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Sample records for ablative materials final

  1. Advances in laser ablation of materials

    International Nuclear Information System (INIS)

    Singh, R.K.; Lowndes, D.H.; Chrisey, D.B.; Fogarassy, E.; Narayan, J.

    1998-01-01

    The symposium, Advances in Laser Ablation of Materials, was held at the 1998 MRS Spring Meeting in San Francisco, California. The papers in this symposium illustrate the advances in pulsed laser ablation for a wide variety of applications involving semiconductors, superconductors, metals, ceramics, and polymers. In particular, advances in the deposition of oxides and related materials are featured. Papers dealing with both fundamentals and the applications of laser ablation are presented. Topical areas include: fundamentals of ablation and growth; in situ diagnostics and nanoscale synthesis advances in laser ablation techniques; laser surface processing; pulsed laser deposition of ferroelectric, magnetic, superconducting and optoelectronic thin films; and pulsed laser deposition of carbon-based and polymeric materials. Sixty papers have been processed separately for inclusion on the data base

  2. Current Situation Development of Lightweight Ablation Materials for Thermal Protection

    Directory of Open Access Journals (Sweden)

    XUE Hua- fei

    2017-02-01

    Full Text Available In view of demand of lighter thermal protection system for our national space vehicle,recent development of investigation and practical application of lightweight thermal protection ablation materials are summarized systematically at home and abroad,in which the silicon or resin reinforced with honeycomb structural reinforcement and resin impregnated fibrous substrate ablators are included,focuses On silicone resin reinforced with glass,silica or carbon fiber/phenolic honeycomb as well as silicon,phenolic and Silicone Impregnated Reusable tendency Ceramic Ablator(SIRCA and Phenolic Impregnated Carbon Ablator( in the future of aboard lightweight ablators is proposed,which can PICA,finally the development directly borrow or simply draw inspiration for our country in this field.

  3. Ablative Material Testing at Lewis Rocket Lab

    Science.gov (United States)

    1997-01-01

    The increasing demand for a low-cost, reliable way to launch commercial payloads to low- Earth orbit has led to the need for inexpensive, expendable propulsion systems for new launch vehicles. This, in turn, has renewed interest in less complex, uncooled rocket engines that have combustion chambers and exhaust nozzles fabricated from ablative materials. A number of aerospace propulsion system manufacturers have utilized NASA Lewis Research Center's test facilities with a high degree of success to evaluate candidate materials for application to new propulsion devices.

  4. Computational Modeling of Ablative Materials: Application to Phenolic Pyrolysis

    Data.gov (United States)

    National Aeronautics and Space Administration — Many NASA missions (ESMD, SMD), including crewed missions to Mars, are not possible with current ablative materials. Improved understanding will (1) facilitate the...

  5. X-ray Micro-Tomography of Ablative Heat Shield Materials

    Science.gov (United States)

    Panerai, Francesco; Ferguson, Joseph; Borner, Arnaud; Mansour, Nagi N.; Barnard, Harold S.; MacDowell, Alastair A.; Parkinson, Dilworth Y.

    2016-01-01

    X-ray micro-tomography is a non-destructive characterization technique that allows imaging of materials structures with voxel sizes in the micrometer range. This level of resolution makes the technique very attractive for imaging porous ablators used in hypersonic entry systems. Besides providing a high fidelity description of the material architecture, micro-tomography enables computations of bulk material properties and simulations of micro-scale phenomena. This presentation provides an overview of a collaborative effort between NASA Ames Research Center and Lawrence Berkeley National Laboratory, aimed at developing micro-tomography experiments and simulations for porous ablative materials. Measurements are carried using x-rays from the Advanced Light Source at Berkeley Lab on different classes of ablative materials used in NASA entry systems. Challenges, strengths and limitations of the technique for imaging materials such as lightweight carbon-phenolic systems and woven textiles are discussed. Computational tools developed to perform numerical simulations based on micro-tomography are described. These enable computations of material properties such as permeability, thermal and radiative conductivity, tortuosity and other parameters that are used in ablator response models. Finally, we present the design of environmental cells that enable imaging materials under simulated operational conditions, such as high temperature, mechanical loads and oxidizing atmospheres.Keywords: Micro-tomography, Porous media, Ablation

  6. Water absorption and desorption in shuttle ablator and insulation materials

    Science.gov (United States)

    Whitaker, A. F.; Smith, C. F.; Wooden, V. A.; Cothren, B. E.; Gregory, H.

    1982-01-01

    Shuttle systems ablator and insulation materials underwent water soak with subsequent water desorption in vacuum. Water accumulation in these materials after a soak for 24 hours ranged from +1.1% for orbiter tile to +161% for solid rocket booster MSA-1. After 1 minute in vacuum, water retention ranged from none in the orbiter tile to +70% for solid rocket booster cork.

  7. Resin-Impregnated Carbon Ablator: A New Ablative Material for Hyperbolic Entry Speeds

    Science.gov (United States)

    Esper, Jaime; Lengowski, Michael

    2012-01-01

    Ablative materials are required to protect a space vehicle from the extreme temperatures encountered during the most demanding (hyperbolic) atmospheric entry velocities, either for probes launched toward other celestial bodies, or coming back to Earth from deep space missions. To that effect, the resin-impregnated carbon ablator (RICA) is a high-temperature carbon/phenolic ablative thermal protection system (TPS) material designed to use modern and commercially viable components in its manufacture. Heritage carbon/phenolic ablators intended for this use rely on materials that are no longer in production (i.e., Galileo, Pioneer Venus); hence the development of alternatives such as RICA is necessary for future NASA planetary entry and Earth re-entry missions. RICA s capabilities were initially measured in air for Earth re-entry applications, where it was exposed to a heat flux of 14 MW/sq m for 22 seconds. Methane tests were also carried out for potential application in Saturn s moon Titan, with a nominal heat flux of 1.4 MW/sq m for up to 478 seconds. Three slightly different material formulations were manufactured and subsequently tested at the Plasma Wind Tunnel of the University of Stuttgart in Germany (PWK1) in the summer and fall of 2010. The TPS integrity was well preserved in most cases, and results show great promise.

  8. Aerothermal Testing of Woven TPS Ablative Materials

    Science.gov (United States)

    Stackpoole, Mairead; Feldman, Jay; Olson, Michael; Venkatapathy, Ethiraj

    2012-01-01

    Woven Thermal Protection Systems (WTPS) is a new TPS concept that is funded by NASAs Office of the Chief Technologist (OCT) Game Changing Division. The WTPS project demonstrates the potential for manufacturing a variety of TPS materials capable of wide ranging performances demanded by a spectrum of solar system exploration missions. Currently, missions anticipated to encounter heat fluxes in the range of 1500 4000 Watts per square centimeter are limited to using one proven material fully dense Carbon Phenolic. However, fully dense carbon phenolic is only mass efficient at heat fluxes greater than 4000 Watts per square centimeter, and current mission designs suffer this mass inefficiency for lack of an alternative mid-density TPS. WTPS not only bridges this gap but also offers a replacement for carbon phenolic, which itself requires a significant and costly redevelopment effort to re-establish its capability for use in the high heat flux missions recently prioritized in the NRC Decadal survey, including probe missions to Venus, Saturn and Neptune. This poster will summarize some recent arc jet testing to evaluate the performance of WTPS. Both mid density and fully dense WTPS test results will be presented and results compared to heritage carbon phenolic where applicable.

  9. Method for materials deposition by ablation transfer processing

    Science.gov (United States)

    Weiner, Kurt H.

    1996-01-01

    A method in which a thin layer of semiconducting, insulating, or metallic material is transferred by ablation from a source substrate, coated uniformly with a thin layer of said material, to a target substrate, where said material is desired, with a pulsed, high intensity, patternable beam of energy. The use of a patternable beam allows area-selective ablation from the source substrate resulting in additive deposition of the material onto the target substrate which may require a very low percentage of the area to be covered. Since material is placed only where it is required, material waste can be minimized by reusing the source substrate for depositions on multiple target substrates. Due to the use of a pulsed, high intensity energy source the target substrate remains at low temperature during the process, and thus low-temperature, low cost transparent glass or plastic can be used as the target substrate. The method can be carried out atmospheric pressures and at room temperatures, thus eliminating vacuum systems normally required in materials deposition processes. This invention has particular application in the flat panel display industry, as well as minimizing materials waste and associated costs.

  10. Equation of state study of Laser Megajoule capsules ablator materials

    International Nuclear Information System (INIS)

    Colin-Lalu, Pierre

    2016-01-01

    This PhD thesis enters the field of inertial confinement fusion studies. In particular, it focuses on the equation of state tables of ablator materials synthesized on LMJ capsules. This work is indeed aims at improving the theoretical models introduced into the equation of state tables. We focused in the Mbar-eV pressure-temperature range because it can be access on kJ-scale laser facilities.In order to achieve this, we used the QEOS model, which is simple to use, configurable, and easily modifiable.First, quantum molecular dynamics (QMD) simulations were performed to generate cold compression curve as well as shock compression curves along the principal Hugoniot. Simulations were compared to QEOS model and showed that atomic bond dissociation has an effect on the compressibility. Results from these simulations are then used to parametrize the Grueneisen parameter in order to generate a tabulated equation of state that includes dissociation. It allowed us to show its influence on shock timing in a hydrodynamic simulation.Second, thermodynamic states along the Hugoniot were measured during three experimental campaigns upon the LULI2000 and GEKKO XII laser facilities. Experimental data confirm QMD simulations.This study was performed on two ablator materials which are an undoped polymer CHO, and a silicon-doped polymer CHOSi. Results showed universal shock compression properties. (author) [fr

  11. Reassembling Solid Materials by Femtosecond Laser Ablation: Case of Aluminum Nitride

    Science.gov (United States)

    Kobayashi, Tohru; Matsuo, Yukari

    2013-06-01

    Through atomization and ionization, we could completely alter the composition of a nonconductive material, aluminum nitride, by femtosecond laser ablation. Preferential production of pure aluminum cluster cations Aln+ (n≤32) reflects not only their higher energetic stability compared with mixed clusters AlnNm+ but also completion of thermal relaxation in ablation plasma. Observation of metastable dissociation of Aln+ indicates that cluster cations have still enough internal energy for dissociation to occur, although the process is much slower than the cluster formation. Almost no cluster formation has been observed after nanosecond laser ablation of aluminum nitride, which highlights the distinct nature of ablation plasma produced by femtosecond laser ablation.

  12. Spectroscopic studies of laser ablation plumes of artwork materials

    Science.gov (United States)

    Oujja, M.; Rebollar, E.; Castillejo, M.

    2003-04-01

    Studies on the plasma plume created during KrF laser (248 nm) ablation of dosimeter tempera samples in vacuum have been carried out to investigate the basic interactions of the laser with paint materials. Time resolved optical emission spectroscopy (OES) was used to measure the translational velocity of electronically excited transients in the plasma plume. Laser-induced fluorescence (LIF) studies using a probe dye laser, allowed to determine the velocities of non-emitting species. The propagation velocities of C 2 in the a 3π u and d 3π g electronic states and of excited atomic species are indicative of a high translational temperature. Differences between the velocities of organic and inorganic species and between emissions from the tempera systems and from the pigments as pellets allow to discuss the participation of photochemical mechanisms in the laser irradiation of the paint systems.

  13. Analysis of fabric materials cut using ultraviolet laser ablation

    Science.gov (United States)

    Tsai, Hsin-Yi; Yang, Chih-Chung; Hsiao, Wen-Tse; Huang, Kuo-Cheng; Andrew Yeh, J.

    2016-04-01

    Laser ablation technology has widely been applied in the clothing industry in recent years. However, the laser mechanism would affect the quality of fabric contours and its components. Hence, this study examined carbonization and oxidation conditions and contour variation in nonwoven, cotton, and composite leather fabrics cut by using an ultraviolet laser at a wavelength of 355 nm. Processing parameters such as laser power, pulse frequency, scanning speed, and number of pulses per spot were adjusted to investigate component variation of the materials and to determine suitable cutting parameters for the fabrics. The experimental results showed that the weights of the component changed substantially by pulse frequency but slightly by laser power, so pulse frequency of 100 kHz and laser power of 14 W were the approximate parameters for three fabrics for the smaller carbonization and a sufficient energy for rapidly cutting, which the pulse duration of laser system was fixed at 300 μs and laser irradiance was 0.98 J/mm2 simultaneously. In addition, the etiolate phenomenon of nonwoven was reduced, and the component weight of cotton and composite leather was closed to the value of knife-cut fabric as the scanning speed increased. The approximate scanning speed for nonwoven and composite leather was 200 mm/s, and one for cotton was 150 mm/s, respectively. The sharper and firmer edge is obtained by laser ablation mechanism in comparison with traditional knife cutting. Experimental results can serve as the reference for laser cutting in the clothing industry, for rapidly providing smoother patterns with lower carbonization and oxidation edge in the fashion industry.

  14. Material response reconstruction of ablative TPS using accurate boundary layer modeling

    Data.gov (United States)

    National Aeronautics and Space Administration — For hypersonic atmospheric entry missions, charring ablators are often used. These materials are made of non-pyrolyzing matrices (carbon, ceramic, etc.) combined...

  15. Study on ablation behavior of silicone rubber based insulation material under the condition of boron oxide particles erosion

    Science.gov (United States)

    Zha, B. L.; Shi, Y. A.; Wang, J. J.; Su, Q. D.

    2018-01-01

    Self-designed oxygen-kerosene ablation system was employed to study the ablation characteristics of silicone rubber based thermal insulation materials under the condition of boron oxide particles erosion. The ablation test was designed with a mass fraction of 1.69% boron oxide particles and particles-free, the microstructure and elemental analysis of the specimens before and after ablation were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersion Spectrum (EDS). Experiment results show that the average mass ablation rate of the materials was 0.0099 g•s‑1 and the average ablation rate was -0.025 mm•s‑1 under the condition of pure gas phase ablation; and the average mass ablation rate of the multiphase ablation test group was 0.1775 g•s‑1, whose average ablation rate was 0.437 mm•s‑1 during the ablation process, the boron oxide particles would adhere a molten layer on the flame contact surface of the specimen, which covering the pores on the material surface, blocking the infiltration channel for the oxidizing component and slowing down the oxidation loss rate of the material below the surface, but because the particles erosion was the main reason for material depletion, the combined effect of the above both led to the upward material ablation rates of Silicone Rubber.

  16. Thin film growing by the laser ablation technique: possibilities for growing of dosimetric materials

    International Nuclear Information System (INIS)

    Rojas R, E.M.; Melo M, M.; Enriquez Z, E.; Fernandez G, M.; Haro P, E.; Hernandez P, J.L.

    2005-01-01

    In this talk we will present the basics about the laser ablation technique and how it is used for thin film growing, either as a single film or a stack of thin films, as well as some methods to characterize in real time the film thickness. Finally, we will discuss the possibilities of using laser ablation for growing thin films with applications to dosimetry. (Author)

  17. Analysis and removal of ITER relevant materials and deposits by laser ablation

    International Nuclear Information System (INIS)

    Xiao, Qingmei; Huber, Alexander; Philipps, Volker; Sergienko, Gennady; Gierse, Niels; Mertens, Philippe; Hai, Ran; Ding, Hongbin

    2014-01-01

    The analysis of the deposition of eroded wall material on the plasma-facing materials in fusion devices is one of the crucial issues to maintain the plasma performance and to fulfill safety requirements with respect to tritium retention by co-deposition. Laser ablation with minimal damage to the plasma facing material is a promising method for in situ monitoring and removal of the deposition, especially for plasma-shadowed areas which are difficult to reach by other cleaning methods like plasma discharge. It requires the information of ablation process and the ablation threshold for quantitative analysis and effective removal of the different deposits. This paper presents systemic laboratory experimental analysis of the behavior of the ITER relevant materials, graphite, tungsten, aluminum (as a substitution of beryllium) and mixed deposits ablated by a Nd:YAG laser (1064 nm) with different energy densities (1–27 J/cm 2 , power density 0.3–3.9 GW/cm 2 ). The mixed deposits consisted of W–Al–C layer were deposited on W substrate by magnetron sputtering and arc plasma deposition. The aim was to select the proper parameters for the quantitative analysis and for laser removal of the deposits by investigating the ablation efficiency and ablation threshold for the bulk materials and deposits. The comparison of the ablation and saturation energy thresholds for pure and mixed materials shows that the ablation threshold of the mixed layer depends on the concentration of the components. We propose laser induced breakdown spectroscopy for determination of the elemental composition of deposits and then we select the laser parameters for the layer removal. Comparison of quantitative analysis results from laboratory to that from TEXTOR shows reasonable agreements. The dependence of the spectra on plasma parameters and ambient gas pressure is investigated

  18. Development of improved ablative materials for ASRM. [Advanced Solid Rocket Motor

    Science.gov (United States)

    Canfield, A.; Armour, W.; Clinton, R.

    1991-01-01

    A program to improve ablative materials for the Advanced Solid Rocket Motor (ASRM) is briefly discussed. The main concerns with the baseline material are summarized along with the measures being undertaken to obtain improvements. The materials involved in the program, all of which have been manufactured and are now being evaluated, are mentioned.

  19. New laser materials: Final report

    International Nuclear Information System (INIS)

    1986-10-01

    In the Interim Report No. 1, it was reported that the fluorescence lifetime (≥ 750μs) in Nd doped Y(PO 3 ) 3 was longer by a factor of three as compared to YAG. This means potentially three times as much energy storage and consequently more efficient for flashlamp pumping. It also makes diode pumping easier. In addition, since the Y site is octahedrally coordinated, there is a possibility of energy transfer using Cr as the sensitizing element. As suggested by W. Krupke, we decided to explore the trivalent cation metaphosphates systematically. The compounds investigated can be represented by the general formula A(PO 3 ) 3 where A = Y, Lu, In, Sc, GA and Al. The object is to study the fluorescence characteristics of Nd and Cr as well as the effectiveness of energy transfer from Cr to Nd. In addition, we also investigated other possible laser host crystals, notably CaMgSi 2 O 6 (diopside), LaBO 3 and La(BO 2 ) 3 . Results on these materials will also be discussed

  20. Surface ablation of inorganic transparent materials using 70W femtosecond pulses at 1MHz (Conference Presentation)

    Science.gov (United States)

    Mishchik, Konstantin; Gaudfrin, Kevin; Audouard, Eric F.; Mottay, Eric P.; Lopez, John

    2017-03-01

    Nowadays processing of transparent materials, such as glass, quartz, sapphire and others, is a subject of high interest for worldwide industry since these materials are widely used for mass markets such as consumer electronics, flat display panels manufacturing, optoelectronics or watchmaking industry. The key issue is to combine high throughput, low residual stress and good processing quality in order to avoid chipping and any post-processing step such as grinding or polishing. Complimentary to non-ablative techniques used for zero-kerf glass cutting, surface ablation of such materials is interesting for engraving, grooving as well as full ablation cutting. Indeed this technique enables to process complex parts including via or blind, open or closed, straight or small radius of curvature patterns. We report on surface ablation experiments on transparent materials using a high average power (70W) and high repetition rate (1 MHz) femtosecond laser. These experiments have been done at 1030nm and 515nm on different inorganic transparent materials, such as regular and strengthened glass, borosilicate glass or sapphire, in order to underline their different ablation behavior. Despite the heat accumulation that occurs above 100 kHz we have reached a good compromise between throughput and processing quality. The effects of fluence, pulse-to-pulse overlap and number of passes are discussed in terms of etch rate, ablation efficiency, optimum fluence, maximum achievable depth, micro cracks formation and residual stresses. These experimental results will be also compared with numerical calculations obtained owing to a simple engineering model based on the two-temperature description of the ultrafast ablation.

  1. Off-Hugoniot characterization of alternative inertial confinement fusion ablator materials.

    Science.gov (United States)

    Moore, Alastair S.; Prisbrey, Shon; Baker, Kevin L.; Celliers, Peter M.; Fry, Jonathan; Dittrich, Thomas R.; Wu, Kuang-Jen J.; Kervin, Margaret L.; Schoff, Michael E.; Farrell, Mike; Nikroo, Abbas; Hurricane, Omar A.

    2016-05-01

    The ablation material used during the National Ignition Campaign, a glow- discharge polymer (GDP), does not couple as efficiently as simulations indicated to the multiple- shock inducing radiation drive environment created by laser power profile [1]. We investigate the performance of two other ablators, boron carbide (B4C) and high-density carbon (HDC) and compare with GDP under the same hohlraum conditions. Ablation performance is determined through measurement of the shock speed produced in planar samples of the ablator subjected to the identical multiple-shock inducing radiation drive environments that are similar to a generic three-shock ignition drive. Simulations are in better agreement with the off-Hugoniot performance of B4C than either HDC or GDP.

  2. Replacement of Ablators with Phase-Change Material for Thermal Protection of STS Elements

    Science.gov (United States)

    Kaul, Raj K.; Stuckey, Irvin; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    As part of the research and development program to develop new Thermal Protection System (TPS) materials for aerospace applications at NASA's Marshall Space Flight Center (MSFC), an experimental study was conducted on a new concept for a non-ablative TPS material. Potential loss of TPS material and ablation by-products from the External Tank (ET) or Solid Rocket Booster (SRB) during Shuttle flight with the related Orbiter tile damage necessitates development of a non-ablative thermal protection system. The new Thermal Management Coating (TMC) consists of phase-change material encapsulated in micro spheres and a two-part resin system to adhere the coating to the structure material. The TMC uses a phase-change material to dissipate the heat produced during supersonic flight rather than an ablative material. This new material absorbs energy as it goes through a phase change during the heating portion of the flight profile and then the energy is slowly released as the phase-change material cools and returns to its solid state inside the micro spheres. The coating was subjected to different test conditions simulating design flight environments at the NASA/MSFC Improved Hot Gas Facility (IHGF) to study its performance.

  3. Comparison of Ablation Predictions for Carbonaceous Materials Using CEA and JANAF-Based Species Thermodynamics

    Science.gov (United States)

    Milos, Frank S.

    2011-01-01

    In most previous work at NASA Ames Research Center, ablation predictions for carbonaceous materials were obtained using a species thermodynamics database developed by Aerotherm Corporation. This database is derived mostly from the JANAF thermochemical tables. However, the CEA thermodynamics database, also used by NASA, is considered more up to date. In this work, the FIAT code was modified to use CEA-based curve fits for species thermodynamics, then analyses using both the JANAF and CEA thermodynamics were performed for carbon and carbon phenolic materials over a range of test conditions. The ablation predictions are comparable at lower heat fluxes where the dominant mechanism is carbon oxidation. However, the predictions begin to diverge in the sublimation regime, with the CEA model predicting lower recession. The disagreement is more significant for carbon phenolic than for carbon, and this difference is attributed to hydrocarbon species that may contribute to the ablation rate.

  4. Ablation of carbonaceous materials in a hydrogen-helium arc-jet flow

    Science.gov (United States)

    Park, C.; Lundell, J. H.; Green, M. J.; Winovich, W.; Covington, M. A.

    1983-01-01

    The stagnation-point ablation rates of a graphite, a carbon-carbon composite, and four carbon-phenolic materials are measured in an arc-jet wind tunnel with a 50 percent hydrogen-50 percent helium mixture as the test gas. Flow environments are determined through measurements of static and impact pressures, heat-transfer rates to a calorimeter, and radiation spectra, and through numerical calculation of the flow through the wind tunnel, spectra, and heat-transfer rates. The environments so determined are: impact pressure approximately equal to 3 atm, Mach number approximately equal to 2.1, convective heat-transfer rate approximately equal to 14 kW/sq cm, and radiative heat-transfer rate approximately equal to 7 kW/sq cm in the absence of ablation. Ablation rates are determined from the measured rates of mass loss and recession of the ablation specimens. Compared with the predicted ablation rates obtained by running RASLE and CMA codes, the measured rates are higher by about 15 percent for all tested materials.

  5. Characterization of Candidate Materials for Remote Recession Measurements of Ablative Heat Shield Materials

    Science.gov (United States)

    Butler, Bradley D.; Winter, Michael; Panerai, Francesco; Martin, Alexandre; Bailey, Sean C. C.; Stackpoole, Margaret; Danehy, Paul M.; Splinter, Scott

    2016-01-01

    A method of remotely measuring surface recession of a material sample in a plasma flow through emission spectroscopy of the post shock layer was characterized through experiments in the NASA Langley HYMETS arc jet facility. Different methods for delivering the seed products into the Phenolic Impregnated Carbon Ablator (PICA) material samples were investigated. Three samples were produced by seeding the PICA material with combinations of Al, Si, HfO2, VB2, Al2O3, SiO2, TiC, HfC, NaCl, and MgCl2 through infusing seed materials into a core of PICA, or through encapsulating seed material in an epoxy disk, mechanically bonding the disk to a PICA sample. The PICA samples seeded with the candidate tracers were then tested at surface temperatures near 2400 K under low pressure air plasma. The emission of Al, Ti, V, Na, and Mg in the post-shock layer was observed in the UV with a high resolution imaging spectrometer viewing the whole stagnation line from the side, and from UV to NIR with a fiber-coupled miniaturized spectrometer observing the sample surface in the wavelength range from 200 nm to 1,100 nm from the front through a collimator. Al, Na, and Mg were found to be emitting in the post-shock spectra even before the recession reached the seeding depth - therefore possibly characterizing the pyrolysis process rather than the recession itself. The appearance of Ti and V emission in the spectra was well correlated with the actual recession which was monitored through a video of the front surface of the sample. The applicability of a seed material as an indicator for recession appears to be related to the melting temperature of the seed material. Future parametric studies will be carried out in low power plasma facilities at the University of Kentucky.

  6. Thermal protection for hypervelocity flight in earth's atmosphere by use of radiation backscattering ablating materials

    Science.gov (United States)

    Howe, John T.; Yang, Lily

    1991-01-01

    A heat-shield-material response code predicting the transient performance of a material subject to the combined convective and radiative heating associated with the hypervelocity flight is developed. The code is dynamically interactive to the heating from a transient flow field, including the effects of material ablation on flow field behavior. It accomodates finite time variable material thickness, internal material phase change, wavelength-dependent radiative properties, and temperature-dependent thermal, physical, and radiative properties. The equations of radiative transfer are solved with the material and are coupled to the transfer energy equation containing the radiative flux divergence in addition to the usual energy terms.

  7. Wall ablation of heated compound-materials into non-equilibrium discharge plasmas

    Science.gov (United States)

    Wang, Weizong; Kong, Linghan; Geng, Jinyue; Wei, Fuzhi; Xia, Guangqing

    2017-02-01

    The discharge properties of the plasma bulk flow near the surface of heated compound-materials strongly affects the kinetic layer parameters modeled and manifested in the Knudsen layer. This paper extends the widely used two-layer kinetic ablation model to the ablation controlled non-equilibrium discharge due to the fact that the local thermodynamic equilibrium (LTE) approximation is often violated as a result of the interaction between the plasma and solid walls. Modifications to the governing set of equations, to account for this effect, are derived and presented by assuming that the temperature of the electrons deviates from that of the heavy particles. The ablation characteristics of one typical material, polytetrafluoroethylene (PTFE) are calculated with this improved model. The internal degrees of freedom as well as the average particle mass and specific heat ratio of the polyatomic vapor, which strongly depends on the temperature, pressure and plasma non-equilibrium degree and plays a crucial role in the accurate determination of the ablation behavior by this model, are also taken into account. Our assessment showed the significance of including such modifications related to the non-equilibrium effect in the study of vaporization of heated compound materials in ablation controlled arcs. Additionally, a two-temperature magneto-hydrodynamic (MHD) model accounting for the thermal non-equilibrium occurring near the wall surface is developed and applied into an ablation-dominated discharge for an electro-thermal chemical launch device. Special attention is paid to the interaction between the non-equilibrium plasma and the solid propellant surface. Both the mass exchange process caused by the wall ablation and plasma species deposition as well as the associated momentum and energy exchange processes are taken into account. A detailed comparison of the results of the non-equilibrium model with those of an equilibrium model is presented. The non-equilibrium results

  8. Interfacial Design of Composite Ablative Materials, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research (SBIR) project proposes the development of a computational software package to provide NASA with advanced materials...

  9. Laser ablation of dental materials using a microsecond Nd:YAG laser

    Science.gov (United States)

    Siniaeva, M. L.; Siniavsky, M. N.; Pashinin, V. P.; Mamedov, Ad. A.; Konov, V. I.; Kononenko, V. V.

    2009-05-01

    The action of microsecond laser pulses with a wavelength of 1064 nm on dental tissues (enamel and dentin) and various dental materials used for tooth replacement and filling (ceramics, metal alloys, and composites) is studied. It is demonstrated that the ablation thresholds of all of the dental materials are significantly lower than the threshold laser fluences for the dental tissue ( E thr = 200-300 J/cm2). At the laser fluences that do not allow ablation and damage of the dental tissues, the dental materials are effectively removed at a rate of no greater than 40 μm per pulse. It is shown that the laser ablation of the materials under study involves two processes (evaporation and volume explosion) depending on the optical density. The results obtained indicate that the laser radiation with a wavelength of 1064 nm and the microsecond pulse duration is promising for dental applications, since it allows effective cleaning of the tooth surface from various dental materials in the absence of the damages of dental tissues.

  10. The thermal and mechanical properties of a low-density glass-fiber-reinforced elastomeric ablation material

    Science.gov (United States)

    Engelke, W. T.; Robertson, R. W.; Bush, A. L.; Pears, C. D.

    1974-01-01

    An evaluation of the thermal and mechanical properties was performed on a molded low-density elastomeric ablation material designated as Material B. Both the virgin and charred states were examined to provide meaningful inputs to the design of a thermal protection system. Chars representative of the flight chars formed during ablation were prepared in a laboratory furnace from 600 K to 1700 K and properties of effective thermal conductivity, heat capacity, porosity and permeability were determined on the furnace chars formed at various temperature levels within the range. This provided a boxing of the data which will enable the prediction of the transient response of the material during flight ablation.

  11. Heat generation caused by ablation of dental restorative materials with an ultra short pulse laser (USPL) system

    Science.gov (United States)

    Braun, Andreas; Wehry, Richard; Brede, Olivier; Frentzen, Matthias; Schelle, Florian

    2011-03-01

    The aim of this study was to assess heat generation in dental restoration materials following laser ablation using an Ultra Short Pulse Laser (USPL) system. Specimens of phosphate cement (PC), ceramic (CE) and composite (C) were used. Ablation was performed with an Nd:YVO4 laser at 1064 nm and a pulse length of 8 ps. Heat generation during laser ablation depended on the thickness of the restoration material. A time delay for temperature increase was observed in the PC and C group. Employing the USPL system for removal of restorative materials, heat generation has to be considered.

  12. Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron.

    Science.gov (United States)

    Helber, Bernd; Chazot, Olivier; Hubin, Annick; Magin, Thierry E

    2016-06-09

    Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties. The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale

  13. A simulation-based and analytic analysis of the off-Hugoniot response of alternative inertial confinement fusion ablator materials

    Science.gov (United States)

    Moore, Alastair S.; Prisbrey, Shon; Baker, Kevin L.; Celliers, Peter M.; Fry, Jonathan; Dittrich, Thomas R.; Wu, Kuang-Jen J.; Kervin, Margaret L.; Schoff, Michael E.; Farrell, Mike; Nikroo, Abbas; Hurricane, Omar A.

    2016-09-01

    The attainment of self-propagating fusion burn in an inertial confinement target at the National Ignition Facility will require the use of an ablator with high rocket-efficiency and ablation pressure. The ablation material used during the National Ignition Campaign (Lindl et al. 2014) [1], a glow-discharge polymer (GDP), does not couple as efficiently as simulations indicated to the multiple-shock inducing radiation drive environment created by laser power profile (Robey et al., 2012). We investigate the performance of two other ablators, boron carbide (B4C) and high-density carbon (HDC) compared to the performance of GDP under the same hohlraum conditions. Ablation performance is determined through measurement of the shock speed produced in planar samples of the ablator material subjected to the identical multiple-shock inducing radiation drive environments that are similar to a generic three-shock ignition drive. Simulations are in better agreement with the off-Hugoniot performance of B4C than either HDC or GDP, and analytic estimations of the ablation pressure indicate that while the pressure produced by B4C and GDP is similar when the ablator is allowed to release, the pressure reached by B4C seems to exceed that of HDC when backed by a Au/quartz layer.

  14. Ablation by-products of dental materials from the Er:YAG laser and the dental handpiece

    Science.gov (United States)

    Wigdor, Harvey A.; Visuri, Steven R.; Walsh, Joseph T., Jr.

    1995-05-01

    Recently there has been much interest in lasers and their potential use to replace the dental drill. The research has been directed towards vital dental tissues. It must be understood that any laser to be used in dentistry which will replace the dental drill must also ablate and remove existing dental materials. Some concern exists about the ablation products when the Er:YAG laser is used to ablate dental materials. It is incumbent on the professionals using these lasers to understand the materials being produced by these lasers and protect themselves and their patients from possible toxic products. It is the intent of this paper to evaluate the products produced by the ablation of both dental amalgam and composite dental restorative materials and compare them with those produced by the traditional dental handpiece (drill).

  15. Ablation characteristics and reaction mechanism of insulation materials under slag deposition condition

    Science.gov (United States)

    Guan, Yiwen; Li, Jiang; Liu, Yang

    2017-07-01

    Current understanding of the physical and chemical processes involved in the ablation of insulation materials by highly aluminized solid propellants is limited. The study on the heat transfer and ablation principle of ethylene propylene diene monomer (EPDM) materials under slag deposition condition is essential for future design or modification of large solid rocket motors (SRMs) for launch application. In this paper, the alumina liquid flow pattern and the deposition principle in full-scale SRM engines are discussed. The interaction mechanism between the alumina droplets and the wall are analyzed. Then, an experimental method was developed to simulate the insulation material ablation under slag deposition condition. Experimental study was conducted based on a laboratory-scale device. Meanwhile, from the analysis of the cross-sectional morphology and chemical composition of the charring layer after ablation, the reaction mechanism of the charring layer under deposition condition was discussed, and the main reaction equation was derived. The numerical simulation and experimental results show the following. (i) The alumina droplet flow in the deposition section of the laboratory-scale device is similar to that of a full-scale SRM. (ii) The charring layer of the EPDM insulator displays a porous tight/loose structure under high-temperature slag deposition condition. (iii) A seven-step carbothermal reduction in the alumina is derived and established under high-pressure and high-temperature environment in the SRM combustion chamber. (iv) The analysis using thermodynamic software indicates that the reaction of the alumina and charring layer initially forms Al4C3 during the operation. Then, Al element and Al2OC compound are subsequently produced with the reduction in the release of gas CO as well with continuous environmental heating.

  16. Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Molpeceres, C. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain)], E-mail: carlos.molpeceres@upm.es; Lauzurica, S.; Garcia-Ballesteros, J.J.; Morales, M.; Guadano, G.; Ocana, J.L. [Centro Laser UPM, Univ. Politecnica de Madrid, Crta. de Valencia Km 7.3, 28031 Madrid (Spain); Fernandez, S.; Gandia, J.J. [Dept. de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda, Complutense 22, 28040 Madrid (Spain); Villar, F.; Nos, O.; Bertomeu, J. [CeRMAE Dept. Fisica Aplicada i Optica, Universitat de Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain)

    2009-03-15

    Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

  17. Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

    International Nuclear Information System (INIS)

    Molpeceres, C.; Lauzurica, S.; Garcia-Ballesteros, J.J.; Morales, M.; Guadano, G.; Ocana, J.L.; Fernandez, S.; Gandia, J.J.; Villar, F.; Nos, O.; Bertomeu, J.

    2009-01-01

    Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

  18. Modeling of Heat Transfer and Ablation of Refractory Material Due to Rocket Plume Impingement

    Science.gov (United States)

    Harris, Michael F.; Vu, Bruce T.

    2012-01-01

    CR Tech's Thermal Desktop-SINDA/FLUINT software was used in the thermal analysis of a flame deflector design for Launch Complex 39B at Kennedy Space Center, Florida. The analysis of the flame deflector takes into account heat transfer due to plume impingement from expected vehicles to be launched at KSC. The heat flux from the plume was computed using computational fluid dynamics provided by Ames Research Center in Moffet Field, California. The results from the CFD solutions were mapped onto a 3-D Thermal Desktop model of the flame deflector using the boundary condition mapping capabilities in Thermal Desktop. The ablation subroutine in SINDA/FLUINT was then used to model the ablation of the refractory material.

  19. Degradation of carbon-based materials under ablative conditions produced by a high enthalpy plasma jet

    Directory of Open Access Journals (Sweden)

    Gilberto Petraconi

    2010-04-01

    Full Text Available A stationary experiment was performed to study the degradation of carbon-based materials by immersion in a plasma jet. In the experiment, graphite and C/C composite were chosen as the target materials, and the reactive plasma jet was generated by an air plasma torch. For macroscopic study of the material degradation, the sample’s mass losses were measured as function of the exposure time under various temperatures on the sample surface. A microscopic analysis was then carried out for the study of microscopic aspects of the erosion of material surface. These experiments showed that the mass loss per unit area is approximately proportional to the exposure time and strongly depends on the temperature of the material surface. The mass erosion rate of graphite was appreciably higher than the C/C composite. The ablation rate in the carbon matrix region in C/C composite was also noticeably higher than that in the fiber region. In addition, the latter varied according to the orientation of fibers relatively to the flow direction. These tests indicated an excellent ablation resistance of the C/C composite, thus being a reliable material for rocket nozzles and heat shielding elements of the protection systems of hypersonic apparatuses from aerodynamic heating.

  20. Non-Intrusive Sensor for In-Situ Measurement of Recession Rate of Ablative and Eroding Materials

    Science.gov (United States)

    Papadopoulos, George (Inventor); Tiliakos, Nicholas (Inventor); Benel, Gabriel (Inventor); Thomson, Clint (Inventor)

    2014-01-01

    A non-intrusive sensor for in-situ measurement of recession rate of heat shield ablatives. An ultrasonic wave source is carried in the housing. A microphone is also carried in the housing, for collecting the reflected ultrasonic waves from an interface surface of the ablative material. A time phasing control circuit is also included for time-phasing the ultrasonic wave source so that the waves reflected from the interface surface of the ablative material focus on the microphone, to maximize the acoustic pressure detected by the microphone and to mitigate acoustic velocity variation effects through the material through a de-coupling process that involves a software algorithm. A software circuit for computing the location off of which the ultrasonic waves scattered to focus back at the microphone is also included, so that the recession rate of the heat shield ablative may be monitored in real-time through the scan-focus approach.

  1. Lightweight Ablative and Ceramic Thermal Protection System Materials for NASA Exploration Systems Vehicles

    Science.gov (United States)

    Valentine, Peter G.; Lawrence, Timothy W.; Gubert, Michael K.; Milos, Frank S.; Kiser, James D.; Ohlhorst, Craig W.; Koenig, John R.

    2006-01-01

    As a collaborative effort among NASA Centers, the "Lightweight Nonmetallic Thermal Protection Materials Technology" Project was set up to assist mission/vehicle design trade studies, to support risk reduction in thermal protection system (TPS) material selections, to facilitate vehicle mass optimization, and to aid development of human-rated TPS qualification and certification plans. Missions performing aerocapture, aerobraking, or direct aeroentry rely on advanced heatshields that allow reductions in spacecraft mass by minimizing propellant requirements. Information will be presented on candidate materials for such reentry approaches and on screening tests conducted (material property and space environmental effects tests) to evaluate viable candidates. Seventeen materials, in three classes (ablatives, tiles, and ceramic matrix composites), were studied. In additional to physical, mechanical, and thermal property tests, high heat flux laser tests and simulated-reentry oxidation tests were performed. Space environmental effects testing, which included exposures to electrons, atomic oxygen, and hypervelocity impacts, was also conducted.

  2. Radio-physical properties of radiotransparent thermal protection materials in ablation mode

    Science.gov (United States)

    Petrovskiy, V. P.; Pakhomov, E. P.; Politiko, A. A.; Semenenko, V. N.; Chistyaev, V. A.; Balakirev, B. A.; Pervov, A. Yu; Kamalov, A. D.; Sotskova, L. P.

    2018-01-01

    Experimental method for assessing the impact of the effects of high-temperature ablation processes on the radio physical characteristics of radiotransparent thermal protection materials (RTPM) is developed. Researches for the following RTPM with various structures of glass fillers are completed: press material (radiotransparent thermal protection press material or RTP-200); glass-fiber laminate (glass-fiber radiotransparent organic ceramic matrix or GFR-CM); reinforced composite material of class SiO2–SiO2 (high-temperature radiotransparent ceramic organic matrix or HTRC-OM). The influence of physicochemical transformations in the surface layer of RTPM on transmission and reflection coefficients of electromagnetic waves of RTPM samples and on the value of their complex permittivity is determined.

  3. Femtosecond laser excitation of dielectric materials: experiments and modeling of optical properties and ablation depths

    DEFF Research Database (Denmark)

    Wædegaard, Kristian Juncher; Frislev, Martin Thomas; Balling, Peter

    2013-01-01

    Modeling of the interaction between a dielec- tric material and ultrashort laser pulses provides the tem- poral evolution of the electronic excitation and the optical properties of the dielectric. Experimentally determined re- flectances and ablation depths for sapphire are compared to the calcul...... to the calculations. A decrease in reflectance at high fluences is observed experimentally, which demonstrates the neces- sity of a temperature-dependent electron scattering rate in the model. The comparison thus provides new constraints on the optical parameters of the model....

  4. Ablative material testing for low-pressure, low-cost rocket engines

    Science.gov (United States)

    Richter, G. Paul; Smith, Timothy D.

    1995-01-01

    The results of an experimental evaluation of ablative materials suitable for the production of light weight, low cost rocket engine combustion chambers and nozzles are presented. Ten individual specimens of four different compositions of silica cloth-reinforced phenolic resin materials were evaluated for comparative erosion in a subscale rocket engine combustion chamber. Gaseous hydrogen and gaseous oxygen were used as propellants, operating at a nominal chamber pressure of 1138 kPa (165 psi) and a nominal mixture ratio (O/F) of 3.3. These conditions were used to thermally simulate operation with RP-1 and liquid oxygen, and achieved a specimen throat gas temperature of approximately 2456 K (4420 R). Two high-density composition materials exhibited high erosion resistance, while two low-density compositions exhibited approximately 6-75 times lower average erosion resistance. The results compare favorably with previous testing by NASA and provide adequate data for selection of ablatives for low pressure, low cost rocket engines.

  5. Equation of state and shock compression of carbon-hydrogen and other ablator materials

    Science.gov (United States)

    Zhang, S.; Militzer, B.; Whitley, H.

    2017-12-01

    Dynamic compression experiments in planetary interior studies and fusion sciences often implement carbon-hydrogen or other low-Z elements or compounds as ablators. Accurate quantum simulations of these materials enables theoretical investigation of the equation of state (EOS) over temperatures and pressures that are difficult to access experimentally, and can help guide the design of targets for future experiments. In this work, we use path integral Monte Carlo and density functional molecular dynamics to calculate the equation of state of a series of hydrocarbons and other low-Z materials (B, B4C, and BN). For the hydrocarbon with C:H=1:1, we predict the pressure-compression profile to agree remarkably with experiments at low pressures. At high pressures, we find the Hugoniot curve displays a single compression maximum of 4.7 that corresponds to K-shell ionization. This is slightly higher than that of glow-discharge polymers but both occur at the same pressure (0.47 Gbar). We study the linear mixing approximation for the EOS of hydrocarbons and demonstrate its validity at stellar core conditions. We examine the sensitivity of the fusion yield to the EOS of these candidate ablator materials in radiation-hydrodynamic simulations of a direct-drive implosion. We also make detailed comparisons of the EOS and atomic and electronic structure of C and BN, which is useful for systematic improvement of existing EOS models. Prepared by LLNL under Contract DE-AC52-07NA27344.

  6. Experimental Investigation on the Specific Heat of Carbonized Phenolic Resin-Based Ablative Materials

    Science.gov (United States)

    Zhao, Te; Ye, Hong; Zhang, Lisong; Cai, Qilin

    2017-10-01

    As typical phenolic resin-based ablative materials, the high silica/phenolic and carbon/phenolic composites are widely used in aerospace field. The specific heat of the carbonized ablators after ablation is an important thermophysical parameter in the process of heat transfer, but it is rarely reported. In this investigation, the carbonized samples of the high silica/phenolic and carbon/phenolic were obtained through carbonization experiments, and the specific heat of the carbonized samples was determined by a 3D DSC from 150 °C to 970 °C. Structural and compositional characterizations were performed to determine the mass fractions of the fiber and the carbonized product of phenolic which are the two constituents of the carbonized samples, while the specific heat of each constituent was also measured by 3D DSC. The masses of the carbonized samples were reduced when heated to a high temperature in the specific heat measurements, due to the thermal degradation of the carbonized product of phenolic resin in the carbonized samples. The raw experimental specific heat of the two carbonized samples and the carbonized product of phenolic resin was modified according to the quality changes of the carbonized samples presented by TGA results. Based on the mass fraction and the specific heat of each constituent, a weighted average method was adopted to obtain the calculated results of the carbonized samples. Due to the unconsolidated property of the fiber samples which impacts the reliability of the DSC measurement, there is a certain deviation between the experimental and calculated results of the carbonized samples. Considering the similarity of composition and structure, the data of quartz glass and graphite were used to substitute the specific heat of the high silica fiber and carbon fiber, respectively, resulting in better agreements with the experimental ones. Furthermore, the accurate specific heat of the high silica fiber and carbon fiber bundles was obtained by

  7. Study of the Wavelength Dependence in Laser Ablation of Advanced Ceramics and Glass-Ceramic Materials in the Nanosecond Range.

    Science.gov (United States)

    Sola, Daniel; Peña, Jose I

    2013-11-19

    In this work, geometrical dimensions and ablation yields as a function of the machining method and reference position were studied when advanced ceramics and glass-ceramic materials were machined with pulsed lasers in the nanosecond range. Two laser systems, emitting at 1064 and 532 nm, were used. It was shown that the features obtained depend on whether the substrate is processed by means of pulse bursts or by grooves. In particular, when the samples were processed by grooves, machined depth, removed volume and ablation yields reached their maximum, placing the sample out of focus. It was shown that these characteristics do not depend on the processing conditions, the wavelength or the optical configuration, and that this is intrinsic behavior of the processing method. Furthermore, the existence of a close relation between material hardness and ablation yields was demonstrated.

  8. Buried waste containment system materials. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, J.R.; Shaw, P.G.

    1997-10-01

    This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers.

  9. Modeling Initial Stage of Ablation Material Pyrolysis: Graphitic Precursor Formation and Interfacial Effects

    Science.gov (United States)

    Desai, Tapan G.; Lawson, John W.; Keblinski, Pawel

    2010-01-01

    Reactive molecular dynamics simulations are used to study initial stage of pyrolysis of ablation materials and their composites with carbon nanotubes and carbon fibers. The products formed during pyrolysis are characterized and water is found as the primary product in all cases. The water formation mechanisms are analyzed and the value of the activation energy for water formation is estimated. A detailed study on graphitic precursor formation reveals the presence of two temperature zones. In the lower temperature zone (less than 2000 K) polymerization occurs resulting in formation of large, stable graphitic precursors, and in the high temperature zone (greater than 2000 K) polymer scission results in formation of short polymer chains/molecules. Simulations performed in the high temperature zone on the phenolic resin composites (with carbon nanotubes and carbon fibers) shows that the presence of interfaces had no substantial effect on the chain scission rate or the activation energy value for water formation.

  10. Modeling and experiments of x-ray ablation of National Ignition Facility first wall materials

    International Nuclear Information System (INIS)

    Anderson, A.T.; Burnham, A.K.; Tobin, M.T.; Peterson, P.F.

    1996-01-01

    This paper discusses results of modeling and experiments on the x-ray response of selected materials relevant to NIF target chamber design. X-ray energy deposition occurs in such small characteristic depths (on the order of a micron) that thermal conduction and hydrodynamic motion significantly affect the material response, even during the typical 10-ns pulses. The finite-difference ablation model integrates four separate processes: x-ray energy deposition, heat conduction, hydrodynamics, and surface vaporization. Experiments have been conducted at the Nova laser facility in Livermore on response of various materials to NIF-relevant x-ray fluences. Fused silica, Si nitride, B carbide, B, Si carbide, C, Al2O3, and Al were tested. Response was diagnosed using post-shot examinations of the surfaces with SEM and atomic force microscopes. Judgements were made about the dominant removal mechanisms for each material; relative importances of these processes were also studied with the x-ray response model

  11. Energy Materials Center at Cornell: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Abruña, Héctor [Cornell Univ., Ithaca, NY (United States); Mutolo, Paul F [Cornell Univ., Ithaca, NY (United States)

    2015-01-02

    The mission of the Energy Materials Center at Cornell (emc2) was to achieve a detailed understanding, via a combination of synthesis of new materials, experimental and computational approaches, of how the nature, structure, and dynamics of nanostructured interfaces affect energy conversion and storage with emphasis on fuel cells, batteries and supercapacitors. Our research on these systems was organized around a full system strategy for; the development and improved performance of materials for both electrodes at which storage or conversion occurs; understanding their internal interfaces, such as SEI layers in batteries and electrocatalyst supports in fuel cells, and methods for structuring them to enable high mass transport as well as high ionic and electronic conductivity; development of ion-conducting electrolytes for batteries and fuel cells (separately) and other separator components, as needed; and development of methods for the characterization of these systems under operating conditions (operando methods) Generally, our work took industry and DOE report findings of current materials as a point of departure to focus on novel material sets for improved performance. In addition, some of our work focused on studying existing materials, for example observing battery solvent degradation, fuel cell catalyst coarsening or monitoring lithium dendrite growth, employing in operando methods developed within the center.

  12. Cryocycling of energetic materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, S.; Nilson, R.; Handrock, J.; Revelli, V.; Weingarten, L. [and others

    1997-08-01

    The Cryocycling of Energetic Materials Project was executed in the period FY`94-96 as a Life Cycle Engineering activity in the Memorandum of Understanding (MOU) on advanced conventional munitions. This MOU is an agreement between the Departments of Energy and Defense (Office of Munitions) that facilitates the development of technologies of mutual interest to the two Departments. The cryocycling process is a safe, environmentally friendly, and cost effective means of rubblizing bulk energetic materials so that they can be easily reused in a variety of new products. For this reason, cryocycling of excess solid energetic materials is one of the recycle/reuse strategies under study for demilitarized munitions in the Departments of Energy and Defense. These strategies seek to minimize the environmental damage associated with disposal of decommissioned energetic materials. In addition, they encourage technologies that can be used to derive economic benefit from reuse/reapplication of materials that would otherwise be treated as hazardous wastes. 45 refs., 38 figs., 7 tabs.

  13. Standard Test Method for Oxyacetylene Ablation Testing of Thermal Insulation Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the screening of ablative materials to determine the relative thermal insulation effectiveness when tested as a flat panel in an environment of a steady flow of hot gas provided by an oxyacetylene burner. 1.2 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard of materials, products, or assemblies under actual fire conditions. However, results of this test method may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limi...

  14. Laser ablation inductively coupled plasma optical emission spectrometry for analysis of pellets of plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Marcos S. [Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luís, km 235, 13565-905 São Carlos, SP (Brazil); Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Schenk, Emily R. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Professor Arthur Riedel 275, Diadema, SP (Brazil); Krug, Francisco José [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Almirall, José R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States)

    2014-04-01

    An evaluation of laser ablation inductively coupled plasma optical emission spectroscopy (LAICP OES) for the direct analysis of pelleted plant material is reported. Ground leaves of orange citrus, soy and sugarcane were comminuted using a high-speed ball mill, pressed into pellets and sampled directly with laser ablation and analyzed by ICP OES. The limits of detection (LODs) for the method ranged from as low as 0.1 mg kg{sup −1} for Zn to as high as 94 mg kg{sup −1} for K but were generally below 6 mg kg{sup −1} for most of the elements of interest. A certified reference material consisting of a similar matrix (NIST SRM 1547 peach leaves) was used to check the accuracy of the calibration and the reported method resulted in an average bias of ∼ 5% for all the elements of interest. The precision for the reported method ranged from as low as 4% relative standard deviation (RSD) for Mn to as high as 17% RSD for Zn but averaged ∼ 6.5% RSD for all the elements (n = 10). The proposed method was tested for the determination of Ca, Mg, P, K, Fe, Mn, Zn and B, and the results were in good agreement with those obtained for the corresponding acid digests by ICP-OES, no differences being observed by applying a paired t-test at the 95% confidence level. The reported direct solid sampling method provides a fast alternative to acid digestion that results in similar and appropriate analytical figures of merit with regard to sensitivity, accuracy and precision for plant material analysis. - Highlights: • An evaluation of LA-ICP-OES for the direct analysis of pelleted plant material is reported. • Orange citrus, soy and sugarcane plants were pressed into pellets and sampled directly. • The element menu consisted of Ca, Mg, P, K, Fe, Mn, Zn and B. • LODs for the method ranged from 0.1 mg kg{sup −1} for Zn to 94 mg kg{sup −1} for K. • The precision ranged from 4% RSD for Mn to 17% RSD for Zn (∼ 6.5% RSD average)

  15. Experimental and theoretical studies of picosecond laser interactions with electronic materials-laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Samuel S. [Univ. of California, Berkeley, CA (United States)

    2000-05-01

    Lasers having picosecond and shorter pulse duration are receiving much attention due to their capabilities for direct-write micromachining on many materials with minimal substrate damage. Substantial progress has been made in the understanding of laser ablation processes, particularly the creation of plasmas that often shield the target and reduce the material processing efficiency at nanosecond time scales. However, a considerable challenge that still remains is the understanding of the underlying mechanisms during picosecond laser interactions with electronic solids. In this work we first study picosecond laser-induced electron emission from semiconductor surfaces. A theoretical model was set up based on carrier transport inside the semiconductor material during picosecond laser-semiconductor interactions. We demonstrate that nonequilibrium carrier dynamics plays a significant role for picosecond, as well as short nanosecond, laser induced electron emission from semiconductors. Photoelectric effect is found to be responsible for electron emission at low incident laser fluences, whereas thermionic emission is dominant at higher fluences. We have also performed experimental and theoretical studies on the formation and subsequent evolution of plasmas during laser-metal interactions at the picosecond time scale. Using picosecond time-resolved shadowgrams ahd interferograms, a novel type of plasma is observed, which has an electron density on the order of 1020cm-3.The origin of this picosecond plasma is attributed to gas breakdown, which is caused by laser-induced electron emission fi-om the target surface. After the laser pulse is completed, the longitudinal expansion of the plasma is suppressed. This suppression is found to result from an electric field above the target that prevents, after laser irradiation, fbrther movement of the electrons inside the plasma. Measurements of lateral plasma expansion indicate that the picosecond plasma may absorb

  16. Concrete deck material properties : final report.

    Science.gov (United States)

    2009-01-01

    The two-fold focus of this study was (a) to develop an understanding of the mechanisms responsible for causing : cracking in the concrete; and (b) to study the influence of the local materials on the performance of NYSDOTs HP : concrete mixture. R...

  17. Quantum Materials at the Nanoscale - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Stephen Lance [Univ. of Illinois, Urbana, IL (United States). Dept. of Physics

    2016-01-11

    The central aim of the Quantum Materials at the Nanoscale (QMN) cluster was to understand and control collective behavior involving the interplay of spins, orbitals, and charges, which governs many scientifically interesting and technologically important phenomena in numerous complex materials. Because these phenomena involve various competing interactions, and influence properties on many different length and energy scales in complex materials, tackling this important area of study motivated a collaborative effort that combined the diverse capabilities of QMN cluster experimentalists, the essential theoretical analysis provided by QMN cluster theorists, and the outstanding facilities and staff of the FSMRL. During the funding period 2007-2014, the DOE cluster grant for the Quantum Materials at the Nanoscale (QMN) cluster supported, at various times, 15 different faculty members (14 in Physics and 1 in Materials Science and Engineering), 7 postdoctoral research associates, and 57 physics and materials science PhD students. 41 of these PhD students have since graduated and have gone on to a variety of advanced technical positions at universities, industries, and national labs: 25 obtained postdoctoral positions at universities (14), industrial labs (2 at IBM), DOE national facilities (3 at Argonne National Laboratory, 1 at Brookhaven National Lab, 1 at Lawrence Berkeley National Lab, and 1 at Sandia National Lab), and other federal facilities (2 at NIST); 13 took various industrial positions, including positions at Intel (5), Quantum Design (1), Lasque Industries (1), Amazon (1), Bloomberg (1), and J.P. Morgan (1). Thus, the QMN grant provided the essential support for training a large number of technically advanced personnel who have now entered key national facilities, industries, and institutions. Additionally, during the period 2007-2015, the QMN cluster produced 159 publications (see pages 14-23), including 23 papers published in Physical Review Letters; 16

  18. Simultaneous spatial and temporal focusing of femtosecond pulses: A new paradigm for material processing and tissue ablation

    Science.gov (United States)

    Block, Erica K.

    spatiotemporal control over the intensity distribution at the focus and another degree of freedom in ablation processes. Finally, real-time visualization of the femtosecond machining process is vital for industrial/medical applications, especially in medical where imaging is through scattering materials. At present a secondary imaging laser system is needed in conjunction with the surgical laser. Using complex, off the shelf, refractive optics we have created a real-time, inline (refractive), delivery system that is robust to scattering and integrated within a single machining system. Notably the design decouples the imaging field of view (FOV) and resolution of the cutting beam despite it being the product of a singular system.

  19. Production and characterization of composite material based on ablative phenolic resin and carbon fibers

    International Nuclear Information System (INIS)

    Srebrenkoska, Vineta

    2002-01-01

    The optimisation of technology for production of moulding compound based on short carbon fibers and ablative phenolic resin is carried out. The characterisation of the starting raw materials is performed and moulding compounds With different fiber/matrix ratios and different fiber lengths are prepared. From the different samples, mouldings are produced by thermal compression. All physical, mechanical and thermal properties of the composites are tested. From the obtained results the optimal fiber/matrix ratio, for high temperature moulding compounds production are determined. Also, in order to meet the request for high thermal and mechanics properties of the composite, optimization is carded out on the moulding process itself. The optimization is fulfilled by a planned experiment. The full factorial experimental design is applied in which the following parameters are varied: fiber length, temperature and time of the press cycle. Regression equations for the influence of the parameters to the impact resistance, compression strength, flexural strength and the modulus of elasticity of the molding, are obtained. The obtained mechanical properties of the composite rate this material for potential application in the automotive, leisure, military and other industries.(Author)

  20. Standard Test Method for Obtaining Char Density Profile of Ablative Materials by Machining and Weighing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1996-01-01

    1.1 This test method covers the determination of the char density profile of a charred ablator that can be used with the following limitations: 1.1.1 The local surface imperfections must be removed, and the char must be able to be machined off in a plane parallel to the char-virgin material interface before the density profiles can be determined. 1.1.2 The char must be strong enough to withstand the machining and handling techniques employed. 1.1.3 The material should have orderly density variations. The total thickness of the char and degradation zone must be larger than the machining thicknesses required. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 Exception—Certain inch-pound equivalent units are included in parentheses for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establis...

  1. The kinetics of reaction of the by-products of ablative materials at high temperatures and the rate of heat transfer between hot surfaces and reactive gases

    Science.gov (United States)

    Spokes, G. N.; Beadle, P. C.; Gac, N. A.; Golden, D. M.; King, K. D.; Benson, S. W.

    1971-01-01

    Research has been conducted by means of laboratory experiments to enhance understanding of the fundamental mechanisms of heterogeneous and homogeneous chemical reactions taking place during ablative processes that accompany the reentry or manned space vehicles into planetary atmospheres. Fundamental mechanisms of those chemical reactions believed to be important in the thermal degradation of ablative plastic heat shield materials, and the gases evolved, are described.

  2. Material for Point Design (final summary of DIME material)

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, Paul A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-25

    These slides summarize the motivation of the Defect Induced Mix Experiment (DIME) project, the “point design” of the Polar Direct Drive (PDD) version of the NIF separated reactant capsule, the experimental requirements, technical achievements, and some useful backup material. These slides are intended to provide much basic material in one convenient location and will hopefully be of some use for subsequent experimental projects.

  3. Inorganic polymers and materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sneddon, Larry G.

    2001-01-01

    This DOE-sponsored project was focused on the design, synthesis, characterization, and applications of new types of boron and silicon polymers with a goal of attaining processable precursors to advanced ceramic materials of technological importance. This work demonstrated a viable design strategy for the systematic formation of polymeric precursors to ceramics based on the controlled functionalization of preformed polymers with pendant groups of suitable compositions and crosslinking properties. Both the new dipentylamine-polyborazylene and pinacolborane-hydridopolysilazane polymers, unlike the parent polyborazylene and other polyborosilazanes, are stable as melts and can be easily spun into polymer fibers. Subsequent pyrolyses of these polymer fibers then provide excellent routes to BN and SiNCB ceramic fibers. The ease of synthesis of both polymer systems suggests new hybrid polymers with a range of substituents appended to polyborazylene or polysilazane backbones, as well as other types of preceramic polymers, should now be readily achieved, thereby allowing even greater control over polymer and ceramic properties. This control should now enable the systematic tailoring of the polymers and derived ceramics for use in different technological applications. Other major recent achievements include the development of new types of metal-catalyzed methods needed for the polymerization and modification of inorganic monomers and polymers, and the modification studies of polyvinylsiloxane and related polymers with substituents that enable the formation of single source precursors to high-strength, sintered SiC ceramics.

  4. Final Report for completed IPP Project: Development of Plasma Ablation for Soft Tissue and Bone Surgery

    International Nuclear Information System (INIS)

    Brown, Ian

    2009-01-01

    ArthroCare is a medical device company that develops, manufactures, and markets an advanced surgical tool, a plasma electro-surgical system for cutting and removing tissue. The hand-held electrical discharge device produces plasma in a biocompatible conductive fluid and tissue to which it is applied during surgery. Its products allow surgeons to operate with increased precision and accuracy, limiting damage to surrounding tissue thereby reducing pain and speeding recovery for the patient. In the past, the design of ArthfoCare's plasma wands has been an empirical undertaking. One goal of this R and D program was to put the phenomena involved on a sound scientific footing, allowing optimization of existing plasma based electro-surgery system technology, and the design and manufacture of new and improved kinds of scalpels, in particular for the surgical cutting of bone. Another important related goal of the program was to develop, through an experimental approach, new plasma wand approaches to the cutting ('shaving') of hard bone tissue. The goals of the CRADA were accomplished - computer models were used to predict important parameters of the plasma discharge and the bone environment, and several different approaches to bone-shaving were developed and demonstrated. The primary goal of the project was to develop and demonstrate an atmospheric-pressure plasma tool that is suitable for surgical use for shaving bone in humans. This goal was accomplished, in fact with several different alternative plasma approaches. High bone ablation speeds were measured. The use of probes ('plasma wand' - the surgical tool) with moving active electrodes was also explored, and there are advantages to this method. Another important feature is that the newly-exposed bone surface have only a very thin necrosis layer; this feature was demonstrated. This CRADA has greatly advanced our understanding of bone removal by atmospheric pressure plasmas in liquid, and puts ArthroCare in a good

  5. Flexible, High Char Yield Hybridsil Adhesive Materials for Next Generation Ablative Thermal Protecti, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A Phase II SBIR transition of NanoSonic's HybridSil poly(imide siloxane) ablative adhesive technology will provide a pivotal funding bridge toward its Phase III...

  6. High-Fidelity Modeling of Ablation and Coupled CFD-Material Response

    Data.gov (United States)

    National Aeronautics and Space Administration — This research proposal seeks to improve the state of the art in the modeling and simulation of ablating thermal protection systems (TPS). It will accomplish the...

