Science.gov

Sample records for as-doped buried amorphous

  1. Impact of solid-phase crystallization of amorphous silicon on the chemical structure of the buried Si/ZnO thin film solar cell interface

    SciTech Connect

    Bar, M.; Wimmer, M.; Wilks, R. G.; Roczen, M.; Gerlach, D.; Ruske, F.; Lips, K.; Rech, B.; Weinhardt, L.; Blum, M.; Pookpanratana, S.; Krause, S.; Zhang, Y.; Heske, C.; Yang, W.; Denlinger, J. D.

    2010-04-30

    The chemical interface structure between phosphorus-doped hydrogenated amorphous silicon and aluminum-doped zinc oxide thin films is investigated with soft x-ray emission spectroscopy (XES) before and after solid-phase crystallization (SPC) at 600C. In addition to the expected SPC-induced phase transition from amorphous to polycrystalline silicon, our XES data indicates a pronounced chemical interaction at the buried Si/ZnO interface. In particular, we find an SPC-enhanced formation of Si-O bonds and the accumulation of Zn in close proximity to the interface. For an assumed closed and homogeneous SiO2 interlayer, an effective thickness of (5+2)nm after SPC could be estimated.

  2. Buried oxide layer in silicon

    DOEpatents

    Sadana, Devendra Kumar; Holland, Orin Wayne

    2001-01-01

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  3. Solubility products of amorphous ferric arsenate and crystalline scorodite (FeAsO 4 · 2H 2O) and their application to arsenic behavior in buried mine tailings

    NASA Astrophysics Data System (ADS)

    Langmuir, Donald; Mahoney, John; Rowson, John

    2006-06-01

    Published solubility data for amorphous ferric arsenate and scorodite have been reevaluated using the geochemical code PHREEQC with a modified thermodynamic database for the arsenic species. Solubility product calculations have emphasized measurements obtained under conditions of congruent dissolution of ferric arsenate (pH < 3), and have taken into account ion activity coefficients, and ferric hydroxide, ferric sulfate, and ferric arsenate complexes which have association constants of 10 4.04 (FeH 2AsO 42+), 10 9.86 (FeHAsO 4+), and 10 18.9 (FeAsO 4). Derived solubility products of amorphous ferric arsenate and crystalline scorodite (as log Ksp) are -23.0 ± 0.3 and -25.83 ± 0.07, respectively, at 25 °C and 1 bar pressure. In an application of the solubility results, acid raffinate solutions (molar Fe/As = 3.6) from the JEB uranium mill at McClean Lake in northern Saskatchewan were neutralized with lime to pH 2-8. Poorly crystalline scorodite precipitated below pH 3, removing perhaps 98% of the As(V) from solution, with ferric oxyhydroxide (FO) phases precipitated starting between pH 2 and 3. Between pH 2.18 and 7.37, the apparent log Ksp of ferric arsenate decreased from -22.80 to -24.67, while that of FO (as Fe(OH) 3) increased from -39.49 to -33.5. Adsorption of As(V) by FO can also explain the decrease in the small amounts of As(V)(aq) that remain in solution above pH 2-3. The same general As(V) behavior is observed in the pore waters of neutralized tailings buried for 5 yr at depths of up to 32 m in the JEB tailings management facility (TMF), where arsenic in the pore water decreases to 1-2 mg/L with increasing age and depth. In the TMF, average apparent log Ksp values for ferric arsenate and ferric hydroxide are -25.74 ± 0.88 and -37.03 ± 0.58, respectively. In the laboratory tests and in the TMF, the increasing crystallinity of scorodite and the amorphous character of the coexisting FO phase increases the stability field of scorodite relative to that of

  4. Method of forming buried oxide layers in silicon

    DOEpatents

    Sadana, Devendra Kumar; Holland, Orin Wayne

    2000-01-01

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  5. Electromagnetic modeling of buried objects

    SciTech Connect

    Lee, C.F.

    1994-12-31

    In this paper, radar cross section (RCS) models of buried dipoles, surface steel pipe, and buried steel pipes are discussed. In all these models, the ground is assumed to be a uniform half space. The calculated results for the buried dipoles and the surface steel pipe compare favorably with those measured in the 1993 Yuma ground penetration radar (GPR) experiment. For the buried dipoles, a first-order RCS model is developed. In this model, a solution for an infinitely long conducting cylinder, together with a mirror image approximation (which accounts for the coupling between the dipole and the ground-air interface) is used to calculate the dipole RCS. This RCS model of the buried dipoles explains the observed loss of dipole RCS. For the surface steel pipe, a geometrical optics model, which includes the multipath interaction, is developed. This model explains the observed multipath gain/loss. For the buried steel pipes, a zero order physical optics model is developed. Also discussed is desert radar clutter statistics as a function of depression angle. Preliminary analysis, based on samples of Yuma desert surface profiles, indicates that simple rough-surface models cannot explain the observed average backscatter from desert clutter.

  6. Thin film buried anode battery

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Liu, Ping

    2009-12-15

    A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

  7. Ultrasonic isolation of buried pipes

    NASA Astrophysics Data System (ADS)

    Leinov, Eli; Lowe, Michael J. S.; Cawley, Peter

    2016-02-01

    Long-range guided wave testing (GWT) is used routinely for the monitoring and detection of corrosion defects in above ground pipelines. The GWT test range in buried, coated pipelines is greatly reduced compared to above ground configurations due to energy leakage into the embedding soil. In this paper, the effect of pipe coatings on the guided wave attenuation is investigated with the aim of increasing test ranges for buried pipelines. The attenuation of the T(0,1) and L(0,2) guided wave modes is measured using a full-scale experimental apparatus in a fusion-bonded epoxy (FBE)-coated 8 in. pipe, buried in loose and compacted sand. Tests are performed over a frequency range typically used in GWT of 10-35 kHz and compared with model predictions. It is shown that the application of a low impedance coating between the FBE layer and the sand effectively decouples the influence of the sand on the ultrasound leakage from the buried pipe. Ultrasonic isolation of a buried pipe is demonstrated by coating the pipe with a Polyethylene (PE)-foam layer that has a smaller impedance than both the pipe and sand, and has the ability to withstand the overburden load from the sand. The measured attenuation in the buried PE-foam-FBE-coated pipe is found to be substantially reduced, in the range of 0.3-1.2 dB m-1 for loose and compacted sand conditions, compared to measured attenuation of 1.7-4.7 dB m-1 in the buried FBE-coated pipe without the PE-foam. The acoustic properties of the PE-foam are measured independently using ultrasonic interferometry and incorporated into model predictions of guided wave propagation in buried coated pipe. Good agreement is found between the experimental measurements and model predictions. The attenuation exhibits periodic peaks in the frequency domain corresponding to the through-thickness resonance frequencies of the coating layer. The large reduction in guided wave attenuation for PE-coated pipes would lead to greatly increased GWT test ranges; such

  8. Amorphic complexity

    NASA Astrophysics Data System (ADS)

    Fuhrmann, G.; Gröger, M.; Jäger, T.

    2016-02-01

    We introduce amorphic complexity as a new topological invariant that measures the complexity of dynamical systems in the regime of zero entropy. Its main purpose is to detect the very onset of disorder in the asymptotic behaviour. For instance, it gives positive value to Denjoy examples on the circle and Sturmian subshifts, while being zero for all isometries and Morse-Smale systems. After discussing basic properties and examples, we show that amorphic complexity and the underlying asymptotic separation numbers can be used to distinguish almost automorphic minimal systems from equicontinuous ones. For symbolic systems, amorphic complexity equals the box dimension of the associated Besicovitch space. In this context, we concentrate on regular Toeplitz flows and give a detailed description of the relation to the scaling behaviour of the densities of the p-skeletons. Finally, we take a look at strange non-chaotic attractors appearing in so-called pinched skew product systems. Continuous-time systems, more general group actions and the application to cut and project quasicrystals will be treated in subsequent work.

  9. The Buried Town of Beaver.

    ERIC Educational Resources Information Center

    Jostad, Karen

    Local history as source material for environmental education is uniquely portrayed in this resource kit. Utilizing a Winona County Historical Society publication, "The Beaver Story" and accompanied by a teacher's guide, "The Buried Town of Beaver," and other teaching aids, a case study of the area can be developed. Based on the reminiscences of…

  10. 47 CFR 32.2423 - Buried cable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Buried cable. 32.2423 Section 32.2423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2423 Buried cable. (a) This account shall include the original cost of buried cable as well as the cost of other material...

  11. 47 CFR 32.2423 - Buried cable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Buried cable. 32.2423 Section 32.2423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2423 Buried cable. (a) This account shall include the original cost of buried cable as well as the cost of other material...

  12. Electromagnetic scattering from buried objects

    SciTech Connect

    Brock, B.C.; Sorensen, K.W.

    1994-10-01

    Radar imaging and detection of objects buried in soil has potentially important applications in the areas of nonproliferation of weapons, environmental monitoring, hazardous-waste site location and assessment, and even archeology. In order to understand and exploit this potential, it is first necessary to understand how the soil responds to an electromagnetic wave, and how targets buried within the soil scatter the electromagnetic wave. We examine the response of the soil to a short pulse, and illustrate the roll of the complex dielectric permittivity of the soil in determining radar range resolution. This leads to a concept of an optimum frequency and bandwidth for imaging in a particular soil. We then propose a new definition for radar cross section which is consistent with the modified radar equation for use with buried targets. This radar cross section plays the same roll in the modified radar equation as the traditional radar cross section does in the free-space radar equation, and is directly comparable to it. The radar cross section of several canonical objects in lossy media is derived, and examples are given for several object/soil combinations.

  13. Blast wave from buried charges

    SciTech Connect

    Reichenbach, H.; Behrens, K.; Kuhl, A.L.

    1993-08-01

    While much airblast data are available for height-of-burst (HOB) effects, systematic airblast data for depth-of-burst (DOB) effects are more limited. It is logical to ask whether the spherical 0.5-g Nitropenta charges that, proved to be successful for HOB tests at EMI are also suitable for experiments with buried charges in the laboratory scale; preliminary studies indicated in the alternative. Of special interest is the airblast environment generated by detonations just above or below the around surface. This paper presents a brief summary of the test results.

  14. Nonlinear vibrations of buried landmines.

    PubMed

    Donskoy, Dimitri; Reznik, Alexander; Zagrai, Andrei; Ekimov, Alexander

    2005-02-01

    The seismo-acoustic method is one of the most promising emerging techniques for the detection of landmines. Numerous field tests have demonstrated that buried landmines manifest themselves at the surface through linear and nonlinear responses to acoustic/seismic excitation. The present paper describes modeling of the nonlinear response in the framework of the mass-spring model of the soil-mine system. The perturbation method used in the model allows for the derivation of an analytical solution describing both quadratic and cubic acoustic interactions at the soil-mine interface. This solution has been compared with actual field measurements to obtain nonlinear parameters of the buried mines. These parameters have been analyzed with respect to mine types and burial depths. It was found that the cubic nonlinearity could be a significant contributor to the nonlinear response. This effect has led to the development of a new intermodulation detection algorithm based on dual-frequency excitation. Both quadratic and intermodulation nonlinear algorithms were evaluated at the U.S. Army outdoor testing facilities. The algorithms appear to complement each other in improving the overall detection performance. PMID:15759689

  15. Buried Waste Integrated Demonstration Plan

    SciTech Connect

    Kostelnik, K.M.

    1991-12-01

    This document presents the plan of activities for the Buried Waste Integrated Demonstration (BWID) program which supports the environmental restoration (ER) objectives of the Department of Energy (DOE) Complex. Discussed in this plan are the objectives, organization, roles and responsibilities, and the process for implementing and managing BWID. BWID is hosted at the Idaho National Engineering Laboratory (INEL), but involves participants from throughout the DOE Complex, private industry, universities, and the international community. These participants will support, demonstrate, and evaluate a suite of advanced technologies representing a comprehensive remediation system for the effective and efficient remediation of buried waste. The processes for identifying technological needs, screening candidate technologies for applicability and maturity, selecting appropriate technologies for demonstration, field demonstrating, evaluation of results and transferring technologies to environmental restoration programs are also presented. This document further describes the elements of project planning and control that apply to BWID. It addresses the management processes, operating procedures, programmatic and technical objectives, and schedules. Key functions in support of each demonstration such as regulatory coordination, safety analyses, risk evaluations, facility requirements, and data management are presented.

  16. Chemical detection of buried landmines

    SciTech Connect

    Phelan, J.M.; Webb, S.W.

    1998-03-01

    Of all the buried landmine identification technologies currently available, sensing the chemical signature from the explosive components found in landmines is the only technique that can classify non-explosive objects from the real threat. In the last two decades, advances in chemical detection methods has brought chemical sensing technology to the foreground as an emerging technological solution. In addition, advances have been made in the understanding of the fundamental transport processes that allow the chemical signature to migrate from the buried source to the ground surface. A systematic evaluation of the transport of the chemical signature from inside the mine into the soil environment, and through the soil to the ground surface is being explored to determine the constraints on the use of chemical sensing technology. This effort reports on the results of simulation modeling using a one-dimensional screening model to evaluate the impacts on the transport of the chemical signature by variation of some of the principal soil transport parameters.

  17. Amorphous metal composites

    DOEpatents

    Byrne, Martin A.; Lupinski, John H.

    1984-01-01

    An improved amorphous metal composite and process of making the composite. The amorphous metal composite comprises amorphous metal (e.g. iron) and a low molecular weight thermosetting polymer binder. The process comprises placing an amorphous metal in particulate form and a thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite.

  18. Mining metrics for buried treasure

    NASA Astrophysics Data System (ADS)

    Konkowski, D. A.; Helliwell, T. M.

    2006-06-01

    The same but different: That might describe two metrics. On the surface CLASSI may show two metrics are locally equivalent, but buried beneath may be a wealth of further structure. This was beautifully described in a paper by Malcolm MacCallum in 1998. Here I will illustrate the effect with two flat metrics — one describing ordinary Minkowski spacetime and the other describing a threeparameter family of Gal'tsov-Letelier-Tod spacetimes. I will dig out the beautiful hidden classical singularity structure of the latter (a structure first noticed by Tod in 1994) and then show how quantum considerations can illuminate the riches. I will then discuss how quantum structure can help us understand classical singularities and metric parameters in a variety of exact solutions mined from the Exact Solutions book.

  19. Amorphous Computing

    NASA Astrophysics Data System (ADS)

    Sussman, Gerald

    2002-03-01

    agents constructed by engineered cells, but we have few ideas for programming them effectively: How can one engineer prespecified, coherent behavior from the cooperation of immense numbers of unreliable parts that are interconnected in unknown, irregular, and time-varying ways? This is the challenge of Amorphous Computing.

  20. 7 CFR 1755.505 - Buried services.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Buried services. 1755.505 Section 1755.505 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.505 Buried services. (a)...

  1. 7 CFR 1755.505 - Buried services.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Buried services. 1755.505 Section 1755.505 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.505 Buried services. (a)...

