    Rafael A. Maioli

    2015-10-01

    Full Text Available ABSTRACT Objective: The purpose of this video is to present the laparoscopic repair of a VUF in a 42-year-old woman, with gross hematuria, in the immediate postoperative phase following a cesarean delivery. The obstetric team implemented conservative management, including Foley catheter insertion, for 2 weeks. She subsequently developed intermittent hematuria and cystitis. The urology team was consulted 15 days after cesarean delivery. Cystoscopy indicated an ulcerated lesion in the bladder dome of approximately 1.0cm in size. Hysterosalpingography and a pelvic computed tomography scan indicated a fistula. Materials and Methods: Laparoscopic repair was performed 30 days after the cesarean delivery. The patient was placed in the lithotomy position while also in an extreme Trendelenburg position. Pneumoperitoneum was established using a Veress needle in the midline infra-umbilical region, and a primary 11-mm port was inserted. Another 11-mm port was inserted exactly between the left superior iliac spine and the umbilicus. Two other 5-mm ports were established under laparoscopic guidance in the iliac fossa on both sides. The omental adhesions in the pelvis were carefully released and the peritoneum between the bladder and uterus was incised via cautery. Limited cystotomy was performed, and the specific sites of the fistula and the ureteral meatus were identified; thereafter, the posterior bladder wall was adequately mobilized away from the uterus. The uterine rent was then closed using single 3/0Vicryl sutures and two-layer watertight closure of the urinary bladder was achieved by using 3/0Vicryl sutures. An omental flap was mobilized and inserted between the uterus and the urinary bladder, and was fixed using two 3/0Vicryl sutures, followed by tube drain insertion. Results: The operative time was 140 min, whereas the blood loss was 100ml. The patient was discharged 3 days after surgery, and the catheter was removed 12 days after surgery

  7. Underwater coating repair cuts nuclear maintenance costs

    International Nuclear Information System (INIS)

    Stuart, C.O.

    1993-01-01

    This article discusses the cleaning and recoating/repair of condensate tanks or other vessels in a nuclear power plant. The topics of the article include the safety and regulatory need for this system of repair, a description of the work done on the Brown's Ferry MK-1 suppression chamber, coating failure mechanisms, qualitative inspection, quantitative inspection, quantitative inspection results, spot repairs, and economic considerations

  8. PTMC in post-MV repair status

    Directory of Open Access Journals (Sweden)

    Lachikarathman Devegowda

    2016-09-01

    Full Text Available MV repair in the rheumatic population is feasible with acceptable long-term results.1 Incidence of mitral stenosis (MS following mitral valve (MV repair for severe rheumatic mitral regurgitation (MR and usefulness of percutaneous transluminal mitral valvuloplasty (PTMC in these patients is not described in literature. We report a case of successful PTMC in severe MS following MV repair for severe rheumatic MR.

  9. Early discharge after external anal sphincter repair

    DEFF Research Database (Denmark)

    Rosenberg, J; Kehlet, H

    1999-01-01

    PURPOSE: The aim of this study was to describe an accelerated-stay program for repair of the external anal sphincter. METHODS: Twenty consecutive patients undergoing overlapping repair of the external anal sphincter were included in the study. Effect parameters were length of hospitalization....... CONCLUSION: We have described a safe accelerated-stay program (24 to 48 hours) for overlapping repair of external anal sphincter....

  10. Endogenous DNA Damage and Repair Enzymes

    Directory of Open Access Journals (Sweden)

    Arne Klungland

    2016-06-01

    Full Text Available Tomas Lindahl completed his medical studies at Karolinska Institute in 1970. Yet, his work has always been dedicated to unraveling fundamental mechanisms of DNA decay and DNA repair. His research is characterized with groundbreaking discoveries on the instability of our genome, the identification of novel DNA repair activities, the characterization of DNA repair pathways, and the association to diseases, throughout his 40 years of scientific career.

  11. Hepatopancreaticobiliary Values after Thoracoabdominal Aneurysm Repair

    OpenAIRE

    Wu, Darrell; Coselli, Joseph S.; Johnson, Michael L.; LeMaire, Scott A.

    2014-01-01

    Background: After thoracoabdominal aortic aneurysm (TAAA) repair, blood tests assessing hepatopancreaticobiliary (HPB) organs commonly have abnormal results. The clinical significance of such abnormalities is difficult to determine because the expected postoperative levels have not been characterized. Therefore, we sought to establish expected trends in HPB laboratory values after TAAA repair. Methods: This 5-year study comprised 155 patients undergoing elective Crawford extent II TAAA repair...

  12. Chromatin dynamics during DSB repair

    Czech Academy of Sciences Publication Activity Database

    Falk, Martin; Lukášová, Emilie; Gabrielová, Barbora; Ondřej, Vladan; Kozubek, Stanislav

    2007-01-01

    Roč. 1773, č. 10 (2007), s. 1534-1545 ISSN 0167-4889 R&D Projects: GA ČR(CZ) GP204/06/P349; GA ČR(CZ) 1QS500040508; GA AV ČR(CZ) IAA1065203; GA MŠk(CZ) 1P05OC084 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : chromatin structure * double- strand breaks (DSB) * DNA repair Subject RIV: BO - Biophysics Impact factor: 4.374, year: 2007

  13. Root justifications for ontology repair

    CSIR Research Space (South Africa)

    Moodley, K

    2011-08-01

    Full Text Available stream_source_info Moodley_2011.pdf.txt stream_content_type text/plain stream_size 32328 Content-Encoding ISO-8859-1 stream_name Moodley_2011.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Root Justi cations... the ontology, based on the no- tion of root justi cations [8, 9]. In Section 5, we discuss the implementation of a Prot eg e3 plugin which demonstrates our approach to ontology repair. In this section we also discuss some experimental results comparing...

  14. Concrete structures protection, repair and rehabilitation

    CERN Document Server

    Woodson, R Dodge

    2009-01-01

    The success of a repair or rehabilitation project depends on the specific plans designed for it. Concrete Structures: Protection, Repair and Rehabilitation provides guidance on evaluating the condition of the concrete in a structure, relating the condition of the concrete to the underlying cause or causes of that condition, selecting an appropriate repair material and method for any deficiency found, and using the selected materials and methods to repair or rehabilitate the structure. Guidance is also provided for engineers focused on maintaining concrete and preparing concrete investigation r

  15. Induced repair and mutagenesis in animal cells

    International Nuclear Information System (INIS)

    Takimoto, Koichi

    1981-01-01

    Induced repair and mutagenesis of animal cells against UV were studied in contrast with SOS repair of E. coli primarily by the use of viruses. Since UV-enhanced reactivation is a phenomenon similar to UV-reactivation (mutagenesis) and the presence of lesion bypass synthsis has been suggested, UV-enhanced reactivation has several common aspects with SOS reactivation of E. coli. However, correlation is not necessarily noted between increase in the viral survival rate and mutagenesis, nor do protease blockers exert any effect. Therefore, SOS repair of E. coli may have different mechansms from induced repair and mutagenesis in animal cells. (Ueda, J.)

  16. DNA damage and repair in plants

    International Nuclear Information System (INIS)

    Britt, A.B.

    1996-01-01

    The biological impact of any DNA damaging agent is a combined function of the chemical nature of the induced lesions and the efficiency and accuracy of their repair. Although much has been learned frommicrobes and mammals about both the repair of DNA damage and the biological effects of the persistence of these lesions, much remains to be learned about the mechanism and tissue-specificity of repair in plants. This review focuses on recent work on the induction and repair of DNA damage in higher plants, with special emphasis on UV-induced DNA damage products. (author)

  17. DNA repair in non-mammalian animals

    International Nuclear Information System (INIS)

    Mitani, Hiroshi

    1984-01-01

    Studies on DNA repair have been performed using microorganisms such as Escherichia coli and cultured human and mammalian cells. However, it is well known that cultured organic cells differ from each other in many respects, although DNA repair is an extremely fundamental function of organisms to protect genetic information from environmental mutagens such as radiation and 0 radicals developing in the living body. To answer the question of how DNA repair is different between the animal species, current studies on DNA repair of cultured vertebrate cells using the methods similar to those in mammalian experiments are reviewed. (Namekawa, K.)

  18. X-ray repair cross complementing protein 1 in base excision repair

    DEFF Research Database (Denmark)

    Hanssen-Bauer, Audun; Solvang-Garten, Karin; Akbari, Mansour

    2012-01-01

    X-ray Repair Cross Complementing protein 1 (XRCC1) acts as a scaffolding protein in the converging base excision repair (BER) and single strand break repair (SSBR) pathways. XRCC1 also interacts with itself and rapidly accumulates at sites of DNA damage. XRCC1 can thus mediate the assembly of large...

  19. CrowdAidRepair: A Crowd-Aided Interactive Data Repairing Method

    KAUST Repository

    Zhou, Jian

    2016-03-25

    Data repairing aims at discovering and correcting erroneous data in databases. Traditional methods relying on predefined quality rules to detect the conflict between data may fail to choose the right way to fix the detected conflict. Recent efforts turn to use the power of crowd in data repairing, but the crowd power has its own drawbacks such as high human intervention cost and inevitable low efficiency. In this paper, we propose a crowd-aided interactive data repairing method which takes the advantages of both rule-based method and crowd-based method. Particularly, we investigate the interaction between crowd-based repairing and rule-based repairing, and show that by doing crowd-based repairing to a small portion of values, we can greatly improve the repairing quality of the rule-based repairing method. Although we prove that the optimal interaction scheme using the least number of values for crowd-based repairing to maximize the imputation recall is not feasible to be achieved, still, our proposed solution identifies an efficient scheme through investigating the inconsistencies and the dependencies between values in the repairing process. Our empirical study on three data collections demonstrates the high repairing quality of CrowdAidRepair, as well as the efficiency of the generated interaction scheme over baselines.

  20. DNA damage repair and radiosensitivity

    International Nuclear Information System (INIS)

    Suzuki, Norio

    2003-01-01

    Tailored treatment is not new in radiotherapy; it has been the major subject for the last 20-30 years. Radiation responses and RBE (relative biological effectiveness) depend on assay systems, endpoints, type of tissues and tumors, radiation quality, dose rate, dose fractionation, physiological and environmental factors etc, Latent times to develop damages also differ among tissues and endpoints depending on doses and radiation quality. Recent progress in clarification of radiation induced cell death, especially of apoptotic cell death, is quite important for understanding radiosensitivity of tumor cure process as well as of tumorigenesis. Apoptotic cell death as well as dormant cells had been unaccounted and missed into a part of reproductive cell death. Another area of major progress has been made in clarifying repair mechanisms of radiation damage, i.e., non-homologous end joining (NHEJ) and homologous recombinational repair (HRR). New approaches and developments such as cDNA or protein micro arrays and so called informatics in addition to basic molecular biological analysis are expected to aid identifying molecules and their roles in signal transduction pathways, which are multi-factorial and interactive each other being involved in radiation responses. (authors)

  1. Predictable repair of provisional restorations.

    Science.gov (United States)

    Hammond, Barry D; Cooper, Jeril R; Lazarchik, David A

    2009-01-01

    The importance of provisional restorations is often downplayed, as they are thought of by some as only "temporaries." As a result, a less-than-ideal provisional is sometimes fabricated, in part because of the additional chair time required to make provisional modifications when using traditional techniques. Additionally, in many dental practices, these provisional restorations are often fabricated by auxillary personnel who may not be as well trained in the fabrication process. Because provisionals play an important role in achieving the desired final functional and esthetic result, a high-quality provisional restoration is essential to fabricating a successful definitive restoration. This article describes a method for efficiently and predictably repairing both methacrylate and bis-acryl provisional restorations using flowable composite resin. By use of this relatively simple technique, provisional restorations can now be modified or repaired in a timely and productive manner to yield an exceptional result. Successful execution of esthetic and restorative dentistry requires attention to detail in every aspect of the case. Fabrication of high-quality provisional restorations can, at times, be challenging and time consuming. The techniques for optimizing resin provisional restorations as described in this paper are pragmatic and will enhance the delivery of dental treatment.

  2. Repairing liner of the reactor

    International Nuclear Information System (INIS)

    Aguilar H, F.

    2001-07-01

    Due to the corrosion problems of the aluminum coating of the reactor pool, a periodic inspections program by ultrasound to evaluate the advance grade and the corrosion speed was settled down. This inspections have shown the necessity to repair some areas, in those that the slimming is significant, of not making it can arrive to the water escape of the reactor pool. The objective of the repair is to place patches of plates of 1/4 inch aluminum thickness in the areas of the reactor 'liner', in those that it has been detected by ultrasound a smaller thickness or similar to 3 mm. To carry out this the fuels are move (of the core and those that are decaying) to a temporary storage, the structure of the core is confined in a tank that this placed inside the pool of the reactor, a shield is placed in the thermal column and it is completely extracted the water for to leave uncover the 'liner' of the reactor. (Author)

  3. KNEE PROPRIOCEPTION FOLLOWING MENISCAL REPAIR

    Directory of Open Access Journals (Sweden)

    Brytsko A. A.

    2018-02-01

    Full Text Available Background. It is well known that meniscectomy leads to osteoarthritis of the knee and proprioception impairment. Objective. The aim of this study was to assess retrospectively the joint position sense after meniscal suture and partial medial meniscal resection and to estimate the patients’ satisfaction with knee function. Material and Methods. We evaluated the outcomes of 27 patients after meniscal repair and compared them to those of 24 patients after partial meniscal resection. We estimated the joint position sense at 30°, 45° and 60° of flexion using the Biodex system 4 Pro. All patients were assessed with the IKDC 2000 subjective knee score. Results. A statistically significant worsening in reproducing the injured joint position in comparison to the healthy limb in both groups was observed. These impairments were mostly expressed at 45° and 60° of knee flexion, and were worsening over time in the group of patients who had undergone medial meniscal resection. An average value by the IKDC 2000 scale after 24 months in the meniscorrhaphy group was 76.73 ± 11.17% and 68.93 ± 14.76% after partial medial meniscal resection. Сonclusion. The control over position of the knee is not impaired after meniscal repair. An overall satisfaction with joint function is higher in patients who undergo meniscal suture in comparison to the partial medial meniscal resection group.

  4. A geometric process repair model for a repairable cold standby system with priority in use and repair

    International Nuclear Information System (INIS)

    Zhang Yuanlin; Wang Guanjun

    2009-01-01

    In this paper, a deteriorating cold standby repairable system consisting of two dissimilar components and one repairman is studied. For each component, assume that the successive working times form a decreasing geometric process while the consecutive repair times constitute an increasing geometric process, and component 1 has priority in use and repair. Under these assumptions, we consider a replacement policy N based on the number of repairs of component 1 under which the system is replaced when the number of repairs of component 1 reaches N. Our problem is to determine an optimal policy N* such that the average cost rate (i.e. the long-run average cost per unit time) of the system is minimized. The explicit equation of the average cost rate of the system is derived and the corresponding optimal replacement policy N* can be determined analytically or numerically. Finally, a numerical example with Weibull distribution is given to illustrate some theoretical results in this paper.

  5. Repairing method and repairing device of incore structure

    International Nuclear Information System (INIS)

    Uraki, Keiichi; Okamura, Hisanobu; Matsumoto, Toshimi

    1998-01-01

    In structures or equipment made of stainless steel, Ni-based alloy or a low alloy steel and undergoing neutron irradiation and causing a crack-like defect in a reactor pressure vessel, a plate is applied to a region where the crack-like detect is caused, and pressure is applied locally to bond the plate by generated resistance. Namely, electric current is supplied to the portion to be bonded while pressurizing to bond it by generated resistance heat. Then the propagation of cracks can be prevented and occurrence of cracks upon repairing can be prevented relative to a structural member undergoing neutron irradiation in the reactor pressure vessel and causing a crack-like defect thereby enabling to provide effects of preventing occurrence of an accident due to stress corrosion cracking of a nuclear power plant and prolonging the integrity of the plant. (N.H.)

  6. Improvement of adhesion performance of mortar-repair interface with inducing crack path into repair

    Directory of Open Access Journals (Sweden)

    A. Satoh

    2015-10-01

    Full Text Available The most important performance for repair materials is adhesion to the substrate. The authors experimentally find out that high modulus fine aggregates in repair material enhance strength of it as well as the strength of the interface repaired with it, compared to the ordinary repair without fine aggregates. This paper elaborates the mechanisms for that with fractographic observation and FEM analysis based on the results of experiment. Also the authors discuss the ways for enhancing the strength and ductility of the repaired mortar

  7. International congress on DNA damage and repair: Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation. (TEM)

  8. International congress on DNA damage and repair: Book of abstracts

    International Nuclear Information System (INIS)

    1987-01-01

    This document contains the abstracts of 105 papers presented at the Congress. Topics covered include the Escherichia coli nucleotide excision repair system, DNA repair in malignant transformations, defective DNA repair, and gene regulation

  9. Laparoscopic Inguinal Hernia Repair in a Developing Nation: Short ...

    African Journals Online (AJOL)

    bilateral hernias, and recurrent hernias), there are data demonstrating an ... no reports of laparoscopic inguinal hernia repair from the. Anglophone ... MATERIALS AND METHODS .... inguinal hernia repair has advantages over open repair for.

  10. DNA Repair and Ethnic Differences in Prostate Cancer Risk

    National Research Council Canada - National Science Library

    Goldman, Radoslav

    2008-01-01

    .... To evaluate this hypothesis we quantify DNA repair capacity in blood cells using comet assay and evaluate how this repair capacity is related to genetic variants in OGG1 and XRCC1 DNA repair genes...

  11. DNA Repair and Ethnic Differences in Prostate Cancer Risk

    National Research Council Canada - National Science Library

    Goldman, Radoslav

    2007-01-01

    .... To evaluate this hypothesis we quantify DNA repair capacity in blood cells using comet assay and evaluate how this repair capacity is related to genetic variants in OGG1 and XRCC1 DNA repair genes...

  12. DNA Repair and Ethnic Differences in Prostate Cancer Risk

    National Research Council Canada - National Science Library

    Goldman, Radoslav

    2006-01-01

    .... To evaluate this hypothesis, we quantify DNA repair capacity in blood cells using comet assay and evaluate how this repair capacity is related to genetic variants in OGG1 and XRCC1 DNA repair genes...

  13. DNA repair related to radiation therapy

    International Nuclear Information System (INIS)

    Klein, W.

    1979-01-01

    The DNA excision repair capacity of peripheral human lymphocytes after radiation therapy has been analyzed. Different forms of application of the radiation during the therapy have been taken into account. No inhibition of repair was found if cells were allowed a certain amount of accomodation to radiation, either by using lower doses or longer application times. (G.G.)

  14. Maintenance and Repair of Concrete Structures

    NARCIS (Netherlands)

    Bijen, J.M.J.M.

    1989-01-01

    In 1987 and 1988 a series of articles was published in the Dutchjournal "Cement" about maintenance and repair of concrete structures. The series was written to promote the transfer of know-how concerning maintenance and repair of concrete structures. Use has been made of know-how developed in the

  15. VEHICLE REPAIR AND MAINTENANCE COSTS IN NIGERIA ...

    African Journals Online (AJOL)

    A standard model was established for the prediction of repair and maintenance costs of vehicles in a non-profit making government parastatal. The model was derived based on data collected over a ten year period from a non-profit making government parastatal, and it predicts repair and maintenance costs as a linear ...

  16. 30 CFR 57.6801 - Vehicle repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Vehicle repair. 57.6801 Section 57.6801 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... and Underground § 57.6801 Vehicle repair. Vehicles containing explosive material and oxidizers shall...

  17. Dysphagia in children with repaired oesophageal atresia

    NARCIS (Netherlands)

    Coppens, C.H.; Engel-Hoek, L. van den; Scharbatke, H.E.; Groot, S.A. de; Draaisma, J.M.T.

    2016-01-01

    Dysphagia is a common problem in children with repaired oesophageal atresia (OA). Abnormalities in the oropharyngeal and oesophageal phase have hardly been studied. The aims of this study were to assess the prevalence of dysphagia in children with repaired OA and to identify and differentiate oral

  18. Human DNA repair and recombination genes

    International Nuclear Information System (INIS)

    Thompson, L.H.; Weber, C.A.; Jones, N.J.

    1988-09-01

    Several genes involved in mammalian DNA repair pathways were identified by complementation analysis and chromosomal mapping based on hybrid cells. Eight complementation groups of rodent mutants defective in the repair of uv radiation damage are now identified. At least seven of these genes are probably essential for repair and at least six of them control the incision step. The many genes required for repair of DNA cross-linking damage show overlap with those involved in the repair of uv damage, but some of these genes appear to be unique for cross-link repair. Two genes residing on human chromosome 19 were cloned from genomic transformants using a cosmid vector, and near full-length cDNA clones of each gene were isolated and sequenced. Gene ERCC2 efficiently corrects the defect in CHO UV5, a nucleotide excision repair mutant. Gene XRCC1 normalizes repair of strand breaks and the excessive sister chromatid exchange in CHO mutant EM9. ERCC2 shows a remarkable /approximately/52% overall homology at both the amino acid and nucleotide levels with the yeast RAD3 gene. Evidence based on mutation induction frequencies suggests that ERCC2, like RAD3, might also be an essential gene for viability. 100 refs., 4 tabs

  19. Tumor relapse present in oncologic nasal repair

    International Nuclear Information System (INIS)

    Galvez Chavez, Julio Cesar; Sanchez Wals, Lenia; Monzon Fernandez, Abel Nicolas; Morales Tirado, Roxana

    2009-01-01

    Tumor relapse is one of the more fearsome complications of the oncologic course and also to obscure the life prognosis, causing the loss of many reconstructions and of exhausting the repairing surgical possibilities. The aim of this study was to determine the relapse frequency, the repercussion on the repair and the subsequent medical course of patients operated on malign nasal tumors

  20. The Weekend Effect in AAA Repair.

    Science.gov (United States)

    O'Donnell, Thomas F X; Li, Chun; Swerdlow, Nicholas J; Liang, Patric; Pothof, Alexander B; Patel, Virendra I; Giles, Kristina A; Malas, Mahmoud B; Schermerhorn, Marc L

    2018-04-18

    Conflicting reports exist regarding whether patients undergoing surgery on the weekend or later in the week experience worse outcomes. We identified patients undergoing abdominal aortic aneurysm (AAA) repair in the Vascular Quality Initiative between 2009 and 2017 [n = 38,498; 30,537 endovascular aneurysm repair (EVAR) and 7961 open repair]. We utilized mixed effects logistic regression to compare adjusted rates of perioperative mortality based on the day of repair. Tuesday was the most common day for elective repair (22%), Friday for symptomatic repairs (20%), and ruptured aneurysms were evenly distributed. Patients with ruptured aneurysms experienced similar adjusted mortality whether they underwent repair during the week or on weekends. Transfers of ruptured AAA were more common over the weekend. However, patients transferred on the weekend experienced higher adjusted mortality than those transferred during the week (28% vs 21%, P = 0.02), despite the fact that during the week, transferred patients actually experienced lower adjusted mortality than patients treated at the index hospital (21% vs 31%, P AAA repair. However, patients with ruptured AAA transferred on the weekend experienced higher mortality than those transferred during the week, suggesting a need for improvement in weekend transfer processes.

  1. Self repairing composites for drone air vehicles

    Science.gov (United States)

    Dry, Carolyn

    2015-04-01

    The objective of this effort was to demonstrate the feasibility of impact-initiated delivery of repair chemicals through hollow fiber architectures embedded within graphite fiber reinforced polymer matrix composites, representative of advanced drone aircraft component material systems. Self-repairing structures through coupon and elements were demonstrated, and evaluated.

  2. 26 CFR 1.162-4 - Repairs.

    Science.gov (United States)

    2010-04-01

    ... the cost of acquisition or production or the gain or loss basis of the taxpayer's plant, equipment, or other property, as the case may be, is not increased by the amount of such expenditures. Repairs in the... incidental repairs which neither materially add to the value of the property nor appreciably prolong its life...

  3. DNA Damage, Repair, and Cancer Metabolism

    Science.gov (United States)

    Turgeon, Marc-Olivier; Perry, Nicholas J. S.; Poulogiannis, George

    2018-01-01

    Although there has been a renewed interest in the field of cancer metabolism in the last decade, the link between metabolism and DNA damage/DNA repair in cancer has yet to be appreciably explored. In this review, we examine the evidence connecting DNA damage and repair mechanisms with cell metabolism through three principal links. (1) Regulation of methyl- and acetyl-group donors through different metabolic pathways can impact DNA folding and remodeling, an essential part of accurate double strand break repair. (2) Glutamine, aspartate, and other nutrients are essential for de novo nucleotide synthesis, which dictates the availability of the nucleotide pool, and thereby influences DNA repair and replication. (3) Reactive oxygen species, which can increase oxidative DNA damage and hence the load of the DNA-repair machinery, are regulated through different metabolic pathways. Interestingly, while metabolism affects DNA repair, DNA damage can also induce metabolic rewiring. Activation of the DNA damage response (DDR) triggers an increase in nucleotide synthesis and anabolic glucose metabolism, while also reducing glutamine anaplerosis. Furthermore, mutations in genes involved in the DDR and DNA repair also lead to metabolic rewiring. Links between cancer metabolism and DNA damage/DNA repair are increasingly apparent, yielding opportunities to investigate the mechanistic basis behind potential metabolic vulnerabilities of a substantial fraction of tumors. PMID:29459886

  4. FLEXOR TENDON REPAIR IN THE HAND

    African Journals Online (AJOL)

    Method of Repair. Cases. AGE, SEX ... method is at fault and not the dexterity of the operator or his technique. .... Physio- therapy seldom makes stiff fingers work, but it prevents .... or repaired later by direct suture, graft or transplant. No. of.

  5. Plan Repair as an Extension of Planning

    NARCIS (Netherlands)

    Van der Krogt, R.P.J.; De Weerdt, M.M.

    2005-01-01

    In dynamic environments, agents have to deal with changing situations. In these cases, repairing a plan is often more efficient than planning from scratch, but existing planning techniques are more advanced than existing plan repair techniques. Therefore, we propose a straightforward method to

  6. Using repair priorities in systems with redundacies

    NARCIS (Netherlands)

    Sleptchenko, A.V.; Adan, I.J.B.F.; Van Houtum, G.-J.

    2014-01-01

    In this paper, we present and analyze a mathematical model for the computation of the system availability for a system of parallel machines with redundancies and repair priorities. Using the presented models, we show that the repair priorities have a strong effect on the performance of the system.

  7. Mutagenesis and repair of DNA

    International Nuclear Information System (INIS)

    Janion, C.; Grzesiuk, E.; Fabisiewicz, A.; Tudek, B.; Ciesla, J.; Graziewicz, M.; Wojcik, A.; Speina, E.

    1998-01-01

    Full text. The discovery that the mfd gene codes for a transcription-coupling repair factor (TRCF) prompted us to re-investigate the MFD (mutation frequency decline) phenomenon in E.coli K-12 strain when mutations were induced by ultraviolet light, halogen light or MMS-treatment. These studies revealed that: (i) the process of MFD involves the proofreading activity of DNA pol III and the mismatch repair system, as well as, TRCF and the UvrABC-excinuclease (ii) a semi-rich plate test may be replaced by a rich liquid medium, (iii) the T-T pyrimidine dimers are the lesions excised with the highest activity, and (iv) overproduction of UmuD(D'C) proteins leads to a great increase in mutant frequency in irradiated and MMS-treated cells. The role of mismatch repair (MR) in MMS-induced mutagenesis is obscured by the fact that the spectra of mutational specificity are different in bacteria proficient and deficient in MR. It has been found that transposons Tn10 (and Tn5) when inserted into chromosomal DNA of E. coli influence the phenotype lowering the survival and frequency of mutations induced by UV or halogen light irradiation. This is connected with a deficiency of UmuD(D') and UmuC proteins. Transformation of bacteria with plasmids bearing the umuD(D')C genes, suppresses the effects of the transposon insertion, a phenomenon which has not been described before. Single-stranded DNA of M13mp18 phage was oxidized in vitro by a hydroxyl radical generating system including hypoxanthine/xanthine oxidase/Fe3+/EDTA, and it was found that Fapy-Ade, Fapy-Gua, 8-oxyAde and thymine glycol were the main products formed. Replication of the oxidized template by T7 phage DNA polymerase, Klenow fragment of polymerase I, or polymerase beta from bovine thymus has revealed that oxidized pyrimidines are stronger blockers than oxidized purines for T7 phage and Klenow fragment polymerases and the blocking potency depends on the neighboring bases and on the type of polymerase. Studies of

  8. Saturation of DNA repair in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, F E; Setlow, R B

    1979-01-01

    Excision repair seems to reach a plateau in normal human cells at a 254 nm dose near 20 J/m/sup 2/. We measured excision repair in normal human fibroblasts up to 80 J/m/sup 2/. The four techniques used (unscheduled DNA synthesis, photolysis of BrdUrd incorporated during repair, loss of sites sensitive to a UV endonuclease from Micrococcus luteus, and loss of pyrimidine dimers from DNA) showed little difference between the two doses. Moreover, the loss of endonuclease sites in 24h following two 20 J/m/sup 2/ doses separated by 24h was similar to the loss observed following one dose. Hence, we concluded that the observed plateau in excision repair is real and does not represent some inhibitory process at high doses but a true saturation of one of the rate limiting steps in repair.

