bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mcc Corrosion Tests at Reference Testing Conditions for A27 Cast steel in Hanford Ground Water
Authors: Merz M.D. , Gerber F. , Wang R. 
Published: June 2019

AbstractThe Materials Characterization Center (MCC) at Pacific Northwest Lab- oratory is performing three kinds of corrosion tests for the Basalt Waste Isolation Project (BWIP) to establish the interlaboratory reproducibility and uncertainty of corrosion rates of container materials for high-level nuclear waste. The three types of corrosion tests were selected to address two distinct conditions that are expected in a repository constructed in basalt. An air/steam test is designed to address corrosion during the operational period and static pressure vessel and flowby tests are designed to address corrosion under conditions that bound the condi ring the post-closure period of the repository.The results of tests at reference testing conditions, which were defined to facilitate interlaboratory comparison of data, are presented. Data are reported for the BWIP/MCC-105.5 Air/Steam Test, BWIP/MCC-105.1 Static Pressure Vessel, and BWIP/MC-105.4 Flowby Test. In those cases where data are available from a second laboratory, a statistical analysis of interlaboratory results is reported and expected confidence intervals for mean corrosion rates are given. Other statistical treatment of data include analyses of the effects of vessel-to-vessel variations, test capsule variations for the flowby test, and oven-to-oven variations for air/steam tests.
Statistics of Pit Initiation: Analysis of Current Transients During Passive Film Breakdown
Authors: Bertocci Ugo , Leigh S. , Orden A. C. Van , Yang G. 
Published: June 2019

AbstractDuring the incubation period preceding pitting, current fluctuations indicate the beginning of the breakdown of the passive film. The charac- teristics of these current transients are being examined as a possible way to predict pitting. Stochastic models applied to the breakdown process have been proposed, and in order to test how well they account for the experi- mental results, various forms of processing of the current vs. time records are necessary. This paper describes the experimental data-taking methods, the processing routines so far developed for the statistical analysis of the data, and compares the experimental results with computer simulations based on a stochastic model.
The Theoretical Evaluation of Localised Corrosion in Radioactive Waste Canisters.
Authors: Sharland S.M. 
Published: June 2019

AbstractUnder repository conditions, it is likely that radioactive waste canisters will be subjected to both uniform and localised corrosion. Localised corrosion can take many forms depending on the precise physical and chemical environment of the metal at the time of attack, but generally the rates of penetration are much greater than those associated with uniform corrosion. The most likely forms under aerated repository conditions are pitting and crevice corrosion. To ensure adequate radionuclide containment an allowance for these rates must be included in the final canister dimensions. It is considered the best way to predict long term penetration rates is to develop mathematical models, which include all the physical and chemical processes necessary to describe the system and use experimentally determined input parameters relating to these processes. These models must then draw on further experimental data for validation over short timescales. In this paper, we discuss several techniques of modelling long term pit propagation in waste canisters. The complexity of the problem has lead to a number of physical and chemical approximations in the modelling. We investigate the applicability and ranges of validity of several of the more common approximations, both in our own models and in the literature, and compare the predictions with experimental pit growth rates. An investigatation of the sensitivity of the models to the various empirical input parameters indicates which need to be determined most accurately.
Solubility Modelling of Cements: Implications for Radioactive Waste Immobilisation.
Authors: Glasser F.P. , Macphee D.E. , Lachowski E.E. 
Published: June 2019

AbstractThe suitability of cement matrices for the long-term immobilisation of radionuclides cannot be predicted from short-term experimental data alone, because the chemical properties of cementitious systems change continuously over the repository lifetime. To model such changes is complex, so a stepwise approach has been adopted. A chemically simplified model for the solubility and compositional properties of calcium silicate hydrate gels in the system CaO-SiO2 -H20 was previously developed but has now been extended and improved and is applicable to gels in the wider composition range 0.8 < Ca/Si < 1.7. The effects of silicate speciation in aqueous solution on the formation of the solid phase have been more fully considered and the dissolution equilibrium has been revised. Solubility products and free energies of C-S-H formation have been evaluated and predictive applications of the model are discussed.
A Structured Programme of Research into the Chemical Aspects of Radioactive Waste Disposal
Authors: Read D. , Krol A.A. , Thompson B.G.J. 
Published: June 2019