  7. Investigation of the particle size distribution of the ejected material generated during the single femtosecond laser pulse ablation of aluminium

    International Nuclear Information System (INIS)

    Wu, Han; Zhang, Nan; Zhu, Xiaonong

    2014-01-01

    Highlights: • Single 50 fs laser pulse ablation of an aluminium target in vacuum is investigated in our experiments. • Nanoparticles with large radii of several hundred nanometers are observed. • The nanoparticles are most likely from the mechanical tensile stress relaxation. - Abstract: Single femtosecond laser pulses are employed to ablate an aluminium target in vacuum, and the particle size distribution of the ablated material deposited on a mica substrate is examined with atomic force microscopy (AFM). The recorded AFM images show that these particles have a mean radius of several tens of nanometres. It is also determined that the mean radius of these deposited nanoparticles increases when the laser fluence at the aluminium target increases from 0.44 J/cm 2 to 0.63 J/cm 2 . The mechanism of the laser-induced nanoparticle generation is thought to be photomechanical tensile stress relaxation. Raman spectroscopy measurements confirm that the nanoparticles thus produced have the same structure as the bulk aluminium

  8. Interaction of graphite and ablative materials with CO2-laser, carbon-arc, and xenon-arc radiation. M.S. Thesis - George Washington Univ., Washington, D. C.

    Science.gov (United States)

    Brewer, W. D.

    1975-01-01

    The behavior of graphite and several charring ablators in a variety of high radiative heat flux environments was studied in various radiative environments produced by a CO2 laser and a carbon arc facility. Graphite was also tested in xenon arc radiation. Tests were conducted in air nitrogen, helium, and a mixture of CO2 and nitrogen, simulating the Venus atmosphere. The experimental results are compared with theoretical results obtained with a one dimensional charring ablator analysis and a two dimensional subliming ablator analysis. Photomicroscopy showed no significant differences in appearance or microstructure of the charring ablators or graphite after testing in the three different facilities, indicating that the materials respond fundamentally the same to the radiation of different frequencies. The performance of phenolic nylon and graphite was satisfactorily predicted with existing analyses and published material property data.

  9. Instability growth seeded by ablator material inhomogeneity in indirect drive implosions on the National Ignition Facility

    Science.gov (United States)

    Haan, Steven; Ali, S. J.; Baxamusa, S. H.; Celliers, P. M.; Clark, D. S.; Kritcher, A. L.; Nikroo, A.; Stadermann, M.; Biener, J.; Wallace, R.; Smalyuk, V.; Robey, H.; Weber, C. R.; Huang, H.; Reynolds, H.; Carlson, L.; Rice, N.; Kline, J. L.; Simakov, A. N.; Yi, S. A.

    2017-10-01

    NIF indirect drive ablators (CH, Be, and high density carbon HDC) show hydrodynamic irregularity beyond that expected from surface features. Characterizing these seeds and estimating their growth is important in projecting performance. The resulting modulations can be measured in x-ray backlit implosions on NIF called Hydro Growth Radiography, and on Omega with 2D velocimetry. This presentation summarizes the experiments for the three ablators, along with simulations thereof and projections of the significance for NIF. For CH, dominant seeds are photo-induced oxidation, which might be mitigated with alumina coating. For Be, perturbations result from Ar and O contamination. For HDC, perturbations are seeded by shock propagation around melt, depend on shock strength, and may constrain the adiabat of future HDC implosions. Work performed under the auspices of the U.S. D.O.E. by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  10. Final Report: Imaging of Buried Nanoscale Optically Active Materials

    Energy Technology Data Exchange (ETDEWEB)

    Appelbaum, Ian

    2011-07-05

    This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.

  11. Laser ablation microprobe inductively coupled plasma mass spectrometry study on diffusion of uranium into cement materials

    International Nuclear Information System (INIS)

    Sugiyama, D.; Chida, T.; Cowper, M.

    2008-01-01

    The diffusion of uranium (U(VI)) in solid cement monoliths of ordinary portland cement (OPC) and low-heat portland cement containing 30 wt.% fly ash (FAC) was measured by an in-diffusion technique. Detailed sharp depth profiles of uranium in the solid cement matrices were successively and quantitatively measured using laser ablation microprobe inductively coupled plasma mass spectrometry (LAMP-ICP-MS), and the apparent (D a ) and effective (D e ) diffusion coefficient of uranium in cement matrix were calculated as: D a =∝ 4 x 10 -16 m 2 s -1 and D e =∝ 3 x 10 -11 m 2 s -1 for OPC, and D a =∝ 2 x 10 -17 m 2 s -1 and D e =∝ 6 x 10 -13 m 2 s -1 for FAC. (orig.)

  12. Determination of Physical Properties of Carbon Materials by Results of Ablative Experiments Con-ducted in the Jets of Gas Dynamic Units

    Directory of Open Access Journals (Sweden)

    V. V. Gorsky

    2015-01-01

    Full Text Available The process of hypersonic vehicles’ movement in the dense layers of the atmosphere is accompanied by the considerable combustion of heat shield, which effects on the aerodynamic, mass-inertial and centering characteristics of the product.For correct calculation of model's movement parameters it is necessary:* Using the theoretical and computation methods for determining ablative characteristics of heat-protective materials;* Taking into account all the basic physical and chemical processes, involved in their ablation, using the above mentioned methods;* Testing these techniques in the wide range of experimental data. This physic-mathematical model of carbon materials (CM aerothermochemical destruction is based on using the following:* Arrhenius equations to calculate carbon kinetic oxidation;* Langmuir-Knudsen formula to calculate the velocity of non-equilibrium carbon’s sublimation;* Carbon erosion law represented as a unique dependence of this process velocity on the gas pressure on the wall.Mathematical description of all major processes included in this formulation of the problem, contains a number of "free" parameters that can be determined only on the basis of comparison of theoretical and experimental data according to total ablation characteristics of these materials.This comparison was performed in the article applicable to the tests conditions of modern CM in the stream of electric arc plant and in combustion products of liquid-propellant rocket engines.As the result, the data of kinetic of carbon oxidation by atomic oxygen at sublimation mode of material ablation were obtained for the first time. Carbon erosion law under high pressure was established for the first time.The new approach to processing of ablation experiments is enunciated. Using this approach allows to turn this experiments for CM from comparative tests into the tests to determine ablation properties of thermal protection. Moreover, it enables us also to use the

  13. Significant Volume Expansion as a Precursor to Ablation and Micropattern Formation in Phase Change Material Induced by Intense Terahertz Pulses.

    Science.gov (United States)

    Makino, Kotaro; Kato, Kosaku; Takano, Keisuke; Saito, Yuta; Tominaga, Junji; Nakano, Takashi; Isoyama, Goro; Nakajima, Makoto

    2018-02-13

    With rapid advances occurring in terahertz (THz) radiation generation techniques, the interaction between matter and intense THz fields has become an important research topic. Among different types of THz radiation sources, the free electron laser (FEL) is a promising experimental tool that is expected to pave the way for new forms of material processing, control of phase transitions, and serve as a test bench for extreme operating conditions in high-speed small-size electrical and magnetic devices through the exploitation of strong THz electrical and magnetic fields without the presence of interband electronic excitation. In the current work, we irradiated Ge 2 Sb 2 Te 5 phase change memory material with intense THz pulse trains from an FEL and observed THz-induced surface changes due to damage as a precursor to ablation and the formation of fine surface undulations whose spatial period is comparable to or slightly smaller than the wavelength of the excitation THz pulses in the material. The formation of undulations as well as the fact that no significant thermal effect was observed below the volume expansion threshold suggests that THz-induced effects mainly contributed to the observed changes. To the best of our knowledge, this is the first experimental observation of THz-induced undulations (so-called "LIPSS"), which are of potential importance for laser material processing.

  14. Experimental assessment of the performance of ablative heat shield materials from plasma wind tunnel testing

    Science.gov (United States)

    Löhle, S.; Hermann, T.; Zander, F.

    2017-12-01

    A method for assessing the performance of typical heat shield materials is presented in this paper. Three different material samples, the DLR material uc(Zuram), the Airbus material uc(Asterm) and the carbon preform uc(Calcarb) were tested in the IRS plasma wind tunnel PWK1 at the same nominal condition. State of the art diagnostic tools, i.e., surface temperature with pyrometry and thermography and boundary layer optical emission spectroscopy were completed by photogrammetric surface recession measurements. These data allow the assessment of the net heat flux for each material. The analysis shows that the three materials each have a different effect on heat flux mitigation with ASTERM showing the largest reduction in surface heat flux. The effect of pyrolysis and blowing is clearly observed and the heat flux reduction can be determined from an energy balance.

  15. Phosphate bonded ceramics as candidate final-waste-form materials

    International Nuclear Information System (INIS)

    Singh, D.; Wagh, A.S.; Cunnane, J.; Sutaria, M.; Kurokawa, S.; Mayberry, J.

    1994-04-01

    Room-temperature setting phosphate-bonded ceramics were studied as candidate materials for stabilization of DOE low-level problem mixed wastes which cannot be treated by other established stabilization techniques. Phosphates of Mg, Mg-Na, Al and Zr were studied to stabilize ash surrogate waste containing RCRA metals as nitrates and RCRA organics. We show that for a typical loading of 35 wt.% of the ash waste, the phosphate ceramics pass the TCLP test. The waste forms have high compression strength exceeding ASTM recommendations for final waste forms. Detailed X-ray diffraction studies and differential thermal analyses of the waste forms show evidence of chemical reaction of the waste with phosphoric acid and the host matrix. The SEM studies show evidence of physical bonding. The excellent performance in the leaching tests is attributed to a chemical solidification and physical as well as chemical bonding of ash wastes in these phosphate ceramics

  16. New Materials for Electric Drive Vehicles - Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J. David [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-18

    This project was sponsored by the US DOE Global Initiatives for Proliferation Prevention. The object was for Ukrainian and US partners, including Argonne, AETC, and Dontech to develop special carbon materials and factory production equipment with the goal of making better car batteries to achieve DOE's goals for all-electric and plug-in hybrid electric vehicles. Carbon materials are used in designs for lithium-ion batteries and metal-air batteries, both leading contenders for future electric cars. Specifically, the collaborators planned to use the equipment derived from this project to develop a rechargeable battery system that will use the carbon materials produced by the innovative factory process equipment. The final outcome of the project was that the Ukrainian participants consisting of the Kharkov Institute of Physics and Technology (KIPT), the Institute of Gas of National Academy of Sciences of Ukraine and the Materials Research Center, Ltd. designed, built, tested and delivered 14 pieces of processing equipment for pilot scale carbon production lines at the AETC, Arlington Heights facilities. The pilot scale equipment will be used to process materials such as activated carbon, thermally expanded graphite and carbon coated nano-particles. The equipment was shipped from Ukraine to the United States and received by AETC on December 3, 2013. The equipment is on loan from Argonne, control # 6140. Plug-in hybrid electric vehicles (PHEV) and all-electric vehicles have already demostrated success in the U.S. as they begin to share the market with older hybrid electric designs. When the project was conceived, PHEV battery systems provided a ~40 mile driving range (2011 figures). DOE R&D targets increased this to >100 miles at reduced cost less than $250/kWh (2011 figures.) A 2016 Tesla model S has boasted 270 miles. The project object was to develop pilot-production line equipment for advanced hybrid battery system that achieves cycle life of 1000, an energy

  17. Towards the Industrial Application of Spark Ablation for Nanostructured Functional Materials

    NARCIS (Netherlands)

    Pfeiffer, T.V.

    2014-01-01

    Nanostructuring of functional materials is an essential part in the design of energy related devices – but the industrial tools we have to make these materials are lacking. This dissertation explores the green, flexible, and scalable spark discharge process for the fabrication of complex

  18. On-line double isotope dilution laser ablation inductively coupled plasma mass spectrometry for the quantitative analysis of solid materials.

    Science.gov (United States)

    Fernández, Beatriz; Rodríguez-González, Pablo; García Alonso, J Ignacio; Malherbe, Julien; García-Fonseca, Sergio; Pereiro, Rosario; Sanz-Medel, Alfredo

    2014-12-03

    We report on the determination of trace elements in solid samples by the combination of on-line double isotope dilution and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The proposed method requires the sequential analysis of the sample and a certified natural abundance standard by on-line IDMS using the same isotopically-enriched spike solution. In this way, the mass fraction of the analyte in the sample can be directly referred to the certified standard so the previous characterization of the spike solution is not required. To validate the procedure, Sr, Rb and Pb were determined in certified reference materials with different matrices, including silicate glasses (SRM 610, 612 and 614) and powdered samples (PACS-2, SRM 2710a, SRM 1944, SRM 2702 and SRM 2780). The analysis of powdered samples was carried out both by the preparation of pressed pellets and by lithium borate fusion. Experimental results for the analysis of powdered samples were in agreement with the certified values for all materials. Relative standard deviations in the range of 6-21% for pressed pellets and 3-21% for fused solids were obtained from n=3 independent measurements. Minimal sample preparation, data treatment and consumption of the isotopically-enriched isotopes are the main advantages of the method over previously reported approaches. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Materials, Strands, and Cables for Superconducting Accelerator Magnets. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sumption, Mike D. [Ohio State University, Columbia, OH (United States); Collings, Edward W. [Ohio State University, Columbia, OH (United States)

    2014-09-19

    This report focuses on Materials, Strands and Cables for High Energy Physics Particle accelerators. In the materials area, work has included studies of basic reactions, diffusion, transformations, and phase assemblage of Nb3Sn. These materials science aspects have been married to results, in the form of flux pinning, Bc2, Birr, and transport Jc, with an emphasis on obtaining the needed Jc for HEP needs. Attention has also been paid to the “intermediate-temperature superconductor”, magnesium diboride emphasis being placed on (i) irreversibility field enhancement, (ii) critical current density and flux pinning, and (iii) connectivity. We also report on studies of Bi-2212. The second area of the program has been in the area of “Strands” in which, aside from the materials aspect of the conductor, its physical properties and their influence on performance have been studied. Much of this work has been in the area of magnetization estimation and flux jump calculation and control. One of the areas of this work was strand instabilities in high-performance Nb3Sn conductors due to combined fields and currents. Additionally, we investigated quench and thermal propagation in YBCO coated conductors at low temperatures and high fields. The last section, “Cables”, focussed on interstrand contact resistance, ICR, it origins, control, and implications. Following on from earlier work in NbTi, the present work in Nb3Sn has aimed to make ICR intermediate between the two extremes of too little contact (no current sharing) and too much (large and unacceptable magnetization and associated beam de-focussing). Interstrand contact and current sharing measurements are being made on YBCO based Roebel cables using transport current methods. Finally, quench was investigated for YBCO cables and the magnets wound from them, presently with a focus on 50 T solenoids for muon collider applications.

  20. Characterization of nuclear materials by laser ablation ICP(SF)MS for nuclear forensic purposes

    International Nuclear Information System (INIS)

    Stefanka, Z.; Katona, R.; Varga, Z.

    2009-01-01

    Full text: The task of the categorization and characterization of nuclear materials of unknown origin has been delegated to the Institute of Isotopes of the Hungarian Academy of Sciences in 1996 by a governmental decree. Since the investigated materials are forensic evidences special attention was paid for minimizing the required sample amount. Therefore LA-ICP(SF)MS has been developed and also applied for the determination of isotopic composition, production date and the concentration of trace impurities. The LA-ICP(SF)MS methods were validated by inter-laboratory comparisons and were applied for analysis of uranium oxide pellets seized in Hungary. (author)

  1. State surveillance of radioactive material transportation. Final report

    International Nuclear Information System (INIS)

    Salomon, S.N.

    1984-02-01

    The main objective of this final report on the state surveillance of the transportation of radioactive material (RAM) is to suggest the most cost-effective inspection areas where enforcement actions might be taken by the states during their participation in the State Hazardous Materials Enforcement Development (SHMED) Program. On the basis of the lessons learned from the surveillance program, these actions are enforcement at low-level radioactive burial sites by means of civil penalties and site use suspension; enforcement at airports and at terminals that forward freight; and enforcement of courier companies. More effective and efficient enforcement can be achieved through instrumented police patrol cars and remote surveillance because they require the least amount of time of enforcement personnel. In addition, there is a strong relationship between effective emergency response and enforcement because the appropriate shipping papers, placarding and knowledge of appropriate emergency response procedures lead to improved emergency response. These lessons originate from a ten-state surveillance program from 1977 through 1981 jointly sponsored by the US Nuclear Regulatory Commission (NRC) and DOT. The states give recommendations in the categories of education, training, expanded surveillance, coordination and enforcement. The topics of special interest covered include low-level radioactive waste disposal sites, airports, cargo terminals, highways, ports, and accidents and incidents. The three most common problems in compliance with RAM transportation regulations reported by the states are incorrect package labeling; improper shipping papers; and incorrect or missing placards. Other common problems reported by the states are summarized. The relationship to other studies, the status of the SHMED Program, a synopsis of state RAM surveillance reports, and NRC/DOT expenditures are given

  2. 10 CFR 51.97 - Final environmental impact statement-materials license.

    Science.gov (United States)

    2010-01-01

    .... 10168 (a), (c)) a final environmental impact statement for the construction of a monitored retrievable... 10 Energy 2 2010-01-01 2010-01-01 false Final environmental impact statement-materials license. 51...-Regulations Implementing Section 102(2) Final Environmental Impact Statements-Materials Licenses § 51.97 Final...

  3. Seven-wavelength pyrometer for determining surface temperature of ablation materials

    Science.gov (United States)

    Yi, H.

    1985-01-01

    Results which were achieved by a seven-wavelength pyrometer last year are reported in this paper. These studies are directed toward the development of a method for determining the real surface temperature of thermal protection materials and for evaluating its emittance under varieties of reentry environment. A description of the data processing method and apparatus is also included.

  4. Laser ablation of the lysozyme protein: a model system for soft materials

    DEFF Research Database (Denmark)

    Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin

    Lysozyme is a well-known protein which is used in food processing and is also an important constituent of human secretions such as sweat and saliva. It has a well-defined mass (14307 u) and can easily be detected by mass spectrometric methods such as MALDI (Matrix-assisted laser desorption...... ionization) in contrast to many other organic materials. Also the thermal properties, including the heat-induced decomposition behavior are comparatively well-known. For laser-irradiation at wavelengths above 310 nm, no photochemical processes occur initially, but the material is ejected via photothermal...... is expected in MAPLE, but is surprising in PLD, where a high degree of thermal fragmentation is typically required for generation of a sufficient amount of volatile decomposition products that drive the transfer of molecules to the film substrate. The experimental results will be discussed based...

  5. Laser ablation of the lysozyme protein: a model system for soft materials

    OpenAIRE

    Schou, Jørgen; Matei, Andreea; Constantinescu, Catalin; Canulescu, Stela; Dinescu, Maria; Tabetah, Marshall; Zhigilei, Leonid; Amoruso, Salvatore; Wang, Xuan

    2011-01-01

    Lysozyme is a well-known protein which is used in food processing and is also an important constituent of human secretions such as sweat and saliva. It has a well-defined mass (14307 u) and can easily be detected by mass spectrometric methods such as MALDI (Matrix-assisted laser desorption ionization) in contrast to many other organic materials. Also the thermal properties, including the heat-induced decomposition behavior are comparatively well-known. For laser-irradiation at wavelengths abo...

  6. Final Report for completed IPP Project:"Development of Plasma Ablation for Soft Tissue and Bone Surgery"

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Ian

    2009-09-01

    ArthroCare is a medical device company that develops, manufactures, and markets an advanced surgical tool, a plasma electro-surgical system for cutting and removing tissue. The hand-held electrical discharge device produces plasma in a biocompatible conductive fluid and tissue to which it is applied during surgery. Its products allow surgeons to operate with increased precision and accuracy, limiting damage to surrounding tissue thereby reducing pain and speeding recovery for the patient. In the past, the design of ArthfoCare's plasma wands has been an empirical undertaking. One goal of this R&D program was to put the phenomena involved on a sound scientific footing, allowing optimization of existing plasma based electro-surgery system technology, and the design and manufacture of new and improved kinds of scalpels, in particular for the surgical cutting of bone. Another important related goal of the program was to develop, through an experimental approach, new plasma wand approaches to the cutting ('shaving') of hard bone tissue. The goals of the CRADA were accomplished - computer models were used to predict important parameters of the plasma discharge and the bone environment, and several different approaches to bone-shaving were developed and demonstrated. The primary goal of the project was to develop and demonstrate an atmospheric-pressure plasma tool that is suitable for surgical use for shaving bone in humans. This goal was accomplished, in fact with several different alternative plasma approaches. High bone ablation speeds were measured. The use of probes ('plasma wand' - the surgical tool) with moving active electrodes was also explored, and there are advantages to this method. Another important feature is that the newly-exposed bone surface have only a very thin necrosis layer; this feature was demonstrated. This CRADA has greatly advanced our understanding of bone removal by atmospheric pressure plasmas in liquid, and puts Arthro

  7. Electroceramic functional gradient materials. Final report 1995 - 1998

    Energy Technology Data Exchange (ETDEWEB)

    Toft Soerensen, O. [ed.

    1999-10-01

    In this programme the research and development is focused on electroceramic materials, which are of direct interest for the Danish producers of electronic components (AMP Danmark) and ceramic gas sensors (PBI-Dansensor) as well as companies involved in development of fuel cells (Haldor Topsoee). The R and D work has been focused on strategic materials research, both application oriented and more basic research, and on development of new techniques for fabrication of EFGM (Electroceramic Functional Gradient Materials) of three types: LC circuit materials (electronic noise filters), oxides for electrochemical reactors and solid oxide fuel cell applications (SOFC) and materials (semiconductors, oxygen ion conductors) for oxygen sensors. This work has been carried out in five projects: 1) Integrated filter components; 2) Electrochemical reactor materials; 3) Oxygen sensors based on semiconductors and oxygen ion conductors; 4) Interface models - synthesis and characterisation; 5) Suppression of cracking in multilayered ceramic materials. (EHS)

  8. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Effect of nonlinear light scattering in air on ablation of materials produced by femtosecond laser pulses

    Science.gov (United States)

    Klimentov, Sergei M.; Kononenko, Taras V.; Pivovarov, Pavel A.; Konov, Vitalii I.; Prokhorov, A. M.; Breitling, D.; Dausinger, F.

    2002-05-01

    Nonlinear light scattering appearing upon air breakdown induced by high-power ultrashort pulses (110 — 5200 fs) from a Ti:Al2O3 laser is studied. As a result of forward scattering, the beam profile is severely deformed, which is accompanied by spectral conversion of the incident radiation to a series of shorter-wavelength peaks extending into the visible spectral range. Measurements are made of the thresholds and the scattered radiation energy, which amounts to 75% of the incident energy. The effect of scattering on the material ablation in air is investigated. The obtained data offer an explanation for the experimentally observed paradoxical morphology of the channels ablated by high-power femtosecond pulses.

  9. Organic materials for second harmonic generation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Twieg, R.J. (comp.)

    1985-03-31

    Materials were chosen by screening the Cambridge Crystallographic Index for new noncentrosymmetric crystalline compounds, by screening commercially available materials or by synthesis of unique new substances. Measurements were then made on the powder form of these materials. Langmuir-Blodgett films were deposited and studied. In addition to the above studies, a computer program was developed to calculate (hyper) polarizabilities of organic molecules and thus aid in the selection of materials for testing. The nonlinear molecules have been divided into three classes according to absorption cutoff: 400 to 500 nm, 300 to 400 nm, and 200 to 300 nm. 108 refs., 7 tabs. (WRF)

  10. Organic materials for second harmonic generation. Final report

    International Nuclear Information System (INIS)

    Twieg, R.J.

    1985-01-01

    Materials were chosen by screening the Cambridge Crystallographic Index for new noncentrosymmetric crystalline compounds, by screening commercially available materials or by synthesis of unique new substances. Measurements were then made on the powder form of these materials. Langmuir-Blodgett films were deposited and studied. In addition to the above studies, a computer program was developed to calculate (hyper) polarizabilities of organic molecules and thus aid in the selection of materials for testing. The nonlinear molecules have been divided into three classes according to absorption cutoff: 400 to 500 nm, 300 to 400 nm, and 200 to 300 nm. 108 refs., 7 tabs

  11. Thin film growing by the laser ablation technique: possibilities for growing of dosimetric materials; Crecimiento de capas delgadas por la tecnica de ablacion laser: posibilidades para crecimiento de materiales dosimetricos

    Energy Technology Data Exchange (ETDEWEB)

    Rojas R, E.M.; Melo M, M.; Enriquez Z, E.; Fernandez G, M.; Haro P, E.; Hernandez P, J.L. [UAM-I, Laboratorio de Optica Cuantica, 09340 Mexico D.F. (Mexico)

    2005-07-01

    In this talk we will present the basics about the laser ablation technique and how it is used for thin film growing, either as a single film or a stack of thin films, as well as some methods to characterize in real time the film thickness. Finally, we will discuss the possibilities of using laser ablation for growing thin films with applications to dosimetry. (Author)

  12. Final report for Assembling Microorganisms into Energy Converting Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Ozgur

    2018-03-26

    The goal of this project was to integrate microorganisms capable of reversible energy transduction in response to changing relative humidity with non-biological materials to create hybrid energy conversion systems. While plants and many other biological organisms have developed structures that are extraordinarily effective in converting changes in relative humidity into mechanical energy, engineered energy transduction systems rarely take advantage of this powerful phenomenon. Rather than developing synthetic materials that can convert changes in relative humidity in to mechanical energy, we developed approaches to assemble bacterial spores into larger materials. These materials can convert energy from evaporation of water in dry atmospheric conditions, which we demonstrated by building energy harvesters from these materials. We have also developed experiments to investigate the interaction of water with the spore material, and to determine how this interaction imposes limits on energy conversion. In addition, we carried out theoretical calculations to investigate the limits imposed by the environmental conditions to the power available in the energy harvesting process. These calculations took into account heat and water vapor transfer in the atmosphere surrounding the spore based materials. Overall, our results suggest that biomolecular materials are promising candidates to convert energy from evaporation.

  13. Laser ablation particle beam glow discharge time of flight mass spectrometry for the analysis of halogenated polymers and inorganic solid material

    Science.gov (United States)

    Fliegel, Daniel; Günther, Detlef

    2009-05-01

    A laser ablation particle beam pulsed glow discharge mass spectrometer (LA-PB-GD-TOFMS) was designed and used for fundamental studies. The instrument consists of a three stage aerodynamic lens system, a hollow cathode pulsed glow discharge and a time-of-flight mass spectrometer. The particle beam interface was constructed to provide an efficient particle transfer into the hollow cathode. Calculations showed that particles between 1 and 3000 nm in diameter are able to pass through this interface. Glass and metal (SRM NIST610 and CRM JK37) ablated by laser ablation and introduced into a pulsed, He glow discharge showed no ionization, even for major elements such as 27Al +, 28Si +, 23Na + or 56Fe +. This can be explained by the low gas temperature of a pulsed glow discharge which is not sufficient to vaporize particles with high melting and vaporization points. In contrast, ablated particles of soft materials such as PTFE or PVC polymers were vaporized and ionized in a pulsed glow discharge. Ion signals for elements such as carbon ( 12C +), hydrogen ( 1H 3+), fluorine ( 19F +) and chlorine ( 35/37Cl +) were detected when generating an aerosol by laser ablation and introduced into the hollow cathode. Furthermore, various fragments such as 12C x1H v19F y+ and 12C x1H v35/37Cl y+ were identified and provide a "fingerprint" of the ablated polymer. The influence of the laser fluence and glow discharge voltage was investigated with respect to the ratio of fragments to elemental ion signals. The decrease in laser energy leads to an increase of the 12C +/ 12C 19F x+ ratio. Lowering the glow discharge plasma power favors the appearance of fragments such as 12C 19F x+ whereas higher plasma power favors the ion signals of the elements, such as 12C + and 19F +. A set of experiments comparing different PVC polymers with increasing PVC content was evaluated with respect to the 12C +/ 35Cl + ratio. A correlation between the ratio and the concentration of the PVC in the sample was

  14. IFE Liquid Wall Response to the Prompt X-Ray Energy Deposition: Investigation of Physical Processes and Assessment of Ablated Material

    International Nuclear Information System (INIS)

    Zaghloul, Mofreh R.; Raffray, A. Rene

    2005-01-01

    This paper considers the physical processes and material removal mechanisms associated with the energy deposition in an inertial fusion energy liquid wall from the prompt X-ray spectrum of an indirect-drive inertial fusion target. These are important as the ablated material could generate aerosol in the chamber, which without adequate chamber clearing could result in a chamber environment unsuitable for driver propagation and/or target injection. Simple computations were used to identify and characterize the important material removal mechanisms relevant to the energy deposition regime under consideration. Explosive boiling was found to be the most relevant thermal response mechanism due to the high heating rate from the X-ray photon energy deposition. Investigation showed that explosive boiling occurs when the material temperature approaches the critical temperature and has a threshold value that can be derived from the material equation of state or the rate of homogeneous nucleation. Another important mechanism is mechanical spall that can result when shock wave-induced local tensile stresses exceed the spall strength of the material. Both explosive boiling and mechanical spall occur upon crossing the thermodynamic stability border (spinodal curve) either through rapid heating or through overexpansion of the material.Relevant material properties of the candidate liquid wall materials needed to perform the present assessment are compiled, derived, and presented. A simple energy deposition volumetric analysis is used to estimate both thermally ablated and mechanically spalled regions of the liquid wall material. The choice of liquid/wall combination is found to play an important role in reducing or eliminating the occurrence of spall in the liquid wall

  15. Numerical analysis of laser ablation using the axisymmetric two-temperature model

    Science.gov (United States)

    Dziatkiewicz, Jolanta; Majchrzak, Ewa

    2018-01-01

    Laser ablation of the axisymmetric micro-domain is analyzed. To describe the thermal processes occurring in the micro-domain the two-temperature hyperbolic model supplemented by the boundary and initial conditions is used. This model takes into account the phase changes of material (solid-liquid and liquid-vapour) and the ablation process. At the stage of numerical computations the finite difference method with staggered grid is used. In the final part the results of computations are shown.

  16. Materials Technology Support for Radioisotope Power Systems Final Report

    International Nuclear Information System (INIS)

    Kramer, Daniel P.; Barklay, Chadwick D.

    2008-01-01

    Over the period of this sponsored research, UDRI performed a number of materials related tasks that helped to facilitate increased understanding of the properties and applications of a number of candidate program related materials including; effects of neutron irradiation on tantalum alloys using a 500kW reactor, thermodynamic based modeling of the chemical species in weld pools, and the application of candidate coatings for increased oxidation resistance of FWPF (Fine Weave Pierced Fabric) modules

  17. Fabrication of SiOx Ultra-Fine Nanoparticles by IR nanosecond laser ablation as anode materials for lithium ion battery

    Science.gov (United States)

    Qiang, Wei; Huanhuan, Huang; Jian, Wang; Zhurui, Shen

    2017-11-01

    Silicon based materials have been suggested as promising alternative anode materials for their high higher theoretical capacity and lower working potential. As a novel method of preparing ultrafine oxide nanoparticles, laser ablation method provides an important way for the preparation of anode materials for lithium ion batteries. When a silicon chip was irradiated by a flat-top high energy infrared laser, large yellow ultrafine SiOx nanoparticles with high oxygen content were produced at the edge of the ablation area due to the strong heat interaction. The resulting sample had a Si: O atom ratio of 1: 1.3. The results suggested that the ultrafine nanoparticles were composed of two phases: SiO1.35 and SiO0.93. When the synthesized SiOx ultrafine nanoparticles were utilized as anode material for lithium batteries (LIBs), the specific capacity of the electrode gradually increased at a current density of 0.2 A g-1, and delivered a maximum of 438 mA h g-1 at the 451th cycle before it stabilized. In the following cycles, there was only sight degradation for specific capacity, and the specific capacity of the electrode was maintained at 344 mA h g-1 after 800 cycles.

  18. Superhard nanophase cutter materials for rock drilling applications; FINAL

    International Nuclear Information System (INIS)

    Voronov, O.; Tompa, G.; Sadangi, R.; Kear, B.; Wilson, C.; Yan, P.

    2000-01-01

    The Low Pressure-High Temperature (LPHT) System has been developed for sintering of nanophase cutter and anvil materials. Microstructured and nanostructured cutters were sintered and studied for rock drilling applications. The WC/Co anvils were sintered and used for development of High Pressure-High Temperature (HPHT) Systems. Binderless diamond and superhard nanophase cutter materials were manufactured with help of HPHT Systems. The diamond materials were studied for rock machining and drilling applications. Binderless Polycrystalline Diamonds (BPCD) have high thermal stability and can be used in geothermal drilling of hard rock formations. Nanophase Polycrystalline Diamonds (NPCD) are under study in precision machining of optical lenses. Triphasic Diamond/Carbide/Metal Composites (TDCC) will be commercialized in drilling and machining applications

  19. Multiyear Program Plan for the High Temperature Materials Laboratory; FINAL

    International Nuclear Information System (INIS)

    Arvid E. Pasto

    2000-01-01

    Recently, the U.S. Department of Energy's (DOE) Office of Heavy Vehicle Technologies (OHVT) prepared a Technology Roadmap describing the challenges facing development of higher fuel efficiency, less polluting sport utility vehicles, vans, and commercial trucks. Based on this roadmap, a multiyear program plan (MYPP) was also developed, in which approaches to solving the numerous challenges are enumerated. Additional planning has been performed by DOE and national laboratory staff, on approaches to solving the numerous challenges faced by heavy vehicle system improvements. Workshops and planning documents have been developed concerning advanced aerodynamics, frictional and other parasitic losses, and thermal management. Similarly, the Heavy Vehicle Propulsion Materials Program has developed its own multiyear program plan. The High Temperature Materials Laboratory, a major user facility sponsored by OHVT, has now developed its program plan, described herein. Information was gathered via participation in the development of OHVT's overall Technology Roadmap and MYPP, through personal contacts within the materials-user community, and from attendance at conferences and expositions. Major materials issues for the heavy vehicle industry currently center on trying to increase efficiency of (diesel) engines while at the same time reducing emissions (particularly NO(sub x) and particulates). These requirements dictate the use of increasingly stronger, higher-temperature capable and more corrosion-resistant materials of construction, as well as advanced catalysts, particulate traps, and other pollution-control devices. Exhaust gas recirculation (EGR) is a technique which will certainly be applied to diesel engines in the near future, and its use represents a formidable challenge, as will be described later. Energy-efficient, low cost materials processing methods and surface treatments to improve wear, fracture, and corrosion resistance are also required

  20. Materials Degradation and Detection (MD2): Deep Dive Final Report

    Energy Technology Data Exchange (ETDEWEB)

    McCloy, John S.; Montgomery, Robert O.; Ramuhalli, Pradeep; Meyer, Ryan M.; Hu, Shenyang Y.; Li, Yulan; Henager, Charles H.; Johnson, Bradley R.

    2013-02-01

    An effort is underway at Pacific Northwest National Laboratory (PNNL) to develop a fundamental and general framework to foster the science and technology needed to support real-time monitoring of early degradation in materials used in the production of nuclear power. The development of such a capability would represent a timely solution to the mounting issues operators face with materials degradation in nuclear power plants. The envisioned framework consists of three primary and interconnected “thrust” areas including 1) microstructural science, 2) behavior assessment, and 3) monitoring and predictive capabilities. A brief state-of-the-art assessment for each of these core technology areas is discussed in the paper.

  1. Relationships between fracture toughness and other material properties. Final report

    International Nuclear Information System (INIS)

    Perra, M.; Finnie, I.

    1974-01-01

    The key experimental and analytical studies which have led to our present understanding of the mechanisms of ductile fracture are reviewed. It is concluded that insufficient progress has been made in the quantitative description of ductile separation mechanisms on a microscale to allow the realistic prediction of fracture toughness from material properties and microstructure. An experimental study of ductile fracture is underway which has the aim of determining the growth rate of voids in known plastic deformation fields as a function of triaxiality of stress and material work-hardening. Novel specimens of particularly well characterized microstructure are utilized

  2. Source book of educational materials for radiation therapy. Final report

    International Nuclear Information System (INIS)

    Pijar, M.L.

    1979-08-01

    The Source Book is a listing of educational materials in radiation therapy technology. The first 17 sections correspond to the subjects identified in the ASRT Curriculum Guide for schools of radiation therapy. Each section is divided into publications and in some sections audiovisuals and training aids. Entries are listed without endorsement

  3. Trace elements in landfill calcite: a comparison of solution & laser ablation ICP-MS and calibration to different standard material (SRM NIST glass and USGS MACS carbonate)

    Czech Academy of Sciences Publication Activity Database

    Strnad, L.; Ettler, V.; Mihaljevič, M.; Hladil, Jindřich

    2008-01-01

    Roč. 9, - (2008), s. 235-236 ISSN 1885-7264. [Reunión de la Sociedad Española de Mineralogía /28./ ; Reunión de la Sociedad Española de Arcillas /21./. Zaragoza, 16.09.2008-19.09.2008] R&D Projects: GA AV ČR IAA300130702 Institutional research plan: CEZ:AV0Z30130516 Keywords : trace elements * reference material * carbonate * ICP-MS * laser ablation Subject RIV: DB - Geology ; Mineralogy http://www.ehu.es/sem/macla_pdf/macla9/macla9_235.pdf

  4. Hydrogen film cooling of a small hydrogen-oxygen thrust chamber and its effect on erosion rates of various ablative materials

    Science.gov (United States)

    Hannum, N.; Roberts, W. E.; Russell, L. M.

    1977-01-01

    An experimental investigation was conducted to determine what arrangement of film-coolant-injection orifices should be used to decrease the erosion rates of small, high temperature, high pressure ablative thrust chambers without incurring a large penalty in combustion performance. All of the film cooling was supplied through holes in a ring between the outer row of injector elements and the chamber wall. The best arrangement, which had twice the number of holes as there were outer row injection elements, was also the simplest. The performance penalties, presented as a reduction in characteristic exhaust velocity efficiency, were 0.8 and 2.8 percentage points for the 10 and 20 percent cooling flows, respectively, The best film-coolant injector was then used to obtain erosion rates for 19 ablative materials. The throat erosion rate was reduced by a factor of 2.5 with a 10 percent coolant flow. Only the more expensive silica phenolic materials had low enough erosion rates to be considered for use in the nozzle throat. However, some of the cheaper materials might qualify for use in other areas of small nozzles with large throat diameters where the higher erosion rates are more acceptable.

  5. Power Laser Ablation Symposia

    CERN Document Server

    Phipps, Claude

    2007-01-01

    Laser ablation describes the interaction of intense optical fields with matter, in which atoms are selectively driven off by thermal or nonthermal mechanisms. The field of laser ablation physics is advancing so rapidly that its principal results are seen only in specialized journals and conferences. This is the first book that combines the most recent results in this rapidly advancing field with authoritative treatment of laser ablation and its applications, including the physics of high-power laser-matter interaction. Many practical applications exist, ranging from inertial confinement fusion to propulsion of aerostats for pollution monitoring to laser ignition of hypersonic engines to laser cleaning nanoscale contaminants in high-volume computer hard drive manufacture to direct observation of the electronic or dissociative states in atoms and molecules, to studying the properties of materials during 200kbar shocks developed in 200fs. Selecting topics which are representative of such a broad field is difficu...

  6. Spectral absorption studies of visible materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bass, M.; Swimm, R.T.

    1986-01-01

    Results of studies of optical absorption in twelve thin-film optical coatings at 482 nm wavelength, surface and bulk absorption in sapphire throughout the visible and near IR, and initial measurements in KDP are described. Laser calorimetry was carried out at room temperature, using an unfocused laser beam at normal incidence. All thin-film absorption data yielded values of P/sub abs//P/sub inc/ in the range 3 x 10 U to 3 x 10 T at a wavelength of 482 nm. Sapphire absorption showed Urbach-tail behavior at 350 nm to 1300 nm. The range of absorption, being far lower than usual, extends the range of application of Urbach's rule. Finally, KDP measurements were attempted, but surface degradation due to the hydroscopic nature of the samples resulted in excessive light scatter.

  7. Fissile material disposition program final immobilization form assessment and recommendation

    International Nuclear Information System (INIS)

    Cochran, S.G.; Dunlop, W.H.; Edmunds, T.A.; MacLean, L.M.; Gould, T.H.

    1997-01-01

    Lawrence Livermore National Laboratory (LLNL), in its role as the lead laboratory for the development of plutonium immobilization technologies for the Department of Energy's Office of Fissile Materials Disposition (MD), has been requested by MD to recommend an immobilization technology for the disposition of surplus weapons- usable plutonium. The recommendation and supporting documentation was requested to be provided by September 1, 1997. This report addresses the choice between glass and ceramic technologies for immobilizing plutonium using the can-in-canister approach. Its purpose is to provide a comparative evaluation of the two candidate technologies and to recommend a form based on technical considerations

  8. Engineered Materials for Cesium and Strontium Storage. Final Technical Report

    International Nuclear Information System (INIS)

    McDeavitt, Sean M.

    2010-01-01

    Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at Purdue

  9. Engineered Materials for Cesium and Strontium Storage Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Sean M. McDeavitt

    2010-04-14

    Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at

  10. Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

    International Nuclear Information System (INIS)

    Jiao, Zhujie; Was, Gary; Bartels, David

    2015-01-01

    This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

  11. Irradiation-Accelerated Corrosion of Reactor Core Materials. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhujie [Univ. of Michigan, Ann Arbor, MI (United States); Was, Gary [Univ. of Michigan, Ann Arbor, MI (United States); Bartels, David [Univ. of Notre Dame, IN (United States)

    2015-04-02

    This project aims to understand how radiation accelerates corrosion of reactor core materials. The combination of high temperature, chemically aggressive coolants, a high radiation flux and mechanical stress poses a major challenge for the life extension of current light water reactors, as well as the success of most all GenIV concepts. Of these four drivers, the combination of radiation and corrosion places the most severe demands on materials, for which an understanding of the fundamental science is simply absent. Only a few experiments have been conducted to understand how corrosion occurs under irradiation, yet the limited data indicates that the effect is large; irradiation causes order of magnitude increases in corrosion rates. Without a firm understanding of the mechanisms by which radiation and corrosion interact in film formation, growth, breakdown and repair, the extension of the current LWR fleet beyond 60 years and the success of advanced nuclear energy systems are questionable. The proposed work will address the process of irradiation-accelerated corrosion that is important to all current and advanced reactor designs, but remains very poorly understood. An improved understanding of the role of irradiation in the corrosion process will provide the community with the tools to develop predictive models for in-reactor corrosion, and to address specific, important forms of corrosion such as irradiation assisted stress corrosion cracking.

  12. Development of chemical vapor composites, CVC materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-10-05

    Industry has a critical need for high-temperature operable ceramic composites that are strong, non-brittle, light weight, and corrosion resistant. Improvements in energy efficiency, reduced emissions and increased productivity can be achieved in many industrial processes with ceramic composites if the reaction temperature and pressure are increased. Ceramic composites offer the potential to meet these material requirements in a variety of industrial applications. However, their use is often restricted by high cost. The Chemical Vapor composite, CVC, process can reduce the high costs and multiple fabrication steps presently required for ceramic fabrication. CVC deposition has the potential to eliminate many difficult processing problems and greatly increase fabrication rates for composites. With CVC, the manufacturing process can control the composites` density, microstructure and composition during growth. The CVC process: can grow or deposit material 100 times faster than conventional techniques; does not require an expensive woven preform to infiltrate; can use high modulus fibers that cannot be woven into a preform; can deposit composites to tolerances of less than 0.025 mm on one surface without further machining.

  13. Final Report: Nanoscale Dynamical Heterogeneity in Complex Magnetic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Kevan, Stephen [Univ. of Oregon, Eugene, OR (United States)

    2016-05-27

    A magnetic object can be demagnetized by dropping it on a hard surface, but what does ‘demagnetized’ actually mean? In 1919 Heinrich Barkhausen proved the existence of magnetic domains, which are regions of uniform magnetization that are much larger than atoms but much smaller than a macroscopic object. A material is fully magnetized when domain magnetizations are aligned, while it is demagnetized when the domain magnetizations are randomly oriented and the net magnetization is zero. The heterogeneity of a demagnetized object leads to interesting questions. Magnets are unstable when their poles align, and stable when their poles anti-align, so why is the magnetized state ever stable? What do domains look like? What is the structure of a domain wall? How does the magnetized state transform to the demagnetized state? How do domains appear and disappear? What are the statistical properties of domains and how do these vary as the domain pattern evolves? Some of these questions remain the focus of intense study nearly a century after Barkhausen’s discovery. For example, just a few years ago a new kind of magnetic texture called a skyrmion was discovered. A skyrmion is a magnetic domain that is a nanometer-scale, topologically protected vortex. ‘Topologically protected’ means that skyrmions are hard to destroy and so are stable for extended periods. Skyrmions are characterized by integral quantum numbers and are observed to move with little dissipation and so could store and process information with very low power input. Our research project uses soft x-rays, which offer very high magnetic contrast, to probe magnetic heterogeneity and to measure how it evolves in time under external influences. We will condition a soft x-ray beam so that the wave fronts will be coherent, that is, they will be smooth and well-defined. When coherent soft x-ray beam interacts with a magnetic material, the magnetic heterogeneity is imprinted onto the wave fronts and projected into

  14. Provisional material considerations: creating a blueprint of the final restorations.

    Science.gov (United States)

    Helvey, Gregg A

    2014-01-01

    Indirect restorative dentistry generally requires temporization of prepared teeth during the laboratory fabrication phase. Over the years, the physical properties of newer provisional materials have improved, which has enabled an expansion of the function of provisional restorations. Better strength, surface finish, and color match have increased their acceptability by patients and clinicians. In some clinical situations provisional restorations can provide information that is critical to the overall success of a case. Such information allows the clinician to verify and confirm with the patient the esthetics, phonetics, and function of the proposed anterior restorative treatment. The provisional restorations can also provide valuable information to the laboratory technician regarding design, contour, length, shade, and even correct articulation of the master model. The success of the definitive restoration is dependent on the accurate transfer of this information to the laboratory technician.

  15. Radiation effects on organic materials in nuclear plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, M B; Davis, M V

    1981-11-01

    A literature search was conducted to identify information useful in determining the lowest level at which radiation causes damage to nuclear plant equipment. Information was sought concerning synergistic effects of radiation and other environmental stresses. Organic polymers are often identified as the weak elements in equipment. Data on radiation effects are summarized for 50 generic name plastics and 16 elastomers. Coatings, lubricants, and adhesives are treated as separate groups. Inorganics and metallics are considered briefly. With a few noted exceptions, these are more radiation resistant than organic materials. Some semiconductor devices and electronic assemblies are extremely sensitive to radiation. Any damage threshold including these would be too low to be of practical value. With that exception, equipment exposed to less than 10/sup 4/ rads should not be significantly affected. Equipment containing no Teflon should not be significantly affected by 10/sup 5/ rads. Data concerning synergistic effects and radiation sensitization are discussed. The authors suggest correlations between the two effects.

  16. Radiation effects on organic materials in nuclear plants. Final report

    International Nuclear Information System (INIS)

    Bruce, M.B.; Davis, M.V.

    1981-11-01

    A literature search was conducted to identify information useful in determining the lowest level at which radiation causes damage to nuclear plant equipment. Information was sought concerning synergistic effects of radiation and other environmental stresses. Organic polymers are often identified as the weak elements in equipment. Data on radiation effects are summarized for 50 generic name plastics and 16 elastomers. Coatings, lubricants, and adhesives are treated as separate groups. Inorganics and metallics are considered briefly. With a few noted exceptions, these are more radiation resistant than organic materials. Some semiconductor devices and electronic assemblies are extremely sensitive to radiation. Any damage threshold including these would be too low to be of practical value. With that exception, equipment exposed to less than 10 4 rads should not be significantly affected. Equipment containing no Teflon should not be significantly affected by 10 5 rads. Data concerning synergistic effects and radiation sensitization are discussed. The authors suggest correlations between the two effects

  17. Safeguards systems concepts for nuclear material transportation. Final report

    International Nuclear Information System (INIS)

    Baldonado, O.C.; Kevany, M.; Rodney, D.; Pitts, D.; Mazur, M.

    1977-09-01

    The report describes the development of system concepts for the safeguarding of special strategic nuclear materials (SNM) against malevolent adversary action during the interfacility transport of the SNM. The methodology used includes techniques for defining, classifying, and analyzing adversary action sequences; defining safeguards system components; assessing the vulnerability of various safeguards systems and their component parts to the potential adversary action sequences, and conceptualizing system design requirements. The method of analysis is based primarily on a comparison of adversary actions with safeguards measures, to estimate vulnerability. Because of the paucity of the data available for assessing vulnerability, the Delphi approach was used to generate data: values were estimated in a structured exercise by a panel of experts in the safeguards and terrorist fields. It is concluded that the probability of successful attack against a truck/escort convoy manned by well-trained, well-armed personnel is low enough to discourage all but the strongest adversaries. Secrecy of operations and careful screening of personnel are very important. No reliance should be placed on current capabilities of local law enforcement agencies. The recommendation of the study is the use of road transport in the near future and air transport at a later time when the number of shipments reaches a level to justify it, and when present safety problems are resolved

  18. 77 FR 23713 - Pesticides; Final Guidance on Material Safety Data Sheets as Pesticide Labeling; Request for...

    Science.gov (United States)

    2012-04-20

    ... AGENCY Pesticides; Final Guidance on Material Safety Data Sheets as Pesticide Labeling; Request for... ``Pesticide Registration (PR) Notice 2012-1: Material Safety Data Sheets as Pesticide Labeling.'' This PR..., and Rodenticide Act (FIFRA), and the Material Safety Data Sheet (MSDS, also referred to as Safety Data...

  19. Laboratory Simulations of Micrometeoroid Ablation

    Science.gov (United States)

    Thomas, Evan Williamson

    Each day, several tons of meteoric material enters Earth's atmosphere, the majority of which consist of small dust particles (micrometeoroids) that completely ablate at high altitudes. The dust input has been suggested to play a role in a variety of phenomena including: layers of metal atoms and ions, nucleation of noctilucent clouds, effects on stratospheric aerosols and ozone chemistry, and the fertilization of the ocean with bio-available iron. Furthermore, a correct understanding of the dust input to the Earth provides constraints on inner solar system dust models. Various methods are used to measure the dust input to the Earth including satellite detectors, radar, lidar, rocket-borne detectors, ice core and deep-sea sediment analysis. However, the best way to interpret each of these measurements is uncertain, which leads to large uncertainties in the total dust input. To better understand the ablation process, and thereby reduce uncertainties in micrometeoroid ablation measurements, a facility has been developed to simulate the ablation of micrometeoroids in laboratory conditions. An electrostatic dust accelerator is used to accelerate iron particles to relevant meteoric velocities (10-70 km/s). The particles are then introduced into a chamber pressurized with a target gas, and they partially or completely ablate over a short distance. An array of diagnostics then measure, with timing and spatial resolution, the charge and light that is generated in the ablation process. In this thesis, we present results from the newly developed ablation facility. The ionization coefficient, an important parameter for interpreting meteor radar measurements, is measured for various target gases. Furthermore, experimental ablation measurements are compared to predictions from commonly used ablation models. In light of these measurements, implications to the broader context of meteor ablation are discussed.

  20. Revisions to the Clean Water Act Regulatory Definition of Discharge of Dredged Material; Final Rule

    Science.gov (United States)

    The U.S. Army Corps of Engineers (Corps) and the Environmental Protection Agency (EPA) promulgated a final rule Amending a Clean Water Act (CWA) section 404 regulation that defines the term discharge of dredged material.

  1. 36 CFR 1206.86 - What additional materials must I submit with the final narrative report?

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false What additional materials must I submit with the final narrative report? 1206.86 Section 1206.86 Parks, Forests, and Public... narrative report? You must submit the materials determined by the Commission as found in the NHPRC grant...

  2. Colloids and composite materials Au/Pvp and Ag/Pvp generated by laser ablation in polymeric liquid environment

    Energy Technology Data Exchange (ETDEWEB)

    Larez, J.; Rojas, C. [Universidad Central de Venezuela, Faculty of Science, Center of Experimental Solid State Physics, Paseo Los Ilustres, Los Chaguaramos, Apdo. Postal 20513, Caracas 1020-A (Venezuela, Bolivarian Republic of); Castell, R., E-mail: jlarez@fisica.ciens.ucv.ve [Universidad Simon Bolivar, Department of Physics, Plasma and Laser Spectroscopy Laboratory, Valle de Sartenejas, Baruta, Apdo. Postal 89000, Caracas 1080-A (Venezuela, Bolivarian Republic of)

    2016-11-01

    Pulsed laser ablation of silver and gold targets, immersed in a polymeric solution of Polyvinylpyrrolidone (Pvp), is used to generate colloids and composite metal-polymer. Solutions of Pvp in deionized water at different concentrations are employed. Two Pvp number average molecular weights were considered, 10000 g/mol and 55000 g/mol. The high purity targets are irradiated between 20 min and 40 min with the third harmonic (Thg) (λ = 335 nm) of a Nd:YAG laser operating at a rate of 10 Hz with pulses of 8 ns. Optical spectroscopy in UV and vis regions, scanning electron microscopy, high resolution scanning electron microscopy and X-ray are used to identify and determine the shape and size of the produced particles. Very stable sub-micrometric spherical particles for Au/Pvp and Ag/Pvp samples are obtained with diameters of 0.72 μm and 0.40 μm, respectively. The preparation of colloids is performed in one step and no surfactant or dispersing agent is used in this process. (Author)

  3. Characterization of a 50kW Inductively Coupled Plasma Torch for Testing of Ablative Thermal Protection Materials

    Science.gov (United States)

    Greene, Benton R.; Clemens, Noel T.; Varghese, Philip L.; Bouslog, Stanley A.; Del Papa, Steven V.

    2017-01-01

    With the development of new manned spaceflight capabilities including NASA's Orion capsule and the Space-X Dragon capsule, there is a renewed importance of understanding the dynamics of ablative thermal protection systems. To this end, a new inductively coupled plasma torch facility is being developed at UT-Austin. The torch operates on argon and/or air at plasma powers up to 50 kW. In the present configuration the flow issues from a low-speed subsonic nozzle and the hot plume is characterized using slug calorimetry and emission spectroscopy. Preliminary measurements using emission spectroscopy have indicated that the torch is capable of producing an air plasma with a temperature between 6,000 K and 8,000 K depending on the power and flow settings and an argon plasma with a temperature of approximately 12,000 K. The operation envelope was measured, and heat flux measured for every point within the envelope using both a slug calorimeter and a Gardon gauge heat flux sensor. The torch was found to induce a stagnation point heat flux of between 90 and 225 W/sq cm.

  4. Attachment and proliferation of human osteoblast-like cells (MG-63) on laser-ablated titanium implant material.

    Science.gov (United States)

    Györgyey, Ágnes; Ungvári, Krisztina; Kecskeméti, Gabriella; Kopniczky, Judit; Hopp, Béla; Oszkó, Albert; Pelsöczi, István; Rakonczay, Zoltán; Nagy, Katalin; Turzó, Kinga

    2013-10-01

    Demand is increasing for shortening the long (3-6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm(2), FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm(2), 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti(3+)) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly. © 2013.

  5. Advanced 3D Characterization and Reconstruction of Reactor Materials FY16 Final Report

    International Nuclear Information System (INIS)

    Fromm, Bradley; Hauch, Benjamin; Sridharan, Kumar

    2016-01-01

    A coordinated effort to link advanced materials characterization methods and computational modeling approaches is critical to future success for understanding and predicting the behavior of reactor materials that operate at extreme conditions. The difficulty and expense of working with nuclear materials have inhibited the use of modern characterization techniques on this class of materials. Likewise, mesoscale simulation efforts have been impeded due to insufficient experimental data necessary for initialization and validation of the computer models. The objective of this research is to develop methods to integrate advanced materials characterization techniques developed for reactor materials with state-of-the-art mesoscale modeling and simulation tools. Research to develop broad-ion beam sample preparation, high-resolution electron backscatter diffraction, and digital microstructure reconstruction techniques; and methods for integration of these techniques into mesoscale modeling tools are detailed. Results for both irradiated and un-irradiated reactor materials are presented for FY14 - FY16 and final remarks are provided.

  6. Advanced 3D Characterization and Reconstruction of Reactor Materials FY16 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Fromm, Bradley [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hauch, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sridharan, Kumar [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    A coordinated effort to link advanced materials characterization methods and computational modeling approaches is critical to future success for understanding and predicting the behavior of reactor materials that operate at extreme conditions. The difficulty and expense of working with nuclear materials have inhibited the use of modern characterization techniques on this class of materials. Likewise, mesoscale simulation efforts have been impeded due to insufficient experimental data necessary for initialization and validation of the computer models. The objective of this research is to develop methods to integrate advanced materials characterization techniques developed for reactor materials with state-of-the-art mesoscale modeling and simulation tools. Research to develop broad-ion beam sample preparation, high-resolution electron backscatter diffraction, and digital microstructure reconstruction techniques; and methods for integration of these techniques into mesoscale modeling tools are detailed. Results for both irradiated and un-irradiated reactor materials are presented for FY14 - FY16 and final remarks are provided.

  7. Attachment and proliferation of human osteoblast-like cells (MG-63) on laser-ablated titanium implant material

    International Nuclear Information System (INIS)

    Györgyey, Ágnes; Ungvári, Krisztina; Kecskeméti, Gabriella; Kopniczky, Judit; Hopp, Béla; Oszkó, Albert; Pelsöczi, István; Rakonczay, Zoltán; Nagy, Katalin; Turzó, Kinga

    2013-01-01

    Demand is increasing for shortening the long (3–6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm 2 , FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm 2 , 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO 2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti 3+ ) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly. - Highlights: • CP4 titanium implant surfaces were modified with Nd:YAG and KrF excimer laser. • SEM and AFM revealed significant changes in morphology and roughness. • XPS confirmed the presence of TiO 2 on each sample; after Nd:YAG treatment a reduced state of Ti (Ti 3+ ) was found. • Cell proliferation experiments detected an increased number of MG-63 cells between the 24 h and 72 h observations. • Laser treatments neither disturbed, nor enhanced MG-63 cell attachment and proliferation significantly

  8. Design finalization and material qualification towards procurement of the ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Ioki, K., E-mail: Kimihiro.Ioki@iter.org [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France); Barabash, V.; Bachmann, C.; Chappuis, P.; Choi, C.H.; Cordier, J-J.; Giraud, B.; Gribov, Y. [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France); Heitzenroeder, Ph. [PPPL MS41, Princeton University, PO Box 451, Princeton, NJ 08543 (United States); Her, N.; Johnson, G. [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France); Jones, L. [F4E, c/Josep Pla, n.2, Torres Diagonal Litoral, Edificio B3, E-08019, Barcelona (Spain); Jun, C. [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France); Kim, B.C. [NFRI, 52 Yeoeundong Yuseonggu, Daejeon 305-333 (Korea, Republic of); Kuzmin, E. [NTC ' Sintez' , Efremov Inst., 189631 Metallostroy, St. Petersburg (Russian Federation); Loesser, D. [PPPL MS41, Princeton University, PO Box 451, Princeton, NJ 08543 (United States); Martin, A.; Merola, M. [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France); Pathak, H. [IPR, Near Indira Bridge, Bhat, Gandhinagar 382 428 (India); Readman, P. [ITER Organization, CS 90 046, 13067 St. Paul-lez-Durance CEDEX (France)

    2011-10-01

    Procurement arrangements for ITER key components including the vacuum vessel (VV) have been signed and the ITER activities are now fully devoted towards construction. Final design reviews have been carried out for the main vessel and ports. One of the design review topics is the selection of materials, material procurement, and assessment of material performance during operation. The width of the inner shell splice plates was increased from 120 mm to 160 mm to minimize risk during the assembly of the Thermal shields and the VV. Instead of facet shaping, 3D shaping was introduced for the outboard inner shell. The material qualification procedures have been started for VV structural materials such as 316L(N) IG for licensing as a nuclear pressure equipment component. In accordance with the regulatory requirements and quality requirements for operation, common material specifications have been prepared in collaboration with the domestic agencies.

  9. New Ablation-Resistant Material Candidate for Hypersonic Applications: Synthesis, Composition, and Oxidation Resistance of HfIr3-Based Solid Solution.

    Science.gov (United States)

    Lozanov, Victor V; Baklanova, Natalya I; Bulina, Natalia V; Titov, Anatoly T

    2018-04-18

    The peculiarities of the solid-state interaction in the HfC-Ir system have been studied within the 1000-1600 °C temperature range using a set of modern analytical techniques. It was stated that the interaction of HfC with iridium becomes noticeable at temperatures as low as 1000-1100 °C and results in the formation of HfIr 3 -based substitutional solid solution. The homogeneity range of the HfIr 3± x phase was evaluated and refined as HfIr 2.43 -HfIr 3.36 . The durability of the HfIr 3 -based system under extreme environmental conditions was studied. It was shown that the HfIr 3 -based material displays excellent ablation resistance under extreme environmental conditions. The benefits of the new designed material result from its relative oxygen impermeability and special microstructure similar to superalloys. The results obtained in this work allow us to consider HfIr 3 as a very promising candidate for extreme applications.

  10. Attachment and proliferation of human osteoblast-like cells (MG-63) on laser-ablated titanium implant material

    Energy Technology Data Exchange (ETDEWEB)

    Györgyey, Ágnes; Ungvári, Krisztina [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Kecskeméti, Gabriella; Kopniczky, Judit [Department of Optics and Quantum Electronics, Faculty of Science and Informatics, University of Szeged, H-6720 Szeged (Hungary); Hopp, Béla [Research Group on Laser Physics, Hungarian Academy of Sciences and University of Szeged, H-6720 Szeged (Hungary); Oszkó, Albert [Department of Physical Chemistry and Materials Science, Faculty of Science and Informatics, University of Szeged, H-6720 Szeged (Hungary); Pelsöczi, István; Rakonczay, Zoltán [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Nagy, Katalin [Department of Oral Surgery, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary); Turzó, Kinga, E-mail: kturzo@yahoo.com [Department of Oral Biology and Experimental Dental Research, Faculty of Dentistry, University of Szeged, H-6720 Szeged (Hungary)

    2013-10-15

    Demand is increasing for shortening the long (3–6 months) osseointegration period to rehabilitate patients' damaged chewing apparatus in as short a time as possible. For dental implants, as for biomaterials in general, the bio- and osseointegration processes can be controlled at molecular and cellular levels by modification of the implant surface. One of the most promising of such surface modifications is laser ablation, as demonstrated by our previous results [46]. Commercially pure (CP4) sand-blasted, acid-etched titanium disks (Denti® System Ltd., Hungary) were irradiated with a KrF excimer laser (248 nm, fluence 0.4 J/cm{sup 2}, FWHM 18 ns, 2000 pulses), or with a Nd:YAG laser (532 nm, 1.3 J/cm{sup 2}, 10 ns, 200 pulses) then examined by SEM, AFM, and XPS. In vitro attachment (24 h) and proliferation (72 h) of MG-63 osteoblast cells were investigated via dimethylthiazol-diphenyl tetrazolium bromide (MTT), alamarBlue (AB) assays alkaline phosphatase quantification (ALP) and SEM. SEM and AFM revealed significant changes in morphology and roughness. XPS confirmed the presence of TiO{sub 2} on each sample; after Nd:YAG treatment a reduced state of Ti (Ti{sup 3+}) was also observed. MTT, AB and ALP measurements detected an increase in the number of cells between the 24- and 72 hour observations; however, laser treatment did not affect cell attachment and proliferation significantly. - Highlights: • CP4 titanium implant surfaces were modified with Nd:YAG and KrF excimer laser. • SEM and AFM revealed significant changes in morphology and roughness. • XPS confirmed the presence of TiO{sub 2} on each sample; after Nd:YAG treatment a reduced state of Ti (Ti{sup 3+}) was found. • Cell proliferation experiments detected an increased number of MG-63 cells between the 24 h and 72 h observations. • Laser treatments neither disturbed, nor enhanced MG-63 cell attachment and proliferation significantly.

  11. Metamaterials as a Platform for the Development of Novel Materials for Energy Applications. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, Willie [Boston College, Chestnut Hill, MA (United States)

    2016-02-11

    Final report detailing the work performed on DESC0005240 at Boston College. Report details research into metamaterial absorber theory, thermophotovoltaics a dynamic 3 state material capable of switching between transmissive, reflective, and absorptive states. Also high temperature NIR metamaterials are explored.