  2. Probing the Buried Magnetic Interfaces.

    PubMed

    Liu, Wenqing; Zhou, Qionghua; Chen, Qian; Niu, Daxin; Zhou, Yan; Xu, Yongbing; Zhang, Rong; Wang, Jinlan; van der Laan, Gerrit

    2016-03-01

    Understanding magnetism in ferromagnetic metal/semiconductor (FM/SC) heterostructures is important to the development of the new-generation spin field-effect transistor. Here, we report an element-specific X-ray magnetic circular dichroism study of the interfacial magnetic moments for two FM/SC model systems, namely, Co/GaAs and Ni/GaAs, which was enabled using a specially designed FM1/FM2/SC superstructure. We observed a robust room temperature magnetization of the interfacial Co, while that of the interfacial Ni was strongly diminished down to 5 K because of hybridization of the Ni d(eg) and GaAs sp(3) states. The validity of the selected method was confirmed by first-principles calculations, showing only small deviations (<0.02 and <0.07 μB/atom for Co/GaAs and Ni/GaAs, respectively) compared to the real FM/SC interfaces. Our work proved that the electronic structure and magnetic ground state of the interfacial FM2 is not altered when the topmost FM2 is replaced by FM1 and that this model is applicable generally for probing the buried magnetic interfaces in the advanced spintronic materials.. PMID:26887429

  3. Mapping Buried Hydrogen-Bonding Networks.

    PubMed

    Thomas, John C; Goronzy, Dominic P; Dragomiretskiy, Konstantin; Zosso, Dominique; Gilles, Jérôme; Osher, Stanley J; Bertozzi, Andrea L; Weiss, Paul S

    2016-05-24

    We map buried hydrogen-bonding networks within self-assembled monolayers of 3-mercapto-N-nonylpropionamide on Au{111}. The contributing interactions include the buried S-Au bonds at the substrate surface and the buried plane of linear networks of hydrogen bonds. Both are simultaneously mapped with submolecular resolution, in addition to the exposed interface, to determine the orientations of molecular segments and directional bonding. Two-dimensional mode-decomposition techniques are used to elucidate the directionality of these networks. We find that amide-based hydrogen bonds cross molecular domain boundaries and areas of local disorder. PMID:27096290

  4. Implementation of the buried waste integrated demonstration

    SciTech Connect

    Kostelnik, K.M.; Merrill, S.K.

    1992-09-01

    The Department of Energy (DOE), Office of Technology Development (OTD) has initiated the Buried Waste Integrated Demonstration (BWID) to resolve technological deficiencies associated with the remediation of radioactive and hazardous buried waste. The BWID mission is to identify, demonstrate, and transfer innovative technologies for the remediation of DOE buried waste. To accomplish the mission, BWID is using a systems approach which supports the development of a suite of advanced and innovative technologies for the effective and efficient remediation of buried waste. This systems approach includes technologies for theentire remediation cycle. Specifically, BWID sponsors technology development in the following technology categories: site and waste characterization, retrieval, preprocessing, ex situ treatment, packaging, transportation, storage, disposal, and post-disposal monitoring.

  5. Implementation of the buried waste integrated demonstration

    SciTech Connect

    Kostelnik, K.M.; Merrill, S.K.

    1992-01-01

    The Department of Energy (DOE), Office of Technology Development (OTD) has initiated the Buried Waste Integrated Demonstration (BWID) to resolve technological deficiencies associated with the remediation of radioactive and hazardous buried waste. The BWID mission is to identify, demonstrate, and transfer innovative technologies for the remediation of DOE buried waste. To accomplish the mission, BWID is using a systems approach which supports the development of a suite of advanced and innovative technologies for the effective and efficient remediation of buried waste. This systems approach includes technologies for theentire remediation cycle. Specifically, BWID sponsors technology development in the following technology categories: site and waste characterization, retrieval, preprocessing, ex situ treatment, packaging, transportation, storage, disposal, and post-disposal monitoring.

  6. Is simulated amorphous'' silica really amorphous

    SciTech Connect

    Binggeli, N. , PHB Ecublens, 1015 Lausanne ); Chelikowsky, J.R. )

    1994-07-10

    We have carried out extensive molecular dynamics simulations for the pressure induced amorphization of quartz by means of a classical force-field model. In agreement with earlier simulations, we find that a phase transition occurs within the experimental pressure range of the amorphization. However, in contrast to the interpretation of previous simulations, we demonstrate that the new phase is [ital not] amorphous, since the correlation functions for the equilibrated structure can be shown to be consistent with those of a crystalline phase. In addition, two transformations to ordered structures are found to occur sequentially during the simulations. The first transformation is likely to be related to the recently discovered transition of quartz to an intermediate crystalline phase before its amorphization. The second transformation, instead, yields a compact, octahedrally coordinated Si sublattice. The latter may be an artifact of the pair-potential simulation. [copyright] 1994 American Institute of Physics

  7. Buried Waste Integrated Demonstration. Technology summary

    SciTech Connect

    Not Available

    1994-03-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that offer promising solutions to the problems associated with the remediation of buried waste. BWID addresses the difficult remediation problems associated with DOE complex-wide buried waste, particularly transuranic (TRU) contaminated buried waste. BWID has implemented a systems approach to the development and demonstration of technologies that will characterize, retrieve, treat, and dispose of DOE buried wastes. This approach encompasses the entire remediation process from characterization to post-monitoring. The development and demonstration of the technology is predicated on how a technology fits into the total remediation process. To address all of these technological issues, BWID has enlisted scientific expertise of individuals and groups from within the DOE Complex, as well as experts from universities and private industry. The BWID mission is to support development and demonstration of a suite of technologies that, when integrated with commercially-available technologies, forms a comprehensive, remediation system for the effective and efficient remediation of buried waste throughout the DOE Complex. BWID will evaluate and validate demonstrated technologies and transfer this information and equipment to private industry to support the Office of Environmental Restoration (ER), Office of Waste Management (WM), and Office of Facility Transition (FT) remediation planning and implementation activities.

  8. TNX Burying Ground: Environmental information document

    SciTech Connect

    Dunaway, J.K.W.; Johnson, W.F.; Kingley, L.E.; Simmons, R.V.; Bledsoe, H.W.

    1987-03-01

    The TNX Burying Ground, located within the TNX Area of the Savannah River Plant (SRP), was originally built to dispose of debris from an experimental evaporator explosion at TNX in 1953. This evaporator contained approximately 590 kg of uranyl nitrate. From 1980 to 1984, much of the waste material buried at TNX was excavated and sent to the SRP Radioactive Waste Burial Grounds for reburial. An estimated 27 kg of uranyl nitrate remains buried at TNX. The TNX Burying Ground consists of three sites known to contain waste and one site suspected of containing waste material. All four sites are located within the TNX security fenceline. Groundwater at the TNX Burying Ground was not evaluated because there are no groundwater monitoring wells installed in the immediate vicinity of this waste site. The closure options considered for the TNX Burying Ground are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated.

  9. Arsenic complexes optical signatures in As-doped HgCdTe

    SciTech Connect

    Gemain, F.; Robin, I. C.; Brochen, S.; Ballet, P.; Gravrand, O.; Feuillet, G.

    2013-04-08

    In this paper, the optical signatures of arsenic complexes in As-doped HgCdTe samples grown by molecular beam epitaxy are clearly identified using comparison between photoluminescence spectra, Extended X-Ray Absorption Fine Structure, and Hall measurements. The ionization energies of the different complexes are measured both by photoluminescence and Hall measurements.

  10. Improved charge collection of the buried p-i-n a-Si:H radiation detectors

    SciTech Connect

    Fujieda, I.; Cho, G.; Conti, M.; Drewery, J.; Kaplan, S.N.; Perez-Mendez, V.; Qureshi, S.; Street, R.A.; Xerox Palo Alto Research Center, CA )

    1989-09-01

    Charge collection in hydrogenated amorphous silicon (a-Si:H) radiation detectors is improved for high LET particle detection by adding thin intrinsic layers to the usual p-i-n structure. This buried p-i-n structure enables us to apply higher bias and the electric field is enhanced. When irradiated by 5.8 MeV {alpha} particles, the 5.7 {mu}m thick buried p-i-n detector with bias 300V gives a signal size of 60,000 electrons, compared to about 20,000 electrons with the simple p-i-n detectors. The improved charge collection in the new structure is discussed. The capability of tailoring the field profile by doping a-Si:H opens a way to some interesting device structures. 17 refs., 7 figs.

  11. Nanocrystal dispersed amorphous alloys

    NASA Technical Reports Server (NTRS)

    Perepezko, John H. (Inventor); Allen, Donald R. (Inventor); Foley, James C. (Inventor)

    2001-01-01

    Compositions and methods for obtaining nanocrystal dispersed amorphous alloys are described. A composition includes an amorphous matrix forming element (e.g., Al or Fe); at least one transition metal element; and at least one crystallizing agent that is insoluble in the resulting amorphous matrix. During devitrification, the crystallizing agent causes the formation of a high density nanocrystal dispersion. The compositions and methods provide advantages in that materials with superior properties are provided.

  12. Frost heave induced mechanics of buried pipelines

    SciTech Connect

    Selvadurai, A.P.S.; Shinde, S.B.

    1993-12-01

    This paper examines the problem of the flexural interaction between a long-distance buried pipeline embedded in a soil medium that experiences differential frost heave. The modeling takes into consideration the interaction at a transition zone between a frozen region and a frost-susceptible region that experiences a time-dependent growth of a frost bulb around the buried pipeline. The heave that accompanies the development of a frost bulb induces the soil-pipeline interaction process. The analysis focuses on the development of a computational scheme that addresses the three-dimensional nature of the soil-pipeline interaction problem, the creep susceptibility of the frozen region, and a prescribed time- and stress-dependent heave in an evolving frost bulb zone. The numerical results presented in the paper illustrate the influence of the heave process and the creep behavior of the frozen soil on the displacements and stresses in the buried pipeline.

  13. Prioritization for rehabilitation of buried lifelines

    SciTech Connect

    Wang, L.R.L.; Ishibashi, I.; Li, H.

    1995-12-31

    Seismic rehabilitation or retrofit is a cost-effective way to prevent pipeline damage caused by future earthquakes. In general, it is very difficult, if not impossible, to rehabilitate all buried pipelines at the same time because of limited funds and time available. The purpose of this study is to establish a priority strategy for rehabilitation of buried pipelines considering several important factors such as pipeline damage probability, rehabilitation cost, rehabilitation rate (e.g. km/day), pipeline importance and total funds available.

  14. Buried Waste Integrated Demonstration test objectives

    SciTech Connect

    Morrison, J.L.; Heard, R.E.

    1993-05-01

    The mission of the Buried Waste Integrated Demonstration Program (BWID) is to support the development and demonstration of a suite of technologies that when integrated with commercially available baseline technologies form a comprehensive system for the effective and efficient remediation of buried waste throughout the US Department of Energy complex. To accomplish this mission of identifying technology solutions for remediation deficiencies, the Office of Technology Development initiated the BWID at the Idaho National Engineering Laboratory in fiscal year (FY) 1991. This document provides the test objectives against which the demonstrations will be tested during FY-93.

  15. Silicon on insulator with active buried regions

    DOEpatents

    McCarthy, Anthony M.

    1998-06-02

    A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

  16. Silicon on insulator with active buried regions

    DOEpatents

    McCarthy, Anthony M.

    1996-01-01

    A method for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors.

  17. Silicon on insulator with active buried regions

    DOEpatents

    McCarthy, A.M.

    1998-06-02

    A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

  18. Silicon on insulator with active buried regions

    DOEpatents

    McCarthy, A.M.

    1996-01-30

    A method is disclosed for forming patterned buried components, such as collectors, sources and drains, in silicon-on-insulator (SOI) devices. The method is carried out by epitaxially growing a suitable sequence of single or multiple etch stop layers ending with a thin silicon layer on a silicon substrate, masking the silicon such that the desired pattern is exposed, introducing dopant and activating in the thin silicon layer to form doped regions. Then, bonding the silicon layer to an insulator substrate, and removing the silicon substrate. The method additionally involves forming electrical contact regions in the thin silicon layer for the buried collectors. 10 figs.

  19. Limited Panniculectomy for Adult Buried Penis Repair.

    PubMed

    Figler, Bradley D; Chery, Lisly; Friedrich, Jeffrey B; Wessells, Hunter; Voelzke, Bryan B

    2015-11-01

    Patients with buried or hidden penis may be unable to carry out normal hygiene, void with a directable urine stream, or be sexually active as a result of the condition. Although these patients are nearly always obese, weight loss often does not reverse the problem, as the mons pannus may remain after weight loss. Furthermore, associated penile skin changes such as lichen sclerosus or stenosis of the penile shaft skin are often irreversible. Treatment includes removal of the diseased shaft skin surrounding the penis, in combination with a limited panniculectomy. The authors present their technique for this procedure in a typical patient with buried penis that prevented him from voiding effectively. PMID:26182174

  20. Detection of buried mines with seismic sonar

    NASA Astrophysics Data System (ADS)

    Muir, Thomas G.; Baker, Steven R.; Gaghan, Frederick E.; Fitzpatrick, Sean M.; Hall, Patrick W.; Sheetz, Kraig E.; Guy, Jeremie

    2003-10-01

    Prior research on seismo-acoustic sonar for detection of buried targets [J. Acoust. Soc. Am. 103, 2333-2343 (1998)] has continued with examination of the target strengths of buried test targets as well as targets of interest, and has also examined detection and confirmatory classification of these, all using arrays of seismic sources and receivers as well as signal processing techniques to enhance target recognition. The target strengths of two test targets (one a steel gas bottle, the other an aluminum powder keg), buried in a sand beach, were examined as a function of internal mass load, to evaluate theory developed for seismic sonar target strength [J. Acoust. Soc. Am. 103, 2344-2353 (1998)]. The detection of buried naval and military targets of interest was achieved with an array of 7 shaker sources and 5, three-axis seismometers, at a range of 5 m. Vector polarization filtering was the main signal processing technique for detection. It capitalizes on the fact that the vertical and horizontal components in Rayleigh wave echoes are 90 deg out of phase, enabling complex variable processing to obtain the imaginary component of the signal power versus time, which is unique to Rayleigh waves. Gabor matrix processing of this signal component was the main technique used to determine whether the target was man-made or just a natural target in the environment. [Work sponsored by ONR.

  1. 47 CFR 32.2423 - Buried cable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2423 Buried cable. (a... other associated material used in constructing a physical path for the transmission of... single or paired conductor cable, wire and other associated material used in constructing a physical...

  2. Seismic response of buried submarine pipelines

    SciTech Connect

    Datta, T.K.; Mashaly, E.A.

    1988-12-01

    Submarine pipelines are many a time buried into a jet-blasted channel in the seabed. Seismic response of such buried pipelines are investigated in this paper. The earthquake is considered as a partially correlated stationary random proceeds characterized by a power spectral density function (PSDF). The cross-spectral density function between two random inputs along the length of the pipe is defined with the help of the local earthquake PSDF, which is the same for all points, and a frequency-dependent, exponentially decaying function (with distance). A lumped-mass model with 2-D beam elements is used to write the equation of motion. Soil resistance to dynamic excitation along the pipe length is obtained in an approximate manner with the help of frequency-independent impedance functions derived from half-space analysis and Mindlin's static stresses within the soil due to point loads. The responses are obtained by a spectral analysis for horizontal ground motions in two principal directions, which are assumed to coincide with pipe axis and the perpendicular to it. Using the proposed method of analysis, a parametric study is conducted. The results of the study help in understanding the behavior of buried submarine pipelines under seismic forces and its differences from that of the buried pipelines on land.

  3. In situ vitrification on buried waste

    SciTech Connect

    Bates, S.O.

    1992-01-01

    In situ vitrification (ISV) is being evaluated as a remedial treatment technology for buried mixed and transuranic (TRU) wastes at the Subsurface Disposal Area (SDA) at Idaho National Engineering Laboratory (INEL) and can be related to buried wastes at other Department of Energy (DOE) sites. There are numerous locations around the DOE Complex where wastes were buried in the ground or stored for future burial. The Buried Waste Program (BWP) is conducting a comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the Department of Energy - Field Office Idaho (DOE-ID). As part of the RI/FS, an ISV scoping study on the treatability of the SDA mixed low-level and mixed TRU waste is being performed for applicability to remediation of the waste at the Radioactive Waste Management Complex (RWMC). The ISV project being conducted at the INEL by EG G Idaho, Inc. consists of a treatability investigation to collect data to satisfy nine CERCLA criteria with regards to the SDA. This treatability investigation involves a series of experiments and related efforts to study the feasibility of ISV for remediation of mixed and TRU waste disposed of at the SDA.

  4. In situ vitrification on buried waste

    SciTech Connect

    Bates, S.O.