AbstractThe UK Department of the Environment (DOE) is developing an independent capability to assess proposals made by the nuclear industry for the underground disposal of low and intermediate level radioactive waste. Modelling chemical processes forms an integral part of the underlying DOE research programme which includes the development of probabilistic risk assessment codes, more detailed deterministic models and supporting field and laboratory studies, in a co-ordinated, hierarchical approach. This paper summarises the results of a survey on the current status of this and related research, with emphasis on the assessment of a safety case for shallow land disposal of low level waste in about two years time. Shortcomings in existing work are identified, and a structured programme for future research described.
Biodegradation Testing of Bitumen
Authors: Barletta R. E. , Bowerman B. S. , Davis R. E. , Shea C. E. 
Published: June 2019

AbstractAn estimate of the rate of biodegradation of bituminous material is necessary to predict the long-term stability of low- and intermediate- level waste solidified using bitumen. Data from a series of scoping experiments have been analyzed to determine the rate of degradation of blown bitumen samples under a variety of conditions. Among the variables investigated were the effect of soil type, moisture, sample surface area and microbial strain. The rate of degradation was measured by monitoring metabolic CO2release. Using this data it was found that, for degradation in soil, a mean rate of 5.5 × 10−4 cm/yr represented all data to within a factor of about two. This mean rate is nearly that for distilled bitumen samples measured by other workers.
Waste Glass Leaching: Chemistry and Kinetics
Authors: Bunker Bruce C. 
Published: June 2019

AbstractNuclear waste glass leaching has been studied extensively during the past ten years. Although much has been learned concerning the kinetics and mechanisms of glass dissolution, it does not appear that accurate predictions can yet be made concerning the release kinetics for specific elements from a given glass as a function of environmental conditions. In order to reliably predict elemental release rates, one needs to know: 1) how a given element is incorporated into the glass structure, 2) how specific sites in the glass react with water, 3) how the composition and reactivity of the leachate influence glass reactivity, 4) how the structure and reactivity of the glass changes in surface alteration layers, and 5) how glass dissolution modifies the chemistry of the leachate. At our current level of understanding, we are only able to make qualitative predictions concerning each of the above factors which allow us to make “order of magnitude” or “upper limit” predictions for radionuclide release rates.
Diffusion Mecflanisms of Srrontium and Cesium in Compacrtd Sodium Bentonite
Authors: Muurinen Armo , Penitä-Hiltunen Pirkkd , Rantanen Juba 
Published: June 2019

AbstractIn this research the diffusion of strontium and cesium through bento- nite slabs in stationary state has been measured. The measurement gives directly the transport through the sample and the corresponding effective diffusivity. The apparent diffusivity, diffusivity of the sorbed ions as well as the sorption factors can also be evaluated on the basis of the same diffusion measurement. The sorption on the coxmpacted bentonite has also been measured in a special sorption test where a radioactive tracer has been allowed to diffuse into compacted bentonite until equilibrium was reached.The measured effective diffusivities were clearly higher than they would be in the case of pure pore diffusion. The effective diffusivities also increase with K and the apparent diffusivities are almost independent on KD. This supports the theory that also the sorbed ions diffuse in their own phase. The sorption factors of the compacted bentonite correspond to the values of the batch experiments.
Advanced Resonant-Ultrasound Spectroscopy for Studying Anisotropic Elastic Constants of Thin Films
Authors: Ogi Hirotsugu , Nakamura Nobutomo , Tanei Hiroshi , Hirao Masahiko 
Published: June 2019