  12. Fusion Bead Procedure for Nuclear Forensics Employing Synthetic Enstatite to Dissolve Uraniferous and Other Challenging Materials Prior to Laser Ablation Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Reading, David G; Croudace, Ian W; Warwick, Phillip E

    2017-06-06

    There is an increasing demand for rapid and effective analytical tools to support nuclear forensic investigations of seized or suspect materials. Some methods are simply adapted from other scientific disciplines and can effectively be used to rapidly prepare complex materials for subsequent analysis. A novel sample fusion method is developed, tested, and validated to produce homogeneous, flux-free glass beads of geochemical reference materials (GRMs), uranium ores, and uranium ore concentrates (UOC) prior to the analysis of 14 rare earth elements (REE) via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The novelty of the procedure is the production of glass beads using 9 parts high purity synthetic enstatite (MgSiO 3 ) as the glass former with 1 part of sample (sample mass ∼1.5 mg). The beads are rapidly prepared (∼10 min overall time) by fusing the blended mixture on an iridium strip resistance heater in an argon-purged chamber. Many elements can be measured in the glass bead, but the rare earth group in particular is a valuable series in nuclear forensic studies and is well-determined using LA-ICP-MS. The REE data obtained from the GRMs, presented as chondrite normalized patterns, are in very good agreement with consensus patterns. The UOCs have comparable patterns to solution ICP-MS methods and published data. The attractions of the current development are its conservation of sample, speed of preparation, and suitability for microbeam analysis, all of which are favorable for nuclear forensics practitioners and geochemists requiring REE patterns from scarce or valuable samples.

  13. A Self-Limiting Electro-Ablation Technique for the Top-Down Synthesis of Large-Area Monolayer Flakes of 2D Materials

    Energy Technology Data Exchange (ETDEWEB)

    Das, Saptarshi; Bera, Mrinal K.; Tong, Sheng; Narayanan, Badri; Kamath, Ganesh; Mane, Anil; Paulikas, Arvydas P.; Antonio, Mark R.; Sankaranarayanan, Subramanian K. R. S.; Roelofs, Andreas K.

    2016-06-21

    We report the discovery of an electrochemical process that converts two dimensional layered materials of arbitrary thicknesses into monolayers. The lateral dimensions of the monolayers obtained by the process within a few seconds time at room temperature were as large as 0.5 mm. The temporal and spatial dynamics of this physical phenomenon, studied on MoS2 flakes using ex-situ AFM imaging, Raman mapping, and photoluminescence measurements trace the origin of monolayer formation to a substrate-assisted self-limiting electrochemical ablation process. Electronic structure and atomistic calculations point to the interplay between three essential factors in the process: (1) strong covalent interaction of monolayer MoS2 with the substrate; (2) electric-field induced differences in Gibbs free energy of exfoliation; (3) dispersion of MoS2 in aqueous solution of hydrogen peroxide. This process was successful in obtaining monolayers of other 2D transition metal dichalcogenides, like WS2 and MoTe2 as well.

  14. A new binder-free and conductive-additive-free TiO2/WO3-W integrative anode material produced by laser ablation

    Science.gov (United States)

    Su, Yibo; Zhang, Hongjun; Liang, Peng; Liu, Kai; Cai, Mingyong; Huang, Zeya; Wang, Chang-An; Zhong, Minlin

    2018-02-01

    Although transition metal oxides anodes have attracted lots of attention, there are still many problems to be resolved. Complicated fabrication process, high cost and poor electrochemical performances are the most important ones, together hindering transition metal oxides anodes for practical use. Herein, we provide a new approach to fabricate a binder-free and conductive-additive-free TiO2/WO3-W integrative anode material through the nanosecond laser ablation and dip-coating technology, which simplifies the entire anode preparation process with no need for a conventional tape-casting procedure. Using this method, great time cost, machine cost and labor cost related to mixing and tape-casting process can be saved on the basis of good electrochemical performances. The prepared TiO2/WO3-W integrative anode realizes a first Coulombic efficiency of 75.6% and attains to a stable capacity within the first five cycles. It can still maintain a capacity of 600 mAh g-1 in the range of 0.01-3 V vs. Li+/Li at a current rate of 0.2 C after 500 cycles. This work offers a new way to achieve a fast fabrication of the integrative anode for lithium ion battery, which is universal for other transition metals (such as Fe, Cu, Ni, Co, Mo, W etc.).

  15. UV solid state laser ablation of intraocular lenses

    Science.gov (United States)

    Apostolopoulos, A.; Lagiou, D. P.; Evangelatos, Ch.; Spyratou, E.; Bacharis, C.; Makropoulou, M.; Serafetinides, A. A.

    2013-06-01

    Commercially available intraocular lenses (IOLs) are manufactured from silicone and acrylic, both rigid (e.g. PMMA) and foldable (hydrophobic or hydrophilic acrylic biomaterials), behaving different mechanical and optical properties. Recently, the use of apodizing technology to design new diffractive-refractive multifocals improved the refractive outcome of these intraocular lenses, providing good distant and near vision. There is also a major ongoing effort to refine laser refractive surgery to correct other defects besides conventional refractive errors. Using phakic IOLs to treat high myopia potentially provides better predictability and optical quality than corneal-based refractive surgery. The aim of this work was to investigate the effect of laser ablation on IOL surface shaping, by drilling circular arrays of holes, with a homemade motorized rotation stage, and scattered holes on the polymer surface. In material science, the most popular lasers used for polymer machining are the UV lasers, and, therefore, we tried in this work the 3rd and the 5th harmonic of a Q-switched Nd:YAG laser (λ=355 nm and λ=213 nm respectively). The morphology of the ablated IOL surface was examined with a scanning electron microscope (SEM, Fei - Innova Nanoscope) at various laser parameters. Quantitative measurements were performed with a contact profilometer (Dektak-150), in which a mechanical stylus scanned across the surface of gold-coated IOLs (after SEM imaging) to measure variations in surface height and, finally, the ablation rates were also mathematically simulated for depicting the possible laser ablation mechanism(s). The experimental results and the theoretical modelling of UV laser interaction with polymeric IOLs are discussed in relation with the physical (optical, mechanical and thermal) properties of the material, in addition to laser radiation parameters (laser energy fluence, number of pulses). The qualitative aspects of laser ablation at λ=213 nm reveal a

  16. Shock-Driven Hydrodynamic Instability Growth Near Phase Boundaries and Material Property Transitions: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peralta, Pedro [Arizona State Univ., Tempe, AZ (United States); Fortin, Elizabeth [Arizona State Univ., Tempe, AZ (United States); Opie, Saul [Arizona State Univ., Tempe, AZ (United States); Gautam, Sudrishti [Arizona State Univ., Tempe, AZ (United States); Gopalakrishnan, Ashish [Arizona State Univ., Tempe, AZ (United States); Lynch, Jenna [Arizona State Univ., Tempe, AZ (United States); Chen, Yan [Arizona State Univ., Tempe, AZ (United States); Loomis, Eric [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-01

    Activities for this grant included: 1) Development of dynamic impact experiments to probe strength and phase transition influence on dynamic deformation, 2) development of modern strength and phase aware simulation capabilities, 3) and post-processing of experimental data with simulation and closed form analytical techniques. Two different dynamic experiments were developed to probe material strengths in solid metals (largely copper and iron in this effort). In the first experiment a flyer plate impacts a flat target with an opposite rippled surface that is partially supported by a weaker window material. Post mortem analysis of the target sample showed a strong and repeatable residual plastic deformation dependence on grain orientation. Yield strengths for strain rates near 105 s-1 and plastic strains near ~50% were estimated to be around 180 to 240 MPa, varying in this range with grain orientation. Unfortunately dynamic real-time measurements were difficult with this setup due to diagnostic laser scattering; hence, an additional experimental setup was developed to complement these results. In the second set of experiments a rippled surface was ablated by a controlled laser pulsed, which launched a rippled shock front to an opposite initially flat diagnostic surface that was monitored in real-time with spatially resolved velocimetry techniques, e.g., line VISAR in addition to Transient Imaging Displacement Interferometry (TIDI) displacement measurements. This setup limited the displacements at the diagnostic surface to a reasonable level for TIDI measurements (~ less than one micrometer). These experiments coupled with analytical and numerical solutions provided evidence that viscous and elastic deviatoric strength affect shock front perturbation evolution in clearly different ways. Particularly, normalized shock front perturbation amplitudes evolve with viscosity (η) and perturbation wavelength (λ) as η/λ, such that increasing viscosity

  17. Flexible Ablators

    Science.gov (United States)

    Stackpoole, Margaret M. (Inventor); Ghandehari, Ehson M. (Inventor); Thornton, Jeremy J. (Inventor); Covington, Melmoth Alan (Inventor)

    2017-01-01

    A low-density article comprising a flexible substrate and a pyrolizable material impregnated therein, methods of preparing, and devices using the article are disclosed. The pyrolizable material pyrolizes above 350 C and does not flow at temperatures below the pyrolysis temperature. The low-density article remains flexible after impregnation and continues to remain flexible when the pyrolizable material is fully pyrolized.

  18. Ablative Ceramic Foam Based TPS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel composite material ablative TPS for planetary vehicles that can survive a dual heating exposure is proposed. NextGen's TPS concept is a bi-layer functional...

  19. Study of materials for use in final deposits of radioactive waste

    International Nuclear Information System (INIS)

    Amaral, Andre F.; Tello, Cledola C.O.

    2011-01-01

    Clays are used in repositories (final deposits of radioactive waste) due to their radionuclide sorption and soil waterproofing capacities. The objectives of this work are to research and develop tests of characterization relevant to the use of clays in repositories, to characterize national clays and to assemble a database with information on the suppliers and the tests that were done. Results are shown for the mineral identification test, for the determination of the normal Proctor compaction curve, size distribution, cationic exchange capacity, specific surface, and others, for two materials. Such information will allow the selection of the best among these materials for use in the backfill and in other applications, besides indicating the most reliable test for estimating characteristics of different materials. (author)

  20. Laser ablation synthesis of monodispersed magnetic alloy nanoparticles

    International Nuclear Information System (INIS)

    Seto, Takafumi; Koga, Kenji; Akinaga, Hiroyuki; Takano, Fumiyoshi; Orii, Takaaki; Hirasawa, Makoto

    2006-01-01

    Monodispersed CoPt alloy nanoparticles were synthesized by a pulsed laser ablation (PLA) technique coupled with a low-pressure operating differential mobility analyzer (LP-DMA). The CoPt alloy nanoparticles were generated by laser ablating a solid Co-Pt target. In CoPt alloy nanoparticles synthesized from a target with a Co composition of 75 at%, the nanoparticle surfaces were covered by an oxide layer and exhibited a core-shell structure. In contrast, no shell was observed in particles generated from a target with a Co:Pt ratio of 50:50 at%. According to an EDX analysis, the compositions of the individual nanoparticles were almost the same as that of the target material. Finally, the magnetic hysteresis loops of the CoPt alloy nanoparticles exhibited ferromagnetism

  1. Study of hydrological and geochemical data on materials for the final cover of subsurface storage sites

    International Nuclear Information System (INIS)

    Sauter, M.M.; Barres, M.; Faby, J.

    1987-01-01

    The European Research program includes studies on highly watertight materials likely to sait the final cover of low-level and intermediate-level waste disposal. The experimental equipment is composed of a 26 sq. m collector placed on an inclined plane, just below the material to be tested and connected by means of a gutter with a measuring room where the infiltration waters flow rate is steadily measured. On the surface of the tumulus, a 300 sq.m inclined plane permits the measure of the running off water. The recording raingauge completes the device. Water vapour pressures are measured at different depths within the material. Total watercontents are registered along vertical profils using a special neutron logging tool. Numerous physico-chemical measures are carried out on the infiltration and running off waters: pH, Eh, temperature, dissolved oxygen, conductivity, turbidity and major anions and cations. Two materials have been tested with this device: - weathered schists; Compacted clay. The first material showed that, on average over the six months period of measurements, the overall rainfall brokedown into 11% running waters, 13% infiltration and 76% evaporation because infiltration accounts for a large part of rainfall. It resulted in a complete saturation of the material during certain periods of the year. Humidity measurements performed at different places pointed out large heterogeneities inside the material. It is worth noting that, despite some problems due to calibration, the whole instrumentation located in the measuring room worked rather well and permitted to demonstate the bad qualities of the material. The second material was subsequently covered by a 20 cm thick layer made of a mixture of sand in order to regularize water infiltration under the soil vegetation constituted by a special grass growing

  2. The 2016-2018 National Plan of Management of Radioactive Materials and Wastes. Final report

    International Nuclear Information System (INIS)

    2017-01-01

    A first document contains the final version of the French National Plan of Management of Radioactive Materials and Wastes (PNGMDR) for the period 2016-2018: principles and objectives (presentation of radioactive materials and wastes, principles to be taken into account to define pathways of management of radioactive wastes, legal and institutional framework, information transparency), the management of radioactive materials (context and challenges, management pathways, works on fast breeder reactors of fourth generation), assessment and perspectives of existing pathways of management of radioactive wastes (management of historical situations, management of residues of mining and sterile processing, management of waste with a high natural radioactivity, management of very short life waste, of very low activity wastes, and low and medium activity wastes), needs and perspectives regarding management processes to be implemented for the different types of radioactive wastes. Appendices to this document contain: a recall of the content of previous PNGMDR since 2007, a synthesis of realisations and researches performed abroad, research orientations for the concerned period, and international agreement on spent fuel and radioactive waste management. A second document, released by the ASN, proposes an environmental and strategic assessment of the plan. A third one and a fourth one contain the opinion of the Environmental Authority on the plan preliminary focus and the answer to the Environmental Authority by the ASN. Finally, a synthesis of the remarks made by the public about the PNGMDR and the answers to these remarks conclude the document

  3. Femtosecond laser ablation of dentin

    Science.gov (United States)

    Alves, S.; Oliveira, V.; Vilar, R.

    2012-06-01

    The surface morphology, structure and composition of human dentin treated with a femtosecond infrared laser (pulse duration 500 fs, wavelength 1030 nm, fluences ranging from 1 to 3 J cm-2) was studied by scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The average dentin ablation threshold under these conditions was 0.6 ± 0.2 J cm-2 and the ablation rate achieved in the range 1 to 2 µm/pulse for an average fluence of 3 J cm-2. The ablation surfaces present an irregular and rugged appearance, with no significant traces of melting, deformation, cracking or carbonization. The smear layer was entirely removed by the laser treatment. For fluences only slightly higher than the ablation threshold the morphology of the laser-treated surfaces was very similar to the dentin fracture surfaces and the dentinal tubules remained open. For higher fluences, the surface was more porous and the dentin structure was partially concealed by ablation debris and a few resolidified droplets. Independently on the laser processing parameters and laser processing method used no sub-superficial cracking was observed. The dentin constitution and chemical composition was not significantly modified by the laser treatment in the processing parameter range used. In particular, the organic matter is not preferentially removed from the surface and no traces of high temperature phosphates, such as the β-tricalcium phosphate, were observed. The achieved results are compatible with an electrostatic ablation mechanism. In conclusion, the high beam quality and short pulse duration of the ultrafast laser used should allow the accurate preparation of cavities, with negligible damage of the underlying material.

  4. Femtosecond laser ablation of dentin

    International Nuclear Information System (INIS)

    Alves, S; Vilar, R; Oliveira, V

    2012-01-01

    The surface morphology, structure and composition of human dentin treated with a femtosecond infrared laser (pulse duration 500 fs, wavelength 1030 nm, fluences ranging from 1 to 3 J cm -2 ) was studied by scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The average dentin ablation threshold under these conditions was 0.6 ± 0.2 J cm -2 and the ablation rate achieved in the range 1 to 2 µm/pulse for an average fluence of 3 J cm -2 . The ablation surfaces present an irregular and rugged appearance, with no significant traces of melting, deformation, cracking or carbonization. The smear layer was entirely removed by the laser treatment. For fluences only slightly higher than the ablation threshold the morphology of the laser-treated surfaces was very similar to the dentin fracture surfaces and the dentinal tubules remained open. For higher fluences, the surface was more porous and the dentin structure was partially concealed by ablation debris and a few resolidified droplets. Independently on the laser processing parameters and laser processing method used no sub-superficial cracking was observed. The dentin constitution and chemical composition was not significantly modified by the laser treatment in the processing parameter range used. In particular, the organic matter is not preferentially removed from the surface and no traces of high temperature phosphates, such as the β-tricalcium phosphate, were observed. The achieved results are compatible with an electrostatic ablation mechanism. In conclusion, the high beam quality and short pulse duration of the ultrafast laser used should allow the accurate preparation of cavities, with negligible damage of the underlying material. (paper)

  5. Joint research project AkoF. Optimization of the process chain ''ablation of contaminated surfaces'' under the aspect of ablation rate maximization. Final report

    International Nuclear Information System (INIS)

    Hentschel, Sebastian; Gentes, Sascha; Bussmann, Andrea; Boersch, Fabian; Feil, Hartmut

    2014-01-01

    In order to minimize contaminated secondary waste, the decommissioning of nuclear facilities involves the efficient decontamination of concrete walls and floors. For example, the German NPP Wuergassen and NPP Obrigheim require ceiling, wall, pillar, and floor decontamination of up to 140.000 m 2 and estimated several 10.000 m 2 , respectively. In a first step, the surfaces are manually selected, subdivided, and measured for their decontamination. These results are manually recorded and analysed. The appropriate decontamination method will be selected based on these values from a number of available techniques. The state of the art still involves conventional approaches, e.g. chiselling, pinning, or grinding techniques. These procedures are considerably staff-intensive and time-consuming. The surfaces will be re-measured after decontamination. Possibly, remaining surface contamination will subsequently be removed in order to comply with the German regulation paragraph 29 StriSchV, i.e. the material can be released. In the past years, the use of floor planers has proven a successful alternative decontamination device for large surface areas, improving the efficiency of the process chain. The device contains a tool drum with rotating carbide blades hitting the concrete surface and thereby removing it. Conventional applications of floor planers include the processing of screed and low-strength concrete. However, concrete structures in NPP mainly consist of conventional concrete with a compressive strength of f c ≥ 25 MPa. This increased strength decreases the carbide blade lifetime T L and limits the removal depth to 3-4 mm. As a result, this requires additional working steps and tool changes and increases material cost and staff deployment. The Karlsruhe Institute of Technology (KIT) has developed a milling unit in a joint project with Energie Baden-Wuerttemberg AG (EnBW), funded by the German Federal Ministry of Education and Research (funding code 0288770). This

  6. Transarterial embolization (TAE) as add-on to percutaneous radiofrequency ablation (RFA) for the treatment of renal tumors: Review of the literature, overview of state-of-the-art embolization materials and further perspective of advanced image-guided tumor ablation

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, C.M., E-mail: christof.sommer@med.uni-heidelberg.de [Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Clinic for Diagnostic and Interventional Radiology, Klinikum Stuttgart, Katharinenhospital, Stuttgart (Germany); Pallwein-Prettner, L., E-mail: leo.pallwein-prettner@bhs.at [Department of Diagnostic and Interventional Radiology, Krankenhaus der Barmherzigen Schwestern Linz, Linz (Austria); Vollherbst, D.F., E-mail: dominik@vollherbst.de [Clinic for Radiology, Minimally-Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Heilbronn (Germany); Seidel, R., E-mail: roland.seidel@uks.eu [Clinic for Diagnostic and Interventional Radiology, Saarland University Medical Center, Homburg/Saar (Germany); Rieder, C., E-mail: christian.rieder@mevis.fraunhofer.de [Fraunhofer MEVIS, Institute for Medical Image Computing, Bremen (Germany); Radeleff, B.A., E-mail: boris.radeleff@med.uni-heidelberg.de [Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Kauczor, H.U., E-mail: hu.kauczor@med.uni-heidelberg.de [Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Wacker, F., E-mail: wacker.frank@mh-hannover.de [Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover (Germany); Richter, G.M., E-mail: g.richter@klinikum-stuttgart.de [Clinic for Diagnostic and Interventional Radiology, Klinikum Stuttgart, Katharinenhospital, Stuttgart (Germany); Bücker, A., E-mail: arno.buecker@uks.eu [Clinic for Diagnostic and Interventional Radiology, Saarland University Medical Center, Homburg/Saar (Germany); Rodt, T., E-mail: rodt.thomas@mh-hannover.de [Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover (Germany); and others

    2017-01-15

    Highlights: • TAE as add-on to percutaneous RFA is feasible, safe, and very effective. • State-of-the-art embolization materials include tightly-size-calibrated microspheres. • MWA, cryoablation and IRE are TA systems beyond RFA. • Visible beads rank among the most promising innovative embolization materials. • Software-based solutions will be increasingly important for treatment guidance. - Abstract: Percutaneous radiofrequency ablation (RFA) for the treatment of stage I renal cell carcinoma has recently gained significant attention as the now available long-term and controlled data demonstrate that RFA can result in disease-free and cancer-specific survival comparable with partial and/or radical nephrectomy. In the non-controlled single center trials, however, the rates of treatment failure vary. Operator experience and ablation technique may explain some of the different outcomes. In the controlled trials, a major limitation is the lack of adequate randomization. In case reports, original series and overview articles, transarterial embolization (TAE) before percutaneous RFA was promising to increase tumor control and to reduce complications. The purpose of this study was to systematically review the literature on TAE as add-on to percutaneous RFA for renal tumors. Specific data regarding technique, tumor and patient characteristics as well as technical, clinical and oncologic outcomes have been analyzed. Additionally, an overview of state-of-the-art embolization materials and the radiological perspective of advanced image-guided tumor ablation (TA) will be discussed. In conclusion, TAE as add-on to percutaneous RFA is feasible and very effective and safe for the treatment of T1a tumors in difficult locations and T1b tumors. Advanced radiological techniques and technologies such as microwave ablation, innovative embolization materials and software-based solutions are now available, or will be available in the near future, to reduce the limitations of

  7. Final-impression techniques and materials for making complete and removable partial dentures.

    Science.gov (United States)

    Jayaraman, Srinivasan; Singh, Balendra P; Ramanathan, Balasubramanian; Pazhaniappan Pillai, Murukan; MacDonald, Laura; Kirubakaran, Richard

    2018-04-04

    Endentulism is relatively common and is often treated with the provision of complete or partial removable dentures. Clinicians make final impressions of complete dentures (CD) and removable partial dentures (RPD) using different techniques and materials. Applying the correct impression technique and material, based on an individual's oral condition, improves the quality of the prosthesis, which may improve quality of life. To assess the effects of different final-impression techniques and materials used to make complete dentures, for retention, stability, comfort, and quality of life in completely edentulous people.To assess the effects of different final-impression techniques and materials used to make removable partial dentures, for stability, comfort, overextension, and quality of life in partially edentulous people. Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 22 November 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Register of Studies, to 22 November 2017), MEDLINE Ovid (1946 to 22 November 2017), and Embase Ovid (21 December 2015 to 22 November 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases, however the search of Embase was restricted by date due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL. We included randomised controlled trials (RCTs) comparing different final-impression techniques and materials for treating people with complete dentures (CD) and removable partial dentures (RPD). For CD, we included trials that compared different materials or different techniques or both. In RPD for tooth-supported conditions, we included trials comparing the

  8. Tungsten carbide precursors as an example for influence of a binder on the particle formation in the nanosecond laser ablation of powdered materials

    Czech Academy of Sciences Publication Activity Database

    Holá, M.; Mikuška, Pavel; Hanzlíková, Renáta; Kaiser, J.; Kanický, V.

    2010-01-01

    Roč. 80, č. 5 (2010), s. 1862-1867 ISSN 0039-9140 Institutional research plan: CEZ:AV0Z40310501; CEZ:AV0Z20650511 Keywords : laser ablation * inductively coupled plasma mass * ICP-MS spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.722, year: 2010

  9. "Non-invasive" portable laser ablation sampling of art and archaeological materials with subsequent Sr-Nd isotope analysis by TIMS using 1013 Ω amplifiers

    NARCIS (Netherlands)

    Knaf, A.C.S.; Koornneef, Janne; Davies, Gareth R

    2017-01-01

    A new integrated trace element and multi-isotope provenancing methodology is presented that uses a portable “non-invasive” pulsed laser ablation sampling technique. Samples are collected on location onto Teflon filters for return to a clean laboratory for low blank (pg) geochemical procedures.

  10. X-ray ablation measurements and modeling for ICF applications

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Andrew Thomas [Univ. of California, Berkeley, CA (United States)

    1996-09-01

    X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. Experiments have been conducted at the Nova laser on the effects of relevant x-ray fluences on various materials. The response was diagnosed using post-shot examinations of the surfaces with scanning electron microscope and atomic force microscope instruments. Judgments were made about the dominant removal mechanisms for each material. Measurements of removal depths were made to provide data for the modeling. The finite difference ablation code developed here (ABLATOR) combines the thermomechanical response of materials to x-rays with models of various removal mechanisms. The former aspect refers to energy deposition in such small characteristic depths (~ micron) that thermal conduction and hydrodynamic motion are significant effects on the nanosecond time scale. The material removal models use the resulting time histories of temperature and pressure-profiles, along with ancillary local conditions, to predict rates of surface vaporization and the onset of conditions that would lead to spallation.

  11. Final Report: Photo-Directed Molecular Assembly of Multifunctional Inorganic Materials

    Energy Technology Data Exchange (ETDEWEB)

    B.G. Potter, Jr.

    2010-10-15

    This final report details results, conclusions, and opportunities for future effort derived from the study. The work involved combining the molecular engineering of photoactive Ti-alkoxide systems and the optical excitation of hydrolysis and condensation reactions to influence the development of the metal-oxygen-metal network at the onset of material formation. Selective excitation of the heteroleptic alkoxides, coupled with control of alkoxide local chemical environment, enabled network connectivity to be influenced and formed the basis for direct deposition and patterning of Ti-oxide-based materials. The research provided new insights into the intrinsic photoresponse and assembly of these complex, alkoxide molecules. Using a suite of electronic, vibrational, and nuclear spectroscopic probes, coupled with quantum chemical computation, the excitation wavelength and fluence dependence of molecular photoresponse and the nature of subsequent hydrolysis and condensation processes were probed in pyridine-carbinol-based Ti-alkoxides with varied counter ligand groups. Several methods for the patterning of oxide material formation were demonstrated, including the integration of this photoprocessing approach with conventional, dip-coating methodologies.

  12. Evaluation of dry-solids-blend material source for grouts containing 106-AN waste: Final report

    International Nuclear Information System (INIS)

    Spence, R.D.; Gilliam, T.M.; Osborne, S.C.; Francis, C.L.; Trotter, D.R.

    1993-09-01

    Stabilization/solidification technology is one of the most widely used techniques for the treatment and ultimate disposal of both radioactive and chemically hazardous wastes. Cement-based products, commonly referred to as grouts, are the predominant materials of choice because of their low associated processing costs, compatibility with a wide variety of disposal scenarios, and ability to meet stringent processing and performance requirements. Such technology is being utilized in a Grout Treatment Facility (GTF) by the Westinghouse Hanford Company (WHC) for the disposal of various wastes, including 106-AN wastes, located on the Hanford Reservation. The WHC personnel have developed a grout formula for 106-AN disposal that is designed to meet stringent performance requirements. This formula consists of a dry-solids blend containing 40 wt % limestone, 28 wt % granulated blast furnace slag (BFS), 28 wt % American Society for Testing and Materials (ASTM) Class F fly ash, and 4 wt % Type I-II-LA Portland cement. This blend is mixed with 106-AN at a mix ratio of 9 lb of dry-solids blend per gallon of waste. This report documents the final results of efforts at Oak Ridge National Laboratory in support of WHC's Grout Technology Program to assess the effects of the source of the dry-solids-blend materials on the resulting grout formula

  13. Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions.

    Science.gov (United States)

    Kuščer, Lovro; Diaci, Janez

    2013-10-01

    Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a "hydrokinetic" effect that has been proposed as an alternative to the "subsurface water expansion" mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed.

  14. Pulmonary ablation: a primer.

    Science.gov (United States)

    Roberton, Benjamin J; Liu, David; Power, Mark; Wan, John M C; Stuart, Sam; Klass, Darren; Yee, John

    2014-05-01

    Percutaneous image-guided thermal ablation is safe and efficacious in achieving local control and improving outcome in the treatment of both early stage non-small-cell lung cancer and pulmonary metastatic disease, in which surgical treatment is precluded by comorbidity, poor cardiorespiratory reserve, or unfavorable disease distribution. Radiofrequency ablation is the most established technology, but new thermal ablation technologies such as microwave ablation and cryoablation may offer some advantages. The use of advanced techniques, such as induced pneumothorax and the popsicle stick technique, or combining thermal ablation with radiotherapy, widens the treatment options available to the multidisciplinary team. The intent of this article is to provide the reader with a practical knowledge base of pulmonary ablation by concentrating on indications, techniques, and follow-up. Copyright © 2014 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

  15. Chemotoxic materials in a final repository for high-level radioactive wastes. CHEMOTOX concept for defence in depth concerning ground water protection from chemotoxic materials in a final high-level waste repository

    International Nuclear Information System (INIS)

    Alt, Stefan; Sailer, Michael; Schmidt, Gerhard; Herbert, Horst-Juergen; Krone, Juergen; Tholen, Marion

    2009-01-01

    The disposal of high-level radioactive wastes in a final repository includes chemotoxic materials. The chemotoxic materials are either part of the radioactive material or part of the packaging material, or the structures within the repository. In the frame of the licensing procedure it has to be demonstrated that no hazardous pollution of the ground water or other disadvantageous changes can occur. The report describes the common project of the Oeko-Institut e.V., the DBE Technology GmbH and the GRS mbH concerning the possible demonstration of a systematic protection of the groundwater against chemotoxic materials in case of a final high-level-radioactive waste repository in the host materials salt and clay stone.

  16. Femtosecond laser ablation of carbon reinforced polymers

    International Nuclear Information System (INIS)

    Moreno, P.; Mendez, C.; Garcia, A.; Arias, I.; Roso, L.

    2006-01-01

    Interaction of intense ultrashort laser pulses (120 fs at 795 nm) with polymer based composites has been investigated. We have found that carbon filled polymers exhibit different ultrafast ablation behaviour depending on whether the filling material is carbon black or carbon fiber and on the polymer matrix itself. The shape and dimensions of the filling material are responsible for some geometrical bad quality effects in the entrance and inner surfaces of drilled microholes. We give an explanation for these non-quality effects in terms of fundamentals of ultrafast ablation process, specifically threshold laser fluences and material removal paths. Since carbon fiber reinforced polymers seemed particularly concerned, this could prevent the use of ultrafast ablation for microprocessing purposes of some of these materials

  17. Cladding and Structural Materials for Advanced Nuclear Energy Systems Final Report

    International Nuclear Information System (INIS)

    Was, G.S.; Allen, T.R.; Ila, D.; Levi, C.; Morgan, D.; Motta, A.; Wang, L.; Wirth, B.

    2011-01-01

    The goal of this consortium is to address key materials issues in the most promising advanced reactor concepts that have yet to be resolved or that are beyond the existing experience base of dose or burnup. The research program consists of three major thrusts: (1) high-dose radiation stability of advanced fast reactor fuel cladding alloys, (2) irradiation creep at high temperature, and (3) innovative cladding concepts embodying functionally-graded barrier materials. This NERI-Consortium final report represents the collective efforts of a large number of individuals over a period of three and a half years and included 9 PIs, 4 scientists, 3 post-docs and 12 students from the seven participating institutions and 8 partners from 5 national laboratories and 3 industrial institutions (see table). University participants met semi-annually and participants and partners met annually for meetings lasting 2-3 days and designed to disseminate and discuss results, update partners, address outstanding issues and maintain focus and direction toward achieving the objectives of the program. The participants felt that this was a highly successful program to address broader issues that can only be done by the assembly of a range of talent and capabilities at a more substantial funding level than the traditional NERI or NEUP grant. As evidence of the success, this group, collectively, has published 20 articles in archival journals and made 57 presentations at international conferences on the results of this consortium.

  18. Laser ablation in analytical chemistry - A review

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Richard E.; Mao, Xianglei; Liu, Haichen; Gonzalez, Jhanis; Mao, Samuel S.

    2001-10-10

    Laser ablation is becoming a dominant technology for direct solid sampling in analytical chemistry. Laser ablation refers to the process in which an intense burst of energy delivered by a short laser pulse is used to sample (remove a portion of) a material. The advantages of laser ablation chemical analysis include direct characterization of solids, no chemical procedures for dissolution, reduced risk of contamination or sample loss, analysis of very small samples not separable for solution analysis, and determination of spatial distributions of elemental composition. This review describes recent research to understand and utilize laser ablation for direct solid sampling, with emphasis on sample introduction to an inductively coupled plasma (ICP). Current research related to contemporary experimental systems, calibration and optimization, and fractionation is discussed, with a summary of applications in several areas.

  19. Phenolic Impregnated Carbon Ablator (PICA) Gap Filler for Heat Shield Assemblies, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — During this program Fiber Materials, Inc. (FMIREG) will develop practical methods for preparing Phenolic Impregnated Carbon Ablator (PICA) materials for joining...

  20. Phenolic Impregnated Carbon Ablator (PICA) Gap Filler for Heat Shield Assemblies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During this program, Fiber Materials, Inc. (FMI) will develop practical methods for preparing Phenolic Impregnated Carbon Ablator (PICA) materials for joining...

  1. Fast Surface Temperature Measurement of Teflon Propellant in Pulsed Ablative Discharges Using HgCdTe Photovoltaic Cells (PREPRINT)

    National Research Council Canada - National Science Library

    Antonsen, Erik L; Burton, Rodney L; Reed, Garrett A; Spanjers, Gregory G

    2006-01-01

    ... ablative discharge with Teflon(TradeMark) as the ablated material. Analysis is used to derive a governing equation for detector output voltage for materials with wavelength dependent emissivity...

  2. Laser ablation principles and applications

    CERN Document Server

    1994-01-01

    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  3. Characterization of Material Response During Arc-Jet Testing with Optical Methods Status and Perspectives

    Science.gov (United States)

    Winter, Michael

    2012-01-01

    The characterization of ablation and recession of heat shield materials during arc jet testing is an important step towards understanding the governing processes during these tests and therefore for a successful extrapolation of ground test data to flight. The behavior of ablative heat shield materials in a ground-based arc jet facility is usually monitored through measurement of temperature distributions (across the surface and in-depth), and through measurement of the final surface recession. These measurements are then used to calibrate/validate materials thermal response codes, which have mathematical models with reasonably good fidelity to the physics and chemistry of ablation, and codes thus calibrated are used for predicting material behavior in flight environments. However, these thermal measurements only indirectly characterize the pyrolysis processes within an ablative material pyrolysis is the main effect during ablation. Quantification of pyrolysis chemistry would therefore provide more definitive and useful data for validation of the material response codes. Information of the chemical products of ablation, to various levels of detail, can be obtained using optical methods. Suitable optical methods to measure the shape and composition of these layers (with emphasis on the blowing layer) during arc jet testing are: 1) optical emission spectroscopy (OES) 2) filtered imaging 3) laser induced fluorescence (LIF) and 4) absorption spectroscopy. Several attempts have been made to optically measure the material response of ablative materials during arc-jet testing. Most recently, NH and OH have been identified in the boundary layer of a PICA ablator. These species are suitable candidates for a detection through PLIF which would enable a spatially-resolved characterization of the blowing layer in terms of both its shape and composition. The recent emission spectroscopy data will be presented and future experiments for a qualitative and quantitative

  4. Hard tissue ablation with a spray-assisted mid-IR laser

    International Nuclear Information System (INIS)

    Kang, H W; Rizoiu, I; Welch, A J

    2007-01-01

    The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depth were measured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a 60% higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitial water explosion and possibly liquid-jet formation. With water cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment

  5. Ablative microstructuring with plasma-based XUV lasers and efficient processing of materials by dual action of XUV/NIR–VIS ultrashort pulses

    Czech Academy of Sciences Publication Activity Database

    Mocek, Tomáš; Jakubczak, Krzysztof; Kozlová, Michaela; Polan, Jiří; Homer, Pavel; Hřebíček, J.; Sawicka, Magdalena; Kim, I. J.; Park, S.B.; Kim, C. M.; Lee, G.H.; Kim, T.K.; Nam, C. H.; Chalupský, Jaromír; Hájková, Věra; Juha, Libor; Sobota, Jaroslav; Fořt, Tomáš; Rus, Bedřich

    2010-01-01

    Roč. 165, 6-10 (2010), s. 551-558 ISSN 1042-0150 R&D Projects: GA AV ČR KAN300100702; GA MŠk(CZ) LC528; GA MŠk LA08024; GA ČR GC202/07/J008 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20650511 Keywords : XUV lasers * ablation * microstructuring * laser-induced periodic surface structures Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.660, year: 2010

  6. Tailings neutralization and other alternatives for immobilizing toxic materials in tailings. Final report

    International Nuclear Information System (INIS)

    Opitz, B.E.; Sherwood, D.R.; Dodson, M.E.; Serne, R.J.

    1985-09-01

    This document, ''Tailing Neutralization and Other Alternatives for Immobilizing Toxic Materials in Tailings,'' is the final report in a series of six. It summarizes research completed since the beginning of the project. Three subtasks are included: Subtask A - Neutralization Methods Selection; Subtask B - Laboratory Analysis; and Subtask C - Field Testing. Subtask A reviews treatment processes from other industries to evaluate whether current waste technology from other fields is applicable to the uranium industry. This task also identifies several reagents that were tested for their effectiveness in treating acidic tailings and tailings solution in order to immobilize the contaminants associated with the acid waste. Subtask B describes the laboratory batch and column treatment studies performed on solid waste tailings and tailings solutions over the course of the project. The evaluation of several reagents identified in Subtask A was based on three criteria: (1) treated effluent water quality; (2) neutralized sludge handling and hydraulic properties; and (3) reagent costs and acid neutralizing efficiency. Subtask C presents a field demonstration plan that will evaluate the effectiveness, costs, and benefits of neutralizing acidic uranium mill tailings solution to reduce the potential leaching of toxic trace metals, radionuclides, and macro ions from a tailings impoundment. Details of the related research can be found in the documents listed in the ''Previous Documents in Series.'' 43 refs., 9 figs., 46 tabs

  7. Micrometeoroid ablation simulated in the laboratory

    Science.gov (United States)

    Sternovsky, Zoltan; Thomas, Evan W.; DeLuca, Michael; Horanyi, Mihaly; Janches, Diego; Munsat, Tobin L.; Plane, John M. C.

    2016-04-01

    A facility is developed to simulate the ablation of micrometeoroids in laboratory conditions, which also allows measuring the ionization probability of the ablated material. An electrostatic dust accelerator is used to generate iron and meteoric analog particles with velocities 10-50 km/s. The particles are then introduced into a cell filled with nitrogen, air or carbon dioxide gas with pressures adjustable in the 0.02 - 0.5 Torr range, where the partial or complete ablation of the particle occurs over a short distance. An array of biased electrodes is used to collect the ionized products with spatial resolution along the ablating particles' path, allowing thus the study of the temporal resolution of the process. A simple ablation model is used to match the observations. For completely ablated particles the total collected charge directly yields the ionization efficiency for. The measurements using iron particles in N2 and air are in relatively good agreement with earlier data. The measurements with CO2 and He gases, however, are significantly different from the expectations.

  8. Radiofrequency ablation with epinephrine injection: in vivo study in normal pig livers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoung Jung; Lee, Dong Hoo; Lim, Joo Won; Ko, Young Tae; Kim, Youn Wha; Choi, Bong Keun [Kyung Hee University Medical Center, Seoul (Korea, Republic of)

    2007-07-15

    We wanted to evaluate whether epinephrine injection prior to radiofrequency (RF) ablation can increase the extent of thermally mediated coagulation in vivo normal pig liver tissue. Eighteen RF ablation zones were created in six pigs using a 17-gauge internally cooled electrode under ultrasound guidance. Three RF ablation zones were created in each pig under three conditions: RF ablation alone, RF ablation after the injection of 3 mL of normal saline, and RF ablation after the injection of 3 mL of epinephrine (1:10,000 solution). After the RF ablation, we measured the short and long diameters of the white zones in the gross specimens. Three of the RF ablations were technically unsuccessful; therefore, measurement of white zone was finally done in 15 RF ablation zones. The mean short and long diameters of the white zone of the RF ablation after epinephrine injection (17.2 mm {+-} 1.8 and 20.8 mm {+-} 3.7, respectively) were larger than those of RF ablation only (10 mm {+-} 1.2 and 12.2 mm {+-} 1.1, respectively) and RF ablation after normal saline injection (12.8 mm {+-} 1.5 and 15.6 mm {+-} 2.5, respectively) ({rho} < .05). RF ablation with epinephrine injection can increase the diameter of the RF ablation zone in normal pig liver tissue.

  9. Pulsed laser ablation of solids basics, theory and applications

    CERN Document Server

    Stafe, Mihai; Puscas, Niculae N

    2014-01-01

    The book introduces ‘the state of the art' of pulsed laser ablation and its applications. It is based on recent theoretical and experimental studies. The book reaches from the basics to advanced topics of pulsed laser ablation. Theoretical and experimental fundamental phenomena involved in pulsed laser ablation are discussed with respect to material properties, laser wavelength, fluence and intensity regime of the light absorbed linearly or non-linearly in the target material. The energy absorbed by the electrons leads to atom/molecule excitation, ionization and/or direct chemical bond breaking and is also transferred to the lattice leading to material heating and phase transitions. Experimental  non-invasive optical methods for analyzing these phenomena in real time are described. Theoretical models for pulsed laser ablation and phase transitions induced by laser beams and laser-vapour/plasma interaction during the plume expansion above the target are also presented. Calculations of the ablation speed and...

  10. Testing of Advanced Conformal Ablative TPS

    Science.gov (United States)

    Gasch, Matthew; Agrawal, Parul; Beck, Robin

    2013-01-01

    In support of the CA250 project, this paper details the results of a test campaign that was conducted at the Ames Arcjet Facility, wherein several novel low density thermal protection (TPS) materials were evaluated in an entry like environment. The motivation for these tests was to investigate whether novel conformal ablative TPS materials can perform under high heat flux and shear environment as a viable alternative to rigid ablators like PICA or Avcoat for missions like MSL and beyond. A conformable TPS over a rigid aeroshell has the potential to solve a number of challenges faced by traditional rigid TPS materials (such as tiled Phenolic Impregnated Carbon Ablator (PICA) system on MSL, and honeycomb-based Avcoat on the Orion Multi Purpose Crew Vehicle (MPCV)). The compliant (high strain to failure) nature of the conformable ablative materials will allow better integration of the TPS with the underlying aeroshell structure and enable monolithic-like configuration and larger segments to be used in fabrication.A novel SPRITE1 architecture, developed by the researchers at NASA Ames was used for arcjet testing. This small probe like configuration with 450 spherecone, enabled us to test the materials in a combination of high heat flux, pressure and shear environment. The heat flux near the nose were in the range of 500-1000 W/sq cm whereas in the flank section of the test article the magnitudes were about 50 of the nose, 250-500W/sq cm range. There were two candidate conformable materials under consideration for this test series. Both test materials are low density (0.28 g/cu cm) similar to Phenolic Impregnated Carbon Ablator (PICA) or Silicone Impregnated Refractory Ceramic Ablator (SIRCA) and are comprised of: A flexible carbon substrate (Carbon felt) infiltrated with an ablative resin system: phenolic (Conformal-PICA) or silicone (Conformal-SICA). The test demonstrated a successful performance of both the conformable ablators for heat flux conditions between 50

  11. 3D transient model to predict temperature and ablated areas during laser processing of metallic surfaces

    Directory of Open Access Journals (Sweden)

    Babak. B. Naghshine

    2017-02-01

    Full Text Available Laser processing is one of the most popular small-scale patterning methods and has many applications in semiconductor device fabrication and biomedical engineering. Numerical modelling of this process can be used for better understanding of the process, optimization, and predicting the quality of the final product. An accurate 3D model is presented here for short laser pulses that can predict the ablation depth and temperature distribution on any section of the material in a minimal amount of time. In this transient model, variations of thermal properties, plasma shielding, and phase change are considered. Ablation depth was measured using a 3D optical profiler. Calculated depths are in good agreement with measured values on laser treated titanium surfaces. The proposed model can be applied to a wide range of materials and laser systems.

  12. Influence of ablation wavelength and time on optical properties of laser ablated carbon dots

    Science.gov (United States)

    Isnaeni, Hanna, M. Yusrul; Pambudi, A. A.; Murdaka, F. H.

    2017-01-01

    Carbon dots, which are unique and applicable materials, have been produced using many techniques. In this work, we have fabricated carbon dots made of coconut fiber using laser ablation technique. The purpose of this work is to evaluate two ablation parameters, which are ablation wavelength and ablation time. We used pulsed laser from Nd:YAG laser with emit wavelength at 355 nm, 532 nm and 1064 nm. We varied ablation time one hour and two hours. Photoluminescence and time-resolved photoluminescence setup were used to study the optical properties of fabricated carbon dots. In general, fabricated carbon dots emit bluish green color emission upon excitation by blue laser. We found that carbon dots fabricated using 1064 nm laser produced the highest carbon dots emission among other samples. The peak wavelength of carbon dots emission is between 495 nm until 505 nm, which gives bluish green color emission. Two hours fabricated carbon dots gave four times higher emission than one hour fabricated carbon dot. More emission intensity of carbon dots means more carbon dots nanoparticles were fabricated during laser ablation process. In addition, we also measured electron dynamics of carbon dots using time-resolved photoluminescence. We found that sample with higher emission has longer electron decay time. Our finding gives optimum condition of carbon dots fabrication from coconut fiber using laser ablation technique. Moreover, fabricated carbon dots are non-toxic nanoparticles that can be applied for health, bio-tagging and medical applications.

  13. Neutron Scattering Studies of Fundamental Processes in Earth Materials, Final Report

    International Nuclear Information System (INIS)

    McCall, K. R.

    2007-01-01

    The aim of this work was to use neutron scattering techniques to explore the dynamics and structure of water in rock samples. The dynamics of water in rock at low (residual) saturation are directly related to the transport properties of fluids within the host rock. The structure of water in rock may be related to the elastic behavior of the rock, which in many cases is nonlinear and hysteretic. Neutron scattering techniques allow us to study water in intact rock samples at both the molecular and microstructural scales. Our samples were Berea sandstone, Calico Hills and Prow Pass tuffs from Yucca Mountain, NV, and pure samples of the tuff constituents, specifically mordenite and clinoptilolite. We chose Berea sandstone because its macroscopic elastic behavior is known to be highly unusual, and the microscopic mechanisms producing this behavior are not understood. We chose Yucca Mountain tuff, because the fluid transport properties of the geologic structure at Yucca Mountain, Nevada could be relevant to the performance of a high level nuclear waste repository at that site. Neutron scattering methods have a number of properties that are extremely useful for the study of earth materials. In contrast to X-rays, neutrons have very low absorption cross-sections for most elements so that entire bulk samples of considerable size can be 'illuminated' by the neutron beam. Similarly, samples that are optically opaque can be readily investigated by inelastic neutron scattering techniques. Neutrons are equally sensitive to light atoms as to heavy atoms, and can, for example, readily distinguish between Al and Si, neighboring atoms in the periodic table that are difficult to tell apart by X-ray diffraction. Finally, neutrons are particularly sensitive to hydrogen and thus can be used to study the motions, both vibrational and diffusive, of H-containing molecules in rocks, most notably of course, water. Our studies were primarily studies of guest molecules (in our case, water) in

  14. Numerical Modeling of Ablation Heat Transfer

    Science.gov (United States)

    Ewing, Mark E.; Laker, Travis S.; Walker, David T.

    2013-01-01

    A unique numerical method has been developed for solving one-dimensional ablation heat transfer problems. This paper provides a comprehensive description of the method, along with detailed derivations of the governing equations. This methodology supports solutions for traditional ablation modeling including such effects as heat transfer, material decomposition, pyrolysis gas permeation and heat exchange, and thermochemical surface erosion. The numerical scheme utilizes a control-volume approach with a variable grid to account for surface movement. This method directly supports implementation of nontraditional models such as material swelling and mechanical erosion, extending capabilities for modeling complex ablation phenomena. Verifications of the numerical implementation are provided using analytical solutions, code comparisons, and the method of manufactured solutions. These verifications are used to demonstrate solution accuracy and proper error convergence rates. A simple demonstration of a mechanical erosion (spallation) model is also provided to illustrate the unique capabilities of the method.

  15. Radiofrequency ablation in dermatology

    Directory of Open Access Journals (Sweden)

    Sachdeva Silonie

    2007-01-01

    Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

  16. Laser ablation of lysozyme with UV, visible and infrared femto- and nanosecond pulses

    OpenAIRE

    Schou, Jørgen; Canulescu, Stela; Matei, Andreea; Cazzaniga, Andrea Carlo; Constantinescu, Catalin; Amoruso, S.; Wang, X.; Bruzzese, R.; Dinescu, M.

    2013-01-01

    Lysozyme is an interesting molecule for laser ablation of organic materials, because the ablation has been comprehensively studied, it is a medium heavy molecule with a mass of 14305 Da, which can be detected by standard techniques, and because it is used as a bactericidal protein in the food industry. Lysozyme molecules do not absorb energy for wavelengths above 310 nm, but nevertheless there is a strong mass loss by ablation for laser irradiation in the visible regime. The total ablation yi...

  17. Material and component qualification of ceramic hot gas filter elements. Final report; Material- und Bauteilqualifizierung keramischer Heissgasfilterelemente. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Westerheide, R.; Adler, J.; Wehd, C. von der; Baumgarten, J.; Rehak, P.

    2003-04-01

    Hot gas filtering in modern power plants takes place at temperatures above 600 C. Filter elements are often based on ceramic materials, especially silicon carbide, which is a temperature and corrosion-sensitive material. The report characterises common filter materials and describes the development of new filter materials based on silicon carbide, Al{sub 2}O{sub 3}, and spinell, which were investigated under thermal, mechanical and corrosive stress for the purpose of identifying suitable filter materials. (orig.) [German] Die Heissgasreinigung einer Vielzahl moderner Kraftwerke arbeitet bei Betriebstemperaturen oberhalb 600 C. Die Filterelemente fuer diese Technologie basieren haeufig auf keramischen Materialien, insbesondere auf Siliziumcarbid. Die meisten Siliziumcarbid-Werkstoffe unterliegen jedoch Schaedigung durch Temperatur und Korrosion. Beides kann mit Veraenderungen des Gefuegeaufbaus einhergehen. In diesem Bericht ist die Charakterisierung bestehender Filtermaterialien und die Entwicklung neuer Filtermaterialien, die auf Siliziumcarbid, Al{sub 2}O{sub 3} und Spinell basieren, beschrieben. Das Ziel war, die Materialbestaendigkeit gegenueber thermischen, mechanischen und korrosiven Belastungen zu untersuchen und dafuer geeignete Filtermaterlialien weiterzuentwickeln. (orig.)

  18. Lesion size in relation to ablation site during radiofrequency ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, A

    1998-01-01

    This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation was perfor......This study was designed to investigate the effect of the convective cooling of the tip of the ablation electrode during temperature controlled radiofrequency ablation. In vivo two different application sites in the left ventricle of anaesthetised pigs were ablated and in vitro ablation.......61 in vitro). We conclude that during temperature controlled radiofrequency ablation lesion size differs for septal and apical left ventricular applications. Differences in convective cooling might play an important role in this respect. This is supported by our in vitro experiments, where increased...

  19. Temperature Controlled Radiofrequency Ablation

    Directory of Open Access Journals (Sweden)

    Olaf J. Eick

    2002-07-01

    Full Text Available Since its introduction in 1987, radiofrequency (RF ablation has developed to become the treatment of choice for symptoms caused by atrio ventricular (AV reentrant tachycardia, isthmus related atrial flutter, AV-nodal reentrant tachycardia and to some extent also for certain types of ventricular tachycardias. The introduction of new cardiac activation mapping systems has further contributed to the successful and safe application of RF ablation for various tachyarrhythmias.

  20. Review of the management of materials research and development in the Department of Energy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    The Materials Working Group of DOE findings and recommendations of a management nature to improve the handling of materials R and D within DOE are presented. The special role of materials in the development of new energy technologies is provided. (FS)

  1. Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition

    International Nuclear Information System (INIS)

    Geohegan, D.B.

    1994-01-01

    Characteristics of laser plasmas used for pulsed laser deposition (PLD) of thin films are examined with four in situ diagnostic techniques: Optical emission spectroscopy, optical absorption spectroscopy, ion probe studies, and gated ICCD (intensified charge-coupled-device array) fast photography. These four techniques are complementary and permit simultaneous views of the transport of ions, excited states, ground state neutrals and ions, and hot particulates following KrF laser ablation of YBCO, BN, graphite and Si in vacuum and background gases. The implementation and advantages of the four techniques are first described in order to introduce the key features of laser plasmas for pulsed laser deposition. Aspects of the interaction of the ablation plume with background gases (i.e., thermalization, attenuation, shock formation) and the collision of the plasma plume with the substrate heater are then summarized. The techniques of fast ICCD photography and gated photon counting are then applied to investigate the temperature, velocity, and spatial distribution of hot particles generated during KrF ablation of YBCO, BN, Si and graphite. Finally, key features of fast imaging of the laser ablation of graphite into high pressure rare gases are presented in order to elucidate internal reflected shocks within the plume, redeposition of material on a surface, and formation of hot nanoparticles within the plume

  2. Time-resolved diagnostics of excimer laser-generated ablation plasmas used for pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Geohegan, D.B.

    1994-09-01

    Characteristics of laser plasmas used for pulsed laser deposition (PLD) of thin films are examined with four in situ diagnostic techniques: Optical emission spectroscopy, optical absorption spectroscopy, ion probe studies, and gated ICCD (intensified charge-coupled-device array) fast photography. These four techniques are complementary and permit simultaneous views of the transport of ions, excited states, ground state neutrals and ions, and hot particulates following KrF laser ablation of YBCO, BN, graphite and Si in vacuum and background gases. The implementation and advantages of the four techniques are first described in order to introduce the key features of laser plasmas for pulsed laser deposition. Aspects of the interaction of the ablation plume with background gases (i.e., thermalization, attenuation, shock formation) and the collision of the plasma plume with the substrate heater are then summarized. The techniques of fast ICCD photography and gated photon counting are then applied to investigate the temperature, velocity, and spatial distribution of hot particles generated during KrF ablation of YBCO, BN, Si and graphite. Finally, key features of fast imaging of the laser ablation of graphite into high pressure rare gases are presented in order to elucidate internal reflected shocks within the plume, redeposition of material on a surface, and formation of hot nanoparticles within the plume.

  3. Comparison of the Three NIF Ablators

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Clark, D. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Haan, S. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yi, S. A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zylstra, A. B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ralph, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weber, C. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-11-01

    Indirect drive implosion experiments on NIF have now been performed using three different ablator materials: glow discharge polymer (GDP) or CH, high density carbon (HDC, which we also refer to as diamond), and sputtered beryllium (Be). It has been appreciated for some time that each of these materials has specific advantages and disadvantages as an ICF ablator.[1-4] In light of experiments conducted on NIF in the last few years, how do these ablators compare? Given current understanding, is any ablator more or less likely to reach ignition on NIF? Has the understanding of their respective strengths and weaknesses changed since NIF experiments began? How are those strengths and weaknesses highlighted by implosion designs currently being tested or planned for testing soon? This document aims to address these questions by combining modern simulation results with a survey of the current experimental data base. More particularly, this document is meant to fulfill an L2 Milestone for FY17 to “Document our understanding of the relative advantages and disadvantages of CH, HDC, and Be designs.” Note that this document does not aim to recommend a down-selection of the current three ablator choices. It is intended only to gather and document the current understanding of the differences between these ablators and thereby inform the choices made in planning future implosion experiments. This document has two themes: (i) We report on a reanalysis project in which post-shot simulations were done on a common basis for layered shots using each ablator. This included data from keyholes, 2D ConA, and so forth, from each campaign, leading up to the layered shots. (“Keyholes” are shots dedicated to measuring the shock timing in a NIF target, as described in Ref. 5. “2DConAs” are backlit implosions in which the symmetry of the implosion is measured between about half and full convergence, as described in Ref. 6.) This set of common-basis postshot simulations is compared to

  4. Study of nuclear material accounting. Final report, July 1, 1976--April 1, 1977

    International Nuclear Information System (INIS)

    Siri, W.E.; Gozani, T.; Maly, J.

    1977-04-01

    The following topics are discussed: hierarchy of accountability measurements; survey of analytical methods; accuracies of analytical methods for material accountability; and vulnerability of accountability measurements

  5. Performance testing of elastomeric seal materials under low and high temperature conditions: Final report

    Energy Technology Data Exchange (ETDEWEB)

    BRONOWSKI,DAVID R.

    2000-06-01

    The US Department of Energy Offices of Defense Programs and Civilian Radioactive Waste Management jointly sponsored a program to evaluate elastomeric O-ring seal materials for radioactive material shipping containers. The report presents the results of low- and high-temperature tests conducted on 27 common elastomeric compounds.

  6. Analysis and forecast of electrical distribution system materials. Final report. Volume III. Appendix

    Energy Technology Data Exchange (ETDEWEB)

    Love, C G

    1976-08-23

    These appendixes are referenced in Volume II of this report. They contain the detailed electrical distribution equipment requirements and input material requirements forecasts. Forecasts are given for three electric energy usage scenarios. Also included are data on worldwide reserves and demand for 30 raw materials required for the manufacture of electrical distribution equipment.

  7. The Development of Environmental Education Materials for Investigating Fire-Environment-Man Relationships: Final Report.

    Science.gov (United States)

    Hanselman, David L.; Reider, David A.

    This publication details the development and use of environmental education materials based on the United States Forest Service "Process Approach." This publication focuses on materials that teach the ecology and management of natural and man-made forest and brush fires. The main body of the contents develop and document a rationale for…

  8. Final versions of the initial package of classroom materials and guidelines

    NARCIS (Netherlands)

    Doorman, Michiel; Jonker, Vincent

    2014-01-01

    The main aim of the mascil Work Package 3 ‘classroom materials’ is to present guidelines and an online collection of teaching materials that encourage and support teachers to design their own classroom materials that connect IBL and the WoW in mathematics and science education.The collection

  9. Probable approaches to develop particle beam energy drivers and to calculate wall material ablation with X ray radiation from imploded targets

    International Nuclear Information System (INIS)

    Kasuya, K.; Funatsu, M.; Saitoh, S.

    2001-01-01

    The first subject was the development of future ion beam driver with medium-mass ion specie. This may enable us to develop a compromised driver from the point of view of the micro-divergence angle and the cost. We produced nitrogen ion beams, and measured the micro-divergence angle on the anode surface. The measured value was 5-6mrad for the above beam with 300-400keV energy, 300A peak current and 50ns duration. This value was enough small and tolerable for the future energy driver. The corresponding value for the proton beam with higher peak current was 20-30mrad, which was too large. So that, the scale-up experiment with the above kind of medium-mass ion beam must be realized urgently to clarify the beam characteristics in more details. The reactor wall ablation with the implosion X-ray was also calculated as the second subject in this paper. (author)

  10. Center for Fundamental and Applied Research in Nanostructured and Lightweight Materials. Final Technical Summary

    Energy Technology Data Exchange (ETDEWEB)

    Mullins, Michael; Rogers, Tony; King, Julia; Keith, Jason; Cornilsen, Bahne; Allen, Jeffrey; Gilbert, Ryan; Holles, Joseph

    2010-09-28

    The core projects for this DOE-sponsored Center at Michigan Tech have focused on several of the materials problems identified by the NAS. These include: new electrode materials, enhanced PEM materials, lighter and more effective bipolar plates, and improvement of the carbon used as a current carrier. This project involved fundamental and applied research in the development and testing of lightweight and nanostructured materials to be used in fuel cell applications and for chemical synthesis. The advent of new classes of materials engineered at the nanometer level can produce materials that are lightweight and have unique physical and chemical properties. The grant was used to obtain and improve the equipment infrastructure to support this research and also served to fund seven research projects. These included: 1. Development of lightweight, thermally conductive bipolar plates for improved thermal management in fuel cells; 2. Exploration of pseudomorphic nanoscale overlayer bimetallic catalysts for fuel cells; 3. Development of hybrid inorganic/organic polymer nanocomposites with improved ionic and electronic properties; 4. Development of oriented polymeric materials for membrane applications; 5. Preparation of a graphitic carbon foam current collectors; 6. The development of lightweight carbon electrodes using graphitic carbon foams for battery and fuel cell applications; and 7. Movement of water in fuel cell electrodes.

  11. Final Project Report for ER15351 ''A Study of New Actinide Zintl Ions Materials''

    International Nuclear Information System (INIS)

    Peter K. Dorhout

    2007-01-01

    The structural chemistry of actinide main-group metal materials provides the fundamental basis for the understanding of structural coordination chemistry and the formation of materials with desired or predicted structural features. The main-group metal building blocks, comprising sulfur-group, phosphorus-group, or silicon-group elements, have shown versatility in oxidation state, coordination, and bonding preferences. These building blocks have allowed us to elucidate a series of structures that are unique to the actinide elements, although we can find structural relationships to transition metal and 4f-element materials. In the past year, we investigated controlled metathesis and self-propagating reactions between actinide metal halides and alkali metal salts of main-group metal chalcogenides such as K-P-S salts. Ternary plutonium thiophosphates have resulted from these reactions at low temperature in sealed ampules. we have also focused efforts to examine reactions of Th, U, and Pu halide salts with other alkali metal salts such as Na-Ge-S and Na-Si-Se and copper chloride to identify if self-propagating reactions may be used as a viable reaction to prepare new actinide materials and we prepared a series of U and Th copper chalcogenide materials. Magnetic measurements continued to be a focus of actinide materials prepared in our laboratory. We also contributed to the XANES work at Los Alamos by preparing materials for study and for comparison with environmental samples

  12. Materials for high-temperature hydrogen fluorine environments. Final report, June 1976-December 1978

    International Nuclear Information System (INIS)

    Holcombe, C.E. Jr.; Kovach, L.

    1981-03-01

    A determination has been made of the stability of 35 materials under high-temperature, fluorine rich, hydrogen fluoride torch testing. Refractory materials tested included 4 borides, 3 carbides, 3 nitrides, 12 oxides, 1 oxynitride, 1 sulfide, 10 metals, and carbon (10 types). Three materials distinctly performed better than nickel: lanthanum hexaboride, calcium hexaboride, and lanthanum silicon oxynitride. Of these, lanthanum hexaboride is the best candidate tested since it has an estimated upper use temperature > 1726 K, which is above the melting point and more than 300 K above the upper use temperature of nickel

  13. Quantum Simulations of Materials and Nanostructures (Q-SIMAN). Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Galli, Giulia [Univ. of California, Davis, CA (United States); Bai, Zhaojun [Univ. of California, Davis, CA (United States); Ceperley, David [Univ. of Illinois, Urbana, IL (United States); Cai, Wei [Stanford Univ., CA (United States); Gygi, Francois [Univ. of California, Davis, CA (United States); Marzari, Nicola [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Pickett, Warren [Univ. of California, Davis, CA (United States); Spaldin, Nicola [Univ. of California, Santa Barbara, CA (United States); Fattebert, Jean-Luc [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schwegler, Eric [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-09-16

    The focus of this SciDAC SAP (Scientific Application) is the development and use of quantum simulations techniques to understand materials and nanostructures at the microscopic level, predict their physical and chemical properties, and eventually design integrated materials with targeted properties. (Here the word ‘materials’ is used in a broad sense and it encompasses different thermodynamic states of matter, including solid, liquids and nanostructures.) Therefore our overarching goal is to enable scientific discoveries in the field of condensed matter and advanced materials through high performance computing.

  14. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Martone, M. [ENEA, Centro Ricerche Frascati, Rome (Italy)

    1997-01-01

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member.

  15. IFMIF : International Fusion Materials Irradiation Facility Conceptual Design Activity: Final report

    International Nuclear Information System (INIS)

    Martone, M.