  9. On the optimal degree of imperfect repair

    International Nuclear Information System (INIS)

    Finkelstein, Maxim

    2015-01-01

    A simple cost-wise comparison between the minimal and perfect repair of a system is discussed first using a relevant example. The main focus of this note, however, is on imperfect (general) repair. The best repair for our system in this case is defined as the one that corresponds to the optimal level (extent) of repair actions that minimize the long-run expected cost per unit of time. This complex optimization problem is considered for a specific imperfect repair model (Kijima II), using the developed earlier asymptotic approach to the corresponding virtual age modelling. It is shown that the optimal solution exists when the failure rate of a system tends to infinity as t tends to infinity and the corresponding cost function decreases sufficiently fast. An example illustrating the optimization procedure is considered

  10. Contact Dermatitis In Automobile Repair workers

    Directory of Open Access Journals (Sweden)

    Joshi M P

    1997-01-01

    Full Text Available Automobile repair workers are at risk of developing skin morbidity including occupational dermatoses because of their exposure to mineral oils, petroleum products and its derivatives and lubricating oil. This cross- sectional study was carried out at Maharashtra State Road Transport Corporation workshops in Nagpur city to investigate prevalence of skin morbidity including contact dermatitis in automobile repair workers. The study included 288 (49.9% automobile repair workers 180 (31.3% workshop office staff and 109 (18.8% divisional office employees. Dermatitis was the commonest skin morbidity in all the study subjects and it was significantly more prevalent in automobile repair workers. Folliculitis was detected in 13.2% of auto â€" repair workers and was not seen in the other two groups. Increasing trend of skin morbidity was correlated with the length of service of employees. Proper protective measures along with suitable washing facilities should be provided

  11. Imperfect repair and lifesaving in heterogeneous populations

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, Maxim [Department of Mathematical Statistics, University of the Free State, PO Box 339, 9300 Bloemfontein (South Africa) and Max Planck Institute for Demographic Research, Rostock (Germany)]. E-mail: FinkelM.SCl@mail.uovs.ac.za

    2007-12-15

    In this theoretical paper we generalize the notion of minimal repair to the heterogeneous case, when the lifetime distribution function can be modeled by continuous or a discrete mixture of distributions. The statistical (black box) minimal repair and the minimal repair based on information just before the failure of an object are considered. The corresponding failure (intensity) rate processes are defined and analyzed. Demographic lifesaving model is also considered: each life is saved (cured) with some probability (or equivalently a proportion of individuals who would have died are now resuscitated and given another chance). Those who are saved experience the statistical minimal repair. Both of these models are based on the Poisson or non-homogeneous Poisson processes of underlying events, which allow for considering heterogeneity. We also consider the new model of imperfect repair in the homogeneous case and present generalizations to the heterogeneous setting.

  12. Stochastic Modelling Of The Repairable System

    Directory of Open Access Journals (Sweden)

    Andrzejczak Karol

    2015-11-01

    Full Text Available All reliability models consisting of random time factors form stochastic processes. In this paper we recall the definitions of the most common point processes which are used for modelling of repairable systems. Particularly this paper presents stochastic processes as examples of reliability systems for the support of the maintenance related decisions. We consider the simplest one-unit system with a negligible repair or replacement time, i.e., the unit is operating and is repaired or replaced at failure, where the time required for repair and replacement is negligible. When the repair or replacement is completed, the unit becomes as good as new and resumes operation. The stochastic modelling of recoverable systems constitutes an excellent method of supporting maintenance related decision-making processes and enables their more rational use.

  13. Male Fertility After Inguinal Hernia Mesh Repair

    DEFF Research Database (Denmark)

    Kohl, Andreas Pagh; Andresen, Kristoffer; Rosenberg, Jacob

    2017-01-01

    OBJECTIVE:: To determine whether patients who receive an inguinal hernia repair father the same number of children as the background population. BACKGROUND:: Although the effect of inguinal hernia repair on male fertility has previously been investigated through indirect measures, no previous...... studies have evaluated the final measure of male fertility, which is the number of children fathered by patients. METHODS:: Prospectively collected data on 32,621 male patients between the ages of 18 and 55 years who received 1 or more inguinal hernia repairs during the years 1998 to 2012 were found in 5...... hernia repair using Lichtenstein technique or laparoscopic approach did not father fewer children than expected. Thus, inguinal hernia repair using Lichtenstein or laparoscopic approach did not impair male fertility....

  14. Oxidative DNA damage & repair: An introduction.

    Science.gov (United States)

    Cadet, Jean; Davies, Kelvin J A

    2017-06-01

    This introductory article should be viewed as a prologue to the Free Radical Biology & Medicine Special Issue devoted to the important topic of Oxidatively Damaged DNA and its Repair. This special issue is dedicated to Professor Tomas Lindahl, co-winner of the 2015 Nobel Prize in Chemistry for his seminal discoveries in the area repair of oxidatively damaged DNA. In the past several years it has become abundantly clear that DNA oxidation is a major consequence of life in an oxygen-rich environment. Concomitantly, survival in the presence of oxygen, with the constant threat of deleterious DNA mutations and deletions, has largely been made possible through the evolution of a vast array of DNA repair enzymes. The articles in this Oxidatively Damaged DNA & Repair special issue detail the reactions by which intracellular DNA is oxidatively damaged, and the enzymatic reactions and pathways by which living organisms survive such assaults by repair processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Repair of DNA in xeroderma pigmentosum conjunctiva

    International Nuclear Information System (INIS)

    Newsome, D.A.; Kraemer, K.H.; Robbins, J.H.

    1975-01-01

    Xeroderma pigmentosum (XP) is an autosomal recessive disease with tumor formation on sun-exposed areas of the skin and eyes. Cells from most XP patients are deficient in repairing DNA damaged by ultraviolet (uv) light as shown by a reduced rate of tritiated thymidine (3HTdR) incorporation during their DNA repair synthesis. We have studied such repair synthesis in conjunctival cells from an XP patient with a conjunctival epithelioma and from normal cadaver conjunctiva. Cultured conjunctival cells were irradiated with uv light and then incubated with 3HTdR. Autoradiograms were prepared and showed that uv radiation induced a considerably slower rate of DNA repair synthesis in the XP cells than in normal cells. Many of the ocular abnormalities of XP, including tumor formation, may be the result of this defective DNA repair process

  16. Laparoscopic repair of large suprapubic hernias.

    Science.gov (United States)

    Sikar, Hasan Ediz; Çetin, Kenan; Eyvaz, Kemal; Kaptanoglu, Levent; Küçük, Hasan Fehmi

    2017-09-01

    Suprapubic hernia is the term to describe ventral hernias located less than 4 cm above the pubic arch in the midline. Hernias with an upper margin above the arcuate line encounter technical difficulties, and the differences in repair methods forced us to define them as large suprapubic hernias. To present our experience with laparoscopic repair of large suprapubic hernias that allows adequate mesh overlap. Nineteen patients with suprapubic incisional hernias who underwent laparoscopic repair between May 2013 and January 2015 were included in the study. Patients with laparoscopic extraperitoneal repair who had a suprapubic hernia with an upper margin below the arcuate line were excluded. Two men and 17 women, with a mean age of 58.2, underwent laparoscopic repair. Most of the incisions were midline vertical (13/68.4%). Twelve (63.1%) of the patients had previous incisional hernia repair (PIHR group); the mean number of previous incisional hernia repair was 1.4. Mean defect size of the PIHR group was higher than in patients without previous repair - 107.3 cm 2 vs. 50.9 cm 2 (p < 0.05). Mean operating time of the PIHR group was higher than in patients without repair - 126 min vs. 77.9 min (p < 0.05). Although all complications occurred in the PIHR group, there was no statistically significant difference. Laparoscopic repair of large suprapubic hernias can be considered as the first option in treatment. The low recurrence rates reported in the literature and the lack of recurrence, as observed in our study, support this view.

  17. Systems Maintenance Automated Repair Tasks (SMART)

    Science.gov (United States)

    Schuh, Joseph; Mitchell, Brent; Locklear, Louis; Belson, Martin A.; Al-Shihabi, Mary Jo Y.; King, Nadean; Norena, Elkin; Hardin, Derek

    2010-01-01

    SMART is a uniform automated discrepancy analysis and repair-authoring platform that improves technical accuracy and timely delivery of repair procedures for a given discrepancy (see figure a). SMART will minimize data errors, create uniform repair processes, and enhance the existing knowledge base of engineering repair processes. This innovation is the first tool developed that links the hardware specification requirements with the actual repair methods, sequences, and required equipment. SMART is flexibly designed to be useable by multiple engineering groups requiring decision analysis, and by any work authorization and disposition platform (see figure b). The organizational logic creates the link between specification requirements of the hardware, and specific procedures required to repair discrepancies. The first segment in the SMART process uses a decision analysis tree to define all the permutations between component/ subcomponent/discrepancy/repair on the hardware. The second segment uses a repair matrix to define what the steps and sequences are for any repair defined in the decision tree. This segment also allows for the selection of specific steps from multivariable steps. SMART will also be able to interface with outside databases and to store information from them to be inserted into the repair-procedure document. Some of the steps will be identified as optional, and would only be used based on the location and the current configuration of the hardware. The output from this analysis would be sent to a work authoring system in the form of a predefined sequence of steps containing required actions, tools, parts, materials, certifications, and specific requirements controlling quality, functional requirements, and limitations.

  18. [SOS-repair--60 years].

    Science.gov (United States)

    Zavil'gel'skiĭ, G B

    2013-01-01

    This review integrates 60 years of research on SOS-repair and SOS-mutagenesis in procaryotes and eucaryotes, from Jean Weigle experiment in 1953 year (mutagenesis of lambda bacteriophage in UV-irradiated bacteria) to the latest achievements in studying SOS-mutagenesis on all living organisms--Eukarya, Archaea and Bacteria. A key role in establishing of a biochemical basis for SOS-mutagenesis belonges to the finding in 1998-1999 years that specific error-prone DNA polymerases (PolV and others) catalysed translesion synthesis on damaged DNA. This review focuses on recent studies addressing the new models for SOS-induced mutagenesis in Escherichia coli and Home sapiens cells.

  19. Laparoscopic repair of vesicovaginal fistula

    Directory of Open Access Journals (Sweden)

    Miłosz Wilczyński

    2011-06-01

    Full Text Available A vesicovaginal fistula is one of the complications that a gynaecologist is bound to face after oncological operations, especially in postmenopausal women. Over the years there have been introduced many techniques of surgical treatment of this entity, including transabdominal and transvaginal approaches.We present a case of a 46-year-old patient who suffered from urinary leakage via the vagina due to the presence of a vesicovaginal fistula that developed after radical abdominal hysterectomy and subsequent radiotherapy. The decision was made to repair it laparoscopically due to retracted, fibrous and scarred tissue in the vaginal apex that precluded a transvaginal approach. A small cystotomy followed by an excision of fistula borders was performed. After six-month follow-up no recurrence of the disease has been noted.We conclude that laparoscopy is an interesting alternative to traditional approaches that provides comparable results.

  20. Vibration in car repair work.

    Science.gov (United States)

    Hansson, J E; Eklund, L; Kihlberg, S; Ostergren, C E

    1987-03-01

    The main objective of the study was to find efficient hand tools which caused only minor vibration loading. Vibration measurements were carried out under standardised working conditions. The time during which car body repairers in seven companies were exposed to vibration was determined. Chisel hammers, impact wrenches, sanders and saws were the types of tools which generated the highest vibration accelerations. The average daily exposure at the different garages ranged from 22 to 70 min. The risk of vibration injury is currently rated as high. The difference between the highest and lowest levels of vibration was considerable in most tool categories. Therefore the choice of tool has a major impact on the magnitude of vibration exposure. The importance of choosing the right tools and working methods is discussed and a counselling service on vibration is proposed.

  1. Shuttle Repair Tools Automate Vehicle Maintenance

    Science.gov (United States)

    2013-01-01

    Successfully building, flying, and maintaining the space shuttles was an immensely complex job that required a high level of detailed, precise engineering. After each shuttle landed, it entered a maintenance, repair, and overhaul (MRO) phase. Each system was thoroughly checked and tested, and worn or damaged parts replaced, before the shuttle was rolled out for its next mission. During the MRO period, workers needed to record exactly what needed replacing and why, as well as follow precise guidelines and procedures in making their repairs. That meant traceability, and with it lots of paperwork. In 2007, the number of reports generated during electrical system repairs was getting out of hand-placing among the top three systems in terms of paperwork volume. Repair specialists at Kennedy Space Center were unhappy spending so much time at a desk and so little time actually working on the shuttle. "Engineers weren't spending their time doing technical work," says Joseph Schuh, an electrical engineer at Kennedy. "Instead, they were busy with repetitive, time-consuming processes that, while important in their own right, provided a low return on time invested." The strain of such inefficiency was bad enough that slow electrical repairs jeopardized rollout on several occasions. Knowing there had to be a way to streamline operations, Kennedy asked Martin Belson, a project manager with 30 years experience as an aerospace contractor, to co-lead a team in developing software that would reduce the effort required to document shuttle repairs. The result was System Maintenance Automated Repair Tasks (SMART) software. SMART is a tool for aggregating and applying information on every aspect of repairs, from procedures and instructions to a vehicle s troubleshooting history. Drawing on that data, SMART largely automates the processes of generating repair instructions and post-repair paperwork. In the case of the space shuttle, this meant that SMART had 30 years worth of operations

  2. Analysis for a two-dissimilar-component cold standby repairable system with repair priority

    International Nuclear Information System (INIS)

    Leung, Kit Nam Francis; Zhang Yuanlin; Lai, Kin Keung

    2011-01-01

    In this paper, a cold standby repairable system consisting of two dissimilar components and one repairman is studied. Assume that working time distributions and repair time distributions of the two components are both exponential, and Component 1 has repair priority when both components are broken down. After repair, Component 1 follows a geometric process repair while Component 2 obeys a perfect repair. Under these assumptions, using the perfect repair model, the geometric process repair model and the supplementary variable technique, we not only study some important reliability indices, but also consider a replacement policy T, under which the system is replaced when the working age of Component 1 reaches T. Our problem is to determine an optimal policy T* such that the long-run average loss per unit time (i.e. average loss rate) of the system is minimized. The explicit expression for the average loss rate of the system is derived, and the corresponding optimal replacement policy T* can be found numerically. Finally, a numerical example for replacement policy T is given to illustrate some theoretical results and the model's applicability. - Highlights: → A two-dissimilar-component cold standby system with repair priority is formulated. → The successive up/repair times of Component 1 form a decreasing/increasing geometric process. → Not only some reliability indices but also a replacement policy are studied.

  3. Phenomenology of an inducible mutagenic DNA repair pathway in Escherichia coli: SOS repair hypothesis

    International Nuclear Information System (INIS)

    Radman, M.

    1974-01-01

    A hypothesis is proposed according to which E. coli possesses an inducible DNA repair system. This hypothetical repair, which we call SOS repair, is manifested only following damage to DNA, and requires de novo protein synthesis. SOS repair in E. coli requires some known genetic elements: recA + , lex + and probably zab + . Mutagenesis by ultraviolet light is observed only under conditions of functional SOS repair: we therefore suspect that this is a mutation-prone repair. A number of phenomena and experiments is reviewed which at this point can best be interpreted in terms of an inducible mutagenic DNA repair system. Two recently discovered phenomena support the proposed hypothesis: existence of a mutant (tif) which, after a shift to elevated temperature, mimicks the effect of uv irradiation in regard to repair of phage lambda and uv mutagenesis, apparent activation of SOS repair by introduction into the recipient cell of damaged plasmid or Hfr DNA. Several specific predictions based on SOS repair hypothesis are presented in order to stimulate further experimental tests. (U.S.)

  4. Initial experience of laparoscopic incisional hernia repair.

    Science.gov (United States)

    Razman, J; Shaharin, S; Lukman, M R; Sukumar, N; Jasmi, A Y

    2006-06-01

    Laparoscopic repair of ventral and incisional hernia has become increasingly popular as compared to open repair. The procedure has the advantages of minimal access surgery, reduction of post operative pain and the recurrence rate. A prospective study of laparoscopic incisional hernia repair was performed in our center from August 2002 to April 2004. Eighteen cases (n: 18) were performed during the study period. Fifteen cases (n: 15) had open hernia repair previously. Sixteen patients (n: 16) had successful repair of the hernia with the laparoscopic approach and two cases were converted to open repair. The mean hernia defect size was 156cm2. There was no intraoperative or immediate postoperative complication. The mean operating time was 100 +/- 34 minutes (75 - 180 minutes). The postoperative pain was graded as mild to moderate according to visual analogue score. The mean day of discharge after surgery was two days (1 - 3 days). During follow up, three patients (16.7%) developed seroma at the hernia sac which was resolved with conservative management after three weeks. One (5.6%) patient developed recurrence six months after surgery. In conclusion, laparoscopic repair of incisional hernia particularly recurrent hernia has been shown to be safe and effective in our centre. However, careful patient selection and acquiring the necessary advanced laparoscopic surgical skills coupled with the proper use of equipment are mandatory before embarking on this procedure.

  5. Repair of DNA damage in Deinococcus radiodurans

    International Nuclear Information System (INIS)

    Evans, D.M.

    1984-01-01

    The repair of DNA lesions in Deinococcus radiodurans was examined with particular reference to DNA excision repair of ultraviolet light (UV) induced pyrimidine dimers. The characteristics of excision repair via UV endonucleases α and β in vivo varied with respect to (a) the substrate range of the enzymes, (b) the rate of repair of DNA damage (c) the requirement for a protein synthesised in response to DNA damage to attenuate exonuclease action at repairing regions. UV endonuclease α is postulated to incise DNA in a different manner from UV endonuclease β thus defining the method of subsequent repair. Several DNA damage specific endonuclease activities independent of α and β are described. Mutations of the uvsA, uvsF and uvsG genes resulted in an increase in single-strand breaks in response to DNA damage producing uncontrolled DNA degradation. Evidence is presented that these genes have a role in limiting the access of UV endonuclease β to DNA lesions. uvsF and uvsG are also shown to be linked to the mtoA gene. Mutation of uvsH and reo-1 produces further distinct phenotypes which are discussed. An overall model of excision repair of DNA damage in Deinococcus radiodurans is presented. (author)

  6. Magnetic Resonance Imaging of Cartilage Repair

    Science.gov (United States)

    Trattnig, Siegfried; Winalski, Carl S.; Marlovits, Stephan; Jurvelin, Jukka S.; Welsch, Goetz H.; Potter, Hollis G.

    2011-01-01

    Articular cartilage lesions are a common pathology of the knee joint, and many patients may benefit from cartilage repair surgeries that offer the chance to avoid the development of osteoarthritis or delay its progression. Cartilage repair surgery, no matter the technique, requires a noninvasive, standardized, and high-quality longitudinal method to assess the structure of the repair tissue. This goal is best fulfilled by magnetic resonance imaging (MRI). The present article provides an overview of the current state of the art of MRI of cartilage repair. In the first 2 sections, preclinical and clinical MRI of cartilage repair tissue are described with a focus on morphological depiction of cartilage and the use of functional (biochemical) MR methodologies for the visualization of the ultrastructure of cartilage repair. In the third section, a short overview is provided on the regulatory issues of the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) regarding MR follow-up studies of patients after cartilage repair surgeries. PMID:26069565

  7. High performance repairing of reinforced concrete structures

    International Nuclear Information System (INIS)

    Iskhakov, I.; Ribakov, Y.; Holschemacher, K.; Mueller, T.

    2013-01-01

    Highlights: ► Steel fibered high strength concrete is effective for repairing concrete elements. ► Changing fibers’ content, required ductility of the repaired element is achieved. ► Experiments prove previously developed design concepts for two layer beams. -- Abstract: Steel fibered high strength concrete (SFHSC) is an effective material that can be used for repairing concrete elements. Design of normal strength concrete (NSC) elements that should be repaired using SFHSC can be based on general concepts for design of two-layer beams, consisting of SFHSC in the compressed zone and NSC without fibers in the tensile zone. It was previously reported that such elements are effective when their section carries rather large bending moments. Steel fibers, added to high strength concrete, increase its ultimate deformations due to the additional energy dissipation potential contributed by fibers. When changing the fibers’ content, a required ductility level of the repaired element can be achieved. Providing proper ductility is important for design of structures to dynamic loadings. The current study discusses experimental results that form a basis for finding optimal fiber content, yielding the highest Poisson coefficient and ductility of the repaired elements’ sections. Some technological issues as well as distribution of fibers in the cross section of two-layer bending elements are investigated. The experimental results, obtained in the frame of this study, form a basis for general technological provisions, related to repairing of NSC beams and slabs, using SFHSC.

  8. Hepatopancreaticobiliary Values after Thoracoabdominal Aneurysm Repair

    Science.gov (United States)

    Wu, Darrell; Coselli, Joseph S.; Johnson, Michael L.; LeMaire, Scott A.

    2014-01-01

    Background: After thoracoabdominal aortic aneurysm (TAAA) repair, blood tests assessing hepatopancreaticobiliary (HPB) organs commonly have abnormal results. The clinical significance of such abnormalities is difficult to determine because the expected postoperative levels have not been characterized. Therefore, we sought to establish expected trends in HPB laboratory values after TAAA repair. Methods: This 5-year study comprised 155 patients undergoing elective Crawford extent II TAAA repair. In accordance with a prospective study protocol, all repairs involved left-sided heart bypass, selective visceral perfusion, and cold renal perfusion. Blood levels of aspartate transaminase (AST), alanine transaminase (ALT), γ-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), total bilirubin, amylase, and lipase were measured before TAAA repair and for 7 days afterward. Ratios between postoperative and baseline levels were compared for each time point with 95% confidence intervals. Results: Temporal patterns for the laboratory values varied greatly. Amylase, lipase, and AST underwent significant early increases before decreasing to preoperative levels. LDH increased immediately and remained significantly elevated, whereas ALT increased more gradually. GGT remained near baseline through postoperative day 4, and then increased to more than twice baseline. Total bilirubin never differed significantly from baseline. After adjusted analysis, the ischemic time predicted the maximum AST, lipase, GGT, and LDH values. Conclusions: Although most HPB laboratory values increase significantly after elective TAAA repair, the temporal trends for different values vary substantially. The ischemic time predicts the maximum AST, lipase, GGT, and LDH levels. These trends should be considered when laboratory values are assessed after TAAA repair. PMID:26798731

  9. Radiation damage and its repair in non-sporulating bacteria

    International Nuclear Information System (INIS)

    Moseley, B.E.B.

    1984-01-01

    A review is given of radiation damage and its repair in non-sporulating bacteria. The identification and measurement of radiation damage in the DNA of the bacteria after exposure to ultraviolet radiation and ionizing radiation is described. Measuring the extent of DNA repair and ways of isolating repair mutants are also described. The DNA repair mechanisms for UV-induced damage are discussed including photoreactivation repair, excision repair, post-replication recombination repair and induced error-prone repair. The DNA repair mechanisms for ionizing radiation damage are also discussed including the repair of both single and double-strand breaks. Other aspects discussed include the effects of growth, irradiation medium and recovery medium on survival, DNA repair in humans, the commercial use of UV and ionizing radiations and the future of ionizing irradiation as a food treatment process. (U.K.)

  10. Diverless pipeline repair system for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Carlo M. [Eni Gas and Power, Milan (Italy); Fabbri, Sergio; Bachetta, Giuseppe [Saipem/SES, Venice (Italy)

    2009-07-01

    SiRCoS (Sistema Riparazione Condotte Sottomarine) is a diverless pipeline repair system composed of a suite of tools to perform a reliable subsea pipeline repair intervention in deep and ultra deep water which has been on the ground of the long lasting experience of Eni and Saipem in designing, laying and operating deep water pipelines. The key element of SiRCoS is a Connection System comprising two end connectors and a repair spool piece to replace a damaged pipeline section. A Repair Clamp with elastomeric seals is also available for pipe local damages. The Connection System is based on pipe cold forging process, consisting in swaging the pipe inside connectors with suitable profile, by using high pressure seawater. Three swaging operations have to be performed to replace the damaged pipe length. This technology has been developed through extensive theoretical work and laboratory testing, ending in a Type Approval by DNV over pipe sizes ranging from 20 inches to 48 inches OD. A complete SiRCoS system has been realised for the Green Stream pipeline, thoroughly tested in workshop as well as in shallow water and is now ready, in the event of an emergency situation.The key functional requirements for the system are: diverless repair intervention and fully piggability after repair. Eni owns this technology and is now available to other operators under Repair Club arrangement providing stand-by repair services carried out by Saipem Energy Services. The paper gives a description of the main features of the Repair System as well as an insight into the technological developments on pipe cold forging reliability and long term duration evaluation. (author)

  11. Repair-modification of radiodamaged genes

    International Nuclear Information System (INIS)

    Volpe, P.; Institute of Experimental Medicine, Rome; Eremenko, T.

    1995-01-01

    It is proposed that through repair-modification, the modified base 5mC may have facilitated the divergent evolution of coding (hypomethylated exon) and uncoding (hypermethylated promoter and intron) sequences in eukaryotic genes. The radioinduced repair patches appearing in regions lacking 5mC are fully reconstructed by excision-repair, whereas those appearing in regions containing 5mC are incompletely reconstructed by this conventional mechanism. Such a second class of repair patches may, however, become fully reconstructed, in the S phase, by repair-modification. In fact, while DNA polymerase β - which is a key enzyme of excision-repair - is active through the whole interphase. DNA methylase - which is responsible for post-synthetic DNA modification - is essentially active in S. Uncoupling of these two enzyme systems, outside S, might explain why in unsynchronised cells repair patches of non-replicating strands are hypomethylated when compared with specific methylation of replicating strands. In other words, excision-repair would always be able to re-establish the primary ATGC language of both damaged unmethylated and methylated regions, while repair-modification would be able to re-establish the modified ATGC(5mC) language of the damaged methylated regions, only in S, but not in G 1 or G 2 . In these two phases, when DNA methylation is inversely correlated with pre-mRNA transcription (as in the case of many tissue-specific genes), such demethylation might induce a silent transcriptional unit to become active. (Author)

  12. DNA excision repair in permeable human fibroblasts

    International Nuclear Information System (INIS)

    Kaufmann, W.K.; Bodell, W.J.; Cleaver, J.E.

    1983-01-01

    U.v. irradiation of confluent human fibroblasts activated DNA repair, aspects of which were characterized in the cells after they were permeabilized. Incubation of intact cells for 20 min between irradiation and harvesting was necessary to obtain a maximum rate of reparative DNA synthesis. Cells harvested immediately after irradiation before repair was initiated displayed only a small stimulation of DNA synthesis, indicating that permeable cells have a reduced capacity to recognize pyrimidine dimers and activate repair. The distribution of sizes of DNA strands labeled during 10 min of reparative DNA synthesis resembled that of parental DNA. However, during a 60-min incubation of permeable cells at 37 degrees C, parental DNA and DNA labeled by reparative DNA synthesis were both cleaved to smaller sizes. Cleavage also occurred in unirradiated cells, indicating that endogenous nuclease was active during incubation. Repair patches synthesized in permeable cells displayed increased sensitivity to digestion by micrococcal nuclease. However, the change in sensitivity during a chase with unlabeled DNA precursors was small, suggesting that reassembly of nucleosome structure at sites of repair was impaired. To examine whether this deficiency was due to a preponderance of incomplete or unligated repair patches, 3H-labeled (repaired) DNA was purified, then digested with exonuclease III and nuclease S1 to probe for free 3' ends and single-stranded regions. About 85% of the [3H]DNA synthesized during a 10-min pulse resisted digestion, suggesting that a major fraction of the repair patches that were filled were also ligated. U.v. light-activated DNA synthesis in permeable cells, therefore, appears to represent the continuation of reparative gap-filling at sites of excision repair activated within intact cells. Gap-filling and ligation were comparatively efficient processes in permeable cells

  13. [Compressive anterior thoracoplasty (modified Abramson's repair) for pectus carinatum repair].