AbstractThis paper presents two advanced acoustic methods for the determination of anisotropic elastic constants of deposited thin films. They are resonant-ultrasound spectroscopy with laser-Doppler interferometry (RUS/Laser method) and picosecond-laser ultrasound method. Deposited thin films usually exhibit elastic anisotropy between the film-growth direction and an in-plane direction, and they show five independent elastic constants denoted by C11,C33,C44,C66 and C13 when the x3 axis is set along the film-thickness direction. The former method determines four moduli except C44, the out-of-plane shear modulus, through free-vibration resonance frequencies of the film/substrate specimen. This method is applicable to thin films thicker than about 200 nm. The latter determines C33, the out-of-plane modulus, accurately bymeasuring the round-trip time of the longitudinal wave traveling along the film-thickness direction. This method is applicable to thin films thicker than about 20 nm. Thus, combination of these two methods allows us to discuss the elastic anisotropy of thin films. The results for Co/Pt superlattice thin film and copper thin film are presented.
Intrinsic stress and alloying effect in Mo/Ni superlattices: a comparison between ion beam sputtering and thermal evaporation
Authors: Debelle A. , Abadias G. , Michel A. , Jaouen C. , Guérin Ph. , Marteau M. , Drouet M. 
Published: June 2019

AbstractEpitaxial Mo(110)/Ni(111) superlattices were grown on (1120) single-crystal sapphiresubstrates, by ion beam sputtering (IBS) and thermal evaporation (TE), in order to investigate the role of deposited energy on the interfacial mixing process observed in Mo sublayers. To separate intermixing and growth stress contributions, a careful and detailed characterization of the stress/strain state of both samples was performed by X-ray Diffraction (XRD). Non-equal biaxial coherency stresses are observed in both samples. For the IBS specimen, an additional source of stress, of hydrostatic type, due to growth-induced point defects, is present, resulting in a triaxial stress state. The use of ion irradiation to achieve a controlled stress relaxation can provide additional data and, as shown elsewhere, allows to obtain the stress-free lattice parameter a0 solely linked to chemical effects. For the TE sample, a standard biaxial analysis gives a0. In both samples, the a0 value is lower than the bulk lattice parameter, due to the presence of intermixed Mo(Ni) layers. However, the intermixing is larger in the sputtered Mo sublayers than in the thermal evaporated ones, putting forward the prime role of energy and/or momentum transfer occurring during energetic bombardment.
Practical Work of Adhesion of Polymer Coatings Studied by Laser Induced Delamination
Authors: Fedorov A. , Hosson J. Th. M. De , Tijum R. van , Vellinga W.-P. 
Published: June 2019

AbstractLaser Induced Delamination is a novel technique aimed at measuring the practical work of adhesion of thin polymer coatings on metal substrates. In this technique a laser pulse is used to create initial blisters which initiate further delamination of the film under the blister pressure. A simple elastic model is developed to describe the formation of the blisters. The model predicts the values for the blister height and pressure, which are in fair agreement with the experimental results. In order to account for possible plastic deformations, simulations using a finite element model with a mixed mode cohesive zone were carried out. The calculated stress fields are in agreement with those predicted by the elastic model suggesting that the contribution of plastic deformation to the measured work of fracture is rather limited.Measurements are carried out on a number of samples, presenting ECCS steel substrate covered with 35 μm thick polyethylene terephthalate (PET) film. The tensile stresses created in the film at the interface required for delamination are estimated at 7-8 MPa, which corresponds to the practical work of adhesion G = (0.6± 0.1) J/m2.
Strain Relaxation in Si1-xGex Thin Films on Si (100) Substrates: Modeling and Comparisons with Experiments
Authors: Kolluri Kedarnath , Zepeda-Ruiz Luis A. , Murthy Cheruvu S. , Maroudas Dimitrios 
Published: June 2019