    1997-01-01

    This report documents the results of the Conceptual Design Activity (CDA) on the International Fusion Materials Irradiation Facility (IFMIF), conducted during 1995 and 1996. The activity is under the auspices of the International Energy Agency (IEA) Implementing Agreement for a Programme of Research and Development on Fusion Materials. An IEA Fusion Materials Executive Subcommittee was charged with overseeing the IFMIF-CDA work. Participants in the CDA are the European Union, Japan, and the United States, with the Russian Federation as an associate member

  16. Laser ablation with applied magnetic field for electric propulsion

    Science.gov (United States)

    Batishcheva, Alla; Batishchev, Oleg; Cambier, Jean-Luc

    2012-10-01

    Using ultrafast lasers with tera-watt-level power allows efficient ablation and ionization of solid-density materials [1], creating dense and hot (˜100eV) plasma. We propose ablating small droplets in the magnetic nozzle configurations similar to mini-helicon plasma source [2]. Such approach may improve the momentum coupling compared to ablation of solid surfaces and facilitate plasma detachment. Results of 2D modeling of solid wire ablation in the applied magnetic field are presented and discussed. [4pt] [1] O. Batishchev et al, Ultrafast Laser Ablation for Space Propulsion, AIAA technical paper 2008-5294, -16p, 44th JPC, Hartford, 2008.[0pt] [2] O. Batishchev and J.L. Cambier, Experimental Study of the Mini-Helicon Thruster, Air Force Research Laboratory Report, AFRL-RZ-ED-TR-2009-0020, 2009.

  17. Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H.-X.; Xie, X.-Y.; Lu, M.-D. E-mail: lumd@21cn.com; Chen, J.-W.; Yin, X.-Y.; Xu, Z.-F.; Liu, G.-J

    2004-01-01

    AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours{<=}2.0, 2.1-3.9 and {>=}4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours{<=}2.0, 2.1-3.9 and {>=}4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up.

  18. Ultrasound-guided percutaneous thermal ablation of hepatocellular carcinoma using microwave and radiofrequency ablation

    International Nuclear Information System (INIS)

    Xu, H.-X.; Xie, X.-Y.; Lu, M.-D.; Chen, J.-W.; Yin, X.-Y.; Xu, Z.-F.; Liu, G.-J.

    2004-01-01

    AIM: To investigate the therapeutic efficacy of thermal ablation for treatment of hepatocellular carcinoma (HCC) using microwave and radiofrequency (RF) energy application. MATERIALS AND METHODS: A total of 190 nodules in 97 patients (84 male, 13 female; mean age 53.4 years, range 24-74 years) with HCC were treated with microwave or RF ablation in the last 4 years. The applicators were introduced into the tumours under conscious analgesic sedation by intravenous administration of fentanyl citrate and droperidol and local anaesthesia in both thermal ablation procedures. The patients were then followed up with contrast-enhanced computed tomography (CT) to evaluate treatment response. Survival was analysed using the Kaplan-Meier method. RESULTS: Complete ablation was obtained in 92.6% (176/190) nodules. The complete ablation rates were 94.6% (106/112) in microwave ablation and 89.7% (70/78) in RF ablation. The complete ablation rates in tumours≤2.0, 2.1-3.9 and ≥4.0 cm were 93.1, 93.8 and 86.4%, respectively. Local recurrence was found in 9.5% nodules and the rates in tumours≤2.0, 2.1-3.9 and ≥4.0 cm in diameter were 3.4, 9.9 and 31.8%, respectively. In the follow-up period, 7.1% nodules ablated by microwave and 12.8% by RF presented local recurrence. The 1, 2 and 3-year distant recurrence-free survivals were 47.2, 34.9 and 31.0%, respectively. Estimated mean survival was 32 months, and 1, 2 and 3-year cumulative survivals were 75.6, 58.5, and 50.0%, respectively. One and 2 years survivals of Child-Pugh class A, B and C patients were 83.8 and 70.4%, 78.2 and 53.2%, 36.3 and 27.3%, respectively. CONCLUSION: Thermal ablation therapy by means of microwave and RF energy application is an effective and safe therapeutic technique for hepatocellular carcinoma. Large tumours can be completely ablated, but have a significantly higher risk of local recurrence at follow-up

  19. Hazardous materials safety and security technology field operational test. Volume II, evaluation final report synthesis

    Science.gov (United States)

    2004-11-11

    The catastrophic events of September 11, 2001 and the ongoing war on terrorism have heightened the level of concern from Federal government officials and the transportation industry regarding the secure transport of hazardous materials (HAZMAT). Secu...

  20. Solar-collector-materials exposure to the IPH site environment. Volume 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Morris, V.L.

    1982-01-01

    In-situ environmental exposure tests were conducted at nine proposed intermediate-temperature Industrial Process Heat (IPH) sites. Three types of reflector materials were evaluated for survivability at the nine sites: second-surface silvered glass, aluminized acrylic FEK-244 film on aluminumsubstrate and Alzak (electropolished aluminum) on aluminium substrate. Black chrome absorber material and low-iron float glass were evaluated for thermal, photochemical, and environmental degradation. The reflector specimens were monitored for decreases in specular and hemispherical reflectance due to soil buildup. The absorber material was evaluated for changes in solar absorptivity and emissivity, and the float glass was monitored for changes in transmissivity. Surface and subsurface defects on all materials were examined microscopically and, where deemed of note, were documented photographically.

  1. Optimization and management of materials in earthwork construction : final report, April 2010.

    Science.gov (United States)

    2010-04-01

    As a result of forensic investigations of problems across Iowa, a research study was developed aimed at providing solutions to identified : problems through better management and optimization of the available pavement geotechnical materials and throu...

  2. Evaluation of epoxy compounds as a material for patching and protecting concrete : final report.

    Science.gov (United States)

    1971-01-01

    The final report summarizes the results of a study of the use of epoxy compounds in the shallow surface repair and sealing of concrete bridge decks. The research effort concentrated on the use of epoxy resin systems as bonded overlays and included ev...

  3. Final environmental statement on the transportation of radioactive material by air and other modes

    International Nuclear Information System (INIS)

    1977-12-01

    An assessment is presented of the environmental impact from transportation of shipments of radioactive material into, within, and out of the United States. It is intended to serve as background material for a review by the United States Nuclear Regulatory Commission (NRC) of regulations dealing with transportation of radioactive materials. The impetus for such a review results not only from a general need to examine regulations to ensure their continuing consistency with the goal of limiting radiological impact to a level that is as low as reasonably achievable, but also from a need to respond to current national discussions of the safety and security aspects of nuclear fuel cycle materials. Chapters are included on regulations governing the transportation of radioactive materials, radiological effects, transport impact under normal conditions, impacts of transportation accidents, alternatives, and security and safeguards. A standard shipments model is also included along with a demographic model, excerpts from federal regulations, data on Pu, Population dose formulas, a list of radioactive material incidents, accident analysis methodology, and an analysis of risk assessment sensitivity

  4. FY98 Final Report Initial Interfacial Chemical Control for Enhancement of Composite Material Strength; TOPICAL

    International Nuclear Information System (INIS)

    GE Fryxell; KL Alford; KL Simmons; RD Voise; WD Samuels

    1999-01-01

    The U.S. Army Armament Research Development and Engineering Center (ARDEC) sponsored this research project to support the development of new self-assembled monolayer fiber coatings. These coatings can greatly increase the bond strength between the fiber and the resin matrix of a composite material. Composite ammunition components molded from such materials will exhibit higher strength than current materials, and will provide a major improvement in the performance of composites in military applications. Use of composite materials in military applications is desirable because of the lighter weight of the materials and their high strengths. The FY97 project investigated initial interfacial chemical control for enhancement of composite material strength. The core of the project was to modify the covalent interface of glass fibers (or other reinforcing fibers) to induce strong, uniform, defect-free adhesion between the fibers' surfaces and the polymer matrix. Installing a self-assembled monolayer tailored to the specific matrix resin accomplished this. Simply, the self-assembled monolayer modifies the fiber to make it appear to have the same chemical composition as the resin matrix. The self-assembled monolayer creates a receptive, hydrophobic interface that the thermoset resin (or polymer precursors) would wet more effectively, leading to a higher contact surface area and more efficient adhesion. The FY97 work phase demonstrated that it is possible to increase the adhesive strength, as well as increase the heat deflection temperature through the use of self-assembled monolayer

  5. Suitability of dredged material for reclamation of surface-mined land. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, W.; Van Luik, A.

    1979-12-01

    Eroding ridges of acidic coal-mine spoil in La Salle County, Illinois, were leveled to form a gently-sloped raised plateau. Four test plots were constructed: a control plot and three treatment plots that received a 0.9-m-thick cover of dredged material obtained from the Metropolitan Sanitary District of Greater Chicago. Two treatment plots received lime applications and all plots were seeded with a mixture of grasses. Pressure-vacuum soil water samplers were installed, in duplicate, at two levels in the control plot and at three levels in each treatment plot. The three levels in the treatment plots coincided with dredged material, the dredged-material mine-spoil interface, and the underlying mine spoil. Surface water, soil water, and groundwater were monitored for 29 water-quality parameters for one year. Rainfall, air temperature, runoff, and water-level elevation data were collected also. Detailed analysis of the data indicates that the dredged material used in this study does not adversely affect water quality; it supports abundant plant growth, lessens groundwater contamination, and controls acid runoff. The dredged material is judged to be a suitable material for use in reclamation of surface-mined land.

  6. Development & Optimization of Materials and Processes for a Cost Effective Photoelectrochemical Hydrogen Production System. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Eric W

    2011-01-17

    The overall project objective was to apply high throughput experimentation and combinatorial methods together with novel syntheses to discover and optimize efficient, practical, and economically sustainable materials for photoelectrochemical production of bulk hydrogen from water. Automated electrochemical synthesis and photoelectrochemical screening systems were designed and constructed and used to study a variety of new photoelectrocatalytic materials. We evaluated photocatalytic performance in the dark and under illumination with or without applied bias in a high-throughput manner and did detailed evaluation on many materials. Significant attention was given to -Fe2O3 based semiconductor materials and thin films with different dopants were synthesized by co-electrodeposition techniques. Approximately 30 dopants including Al, Zn, Cu, Ni, Co, Cr, Mo, Ti, Pt, etc. were investigated. Hematite thin films doped with Al, Ti, Pt, Cr, and Mo exhibited significant improvements in efficiency for photoelectrochemical water splitting compared with undoped hematite. In several cases we collaborated with theorists who used density functional theory to help explain performance trends and suggest new materials. The best materials were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visual spectroscopy (UV-Vis), X-ray photoelectron spectroscopy (XPS). The photoelectrocatalytic performance of the thin films was evaluated and their incident photon

  7. Thermal protection system ablation sensor

    Science.gov (United States)

    Gorbunov, Sergey (Inventor); Martinez, Edward R. (Inventor); Scott, James B. (Inventor); Oishi, Tomomi (Inventor); Fu, Johnny (Inventor); Mach, Joseph G. (Inventor); Santos, Jose B. (Inventor)

    2011-01-01

    An isotherm sensor tracks space vehicle temperatures by a thermal protection system (TPS) material during vehicle re-entry as a function of time, and surface recession through calibration, calculation, analysis and exposed surface modeling. Sensor design includes: two resistive conductors, wound around a tube, with a first end of each conductor connected to a constant current source, and second ends electrically insulated from each other by a selected material that becomes an electrically conductive char at higher temperatures to thereby complete an electrical circuit. The sensor conductors become shorter as ablation proceeds and reduced resistance in the completed electrical circuit (proportional to conductor length) is continually monitored, using measured end-to-end voltage change or current in the circuit. Thermocouple and/or piezoelectric measurements provide consistency checks on local temperatures.

  8. Relationship between geochemical and geomechanical properties of magnesia building material. Final report

    International Nuclear Information System (INIS)

    Freyer, Daniela

    2015-06-01

    Long-term isolation of radioactive wastes from the biosphere imposes particular demands an potential building materials for engineered barrier systems (EBS). Due to its proposed longterm stability in salt formations MgO-based (''Sorel'') mortar or concrete is the preferred material option for construction of dam or shaft seals based and more than 100 years practical experiences. Fundamental investigations concerning geochemical and geomechanical properties of the Sorel-building material were performed in the framework of an interdisciplinary research project of the IfAC (Institut fuer Anorganische Chemie) and the IfBUS (Institut fuer Bergbau und Spezialtiefbau) both of University TU Bergakademie Freiberg in cooperation with the IfG Leipzig (Institut fuer Gebirgsmechanik GmbH). The sophisticated investigation approach consisting of a step-by-step procedure, which delivers a comprehensive understanding of the strongly interrelated aspects and processes. This facilitates development of tailored building material mixtures for all technical purposes, e.g. for shotcrete or site concrete applications. Chemical phase formation and stability of sorel binder phases of the magnesia building material were investigated focusing and the solubility equilibria in the basic system Mg(OH) 2 - MgCI 2 - H 2 O and Mg(OH) 2 - MgSO 4 - H 2 .Two building material mixtures were developed. Both mixtures are optimized under consideration of their flow and solidification behavior and the rheology of the binder suspension, which was modified by adding filler materials. In particular, the used magnesium oxide reactivity was found to be the prime factor for the temporary binder phase formation and heat supply, e.g. too reactive MgO leads to earlier and higher setting temperatures correlating to earlier hardening which affects the material workability. The reliability of results was proven by comparisons with measured properties during large in situ-tests. Time

  9. Final Technical Report for DE-SC0001878 [Theory and Simulation of Defects in Oxide Materials

    Energy Technology Data Exchange (ETDEWEB)

    Chelikowsky, James R. [University of Texas at Austin

    2014-04-14

    We explored a wide variety of oxide materials and related problems, including materials at the nanoscale and generic problems associated with oxide materials such as the development of more efficient computational tools to examine these materials. We developed and implemented methods to understand the optical and structural properties of oxides. For ground state properties, our work is predominantly based on pseudopotentials and density functional theory (DFT), including new functionals and going beyond the local density approximation (LDA): LDA+U. To study excited state properties (quasiparticle and optical excitations), we use time dependent density functional theory, the GW approach, and GW plus Bethe-Salpeter equation (GW-BSE) methods based on a many-body Green function approaches. Our work focused on the structural, electronic, optical and magnetic properties of defects (such as oxygen vacancies) in hafnium oxide, titanium oxide (both bulk and clusters) and related materials. We calculated the quasiparticle defect states and charge transition levels of oxygen vacancies in monoclinic hafnia. we presented a milestone G0W0 study of two of the crystalline phases of dye-sensitized TiO{sub 2} clusters. We employed hybrid density functional theory to examine the electronic structure of sexithiophene/ZnO interfaces. To identify the possible effect of epitaxial strain on stabilization of the ferromagnetic state of LaCoO{sub 3} (LCO), we compare the total energy of the magnetic and nonmagnetic states of the strained theoretical bulk structure.

  10. Final Report, Materials for Industrial Heat Recovery Systems, Task 1 Improved Materials and Operation of Recuperators for Aluminum Melting Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R.; Sarma, Gorti B.; Thekdi, Arvind; Meisner Roberta A.; Phelps, Tony; Willoughby, Adam W.; Gorog, J. Peter; Zeh, John; Ningileri, Shridas; Liu, Yansheng; Xiao, Chenghe

    2007-09-30

    Production of aluminum is a very energy intensive process which is increasingly more important in the USA. This project concentrated on the materials issues associated with recovery of energy from the flue gas stream in the secondary industry where scrap and recycled metal are melted in large furnaces using gas fired burners. Recuperators are one method used to transfer heat from the flue gas to the air intended for use in the gas burners. By preheating this combustion air, less fuel has to be used to raise the gas temperature to the desired level. Recuperators have been successfully used to preheat the air, however, in many cases the metallic recuperator tubes have a relatively limited lifetime – 6 to 9 months. The intent of this project was to determine the cause of the rapid tube degradation and then to recommend alternative materials or operating conditions to prolong life of the recuperator tubes. The first step to understanding degradation of the tubes was to examine exposed tubes to identify the corrosion products. Analyses of the surface scales showed primarily iron oxides rather than chromium oxide suggesting the tubes were probably cycled to relatively high temperatures to the extent that cycling and subsequent oxide spalling reduced the surface concentration of chromium below a critical level. To characterize the temperatures reached by the tubes, thermocouples were mounted on selected tubes and the temperatures measured. During the several hour furnace cycle, tube temperatures well above 1000°C were regularly recorded and, on some occasions, temperatures of more than 1100°C were measured. Further temperature characterization was done with an infrared camera, and this camera clearly showed the variations in temperature across the first row of tubes in the four recuperator modules. Computational fluid dynamics was used to model the flow of combustion air in the tubes and the flue gas around the outside of the tubes. This modeling showed the

  11. Industry to Education Technical Transfer Program & Composite Materials. Composite Materials Course. Fabrication I Course. Fabrication II Course. Composite Materials Testing Course. Final Report.

    Science.gov (United States)

    Massuda, Rachel

    These four reports provide details of projects to design and implement courses to be offered as requirements for the associate degree program in composites and reinforced plastics technology. The reports describe project activities that led to development of curricula for four courses: composite materials, composite materials fabrication I,…

  12. Molecular Environmental Science Using Synchrotron Radiation: Chemistry and Physics of Waste Form Materials. Final Report

    International Nuclear Information System (INIS)

    Lindle, Dennis W.

    2011-01-01

    Production of defense-related nuclear materials has generated large volumes of complex chemical wastes containing a mixture of radionuclides. The disposition of these wastes requires conversion of the liquid and solid-phase components into durable, solid forms suitable for long-term immobilization. Specially formulated glass compositions and ceramics such as pyrochlores and apatites are the main candidates for these wastes. An important consideration linked to the durability of waste-form materials is the local structure around the waste components. Equally important is the local structure of constituents of the glass and ceramic host matrix. Knowledge of the structure in the waste-form host matrices is essential, prior to and subsequent to waste incorporation, to evaluate and develop improved waste-form compositions based on scientific considerations. This project used the soft-x-ray synchrotron-radiation-based technique of near-edge x-ray-absorption fine structure (NEXAFS) as a unique method for investigating oxidation states and structures of low-Z elemental constituents forming the backbones of glass and ceramic host matrices for waste-form materials. In addition, light metal ions in ceramic hosts, such as titanium, are also ideal for investigation by NEXAFS in the soft-x-ray region. Thus, one of the main objectives was to understand outstanding issues in waste-form science via NEXAFS investigations and to translate this understanding into better waste-form materials, followed by eventual capability to investigate 'real' waste-form materials by the same methodology. We conducted several detailed structural investigations of both pyrochlore ceramic and borosilicate-glass materials during the project and developed improved capabilities at Beamline 6.3.1 of the Advanced Light Source (ALS) to perform the studies.

  13. Material development for waste to energy plants. Overlay welding and refractory linings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Noergaard Hansson, A.

    2011-02-15

    Waste is an extremely corrosive fuel. In order to recover a higher percentage of the energy in waste, waste incineration plants have developed from purely heat producing units to heat and power producing units. The change in concept results in higher material temperatures and thereby faster material degradation. As a result material failures have been observed in many waste incineration plants. The purpose of this project was to develop materials with higher resistance to the corrosive elements, in order to reduce the cost of maintenance, increase the availability, and increase the efficiency. The focus is on overlay welding and refractory linings. Inconel 625, alloy 50, alloy 686, and Super 625 offer equivalent corrosion protection at panel walls. 100% overlay performs better than 50% overlay. The corrosion morphology changes with increasing temperature from pitting and general corrosion to pitting and selective corrosion (dendritic core or grain boundaries). The previously observed detrimental effect of Fe on the corrosion resistance was not confirmed. It probably depends on factors such as microstructure of the alloy and local metal temperature. Ni-overlay also reduces the corrosion rates on superheater tubes. However, the superheater environment is less aggressive than the water wall environment. Failure of refractory linings is linked to excess porosity, detrimental reactions between raw materials and other mix constituents, volume growth reactions between base material and salt depositions, and thermal stress induced crack formation. Free water and not decomposition of hydrates causes spalling and cracking during the initial heating of refractory linings. Finite Element analysis confirms the stress levels between steel and refractory with the higher stress level at the top of the panel wall tube. A number of LCC mixes were formulated, adjusted and tested. Mixes with low open porosities ({approx} 10%) and state of the art resistance to KCl were achieved. (LN)

  14. Research and development activities at INE concerning corrosion of final repository container materials

    International Nuclear Information System (INIS)

    Kienzler, Bernhard

    2017-01-01

    The present work provides a historical overview of the research and development activities carried out at the (Nuclear) Research Center Karlsruhe (today KIT) since the beginning of the 1980s on the corrosion of materials which might be suitable for construction of containers for highly radioactive wastes. The report relates almost exclusively to the work performed by Dr. Emmanuel Smailos, who elaborated the corrosion of various materials at the Institute for Nuclear Waste Disposal (INE). The requirements for the containers and materials, which were subject to changes in time, are presented. The changes were strongly influenced by the changed perception of the use of nuclear energy. The selection of the materials under investigations, the boundary conditions for the corrosion experiments and the analytical methods are described. Results of the corrosion of the materials such as finegrained steel, Hastelloy C4, nodular cast iron, titanium-palladium and copper or copper-nickel alloys in typical salt solutions are summarized. The findings of special investigations, e.g. corrosion under irradiation or the influence of sulfide on the corrosion rates are shown. For construction of disposal canisters, experiments were conducted to determine the contact corrosion, the influence of the hydrogen embrittlement of Ti-Pd and fine-grained steels on the corrosion behavior as well as the corrosion behavior of welding and the influence of different welding processes with the resulting heat-affected zones on the corrosion behavior. The work was contributed to several European research programs and was well recognized in the USA. Investigations on the corrosion of steels in non-saline solutions and corrosion under interim storage conditions as well as under the expected conditions of the Konrad repository for low-level radioactive wastes are also described. In addition, the experiments on ceramic materials are presented and the results of the corrosion of Al 2 O 3 and ZrO 2 ceramics

  15. Executive summary of safeguards systems concepts for nuclear material transportation. Final report

    International Nuclear Information System (INIS)

    Baldonado, O.C.; Kevany, M.; Rodney, D.; Pitts, D.; Mazur, M.

    1977-09-01

    The U.S. Nuclear Regulatory Commission contracted with System Development Corporation to develop integrated system concepts for the safeguard of special strategic nuclear materials (SSNM), which include plutonium, uranium 233 and uranium 235 of at least 20 percent enrichment, against malevolent action during interfacility transport. This executive summary outlines the conduct and findings of the project. The study was divided into three major subtasks: (1) The development of adversary action sequences; (2) The assessment of the vulnerability of the transport of nuclear materials to adversary action; (3) The development of conceptual safeguards system design requirements to reduce vulnerabilities

  16. Test methods for the dynamic mechanical properties of polymeric materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Baker, G.K.

    1980-06-01

    Various test geometries and procedures for the dynamic mechanical analysis of polymers employing a mechanical spectrometer have been evaluated. The methods and materials included in this work are forced torsional pendulum testing of Kevlar/epoxy laminates and rigid urethane foams, oscillatory parallel plate testing to determine the kinetics of the cure of VCE with Hylene MP, oscillatory compressive testing of B-3223 cellular silicone, and oscillatory tensile testing of Silastic E and single Kevlar filaments. Fundamental dynamic mechanical properties, including the storage and loss moduli and loss tangent of the materials tested, were determined as a function of temperature and sometimes of frequency.

  17. Preparation of Silicon Rubber/2,2'-(3-methyl-4-dihydro-1,3,2-benzoxazinePropane Ablative-resistant Composites and Its Ablative Structure

    Directory of Open Access Journals (Sweden)

    DONG Yimin

    2017-10-01

    Full Text Available Benzoxazine resin is a new generation of anti-ablation resin with high char yield and high-temperature oxidation resistance. Using high temperature vulcanized silicon rubber as ablation resistance matrix and 2,2'-(3-methyl-4-dihydro-1,3,2-benzoxazinepropane as anti-ablation resin, silicon rubber/polybenzoxazine anti-ablation composite was prepared by blending method. The mechanical properties were tested,and the ablation structure and the composition of the composite were investigated by DSC,SEM,FT-IR and Raman.Experimental results show that the polybenzoxazine resin can improve the ablation resistance property of silicone rubber composite. The composite has good ablation resistance and mechanical property when the addition of polybenzoxazine resin reaches 20 phr. After ablated by oxygen acetylene flame,the ablation layer is divided into three obvious layers as surface ceramic layer,pyrolysis carbonization layer and base layer. The surface ceramic layer formed in the progress of ablation plays a positive role in the ablation property of the composite material.

  18. Final report on CCQM-K80: Comparison of value-assigned CRMs and PT materials: Creatinine in human serum

    Science.gov (United States)

    Camara, Johanna E.; Duewer, David L.; Gasca Aragon, Hugo; Lippa, Katrice A.; Toman, Blaza

    2013-01-01

    regression was used to establish the key comparison reference function (KCRF) relating the assigned values to the repeatability measurements. Parametric bootstrap Monte Carlo was used to estimate 95% level-of-confidence coverage intervals for the degrees of equivalence of materials, d +/- U95(d), and of the participating NMIs, D +/- U95(D). Because of the wide range of creatinine mass fraction in the materials, these degrees of equivalence are expressed in percent relative form: %d +/- U95(%d) and %D +/- U95(%D). On the basis of leave-one-out cross-validation, the assigned values for 16 of the 17 materials were deemed equivalent at the 95% level of confidence. These materials were used to define the KCRF. The excluded material was identified as having a marginally underestimated assigned uncertainty, giving it large and potentially anomalous influence on the KCRF. However, this material's %d of 1.4 +/- 1.5 indicates that it is equivalent with the other materials at the 95% level of confidence. The median |%d| for all 17 of the materials is 0.3 with a median U95(%d) of 1.9. All of these higher-order CRMs for creatinine in human serum are equivalent within their assigned uncertainties. The median |%D| for the participating NMIs is 0.3 with a median U95(%D) of 2.1. These results demonstrate that all participating NMIs have the ability to correctly value-assign CRMs and proficiency test materials for creatinine in human serum and similar measurands. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  19. Regeneration of FGD dry-sorbent materials. Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kapsalopoulou, A.J.; Sargent, D.H.; Rissman, E.F.

    1982-05-01

    Sodium-based sorbent injection directly into the flue gas duct of a coal-burning power plant has been investigated since 1975 by GFETC (using laboratory and pilot plant apparatus) as an SO/sub 2/ control technology. Regeneration of sorbent from spent sorbent material is highly desirable to reduce the sorbent cost, and to alleviate the leaching and potential pollution problems of soluble sodium compounds when disposing of spent sorbent materials in landfills. The work reported herein was initiated to develop a continuous, aqueous-based process for regeneration of sodium carbonate-type sorbents from spent sodium-base sorbent/flyash materials. Specific project objectives are to: (1) retain process simplicity and to avoid difficult process conditions; (2) maximize recovery of sodium from spent sorbents; (3) minimize process costs and energy requirements; (4) maximize reactivity of the regenerated sodium bicarbonate sorbent; and (5) produce process waste materials that may be disposed of in an environmental acceptable manner. The sorbent regeneration process which has been developed during the laboratory investigation (Phase I) of this project may be divided into three parts: (1) leaching of the spent sodium-based sorbent; (2) conversion of the leachate to a NaCl brine; and (3) production of NaHCO/sub 3/ (regenerated sorbent) using commercially-proven Solvay (ammonia-soda) process technology. Significant results from the laboratory study are as given.

  20. A Model for Producing and Sharing Instructional Materials in Veterinary Medicine. Final Report.

    Science.gov (United States)

    Ward, Billy C.; Niec, Alphonsus P.

    This report describes a study of factors which appear to influence the "shareability" of audiovisual materials in the field of veterinary medicine. Specific factors addressed are content quality, instructional effectiveness, technical quality, institutional support, organization, logistics, and personal attitudes toward audiovisuals. (Author/CO)

  1. Improvement of the fracture toughness in the PWR pressurizer surgeline material (Final report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jun Hwa; Lee, Bong Sang; Oh, Yong Jun; Yoon, Ji Hyun; Oh, Jong Myung; Park, Buk Gyun; Kim, Ju Hak; Kuk Il Hyun; Byun, Taek Sang [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-12-01

    Fracture toughness property of PWR surgeline pipe materials is one of the most important factor for Leak Before Break(LBB) analysis. In order to improve fracture toughness of the surgeline material (SA312-TP347 stainless steel), base on the evaluation and analysis of the commercial TP347 alloys, eleven TP347 model alloys were designed and manufactured. Tensile and fracture resistance properties of the model alloys, as well as microstructure, were evaluated. It is concluded that the nitrogen shall be added more than 0.1% for high tensile property and the carbon shall be in the range of 0.02 to 0.04% for high fracture resistance. In addition, four TP316N stainless steels were manufactured and evaluated to find out the applicability as a candidate material for PWR surgeline pipe. As a conclusion, TP316N stainless steels had an excellent property to be used for surgeline piping materials, substituting the present TP347 stainless steels. (author). 11 refs., 50 figs., 12 tabs.

  2. Safety analysis report for packages: packaging of fissile and other radioactive materials. Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1984-01-01

    The 9965, 9966, 9967, and 9968 packages are designed for surface shipment of fissile and other radioactive materials where a high degree of containment (either single or double) is required. Provisions are made to add shielding material to the packaging as required. The package was physically tested to demonstrate that it meets the criteria specified in USDOE Order No. 5480.1, chapter III, dated 5/1/81, which invokes Title 10, Code of Federal Regulations, Part 71 (10 CFR 71), Packing and Transportation of Radioactive Material, and Title 49, Code of Federal Regulations, Part 100-179, Transportation. By restricting the maximum normal operating pressure of the packages to less than 7 kg/cm 2 (gauge) (99 to 54 psig), the packages will comply with Type B(U) regulations of the International Atomic Energy Agency (IAEA) in its Regulations for the Safe Transport of Radioactive Materials, Safety Series No. 6, 1973 Revised Edition, and may be used for export and import shipments. These packages have been assessed for transport of up to 14.5 kilograms of uranium, excluding uranium-233, or 4.4 kilograms of plutonium metal, oxides, or scrap having a maximum radioactive decay energy of 30 watts. Specific maximum package contents are given. This quantity and the configuration of uranium or plutonium metal cannot be made critical by any combination of hydrogeneous reflection and moderation regardless of the condition of the package. For a uranium-233 shipment, a separate criticality evaluation for the specific package is required

  3. Economic assessment of using nonmetallic materials in the direct utilization of geothermal energy. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cabibbo, S.V.; Ammerlaan, T.

    1979-02-01

    The cost effectiveness of nonmetallic materials in three direct-use geothermal applications was assessed. An extensive review of the available literature was conducted in order to ascertain those processes for which sufficient design and cost data had been published to permit this economic assessment to be made. Only three such processes could be found and they are discussed.

  4. Executive summary of the special safeguards study on material control and accounting systems. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    This report assesses the feasibility of real-time systems applied to mixed-oxide fuel rod fabrication. Their interaction with other material control and accounting measures are considered. Economics, effectiveness, and acceptance factors are discussed. A cost-benefit evaluation is made and recommendations given for safeguards improvements

  5. Secondary materials: Engineering properties, environmental consequences, and social and economic impacts. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Breslin, V.; Reaven, S.; Schwartz, M.; Swanson, L.; Zweig, M.; Bortman, M.; Schubel, J.

    1993-08-01

    This report investigates two secondary materials, plastic lumber made from mixed plastic waste, and cement blocks and structures made with incinerator ash. Engineering properties, environmental impacts, and energy costs and savings of these secondary materials are compared to standard lumber products and cement blocks. Market capacity and social acceptance of plastic lumber and stabilized ash products are analyzed. These secondary materials apparently have potential markets; however, their economic value is primarily that they will not take up landfill space. For plastic lumber and stabilized incinerator ash products, marine and highway construction seem ideal public works applications. Incinerator ash may be suitable to use in seawalls, jetties, fishing reefs, highway barriers, and roadbed applications. Docks, piers, highway sound barriers, parking stops, and park furniture may all be made from plastic lumber. To encourage public acceptance and improve the market potential of secondary materials, these activities could be beneficial: industry should emphasize developing useful, long-lived products; industry and governments should create product performance criteria; government should provide rigorous testing and demonstration programs; and government and industry should cooperate to improve public outreach and educational programs.

  6. Fellowship Program in the Design and Development of Instructional Materials. Final Report.

    Science.gov (United States)

    Fleming, Malcolm; Pett, Dennis

    A two-year graduate program leading to a specialists's degree was administered to train individuals in the design of instructional materials for elementary, secondary, vocational and special education curricula. The program sought to achieve a multiplier effect by placing its graduates in positions in which they could help other educators to…

  7. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

    International Nuclear Information System (INIS)

    Naus, Dan J.; Mattus, Catherine H.; Dole, Leslie Robert

    2007-01-01

    The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a 'primer' on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a 'bench-scale' laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the 'primer,' a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures

  9. Final Report - Assessment of Potential Phosphate Ion-Cementitious Materials Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Naus, Dan J [ORNL; Mattus, Catherine H [ORNL; Dole, Leslie Robert [ORNL

    2007-06-01

    The objectives of this limited study were to: (1) review the potential for degradation of cementitious materials due to exposure to high concentrations of phosphate ions; (2) provide an improved understanding of any significant factors that may lead to a requirement to establish exposure limits for concrete structures exposed to soils or ground waters containing high levels of phosphate ions; (3) recommend, as appropriate, whether a limitation on phosphate ion concentration in soils or ground water is required to avoid degradation of concrete structures; and (4) provide a "primer" on factors that can affect the durability of concrete materials and structures in nuclear power plants. An assessment of the potential effects of phosphate ions on cementitious materials was made through a review of the literature, contacts with concrete research personnel, and conduct of a "bench-scale" laboratory investigation. Results of these activities indicate that: no harmful interactions occur between phosphates and cementitious materials unless phosphates are present in the form of phosphoric acid; phosphates have been incorporated into concrete as set retarders, and phosphate cements have been used for infrastructure repair; no standards or guidelines exist pertaining to applications of reinforced concrete structures in high-phosphate environments; interactions of phosphate ions and cementitious materials has not been a concern of the research community; and laboratory results indicate similar performance of specimens cured in phosphate solutions and those cured in a calcium hydroxide solution after exposure periods of up to eighteen months. Relative to the "primer," a separate NUREG report has been prepared that provides a review of pertinent factors that can affect the durability of nuclear power plant reinforced concrete structures.

  10. Procedural law problems with the construction of installations (plants) for the final storage of radioactive materials

    International Nuclear Information System (INIS)

    Hoppe, W.; Bunse, B.

    1984-01-01

    The underground exploration of the salt-mine Gorleben has to be permitted according to sec. 126 para. 3, 51 et seq. Federal Mining Act. There is, however, no need for carrying out a nuclear law procedure for the official approval of the plan because the construction of the exploration mine does not represent the construction of a final storage facility. The operation of exploration measures does not create legally relevant prejudices for procedures of the official approval of the plan according to Atomic Energy Law. (HP) [de

  11. Novel Contact Materials for Improved Performance CdTe Solar Cells Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rockett, Angus [Colorado School of Mines, Golden, CO (United States); Marsillac, Sylvain [Old Dominion Univ., Norfolk, VA (United States); Collins, Robert [Univesity of Toledo

    2018-04-15

    This program has explored a number of novel materials for contacts to CdTe solar cells in order to reduce the back contact Schottky barrier to zero and produce an ohmic contact. The project tested a wide range of potential contact materials including TiN, ZrN, CuInSe2:N, a-Si:H and alloys with C, and FeS2. Improved contacts were achieved with FeS2. As part of understanding the operation of the devices and controlling the deposition processes, a number of other important results were obtained. In the process of this project and following its conclusion it led to research that resulted in seven journal articles, nine conference publications, 13 talks presented at conferences, and training of eight graduate students. The seven journal articles were published in 2015, 2016, and 2017 and have been cited, as of March 2018, 52 times (one cited 19 times and two cited 11 times). We demonstrated high levels of doping of CIS with N but electrical activity of the resulting N was not high and the results were difficult to reproduce. Furthermore, even with high doping the contacts were not good. Annealing did not improve the contacts. A-Si:H was found to produce acceptable but unstable contacts, degrading even over a day or two, apparently due to H incorporation into the CdTe. Alloying with C did not improve the contacts or stability. The transition metal nitrides produced Schottky type contacts for all materials tested. While these contacts were found to be unsatisfactory, we investigated FeS2 and found this material to be effective and comparable to the best contacts currently available. The contacts were found to be chemically stable under heat treatment and preferable to Cu doped contacts. Thus, we demonstrated an improved contact material in the course of this project. In addition, we developed new ways of controlling the deposition of CdTe and other materials, demonstrated the nature of defects in CdTe, and studied the distribution of conductivity and carrier type in Cd

  12. Review of world experience and properties of materials for encapsulation of terrestrial photovoltaic arrays. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Carmichael, D.C.; Gaines, G.B.; Sliemers, F.A.; Kistler, C.W.; Igou, R.D.

    1976-07-21

    Available information defining the state of the art of encapsulation materials and processes for terrestrial photovoltaic devices and related applications were collected and analyzed. Based on criteria of properties, processability, availability, and cost, candidate materials were identified which have potential for use in encapsulation systems for low-cost, long-life terrestrial photovoltaic arrays manufactured by automated, high-volume processes. The criteria for consideration of the encapsulation systems were based on the goals for arrays with a lifetime of over 20 years high reliability, an efficiency greater than 10 percent, a total array price less than $500/kW, and a production capacity of 5 x 10/sup 5/ kW/yr. (WDM)

  13. Corrosion behavior of copper-base materials in a gamma-irradiated environment; Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yunker, W.H.

    1990-09-01

    Specimens of three copper-base materials were corrosion tested with gamma radiation exposure dose rates in the range of 1.9 {times} 10{sup 3} R/h to 4.9 {times} 10{sup 5} R/h. Materials used were pure copper, 7% aluminum bronze and 30% copper-nickel. Exposures were performed in moist air at 95{degree}C and 150{degree}C and liquid Well J-13 water at 95{degree}C, for periods of up to 16 months. Specimens were monitored for uniform weight loss, stress-induced corrosion and crevice corrosion. Specimen surfaces were examined visually at 10X magnification as well as by Auger Electron Spectroscopy, x-ray diffraction and metallography. Corrosion was not severe in any of the cases. In general, the pure copper was corroded most uniformly while the copper-nickel was the least reproducibly corroded. 11 refs, 40 figs., 15 tabs.

  14. Materials and fabrication methods for the next generation of respiratory protection (RESPO 21). Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Katz, H.S.; Agarwal, R.

    1990-11-02

    Although excellent protective items have been developed in the past, it has become very apparent that there is an urgent need for better masks, hoods, and garments that will protect soldiers and civilians from the chemical threats of terrorist groups and countries. There is much room for improvement in performance and cost in order to make the protection more readily available for military personnel and for mass distribution to civilians. We have prepared an overview of currently available materials and fabrication methods, and have recommended materials and methods that should be considered for future ijmprovements in this field. This overview is presented in addition to our report on the four tasks that were given to us in the statement of work for this program.

  15. LDRD final report : mesoscale modeling of dynamic loading of heterogeneous materials

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dingreville, Remi Philippe Michel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Voth, Thomas Eugene [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Furnish, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-12-01

    Material response to dynamic loading is often dominated by microstructure (grain structure, porosity, inclusions, defects). An example critically important to Sandia's mission is dynamic strength of polycrystalline metals where heterogeneities lead to localization of deformation and loss of shear strength. Microstructural effects are of broad importance to the scientific community and several institutions within DoD and DOE; however, current models rely on inaccurate assumptions about mechanisms at the sub-continuum or mesoscale. Consequently, there is a critical need for accurate and robust methods for modeling heterogeneous material response at this lower length scale. This report summarizes work performed as part of an LDRD effort (FY11 to FY13; project number 151364) to meet these needs.

  16. Hydrogel modified materials surfaces for the ERDA artificial heart. Final report

    International Nuclear Information System (INIS)

    Hoffman, A.S.

    1978-01-01

    This report summarizes a series of studies on the suitability of silicone surgical grafts. The studies performed include an evaluation of vena cava rings to study thrombogenicity of grafted polymer coatings, the interaction of platelets with radiation grafted polymers, an in vitro evaluation of knitted dacron artery sections, the tissue compatibility of HEMA-EMA copolymers, the in vitro cell adhesion to polymeric materials, and the use of the ESCA technique for determining HEMA/EMA ratios

  17. A regulatory analysis on emergency preparedness for fuel cycle and other radioactive material licensees: Final report

    International Nuclear Information System (INIS)

    McGuire, S.A.

    1988-01-01

    The question this Regulatory Analysis sought to answer is: should the NRC impose additional emergency preparedness requirements on certain fuel cycle and other radioactive material licensees for dealing with accidents that might have offsite releases of radioactive material. To answer the question, we analyzed potential accidents for 15 types of fuel cycle and other radioactive material licensees. An appropriate plan would: (1) identify accidents for which protective actions should be taken by people offsite; (2) list the licensee's responsibilities for each type of accident, including notification of local authorities (fire and police generally); and (3) give sample messages for local authorities including protective action recommendations. This approach more closely follows the approach used for research reactors than for power reactors. The low potential offsite doses (acute fatalities and injuries not possible except possibly for UF 6 releases), the small areas where actions would be warranted, the small number of people involved, and the fact that the local police and fire departments would be doing essentially the same things they normally do, are all factors that tend to make a simple plan adequate. This report discusses the potentially hazardous accidents, and the likely effects of these accidents in terms of personnel danger

  18. Chemical Processing Department Control Study: Final report on the control of CPD product materials

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, D.F.; Hough, C.G.; Burke, R.C.; Stewart, K.B.

    1959-01-05

    The purpose of this report is to present the conclusions and recommendations obtained during the course of the CPD Control Study and the conceptual framework upon which they are based. Primary emphasis has been given to the control of product materials. In order to logically present the background for the definition and delineation of an appropriate CPD Control System, Section III of this report discusses a control system in the following manner; (1) the description of the control system information requirements, (2) the definition of the conceptual framework of product material control, (3) the discussion of the interrelationships of production scheduling, process control and accountability and (4) the methods for the effective utilization of control system information. Section IV utilizes this conceptual framework in order to enable a logical presentation of a proposed product material control system for the CPD. A summary of conclusions and recommendations is included in Section II. The Appendices consist of discussions of specific analysis conducted during the study. Other related reports that have been issued during the course of the study are included in the references.

  19. Materials, process, product analysis of coal process technology. Phase I final report

    Energy Technology Data Exchange (ETDEWEB)

    Saxton, J. C.; Roig, R. W.; Loridan, A.; Leggett, N. E.; Capell, R. G.; Humpstone, C. C.; Mudry, R. N.; Ayres, E.

    1976-02-01

    The purpose of materials-process-product analysis is a systematic evaluation of alternative manufacturing processes--in this case processes for converting coal into energy and material products that can supplement or replace petroleum-based products. The methodological steps in the analysis include: Definition of functional operations that enter into coal conversion processes, and modeling of alternative, competing methods to accomplish these functions; compilation of all feasible conversion processes that can be assembled from combinations of competing methods for the functional operations; systematic, iterative evaluation of all feasible conversion processes under a variety of economic situations, environmental constraints, and projected technological advances; and aggregative assessments (economic and environmental) of various industrial development scenarios. An integral part of the present project is additional development of the existing computer model to include: A data base for coal-related materials and coal conversion processes; and an algorithmic structure that facilitates the iterative, systematic evaluations in response to exogenously specified variables, such as tax policy, environmental limitations, and changes in process technology and costs. As an analytical tool, the analysis is intended to satisfy the needs of an analyst working at the process selection level, for example, with respect to the allocation of RDandD funds to competing technologies.

  20. Final Report, Fundamental Mechanisms of Transient States in Materials Quantified by DTEM

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, G. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McKeown, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-12-01

    At the project’s inception, there was growing evidence that the time domain for in situ observations of material evolution held great promise for allowing measurements to be made in never previously contemplated regimes. Also, central to the development of the project was the knowledge that phase transformations are of central importance to the development of materials microstructure and hence properties. We addressed this opportunity by developing a transmission electron microscope that could be operated in the pulsed mode (DTEM), with exposure times down to 20 ns and interframe times down to 20 ns in the nine-frame movie mode, designed with the intent of performing in situ experiments. This unprecedented capability allowed us to investigate structural phase transformations, intermetallic formation reactions, crystallization from the amorphous phase, rapid solidification of liquid metals, transformations in phase change materials, and catalyst nanoparticles. The ability of the electron microscope to create images with high spatial resolution allows for the accurate measurement of position. Common to all of the transformations mentioned above is the presence of a distinct interface between the old phase and the growing new phase. Measuring the position of the interface as a function of time, combined with the ability to count nucleation sites as a function of time, allowed for the exceptionally accurate measure of transformation kinetics. These measurements were used to guide and constrain the development of models and simulation methods for the classes of transformations studied.

  1. Study of nuclear material accounting. Final report, July 1, 1976--April 1, 1977

    International Nuclear Information System (INIS)

    Siri, W.E.; Ruderman, H.; Winsen, J.; Dresher, M.

    1977-04-01

    The basic result of this study was to affirm the utility of material accounting as a tool for safeguards purposes. Periodic inventories and proper interpretation of material unaccounted for (MUF) can be an effective procedure for estimating diversion and taking necessary follow-on action. We have developed a new approach in this study based upon the theory of games that eliminates many of the deficiencies of the classical statistical hypothesis testing approach. This new approach explicitly considers a malevolent Diverter as a basic ingredient of the analysis. This permits a different and more effective interpretation of MUF for safeguards purposes. At the present time MUF interpretation for major nuclear facilities cannot adequately support statements about diversion. Consequently NRC does not rely solely on MUF analysis for such statements. Diversion statements now are primarily based upon other safeguards systems and information. However, the game theoretic approach can make the periodic inventory-MUF concept work better for safeguards. With its use, MUF data by itself can be useful in directly interpreting possible unauthorized diversion of special nuclear material

  2. Final report on CCQM-K79: Comparison of value-assigned CRMs and PT materials: Ethanol in aqueous matrix

    Science.gov (United States)

    Hein, Sebastian; Philipp, Rosemarie; Duewer, David L.; Gasca Aragon, Hugo; Lippa, Katrice A.; Toman, Blaza

    2013-01-01

    -weighted generalized distance regression was used to establish the key comparison reference function (KCRF) relating the assigned values to the repeatability measurements. On the basis of leave-one-out cross-validation, all of the assigned values for all 27 materials were deemed equivalent at the 95% level of confidence. These materials were used to define the KCRF. Parametric bootstrap Monte Carlo was used to estimate 95% level-of-confidence coverage intervals for the degrees of equivalence of materials, d +/- U95(d), and of the participating NMIs, D +/- U95(D). Because of the very wide range of ethanol mass fraction in the materials, these degrees of equivalence are expressed in percent relative form: %d +/- U95(%d) and %D +/- U95(%D). The median of the absolute values of the %D for the participating NMIs is less than 0.05% with a median U95(%D) of less than 1%. These results demonstrate that the participating NMIs have the ability to correctly value-assign CRMs and proficiency test materials for ethanol in aqueous media and similar measurands. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  3. Final Report: Characterization of Hydrogen Adsorption in Carbon-Based Materials by NMR

    International Nuclear Information System (INIS)

    Wu, Yue; Kleinhammes, Alfred

    2011-01-01

    In support of DOE/EERE's Fuel Cell Technologies Program Hydrogen Sorption Center of Excellence (HSCoE), UNC conducted Nuclear Magnetic Resonance (NMR) measurements that contributed spectroscopic information as well as quantitative analysis of adsorption processes. While NMR based Langmuir isotherms produce reliable H2 capacity measurements, the most astute contribution to the center is provided by information on dihydrogen adsorption on the scale of nanometers, including the molecular dynamics of hydrogen in micropores, and the diffusion of dihydrogen between macro and micro pores. A new method to assess the pore width using H2 as probe of the pore geometry was developed and is based on the variation of the observed chemical shift of adsorbed dihydrogen as function of H2 pressure. Adsorbents designed and synthesized by the Center were assessed for their H2 capacity, the binding energy of the adsorption site, their pore structure and their ability to release H2. Feedback to the materials groups was provided to improve the materials properties. To enable in situ NMR measurements as a function of H2 pressure and temperature, a unique, specialized NMR system was designed and built. Pressure can be varied between 10-4 and 107 Pa while the temperature can be controlled between 77K and room temperature. In addition to the 1H investigation of the H2 adsorption process, NMR was implemented to measure the atomic content of substituted elements, e.g. boron in boron substituted graphitic material as well as to determine the local environment and symmetry of these substituted nuclei. The primary findings by UNC are the following: (1) Boron substituted for carbon in graphitic material in the planar BC3 configuration enhances the binding energy for adsorbed hydrogen; (2) Arrested kinetics of H2 was observed below 130K in the same boron substituted carbon samples that combine enhanced binding energy with micropore structure; (3) Hydrogen storage material made from activated PEEK

  4. Final Report: Characterization of Hydrogen Adsorption in Carbon-Based Materials by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yue; Kleinhammes, Alfred

    2011-07-11

    In support of DOE/EERE's Fuel Cell Technologies Program Hydrogen Sorption Center of Excellence (HSCoE), UNC conducted Nuclear Magnetic Resonance (NMR) measurements that contributed spectroscopic information as well as quantitative analysis of adsorption processes. While NMR based Langmuir isotherms produce reliable H2 capacity measurements, the most astute contribution to the center is provided by information on dihydrogen adsorption on the scale of nanometers, including the molecular dynamics of hydrogen in micropores, and the diffusion of dihydrogen between macro and micro pores. A new method to assess the pore width using H2 as probe of the pore geometry was developed and is based on the variation of the observed chemical shift of adsorbed dihydrogen as function of H2 pressure. Adsorbents designed and synthesized by the Center were assessed for their H2 capacity, the binding energy of the adsorption site, their pore structure and their ability to release H2. Feedback to the materials groups was provided to improve the materials’ properties. To enable in situ NMR measurements as a function of H2 pressure and temperature, a unique, specialized NMR system was designed and built. Pressure can be varied between 10-4 and 107 Pa while the temperature can be controlled between 77K and room temperature. In addition to the 1H investigation of the H2 adsorption process, NMR was implemented to measure the atomic content of substituted elements, e.g. boron in boron substituted graphitic material as well as to determine the local environment and symmetry of these substituted nuclei. The primary findings by UNC are the following: • Boron substituted for carbon in graphitic material in the planar BC3 configuration enhances the binding energy for adsorbed hydrogen. • Arrested kinetics of H2 was observed below 130K in the same boron substituted carbon samples that combine enhanced binding energy with micropore structure. • Hydrogen storage material made from

  5. High frequency dielectric reference materials BCR projekt 43. Final report of phase 1

    International Nuclear Information System (INIS)

    Chantry, G.

    1980-01-01

    The Group of High Frequency Specialists from Belgium, France, Germany, The Netherlands and the UK, was awarded contracts in 1975 to carry out a programme of measurements on the high frequency dielectric properties of materials. The object of this first phase of a projected three phase programme was to establish the reliability of existing methods of measurement and to examine the possibilities of specifying and producing some standard reference materials, both liquid and solid, which could be used for calibrating and checking the performance of industrial measurement equipment. The liquids chosen for the first phase were cyclohexane, cis and trans decalin, chlorobenzene and 0.1, 1, and 10% solutions of chlorobenzene in cyclohexane. Each group had a limited frequency range over which it could make meaningful measurements but there was sufficient overlap to ensure that all random and systematic errors could be quantitatively assayed. The real (epsilon') and imaginary (epsilon'') components of the complex permittivity for all the liquids were measured over the frequency range 10 - 3,000 GHz and for the two most lossy liquids (chlorobenzene and 10% chlorobenzene in cyclohexane) this range was extended downwards to one GHz. The programme established for the first time the possible experimental imprecisions to be expected in high frequency dielecric measurements and showed that the chosen liquids could be useful standard reference materials if sufficiently pure specimens could be obtained commercially at a reasonable price. The programme did however reveal an unexpected snag in that the liquids, especially cyclohexane, were found to be rather more liable to contamination than expected. Since cyclohexane is a very low-loss liquid, only a small amount of a lossy contaminant need be absorbed to make the observed loss increase dramatically. This report contains all the measured results in both tabular and graphical form and in addition full technical details are given of the

  6. Sealing properties of cement-based grout materials. Final report on the Rock sealing project

    International Nuclear Information System (INIS)

    Onofrei, M.; Gray, Malcolm; Shenton, B.; Walker, Brad; Pusch, R.; Boergesson, L.; Karnland, O.

    1992-10-01

    This report presents the results of laboratory studies of material properties. A number of different high performance grouts were investigated. The laboratory studies focused on mixtures of sulphate resistant portland cement, silica fume, superplasticizer and water. The ability of the thin films to self seal was confirmed. The surface reactions were studied in specimens of hardened grouts. The leach rates were found to vary with grout and water composition and with temperature. The short-term hydraulic and strength or properties of the hardened grout were determined. These properties were determined for the grouts both in-bulk and as thin-films. The hydraulic conductivities of the bulk, hardened material were found to be less than 10 -14 m/s. The hydraulic conductivities of thin films were found to be less than 10 -11 m/s. Broken, the hydraulic conductivity of the thin films could be increased to 10 -7 m/s. Examination of the leached grout specimens revealed a trend for the pore sizes to decrease with time. The propensity for fractured grouts to self seal was also observed in tests in which the hydraulic conductivity of recompacted mechanically disrupted, granulated grouts was determined. These tests showed that the hydraulic conductivity decreased rapidly with time. The decreases were associated with decreases in mean pore size. In view of the very low hydraulic conductivity it is likely that surface leaching at the grout/groundwater interface will be that major process by which bulk high-performance grouts may degrade. With the completion of the laboratory, in situ and modelling studies it appears that high-performance cement based grouts can be considered as viable materials for some repository sealing applications. Some of the uncertainties that remain are identified in this report. (54 refs.)

  7. Nuclear reactor and materials science research: Final technical report, May 1, 1985-September 30, 1986

    International Nuclear Information System (INIS)

    Harling, O.K.

    1987-01-01

    Throughout the 17-month period of the grant, May 1, 1985 - September 30, 1986, the MIT Research Reactor (MITR-II) was operated in support of research and academic programs in the physical and life sciences and in related engineering fields. The period encompassed MIT's fiscal year utilization of the reactor during that period may be classified as follows: neutron beam tube research, nuclear materials research and development, radiochemistry and trace analysis, nuclear medicine, radiation health physics, computer control of reactors, dose reduction in nuclear power reactors, reactor irradiations and services for groups outside MIT, and MIT research reactor. This paper provides detailed information on this research academic utilization

  8. Final results of the FY'78 chemistry and materials science research program review

    International Nuclear Information System (INIS)

    Frazer, J.W.

    1977-01-01

    18 projects which were selected to be sponsored by ''Chemistry Research Program'' are summarized. These include: lasers for chemical analysis; multi-element analysis systems; spectroscopic analysis of surface passivation; non-aqueous titrimetry; materials damage prediction for fiber composites; safe high energy explosives; single photon absorption reaction chemistry; reaction in shock waves; cryogenic heavy hydrogen technology; acoustic emission; metallic alloy glasses; basic study of toughness in steel; static equation-of-state at 100 GPa; transuranium element research; nuclear structure research; neutron capture gamma measurements; x-ray fluorescence analysis; and pyrochemical investigation

  9. Development and characterization of semiconductor materials by ion beams. Final report of a co-ordinated research project

    International Nuclear Information System (INIS)

    2002-06-01

    This CRP was recommended by the Consultants meeting on Ion Beam Techniques Applied to Semiconductor and Related Advanced Materials, held in April 1997 in Vienna. The consultants proposed to have a CRP in the field of application of MeV ion beams for the development and characterization of semiconductor materials. The CRP was approved and a first RCM was held in Vienna between 2-5 June 1998, in order to stimulate ideas and to promote collaborations among CRP participants. The goals and practical outcomes of the CRP were defined and several specific topics were identified including: optoelectronic characterization of semiconductor materials and devices by ion microbeams, characterization of thin films, defect transformations in semiconductors, light element analysis. One important recommendation was that sample exchanges among different laboratories be strongly encouraged. The participants presented individual activities on their projects, all subjects of research were identified and linked with approved individual projects. Collaboration among the participants was discussed and established. Some modifications to work plans were adopted. As proposed during the first RCM, the final RCM was held at the Ruder Boskovic Institute, Zagreb, Croatia, between 25 and 29 September 2000, with the purpose of reviewing/discussing the results achieved during the course of the CRP and to prepare a draft of the final report and associated publication. This document contains summary of the CRP and ten individual reports presented by participants. Each of the reports has been indexed separately

  10. Capsule physics comparison of different ablators for NIF implosion designs

    Science.gov (United States)

    Clark, Daniel; Kritcher, Andrea; Yi, Austin; Zylstra, Alex; Haan, Steven; Ralph, Joseph; Weber, Christopher

    2017-10-01

    Indirect drive implosion experiments on the Naitonal Ignition Facility (NIF) have now tested three different ablator materials: glow discharge polymer (GDP) plastic, high density carbon (HDC), and beryllium. How do these different ablator choices compare in current and future implosion experiments on NIF? What are the relative advantages and disadvantages of each? This talk compares these different ablator options in capsule-only simulations of current NIF experiments and proposed future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Water Resources Research Program. Abatement of malodors at diked, dredged-material disposal sites. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, W.; Dravnieks, A.; Zussman, R.; Goltz, R.

    1976-06-01

    Samples of malodorous air and dredged material were collected at diked disposal sites at the following locations: Buffalo, NY; Milwaukee, WI; Mobile, AL; York Harbor, ME; Houston, TX; Detroit, MI; and Anacortes, WA; during the period July--October, 1975. Odorous compounds in the air samples were identified by gas chromatography/mass spectrometry, while the detection threshold, intensity, and character of the various odors were determined by experienced panelists using a dynamic, forced-choice-triangle olfactometer. Although significant problems with malodors were not observed beyond the disposal-area dikes during site visits, noteworthy odor episodes had occurred at some sites. An odor-abatement strategy is presented for handling the expected range of odor conditions at dredged-material disposal sites. Its aim is to reduce to an acceptable level the intensity of malodors in an affected community. The main steps in the strategy cover selection of the disposal site, site preparation, odor characterization of sediments to be dredged, malodor abatement during dredging and disposal operations, malodor abatement after filling of the disposal site, and the handling of malodor complaints.

  12. Sealing performance of fractured claystone and clay-based materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang

    2017-03-15

    The geological disposal concepts for radioactive waste are generally based on a multibarrier system comprising the natural geological formations and engineered barriers. After waste emplacement, disposal cells, access drifts and shafts will be backfilled and sealed with suitable materials to prevent release of radionuclides into the biosphere. In the framework of the THM-TON project during the last ten years from 2007 to 2016, which was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) under contract number 02E10377, GRS investigated the thermo-hydro-mechanical properties and responses of clay rocks and clay-based backfill/seal materials. The results obtained during the first time period of 2007 to 2013 are summarized in the GRS report ''Thermo-Hydro-Mechanical Processes in the Nearfield around a HLW Repository in Argillaceous Formations'' with two volumes: Volume I - Laboratory Investigations (GRS-312) /ZHA 13a/ and Volume II - In-situ-Investigations and Interpretative Modelling (GRS-313) /ZHA 14a/.

  13. Development of materials for open-cycle magnetohydrodynamics (MHD): ceramic electrode. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.L.; Marchant, D.D.

    1986-09-01

    Pacific Northwest Laboratory, supported by the US Department of Energy, developed advanced materials for use in open-cycle, closed cycle magnetohydrodynamics (MHD) power generation, an advanced energy conversion system in which the flow of electrically conducting fluid interacts with an electric field to convert the energy directly into electricity. The purpose of the PNL work was to develop electrodes for the MHD channel. Such electrodes must have: (1) electrical conductivity above 0.01 (ohm-cm)/sup -1/ from near room temperature to 1900/sup 0/K, (2) resistance to both electrochemical and chemical corrosion by both slag and potassium seed, (3) resistance to erosion by high-velocity gases and particles, (4) resistance to thermal shock, (5) adequate thermal conductivity, (6) compatibility with other channel components, particularly the electrical insulators, (7) oxidation-reduction stability, and (8) adequate thermionic emission. This report describes the concept and development of high-temperature, graded ceramic composite electrode materials and their electrical and structural properties. 47 refs., 16 figs., 13 tabs.

  14. Statistical and inventory procedures applied to nuclear-materials management. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dresch, F.W.; Butterfield, P.H.; Kinderman, E.M.

    1966-04-01

    This report recommends centralized data reporting and analysis applied to inventory management and materials control. Adoption of this report will require a two-stage development program. In the first or study phase, a computer system (software) organization will take the lead role but will work closely with the AEC organization affected. The study phase, lasting three to four months, will delineate clearly the specific approaches to be taken, potential difficulties and advantages, costs, and the preliminary systems concept and specifications for the basic information system and procedures needed for statistical control and inventory management. The AEC, after review of the study phase, would normally proceed with detailed development, programming, and implementation in which it would be assisted by outside organizations, but in which it must play the dominant role. The basic information system needed for monitoring and statistical control of nuclear materials probably could be operable within a year from the start of the study phase. Implementation of more complex and specialized statistical and inventory management techniques would extend over another four to eight months.

  15. Final Report: Stability and Novel Properties of Magnetic Materials and Ferromagnet / Insulator Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, Paul M. [Univ. of Wisconsin, Madison, WI (United States); Chang, Y. Austin [Univ. of Wisconsin, Madison, WI (United States)

    2013-07-24

    We report investigations of the synthesis, structure, and properties of new materials for spintronic applications integrated onto silicon substrates. Our primary focus is materials with very high, negative, intrinsic spin polarization of the density of states at the Fermi level. We have developed a new synthesis method for Fe3O4 thin films through selective oxidation of Fe, resulting in smooth, low-defect density films. We have synthesized Fe4N films and shown that they preferentially oxidize to Fe3O4. When integrated into magnetic tunnel junctions consisting of Fe4N / AlOx / Fe, oxidation at the Fe4N / AlOx interface creates Fe3O4, leading to negative tunneling magnetoresistance (TMR). Oxidation of Fe in nominally symmetric CoFe / AlOx / CoFe also produces Fe3O4 and negative TMR under selected oxidation conditions.

  16. Republic of Lithuania national energy strategy. Vol. 2: Background material for strategy development. Final report

    International Nuclear Information System (INIS)

    1993-12-01

    Volume II presents supplementary Background Material collected and analysed during the course of the project. Volume II consists of two parts: PART A (Sources and Methods) and PART B (Special Sub sector Issues). PART A contains seven chapters. The subject of Chapter 1 is to integrate the material of this volume into the analytical approach as a whole and to give an outline of the tools applied in the Strategy development. Reference data provided in Chapter 2 summarizes the information as to the past energy consumption and the future economic development. Chapter 3 compiles basic parameters and assumptions with regard to energy forms, costs, the economic development as laid down for use in the project. Chapter 4 discusses in detail the projection of energy demand. Chapter 5 draws up the Projects under consideration. Chapter 6 presents key results of energy scenario computations, and Chapter 7 provides energy scenario indicators and assessment information. PART B of this Volume II contains full reports regarding topics, which have only briefly been addressed in Volume I. (author).[Data

  17. Long term test of buffer material. Final Report on the pilot parcels

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Sanden, Torbjoern; Johannesson, Lars-Erik [Clay Technology AB, Lund (Sweden); Eriksen, Trygve E; Jansson, Mats; Wold, Susanna [Royal Inst. of Tech., Stockholm (Sweden); Pedersen, Karsten; Motamedi, Mehrdad [Goeteborg Univ. (Sweden); Rosborg, Bo [Studsvik Material AB, Nykoeping (Sweden)

    2000-12-01

    The 'Long Term Test of Buffer Material' (LOT) series at the Aespoe HRL aims at checking models and hypotheses for a bentonite buffer material under conditions similar to those in a KBS3 repository. The test series comprises seven test parcels, which are exposed to repository conditions for 1, 5 and 20 years. This report concerns the two completed pilot tests (1-year tests) with respect to construction, field data and laboratory results. Four research groups were engaged in this part of the project working on physical properties - mineralogy, cation diffusion, bacteria and copper corrosion, respectively. The experimental layout was to place parcels containing heater, central copper tube, pre-compacted bentonite blocks and instruments in vertical boreholes in crystalline rock. The heaters were used for simulating the decay power from spent nuclear fuel at standard KBS3 conditions (S1 parcel, 90 deg C) and to give adverse conditions (A1 parcel, 130 deg C). The latter was used in order to accelerate possible processes. Temperature, total pressure, water pressure and water content were measured during the heating period. The two pilot tests were terminated after approximately 12 months of heating, and the parcels were extracted by overlapping core drilling outside the original borehole. The entire 4.5 m long S1-parcel with approximately 20 cm rock cover was successfully lifted in one piece from the rock, whereas the central part of the A1 parcel was lost during drilling. The upper and lower parts were however retrieved. Reference and exposed bentonite material were analysed with respect to physical properties (triaxial, beam and oedometer tests), and to mineralogical properties (XRD, CEC, ICP-AES and SEM analyses) according to a defined test program. Some precipitation, mainly gypsum, was found in the warmest part of the parcels, and the only unpredicted change was minor uptake of Cu into the clay matrix. An overarching conclusion is that no degrading

  18. Material development for waste-to-energy plants. Refractory linings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hede Larsen, O.