    Science.gov (United States)

    Álvarez Muñoz, V; Prado Valle, M A; López López, A J; Martínez Suárez, M A; Oviedo Gutiérrez, M; Montalvo Ávalos, C; Fernández García, L

    2014-04-15

    For anterior protruding chest wall deformities treatment, mainly pectus carinatum, pediatric surgeons have been managing either orthotic methods or open surgical repairs. Anterior compressive thoracoplasty (Abramson's technique) has widened the therapeutic options. We describe herein a modification of this technique in the first reported Europen series. From 2010 to 2012, a total of five patients (four male and one female) underwent a modified Abramson's technique to correct pectus carinatum or combined protrusion of the chest at our center. We report the operative technique used for these reconstructions. In all five cases, the operation was completed uneventfully and with excellent results either for the surgical team or the patients. Mean operative time was 190 minutes and hospitalization lasted for three to six days, at the time of analgesic drugs withdrawal. We consider the anterior compresive thorocoplasty (modified Abramson's technique) a safe and feasible method to correct protruding chest deformities, particularly in those patients with stiff chest or lack of compliance, in order to avoid the agressive open procedures.

  14. Equipment for construction and repair of pipework

    International Nuclear Information System (INIS)

    Roehrich, H.

    1987-01-01

    More stringent requirements on the integrity of safety-related components in power plants with a view to ensuring the availability of these installations and to rationalizing in-service inspections and repairs have resulted in rapid enhancement of the inspection and repair methods used. Piping systems are increasingly being visually inspected, tested and possibly subjected to remote-control repair from the interior using remotely controlled inspection vehicles. This calls for machines with high levels of reliability which may be operated by means of remote control. Technical developments make it possible nowadays to perform operations that were largely out of the question a decade ago. (orig.) [de

  15. Weld Repair of Thin Aluminum Sheet

    Science.gov (United States)

    Beuyukian, C. S.; Mitchell, M. J.

    1986-01-01

    Weld repairing of thin aluminum sheets now possible, using niobium shield and copper heat sinks. Refractory niobium shield protects aluminum adjacent to hole, while copper heat sinks help conduct heat away from repair site. Technique limits tungsten/inert-gas (TIG) welding bombardment zone to melt area, leaving surrounding areas around weld unaffected. Used successfully to repair aluminum cold plates on Space Shuttle, Commercial applications, especially in sealing fractures, dents, and holes in thin aluminum face sheets or clad brazing sheet in cold plates, heat exchangers, coolers, and Solar panels. While particularly suited to thin aluminum sheet, this process also used in thicker aluminum material to prevent surface damage near weld area.

  16. Initial Development of Composite Repair Resins With Low Hazardous Air Pollutant Contents

    National Research Council Canada - National Science Library

    LaScala, John J; Bingham, Scott; Andrews, Kevin S; Sands, James M; Palmese, Guiseppe R

    2008-01-01

    Unsaturated polyester-based repair resins, such a Bondo, are widely used for automotive repair, marine repair, sporting equipment repair, and household repair of metal, composites, plastics, and wood...

  17. A history of the DNA repair and mutagenesis field: The discovery of base excision repair.

    Science.gov (United States)

    Friedberg, Errol C

    2016-01-01

    This article reviews the early history of the discovery of an DNA repair pathway designated as base excision repair (BER), since in contrast to the enzyme-catalyzed removal of damaged bases from DNA as nucleotides [called nucleotide excision repair (NER)], BER involves the removal of damaged or inappropriate bases, such as the presence of uracil instead of thymine, from DNA as free bases. Copyright © 2015. Published by Elsevier B.V.

  18. Pulpal progenitors and dentin repair.

    Science.gov (United States)

    Harichane, Y; Hirata, A; Dimitrova-Nakov, S; Granja, I; Goldberg, A; Kellermann, O; Poliard, A

    2011-07-01

    Mesenchymal stem cells are present in the dental pulp. They have been shown to contribute to dentin-like tissue formation in vitro and to participate in bone repair after a mandibular lesion. However, their capacity to contribute efficiently to reparative dentin formation after pulp lesion has never been explored. After pulp exposure, we have identified proliferative cells within 3 zones. In the crown, zone I is near the cavity, and zone II corresponds to the isthmus between the mesial and central pulp. In the root, zone III, near the apex, at a distance from the inflammatory site, contains mitotic stromal cells which may represent a source of progenitor cells. Stem-cell-based strategies are promising treatments for tissue injury in dentistry. Our experiments focused on (1) location of stem cells induced to leave their quiescent state early after pulp injury and (2) implantation of pulp progenitors, a substitute for classic endodontic treatments, paving the way for pulp stem-cell-based therapies.

  19. Fanconi anemia and DNA repair.

    Science.gov (United States)

    Grompe, M; D'Andrea, A

    2001-10-01

    Fanconi anemia (FA) is an autosomal recessive disorder caused by defects in at least eight distinct genes FANCA, B, C, D1, D2, E, F and G. The clinical phenotype of all FA complementation groups is similar and is characterized by progressive bone marrow failure, cancer proneness and typical birth defects. The principal cellular phenotype is hypersensitivity to DNA damage, particularly interstrand DNA crosslinks. The FA proteins constitute a multiprotein pathway whose precise biochemical function(s) remain unknown. Five of the FA proteins (FANCA, C, E, F and G) interact in a nuclear complex upstream of FANCD2. FANCB and FANCD1 have not yet been cloned, but it is likely that FANCB is part of the nuclear complex and that FANCD1 acts downstream of FANCD2. The FA nuclear complex regulates the mono-ubiquitination of FANCD2 in response to DNA damage, resulting in targeting of this protein into nuclear foci. These foci also contain BRCA1 and other DNA damage response proteins. In male meiosis, FANCD2 also co-localizes with BRCA1 at synaptonemal complexes. Together, these data suggest that the FA pathway functions primarily as a DNA damage response system, although its exact role (direct involvement in DNA repair versus indirect, facilitating role) has not yet been defined.

  20. Method for repairing failed fuel

    International Nuclear Information System (INIS)

    Shakudo, Taketomi.

    1986-01-01

    Purpose: To repair fuel elements that became failed during burnup in a reactor or during handling. Method: After the surface in the vicinity of a failed part of a fuel element is cleaned, a socket made of a shape-memory alloy having a ring form or a horseshoe form made by cutting a part of the ring form is inserted into the failed position according to the position of the failed fuel element. The shape memory alloy socket remembers a slightly larger inside diameter in its original phase (high-temperature side) than the outside diameter of the cladding tube and also a slightly larger inside diameter of the socket in the martensite phase (low-temperature side) than the outside diameter of the cladding tube, such that the socket can easily be inserted into the failed position. The socket, inserted into the failed part of the cladding tube, is heated by a heating jig. The socket recovers the original phase, and the shape also tends to recover a smaller diameter than the outside diameter of the cladding tube that has been remembered, and accordingly the failed part of the cladding tube is fastened with a great force and the failed part is fully closed with the socket, thus keeping radioactive materials from going out. (Horiuchi, T.)

  1. Radar rainfall image repair techniques

    Directory of Open Access Journals (Sweden)

    Stephen M. Wesson

    2004-01-01

    Full Text Available There are various quality problems associated with radar rainfall data viewed in images that include ground clutter, beam blocking and anomalous propagation, to name a few. To obtain the best rainfall estimate possible, techniques for removing ground clutter (non-meteorological echoes that influence radar data quality on 2-D radar rainfall image data sets are presented here. These techniques concentrate on repairing the images in both a computationally fast and accurate manner, and are nearest neighbour techniques of two sub-types: Individual Target and Border Tracing. The contaminated data is estimated through Kriging, considered the optimal technique for the spatial interpolation of Gaussian data, where the 'screening effect' that occurs with the Kriging weighting distribution around target points is exploited to ensure computational efficiency. Matrix rank reduction techniques in combination with Singular Value Decomposition (SVD are also suggested for finding an efficient solution to the Kriging Equations which can cope with near singular systems. Rainfall estimation at ground level from radar rainfall volume scan data is of interest and importance in earth bound applications such as hydrology and agriculture. As an extension of the above, Ordinary Kriging is applied to three-dimensional radar rainfall data to estimate rainfall rate at ground level. Keywords: ground clutter, data infilling, Ordinary Kriging, nearest neighbours, Singular Value Decomposition, border tracing, computation time, ground level rainfall estimation

  2. Protection and repair of the ischemic heart

    NARCIS (Netherlands)

    Koudstaal, S.

    2014-01-01

    This thesis aimed to elucidate and advance strategies for cardioprotection and cardiac repair, translate preclinical findings towards future clinical studies and optimize the translational research process for IHD. So far, many cardioprotective strategies against reperfusion injury could not be

  3. Radiation repair models for clinical application.

    Science.gov (United States)

    Dale, Roger G

    2018-02-28

    A number of newly emerging clinical techniques involve non-conventional patterns of radiation delivery which require an appreciation of the role played by radiation repair phenomena. This review outlines the main models of radiation repair, focussing on those which are of greatest clinical usefulness and which may be incorporated into biologically effective dose assessments. The need to account for the apparent "slowing-down" of repair rates observed in some normal tissues is also examined, along with a comparison of the relative merits of the formulations which can be used to account for such phenomena. Jack Fowler brought valuable insight to the understanding of radiation repair processes and this article includes reference to his important contributions in this area.

  4. BIDIRECTIONAL FUNCTION OF SHENGHE POWDER ON REPAIR ...

    African Journals Online (AJOL)

    USER

    Keywords: DNA repair, radiation, glioma, astrocyte, Chinese herbs. Introduction .... Wet transfer was performed for 4 hr at constant voltage (40 V) using polyvinylidene difluoride membrane ..... Mitochondrial survivin inhibits apoptosis and.

  5. Optimal maintenance policies in incomplete repair models

    International Nuclear Information System (INIS)

    Kahle, Waltraud

    2007-01-01

    We consider an incomplete repair model, that is, the impact of repair is not minimal as in the homogeneous Poisson process and not 'as good as new' as in renewal processes but lies between these boundary cases. The repairs are assumed to impact the failure intensity following a virtual age process of the general form proposed by Kijima. In previous works field data from an industrial setting were used to fit several models. In most cases the estimated rate of occurrence of failures was that of an underlying exponential distribution of the time between failures. In this paper, it is shown that there exist maintenance schedules under which the failure behavior of the failure-repair process becomes a homogeneous Poisson process

  6. F-111 Bonded Panel Repair Status

    National Research Council Canada - National Science Library

    Rider, Andrew

    1999-01-01

    A visit was made to Amberley Airbase between the 6th and 9th of September to consult with RAAF staff on current procedures and problems involved in the maintenance and repair of F-lll honeycomb panels...

  7. Feedwater connection repair and modification at GKN

    Energy Technology Data Exchange (ETDEWEB)

    Witteman, C; Klees, J E

    1985-03-01

    From January to March 1983 the feedwater connection of GKN was repaired using a boring lathe, spark machining and semi-automatic welding. Nondestructive examination was performed by ultrasonic and eddy-current testing.

  8. Resterilized Polypropylene Mesh for Inguinal Hernia Repair

    African Journals Online (AJOL)

    2018-04-19

    Apr 19, 2018 ... Conclusion: The use of sterilized polypropylene mesh for the repair of inguinal ... and nonabsorbable materials to reduce the tissue–mesh. INTRODUCTION ... which we have been practicing in our center since we introduced ...

  9. DNA repair phenotype and dietary antioxidant supplementation

    DEFF Research Database (Denmark)

    Guarnieri, Serena; Loft, Steffen; Riso, Patrizia

    2008-01-01

    Phytochemicals may protect cellular DNA by direct antioxidant effect or modulation of the DNA repair activity. We investigated the repair activity towards oxidised DNA in human mononuclear blood cells (MNBC) in two placebo-controlled antioxidant intervention studies as follows: (1) well-nourished......Phytochemicals may protect cellular DNA by direct antioxidant effect or modulation of the DNA repair activity. We investigated the repair activity towards oxidised DNA in human mononuclear blood cells (MNBC) in two placebo-controlled antioxidant intervention studies as follows: (1) well......-nourished subjects who ingested 600 g fruits and vegetables, or tablets containing the equivalent amount of vitamins and minerals, for 24 d; (2) poorly nourished male smokers who ingested 500 mg vitamin C/d as slow- or plain-release formulations together with 182 mg vitamin E/d for 4 weeks. The mean baseline levels...

  10. Chemical repair of trypsin-histidinyl radical

    International Nuclear Information System (INIS)

    Jovanovic, S.V.; Ruvarac, I.; Jankovic, I.; Josimovic, L.

    1991-01-01

    Oxyl radicals, such as hydroxyl, alkoxyl and peroxyl, react with biomolecules to produce bioradicals. Unless chemically repaired by suitable antioxidants, these bioradicals form stable products. This leads to loss of biological function of parent biomolecules with deleterious biological results, such as mutagenesis and cancer. Consequently, the understanding of the mechanisms of oxyl radical damage to biomolecules and chemical repair of such damage is crucial for the development of strategies for anticarcinogenesis and radioprotection. In this study the chemical repair of the histidinyl radical generated upon the trichloromethylperoxyl radical reaction with trypsin vas investigated by gamma radiolysis. The trypsin histidinyl radical is a resonance-stabilized heterocyclic free radical which was found to be unreactive with oxygen. The efficacy of the chemical repair of the trypsin-histidinyl radical by endogenous antioxidants which are electron donors (e.g. 5-hydroxytryptophan, uric acid) is compared to that of antioxidants which are H-atom donors (e. g. glutathione). 9 refs., 2 figs., 1 tab

  11. Feedwater connection repair and modification at GKN

    International Nuclear Information System (INIS)

    Witteman, C.; Klees, J.E.

    1985-01-01

    From Jan. to March 1983 the feedwater connection of GKN was repaired using a boring lathe, spark machining and semi-automatic welding. Nondestructive examination was performed by ultrasonic and eddy-current testing

  12. DNA replication and repair in Tilapia cells

    International Nuclear Information System (INIS)

    Yew, F.H.; Chang, L.M.

    1984-01-01

    The effect of ultraviolet radiation on a cell line established from the warm water fish Tilapia has been assessed by measuring the rate of DNA synthesis, excision repair, post-replication repair and cell survival. The cells tolerate ultraviolet radiation better than mammalian cells with respect to DNA synthesis, post-replication repair and cell survival. They are also efficient in excision repair, which in other fish cell lines has been found to be at a low level or absent. Their response to the inhibitors hydroxyurea and 1-β-D-arabinofuranosylcytosine is less sensitive than that of other cell lines, yet the cells seem to have very small pools of DNA precursor. (author)

  13. Funding of Facility Repairs and Renovation.

    Science.gov (United States)

    Kaiser, Harvey H.

    1984-01-01

    Compares the life cycle approach for campus building repair and renovation to the University of California's comprehensive building maintenance formula and advises that formulas be used cautiously as a method of determining appropriate budget levels. (MLF)

  14. 49 CFR 192.719 - Transmission lines: Testing of repairs.

    Science.gov (United States)

    2010-10-01

    ... pipe before it is installed. (b) Testing of repairs made by welding. Each repair made by welding in... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Testing of repairs. 192.719... Transmission lines: Testing of repairs. (a) Testing of replacement pipe. If a segment of transmission line is...

  15. Arthroscopic Hip Labral Repair: The Iberian Suture Technique

    OpenAIRE

    Stubbs, Allston J.; Andersen, Jason S.; Mannava, Sandeep; Wooster, Benjamin M.; Howse, Elizabeth A.; Winter, S. Bradley

    2014-01-01

    Arthroscopic hip labral repair has beneficial short-term outcomes; however, debate exists regarding ideal surgical labral repair technique. This technical note presents an arthroscopic repair technique that uses intrasubstance labral suture passage to restore the chondrolabral interface. This “Iberian suture technique” allows for an anatomic repair while posing minimal risk of damage to the labral and chondral tissues.

  16. A Minimum Cost Flow model for Level of Repair Analysis

    NARCIS (Netherlands)

    Basten, Robertus Johannes Ida; Schutten, Johannes M.J.; van der Heijden, Matthijs C.

    2008-01-01

    Given a product design and a repair network for capital goods, a level of repair analysis determines for each component in the product (1) whether it should be discarded or repaired upon failure and (2) at which location in the repair network to do this. In this paper, we show how the problem can be

  17. A minimum cost flow model for level of repair analysis

    NARCIS (Netherlands)

    Basten, Robertus Johannes Ida; van der Heijden, Matthijs C.; Schutten, Johannes M.J.

    2011-01-01

    Given a product design and a repair network for capital goods, a level of repair analysis determines for each component in the product (1) whether it should be discarded or repaired upon failure and (2) at which location in the repair network to do this. In this paper, we show how the problem can be

  18. Autologous chondrocyte implantation: superior biologic properties of hyaline cartilage repairs.

    Science.gov (United States)

    Henderson, Ian; Lavigne, Patrick; Valenzuela, Herminio; Oakes, Barry

    2007-02-01

    Information regarding the quality of autologous chondrocyte implantation repair is needed to determine whether the current autologous chondrocyte implantation surgical technology and the subsequent biologic repair processes are capable of reliably forming durable hyaline or hyaline-like cartilage in vivo. We report and analyze the properties and qualities of autologous chondrocyte implantation repairs. We evaluated 66 autologous chondrocyte implantation repairs in 57 patients, 55 of whom had histology, indentometry, and International Cartilage Repair Society repair scoring at reoperation for mechanical symptoms or pain. International Knee Documentation Committee scores were used to address clinical outcome. Maximum stiffness, normalized stiffness, and International Cartilage Repair Society repair scoring were higher for hyaline articular cartilage repairs compared with fibrocartilage, with no difference in clinical outcome. Reoperations revealed 32 macroscopically abnormal repairs (Group B) and 23 knees with normal-looking repairs in which symptoms leading to arthroscopy were accounted for by other joint disorders (Group A). In Group A, 65% of repairs were either hyaline or hyaline-like cartilage compared with 28% in Group B. Autologous chondrocyte repairs composed of fibrocartilage showed more morphologic abnormalities and became symptomatic earlier than hyaline or hyaline-like cartilage repairs. The hyaline articular cartilage repairs had biomechanical properties comparable to surrounding cartilage and superior to those associated with fibrocartilage repairs.

  19. Mesoscale simulation of concrete spall failure

    Science.gov (United States)

    Knell, S.; Sauer, M.; Millon, O.; Riedel, W.

    2012-05-01

    Although intensively studied, it is still being debated which physical mechanisms are responsible for the increase of dynamic strength and fracture energy of concrete observed at high loading rates, and to what extent structural inertia forces on different scales contribute to the observation. We present a new approach for the three dimensional mesoscale modelling of dynamic damage and cracking in concrete. Concrete is approximated as a composite of spherical elastic aggregates of mm to cm size embedded in an elastic cement stone matrix. Cracking within the matrix and at aggregate interfaces in the μm range are modelled with adaptively inserted—initially rigid—cohesive interface elements. The model is applied to analyse the dynamic tensile failure observed in Hopkinson-Bar spallation experiments with strain rates up to 100/s. The influence of the key mesoscale failure parameters of strength, fracture energy and relative weakening of the ITZ on macromechanic strength, momentum and energy conservation is numerically investigated.

  20. A systematization of glaze spalling in azulejos

    Directory of Open Access Journals (Sweden)

    João Manuel Mimoso

    2016-01-01

    Full Text Available The detachment of the glaze in azulejos is the ultimate form of decay, since it leads to the loss of the pictorial content. The detachment is usually considered in a diffuse way, however a close observation allows recognizing several types, often related to crazing, which this paper proposes to systematize.

  1. Repair of UV-irradiated plasmid DNA in excision repair deficient mutants of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Ikai, K.; Tano, K.; Ohnishi, T.; Nozu, K.

    1985-01-01

    The repair of UV-irradiated DNA of plasmid YEp13 was studied in the incision defective strains by measurement of cell transformation frequency. In Saccharomyces cerevisiae, rad1,2,3 and 4 mutants could repair UV-damaged plasmid DNA. In Escherichia coli, uvrA mutant was unable to repair UV-damaged plasmid DNA; however, pretreatment of the plasmid with Micrococcus luteus endonuclease increased repair. It was concluded that all the mutations of yeast were probably limited only to the nuclear DNA. (author)

  2. Repair of furocoumarin adducts in mammalian cells

    International Nuclear Information System (INIS)

    Zolan, M.E.; Smith, C.A.; Hanawalt, P.C.

    1984-01-01

    DNA repair was studied in cultured mammalian cells treated with the furocoumarins 8-methoxypsoralen (8-MOP), aminomethyl trioxsalen, or angelicin and irradiated with near UV light. The amount of DNA cross-linked by 8-MOP in normal human cells decreased by about one-half in 24 hours after treatment; no decrease was observed in xeroderma pigmentosum cells, group A. At present, it is not known to what extent this decrease represents complete repair events at the sites of cross-links. Furocoumarin adducts elicited excision repair in normal human and monkey cells but not in xeroderma pigmentosum group A cells. This excision repair resembled in several aspects that elicited by pyrimidine dimers, formed in DNA by irradiation with 254-nm UV light; however, it appeared that for at least 8-MOP and aminomethyl trioxsalen, removal of adducts was not as efficient as was the removal of pyrimidine dimers. A comparison was also made of repair in the 172-base-pair repetitive alpha-DNA component of monkey cells to repair in the bulk of the genome. Although repair elicited by pyrimidine dimers in alpha-DNA was the same as in the bulk DNA, that following treatment of cells with either aminomethyl trioxsalen or angelicin and near UV was markedly deficient in alpha-DNA. This deficiency reflected the removal of fewer adducts from alpha-DNA after the same initial adduct frequencies. These results could mean that each furocoumarin may produce several structurally distinct adducts to DNA in cells and that the capacity of cellular repair systems to remove these various adducts may vary greatly

  3. Advanced repair methods for enhanced reactor safety

    International Nuclear Information System (INIS)

    Kornfeldt, H.

    1993-01-01

    A few innovative concepts are described of the ABB Atom Service Division for repair and mitigation techniques for primary systems in nuclear power plants. The concepts are based on Shape Memory Alloy (SMA) technology. A basic feature of all methods is that welding and component replacement is being avoided and the radiation dose imposed on maintenance personnel reduced. The SMA-based repair methods give plant operators new ways to meet increased safety standards and rising maintenance costs. (Z.S.) 4 figs

  4. Histone displacement during nucleotide excision repair

    DEFF Research Database (Denmark)

    Dinant, C.; Bartek, J.; Bekker-Jensen, S.

    2012-01-01

    Nucleotide excision repair (NER) is an important DNA repair mechanism required for cellular resistance against UV light and toxic chemicals such as those found in tobacco smoke. In living cells, NER efficiently detects and removes DNA lesions within the large nuclear macromolecular complex called...... of histone variants and histone displacement (including nucleosome sliding). Here we review current knowledge, and speculate about current unknowns, regarding those chromatin remodeling activities that physically displace histones before, during and after NER....

  5. Nucleotide excision repair in differentiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Wees, Caroline van der [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Jansen, Jacob [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Vrieling, Harry [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Laarse, Arnoud van der [Department of Cardiology, Leiden University Medical Center, Leiden (Netherlands); Zeeland, Albert van [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands); Mullenders, Leon [Department of Toxicogenetics, Leiden University Medical Center, Leiden (Netherlands)]. E-mail: l.mullenders@lumc.nl

    2007-01-03

    Nucleotide excision repair (NER) is the principal pathway for the removal of a wide range of DNA helix-distorting lesions and operates via two NER subpathways, i.e. global genome repair (GGR) and transcription-coupled repair (TCR). Although detailed information is available on expression and efficiency of NER in established mammalian cell lines, little is known about the expression of NER pathways in (terminally) differentiated cells. The majority of studies in differentiated cells have focused on repair of UV-induced cyclobutane pyrimidine dimers (CPD) and 6-4-photoproducts (6-4PP) because of the high frequency of photolesions at low level of toxicity and availability of sensitive technologies to determine photolesions in defined regions of the genome. The picture that emerges from these studies is blurred and rather complex. Fibroblasts and terminally differentiated myocytes of the rat heart display equally efficient GGR of 6-4PP but poor repair of CPD due to the absence of p48 expression. This repair phenotype is clearly different from human terminal differentiated neurons. Furthermore, both cell types were found to carry out TCR of CPD, thus mimicking the repair phenotype of established rodent cell lines. In contrast, in intact rat spermatogenic cells repair was very inefficient at the genome overall level and in transcriptionally active genes indicating that GGR and TCR are non-functional. Also, non-differentiated mouse embryonic stem (ES) cells exhibit low levels of NER after UV irradiation. However, the mechanisms that lead to low NER activity are clearly different: in differentiated spermatogenic cells differences in chromatin compaction and sequestering of NER proteins may underlie the lack of NER activity in pre-meiotic cells, whereas in non-differentiated ES cells NER is impaired by a strong apoptotic response.

  6. Success of Meniscal Repair at ACL Reconstruction

    Science.gov (United States)

    Toman, Charles; Spindler, Kurt P.; Dunn, Warren R.; Amendola, Annunziata; Andrish, Jack T.; Bergfeld, John A.; Flanigan, David; Jones, Morgan; Kaeding, Christopher C.; Marx, Robert G.; Matava, Matthew J.; McCarty, Eric C.; Parker, Richard D.; Wolcott, Michelle; Vidal, Armando; Wolf, Brian R.; Huston, Laura J.; Harrell, Frank E.; Wright, Rick W.

    2013-01-01

    Background Meniscal repair is performed in an attempt to prevent posttraumatic arthritis resulting from meniscal dysfunction after meniscal tears. The socioeconomic implications of premature arthritis are significant in the young patient population. Investigations and techniques focusing on meniscus preservation and healing are now at the forefront of orthopaedic sports medicine. Hypothesis Concomitant meniscal repair with ACL reconstruction is a durable and successful procedure at two year follow-up. Study Design Case Series; Level of evidence, 4. Methods All unilateral primary ACL reconstructions entered in 2002 in a prospective cohort who had meniscal repair at the time of ACLR were evaluated. Validated patient oriented outcome instruments were completed preoperatively and then again at the two-year postoperative time point. Reoperation after the index procedure was also documented and confirmed by operative reports. Results 437 unilateral primary ACL reconstructions were performed with 86 concomitant meniscal repairs (57 medial, 29 lateral) in 84 patients during the study period. Patient follow-up was obtained on 94% (81/86) of the meniscal repairs, allowing confirmation of meniscal repair success (defined as no repeat arthroscopic procedure) or failure. The overall success rate for meniscal repairs was 96% (76/79 patients) at two-year follow-up. Conclusions Meniscal repair is a successful procedure in conjunction with ACL reconstruction. When confronted with a “repairable” meniscal tear at the time of ACL reconstruction, orthopaedic surgeons can expect an estimated >90% clinical success rate at two-year follow-up using a variety of methods as shown in our study. PMID:19465734

  7. Dysphagia in children with repaired oesophageal atresia

    OpenAIRE

    Coppens, C.H.; Engel-Hoek, L. van den; Scharbatke, H.E.; Groot, S.A. de; Draaisma, J.M.T.

    2016-01-01

    Dysphagia is a common problem in children with repaired oesophageal atresia (OA). Abnormalities in the oropharyngeal and oesophageal phase have hardly been studied. The aims of this study were to assess the prevalence of dysphagia in children with repaired OA and to identify and differentiate oral and pharyngeal dysphagia based on videofluoroscopic swallow study (VFSS) findings in a limited number of children in this cohort. Medical records of 111 patients, born between January 1996 and July ...

  8. Inspection and repair of nuclear components

    International Nuclear Information System (INIS)

    Lahner, K.; Poetz, F.