    1992-08-01

    In situ vitrification (ISV) is being evaluated as a remedial treatment technology for buried mixed and transuranic (TRU) wastes at the Subsurface Disposal Area (SDA) at Idaho National Engineering Laboratory (INEL) and can be related to buried wastes at other Department of Energy (DOE) sites. There are numerous locations around the DOE Complex where wastes were buried in the ground or stored for future burial. The Buried Waste Program (BWP) is conducting a comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the Department of Energy - Field Office Idaho (DOE-ID). As part of the RI/FS, an ISV scoping study on the treatability of the SDA mixed low-level and mixed TRU waste is being performed for applicability to remediation of the waste at the Radioactive Waste Management Complex (RWMC). The ISV project being conducted at the INEL by EG&G Idaho, Inc. consists of a treatability investigation to collect data to satisfy nine CERCLA criteria with regards to the SDA. This treatability investigation involves a series of experiments and related efforts to study the feasibility of ISV for remediation of mixed and TRU waste disposed of at the SDA.

  5. Hydrogen in amorphous silicon

    SciTech Connect

    Peercy, P. S.

    1980-01-01

    The structural aspects of amorphous silicon and the role of hydrogen in this structure are reviewed with emphasis on ion implantation studies. In amorphous silicon produced by Si ion implantation of crystalline silicon, the material reconstructs into a metastable amorphous structure which has optical and electrical properties qualitatively similar to the corresponding properties in high-purity evaporated amorphous silicon. Hydrogen studies further indicate that these structures will accomodate less than or equal to 5 at.% hydrogen and this hydrogen is bonded predominantly in a monohydride (SiH/sub 1/) site. Larger hydrogen concentrations than this can be achieved under certain conditions, but the excess hydrogen may be attributed to defects and voids in the material. Similarly, glow discharge or sputter deposited amorphous silicon has more desirable electrical and optical properties when the material is prepared with low hydrogen concentration and monohydride bonding. Results of structural studies and hydrogen incorporation in amorphous silicon were discussed relative to the different models proposed for amorphous silicon.

  6. Subcritical scattering from buried elastic shells.

    PubMed

    Lucifredi, Irena; Schmidt, Henrik

    2006-12-01

    Buried objects have been largely undetectable by traditional high-frequency sonars due to their insignificant bottom penetration. Further, even a high grazing angle sonar approach is vastly limited by the coverage rate dictated by the finite water depth, making the detection and classification of buried objects using low frequency, subcritical sonar an interesting alternative. On the other hand, such a concept would require classification clues different from the traditional high-resolution imaging and shadows to maintain low false alarm rates. A potential alternative, even for buried targets, is classification based on the acoustic signatures of man-made elastic targets. However, the elastic responses of buried and proud targets are significantly different. The objective of this work is to identify, analyze, and explain some of the effects of the sediment and the proximity of the seabed interface on the scattering of sound from completely and partially buried elastic shells. The analysis was performed using focused array processing of data from the GOATS98 experiment carried out jointly by MIT and SACLANTCEN, and a new hybrid modeling capability combining a virtual source-or wave-field superposition-approach with an exact spectral integral representation of the Green's functions for a stratified ocean waveguide, incorporating all multiple scattering between the object and the seabed. Among the principal results is the demonstration of the significant role of structural circumferential waves in converting incident, evanescent waves into backscattered body waves, emanating to the receivers at supercritical grazing angles, in effect making the target appear closer to the sonar than predicted by traditional ray theory. PMID:17225387

  7. Sensor feature fusion for detecting buried objects

    SciTech Connect

    Clark, G.A.; Sengupta, S.K.; Sherwood, R.J.; Hernandez, J.E.; Buhl, M.R.; Schaich, P.C.; Kane, R.J.; Barth, M.J.; DelGrande, N.K.

    1993-04-01

    Given multiple registered images of the earth`s surface from dual-band sensors, our system fuses information from the sensors to reduce the effects of clutter and improve the ability to detect buried or surface target sites. The sensor suite currently includes two sensors (5 micron and 10 micron wavelengths) and one ground penetrating radar (GPR) of the wide-band pulsed synthetic aperture type. We use a supervised teaming pattern recognition approach to detect metal and plastic land mines buried in soil. The overall process consists of four main parts: Preprocessing, feature extraction, feature selection, and classification. These parts are used in a two step process to classify a subimage. Thee first step, referred to as feature selection, determines the features of sub-images which result in the greatest separability among the classes. The second step, image labeling, uses the selected features and the decisions from a pattern classifier to label the regions in the image which are likely to correspond to buried mines. We extract features from the images, and use feature selection algorithms to select only the most important features according to their contribution to correct detections. This allows us to save computational complexity and determine which of the sensors add value to the detection system. The most important features from the various sensors are fused using supervised teaming pattern classifiers (including neural networks). We present results of experiments to detect buried land mines from real data, and evaluate the usefulness of fusing feature information from multiple sensor types, including dual-band infrared and ground penetrating radar. The novelty of the work lies mostly in the combination of the algorithms and their application to the very important and currently unsolved operational problem of detecting buried land mines from an airborne standoff platform.

  8. Amorphous diamond films

    DOEpatents

    Falabella, S.

    1998-06-09

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  9. 47 CFR 32.6423 - Buried cable expense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Buried cable expense. 32.6423 Section 32.6423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6423 Buried cable expense. (a) This account shall include expenses associated with buried cable. (b) Subsidiary record...

  10. 47 CFR 32.6423 - Buried cable expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Buried cable expense. 32.6423 Section 32.6423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6423 Buried cable expense. (a) This account shall include expenses associated with buried cable. (b) Subsidiary record...

  11. 47 CFR 32.6423 - Buried cable expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Buried cable expense. 32.6423 Section 32.6423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6423 Buried cable expense. (a) This account shall include expenses associated with buried cable. (b) Subsidiary record...

  12. 47 CFR 32.6423 - Buried cable expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Buried cable expense. 32.6423 Section 32.6423... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6423 Buried cable expense. (a) This account shall include expenses associated with buried cable. (b) Subsidiary record...

  13. Amorphous metal alloy

    DOEpatents

    Wang, R.; Merz, M.D.

    1980-04-09

    Amorphous metal alloys of the iron-chromium and nickel-chromium type have excellent corrosion resistance and high temperature stability and are suitable for use as a protective coating on less corrosion resistant substrates. The alloys are stabilized in the amorphous state by one or more elements of titanium, zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten. The alloy is preferably prepared by sputter deposition.

  14. Process for buried metallization in diamond film

    NASA Astrophysics Data System (ADS)

    Lake, Max L.; Ting, Jyh-Ming; Lagounov, Alex; Tang, Chi

    1996-03-01

    The objective of this research was to investigate methods of combining chemical vapor deposition diamond growth techniques with state-of-the-art physical vapor deposition or ion beam enhanced deposition to produce buried metallization of polycrystalline diamond films. The mechanical and electrical integrity of both the insulating and conducting elements following metallization and diamond overgrowth was shown. Both methods were shown to have bonding strength sufficient to withstand tape lift-off, which is regarded to be a good indication of strength needed for die attachment and wire bonding. Diamond overgrowth was also shown, thus enabling buried metallized layers to be created. Electrical resistivity property measurements on metallized layers and between metallization separated by diamond films were shown to be sufficient to allow the use of diamond as an insulating inter-layer material for multi-layer circuit boards.

  15. Buried pipelines in large fault movements

    SciTech Connect

    Wang, L.J.; Wang, L.R.L.

    1995-12-31

    Responses of buried pipelines in large fault movements are examined based upon a non-linear cantilever beam analogy. This analogy assumes that the pipeline in a large deflection zone behaves like a cantilever beam under a transverse-concentrated shear at the inflection point with a uniformly distributed soil pressure along the entire span. The tangent modulus approach is adopted to analyze the coupled axial force-bending moment interaction on pipeline deformations in the inelastic range. The buckling load of compressive pipeline is computed by the modified Newmark`s numerical integration scheme. Parametric studies of both tensile and compressive pipeline responses to various fault movements, pipeline/fault crossing angles, soil/pipe friction angles, buried depths, pipe diameters and thickness are investigated. It is shown by the comparisons that previous findings were unconservative.

  16. Buried Waste Integrated Demonstration Strategy Plan

    SciTech Connect

    Kostelnik, K.M.

    1993-02-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. These efforts are identified and coordinated in support of the US Department of Energy (DOE), Environmental Restoration and Waste Management (ERWM) needs and objectives. The present focus of BWID is to support retrieval and ex situ treatment configuration options. Future activities will explore and support containment and stabilization efforts in addition to the retrieval/ex situ treatment options. Long and short term strategies of the BWID are provided. Processes for identifying technological needs, screening candidate technologies for BWID applicability, researching technical issues, field demonstrating technologies, evaluating demonstration results to determine each technology`s threshold of capability, and commercializing successfully demonstrated technologies for implementation for environmental restoration also are presented in this report.

  17. Buried Waste Integrated Demonstration Strategy Plan

    SciTech Connect

    Kostelnik, K.M.

    1993-02-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. These efforts are identified and coordinated in support of the US Department of Energy (DOE), Environmental Restoration and Waste Management (ERWM) needs and objectives. The present focus of BWID is to support retrieval and ex situ treatment configuration options. Future activities will explore and support containment and stabilization efforts in addition to the retrieval/ex situ treatment options. Long and short term strategies of the BWID are provided. Processes for identifying technological needs, screening candidate technologies for BWID applicability, researching technical issues, field demonstrating technologies, evaluating demonstration results to determine each technology's threshold of capability, and commercializing successfully demonstrated technologies for implementation for environmental restoration also are presented in this report.

  18. Coaxial inverted geometry transistor having buried emitter

    NASA Technical Reports Server (NTRS)

    Hruby, R. J.; Cress, S. B.; Dunn, W. R. (Inventor)

    1973-01-01

    The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed.

  19. Buried caldera of mauna kea volcano, hawaii.

    PubMed

    Porter, S C

    1972-03-31

    An elliptical caldera (2.1 by 2.8 kilometers) at the summit of Mauna Kea volcano is inferred to lie buried beneath hawaiite lava flows and pyroclastic cones at an altitude of approximately 3850 meters. Stratigraphic relationships indicate that hawaiite eruptions began before a pre-Wisconsin period of ice-cap glaciation and that the crest of the mountain attained its present altitude and gross form during a glaciation of probable Early Wisconsin age. PMID:17842285

  20. Laser neutralization of surface and buried munitions

    NASA Astrophysics Data System (ADS)

    Habersat, James D.; Schilling, Bradley W.; Alexander, Joe; Lehecka, Thomas

    2012-06-01

    In recent years NVESD has been investigating laser-based neutralization of buried mines and minelike targets. This paper covers the most recent efforts in this area. A field-test was conducted to demonstrate the state-of-the-art capability for standoff laser neutralization of surface and buried mines. The neutralization laser is a Ytterbium fiber laser with a nominal power output of 10 kW and a beam quality of M2 ~ 1.8 at maximum power. Test trials were conducted at a standoff range of 50 meters with a 20° angle of attack. The laser was focused to a submillimeter spot using a Cassegrain telescope with a 12.5 inch diameter primary mirror. The targets were 105 mm artillery rounds with a composition B explosive fill. Three types of overburden were studied: sand, soil, and gravel. Laser neutralization capability was demonstrated under these conditions for live rounds buried under 7 cm of dry sand, 4 cm of soil, and 2 cm of gravel.

  1. Bearingless Segment Motor with Buried Magnets

    NASA Astrophysics Data System (ADS)

    Gruber, Wolfgang; Amrhein, Wolfgang; Stallinger, Thomas; Grabner, Herbert

    Bearingless motors combine contactless levitation and rotation in a preferably compact system design, because bearing as well as motor windings are located on the same lamination stack. The bearingless slice motor features comparatively low complexity for a fully magnetically levitated drive system, because it allows the passive stabilization of three degrees of freedom by reluctance forces. By the use of a proper control scheme and the superposition of different current components, bearing forces and motor torque can be generated simultaneously by applying concentrated windings. This leads to a further simplification of the mechanical configuration. The bearingless segment motor features such concentrated coils on separated stator elements, which reduce the stator iron and therefore weight and cost, especially for constructions with large diameter. However, so far all bearingless slice motors are designed with surface mounted permanent magnets on the rotor, neglecting the advantages of buried permanent magnets. In this paper a novel bearingless segment motor featuring a rotor with buried permanent magnets is investigated. The motor specific mathematical model of force and torque generation is presented, a proper control scheme is introduced and the optimization of the prototype motor is outlined. Motor specific considerations concerning the angular sensors are given. Finally, the performance of the bearingless segment motor with buried permanent magnets is shown by the comparison of simulation results with measurement data of the manufactured prototype.

  2. DOE complex buried waste characterization assessment

    SciTech Connect

    Kaae, P.S.; Holter, G.M.; Garrett, S.M.K.

    1993-01-01

    The work described in this report was conducted by Pacific Northwest Laboratory to provide information to the Buried Waste Integrated Demonstration (BWID) program. The information in this report is intended to provide a complex-wide planning base for th.e BWID to ensure that BWID activities are appropriately focused to address the range of remediation problems existing across the US Department of Energy (DOE) complex. This report contains information characterizing the 2.1 million m[sup 3] of buried and stored wastes and their associated sites at six major DOE facilities. Approximately 85% of this waste is low-level waste, with about 12% TRU or TRU mixed waste; the remaining 3% is low-level mixed waste. In addition, the report describes soil contamination sites across the complex. Some of the details that would be useful in further characterizing the buried wastes and contaminated soil sites across the DOE complex are either unavailable or difficult to locate. Several options for accessing this information and/or improving the information that is available are identified in the report. This document is a companion to Technology Needs for Remediation: Hanford and Other DOE Sites, PNL-8328 (Stapp 1993).

  3. Multiple instance learning for buried hazard detection

    NASA Astrophysics Data System (ADS)

    Rice, Joseph; Pinar, Anthony; Havens, Timothy C.; Webb, Adam; Schulz, Timothy J.

    2016-05-01

    Buried explosives hazards are one of the many deadly threats facing our Soldiers, thus the U.S. Army is interested in the detection and neutralization of these hazards. One method of buried target detection uses forward-looking ground-penetrating radar (FLGPR), and it has grown in popularity due to its ability to detect buried targets at a standoff distance. FLGPR approaches often use machine learning techniques to improve the accuracy of detection. We investigate an approach to explosive hazard detection that exploits multi-instance features to discriminate between hazardous and non-hazardous returns in FLGPR data. One challenge this problem presents is a high number of clutter and non-target objects relative to the number of targets present. Our approach learns a bag of words model of the multi-instance signatures of potential targets and confuser objects in order to classify alarms as either targets or false alarms. We demonstrate our method on test data collected at a U.S. Army test site.

  4. Formation of amorphous materials

    DOEpatents

    Johnson, William L.; Schwarz, Ricardo B.

    1986-01-01

    Metastable amorphous or fine crystalline materials are formed by solid state reactions by diffusion of a metallic component into a solid compound or by diffusion of a gas into an intermetallic compound. The invention can be practiced on layers of metals deposited on an amorphous substrate or by intermixing powders with nucleating seed granules. All that is required is that the diffusion of the first component into the second component be much faster than the self-diffusion of the first component. The method is practiced at a temperature below the temperature at which the amorphous phase transforms into one or more crystalline phases and near or below the temperature at which the ratio of the rate of diffusion of the first component to the rate of self-diffusion is at least 10.sup.4. This anomalous diffusion criteria is found in many binary, tertiary and higher ordered systems of alloys and appears to be found in all alloy systems that form amorphous materials by rapid quenching. The method of the invention can totally convert much larger dimensional materials to amorphous materials in practical periods of several hours or less.