    2010-10-15

    Evaluation and SEM analysis of plant exposed, failed linings confirm over and again that failure in broad lines is linked to excess porosity, inferior quality on raw materials, detrimental reactions between raw materials and other mix constituents, volume growth reactions between base material and salt depositions, thermal stress induced crack formation, and uncontrolled craftsmanship. Extensive evaluations, calculations and considerations revealed numerous ways to execute the formulation of experimental castable mixes, of which some formed a broad base for phase I trials. Three mixes of the experimental castable phase II batches reached apparent porosities of {approx} 10% measured with alcohol, estimated to less than 8%-9% if measured in water. These results compare favourably to the open porosities measure with water of generally applied LCCs in the Danish marketplace of 15.5-16.0%. Converted to bonding phase porosities the low levels realised in experiments look rather good: 28% vs 55-57%. Salt cup tests confirm state of the art resistance. Experiments and assessment of surface oxidation of Silicon Carbide grains of three levels of purity confirm that it is impossible to stabilise SiC by pre-oxydation for the purpose of creating a thicker, protective surface layer of SiO{sub 2}. It is evident from the literature and qualified assessment that free Si, as a remnant surplus from SiC manufacture, does indeed hydrolyse in the castable basic environment under development of H{sub 2} gas bubbles adding on to unwanted porosity. Heat conductivity measurements of six different, representative products conducted by the Danish Technological Institute from 300 dec. C to 750 dec. C according to their credited calorimetric method confirm that the pre-firing to excess temperatures and subsequent measurement according to the DIN/EUN norm does indeed give misleading data of up to 45% for a castable containing {approx} 55% Silicon Carbide. Finite Element analysis confirms the

  19. Characterization of susceptibility of metallic materials to environmentally assisted cracking. Final report

    International Nuclear Information System (INIS)

    Dietzel, W.

    1999-01-01

    The stress corrosion cracking (SCC) of three different material/environment combinations was investigated in an inter-laboratory test programme using five different SCC test methods, with special emphasis laid on a new rising displacement test method which was to be further developed in the course of this project. The degree of reliability that could be obtained with each of the test methods and their usability were assessed. In all cases the experimental data characterising the occurrence of SCC show considerable scatter, irrespective of the test method. Based on the experience gained in the test programme, a draft for a new part of the ISO standard 7539 was elaborated and has meanwhile attained the status of an ISO Draft International Standard (ISO/DIS). (orig.) [de

  20. Investigations on deflagration to detonation transition in porous energetic materials. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, D.S. [Univ. of Illinois, Urbana, IL (United States)

    1999-07-01

    The research carried out by this contract was part of a larger effort funded by LANL in the areas of deflagration to detonation in porous energetic materials (DDT) and detonation shock dynamics in high explosives (DSD). In the first three years of the contract the major focus was on DDT. However, some researchers were carried out on DSD theory and numerical implementation. In the last two years the principal focus of the contract was on DSD theory and numerical implementation. However, during the second period some work was also carried out on DDT. The paper discusses DDT modeling and DSD modeling. Abstracts are included on the following topics: modeling deflagration to detonation; DSD theory; DSD wave front tracking; and DSD program burn implementation.

  1. Natural radioactivity of building materials particularly of concretes with industrial by-products. Final report

    International Nuclear Information System (INIS)

    Schiessl, P.; Hohberg, I.

    1995-01-01

    Within the scope of this project different concretes produced with industrial by-products (coal flue ashes, slag sand and metal slag) have been tested. In the focus was the impact of measures of concrete technology on the radon exhalation rate. The test results show that concretes with coal flue ashes and slag sand do not have an increased radon exhalation rate despite their relatively high radium activities compared to Portland cement and other natural building materials. The exhalation rates depend on the structure of the pore volume of concrete. When metal slag is used as concrete aggregate the specific radium activity of the concrete is increased. The radon exhalation rates lie in the order of magnitude of other concretes. (orig./MM) [de

  2. Characterization of the Tribological Behavior of Oxide-Based NanoMaterials: Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, George [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-04

    Under the Argonne/Pixelligent cooperative research and development agreement (CRADA – C1200801), Argonne performed labscale tribological tests on proprietary nano-sized ZrO2 material developed by Pixelligent. Pixelligent utilized their proprietary process to prepare variants with different surfactants at different loadings in different carrier fluids for testing and evaluation at Argonne. Argonne applied a range of benchtop tribological test rigs to evaluate friction and wear under a range of conditions (contact geometry, loads, speeds, and temperature) that simulated a broad range of conditions experienced in engines and driveline components. Post-test analysis of worn surfaces provided information on the structure and chemistry of the tribofilms produced during the tests.

  3. Bipolar plate materials in molten carbonate fuel cells. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.

    2004-06-01

    Advantages of implementation of power plants based on electrochemical reactions are successfully demonstrated in the USA and Japan. One of the msot promising types of fuel cells (FC) is a type of high temperature fuel cells. At present, thanks to the efforts of the leading countries that develop fuel cell technologies power plants on the basis of molten carbonate fuel cells (MCFC) and solid oxide fuel cells (SOFC) are really close to commercialization. One of the problems that are to be solved for practical implementation of MCFC and SOFC is a problem of corrosion of metal components of stacks that are assembled of a number of fuel cells. One of the major components of MCFC and SOFC stacks is a bipolar separator plate (BSP) that performs several functions - it is separation of reactant gas flows sealing of the joints between fuel cells, and current collection from the surface of electrodes. The goal of Task 1 of the project is to develop new cost-effective nickel coatings for the Russian 20X23H18 steel for an MCFC bipolar separator plate using technological processes usually implemented to apply corrosion stable coatings onto the metal parts for products in the defense. There was planned the research on production of nickel coatings using different methods, first of all the galvanic one and the explosion cladding one. As a result of the works, 0.4 x 712 x 1296 mm plates coated with nickel on one side were to be made and passed to ANL. A line of 4 galvanic baths 600 liters was to be built for the galvanic coating applications. The goal of Task 2 of the project is the development of a new material of an MCFC bipolar separator plate with an upgraded corrosion stability, and development of a technology to produce cold roll sheets of this material the sizes of which will be 0.8 x 712x 1296 mm. As a result of these works, a pilot batch of the rolled material in sheets 0.8 x 712 x 1296 mm in size is to be made (in accordance with the norms and standards of the Russian

  4. Laser Materials Processing Final Report CRADA No. TC-1526-98

    Energy Technology Data Exchange (ETDEWEB)

    Crane, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lehane, C. J. [United Technologies Corp., East Hartford, CT (United States)

    2017-09-08

    This CRADA project was a joint effort between Lawrence Livermore National Laboratory (LLNL) and United Technologies Corporation (UTC)/Pratt & Whitney (P&W) to demonstrate process capability for drilling holes in turbine airfoils using LLNL-developed femtosecond laser machining technology. The basis for this development was the ability of femtosecond lasers to drill precision holes in variety of materials with little or no collateral damage. The ultimate objective was to develop a laser machine tool consisting of an extremely advanced femtosecond laser subsystem to be developed by LLNL on a best-effort basis and a drilling station for turbine blades and vanes to be developed by P&W. In addition, P&W was responsible for commercializing the system. The goal of the so called Advanced Laser Drilling (ALD) system was to drill specified complex hole-shapes in turbine blades and vanes with a high degree precision and repeatability and simultaneously capable of very high speed processing.

  5. Powder-based synthesis of nanocrystalline material components for structural application. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ilyuschenko, A.F.; Ivashko, V.S.; Okovity, V.A. [Powder Metallurgy Research Inst., Minsk (Belarus)] [and others

    1998-12-01

    Hydroxiapate spray coatings and substrates for implant production as well as multilayered metal ceramic coatings from nanocrystalline materials are a subject of the investigation. The work aims at the improvement of quality of said objects. This study has investigated the processes of hydroxiapatite powder production. Sizes, shapes and relief of initial HA powder surface are analyzed using SEM and TEM. Modes of HA plasma spraying on a substrate from titanium and associated compositions of traditional and nanocrystalline structure are optimized. The quality of the sprayed samples are studied using X-ray phase analysis and metallographic analysis. The results of investigations of bioceramic coating spraying on titanium are theoretically generalized, taking into account obtained experimental data. The results of investigations of ion-beam technology are presented for spraying multilayered coatings consisting of alternating metal-ceramic layers of nanocrystalline structure.

  6. Ferrocyanide safety program: Final report on adiabatic calorimetry and tube propagation tests with synthetic ferrocyanide materials

    International Nuclear Information System (INIS)

    Fauske, H.F.; Meacham, J.E.; Cash, R.J.

    1995-01-01

    Based on Fauske and Associates, Inc. Reactive System Screening Tool tests, the onset or initiation temperature for a ferrocyanide-nitrate propagating reaction is about 250 degrees Celcius. This is at about 200 degrees Celcius higher than current waste temperatures in the highest temperature ferrocyanide tanks. Furthermore, for current ambient waste temperatures, the tube propagation tests show that a ferrocyanide concentration of 15.5 wt% or more is required to sustain a propagation reaction in the complete absence of free water. Ignoring the presence of free water, this finding rules out propagating reactions for all the Hanford flowsheet materials with the exception of the ferrocyanide waste produced by the original In Farm flowsheet

  7. X-ray Studies of Materials Dynamics at MHATT-CAT Sector 7 , Advanced Photon Source. Final report

    International Nuclear Information System (INIS)

    Roy Clarke

    2006-01-01

    This Final Report describes the scientific accomplishments that have been achieved with support from grant DE-FG02-03ER46023 during the period 12/01/02-11/30/05. The funding supported a vigorous scientific program allowing the PI to achieve leadership in a number of important areas. In particular, research carried out during this period has opened way to ultrafast dynamics studies of materials by combining the capabilities of synchrotron radiation with those of ultrafast lasers. This enables the initiation of laser-induced excitations and studies of their subsequent dynamics using laser-pump/x-ray probe techniques. Examples of such excitations include phonons, shock waves, excitons, spin-waves, and polaritons. The breadth of phenomena that can now be studied in the time-domain is very broad, revealing new phenomena and mechanisms that are critical to many applications of materials

  8. Regulatory analysis on criteria for the release of patients administered radioactive material. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, S.; McGuire, S.A.

    1997-02-01

    This regulatory analysis was developed to respond to three petitions for rulemaking to amend 10 CFR parts 20 and 35 regarding release of patients administered radioactive material. The petitions requested revision of these regulations to remove the ambiguity that existed between the 1-millisievert (0.1-rem) total effective dose equivalent (TEDE) public dose limit in Part 20, adopted in 1991, and the activity-based release limit in 10 CFR 35.75 that, in some instances, would permit release of individuals in excess of the current public dose limit. Three alternatives for resolution of the petitions were evaluated. Under Alternative 1, NRC would amend its patient release criteria in 10 CFR 35.75 to match the annual public dose limit in Part 20 of 1 millisievert (0.1 rem) TEDE. Alternative 2 would maintain the status quo of using the activity-based release criteria currently found in 10 CFR 35.75. Under Alternative 3, the NRC would revise the release criteria in 10 CFR 35.75 to specify a dose limit of 5 millisieverts (0.5 rem) TEDE.

  9. Regulatory analysis on criteria for the release of patients administered radioactive material. Final report

    International Nuclear Information System (INIS)

    Schneider, S.; McGuire, S.A.

    1997-02-01

    This regulatory analysis was developed to respond to three petitions for rulemaking to amend 10 CFR parts 20 and 35 regarding release of patients administered radioactive material. The petitions requested revision of these regulations to remove the ambiguity that existed between the 1-millisievert (0.1-rem) total effective dose equivalent (TEDE) public dose limit in Part 20, adopted in 1991, and the activity-based release limit in 10 CFR 35.75 that, in some instances, would permit release of individuals in excess of the current public dose limit. Three alternatives for resolution of the petitions were evaluated. Under Alternative 1, NRC would amend its patient release criteria in 10 CFR 35.75 to match the annual public dose limit in Part 20 of 1 millisievert (0.1 rem) TEDE. Alternative 2 would maintain the status quo of using the activity-based release criteria currently found in 10 CFR 35.75. Under Alternative 3, the NRC would revise the release criteria in 10 CFR 35.75 to specify a dose limit of 5 millisieverts (0.5 rem) TEDE

  10. Final Technical Report: Mathematical Foundations for Uncertainty Quantification in Materials Design

    Energy Technology Data Exchange (ETDEWEB)

    Plechac, Petr [Univ. of Delaware, Newark, DE (United States); Vlachos, Dionisios G. [Univ. of Delaware, Newark, DE (United States)

    2018-01-23

    We developed path-wise information theory-based and goal-oriented sensitivity analysis and parameter identification methods for complex high-dimensional dynamics and in particular of non-equilibrium extended molecular systems. The combination of these novel methodologies provided the first methods in the literature which are capable to handle UQ questions for stochastic complex systems with some or all of the following features: (a) multi-scale stochastic models such as (bio)chemical reaction networks, with a very large number of parameters, (b) spatially distributed systems such as Kinetic Monte Carlo or Langevin Dynamics, (c) non-equilibrium processes typically associated with coupled physico-chemical mechanisms, driven boundary conditions, hybrid micro-macro systems, etc. A particular computational challenge arises in simulations of multi-scale reaction networks and molecular systems. Mathematical techniques were applied to in silico prediction of novel materials with emphasis on the effect of microstructure on model uncertainty quantification (UQ). We outline acceleration methods to make calculations of real chemistry feasible followed by two complementary tasks on structure optimization and microstructure-induced UQ.

  11. Electronic and magnetic interactions in high temperature superconducting and high coercivity materials. Final performance report

    International Nuclear Information System (INIS)

    Cooper, B.R.

    1997-01-01

    The issue addressed in the research was how to understand what controls the competition between two types of phase transition (ordering) which may be present in a hybridizing correlated-electron system containing two transition-shell atomic species; and how the variation of behavior observed can be used to understand the mechanisms giving the observed ordered state. This is significant for understanding mechanisms of high-temperature superconductivity and other states of highly correlated electron systems. Thus the research pertains to magnetic effects as related to interactions giving high temperature superconductivity; where the working hypothesis is that the essential feature governing the magnetic and superconducting behavior of copper-oxide-type systems is a cooperative valence fluctuation mechanism involving the copper ions, as mediated through hybridization effects dominated by the oxygen p electrons. (Substitution of praseodymium at the rare earth sites in the 1·2·3 material provides an interesting illustration of this mechanism since experimentally such substitution strongly suppresses and destroys the superconductivity; and, at 100% Pr, gives Pr f-electron magnetic ordering at a temperature above 16K). The research was theoretical and computational and involved use of techniques aimed at correlated-electron systems that can be described within the confines of model hamiltonians such as the Anderson lattice hamiltonian. Specific techniques used included slave boson methodology used to treat modification of electronic structure and the Mori projection operator (memory function) method used to treat magnetic response (dynamic susceptibility)

  12. Final Scientific Report, New Proton Conductive Composite Materials for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lvov, Serguei

    2010-11-08

    This project covered one of the main challenges in present-day PEM fuel cell technology: to design a membrane capable of maintaining high conductivity and mechanical integrity when temperature is elevated and water vapor pressure is severely reduced. The DOE conductivity milestone of 0.1 S cm-1 at 120 degrees C and 50 % relative humidity (RH) for designed membranes addressed the target for the project. Our approach presumed to develop a composite membrane with hydrophilic proton-conductive inorganic material and the proton conductive polymeric matrix that is able to “bridge” the conduction paths in the membrane. The unique aspect of our approach was the use of highly functionalized inorganic additives to benefit from their water retention properties and high conductivity as well. A promising result turns out that highly hydrophilic phosphorsilicate gels added in Nafion matrix improved PEM fuel cell performance by over 50% compared with bare Nafion membrane at 120 degrees C and 50 % RH. This achievement realizes that the fuel cell operating pressure can be kept low, which would make the PEM fuel cell much more cost efficient and adaptable to practical operating conditions and facilitate its faster commercialization particularly in automotive and stationary applications.

  13. Midinfrared ablation of dentin with the Vanderbilt FEL

    Science.gov (United States)

    Harris, David M.; Reinisch, Lou; Edwards, Glenn S.; Yessik, Michael J.; Ashrafi, Shahid; Santos-Sacchi, Joseph

    1996-04-01

    Absorption spectra of 0.1 - 0.2 mm thick, dehydrated sections of human teeth were measured in the transmission mode with a Bruker FT-IR spectrometer from 2.5 - 20 micrometers . Absorption peaks for amide I, II and III, carbonate and phosphate were identified. Craters were ablated in dentin and enamel using a tunable FEL at 6.45 micrometers at various fluences. Pulse duration: 3 microsecond(s) ; spot size (Gaussian, FWHM): 300 micrometers ; repetition rate: 10 Hz. Crater depth and width were measured from digitized optical images. Ablation rates were computed from crater depth and volume data. Selected specimens were examined with scanning electron microscopy to determine ablation surface characteristics. Depth of thermal damage and dentinal tubule morphology were estimated from SEM examination of fractures through ablation sites. Functions describing crater depth vs. number of pulses (quadratic function) were not the same as crater volume vs. number of pulses (linear function). Crater depth decreases with successive pulses, concurrently, the crater width increases. Thus, each pulse removes approximately a constant volume. Material was observed to flow through the dentinal tubules during and after ablation. Patent tubules on crater walls and floor were observed with SEM. Ablation rates in dentin were approximately 3X those in enamel at 6.45 micrometers . Ablation rates and surface characteristics varied across wavelengths from 5.8 to 8.0 micrometers .

  14. Ames Infusion Stories for NASA Annual Technology Report: Development of an Ablative 3D Quartz / Cyanate Ester Composite Multi-Functional Material for the Orion Spacecraft Compression Pad

    Science.gov (United States)

    Smith, Brandon; Jan, Darrell Leslie; Venkatapathy, Ethiraj

    2015-01-01

    Vehicles re-entering Earth's atmosphere require protection from the heat of atmospheric friction. The Orion Multi-Purpose Crew Vehicle (MPCV) has more demanding thermal protection system (TPS) requirements than the Low Earth Orbit (LEO) missions, especially in regions where the structural load passes through. The use of 2-dimensional laminate materials along with a metal insert, used in EFT1 flight test for the compression pad region, are deemed adequate but cannot be extended for Lunar return missions.

  15. Center for Electrocatalysis, Transport Phenomena, and Materials (CETM) for Innovative Energy Storage - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Soloveichik, Grigorii [GE Global Research, Niskayuna, New York (United States)

    2015-11-30

    EFRC vision. The direct use of organic hydrides in fuel cells as virtual hydrogen carriers that generate stable organic molecules, protons, and electrons upon electro-oxidation and can be electrochemically charged by re-hydrogenating the oxidized carrier was the major focus of the Center for Electrocatalysis, Transport Phenomena and Materials for Innovative Energy Storage (EFRC-ETM). Compared to a hydrogen-on-demand design that includes thermal decomposition of organic hydrides in a catalytic reactor, the proposed approach is much simpler and does not require additional dehydrogenation catalysts or heat exchangers. Further, this approach utilizes the advantages of a flow battery (i.e., separation of power and energy, ease of transport and storage of liquid fuels) with fuels that have system energy densities similar to current hydrogen PEM fuel cells. EFRC challenges. Two major EFRC challenges were electrocatalysis and transport phenomena. The electrocatalysis challenge addresses fundamental processes which occur at a single molecular catalyst (microscopic level) and involve electron and proton transfer between the hydrogen rich and hydrogen depleted forms of organic liquid fuel and the catalyst. To form stable, non-radical dehydrogenation products from the organic liquid fuel, it is necessary to ensure fast transport of at least two electrons and two protons (per double bond formation). The same is true for the reverse hydrogenation reaction. The transport phenomena challenge addresses transport of electrons to/from the electrocatalyst and the current collector as well as protons across the polymer membrane. Additionally it addresses prevention of organic liquid fuel, water and oxygen transport through the PEM. In this challenge, the transport of protons or molecules involves multiple sites or a continuum (macroscopic level) and water serves as a proton conducting medium for the majority of known sulfonic acid based PEMs. Proton transfer in the presence of

  16. Literature review of FGD construction materials. Final report. [Extension of EPRI-CS-1736; 237 references

    Energy Technology Data Exchange (ETDEWEB)

    Koch, G.H.; Beavers, J.A.; Thompson, N.G.; Berry, W.E.

    1982-08-01

    A survey of the literature was performed on Corrosion Related Failures in Flue Gas Desulfurization Systems. It was found that pitting and crevice corrosion of alloys occurred throughout scrubbers and were the major cause of failure. Stress-corrosion cracking failures were found in the prescrubber and in the reheater while erosion-corrosion failures occurred most frequently in the prescrubber. Pitting and crevice corrosion were associated with the presence of chlorides and low pH conditions while these factors, in conjunction with higher temperatures, appeared to be responsible for the occurrence of stress-corrosion cracking. Erosion-corrosion failures were associated with high velocities and the presence of particulates in the incoming flue gas. Failures of organic linings occurred primarily as a result of debonding, caused by temperature upsets, and, occasionally, as a result of improper application. Erosion-corrosion failures of organic linings also were reported. Failures of inorganic linings have occurred as a result of improper materials selection and permeability to aqueous solutions. Solutions to these problems generally are dependent upon the specific application. The nickel-base alloys that contain molybdenum are highly resistant to pitting, crevice corrosion, erosion-corrosion and stress-corrosion cracking, but are expensive and difficult to fabricate. Recently developed organic coatings, such as the fluoroelastomers, are much more tolerant of temperature upsets than are the organic coatings that are commonly used, but the former are difficult to successfully apply. Acid resistant bricks and mortars are much more resistant to attack in scrubbers than are calcium aluminate concrete and mortars or Portland cement. However, protection of the underlying carbon steel support structure continues to be a problem with inorganic linings.

  17. Concept and Idea-Project for Yugoslav Low and Intermediate level Radioactive Waste Materials Final Disposal Facility

    International Nuclear Information System (INIS)

    Peric, A.

    1997-01-01

    Encapsulation of rad waste in a mortar matrix and displacement of such solidified waste forms into the shallow land burial system, engineered trench system type is suggested concept for the final disposal of low and intermediate level rad waste. The mortar-rad waste mixtures are cured in containers of either concrete or metal for an appropriate period of time, after which solidified rad waste-mortar monoliths are then placed in the engineered trench system, parallelepiped honeycomb structure. Trench consists of vertical barrier-walls, bottom barrier-floors, surface barrier-caps and permeable-reactive walls. Surroundings of the trench consists of buffer barrier materials, mainly clay. Each segment of the trench is equipped with the independent drainage system, as a part of the main drainage. Encapsulation of each filled trench honeycomb segment is performed with concrete cap. Completed trench is covered with impermeable plastic foil and soil leaner, preferably clay. Paper presents an overview of the final disposal facility engineered trench system type. Advantages in comparison with other types of final disposal system are given. (author)

  18. Consolidated guidance about materials licenses: Program-specific guidance about portable gauge licenses. Final report; Volume 1

    International Nuclear Information System (INIS)

    Vacca, P.C.; Whitten, J.E.; Pelchat, J.M.; Arredondo, S.A.; Matson, E.R.; Lewis, S.H.; Collins, D.J.; Santiago, P.A.; Tingle, W.

    1997-05-01

    As part of its redesign of the materials licensing process, NRC is consolidating and updating numerous guidance documents into a single comprehensive repository as described in NUREG-1539 and draft NUREG-1541. NUREG-1556, Vol. 1, is the first program-specific guidance developed for the new process and will serve as a template for subsequent program-specific guidance. This document is intended for use by applicants, licensees, and NRC staff and will also be available to Agreement States. This document supersedes the guidance previously found in draft Regulatory Guide DG-0008, ''Applications for the Use of Sealed Sources in Portable Gauging Devices,'' and in NMSs Policy and guidance Directive 2-07, ''Standard Review Plan for Applications for Use of Sealed Sources in Portable Gauging Devices.'' This final report takes a more risk-informed, performance-based approach to licensing portable gauges, and reduces the information(amount and level of detail) needed to support an application to use these devices. It incorporates many suggests submitted during the comment period on draft NUREG-1556, Volume 1. When published, this final report should be used in preparing portable gauge license applications. NRC staff will use this final report in reviewing these applications

  19. Field enhancement induced laser ablation

    DEFF Research Database (Denmark)

    Fiutowski, Jacek; Maibohm, Christian; Kjelstrup-Hansen, Jakob

    Sub-diffraction spatially resolved, quantitative mapping of strongly localized field intensity enhancement on gold nanostructures via laser ablation of polymer thin films is reported. Illumination using a femtosecond laser scanning microscope excites surface plasmons in the nanostructures....... The accompanying field enhancement substantially lowers the ablation threshold of the polymer film and thus creates local ablation spots and corresponding topographic modifications of the polymer film. Such modifications are quantified straightforwardly via scanning electron and atomic force microscopy. Thickness...

  20. Graded Density Carbon Bonded Carbon Fiber (CBCF) Preforms for Lightweight Ablative Thermal Protection Systems (TPS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — FMI has developed graded density CBCF preforms for graded density phenolic impregnated carbon ablator (PICA) material to meet NASA's future exploration mission...

  1. Graded Density Carbon Bonded Carbon Fiber (CBCF) Preforms for Lightweight Ablative Thermal Protection Systems (TPS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — FMI currently manufactures Phenolic Impregnated Carbon Ablator (PICA) material for Thermal Protection Systems (TPS) systems, such as the Stardust Sample Return...

  2. Recombinant TSH stimulated remnant ablation therapy in thyroid cancer: the success rate depends on the definition of ablation success--an observational study.

    Directory of Open Access Journals (Sweden)

    Anouk N A van der Horst-Schrivers

    Full Text Available Patients with differentiated thyroid cancer (DTC are treated with (near-total thyroidectomy followed by remnant ablation. Optimal radioiodine-131 (131I uptake is achieved by withholding thyroid hormone (THW, pretreatment with recombinant human Thyrotropin Stimulating Hormone (rhTSH is an alternative. Six randomized trials have been published comparing THW and rhTSH, however comparison is difficult because an uniform definition of ablation success is lacking. Using a strict definition, we performed an observational study aiming to determine the efficacy of rhTSH as preparation for remnant ablation.Adult DTC patients with, tumor stage T1b to T3, Nx, N0 and N1, M0 were included in a prospective multicenter observational study with a fully sequential design, using a stopping rule. All patients received remnant ablation with 131I using rhTSH. Ablation success was defined as no visible uptake in the original thyroid bed on a rhTSH stimulated 150 MBq 131I whole body scan (WBS 9 months after remnant ablation, or no visible uptake in the original thyroid bed on a post therapeutic WBS when a second high dose was necessary.After interim analysis of the first 8 patients, the failure rate was estimated to be 69% (90% confidence interval (CI 20-86% and the inclusion of new patients had to be stopped. Final analysis resulted in an ablation success in 11 out of 17 patients (65%, 95% CI 38-86%.According to this study, the efficacy of rhTSH in the preparation of 131I ablation therapy is inferior, when using a strict definition of ablation success. The current lack of agreement as to the definition of successful remnant ablation, makes comparison between different ablation strategies difficult. Our results point to the need for an international consensus on the definition of ablation success, not only in routine patient's care but also for scientific reasons.Dutch Trial Registration NTR2395.

  3. Study of ablation on surfaces of nuclear-use metals irradiated with Femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Alessandro F.; Samad, Ricardo E.; Vieira Junior, Nilson D.; Rossi, Wagner de, E-mail: alessandro.nogueira@usp.br, E-mail: resamad@ipen.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sorocaba, SP (Brazil); Faculdade de Engenharia de Sorocaba (FACENS), Ipero, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    The use of ultrashort pulsed lasers is an alternative for micro-machining in metal surfaces, with diverse applications in several industrial areas, such as aeronautics, aerospace, naval, nuclear, among others, where there is a growing concern with reliability in service. In this work, micro-machining were performed on titanium surfaces using femtosecond ultrashort pulses. Such a process resulted in minimal heat transfer to the material, thus avoiding and surface deformation of the titanium plate and the formation of resolidified material in the ablated region, which are drawbacks present in the use of the long pulsed keyed laser of the order of nanoseconds. Three types of micro-machining were performed, with variations in the distances between the machined lines. It was also verified that the wettability increases when there is an increase in the distance between machined lines. Finally, in order to change the surface with minimal removal of material, it has been found that the use of ultra-short pulse lasers provide great benefits for the integrity of the ablated material. This initial study is the starting point for the study of other metals, such as Maraging Steels and Zircaloy that will be the target of future work. (author)

  4. Study of ablation on surfaces of nuclear-use metals irradiated with Femtosecond laser

    International Nuclear Information System (INIS)

    Nogueira, Alessandro F.; Samad, Ricardo E.; Vieira Junior, Nilson D.; Rossi, Wagner de

    2017-01-01

    The use of ultrashort pulsed lasers is an alternative for micro-machining in metal surfaces, with diverse applications in several industrial areas, such as aeronautics, aerospace, naval, nuclear, among others, where there is a growing concern with reliability in service. In this work, micro-machining were performed on titanium surfaces using femtosecond ultrashort pulses. Such a process resulted in minimal heat transfer to the material, thus avoiding and surface deformation of the titanium plate and the formation of resolidified material in the ablated region, which are drawbacks present in the use of the long pulsed keyed laser of the order of nanoseconds. Three types of micro-machining were performed, with variations in the distances between the machined lines. It was also verified that the wettability increases when there is an increase in the distance between machined lines. Finally, in order to change the surface with minimal removal of material, it has been found that the use of ultra-short pulse lasers provide great benefits for the integrity of the ablated material. This initial study is the starting point for the study of other metals, such as Maraging Steels and Zircaloy that will be the target of future work. (author)

  5. Thermal Convection on an Ablating Target

    Science.gov (United States)

    Mehmedagic, Igbal; Thangam, Siva

    2015-11-01

    Modeling and analysis of thermal convection of a metallic targets subject to radiative flux is of relevance to various manufacturing processes as well as for the development of protective shields. The present work involves the computational modeling of metallic targets subject to high heat fluxes that are both steady and pulsed. Modeling of the ablation and associated fluid dynamics when metallic surfaces are exposed to high intensity pulsed laser fluence at normal atmospheric conditions is considered. The incident energy from the laser is partly absorbed and partly reflected by the surface during ablation and subsequent vaporization of the convecting melt also participates in the radiative exchange. The energy distribution during the process between the bulk and vapor phase strongly depends on optical and thermodynamic properties of the irradiated material, radiation wavelength, and laser pulse intensity and duration. Computational findings based on effective representation and prediction of the heat transfer, melting and vaporization of the targeting material as well as plume formation and expansion are presented and discussed in the context of various ablation mechanisms, variable thermo-physical and optical properties, plume expansion and surface geometry. Funded in part by U. S. Army ARDEC, Picatinny Arsenal, NJ.

  6. Hydrodynamic stability theory of double ablation front structures in inertial confinement fusion

    International Nuclear Information System (INIS)

    Yanez Vico, C.

    2012-11-01

    For moderate-Z materials, the hydrodynamic structure of the ablation region formed by the irradiation of high intensity laser beams differs from that of low-Z materials (hydrogenic ablators). In particular, the role played by the radiative energy flux becomes non-negligible for increasing atomic number material and ended up forming a second ablation front. This structure of two separated ablation fronts, called double ablation (DA) front, was confirmed in the simulations carried out by Fujioka et al. In this work a linear stability theory of DA fronts is developed for direct-drive inertial confinement fusion targets. Two models are proposed. First, a sharp boundary model where the thin front approximation is assumed for both ablation fronts. The information about the corona region that permits to close the sharp boundary model is obtained from a prior self-consistent analysis of the electronic-radiative ablation (ERA) front. Numerical results are presented as well as an analytical approach for the radiation dominated regime of very steep double ablation front structure. Second, a self-consistent numerical method where the finite length of the ablation fronts is considered. Accurate hydrodynamic profiles are taken into account in the theoretical model by means of a fitting parameters method using one-dimensional simulation results. Numerical dispersion relation is compared to the analytical sharp boundary model showing an excellent agreement for the radiation dominated regime, and the stabilization due to smooth profiles. 2D simulations are presented to validate the linear stability theory

  7. Measurement and modeling of energetic-material mass transfer to soil-pore water - Project CP-1227 final technical report.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Sallaberry, Cedric M.; Webb, Stephen Walter; Phelan, James M.; Hadgu, Teklu

    2006-05-01

    Military test and training ranges operate with live-fire engagements to provide realism important to the maintenance of key tactical skills. Ordnance detonations during these operations typically produce minute residues of parent explosive chemical compounds. Occasional low-order detonations also disperse solid-phase energetic material onto the surface soil. These detonation remnants are implicated in chemical contamination impacts to groundwater on a limited set of ranges where environmental characterization projects have occurred. Key questions arise regarding how these residues and the environmental conditions (e.g., weather and geostratigraphy) contribute to groundwater pollution. This final report documents the results of experimental and simulation model development for evaluating mass transfer processes from solid-phase energetics to soil-pore water.

  8. Thermal Performance of Ablative/ Ceramic Composite

    Directory of Open Access Journals (Sweden)

    Adriana STEFAN

    2014-12-01

    Full Text Available A hybrid thermal protection system for atmospheric earth re-entry based on ablative materials on top of ceramic matrix composites is investigated for the protection of the metallic structure in oxidative and high temperature environment of the space vehicles. The paper focuses on the joints of ablative material (carbon fiber based CALCARB® or cork based NORCOAT TM and Ceramic Matrix Composite (CMC material (carbon fibers embedded in silicon carbide matrix, Cf/SiC, SICARBON TM or C/C-SiC using commercial high temperature inorganic adhesives. To study the thermal performance of the bonded materials the joints were tested under thermal shock at the QTS facility. For carrying out the test, the sample is mounted into a holder and transferred from outside the oven at room temperature, inside the oven at the set testing temperature (1100°C, at a heating rate that was determined during the calibration stage. The dwell time at the test temperature is up to 2 min at 1100ºC at an increasing rate of temperature up to ~ 9,5°C/s. Evaluating the atmospheric re-entry real conditions we found that the most suited cooling method is the natural cooling in air environment as the materials re-entering the Earth atmosphere are subjected to similar conditions. The average weigh loss was calculated for all the samples from one set, without differentiating the adhesive used as the weight loss is due to the ablative material consumption that is the same in all the samples and is up to 2%. The thermal shock test proves that, thermally, all joints behaved similarly, the two parts withstanding the test successfully and the assembly maintaining its integrity.

  9. Avoiding Complications in Bone and Soft Tissue Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Kurup, A. Nicholas, E-mail: kurup.anil@mayo.edu; Schmit, Grant D., E-mail: schmit.grant@mayo.edu; Morris, Jonathan M., E-mail: morris.jonathan@mayo.edu; Atwell, Thomas D., E-mail: atwell.thomas@mayo.edu; Schmitz, John J., E-mail: schmitz.john@mayo.edu; Weisbrod, Adam J., E-mail: weisbrod.adam@mayo.edu; Woodrum, David A., E-mail: woodrum.david@mayo.edu; Eiken, Patrick W., E-mail: eiken.patrick@mayo.edu; Callstrom, Matthew R., E-mail: callstrom.matthew@mayo.edu [Mayo Clinic, Department of Radiology (United States)

    2017-02-15

    As with percutaneous ablation of tumors in the liver, lungs, and kidneys, ablation of bone and non-visceral soft tissue tumors carries risk, primarily from collateral damage to vital structures in proximity to the target tumor. Certain risks are of particular interest when ablating bone and non-visceral soft tissue tumors, namely neural or skin injury, bowel injury, fracture, and gas embolism from damaged applicators. Ablation of large volume tumors also carries special risk. Many techniques may be employed by the interventional radiologist to minimize complications when treating tumors in the musculoskeletal system. These methods include those to depict, displace, or monitor critical structures. Thus, measures to provide thermoprotection may be active, such as careful ablation applicator placement and use of various displacement techniques, as well as passive, including employment of direct temperature, radiographic, or neurophysiologic monitoring techniques. Cementoplasty should be considered in certain skeletal locations at risk of fracture. Patients treated with large volume tumors should be monitored for renal dysfunction and properly hydrated. Finally, ablation applicators should be cautiously placed in the constrained environment of intact bone.

  10. Avoiding Complications in Bone and Soft Tissue Ablation

    International Nuclear Information System (INIS)

    Kurup, A. Nicholas; Schmit, Grant D.; Morris, Jonathan M.; Atwell, Thomas D.; Schmitz, John J.; Weisbrod, Adam J.; Woodrum, David A.; Eiken, Patrick W.; Callstrom, Matthew R.

    2017-01-01

    As with percutaneous ablation of tumors in the liver, lungs, and kidneys, ablation of bone and non-visceral soft tissue tumors carries risk, primarily from collateral damage to vital structures in proximity to the target tumor. Certain risks are of particular interest when ablating bone and non-visceral soft tissue tumors, namely neural or skin injury, bowel injury, fracture, and gas embolism from damaged applicators. Ablation of large volume tumors also carries special risk. Many techniques may be employed by the interventional radiologist to minimize complications when treating tumors in the musculoskeletal system. These methods include those to depict, displace, or monitor critical structures. Thus, measures to provide thermoprotection may be active, such as careful ablation applicator placement and use of various displacement techniques, as well as passive, including employment of direct temperature, radiographic, or neurophysiologic monitoring techniques. Cementoplasty should be considered in certain skeletal locations at risk of fracture. Patients treated with large volume tumors should be monitored for renal dysfunction and properly hydrated. Finally, ablation applicators should be cautiously placed in the constrained environment of intact bone.

  11. Influence of liquid environments on femtosecond laser ablation of silicon

    International Nuclear Information System (INIS)

    Liu Hewei; Chen Feng; Wang Xianhua; Yang Qing; Bian Hao; Si Jinhai; Hou Xun

    2010-01-01

    Liquid-assisted ablation of solids by femtosecond laser pulses has proved to be an efficient tool for highly precise microfabrication, which evokes numerous research interests in recent years. In this paper, we systematically investigate the interaction of femtosecond laser pulses with silicon wafer in water, alcohol, and as a comparison, in air. After producing a series of multiple-shot craters on a silicon wafer in the three types of environments, surface morphologies and femtosecond laser-induced periodic surface structures are comparatively studied via the scanning electron microscope investigations. Meanwhile, the influence of liquid mediums on ablation threshold fluence and ablation depth is also numerically analyzed. The experimental results indicate that the ablation threshold fluences of silicon are reduced by the presence of liquids (water/alcohol) and ablation depths of craters are deepened in ambient water. Furthermore, smoother surfaces tend to be obtained in alcohol-mediated ablation at smaller shot numbers. Finally, the evolution of the femtosecond laser-induced periodic surface structures in air, water and alcohol is also discussed.

  12. Final report. Superconducting materials

    International Nuclear Information System (INIS)

    John Ruvalds

    1999-01-01

    Our group has discovered a many body effect that explains the surprising divergence of the spin susceptibility which has been measured by neutron scattering experiments on high temperature superconductors and vanadium oxide metals. Electron interactions on nested - i.e., nearly parallel paths - have been analyzed extensively by our group, and such processes provide a physical explanation for many anomalous features that distinguish cuprate superconductors from ordinary metals

  13. Radiofrequency ablation of osteoid osteoma

    NARCIS (Netherlands)

    Vanderschueren, Geert Maria Joris Michael

    2009-01-01

    The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency

  14. Laser ablation of lysozyme with UV, visible and infrared femto- and nanosecond pulses

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Matei, Andreea

    Lysozyme is an interesting molecule for laser ablation of organic materials, because the ablation has been comprehensively studied, it is a medium heavy molecule with a mass of 14305 Da, which can be detected by standard techniques, and because it is used as a bactericidal protein in the food...... industry. Lysozyme molecules do not absorb energy for wavelengths above 310 nm, but nevertheless there is a strong mass loss by ablation for laser irradiation in the visible regime. The total ablation yield of lysozyme at 355 nm and at 2 J/cm2 is about 155 µg/pulse, possibly one of the highest ablation...... yields ever measured. The mass loss is mainly caused by fragmentation of the lysozyme into simple gases, such as H2S, H2O and CO2 , which are rapidly pumped away in the vacuum chamber. We have investigated the mass loss by ablation of lysozyme in all regimes to see whether a similar mechanism governs...

  15. Assisted laser ablation: silver/gold nanostructures coated with silica

    Science.gov (United States)

    González-Castillo, J. R.; Rodríguez-González, Eugenio; Jiménez-Villar, Ernesto; Cesar, Carlos Lenz; Andrade-Arvizu, Jacob Antonio

    2017-11-01

    The synthesis processes of metallic nanoparticles have seen a growing interest in recent years, mainly by the potential applications of the phenomenon of localized surface plasmon resonance associated with metallic nanoparticles. This paper shows a fast method to synthesize silver, gold and silver/gold alloy nanoparticles coated with a porous silica shell by the assisted laser ablation method in three steps. The method involves a redox chemical reaction where the reducing agent is supplied in nanometric form by laser ablation. In the first step, a silicon target immersed in water is ablated for several minutes. Later, AgNO3 and HAuCl4 aliquots are added to the solution. The redox reaction between the silver and gold ions and products resulting from ablation process can produce silver, gold or silver/gold alloy nanoparticles coated with a porous silica shell. The influence of the laser pulse energy, ablation time, Ag+ and Au3+ concentration, as well as the Ag+/Au3+ ratio, on optical and structural properties of the nanostructures was investigated. This work represents a step forward in the study of reaction mechanisms that take place during the synthesis of nanoscale materials by the assisted laser ablation technique.

  16. Radiofrequency Ablation for the Treatment of Hepatocellular Carcinoma in Patients with Transjugular Intrahepatic Portosystemic Shunts

    International Nuclear Information System (INIS)

    Park, Jonathan K.; Al-Tariq, Quazi Z.; Zaw, Taryar M.; Raman, Steven S.; Lu, David S.K.

    2015-01-01

    PurposeTo assess radiofrequency (RF) ablation efficacy, as well as the patency of transjugular intrahepatic portosystemic shunts (TIPSs), in patients with hepatocellular carcinoma (HCC).Materials and MethodsRetrospective database review of patients with pre-existing TIPS undergoing RF ablation of HCC was conducted over a 159-month period ending in November 2013. TIPS patency pre- and post-RF ablation was assessed by ultrasound, angiography, and/or contrast-enhanced CT or MRI. Patient demographics and immediate post-RF ablation outcomes and complications were also reviewed.Results19 patients with 21 lesions undergoing 25 RF ablation sessions were included. Child-Pugh class A, B, and C scores were seen in 1, 13, and 5 patients, respectively. Eleven patients (58 %) ultimately underwent liver transplantation. Immediate technical success was seen in all ablation sessions without residual tumor enhancement (100 %). No patients (0 %) suffered liver failure within 1 month of ablation. Pre-ablation TIPS patency was demonstrated in 22/25 sessions (88 %). Of 22 cases with patent TIPS prior to ablation, post-ablation patency was demonstrated in 22/22 (100 %) at immediate post-ablation imaging and in 21/22 (95 %) at last follow-up (1 patient was incidentally noted to have occlusion 31 months later). No immediate complications were observed.ConclusionAblation efficacy was similar to the cited literature values for patients without TIPS. Furthermore, TIPS patency was preserved in the majority of cases. Patients with both portal hypertension and HCC are not uncommonly encountered, and a pre-existing TIPS does not appear to be a definite contraindication for RF ablation

  17. Evaluation of ablation efficiency and surface morphology of human teeth upon irradiation with femtosecond laser pulses

    Science.gov (United States)

    Shaheen, M. E.; Gagnon, J. E.; Fryer, B. J.

    2014-11-01

    This study investigates changes in ablation efficiency and surface morphology induced in human dental enamel and dentin upon interaction with femtosecond laser pulses at variable energies and number of laser pulses. Craters were created using a Ti:sapphire femtosecond laser ablation system operating at a wavelength of 785 nm, pulse width of 130 fs, and repetition rate of 20 Hz. Various techniques, such as optical and scanning electron microscopy and inductively coupled plasma mass spectrometry (ICP-MS), were used to evaluate ablation depth, amount of material ablated, and surface morphology of the craters. Ablation rate (ablation depth per pulse) was found to be lower in enamel than dentin with the maximum rate occurring at fluence of 12.4 J cm-2 in both materials. A drop in ablation rate was observed for fluence greater than 12.4 J cm-2 and was attributed to attenuation of laser energy due to interaction with the laser-generated particles. Above this fluence, signs of thermal effects, such as melting and formation of droplets of molten material at the sample surface, were observed. The response of the ICP-MS indicated that the amount of ablated material removed from dentin is greater than that removed from enamel by a factor of 1.5 or more at all investigated fluence.

  18. Evaluation of Novel Semiconductor Materials Potentially Useful in Solar Cells: Cooperative Research and Development Final Report, CRADA number CRD-06-00172

    Energy Technology Data Exchange (ETDEWEB)

    Geisz, J.

    2010-07-01

    Evaluation of novel semiconductor materials potentially useful in solar cells. NREL will fabricate, test and analyze solar cells from EpiWorks' wafers produced in 2-3 separate growth campaigns. NREL will also characterize material from 2-3 separate EpiWorks material development campaigns. Finally, NREL will visit EpiWorks and help establish any necessary process, such as spectral CV measurements and III-V on Si metalization processes and help validate solar cell designs and performance.

  19. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    Science.gov (United States)

    See, Tian Long; Liu, Zhu; Li, Lin; Zhong, Xiang Li

    2016-02-01

    This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser-material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (Fth = 0.087 J/cm2) than that for the femtosecond laser ablation of ABS (Fth = 1.576 J/cm2), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α-1 = 223 nm) than that for femtosecond laser ablation (α-1 = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the Cdbnd C bond completely through the chain scission process whereas Cdbnd C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the Cdbnd C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (Csbnd O and Cdbnd O bond) and nitrogen-rich (Csbnd N) functional groups.

  20. Nephron-sparing percutaneous ablation of a 5 cm renal cell carcinoma by superselective embolization and percutaneous RF-ablation

    International Nuclear Information System (INIS)

    Tacke, J.; Mahnken, A.; Buecker, A.; Guenther, R.W.; Rohde, D.

    2001-01-01

    Purpose: To report on the nephron-sparing, percutaneous ablation of a large renal cell carcinoma by combined superselective embolization and percutaneous radiofrequency ablation. Materials and Methods: A 5 cm renal cell carcinoma of a 43-year-old drug abusing male with serologically proven HIV, hepatitis B and C infection, who refused surgery, was superselectively embolized using microspheres (size: 500 - 700 μm) and a platinum coil under local anesthesia. Percutaneous radiofrequency ablation using a 7F LeVeen probe (size of expanded probe tip: 40 mm) and a 200 Watt generator was performed one day after transcatheter embolization under general anesthesia. Results: The combined treatment resulted in complete destruction of the tumor without relevant damage of the surrounding healthy renal tissue. The patient was discharged 24 hours after RF ablation. No complications like urinary leaks or fistulas were observed and follow up CT one day and 4 weeks after the radiofrequency intervention revealed no signs of residual tumor growth. Conclusion: The combined transcatheter embolization and percutaneous radiofrequency ablation of renal cell carcinoma has proved technically feasible, effective, and safe in this patient. It may be offered as an alternative treatment to partial or radical nephrectomy under certain circumstances. Abbreviations: RF = radiofrequency ablation; CT = computed tomography; HIV = human immunodeficiency virus. (orig.) [de

  1. Fractional ablative erbium YAG laser

    DEFF Research Database (Denmark)

    Taudorf, Elisabeth H; Haak, Christina S; Erlendsson, Andrés M

    2014-01-01

    BACKGROUND AND OBJECTIVES: Treatment of a variety of skin disorders with ablative fractional lasers (AFXL) is driving the development of portable AFXLs. This study measures micropore dimensions produced by a small 2,940 nm AFXL using a variety of stacked pulses, and determines a model correlating...... energies of 2.3-12.8 mJ/microbeam and total energy levels of 4.6-640 mJ/microchannel. Histological endpoints were ablation depth (AD), coagulation zone (CZ) and ablation width (AW). Data were logarithmically transformed if required prior to linear regression analyses. Results for histological endpoints...

  2. Comparison of different target material options for the European Spallation Source based on certain aspects related to the final disposal

    Science.gov (United States)

    Kókai, Zsófia; Török, Szabina; Zagyvai, Péter; Kiselev, Daniela; Moormann, Rainer; Börcsök, Endre; Zanini, Luca; Takibayev, Alan; Muhrer, Günter; Bevilacqua, Riccardo; Janik, József

    2018-02-01

    Different target options have been examined for the European Spallation Source, which is under construction in Lund, Sweden. During the design update phase, parameters and characteristics for the target design have been optimized not only for neutronics but also with respect to the waste characteristics related to the final disposal of the target. A rotating, solid tungsten target was eventually selected as baseline concept; the other options considered included mercury and lead-bismuth (LBE) targets suitable for a pulsed source. Since the licensee is obliged to present a decommissioning plan even before the construction phase starts, the radioactive waste category of the target after full operation time is of crucial importance. The results obtained from a small survey among project partners of 7th Framework Program granted by EU 202247 contract have been used. Waste characteristics of different potential spallation target materials were compared. Based on waste index, the tungsten target is the best alternative and the second one is the mercury target. However, all alternatives have HLW category after a 10 year cooling. Based on heat generation alone all of the options would be below the HLW limit after this cooling period. The LBE is the least advantageous alternative based on waste index and heat generation comparison. These results can be useful in compiling the licensing documents of the ESS facility as the target alternatives can be compared from various aspects related to their disposal.

  3. Fractional ablative erbium YAG laser

    DEFF Research Database (Denmark)

    Taudorf, Elisabeth H; Haak, Christina S; Erlendsson, Andrés M

    2014-01-01

    BACKGROUND AND OBJECTIVES: Treatment of a variety of skin disorders with ablative fractional lasers (AFXL) is driving the development of portable AFXLs. This study measures micropore dimensions produced by a small 2,940 nm AFXL using a variety of stacked pulses, and determines a model correlating...... laser parameters with tissue effects. MATERIALS AND METHODS: Ex vivo pig skin was exposed to a miniaturized 2,940 nm AFXL, spot size 225 µm, density 5%, power levels 1.15-2.22 W, pulse durations 50-225 microseconds, pulse repetition rates 100-500 Hz, and 2, 20, or 50 stacked pulses, resulting in pulse...... 190 to 347 µm. CONCLUSIONS: Pulse stacking with a small, low power 2,940 nm AFXL created reproducible shallow to deep micropores, and influenced micropore configuration. Mathematical modeling established relations between laser settings and micropore dimensions, which assists in choosing laser...

  4. Femtosecond laser ablation of polytetrafluoroethylene (Teflon) in ambient air

    International Nuclear Information System (INIS)

    Wang, Z.B.; Hong, M.H.; Lu, Y.F.; Wu, D.J.; Lan, B.; Chong, T.C.

    2003-01-01

    Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (bio-compatible, nonflammable, antiadhesive, and heat resistant). The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this paper, laser processing of PTFE in ambient air by a Ti:sapphire femtosecond laser (780 nm, 110 fs) is investigated. It is found that the pulse number on each irradiated surface area must be large enough for a clear edge definition and the ablated depth increases with the pulse number. The air ionization effect at high laser fluences not only degrades the ablated structures quality but also reduces the ablation efficiency. High quality microstructures are demonstrated with controlling laser fluence below a critical fluence to exclude the air ionization effect. The ablated microstructures show strong adhesion property to liquids and clear edges that are suitable for bio-implantation applications. Theoretical calculation is used to analyze the evolution of the ablated width and depth at various laser fluences

  5. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    Energy Technology Data Exchange (ETDEWEB)

    See, Tian Long, E-mail: tianlong.see@postgrad.manchester.ac.uk [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Liu, Zhu [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Li, Lin [Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Zhong, Xiang Li [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom)

    2016-02-28

    Highlights: • Ablation threshold for excimer laser is lower compared to femtosecond laser. • Effective optical penetration depth for excimer laser is lower compared to femtosecond laser. • Two ablation characteristic regimes are observed for femtosecond laser ablation. • Reduction of C=C bond following excimer or fs laser ablation is observed. • Addition of oxygen- and nitrogen-rich functional groups is observed. - Abstract: This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser–material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (F{sub th} = 0.087 J/cm{sup 2}) than that for the femtosecond laser ablation of ABS (F{sub th} = 1.576 J/cm{sup 2}), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α{sup −1} = 223 nm) than that for femtosecond laser ablation (α{sup −1} = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the C=C bond completely through the chain scission process whereas

  6. UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

    International Nuclear Information System (INIS)

    Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A.

    2010-01-01

    Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

  7. Final report for NIF chamber dynamics studies. Final report (May 1997), Subcontract No. B291847

    International Nuclear Information System (INIS)

    Peterson, P.F.; Jin, H.; Scott, J.M.

    1997-01-01

    The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. Various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the final optics debris shields from an excessive coating (> 10 Angstrom) of target debris and ablated material, thereby prolonging their lifetime between change- outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. In addition to the work described briefly above, we performed extensive analysis of the target-chamber thermal response to in- chamber CO 2 Cleaning and of work performed to model the behavior of silica vapor. The work completed this year has been published in several papers and a dissertation -6 This report provides a summary of the work completed this year, as well as copies of

  8. Ignition relevant ablator response of boron carbide and high-density carbon driven by multiple shocks

    Science.gov (United States)

    Prisbrey, Shon T.; Baker, Kevin; Celliers, Peter; Dittrich, Tom; Moore, Alastair; Wu, Kuang Jen; Kervin, Peggy; Hurricane, Omar

    2013-10-01

    The attainment of self-propagating fusion burn in an inertial confinement target at the National Ignition Facility will require the use of an ablator with high rocket-efficiency and ablation pressure. The current ablation material, a glow-discharge polymer (GDP), does not couple as efficiently as simulations indicated to the multiple-shock inducing radiation drive environment created by laser power profile. In an effort to evaluate the performance of other possible ablators that could be suitable for achieving self-propagating fusion burn we have inferred the ablation performance of two possible ablators, boron carbide and high-density carbon, by measuring the shock speed of induced shocks while subjecting the ablators to a multiple-shock inducing radiation drive environment similar to a generic three-shock ignition drive. We present the platform used, velocity measurements used to infer the ablation response, and matching simulations to show the relative performance of boron carbide and high-density carbon with a general comparison to current performance of the currently used glow-discharge polymer ablator. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC. LLNL-ABS-640519.

  9. Specifications of nanosecond laser ablation with solid targets, aluminum, silicon rubber, and polymethylmethacrylate (PMMA)

    Science.gov (United States)

    Morshedian, Nader

    2017-09-01

    The ablation parameters such as threshold fluence, etch depth, ablation rate and the effect of material targets were investigated under the interaction of laser pulse with low intensity. The parameters of the laser system are: laser pulse energy in the range of 110-140 mJ, wavelength 1064 nm and pulse duration 20 ns. By macroscopic estimation of the outward images of the ablation and data obtained, we can conclude that the photothermal and photoionization processes have more influence for aluminum ablation. In contrast, for polymer samples, from the macroscopic observation of the border pattern at the irradiated spot, and also the data obtained from the experiment results, we deduce that both chemical change due to heating and photochemical dissociation were effective mechanisms of ablation. However, concerning the two polymer samples, apart from considering the same theoretical ablation model, it is conceived that the photomehanical specifications of PMMA are involved in the ablation parameters. The threshold fluence for an ablation rate of 30 laser shots were obtained as 12.4, 24.64, and 11.71 J cm-2, for aluminum, silicon rubber and polymethylmethacrylate (PMMA) respectively. The ablation rate is exponentially decreased by the laser-shot number, especially for aluminum. Furthermore, the etch depth after 30 laser shots was measured as 180, 630 and 870 μm, for aluminum, silicon rubber and PMMA, respectively.

  10. Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

    Science.gov (United States)

    Devismes, D.; Cohen, Barbara A.

    2014-01-01

    In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K-Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some µg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example

  11. Zinc nanoparticles in solution by laser ablation technique

    Indian Academy of Sciences (India)

    TECS

    Physical and chemical properties of these materi- als are highly size dependent. Therefore, it is important ... provided a powerful tool for the synthesis of nanomaterials in both solutions and gas matrices (Hodak et al ... 2006) and magnetic characterization of Co–Pt nanoparti- cles are reported by laser ablation of Co–Pt bulk ...

  12. Water spray assisted ultrashort laser pulse ablation

    International Nuclear Information System (INIS)

    Silvennoinen, M.; Kaakkunen, J.J.J.; Paivasaari, K.; Vahimaa, P.

    2013-01-01

    Highlights: ► We show the novel method to use multibeam processing with ultrashort pulses efficiently. ► Sprayed thin water layer on ablation zone enhances ablation rate and quality. ► In some cases this method also enables ablation of the deeper and straighter holes compared to ones made without the water layer. ► Method also makes possible to directly write features without the self-organizing structures. - Abstract: We have studied femtosecond ablation under sprayed thin water film and its influence and benefits compared with ablation in the air atmosphere. These have been studied in case of the hole and the groove ablation using IR femtosecond laser. Water enhances the ablation rate and in some situations it makes possible to ablate the holes with a higher aspect ratio. While ablating the grooves, the water spray allows using the high fluences without the generation of the self-organized structures.

  13. Molybdenum oxide nanocolloids prepared by an external field-assisted laser ablation in water

    Directory of Open Access Journals (Sweden)

    Spadaro Salvatore

    2018-01-01

    Full Text Available he synthesis of extremely stable molybdenum oxide nanocolloids by pulsed laser ablation was studied. This green technique ensures the formation of contaminant-free nanostructures and the absence of by-products. A focused picosecond pulsed laser beam was used to ablate a solid molybdenum target immersed in deionized water. Molybdenum oxide nearly spherical nanoparticles with dimensions within few nanometers (20-100 nm are synthesized when the ablation processes were carried out, in water, at room temperature and 80°C. The application of an external electric field during the ablation process induces a nanostructures reorganization, as indicated by Scanning-Transmission Electron Microscopy images analysis. The ablation products were also characterized by some spectroscopic techniques: conventional UV-vis optical absorption, atomic absorption, dynamic light scattering, micro-Raman and X-ray photoelectron spectroscopies. Finally, NIH/3T3 mouse fibroblasts were used to evaluate cell viability by the sulforhodamine B assay

  14. Theoretical and experimental analysis of the impact on ablation depth of microchannel milling using femtosecond laser

    Science.gov (United States)

    Lei, Chen; Pan, Zhang; Jianxiong, Chen; Tu, Yiliu

    2018-04-01

    The plasma brightness cannot be used as a direct indicator of ablation depth detection by femtosecond laser was experimentally demonstrated, which led to the difficulty of depth measurement in the maching process. The tests of microchannel milling on the silicon wafer were carried out in the micromachining center in order to obtain the influences of parameters on the ablation depth. The test results showed that the defocusing distance had no significant impact on ablation depth in LAV effective range. Meanwhile, the reason of this was explained in this paper based on the theoretical analysis and simulation calculation. Then it was proven that the ablation depth mainly depends on laser fluence, step distance and scanning velocity. Finally, a research was further carried out to study the laser parameters which relate with the microchannel ablation depth inside the quartz glass for more efficiency and less cost in processing by femtosecond laser.

  15. Fundamental Mechanisms of Pulsed Laser Ablation of Biological Tissue

    Science.gov (United States)

    Albagli, Douglas

    The ability to cut and remove biological tissue with short pulsed laser light, a process called laser ablation, has the potential to revolutionize many surgical procedures. Ablation procedures using short pulsed lasers are currently being developed or used in many fields of medicine, including cardiology, ophthalmology, dermatology, dentistry, orthopedics, and urology. Despite this, the underlying physics of the ablation process is not well understood. In fact, there is wide disagreement over whether the fundamental mechanism is primarily photothermal, photomechanical, or photochemical. In this thesis, both experimental and theoretical techniques are developed to explore this issue. The photothermal model postulates that ablation proceeds through vaporization of the target material. The photomechanical model asserts that ablation is initiated when the laser-induced tensile stress exceeds the ultimate tensile strength of the target. I have developed a three dimensional model of the thermoelastic response of tissue to short pulsed laser irradiation which allows the time dependent stress distribution to be calculated given the optical, thermal and mechanical properties of the target. A complimentary experimental technique has been developed to verify this model, measure the needed physical properties of the tissue, and record the thermoelastic response of the tissue at the onset of ablation. The results of this work have been widely disseminated to the international research community and have led to significant findings which support the photomechanical model of ablation of tissue. First, the energy deposited in tissue is an order of magnitude less than that required for vaporization. Second, unlike the one-dimensional thermoelastic model of laser-induced stress generation that has appeared in the literature, the full three-dimensional model predicts the development of significant tensile stresses on the surface of the target, precisely where ablation is observed to

  16. Ablation of Solid Hydrogen in a Plasma

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment.......Several hydrogen pellet ablation models based on the formation of a shielding neutral cloud have been reported by different authors. The predicted ablation rates are shown to follow almost the same scaling law and this is used to explain the authors' ablation experiment....

  17. Infrared Laser Ablation with Vacuum Capture for Fingermark Sampling

    Science.gov (United States)

    Donnarumma, Fabrizio; Camp, Eden E.; Cao, Fan; Murray, Kermit K.

    2017-09-01

    Infrared laser ablation coupled to vacuum capture was employed to collect material from fingermarks deposited on surfaces of different porosity and roughness. Laser ablation at 3 μm was performed in reflection mode with subsequent capture of the ejecta with a filter connected to vacuum. Ablation and capture of standards from fingermarks was demonstrated on glass, plastic, aluminum, and cardboard surfaces. Using matrix assisted laser desorption ionization (MALDI), it was possible to detect caffeine after spiking with amounts as low as 1 ng. MALDI detection of condom lubricants and detection of antibacterial peptides from an antiseptic cream was demonstrated. Detection of explosives from fingermarks left on plastic surfaces as well as from direct deposition on the same surface using gas chromatography mass spectrometry (GC-MS) was shown. [Figure not available: see fulltext.

  18. A survey of U.S. prosthodontists and dental schools on the current materials and methods for final impressions for complete denture prosthodontics.