    1993-01-01

    Despite careful design, manufacturing and operation, some of the important safety-relevant components show deterioration with time. Because of activation and contamination of these components, their inspection and repair has to be performed with manipulators. Some sophisticated manipulators are described, built by ABB Reaktor and used for inspection, maintenance and repair of PWR steam generators, fuel alignment pins, core baffle former bolts and reactor pressure vessel head penetrations. (Z.S.) 7 figs

  9. Studies on maternal repair in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Mendelson, D.

    1976-01-01

    The work reported in this thesis is mainly concerned with studies on the nature of the repair mechanism(s) operating in Drosophila oocytes, and which act on chromosome damage induced by X-irradiation of post-meiotic male germ-cells. Caffeine treatment of the females has been used as an analytical tool to gain an insight into the nature of this repair mechanism and its genetic basis

  10. Value maximizing maintenance policies under general repair

    International Nuclear Information System (INIS)

    Marais, Karen B.

    2013-01-01

    One class of maintenance optimization problems considers the notion of general repair maintenance policies where systems are repaired or replaced on failure. In each case the optimality is based on minimizing the total maintenance cost of the system. These cost-centric optimizations ignore the value dimension of maintenance and can lead to maintenance strategies that do not maximize system value. This paper applies these ideas to the general repair optimization problem using a semi-Markov decision process, discounted cash flow techniques, and dynamic programming to identify the value-optimal actions for any given time and system condition. The impact of several parameters on maintenance strategy, such as operating cost and revenue, system failure characteristics, repair and replacement costs, and the planning time horizon, is explored. This approach provides a quantitative basis on which to base maintenance strategy decisions that contribute to system value. These decisions are different from those suggested by traditional cost-based approaches. The results show (1) how the optimal action for a given time and condition changes as replacement and repair costs change, and identifies the point at which these costs become too high for profitable system operation; (2) that for shorter planning horizons it is better to repair, since there is no time to reap the benefits of increased operating profit and reliability; (3) how the value-optimal maintenance policy is affected by the system's failure characteristics, and hence whether it is worthwhile to invest in higher reliability; and (4) the impact of the repair level on the optimal maintenance policy. -- Highlights: •Provides a quantitative basis for maintenance strategy decisions that contribute to system value. •Shows how the optimal action for a given condition changes as replacement and repair costs change. •Shows how the optimal policy is affected by the system's failure characteristics. •Shows when it is

  11. An apology for primary repair of tetralogy of Fallot.

    Science.gov (United States)

    Van Arsdell, Glen; Yun, Tae-Jin

    2005-01-01

    The first repair of tetralogy of Fallot (TOF) was 50 years ago, so it would seem that the details for optimal management strategies would be clear. Timing of repair and operative repair strategy for TOF are still a source of debate. Varying institutions have published excellent outcomes with a primary repair strategy or a selective staged repair strategy. In this article, the current and historic strategy for repair of TOF at the Hospital for Sick Children in Toronto is delineated along with associated outcomes. Data from our institution indicate a clear survival advantage for primary repair of TOF.

  12. Laparoscopic hernia repair and bladder injury.

    Science.gov (United States)

    Dalessandri, K M; Bhoyrul, S; Mulvihill, S J

    2001-01-01

    Bladder injury is a complication of laparoscopic surgery with a reported incidence in the general surgery literature of 0.5% and in the gynecology literature of 2%. We describe how to recognize and treat the injury and how to avoid the problem. We report two cases of bladder injury repaired with a General Surgical Interventions (GSI) trocar and a balloon device used for laparoscopic extraperitoneal inguinal hernia repair. One patient had a prior appendectomy; the other had a prior midline incision from a suprapubic prostatectomy. We repaired the bladder injury, and the patients made a good recovery. When using the obturator and balloon device, it is important to stay anterior to the preperitoneal space and bladder. Prior lower abdominal surgery can be considered a relative contraindication to extraperitoneal laparoscopic hernia repair. Signs of gas in the Foley bag or hematuria should alert the surgeon to a bladder injury. A one- or two-layer repair of the bladder injury can be performed either laparoscopically or openly and is recommended for a visible injury. Mesh repair of the hernia can be completed provided no evidence exists of urinary tract infection. A Foley catheter is placed until healing occurs.

  13. Human diseases associated with defective DNA repair

    International Nuclear Information System (INIS)

    Friedberg, E.C.; Ehmann, U.K.; Williams, J.I.

    1979-01-01

    The observations on xeroderma pigmentosum (XP) cells in culture were the first indications of defective DNA repair in association with human disease. Since then, a wealth of information on DNA repair in XP, and to a lesser extent in other diseases, has accumulated in the literature. Rather than clarifying the understanding of DNA repair mechanisms in normal cells and of defective DNA repair in human disease, the literature suggests an extraordinary complexity of both of the phenomena. In this review a number of discrete human diseases are considered separately. An attempt was made to systematically describe the pertinent clinical features and cellular and biochemical defects in these diseases, with an emphasis on defects in DNA metabolism, particularly DNA repair. Wherever possible observations have been correlated and unifying hypotheses presented concerning the nature of the basic defect(s) in these diseases. Discussions of the following diseases are presented: XP, ataxia telangiectasia; Fanconi's anemia; Hutchinson-Gilford progeria syndrome; Bloom's syndrome, Cockayne's syndrome; Down's syndrome; retinoblastoma; chronic lymphocytic leukemia; and other miscellaneous human diseases with possble DNA repair defects

  14. Repair of radiation damage in mammalian cells

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis.

  15. The forked flap repair for hypospadias

    Directory of Open Access Journals (Sweden)

    Anil Chadha

    2012-01-01

    Full Text Available Context: Despite the abundance of techniques for the repair of Hypospadias, its problems still persist and a satisfactory design to correct the penile curvature with the formation of neourethra from the native urethral tissue or genital or extragenital tissues, with minimal postoperative complications has yet to evolve. Aim: Persisting with such an endeavor, a new technique for the repair of distal and midpenile hypospadias is described. Materials and Methods: The study has been done in 70 cases over the past 11 years. The "Forked-Flap" repair is a single stage method for the repair of such Hypospadias with chordee. It takes advantage of the rich vascular communication at the corona and capitalizes on the established reliability of the meatal based flip-flap. The repair achieves straightening of the curvature of the penis by complete excision of chordee tissue from the ventral surface of the penis beneath the urethral plate. The urethra is reconstructed using the native plate with forked flap extensions and genital tissue relying on the concept of meatal based flaps. Water proofing by dartos tissue and reinforcement by Nesbit′s prepucial tissue transfer completes the one stage procedure. Statistical Analysis: An analysis of 70 cases of this single stage technique of repair of penile hypospadias with chordee, operated at 3 to 5 years of age over the past 11 years is presented. Results and Conclusion: The Forked Flap gives comparable and replicable results; except for a urethrocutaneous fistula rate of 4% no other complications were observed.

  16. Chitosan adhesive for laser tissue repair

    Science.gov (United States)

    Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

    2006-02-01

    Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

  17. Regulatory Challenges for Cartilage Repair Technologies.

    Science.gov (United States)

    McGowan, Kevin B; Stiegman, Glenn

    2013-01-01

    In the United States, few Food and Drug Administration (FDA)-approved options exist for the treatment of focal cartilage and osteochondral lesions. Developers of products for cartilage repair face many challenges to obtain marketing approval from the FDA. The objective of this review is to discuss the necessary steps for FDA application and approval for a new cartilage repair product. FDA Guidance Documents, FDA Panel Meetings, scientific organization recommendations, and clinicaltrials.gov were reviewed to demonstrate the current thinking of FDA and the scientific community on the regulatory process for cartilage repair therapies. Cartilage repair therapies can receive market approval from FDA as medical devices, drugs, or biologics, and the specific classification of product can affect the nonclinical, clinical, and regulatory strategy to bring the product to market. Recent FDA guidance gives an outline of the required elements to bring a cartilage repair product to market, although these standards are often very general. As a result, companies have to carefully craft their study patient population, comparator group, and clinical endpoint to best showcase their product's attributes. In addition, regulatory strategy and manufacturing process validation need to be considered early in the clinical study process to allow for timely product approval following the completion of clinical study. Although the path to regulatory approval for a cartilage repair therapy is challenging and time-consuming, proper clinical trial planning and attention to the details can eventually save companies time and money by bringing a product to the market in the most expeditious process possible.

  18. Repair of radiation damage in mammalian cells

    International Nuclear Information System (INIS)

    Setlow, R.B.

    1981-01-01

    The responses, such as survival, mutation, and carcinogenesis, of mammalian cells and tissues to radiation are dependent not only on the magnitude of the damage to macromolecular structures - DNA, RNA, protein, and membranes - but on the rates of macromolecular syntheses of cells relative to the half-lives of the damages. Cells possess a number of mechanisms for repairing damage to DNA. If the repair systems are rapid and error free, cells can tolerate much larger doses than if repair is slow or error prone. It is important to understand the effects of radiation and the repair of radiation damage because there exist reasonable amounts of epidemiological data that permits the construction of dose-response curves for humans. The shapes of such curves or the magnitude of the response will depend on repair. Radiation damage is emphasized because: (a) radiation dosimetry, with all its uncertainties for populations, is excellent compared to chemical dosimetry; (b) a number of cancer-prone diseases are known in which there are defects in DNA repair and radiation results in more chromosomal damage in cells from such individuals than in cells from normal individuals; (c) in some cases, specific radiation products in DNA have been correlated with biological effects, and (d) many chemical effects seem to mimic radiation effects. A further reason for emphasizing damage to DNA is the wealth of experimental evidence indicating that damages to DNA can be initiating events in carcinogenesis

  19. Evaluation of Repair Tension in Arthroscopic Rotator Cuff Repair: Does It Really Matter to the Integrity of the Rotator Cuff?

    Science.gov (United States)

    Kim, Do Hoon; Jang, Young Hoon; Choi, Young Eun; Lee, Hwa-Ryeong; Kim, Sae Hoon

    2016-11-01

    Repair tension of a torn rotator cuff can affect healing after repair. However, a measurement of the actual tension during arthroscopic rotator cuff repair is not feasible. The relationship between repair tension and healing of a rotator cuff repair remains unclear. The purpose of this study was to evaluate the effect of repair tension on healing at the repair site. The hypothesis was that repair tension would be a major factor in determining the anatomic outcome of rotator cuff repair. Cohort study; Level of evidence, 2. Arthroscopic rotator cuff repairs (132 patients) for full-thickness rotator cuff tears were analyzed. An intraoperative model was designed for the estimation of repair tension using a tensiometer. Magnetic resonance imaging (MRI) was performed approximately 1 year (mean [±SD], 12.7 ± 3.2 months) postoperatively for the evaluation of healing at the repair site. Multivariable analysis was performed for tear size, amount of retraction, and fatty degeneration (FD) of rotator cuff muscles. The mean repair tension measured during the arthroscopic procedure was 28.5 ± 23.1 N. There was a statistically significant correlation between tension and tear size (Pearson correlation coefficient [PCC], 0.529; P repair tension also showed a significant inverse correlation with healing at the repair site (SCC, 0.195; P = .025). However, when sex, age, tear size, amount of retraction, tendon quality, and FD of rotator cuff muscles were included for multivariable logistic regression analysis, only FD of the infraspinatus showed an association with the anatomic outcome of repair (Exp(B) = 0.596; P = .010). Our intraoperative model for the estimation of rotator cuff repair tension showed an inverse correlation of repair tension with healing at the repair site, suggesting that complete healing is less likely with high-tension repairs. A significant association was observed on MRI between a high level of FD of the infraspinatus and repaired tendon integrity. © 2016

  20. DNA Damage Induced by Alkylating Agents and Repair Pathways

    OpenAIRE

    Natsuko Kondo; Akihisa Takahashi; Koji Ono; Takeo Ohnishi

    2010-01-01

    The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O 6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O 6-methylguanine-DNA methyltransferase, and O 6MeG:T mispairs are recognized...

  1. The relationship of transcription and repair of radioinduced DNA damage

    International Nuclear Information System (INIS)

    Zhestyanikov, V.D.; Igusheva, O.A.

    1997-01-01

    The data are discussed which has become a basement of such important findings as involvement of transcription into repair or existence of transcription-coupling repair factors. Thymine glycols which are appear under ionizing radiation exposure, are repaired preferentially in transcribed DNA. In present review the preferential repair of ionizing radiation-induced singlestrand breaks (SSBa) in transcribed DNA of human cells. Discontinuous distribution of DNA repair along hole genome has a grate role in biological processes

  2. Repairable-conditionally repairable damage model based on dual Poisson processes.

    Science.gov (United States)

    Lind, B K; Persson, L M; Edgren, M R; Hedlöf, I; Brahme, A

    2003-09-01

    The advent of intensity-modulated radiation therapy makes it increasingly important to model the response accurately when large volumes of normal tissues are irradiated by controlled graded dose distributions aimed at maximizing tumor cure and minimizing normal tissue toxicity. The cell survival model proposed here is very useful and flexible for accurate description of the response of healthy tissues as well as tumors in classical and truly radiobiologically optimized radiation therapy. The repairable-conditionally repairable (RCR) model distinguishes between two different types of damage, namely the potentially repairable, which may also be lethal, i.e. if unrepaired or misrepaired, and the conditionally repairable, which may be repaired or may lead to apoptosis if it has not been repaired correctly. When potentially repairable damage is being repaired, for example by nonhomologous end joining, conditionally repairable damage may require in addition a high-fidelity correction by homologous repair. The induction of both types of damage is assumed to be described by Poisson statistics. The resultant cell survival expression has the unique ability to fit most experimental data well at low doses (the initial hypersensitive range), intermediate doses (on the shoulder of the survival curve), and high doses (on the quasi-exponential region of the survival curve). The complete Poisson expression can be approximated well by a simple bi-exponential cell survival expression, S(D) = e(-aD) + bDe(-cD), where the first term describes the survival of undamaged cells and the last term represents survival after complete repair of sublethal damage. The bi-exponential expression makes it easy to derive D(0), D(q), n and alpha, beta values to facilitate comparison with classical cell survival models.

  3. Preclinical Studies for Cartilage Repair

    Science.gov (United States)

    Hurtig, Mark B.; Buschmann, Michael D.; Fortier, Lisa A.; Hoemann, Caroline D.; Hunziker, Ernst B.; Jurvelin, Jukka S.; Mainil-Varlet, Pierre; McIlwraith, C. Wayne; Sah, Robert L.; Whiteside, Robert A.

    2011-01-01

    Investigational devices for articular cartilage repair or replacement are considered to be significant risk devices by regulatory bodies. Therefore animal models are needed to provide proof of efficacy and safety prior to clinical testing. The financial commitment and regulatory steps needed to bring a new technology to clinical use can be major obstacles, so the implementation of highly predictive animal models is a pressing issue. Until recently, a reductionist approach using acute chondral defects in immature laboratory species, particularly the rabbit, was considered adequate; however, if successful and timely translation from animal models to regulatory approval and clinical use is the goal, a step-wise development using laboratory animals for screening and early development work followed by larger species such as the goat, sheep and horse for late development and pivotal studies is recommended. Such animals must have fully organized and mature cartilage. Both acute and chronic chondral defects can be used but the later are more like the lesions found in patients and may be more predictive. Quantitative and qualitative outcome measures such as macroscopic appearance, histology, biochemistry, functional imaging, and biomechanical testing of cartilage, provide reliable data to support investment decisions and subsequent applications to regulatory bodies for clinical trials. No one model or species can be considered ideal for pivotal studies, but the larger animal species are recommended for pivotal studies. Larger species such as the horse, goat and pig also allow arthroscopic delivery, and press-fit or sutured implant fixation in thick cartilage as well as second look arthroscopies and biopsy procedures. PMID:26069576

  4. Self-repair of cracks in brittle material systems

    Science.gov (United States)

    Dry, Carolyn M.

    2016-04-01

    One of the most effective uses for self repair is in material systems that crack because the cracks can allow the repair chemical to flow into the crack damage sites in all three dimensions. In order for the repair chemical to stay in the damage site and flow along to all the crack and repair there must be enough chemical to fill the entire crack. The repair chemical must be designed appropriately for the particular crack size and total volume of cracks. In each of the three examples of self repair in crackable brittle systems, the viscosity and chemical makeup and volume of the repair chemicals used is different for each system. Further the chemical delivery system has to be designed for each application also. Test results from self repair of three brittle systems are discussed. In "Self Repair of Concrete Bridges and Infrastructure" two chemicals were used due to different placements in bridges to repair different types of cracks- surface shrinkage and shear cracks, In "Airplane Wings and Fuselage, in Graphite" the composite has very different properties than the concrete bridges. In the graphite for airplane components the chemical also had to survive the high processing temperatures. In this composite the cracks were so definite and deep and thin that the repair chemical could flow easily and repair in all layers of the composite. In "Ceramic/Composite Demonstrating Self Repair" the self repair system not only repaired the broken ceramic but also rebounded the composite to the ceramic layer

  5. Energy and Technology Review: Unlocking the mysteries of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Quirk, W.A.

    1993-04-01

    DNA, the genetic blueprint, has the remarkable property of encoding its own repair following diverse types of structural damage induced by external agents or normal metabolism. We are studying the interplay of DNA damaging agents, repair genes, and their protein products to decipher the complex biochemical pathways that mediate such repair. Our research focuses on repair processes that correct DNA damage produced by chemical mutagens and radiation, both ionizing and ultraviolet. The most important type of DNA repair in human cells is called excision repair. This multistep process removes damaged or inappropriate pieces of DNA -- often as a string of 29 nucleotides containing the damage -- and replaces them with intact ones. We have isolated, cloned, and mapped several human repair genes associated with the nucleotide excision repair pathway and involved in the repair of DNA damage after exposure to ultraviolet light or mutagens in cooked food. We have shown that a defect in one of these repair genes, ERCC2, is responsible for the repair deficiency in one of the groups of patients with the recessive genetic disorder xeroderma pigmentosum (XP group D). We are exploring ways to purify sufficient quantities (milligrams) of the protein products of these and other repair genes so that we can understand their functions. Our long-term goals are to link defective repair proteins to human DNA repair disorders that predispose to cancer, and to produce DNA-repair-deficient mice that can serve as models for the human disorders.

  6. Repair welding of cracked steam turbine blades

    International Nuclear Information System (INIS)

    Bhaduri, A.K.; Gill, T.P.S.; Albert, S.K.; Shanmugam, K.; Iyer, D.R.

    1999-01-01

    The procedure for repair welding of cracked steam turbine blades made of martensitic stainless steels has been developed using the gas tungsten arc welding process. Weld repair procedures were developed using both ER316L austenitic stainless steel filler wire and ER410 martensitic stainless steel filler wire. The repair welding procedure with austenitic filler wire was developed to avoid preheating of the blade as also hydrogen induced cold cracking, and involved evaluation of three different austenitic filler wires, viz. ER309L, ER316L and ERNiCr-3. The overall development of the repair welding procedure included selection of welding consumables (for austenitic filler metal), optimisation of post weld heat treatment parameters, selection of suitable method for local pre-heating and post-weld heat treatment (PWHT) of the blades, determination of mechanical properties of weldments in as-welded and PWHT conditions, and microstructural examination. After various trials using different procedures, the procedure of local PWHT using electrical resistance heating on the top surface of the weldment and monitoring the temperature by placing a thermocouple at the bottom of the weld, was found to give the most satisfactory results. A similar procedure was used for preheating while using ER410 filler metal. Mechanical testing of weldments before and after PWHT involved tensile tests at room temperature, face and root bend tests, and microhardness measurements across the fusion line and heat affected zone. During procedure qualification, mock-ups and actual repair welding, dye penetrant testing was used at different stages and where ever possible radiography was carried out. These procedures were developed for repair welding of cracked blades in the low-pressure (LP) steam turbines of Indian nuclear power plants. The procedure with ER316 L filler wire has so far been applied for repair welding of 2 cracked blades (made of AISI 410 SS) of LP steam turbines, while the procedure

  7. Characteristics of repair following very low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Metting, N.F.; Nelson, J.M.

    1987-01-01

    The effects of ionizing radiation on living systems being with the physical processes of energy deposition and develop through many stages of chemical reaction and biological response. The modeling effort attempts to organize the available data and theories of all of these stages into self-consistent models that can be compared and tested. In some cases, important differences among models result in only small differences in cell survival within the ranges of dose and dose rate that are normally investigated. To overcome this limitation, new ways of irradiating cells at extremes of dose rate, or ways of evaluating the effects of very small doses, are developed. Mathematical modeling and cellular studies complement each other. It has recently been found that some mechanisms are not adequate to account for the interaction of dose and repair time as they affect the reproductive survival of plateau-phase Chinese hamster ovary (CHO) cells. Repair of radiation-induced cellular damage plays a central role in the survival of cells exposed to doses of 1 Gy or more. This repair is responsible for the dose rate, split-dose and delayed plating effect and can be evaluated. Because split-dose and dose-rate experiments involve repair during irradiation and delayed plating experiments involve repair after irradiation is completed, it was originally thought that different repair processes were involved. It is now clear that this is not necessarily the case. Appropriately designed models can account for observed effects at conventional doses (1 Gy or more) whether they assume all damage is lethal unless repaired or some damage is innocuous unless it interacts with additional damage. The fact that the survival following a plating delay is always less than the survival following immediate plating at low doses indicates that the damage produced is probably not potentially lethal

  8. Stripped-down DNA repair in a highly reduced parasite

    Directory of Open Access Journals (Sweden)

    Fast Naomi M

    2007-03-01

    Full Text Available Abstract Background Encephalitozoon cuniculi is a member of a distinctive group of single-celled parasitic eukaryotes called microsporidia, which are closely related to fungi. Some of these organisms, including E. cuniculi, also have uniquely small genomes that are within the prokaryotic range. Thus, E. cuniculi has undergone a massive genome reduction which has resulted in a loss of genes from diverse biological pathways, including those that act in DNA repair. DNA repair is essential to any living cell. A loss of these mechanisms invariably results in accumulation of mutations and/or cell death. Six major pathways of DNA repair in eukaryotes include: non-homologous end joining (NHEJ, homologous recombination repair (HRR, mismatch repair (MMR, nucleotide excision repair (NER, base excision repair (BER and methyltransferase repair. DNA polymerases are also critical players in DNA repair processes. Given the close relationship between microsporidia and fungi, the repair mechanisms present in E. cuniculi were compared to those of the yeast Saccharomyces cerevisiae to ascertain how the process of genome reduction has affected the DNA repair pathways. Results E. cuniculi lacks 16 (plus another 6 potential absences of the 56 DNA repair genes sought via BLASTP and PSI-BLAST searches. Six of 14 DNA polymerases or polymerase subunits are also absent in E. cuniculi. All of these genes are relatively well conserved within eukaryotes. The absence of genes is not distributed equally among the different repair pathways; some pathways lack only one protein, while there is a striking absence of many proteins that are components of both double strand break repair pathways. All specialized repair polymerases are also absent. Conclusion Given the large number of DNA repair genes that are absent from the double strand break repair pathways, E. cuniculi is a prime candidate for the study of double strand break repair with minimal machinery. Strikingly, all of the

  9. The impact of endovascular repair on specialties performing abdominal aortic aneurysm repair

    NARCIS (Netherlands)

    K.H.J. Ultee (Klaas); R. Hurks (Rob); D.B. Buck (Dominique B.); G.S. Dasilva (George S.); P.A. Soden (Peter A.); J.A. van Herwaarden (Joost); H.J.M. Verhagen (Hence); M.L. Schermerhorn (Marc)

    2015-01-01

    textabstractBackground Abdominal aortic aneurysm (AAA) repair has been performed by various surgical specialties for many years. Endovascular aneurysm repair (EVAR) may be a disruptive technology, having an impact on which specialties care for patients with AAA. Therefore, we examined the proportion

  10. CrowdAidRepair: A Crowd-Aided Interactive Data Repairing Method

    KAUST Repository

    Zhou, Jian; Li, Zhixu; Gu, Binbin; Xie, Qing; Zhu, Jia; Zhang, Xiangliang; Li, Guoliang

    2016-01-01

    turn to use the power of crowd in data repairing, but the crowd power has its own drawbacks such as high human intervention cost and inevitable low efficiency. In this paper, we propose a crowd-aided interactive data repairing method which takes

  11. The impact of endovascular repair on specialties performing abdominal aortic aneurysm repair

    NARCIS (Netherlands)

    Ultee, Klaas H J; Hurks, Rob; Buck, Dominique B.; Dasilva, George S.; Soden, Peter A.; Van Herwaarden, Joost A.; Verhagen, Hence J M; Schermerhorn, Marc L.

    2015-01-01

    Background Abdominal aortic aneurysm (AAA) repair has been performed by various surgical specialties for many years. Endovascular aneurysm repair (EVAR) may be a disruptive technology, having an impact on which specialties care for patients with AAA. Therefore, we examined the proportion of AAA

  12. Cost-effectiveness of endovascular repair, open repair, and conservative management of splenic artery aneurysms

    NARCIS (Netherlands)

    Hogendoorn, Wouter; Lavida, Anthi; Hunink, M. G Myriam; Moll, Frans L.; Geroulakos, George; Muhs, Bart E.; Sumpio, Bauer E.

    2015-01-01

    Objective Open repair (OPEN) and conservative management (CONS) have been the treatments of choice for splenic artery aneurysms (SAAs) for many years. Endovascular repair (EV) has been increasingly used with good short-term results. In this study, we evaluated the cost-effectiveness of OPEN, EV, and

  13. General Mechanical Repair. Minor Automotive Maintenance, Small Engine [Repair, and] Welding: Curriculum Guide and Lesson Plans.

    Science.gov (United States)

    Hamlin, Larry

    This document contains a curriculum guide and lesson plans for a general mechanical repair course with three sections: minor automotive maintenance, small engine repair, and welding. The curriculum guide begins with a matrix that relates the lesson plans to essential elements of math, science, language arts, and social studies and to Texas…

  14. General Mechanical Repair. Minor Automotive Maintenance, Small Engine [Repair, and] Welding: Student Manual.

    Science.gov (United States)

    Hamlin, Larry

    This document is a student manual for a general mechanical repair course. Following a list of common essential elements of trade and industrial education, the manual is divided into three sections. The first section, on minor automotive maintenance, contains 13 units: automotive shop safety; engine principles; fuel system operation and repair;…

  15. Connecting inventory control and repair shop control : a differentiated control structure for repairable spare parts

    NARCIS (Netherlands)

    Driessen, M.A.; Rustenburg, W.D.; Houtum, van G.J.J.A.N.; Wiers, V.C.S.