  5. Structural Amorphous Steels

    NASA Astrophysics Data System (ADS)

    Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

    2004-06-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

  6. Regrowth-related defect formation and evolution in 1 MeV amorphized (001) Ge

    SciTech Connect

    Hickey, D. P.; Bryan, Z. L.; Jones, K. S.; Elliman, R. G.; Haller, E. E.

    2007-03-26

    Ge implanted with 1 MeV Si{sup +} at a dose of 1x10{sup 15} cm{sup -2} creates a buried amorphous layer that, upon regrowth, exhibits several forms of defects-end-of-range (EOR), regrowth-related, and clamshell defects. Unlike Si, no planar (311) defects are observed. The minimal EOR defects are small dotlike defects and are very unstable, dissolving between 450 and 550 deg. C. This is in contrast to Si, where the EOR defects are very stable. The amorphous layer results in both regrowth-related defects and clamshell defects, which were more stable than the EOR damage.

  7. Buried Alive: Microbes from Ancient Halite.

    PubMed

    Jaakkola, Salla T; Ravantti, Janne J; Oksanen, Hanna M; Bamford, Dennis H

    2016-02-01

    Halite is one of the most extreme environments to support life. From the drought of the Atacama Desert to salt deposits up to Permian in age and 2000 meters in burial depth, live microbes have been found. Because halite is geologically stable and impermeable to ground water, the microbes allegedly have a syndepositional origin, making them the oldest organisms known to live on Earth. Recently, our understanding of the microbial diversity inside halite has broadened, and the first genome sequences of ancient halite-buried microbes are now available. The secrets behind prolonged survival in salt are also starting to be revealed. PMID:26796472

  8. Fabrication of Buried Nanochannels From Nanowire Patterns

    NASA Technical Reports Server (NTRS)

    Choi, Daniel; Yang, Eui-Hyeok

    2007-01-01

    A method of fabricating channels having widths of tens of nanometers in silicon substrates and burying the channels under overlying layers of dielectric materials has been demonstrated. With further refinement, the method might be useful for fabricating nanochannels for manipulation and analysis of large biomolecules at single-molecule resolution. Unlike in prior methods, burying the channels does not involve bonding of flat wafers to the silicon substrates to cover exposed channels in the substrates. Instead, the formation and burying of the channels are accomplished in a more sophisticated process that is less vulnerable to defects in the substrates and less likely to result in clogging of, or leakage from, the channels. In this method, the first step is to establish the channel pattern by forming an array of sacrificial metal nanowires on an SiO2-on-Si substrate. In particular, the wire pattern is made by use of focused-ion-beam (FIB) lithography and a subsequent metallization/lift-off process. The pattern of metal nanowires is then transferred onto the SiO2 layer by reactive-ion etching, which yields sacrificial SiO2 nanowires covered by metal. After removal of the metal covering the SiO2 nanowires, what remains are SiO2 nanowires on an Si substrate. Plasma-enhanced chemical vapor deposition (PECVD) is used to form a layer of a dielectric material over the Si substrate and over the SiO2 wires on the surface of the substrate. FIB milling is then performed to form trenches at both ends of each SiO2 wire. The trenches serve as openings for the entry of chemicals that etch SiO2 much faster than they etch Si. Provided that the nanowires are not so long that the diffusion of the etching chemicals is blocked, the sacrificial SiO2 nanowires become etched out from between the dielectric material and the Si substrate, leaving buried channels. At the time of reporting the information for this article, channels 3 m long, 20 nm deep, and 80 nm wide (see figure) had been

  9. Amorphous semiconductor solar cell

    DOEpatents

    Dalal, Vikram L.

    1981-01-01

    A solar cell comprising a back electrical contact, amorphous silicon semiconductor base and junction layers and a top electrical contact includes in its manufacture the step of heat treating the physical junction between the base layer and junction layer to diffuse the dopant species at the physical junction into the base layer.

  10. Disorder-induced amorphization

    SciTech Connect

    Lam, N.Q.; Okamoto, P.R.; Li, Mo

    1997-03-01

    Many crystalline materials undergo a crystalline-to-amorphous (c-a) phase transition when subjected to energetic particle irradiation at low temperatures. By focusing on the mean-square static atomic displacement as a generic measure of chemical and topological disorder, we are led quite naturally to a generalized version of the Lindemann melting criterion as a conceptual framework for a unified thermodynamic approach to solid-state amorphizing transformations. In its simplest form, the generalized Lindemann criterion assumes that the sum of the static and dynamic mean-square atomic displacements is constant along the polymorphous melting curve so that c-a transformations can be understood simply as melting of a critically-disordered crystal at temperatures below the glass transition temperature where the supercooled liquid can persist indefinitely in a configurationally-frozen state. Evidence in support of the generalized Lindemann melting criterion for amorphization is provided by a large variety of experimental observations and by molecular dynamics simulations of heat-induced melting and of defect-induced amorphization of intermetallic compounds.

  11. Amorphous silicon photovoltaic devices

    SciTech Connect

    Carlson, David E.; Lin, Guang H.; Ganguly, Gautam

    2004-08-31

    This invention is a photovoltaic device comprising an intrinsic or i-layer of amorphous silicon and where the photovoltaic device is more efficient at converting light energy to electric energy at high operating temperatures than at low operating temperatures. The photovoltaic devices of this invention are suitable for use in high temperature operating environments.

  12. Substrate discrimination in burying beetles, Nicrophorus orbicollis (Coleoptera: Silphidae)

    USGS Publications Warehouse

    Muths, Erin Louise

    1991-01-01

    Burying beetles Nicrophorus orbicollis (Coleoptera: Silphidae) secure and bury small vertebrate carcasses as a food resource for their offspring and themselves. Burial may take place at the point of carcass discovery or at some distance from that site. Burying beetles were tested to determine if they discriminate between different substrates when burying a carcass. Three substrates were presented simultaneously. Substrate one contained soil from typical beetle habitat; substrates two and three contained 2:1 and 5:1 ratios, respectively, of soil and a senescent prairie grass (Panicum virgatum), which added a bulk structural component to the soil. Beetles generally moved and buried the carcass within 24 hours. Results for both paired and individual trials suggest that burying beetles discriminate between substrates, preferring substrates with added bulk over those without.

  13. Virtual environmental applications for buried waste characterization technology evaluation report

    SciTech Connect

    1995-05-01

    The project, Virtual Environment Applications for Buried Waste Characterization, was initiated in the Buried Waste Integrated Demonstration Program in fiscal year 1994. This project is a research and development effort that supports the remediation of buried waste by identifying and examining the issues, needs, and feasibility of creating virtual environments using available characterization and other data. This document describes the progress and results from this project during the past year.

  14. Sensor system for buried waste containment sites

    DOEpatents

    Smith, Ann Marie; Gardner, Bradley M.; Kostelnik, Kevin M.; Partin, Judy K.; Lancaster, Gregory D.; Pfeifer, May Catherine

    2000-01-01

    A sensor system is disclosed for a buried waste containment site having a bottom wall barrier and/or sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

  15. Computer vision for locating buried objects

    SciTech Connect

    Clark, G.A.; Hernandez, J.E.; DelGrande, N.K.; Sherwood, R.J.; Lu, Shin-Yee; Schaich, P.C.; Durbin, P.F.

    1991-11-01

    Given two registered images of the earth, measured with aerial dual-band infrared (IR) sensors, we use advanced computer vision/automatic target recognition techniques to estimate the positions of buried land mines. The images are very difficult to interpret, because of large amounts of clutter. Conventional techniques use single-band imagery and simple correlations. They rely heavily on the judgment of the human doing the interpretation, and give unsatisfactory results with difficult data sets of the type we analyzed. Our automatic algorithms are able to eliminate most of the clutter and give greatly improved indications of regions in the image that could be interpreted as mines. The novelty of our approach lies in the following aspects: (1) a patented data fusion technique using two IR images and physical principles based on Planck`s law, (2) a new region-based texture segmentation algorithm using Gabor Transform features and a clustering/thresholding algorithm based on a neural network (Self-Organizing Feature Map), (3) Prior knowledge of measured feasible temperatures and emissivities, and (4) results with real data using buried surrogate mines.

  16. Computer vision for locating buried objects

    SciTech Connect

    Clark, G.A.; Hernandez, J.E.; DelGrande, N.K.; Sherwood, R.J.; Lu, Shin-Yee; Schaich, P.C.; Durbin, P.F.

    1991-11-01

    Given two registered images of the earth, measured with aerial dual-band infrared (IR) sensors, we use advanced computer vision/automatic target recognition techniques to estimate the positions of buried land mines. The images are very difficult to interpret, because of large amounts of clutter. Conventional techniques use single-band imagery and simple correlations. They rely heavily on the judgment of the human doing the interpretation, and give unsatisfactory results with difficult data sets of the type we analyzed. Our automatic algorithms are able to eliminate most of the clutter and give greatly improved indications of regions in the image that could be interpreted as mines. The novelty of our approach lies in the following aspects: (1) a patented data fusion technique using two IR images and physical principles based on Planck's law, (2) a new region-based texture segmentation algorithm using Gabor Transform features and a clustering/thresholding algorithm based on a neural network (Self-Organizing Feature Map), (3) Prior knowledge of measured feasible temperatures and emissivities, and (4) results with real data using buried surrogate mines.

  17. Buried Waste Integrated Demonstration Plan. Revision 1

    SciTech Connect

    Kostelnik, K.M.

    1991-12-01

    This document presents the plan of activities for the Buried Waste Integrated Demonstration (BWID) program which supports the environmental restoration (ER) objectives of the Department of Energy (DOE) Complex. Discussed in this plan are the objectives, organization, roles and responsibilities, and the process for implementing and managing BWID. BWID is hosted at the Idaho National Engineering Laboratory (INEL), but involves participants from throughout the DOE Complex, private industry, universities, and the international community. These participants will support, demonstrate, and evaluate a suite of advanced technologies representing a comprehensive remediation system for the effective and efficient remediation of buried waste. The processes for identifying technological needs, screening candidate technologies for applicability and maturity, selecting appropriate technologies for demonstration, field demonstrating, evaluation of results and transferring technologies to environmental restoration programs are also presented. This document further describes the elements of project planning and control that apply to BWID. It addresses the management processes, operating procedures, programmatic and technical objectives, and schedules. Key functions in support of each demonstration such as regulatory coordination, safety analyses, risk evaluations, facility requirements, and data management are presented.

  18. Healing from incest: resurrecting the buried self.

    PubMed

    Godbey, J K; Hutchinson, S A

    1996-10-01

    Writers on the incest experience estimate conservatively that 10% to 30% of all girls and 30% of all boys have had at least one childhood experience of incest. Incest is emotionally devastating to a child as it involves betrayal, and the irretrievable loss of trust in the adults in the child's life. Little is written about the healing processes of incest survivors. The purpose of this study was to generate a substantive grounded theory that provides an explanatory schema for understanding the healing process of adult female incest survivors. The sample consisted of 10 adult women who had a history of incest and who volunteered to participate in in-depth interviews. Data were analyzed using grounded theory techniques. Data analysis revealed that these women had buried an integral part of the self because of the trauma of incest; The healing process required resurrecting the buried self through a series of seven phases. The model generated from this research provides a heuristic for nurse therapists that assists in assessing and counseling incest survivors. PMID:8897713

  19. System and method for removal of buried objects

    SciTech Connect

    Alexander, Robert G.; Crass, Dennis; Grams, William; Phillips, Steven J.; Riess, Mark

    2008-06-03

    The present invention is a system and method for removal of buried objects. According to one embodiment of the invention, a crane with a vibrator casing driver is used to lift and suspend a large diameter steel casing over the buried object. Then the casing is driven into the ground by the vibratory driver until the casing surrounds the buried object. Then the open bottom of the casing is sealed shut by injecting grout into the ground within the casing near its bottom. When the seal has cured and hardened, the top of the casing is lifted to retrieve the casing, with the buried object inside, from the ground.

  20. Multi channel FM reflection profiler for buried pipeline surveying

    SciTech Connect

    Schock, S.G.; LeBlanc, L.R.

    1996-12-31

    A towed multi-channel FM acoustic reflection profiler has been developed for locating and generating images of buried objects. One significant application of this sonar is buried pipeline surveying. The multi-channel reflection profiler uses 16 line arrays mounted in a towed vehicle to determine the position and burial depth of an 18 inch steel pipe filled with concrete buried under 1.5 meters of sand. This sonar will allow a survey vessel to continuously track a buried pipeline providing a continuous record of pipe burial depth and position.

  1. Amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  2. Amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Perez-Mendez, Victor; Kaplan, Selig N.

    1992-01-01

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  3. Backyard bolides: finding a buried impact crater.

    NASA Astrophysics Data System (ADS)

    Poag, C. W.

    1998-10-01

    The author reports the scientific activities that led to his discovery of a huge submerged impact crater in Chesapeake Bay, some 140 km east of Atlantic City, New Jersey. This crater, buried under 350 m of sediment is 80 km wide and almost 1 km deep. Microfossil evidence shows that the crater is approximately 35 million years old. The author futher identified 14 small secondary craters with diamters of 0.4 to 0.5 km diameter within 60 km of the primary crater. These were caused by the impact of huge blocks of material ejected by the primary impact event. In addition, the author identified an intermediate-size primary crater (19 km diameter) in Toms Canyon, some 300 km from the Chesapeake crater and, again from microfossil evidence, identical in age.

  4. Buried waste integrated demonstration technology integration process

    SciTech Connect

    Ferguson, J.S.; Ferguson, J.E.

    1992-04-01

    A Technology integration Process was developed for the Idaho National Energy Laboratories (INEL) Buried Waste Integrated Demonstration (BWID) Program to facilitate the transfer of technology and knowledge from industry, universities, and other Federal agencies into the BWID; to successfully transfer demonstrated technology and knowledge from the BWID to industry, universities, and other Federal agencies; and to share demonstrated technologies and knowledge between Integrated Demonstrations and other Department of Energy (DOE) spread throughout the DOE Complex. This document also details specific methods and tools for integrating and transferring technologies into or out of the BWID program. The document provides background on the BWID program and technology development needs, demonstrates the direction of technology transfer, illustrates current processes for this transfer, and lists points of contact for prospective participants in the BWID technology transfer efforts. The Technology Integration Process was prepared to ensure compliance with the requirements of DOE's Office of Technology Development (OTD).

  5. Buried waste integrated demonstration technology integration process

    SciTech Connect

    Ferguson, J.S.; Ferguson, J.E.

    1992-04-01

    A Technology integration Process was developed for the Idaho National Energy Laboratories (INEL) Buried Waste Integrated Demonstration (BWID) Program to facilitate the transfer of technology and knowledge from industry, universities, and other Federal agencies into the BWID; to successfully transfer demonstrated technology and knowledge from the BWID to industry, universities, and other Federal agencies; and to share demonstrated technologies and knowledge between Integrated Demonstrations and other Department of Energy (DOE) spread throughout the DOE Complex. This document also details specific methods and tools for integrating and transferring technologies into or out of the BWID program. The document provides background on the BWID program and technology development needs, demonstrates the direction of technology transfer, illustrates current processes for this transfer, and lists points of contact for prospective participants in the BWID technology transfer efforts. The Technology Integration Process was prepared to ensure compliance with the requirements of DOE`s Office of Technology Development (OTD).

  6. Strain field of a buried oxide aperture

    NASA Astrophysics Data System (ADS)

    Kießling, F.; Niermann, T.; Lehmann, M.; Schulze, J.-H.; Strittmatter, A.; Schliwa, A.; Pohl, U. W.

    2015-02-01

    The strain field of an AlOx current aperture, fabricated by selective oxidation of an AlAs/GaAs layer buried in a circular GaAs mesa, is studied. Components of the strain tensor for a thin cross-section lamella cut out of such a structure are evaluated from dark-field electron holography, proving the validity of simulations based on linear elasticity. Simulation of the entire structure is utilized to prepare mesa surfaces with tailored strain fields for controlling the nucleation site of InGaAs quantum dots. The experimental proof of strain simulations allows estimating the magnitude of piezoelectricity, yielding for the studied mesa structures a piezoelectric potential up to 50 mV.