    Science.gov (United States)

    Petrie, Cynthia S; Walker, Mary P; Williams, Karen

    2005-12-01

    The purpose of this study was to survey members of The American College of Prosthodontists (ACP) to evaluate current materials and methods for final impressions for complete denture prosthodontics in the United States. In addition, those methods were compared with methods and materials taught in U.S. dental schools via a second survey sent to the chairpersons of prosthodontic/restorative departments. An anonymous questionnaire was mailed to all 1762 active ACP members in the United States in 2003. A slightly modified questionnaire was also distributed to chairpersons of prosthodontic/restorative departments in the 54 U.S. dental schools. Data analysis was performed via frequency distribution and chi-square statistics. Nine hundred and forty-five questionnaires were returned by members of the ACP (54% return rate) and 42 questionnaires were returned by the U.S. dental schools (78% return rate). The majority of the reporting prosthodontists (88%) and dental schools (98%) use a border-molded custom tray for final impressions for complete denture prosthodontics. The most popular material for border molding was plastic modeling compound (67% of reporting ACP members, and 95% of the responding dental schools). Variability of the materials used for final impressions was observed, with the most popular materials being polyvinylsiloxane for the ACP members (36%) and polysulfide for the dental schools (64%). Statistically significant differences were found in the materials used for border molding by prosthodontists based on the time elapsed since completion of prosthodontic training. No differences were found in the materials used for impression of edentulous arches based on years of experience. Geographic location did not influence the materials and methods used by prosthodontists for complete denture final impressions. There was variability of the materials and techniques used for final impressions by ACP members and dental schools; however, overall there was an agreement

  19. Microwave ablation of primary and secondary liver tumours: ex vivo, in vivo, and clinical characterisation.

    Science.gov (United States)

    Amabile, Claudio; Ahmed, Muneeb; Solbiati, Luigi; Meloni, Maria Franca; Solbiati, Marco; Cassarino, Simone; Tosoratti, Nevio; Nissenbaum, Yitzhak; Ierace, Tiziana; Goldberg, S Nahum

    2017-02-01

    The aim of this study was to compare the performance of a microwave ablation (MWA) apparatus in preclinical and clinical settings. The same commercial 2.45 GHz MWA apparatus was used throughout this study. In total 108 ablations at powers ranging from 20 to 130 W and lasting from 3 to 30 min were obtained on ex vivo bovine liver; 28 ablations at 60 W, 80 W and 100 W lasting 5 and 10 min were then obtained in an in vivo swine model. Finally, 32 hepatocellular carcinomas (HCCs) and 19 liver metastases in 46 patients were treated percutaneously by administering 60 W for either 5 or 10 min. The treatment outcome was characterised in terms of maximum longitudinal and transversal axis of the induced ablation zone. Ex vivo ablation volumes increased linearly with deposited energy (r 2  = 0.97), with higher sphericity obtained at lower power for longer ablation times. Larger ablations were obtained on liver metastases compared to HCCs treated with 60 W for 10 min (p  0.08). For the selected MW ablation device, ex vivo data on bovine liver was more predictive of the actual clinical performance on liver malignancies than an in vivo porcine model. Equivalent MW treatments yielded a significantly different response for HCC and metastases at higher deposited energy, suggesting that outcomes are not only device-specific but must also be characterised on a tissue-by-tissue basis.

  20. Percutaneous Renal Tumor Ablation: Radiation Exposure During Cryoablation and Radiofrequency Ablation

    Energy Technology Data Exchange (ETDEWEB)

    McEachen, James C., E-mail: james.mceachen2@gmail.com [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Leng, Shuai; Atwell, Thomas D. [Mayo Clinic, Department of Radiology (United States); Tollefson, Matthew K. [Mayo Clinic, Department of Urology (United States); Friese, Jeremy L. [Mayo Clinic, Department of Radiology (United States); Wang, Zhen; Murad, M. Hassan [Mayo Clinic, Division of Preventive, Occupational, and Aerospace Medicine (United States); Schmit, Grant D. [Mayo Clinic, Department of Radiology (United States)

    2016-02-15

    IntroductionOnce reserved solely for non-surgical cases, percutaneous ablation is becoming an increasingly popular treatment option for a wider array of patients with small renal masses and the radiation risk needs to be better defined as this transition continues.Materials and MethodsRetrospective review of our renal tumor ablation database revealed 425 patients who underwent percutaneous ablation for treatment of 455 renal tumors over a 5-year time period. Imparted radiation dose information was reviewed for each procedure and converted to effective patient dose and skin dose using established techniques. Statistical analysis was performed with each ablative technique.ResultsFor the 331 cryoablation procedures, the mean DLP was 6987 mGycm (SD = 2861) resulting in a mean effective dose of 104.7 mSv (SD = 43.5) and the mean CTDI{sub vol} was 558 mGy (SD = 439) resulting in a mean skin dose of 563.2 mGy (SD = 344.1). For the 124 RFA procedures, the mean DLP was 3485 mGycm (SD = 1630) resulting in a mean effective dose of 50.3 mSv (SD = 24.0) and the mean CTDI{sub vol} was 232 mGy (SD = 149) resulting in a mean skin dose of 233.2 mGy (SD = 117.4). The difference in patient radiation exposure between the two renal ablation techniques was statistically significant (p < 0.001).ConclusionBoth cryoablation and RFA imparted an average skin dose that was well below the 2 Gy deterministic threshold for appreciable sequela. Renal tumor cryoablation resulted in a mean skin and effective radiation dose more than twice that for RFA. The radiation exposure for both renal tumor ablation techniques was at the high end of the medical imaging radiation dose spectrum.

  1. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available community. The construction industry is a significantly consumer of materials, using 50 per cent of all products produced globally. Building materials is any material which is used for a construction purpose. Many of these materials are sources from natural...

  2. Uncovering the Chemical Processes during Atmospheric Entry of a Carbon/Phenolic Ablator: Laboratory Studies by In Situ Mass Spectrometric and Molecular Beam Techniques

    Data.gov (United States)

    National Aeronautics and Space Administration — Several advanced thermal protection system (TPS) materials currently under development, such as conformal and woven systems, leverage the porous ablator technology...

  3. Image and pathological changes after microwave ablation of breast cancer: A pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wenbin [Department of Breast Surgery, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Jiang, Yanni [Department of Radiology, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Chen, Lin; Ling, Lijun; Liang, Mengdi; Pan, Hong [Department of Breast Surgery, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Wang, Siqi [Department of Radiology, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Ding, Qiang [Department of Breast Surgery, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Liu, Xiaoan, E-mail: liuxiaoan@126.com [Department of Breast Surgery, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China); Wang, Shui, E-mail: ws0801@hotmail.com [Department of Breast Surgery, The First Affiliated Hospital, Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029 (China)

    2014-10-15

    Highlights: • We report successful experience of MWA in breast cancer under local anesthesia. • We report MR imaging evaluation of microwave ablation zone in breast cancer. • Pathological changes after microwave ablation in breast cancer was reported. • 2 min MWA caused an ablation zone with three diameters > 2 cm in breast cancer. - Abstract: Purpose: To prospectively assess MR imaging evaluation of the ablation zone and pathological changes after microwave ablation (MWA) in breast cancer. Materials and methods: Twelve enrolled patients, diagnosed with non-operable locally advanced breast cancer (LABC), were treated by MWA and then neoadjuvant chemotherapy, followed by surgery. MR imaging was applied to evaluate the effect of MWA. Hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM) were applied to analyze the ablated area. Results: All MWA procedures were performed successfully under local anesthesia. For a mean duration of 2.15 min, the mean largest, middle and smallest diameters in the ablated zone 24-h post-ablation in MR imaging were 2.98 cm ± 0.53, 2.51 cm ± 0.41 and 2.23 cm ± 0.41, respectively. The general shape of the ablation zone was close to a sphere. The ablated area became gradually smaller in MR imaging. No adverse effects related to MWA were noted in all 12 patients during and after MWA. HE staining could confirm the effect about 3 months after MWA, which was confirmed by TEM. Conclusions: 2 min MWA can cause an ablation zone with three diameters larger than 2 cm in breast cancer, which may be suitable for the local treatment of breast cancer up to 2 cm in largest diameter. However, the long-term effect of MWA in the treatment of small breast cancer should be determined in the future.

  4. B4C-MODIFIED SiO2-PHENOLIC Composites for Enhanced Ablation Resistance

    Science.gov (United States)

    Li, Maoyuan; Lu, Lin; Dai, Zhen; Hong, Yiqiang; Chen, Weiwei; Zhang, Yuping; Qiao, Yingjie

    In the present paper, the silica-phenolic composite (S-Ph) composites with different amount of B4C were prepared, and the ablation tests of these composites were carried out using oxygen-acetylene jet. The ablation process was systematically investigated. The addition of B4C with appropriate amount can efficiently improve the ablation resistance of S-Ph. The results showed that S-Ph containing B4C powder of 2wt.% exhibited the lowest linear and mass ablation rate. The influence mechanism for the results was analyzed deeply. The surface morphologies, phase composition, density and thermal conductivity of composites were characterized using a scanning electron microscope (SEM), X-Ray Diffraction (XRD), Archimedes method, and thermal conductivity meter, respectively. The present investigation will provide a theoretical basis for the preparation of the ablation resistant material.

  5. Advanced EDL Materials (AEDLM)

    Data.gov (United States)

    National Aeronautics and Space Administration — Via the exploration of alternate resins and substrate materials for ablative TPS, and the development of new high heat flux resistant flexible TPS systems, we intend...

  6. Three Achilles’ heels of alcohol septal ablation

    Directory of Open Access Journals (Sweden)

    M. G. Kashtanov

    2017-11-01

    Full Text Available This manuscript looks at basic limitations of alcohol septal ablation in obstructive hypertrophic cardiomyopathy. They include high-grade atrioventricular blockages, residual obstructions of the left ventricular outflow tract and the so-called proarrhythmic effects of alcohol septal ablation procedure. All these weaknesses are reviewed in the context of incidence, etiology, and prevention.Received 25 February 2017. Accepted 10 April 2017.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest.Author contributionsConception and study design: M.G. Kashtanov.Data collection and analysis: M.G. Kashtanov.Drafting the article: M.G. Kashtanov, E.M. Idov.Final approval of the version to be published: M.G. Kashtanov, S.D. Chernyshev, L.V. Kardapoltsev, S.V. Berdnikov, E.M. Idov.Full text of the article is in the online version of this paper at http://dx.doi.org/10.21688/1681-3472-2017-3-12-22

  7. DOE Final Report -NON-LINEAR WAVES IN CONTINUOUS MEDIA- BES- Division of Engineering and Materials Science

    International Nuclear Information System (INIS)

    Seth J. Putterman

    2006-01-01

    FINAL REPORT ON : NON-LINEAR WAVES IN CONTINUOUS MEDIA Doe DE FG03-87ER13686 (001312-001) Submitted January 10, 2006 by Seth J. Putterman 310-8252269 Physics Department University of California Los Angeles, CA 90095 puherman at ritva.physics.ucla.edu NON-LINEAR WAVES IN CONTINUOUS MEDIA I am happy to report that this project has been a big success. For over 10 years the DOE [Division of Materials Sciences and Engineering] has funded our research program on the overarching theme of spontaneous energy focusing phenomena. These effects occur when a nonlinear macroscopic system is excited so as to drive it far from equilibrium. The subsequent relaxation to equilibrium does not occur smoothly but instead is accompanied by the formation of structured domains where the energy density is highly concentrated. A signature example is picosecond sonoluminescence [1] wherein a smooth sound wave has its energy density focused by 12 orders of magnitude to generate a clock-like string of picosecond flashes of ultraviolet light. Our earlier work on solitons [2] demonstrated how uniform surface waves break up into stable localized structures. Our experimental work on turbulence produced photos of localized structures lying many standard deviations outside the range of gaussian statistics[3]. This effect is referred to as intermittency. Our recent work on friction finds its motivation in those theories of sonoluminescence which invoke frictional electricity. In its most common form this is the generation of a spark when we touch a doorknob after walking over a carpet. Our reading of the literature on this subject indicated that frictional electricity like sonoluminescence is not understood. So to probe triboelectrification we set up a modern version of an experiment performed by Bernoulli in 1700. Here sparking is caused by the rubbing of glass against mercury. We indeed observed flashes of light which were accompanied by events of stick-slip friction at the interface between the

  8. DOE A9024 Final Report Functional and Nanoscale Materials Systems: Frontier Programs of Science at the Frederick Seitz Materials Research Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Jennifer A.

    2009-03-24

    The scientific programs of the FSMRL supported under the DOE A9024 Grant consisted of four interdisciplinary research clusters, as described. The clusters were led by Professors Tai Chiang (Physics), Jeffrey Moore (Chemistry), Paul Goldbart (Physics), and Steven Granick (Materials Science and Engineering). The completed work followed a dominant theme--Nanoscale Materials Systems--and emphasized studies of complex phenomena involving surfaces, interfaces, complex materials, dynamics, energetics, and structures and their transformations. A summary of our key accomplishments is provided for each cluster.

  9. Formation and characterization of nanoparticles via laser ablation in solution

    Science.gov (United States)

    Golightly, Justin Samuel

    The work presented in this thesis encompassed laser ablation of various transition metals within a liquid environment. Through an improved understanding of the ablation process, control over the properties of the resultant nanoparticles can be obtained, and thusly nanoparticles can be tailored with specific properties. Creation of nanoparticles via laser ablation in solution is a relatively youngtechnique for nanoparticle synthesis, and the work presented should prove useful in guiding further exploration in ablation processes in liquids for nanomaterial production. When a laser is focused onto a target under a liquid environment, the target material and its surrounding liquid are vaporized. The concoction of vapor is ejected normal to the surface as a bubble. The bubble has a temperature reaching the boiling point of the metal, and has a gradient to the boiling point of the solvent. The bubble expands until it reaches a critical volume, and then subsequently collapses. It is within this bubble that nanoparticle formation occurs. As the bubble expands, the vapor cools and nanoparticle growth transpires. During the bubble collapse, pressures reaching GigaPascals have been reported, and a secondary nanoparticle formation occurs as a result of these high pressures. Chapter 1 delves a little more into the nanoparticle formation mechanisms, as well as an introduction to the analytical techniques used for characterization. Ablation of titanium took place in isopropanol, ethanol, water, and n-hexane, under various fluences, with a 532 nm Nd:YAG operating at 10 Hz. It was found that a myriad of nanoparticles could be made with vastly different compositions that were both solvent and fluence dependent. Nanoparticles were made that incorporated carbon and oxygen from the solvent, showing how solvent choice is an important factor in nanoparticle creation. Chapter 3 discusses the results of the titanium work in great detail and demonstrates carbide production with ablation in

  10. Influence of Coupled Radiation and Ablation on the Aerothermodynamic Environment of Planetary Entry Vehicles

    Science.gov (United States)

    Johnston, Christopher O.; Gnoffo, Peter A.; Mazaheri, Alireza

    2013-01-01

    A review of recently published coupled radiation and ablation capabilities involving the simulation of hypersonic flowfields relevant to Earth, Mars, or Venus entry is presented. The three fundamental mechanisms of radiation coupling are identified as radiative cooling, precursor photochemistry, and ablation-radiation interaction. The impact of these mechanisms are shown to be significant for a 3 m radius sphere entering Earth at hypothetical Mars return conditions (approximately 15 km/s). To estimate the influence precursor absorption on the radiative flux for a wide range of conditions, a simplified approach is developed that requires only the non-precursor solution. Details of a developed coupled ablation approach, which is capable of treating both massively ablating flowfields in the sublimation regime and weakly ablating diffusion Climited oxidation cases, are presented. A review of the two primary uncoupled ablation approximations, identified as the blowing correction and film coefficient approximations, is made and their impact for Earth and Mars entries is shown to be significant for recession and convective heating predictions. Fully coupled ablation and radiation simulations are presented for the Mars return sphere throughout its entire trajectory. Applying to the Mars return sphere the Pioneer- Venus heritage carbon phenolic heatshield, which has properties available in the open literature, the differences between steady state ablation and coupling to a material response code are shown to be significant.

  11. Evaluation of improved materials for stationary diesel engines operating on residual and coal based fuels. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    Experimental results to date from an on-going research program on improved materials for stationary diesel engines using residual or coal-based fuels are presented with little discussion of conclusions about these results. Information is included on ring and liner wear, fuel oil qualities, ceramic materials, coatings, test procedures and equipment, and tribology test results. (LCL)

  12. Evaluation and use of the Materials and Test (MATT) Data System for quality of construction and management review : final report.

    Science.gov (United States)

    1985-12-01

    This report documents the review of the MATerials and Test (MATT) Data System to check the validity of data within the system. A computer program to generate the quality level of a construction material was developed. Programs were also developed to ...

  13. Effect of Left Atrial Ablation Process and Strategy on Microemboli Formation During Irrigated Radiofrequency Catheter Ablation in an In Vivo Model.

    Science.gov (United States)

    Takami, Mitsuru; Lehmann, H Immo; Parker, Kay D; Welker, Kirk M; Johnson, Susan B; Packer, Douglas L

    2016-01-01

    Formation of microemboli during catheter ablation has been suggested as a cause for asymptomatic cerebral emboli. However, it is unknown which part of the process and ablation setting/strategy is most strongly related to this occurrence. A total of 27 pigs were used. Catheter/sheath manipulations in left atrium were performed in 25 of 27 pigs outfitted with microemboli monitoring systems. Ablations using open-irrigated radiofrequency catheters were performed in 18 of 25 pigs. Two of 27 pigs did not undergo left atrial procedures and were injected with microembolic materials in the carotid artery to serve as positive controls. In total, 334 sheath/catheter manipulations (transseptal puncture, sheath flushing, catheter insertion, pulmonary vein venography, and sheath exchange) and 333 radiofrequency applications (power setting, 30/50 W; point-by-point/drag ablations) were analyzed. High microbubble volume in the extracorporeal circulation loop and a high number of microembolic signals in carotid artery were observed during sheath/catheter manipulations especially in saline/contrast injections at fast speed and ablations with steam pop. Fast sheath flushing produced significantly higher microbubble volume than slow sheath flushing (median, 12 200 versus 121 nL; Pdrag ablations, and steam pop. Brain magnetic resonance imaging showed positive-embolic lesions in control pigs. Formation of microbubbles was the greatest during fast saline/contrast injections and steam pops, whereas high-power radiofrequency applications, drag ablations, and steam pops produced most of the microparticles. © 2016 American Heart Association, Inc.

  14. Final environmental impact statement, interim management of nuclear materials, Savannah River Site, Aiken, South Carolina (DOE/EIS-0220)

    Energy Technology Data Exchange (ETDEWEB)

    Grainger, A R

    1995-10-01

    This document evaluates the potential environmental impacts of alternatives for the stabilization of nuclear materials currently stored at various locations on the Savannah River Site (SRS). These materials remain from past defense-related production, testing, and other activities at the SRS and from chemical separations and related activities that DOE suspended in 1992. The EIS analyzes the following alternatives: Continuing Storage (No Action), Processing to Metal, Processing to Oxide, Blending Down to Low Enriched Uranium, Processing and Storage for Vitrification in the Defense Waste Processing Facility, Vitrification (F-Canyon), and Improving Storage. The preferred alternatives cover a combination of these in relation to the different types of material.

  15. Influence of consecutive picosecond pulses at 532 nm wavelength on laser ablation of human teeth

    Science.gov (United States)

    Mirdan, Balsam M.; Antonelli, Luca; Batani, Dimitri; Jafer, Rashida; Jakubowska, Katarzyna; Tarazi, Saad al; Villa, Anna Maria; Vodopivec, Bruno; Volpe, Luca

    2014-07-01

    The interaction of 40 ps pulse duration laser emitting at 532 nm wavelength with human dental tissue (enamel, dentin, and dentin-enamel junction) has been investigated. The crater profile and the surface morphology have been studied by using a confocal auto-fluorescence microscope (working in reflection mode) and a scanning electron microscope. Crater profile and crater morphology were studied after applying consecutive laser pulses and it was found that the ablation depth increases with the number of consecutive pulses, leaving the crater diameter unchanged. We found that the thermal damage is reduced by using short duration laser pulses, which implies an increased retention of restorative material. We observe carbonization of the irradiated samples, which does not imply changes in the chemical composition. Finally, the use of 40 ps pulse duration laser may become a state of art in conservative dentistry.

  16. Image-guided radiofrequency ablation of hepatocellular carcinoma (HCC): Is MR guidance more effective than CT guidance?

    International Nuclear Information System (INIS)

    Clasen, Stephan; Rempp, Hansjörg; Hoffmann, Rüdiger; Graf, Hansjörg; Pereira, Philippe L.; Claussen, Claus D.

    2014-01-01

    Objectives: The purpose of the study was to retrospectively compare technique effectiveness of computed tomography (CT)-guided versus magnetic resonance (MR)-guided radiofrequency (RF) ablation of hepatocellular carcinoma (HCC). Materials and methods: In 35 consecutive patients 53 CT-guided (n = 29) or MR-guided (n = 24) ablation procedures were performed in the treatment of 56 (CT: 29; MR: 27) HCC. The entire ablation procedure was performed at a multislice CT-scanner or an interventional 0.2-Tesla MR-scanner. Assessment of treatment response was based on dynamic MR imaging at 1.5 Tesla. The mean follow-up was 22.9 months. Primary technique effectiveness was assessed 4 months after ablation therapy. Secondary technique effectiveness was assessed 4 months after a facultative second ablation procedure. Primary and secondary technique effectiveness of CT-guided and MR-guided RF ablation was compared by using Chi-Square (likelihood ratio) test. Results: Primary technique effectiveness after a single session was achieved in 26/27 (96.3%) HCC after MR-guided RF ablation and 23/29 (79.3%) HCC after CT-guided RF ablation (Chi-Square: p = 0.04). Secondary technique effectiveness was achieved in 26/27 (96.3%) HCC after MR-guided RF ablation and in 26/29 (89.7%) HCC after CT-guided RF ablation (Chi-Square: p = 0.32). A local tumor progression was detected in 8/52 (15.4%) tumors after initial technique effectiveness. Major complications were detected after 3/53 (5.7%) ablation procedures. Conclusions: CT-guided and MR-guided RF ablations are locally effective therapies in the treatment of HCC. Due to a higher rate of primary technique effectiveness MR-guided RF ablation may reduce the number of required sessions for complete tumor treatment

  17. Laser ablation of the protein lysozyme

    DEFF Research Database (Denmark)

    Schou, Jørgen; Canulescu, Stela; Amoruso, Salvatore

    Lysozyme is a well-known protein, which is used in food processing because of its bactericidal properties. The mass (14307 amu) is in the range in which it easily can be monitored by mass spectrometric methods, for example by MALDI (Matrix assisted laser desorption ionization). We have recently...... to a substrate as intact molecules by the violent laser impact ( up to 50 mJ/pulse) has not yet been understood. One issue is that up to 150 ng/pulse is removed by the laser, and much of the material is ejected from the target in relatively large chunks. We have explored as well the excitation mechanics by laser...... impact. Samples of pressed lysozyme prepared in the same manner as in ns-experiments have been irradiated at 527 nm with >>300-fs pulses and at a similar fluence as in ns ablation. Even though the pulse energy was much smaller, there was a considerable ablation weight loss of lysozyme from each shot...

  18. Laser Guidance in C-Arm Cone-Beam CT-Guided Radiofrequency Ablation of Osteoid Osteoma Reduces Fluoroscopy Time

    NARCIS (Netherlands)

    Kroes, M.W.; Busser, W.M.H.; Hoogeveen, Y.L.; Lange, F. de; Schultze Kool, L.J.

    2017-01-01

    PURPOSE: To assess whether laser guidance can reduce fluoroscopy and procedure time of cone-beam computed tomography (CBCT)-guided radiofrequency (RF) ablations of osteoid osteoma compared to freehand CBCT guidance. MATERIALS AND METHODS: 32 RF ablations were retrospectively analyzed, 17

  19. Tissue ablation and gas formation of two excimer laser systems: an in vitro evaluation on porcine aorta

    NARCIS (Netherlands)

    Appelman, Y. E.; Piek, J. J.; Verhoofstad, G. G.; Gijsbers, G. H.; van Gemert, M. J.

    1996-01-01

    BACKGROUND and The relationship between tissue ablation volume and the formation of insoluble gas of the currently available excimer laser systems is unknown. This aspect was evaluated in two excimer laser systems. STUDY DESIGN/MATERIALS and We measured tissue ablation volume and gas production of

  20. R&D of Novel Materials for Animal Litters Using High Carbon Fly Ash Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Boxley, Chett J. [Ceramatec, Inc., Salt Lake City, UT (United States); Kadota, Rod [Ceramatec, Inc., Salt Lake City, UT (United States)

    2012-10-29

    This research program performed by Ceramatec may significantly increase the beneficial utilization of fly ash, and improve the overall performance of high quality animal litter products. Ceramatec has developed a novel high surface area material, which is capable of ammonia adsorption. High surface area zeolites when combined with agglomerated fly ash can significantly reduce the use of naturally mined materials (i.e. clay bentonite) for animal litter manufacture. This not only preserves natural resources and the natural environment, but it also will reduce CO2 emissions, via the reduced need for heavy mining equipment. This novel animal litter is made with over 85% of recycled materials, thus preventing their disposition to landfills. The novel litter material is similar to traditional clay-like litters, and it is clumpable and has superior odor control properties.

  1. Investigation of Springback Associated with Composite Material Component Fabrication (MSFC Center Director's Discretionary Fund Final Report, Project 94-09)

    Science.gov (United States)

    Benzie, M. A.

    1998-01-01

    The objective of this research project was to examine processing and design parameters in the fabrication of composite components to obtain a better understanding and attempt to minimize springback associated with composite materials. To accomplish this, both processing and design parameters were included in a Taguchi-designed experiment. Composite angled panels were fabricated, by hand layup techniques, and the fabricated panels were inspected for springback effects. This experiment yielded several significant results. The confirmation experiment validated the reproducibility of the factorial effects, error recognized, and experiment as reliable. The material used in the design of tooling needs to be a major consideration when fabricating composite components, as expected. The factors dealing with resin flow, however, raise several potentially serious material and design questions. These questions must be dealt with up front in order to minimize springback: viscosity of the resin, vacuum bagging of the part for cure, and the curing method selected. These factors directly affect design, material selection, and processing methods.

  2. 2nd (final) IAEA research co-ordination meeting on 'plasma-material interaction data for mixed plasma facing materials in fusion reactors'. Summary report

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2001-11-01

    The proceedings and conclusions of the 2nd Research Co-ordination Meeting on 'Plasma-Material Interaction Data for Mixed Plasma Facing Materials in Fusion Reactors', held on October 16 and 17, 2000 at the IAEA Headquarters in Vienna, are briefly described. This report includes a summary of the presentations made by the meeting participants and a review of the accomplishments of the Co-ordinated Research Project (CRP). In addition, short summaries from the participants are included indicating the specific research completed in support of this CRP. (author)

  3. Research at and Operation of the Materials Science Beamline (X-11) at the National Synchrotron Light Source. Final Report

    International Nuclear Information System (INIS)

    Sayers, Dale E.

    2003-01-01

    This is the final report for DOE DE-FG02-89ER45384. An overview of the operational history and status of beamline X-11A at the end of the contract period, and a brief review of the core science program at NCSU and the scientific results of X-11A since the last progress report is also presented

  4. Nuclear material inventory estimation in solvent extraction contactors III. Final report for the period 1 January 1988 - 28 February 1989

    International Nuclear Information System (INIS)

    Beyerlein, A.L.; Geldard, J.F.

    1989-03-01

    Simple mathematical models have been developed for estimating the nuclear material inventory in the solvent extraction contactors of nuclear fuel reprocessing facilities from measured nuclear material concentrations in the tanks feeding the purification cycles. The report describes the models and their application to the Eurochemic Reprocessing Plant in Belgium, and the development of a computer simulation program, PUPART, for investigating the effects of process variation as well as measurement error on near-real-time accounting methods. Figs and tabs

  5. Medical Devices; Immunology and Microbiology Devices; Classification of the Assayed Quality Control Material for Clinical Microbiology Assays. Final order.

    Science.gov (United States)

    2017-07-27

    The Food and Drug Administration (FDA, Agency, or we) is classifying the assayed quality control material for clinical microbiology assays into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the assayed quality control material for clinical microbiology assays' classification. The Agency is classifying the device into class II (special controls) to provide a reasonable assurance of safety and effectiveness of the device.

  6. Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jianmin [Northwestern Univ., Evanston, IL (United States)

    2017-09-20

    Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

  7. Predictive characterization of aging and degradation of reactor materials in extreme environments. Final report, December 20, 2013 - September 20, 2017

    International Nuclear Information System (INIS)

    Qu, Jianmin

    2017-01-01

    Understanding of reactor material behavior in extreme environments is vital not only to the development of new materials for the next generation nuclear reactors, but also to the extension of the operating lifetimes of the current fleet of nuclear reactors. To this end, this project conducted a suite of unique experimental techniques, augmented by a mesoscale computational framework, to understand and predict the long-term effects of irradiation, temperature, and stress on material microstructures and their macroscopic behavior. The experimental techniques and computational tools were demonstrated on two distinctive types of reactor materials, namely, Zr alloys and high-Cr martensitic steels. These materials are chosen as the test beds because they are the archetypes of high-performance reactor materials (cladding, wrappers, ducts, pressure vessel, piping, etc.). To fill the knowledge gaps, and to meet the technology needs, a suite of innovative in situ transmission electron microscopy (TEM) characterization techniques (heating, heavy ion irradiation, He implantation, quantitative small-scale mechanical testing, and various combinations thereof) were developed and used to elucidate and map the fundamental mechanisms of microstructure evolution in both Zr and Cr alloys for a wide range environmental boundary conditions in the thermal-mechanical-irradiation input space. Knowledge gained from the experimental observations of the active mechanisms and the role of local microstructural defects on the response of the material has been incorporated into a mathematically rigorous and comprehensive three-dimensional mesoscale framework capable of accounting for the compositional variation, microstructural evolution and localized deformation (radiation damage) to predict aging and degradation of key reactor materials operating in extreme environments. Predictions from this mesoscale framework were compared with the in situ TEM observations to validate the model.

  8. The internal structure and dynamics of the railgun plasma armature between infinitely wide ablating rails

    International Nuclear Information System (INIS)

    Frese, M.F.

    1991-01-01

    This paper reports on computer simulations of the plasma flow in two-dimensionally symmetric railgun plasma arcs that were performed. The direction of symmetry is normal to the insulator surface, so that the rails are effectively infinite in width. The rail surface ablates according to one of two ablation models, in which either all absorbed energy flux, or only the excess over that which the rail material can conduct away, ablates mass. A number of combinations of initial conditions, boundary conditions and resistivity models were explored. The full ablation model produces an arc of continuously growing mass and length, in which the current distribution reaches from the projectile half-way to the breech. The conduction limited ablation model produces a compact arc approximately eight times the bore height in length, which ceases to ablate material from the rails before the projectile reaches a velocity of 1 km/s. There is need for further study in several areas. These include the arc initiation process, the ablation of the insulators, and three-dimensional effects

  9. Data Fitting to Study Ablated Hard Dental Tissues by Nanosecond Laser Irradiation.

    Directory of Open Access Journals (Sweden)

    Y Al-Hadeethi

    Full Text Available Laser ablation of dental hard tissues is one of the most important laser applications in dentistry. Many works have reported the interaction of laser radiations with tooth material to optimize laser parameters such as wavelength, energy density, etc. This work has focused on determining the relationship between energy density and ablation thresholds using pulsed, 5 nanosecond, neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12 (Nd:YAG laser at 1064 nanometer. For enamel and dentin tissues, the ablations have been performed using laser-induced breakdown spectroscopy (LIBS technique. The ablation thresholds and relationship between energy densities and peak areas of calcium lines, which appeared in LIBS, were determined using data fitting. Furthermore, the morphological changes were studied using Scanning Electron Microscope (SEM. Moreover, the chemical stability of the tooth material after ablation has been studied using Energy-Dispersive X-Ray Spectroscopy (EDX. The differences between carbon atomic % of non-irradiated and irradiated samples were tested using statistical t-test. Results revealed that the best fitting between energy densities and peak areas of calcium lines were exponential and linear for enamel and dentin, respectively. In addition, the ablation threshold of Nd:YAG lasers in enamel was higher than that of dentin. The morphology of the surrounded ablated region of enamel showed thermal damages. For enamel, the EDX quantitative analysis showed that the atomic % of carbon increased significantly when laser energy density increased.

  10. Data Fitting to Study Ablated Hard Dental Tissues by Nanosecond Laser Irradiation.

    Science.gov (United States)

    Al-Hadeethi, Y; Al-Jedani, S; Razvi, M A N; Saeed, A; Abdel-Daiem, A M; Ansari, M Shahnawaze; Babkair, Saeed S; Salah, Numan A; Al-Mujtaba, A

    2016-01-01

    Laser ablation of dental hard tissues is one of the most important laser applications in dentistry. Many works have reported the interaction of laser radiations with tooth material to optimize laser parameters such as wavelength, energy density, etc. This work has focused on determining the relationship between energy density and ablation thresholds using pulsed, 5 nanosecond, neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12 (Nd:YAG) laser at 1064 nanometer. For enamel and dentin tissues, the ablations have been performed using laser-induced breakdown spectroscopy (LIBS) technique. The ablation thresholds and relationship between energy densities and peak areas of calcium lines, which appeared in LIBS, were determined using data fitting. Furthermore, the morphological changes were studied using Scanning Electron Microscope (SEM). Moreover, the chemical stability of the tooth material after ablation has been studied using Energy-Dispersive X-Ray Spectroscopy (EDX). The differences between carbon atomic % of non-irradiated and irradiated samples were tested using statistical t-test. Results revealed that the best fitting between energy densities and peak areas of calcium lines were exponential and linear for enamel and dentin, respectively. In addition, the ablation threshold of Nd:YAG lasers in enamel was higher than that of dentin. The morphology of the surrounded ablated region of enamel showed thermal damages. For enamel, the EDX quantitative analysis showed that the atomic % of carbon increased significantly when laser energy density increased.

  11. Radiofrequency ablation of liver metastases

    International Nuclear Information System (INIS)

    Pereira, P.L.; Clasen, S.; Schmidt, D.; Wiskirchen, J.; Tepe, G.; Claussen, C.D.; Boss, A.; Gouttefangeas, C.; Burkart, C.

    2004-01-01

    The liver is the second only to lymph nodes as the most common site of metastatic disease irrespective of the primary tumor. Up to 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improvement of the survival time, only approximately 20% of the patients are eligible for surgical intervention. Radiofrequency (RF) ablation represents one of the most important alternatives as well as complementary methods for the therapy of liver metastases. RF ablation can lead in a selected patient group to a palliation or to an increased life expectancy. RF ablation appears either safer (vs. cryotherapy) or easier (vs. laser) or more effective (percutaneous ethanol instillation [PEI]), transarterial chemoembolisation [TACE] in comparison with other minimal invasive procedures. RF ablation can be performed percutaneously, laparoscopically or intraoperatively and may be combined with chemotherapy as well as with surgical resection. Permanent technical improvements of RF systems, a better understanding of the underlying electrophysiological principles and an interdisciplinary approach will lead to a prognosis improvement in patients with liver metastases. (orig.) [de

  12. [Radiofrequency ablation of liver metastases].

    Science.gov (United States)

    Pereira, P L; Clasen, S; Boss, A; Schmidt, D; Gouttefangeas, C; Burkart, C; Wiskirchen, J; Tepe, G; Claussen, C D

    2004-04-01

    The liver is the second only to lymph nodes as the most common site of metastatic disease irrespective of the primary tumor. Up to 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improvement of the survival time, only approximately 20% of the patients are eligible for surgical intervention. Radiofrequency (RF) ablation represents one of the most important alternatives as well as complementary methods for the therapy of liver metastases. RF ablation can lead in a selected patient group to a palliation or to an increased life expectancy. RF ablation appears either safer (vs. cryotherapy) or easier (vs. laser) or more effective (percutaneous ethanol instillation [PEI], transarterial chemoembolisation [TACE]) in comparison with other minimal invasive procedures. RF ablation can be performed percutaneously, laparoscopically or intraoperatively and may be combined with chemotherapy as well as with surgical resection. Permanent technical improvements of RF systems, a better understanding of the underlying electrophysiological principles and an interdisciplinary approach will lead to a prognosis improvement in patients with liver metastases.

  13. Endometrial ablation with paracervical block

    NARCIS (Netherlands)

    Penninx, Josien P. M.; Mol, Ben Willem; Bongers, Marlies Y.

    2009-01-01

    OBJECTIVE: To evaluate the safety, feasibility and efficacy of endometrial ablation under local anesthesia. STUDY DESIGN: A prospective cohort study was performed at the gynecology department of a large teaching hospital. Women with dysfunctional uterine bleeding were included to undergo NovaSure

  14. Further research on melting activated and contaminated materials from the decommissioning of nuclear installations for the final storage

    International Nuclear Information System (INIS)

    Deipenau, H.; Seidler, M.

    1990-07-01

    The unconditional reuse of activated and contaminated materials by melting and the production of qualified casks (type A- and type B-containers) was proved. Investigations on nuclide distribution in the melting furnace, molten material, dust and slag were used as a basis for the erection of a new central melting facility. Melting contaminated carbon steel a mass of 2-5% of the contaminated material was generated as dust and slag. They must be handled and transported as radioactive waste. Melting non-ferrous material activity contents could be reached for unconditional reuse. Binding radioactive carbon in the metal matrix of cast iron is only possible by using crushed graphite. The investigations of this project showed that unconditional reuse of contaminated material is possible in industrial scale. Doses of the workers and of the people in the environment of the facility resulting from melting were far below the limits of the German radiation protection law. Up to 1990 a mass of 2000 Mg of contaminated material was melted in the Siempelkamp foundry. Mass inventories for the dismantling of a reference power plant SWR 900 MWe are calculated. (orig./HP) With 7 refs., 18 tabs., 12 figs [de

  15. Hydrodynamic instabilities in an ablation front

    Energy Technology Data Exchange (ETDEWEB)

    Piriz, A R; Portugues, R F [E.T.S.I. Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2004-06-01

    The hydrodynamic stability of an ablation front is studied for situations in which the wavelength of the perturbations is larger than the distance to the critical surface where the driving radiation is absorbed. An analytical model is presented, and it shows that under conditions in which the thermal flux is limited within the supercritical region of the ablative corona, the front may behave like a flame or like an ablation front, depending on the perturbation wavelength. For relatively long wavelengths the critical and ablation surfaces practically lump together into a unique surface and the front behaves like a flame, whereas for the shortest wavelengths the ablation front substructure is resolved.

  16. A Study of the State of Bilingual Materials Development and the Transition of Materials to the Classroom. A Final Report: LEA Survey, Volume 3.

    Science.gov (United States)

    Development Associates, Inc., Arlington, VA.

    This study describes and assesses the state of bilingual curriculum development activities in the National Network of Centers for Bilingual Education. Recommendations are made for improvement in the creation, production, and distribution of bilingual instructional materials. The overall approach to the study was tripartite and focused on: (1) the…

  17. A Study of the State of Bilingual Materials Development and the Transition of Materials to the Classroom. A Final Report: Volume 1.

    Science.gov (United States)

    Development Associates, Inc., Arlington, VA.

    This study describes and assesses the state of bilingual curriculum development activities in the National Network of Centers for Bilingual Education. Recommendations are made for improvement in the creation, production, and distribution of bilingual instructional materials. The overall approach to the study was tripartite and focused on: (1) the…

  18. A Study of the State of Bilingual Materials Development and the Transition of Materials to the Classroom. A Final Report: Inventory, Volume 2.

    Science.gov (United States)

    Development Associates, Inc., Arlington, VA.

    This study describes and assesses the state of bilingual curriculum development activities in the National Network of Centers for Bilingual Education. Recommendations are made for improvement in the creation, production, and distribution of bilingual instructional materials. The overall approach to the study was tripartite and focused on: (1) the…

  19. Effort on calibration of infrared spark ablation of copper with synthetic copper standards

    Energy Technology Data Exchange (ETDEWEB)

    Wienold, Julia, E-mail: julia.wienold@bam.de; Traub, Heike; Bresch, Harald; Seeger, Stefan; Recknagel, Sebastian; Kipphardt, Heinrich

    2011-06-15

    Two types of copper samples, compact certified copper reference materials and calibration samples prepared from liquid doped, pressed copper powders, were studied in terms of accuracy of obtained calibration functions originating from infrared spark ablation. Additionally, corresponding particle size distributions of the aerosols from infrared spark ablation were recorded. It is shown that the differences in quantification results, originating from the two sets of calibration functions, could not mainly be ascribed to different particle size distributions of the two copper sample types. Possible other causes, as different ablation rates, parts of melting and differences of the chemical constitutions of the two sample types were explored.

  20. Final Report on Developing Microstructure-Property Correlation in Reactor Materials using in situ High-Energy X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meimei [Argonne National Lab. (ANL), Argonne, IL (United States); Almer, Jonathan D. [Argonne National Lab. (ANL), Argonne, IL (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States); Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-01-01

    This report provides a summary of research activities on understanding microstructure – property correlation in reactor materials using in situ high-energy X-rays. The report is a Level 2 deliverable in FY16 (M2CA-13-IL-AN_-0403-0111), under the Work Package CA-13-IL-AN_- 0403-01, “Microstructure-Property Correlation in Reactor Materials using in situ High Energy Xrays”, as part of the DOE-NE NEET Program. The objective of this project is to demonstrate the application of in situ high energy X-ray measurements of nuclear reactor materials under thermal-mechanical loading, to understand their microstructure-property relationships. The gained knowledge is expected to enable accurate predictions of mechanical performance of these materials subjected to extreme environments, and to further facilitate development of advanced reactor materials. The report provides detailed description of the in situ X-ray Radiated Materials (iRadMat) apparatus designed to interface with a servo-hydraulic load frame at beamline 1-ID at the Advanced Photon Source. This new capability allows in situ studies of radioactive specimens subject to thermal-mechanical loading using a suite of high-energy X-ray scattering and imaging techniques. We conducted several case studies using the iRadMat to obtain a better understanding of deformation and fracture mechanisms of irradiated materials. In situ X-ray measurements on neutron-irradiated pure metal and model alloy and several representative reactor materials, e.g. pure Fe, Fe-9Cr model alloy, 316 SS, HT-UPS, and duplex cast austenitic stainless steels (CASS) CF-8 were performed under tensile loading at temperatures of 20-400°C in vacuum. A combination of wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and imaging techniques were utilized to interrogate microstructure at different length scales in real time while the specimen was subject to thermal-mechanical loading. In addition, in situ X-ray studies were

  1. Ablation experiment and threshold calculation of titanium alloy irradiated by ultra-fast pulse laser

    Directory of Open Access Journals (Sweden)

    Buxiang Zheng

    2014-02-01

    Full Text Available The interaction between an ultra-fast pulse laser and a material's surface has become a research hotspot in recent years. Micromachining of titanium alloy with an ultra-fast pulse laser is a very important research direction, and it has very important theoretical significance and application value in investigating the ablation threshold of titanium alloy irradiated by ultra-fast pulse lasers. Irradiated by a picosecond pulse laser with wavelengths of 1064 nm and 532 nm, the surface morphology and feature sizes, including ablation crater width (i.e. diameter, ablation depth, ablation area, ablation volume, single pulse ablation rate, and so forth, of the titanium alloy were studied, and their ablation distributions were obtained. The experimental results show that titanium alloy irradiated by a picosecond pulse infrared laser with a 1064 nm wavelength has better ablation morphology than that of the green picosecond pulse laser with a 532 nm wavelength. The feature sizes are approximately linearly dependent on the laser pulse energy density at low energy density and the monotonic increase in laser pulse energy density. With the increase in energy density, the ablation feature sizes are increased. The rate of increase in the feature sizes slows down gradually once the energy density reaches a certain value, and gradually saturated trends occur at a relatively high energy density. Based on the linear relation between the laser pulse energy density and the crater area of the titanium alloy surface, and the Gaussian distribution of the laser intensity on the cross section, the ablation threshold of titanium alloy irradiated by an ultra-fast pulse laser was calculated to be about 0.109 J/cm2.

  2. Development of Advanced Materials for Electro-Ceramic Application Final Report CRADA No. TC-1331-96

    Energy Technology Data Exchange (ETDEWEB)

    Caplan, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Olstad, R. [General Atomics, San Diego, CA (United States); McMillan, L. [Symetrix International, Inc., Colorado Springs, CO (United States); Tulupov, A. [Soliton-NTT, Moscow (Russia)

    2017-10-19

    The goal of this project was to further develop and characterize the electrochemical methods originating in Russia for producing ultra high purity organometallic compounds utilized as precursors in the production of high quality electro-ceramic materials. Symetrix planned to use electro-ceramic materials with high dielectric constant for microelectronic memory circuit applications. General Atomics planned to use the barium titanate type ceramics with low loss tangent for producing a high power ferroelectric tuner used to match radio frequency power into their Dill-D fusion machine. Phase I of the project was scheduled to have a large number of organometallic (alkoxides) chemical samples produced using various methods. These would be analyzed by LLNL, Soliton and Symetrix independently to determine the level of chemical impurities thus verifying each other's analysis. The goal was to demonstrate a cost-effective production method, which could be implemented in a large commercial facility to produce high purity organometallic compounds. In addition, various compositions of barium-strontium-titanate ceramics were to be produced and analyzed in order to develop an electroceramic capacitor material having the desired characteristics with respect to dielectric constant, loss tangent, temperature characteristics and non-linear behavior under applied voltage. Upon optimizing the barium titanate material, 50 capacitor preforms would be produced from this material demonstrating the ability to produce, in quantity, the pills ultimately required for the ferroelectric tuner (approx 2000-3000 ceramic pills).

  3. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Stinis, Panos [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-07

    This is the final report for the work conducted at the University of Minnesota (during the period 12/01/12-09/18/14) by PI Panos Stinis as part of the "Collaboratory on Mathematics for Mesoscopic Modeling of Materials" (CM4). CM4 is a multi-institution DOE-funded project whose aim is to conduct basic and applied research in the emerging field of mesoscopic modeling of materials.

  4. Contaminant Area Aquaculture Program. Determination of the chemical suitability of a dredged material containment area for aquaculture. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Tatem, H.E.

    1990-12-01

    This concerns use of dredged material containment areas (DMCA) for aquaculture, specifically for production of a crop intended for human consumption. New DMCA's used only periodically for dredged material disposal could be managed to produce valuable crops. Previous studies conducted by the Corps of Engineers, including one where shrimp was raised at a DMCA, and others relating to the effects of sediment contaminants on aquatic organisms, are reviewed. The literature indicated that most dredged material is uncontaminated and that many sediment constituents such as metal are relatively unavailable to aquatic animals; DMCAs containing parts-per-million levels of organic contaminants such as pesticides, polychlorinated biphenyls, or petroleum hydrocarbons should not be used for aquaculture without extensive testing.

  5. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    Energy Technology Data Exchange (ETDEWEB)

    Bordia, Rajendra [Univ. of Washington, Seattle, WA (United States); Tomar, Vikas [Purdue Univ., West Lafayette, IN (United States); Henager, Chuck [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-08

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  6. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    International Nuclear Information System (INIS)

    Bordia, Rajendra; Tomar, Vikas; Henager, Chuck

    2015-01-01

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  7. On-site transportation and handling of uranium-233 special nuclear material: Preliminary hazards and accident analysis. Final

    International Nuclear Information System (INIS)

    Solack, T.; West, D.; Ullman, D.; Coppock, G.; Cox, C.

    1995-01-01

    U-233 Special Nuclear Material (SNM) currently stored at the T-Building Storage Areas A and B must be transported to the SW/R Tritium Complex for repackaging. This SNM is in the form of oxide powder contained in glass jars which in turn are contained in heat sealed double polyethylene bags. These doubled-bagged glass jars have been primarily stored in structural steel casks and birdcages for approximately 20 years. The three casks, eight birdcages, and one pail/pressure vessel will be loaded onto a transport truck and moved over an eight day period. The Preliminary Hazards and Accident Analysis for the on-site transportation and handling of Uranium-233 Special Nuclear Material, documented herein, was performed in accordance with the format and content guidance of DOE-STD-3009-94, Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports, dated July 1994, specifically Chapter Three, Hazard and Accident Analysis. The Preliminary Hazards Analysis involved detailed walkdowns of all areas of the U-233 SNM movement route, including the T-Building Storage Area A and B, T-Building truck tunnel, and the roadway route. Extensive discussions were held with operations personnel from the Nuclear Material Control Group, Nuclear Materials Accountability Group, EG and G Mound Security and the Material Handling Systems Transportation Group. Existing documentation related to the on-site transportation of hazardous materials, T-Building and SW/R Tritium Complex SARs, and emergency preparedness/response documentation were also reviewed and analyzed to identify and develop the complete spectrum of energy source hazards

  8. Screening of candidate corrosion resistant materials for coal combustion environments -- Volume 4. Final report, January 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Boss, D.E.

    1997-12-31

    The development of a silicon carbide heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structural materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal-shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. The candidate protective materials identified in a previous effort were screened for their stability to the EFCC combustion environment. Bulk samples of each of the eleven candidate materials were prepared, and exposed to coal slag for 100 hours at 1,370 C under flowing air. After exposure the samples were mounted, polished, and examined via x-ray diffraction, energy dispersive spectroscopy, and scanning electron microscopy. In general, the alumina-based materials behaved well, with comparable corrosion depths in all five samples. Magnesium chromite formed a series of reaction products with the slag, which included an alumina-rich region. These reaction products may act as a diffusion barrier to slow further reaction between the magnesium chromite and the slag and prove to be a protective coating. As for the other materials; calcium titanate failed catastrophically, the CS-50 exhibited extension microstructural and compositional changes, and zirconium titanate, barium zironate, and yttrium chromite all showed evidence of dissolution with the slag.

  9. Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

    Science.gov (United States)

    Galmed, A. H.; du Plessis, A.; le Roux, S. G.; Hartnick, E.; Von Bergmann, H.; Maaza, M.

    2018-01-01

    Laboratory X-ray computed tomography is an emerging technology for the 3D characterization and dimensional analysis of many types of materials. In this work we demonstrate the usefulness of this characterization method for the full three dimensional analysis of laser ablation craters, in the context of a laser induced breakdown spectroscopy setup. Laser induced breakdown spectroscopy relies on laser ablation for sampling the material of interest. We demonstrate here qualitatively (in images) and quantitatively (in terms of crater cone angles, depths, diameters and volume) laser ablation crater analysis in 3D for metal (aluminum) and rock (false gold ore). We show the effect of a Gaussian beam profile on the resulting crater geometry, as well as the first visual evidence of undercutting in the rock sample, most likely due to ejection of relatively large grains. The method holds promise for optimization of laser ablation setups especially for laser induced breakdown spectroscopy.

  10. Safety Analysis Report: Packages, Pu oxide and Am oxide shipping cask: Packaging of fissile and other radioactive materials: Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1984-12-01

    The PuO 2 cask or 5320-3 cask is designed for shipment of americium or plutonium by surface transportation modes. The cask design was physically tested to demonstrate that it met the criteria specified in US ERDA Manual Chapter 0529, dated 12/21/76, which invokes Title 10 Code of Federal Regulations, Part 71 (10 CFR 71) ''Packaging of Radioactive Materials for Transport,'' and Title 49 CFR Parts 171.179 ''Hazardous Materials Regulations.'' (US DOE Order 4580.1A, Chapter III, superseded manual chapter 0529 effective May 1981, but it retained the same 10 CFR 71 and 49 CFR 171-179 references

  11. Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction; FINAL

    International Nuclear Information System (INIS)

    Ostowari, Ken; Nosson, Ali

    2000-01-01

    The project developed high-recycled-content concrete material with balanced structural and thermal attributes for use in energy-efficient building construction. Recycled plastics, tire, wool, steel and concrete were used as replacement for coarse aggregates in concrete and masonry production. With recycled materials the specific heat and thermal conductivity of concrete could be tailored to enhance the energy-efficiency of concrete buildings. A comprehensive field project was implemented which confirmed the benefits of high-recycled-content concrete for energy-efficient building construction

  12. Medical devices; immunology and microbiology devices; classification of quality control material for cystic fibrosis nucleic acid assays. Final rule.

    Science.gov (United States)

    2007-01-10

    The Food and Drug Administration (FDA) is classifying quality control material for cystic fibrosis nucleic acid assays into class II (special controls). The special control that will apply to the device is the guidance document entitled "Class II Special Controls Guidance Document: Quality Control Material for Cystic Fibrosis Nucleic Acid Assays." The agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for this device.

  13. Safety analysis report: packages 238Pu oxide shipping cask (packaging of fissile and other radioactive materials). Final report

    International Nuclear Information System (INIS)

    Evans, J.E.; Gates, A.A.

    1975-06-01

    Plutonium-238 (as PuO 2 powder) is shipped in triple-container stainless steel shipping casks in compliance with ERDA Manual Chapter 0529 (ERDAM 0529), Safety Standards for the Packaging of Fissile and Other Radioactive Materials. (U.S.)

  14. LL13-MatModelRadDetect-PD2Jf Final Report: Materials Modeling for High-Performance Radiation Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lordi, Vincenzo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-12-11

    The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd1-xZnxTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achieve improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.

  15. Safety analysis report: packages. Argonne National Laboratory SLSF test train shipping container, P-1 shipment. Fissile material. Final report

    International Nuclear Information System (INIS)

    Meyer, C.A.

    1975-06-01

    The package is used to ship an instrumented test fuel bundle (test train) containing fissile material. The package assembly is Argonne National Laboratory (ANL) Model R1010-0032. The shipment is fissile class III. The packaging consists of an outer carbon steel container into which an inner container is placed; the inner container is separated from the outer container by urethane foam cushioning material. The test train is supported in the inner container by a series of transverse supports spaced along the length of the test train. Both the inner and outer containers are closed with bolted covers. The covers do not seal the containers in a leaktight manner. The gross weight of the shipment is about 8350 lb. The unirradiated fissile material content is less than 3 kg of UO 2 of up to 93.2 percent enrichment. This is a Type A quantity (transport group III and less than 3 curies) of radioactive material which does not require shielding, cooling or heating, or neutron absorption or moderation functions in its packaging. The maximum exterior dimensions of the container are 37 ft 11 in. long, 24 1 / 2 in. wide, and 19 3 / 4 in. high

  16. Synchrotron Studies of Narrow Band and Low-Dimensional Materials. Final Report for July 1, 1990---December 31, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Allen, J. W.

    2003-05-13

    This report summarizes a 12-year program of various kinds of synchrotron spectroscopies directed at the electronic structures of narrow band and low-dimensional materials that display correlated electron behaviors such as metal-insulator transitions, mixed valence, superconductivity, Kondo moment quenching, heavy Fermions, and non-Fermi liquid properties.

  17. Low-Density and High Porosity Hydrogen Storage Materials Built from Ultra-Light Elements. Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Pingyun [Univ. of California, Riverside, CA (United States)

    2014-01-10

    A number of significant advances have been achieved, opening up new opportunities for the synthetic development of novel porous materials and their energy-related applications including gas storage and separation and catalysis. These include lithium-based metal-organic frameworks, magnesium-based metal-organic frameworks, and high gas uptake in porous frameworks with high density of open donor sites.

  18. A theoretical and numerical study of the flow of granular materials down an inclined plane. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K.R.

    1995-12-31

    The mechanics of the flowing granular materials such as coal, agricultural products, at deal of attention as it has fertilizers, dry chemicals, metal ores, etc. have received a great deal of attention as it has relevance to several important technological problems. Despite wide interest and more than five decades of experimental and theoretical investigations, most aspects of the behavior of flowing granular materials are still not well understood. So Experiments have to be devised which quantify and describe the non-linear behavior of the modular materials, and theories developed which can explain the experimentally observed facts. As many models have been suggested for describing the behavior of granular materials, from both continuum and kinetic theory viewpoints, we proposed to investigate the validity and usefulness of representative models from both the continuum and kinetic theory points of view, by determining the prediction of such a theory, in a representative flow, with respect to existence, non-existence, multiplicity and stability of solutions. The continuum model to be investigated is an outgrowth of a model due to Goodman and Cowin (1971, 1972) and the kinetic theory models being those due to Jenkins and Richman (1985) and Boyle and Massoudi (1989). In this report we present detailed results regarding the same. Interestingly, we find that the predictions of all the theories, in certain parameter space associated with these models, are qualitatively similar. This ofcourse depends on the values assumed for various material parameters in the models, which as yet are unknown, as reliable experiments have not been carried out as yet for their determination.

  19. Review of the sorption of radionuclides on the bedrock of Haestholmen and on construction and backfill materials of a final repository for reactor wastes

    International Nuclear Information System (INIS)

    Kulmala, S.; Hakanen, M.

    1992-10-01

    Imatran Voima Oy (IVO) has plans to build a final repository for reactor wastes in the bedrock of the nuclear power plant site at Haestholmen, Loviisa. This report summarizes the sorption studies of radionuclides in Finnish bedrock performed at the Department of Radiochemistry, University of Helsinki. The values of mass distribution ratios, K d , and surface distribution ratios, K a ; of carbon, calsium, Zirconium, niobium, cobalt, nickel, strontium, cesium, uranium, plutonium, americium, thorium, chlorine, iodine and technetium are surveyed. Special attention is paid to the sorption data for construction and backfill materials of rector waste repository and the bedrock of Haestholmen. Safety assessment of a repository includes calculations of migration of the waste element in construction materials and backfill in the nearfield and in bedrock. Retardation by sorption of waste nuclides compared to groundwater flow is described by using distribution ratios between solid materials and water. (orig.)

  20. X-ray ablation of hyaluronan hydrogels: Fabrication of three-dimensional microchannel networks

    Science.gov (United States)

    Weon, B. M.; Chang, S.; Yeom, J.; Hahn, S. K.; Je, J. H.; Hwu, Y.; Margaritondo, G.

    2009-09-01

    We present a simple and highly versatile protocol for polymer ablation: hard x-ray irradiation makes it possible to rapidly depolymerize hyaluronan hydrogels and fabricate three-dimensional network of microchannels. Photodynamic and photochemical analyses show that x-ray irradiation directly cleaves the polymer backbone and the total dose controls the degradation kinetics. This nonthermal ablation protocol may offer opportunities for processing organic polymers and biological materials.

  1. The contemporary role of ablative treatment approaches in the management of renal cell carcinoma (RCC): focus on radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), and cryoablation.

    Science.gov (United States)

    Klatte, Tobias; Kroeger, Nils; Zimmermann, Uwe; Burchardt, Martin; Belldegrun, Arie S; Pantuck, Allan J

    2014-06-01

    Currently, most of renal tumors are small, low grade, with a slow growth rate, a low metastatic potential, and with up to 30 % of these tumors being benign on the final pathology. Moreover, they are often diagnosed in elderly patients with preexisting medical comorbidities in whom the underlying medical conditions may pose a greater risk of death than the small renal mass. Concerns regarding overdiagnosis and overtreatment of patients with indolent small renal tumors have led to an increasing interest in minimally invasive, ablative as an alternative to extirpative interventions for selected patients. To provide an overview about the state of the art in radiofrequency ablation (RFA), high-intensity focused ultrasound, and cryoablation in the clinical management of renal cell carcinoma. A PubMed wide the literature search of was conducted. International consensus panels recommend ablative techniques in patients who are unfit for surgery, who are not considered candidates for or elect against elective surveillance, and who have small renal masses. The most often used techniques are cryoablation and RFA. These ablative techniques offer potentially curative outcomes while conferring several advantages over extirpative surgery, including improved patient procedural tolerance, faster recovery, preservation of renal function, and reduction in the risk of intraoperative and postsurgical complications. While it is likely that outcomes associated with ablative modalities will improve with further advances in technology, their application will expand to more elective indications as longer-term efficacy data become available. Ablative techniques pose a valid treatment option in selected patients.

  2. Glass particles produced by laser ablation for ICP-MSmeasurements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.; Liu, C.; Wen, S.; Mao, X.; Russo, R.E.

    2007-06-01

    Pulsed laser ablation (266nm) was used to generate glass particles from two sets of standard reference materials using femtosecond (150fs) and nanosecond (4ns) laser pulses with identical fluences of 50 J cm{sup -2}. Scanning electron microscopy (SEM) images of the collected particles revealed that there are more and larger agglomerations of particles produced by nanosecond laser ablation. In contrast to the earlier findings for metal alloy samples, no correlation between the concentration of major elements and the median particle size was found. When the current data on glass were compared with the metal alloy data, there were clear differences in terms of particle size, crater depth, heat affected zone, and ICP-MS response. For example, glass particles were larger than metal alloy particles, the craters in glass were less deep than craters in metal alloys, and damage to the sample was less pronounced in glass compared to metal alloys samples. The femtosecond laser generated more intense ICP-MS signals compared to nanosecond laser ablation for both types of samples, although glass sample behavior was more similar between ns and fs-laser ablation than for metals alloys.

  3. A randomized prospective long-term (>1 year) clinical trial comparing the efficacy and safety of radiofrequency ablation to 980 nm laser ablation of the great saphenous vein.

    Science.gov (United States)

    Sydnor, Malcolm; Mavropoulos, John; Slobodnik, Natalia; Wolfe, Luke; Strife, Brian; Komorowski, Daniel

    2017-07-01

    Purpose To compare the short- and long-term (>1 year) efficacy and safety of radiofrequency ablation (ClosureFAST™) versus endovenous laser ablation (980 nm diode laser) for the treatment of superficial venous insufficiency of the great saphenous vein. Materials and methods Two hundred patients with superficial venous insufficiency of the great saphenous vein were randomized to receive either radiofrequency ablation or endovenous laser ablation (and simultaneous adjunctive therapies for surface varicosities when appropriate). Post-treatment sonographic and clinical assessment was conducted at one week, six weeks, and six months for closure, complications, and patient satisfaction. Clinical assessment of each patient was conducted at one year and then at yearly intervals for patient satisfaction. Results Post-procedure pain ( p radiofrequency ablation group. Improvements in venous clinical severity score were noted through six months in both groups (endovenous laser ablation 6.6 to 1; radiofrequency ablation 6.2 to 1) with no significant difference in venous clinical severity score ( p = 0.4066) or measured adverse effects; 89 endovenous laser ablation and 87 radiofrequency patients were interviewed at least 12 months out with a mean long-term follow-up of 44 and 42 months ( p = 0.1096), respectively. There were four treatment failures in each group, and every case was correctable with further treatment. Overall, there were no significant differences with regard to patient satisfaction between radiofrequency ablation and endovenous laser ablation ( p = 0.3009). There were no cases of deep venous thrombosis in either group at any time during this study. Conclusions Radiofrequency ablation and endovenous laser ablation are highly effective and safe from both anatomic and clinical standpoints over a multi-year period and neither modality achieved superiority over the other.

  4. Transport of radioactive material in the United States: results of a survey to determine the magnitude and characteristics of domestic, unclassified shipments of radioactive materials. Final report

    International Nuclear Information System (INIS)

    Javitz, H.S.; Lyman, T.R.; Maxwell, C.; Myers, E.L.; Thompson, C.R.

    1985-04-01

    SRI International has completed a project for the Sandia National Laboratories designed to create a statistical data base identifying the volume and characteristics of shipments of unclassified radioactive materials (RAM)* in the continental United States. Agencies providing resources for this project have included: Nuclear Regulatory Commission (NRC) Department of Transportation (DOT) Department of Energy (DOE) Federal Emergency Management Agency (FEMA). Technical management of the project was the responsibility of the Transportation Technology Center (TTC) of Sandia National Laboratories. This report is intended only as a brief summary of a project having as its primary product the Radioactive Materials Transportation (RAMT) survey data base provided by SRI to TTC. The data in the RAMT data base comes from two principal sources - a survey of NRC and Agreement State licensees (referred to as the Licensee survey) and a survey of DOE contractors (referred to as the DOE survey). This report provides summary information on: project background; objectives; approach; survey response; basic tables and discussion of shipment characteristics; and technical appendices. 21 figs., 15 tabs

  5. Aerospace Laser Ignition/Ablation Variable High Precision Thruster

    Science.gov (United States)

    Campbell, Jonathan W. (Inventor); Edwards, David L. (Inventor); Campbell, Jason J. (Inventor)

    2015-01-01

    A laser ignition/ablation propulsion system that captures the advantages of both liquid and solid propulsion. A reel system is used to move a propellant tape containing a plurality of propellant material targets through an ignition chamber. When a propellant target is in the ignition chamber, a laser beam from a laser positioned above the ignition chamber strikes the propellant target, igniting the propellant material and resulting in a thrust impulse. The propellant tape is advanced, carrying another propellant target into the ignition chamber. The propellant tape and ignition chamber are designed to ensure that each ignition event is isolated from the remaining propellant targets. Thrust and specific impulse may by precisely controlled by varying the synchronized propellant tape/laser speed. The laser ignition/ablation propulsion system may be scaled for use in small and large applications.

  6. Evaluation of the potential of optical switching materials for overheating protection of thermal solar collectors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huot, G.; Roecker, Ch.; Schueler, A.