    2014-01-01

    This paper presents a control structure for integrating decisions on spare parts inventory control and the control of repair shops for maintenance spare parts. A dierentiated control structure is proposed for the various repair shop types recognized in practice. Decisions functions are mapped and

  16. Optimizing pressurized contact area in rotator cuff repair: the diamondback repair.

    Science.gov (United States)

    Burkhart, Stephen S; Denard, Patrick J; Obopilwe, Elifho; Mazzocca, Augustus D

    2012-02-01

    The purpose of this study was to compare tendon-bone footprint contact area over time under physiologic loads for 4 different rotator cuff repair techniques: single row (SR), triangle double row (DR), chain-link double row (CL), and diamondback double row (DBK). A supraspinatus tear was created in 28 human cadavers. Tears were fixed with 1 of 4 constructs: SR, DR, CL, or DBK. Immediate post-repair measurements of pressurized contact area were taken in neutral rotation and 0° of abduction. After a static tensile load, pressurized contact area was observed over a 160-minute period after repair. Cyclic loading was then performed. The DBK repair had the highest pressurized contact area initially, as well as the highest pressurized contact area and lowest percentage decrease in pressurized contact area after 160 minutes of testing. The DBK repair had significantly larger initial pressurized contact than CL (P = .003) and SR (P = .004) but not DR (P = .06). The DBK technique was the only technique that produced a pressurized contact area that exceeded the native footprint both at initial repair (P = .01) and after 160 minutes of testing (P = .01). DBK had a significantly larger mean pressurized contact area than all the repairs after 160 minutes of testing (P = .01). DBK had a significantly larger post-cyclic loading pressurized contact area than CL (P = .01) and SR (P = .004) but not DR (P = .07). This study showed that a diamondback repair (a modification of the transosseous repair) can significantly increase the rotator cuff pressurized contact area in comparison with other standard rotator cuff repair constructs when there is sufficient tendon mobility to perform a double-row repair without excessive tension on the repair site. The persistent pressurized contact area of a DBK repair may be desirable to enhance healing potential when there is sufficient tendon mobility to perform a double-row repair, particularly for large or massive rotator cuff tears where it is

  17. Wellbore Seal Repair Using Nanocomposite Materials

    Energy Technology Data Exchange (ETDEWEB)

    Stormont, John [Univ. of New Mexico, Albuquerque, NM (United States)

    2016-08-31

    Nanocomposite wellbore repair materials have been developed, tested, and modeled through an integrated program of laboratory testing and numerical modeling. Numerous polymer-cement nanocomposites were synthesized as candidate wellbore repair materials using various combinations of base polymers and nanoparticles. Based on tests of bond strength to steel and cement, ductility, stability, flowability, and penetrability in opening of 50 microns and less, we identified Novolac epoxy reinforced with multi-walled carbon nanotubes and/or alumina nanoparticles to be a superior wellbore seal material compared to conventional microfine cements. A system was developed for testing damaged and repaired wellbore specimens comprised of a cement sheath cast on a steel casing. The system allows independent application of confining pressures and casing pressures while gas flow is measured through the specimens along the wellbore axis. Repair with the nanocomposite epoxy base material was successful in dramatically reducing the flow through flaws of various sizes and types, and restoring the specimen comparable to an intact condition. In contrast, repair of damaged specimens with microfine cement was less effective, and the repair degraded with application of stress. Post-test observations confirm the complete penetration and sealing of flaws using the nanocomposite epoxy base material. A number of modeling efforts have supported the material development and testing efforts. We have modeled the steel-repair material interface behavior in detail during slant shear tests, which we used to characterize bond strength of candidate repair materials. A numerical model of the laboratory testing of damaged wellbore specimens was developed. This investigation found that microannulus permeability can satisfactorily be described by a joint model. Finally, a wellbore model has been developed that can be used to evaluate the response of the wellbore system (casing, cement, and microannulus

  18. Nuclear translocation contributes to regulation of DNA excision repair activities

    DEFF Research Database (Denmark)

    Knudsen, Nina Østergaard; Andersen, Sofie Dabros; Lützen, Anne

    2009-01-01

    for regulation of nuclear import that is necessary for proper localization of the repair proteins. This review summarizes the current knowledge on nuclear import mechanisms of DNA excision repair proteins and provides a model that categorizes the import by different mechanisms, including classical nuclear import......DNA mutations are circumvented by dedicated specialized excision repair systems, such as the base excision repair (BER), nucleotide excision repair (NER), and mismatch repair (MMR) pathways. Although the individual repair pathways have distinct roles in suppressing changes in the nuclear DNA......, it is evident that proteins from the different DNA repair pathways interact [Y. Wang, D. Cortez, P. Yazdi, N. Neff, S.J. Elledge, J. Qin, BASC, a super complex of BRCA1-associated proteins involved in the recognition and repair of aberrant DNA structures, Genes Dev. 14 (2000) 927-939; M. Christmann, M...

  19. Repair-misrepair model of cell survival

    International Nuclear Information System (INIS)

    Tobias, C.A.; Blakely, E.A.; Ngo, F.Q.H.

    1980-01-01

    During the last three years a new model, the repair-misrepair model (RMR) has been proposed, to interpret radiobiological experiments with heavy ions. In using the RMR model it became apparent that some of its features are suitable for handling the effects produced by a variety of environmental agents in addition to ionizing radiation. Two separate sequences of events are assumed to take place in an irradiated cell. The first sequence begins with an initial energy transfer consisting of ionizations and excitations, culminating via fast secondary physical and chemical processes in established macromolecular lesions in essential cell structures. The second sequence contains the responses of the cell to the lesions and consists of the processes of recognition and molecular repair. In normal cells there exists one repair process or at most a few enzymatic repair processes for each essential macromolecular lesion. The enzymatic repair processes may last for hours and minutes, and can be separated in time from the initial physicochemical and later genetic phases

  20. Inhibition of DNA repair by trifluoperazine

    Energy Technology Data Exchange (ETDEWEB)

    Charp, P.A.; Regan, J.D.

    1985-01-01

    The authors examined the possible role of calmodulin in the excision repair of ultraviolet light-induced pyrimidine dimers in damaged DNA by means of specialized assay systems. These assays included bromodeoxyuridine photolysis, dimer chromatography and cytosine arabinoside incorporation in conjunction with hydroxyurea. The calmodulin antagonist, trifluoperazine, and the calcium-chelating agent, EGTA, were employed to ascertain what affect calmodulin played in the repair process. Normal human fibroblast cells are used in all studies described in this report. After exposure to 10 J/m2 of 254 nm light, the authors observed a decrease of about 30% in the number of single-strand breaks produced in the presence of 25 M trifluoperazine (1.9 vs. 3.3) in controls although the numbers of bases re-inserted in the repaired regions were similar (64 vs. 72). Measurement of thymine-containing dimers remaining throughout a 24 h time period indicated a 30% difference decrease in the number of cytosine arabinoside arrested repair sites in the presence of either EGTA or trifluoperazine. The results are discussed with relation to the possibility of calmodulin altering the initial incision by repair endonuclease. 27 references, 3 figures.

  1. Combining rhinoplasty with septal perforation repair.

    Science.gov (United States)

    Foda, Hossam M T; Magdy, Emad A

    2006-11-01

    A combined septal perforation repair and rhinoplasty was performed in 80 patients presenting with septal perforations (size 1 to 5 cm) and external nasal deformities. The external rhinoplasty approach was used for all cases and the perforation was repaired using bilateral intranasal mucosal advancement flaps with a connective tissue interposition graft in between. Complete closure of the perforation was achieved in 90% of perforations of size up to 3.5 cm and in only 70% of perforations that were larger than 3.5 cm. Cosmetically, 95% were very satisfied with their aesthetic result. The external rhinoplasty approach proved to be very helpful in the process of septal perforation repair especially in large and posteriorly located perforations and in cases where the caudal septal cartilage was previously resected. Our results show that septal perforation repair can be safely combined with rhinoplasty and that some of the routine rhinoplasty maneuvers, such as medial osteotomies and dorsal lowering, could even facilitate the process of septal perforation repair.

  2. Potentially lethal damage and its repair

    International Nuclear Information System (INIS)

    Utsumi, Hiroshi

    1989-01-01

    Two forms termed fast-and slow-potentially lethal lethal damage (PLD) are introduced and discussed. The effect on the survival of x-irradiated Chinese hamster cells (V79) of two different post-treatments is examined in plateau- and in log-phases of growth. The postirradiation treatments used : a) incubation in hypertonic solution, and b) incubation in conditioned medium obtained from plateau-phase. Similar reduction in survival was caused by postirradiation treatment with hypertonic phosphate buffered saline, and similar increased in survival was effected by treatment in conditioned medium in plateau- and in log-phases cells. However, repair of PLD sensitive to hypertonic treatment was faster (half time, 5-10 min)(f-PLD repair) and independent from the repair of PLD (half time, 1-2 hour)(s-PLD repair) observed in conditioned medium. The results indicate the induction of two forms of PLD by radiation. Induction of both PLD was found to decrease with increasing LET of the radiation used. Identification of the molecular processes underlying repair and fixation of PLD is a task of particular interest, since it may allow replacement of a phenomenological definition with a molecular definition. Evidence is reviewed indicating the DNA double strand breaks (directly or indirectly induced) may be the DNA lesions underlying PLD. (author)

  3. Repair in Ehrlich ascites tumor cells

    International Nuclear Information System (INIS)

    Wanna-Nakamura, S.S.

    1981-01-01

    Unscheduled DNA synthesis (UDS), an indicator of excision repair, was induced in freshly drawn Ehrlich ascites tumor cells (EAT), using ionizing radiation, far ultraviolet light (254 nm) or near uv light (365 nm) in combination with 8-methoxypsoralen. UDS was scored by grain counts in autoradiographs following the incorporation of tritium-labelled thymidine. The amount of UDS after each of these agents was expressed in terms of two parameters, viz. numer of cells showing repair and the mean number of grains per nucleus. The influence of radiation dose and of the duration of radioactive thymidine incubation were also examined. To test for a possible relationship between low mitotic index and repair capability, EAT cells were incubated in buffered salt media to lower the mitotic index. Cells kept in a buffered salt solution for 7 h show a marked drop in mitotic index compared to those incubated in minimal medium containing 15% fetal calf serum (MEM + FCS). This drop in mitotic index was reversible for up to 5 h, if cells were returned to MEM + FCS. Cells incubated in MEM + FCS also showed a decrease in mitotic activity compared to freshly drawn cells. This reduced mitotic index is approximately constant for up to 24 h. With the drop in mitotic index, EAT cells also show a drop in repair compared to freshly drawn cells. The repair capability of cells incubated in buffer can be restored by returning cells to MEM + FCS

  4. Safety of repair for severe duodenal injuries.

    Science.gov (United States)

    Velmahos, George C; Constantinou, Constantinos; Kasotakis, George

    2008-01-01

    There is ongoing debate about the management of severe duodenal injuries (SDIs), and earlier studies have recommended pyloric exclusion. The objective of this study was to compare primary repair with pyloric exclusion to examine if primary repair can be safely used in SDIs. The medical records of 193 consecutive patients who were admitted between August 1992 and January 2004 with duodenal injuries were reviewed. After excluding early deaths (n = 50), low-grade duodenal injuries (n = 81), and pancreatoduodenectomies for catastrophic trauma (n = 12), a total of 50 patients with SDIs (grade III, IV, or V) were analyzed. Primary repair (PR--simple duodenorrhaphy or resection and primary anastomosis) was performed in 34 (68%) and pyloric exclusion (PE) in 16 (32%). Characteristics and outcomes of these two groups were compared. PE and PR patients were similar for age, injury severity score, abdominal abbreviated injury score, physiologic status on admission, time to operation, and most abdominal organs injured. PE patients had more pancreatic injuries (63% vs. 24%, p duodenum (79% vs. 42%, p = 0.02), and a nonsignificant trend toward more grade IV and V injuries (37% vs. 18%, p = 0.11). There was no difference in morbidity (including complications specific to the duodenal repair), mortality, and intensive care unit and hospital length of stay between the two groups. Pyloric exclusion is not necessary for all patients with SDIs, as previously suggested. Selected SDI patients can be safely managed by simple primary repair.

  5. [Flexor tendon repair: a short story].

    Science.gov (United States)

    Moutet, F; Corcella, D; Forli, A; Mesquida, V

    2014-12-01

    This short story of flexor tendon repair aims to illustrate hesitations and wanderings of this surgery. Obviously tendon repair was very early considered, but it developed and diffused rather lately. It became a routine practice only in 20th century. This was due on the one hand, in Occident, to the Galen's dogmatic interdiction, on the other hand, to the repair difficulties of this paradoxical structure. Actually tendon is made of fibroblasts and collagen (sticky substances), and then its only goal is to move. According to this necessity, whatever the used techniques are, gliding is the final purpose. Technical evolutions are illustrated by historical contributions to flexor tendon surgery of several "giants" of hand surgery. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. Designing Hydrogel Adhesives for Corneal Wound Repair

    Science.gov (United States)

    Grinstaff, Mark W.

    2013-01-01

    Today, corneal wounds are repaired using nylon sutures. Yet there are a number of complications associated with suturing the cornea, and thus there is interest in an adhesive to replace or supplement sutures in the repair of corneal wounds. We are designing and evaluating corneal adhesives prepared from dendrimers – single molecular weight, highly branched polymers. We have explored two strategies to form these ocular adhesives. The first involves a photocrosslinking reaction and the second uses a peptide ligation reactions to couple the individual dendrimers together to from the adhesive. These adhesives were successfully used to repair corneal perforations, close the flap produced in a LASIK procedure, and secure a corneal transplant. PMID:17889330

  7. Semiconductors detectors: basics principals, fabrication and repair

    International Nuclear Information System (INIS)

    Souza Coelho, L.F. de.

    1982-05-01

    The fabrication and repairing techniques of semiconductor detectors, are described. These methods are shown in the way they are applied by the semiconductor detector laboratory of the KFA-Julich, where they have been developed during the last 15 years. The history of the semiconductor detectors is presented here, being also described the detector fabrication experiences inside Brazil. The key problems of manufacturing are raised. In order to understand the fabrication and repairing techniques the working principles of these detectors, are described. The cases in which worked during the stay in the KFA-Julich, particularly the fabrication of a plane Ge (Li) detector, with side entry, and the repair of a coaxial Ge (Li) is described. The vanguard problems being researched in Julich are also described. Finally it is discussed a timetable for the semiconductor detector laboratory of the UFRJ, which laboratory is in the mounting stage now. (Author) [pt

  8. Repair replication in permeabilized Escherichia coli

    International Nuclear Information System (INIS)

    Masker, W.E.; Simon, T.J.; Hanawalt, P.C.

    1975-01-01

    We have examined the modes of DNA synthesis in Escherichia coli strains made permeable to nucleoside triphosphates by treatment with toluene. In this quasi in vitro system, polymerase-I-deficient mutants exhibit a nonconservative mode of synthesis with properties expected for the resynthesis step of excision-repair. This uv-stimulated DNA synthesis can be performed by either DNA polymerase II or III and it also requires the uvrA gene product. It requires the four deoxynucleoside triphosphates; but, in contrast to the semiconservative mode, the ATP requirement can be partially satisfied by other nucleoside triphosphates. The ATP-dependent recBC nuclease is not involved. The observed uv-stimulated mode of DNA synthesis may be part of an alternate excision-repair mechanism which supplements or complements DNA-polymerase-I-dependent repair in vivo

  9. Chronic pain after childhood groin hernia repair

    DEFF Research Database (Denmark)

    Aasvang, Eske Kvanner; Kehlet, Henrik

    2007-01-01

    BACKGROUND: In contrast to the well-described 10% risk of chronic pain affecting daily activities after adult groin hernia repair, chronic pain after childhood groin hernia repair has never been investigated. Studies of other childhood surgery before the age of 3 months suggest a risk of increased...... pain responsiveness later in life, but its potential relationship to chronic pain in adult life is unknown. METHODS: This was a nationwide detailed questionnaire study of chronic groin pain in adults having surgery for a groin hernia repair before the age of 5 years (n = 1075). RESULTS: The response...... rate was 63.3%. In the 651 patients available for analysis, pain from the operated groin was reported by 88 (13.5%) patients whereof 13 (2.0%) patients reported frequent and moderate or severe pain. Pain occurred primarily when exercising sports or other leisure activities. Patients operated on before...

  10. Open preperitoneal groin hernia repair with mesh

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Rosenberg, Jacob

    2017-01-01

    Background For the repair of inguinal hernias, several surgical methods have been presented where the purpose is to place a mesh in the preperitoneal plane through an open access. The aim of this systematic review was to describe preperitoneal repairs with emphasis on the technique. Data sources...... A systematic review was conducted and reported according to the PRISMA statement. PubMed, Cochrane library and Embase were searched systematically. Studies were included if they provided clinical data with more than 30 days follow up following repair of an inguinal hernia with an open preperitoneal mesh......-analysis. Open preperitoneal techniques with placement of a mesh through an open approach seem promising compared with the standard anterior techniques. This systematic review provides an overview of these techniques together with a description of surgical methods and clinical outcomes....

  11. Open preperitoneal groin hernia repair with mesh

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Rosenberg, Jacob

    2017-01-01

    BACKGROUND: For the repair of inguinal hernias, several surgical methods have been presented where the purpose is to place a mesh in the preperitoneal plane through an open access. The aim of this systematic review was to describe preperitoneal repairs with emphasis on the technique. DATA SOURCES......: A systematic review was conducted and reported according to the PRISMA statement. PubMed, Cochrane library and Embase were searched systematically. Studies were included if they provided clinical data with more than 30 days follow up following repair of an inguinal hernia with an open preperitoneal mesh......-analysis. Open preperitoneal techniques with placement of a mesh through an open approach seem promising compared with the standard anterior techniques. This systematic review provides an overview of these techniques together with a description of surgical methods and clinical outcomes....

  12. Weld repair of creep damaged steels

    International Nuclear Information System (INIS)

    Croker, A.B.L.; Harrison, R.P.; Moss, C.J.

    1995-01-01

    A cooperative research centre project 'Welding of Thermally Modified Structures' was commenced in June 1993 with support from ANSTO, CSIRO, BHP, University of Wollongong and the CRC for Materials, Welding and Joining. The main aims of the project are to quantify the effects of performing repair welds on materials which have operated for extended periods at elevated temperature. Welding is an increasingly used method for performing repairs, replacements, retrofits and modifications to elevated temperature plant, however, the effects of these repairs on the ultimate life of a component are poorly understood. This paper presents details of the three ex-service materials chosen for the project, a carbon steel and two alloy steels. Work is also presented on development of new methods of assessing materials and components both destructively, along with new methods of modelling welded components in high temperature service. 6 figs, 3 tabs

  13. Vesicovaginal fistula repair through vaginal approach

    International Nuclear Information System (INIS)

    Ashraf, S.; Rahim, J.

    2014-01-01

    Objectives: To evaluate the outcome of trans-vaginal repair of vesico-vaginal fistula through vaginal approach. Study Design: Prospective study. Material and Methods: This study was carried out in Department of Urology, Shaikh Zayed Postgraduate Medical Institute and National institute of Kidney Diseases, Lahore for the period extending from April 2009 to April 2014. Total 17 patients were included in the study. History, physical examination and findings on investigations were reviewed. In all patients cystoscopy and vaginal examination was performed to see fistula site and ureteral orfices. Then trans-vaginal repair was done in all cases. Results: VVF repair was performed on 17 patients aging 25 to 45 years (mean 35.83 ± 7.37 years). The symptoms preceded for a period of 3 months to 8 years. The cause was gynecological hysterectomy 8 (47.05%), obstetric C-section 7 (41.17%) and obstructed labor 2(11.76%). In three of our patients VVF was previously repaired trans-abdominally. On cystoscopy no patients had more than one fistula. In two (11.76%) patients fistula was supratrigonal. The average size of fistula was 2.05 em, detail of fistula site and size is given in table. One patient had leakage on second postop day that was managed with change of Foleys catheter. Successful repair was achieved in all patients and no patient required second attempt. No ureteric injury and other complications were observed. Conclusion: Trans-vaginal repair of VVF avoid laparotomy and bladder bisection. It has reduced hospital stay and morbidity. (author)

  14. Both base excision repair and nucleotide excision repair in humans are influenced by nutritional factors.

    Science.gov (United States)

    Brevik, Asgeir; Karlsen, Anette; Azqueta, Amaya; Tirado, Anna Estaban; Blomhoff, Rune; Collins, Andrew

    2011-01-01

    Lack of reliable assays for DNA repair has largely prevented measurements of DNA repair from being included in human biomonitoring studies. Using newly developed modifications of the comet assay we tested whether a fruit- and antioxidant-rich plant-based intervention could affect base excision repair (BER) and nucleotide excision repair (NER) in a group of 102 male volunteers. BER and NER repair capacities were measured in lymphocytes before and after a dietary intervention lasting 8 weeks. The study had one control group, one group consuming three kiwifruits per day and one group consuming a variety of antioxidant-rich fruits and plant products in addition to their normal diet. DNA strand breaks were reduced following consumption of both kiwifruits (13%, p = 0.05) and antioxidant-rich plant products (20%, p = 0.02). Increased BER (55%, p = 0.01) and reduced NER (-39%, p plant products. Reduced NER was also observed in the kiwifruit group (-38%, p = 0.05), but BER was not affected in this group. Here we have demonstrated that DNA repair is affected by diet and that modified versions of the comet assay can be used to assess activity of different DNA repair pathways in human biomonitoring studies. Copyright © 2010 John Wiley & Sons, Ltd.

  15. A self-repairing polymer waveguide sensor

    International Nuclear Information System (INIS)

    Song, Young J; Peters, Kara J

    2011-01-01

    This paper presents experimental demonstrations of a self-repairing strain sensor waveguide created by self-writing in a photopolymerizable resin system. The sensor is fabricated between two multi-mode optical fibers via lightwaves in the ultraviolet (UV) wavelength range and operates as a sensor through interrogation of the power transmitted through the waveguide in the infrared (IR) wavelength range. After failure of the sensor occurs due to loading, the waveguide re-bridges the gap between the two optical fibers through the UV resin. The response of the original sensor and the self-repaired sensor to strain are measured and show similar behaviors

  16. Repairing organs: lessons from intestine and liver.

    Science.gov (United States)

    Gehart, Helmuth; Clevers, Hans

    2015-06-01

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and liver have uncovered significant plasticity in epithelial tissues. Harnessing this knowledge, researchers have recently created culture systems that enable the expansion of stem cells into transplantable tissue in vitro. Here we discuss how the growing tool set of stem cell biology can bring organ repair from fictitious narrative to medical practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Leak testing and repair of fusion devices

    International Nuclear Information System (INIS)

    Kozman, T.A.

    1983-01-01

    The leak testing, reporting and vacuum leak repair techniques of the MFTF yin-yang number one magnet system, the world's largest superconducting magnet system, are discussed. Based on this experience, techniques will be developed for testing and repairing leaks on the 42 MFTF-B magnets. The leak-hunting techniques for the yin-yang magnet systems were applied to two helium circuits (the coil bundle and guard vacuum; both require helium flow for magnet cooldown), their associated piping, liquid nitrogen radiation shields, and piping. Additionally, during MFTF-B operation there will be warm water plasma shields and piping that require leak checking

  18. Rotator Cuff Repair in Adolescent Athletes.

    Science.gov (United States)

    Azzam, Michael G; Dugas, Jeffrey R; Andrews, James R; Goldstein, Samuel R; Emblom, Benton A; Cain, E Lyle

    2018-04-01

    Rotator cuff tears are rare injuries in adolescents but cause significant morbidity if unrecognized. Previous literature on rotator cuff repairs in adolescents is limited to small case series, with few data to guide treatment. Adolescent patients would have excellent functional outcome scores and return to the same level of sports participation after rotator cuff repair but would have some difficulty with returning to overhead sports. Case series; Level of evidence 4. A retrospective search of the practice's billing records identified all patients participating in at least 1 sport who underwent rotator cuff repair between 2006 and 2014 with an age Rotator Cuff Index. Thirty-two consecutive adolescent athletes (28 boys and 4 girls) with a mean age of 16.1 years (range, 13.2-17.9 years) met inclusion criteria. Twenty-nine patients (91%) had a traumatic event, and 27 of these patients (93%) had no symptoms before the trauma. The most common single tendon injury was to the supraspinatus (21 patients, 66%), of which 2 were complete tendon tears, 1 was a bony avulsion of the tendon, and 18 were high-grade partial tears. Fourteen patients (56%) underwent single-row repair of their rotator cuff tear, and 11 (44%) underwent double-row repair. All subscapularis injuries were repaired in open fashion, while all other tears were repaired arthroscopically. Twenty-seven patients (84%) completed the outcome questionnaires at a mean 6.2 years after surgery (range, 2-10 years). The mean ASES score was 93 (range, 65-100; SD = 9); mean Western Ontario Rotator Cuff Index, 89% (range, 60%-100%; SD = 13%); and mean numeric pain rating, 0.3 (range, 0-3; SD = 0.8). Overall, 25 patients (93%) returned to the same level of play or higher. Among overhead athletes, 13 (93%) were able to return to the same level of play, but 8 (57%) were forced to change positions. There were no surgical complications, but 2 patients did undergo a subsequent operation. Surgical repair of high-grade partial

  19. Cellular and Acellular Approaches for Cartilage Repair

    Science.gov (United States)

    2015-01-01

    There are several choices of cells to use for cartilage repair. Cells are used as internal or external sources and sometimes in combination. In this article, an analysis of the different cell choices and their use and potential is provided. Embryonic cartilage formation is of importance when finding more about how to be able to perfect cartilage repair. Some suggestions for near future research based on up-to-date knowledge on chondrogenic cells are given to hopefully stimulate more studies on the final goal of cartilage regeneration. PMID:27340516

  20. Prosthetic Mesh Repair for Incarcerated Inguinal Hernia

    Directory of Open Access Journals (Sweden)

    Cihad Tatar

    2016-08-01

    Full Text Available Background: Incarcerated inguinal hernia is a commonly encountered urgent surgical condition, and tension-free repair is a well-established method for the treatment of noncomplicated cases. However, due to the risk of prosthetic material-related infections, the use of mesh in the repair of strangulated or incarcerated hernia has often been subject to debate. Recent studies have demonstrated that biomaterials represent suitable materials for performing urgent hernia repair. Certain studies recommend mesh repair only for cases where no bowel resection is required; other studies, however, recommend mesh repair for patients requiring bowel resection as well. Aim: The aim of this study was to compare the outcomes of different surgical techniques performed for strangulated hernia, and to evaluate the effect of mesh use on postoperative complications. Study Design: Retrospective cross-sectional study. Methods: This retrospective study was performed with 151 patients who had been admitted to our hospital’s emergency department to undergo surgery for a diagnosis of incarcerated inguinal hernia. The patients were divided into two groups based on the applied surgical technique. Group 1 consisted of 112 patients treated with mesh-based repair techniques, while Group 2 consisted of 39 patients treated with tissue repair techniques. Patients in Group 1 were further divided into two sub-groups: one consisting of patients undergoing bowel resection (Group 3, and the other consisting of patients not undergoing bowel resection (Group 4. Results: In Group 1, it was observed that eight (7.14% of the patients had wound infections, while two (1.78% had hematomas, four (3.57% had seromas, and one (0.89% had relapse. In Group 2, one (2.56% of the patients had a wound infection, while three (7.69% had hematomas, one (2.56% had seroma, and none had relapses. There were no statistically significant differences between the two groups with respect to wound infection

  1. Chromatin challenges during DNA replication and repair

    DEFF Research Database (Denmark)

    Groth, Anja; Rocha, Walter; Verreault, Alain

    2007-01-01

    Inheritance and maintenance of the DNA sequence and its organization into chromatin are central for eukaryotic life. To orchestrate DNA-replication and -repair processes in the context of chromatin is a challenge, both in terms of accessibility and maintenance of chromatin organization. To meet...... the challenge of maintenance, cells have evolved efficient nucleosome-assembly pathways and chromatin-maturation mechanisms that reproduce chromatin organization in the wake of DNA replication and repair. The aim of this Review is to describe how these pathways operate and to highlight how the epigenetic...... landscape may be stably maintained even in the face of dramatic changes in chromatin structure....

  2. Valve radio and audio repair handbook

    CERN Document Server

    MILLER, CHAS

    2000-01-01

    This book is not only an essential read for every professional working with antique radio and gramophone equipment, but also dealers, collectors and valve technology enthusiasts the world over. The emphasis is firmly on the practicalities of repairing and restoring, so technical content is kept to a minimum, and always explained in a way that can be followed by readers with no background in electronics. Those who have a good grounding in electronics, but wish to learn more about the practical aspects, will benefit from the emphasis given to hands-on repair work, covering mechanical as

  3. Peripherally Inserted Central Catheters in Pediatric Patients: To Repair or Not Repair

    International Nuclear Information System (INIS)

    Gnannt, Ralph; Patel, Premal; Temple, Michael; Al Brashdi, Yahya; Amaral, Joao; Parra, Dimitri; Rea, Vanessa; Stephens, Derek; Connolly, Bairbre

    2017-01-01

    IntroductionPreservation of venous access in children is a major concern in pediatric interventional radiology. If a peripherally inserted central catheter (PICC) breaks, there are two options: repair the line with a repair kit or exchange the line over a wire in the interventional suite. The purpose of this study is to assess the outcome of PICC repairs in children and to compare these with the outcomes of PICC exchange.Materials and MethodsThis is a single-center, retrospective study of central line-associated bloodstream infection (CLABSI) following management of externally broken PICCs (2010–2014). The occurrence of CLABSI within 30 days after repair (Group A) or exchange (Group B) of a line was analyzed, as well as PICCs exchanged following an initial and failed repair.ResultsA total of 235 PICC breaks were included in the study, of which 161 were repaired, and 116 of whom were successful (68%, Group A). No repair was performed in 74 PICCs—55/74 of these were exchanged over a wire (74%, Group B), and 19/74 lines were removed. The 30 days post-repair CLABSI rate (Group A) was 2.0 infections per 1000 catheter days, and the calculated risk was 4.3%. In comparison the 30 days post-exchange CLABSI rate (Group B) was 4.0 per 1000 catheter days and the calculated risk 10.9%. This difference was significant when adjusted for antibiotic use (OR 3.87; 95% CI 1.07–14.0, p = 0.039).ConclusionThe results of this study support repairing a broken PICC instead of removing or replacing the line.