  7. Landslide Buries Valley of the Geysers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Geysers are a rare natural phenomena found only in a few places, such as New Zealand, Iceland, the United States (Yellowstone National Park), and on Russia's far eastern Kamchatka Peninsula. On June 3, 2007, one of these rare geyser fields was severely damaged when a landslide rolled through Russia's Valley of the Geysers. The landslide--a mix of mud, melting snow, trees, and boulders--tore a scar on the land and buried a number of geysers, thermal pools, and waterfalls in the valley. It also blocked the Geyser River, causing a new thermal lake to pool upstream. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this infrared-enhanced image on June 11, 2007, a week after the slide. The image shows the valley, the landslide, and the new thermal lake. Even in mid-June, just days from the start of summer, the landscape is generally covered in snow, though the geologically heated valley is relatively snow free. The tree-covered hills are red (the color of vegetation in this false-color treatment), providing a strong contrast to the aquamarine water and the gray-brown slide. According to the Russian News and Information Agency (RIA) [English language], the slide left a path roughly a kilometer and a half (one mile) long and 200 meters (600 feet) wide. Within hours of the landslide, the water in the new lake inundated a number of additional geysers. The geysers directly buried under the landslide now lie under as much as 60 meters (180 feet) of material, according to RIA reports. It is unlikely that the geysers will be able to force a new opening through this thick layer, adds RIA. Among those directly buried is Pervenets (Firstborn), the first geyser found in the valley, in 1941. Other geysers, such as the Bolshoi (Greater) and Maly (Lesser) Geysers, were silenced when buried by water building up behind the new natural dam. According to Vladimir and Andrei Leonov of the Russian Federation Institute of

  8. Buried bumper syndrome: a rare complication of percutaneous endoscopic gastrostomy.

    PubMed

    Kurek, Krzysztof; Baniukiewicz, Andrzej; Świdnicka-Siergiejko, Agnieszka

    2015-09-01

    Feeding via percutaneous endoscopic gastrostomy (PEG) is the preferred form of alimentation when oral feeding is impossible. Although it is a relatively safe method, some complications may occur. One uncommon PEG complication is buried bumper syndrome. In this paper we report a case of buried bumper syndrome, successfully managed with PEG tube repositioning. PMID:26649105

  9. DOE complex buried waste characterization assessment. Buried Waste Integrated Demonstration Program

    SciTech Connect

    Kaae, P.S.; Holter, G.M.; Garrett, S.M.K.

    1993-01-01

    The work described in this report was conducted by Pacific Northwest Laboratory to provide information to the Buried Waste Integrated Demonstration (BWID) program. The information in this report is intended to provide a complex-wide planning base for th.e BWID to ensure that BWID activities are appropriately focused to address the range of remediation problems existing across the US Department of Energy (DOE) complex. This report contains information characterizing the 2.1 million m{sup 3} of buried and stored wastes and their associated sites at six major DOE facilities. Approximately 85% of this waste is low-level waste, with about 12% TRU or TRU mixed waste; the remaining 3% is low-level mixed waste. In addition, the report describes soil contamination sites across the complex. Some of the details that would be useful in further characterizing the buried wastes and contaminated soil sites across the DOE complex are either unavailable or difficult to locate. Several options for accessing this information and/or improving the information that is available are identified in the report. This document is a companion to Technology Needs for Remediation: Hanford and Other DOE Sites, PNL-8328 (Stapp 1993).

  10. Buried antenna analysis at VHF. Part 1: The buried horizontal electric dipole

    NASA Astrophysics Data System (ADS)

    Burks, J. W.

    1984-01-01

    A method was developed to find the far field radiation pattern of a buried horizontal electric dipole (HED) at 37.5 MHz. The imaginary part of the index of refraction was shown to be negligible for dry soil at this frequency so standard antenna theory and ray optic theory was used. The effect of the ground-air interface was modeled using the transmission coefficient and Snell's law for a dielectric interface. Because the current distribution for the buried HED depends on antenna construction, results are shown for the far field pattern in the air for different current distributions on the HED. The literature on this problem was reviewed; most used the Sommerfeld or moment methods to make the same calculations. The results of one of the reports using the Sommerfeld method could be compared and were found to be similar. An extensive bibliography is included. The analysis was then applied to a buried antenna array. The current distribution was known and was used to calculate the far field pattern. It was concluded that the far field pattern is highly dependent on the current distribution. This part is classified.

  11. Reduction of threading dislocation density in Ge/Si using a heavily As-doped Ge seed layer

    NASA Astrophysics Data System (ADS)

    Lee, Kwang Hong; Bao, Shuyu; Wang, Bing; Wang, Cong; Yoon, Soon Fatt; Michel, Jurgen; Fitzgerald, Eugene A.; Tan, Chuan Seng

    2016-02-01

    High quality germanium (Ge) epitaxial film is grown directly on silicon (001) substrate with 6° off-cut using a heavily arsenic (As) doped Ge seed layer. The growth steps consists of (i) growth of a heavily As-doped Ge seed layer at low temperature (LT, at 400 °C), (ii) Ge growth with As gradually reduced to zero at high temperature (HT, at 650 °C), (iii) pure Ge growth at HT. This is followed by thermal cyclic annealing in hydrogen at temperature ranging from 600 to 850 °C. Analytical characterization have shown that the Ge epitaxial film with a thickness of ˜1.5 µm experiences thermally induced tensile strain of 0.20% with a treading dislocation density (TDD) of mid 106/cm2 which is one order of magnitude lower than the control group without As doping and surface roughness of 0.37 nm. The reduction in TDD is due to the enhancement in velocity of dislocations in an As-doped Ge film.

  12. Dual-band infrared capabilities for imaging buried object sites

    SciTech Connect

    Del Grande, N.K.; Durbin, P.F.; Gorvad, M.R.; Perkins, D.E.; Clark, G.A.; Hernandez, J.E.; Sherwood, R.J.

    1993-04-02

    We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness variations; weather conditions and measurement times. We use good instrumentation to measure the time-varying temperature differences between buried object sites and undisturbed soil sites. We compare near surface soil temperature differences with radiometric infrared (IR) surface temperature differences recorded at 4.7 {plus_minus} 0.4 {mu}m and at 10.6 {plus_minus} 1.0 {mu}m. By producing selective DBIR image ratio maps, we distinguish temperature-difference patterns from surface emissivity effects. We discuss temperature differences between buried object sites, filled hole site (without buried objects), cleared (undisturbed) soil sites, and grass-covered sites (with and without different types of surface clutter). We compare temperature, emissivity-ratio, visible and near-IR reflectance signatures of surface objects, leafy plants and sod. We discuss the physical aspects of environmental, surface and buried target features affecting interpretation of buried targets, surface objects and natural backgrounds.

  13. Nanomoulding with amorphous metals.

    PubMed

    Kumar, Golden; Tang, Hong X; Schroers, Jan

    2009-02-12

    Nanoimprinting promises low-cost fabrication of micro- and nano-devices by embossing features from a hard mould onto thermoplastic materials, typically polymers with low glass transition temperature. The success and proliferation of such methods critically rely on the manufacturing of robust and durable master moulds. Silicon-based moulds are brittle and have limited longevity. Metal moulds are stronger than semiconductors, but patterning of metals on the nanometre scale is limited by their finite grain size. Amorphous metals (metallic glasses) exhibit superior mechanical properties and are intrinsically free from grain size limitations. Here we demonstrate direct nanopatterning of metallic glasses by hot embossing, generating feature sizes as small as 13 nm. After subsequently crystallizing the as-formed metallic glass mould, we show that another amorphous sample of the same alloy can be formed on the crystallized mould. In addition, metallic glass replicas can also be used as moulds for polymers or other metallic glasses with lower softening temperatures. Using this 'spawning' process, we can massively replicate patterned surfaces through direct moulding without using conventional lithography. We anticipate that our findings will catalyse the development of micro- and nanoscale metallic glass applications that capitalize on the outstanding mechanical properties, microstructural homogeneity and isotropy, and ease of thermoplastic forming exhibited by these materials. PMID:19212407

  14. ISV technology development plan for buried waste

    SciTech Connect

    Nickelson, D.F.; Callow, R.A. ); Luey, J.K. )

    1992-07-01

    This report identifies the main technical issues facing the in situ vitrification (ISV) application to buried waste, and presents a plan showing the top-level schedule and projected resources needed to develop and demonstrate the technology for meeting Environmental Restoration Department (ERD) needs. The plan also proposes a model strategy for the technology transfer from the Department of Energy's Office of Technology Development (DOE-OTD) to the Office of Environmental Restoration (DOE-ER) as the technology proceeds from issues resolution (development) to demonstration and remedial readiness. Implementation of the plan would require $34,91 1K in total funding to be spread in the years FY-93 through FY-98. Of this amount, $10,183K is planned to be funded by DOE-OTD through the ISV Integrated Program. The remaining amount, $24,728K, is recommended to be split between the Department of Energy (DOE) Office of Technology Development ($6,670K) and DOE Office of Environmental Restoration ($18,058K).

  15. ISV technology development plan for buried waste

    SciTech Connect

    Nickelson, D.F.; Callow, R.A.; Luey, J.K.

    1992-07-01

    This report identifies the main technical issues facing the in situ vitrification (ISV) application to buried waste, and presents a plan showing the top-level schedule and projected resources needed to develop and demonstrate the technology for meeting Environmental Restoration Department (ERD) needs. The plan also proposes a model strategy for the technology transfer from the Department of Energy`s Office of Technology Development (DOE-OTD) to the Office of Environmental Restoration (DOE-ER) as the technology proceeds from issues resolution (development) to demonstration and remedial readiness. Implementation of the plan would require $34,91 1K in total funding to be spread in the years FY-93 through FY-98. Of this amount, $10,183K is planned to be funded by DOE-OTD through the ISV Integrated Program. The remaining amount, $24,728K, is recommended to be split between the Department of Energy (DOE) Office of Technology Development ($6,670K) and DOE Office of Environmental Restoration ($18,058K).

  16. Xenon Isotope Releases from Buried Transuranic Waste

    NASA Astrophysics Data System (ADS)

    Dresel, P. E.; Waichler, S. R.; Kennedy, B. M.; Hayes, J. C.; McIntyre, J. I.; Giles, J. R.; Sondrup, A. J.

    2004-12-01

    Xenon is an inert rare gas produced as a fission product in nuclear reactors and through spontaneous fission of some transuranic isotopes. Thus, xenon will be released from buried transuranic waste. Two complementary methods are used to measure xenon isotopes: radiometric analysis for short-lived radioxenon isotopes and mass spectrometry for detection of stable xenon isotopes. Initial measurements near disposal facilities at the U.S. Department of Energy's Hanford Site show radioxenon and stable xenon isotopic signatures that are indicative of transuranic waste. Radioxenon analysis has greater sensitivity due to the lower background concentrations and indicates spontaneous fission due to the short half life of the isotopes. Stable isotope ratios may be used to distinguish irradiated fuel sources from pure spontaneous fission sources and are not as dependent on rapid release from the waste form. The release rate is dependent on the type of waste and container integrity and is the greatest unknown in application of this technique. Numerical multi-phase transport modeling of burial grounds at the Idaho National Engineering and Environmental Laboratory indicates that, under generalized conditions, the radioxenon isotopes will diffuse away from the waste and be found in the soil cap and adjacent to the burial ground at levels many orders of magnitude above the detection limit.

  17. Common trenching reduces damage to buried utilities

    SciTech Connect

    Alfiere, E.P.

    1982-09-01

    Since 1972 Niagara Mohawk Power Co. has established a utility corridor, installing 503 miles of buried gas mains and electric cables in a common trench. Their guidelines for common trenching included (1) the developer's responsibility for providing a subdivision map showing the location of each sidewalk, lot, and roadway, (2) an easement strip paralleling the front lot (street) line that is to be cleared and graded by the developer before construction is started, (3) an electric planning department to prepare detailed construction drawings, coordinate plans with other utilities, determine the responsibility for trenching and backfilling, and determine that all the necessary easements have been secured, and (4) construction specifications varying the width and depth of the trench with the number and type of utilties occupying the joint trench. Advantages of the common trench program comprise reduced exposure to digups, communication and concern for each utility's facility, water and sewer construction installed before the common trench, and cost sharing that would reduce each facility's construction and restoration costs.

  18. Odor analysis of decomposing buried human remains

    SciTech Connect

    Vass, Arpad Alexander; Smith, Rob R; Thompson, Cyril V; Burnett, Michael N; Dulgerian, Nishan; Eckenrode, Brian A

    2008-01-01

    This study, conducted at the University of Tennessee's Anthropological Research Facility (ARF), lists and ranks the primary chemical constituents which define the odor of decomposition of human remains as detected at the soil surface of shallow burial sites. Triple sorbent traps were used to collect air samples in the field and revealed eight major classes of chemicals which now contain 478 specific volatile compounds associated with burial decomposition. Samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and were collected below and above the body, and at the soil surface of 1.5-3.5 ft. (0.46-1.07 m) deep burial sites of four individuals over a 4-year time span. New data were incorporated into the previously established Decompositional Odor Analysis (DOA) Database providing identification, chemical trends, and semi-quantitation of chemicals for evaluation. This research identifies the 'odor signatures' unique to the decomposition of buried human remains with projected ramifications on human remains detection canine training procedures and in the development of field portable analytical instruments which can be used to locate human remains in shallow burial sites.

  19. Buried nanoantenna arrays: versatile antireflection coating.

    PubMed

    Kabiri, Ali; Girgis, Emad; Capasso, Federico

    2013-01-01

    Reflection is usually a detrimental phenomenon in many applications such as flat-panel-displays, solar cells, photodetectors, infrared sensors, and lenses. Thus far, to control and suppress the reflection from a substrate, numerous techniques including dielectric interference coatings, surface texturing, adiabatic index matching, and scattering from plasmonic nanoparticles have been investigated. A new technique is demonstrated to manage and suppress reflection from lossless and lossy substrates. It provides a wider flexibility in design versus previous methods. Reflection from a surface can be suppressed over a narrowband, wideband, or multiband frequency range. The antireflection can be dependent or independent of the incident wave polarization. Moreover, antireflection at a very wide incidence angle can be attained. The reflection from a substrate is controlled by a buried nanoantenna array, a structure composed of (1) a subwavelength metallic array and (2) a dielectric cover layer referred to as a superstrate. The material properties and thickness of the superstrate and nanoantennas' geometry and periodicity control the phase and intensity of the wave circulating inside the superstrate cavity. A minimum reflectance of 0.02% is achieved in various experiments in the mid-infrared from a silicon substrate. The design can be integrated in straightforward way in optical devices. The proposed structure is a versatile AR coating to optically impedance matches any substrate to free space in selected any narrow and broadband spectral response across the entire visible and infrared spectrum. PMID:24266700

  20. Seismic sonar sources for buried mine detection

    NASA Astrophysics Data System (ADS)

    Baker, Steven R.; Muir, Thomas G.; Gaghan, Frederick E.; Fitzpatrick, Sean M.; Sheetz, Kraig E.; Guy, Jeremie

    2003-10-01

    Prior research on seismo-acoustic sonar for detection of buried targets [J. Acoust. Soc. Am. 103, 2333-2343 (1998)] has continued with examination of various means for exciting interface waves (Rayleigh or Scholte) used to reflect from targets. Several seismic sources were examined for sand beach applications, including vibrating shakers, shaker devices configured to preferentially excite interface waves, linear force actuators, and arrays of shaker sources to create directional interface wave beams. Burial of some plate-like or rod-like portion of the vibrating devices was found to ensure good coupling to the beach. The preferential interface excitation device employed two degrees of freedom to mimic the two components of elliptically polarized interface waves, and was successfully demonstrated. However, it was found that at long ranges, the medium itself created two component interface waves from vibrating source radiations operating with one degree of freedom in the vertical plane. Linear force actuators were functional in this mode. An array of seven vertical shakers was utilized to create interface waves at ranges of 5 m, in the form of directional beams, some 8 deg wide at the half-power points, at frequencies around 100 Hz. Application of these devices for target detection is discussed in the companion paper. [Work sponsored by ONR.