AbstractStrained semiconductor thin films grown epitaxially on semiconductor substrates of different composition, such as Si1-xGex/Si, are becoming increasingly important in modern microelectronic technologies. In this paper, we report a hierarchical computational approach for analysis of dislocation formation, glide motion, multiplication, and annihilation in Si1-xGex epitaxial thin films on Si substrates. Specifically, a condition is developed for determining the critical film thickness with respect to misfit dislocation generation as a function of overall film composition, film compositional grading, and (compliant) substrate thickness. In addition, the kinetics of strain relaxation in the epitaxial film during growth or thermal annealing (including post-implantation annealing) is analyzed using a properly parameterized dislocation mean-field theoretical model, which describes plastic deformation dynamics due to threading dislocation propagation. The theoretical results for Si1-xGex epitaxial thin films grown on Si (100) substrates are compared with experimental measurements and are used to discuss film growth and thermal processing protocols toward optimizing the mechanical response of the epitaxial film.
An Investigation of Film Thickness Effect on Mechanical Properties of Au Films Using Nanoindentation Techniques
Authors: Cao Yifang , Zong Zong , Soboyejo Wole 
Published: June 2019

AbstractThis paper presents the results of nanoindentation experimental studies of Au thin films with different thicknesses. The effects of film thickness and microstructure on the hardnesses of electron-beam deposited Au films were studied in terms of Hall-Petch relationship. The effects of different thicknesses on indentation size effects (ISE) are explained within the framework of mechanism-based strain gradient (MSG) theory using the concept of microstructural length scale.
A New Dislocation-Dynamics Model and Its Application in Thin Film-Substrate Systems
Authors: Tan E.H. , Sun L.Z. 
Published: June 2019

AbstractBased on the physical background, a new dislocation dynamics model fully incorporating the interaction among differential dislocation segments is developed to simulate 3D dislocation motion in crystals. As the numerical simulation results demonstrate, this new model completely solves the long-standing problem that simulation results are heavily dependent on dislocation-segment lengths in the classical dislocation dynamics theory. The proposed model is applied to simulate the effect of dislocations on the mechanical performance of thin films. The interactions among the dislocation loops, free surface and interfaces are rigorously computed by a decomposition method. This framework can be used to simulate how a surface loop evolves into two threading dislocations and to determine the critical thickness of thin films. Furthermore, the relationship between the film thickness and yield strength is established and compared with the conventional Hall-Petch relation.
Diode Pumped 2-μm Lasers Using Tm,Ho Codoped YLF, LuLF, LuAG and GdVO4 Crystals
Authors: Asai Kazuhiro , Sato Atsushi , Mizutani Kohei 
Published: June 2019

AbstractTm, Ho codoped YLF, LuLF,and LuAG and GdVO4 crystals are very attractive for diode pumped 2-μm lasers. A comparison study of laser performance was made using a diode-pumped, quasi-end-pump scheme at various pulse repetition frequencies and temperatures. At 5 Hz and at an operating temperature of 300 K, normal mode laser output energies of 15.7 mJ (YLF) with a slope efficiency of 7.3%, 26.8mJ (LuLF) with that of 12.6% and 20.0 mJ (LuAG) with that of 10.8% were achieved using 5%Tm and 0.5%Ho, respectively. A Tm,Ho:GdVO4 laser was also investigated. It was found, in the case of GdVO4, that optimum Tm and Ho dopant concentrations were slightly lower than those for garnet and fluoride crystals. Using a 3% Tm,0.3% Ho:GdVO4 crystal, an output energy of 31.2 mJ with a slope efficiency of 14.5% was obtained in normal mode operation at room temperature.
Chip-Scale, High Power Microstructure Fiber Laser
Authors: Peyghambarian Nasser , Schülzgen Axel , Mansuripur Masud , Moloney Jerome V. , Qiu Tiequn , Kaneda Yushi , Polynkin Pavel , Li Li , Wu Jianfeng , Polynkin Alex , Temyanko Valery L. , Mafi Arash , Jiang Shibin , Spiegelberg Christine , Chavez Arturo , Geng Jihong , Luo Tao 
Published: June 2019

AbstractCompact, robust, high power fiber lasers have been demonstrated. In fiber lasers of only a few cm length we obtained up to 10 W of cw output power, diffraction limited beam profiles at 4 W cw operation, 1.6 W output with single frequency operation, and more than 150 mW output with a spectral linewidth of a few kHz. The potential of active microstructured fibers for further improvements in fiber laser performance has been shown. We also demonstrated Q-switching and mode-locking of these compact fiber lasers.
Lidar Remote Sensing Applications: Ready and Waiting
Authors: Hahn John F. 
Published: June 2019