  4. Peripherally Inserted Central Catheters in Pediatric Patients: To Repair or Not Repair

    Energy Technology Data Exchange (ETDEWEB)

    Gnannt, Ralph, E-mail: ralph.gnannt@usz.ch; Patel, Premal; Temple, Michael; Al Brashdi, Yahya; Amaral, Joao; Parra, Dimitri; Rea, Vanessa [University of Toronto, Image Guided Therapy, Diagnostic Imaging, The Hospital for Sick Children (Canada); Stephens, Derek [University of Toronto, Child Health Evaluative Sciences (Canada); Connolly, Bairbre [University of Toronto, Image Guided Therapy, Diagnostic Imaging, The Hospital for Sick Children (Canada)

    2017-06-15

    IntroductionPreservation of venous access in children is a major concern in pediatric interventional radiology. If a peripherally inserted central catheter (PICC) breaks, there are two options: repair the line with a repair kit or exchange the line over a wire in the interventional suite. The purpose of this study is to assess the outcome of PICC repairs in children and to compare these with the outcomes of PICC exchange.Materials and MethodsThis is a single-center, retrospective study of central line-associated bloodstream infection (CLABSI) following management of externally broken PICCs (2010–2014). The occurrence of CLABSI within 30 days after repair (Group A) or exchange (Group B) of a line was analyzed, as well as PICCs exchanged following an initial and failed repair.ResultsA total of 235 PICC breaks were included in the study, of which 161 were repaired, and 116 of whom were successful (68%, Group A). No repair was performed in 74 PICCs—55/74 of these were exchanged over a wire (74%, Group B), and 19/74 lines were removed. The 30 days post-repair CLABSI rate (Group A) was 2.0 infections per 1000 catheter days, and the calculated risk was 4.3%. In comparison the 30 days post-exchange CLABSI rate (Group B) was 4.0 per 1000 catheter days and the calculated risk 10.9%. This difference was significant when adjusted for antibiotic use (OR 3.87; 95% CI 1.07–14.0, p = 0.039).ConclusionThe results of this study support repairing a broken PICC instead of removing or replacing the line.

  5. Thymus repair compared with hemopoiesis repair in spleen after protracted irradiation

    International Nuclear Information System (INIS)

    Mackova, N.

    1987-01-01

    Matured female mice of ICR strain were irradiated from a 60 Co source with a daily dose rate of 5 Gy till total accumulated dose of 10 Gy for 2 days. Animals were examined in various intervals within 42 days after irradiation. The results revealed that protracted irradiation will induce a massive injury to hemopoiesis. The first repair processes occurred in thymus and were characterized by two phases. The first repair wave peaked about the day 10 and the second about the day 30 after irradiation. The repair processes observed in the red pulp of the spleen reached their highest intensity approximately between the days 14-16 after irradiation. (author)

  6. Adaptive repair induced by small doses of γ radiation in repair-defective human cells

    International Nuclear Information System (INIS)

    Zasukhina, G.D.; L'vova, G.N.; Vasil'eva, I.M.; Sinel'shchikova, T.A.; Semyachkina, A.N.

    1993-01-01

    Adaptive repair induced by small doses of gamma radiation was studied in repair-defective xeroderma pigmentosum, gout, and homocystinuria cells. The adaptation of cells induced by small doses of radiation was estimated after subsequent exposure to gamma radiation, 4-nitroquinoline-1-oxide, and N-methyl-N-nitro-N-nitrosoguanidine by three methods: (1) by the reduction in DNA breaks; (2) by induction of resistant DNA synthesis; and (3) by increased reactivation of vaccinia virus. The three cell types in response to the three different mutagens revealed differences in the mechanism of cell defense in excision repair, in the adaptive response, and in Weigl reactivation

  7. DNA repair in neurons: So if they don't divide what's to repair?

    International Nuclear Information System (INIS)

    Fishel, Melissa L.; Vasko, Michael R.; Kelley, Mark R.

    2007-01-01

    Neuronal DNA repair remains one of the most exciting areas for investigation, particularly as a means to compare the DNA repair response in mitotic (cancer) vs. post-mitotic (neuronal) cells. In addition, the role of DNA repair in neuronal cell survival and response to aging and environmental insults is of particular interest. DNA damage caused by reactive oxygen species (ROS) such as generated by mitochondrial respiration includes altered bases, abasic sites, and single- and double-strand breaks which can be prevented by the DNA base excision repair (BER) pathway. Oxidative stress accumulates in the DNA of the human brain over time especially in the mitochondrial DNA (mtDNA) and is proposed to play a critical role in aging and in the pathogenesis of several neurological disorders including Parkinson's disease, ALS, and Alzheimer's diseases. Because DNA damage accumulates in the mtDNA more than nuclear DNA, there is increased interest in DNA repair pathways and the consequence of DNA damage in the mitochondria of neurons. The type of damage that is most likely to occur in neuronal cells is oxidative DNA damage which is primarily removed by the BER pathway. Following the notion that the bulk of neuronal DNA damage is acquired by oxidative DNA damage and ROS, the BER pathway is a likely area of focus for neuronal studies of DNA repair. BER variations in brain aging and pathology in various brain regions and tissues are presented. Therefore, the BER pathway is discussed in greater detail in this review than other repair pathways. Other repair pathways including direct reversal, nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination and non-homologous end joining are also discussed. Finally, there is a growing interest in the role that DNA repair pathways play in the clinical arena as they relate to the neurotoxicity and neuropathy associated with cancer treatments. Among the numerous side effects of cancer treatments, major clinical effects

  8. Satisfaction, function and repair integrity after arthroscopic versus mini-open rotator cuff repair.

    Science.gov (United States)

    Barnes, L A Fink; Kim, H M; Caldwell, J-M; Buza, J; Ahmad, C S; Bigliani, L U; Levine, W N

    2017-02-01

    Advances in arthroscopic techniques for rotator cuff repair have made the mini-open approach less popular. However, the mini-open approach remains an important technique for repair for many surgeons. The aims of this study were to compare the integrity of the repair, the function of the shoulder and satisfaction post-operatively using these two techniques in patients aged > 50 years. We identified 22 patients treated with mini-open and 128 patients treated with arthroscopic rotator cuff repair of July 2007 and June 2011. The mean follow-up was two years (1 to 5). Outcome was assessed using the American Shoulder and Elbow Surgeons (ASES) and Simple Shoulder Test (SST) scores, and satisfaction. The integrity of the repair was assessed using ultrasonography. A power analysis ensured sufficient enrolment. There was no statistically significant difference between the age, function, satisfaction, or pain scores (p > 0.05) of the two groups. The integrity of the repair and the mean SST scores were significantly better in the mini-open group (91% of mini-open repairs were intact versus 60% of arthroscopic repairs, p = 0.023; mean SST score 10.9 (standard deviation (sd) 1.3) in the mini-open group; 8.9 (sd 3.5) in arthroscopic group; p = 0.003). The ASES scores were also higher in the mini-open group (mean ASES score 91.0 (sd 10.5) in mini-open group; mean 82.70 (sd 19.8) in the arthroscopic group; p = 0.048). The integrity of the repair and function of the shoulder were better after a mini-open repair than after arthroscopic repair of a rotator cuff tear in these patients. The functional difference did not translate into a difference in satisfaction. Mini-open rotator cuff repair remains a useful technique despite advances in arthroscopy. Cite this article: Bone Joint J 2017;99-B:245-9. ©2017 The British Editorial Society of Bone & Joint Surgery.

  9. Fragile DNA Repair Mechanism Reduces Ageing in Multicellular Model

    DEFF Research Database (Denmark)

    Bendtsen, Kristian Moss; Juul, Jeppe Søgaard; Trusina, Ala

    2012-01-01

    increases the amount of unrepaired DNA damage. Despite this vicious circle, we ask, can cells maintain a high DNA repair capacity for some time or is repair capacity bound to continuously decline with age? We here present a simple mathematical model for ageing in multicellular systems where cells subjected...... to DNA damage can undergo full repair, go apoptotic, or accumulate mutations thus reducing DNA repair capacity. Our model predicts that at the tissue level repair rate does not continuously decline with age, but instead has a characteristic extended period of high and non-declining DNA repair capacity......DNA damages, as well as mutations, increase with age. It is believed that these result from increased genotoxic stress and decreased capacity for DNA repair. The two causes are not independent, DNA damage can, for example, through mutations, compromise the capacity for DNA repair, which in turn...

  10. Laparoscopic repair of paraesophageal hernia with anterior gastropexy

    DEFF Research Database (Denmark)

    Daigle, Christopher R; Funch-Jensen, Peter; Calatayud, Dan

    2015-01-01

    despite significant dysphagia rates. We present our multicenter prospective data on laparoscopic PEH repairs using a modified Boerema anterior gastropexy without fundoplication. METHODS: We prospectively followed patients after modified Boerema PEH repair at three institutions. Patient demographics...

  11. Situation-dependent repair of DNA damage in yeast

    International Nuclear Information System (INIS)

    von Borstel, R.C.; Hastings, P.J.

    1985-01-01

    The concept of channelling of lesions in DNA into defined repair systems has been used to explain many aspects of induced and spontaneous mutation. The channelling hypothesis states that lesions excluded from one repair process will be taken up by another repair process. This is a simplification. The three known modes of repair of damage induced by radiation are not equivalent modes of repair; they are, instead, different solutions to the problem of replacement of damaged molecules with new molecules which have the same informational content as those that were damaged. The mode of repair that is used is the result of the response to the situation in which the damage takes place. Thus, when the most likely mode of repair does not take place, then the situation changes with respect to the repair of the lesion; the lesion may enter the replication fork and be reparable by another route

  12. Laboratory and Field Investigations of Small Crater Repair Technologies

    National Research Council Canada - National Science Library

    Priddy, Lucy P; Tingle, Jeb S; McCaffrey, Timothy J; Rollings, Ray S

    2007-01-01

    .... This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation...

  13. 28 Comparative Study of Open Mesh Repair and Desarda's No ...

    African Journals Online (AJOL)

    user

    2006-12-02

    Dec 2, 2006 ... Methods: This is a retrospective study of 269 hernias operated by the ... principle and this concept of physiological repair of inguinal hernia ... laparoscopic repairs or the patients given .... 11 obstructed and 17 bilateral hernias.

  14. Recurrence and complications of pediatric inguinal hernia repair ...

    African Journals Online (AJOL)

    complications of inguinal hernia repair in pediatric patients ... surgery. Patients and methods This retrospective study was ... Bilateral inguinal hernia was observed ..... single-blind comparison of laparoscopic versus open repair of pediatric.

  15. Recurrence and Pain after Mesh Repair of Inguinal Hernias

    African Journals Online (AJOL)

    Abstract. Background: Surgery for inguinal hernias has ... repair. Methods: The study was conducted on all inguinal hernia patients operated between 1st. October ... bilateral (1.6%). Only 101 .... Open Mesh Versus Laparoscopic Mesh. Repair ...

  16. Sequelae of Endoscopic Inguinal Hernia Repair : Incidence, evaluation and management

    NARCIS (Netherlands)

    Burgmans, J.P.J.

    2015-01-01

    The endoscopic preperitoneal technique (TEP) is an appealing inguinal hernia repair technique, theoretically superior to other approaches. In practice some problems remain unsolved. Real incidences of chronic postoperative inguinal pain (CPIP) and other important sequelae of endoscopic hernia repair

  17. DNA repair in human xeroderma pigmentosum and chinese hamster cells

    International Nuclear Information System (INIS)

    Zelle, B.

    1980-01-01

    The investigations described were performed to study the genetic heterogeneity of excision repair-deficient XP (xeroderma pigmentosum) strains and the biochemical defects in their repair processes after irradiation with ultraviolet radiation. (Auth.)

  18. Investigation of DNA damage and repair mechanism using deinococcus radiodurans

    International Nuclear Information System (INIS)

    Lau How Mooi; Kikuchi, M.; Kobayashi, Y.; Narumi, I.; Watanabe, H.

    1997-01-01

    Deninococcus Radiodurans, formerly known as Micrococcus Radiodurans, is a popular bacterium because of its high resistance to damage by carcinogens such as ionizing radiation (Dean et. al. 1966; Kitayama and Matsuyama 1968) and UV radiation (Gasvon et. al., 1995; Arrange et. al. 1993). In this report, we investigated the high resistance to ionizing radiation by this bacterium. The bacteria had been exposed from I to 5 kGy of gamma radiation and then incubated in TGY medium to study their ability to repair the broken DNA. The repair time was measured by Pulse Field Gel Electrophoresis (PFGE) method. The repair time for each dose was determined. Also in order to ensure that the repair was perfect, the bacterium was subjected to a second exposure of ionizing radiation after it has fully repaired. It was found that the 'second' repair characteristic was similar to the first repair. This confirmed that the repair after the exposure to the ionizing radiation was perfect

  19. A model system for DNA repair studies

    International Nuclear Information System (INIS)

    Lange, C.S.; Perlmutter, E.

    1984-01-01

    The search for the ''lethal lesion:'' which would yield a molecular explanation of biological survival curves led to attempts to correlate unrepaired DNA lesions with loss of reproductive integrity. Such studies have shown the crucial importance of DNA repair systems. The unrepaired DSB has been sought for such correlation, but in such study the DNA was too large, polydisperse, and/or structurally complex to permit precise measurement of break induction and repair. Therefore, an analog of higher order systems but with a genome of readily measurable size, is needed. Bacteriophage T4 is such an analog. Both its biological (PFU) and molecular (DNA) survival curves are exponentials. Its aerobic /sub PFU/D/sub 37///sub DNA/D/sub 37/ ratio, (410 +- 4.5Gy/540 +- 25 Gy) indicates that 76 +- 4% of lethality at low multiplicity infection (moi 1) the survival is greater than can be explained if the assumption of no parental DSB repair were valid. Both T4 and its host have DSB repair systems which can be studied by the infectious center method. Results of such studies are discussed

  20. Regulation of DNA repair by parkin

    International Nuclear Information System (INIS)

    Kao, Shyan-Yuan

    2009-01-01

    Mutation of parkin is one of the most prevalent causes of autosomal recessive Parkinson's disease (PD). Parkin is an E3 ubiquitin ligase that acts on a variety of substrates, resulting in polyubiquitination and degradation by the proteasome or monoubiquitination and regulation of biological activity. However, the cellular functions of parkin that relate to its pathological involvement in PD are not well understood. Here we show that parkin is essential for optimal repair of DNA damage. Parkin-deficient cells exhibit reduced DNA excision repair that can be restored by transfection of wild-type parkin, but not by transfection of a pathological parkin mutant. Parkin also protects against DNA damage-induced cell death, an activity that is largely lost in the pathological mutant. Moreover, parkin interacts with the proliferating cell nuclear antigen (PCNA), a protein that coordinates DNA excision repair. These results suggest that parkin promotes DNA repair and protects against genotoxicity, and implicate DNA damage as a potential pathogenic mechanism in PD.

  1. Repair of abasic sites in DNA

    Energy Technology Data Exchange (ETDEWEB)

    Dianov, Grigory L.; Sleeth, Kate M.; Dianova, Irina I.; Allinson, Sarah L

    2003-10-29

    Repair of both normal and reduced AP sites is activated by AP endonuclease, which recognizes and cleaves a phosphodiester bond 5' to the AP site. For a short period of time an incised AP site is occupied by poly(ADP-ribose) polymerase and then DNA polymerase {beta} adds one nucleotide into the repair gap and simultaneously removes the 5'-sugar phosphate. Finally, the DNA ligase III/XRCC1 complex accomplishes repair by sealing disrupted DNA ends. However, long-patch BER pathway, which is involved in the removal of reduced abasic sites, requires further DNA synthesis resulting in strand displacement and the generation of a damage-containing flap that is later removed by the flap endonuclease. Strand-displacement DNA synthesis is accomplished by DNA polymerase {delta}/{epsilon} and DNA ligase I restores DNA integrity. DNA synthesis by DNA polymerase {delta}/{epsilon} is dependent on proliferating cell nuclear antigen, which also stimulates the DNA ligase I and flap endonuclease. These repair events are supported by multiple protein-protein interactions.

  2. DNA N-glycosylases and uv repair

    Energy Technology Data Exchange (ETDEWEB)

    Demple, B; Linn, S

    1980-09-18

    Repair of some DNA photoproducts can be mediated by glycosylic bond hydrolysis. Thus, Escherichia coli endonuclease III releases 5,6-hydrated thymines as free bases, while T4 uv endonuclease releases one of two glycosylic bonds holding pyrimidine dimers in DNA. In contrast, uninfected E. coli apparently does not excise pyrimidine dimers via a DNA glycosylase.

  3. ONSTEP versus laparoscopy for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2015-01-01

    repair. Patients are recruited from surgical departments in Denmark and follow-up is one year. In total, 188 patients will be included. DISCUSSION: This protocol describes one of the first randomised clinical trials investigating the ONSTEP technique. To our knowledge, it is the first clinical trial...

  4. DNA repair mechanism in radioresistant bacteria

    International Nuclear Information System (INIS)

    Kitayama, Shigeru

    1992-01-01

    Many radiation resistant bacteria have been isolated from various sources which are not in high background field. Since Deinococcus radiodurans had been isolated first in 1956, studies on the mechanism for radioresistance were carried out mostly using this bacterium. DNA in this bacterium isn't protected against injury induced by not only ionizing radiation but also ultraviolet light. Therefore, DNA damages induced by various treatments are efficiently and accurately repaired in this cells. Damages in base and/or sugar in DNA are removed by endonucleases which, if not all, are synthesized during postirradiation incubation. Following the endonucleolytic cleavage the strand scissions in DNA are seemed to be rejoined by a process common for the repair of strand scissions induced by such as ionizing radiations. Induce protein(s) is also involved in this rejoining process of strand scissions. DNA repair genes were classified into three phenotypic groups. (1)Genes which are responsible for the endonucleolytic activities. (2) Genes involved in the rejoining of DNA strand scissions. (3) Genes which participate in genetic recombination and repair. Three genes belong to (1) and (2) were cloned onto approximately 1 kbp DNA fragments which base sequences have been determined. (author)

  5. Ceramic restoration repair: report of two cases

    Directory of Open Access Journals (Sweden)

    Luís Henrique Araújo Raposo

    2009-04-01

    Full Text Available The esthetic and functional rehabilitation of patients with multiple missing teeth can be performed with several techniques and materials. Ceramic restorations provide reliable masticatory function and good esthetics. However, fracture can occur in some cases due to their brittle behavior. In some cases, the replacement of an extensive prosthesis is a problem due to the high treatment cost. In this paper, two cases are presented, in which fractures occurred in extensive metal-ceramic fixed partial dentures, and their replacement was not possible. Ceramic repair was chosen and the sequences of treatment with and without presence of the ceramic fragment are also discussed. The cases illustrate that, in some situations, fractured metal-ceramic partial dentures can be successfully repaired when prosthetic replacement is not a choice. Prosthodontists must use alternatives that allow a reliable repair to extensive metal-ceramic fixed partial dentures. Surface preparation of the ceramic with hydrofluoric acid in conjunction with a silane coupling agent is essential for a predictable bonding of composite resin. The repair performed with composite resin is an esthetic and functional alternative when extensive fixed partial dentures cannot be replaced.

  6. Laparoscopic Pelvic Floor Repair Using Polypropylene Mesh

    Directory of Open Access Journals (Sweden)

    Shih-Shien Weng

    2008-09-01

    Conclusion: Laparoscopic pelvic floor repair using a single piece of polypropylene mesh combined with uterosacral ligament suspension appears to be a feasible procedure for the treatment of advanced vaginal vault prolapse and enterocele. Fewer mesh erosions and postoperative pain syndromes were seen in patients who had no previous pelvic floor reconstructive surgery.

  7. Auto Body Repair 103, 203, 303.

    Science.gov (United States)

    Manitoba Dept. of Education, Winnipeg.

    As part of the high school vocational industrial program in Manitoba, this course has been designed to provide students with the foundation for a career in auto-body repair. The program introduces and provides opportunities for student skill development in the theories and techniques of tool and equipment operation, metallurgy and welding, damage…

  8. Biological repair with time-dependent irradiation

    International Nuclear Information System (INIS)

    Broyles, A.A.; Shapiro, C.S.

    1985-01-01

    Recent experiments have provided new data that explore the effectiveness of biological repair in assessing damage due to exposures from ionizing radiation. These data are mainly from experiments conducted at constant dose rates, to study the effectiveness per unit dose of different dose rates. Here, we develop new formulae to estimate the effectiveness of an arbitrary time-dependent dose rate exposure

  9. Repair of the spondylolysis in lumbar spine

    International Nuclear Information System (INIS)

    Matta Ibarra, Javier; Arrieta Maria, Victor; Torres Romero Fernando; Ramirez Cabrales, Vladimir

    2005-01-01

    The objective is to present the surgical experience in the repair of the spondylolysis in lumbar spine. Background: Spodylolysis is an important cause of low back pain in young adults and is responsible for high grade of incapacity. Classically, patients with surgical indications with Spondylolysis have been treated with vertebral arthrodesis arthrodesis, with the following functional lost of the intervened segment and biomechanical overload of the upper contiguous segment. There are not previous reports about repairing of lysis in national literature and international references in this technique are scarce. Materials and methods: Eight patients within 2002-2004 were operated, a direct repairing of the lyses by in situ, fusion and interfragmental osteosynthesis with AO 3.5 mm titanium cortical screws with autogenous bone grafts was achieved. The casuistic was analyzed depending on clinical presentation, consolidation, mobility and vitality of the disc in imaginology studies. Results: During the follow-up a firm fusion in all cases, mobility and vitality preservation of the L5-S1 intervertebral disc was detected. There was neither infection nor neurological deficit. Recommendations: Repairing of spondylolysis in lumbar column, in young symptomatic patients without or with mild lystesis (grade I) and without associated disc damage, is a safe surgical technique

  10. Cockayne syndrome: defective repair of transcription?

    NARCIS (Netherlands)

    A.J. van Gool (Alain); G.T.J. van der Horst (Gijsbertus); E. Citterio (Elisabetta); J.H.J. Hoeijmakers (Jan)

    1997-01-01

    textabstractIn the past years, it has become increasingly evident that basal metabolic processes within the cell are intimately linked and influenced by one another. One such link that recently has attracted much attention is the close interplay between nucleotide excision DNA repair and

  11. Repair technology for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating.

  12. Learning-based diagnosis and repair

    NARCIS (Netherlands)

    Roos, Nico

    2017-01-01

    This paper proposes a new form of diagnosis and repair based on reinforcement learning. Self-interested agents learn locally which agents may provide a low quality of service for a task. The correctness of learned assessments of other agents is proved under conditions on exploration versus

  13. DNA repair mechanism in radioresistant bacteria

    International Nuclear Information System (INIS)

    Kitayama, Shigeru

    1992-01-01

    Many radiation resistant bacteria have been isolated from various sources which are not in high background field. Since Deinococcus radiodurans had been isolated first in 1956, the studies on the mechanism of radioresistance were mostly carried out using this bacterium. DNA in this bacterium isn't protected against injury induced by not only ionizing radiation but also ultraviolet light. Therefore, DNA damages induced by various treatments are efficiently and accurately repaired in this cells. Damages in base and/or sugar in DNA are removed by endonucleases which, if not all, are synthesized during postirradiation incubation. Following the endonucleolytic cleavage the strand scissions in DNA are seemed to be rejoined by a process common for the repair of strand scissions induced by such as ionizing radiations. Induce protein(s) is also involved in this rejoining process of strand scissions. DNA repair genes were classified into three phenotypic groups. (1) Genes which are responsible for the endonucleolytic activities. (2) Genes involved in the rejoining of DNA strand scissions. (3) Genes which participate in genetic recombination and repair. Three genes belong to (1) and (2) were cloned onto approximately 1 kbp DNA fragments which base sequences have been determined. (author)

  14. [Aesthetic effect of wound repair with flaps].

    Science.gov (United States)

    Tan, Qian; Zhou, Hong-Reng; Wang, Shu-Qin; Zheng, Dong-Feng; Xu, Peng; Wu, Jie; Ge, Hua-Qiang; Lin, Yue; Yan, Xin

    2012-08-01

    To investigate the aesthetic effect of wound repair with flaps. One thousand nine hundred and ninety-six patients with 2082 wounds hospitalized from January 2004 to December 2011. These wounds included 503 deep burn wounds, 268 pressure sores, 392 soft tissue defects caused by trauma, 479 soft tissue defects due to resection of skin cancer and mole removal, 314 soft tissue defects caused by scar excision, and 126 other wounds. Wound area ranged from 1.5 cm x 1.0 cm to 30.0 cm x 22.0 cm. Sliding flaps, expanded flaps, pedicle flaps, and free flaps were used to repair the wounds in accordance with the principle and timing of wound repair with flaps. Five flaps showed venous congestion within 48 hours post-operation, 2 flaps of them improved after local massage. One flap survived after local heparin wet packing and venous bloodletting. One flap survived after emergency surgical embolectomy and bridging with saphenous vein graft. One flap showed partial necrosis and healed after skin grafting. The other flaps survived well. One thousand three hundred and twenty-one patients were followed up for 3 months to 2 years, and flaps of them were satisfactory in shape, color, and elasticity, similar to that of normal skin. Some patients underwent scar revision later with good results. Application of suitable flaps in wound repair will result in quick wound healing, good function recovery, and satisfactory aesthetic effect.

  15. Lichtenstein versus Onstep for inguinal hernia repair

    DEFF Research Database (Denmark)

    Andresen, Kristoffer; Burcharth, Jakob; Rosenberg, Jacob

    2013-01-01

    Inguinal hernia is a common condition that affects millions of people world-wide every year. In Denmark (population of 5.5 million), more than 10,000 repairs of inguinal hernias are performed annually. The optimal surgical procedure for mesh placement and fixation is still being debated because o...

  16. Systems with randomly failing repairable components

    DEFF Research Database (Denmark)

    Der Kiureghian, Armen; Ditlevsen, Ove Dalager; Song, Junho

    2005-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in time and rep...

  17. Weightbearing Versus Nonweightbearing After Meniscus Repair.

    Science.gov (United States)

    VanderHave, Kelly L; Perkins, Crystal; Le, Michael

    2015-01-01

    Optimal rehabilitation after meniscal repair remains controversial. To review the current literature on weightbearing status after meniscal repairs and to provide evidence-based recommendations for postoperative rehabilitation. MEDLINE (January 1, 1993 to July 1, 2014) and Embase (January 1, 1993 to July 1, 2014) were queried with use of the terms meniscus OR/AND repair AND rehabilitation. Included studies were those with levels of evidence 1 through 4, with minimum 2 years follow-up and in an English publication. Systematic review. Level 4. Demographics and clinical and radiographic outcomes of meniscus repair at a minimum of 2 years follow-up were extracted. Successful clinical outcomes ranged from 70% to 94% with conservative rehabilitation. More recent studies using an accelerated rehabilitation protocol with full weightbearing and early range of motion reported 64% to 96% good results. Outcomes after both conservative (restricted weightbearing) protocols and accelerated rehabilitation (immediate weightbearing) yielded similar good to excellent results; however, lack of similar objective criteria and consistency among surgical techniques and existing studies makes direct comparison difficult. © 2015 The Author(s).

  18. Macrophage diversity in renal injury and repair

    NARCIS (Netherlands)

    Ricardo, Sharon D.; van Goor, Harry; Eddy, Allison A.

    Monocyte-derived macrophages can determine the outcome of the immune response and whether this response contributes to tissue repair or mediates tissue destruction. In addition to their important role in immune-mediated renal disease and host defense, macrophages play a fundamental role in tissue

  19. Biomaterial and Cell Based Cartilage Repair

    NARCIS (Netherlands)

    Zhao, X

    2015-01-01

    Injuries to human native cartilage tissue are particularly troublesome because cartilage has little ability to heal or regenerate itself. The reconstruction, repair, and regeneration of cartilage tissue continue to be one of the greatest clinical challenges, especially in orthopaedic and plastic

  20. Stem Cells in Tissue Repair and Regeneration

    OpenAIRE

    Falanga, Vincent

    2012-01-01

    The field of tissue repair and wound healing has blossomed in the last 30 years. We have gone from recombinant growth factors, to living tissue engineering constructs, to stem cells. The task now is to pursue true regeneration, thus achieving full restoration of structures and their function.

  1. Collaborative Repair in EFL Classroom Talk.

    Science.gov (United States)

    Iles, Zara

    1996-01-01

    Drawing data from audiotaped lessons with 10 native-speaker English-as-a-Foreign-Language (EFL) teachers and 12 EFL learners of varied linguistic backgrounds, a study explored some of the ways in which classroom talk by learners is collaboratively built to repair errors, misunderstandings, and non-communication. Focus is on both explicit and…

  2. Mutagenic DNA repair in Escherichia coli. VII

    International Nuclear Information System (INIS)

    Bridges, B.A.; Mottershead, R.P.