  1. Compressive strain limits for buried pipelines

    SciTech Connect

    Zimmerman, T.J.E.; Stephens, M.J.; DeGeer, D.D.; Chen, Q.

    1995-12-31

    Buried pipelines subjected to large differential ground movements experience deformation-induced stresses and strains that can cause local buckling, or pipe wrinkling. Severe wrinkling is a structural integrity concern, as it can lead to pipeline rupture. To assess this situation, current practice takes a conservative approach that suggests that compressive strains in a pipeline should be limited in order to avoid local buckle initiation. The research project discussed in this paper has developed an alternative approach that recognizes the ability of a pipe to plastically deform and wrinkle without being functionally impaired, provided a rational limit is set on the amount of wrinkling that is allowed to take place. This paper presents and discusses selected results from the four phases of this research work: (1) an assessment of existing data and analytical methods; (2) a large-scale experimental testing program; (3) development of a non-linear finite element model; and (4) development of new design criteria and semi-empirical prediction methods.

  2. Simulation of EUV multilayer mirror buried defects

    NASA Astrophysics Data System (ADS)

    Brukman, Matthew J.; Deng, Yunfei; Neureuther, Andrew R.

    2000-07-01

    A new interface has been created to link existing deposition/etching and electromagnetic simulation software, allowing the user to program deposition and etching conditions and then find the reflective properties of the resultant structure. The application studied in this paper is the problem of three-dimensional defects which become buried during fabrication of multilayer mirrors for extreme ultraviolet lithography. The software link reads in surface information in the form of linked triangles, determines all nodes within the triangles, and then creates nodes lying between triangles of different layers to create a 3- dimensional inhomogeneous matrix containing the materials' indices of refraction. This allows etching and depositions to be input into SAMPLE-3D, a multi-surface topology to be generated, and then the electromagnetic properties of the structure to be assessed with TEMPEST. This capability was used to study substrate defects in multilayer mirrors by programming a defect and then sputter-depositing some forty layers on top of the defect. Specifically examined was how the topography depended on sputter conditions and determined the defects' impact on the mirrors' imaging properties. While this research was focused on application to EUV lithography, the general technique may be extended to other optical processes such as alignment and mask defects.

  3. Computer vision and sensor fusion for detecting buried objects

    SciTech Connect

    Clark, G.A.; Hernandez, J.E.; Sengupta, S.K.; Sherwood, R.J.; Schaich, P.C.; Buhl, M.R.; Kane, R.J.; DelGrande, N.K.

    1992-10-01

    Given multiple images of the surface of the earth from dual-band infrared sensors, our system fuses information from the sensors to reduce the effects of clutter and improve the ability to detect buried or surface target sites. Supervised learning pattern classifiers (including neural networks,) are used. We present results of experiments to detect buried land mines from real data, and evaluate the usefulness of fusing information from multiple sensor types. The novelty of the work lies mostly in the combination of the algorithms and their application to the very important and currently unsolved problem of detecting buried land mines from an airborne standoff platform.

  4. The problem of burying radioactive wastes containing transplutonium elements (TPE)

    SciTech Connect

    Bryzgalova, R.V.; Krivokhatskii, A.S.; Rogozin, Y.M.; Sinitsyna, G.S.

    1986-09-01

    This paper discusses the problem of burying radioactive wastes containing TPE. The most acceptable and developed method at present is that of disposal into continental, deep-lying, geological formatins. Based on an analysis of estimates of the thermal conditions on burying highly active wastes, including TPE concentrates, data on the filtration and sorption characteristics of rocks, estimates of the diffusion of radionuclide species capable of migrating, and taking into account the retention powers of rocks it is concluded that it is possible to bury such wastes in weakly permeable geological formations possessing shielding characteristics which ensure reliability and safety in burial.

  5. Designable buried waveguides in sapphire by proton implantation

    SciTech Connect

    Laversenne, L.; Hoffmann, P.; Pollnau, M.; Moretti, P.; Mugnier, J.

    2004-11-29

    Buried and stacked planar as well as buried single and parallel channel waveguides are fabricated in sapphire by proton implantation. Good control of the implantation parameters provides excellent confinement of the guided light in each structure. Low propagation losses are obtained in fundamental-mode, buried channel waveguides without postimplantation annealing. Choice of the implantation parameters allows one to design mode shapes with different ellipticity and/or mode asymmetry in each orthogonal direction, thus demonstrating the versatility of the fabrication method. Horizontal and vertical parallelization is demonstrated for the design of one- or two-dimensional waveguide arrays in hard crystalline materials.

  6. Identification of buried structures (aerial surveillance and analysis of buried waste) long-range project plan

    SciTech Connect

    Williams, K.L.

    1991-11-01

    This long-range plan presents the plan (i.e., budget, schedule, justification, and plans for technology deployment) for implementation of the Identification of Buried Structures project. Two subcontractors will test and demonstrate their technologies at the Idaho National Engineering Laboratory during October and November 1991, and will analyze their data and submit final reports to EG&G Idaho, Inc., by the end of December 1991. By February 21, 1992, EG&G Idaho will present a final report to the Department of Energy, assessing the subcontractor`s results and recommending further action.

  7. Amorphous silicon ionizing particle detectors

    DOEpatents

    Street, R.A.; Mendez, V.P.; Kaplan, S.N.

    1988-11-15

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation. 15 figs.

  8. Amorphous silicon ionizing particle detectors

    DOEpatents

    Street, Robert A.; Mendez, Victor P.; Kaplan, Selig N.

    1988-01-01

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  9. Compensated amorphous silicon solar cell

    DOEpatents

    Devaud, Genevieve

    1983-01-01

    An amorphous silicon solar cell including an electrically conductive substrate, a layer of glow discharge deposited hydrogenated amorphous silicon over said substrate and having regions of differing conductivity with at least one region of intrinsic hydrogenated amorphous silicon. The layer of hydrogenated amorphous silicon has opposed first and second major surfaces where the first major surface contacts the electrically conductive substrate and an electrode for electrically contacting the second major surface. The intrinsic hydrogenated amorphous silicon region is deposited in a glow discharge with an atmosphere which includes not less than about 0.02 atom percent mono-atomic boron. An improved N.I.P. solar cell is disclosed using a BF.sub.3 doped intrinsic layer.

  10. Mars - Paleostratigraphic restoration of buried surfaces in Tharsis montes

    NASA Technical Reports Server (NTRS)

    Scott, D. H.; Tanaka, K. L.

    1981-01-01

    Volcanism in the Tharsis province of Mars occurred in several different areas and was generally continuous without large time intervals between eruptive episodes. Major lava flow units are numerous and extensive, but relatively thin. In many places, impact craters on buried surfaces project above younger flows that overlie them. A new application of crater dating methods has been developed to aid in the identification of these buried surfaces and to determine their lateral extent. The technique is especially adaptable to the Tharsis region where the stratigraphic succession of major flow units has been established by detailed geologic mapping. Knowledge of the overall stratigraphy allows correlations to be made between known and unknown surfaces by comparing their crater frequencies at diameters large enough to insure their recognition on the buried unit. The method has been applied to aid in the restoration of buried rock units and to construct a series of paleostratigraphic maps showing the sequence of major eruptive events in the Tharsis region.

  11. Carbon limitation patterns in buried and open urban streams

    EPA Science Inventory

    Urban streams alternate between darkened buried segments dominated by heterotrophic processes and lighted open segments dominated by autotrophic processes. We hypothesized that labile carbon leaking from autotrophic cells would reduce heterotrophic carbon limitation in open chan...

  12. Airblast environments from buried HE charges

    SciTech Connect

    Reichenbach, H.; Behrens, K.; Kuhl, A.

    1993-01-01

    Laboratory experiments were conducted to measure the airblast environment generated by the detonation of buried HE charges. Spherical 0.5-g charges of Nitropenta were used as the HE source. Three ground materials were used: (1) a porous, crushable grout (YTONG, {rho} = 0.4 g/cm{sup 3}); (2) a water-saturated grout ({rho} {approx_equal} 0.7 g/Cm{sup 3}) to investigate the effects of density increase; and (3) a clay-loam material ({rho} {approx_equal} 1.8 g/cm{sup 3}) to simulate some of the previous field tests conducted in clay. Diagnostics consisted of 13 flush-mounted pressure gauges, and single-frame schlieren photography. A special shock isolation system was used to eliminate the acceleration effects on the gauges that were induced by the cratering process. Analysis of the pressure measurements resulted in an experimental definition of the airblast environment as a function of ground range (GR) and depth-of-burst (DOB). Synthesis of these results allowed one to construct airblast DOB curves, similar to the airblast height-of-burst curves that we published previously for Nitropenta charges. Variables analyzed were: peak pressure, arrival time, positive phase duration and impulse. As in field tests, we found that the airblast waveforms changed character with increasing DOB. The crater characteristics (e.a., depth, radius and volume) were also measured. The cube-root-scaled crater volume was in qualitative agreement with data from field tests (e.g., charge weights up to 10{sup 4} lbs.). Since the present scaled results compare well with data from large-scale HE tests, we conclude that the present experimental technique provides a useful tool for parametric investigations of explosion effects in the laboratory.

  13. Decomposition of forest products buried in landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; Powell, John S; Barlaz, Morton A

    2013-11-01

    The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C+H) loss of up to 38%, while loss for the other wood types was 0-10% in most samples. The C+H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27gOCg(-1) dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported. PMID:23942265

  14. Decomposition of forest products buried in landfills

    SciTech Connect

    Wang, Xiaoming; Padgett, Jennifer M.; Powell, John S.; Barlaz, Morton A.

    2013-11-15

    Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g{sup −1} dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than

  15. Bulk amorphous materials

    SciTech Connect

    Schwarz, R.B.; Archuleta, J.I.; Sickafus, K.E.

    1998-12-01

    This is the final report for a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this work was to develop the competency for the synthesis of novel bulk amorphous alloys. The authors researched their synthesis methods and alloy properties, including thermal stability, mechanical, and transport properties. The project also addressed the development of vanadium-spinel alloys for structural applications in hostile environments, the measurement of elastic constants and thermal expansion in single-crystal TiAl from 300 to 750 K, the measurement of elastic constants in gallium nitride, and a study of the shock-induced martensitic transformations in NiTi alloys.

  16. Amorphous and Cellular Computing

    NASA Astrophysics Data System (ADS)

    Abelson, Harold; Sussman, Gerald J.; Knight, Thomas F., Jr

    2001-08-01

    The objective of this research is to create the architectural, algorithmic, and technological foundations for exploiting programmable materials. These are materials that incorporate vast numbers of programmable elements that react to each other and to their environment. Such materials can be fabricated economically, provided that the computing elements are amassed in bulk without arranging for precision interconnect and testing. In order to exploit programmable materials we must identify engineering principles for organizing and instructing myriad programmable entities to cooperate to robustly achieve pre-established goals, even though the individual entities are unreliable and interconnected in unknown, irregular, and time-varying ways. Progress in microfabrication and in bioengineering will make it possible to assemble such amorphous systems at almost no cost, provided that (1) the units need not all work correctly; (2) the units are identically programmed; and (3) there is no need to manufacture precise geometrical arrangements of the units or precise interconnections among them.

  17. Compact Buried Ducts in a Hot-Humid Climate House

    SciTech Connect

    Mallay, D.

    2016-01-01

    A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval.

  18. Data fusion for the detection of buried land mines

    SciTech Connect

    Clark, G.A.; Sengupta, S.K.; Schaich, P.C.; Sherwood, R.J.; Buhl, M.R.; Hernandez, J.E.; Kane, R.J.; Barth, M.J.; Fields, D.J.; Carter, M.R.

    1993-10-01

    The authors conducted experiments to demonstrate the enhanced delectability of buried land mines using sensor fusion techniques. Multiple sensors, including imagery, infrared imagery, and ground penetrating radar, have been used to acquire data on a number of buried mines and mine surrogates. The authors present this data along with a discussion of the application of sensor fusion techniques for this particular detection problem. The authors describe the data fusion architecture and discuss some relevant results of these classification methods.

  19. Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)

    SciTech Connect

    Not Available

    2013-11-01

    Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation. There are three possible combinations of BED strategies: (1) buried ducts; (2) encapsulated ducts (with ccSPF); and (3) buried and encapsulated ducts. The best solution for each situation depends on the climate, age of the house, and the configuration of the HVAC system and attic. For new construction projects, the team recommends that ducts be both encapsulated and buried as the minimal planning and costs required for this will yield optimal energy savings. The encapsulated/buried duct strategy, which utilizes ccSPF to address condensation concerns, is an approach that was developed specifically for humid climates.

  20. Perspective on photovoltaic amorphous silicon

    SciTech Connect

    Luft, W.; Stafford, B.; von Roedern, B.

    1992-05-01

    Amorphous silicon is a thin film option that has the potential for a cost-effective product for large-scale utility photovoltaics application. The initial efficiencies for single-junction and multijunction amorphous silicon cells and modules have increased significantly over the past 10 years. The emphasis of research and development has changed to stabilized efficiency, especially that of multijunction modules. NREL has measured 6.3%--7.2% stabilized amorphous silicon module efficiencies for US products, and 8.1% stable efficiencies have been reported by Fuji Electric. This represents a significant increase over the stabilized efficiencies of modules manufactured only a few years ago. An increasing portion of the amorphous silicon US government funding is now for manufacturing technology development to reduce cost. The funding for amorphous silicon for photovoltaics by Japan over the last 5 years has been about 50% greater than that in the United State, and by Germany in the last 2--3 years more than twice that of the US Amorphous silicon is the only thin-film technology that is selling large-area commercial modules. The cost for amorphous silicon modules is now in the $4.50 range; it is a strong function of plant production capacity and is expected to be reduced to $1.00--1.50/W{sub p} for plants with 10 MW/year capacities. 10 refs.

  1. Perspective on photovoltaic amorphous silicon

    SciTech Connect

    Luft, W.; Stafford, B.; von Roedern, B. )

    1992-12-01

    Amorphous silicon is a thin film option that has the potential for a cost-effective product for large-scale utility photovoltaics application. The initial efficiencies for single-junction and multijunction amorphous silicon cells and modules have increased significantly over the past 10 years. The emphasis of research and development has changed to stabilized efficiency, especially that of multijunction modules. NREL has measured 6.3%--7.2% stabilized amorphous silicon module efficiencies for U.S. products, and 8.1% stable efficiencies have been reported by Fuji Electric. This represents a significant increase over the stabilized efficiencies of modules manufactured only a few years ago. An increasing portion of the amorphous silicon U.S. government funding is now for manufacturing technology development to reduce cost. The funding for amorphous silicon for photovoltaics by Japan over the last 5 years has been about 50% greater than that in the United States, and by Germany in the last 2--3 years more than twice that of the U.S. Amorphous silicon is the only thin-film technology that is selling large-area commercial modules. The cost for amorphous silicon modules is now in the $4.50 range; it is a strong function of plant production capacity and is expected to be reduced to $1.00--1.50/W[sub [ital p

  2. Containerless processing of amorphous ceramics

    NASA Technical Reports Server (NTRS)

    Weber, J. K. Richard; Krishnan, Shankar; Schiffman, Robert A.; Nordine, Paul C.

    1990-01-01

    The absence of gravity allows containerless processing of materials which could not otherwise be processed. High melting point, hard materials such as borides, nitrides, and refractory metals are usually brittle in their crystalline form. The absence of dislocations in amorphous materials frequently endows them with flexibility and toughness. Systematic studies of the properties of many amorphous materials have not been carried out. The requirements for their production is that they can be processed in a controlled way without container interaction. Containerless processing in microgravity could permit the control necessary to produce amorphous forms of hard materials.