    2008-01-15

    Providing renewable energy for domestic hot water production and space heating, thermal solar collectors are more and more widespread, and users' expectations with respect to performance and service lifetime are rising continuously. The durability of solar collector materials is a critical point as the collector lifetime should be at least 25 years. Overheating and the resulting stagnation of the collector is a common problem with solar thermal systems. During stagnation high temperatures lead to water evaporation, glycol degradation, and stresses in the collector with increasing pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. Additionally, the occurring elevated temperatures lead to degradation of the materials that compose collectors: seals, insulation materials, and also the selective coating which is the most important part of the collector. A promising way to achieve active cooling of collectors without any mechanical device for pressure release or collector emptying is to produce a selective coating which is able to switch its optical properties at a critical temperature Tc. An optical switch allows changing the selective coating efficiency; the goal is to obtain a coating with a poor selectivity above Tc (decreasing of absorptance, increasing of emittance). Obtaining self-cooling collectors will allow increasing collector surfaces on facades and roofs in order to get high efficiency and hot water production during winter without inconvenient overheating during summer. Optical switching of materials can be obtained by many ways. Inorganic and organic thermochromic compounds, and organic thermotropic coatings are the main types of switching coatings that have been studied at EPFL-LESO-PB. Aging studies of organic thermochromic paints fabricated at EPFL suggest that the durability of organic compounds might not be sufficient for glazed metallic collectors. First samples of inorganic coatings

  7. Safety Analysis Report--packages: cobalt-60 shipping cask (packaging of radioactive and fissile materials). Final report

    International Nuclear Information System (INIS)

    Cherney, J.R.; Gates, A.A.

    1976-08-01

    Safety Analysis Report DPSPU 73-124-1 is revised to permit shipment of 8 slugs (max), each slug containing an average of 43,750 curies of 60 Co and contained in a stainless steel can with a double-plug closure in cobalt-60 shipping casks in compliance with 10 CFR 71, Packaging of Radioactive Materials for Transport. This is in addition to the forms already discussed in DPSPU 73-124-1

  8. Pilot Study to Assess Safety and Clinical Outcomes of Irreversible Electroporation for Partial Gland Ablation in Men with Prostate Cancer

    Science.gov (United States)

    Murray, Katie S.; Ehdaie, Behfar; Musser, John; Mashni, Joseph; Srimathveeravalli, Govindarajan; Durack, Jeremy C.; Solomon, Stephen B.; Coleman, Jonathan A.

    2016-01-01

    Purpose Partial prostate gland ablation is a strategy to manage localized prostate cancer. Irreversible electroporation can ablate localized soft tissues. We sought to describe 30- and 90-day complications and intermediate-term functional outcomes in men undergoing prostate gland ablation using irreversible electroporation. Materials and Methods We reviewed the charts of 25 patients with prostate cancer who underwent prostate gland ablation using irreversible electroporation as a primary procedure and who were followed for at least 6 months. Results Median follow-up was 10.9 months. Grade 3 complications occurred in 2 patients including epididymitis (1) and urinary tract infection (1). Fourteen patients experienced grade ≤ 2 complications, mainly transient urinary symptoms, hematuria, and urinary tract infections. Of 25 patients, 4 (16%) had cancer in the zone of ablation on routine follow-up biopsy at 6 months. Of those with normal urinary function at baseline, 88% and 94% reported normal urinary function at 6 and 12 months after prostate gland ablation, respectively. By 12 months, only 1 patient with normal erectile function at baseline reported new difficulty with potency and only 2 patients (8%) required a pad for urinary incontinence. Conclusions Prostate gland ablation with irreversible electroporation is feasible and safe in selected men with localized prostate cancer. Intermediate-term urinary and erectile function outcomes appear reasonable. Irreversible electroporation is effective in ablation of tumor-bearing prostate tissue, as a majority of men had no evidence of residual cancer on biopsy 6 months after prostate gland ablation. PMID:27113966

  9. A comparison of the DPSS UV laser ablation characteristic of 1024 and H10F WC-Co

    Science.gov (United States)

    See, Tian Long; Chantzis, Dimitrios; Royer, Raphael; Metsios, Ioannis; Antar, Mohammad; Marimuthu, Sundar

    2017-07-01

    An investigation on ablation characteristics of 1024 and H10F cobalt cemented tungsten carbide (WC-Co) with a DPSS nanosecond UV laser (50 ns pulse width, 355 nm wavelength, 90 W average power and 10 kHz repetition rate) is presented. The ablation characteristic parameters such as ablation threshold, incubation effect and optical penetration depth were evaluated based on the spot ablation diameter and depth. It was observed that the ablation threshold is significantly influenced by the number of pulses (NOP) and it decreases with increase NOP which is attributed to the incubation effect. Only one ablation region is observed at low laser fluence and an additional molten ablation region is observed at high laser fluence accompanied with cracks. The cracks formation is due to the thermal induced stress and changes in WC microstructure during laser beam irradiation. The crack depth is proportional to the thickness of the molten WC region. The ablation threshold of 1024 WC-Co and H10F WC-Co were found to be Fth1 =4.32 J/cm2 and Fth1 =4.26 J/cm2 respectively. The difference in chemical composition has insignificant effect on the ablation threshold value of the material. The incubation factor and optical penetration depth values of 1024 WC-Co and H10F WC-Co were found to be ξ=0.73, α-1 =411 nm and ξ=0.75, α-1 =397 nm respectively.

  10. Reference materials for microanalytical nuclear techniques. Final report of a co-ordinated research project 1994-1999

    International Nuclear Information System (INIS)

    2002-06-01

    A significant problem in the use of solid- and small-sample techniques is a general lack in suitable certified reference materials (CRM). Essentially, no CRM are certified for the small sample sizes typically used. Direct utilization of most existing CRM in solid sampling analysis procedures, typically 1 mg sample size, is often difficult or even impossible because trace components may not be sufficiently homogeneously distributed in the sample or their homogeneous distribution has not been tested. To explore the production, characterization and use of CRM for determinations with sample sizes much smaller than currently used, the Coordinated Research Program focused on selection of biological and environmental materials suitable for microanalytical techniques, definition of specifications for suitable CRM, evaluation of existing CRM for use with microanalytical techniques, evaluation of requirements for sample pre-treatment, evaluation of analytical techniques and research on development of techniques to be used in characterizing the homogeneity and chemical composition of small samples, and application of analytical techniques to the characterization of candidate reference materials for use with microanalytical techniques

  11. Canister materials proposed for final disposal of high level nuclear waste - a review with respect to corrosion resistance

    International Nuclear Information System (INIS)

    Mattsson, E.

    1981-06-01

    Spent fuel from nuclear reactors has to be disposed of either after reprocessing or without such treatment. Due to toxic radiation the nuclear waste has to be isolated from the biosphere for 300-1,000 years, or in extreme cases for more than 100,000 years. The nuclear waste will be enclosed in corrosion resistant canisters. These will be deposited in repositories in geological formations, such as granite, basalt, clay, bedded or domed salt, or the sediments beneath the deep ocean floor. There the canisters will be exposed to groundwater, brine or seawater at an elevated temperature. Species formed by radiolysis may affect the corrosivity of the agent. The corrosion resistance of candidate canister materials is evaluated by corrosion tests and by thermodynamic and mass transport calculations. Examination of ancient metal objects after long exposure in nature may give additional information. On the basis of the work carried out so far, the principal candiate canister materials are titanium materials, copper, and high-purity alumina. (Auth.)

  12. Investigation of metal fluoride thermal energy storage materials: availability, cost, and chemistry. Final report, July 15, 1976--December 15, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Eichelberger, J.L.

    1976-12-01

    Storage of thermal energy in the 400 to 1000/sup 0/C range is attracting increasing consideration for use in solar power, central power, vehicular, and commercial process systems. This study investigates the practicality of using metal fluorides as the heat storage medium. The projected availability of metal fluorides has been studied and is shown to be adequate for widespread thermal storage use. Costs are projected and discussed in relation to thermal energy storage applications. Phase diagrams, heats of fusion, heat capacities, vapor pressures, toxicity, stability, volume changes, thermal conductivities, fusion kinetics, corrosion, and container materials of construction for a wide range of fluorides have been examined. Analyses of these data in consideration of thermal energy storage requirements have resulted in selection of the most cost-effective fluoride mixture for each of 23 temperature increments between 400 and 1000/sup 0/C. Thermo-physical properties of these 23 materials are presented. Comparison of fluoride with non-fluoride materials shows that the fluorides are suitable candidates for high temperature applications on the bases of cost, heat capacity/unit volume, heat capacity/unit weight, corrosive properties, and availability.

  13. Percutaneous thermal ablation of renal neoplasms

    International Nuclear Information System (INIS)

    Tacke, J.; Mahnken, A.H.; Guenther, R.W.

    2005-01-01

    Due to modern examination techniques such as multidetector computed tomography and high-field magnetic resonance imaging, the detection rate of renal neoplasms is continually increasing. Even though tumors exceeding 4 cm in diameter rarely metastasize, all renal lesions that are possible neoplasms should be treated. Traditional treatment techniques include radical nephrectomy or nephron-sparing resection, which are increasingly performed laparoscopically. Modern thermal ablation techniques such as hyperthermal techniques like radiofrequency ablation RFA, laser induced thermal ablation LITT, focused ultrasound FUS and microwave therapy MW, as well as hypothermal techniques (cryotherapy) may be a useful treatment option for patients who are unfit for or refuse surgical resection. Cryotherapy is the oldest and best known thermal ablation technique and can be performed laparoscopically or percutaneously. Since subzero temperatures have no antistyptic effect, additional maneuvers must be performed to control bleeding. Percutaneous cryotherapy of renal tumors is a new and interesting method, but experience with it is still limited. Radiofrequency ablation is the most frequently used method. Modern probe design allows volumes between 2 and 5 cm in diameter to be ablated. Due to hyperthermal tract ablation, the procedure is deemed to be safe and has a low complication rate. Although there are no randomized comparative studies to open resection, the preliminary results for renal RFA are promising and show RFA to be superior to other thermal ablation techniques. Clinical success rates are over 90% for both, cryo- and radiofrequency ablation. Whereas laser induced thermal therapy is established in hepatic ablation, experience is minimal with respect to renal application. For lesions of more than 2 cm in diameter, additional cooling catheters are required. MR thermometry offers temperature control during ablation. Microwave ablation is characterized by small ablation volumes

  14. Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Canteli, D., E-mail: david.canteli@ciemat.es [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Fernandez, S. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain); Molpeceres, C. [Centro Laser, Universidad Politecnica de Madrid, Ctra. de Valencia Km 7.3, 28031 Madrid (Spain); Torres, I.; Gandia, J.J. [Division de Energias Renovables, Energia Solar Fotovoltaica, CIEMAT, Avda. Complutense, 22, 28040 Madrid (Spain)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. Black-Right-Pointing-Pointer The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. Black-Right-Pointing-Pointer A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 Degree-Sign C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

  15. Nanosecond laser ablation processes in aluminum-doped zinc-oxide for photovoltaic devices

    International Nuclear Information System (INIS)

    Canteli, D.; Fernandez, S.; Molpeceres, C.; Torres, I.; Gandía, J.J.

    2012-01-01

    Highlights: ► A study of the ablation of AZO thin films deposited at different temperature conditions with nanosecond UV laser light for photovoltaic devices has been performed. ► The ablation threshold of AZO thin films was measured and related with the absorption coefficient of the films at the laser wavelength, showing a direct correspondence. ► A change in the material structure in the areas closest to the edges of laser grooves made in samples deposited at temperatures below 100 °C was observed and studied. - Abstract: Aiming to a future use in thin film solar modules, the processing of aluminum doped zinc oxide thin films with good optoelectronic properties with a nanosecond-pulsed ultraviolet laser has been studied. The ablation threshold fluence of the films has been determined and associated with the material properties. The ablation process has been optimized and grooves with good properties for photovoltaic devices have been obtained. The morphology of the ablated surfaces has been observed by confocal microscopy and its structure has been characterized by Raman spectroscopy. The influence of ablation parameters like focus distance, pulse energy and repetition frequency in the groove morphology has been studied with special attention to the thermal effects on the material structure.

  16. Iron-Based Amorphous-Metals: High-Performance Corrosion-Resistant Materials (HPCRM) Development Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Choi, J; Saw, C; Haslem, J; Day, D; Hailey, P; Lian, T; Rebak, R; Perepezko, J; Payer, J; Branagan, D; Beardsley, B; D' Amato, A; Aprigliano, L

    2009-03-16

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal make this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of these iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  17. Nuclear Energy Plant Optimization (NEPO) final report on aging and condition monitoring of low-voltage cable materials.

    Energy Technology Data Exchange (ETDEWEB)

    Assink, Roger Alan; Gillen, Kenneth Todd; Bernstein, Robert

    2005-11-01

    This report summarizes results generated on a 5-year cable-aging program that constituted part of the Nuclear Energy Plant Optimization (NEPO) program, an effort cosponsored by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI). The NEPO cable-aging effort concentrated on two important issues involving the development of better lifetime prediction methods as well as the development and testing of novel cable condition-monitoring (CM) techniques. To address improved life prediction methods, we first describe the use of time-temperature superposition principles, indicating how this approach improves the testing of the Arrhenius model by utilizing all of the experimentally generated data instead of a few selected and processed data points. Although reasonable superposition is often found, we show several cases where non-superposition is evident, a situation that violates the constant acceleration assumption normally used in accelerated aging studies. Long-term aging results over extended temperature ranges allow us to show that curvature in Arrhenius plots for elongation is a common occurrence. In all cases the curvature results in a lowering of the Arrhenius activation energy at lower temperatures implying that typical extrapolation of high temperature results over-estimates material lifetimes. The long-term results also allow us to test the significance of extrapolating through the crystalline melting point of semi-crystalline materials. By utilizing ultrasensitive oxygen consumption (UOC) measurements, we show that it is possible to probe the low temperature extrapolation region normally inaccessible to conventional accelerated aging studies. This allows the quantitative testing of the often-used Arrhenius extrapolation assumption. Such testing indicates that many materials again show evidence of ''downward'' curvature (E{sub a} values drop as the aging temperature is lowered) consistent with the limited

  18. Real time determination of the laser ablated mass by means of electric field-perturbation measurement

    Science.gov (United States)

    Pacheco, P.; Álvarez, J.; Sarmiento, R.; Bredice, F.; Sánchez-Aké, C.; Villagrán-Muniz, M.; Palleschi, V.

    2018-04-01

    A Nd:YAG ns-pulsed laser was used to ablate Al, Cd and Zn targets, which were placed between the plates of a planar charged capacitor. The plasma generates a transient redistribution of the electrical charges on the plates that can be measured as a voltage drop across a resistor connected to the ground plate. This signal is proportional to the capacitor applied voltage, the distance between the plates and the total number of ions produced in the ablation process which in turn is related to the laser energy and the ablated mass. After a series of pulses, the targets were weighed on a thermogravimetric balance to measure the ablated mass. Our results show that the electrical signal measured on the resistor is univocally related to the ablated mass from the target. Therefore, after a proper calibration depending on the material and the experimental geometry, the electrical signal can be used for real time quantitative measurement of the ablated mass in pulsed laser generated plasma experiments. The experiments were repeated on an aluminum target, with and without the presence of the external electric field in order to determine the possible influence of the applied electric field on the ablated mass.

  19. Nanopillar formation from two-shot femtosecond laser ablation of poly-methyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Baset, F.; Popov, K.; Villafranca, A.; Alshehri, A.M.; Guay, J.-M.; Ramunno, L.; Bhardwaj, V.R., E-mail: ravi.bhardwaj@uottawa.ca

    2015-12-01

    Highlights: • We studied morphological evolution and dynamics of two-pulse laser ablation in PMMA. • Nanopillar and volcanic eruption like structures are formed within the ablation crater. • Reflection of shockwave induced by the second laser pulse creates the structures. • Shockwave reflects from the boundary created by the first pulses. • Reflected shockwave causes density pinching in the middle of the ablation region. - Abstract: We present experimental and numerical studies on the morphological evolution and dynamics of femtosecond laser ablation of bulk poly-methyl methacrylate (PMMA) irradiated with a pair of pulses. We show that a nanopillar-like structure is formed in the middle of the ablation crater for pulse energies below single-shot ablation threshold. The nanopillar is ∼400 nm long, lies adjacent to a nanopore, and protrudes ∼150 nm above the sample surface. As the pulse energy is increased gradually, the nanopillar disappears and the nanopore inside the ablation crater becomes larger. At higher pulse energies, a volcanic eruption like structure appears in the middle of the crater whose size and height increases with energy. 2D molecular dynamics simulations reveal that a nanojet and other features observed at higher pulse energies can be formed when the reflection of a shockwave, induced by the second laser pulse, causes density pinching in the middle of the interaction region that rapidly pushes out molten material towards the surface. The shockwave is reflected from the cold boundaries of a modified region created by the first laser pulse.

  20. Pre-Ablation Thyroglobulin Levels and Persistence / Recurrence Associated to Early Differentiated Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Arturo Mejía López

    2014-01-01

    Full Text Available Introduction: Differentiated thyroid cancer is the most frequent endocrine neoplasm in the world and its incidence is growing rapidly. The relationship between levels of pre-ablation thyroglobulin (Tg and early persistence/recurrence of differentiated thyroid cancer was studied. Materials and Methods: 91 patients with papillary thyroid cancer who underwent post-surgical ablation with radioactive iodine registered in the Fundacion Cardioinfantil between January 2006 and January 2010 were evaluated. The analysis of the results was performed using the SPSS statistical package and the research hypothesis was evaluated using nonparametric methods. Results: The disease progressed in 20 patients during the first year post-ablation, at the end of this period (p=0.000 a significant relationship between pre-ablation Tg and disease status was found. In the group of individuals by whom the disease progressed there was no significant change in Tg between the first and the second semester post-ablation (p = 0.554; there were no cases of recurrence/persistence in those with levels less than or equal to 2.7 ng/mL; 80 % of these cases involved individuals with initial levels higher than 24 ng/mL. Conclusion: In patients with papillary thyroid cáncer the serum pre-ablation Tg is related to the disease status at the end of the first year post-ablation. The persistence/recurrence is less frequent in low levels and more frequent in higher levels.

  1. Percutaneous ablation of pancreatic cancer

    Science.gov (United States)

    D’Onofrio, Mirko; Ciaravino, Valentina; De Robertis, Riccardo; Barbi, Emilio; Salvia, Roberto; Girelli, Roberto; Paiella, Salvatore; Gasparini, Camilla; Cardobi, Nicolò; Bassi, Claudio

    2016-01-01

    Pancreatic ductal adenocarcinoma is a highly aggressive tumor with an overall 5-year survival rate of less than 5%. Prognosis and treatment depend on whether the tumor is resectable or not, which mostly depends on how quickly the diagnosis is made. Chemotherapy and radiotherapy can be both used in cases of non-resectable pancreatic cancer. In cases of pancreatic neoplasm that is locally advanced, non-resectable, but non-metastatic, it is possible to apply percutaneous treatments that are able to induce tumor cytoreduction. The aim of this article will be to describe the multiple currently available treatment techniques (radiofrequency ablation, microwave ablation, cryoablation, and irreversible electroporation), their results, and their possible complications, with the aid of a literature review. PMID:27956791

  2. Laser Ablation for Medical Applications

    Science.gov (United States)

    Hayashi, Ken-Ichi

    Medical applications of laser are measurement, laser surgery, in-situ monitoring, and processing of medical devices. In this paper, author briefly reviews the trends of medical applications, describes some new applications, and then discuss about the future trends and problems of medical applications. At present, the domestic market of laser equipment for medical applications is nearly 1/10 of that for industrial applications, which has registered significant growth continuously. Laser surgery as a minimum invasive surgery under arthroscope is expected to decrease the pain of patients. Precise processing such as cutting and welding is suitable for manufacturing medical devices. Pulsed laser deposition has been successfully applied to the thin film coating. The corneal refractive surgery by ArF excimer laser has been widely accepted for its highly safe operation. Laser ablation for retinal implant in the visual prosthesis is one of the promising applications of laser ablation in medicine. New applications with femtosecond laser are expected in the near future.

  3. Radiofrequency Ablation, MR Thermometry, and High-Spatial-Resolution MR Parametric Imaging with a Single, Minimally Invasive Device

    Science.gov (United States)

    Ertürk, M. Arcan; Sathyanarayana Hegde, Shashank

    2016-01-01

    Purpose To develop and demonstrate in vitro and in vivo a single interventional magnetic resonance (MR)–active device that integrates the functions of precise identification of a tissue site with the delivery of radiofrequency (RF) energy for ablation, high-spatial-resolution thermal mapping to monitor thermal dose, and quantitative MR imaging relaxometry to document ablation-induced tissue changes for characterizing ablated tissue. Materials and Methods All animal studies were approved by the institutional animal care and use committee. A loopless MR imaging antenna composed of a tuned microcable either 0.8 or 2.2 mm in diameter with an extended central conductor was switched between a 3-T MR imaging unit and an RF power source to monitor and perform RF ablation in bovine muscle and human artery samples in vitro and in rabbits in vivo. High-spatial-resolution (250–300-μm) proton resonance frequency shift MR thermometry was interleaved with ablations. Quantitative spin-lattice (T1) and spin-spin (T2) relaxation time MR imaging mapping was performed before and after ablation. These maps were compared with findings from gross tissue examination of the region of ablated tissue after MR imaging. Results High-spatial-resolution MR imaging afforded temperature mapping in less than 8 seconds for monitoring ablation temperatures in excess of 85°C delivered by the same device. This produced irreversible thermal injury and necrosis. Quantitative MR imaging relaxation time maps demonstrated up to a twofold variation in mean regional T1 and T2 after ablation versus before ablation. Conclusion A simple, integrated, minimally invasive interventional probe that provides image-guided therapy delivery, thermal mapping of dose, and detection of ablation-associated MR imaging parametric changes was developed and demonstrated. With this single-device approach, coupling-related safety concerns associated with multiple conductor approaches were avoided. © RSNA, 2016 Online

  4. Research & Development of Materials/Processing Methods for Continuous Fiber Ceramic Composites (CFCC) Phase 2 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Szweda, A.

    2001-01-01

    The Department of Energy's Continuous Fiber Ceramic Composites (CFCC) Initiative that begun in 1992 has led the way for Industry, Academia, and Government to carry out a 10 year R&D plan to develop CFCCs for these industrial applications. In Phase II of this program, Dow Corning has led a team of OEM's, composite fabricators, and Government Laboratories to develop polymer derived CFCC materials and processes for selected industrial applications. During this phase, Dow Corning carried extensive process development and representative component demonstration activities on gas turbine components, chemical pump components and heat treatment furnace components.

  5. Technical report on material selection and processing guidelines for BWR [boiling water reactor] coolant pressure boundary piping: Final report

    International Nuclear Information System (INIS)

    Hazelton, W.S.; Koo, W.H.

    1988-01-01

    This report provides the technical bases for the NRC staff's revised recommended methods to control the intergranular stress corrosion cracking susceptibility of BWR piping. For piping that does not fully comply with the material selection, testing, and processing guideline combinations of this document, varying degrees of augmented inservice inspection are recommended. This revision also includes guidance and NRC staff recommendations (not requirements) regarding crack evaluation and weld overlay repair methods for long-term operation or for continuing interim operation of plants until a more permanent solution is implemented

  6. Assessment of state and local notification requirements for transportation of radioactive and other hazardous materials. Final report

    International Nuclear Information System (INIS)

    Dively, D.; Morris, F.; Schilling, A.H.; Shen, E.; Allen, J.

    1985-01-01

    State and local laws requiring notification for shipments of radioactive and other hazardous materials have become increasingly common and controversial during the last decade. Such laws are seen by their proponents as essential for planning and emergency response, while their opponents view them as unnecessary and intrusive. The debate over the value of notification requirements has often been hampered by the lack of information about the extent and nature of these laws. The report is intended to present factual information about notification laws in order to facilitate more informed discussion

  7. Survey of the degradation modes of candidate materials for high-level radioactive waste disposal containers. Final report

    International Nuclear Information System (INIS)

    Vinson, D.W.; Bullen, D.B.

    1995-01-01

    One of the most significant factors impacting the performance of waste package container materials under repository relevant conditions is the thermal environment. This environment will be affected by the areal power density of the repository, which is dictated by facility design, and the dominant heat transfer mechanism at the site. The near-field environment will evolve as radioactive decay decreases the thermal output of each waste package. Recent calculations (Buscheck and Nitao, 1994) have addressed the importance of thermal loading conditions on waste package performance at the Yucca Mountain site. If a relatively low repository thermal loading design is employed, the temperature and relative humidity near the waste package may significantly affect the degradation of corrosion allowance barriers due to moist air oxidation and radiolytically enhanced corrosion. The purpose this report is to present a literature review of the potential degradation modes for moderately corrosion resistant nickel copper and nickel based candidate materials that may be applicable as alternate barriers for the ACD systems in the Yucca Mountain environment. This report presents a review of the corrosion of nickel-copper alloys, summaries of experimental evaluations of oxidation and atmospheric corrosion in nickel-copper alloys, views of experimental studies of aqueous corrosion in nickel copper alloys, a brief review of galvanic corrosion effects and a summary of stress corrosion cracking in these alloys

  8. Investigation of laser-induced pre-breakdown material modifications. Final report, September 15, 1977--March 14, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Braeunlich, P; Schmid, A

    1979-01-01

    A new mechanism is presented for dielectric breakdown of wide gap materials in intense fields of photons having wavelengths in the visible region of the electromagnetic spectrum. It is based on multiphoton generation of free carriers and energy deposition from the photon field to the lattice via electron--photon--phonon collision processes. This laser breakdown model represents an alternative to the so-called avalanche ionization mechanism. It is further demonstrated that laser pulses with peak fluxes below the single-shot threshold for both bulk and surface damage of sodium chloride crystals modify the properties of this material. As a result of multiphoton exciton generation primary defects are formed which lead to intense directional emission of neutral halogen and alkali atoms. As a consequence, the crystal surface is severely perturbed. The technique of thermally stimulated exoemission of particles to assess the degree of surface pertubation after laser exposure was developed. Ongoing experiments present for the first time evidence that the single-shot laser surface damage threshold decreases with laser-induced surface perturbation.

  9. Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

    International Nuclear Information System (INIS)

    Chang H. Oh

    2006-01-01

    Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for state-of-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency

  10. Development of a Supercritical Carbon Dioxide Brayton Cycle: Improving VHTR Efficiency and Testing Material Compatibility - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh

    2006-06-01

    Generation IV reactors will need to be intrinsically safe, having a proliferation-resistant fuel cycle and several advantages relative to existing light water reactor (LWR). They, however, must still overcome certain technical issues and the cost barrier before it can be built in the U.S. The establishment of a nuclear power cost goal of 3.3 cents/kWh is desirable in order to compete with fossil combined-cycle, gas turbine power generation. This goal requires approximately a 30 percent reduction in power cost for stateof-the-art nuclear plants. It has been demonstrated that this large cost differential can be overcome only by technology improvements that lead to a combination of better efficiency and more compatible reactor materials. The objectives of this research are (1) to develop a supercritical carbon dioxide Brayton cycle in the secondary power conversion side that can be applied to the Very-High-Temperature Gas-Cooled Reactor (VHTR), (2) to improve the plant net efficiency by using the carbon dioxide Brayton cycle, and (3) to test material compatibility at high temperatures and pressures. The reduced volumetric flow rate of carbon dioxide due to higher density compared to helium will reduce compression work, which eventually increase plant net efficiency.

  11. Materials development for waste-to-energy plants. New materials for overlay welding. Final report; Udvikling af materialer til affaldsforbraending - Nye materialer til overlagssvejsning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Skat Tiedje, N.

    2010-07-01

    This part of the project was to develop a method for rapid benchmarking of new alloys for overlay welding and to apply the method in combination with thermodynamic modeling of microstructures in welded Ni-based alloys. Based on these analyses new, improved alloys were to be developed to be produced in the laboratory and tested using the benchmarking method. Accelerated electrochemical tests proved to be difficult, and the method that was chosen was unreliable. There were two reasons for this. 1: It was difficult to obtain stable experimental conditions in the measuring cell. 2: The sample geometry and various uncontrolled chemical reactions within the welding and in the salt melt surface. The problems of achieving stability turned out to be an Achilles' heel in this part of the project, and it was the cause of significant delays. Thermodynamic modeling gave a number of interesting results, including the coupling between the content of iron and carbon and in terms of how the various alloying elements segregate in the material. The method alone does not tell anything about the risk of corrosion. Here the coupling to the electrostatic experiments were missing which should give information about the phases of greatest importance for corrosion. Calculations of the chemical equilibrium between the alloying elements, oxygen, and chlorine show that all metals react with both chlorine and oxygen at 450 to 500 deg. C. Oxides are the most stable reaction products viz. that once they are formed, they do not participate in further chemical reactions. (LN)

  12. Radiofrequency Ablation of Hepatic Cysts : Case Report

    International Nuclear Information System (INIS)

    Lee, Ye Ri; Kim, Pyo Nyun

    2005-01-01

    Radiofrequency ablation has been frequently performed on intra-hepatic solid tumor, namely, hepatocellular carcinoma, metastatic tumor and cholangio carcinoma, for take the cure. But, the reports of radiofrequency ablation for intrahepatic simple cysts are few. In vitro experiment of animal and in vivo treatment for intrahepatic cysts of human had been reported in rare cases. We report 4 cases of radiofrequency ablation for symptomatic intrahepatic cysts

  13. Final report of the Buffer Mass Test - Volume 3: Chemical and physical stability of the buffer materials

    International Nuclear Information System (INIS)

    Pusch, R.

    1985-11-01

    The Buffer Mass Test offered a possibility to investigate whether chemical changes took place in the smectite component at heating to 125 degrees C for about one year. The alterations that could possibly take place were a slight charge change in the crystal lattice with an associated precipitation of silica compounds, and a tendency of illite formation. The analysis showed that there were indications of both but to such a slight extent that the processes could not have affected the physical properties, which was also demonstrated by determining the swelling pressure and the hydraulic conductivity. The BMT also showed that the erodibility of bentonite-based buffer materials is less than or about equal to what can be expected on theoretical grounds. (author)

  14. Safety analysis report: packages. Pu oxide and Am oxide shipping cask (Packaging of fissile and other radioactive materials). Final report

    International Nuclear Information System (INIS)

    Chalfant, G.G.

    1980-05-01

    The PuO 2 cask or SP 5320-2 and 3 cask is designed for surface shipment of americium or plutonium. The cask design was physically tested to demonstrate that it met the criteria specified in US ERDA Manual Chapter 0529, and Chapter I, Interstate Commerce Commission. The package has been assessed for transport of up to 357 grams of plutonium (403 grams PuO 2 powder) and up to 176 grams of americium (200 grams AmO 2 powder), having a maximum decay heat of 203 watts. Criticality evaluation alone would allow the shipment as Fissile Class II but the radiation level of the cask, measured at the time of shipment, may exceed 50 mrem/h at the surface and require shipment as Fissile Class III. Sample calculations address only the more restrictive of the two materials, which in most cases is 238 PuO 2

  15. Process Parameter Evaluation and Optimization for Advanced Material Development Final Report CRADA No. TC-1234-96

    Energy Technology Data Exchange (ETDEWEB)

    Hrubesh, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McGann, T. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-19

    This project was established as a three-year collaboration to produce and characterize · silica aerogels prepared by a Rapid Supercritical Extraction (RSCE) process to meet . BNA, Inc. application requirements. The objectives of this project were to study the parameters necessary to produce optimized aerogel parts with narrowly specified properties and establish the range and limits of the process for producing such aerogels. The project also included development of new aerogel materials useful for high temperature applications. The results of the project were expected to set the conditions necessary to produce quantities of aerogels having particular specifications such as size, shape, density, and mechanical strength. BNA, Inc. terminated the project on April 7, 1999, 10-months prior to the anticipated completion date, due to termination of corporate funding for the project. The technical accomplishments achieved are outlined in Paragraph C below.

  16. Environmentally-assisted cracking in austenitic light water reactor structural materials. Final report of the KORA-I project

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, H.-P.; Ritter, S

    2009-03-15

    The following document is the final report of the KORA-I project, which was performed at the Paul Scherrer Institute (PSI) between 2006 and 2008 and was funded by the Swiss Nuclear Safety Inspectorate (ENSI). The three sub-projects of KORA-I covered the experimental characterisation of the effect of the reactor coolant environment on fatigue initiation and crack growth in austenitic stainless steels under boiling and pressurised water reactor conditions, the experimental evaluation of the potential and limits of the electrochemical noise measurement technique for the early detection of stress corrosion cracking initiation in austenitic stainless steels under boiling water reactor/normal water chemistry conditions, as well as the characterisation of the stress corrosion crack growth behaviour in the fusion line region of an Alloy 182-low-alloy reactor pressure vessel steel dissimilar metal weld. The main scientific results and major conclusions of the three sub-projects are discussed in three independent parts of this report. (author)

  17. NSR&D Program Fiscal Year 2015 Funded Research Stochastic Modeling of Radioactive Material Releases Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Andrus, Jason P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Pope, Chad [Idaho State Univ., Pocatello, ID (United States); Toston, Mary [Idaho State Univ., Pocatello, ID (United States); Maas, Andrew [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-12-01

    Nonreactor nuclear facilities operating under the approval authority of the U.S. Department of Energy use unmitigated hazard evaluations to determine if potential radiological doses associated with design basis events challenge or exceed dose evaluation guidelines. Unmitigated design basis events that sufficiently challenge dose evaluation guidelines or exceed the guidelines for members of the public or workers, merit selection of safety structures, systems, or components or other controls to prevent or mitigate the hazard. Idaho State University, in collaboration with Idaho National Laboratory, has developed a portable and simple to use software application called SODA (Stochastic Objective Decision-Aide) that stochastically calculates the radiation dose distribution associated with hypothetical radiological material release scenarios. Rather than producing a point estimate of the dose, SODA produces a dose distribution result to allow a deeper understanding of the dose potential. SODA allows users to select the distribution type and parameter values for all of the input variables used to perform the dose calculation. Users can also specify custom distributions through a user defined distribution option. SODA then randomly samples each distribution input variable and calculates the overall resulting dose distribution. In cases where an input variable distribution is unknown, a traditional single point value can be used. SODA, developed using the MATLAB coding framework, has a graphical user interface and can be installed on both Windows and Mac computers. SODA is a standalone software application and does not require MATLAB to function. SODA provides improved risk understanding leading to better informed decision making associated with establishing nuclear facility material-at-risk limits and safety structure, system, or component selection. It is important to note that SODA does not replace or compete with codes such as MACCS or RSAC; rather it is viewed as an

  18. Clinical outcome of percutaneous RF-ablation of non-operable patients with liver metastasis from breast cancer

    DEFF Research Database (Denmark)

    Kümler, Iben; Parner, Vibeke Kirk; Tuxen, Malgorzata K.

    2015-01-01

    PURPOSE: Despite improved anti-neoplastic treatment the prognosis for patients with liver metastases from metastatic breast cancer remains poor. MATERIALS AND METHODS: Thirty-two consecutive patients with metastatic breast cancer treated with radiofrequency ablation (RFA) at the Department...

  19. Cryoballoon Catheter Ablation in Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Cevher Ozcan

    2011-01-01

    Full Text Available Pulmonary vein isolation with catheter ablation is an effective treatment in patients with symptomatic atrial fibrillation refractory or intolerant to antiarrhythmic medications. The cryoballoon catheter was recently approved for this procedure. In this paper, the basics of cryothermal energy ablation are reviewed including its ability of creating homogenous lesion formation, minimal destruction to surrounding vasculature, preserved tissue integrity, and lower risk of thrombus formation. Also summarized here are the publications describing the clinical experience with the cryoballoon catheter ablation in both paroxysmal and persistent atrial fibrillation, its safety and efficacy, and discussions on the technical aspect of the cryoballoon ablation procedure.

  20. Pulse laser ablation at water-air interface

    Science.gov (United States)

    Utsunomiya, Yuji; Kajiwara, Takashi; Nishiyama, Takashi; Nagayama, Kunihito; Kubota, Shiro

    2010-06-01

    We studied a new pulse laser ablation phenomenon on a liquid surface layer, which is caused by the difference between the refractive indices of the two materials involved. The present study was motivated by our previous study, which showed that laser ablation can occur at the interface between a transparent material and a gas or liquid medium when the laser pulse is focused through the transparent material. In this case, the ablation threshold fluence is reduced remarkably. In the present study, experiments were conducted in water and air in order to confirm this phenomenon for a combination of two fluid media with different refractive indices. This phenomenon was observed in detail by pulse laser shadowgraphy. A high-resolution film was used to record the phenomenon with a Nd:YAG pulse laser with 10-ns duration as a light source. The laser ablation phenomenon on the liquid surface layer caused by a focused Nd:YAG laser pulse with 1064-nm wavelength was found to be followed by the splashing of the liquid surface, inducing a liquid jet with many ligaments. The liquid jet extension velocity was around 1000 m/s in a typical case. The liquid jet decelerated drastically due to rapid atomization at the tips of the ligaments. The liquid jet phenomenon was found to depend on the pulse laser parameters such as the laser fluence on the liquid surface, laser energy, and laser beam pattern. The threshold laser fluence for the generation of a liquid jet was 20 J/cm2. By increasing the incident laser energy with a fixed laser fluence, the laser focused area increased, which eventually led to an increase in the size of the plasma column. The larger the laser energy, the larger the jet size and the longer the temporal behavior. The laser beam pattern was found to have significant effects on the liquid jet’s velocity, shape, and history.

  1. Using FT-IR Spectroscopy to Elucidate the Structures of Ablative Polymers

    Science.gov (United States)

    Fan, Wendy

    2011-01-01

    The composition and structure of an ablative polymer has a multifaceted influence on its thermal, mechanical and ablative properties. Understanding the molecular level information is critical to the optimization of material performance because it helps to establish correlations with the macroscopic properties of the material, the so-called structure-property relationship. Moreover, accurate information of molecular structures is also essential to predict the thermal decomposition pathways as well as to identify decomposition species that are fundamentally important to modeling work. In this presentation, I will describe the use of infrared transmission spectroscopy (FT-IR) as a convenient tool to aid the discovery and development of thermal protection system materials.

  2. Evaporation as a diagnostic test for hydrodynamic cooling of laser-ablated clusters

    International Nuclear Information System (INIS)

    Klots, C.E.

    1991-01-01

    The properties of materials laser-ablated from a surface are of considerable interest. The interrogation of these properties inevitably occurs at a point some distance from the surface. One might then ask what processes have occurred in the intervening path length. Immediately, for example, one wonders whether the material was released as such from the surface or was formed as a result of collisions at a distant point. Similarly, one might ask if an observed ''temperature'' of the materials is characteristic of the ablation process of of subsequent events. We will indicate here how measurements of metastable evaporation rates can provide clues which are pertinent to these questions. 7 refs

  3. Development of LIBS for online analysis of solid nuclear materials

    International Nuclear Information System (INIS)

    Picard, Jessica

    2015-01-01

    With the objective to implement a fast, online analysis technique for control of solid metal nuclear materials, laser-induced breakdown spectroscopy (LIBS) technique is developed for quantitative analysis in uranium and plutonium. Since these matrices have a very dense emission spectrum in the UV-Visible range, the Vacuum Ultra-Violet (VUV) spectral range, less rich in lines, is explored. The aim of this thesis is to perform the analytical development of VUV-LIBS for quantitative analysis between 500 and 5000 ppm with an uncertainty of 3%. For that purpose, four steps were defined. First, for practical and safety reasons, it is generally better to perform experiments on surrogate materials. LIBS based on laser-material interaction, it is relevant to seek a surrogate of material of interest from the viewpoint of the ablated mass. Thus, a complete study of laser ablation of several metals was enabled to build a predictive model of the ablation efficiency. Titanium and stainless steel were defined as surrogate materials of plutonium and uranium for laser ablation. Secondly, the VUV-LIBS setup analytical performances were optimized for several elements of interest in four metals. Then, two calibration methods are used to determine the analytical performances. The limits of quantification are of the order of a few hundreds of ppm for all studied matrices, which validates the objective of impurities quantitation in the 500-5000 ppm range. Uncertainty is lower than 3% in the best cases. Finally, the calibration transfer between the four matrices was studied. A normalization of the nickel net signal measured in three matrices was presented. (author) [fr

  4. Analysis of internal ablation for the thermal control of aerospace vehicles

    Science.gov (United States)

    Camberos, Jose A.; Roberts, Leonard

    1989-01-01

    A new method of thermal protection for transatmospheric vehicles is introduced. The method involves the combination of radiation, ablation and transpiration cooling. By placing an ablating material behind a fixed-shape, porous outer shield, the effectiveness of transpiration cooling is made possible while retaining the simplicity of a passive mechanism. A simplified one-dimensional approach is used to derive the governing equations. Reduction of these equations to non-dimensional form yields two parameters which characterize the thermal protection effectiveness of the shield and ablator combination for a given trajectory. The non-dimensional equations are solved numerically for a sample trajectory corresponding to glide re-entry. Four typical ablators are tested and compared with results obtained by using the thermal properties of water. For the present level of analysis, the numerical computations adequately support the analytical model.

  5. Synthesis of Fe–Ni bimetallic nanoparticles from pixel target ablation: plume dynamics and surface characterization

    International Nuclear Information System (INIS)

    Niu Xiaoxu; Murray, Paul T.; Sarangan, Andrew

    2012-01-01

    A novel Fe–Ni bimetallic nanoparticle synthesis technique, denoted pixel target ablation, is reported. The technique entails ablating a thin film target consisting of patterned Fe and Ni pixels with a selected ratio using a KrF excimer laser. The laser energy breaks a known amount of target materials into metal atoms, which then form nanoparticles by recombination in the gas phase. Due to the nature of thin-film ablation, splashing of large particles was eliminated with the added benefit of minimizing nanoparticle agglomeration. Plume dynamics and surface characterizations were carried out to exploit the formation of Fe–Ni nanoparticles more fully. The composition was readily controlled by varying the initial relative amount of Fe and Ni target pixels. Synthesis of multi-element nanoparticles by pixel target ablation should be possible with any element combination that can be prepared as a thin-film target.

  6. NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Peters, T.; Fink, S.

    2012-01-17

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX{reg_sign}79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX{reg_sign}79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX{reg_sign}79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

  7. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Sanden, Torbjoern; Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jansson, Mats; Eriksen, Trygve E.; Svaerdstroem, Kjell (KTH Royal Inst. of Technology, Stockholm (Sweden)); Rosborg, Bo (Studsvik AB, Nykoeping (Sweden); Rosborg Consulting, Nykoeping (Sweden)); Muurinen, Arto (VTT, Espoo (Finland))

    2011-02-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses

  8. Instrumentation of x-ray diffraction and materials research on the National Synchrotron Light Source. Final report

    International Nuclear Information System (INIS)

    Liedl, G.L.

    1984-11-01

    MATRIX was organized in 1980 to formulate a research team to design and construct a beam line at NSLS for x-ray diffraction studies of materials. A versatile system was designed to allow a full range of experimental capabilities for wide angle x-ray scattering experiments including surface diffraction studies. The design and construction of the system has been completed. Testing of parts of the system was completed at CHESS and with x-ray sources or other equipment at member institutions. Installation of the beam line at NSLS is in progress and will proceed in parallel with the commissioning of the x-ray ring at NSLS. Full operation of the beam line is expected to be ready by December 1, 1984 being limited only by the source power of NSLS at that time. Useful experiments could be started if the power is at least 2 GeV and 100ma. The MATRIX beam line was one of the first x-ray beam lines to see light in the beam line in early spring of 1984. In July of 1984, the MATRIX beam line as the first port at NSLS to have a monochromatic beam and to scan part of the spectrum from the source. As part of this contract, six publications have resulted from the various projects. Three publications are concerned directly with the beam line and/or its operation while the other three publications are the result of research associated with the project

  9. Design guide for composite-material flywheels: rotor dyamic considerations. Part I. System whirling and stability. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bert, C.W.; Ramunujam, G.

    1981-09-01

    Information to designers of flywheels is provided which will enable them to predict many aspects of the dynamic behavior of their flywheel systems when spin-tested with a quill-shaft support and driven by an air turbine. Computer programs are presented for the following dynamic analysis to obtain the results indicated: free whirling for natural frequencies versus rotational speed and the associated mode shapes; rough-type stability analysis for determining the stability limits; and forced whirling analysis for estimating the response of major components of the system to flywheel mass eccentricity and initial tilt. For the first and third kinds of analyses, two different mathematical models of the generic system are investigated. One is a seven-degree-of-freedom lumped-parameter analysis, while the other is a combined distributed- and lumped-parameter analysis. When applied to an existing flywheel system, the two models yielded numerical values for the lowest first-order forward critical speed in very close agreement with each other and with experimental results obtained in spin tests. Therefore, for the second kind of analysis, only the lumped-parameter model is implemented. Qualitative discussions as to why forced retrograde whirling is not as severe as forward whirling are also presented. The analyses are applied to the multi-material ring type flywheel systems, a constant-thickness-diskring type, and a tapered-thickness-disk type. In addition, the effects of the following flywheel design parameters on system dynamics were investigated: flywheel mass; diametral and polar mass moments of inertia; location of mass center from the lower end of the quill shaft; quill shaft length; lower turbine-bearing support stiffness; equivalent viscous damping coefficient of the external damper; flywheel dead weight; and torque applied at the turbine.

  10. Laser ablation of paint in nuclear industry

    International Nuclear Information System (INIS)

    Brygo, Francois; Semerok, Alexandre; Weulersse, Jean-Marc; Thro, Pierre-Yves; Oltra, Roland; Decobert, Guy

    2006-01-01

    Nuclear dismantling faces the challenge of paint removal on large surfaces of painted walls. The conventional methods for paint stripping on concrete walls are mainly based on mechanical grinder and lead to an important volume of aerosols and wastes. Laser ablation has been evaluated as a promising method for paint removal with a number of advantages. The method reduces considerably the waste volume as the removal of paint is selective. The ablated matter can be collected by aerosol aspiration/filtration. The automation of the process can provide a higher capacity of paint removal. Laser ablation of paint was under our extensive studies. Laser ablation with different nanosecond repetition rate lasers was comparatively studied to understand the ablation mechanisms, and to obtain the highest efficiency of paint removal. The investigations were made with three Q-Switched Nd:YAG lasers (λ = 532 nm and λ = 1.064 μm). The different pulse durations (5 ns and 100 ns) demonstrated the different ablation regimes. Ablation with long pulses (100 ns) provided the best removal efficiency while the short ones (5 ns) decreased the ablation threshold fluence. It was demonstrated that the pulse repetition rate increasing in the 20 Hz - 10 kHz range induced heat accumulation in the paint. It resulted in ablation efficiency increase with a large decrease in the ablation threshold fluence. Laser ablation in the 0 - 10 J / cm 2 fluence range was investigated. Various paints were under investigation to obtain the maximum efficiency of paint removal for each specific experimental case. The ejected matter recording with a high speed imaging system allows to analyse the laser-matter interaction. (authors)

  11. Soft x-ray laser ablation of metals and dielectrics

    Science.gov (United States)

    Faenov, A.; Pikuz, T.; Ishino, M.; Inogamov, N.; Zhakhovsky, V.; Skobelev, I.; Hasegawa, N.; Nishikino, M.; Kando, M.; Kodama, R.; Kawachi, T.

    2017-05-01

    We present an overview of our systematic studies of the surface modifications resulting from the interactions of both single and multiple picosecond soft x-ray laser (SXRL) pulses with materials, such as gold (Au), copper (Cu), aluminum (Al), and lithium fluoride (LiF). We show experimentally the possibility of the precise nanometer size structures ( 10-40 nm) formation on their surfaces by ultra-low ( 10-30 mJ/cm2 ) fluencies of single picosecond SXRL pulse. Comparison experimental results with the atomistic model of ablation, which was developed for the single SXRL shot interaction with dielectrics and metals, is provided. Theoretical description of surface nanostructures is considered and is shown that such structures are formed after laser illumination in a process of mechanical spallation of ultrathin surface layer of molten metal. Spallation is accompanied by a strong foaming of melt, breaking of foam, and freezing of foam remnants. Those remnants form chaotic nanostructures, which are observed in experiments. Our measurements show that electron temperature of matter under irradiation of SXRL was lower than 1 eV. The model calculation also predicts that the ablation induced by the SXRL can create the significant low electron temperature. Our results demonstrate that tensile stress created in LiF and metals by short SXRL pulse can produce spallative ablation of target even for drastically small fluencies, which open new opportunities for material nano processing.

  12. Fully Automated Laser Ablation Liquid Capture Sample Analysis using NanoElectrospray Ionization Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Matthias [ORNL; Ovchinnikova, Olga S [ORNL; Van Berkel, Gary J [ORNL

    2014-01-01

    RATIONALE: Laser ablation provides for the possibility of sampling a large variety of surfaces with high spatial resolution. This type of sampling when employed in conjunction with liquid capture followed by nanoelectrospray ionization provides the opportunity for sensitive and prolonged interrogation of samples by mass spectrometry as well as the ability to analyze surfaces not amenable to direct liquid extraction. METHODS: A fully automated, reflection geometry, laser ablation liquid capture spot sampling system was achieved by incorporating appropriate laser fiber optics and a focusing lens into a commercially available, liquid extraction surface analysis (LESA ) ready Advion TriVersa NanoMate system. RESULTS: Under optimized conditions about 10% of laser ablated material could be captured in a droplet positioned vertically over the ablation region using the NanoMate robot controlled pipette. The sampling spot size area with this laser ablation liquid capture surface analysis (LA/LCSA) mode of operation (typically about 120 m x 160 m) was approximately 50 times smaller than that achievable by direct liquid extraction using LESA (ca. 1 mm diameter liquid extraction spot). The set-up was successfully applied for the analysis of ink on glass and paper as well as the endogenous components in Alstroemeria Yellow King flower petals. In a second mode of operation with a comparable sampling spot size, termed laser ablation/LESA , the laser system was used to drill through, penetrate, or otherwise expose material beneath a solvent resistant surface. Once drilled, LESA was effective in sampling soluble material exposed at that location on the surface. CONCLUSIONS: Incorporating the capability for different laser ablation liquid capture spot sampling modes of operation into a LESA ready Advion TriVersa NanoMate enhanced the spot sampling spatial resolution of this device and broadened the surface types amenable to analysis to include absorbent and solvent resistant

  13. Advantages of dual-laser ablation in the growth of multicomponent thin films

    Science.gov (United States)

    Mukherjee, Devajyoti; Hyde, Robert; Mukherjee, Pritish; Witanachchi, Sarath

    2012-07-01

    We report the use of a dual-laser deposition process to grow stoichiometric films of the piezoelectric material PbZr0.52Ti0.48O3 (PZT) and the thermoelectric material Ba8Ga16Ge30. High volatility of Pb and Ba in these materials leads to non-stoichiometric growth in conventional PLD processes. Dual-laser ablation process preserves the Pb and Ba stoichiometry while significantly reducing the thickness variation and particulate density on the deposited films. This lead to the growth of smooth uniform films with enhanced ferroelectric and electrical properties. The dual-laser ablation combines the pulses of a KrF excimer laser (248 nm wavelength, 30 ns pulse width) and a CO2 laser (10.6 μm wavelength, 250 ns pulse width) where the beams are spatially overlapped on the ablation target and temporally delayed. At an optimum delay that is dependent on the physical properties of the material, CO2 pulse energy is coupled into the plume, generating a high temperature plasma (>25,000K). Laser-target interaction studies have shown the evaporation to be stoichiometric. Emission spectroscopy studies have shown ten-fold increase in emission intensities in dual-laser ablation while time-gated 2D ICCD imaging studies revealed the plume expansion to be stoichiometric over a large cone-angle of the plume under these conditions. Time-of-flight investigations in concert with hydrodynamic modeling provided a clear understanding of the mechanism of dual-laser ablation. Furthermore, plasma generated in the process is highly ionized (>75%) leading to films with high density and crystallinity. This paper will show the enhancement in properties attainable by the dual-laser ablation process in comparison to the single laser ablation.

  14. Computational Modeling of Ablation on an Irradiated Target

    Science.gov (United States)

    Mehmedagic, Igbal; Thangam, Siva

    2017-11-01

    Computational modeling of pulsed nanosecond laser interaction with an irradiated metallic target is presented. The model formulation involves ablation of the metallic target irradiated by pulsed high intensity laser at normal atmospheric conditions. Computational findings based on effective representation and prediction of the heat transfer, melting and vaporization of the targeting material as well as plume formation and expansion are presented along with its relevance for the development of protective shields. In this context, the available results for a representative irradiation from 1064 nm laser pulse is used to analyze various ablation mechanisms, variable thermo-physical and optical properties, plume expansion and surface geometry. Funded in part by U. S. Army ARDEC, Picatinny Arsenal, NJ.

  15. Counterclockwise heart rotation affects variation in successful ablation line position in common atrial flutter.

    Science.gov (United States)

    Machino, Takeshi; Tada, Hiroshi; Sekiguchi, Yukio; Naruse, Yoshihisa; Kuroki, Kenji; Yamasaki, Hiro; Igarashi, Miyako; Yoshida, Kentaro; Nogami, Akihiko; Aonuma, Kazutaka

    2014-01-01

     Linear ablation of atrial flutter usually targets a 6 o'clock position on the cavotricuspid isthmus on left anterior oblique view, but the difficulty of the ablation often requires a variation in successful ablation line position from 5 to 7 o'clock.  This study included 94 patients without structural heart disease. A linear lesion was created in turn at the 6, 7, and 5 o'clock positions until bidirectional block of the isthmus was completed; the final lesion was defined as the successful ablation line. The degree of counterclockwise heart rotation (CCW-HR) was evaluated in a blinded fashion according to the angle between the vertical line crossing the His bundle catheter and the line connecting the His bundle catheter and coronary sinus ostium. Successful ablation lines were obtained at the 6 o'clock position in 59 patients (63%); the 7 o'clock position in 19 patients (20%; the oldest group with a moderate radiofrequency burden); and the 5 o'clock position in the remaining 16 (17%; the youngest group with the largest radiofrequency burden). Age-related increase in CCW-HR was the only independent predictor of a more septal successful ablation line (OR, 7.1; 95% CI: 3.3-14.3; Paffected by age-related CCW-HR; its evaluation might reduce radiofrequency burden, especially in the young and elderly.  

  16. Ablation spot area and impulse characteristics of polymers induced by burst irradiation of 1 μm laser pulses

    Science.gov (United States)

    Tsuruta, Hisashi; Dondelewski, Oskar; Katagiri, Yusuke; Wang, Bin; Sasoh, Akihiro

    2017-07-01

    The ablation spot area and impulse characteristics of various polymers were experimentally investigated against burst irradiation of Nd: YLF laser pulses with a pulse repetition frequency of 1 kHz, wavelength of 1047 nm, temporal pulse width of 10 ns, and single-pulse fluence of 6.1 J/cm2 to 17.1 J/cm2. The dependences of ablation area on the pulse energy from 0.72 to 7.48 mJ and the number of pulses from 10 pulses to 1000 pulses were investigated. In order to characterize their impulse performance as a function of fluence, which should not depend on ablation material, an effective ablation spot area was defined as that obtained against aluminum, 1050 A, as the reference material. An impulse that resulted from a single burst of 200 pulses was measured with a torsion-type impulse stand. Various impulse dependences on the fluence, which were not readily predicted from the optical properties of the material without ablation, were obtained. By fitting the experimentally measured impulse performance to Phipps and Sinko's model in the vapor regime, the effective absorption coefficient with laser ablation was evaluated, thereby resulting in three to six orders of magnitude larger than that without ablation. Among the polymers examined using polytetrafluoroethylene (PTFE) as the best volume absorbers, the highest momentum coupling coefficient of 66 μNs/J was obtained with an effective absorption coefficient more than six times smaller than that of the other polymers.

  17. Gallbladder ablation by radiologic intervention

    International Nuclear Information System (INIS)

    Becker, C.D.; Quenville, N.F.; Burhenne, H.J.

    1988-01-01

    Thirty pigs underwent cystic duct occlusion by means of transcatheter endoluminal bipolar radiofrequency electrocoagulation under fluoroscopic guidance. Twenty animals subsequently underwent gallbladder ablation with alcohol and sotradecol; ten animals served as controls. Serial histologic blocking of the common bile duct, cystic duct, and gallbladder in all animals revealed no adverse effects of the sclerosants on the bile ducts or the structures adjacent to the gallbladder. The combination of 95% alcohol plus 3% sotradecol resulted in necrosis of the gallbladder mucosa within 2 weeks (two of two animals) and complete eradication of the mucosa and fibrotic obliteration of the gallbladder lumen within 8 weeks (six of eight animals)

  18. Hyperkalaemia after radiofrequency ablation of hepatocellular carcinoma

    NARCIS (Netherlands)

    Verhoevena, BH; Haagsma, EB; Appeltans, BMG; Slooff, MJH; de Jong, KP

    Radiofrequency ablation of liver tumours is a useful therapy for otherwise unresectable tumours. The complication rate is said to be low. In this case report we describe hyperkalaemia after radiofrequency ablation of a hepatocellular carcinoma in a patient with end-stage renal insufficiency. (C)

  19. Ablation Techniques for Mahaim Fiber Tachycardia

    Directory of Open Access Journals (Sweden)

    Shomu Bohora

    2009-03-01

    Full Text Available Mahaim fiber exhibits atrio-ventricular node like properties and generally is localized at the lateral aspect of the tricuspid annulus. Of the varying methods for localization, ablation at the site of Mahaim potential is the most accepted and successful method. Radiofrequency ablation of Mahaim fiber has high success rates.

  20. Attitudes Towards Catheter Ablation for Atrial Fibrillation

    DEFF Research Database (Denmark)

    Vadmann, Henrik; Pedersen, Susanne S; Nielsen, Jens Cosedis

    2015-01-01

    BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an important but expensive procedure that is the subject of some debate. Physicians´ attitudes towards catheter ablation may influence promotion and patient acceptance. This is the first study to examine the attitudes of Danish...

  1. The Atrial Fibrillation Ablation Pilot Study

    DEFF Research Database (Denmark)

    Arbelo, Elena; Brugada, Josep; Hindricks, Gerhard

    2014-01-01

    AIMS: The Atrial Fibrillation Ablation Pilot Study is a prospective registry designed to describe the clinical epidemiology of patients undergoing an atrial fibrillation (AFib) ablation, and the diagnostic/therapeutic processes applied across Europe. The aims of the 1-year follow-up were to analy...

  2. Testing and evaluation of light ablation decontamination

    International Nuclear Information System (INIS)

    Demmer, R.L.; Ferguson, R.L.

    1994-10-01

    This report details the testing and evaluation of light ablation decontamination. It details WINCO contracted research and application of light ablation efforts by Ames Laboratory. Tests were conducted with SIMCON (simulated contamination) coupons and REALCON (actual radioactive metal coupons) under controlled conditions to compare cleaning effectiveness, speed and application to plant process type equipment

  3. Testing and evaluation of light ablation decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Demmer, R.L.; Ferguson, R.L.

    1994-10-01

    This report details the testing and evaluation of light ablation decontamination. It details WINCO contracted research and application of light ablation efforts by Ames Laboratory. Tests were conducted with SIMCON (simulated contamination) coupons and REALCON (actual radioactive metal coupons) under controlled conditions to compare cleaning effectiveness, speed and application to plant process type equipment.

  4. High Heat Flux Block Ablator-in-Honeycomb Heat Shield Using Ablator/Aerogel-Filled Foam, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultramet and ARA Ablatives Laboratory previously developed and demonstrated advanced foam-reinforced carbon/phenolic ablators that offer substantially increased high...

  5. Hypertrophic Obstructive Cardiomyopathy: Surgical Myectomy and Septal Ablation.

    Science.gov (United States)

    Nishimura, Rick A; Seggewiss, Hubert; Schaff, Hartzell V

    2017-09-15

    Hypertrophic cardiomyopathy is a genetic disorder characterized by marked hypertrophy of the myocardium. It is frequently accompanied by dynamic left ventricular outflow tract obstruction and symptoms of dyspnea, angina, and syncope. The initial therapy for symptomatic patients with obstruction is medical therapy with β-blockers and calcium antagonists. However, there remain a subset of patients who have continued severe symptoms, which are unresponsive to medical therapy. These patients can be treated with septal reduction therapy, either surgical septal myectomy or alcohol septal ablation. When performed by experienced operators working in high-volume centers, septal myectomy is highly effective with a >90% relief of obstruction and improvement in symptoms. The perioperative mortality rate for isolated septal myectomy in most centers is <1%. Alcohol septal ablation is a less invasive treatment. In many patients, the hemodynamic and clinical results are comparable to that of septal myectomy. However, the results of alcohol septal ablation are dependent on the septal perforator artery supplying the area of the contact between the hypertrophied septum and the anterior leaflet of the mitral valve. There are some patients, particularly younger patients with severe hypertrophy, who do not uniformly experience complete relief of obstruction and symptoms. Both techniques of septal reduction therapy are highly operator dependent. The final decision as to which approach should be selected in any given patient is dependent up patient preference and the availability and experience of the operator and institution at which the patient is being treated. © 2017 American Heart Association, Inc.

  6. Use of laser ablation in nuclear decontamination

    International Nuclear Information System (INIS)

    Moggia, Fabrice; Lecardonnel, Xavier; Damerval, Frederique

    2012-09-01

    The development and the use of clean decontamination process appear to be one of the main priorities for industries especially for nuclear industries. This is especially due to the fact of wastes minimization which is one of the principal commitments. One answer would be to use a photonic process such as the LASER process. The principle of this process is based on the absorption, by the contaminant, of the photon's energy. This energy then will propagate into the material and create some mechanical waves responsible of the interfaces embrittlement and de-cohesion. As we can see, this process so called LASER ablation does not use any chemicals and allows us to avoid any production of liquid waste. Since now a couple of years, the Clean-Up Business Unit of AREVA group (BE/CL) investigates this new decontamination technology. Many tests have been done in inactive conditions on various simulants such as paints, inks, resins, metallic oxides firstly in order to estimate its efficiency but also to fully qualify it. After that, we decided to move on hot tests to fully validate this new process and to show its interest for the nuclear industry. Those hot tests have been done on two kinds of contaminated material (on tank pieces covered with a thick metallic oxide layer and on metallic pieces covered with grease). Some information such as Scanning Electron Microscopy (SEM), X-Ray scattering spectroscopy and decontamination factors (DF) will be provided in this paper. (authors)

  7. Catheter ablation of epicardial ventricular tachycardia

    Directory of Open Access Journals (Sweden)

    Takumi Yamada, MD, PhD

    2014-08-01

    Full Text Available Ventricular tachycardias (VTs can usually be treated by endocardial catheter ablation. However, some VTs can arise from the epicardial surface, and their substrate can be altered only by epicardial catheter ablation. There are two approaches to epicardial catheter ablation: transvenous and transthoracic. The transvenous approach through the coronary venous system (CVS has been commonly used because it is easily accessible. However, this approach may be limited by the distribution of the CVS and insufficient radiofrequency energy delivery. Transthoracic epicardial catheter ablation has been developed to overcome these limitations of the transvenous approach. It is a useful supplemental or even preferred strategy to eliminate epicardial VTs in the electrophysiology laboratory. This technique has been applied for scar-related VTs secondary to often non-ischemic cardiomyopathy and sometimes ischemic cardiomyopathy, and idiopathic VTs as the epicardial substrates of these VTs have become increasingly recognized. When endocardial ablation and epicardial ablation through the CVS are unsuccessful, transthoracic epicardial ablation should be the next option. Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery or pericarditis. In such cases, a hybrid procedure involving surgical access with a subxiphoid pericardial window and a limited anterior or lateral thoracotomy might be a feasible and safe method of performing an epicardial catheter ablation in the electrophysiology laboratory. Potential complications associated with this technique include bleeding and collateral damage to the coronary arteries and phrenic nerve. Although the risk of these complications is low, electrophysiologists who attempt epicardial catheter ablation should know the complications associated with this technique, how to minimize their

  8. Determination of ablation threshold for composite resins and amalgam irradiated with femtosecond laser pulses

    Science.gov (United States)

    Freitas, A. Z.; Freschi, L. R.; Samad, R. E.; Zezell, D. M.; Gouw-Soares, S. C.; Vieira, N. D., Jr.