    1978-01-01

    Incubation of E. coli WP2 in the presence of chloramphenicol (CAP) for 90 min before and 60 min after γ-irradiation had no effect on the induction of Trp + mutations. Bacteria that had been treated with CAP for 90 min prior to UV irradiation showed normal or near normal yields of induced mutations to streptomycin or colicin E2 resistance. Most of these mutations lost their photoreversibility (indicating 'fixation') during continued incubation with CAP for a further 60 min after irradiation, during which time neither protein nor DNA synthesis was detectable. It is suggested that CAP-sensitive protein synthesis is not required for mutagenic (error-prone) repair of lesions in pre-existing DNA, arguing against an inducible component in this repair. In contrast the frequency of UV-induced mutations to Trp + (largely at suppressor loci) was drastically reduced by CAP pretreatment, confirming the need for an active replication fork for UV-mutagenesis at these loci. It is known from the work of others that CAP given after UV abolishes mutagenesis at these loci. It is concluded that CAP-sensitive protein synthesis (consistent with a requirement for an inducible function) is necessary for mutagenic repair only in newly-replicated DNA (presumably at daughter strand gaps) and not in pre-existing DNA. The data are consistent with but do not prove the hypothesis that CAP-sensitive and insensitive modes of mutagenesis reflect minor differences in the operation of a single basic mutagenic repair system. (Auth.)

  3. Base excision repair, aging and health span

    Czech Academy of Sciences Publication Activity Database

    Xu, G.; Herzig, M.; Rotrekl, Vladimír; Walter, Ch. A.

    2008-01-01

    Roč. 129, 7-8 (2008), s. 366-382 ISSN 0047-6374 Institutional research plan: CEZ:AV0Z50390512 Keywords : base excision repair * aging * DNA damage Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.915, year: 2008

  4. Repair technology for steam generator tubes

    International Nuclear Information System (INIS)

    Kim, Seung Ho; Jung, Hyun Kyu; Jung, Seung Ho; Kim, Chang Hoi; Jung, Young Moo; Seo, Yong Chil; Kim, Jung Su; Seo, Moo Hong

    2001-02-01

    The most commonly used sleeving materials are thermally treated Alloy 600 and thermally treated Alloy 690 Alloy. Currently, thermally treated Alloy 690 and Alloy 800 are being offered although Alloy 800 has not been licensed in the US. To install sleeve, joint strength, leak tightness, PWSCC resistance, evaluation on process parameter range and the effect of equipments and procedures on repair plan and radiation damage have to be investigated before sleeving. ABB CE provides three type of leak tight Alloy 690 TIG welded and PLUSS sleeve. Currently, Direct Tube Repair technique using Nd:YAG laser has been developed by ABB CE and Westinghouse. FTI has brazed and kinetic sleeve designs for recirculating steam generator and hydraulic and rolled sleeve designs for one-through steam generators. Westinghouse provides HEJ, brazed and laser welded sleeve design. When sleeve is installed in order to repair the damaged S/G tubes, it is certain that defects can be occurred due to the plastic induced stress and thermal stress. Therefore it is important to minimize the residual stress. FTI provides the electrosleeve technique as a future repair candidate using electroplating

  5. ROAD REPAIR WORKS ON THE MEYRIN SITE

    CERN Multimedia

    ST-TFM Group

    2001-01-01

    ST Division will proceed, as from Monday 23 July, in repairing some parts of roads on the Meyrin site (see drawing). This work will last for one week depending on the weather conditions and will cause some traffic hold ups during this period. Please follow the indications on the temporary road signs. Thanking you in advance for your comprehension.

  6. Repair of Bovine and Equine Mandibular Fractures

    OpenAIRE

    Murch, K. M.

    1980-01-01

    Clinical findings, surgical repair and postsurgical care of a unilateral fracture of the mandible of a bull and of a bilateral mandibular fracture in a horse are described. Compression plating limited the pain suffered by the animals and resulted in a quick return to function of the mandibles.

  7. DNA repair in human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Fornace, A.J. Jr.; Lechner, J.F.; Grafstrom, R.C.; Harris, C.C.

    1982-01-01

    The purpose of this investigation was to compare the response of human cell types (bronchial epithelial cells and fibroblasts and skin fibroblasts) to various DNA damaging agents. Repair of DNA single strand breaks (SSB) induced by 5 krads of X-ray was similar for all cell types; approximately 90% of the DNA SSB were rejoined within one hour. During excision repair of DNA damage from u.v.-radiation, the frequencies of DNA SSB as estimated by the alkaline elution technique, were similar in all cell types. Repair replication as measured by BND cellulose chromatography was also similar in epithelial and fibroblastic cells after u.v.-irradiation. Similar levels of SSB were also observed in epithelial and fibroblastic cells after exposure to chemical carcinogens: 7,12-dimethylbenz[a]anthracene; benzo[a]pyrene diol epoxide (BPDE); or N-methyl-N-nitro-N-nitrosoguanidine. Significant repair replication of BPDE-induced DNA damage was detected in both bronchial epithelial and fibroblastic cells, although the level in fibroblasts was approximately 40% of that in epithelial cells. The pulmonary carcinogen asbestos did not damage DNA. DNA-protein crosslinks induced by formaldehyde were rapidly removed in bronchial cells. Further, epithelial and fibroblastic cells, which were incubated with formaldehyde and the polymerase inhibitor combination of cytosine arabinoside and hydroxyurea, accumulated DNA SSB at approximately equal frequencies. These results should provide a useful background for further investigations of the response of human bronchial cells to various DNA damaging agents

  8. From developmental biology to heart repair

    NARCIS (Netherlands)

    Campione, M.; Moorman, A. F.; Kelly, R. G.

    2007-01-01

    Advances in our understanding of cardiac development have fuelled research into cellular approaches to myocardial repair of the damaged heart. In this collection of reviews we present recent advances into the basic mechanisms of heart development and the resident and non-resident progenitor cell

  9. Biomaterials based strategies for rotator cuff repair.

    Science.gov (United States)

    Zhao, Song; Su, Wei; Shah, Vishva; Hobson, Divia; Yildirimer, Lara; Yeung, Kelvin W K; Zhao, Jinzhong; Cui, Wenguo; Zhao, Xin

    2017-09-01

    Tearing of the rotator cuff commonly occurs as among one of the most frequently experienced tendon disorders. While treatment typically involves surgical repair, failure rates to achieve or sustain healing range from 20 to 90%. The insufficient capacity to recover damaged tendon to heal to the bone, especially at the enthesis, is primarily responsible for the failure rates reported. Various types of biomaterials with special structures have been developed to improve tendon-bone healing and tendon regeneration, and have received considerable attention for replacement, reconstruction, or reinforcement of tendon defects. In this review, we first give a brief introduction of the anatomy of the rotator cuff and then discuss various design strategies to augment rotator cuff repair. Furthermore, we highlight current biomaterials used for repair and their clinical applications as well as the limitations in the literature. We conclude this article with challenges and future directions in designing more advanced biomaterials for augmentation of rotator cuff repair. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. New Technology in Automotive Body Repair.

    Science.gov (United States)

    Maze, Ronald W.

    1980-01-01

    The use of plastic and fiberglass materials in the manufacture of automobiles has caused a revolution in the field of collision work. Changes have occurred in tools, techniques, materials, and in the training for auto body repair. The skills necessary for employment in this field are now easier and faster to acquire. (CT)

  11. Repairing organs : lessons from intestine and liver

    NARCIS (Netherlands)

    Gehart, Helmuth; Clevers, Hans

    2015-01-01

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and

  12. ROCLA robots repaired after tough times

    CERN Multimedia

    Patrice Loïezi

    2004-01-01

    The team of five welders and five mechanics, represented by Pascal Mésenge (right) and Fabrice Multon (left), worked during two week-ends to repair the two ROCLA. At the centre, Oliver Boettcher, technical manager for the robot.

  13. Repairing organs : lessons from intestine and liver

    NARCIS (Netherlands)

    Gehart, Helmuth; Clevers, Hans

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and

  14. Mining Repair Actions for Guiding Automated Program Fixing

    OpenAIRE

    Martinez , Matias; Monperrus , Martin

    2012-01-01

    Automated program fixing consists of generating source code in order to fix bugs in an automated manner. Our intuition is that automated program fixing can imitate human-based program fixing. Hence, we present a method to mine repair actions from software repositories. A repair action is a small semantic modification on code such as adding a method call. We then decorate repair actions with a probability distribution also learnt from software repositories. Our probabilistic repair models enab...

  15. An Overview of Corroded Pipe Repair Techniques Using Composite Materials

    OpenAIRE

    K. S. Lim; S. N. A. Azraai; N. M. Noor; N. Yahaya

    2015-01-01

    Polymeric composites are being increasingly used as repair material for repairing critical infrastructures such as building, bridge, pressure vessel, piping and pipeline. Technique in repairing damaged pipes is one of the major concerns of pipeline owners. Considerable researches have been carried out on the repair of corroded pipes using composite materials. This article attempts a short review of the subject matter to provide insight into various techniques used in repa...

  16. Prognostic factors in sensory recovery after digital nerve repair

    OpenAIRE

    Bulut, Tugrul; Akgun, Ulas; Citlak, Atilla; Aslan, Cihan; Sener, Ufuk; Sener, Muhittin

    2018-01-01

    Objective: The prognostic factors that affect sensory nerve recovery after digital nerve repair are variable because of nonhomogeneous data, subjective tests, and different assessment/scoring methods. The aim of this study was to evaluate the success of sensory nerve recovery after digital nerve repair and to investigate the prognostic factors in sensorial healing.Methods: Ninety-six digital nerve repairs of 63 patients were retrospectively evaluated. All nerves were repaired with end-to-end ...

  17. Investigations of DNA-repair in New Zealand mice

    Energy Technology Data Exchange (ETDEWEB)

    Tuschl, H; Kovac, R; Altmann, H

    1974-09-01

    DNA repair was investigated in New Zealand mice strains which developed murine lupus and compared with Swiss control mice. Unscheduled DNA synthesis demonstrated by autoradiography was used to measure the repair capacity of spleen cells. After gamma-irradiation DNA repair was decreased in the autoimmune strains, while it was significantly increased after UV-irradiation. A possible relationship between repair capacity after gamma-respectively UV-irradiation and the etiologic factor of autoimmunity is discussed. (auth)

  18. Method for Qualification of Composite Repairs for Pipelines: Patch Repairs and Considerations for Cathodic Protection

    Science.gov (United States)

    2009-12-03

    While the mechanical properties of composite repairs for pipelines have been investigated extensively, the performance of the entire metal-composite system has not been addressed with regard to corrosion of the substrate, water intrusion at the compo...

  19. Component Repair Times Obtained from MSPI Data

    International Nuclear Information System (INIS)

    Eide, Steven A.; Cadwallader, Lee

    2015-01-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a ''white'' (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant's insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of

  20. Medialized repair for retracted rotator cuff tears.

    Science.gov (United States)

    Kim, Young-Kyu; Jung, Kyu-Hak; Won, Jun-Sung; Cho, Seung-Hyun

    2017-08-01

    The purpose of this study was to evaluate the functional outcomes of medialized rotator cuff repair and the continuity of repaired tendon in chronic retracted rotator cuff tears. Thirty-five consecutive patients were selected from 153 cases that underwent arthroscopic rotator cuff repair for more than medium-sized posterosuperior rotator cuff tears between July 2009 and July 2012 performed with the medialized repair. All cases were available for at least 2 years of postoperative follow-up. The visual analog scale of pain, muscle strength, Constant score, American Shoulder and Elbow Surgeons (ASES) score, and University of California-Los Angeles score were evaluated. At the final follow-up, all clinical outcomes were significantly improved. The visual analog scale score for pain improved from 6 ± 1 preoperatively to 2 ± 1 postoperatively. The range of motion increased from preoperatively to postoperatively: active forward elevation, from 134° ± 49° to 150° ± 16°; active external rotation at the side, from 47° ± 15° to 55° ± 10°; and active internal rotation, from L3 to L1. The shoulder score also improved: Constant score, from 53.5 ± 16.7 to 79 ± 10; American Shoulder and Elbow Surgeons score, from 51 ± 15 to 82 ± 8; and University of California-Los Angeles score, from 14 ± 4 to 28 ± 4. The retear cases at the final follow-up were 6 (17%). Medialized repair may be useful in cases in which anatomic bone-to-tendon repair would be difficult because of the excessive tension of the repaired tendon and a torn tendon that does not reach the anatomic insertion. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  1. Component Repair Times Obtained from MSPI Data

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Steven A. [Curtiss-Wright/Scietech, Ketchum, ID (United States); Cadwallader, Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only

  2. 40 CFR 51.369 - Improving repair effectiveness.

    Science.gov (United States)

    2010-07-01

    ... vehicles that fail I/M tests. (a) Technical assistance. The oversight agency shall provide the repair industry with information and assistance related to vehicle inspection diagnosis and repair. (1) The agency... monitor the performance of individual motor vehicle repair facilities, and provide to the public at the...

  3. Numerical simulation of CFRP-repaired reinforced concrete columns.

    Science.gov (United States)

    2014-07-01

    The overarching goal of this study was to investigate the influence of repair to individual reinforced concrete bridge columns on the : post-repair seismic performance of the bridge system. A method was developed to rapidly repair an earthquake-damag...

  4. DNA mismatch repair, genome instability and cancer in zebrafish

    NARCIS (Netherlands)

    Feitsma, H.

    2008-01-01

    The objective of this study was to find out whether the zebrafish can be an appropriate model for studying DNA repair and cancer. For this purpose three fish lines were used that lack components of an important mechanism for the repair of small DNA damage: DNA mismatch repair. These fish are

  5. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is an...

  6. Reasoning about repairability of workflows at design time

    NARCIS (Netherlands)

    Tagni, Gaston; Ten Teije, Annette; Van Harmelen, Frank

    2009-01-01

    This paper describes an approach for reasoning about the repairability of workflows at design time. We propose a heuristic-based analysis of a workflow that aims at evaluating its definition, considering different design aspects and characteristics that affect its repairability (called repairability

  7. 46 CFR 115.700 - Permission for repairs and alterations.

    Science.gov (United States)

    2010-10-01

    ... replacement in kind, of electrical wiring, fuel lines, tanks, boilers and other pressure vessels, and steering... 46 Shipping 4 2010-10-01 2010-10-01 false Permission for repairs and alterations. 115.700 Section... AND CERTIFICATION Repairs and Alterations § 115.700 Permission for repairs and alterations. (a...

  8. 46 CFR 176.700 - Permission for repairs and alterations.

    Science.gov (United States)

    2010-10-01

    ... repair or replacement, other than replacement in kind, of electrical wiring, fuel lines, tanks, boilers... 46 Shipping 7 2010-10-01 2010-10-01 false Permission for repairs and alterations. 176.700 Section... (UNDER 100 GROSS TONS) INSPECTION AND CERTIFICATION Repairs and Alterations § 176.700 Permission for...

  9. 46 CFR 131.575 - Yearly inspections and repair.

    Science.gov (United States)

    2010-10-01

    ... repaired as needed at least once a year. This procedure includes emptying and cleaning each fuel tank and... 46 Shipping 4 2010-10-01 2010-10-01 false Yearly inspections and repair. 131.575 Section 131.575..., Drills, and Inspections § 131.575 Yearly inspections and repair. (a) Each lifeboat, rescue boat, rigid...

  10. 48 CFR 1371.118 - Changes-ship repair.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Changes-ship repair. 1371.118 Section 1371.118 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE DEPARTMENT SUPPLEMENTAL REGULATIONS ACQUISITIONS INVOLVING SHIP CONSTRUCTION AND SHIP REPAIR Provisions and Clauses 1371.118 Changes—ship repair. Insert clause...

  11. Content-Related Repairing of Inconsistencies in Distributed Data

    Institute of Scientific and Technical Information of China (English)

    Yue-Feng Du; De-Rong Shen; Tie-Zheng Nie; Yue Kou; Ge Yu

    2016-01-01

    Conditional functional dependencies (CFDs) are a critical technique for detecting inconsistencies while they may ignore some potential inconsistencies without considering the content relationship of data. Content-related conditional functional dependencies (CCFDs) are a type of special CFDs, which combine content-related CFDs and detect potential inconsistencies by putting content-related data together. In the process of cleaning inconsistencies, detection and repairing are interactive: 1) detection catches inconsistencies, 2) repairing corrects caught inconsistencies while may bring new incon-sistencies. Besides, data are often fragmented and distributed into multiple sites. It consequently costs expensive shipment for inconsistencies cleaning. In this paper, our aim is to repair inconsistencies in distributed content-related data. We propose a framework consisting of an inconsistencies detection method and an inconsistencies repairing method, which work iteratively. The detection method marks the violated CCFDs for computing the inconsistencies which should be repaired preferentially. Based on the repairing-cost model presented in this paper, we prove that the minimum-cost repairing using CCFDs is NP-complete. Therefore, the repairing method heuristically repairs the inconsistencies with minimum cost. To improve the efficiency and accuracy of repairing, we propose distinct values and rules sequences. Distinct values make less data shipments than real data for communication. Rules sequences determine appropriate repairing sequences to avoid some incorrect repairs. Our solution is proved to be more effective than CFDs by empirical evaluation on two real-life datasets.

  12. A heart team's perspective on interventional mitral valve repair

    DEFF Research Database (Denmark)

    Treede, Hendrik; Schirmer, Johannes; Rudolph, Volker

    2012-01-01

    Surgical mitral valve repair carries an elevated perioperative risk in the presence of severely reduced ventricular function and relevant comorbidities. We sought to assess the feasibility of catheter-based mitral valve repair using a clip-based percutaneous edge-to-edge repair system in selected...

  13. Nucleotide excision repair II: From yeast to mammals

    NARCIS (Netherlands)

    J.H.J. Hoeijmakers (Jan)

    1993-01-01

    textabstractAn intricate network of repair systems safeguards the integrity of genetic material, by eliminating DNA lesions induced by numerous environmental and endogenous genotoxic agents. Nucleotide excision repair (NER) is one of the most versatile DNA repair systems. Deficiencies in this

  14. Performance of shcc with bacteria for concrete patch repair

    NARCIS (Netherlands)

    Sierra Beltran, M.G.; Jonkers, H.M.; Schlangen, E.

    2014-01-01

    The overall performance of concrete patch repair systems depends on the durability of and compatibility between the concrete substrate and the repair material. This paper investigates the performance of a new type of SHCC material with embedded bacteria as a repair material. The bacteria are a

  15. 49 CFR 192.311 - Repair of plastic pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Repair of plastic pipe. 192.311 Section 192.311... Lines and Mains § 192.311 Repair of plastic pipe. Each imperfection or damage that would impair the serviceability of plastic pipe must be repaired or removed. [Amdt. 192-93, 68 FR 53900, Sept. 15, 2003] ...

  16. Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

    International Nuclear Information System (INIS)

    Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

    1976-01-01

    It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

  17. A trade off between emergency repair and inventory investment

    NARCIS (Netherlands)

    Verrijdt, J.H.C.M.; Adan, I.J.B.F.; Kok, de A.G.

    1998-01-01

    In this paper we present an emergency repair model. We model a situation where failed parts arrive at a repair shop according to a Poisson process. If the stock on hand of serviceable spare parts exceeds a given emergency trigger level, the failed part is sent into normal repair. Otherwise the

  18. 27 CFR 555.216 - Repair of magazines.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Repair of magazines. 555... EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Storage § 555.216 Repair of magazines. Before repairing the interior of magazines, all explosive materials are to be removed and the interior...

  19. 29 CFR 541.401 - Computer manufacture and repair.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Computer manufacture and repair. 541.401 Section 541.401... SALES EMPLOYEES Computer Employees § 541.401 Computer manufacture and repair. The exemption for employees in computer occupations does not include employees engaged in the manufacture or repair of...

  20. The time course of repair of ultraviolet-induced DNA damage; implications for the structural organization of repair

    International Nuclear Information System (INIS)

    Collins, A.; Squires, S.

    1986-01-01

    Alternative molecular mechanisms can be envisaged for the cellular repair of UV-damaged DNA. In the 'random collision' model, DNA damage distributed throughout the genome is recognised and repaired by a process of random collision between DNA damage and repair enzymes. The other model assumes a 'processive' mechanism, whereby DNA is scanned for damage by a repair complex moving steadily along its length. Random collision should result in a declining rate of repair with time as the concentration of lesions in the DNA falls; but the processive model predicts a constant rate until scanning is complete. The authors have examined the time course of DNA repair in human fibroblasts given low doses of UV light. Using 3 distinct assays, the authors find no sign of a constant repair rate after 4 J/m 2 or less, even when the first few hours after irradiation are examined. Thus DNA repair is likely to depend on random collision. (Auth.)

  1. Laboratory testing of closure cap repair techniques

    International Nuclear Information System (INIS)

    Persoff, P.; Moridis, G.; Tuck, D.M.

    1996-10-01

    Landfill design requires a low permeability closure cap as well as a low permeability liner. The Savannah River Site, in South Carolina, has approximately 85 acres of mixed waste landfills covered with compacted kaolin clay. Maintaining low permeability of the clay cap requires both that the permeability of the compacted clay itself remain low and that the integrity of the barrier be maintained. Barrier breaches typically result from penetration by roots or animals, and especially cracks caused by uneven settling or desiccation. In this study, clay layers, 0.81 m in diameter and 7.6 cm thick, were compacted in 7 lysimeters to simulate closure caps. The hydraulic conductivity of each layer was measured, and the compacted clay layers (CCL's) were cracked by drying. Then various repair techniques were applied and the effectiveness of each repair was assessed by remeasuring the hydraulic conductivity. Finally the repaired CCL was again dried and measured to determine how the repair responded to the conditions that caused the original failure. For a full report of this investigation see Persoff et al. Six repair techniques have been tested, four of which involve the use of injectable barrier liquids colloidal silica (CS) and polysiloxane (PSX) described below: (I) covering the crack with a bentonite geosynthetic clay liner (GCL), (ii) recompaction of new kaolinite at STD+3 moisture content joined to existing kaolinite that had dried and shrunk, (iii) direct injection of colloidal silica to a crack, (iv) injection of colloidal silica (CS) to wells in an overlying sand layer, (v) direct injection of polysiloxane to a crack, and (vi), injection of polysiloxane (PSX) to wells in an overlying soil layer

  2. Cartilage repair in the degenerative ageing knee

    Science.gov (United States)

    Brittberg, Mats; Gomoll, Andreas H; Canseco, José A; Far, Jack; Lind, Martin; Hui, James

    2016-01-01

    Background and purpose Cartilage damage can develop due to trauma, resulting in focal chondral or osteochondral defects, or as more diffuse loss of cartilage in a generalized organ disease such as osteoarthritis. A loss of cartilage function and quality is also seen with increasing age. There is a spectrum of diseases ranging from focal cartilage defects with healthy surrounding cartilage to focal lesions in degenerative cartilage, to multiple and diffuse lesions in osteoarthritic cartilage. At the recent Aarhus Regenerative Orthopaedics Symposium (AROS) 2015, regenerative challenges in an ageing population were discussed by clinicians and basic scientists. A group of clinicians was given the task of discussing the role of tissue engineering in the treatment of degenerative cartilage lesions in ageing patients. We present the outcomes of our discussions on current treatment options for such lesions, with particular emphasis on different biological repair techniques and their supporting level of evidence. Results and interpretation Based on the studies on treatment of degenerative lesions and early OA, there is low-level evidence to suggest that cartilage repair is a possible treatment for such lesions, but there are conflicting results regarding the effect of advanced age on the outcome. We concluded that further improvements are needed for direct repair of focal, purely traumatic defects before we can routinely use such repair techniques for the more challenging degenerative lesions. Furthermore, we need to identify trigger mechanisms that start generalized loss of cartilage matrix, and induce subchondral bone changes and concomitant synovial pathology, to maximize our treatment methods for biological repair in degenerative ageing joints. PMID:27910738

  3. Endovascular repair of blunt popliteal arterial injuries

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Shan; Zhang, Xiquan; Chen, Zhong; Zhu, Wei; Pan, Xiaolin [Dept. of nterventional Vascular, The 148th Hospital of Chinese People' s Liberation Army, Zibo (China); Dong, Peng; Sun, Yequan [Dept. of Medical Imaging, Weifang Medical University, Weifang (China); Qi, Deming [Dept. of Medical Imaging, Qilu Medical University, Zibo (China)

    2016-09-15

    To evaluate the feasibility and effectiveness of endovascular repair for blunt popliteal arterial injuries. A retrospective analysis of seven patients with clinical suspicion of popliteal arterial injuries that were confirmed by arteriography was performed from September 2009 to July 2014. Clinical data included demographics, mechanism of injury, type of injury, location of injury, concomitant injuries, time of endovascular procedures, time interval from trauma to blood flow restoration, instrument utilized, and follow-up. All patients were male (mean age of 35.9 ± 10.3 years). The type of lesion involved intimal injury (n = 1), partial transection (n = 2), complete transection (n = 2), arteriovenous fistula (n = 1), and pseudoaneurysm (n = 1). All patients underwent endovascular repair of blunt popliteal arterial injuries. Technical success rate was 100%. Intimal injury was treated with a bare-metal stent. Pseudoaneurysm and popliteal artery transections were treated with bare-metal stents. Arteriovenous fistula was treated with bare-metal stent and coils. No perioperative death and procedure-related complication occurred. The average follow-up was 20.9 ± 2.3 months (range 18–24 months). One patient underwent intra-arterial thrombolysis due to stent thrombosis at 18 months after the procedure. All limbs were salvaged. Stent migration, deformation, or fracture was not found during the follow-up. Endovascular repair seems to be a viable approach for patients with blunt popliteal arterial injuries, especially on an emergency basis. Endovascular repair may be effective in the short-term. Further studies are required to evaluate the long-term efficacy of endovascular repair.

  4. A new incision for unilateral cleft lip repair developed using animated simulation of repair on computer

    Directory of Open Access Journals (Sweden)

    Sahay A

    2007-01-01

    Full Text Available Background: Unilateral cleft lip repair continues to leave behind some amount of dissatisfaction, as a scope for further improvement is always felt. Most surgeons do not like to deviate from the standard Millard′s/ triangular techniques, or their minor modifications, as no one likes to experiment on the face for fear of unfavourable outcomes. The computer can be utilized as a useful tool in the analysis and planning of surgery and new methods can be developed and attempted subsequently with greater confidence. Aim: We decided to see if an improved lip repair could be developed with the use of computers. Materials and Methods: Analysis of previous lip repairs was done to determine where an improvement was required. Movement of tissues, by simulating an ideal repair, using image warping software, on digital images of cleft lip was studied in animation sequences. A repair which could reproduce these movements was planned. A new incision emerged, which had combined the principles of Millard′s and Randall / Tennyson repairs, with additional features. The new method was performed on 30 cases. Conclusions: The results were encouraging as the shortcomings of these methods were minimized, and the advantages maximized.

  5. The effect of DNA repair defects on reproductive performance in nucleotide excision repair (NER) mouse models: an epidemiological approach

    NARCIS (Netherlands)

    Tsai, P.S.; Nielen, M.; Horst, G.T.J. van der; Colenbrander, B.; Heesterbeek, J.A.P.; Fentener van Vlissingen, J.M.

    2005-01-01

    In this study, we used an epidemiological approach to analyze an animal database of DNA repair deficient mice on reproductive performance in five Nucleotide Excision Repair (NER) mutant mouse models on a C57BL/6 genetic background, namely CSA, CSB, XPA, XPC [models for the human DNA repair disorders

  6. Meniscal repair by fibrocartilage in the dog : Characterization of the repair tissue and the role of vascularity

    NARCIS (Netherlands)

    Veth, RPH; Jansen, HWB; Nielsen, HKL; deGroot, JH; Pennings, AJ; Kuijer, R

    Lesions in the avascular part of 20 canine menisci were repaired by implantation of a porous polyurethane. Seven menisci were not repaired and served as controls. The repair tissue was characterized by biochemical and immunological analysis. The role of vascularity in healing was studied by

  7. DNA Damage Induced by Alkylating Agents and Repair Pathways

    Science.gov (United States)

    Kondo, Natsuko; Takahashi, Akihisa; Ono, Koji; Ohnishi, Takeo

    2010-01-01

    The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O6-methylguanine-DNA methyltransferase, and O6MeG:T mispairs are recognized by the mismatch repair system (MMR). MMR cannot repair the O6MeG/T mispairs, which eventually lead to double-strand breaks. Bifunctional alkylating agents form interstrand cross-links (ICLs) which are more complex and highly cytotoxic. ICLs are repaired by complex of NER factors (e.g., endnuclease xeroderma pigmentosum complementation group F-excision repair cross-complementing rodent repair deficiency complementation group 1), Fanconi anemia repair, and homologous recombination. A detailed understanding of how cells cope with DNA damage caused by alkylating agents is therefore potentially useful in clinical medicine. PMID:21113301

  8. Wide Panel Testing Technique for Evaluating Repair Weld Strengths

    Science.gov (United States)

    Rogers, Patrick R.; Bynum, Julian E.; Shah, Sandeep R.