  3. Apatite Formation from Amorphous Calcium Phosphate and Mixed Amorphous Calcium Phosphate/Amorphous Calcium Carbonate.

    PubMed

    Ibsen, Casper J S; Chernyshov, Dmitry; Birkedal, Henrik

    2016-08-22

    Crystallization from amorphous phases is an emerging pathway for making advanced materials. Biology has made use of amorphous precursor phases for eons and used them to produce structures with remarkable properties. Herein, we show how the design of the amorphous phase greatly influences the nanocrystals formed therefrom. We investigate the transformation of mixed amorphous calcium phosphate/amorphous calcium carbonate phases into bone-like nanocrystalline apatite using in situ synchrotron X-ray diffraction and IR spectroscopy. The speciation of phosphate was controlled by pH to favor HPO4 (2-) . In a carbonate free system, the reaction produces anisotropic apatite crystallites with large aspect ratios. The first formed crystallites are highly calcium deficient and hydrogen phosphate rich, consistent with thin octacalcium phosphate (OCP)-like needles. During growth, the crystallites become increasingly stoichiometric, which indicates that the crystallites grow through addition of near-stoichiometric apatite to the OCP-like initial crystals through a process that involves either crystallite fusion/aggregation or Ostwald ripening. The mixed amorphous phases were found to be more stable against phase transformations, hence, the crystallization was inhibited. The resulting crystallites were smaller and less anisotropic. This is rationalized by the idea that a local phosphate-depletion zone formed around the growing crystal until it was surrounded by amorphous calcium carbonate, which stopped the crystallization. PMID:27460160

  4. Buried object remote detection technology for law enforcement

    NASA Astrophysics Data System (ADS)

    del Grande, Nancy K.; Clark, Gregory A.; Durbin, Philip F.; Fields, David J.; Hernandez, Jose E.; Sherwood, Robert J.

    1991-08-01

    A precise airborne temperature-sensing technology to detect buried objects for use by law enforcement is developed. Demonstrations have imaged the sites of buried foundations, walls and trenches; mapped underground waterways and aquifers; and been used to locate underground military objects. The methodology is incorporated in a commercially available, high signal-to-noise, dual-band infrared scanner with real-time, 12-bit digital image processing software and display. The method creates color-coded images based on surface temperature variations of 0.2 degree(s)C. Unlike other less-sensitive methods, it maps true (corrected) temperatures by removing the (decoupled) surface emissivity mask equivalent to 1 degree(s)C or 2 degree(s)C; this mask hinders interpretation of apparent (blackbody) temperatures. Once removed, it is possible to identify surface temperature patterns from small diffusivity changes at buried object sites which heat and cool differently from their surroundings. Objects made of different materials and buried at different depths are identified by their unique spectral, spatial, thermal, temporal, emissivity and diffusivity signatures. The authors have successfully located the sites of buried (inert) simulated land mines 0.1 to 0.2 m deep; sod-covered rock pathways alongside dry ditches, deeper than 0.2 m; pavement covered burial trenches and cemetery structures as deep as 0.8 m; and aquifers more than 6 m and less than 60 m deep. The technology could be adapted for drug interdiction and pollution control. For the former, buried tunnels, underground structures built beneath typical surface structures, roof-tops disguised by jungle canopies, and covered containers used for contraband would be located. For the latter, buried waste containers, sludge migration pathways from faulty containers, and the juxtaposition of groundwater channels, if present, nearby, would be depicted. The precise airborne temperature-sensing technology has a promising potential

  5. Fabrication of amorphous diamond films

    DOEpatents

    Falabella, S.

    1995-12-12

    Amorphous diamond films having a significant reduction in intrinsic stress are prepared by biasing a substrate to be coated and depositing carbon ions thereon under controlled temperature conditions. 1 fig.

  6. Raman Spectroscopy of Amorphous Carbon

    SciTech Connect

    Tallant, D.R.; Friedmann, T.A.; Missert, N.A.; Siegal, M.P.; Sullivan, J.P.

    1998-01-01

    Amorphous carbon is an elemental form of carbon with low hydrogen content, which may be deposited in thin films by the impact of high energy carbon atoms or ions. It is structurally distinct from the more well-known elemental forms of carbon, diamond and graphite. It is distinct in physical and chemical properties from the material known as diamond-like carbon, a form which is also amorphous but which has a higher hydrogen content, typically near 40 atomic percent. Amorphous carbon also has distinctive Raman spectra, whose patterns depend, through resonance enhancement effects, not only on deposition conditions but also on the wavelength selected for Raman excitation. This paper provides an overview of the Raman spectroscopy of amorphous carbon and describes how Raman spectral patterns correlate to film deposition conditions, physical properties and molecular level structure.

  7. Amorphous metal alloy and composite

    DOEpatents

    Wang, Rong; Merz, Martin D.

    1985-01-01

    Amorphous metal alloys of the iron-chromium and nickel-chromium type have excellent corrosion resistance and high temperature stability and are suitable for use as a protective coating on less corrosion resistant substrates. The alloys are stabilized in the amorphous state by one or more elements of titanium, zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten. The alloy is preferably prepared by sputter deposition.

  8. Buried object remote detection technology for law enforcement

    SciTech Connect

    Del Grande, N.K.; Clark, G.A.; Durbin, P.F.; Fields, D.J.; Hernandez, J.E.; Sherwood, R.J.

    1991-03-01

    We have developed a precise airborne temperature-sensing technology to detect buried objects for use by law enforcement. Demonstrations have imaged the sites of buried foundations, walls and trenches; mapped underground waterways and aquifers; and been used to locate underground military objects. Our patented methodology is incorporated in a commercially available, high signal-to-noise, dual-band infrared scanner with real-time, 12-bit digital image processing software and display. Our method creates color-coded images based on surface temperature variations of 0.2 {degrees}C. Unlike other less-sensitive methods, it maps true (corrected) temperatures by removing the (decoupled) surface emissivity mask equivalent to 1{degrees}C or 2{degrees}C; this mask hinders interpretation of apparent (blackbody) temperatures. Once removed, were are able to identify surface temperature patterns from small diffusivity changes at buried object sites which heat and cool differently from their surroundings. Objects made of different materials and buried at different depths are identified by their unique spectra, spatial, thermal, temporal, emissivity and diffusivity signatures. We have successfully located the sites of buried (inert) simulated land mines 0.1 to 0.2 m deep; sod-covered rock pathways alongside dry ditches, deeper than 0.2 m; pavement covered burial trenches and cemetery structures as deep as 0.8 m; and aquifers more than 6 m and less 60 m deep. Our technology could be adapted for drug interdiction and pollution control. 16 refs., 14 figs.

  9. Experimental investigation of buried tritium in plant and animal tissues

    SciTech Connect

    Kim, S. B.; Workman, W. J. G.; Davis, P. A.

    2008-07-15

    Buried exchangeable tritium appears as part of organically bound tritium (OBT) in the traditional experimental determination of OBT. Since buried tritium quickly exchanges with hydrogen atoms in the body following ingestion, assuming that it is part of OBT rather than part of tritiated water (HTO) could result in a significant overestimate of the ingestion dose. This paper documents an experimental investigation into the existence, amount and significance of buried tritium in plant and fish samples. OBT concentrations in the samples were determined in the traditional way and also following denaturing with five chemical solutions that break down large molecules and expose buried tritium to exchange with free hydrogen atoms. A comparison of the OBT concentrations before and after denaturing, together with the concentration of HTO in the supernatant obtained after denaturing, suggests that buried OBT may exist but makes up less than 5% of the OBT concentration in plants and at most 20% of the OBT concentration in fish. The effects of rinse time and rinse water volumes were investigated to optimize the removal of exchangeable OBT from the samples. (authors)

  10. Amorphous carbon for photovoltaics

    NASA Astrophysics Data System (ADS)

    Risplendi, Francesca; Grossman, Jeffrey C.

    2015-03-01

    All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

  11. Buried waste integrated demonstration FY 94 deployment plan

    SciTech Connect

    Hyde, R.A.; Walker, S.; Garcia, M.M.

    1994-05-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the U.S. Department of Energy Office of Technology Development. BWID supports the applied research, development, demonstration, testing, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. The fiscal year (FY) 1994 effort will fund thirty-eight technologies in five areas of buried waste site remediation: site characterization, waste characterization, retrieval, treatment, and containment/stabilization. This document is the basic operational planning document for deployment of all BWID projects. Discussed in this document are the BWID preparations for INEL field demonstrations, INEL laboratory demonstrations, non-INEL demonstrations, and paper studies. Each technology performing tests will prepare a test plan to detail the specific procedures, objectives, and tasks of each test. Therefore, information specific to testing each technology is intentionally omitted from this document.

  12. Tabernaemontana divaricata leaves extract exacerbate burying behavior in mice

    PubMed Central

    Chanchal, Raj; Balasubramaniam, Arumugam; Navin, Raj; Nadeem, Sayyed

    2015-01-01

    Objective: Tabernaemontana divaricata (TD) from Apocynaceae family offers the traditional folklore medicinal benefits such as an anti-epileptic, anti-mania, brain tonic, and anti-oxidant. The aim of the present study was to evaluate the effect of ethanolic extract of TD leaves on burying behavior in mice. Materials and Methods: Mice were treated with oral administration (p.o.) of ethanolic extract of TD (100, 200, and 300 mg/kg). Fluoxetine (FLX, a selective serotonin reuptake inhibitor) was used as a reference drug. Obsessive-compulsive behavior was evaluated using marble-burying apparatus. Results: TD at doses of 100, 200, and 300 mg/kg dose-dependently inhibited the obsessive and compulsive behavior. The similar results were obtained from 5, 10, and 20 mg/kg of FLX. TD and FLX did not affect motor activity. Conclusion: The results indicated that TD and FLX produced similar inhibitory effects on marble-burying behavior. PMID:26445709

  13. End effectors and attachments for buried waste excavation equipment

    SciTech Connect

    King, R.H.

    1993-09-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. Their efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER&WM) Department`s needs and objectives. The present focus of BWID is to support retrieval and ex-situ treatment configuration options. Future activities will explore and support containment, and stabilization efforts in addition to the retrieval/ex situ treatment options. This report presents a literature search on the state-of-the-art in end effectors and attachments in support of excavator of buried transuranic waste. Included in the report are excavator platforms and a discussion of the various attachments. Also included is it list of vendors and specifications.

  14. Sensor fusion methodology for remote detection of buried land mines

    SciTech Connect

    Del Grande, N.

    1990-04-01

    We are investigation a sensor fusion methodology for remote detection of buried land mines. Our primary approach is sensor intrafusion. Our dual-channel passive IR methodology decouples true (corrected) surface temperature variations of 0.2{degree}C from spatially dependent surface emissivity noise. It produces surface temperature maps showing patterns of conducted heat from buried objects which heat and cool differently from their surroundings. Our methodology exploits Planck's radiation law. It produces separate maps of surface emissivity variations which allow us to reduce false alarms. Our secondary approach is sensor interfusion using other methodologies. For example, an active IR CO{sub 2} laser reflectance channel helps distinguish surface targets unrelated to buried land mines at night when photographic methods are ineffective. Also, the interfusion of ground penetrating radar provides depth information for confirming the site of buried objects. Together with EG G in Las Vegas, we flew a mission at Nellis AFB using the Daedalus dual-channel (5 and 10 micron) IR scanner mounted on a helicopter platform at an elevation of 60 m above the desert sand. We detected surface temperature patterns associated with buried (inert) land mines covered by as much as 10 cm of dry sand. The respective spatial, spectral, thermal, emissivity and temporal signatures associated with buried targets differed from those associated with surface vegetation, rocks and manmade objects. Our results were consistent with predictions based on the annual Temperature Wave Model.They were confirmed by field measurements. The dual-channel sensor fusion methodology is expected to enhance the capabilities of the military and industrial community for standoff mine detection. Other important potential applications are open skies, drug traffic control and environmental restoration at waste burial sites. 11 figs.

  15. Guided wave attenuation in coated pipes buried in sand

    NASA Astrophysics Data System (ADS)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J. S.

    2016-02-01

    Long-range guided wave testing (GWT) is routinely used for the monitoring and detection of corrosion defects in above ground pipelines in various industries. The GWT test range in buried, coated pipelines is greatly reduced compared to aboveground pipelines due to energy leakage into the embedding soil. In this study, we aim to increase test ranges for buried pipelines. The effect of pipe coatings on the T(0,1) and L(0,2) guided wave attenuation is investigated using a full-scale experimental apparatus and model predictions. Tests are performed on a fusion-bonded epoxy (FBE)-coated 8" pipe, buried in loose and compacted sand over a frequency range of 10-35 kHz. The application of a low impedance coating is shown to effectively decouple the influence of the sand on the ultrasound leakage from the buried pipe. We demonstrate ultrasonic isolation of a buried pipe by coating the pipe with a Polyethylene (PE)-foam layer that has a smaller impedance than both pipe and sand and the ability to withstand the overburden load from the sand. The measured attenuation in the buried PE-foam-FBE-coated pipe is substantially reduced, in the range of 0.3-1.2 dBm-1 for loose and compacted sand conditions, compared to buried FBE-coated pipe without the PE-foam, where the measured attenuation is in the range of 1.7-4.7 dBm-1. The acoustic properties of the PE-foam are measured independently using ultrasonic interferometry technique and used in model predictions of guided wave propagation in a buried coated pipe. Good agreement is found between the attenuation measurements and model predictions. The attenuation exhibits periodic peaks in the frequency domain corresponding to the through-thickness resonance frequencies of the coating layer. The large reduction in guided wave attenuation for PE-coated pipes would lead to greatly increased GWT test ranges, so such coatings would be attractive for new pipeline installations.

  16. Buried wire gage for wall shear stress measurements

    NASA Technical Reports Server (NTRS)

    Murthy, V. S.; Rose, W. C.

    1978-01-01

    A buried wire gage for measuring wall shear stress in fluid flow was studied and further developed. Several methods of making this relatively new type of gage were examined to arrive at a successful technique that is well-suited for wind-tunnel testing. A series of measurements was made to demonstrate the adequacy of a two-point calibration procedure for these gages. The buried wire gage is also demonstrated to be ideally suited for quantitative measurement of wall shear stress in wind-tunnel testing.

  17. Growth and conduction mechanism of As-doped p-type ZnO thin films deposited by MOCVD

    SciTech Connect

    Ma, Y.; Gao, Q.; Wu, G.G.; Li, W.C.; Gao, F.B.; Yin, J.Z.; Zhang, B.L.; Du, G.T.

    2013-03-15

    Highlight: ► P-type As-doped ZnO thin films was fabricated by MOCVD after post-growth annealing. ► The formation mechanism of p-ZnO with high hole concentration above 10{sup 19} cm{sup −3} was elucidated. ► Besides As{sub Zn}–2V{sub Zn} complex, C impurities also played an important role in realizing p-ZnO. ► The formations of As{sub O} and O-C-O complex were partially contributed to the p-type ZnO: As films. - Abstract: As-doped p-type ZnO thin films were fabricated by metal organic chemical vapor deposition (MOCVD) after in situ annealing in a vacuum. The p-type conduction mechanism was suggested by the analysis of X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy. It was found that most of the As dopants in p-ZnO thin films formed As{sub Zn}–2V{sub Zn} shallow acceptor complex, simultaneously, carbon impurities also played an important role in realizing p-type conductivity in ZnO. Substitutional carbon on oxygen site created passivated defect bands by combining with Ga atoms due to the donor-acceptor pair Coulomb binding, which shifted the valence-band maximum upwards for ZnO and thus increased the hole concentration.