AbstractIn this note, lidar materials, ready and waiting, will be discussed. Most lidar applications depend upon “Ready” materials, conventional materials that are part of a design solution to the application. Lidar systems already operating and serving the needs of communities in atmospheric, earth and planetary sciences, include airborne terrain mapping, airborne bathymetric mapping, ground-based imaging rangefinding and ceilometry are included in this category. Even in space application, “Ready” spaceborne applications include orbital rendezvous and docking, precision landing/hazard avoidance and Martian atmospheric evaluation. Other applications, however, have particular materials needs and constitute “Waiting” systems. These include in particular spaceborne differential absorption lidar (DIAL) for the measurement of important trace species such as ozone and water vapor in the Earth's atmosphere (ORACLE, WALES). An evaluation of critical issues facing mission-enabling lidar materials development will be presented, based upon Optech Incorporated's direct experience in these areas.
Efficacy of a Lifestyle Program Designed to Help Indigent, Obese Adult Patients Lose Weight
Authors: Duggins Maurice L. , Lewis Douglas P. , Harvey Anne T. 
Published: June 2019

Introduction. Modest weight loss (5 to 7%) reduced the incidenceof type II diabetes in the Diabetes Prevention Program (DDP) trial.A DPP-inspired lifestyle intervention requiring minimal patientself-data collection and tailored to low-SES patients throughminimal cost was developed for our indigent, obese patients.
Methods. Obese (BMI ≥ 30 kg/m2), indigent (≤ 200% FederalPoverty Level) adults (age 18 - 70) were offered a nocostweight loss intervention as an adjunct to their usual primarycare in a residency outpatient clinic. The interventionprovided options for diet plans and social support. The goalwas to achieve a 5% loss of body weight over six months.
Results. The sample (n = 158) was 86% female and 62% white,with a median age of 45 and median BMI of 40.9. Two-thirds ofsubjects chose the 50% diet; YMCA membership was selected byall but one. The 5% weight loss goal was met by 12.8%; another8.7% gained that amount. Subjects who either had pre-existingYMCA membership or used their provided membership weresuccessful, relative to those who received but never used theirmembership (0.6% loss vs 0.9% gain; p < 0.05). Changes in weightover six months were observed in the youngest (gain of 3.9 lbs.,p < 0.05) and the oldest (loss of 4.0 lbs., p < 0.05) age quartiles.
Conclusions. A DPP-inspired lifestyle intervention tailoredto low-SES patients did not lead to overall weight loss, reinforcingthat weight reduction programs must provide a significantamount of support for participants to see success.Older age and a behavioral commitment to physical activityimproved the likelihood of success. KS J Med 2016;9(4):83-87.
Promoción de un destino turístico a través de las redes sociales: el caso de A Coruña en Facebook
Authors: Sánchez Amboage Eva 
Published: June 2019

Tal como en la década de los 90 comentaba Nicholas Negroponte, en su obra El Mundo Digital, la tecnología, unida a la ciencia, han producido en los últimos decenios un cambio claramente perceptible en nuestra forma de vivir y de entender la realidad. El mundo real en el que vivimos va abriendo camino a un nuevo y atractivo mundo virtual y digital que se adapta rápidamente, a las necesidades de la sociedad. Tanto es así, que hoy en día tener un perfil en Internet, hablar o intercambiar fotografías a través de la red son acciones totalmente comunes y cotidianas. Las redes sociales virtuales han realizado una progresión sorprendente y lo que en un principio parecía un lugar solo para relaciones personales se ha ido extendiendo por otros campos hasta llegar al comercial. De pronto redes sociales virtuales como Facebook, Tuenti, MySpace, etc. se convierten en grandes y accesibles portales de publicidad y promoción de distintos productos. Entre estos, el turismo también tiene su lugar. El presente trabajo pretende demostrar este hecho, a través del análisis de la presencia de una ciudad como A Coruña en Facebook.