    1998-01-01

    This paper describes a new tensile testing technique for evaluating the overall effect of a repair weld on the strength of a welded joint. Previously, repair weld strengths have been evaluated using one-inch width tensile specimens, but this technique does not capture all of the effects that result from a repair. The new technique involves testing of "wide panel" tensile specimens which contain the full length of a repair weld within a longer initial weld, allowing the specimen to capture the combined effects of residual stresses, local strength degradation, and load redistribution around a repair. The development of strains in the repair area of standard aluminum alloy specimens and new high-performance aluminum-lithium alloy specimens was observed and evaluated using photoelastic material. The results of this evaluation show an increased sensitivity to repair welding residual stresses in the aluminum-lithium alloy specimens.

  9. Age replacement policy based on imperfect repair with random probability

    International Nuclear Information System (INIS)

    Lim, J.H.; Qu, Jian; Zuo, Ming J.

    2016-01-01

    In most of literatures of age replacement policy, failures before planned replacement age can be either minimally repaired or perfectly repaired based on the types of failures, cost for repairs and so on. In this paper, we propose age replacement policy based on imperfect repair with random probability. The proposed policy incorporates the case that such intermittent failure can be either minimally repaired or perfectly repaired with random probabilities. The mathematical formulas of the expected cost rate per unit time are derived for both the infinite-horizon case and the one-replacement-cycle case. For each case, we show that the optimal replacement age exists and is finite. - Highlights: • We propose a new age replacement policy with random probability of perfect repair. • We develop the expected cost per unit time. • We discuss the optimal age for replacement minimizing the expected cost rate.

  10. Mechanical characterization of composite repairs for fiberglass wind turbine blades

    Science.gov (United States)

    Chawla, Tanveer Singh

    While in service, wind turbine blades experience various modes of loading. An example is impact loading in the form of hail or bird strikes, which might lead to localized damage or formation of cracks a few plies deep on the blade surface. One of the methods to conduct repairs on wind turbine blades that are damaged while in service is hand lay-up of the repair part after grinding out the damaged portion and some of its surrounding area. The resin used for such repairs usually differs from the parent plate resin in composition and properties such as gel time, viscosity, etc. As a result the properties of the repaired parts are not the same as that of the undamaged blades. Subsequent repetitive loading can be detrimental to weak repairs to such an extent so as to cause delamination at the parent-repair bondline causing the repairs to eventually fall off the blade. Thus the strength and toughness of the repair are of critical importance. Initial part of this work consists of an effort to increase repair strength by identifying an optimum hand layup repair resin for fiberglass wind turbine blades currently being manufactured by a global company. As delamination of the repair from the parent blade is a major concern and unidirectional glass fibers along with a polymer resin are used to manufacture blades under consideration, testing method detailed in ASTM D 5528 (Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites) was followed to determine propagation fracture toughness values of the prospective vinyl ester repair resin candidates. These values were compared to those for a base polyester repair resin used by the company. Experimental procedure and results obtained from the above mentioned testing using double cantilever beam (DCB) specimens are detailed. Three new repair resins were shortlisted through mode I testing. It was also found that variation in the depth of the ground top ply of the parent part

  11. Kinetics and mechanism of DNA repair

    International Nuclear Information System (INIS)

    Meldrum, R.A.; Wharton, C.W.; Shall, S.

    1990-01-01

    Experiments are described in which the feasibility of using caged dideoxy and other nucleoside triphosphate analogues for trapping breaks induced by u.v. radiation damage to mammalian cell DNA is evaluated. These nucleotide analogues that have a photolabile 1-(2-nitrophenyl)ethyl-protecting group attached to the γ-phosphate are placed in situ by permeabilizing cells by exposure to hypo-osmotic medium. The nucleoside triphosphate is released by a 351 nm u.v. laser pulse whence it may incorporate in the growing chain of DNA induced by the excision-repair process and terminate chain elongation. If the photoreleased dideoxynucleoside trisphosphate is isotopically labelled in the α-phosphate position the break is trapped and labelled. Incorporation of radioactivity into trichloroacetic acid insoluble material in these experiments confirms their potential for use in studies of the kinetics of mammalian cell DNA repair. (author)

  12. Inguinal hernia repair: anaesthesia, pain and convalescence

    DEFF Research Database (Denmark)

    Callesen, Torben

    2003-01-01

    of less serious complications is lower by local anaesthesia, compared to other anaesthetic techniques. Of special interest is, that the rate of urinary retention can be eliminated by the use of local anaesthesia. Local anaesthesia results, in comparative studies, in a higher degree of patient satisfaction...... than other anaesthetic techniques. Local anaesthesia also facilitates faster mobilisation and earlier discharge/fulfilment of discharge criteria from post anaesthetic care units than other anaesthetic techniques. Pain after hernia repair is more pronounced at mobilisation or coughing than during rest....... Pain after laparoscopic surgery is less pronounced than after open surgery, while different open repair techniques do not exhibit significant differences. Postoperative pain is best treated with a combination of local analgesia and peripherally acting agents (paracetamol, NSAID or their combination...

  13. Putative Enzymes of UV Photoproduct Repair

    Directory of Open Access Journals (Sweden)

    Cynthia J. Sakofsky

    2011-01-01

    Full Text Available In order to determine the biological relevance of two S. acidocaldarius proteins to the repair of UV photoproducts, the corresponding genes (Saci_1227 and Saci_1096 were disrupted, and the phenotypes of the resulting mutants were examined by various genetic assays. The disruption used integration by homologous recombination of a functional but heterologous pyrE gene, promoted by short sequences attached to both ends via PCR. The phenotypic analyses of the disruptants confirmed that ORF Saci_1227 encodes a DNA photolyase which functions in vivo, but they could not implicate ORF Saci_1096 in repair of UV- or other externally induced DNA damage despite its similarity to genes encoding UV damage endonucleases. The success of the gene-disruption strategy, which used 5′ extensions of PCR primers to target cassette integration, suggests potential advantages for routine construction of Sulfolobus strains.

  14. Remotely controlled repair at Douglas Point

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The Douglas Point nuclear generating station, completed in 1966, was Canada's first venture in commercial nuclear power. The discovery, 11 years later, of two perforations in auxiliary piping in a high radiation area led Atomic Energy of Canada Ltd and Ontario Hydro to develop new approaches to remotely controlled repair that will have much wider applications. Eddy current and ultrasonic testing were used to determine the pattern and extent of wear in a pipe encircled by a U-bolt, without first removing the U-bolt. Progress was monitored using remote TV cameras. Welding tools were designed and fabricated for the repairs, and a manipulator was also designed to transport the tool into its place of work. (author)

  15. Cast iron repair method of stitching pin

    International Nuclear Information System (INIS)

    Yun, In Sik; Yu, Yeong Chul; Kim, Steve S.; Reed, Gary J.

    2003-01-01

    Many cast iron parts are welded and suffer from improper pre-heating and poor welding skills which destroy the castings due to new cracks, deformations etc. This is due mainly to the lack of understanding of the properties of cast iron. Welding, however impractical, was the only alternative for many years. Locks are used to add strength across a crack. Special drilling jigs are used to create a precise hole pattern that locks are driven into. Our locks have a unique ability to pull the sides of a crack together. Bottom locks are stacked or laminated to a depth of 80% of the casting thickness. Thicker surface locks finish off lock installation, allowing repairs in irregular shapes and contours. Installing products can be done quickly with pneumatic tools. Up to one inch of repair can be done in 5 minutes in 1/4 inch thick cast iron.

  16. Nuclear facilities: repair and replacement technologies

    International Nuclear Information System (INIS)

    2005-01-01

    The oldest operating reactors are more than 35 years old and are now facing major maintenance operations. The first replacement of a pressurizer took place in autumn 2005 at the St-Lucie plant (Usa) while steam generators have been currently replaced since 1983. Nuclear industry has to adapt to this new market by proposing innovative technological solutions in the reactor maintenance field. This document gathers the 9 papers presented at the conference. The main improvements concern repair works on internal components of PWR-type reactors, the replacement of major components of the primary coolant circuit and surface treatments to limit the propagation of damages. The first paper shows that adequate design and feedback experience are good assets to manage the ageing of a nuclear unit. Another paper shows that a new repair method of a relief valve can avoid its replacement. (A.C.)

  17. Carbon nanotubes in neuroregeneration and repair.

    Science.gov (United States)

    Fabbro, Alessandra; Prato, Maurizio; Ballerini, Laura

    2013-12-01

    In the last decade, we have experienced an increasing interest and an improved understanding of the application of nanotechnology to the nervous system. The aim of such studies is that of developing future strategies for tissue repair to promote functional recovery after brain damage. In this framework, carbon nanotube based technologies are emerging as particularly innovative tools due to the outstanding physical properties of these nanomaterials together with their recently documented ability to interface neuronal circuits, synapses and membranes. This review will discuss the state of the art in carbon nanotube technology applied to the development of devices able to drive nerve tissue repair; we will highlight the most exciting findings addressing the impact of carbon nanotubes in nerve tissue engineering, focusing in particular on neuronal differentiation, growth and network reconstruction. © 2013.

  18. Emergent cardiopulmonary bypass during pectus excavatum repair

    Directory of Open Access Journals (Sweden)

    Ryan Craner

    2013-01-01

    Full Text Available Pectus excavatum is a chest wall deformity that produces significant cardiopulmonary disability and is typically seen in younger patients. Minimally invasive repair of pectus excavatum or Nuss procedure has become a widely accepted technique for adult and pediatric patients. Although it is carried out through a thoracoscopic approach, the procedure is associated with a number of potential intraoperative and post-operative complications. We present a case of cardiac perforation requiring emergent cardiopulmonary bypass in a 29-year-old male with Marfan syndrome and previous mitral valve repair undergoing a Nuss procedure for pectus excavatum. This case illustrates the importance of vigilance and preparation by the surgeons, anesthesia providers as well as the institution to be prepared with resources to handle the possible complications. This includes available cardiac surgical backup, perfusionist support and adequate blood product availability.

  19. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R

    2007-01-01

    -term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence...... geological timescales. There has been no direct evidence in ancient microbes for the most likely mechanism, active DNA repair, or for the metabolic activity necessary to sustain it. In this paper, we couple PCR and enzymatic treatment of DNA with direct respiration measurements to investigate long...... that this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability....

  20. Lessons learned using Snodgrass hypospadias repair.

    LENUS (Irish Health Repository)

    O'Connor, K M

    2012-02-03

    BACKGROUND: This is a review of our experience with the Snodgrass technique for distal hypospadias repair and we point to lessons learned in improving results. METHODS: We reviewed all patients who underwent Snodgrass hypospadias repair for distal hypospadias over a four-year period by a single surgeon. Chart review followed by parental telephone interview was used to determine voiding function, cosmesis and complication rate. RESULTS: Thirty children and three adults were identified. Age at surgery ranged from seven months to 39 years. The urinary stream was straight in 94%, and 97% reported a good or satisfactory final cosmetic outcome. One patient (3.3%) developed a urethral fistula and 21% developed meatal stenosis which required general anaesthetic. CONCLUSION: The Snodgrass urethroplasty provides satisfactory cosmetic and functional results. High rates of meatal stenosis initially encountered have improved with modifications to technique which include modified meatoplasty and routine meatal dilatation by the parents.

  1. Mini Review: Biomaterials for Enhancing Neuronal Repair

    Science.gov (United States)

    Cangellaris, Olivia V.; Gillette, Martha U.

    2018-04-01

    As they differentiate from neuroblasts, nascent neurons become highly polarized and elongate. Neurons extend and elaborate fine and fragile cellular extensions that form circuits enabling long-distance communication and signal integration within the body. While other organ systems are developing, projections of differentiating neurons find paths to distant targets. Subsequent post-developmental neuronal damage is catastrophic because the cues for reinnervation are no longer active. Advances in biomaterials are enabling fabrication of micro-environments that encourage neuronal regrowth and restoration of function by recreating these developmental cues. This mini-review considers new materials that employ topographical, chemical, electrical, and/or mechanical cues for use in neuronal repair. Manipulating and integrating these elements in different combinations will generate new technologies to enhance neural repair.

  2. Regulation of nucleotide excision repair through ubiquitination

    Institute of Scientific and Technical Information of China (English)

    Jia Li; Audesh Bhat; Wei Xiao

    2011-01-01

    Nucleotide excision repair (NER) is the most versatile DNA-repair pathway in all organisms.While bacteria require only three proteins to complete the incision step of NER,eukaryotes employ about 30 proteins to complete the same step.Here we summarize recent studies demonstrating that ubiquitination,a post-translational modification,plays critical roles in regulating the NER activity either dependent on or independent of ubiquitin-proteolysis.Several NER components have been shown as targets of ubiquitination while others are actively involved in the ubiquitination process.We argue through this analysis that ubiquitination serves to coordinate various steps of NER and meanwhile connect NER with other related pathways to achieve the efficient global DNA-damage response.

  3. Biomaterial applications in neural therapy and repair

    Institute of Scientific and Technical Information of China (English)

    Harmanvir Ghuman; Michel Modo

    2017-01-01

    The use of biomaterials,such as hydrogels,as a scaffold to deliver cells and drugs is becoming increasingly common to treat neurological conditions,including stroke.With a limited intrinsic ability to regenerate after injury,innovative tissue engineering strategies have shown the potential of biomaterials in facilitating neural tissue regeneration and functional recovery.Using biomaterials can not only promote the survival and integration of transplanted cells in the existing circuitry,but also support controlled site specific delivery of therapeutic drugs.This review aims to provide the reader an understanding of the brain tissue microenvironment after injury,biomaterial criteria that support tissue repair,commonly used natural and synthetic biomaterials,benefits of incorporating cells and neurotrophic factors,as well as the potential of endogenous neurogenesis in repairing the injured brain.

  4. Maintenance and repair of LMFBR steam generators

    International Nuclear Information System (INIS)

    Verriere, P.; Alanche, J.; Minguet, J.L.

    1984-06-01

    After some general remarks on the French fast neutron system, this paper presents the state of the program for the construction of fast reactor in France. Then, the general design of Super Phenix 1 steam generator components is outlined and, the in-service monitoring systems and protective devices with which they are equiped are briefly described. The methods used, in the event of leakage, for leak location, steam generator inspection, steam generator repair and putting the affected loop back into service, are discussed. There are two main lines of research, relating respectively to the means of water leak detection in sodium and the inspection arrangements that will be used either periodically, or following a sodium-water reaction. Finally, after a brief description of the steam generator, this paper describes the four incidents (leaks) that occurred on the Phenix steam generator in the course of 1982 and 1983, and the subsequent repair operations

  5. Sublethal damages: their nature and repair

    Energy Technology Data Exchange (ETDEWEB)

    Saenko, A.S.; Synzynys, B.I.; Trofimova, S.F. (Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii, Obninsk (USSR)); Gotlib, V.Ya.; Pelevina, I.I. (AN SSSR, Moscow. Inst. Khimicheskoj Fiziki)

    1983-05-12

    The molecular nature of sublethal damage (SLD) arising after ionizing irradiation of cultured mammalian cells was considered on the basis of data on DNA repair and cell recovery after SLD observed in lymphosarcoma cells as well as of literature data. The rate of SLD recovery and that of restoration of the cell's ability to initiate DNA synthesis were shown to be similar in new replicons. These data along with knowledge about the role of exchange type chromosomal aberrations in reproductive death permitted us to propose the hypothesis that conformational changes of chromatine - most probably, relaxation of condensed chromosomal material - are damage registered as SLD at the cellular level. Double-strand breaks and a slowly repaired part of DNA single-strand breaks are candidates for SLD.

  6. Functional Tricuspid Regurgitation and Ring Annuloplasty Repair

    Directory of Open Access Journals (Sweden)

    William B. Weir, MD

    2018-01-01

    Full Text Available Functional tricuspid regurgitation (TR primarily arises from asymmetric dilation of the tricuspid annulus in the setting of right ventricular dysfunction and enlargement in response to left-sided myocardial and valvular abnormalities. Even if the TR is not severe at the time of mitral valve surgery, it can worsen and even appear late after successful mitral valve surgery, which portends a poor prognosis. Despite data demonstrating inferior outcomes in the presence of residual TR, surgical repair for functional TR remains underused. Acceptance of TR, in the presence of tricuspid annular dilation, may be unacceptable. Surgical repair should consist of placement of a rigid or semirigid annular ring, which has been shown to provide superior durability as compared with suture and flexible band techniques. Finally, percutaneous annuloplasty for correction of functional TR may allow treatment of patients with recurrent TR at high risk of reoperation.

  7. Space-Efficient Re-Pair Compression

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Prezza, Nicola

    2017-01-01

    Re-Pair [5] is an effective grammar-based compression scheme achieving strong compression rates in practice. Let n, σ, and d be the text length, alphabet size, and dictionary size of the final grammar, respectively. In their original paper, the authors show how to compute the Re-Pair grammar...... in expected linear time and 5n + 4σ2 + 4d + √n words of working space on top of the text. In this work, we propose two algorithms improving on the space of their original solution. Our model assumes a memory word of [log2 n] bits and a re-writable input text composed by n such words. Our first algorithm runs...

  8. Convalescence after laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Tolver, Mette Astrup; Rosenberg, Jacob; Bisgaard, Thue

    2016-01-01

    . Furthermore, snowball search was performed in reference lists of identified articles. Randomized controlled trials and prospective comparative or non-comparative trials of high quality were included. Trials with ≥100 patients, >18 years of age and manuscripts in English were included. Scoring systems were...... used for assessment of quality. RESULTS: The literature search identified 1039 papers. Thirty-four trials were included in the final review including 14,273 patients. There was overall a large variation in duration of convalescence. Trials using non-restrictive recommendations of 1-2 days or "as soon...... factors for prolonged convalescence extending more than a few days after laparoscopic inguinal hernia repair. CONCLUSIONS: Patients should be recommended a duration of 1-2 days of convalescence after laparoscopic inguinal hernia repair. Short and non-restrictive recommendations may reduce duration...

  9. Repair by genetic recombination in bacteria: overview

    International Nuclear Information System (INIS)

    Howard-Flanders, P.

    1975-01-01

    DNA molecules that have been damaged in both strands at the same level are not subject to repair by excision but instead can be repaired through recombination with homologous molecules. Examples of two-strand damage include postreplication gaps opposite pyrimidine dimers, two-strand breaks produced by x-rays, and chemically induced interstrand cross-links. In ultraviolet-irradiated bacteria, and newly synthesized DNA is of length equal to the interdimer spacing. With continued incubation, this low-molecular-weight DNA is joined into high-molecular-weight chains (postreplication repair), a process associated with sister exchanges in bacteria. Recombination is initiated by pyrimidine dimers opposite postreplication gaps and by interstrand cross-links that have been cut by excision enzymes. The free ends at the resulting gaps presumably initiate the exchanges. Postreplication repair in Escherichia coli occurs in recB - and recC - but is greatly slowed in recF - mutants. RecB and recC are the structural genes for exonuclease V, which digests two-stranded DNA by releasing oligonucleotides first from one strand and then from the other. The postreplication sister exchanges in ultraviolet-irradiated bacteria result in the distribution of pyrimidine dimers between parental and daughter strands, indicating that long exchanges involving both strands of each duplex occur. The R1 restriction endonuclease from E. coli has been used to cut the DNA of a bacterial drug-resistance transfer factor with one nuclease-sensitive site, and also DNA from the frog Xenopus enriched for ribosomal 18S and 28S genes. The fragments were annealed with the cut plasmid DNA and ligated, producing a new larger plasmid carrying the eukaryotic rDNA and able to infect and replicate in E. coli

  10. LASER SURFACE CLADDING FOR STRUCTURAL REPAIR

    OpenAIRE

    SANTANU PAUL

    2018-01-01

    Laser cladding is a powder deposition technique, which is used to deposit layers of clad material on a substrate to improve its surface properties. It has widespread application in the repair of dies and molds used in the automobile industry. These molds and dies are subjected to cyclic thermo-mechanical loading and therefore undergo localized damage and wear. The final clad quality and integrity is influenced by various physical phenomena, namely, melt pool morphology, microst...

  11. Repairing organs: lessons from intestine and liver

    OpenAIRE

    Gehart Helmuth; Clevers Hans

    2015-01-01

    The concept of organ regeneration has fascinated humanity from ancient mythology to modern science fiction. Recent advances offer the potential to soon bring such technology within the grasp of clinical medicine. Rapidly expanding insights into the intrinsic repair processes of the intestine and liver have uncovered significant plasticity in epithelial tissues. Harnessing this knowledge researchers have recently created culture systems that enable the expansion of stem cells into transplantab...

  12. Promising results after percutaneous mitral valve repair

    DEFF Research Database (Denmark)

    Ihlemann, Nikolaj; Franzen, Olaf; Jørgensen, Erik

    2011-01-01

    Mitral valve regurgitation (MR) is the secondmost frequent valve disease in Europe. Untreated MR causes considerable morbidity and mortality. In the elderly, as many as half of these patients are denied surgery because of an estimated high surgical risk. Percutaneous mitral valve repair with the ...... with the MitraClip system resembles the Alfieristitch where a clip is used to connect the tip of the mitral valve leaflets....

  13. Road repair works on the Meyrin site

    CERN Multimedia

    2003-01-01

    ST Division will proceed, as from Monday 15th of September, in repairing some parts of roads on the Meyrin site (see drawing). This work will last for three weeks depending on the weather conditions and will cause some traffic hold ups during this period. Please follow the indications on the temporary road signs. Thanking you in advance for your comprehension. ST-CE and ST-FM Groups GSM 160224 - 163976

  14. Total Percutaneous Aortic Repair: Midterm Outcomes

    International Nuclear Information System (INIS)

    Bent, Clare L.; Fotiadis, Nikolas; Renfrew, Ian; Walsh, Michael; Brohi, Karim; Kyriakides, Constantinos; Matson, Matthew

    2009-01-01

    The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 ± 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 ± 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

  15. Iatrogenic Urethral Defect Repairment: A Case Report

    Directory of Open Access Journals (Sweden)

    Ulas Fidan

    2013-10-01

    Full Text Available    Iatrogenic urethral defect is a complication that occurs after vaginal surgical procedures. Many surgical methods according to place of defect are described in case of injury of urethra. In this article, we reported the repairment of distal urethral defect with the help of greft taken from labia minor. This defect is made by the excision of the granulation tissue that occurred after chronic paraurethral  gland infection.

  16. Spinal Cord Repair with Engineered Nervous Tissue

    Science.gov (United States)

    2014-04-01

    ganglia ( DRG ) and axons that can be stretch-grown to a length necessary to bridge extensive lesions. In current studies, we have optimized in vivo...survival of DRGs up to 6 weeks post-transplant. If successful, this approach will provide an alternative or additional means to repair large spinal...lesions. 15. SUBJECT TERMS- none listed 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF

  17. Impact of radiotherapy on PBMCs DNA repair capacity - Use of a multiplexed functional repair assay

    International Nuclear Information System (INIS)

    Sauvaigo, S.; Sarrazy, F.; Breton, J.; Caillat, S.; Chapuis, V.

    2012-01-01

    Radiation therapy is an essential part of cancer treatment as about 50% of patients will receive radiations at least once. Significant broad variation in radiosensitivity has been demonstrated in patients. About 5-10% of patients develop acute toxicity after radiotherapy. Therefore there is a need for the identification of markers able to predict the occurrence of adverse effects and thus adapt the radiotherapy regimen for radiosensitive patients. As a first step toward this goal, and considering the DNA repair defects associated with hypersensitivity radiation syndromes, we investigated the DNA repair phenotype of patients receiving radiotherapy. More precisely, we used a functional repair assay on support to follow the evolution of the glycosylases/AP endonuclease activities of PBMCs extracts of a series of patients during the time course of radiotherapy. For each patient, we collected one PBMCs sample before the first radiotherapy application (S1) and three samples after (S2 to S4) (one day and one week after application 1, and one at the end of the radiotherapy protocol). These four samples have been analysed for 11 donors. Clustering analyses of the results demonstrated a great heterogeneity of responses among the patients. Interestingly, this heterogeneity decreased between S1 and S4 where only 2 classes of patients remained if we except one patient that exhibited an atypical DNA repair phenotype. Furthermore, we showed that repair of several oxidized bases significantly increased between S1 and S3 or S4 (8oxoG, thymine glycol, A paired with 8oxoG), suggesting an adaptation of patients repair systems to the oxidative stress generated by the ionising radiations. Our preliminary results provided evidence that the DNA repair phenotype was impacted by the radiotherapy regimen. Further characterization of patients with known repair defects are needed to determine if atypical repair phenotypes could be associated with radiotherapy complications. Finally

  18. Surgical repair of large cyclodialysis clefts.

    Science.gov (United States)

    Gross, Jacob B; Davis, Garvin H; Bell, Nicholas P; Feldman, Robert M; Blieden, Lauren S

    2017-05-11

    To describe a new surgical technique to effectively close large (>180 degrees) cyclodialysis clefts. Our method involves the use of procedures commonly associated with repair of retinal detachment and complex cataract extraction: phacoemulsification with placement of a capsular tension ring followed by pars plana vitrectomy and gas tamponade with light cryotherapy. We also used anterior segment optical coherence tomography (OCT) as a noninvasive mechanism to determine the extent of the clefts and compared those results with ultrasound biomicroscopy (UBM) and gonioscopy. This technique was used to repair large cyclodialysis clefts in 4 eyes. All 4 eyes had resolution of hypotony and improvement of visual acuity. One patient had an intraocular pressure spike requiring further surgical intervention. Anterior segment OCT imaging in all 4 patients showed a more extensive cleft than UBM or gonioscopy. This technique is effective in repairing large cyclodialysis clefts. Anterior segment OCT more accurately predicted the extent of each cleft, while UBM and gonioscopy both underestimated the size of the cleft.

  19. Repairs in 104 Gy/h?

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In 1989 it was found that in each unit of the MAPS Candu nuclear power station in India the centre portion of the heavy water inlet manifold opposite the 300 mm inlet pipe had torn away. Equipment for remote inspection, repair and removal of debris in an area with constricted and difficult access and radiation fields of about 10 4 Gy/h was developed by Ricardo Hitec of the United Kingdom. This consists of a work performing manipulator, TV viewing systems and a posting tube manipulator for insertion of tools and debris containers into the calandria. A variety of special end effector and tools were also developed jointly with AEA Technology. A first repair campaign was carried out on Unit 1 in 1991. Following a detailed TV survey of the damage a reappraisal of the situation was undertaken and a programme of equipment enhancement carried out. In July 1992 a second repair campaign took place on Unit 2. The difficulties encountered and the degree of success achieved are described. Work proceeded at an intensive level for 14 days when the campaign was ended in view of the exhaustion both of personnel and the equipment. Although more work could have been done a major improvement had been achieved. (UK)

  20. Texture Repairing by Unified Low Rank Optimization

    Institute of Scientific and Technical Information of China (English)

    Xiao Liang; Xiang Ren; Zhengdong Zhang; Yi Ma

    2016-01-01

    In this paper, we show how to harness both low-rank and sparse structures in regular or near-regular textures for image completion. Our method is based on a unified formulation for both random and contiguous corruption. In addition to the low rank property of texture, the algorithm also uses the sparse assumption of the natural image: because the natural image is piecewise smooth, it is sparse in certain transformed domain (such as Fourier or wavelet transform). We combine low-rank and sparsity properties of the texture image together in the proposed algorithm. Our algorithm based on convex optimization can automatically and correctly repair the global structure of a corrupted texture, even without precise information about the regions to be completed. This algorithm integrates texture rectification and repairing into one optimization problem. Through extensive simulations, we show our method can complete and repair textures corrupted by errors with both random and contiguous supports better than existing low-rank matrix recovery methods. Our method demonstrates significant advantage over local patch based texture synthesis techniques in dealing with large corruption, non-uniform texture, and large perspective deformation.