    2010-03-01

    The use of laser for caries removal and cavity preparation is already a reality in the dental clinic. The objective of the present study was to consider the viability of ultrashort laser pulses for restorative material selective removal, by determining the ablation threshold fluence for composite resins and amalgam irradiated with femtosecond laser pulses. Lasers pulses centered at 830 nm with 50 fs of duration and 1 kHz of repetition rate, with energies in the range of 300 to 770 μJ were used to irradiate the samples. The samples were irradiated using two different geometrical methods for ablation threshold fluence determinations and the volume ablation was measured by optical coherence tomography. The shape of the ablated surfaces were analyzed by optical microscopy and scanning electron microscopy. The determined ablation threshold fluence is 0.35 J/cm2 for the composite resins Z-100 and Z-350, and 0.25 J/cm2 for the amalgam. These values are half of the value for enamel in this temporal regime. Thermal damages were not observed in the samples. Using the OCT technique (optical coherence tomography) was possible to determine the ablated volume and the total mass removed.

  9. Current and future technology for minimally invasive ablation of renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Branden G Duffey

    2010-01-01

    Full Text Available Purpose of Review : To provide an overview of the technologic advancements in the field of ablative therapy, focusing on the treatment of renal neoplasms. Materials and Methods : A MEDLINE search was performed using each specific ablative technique name as the search term. Articles written in the English language were selected for review. In cases of multiple reports by a single institution, the most recent report was utilized. Pertinent articles specific to the technologic advancement in ablative therapy were selected for review. Recent Findings : Intermediate-term oncologic outcomes of radiofrequency ablation (RFA and cryoablation (CA for the treatment of small renal masses are encouraging. For thermal therapies, molecular adjuvants to enhance cellular kill and local control have been developed. Improvements in microwave technology have allowed for reductions in antenna size and increases in ablation size. Laparoscopic high-intensity focused ultrasound (HIFU probes have been developed to overcome the limitations of transcutaneous energy delivery, but HIFU remains experimental for the treatment of renal lesions. Irreversible electroporation (IRE, a novel nonthermal ablative technique, is currently undergoing clinical investigation in human subjects. Histotripsy causes mechanical destruction of targeted tissue and shows promise in treating renal and prostate pathology. Summary : Ablative techniques are commonly utilized in the primary treatment of urologic malignancies. The purpose of this review is to discuss technologic advances in ablative therapies with emphasis on the treatment of renal masses. RFA and CA show acceptable intermediate-term efficacy and technical refinement continues. Emerging technologies, including microwave thermotherapy, IRE, HIFU and histotripsy, are described with emphasis on the mechanism of cellular kill, energy delivery, and stage in clinical development.

  10. Variables associated with vaginal discharge after ultrasound-guided percutaneous microwave ablation for adenomyosis.

    Science.gov (United States)

    Xu, Rui-Fang; Zhang, Jing; Han, Zhi-Yu; Zhang, Bing-Song; Liu, Hui; Li, Xiu-Mei; Ge, Hai-Long; Dong, Xue-Juan

    2016-08-01

    Objective The aim of this study was to analyse the significant variables for vaginal discharge after ultrasound-guided percutaneous microwave ablation (PMWA) therapy. Materials and methods PMWA was performed on 117 patients with adenomyosis from October 2012 to July 2014. The presence or absence, colour, quantity and duration of vaginal discharge, which was different from pre-ablation, were recorded within 1 year after PMWA. Patients were categorised into G1 (n = 26, without vaginal discharge), G2 (n = 40, vaginal discharge lasting 1 to 19 days), and G3 (n = 51, vaginal discharge lasting ≥20 days) groups. The potentially correlative variables were analysed. Variables with significant correlations with vaginal discharge post-ablation were identified via binary logistic regression analysis. Results The differences in adenomyosis type, pre-ablation uterine volume, total microwave ablation energy, total non-perfused volume (NPV) and minimum distance from the non-perfused lesion (NPL) margin to the endomyometrial junction (EMJ) among groups were statistically significant (p = 0.005, p = 0.000, p = 0.000, p = 0.005 and p = 0.000, respectively). Minimum distance from the NPL margin to the EMJ was the strongest predictor of vaginal discharge post-ablation with odds ratio (OR) 0.632, p = 0.018, 95% CI 0.432-0.923. Patients with diffuse adenomyosis were more likely to have prolonged vaginal discharge (≥20 days) post-ablation (OR 3.461, p = 0.000, 95% CI 1.759-7.536). Conclusion The minimum distance from the NPL margin to the EMJ and adenomyosis type were significantly associated with vaginal discharge post-ablation.

  11. Conformal Ablative Thermal Protection Systems (CA-TPS) for Venus and Saturn Backshells

    Science.gov (United States)

    Beck, R.; Gasch, M.; Stackpoole, M.; Wilder, M.; Boghozian, T.; Chavez-Garcia, J.; Prabhu, Dinesh; Kazemba, Cole D.; Venkatapathy, E.

    2016-01-01

    This poster provides an overview of the work performed to date on the Conformal Ablative TPS (CA-TPS) element of the TPSM project out of GCDP. Under this element, NASA is developing improved ablative TPS materials based on flexible felt for reinforcement rather than rigid reinforcements. By replacing the reinforcements with felt, the resulting materials have much higher strain-to-failure and are much lower in thermal conductivity than their rigid counterparts. These characteristics should allow for larger tile sizes, direct bonding to aeroshells and even lower weight TPS. The conformal phenolic impregnated carbon felt (C-PICA) is a candidate for backshell TPS for both Venus and Saturn entry vehicles.

  12. Feed Materials Production Center. Final phase-in report volume 11 of 15 waste management, October 25, 1985--December 31, 1985

    Energy Technology Data Exchange (ETDEWEB)

    Watts, R.E.

    1986-01-17

    This volume of the Transition Final Report provides the findings, recommendations and corrective actions for the Waste Management areas developed during the phase-in actions by Westinghouse Materials Company (WMCO). The objective is to provide a summary of the studies and investigations performed by the WMCO Company during the transition period. The Waste Management effort at FMPC was expanded in 1984 when a separate group was formed within the NLO organization. This is considered to be an area where significant increase in priority and effort must be applied to resolve waste management problems and to bring the site in conformity to regulations and the Environmental Health/Safety Standards. During the transition, there was a comprehensive investigation in all areas of air, liquid and solid waste management for nuclear, chemical and conventional wastes. Not all of these investigations are documented in this report, but the information gathered was used in the development of the budgets (cost accounts), programs, and organizational planning.

  13. Lung ablation: Best practice/results/response assessment/role alongside other ablative therapies.

    Science.gov (United States)

    de Baere, T; Tselikas, L; Gravel, G; Deschamps, F

    2017-08-01

    Today, in addition to surgery, other local therapies are available for patients with small-size non-small-cell lung cancer (NSCLC) and oligometastatic disease from various cancers. Local therapies include stereotactic ablation radiotherapy (SABR) and thermal ablative therapies through percutaneously inserted applicators. Although radiofrequency ablation (RFA) has been explored in series with several hundreds of patients with pulmonary tumours, investigation of the potential of other ablation technologies including microwave ablation, cryoablation, and irreversible electroporation is ongoing. There are no randomised studies available to compare surgery, SABR, and thermal ablation. In small-size lung metastases, RFA seems to produce results very close to surgical series with >90% local control and 5-year overall survival of 50%. In primary lung cancer, the technique is reserved for non-surgical candidates. In future, the low invasiveness of thermal ablative therapies will allow for a combination of ablation and systemic therapies in order to improve the outcomes of ablation alone. Another major advantage of thermal ablation is the possibility to treat several metastases in close proximity to one another and retreatment in the same location in case of failure, which is not possible with SABR. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Laser ablation studies of solid aerosols on the Baltic coast

    Directory of Open Access Journals (Sweden)

    Robert Jaworski

    2004-09-01

    Full Text Available A Berner cascade impactor was used for the separation of solid urban aerosols in two localities of the Baltic coastal macro-region - Słupsk and Hel - in different seasons and weathers. Ten ranges of aerodynamic diameters between 0.009 and 8.11 µm were used. The elementary composition for each diameter was obtained in a complex procedure consisting of laser ablation of deposits, then their successive ionization in an inductively coupled plasma generator, and finally, mass selection in a quadrupole spectrometer. Despite its complexity, the chemical element analysis method proved to be versatile, allowing the identification air pollution from natural and industrial sources, and road traffic.

  15. Superhydrophobic/superoleophilic magnetic elastomers by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Milionis, Athanasios, E-mail: am2vy@virginia.edu [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy); Fragouli, Despina; Brandi, Fernando; Liakos, Ioannis; Barroso, Suset [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy); Ruffilli, Roberta [Nanochemistry, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy); Athanassiou, Athanassia, E-mail: athanassia.athanassiou@iit.it [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy)

    2015-10-01

    Highlights: • We report the development of magnetic nanocomposite sheets. • Laser irradiation of the nanocomposites induces chemical and structural changes to the surface. • The laser-patterned surfaces exhibit superhydrophobicity and superoleophilicity. • The particle contribution in altering the surface and bulk properties of the material is studied. - Abstract: We report the development of magnetic nanocomposite sheets with superhydrophobic and supeoleophilic surfaces generated by laser ablation. Polydimethylsiloxane elastomer free-standing films, loaded homogeneously with 2% wt. carbon coated iron nanoparticles, were ablated by UV (248 nm), nanosecond laser pulses. The laser irradiation induces chemical and structural changes (both in micro- and nano-scale) to the surfaces of the nanocomposites rendering them superhydrophobic. The use of nanoparticles increases the UV light absorption efficiency of the nanocomposite samples, and thus facilitates the ablation process, since the number of pulses and the laser fluence required are greatly reduced compared to the bare polymer. Additionally the magnetic nanoparticles enhance significantly the superhydrophobic and oleophilic properties of the PDMS sheets, and provide to PDMS magnetic properties making possible its actuation by a weak external magnetic field. These nanocomposite elastomers can be considered for applications requiring magnetic MEMS for the controlled separation of liquids.

  16. Ultrafast laser ablation in liquids for nanomaterials and applications.

    Science.gov (United States)

    Rao, S Venugopal; Podagatlapalli, G Krishna; Hamad, Syed

    2014-02-01

    We present an inclusive overview of the ultrafast ablation technique performed in liquids. Being a comparatively new method, we bring out the recent progress achieved, present the challenges ahead, and outline the future prospects for this technique. The review is conveniently divided into five parts: (a) a succinct preamble to the technique of ultrafast ablation in liquids (ULAL) is provided. A brief introduction to the conventional ns ablation is also presented for the sake of completeness (b) fundamental physical processes involved in this technique are elaborated (c) specific advantages of the technique compared to other physical and chemical methodologies are enumerated (d) applications of this technique in photonics; biomedical and explosives detection [using surface-enhanced Raman scattering (SERS)] is updated (e) future prospects describing the potential of this technique for creating unique nanoparticles (NPs) and nanostructures (NSs) for niche applications. We also discuss some of the recently reported significant results achieved in a variety of materials, especially metals, using this technique. Furthermore, we present some of our own experimental data obtained from ULAL of Ag, Cu, and Zn in a variety of liquids such as acetone, water, acetonitrile etc. The generated NPs (colloidal solutions) and NSs (on substrates) have been successfully utilized for nonlinear optical, SERS, and biomedical applications.

  17. Extensive Characterization of Oxide-Coated Colloidal Gold Nanoparticles Synthesized by Laser Ablation in Liquid

    Directory of Open Access Journals (Sweden)

    Romuald Intartaglia

    2016-09-01

    Full Text Available Colloidal gold nanoparticles are a widespread nanomaterial with many potential applications, but their aggregation in suspension is a critical issue which is usually prevented by organic surfactants. This solution has some drawbacks, such as material contamination and modifications of its functional properties. The gold nanoparticles presented in this work have been synthesized by ultra-fast laser ablation in liquid, which addresses the above issues by overcoating the metal nanoparticles with an oxide layer. The main focus of the work is in the characterization of the oxidized gold nanoparticles, which were made first in solution by means of dynamic light scattering and optical spectroscopy, and then in dried form by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and finally by surface potential measurements with atomic force microscopy. The light scattering assessed the nanoscale size of the formed particles and provided insight in their stability. The nanoparticles’ size was confirmed by direct imaging in transmission electron microscopy, and their crystalline nature was disclosed by X-ray diffraction. The X-ray photoelectron spectroscopy showed measurements compatible with the presence of surface oxide, which was confirmed by the surface potential measurements, which are the novel point of the present work. In conclusion, the method of laser ablation in liquid for the synthesis of gold nanoparticles has been presented, and the advantage of this physical approach, consisting of coating the nanoparticles in situ with gold oxide which provides the required morphological and chemical stability without organic surfactants, has been confirmed by using scanning Kelvin probe microscopy for the first time.

  18. Extensive Characterization of Oxide-Coated Colloidal Gold Nanoparticles Synthesized by Laser Ablation in Liquid

    Science.gov (United States)

    Intartaglia, Romuald; Rodio, Marina; Abdellatif, Mohamed; Prato, Mirko; Salerno, Marco

    2016-01-01

    Colloidal gold nanoparticles are a widespread nanomaterial with many potential applications, but their aggregation in suspension is a critical issue which is usually prevented by organic surfactants. This solution has some drawbacks, such as material contamination and modifications of its functional properties. The gold nanoparticles presented in this work have been synthesized by ultra-fast laser ablation in liquid, which addresses the above issues by overcoating the metal nanoparticles with an oxide layer. The main focus of the work is in the characterization of the oxidized gold nanoparticles, which were made first in solution by means of dynamic light scattering and optical spectroscopy, and then in dried form by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and finally by surface potential measurements with atomic force microscopy. The light scattering assessed the nanoscale size of the formed particles and provided insight in their stability. The nanoparticles’ size was confirmed by direct imaging in transmission electron microscopy, and their crystalline nature was disclosed by X-ray diffraction. The X-ray photoelectron spectroscopy showed measurements compatible with the presence of surface oxide, which was confirmed by the surface potential measurements, which are the novel point of the present work. In conclusion, the method of laser ablation in liquid for the synthesis of gold nanoparticles has been presented, and the advantage of this physical approach, consisting of coating the nanoparticles in situ with gold oxide which provides the required morphological and chemical stability without organic surfactants, has been confirmed by using scanning Kelvin probe microscopy for the first time. PMID:28773897

  19. Permanent atrial fibrillation ablation surgery in patients with advanced age

    Directory of Open Access Journals (Sweden)

    Stephan Geidel

    2005-10-01

    Full Text Available Background: Even if permanent atrial fibrillation (pAF is a frequent concomitant problem in patients undergoing open heart surgery and particularly in those with advanced age, data of pAF ablation surgery in older aged patients are scarce. This study was performed to assess early and late results of combined open heart surgery and pAF ablation procedures in patients with advanced aged, compared to young patients. Material and Methods: A selective group of 126 patients (Group A: age ≥70 [76.4±4.8] years, n=70; Group B: age <70 [62.0±6.2] years: n=56 with pAF (≥6 months underwent either monopolar (Group A, B: n=51 vs. n=44 or bipolar (Group A, B: n=19 vs. n=12 radiofrequency (RF ablation procedures concomitant to open heart surgery. Regular follow-up was performed 3 to 36 months after surgery to assess survival, New York Heart Association (NYHA class and conversion rate to stable sinus rhythm (SR. Results: Early mortality (<30 days was 2.9% in Group A (Group B: 0%, cumulative survival at long-term follow up was 0.78 vs. 0.98 (p=0.03 and NYHA-class improved significantly in both groups, particularly in cases with stable SR. At 12-months follow-up 73% of Group A patients were in stable SR (Group B 78%. Conclusions: Concomitant mono- and bipolar RF ablation surgery represents a safe option to cure pAF during open heart surgery with a very low risk, even in patients with advanced age.

  20. Chemically assisted laser ablation ICP mass spectrometry.

    Science.gov (United States)

    Hirata, Takafumi

    2003-01-15

    A new laser ablation technique combined with a chemical evaporation reaction has been developed for elemental ratio analysis of solid samples using an inductively coupled plasma mass spectrometer (ICPMS). Using a chemically assisted laser ablation (CIA) technique developed in this study, analytical repeatability of the elemental ratio measurement was successively improved. To evaluate the reliability of the CLA-ICPMS technique, Pb/U isotopic ratios were determined for zircon samples that have previously been analyzed by other techniques. Conventional laser ablation for Pb/U shows a serious elemental fractionation during ablation mainly due to the large difference in elemental volatility between Pb and U. In the case of Pb/U ratio measurement, a Freon R-134a gas (1,1,1,2-tetrafluoroethane) was introduced into the laser cell as a fluorination reactant. The Freon gas introduced into the laser cell reacts with the ablated sample U, and refractory U compounds are converted to a volatile U fluoride compound (UF6) under the high-temperature condition at the ablation site. This avoids the redeposition of U around the ablation pits. Although not all the U is reacted with Freon, formation of volatile UF compounds improves the transmission efficiency of U. Typical precision of the 206Pb/238U ratio measurement is 3-5% (2sigma) for NIST SRM 610 and Nancy 91500 zircon standard, and the U-Pb age data obtained here show good agreement within analytical uncertainties with the previously reported values. Since the observed Pb/U ratio for solid samples is relatively insensitive to laser power and ablation time, optimization of ablation conditions or acquisition parameters no longer needs to be performed on a sample-to-sample basis.

  1. Percutaneous ablation of the gallbladder

    International Nuclear Information System (INIS)

    Saini, S.; Mueller, P.R.; Girard, M.; Lee, M.J.; Goldberg, M.; Brink, J.A.; Flotte, T.J.; Ribiero, R.; Ferrucci, J.T.

    1990-01-01

    This paper examines the feasibility of using Holmium: yttrium-aluminum-garnet (YAG) laser to permanently obliterate the cystic duct and then using chemical sclerosants to ablate the gallbladder mucosa. Percutaneous cholecystostomy was performed in 30 domestic pigs. The cystic duct was cannulated and while the laser fiber was withdrawn at a rate of 0.5 cm/sec, pulsed laser energy (10 Hz) was delivered. Animals were sacrificed immediately (n = 7), at 72 hours (n = 4), and 6 weeks (n = 19). In the 6-week group, gallbladder sclerosis (95% alcohol plus sodium tetradecyl sulfate) was performed in 13 animals immediately after occluding the cystic duct. Control animals were included in each group

  2. Ultrashort-pulse laser ablation of gold thin film targets: Theory and experiment

    International Nuclear Information System (INIS)

    Amoruso, S.; Nedyalkov, N.N.; Wang, X.; Ausanio, G.; Bruzzese, R.; Atanasov, P.A.

    2014-01-01

    Laser ablation of a gold thin film irradiated by ultrashort pulses is studied using molecular-dynamics simulations, and compared with that of a bulk target. A film thickness comparable to the ballistic electron depth in gold (≈ 100 nm) is considered, evidencing a significant change of the temperature spatial profile inside the target material, which eventually influences the material decomposition. Particular emphasis is given to the process of nanoparticle generation. The simulations indicate a more uniform heating of the sample in the case of the thin film, which is accompanied by a more homogeneous size distribution of the nanoparticles produced in the ablation process. An experimental characterization of the ultrashort-pulse ablation process is also carried out. The produced nanoparticles are collected on suitable substrates, and atomic force microscopy analysis of less than one layer deposits is performed. An ≈ 2 × narrowing of the nanoparticles equivalent to spherical diameter size distribution is observed in the case of ablation of the gold thin film, in fairly good agreement with the theoretical predictions. Moreover, interesting changes of the nanoparticle shape are evidenced, which are correlated to the changes in the nanoparticle ablation plume dynamics, as studied by time-gated imaging of its self-emission. Our findings suggest ultrashort-pulse laser ablation of thin films as a viable route to achieve a more uniform nanoparticle size distribution. - Highlights: • Nanoparticle generation at fs laser ablation of Au bulk target and thin film is studied. • The spatial confinement in depth at thin film geometry results in homogeneous heating. • Narrower and more homogeneous particle size distribution is observed for thin film

  3. Capsule physics comparison of National Ignition Facility implosion designs using plastic, high density carbon, and beryllium ablators

    Science.gov (United States)

    Clark, D. S.; Kritcher, A. L.; Yi, S. A.; Zylstra, A. B.; Haan, S. W.; Weber, C. R.

    2018-03-01

    Indirect drive implosion experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] have now tested three different ablator materials: glow discharge polymer plastic, high density carbon, and beryllium. How do these different ablators compare in current and proposed implosion experiments on NIF? What are the relative advantages and disadvantages of each? This paper compares these different ablator options in capsule-only simulations of current NIF experiments and potential future designs. The simulations compare the impact of the capsule fill tube, support tent, and interface surface roughness for each case, as well as all perturbations in combination. According to the simulations, each ablator is impacted by the various perturbation sources differently, and each material poses unique challenges in the pursuit of ignition on NIF.

  4. Effects of ablation energy and post-irradiation on the structure and properties of titanium dioxide nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Guillén, G. García [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); Universidad Autónoma de Nuevo León-CIIDIT, Apodaca, Nuevo León, México (Mexico); Palma, M. I. Mendivil [Centro de Investigación en Materiales Avanzados (CIMAV), Unidad Monterrey, PIIT, Apodaca, Nuevo León, México (Mexico); Avellaneda, D.; Castillo, G.A.; Roy, T.K. Das [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, San Nicolás de los Garza, Nuevo León 66455, México (Mexico); and others

    2017-05-31

    Highlights: • Highlights • TiO{sub 2} nanomaterials were prepared by PLALM. • Characterized these nanomaterials using TEM, XPS, XRD, optical and luminescence measurements. • Morphology of these nanomaterials were dependent on ablation wavelength, fluence and post-irradiation time. • Laser post irradiation modified the size, morphology and structure of these TiO{sub 2} nanomaterials. - Abstract: Nanomaterials of titanium oxide were prepared by pulsed laser ablation of a titanium metal target in distilled water. The ablation was performed at different laser energy (fluence) using a nanosecond pulsed Nd:YAG laser output of 1064 and 532 nm. A post-irradiation of titanium oxide nanocolloids obtained by ablation using 532 nm was carried out to explore its effects on the structure and properties. Analysis of morphology, crystalline phase, elemental composition, chemical state, optical and luminescent properties were performed using Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), UV–-vis absorption spectroscopy and room temperature photoluminescence spectroscopy. It was found that titanium oxide nanomaterial morphologies and optical properties were determined by ablation wavelength and fluence. Further, nanocolloids prepared by 532 nm ablation showed a crystalline phase change by laser post-irradiation. The results showed that pulsed laser ablation in liquid as well as post-irradiation were effective in modifying the final structure and properties of titanium oxide nanocolloids.

  5. Pulmonary sinus cusp mapping and ablation: A new concept and approach for idiopathic right ventricular outflow tract arrhythmias.

    Science.gov (United States)

    Zhang, Jinlin; Tang, Cheng; Zhang, Yonghua; Su, Xi

    2018-01-01

    Right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs) may originate from the pulmonary sinus cusps (PSCs) far more frequently than previously recognized. The purpose of this study was to assess whether mapping and ablation in PSCs might be an appropriate first-choice treatment in unselected patients with idiopathic RVOT VAs. Ninety consecutive patients with VAs of RVOT-type origin were prospectively enrolled at our institution between August 2015 and September 2016. Pulmonary valve (PV) and PSCs were precisely localized by pulmonary arteriography. Activation and pace-mapping were performed in the PSCs and RVOT region below the PV, and ablation was preferentially performed in PSCs. In 81 patients (90%), earliest activation of VAs was found in PSCs, and ablation resulted in elimination of VAs without any additional ablation in the RVOT region underneath the PV. The best pace-map was obtained at successful ablation sites in PSCs in 96.3% of patients. In the remaining 9 patients, final successful ablation sites were in the aortic coronary cusps in 5 and at the lowest and most posterior part of the RVOT in 4. During mean follow-up of 15.2 ± 9.5 months, single procedural success rate was 96.7%. In this single-center, prospective study, a strategy based on PSC mapping and ablation eliminated 90% (81/90) of unselected idiopathic RVOT-type VAs with favorable mid-term effectiveness. Copyright © 2017. Published by Elsevier Inc.

  6. Effect of Non-Equilibrium Surface Thermochemistry in Simulation of Carbon Based Ablators

    Science.gov (United States)

    Chen, Yih-Kanq; Gokcen, Tahir

    2012-01-01

    This study demonstrates that coupling of a material thermal response code and a flow solver using non-equilibrium gas/surface interaction model provides time-accurate solutions for the multidimensional ablation of carbon based charring ablators. The material thermal response code used in this study is the Two-dimensional Implicit Thermal-response and AblatioN Program (TITAN), which predicts charring material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis gas mass conservation, and a three-component decomposition model. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation (DPLR) method. Loose coupling between the material response and flow codes is performed by solving the surface mass balance in DPLR and the surface energy balance in TITAN. Thus, the material surface recession is predicted by finite-rate gas/surface interaction boundary conditions implemented in DPLR, and the surface temperature and pyrolysis gas injection rate are computed in TITAN. Two sets of nonequilibrium gas/surface interaction chemistry between air and the carbon surface developed by Park and Zhluktov, respectively, are studied. Coupled fluid-material response analyses of stagnation tests conducted in NASA Ames Research Center arc-jet facilities are considered. The ablating material used in these arc-jet tests was Phenolic Impregnated Carbon Ablator (PICA). Computational predictions of in-depth material thermal response and surface recession are compared with the experimental measurements for stagnation cold wall heat flux ranging from 107 to 1100 Watts per square centimeter.

  7. Ablation front hydrodynamic instability experiments on Nova

    International Nuclear Information System (INIS)

    Remington, B.A.; Marinak, M.M.; Weber, S.V.; Budil, K.S.; Landen, O.L.; Haan, S.W.; Wallace, R.J.

    1995-01-01

    The x-ray driven ablation front hydrodynamic instability experiments at Nova span 1988-present, and can be divided into three generations. The 1st generation experiments consisted of planar foils with perturbations of the form k = k x imposed on the drive side of the foil. A variety of drive pulse shapes, foil materials, and perturbation wavelengths and amplitudes were investigated, with growth factors of up to 80 being observed. The 2nd generation experiments investigated mode-mode interactions with imposed perturbations corresponding to the superposition of modes. They have done experiments with two-mode and eight-mode foils. In the linear regime, the modes grow independently with their own respective growth rates. In the nonlinear regime, in addition to the higher harmonics of the pre-existing modes, coupled terms k i ± k j occur. The 3rd generation experiments focus on 3D Rayleigh-Taylor growth. They have recently done experiments with an imposed 3D single-mode perturbation of the form k = (k x ,k y ), with k x = k y . In the linear regime, this perturbation grows exponentially with wave vector k = (k x 2 + k y 2 ) 1/2 . In the nonlinear regime, the perturbations evolve into broad bubbles surrounded on four corners by very dense, localized spikes with archways or saddle points in between. Simulations suggest that this 3D square mode grows larger than the corresponding 2D perturbation with the same magnitude wavevector and initial amplitude

  8. Pulmonary oligometastases: Metastasectomy or stereotactic ablative radiotherapy?

    International Nuclear Information System (INIS)

    Widder, Joachim; Klinkenberg, Theo J.; Ubbels, Jan F.; Wiegman, Erwin M.; Groen, Harry J.M.; Langendijk, Johannes A.

    2013-01-01

    Background and purpose: Stereotactic ablative radiotherapy (SABR; or stereotactic body radiotherapy, SBRT) emerges as treatment option for pulmonary oligometastatic disease (OMD), but there are no studies comparing SABR with pulmonary metastasectomy (PME). We analysed consecutive patients referred via a university-hospital based multidisciplinary team. Material and methods: Patients were offered PME as first choice and SABR in case they were considered to be less suitable surgical candidates. Overall survival was the primary endpoint. Secondary endpoints were progression-free-survival, local control of treated metastases, and freedom-from-failure of a local-only treatment strategy without systemic therapy. Results: From 2007 until 2010, 110 patients were treated and analysed (PME, n = 68; SABR, n = 42). Median follow-up time was 43 months (minimally, 25). Estimated overall survival rates at one, three, and five years were 87%, 62%, and 41% for PME, and 98%, 60%, and 49% for SABR, respectively (logrank-test, p = 0.43). Local control at two years was 94% for SABR and 90% for PME. Progression-free survival was 17% at three years, but 43% of the patients still had not failed a local-only treatment strategy. Conclusions: Although SABR was second choice after PME, survival after PME was not better than after SABR. Prospective comparative studies are clearly required to define the role of both, SABR and PME in OMD

  9. Fluoroscopy-guided radiofrequency ablation for small hepatocellular carcinoma: a retrospective comparison with ultrasound-guided ablation

    International Nuclear Information System (INIS)

    Kim, J.; Yoon, C.J.; Seong, N.J.; Jeong, S.-H.; Kim, J.W.

    2015-01-01

    Aim: To compare the therapeutic efficacy of fluoroscopy-guided radiofrequency ablation (F-RFA) and ultrasound-guided RFA (US-RFA) in treatment of small hepatocellular carcinoma (HCC). Materials and methods: Between January 2006 and January 2012, 93 patients with small HCCs underwent percutaneous RFA. In 42 patients with 46 HCCs invisible on US, F-RFA was performed following intra-arterial iodised oil injection (group A). The remaining 51 patients with 58 HCCs received US-RFA (group B). Technical effectiveness, complications, local tumour progression, and patient survival were retrospectively compared between the two groups. Results: Technical effectiveness was achieved in 45 HCCs of group A (97.8%) and 64 HCCs of group B (96.6%; p=0.65). There was no major complication in either group. The 1-, 3-, and 5-year local tumour progression rates were lower in group A than those of group B with marginal significance (0%, 3.7% and 3.7% in group A, and 13%, 13%, and 13% in group B; p=0.05). The 1-, 3-, and 5-year patient survival rates were 100%, 58.3%, and 51.2% (group A), and 82.4%, 54.9%, and 46.1% (group B; p=0.26). Conclusions: F-RFA is a feasible and safe treatment for small HCC invisible on US. Its therapeutic efficacy was comparable with that of US-RFA. -- Highlights: •Fluoroscopy-guided radiofrequency ablation can treat small hepatocellular carcinoma invisible on ultrasonography. •Fluoroscopy-guided radiofrequency ablation can treat small hepatocellular carcinoma with unfavorable location. •Therapeutic efficacy of fluoroscopy-guided radiofrequency ablation is comparable with ultrasound-guided procedure

  10. Observation of the stabilizing effect of a laminated ablator on the ablative Rayleigh-Taylor instability.

    Science.gov (United States)

    Masse, L; Casner, A; Galmiche, D; Huser, G; Liberatore, S; Theobald, M

    2011-05-01

    A laminated ablator is explored as an alternative concept for stabilizing the ablative Rayleigh-Taylor instability which develops in inertial fusion targets. Experiments measuring the growth of the Rayleigh-Taylor instability of laminated planar foils are reported. Consistent with both theory and simulations, a significant reduction of the perturbation growth is experimentally observed for laminated ablators in comparison to what is observed for classical uniform ablators. Such an enhanced hydrodynamic stability opens opportunities for the design of high-gain inertial fusion targets. © 2011 American Physical Society

  11. High Metal Removal Rate Process for Machining Difficult Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Robert; McConnell, Elizabeth

    2016-06-29

    Machining methods across many industries generally require multiple operations to machine and process advanced materials, features with micron precision, and complex shapes. The resulting multiple machining platforms can significantly affect manufacturing cycle time and the precision of the final parts, with a resultant increase in cost and energy consumption. Ultrafast lasers represent a transformative and disruptive technology that removes material with micron precision and in a single step manufacturing process. Such precision results from athermal ablation without modification or damage to the remaining material which is the key differentiator between ultrafast laser technologies and traditional laser technologies or mechanical processes. Athermal ablation without modification or damage to the material eliminates post-processing or multiple manufacturing steps. Combined with the appropriate technology to control the motion of the work piece, ultrafast lasers are excellent candidates to provide breakthrough machining capability for difficult-to-machine materials. At the project onset in early 2012, the project team recognized that substantial effort was necessary to improve the application of ultrafast laser and precise motion control technologies (for micromachining difficult-to-machine materials) to further the aggregate throughput and yield improvements over conventional machining methods. The project described in this report advanced these leading-edge technologies thru the development and verification of two platforms: a hybrid enhanced laser chassis and a multi-application testbed.

  12. Rayleigh-Taylor Instability Evolution in Ablatively Driven Cylindrical Implosions^*,**

    Science.gov (United States)

    Hsing, W. W.

    1996-11-01

    The Rayleigh-Taylor instability is an important limitation in ICF capsule designs. Significant work both theoretically and experimentally has been done to demonstrate the stabilizing effects due to material flow through the unstable region. The experimental verification has been done predominantly in planar geometry. Convergent geometry introduces effects not present in planar geometry such as shell thickening and accelerationless growth of modal amplitudes (e.g. Bell-Plesset growth). Amplitude thresholds for the nonlinear regime are reduced, since the wavelength of a mode m decreases with convergence λ ~ r/m, where r is the radius. We have investigated convergent effects using an imploding cylinder driven by x-ray ablation on the NOVA laser. By doping sections of the cylinder with high-Z materials, in conjunction with x-ray backlighting, we have measured the growth and feedthrough of the perturbations from the ablation front to the inner surface of the cylinder for various initial modes and amplitudes from early time through stagnation. Mode coupling of illumination asymmetries with material perturbations is observed, as well as phase reversal of the perturbations from near the ablation front to the inner surface of the cylinder. Imaging is performed with an x-ray pinhole camera coupled to a gated microchannel plate detector. In collaboration with C. W. Barnes, J. B. Beck, N. Hoffman (LANL), D. Galmiche, A. Richard (CEA/L-V), J. Edwards, P. Graham, B. Thomas (AWE). ^**This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

  13. Thermal ablation of liver metastases. Current status and perspectives; Thermische Ablation von Lebermetastasen. Aktueller Stand und Perspektiven

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, T.; Mack, M.; Straub, R.; Zangos, S.; Woitaschek, D.; Eichler, K.; Engelmann, K. [Inst. fuer Diagnostische und Interventionelle Radiologie, Univ. Frankfurt (Germany)

    2001-01-01

    Purpose. To present thermal ablation of liver metastases via laser induced thermotherapy. Material and methods. Different technical procedures of thermal ablation and online monitoring are used, as there are the MR-guided laser induced thermotherapy (LITT) and the radiofrequency ablation thermotherapy (RF). Results. In a prospective non randomized study 606 patients with liver metastases were treated via MR-guided laserinduced thermotherapy. Inclusion criteria were the exclusion of extrahepatic tumor spread and a number of metastases lower than 5 and a size lower than 50 mm in diameter. The local tumor control rate in the 3 month and 6 month control study was 98,3%, the complication rate 3,5% (clinically relevant: 1,2%). The mean survival rate was 40,9 months for all patients with liver metastases without statistically relevant differences for various primaries, like colorectal carcinoma, breast cancer and various other tumors. Results for radiofrequency are so far limited with incidence of a higher local tumor recurrence rate versus LITT. Conclusion. MR-guided LITT results in a high local tumor control rate with improved survival. (orig.) [German] Zielsetzung. Vorstellung der thermischen Ablation von Lebermetastasen mittels laserinduzierter Thermotherapie (LITT). Material und Methodik. Verschiedene technische Verfahren der Ablation sowie 'Online-monitoring-Verfahren' werden vorgestellt. Derzeit gaengige Verfahren der Thermoablation stellen die MR-gesteuerte laserinduzierte Thermotherapie (LITT) sowie die Radiofrequenzablation (RF) dar. Ergebnisse. Im Rahmen einer prospektiven, nichtrandomisierten Studie wurden bislang 606 Patienten mit Lebermetastasen unterschiedlicher Primaertumoren mittels LITT perkutan therapiert. Die erzielte lokale Tumorkontrolle in der 3- bzw. 6-Monatskontrolle betrug dabei 98,3%, die Rate klinisch nicht relevanter Komplikationen 3,5%, die Rate klinisch relevanter Komplikationen 1,2%. Die mittlere Ueberlebensrate fuer das

  14. Thoracoscopic sympathectomy ganglia ablation in the management ...

    African Journals Online (AJOL)

    Thoracoscopic sympathectomy ganglia ablation in the management of palmer hyperhidrosis: A decade experience in a single institution. D Kravarusic, E Freud. Abstract. Background: Hyperhidrosis can cause significant professional and social handicaps. Surgery is the preferred treatment modality for hyperhidrosis.

  15. Anatomic Twist to a Straightforward Ablation

    Directory of Open Access Journals (Sweden)

    Mandeep Singh Randhawa, MD

    2013-03-01

    Full Text Available Atrioventricular (AV junction ablation for treatment of refractory atrial fibrillation is a well defined, standardized procedure and the simplest of commonly performed radiofrequency ablations in the field of cardiac electrophysiology. We report successful AV junction ablation using an inferior approach in a case of inferior vena cava interruption. Inability during the procedure to initially pass the ablation catheter into the right ventricle, combined with low amplitude electrograms, led to suspicion of an anatomic abnormality. This was determined to be a heterotaxy syndrome with inferior vena cava interruption and azygos continuation, draining in turn into the superior vena cava. Advancing Schwartz right 0 (SRO sheath through the venous abnormality into the right atrium allowed adequate catheter stability to successfully induce complete AV block with radiofrequency energy.

  16. Simple spherical ablative-implosion model

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, F.J.; Steele, J.T.; Larsen, J.T.

    1980-06-23

    A simple model of the ablative implosion of a high-aspect-ratio (shell radius to shell thickness ratio) spherical shell is described. The model is similar in spirit to Rosenbluth's snowplow model. The scaling of the implosion time was determined in terms of the ablation pressure and the shell parameters such as diameter, wall thickness, and shell density, and compared these to complete hydrodynamic code calculations. The energy transfer efficiency from ablation pressure to shell implosion kinetic energy was examined and found to be very efficient. It may be possible to attach a simple heat-transport calculation to our implosion model to describe the laser-driven ablation-implosion process. The model may be useful for determining other energy driven (e.g., ion beam) implosion scaling.

  17. Microwave Tissue Ablation: Biophysics, Technology and Applications

    Science.gov (United States)

    2010-01-01

    Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias and other medical conditions. During treatment, microwaves are applied directly to tissues to produce rapid temperature elevations sufficient to produce immediate coagulative necrosis. The engineering design criteria for each application differ, with individual consideration for factors such as desired ablation zone size, treatment duration, and procedural invasiveness. Recent technological developments in applicator cooling, power control and system optimization for specific applications promise to increase the utilization of microwave ablation in the future. This article will review the basic biophysics of microwave tissue heating, provide an overview of the design and operation of current equipment, and outline areas for future research for microwave ablation. PMID:21175404

  18. Selective Laser Ablation and Melting, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this project Advratech will develop a new additive manufacturing (AM) process called Selective Laser Ablation and Melting (SLAM). The key innovation in this...

  19. Introduction to Laser Ablation Video Supplement.

    Science.gov (United States)

    Barnett, Gene H; Sloan, Andrew E; Tatsui, Claudio E

    2018-04-01

    Laser ablation (also known as laser interstitial thermal therapy [LITT]) has emerged as an important new technology for treating various disorders of the brain and spine. As with any new or emerging technology, there is a learning curve for its optimal use, and video tutorials can be important learning tools to help bridge gaps in knowledge for those who wish to become more familiar with laser ablation. In this special supplement to Neurosurgical Focus, videos illustrate laser ablation's use in the treatment of epilepsy and failed radiosurgery, as well as technical aspects of performing these procedures in eloquent brain and in the spine. We hope that these videos will enable you to enhance your understanding of the evolving use of laser ablation for disorders of the brain or spine. It is the editors' sincere hope that this will be helpful either in your own practice or in determining whether to refer to a neurosurgical colleague experienced in this field.

  20. Usefulness of administration of SPIO prior to RF ablation for evaluation of the therapeutic effect: An experimental study using miniature pigs

    International Nuclear Information System (INIS)

    Kakite, Suguru; Fujii, Shinya; Nakamatsu, Satoru; Kanasaki, Yoshiko; Yamashita, Eijirou; Matsusue, Eiji; Ouchi, Yasufumi; Kaminou, Toshio; Tokunaga, Shiho; Koda, Masahiko; Ogawa, Toshihide

    2011-01-01

    Objectives: To evaluate the usefulness of administration of superparamagnetic iron oxide (SPIO) and magnetic resonance (MR) imaging for assessing the efficacy of radiofrequency (RF) liver ablation. Material and methods: Using a protocol approved by the animal research committee of our university, nine RF liver ablations were performed in three miniature pigs. Six ablations were performed after administration of SPIO in two pigs (group A). Three ablations were performed in the other pig without administration of SPIO (group B). All pigs were sacrificed 4 days after the procedure. Harvested livers were scanned with a 1.5 T MR system before and after fixation with 10% buffered formalin, and MR images were precisely compared with histological specimens. Results: There were no histological differences between the two groups. All ablated liver lesions showed coagulation necrosis at the external layer. There were no viable cells inside the coagulation necrosis. All ablated lesions had a hypointense rim on fast low angle shot (FLASH) images. The rims of group A were thicker than those of group B. The rims of group B corresponded histologically to congestion and hemorrhagic necrosis area. The rims of the group A corresponded to hemorrhagic necrosis and coagulation necrosis areas. In group A, the hypointense rim reflected necrotic Kupffer cells that took up SPIO before RF liver ablation. Conclusion: Administration of SPIO made it possible to precisely evaluate ablated liver parenchyma by hypointense rim on FLASH images. This method is helpful for the evaluation of safety margin after RF ablation for liver tumors.

  1. ROLE OF RADIOFREQUENCY ABLATION IN ADENOMA SEBACEUM

    Directory of Open Access Journals (Sweden)

    Ch. Madh

    2016-03-01

    Full Text Available Adenoma sebaceum, pathognomonic of tuberous sclerosis, are tiny angiofibromas which commonly occur over central part of face. Recurrence after treatment is common and hence a need for inexpensive, safe and efficient treatment is required. Radiofrequency ablation is a safe and an economical procedure and has been known to cause less scarring with good aesthetic results compared to other ablative methods such as electrocautery.

  2. Experimental studies and simulations of hydrogen pellet ablation in the stellarator TJ-II

    Science.gov (United States)

    Panadero, N.; McCarthy, K. J.; Koechl, F.; Baldzuhn, J.; Velasco, J. L.; Combs, S. K.; de la Cal, E.; García, R.; Hernández Sánchez, J.; Silvagni, D.; Turkin, Y.; TJ-II team; W7-X team

    2018-02-01

    Plasma core fuelling is a key issue for the development of steady-state scenarios in large magnetically-confined fusion devices, in particular for helical-type machines. At present, cryogenic pellet injection is the most promising technique for efficient fuelling. Here, pellet ablation and fuelling efficiency experiments, using a compact pellet injector, are carried out in electron cyclotron resonance and neutral beam injection heated plasmas of the stellarator TJ-II. Ablation profiles are reconstructed from light emissions collected by silicon photodiodes and a fast-frame camera system, under the assumptions that such emissions are loosely related to the ablation rate and that pellet radial acceleration is negligible. In addition, pellet particle deposition and fuelling efficiency are determined using density profiles provided by a Thomson scattering system. Furthermore, experimental results are compared with ablation and deposition profiles provided by the HPI2 pellet code, which is adapted here for the stellarators Wendelstein 7-X (W7-X) and TJ-II. Finally, the HPI2 code is used to simulate ablation and deposition profiles for pellets of different sizes and velocities injected into relevant W7-X plasma scenarios, while estimating the plasmoid drift and the fuelling efficiency of injections made from two W7-X ports.

  3. Lightning Strike Ablation Damage Characteristic Analysis for Carbon Fiber/Epoxy Composite Laminate with Fastener

    Science.gov (United States)

    Yin, J. J.; Li, S. L.; Yao, X. L.; Chang, F.; Li, L. K.; Zhang, X. H.

    2016-08-01

    In order to analyze the lightning strike ablation damage characteristic of composite laminate with fastener, based on the energy-balance relationship in lightning strike, mathematical analysis model of ablation damage of composite laminate with fastener was constructed. According to the model, an effective three dimensional thermal-electrical coupling analysis finite element model of composite laminate with fastener suffered from lightning current was established based on ABAQUS, and lightning strike ablation damage characteristic was analyzed. Analytical results reveal that lightning current could conduct through the thickness direction of the laminate due to the existence of metallic fastener, and then distribute to all layers, finally conducted in-the-plane of each layer, conductive ability of different layup orientations depend on potential distribution and in-the-plane electrical conductivity along potential gradient declining direction; different potential boundaries correspond to different potential distribution in each layer, and result in conductive ability of different layup orientations was changed, then caused different lightning strike ablation damage distribution. According to the investigation in this paper, we can recognize the lightning strike ablation damage characteristic of composite laminate with fastener qualitatively.

  4. Ablation of supraventricular arrhythmias in adult congenital heart disease: A contemporary review.

    Science.gov (United States)

    Combes, Nicolas; Derval, Nicolas; Hascoët, Sebastien; Zhao, Alexandre; Amet, Denis; Le Bloa, Mathieu; Maltret, Alice; Heitz, François; Thambo, Jean-Benoit; Marijon, Eloi

    2017-05-01

    Supraventricular arrhythmias are an important and increasing cause of morbidity in adults with congenital heart disease, requiring specific management strategies. Pharmacological treatment has limited efficacy, and is often associated with some side-effects. Major improvements in catheter ablation techniques have opened new opportunities to better understand underlying mechanisms of supraventricular arrhythmias, offer better therapy, and eventually improve symptoms and quality of life in these patients. An array of tools and techniques are necessary to access relevant anatomical areas to address the arrhythmogenic substrate. The mechanism of these arrhythmias is mostly related to macroreentry around surgical scars or cavotricuspid isthmus-dependent flutter. The efficacy of catheter ablation is mainly dependent on the underlying congenital heart condition, with the most complex cases typically being associated with atrial switch and Fontan surgeries. Although relatively high rates of recurrence are seen after a single procedure, additional attempts are often helpful to decrease recurrences and improve symptoms. Catheter ablation in such patients continues to present many unique challenges that are best addressed by experienced multidisciplinary teams, at centres equipped with the proper catheters, imaging capabilities, mapping systems and support staff needed to maximize safety and success. Consensus indications have emerged that often support ablation as first-line therapy in these patients. In this comprehensive review, we aim to describe the specific issues associated with ablation of supraventricular arrhythmias in adult congenital heart disease, assess the results in contemporary practice and, finally, review the current indications. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. Final Report: Part 1. In-Place Filter Testing Instrument for Nuclear Material Containers. Part 2. Canister Filter Test Standards for Aerosol Capture Rates.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Austin Douglas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Runnels, Joel T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reeves, Kirk Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-02

    A portable instrument has been developed to assess the functionality of filter sand o-rings on nuclear material storage canisters, without requiring removal of the canister lid. Additionally, a set of fifteen filter standards were procured for verifying aerosol leakage and pressure drop measurements in the Los Alamos Filter Test System. The US Department of Energy uses several thousand canisters for storing nuclear material in different chemical and physical forms. Specialized filters are installed into canister lids to allow gases to escape, and to maintain an internal ambient pressure while containing radioactive contaminants. Diagnosing the condition of container filters and canister integrity is important to ensure worker and public safety and for determining the handling requirements of legacy apparatus. This report describes the In-Place-Filter-Tester, the Instrument Development Plan and the Instrument Operating Method that were developed at the Los Alamos National Laboratory to determine the “as found” condition of unopened storage canisters. The Instrument Operating Method provides instructions for future evaluations of as-found canisters packaged with nuclear material. Customized stainless steel canister interfaces were developed for pressure-port access and to apply a suction clamping force for the interface. These are compatible with selected Hagan-style and SAVY-4000 storage canisters that were purchased from NFT (Nuclear Filter Technology, Golden, CO). Two instruments were developed for this effort: an initial Los Alamos POC (Proof-of-Concept) unit and the final Los Alamos IPFT system. The Los Alamos POC was used to create the Instrument Development Plan: (1) to determine the air flow and pressure characteristics associated with canister filter clogging, and (2) to test simulated configurations that mimicked canister leakage paths. The canister leakage scenarios included quantifying: (A) air leakage due to foreign material (i.e. dust and hair

  6. Distribution of bacterial contamination in non-sterile pharmaceutical materials and assessment of its risk to the health of the final consumers quantitatively

    Directory of Open Access Journals (Sweden)

    Mostafa Essam Eissa

    2016-09-01

    Full Text Available Bacterial contamination control in pharmaceutical products is a critical aspect in the field of drug manufacturing industry due to the encountered risk to the patients' health and possibly their life. The application of commercial bacterial identification system is crucial to identify the type of contamination and its source to anticipate the impact of bioburden on the products and setting corrective and preventive actions. During the period of one year, random samples from raw materials and final products were tested according to United States Pharmacopeia, and those that showed suspect results for specified microorganisms and/or out-of-specification limits or showed out-of-trend results were subjected to further identification by using miniaturized biochemical identification system after performing Gram stain. From the total bacterial isolates of the investigated products, more than 60% were primarily belonging to Micrococcaceae 16.98% (empty hard gelatin capsules, Enterobacteriaceae 18.86% (vaginal cream applicator, plastic caps for bottles, Sorbitol solution, finished hard gelatin capsule product, topical cream and oral suspension and Bacillaceae 24.53% (Talc powder, liquid oral preparation and finished hard gelatin capsule product. Gram Positive and Negative samples were 56.60% and 41.51% respectively from the total investigated sample products and materials. Finished pharmaceutical products constituted 53.33% and 68.18% from Gram-positive and Gram-negative microorganisms respectively. An approach to quantitative risk assessment for pharmaceutical products was conducted on selected medicinal items and showed that Enterobacteriaceae followed by Burkholderiaceae contributed by more than 80% to the major hazard that could be delivered to patients through drugs. The applied risk can be used as a milestone for setting goals by pharmaceutical companies to improve the safety of medicinal products microbiologically and to identify the major sources

  7. Thermal Ablation of Colorectal Lung Metastases: Retrospective Comparison Among Laser-Induced Thermotherapy, Radiofrequency Ablation, and Microwave Ablation.

    Science.gov (United States)

    Vogl, Thomas J; Eckert, Romina; Naguib, Nagy N N; Beeres, Martin; Gruber-Rouh, Tatjana; Nour-Eldin, Nour-Eldin A

    2016-12-01

    The purpose of this study is to retrospectively evaluate local tumor control, time to tumor progression, and survival rates among patients with lung metastatic colorectal cancer who have undergone ablation therapy performed using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA), or microwave ablation (MWA). Data for this retrospective study were collected from 231 CT-guided ablation sessions performed for 109 patients (71 men and 38 women; mean [± SD] age, 68.6 ± 11.2 years; range, 34-94 years) from May 2000 to May 2014. Twenty-one patients underwent LITT (31 ablations), 41 patients underwent RFA (75 ablations), and 47 patients underwent MWA (125 ablations). CT scans were acquired 24 hours after each therapy session and at follow-up visits occurring at 3, 6, 12, 18, and 24 months after ablation. Survival rates were calculated from the time of the first ablation session, with the use of Kaplan-Meier and log-rank tests. Changes in the volume of the ablated lesions were measured using the Kruskal-Wallis method. Local tumor control was achieved in 17 of 25 lesions (68.0%) treated with LITT, 45 of 65 lesions (69.2%) treated with RFA, and 91 of 103 lesions (88.3%) treated with MWA. Statistically significant differences were noted when MWA was compared with LITT at 18 months after ablation (p = 0.01) and when MWA was compared with RFA at 6 months (p = 0.004) and 18 months (p = 0.01) after ablation. The overall median time to local tumor progression was 7.6 months. The median time to local tumor progression was 10.4 months for lesions treated with LITT, 7.2 months for lesions treated with RFA, and 7.5 months for lesions treated with MWA, with no statistically significant difference noted. New pulmonary metastases developed in 47.6% of patients treated with LITT, in 51.2% of patients treated with RFA, and in 53.2% of patients treated with MWA. According to the Kaplan-Meier test, median survival was 22.1 months for patients who underwent LITT, 24.2 months

  8. Ovulation synchrony after follicle ablation in mares.

    Science.gov (United States)

    Bergfelt, D R; Adams, G P

    2000-01-01

    Two experiments were performed to determine the efficacy of ultrasound-guided transvaginal follicle ablation for synchronizing ovarian function in mares. The experiments were initiated at random stages of the oestrous cycle in control (nonablated) and follicle-ablated mares. On day 0, all follicles > or =10 mm in diameter were punctured, aspirated and curettaged in ablated mares, and, on day 4, two doses of PGF2alpha were administered with a 12 h interval between the doses to both ablated and nonablated (control) mares. In Expt 1, hCG was administered to the ablated mares on the first or second day after the largest follicle was > or =30 mm in diameter. In Expt 2, hCG was administered to ablated mares 6 days after PGF2alpha administration, at which time the largest follicle was expected to be > or =30 mm in diameter. FSH concentrations increased initially and decreased subsequently in the ablated mares, and the ablation-induced wave (first detection of a follicle > or =10 mm in diameter) was observed 1.9 days after ablation and was synchronous (1-3 days) in 90% of mares. In both Expts 1 and 2, the uniformity of follicular wave emergence among follicle-ablated mares resulted in significantly better synchrony of ovulation after PGF2alpha administration compared with that of control mares. The variation in the interval from PGF2alpha administration to ovulation in ablated mares was reduced further by hCG administration. In the ablation + hCG groups, ovulation synchrony occurred 6-10 days after PGF2alpha administration in Expt 1 (13/16, 81%) and 7-8 days after PGF2alpha administration in Expt 2 (7/8, 88%). The extended period of ovulation in Expt 1 compared with that of Expt 2 (5 versus 2 days) was inherent in the experimental design, as hCG was not administered in Expt 1 until the largest follicle reached > or =30 mm in diameter, whereas in Expt 2 the experimental design was modified such that hCG was administered 6 days after PGF2alpha administration. As a result, in

  9. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Stephen

    2014-08-31

    Uranium-containing and thorium-containing compounds have been produced using a laser ablation source. Spectral transitions from these compounds in the 6 GHz to 18 GHz frequency region have been recorded using advanced techniques in Fourier transform microwave spectroscopy. The pure rotational spectrum of thorium (II) oxide is particularly strong and rotational transitions have been observed in highly excited vibrational states. These measurements have allowed a further characterization of the molecules potential energy well.

  10. Characterization of a source of carbon particles produced by laser ablation and used for the calibration of erosion measurement made by spectroscopy in a tokamak

    International Nuclear Information System (INIS)

    Naiim Habib, M.

    2011-12-01

    In a tokamak, plasma-wall interactions lead to the erosion of plasma facing components, which can be detrimental to plasma operation and to the safety of the tokamak. In order to fulfill the safety requirements imposed to the ITER project, it is necessary to monitor the amount of eroded material. Optical emission spectroscopy in the visible range is traditionally used to measure particle fluxes from the wall to the plasma. These measurements are done thanks to a collisional radiative model based on atomic physics data. However, these data don't take into account the observation geometry of the spectroscopic diagnostic, and suffer from relatively large uncertainties. Furthermore, transport, deposition and re-erosion phenomena, as well as the evolution of the transmission or the reflection of optical components can lead to an incorrect estimation of the amount of effectively eroded material. An in situ calibration technique, which consists in injecting by laser a known carbon particle source in the line of sight of the spectroscopic diagnostic during plasma operation, is proposed. The experimental study of laser ablation of carbon allowed to determine the optimal conditions for the constitution of this source, and to characterise the ablated species. These experiments are completed by a modelling of the emission spectrum of the laser induced plasma, in order to obtain information on its ionisation degree. Finally, results of the first validation experiments realised in the German TEXTOR tokamak are presented and discussed. (author)

  11. PREFACE AND CONFERENCE INFORMATION: Eighth International Conference on Laser Ablation

    Science.gov (United States)

    Hess, Wayne P.; Herman, Peter R.; Bäuerle, Dieter; Koinuma, Hideomi

    2007-04-01

    Laser ablation encompasses a wide range of delicate to extreme light interactions with matter that present considerably challenging problems for scientists to study and understand. At the same time, laser ablation also represents a basic process of significant commercial importance in laser material processing—defining a multi-billion dollar industry today. These topics were widely addressed at the 8th International Conference on Laser Ablation (COLA), held in Banff, Canada on 11-16 September 2005. The meeting took place amongst the majestic and natural beauty of the Canadian Rocky Mountains at The Banff Centre, where delegates enjoyed many inspiring presentations and discussions in a unique campus learning environment. The conference brought together world leading scientists, students and industry representatives to examine the basic science of laser ablation and improve our understanding of the many physical, chemical and/or biological processes driven by the laser. The multi-disciplinary research presented at the meeting underlies some of our most important trends at the forefront of science and technology today that are represented in the papers collected in this volume. Here you will find new processes that are producing novel types of nanostructures and nano-materials with unusual and promising properties. Laser processes are described for delicately manipulating living cells or modifying their internal structure with unprecedented degrees of control and precision. Learn about short-pulse lasers that are driving extreme physical processes on record-fast time scales and opening new directions from material processing applications. The conference papers further highlight forefront application areas in pulsed laser deposition, nanoscience, analytical methods, materials, and microprocessing applications. Laser ablation continues to grow and evolve, touching forefront areas in science and driving new technological trends in laser processing applications. Please

  12. Incidence and types of complications after ablative oral cancer surgery with primary microvascular free flap reconstruction

    NARCIS (Netherlands)

    Lodders, J.N.; Parmar, S.; Stienen, N.L.M.; Martin, T.J.; Karagozoglu, K.H.; Heymans, M.W.; Nandra, B.; Forouzanfar, T.

    2015-01-01

    BACKGROUND: The aims of the study were 1) to evaluate the incidence and types of postoperative complications after ablative oral cancer surgery with primary free flap reconstruction and 2) identify prognostic variables for postoperative complications. MATERIAL AND METHODS: Desired data was retrieved

  13. Incidence and types of complications after ablative oral cancer surgery with primary microvascular free flap reconstruction

    NARCIS (Netherlands)

    Lodders, J.N.; Parmar, S.; Stienen, N.-L.M.; Martin, T.J.; Karagozoglu, K.H.; Heymans, M.W.; Nandra, B.; Forouzanfar, T.

    2015-01-01

    Background: The aims of the study were 1) to evaluate the incidence and types of postoperative complications after ablative oral cancer surgery with primary free flap reconstruction and 2) identify prognostic variables for postoperative complications. Material and Methods: Desired data was retrieved

  14. Design and Laboratory Validation of a Capacitive Sensor for Measuring the Recession of Thin-Layered Ablator

    Science.gov (United States)

    Noffz, Gregory K.; Bowman, Michael P.

    1996-01-01

    Flight vehicles are typically instrumented with subsurface thermocouples to estimate heat transfer at the surface using inverse analysis procedures. If the vehicle has an ablating heat shield, however, temperature time histories from subsurface thermocouples no longer provide enough information to estimate heat flux at the surface. In this situation, the geometry changes and thermal energy leaves the surface in the form of ablation products. The ablation rate is required to estimate heat transfer to the surface. A new concept for a capacitive sensor has been developed to measure ablator depth using the ablator's dielectric effect on a capacitor's fringe region. Relying on the capacitor's fringe region enables the gage to be flush mounted in the vehicle's permanent structure and not intrude into the ablative heat shield applied over the gage. This sensor's design allows nonintrusive measurement of the thickness of dielectric materials, in particular, the recession rates of low-temperature ablators applied in thin (0.020 to 0.060 in. (0.05 to 0.15 mm)) layers. Twenty capacitive gages with 13 different sensing element geometries were designed, fabricated, and tested. A two-dimensional finite-element analysis was performed on several candidate geometries. Calibration procedures using ablator-simulating shims are described. A one-to-one correspondence between system output and dielectric material thickness was observed out to a thickness of 0.055 in. (1.4 mm) for a material with a permittivity about three times that of air or vacuum. A novel method of monitoring the change in sensor capacitance was developed. This technical memorandum suggests further improvements in gage design and fabrication techniques.

  15. Percutaneous Irreversible Electroporation Lung Ablation: Preliminary Results in a Porcine Model

    International Nuclear Information System (INIS)

    Deodhar, Ajita; Monette, Sébastien; Single, Gordon W.; Hamilton, William C.; Thornton, Raymond H.; Sofocleous, Constantinos T.; Maybody, Majid; Solomon, Stephen B.

    2011-01-01

    Objective: Irreversible electroporation (IRE) uses direct electrical pulses to create permanent “pores” in cell membranes to cause cell death. In contrast to conventional modalities, IRE has a nonthermal mechanism of action. Our objective was to study the histopathological and imaging features of IRE in normal swine lung. Materials and Methods: Eleven female swine were studied for hyperacute (8 h), acute (24 h), subacute (96 h), and chronic (3 week) effects of IRE ablation in lung. Paired unipolar IRE applicators were placed under computed tomography (CT) guidance. Some applicators were deliberately positioned near bronchovascular structures. IRE pulse delivery was synchronized with the cardiac rhythm only when ablation was performed within 2 cm of the heart. Contrast-enhanced CT scan was performed immediately before and after IRE and at 1 and 3 weeks after IRE ablation. Representative tissue was stained with hematoxylin and eosin for histopathology. Results: Twenty-five ablations were created: ten hyperacute, four acute, and three subacute ablations showed alveolar edema and necrosis with necrosis of bronchial, bronchiolar, and vascular epithelium. Bronchovascular architecture was maintained. Chronic ablations showed bronchiolitis obliterans and alveolar interstitial fibrosis. Immediate post-procedure CT images showed linear or patchy density along the applicator tract. At 1 week, there was consolidation that resolved partially or completely by 3 weeks. Pneumothorax requiring chest tube developed in two animals; no significant cardiac arrhythmias were noted. Conclusion: Our preliminary porcine study demonstrates the nonthermal and extracellular matrix sparing mechanism of action of IRE. IRE is a potential alternative to thermal ablative modalities.

  16. Final environmental assessment and Finding-of-No-Significant-Impact - drum storage facility for interim storage of materials generated by environmental restoration operations

    International Nuclear Information System (INIS)

    1994-09-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-0995, for the construction and operation of a drum storage facility at Rocky Flats Environmental Technology Site, Golden, Colorado. The proposal for construction of the facility was generated in response to current and anticipated future needs for interim storage of waste materials generated by environmental restoration operations. A public meeting was held on July 20, 1994, at which the scope and analyses of the EA were presented. The scope of the EA included evaluation of alternative methods of storage, including no action. A comment period from July 5, 1994 through August 4, 1994, was provided to the public and the State of Colorado to submit written comment on the EA. No written comments were received regarding this proposed action, therefore no comment response is included in the Final EA. Based on the analyses in the EA, DOE has determined that the proposed action would not significantly affect the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, preparation of an Environmental Impact Statement is not required and the Department is issuing this Finding of No Significant Impact

  17. NERI FINAL TECHNICAL REPORT, DE-FC07-O5ID14647, OPTIMIZATION OF OXIDE COMPOUNDS FOR ADVANCED INERT MATRIX MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    PI: JUAN C. NINO, ASSOCIATE PROFESSOR

    2009-01-11

    In order to reduce the current excesses of plutonium (both weapon grade and reactor grade) and other transuranium elements, a concept of inert matrix fuel (IMF) has been proposed for an uranium free transmutation of fissile actinides which excludes continuous uranium-plutonium conversion in thermal reactors and advanced systems. Magnesium oxide (MgO) is a promising candidate for inert matrix (IM) materials due to its high melting point (2827 C), high thermal conductivity (13 W/K {center_dot} m at 1000 C), good neutronic properties, and irradiation stability However, MgO reacts with water and hydrates easily, which prevents it from being used in light water reactors (LWRs) as an IM. To improve the hydration resistance of MgO-based inert matrix materials, Medvedev and coworkers have recently investigated the introduction of a secondary phase that acts as a hydration barrier. An MgO-ZrO{sub 2} composite was specifically studied and the results showed that the composite exhibited improved hydration resistance than pure MgO. However, ZrO{sub 2} is insoluble in most acids except HF, which is undesirable for fuel reprocessing. M