  18. Nanostructures having crystalline and amorphous phases

    SciTech Connect

    Mao, Samuel S; Chen, Xiaobo

    2015-04-28

    The present invention includes a nanostructure, a method of making thereof, and a method of photocatalysis. In one embodiment, the nanostructure includes a crystalline phase and an amorphous phase in contact with the crystalline phase. Each of the crystalline and amorphous phases has at least one dimension on a nanometer scale. In another embodiment, the nanostructure includes a nanoparticle comprising a crystalline phase and an amorphous phase. The amorphous phase is in a selected amount. In another embodiment, the nanostructure includes crystalline titanium dioxide and amorphous titanium dioxide in contact with the crystalline titanium dioxide. Each of the crystalline and amorphous titanium dioxide has at least one dimension on a nanometer scale.

  19. Amorphous-diamond electron emitter

    DOEpatents

    Falabella, Steven

    2001-01-01

    An electron emitter comprising a textured silicon wafer overcoated with a thin (200 .ANG.) layer of nitrogen-doped, amorphous-diamond (a:D-N), which lowers the field below 20 volts/micrometer have been demonstrated using this emitter compared to uncoated or diamond coated emitters wherein the emission is at fields of nearly 60 volts/micrometer. The silicon/nitrogen-doped, amorphous-diamond (Si/a:D-N) emitter may be produced by overcoating a textured silicon wafer with amorphous-diamond (a:D) in a nitrogen atmosphere using a filtered cathodic-arc system. The enhanced performance of the Si/a:D-N emitter lowers the voltages required to the point where field-emission displays are practical. Thus, this emitter can be used, for example, in flat-panel emission displays (FEDs), and cold-cathode vacuum electronics.

  20. Generalized melting criterion for amorphization

    SciTech Connect

    Devanathan, R. |; Lam, N.Q.; Okamoto, P.R.; Meshii, M.

    1992-12-01

    We present a thermodynamic model of solid-state amorphization based on a generalization of the well-known Lindemann criterion. The original Lindemann criterion proposes that melting occurs when the root-mean-square amplitude of thermal displacement exceeds a critical value. This criterion can be generalized to include solid-state amorphization by taking into account the static displacements. In an effort to verify the generalized melting criterion, we have performed molecular dynamics simulations of radiation-induced amorphization in NiZr, NiZr{sub 2}, NiTi and FeTi using embedded-atom potentials. The average shear elastic constant G was calculated as a function of the total mean-square atomic displacement following random atom-exchanges and introduction of Frenkel pairs. Results provide strong support for the generalized melting criterion.

  1. Novel back-reflector architecture with nanoparticle based buried light-scattering microstructures for improved solar cell performance

    NASA Astrophysics Data System (ADS)

    Desta, Derese; Ram, Sanjay K.; Rizzoli, Rita; Bellettato, Michele; Summonte, Caterina; Jeppesen, Bjarke R.; Jensen, Pia B.; Tsao, Yao-Chung; Wiggers, Hartmut; Pereira, Rui N.; Balling, Peter; Larsen, Arne Nylandsted

    2016-06-01

    A new back-reflector architecture for light-management in thin-film solar cells is proposed that includes a morphologically smooth top surface with light-scattering microstructures buried within. The microstructures are pyramid shaped, fabricated on a planar reflector using TiO2 nanoparticles and subsequently covered with a layer of Si nanoparticles to obtain a flattened top surface, thus enabling growth of good quality thin-film solar cells. The optical properties of this back-reflector show high broadband haze parameter and wide angular distribution of diffuse light-scattering. The n-i-p amorphous silicon thin-film solar cells grown on such a back-reflector show enhanced light absorption resulting in improved external quantum efficiency. The benefit of the light trapping in those solar cells is evidenced by the gains in short-circuit current density and efficiency up to 15.6% and 19.3% respectively, compared to the reference flat solar cells. This improvement in the current generation in the solar cells grown on the flat-topped (buried pyramid) back-reflector is observed even when the irradiation takes place at large oblique angles of incidence. Finite-difference-time-domain simulation results of optical absorption and ideal short-circuit current density values agree well with the experimental findings. The proposed approach uses a low cost and simple fabrication technique and allows effective light manipulation by utilizing the optical properties of micro-scale structures and nanoscale constituent particles.

  2. Novel back-reflector architecture with nanoparticle based buried light-scattering microstructures for improved solar cell performance.

    PubMed

    Desta, Derese; Ram, Sanjay K; Rizzoli, Rita; Bellettato, Michele; Summonte, Caterina; Jeppesen, Bjarke R; Jensen, Pia B; Tsao, Yao-Chung; Wiggers, Hartmut; Pereira, Rui N; Balling, Peter; Larsen, Arne Nylandsted

    2016-06-01

    A new back-reflector architecture for light-management in thin-film solar cells is proposed that includes a morphologically smooth top surface with light-scattering microstructures buried within. The microstructures are pyramid shaped, fabricated on a planar reflector using TiO2 nanoparticles and subsequently covered with a layer of Si nanoparticles to obtain a flattened top surface, thus enabling growth of good quality thin-film solar cells. The optical properties of this back-reflector show high broadband haze parameter and wide angular distribution of diffuse light-scattering. The n-i-p amorphous silicon thin-film solar cells grown on such a back-reflector show enhanced light absorption resulting in improved external quantum efficiency. The benefit of the light trapping in those solar cells is evidenced by the gains in short-circuit current density and efficiency up to 15.6% and 19.3% respectively, compared to the reference flat solar cells. This improvement in the current generation in the solar cells grown on the flat-topped (buried pyramid) back-reflector is observed even when the irradiation takes place at large oblique angles of incidence. Finite-difference-time-domain simulation results of optical absorption and ideal short-circuit current density values agree well with the experimental findings. The proposed approach uses a low cost and simple fabrication technique and allows effective light manipulation by utilizing the optical properties of micro-scale structures and nanoscale constituent particles. PMID:27244247

  3. Modeling Blast Loading on Buried Reinforced Concrete Structures with Zapotec

    DOE PAGESBeta

    Bessette, Greg C.

    2008-01-01

    A coupled Euler-Lagrange solution approach is used to model the response of a buried reinforced concrete structure subjected to a close-in detonation of a high explosive charge. The coupling algorithm is discussed along with a set of benchmark calculations involving detonations in clay and sand.

  4. Environmental effects on detection of buried mines and UXO

    NASA Astrophysics Data System (ADS)

    Detsch, Richard M.; Jenkins, Thomas F.; Arcone, Steven A.; Koh, Gary; O'Neill, Kevin

    1998-09-01

    Several studies are under way at the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) to define environmental effects on detection and classification of buried mines and unexploded ordnance (UXO). Ground that is very wet, frozen, or snow covered can pose severe constraints on demining operations. The qualitative and quantitative nature of chemical signatures of buried land mines is being documented. Research to date indicates that although 2,4,6- trinitrotoluene constitutes over 99% of military-grade TNT, it is a minor component of the vapor signature at ground level. CRREL operates a year-round test site to determine the effect of weather on radar and IR systems used to detect buried mines. The New England site experiences many of the weather conditions likely to interfere with mine detection around the world. Short-pulse ground penetrating radar (GPR) was used to profile both ordnance and non-ordnance targets at the 40-acre UXO site at Jefferson Proving Ground. Analysis of the data indicates that future systems will have to operate at faster data acquisition rates. Radar modeling is being used to simulate the effects of the environment and identify new techniques for finding and classifying buried ferrous objects.

  5. Melter development needs assessment for RWMC buried wastes

    SciTech Connect

    Donaldson, A.D.; Carpenedo, R.J.; Anderson, G.L.

    1992-02-01

    This report presents a survey and initial assessment of the existing state-of-the-art melter technology necessary to thermally treat (stabilize) buried TRU waste, by producing a highly leach resistant glass/ceramic waste form suitable for final disposal. Buried mixed transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL) represents an environmental hazard requiring remediation. The Environmental Protection Agency (EPA) placed the INEL on the National Priorities List in 1989. Remediation of the buried TRU-contaminated waste via the CERCLA decision process is required to remove INEL from the National Priorities List. A Waste Technology Development (WTD) Preliminary Systems Design and Thermal Technologies Screening Study identified joule-heated and plasma-heated melters as the most probable thermal systems technologies capable of melting the INEL soil and waste to produce the desired final waste form (Iron-Enriched Basalt (IEB) glass/ceramic). The work reported herein then surveys the state of existing melter technology and assesses it within the context of processing INEL buried TRU wastes and contaminated soils. Necessary technology development work is recommended.

  6. Melter development needs assessment for RWMC buried wastes

    SciTech Connect

    Donaldson, A.D.; Carpenedo, R.J.; Anderson, G.L.

    1992-02-01

    This report presents a survey and initial assessment of the existing state-of-the-art melter technology necessary to thermally treat (stabilize) buried TRU waste, by producing a highly leach resistant glass/ceramic waste form suitable for final disposal. Buried mixed transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL) represents an environmental hazard requiring remediation. The Environmental Protection Agency (EPA) placed the INEL on the National Priorities List in 1989. Remediation of the buried TRU-contaminated waste via the CERCLA decision process is required to remove INEL from the National Priorities List. A Waste Technology Development (WTD) Preliminary Systems Design and Thermal Technologies Screening Study identified joule-heated and plasma-heated melters as the most probable thermal systems technologies capable of melting the INEL soil and waste to produce the desired final waste form [Iron-Enriched Basalt (IEB) glass/ceramic]. The work reported herein then surveys the state of existing melter technology and assesses it within the context of processing INEL buried TRU wastes and contaminated soils. Necessary technology development work is recommended.

  7. Risk and cost tradeoffs for remote retrieval of buried waste

    SciTech Connect

    Hyde, R.A.; Grienbenow, B.E.; Nickelson, D.F.

    1994-12-31

    The Buried Waste Integrated Demonstration is supporting the development, demonstration, testing, and evaluation of a suite of technologies that, when integrated with commercially available technologies, form a comprehensive system for the remediation of radioactive and hazardous buried waste. As a part of the program`s technology development, remote retrieval equipment is being developed and tested for the remediation of buried waste. During remedial planning, several factors are considered when choosing remote versus manual retrieval systems. Time that workers are exposed to radioactivity, chemicals, air particulate, and industrial hazards is one consideration. The generation of secondary waste is also a consideration because it amounts to more waste to treat and some wastes may require special handling or treatment. Cost is also a big factor in determining whether remote or manual operations will be used. Other considerations include implementability, effectiveness, and the number of required personnel. This paper investigates each of these areas to show the risk and cost benefits and limitations for remote versus manual retrieval of buried waste.

  8. 49 CFR 195.248 - Cover over buried pipeline.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION...

  9. 49 CFR 195.248 - Cover over buried pipeline.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION...

  10. 49 CFR 195.248 - Cover over buried pipeline.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION...

  11. 49 CFR 195.248 - Cover over buried pipeline.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Cover over buried pipeline. 195.248 Section 195.248 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION...

  12. Detection of concealed and buried chemicals by using multifrequency excitations

    SciTech Connect

    Gao Yaohui; Chen, Meng-Ku; Yang, Chia-En; Chang, Yun-Ching; Yao, Jim; Cheng Jiping; Yin, Stuart; Hui Rongqing; Ruffin, Paul; Brantley, Christina; Edwards, Eugene; Luo, Claire

    2010-08-15

    In this paper, we present a new type of concealed and buried chemical detection system by stimulating and enhancing spectroscopic signatures with multifrequency excitations, which includes a low frequency gradient dc electric field, a high frequency microwave field, and higher frequency infrared (IR) radiations. Each excitation frequency plays a unique role. The microwave, which can penetrate into the underground and/or pass through the dielectric covers with low attenuation, could effectively transform its energy into the concealed and buried chemicals and increases its evaporation rate from the sample source. Subsequently, a gradient dc electric field, generated by a Van De Graaff generator, not only serves as a vapor accelerator for efficiently expediting the transportation process of the vapor release from the concealed and buried chemicals but also acts as a vapor concentrator for increasing the chemical concentrations in the detection area, which enables the trace level chemical detection. Finally, the stimulated and enhanced vapors on the surface are detected by the IR spectroscopic fingerprints. Our theoretical and experimental results demonstrate that more than sixfold increase in detection signal can be achieved by using this proposed technology. The proposed technology can also be used for standoff detection of concealed and buried chemicals by adding the remote IR and/or thermal spectroscopic and imaging detection systems.

  13. Investigating buried polymer interfaces using sum frequency generation vibrational spectroscopy

    PubMed Central

    Chen, Zhan

    2010-01-01

    This paper reviews recent progress in the studies of buried polymer interfaces using sum frequency generation (SFG) vibrational spectroscopy. Both buried solid/liquid and solid/solid interfaces involving polymeric materials are discussed. SFG studies of polymer/water interfaces show that different polymers exhibit varied surface restructuring behavior in water, indicating the importance of probing polymer/water interfaces in situ. SFG has also been applied to the investigation of interfaces between polymers and other liquids. It has been found that molecular interactions at such polymer/liquid interfaces dictate interfacial polymer structures. The molecular structures of silane molecules, which are widely used as adhesion promoters, have been investigated using SFG at buried polymer/silane and polymer/polymer interfaces, providing molecular-level understanding of polymer adhesion promotion. The molecular structures of polymer/solid interfaces have been examined using SFG with several different experimental geometries. These results have provided molecular-level information about polymer friction, adhesion, interfacial chemical reactions, interfacial electronic properties, and the structure of layer-by-layer deposited polymers. Such research has demonstrated that SFG is a powerful tool to probe buried interfaces involving polymeric materials, which are difficult to study by conventional surface sensitive analytical techniques. PMID:21113334

  14. Ice formation in amorphous cellulose

    NASA Astrophysics Data System (ADS)

    Czihak, C.; Müller, M.; Schober, H.; Vogl, G.

    2000-03-01

    We investigate the formation of ice in wet amorphous cellulose in the temperature range of 190 K⩽T⩽280 K. Due to voids and pores in the cellulose film, water molecules are able to form crystalline aggregates. Beyond that, water is able to penetrate between cellulose chains where it can adsorb to hydroxyl side groups. From diffraction data we suggest an aggregation of low-density amorphous (lda) ice at cellulose surfaces. The formation of lda ice shows a clear temperature dependence which will be discussed together with recent inelastic neutron scattering results.

  15. Amorphous-silicon cell reliability testing

    NASA Technical Reports Server (NTRS)

    Lathrop, J. W.

    1985-01-01

    The work on reliability testing of solar cells is discussed. Results are given on initial temperature and humidity tests of amorphous silicon devices. Calibration and measurement procedures for amorphous and crystalline cells are given. Temperature stress levels are diagrammed.

  16. Imprinting bulk amorphous alloy at room temperature

    SciTech Connect

    Kim, Song-Yi; Park, Eun-Soo; Ott, Ryan T.; Lograsso, Thomas A.; Huh, Moo-Young; Kim, Do-Hyang; Eckert, Jürgen; Lee, Min-Ha

    2015-11-13

    We present investigations on the plastic deformation behavior of a brittle bulk amorphous alloy by simple uniaxial compressive loading at room temperature. A patterning is possible by cold-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homogenous flow without the need for thermal energy or shaping at elevated temperatures. The experimental evidence suggests that there is an inconsistency between macroscopic plasticity and deformability of an amorphous alloy. Moreover, imprinting of specific geometrical features on Cu foil and Zr-based metallic glass is represented by using the patterned bulk amorphous alloy as a die. These results demonstrate the ability of amorphous alloys or metallic glasses to precisely replicate patterning features onto both conventional metals and the other amorphous alloys. In conclusion, our work presents an avenue for avoiding the embrittlement of amorphous alloys associated with thermoplastic forming and yields new insight the forming application of bulk amorphous alloys at room temperature without using heat treatment.

  17. Imprinting bulk amorphous alloy at room temperature

    PubMed Central

    Kim, Song-Yi; Park, Eun-Soo; Ott, Ryan T.; Lograsso, Thomas A.; Huh, Moo-Young; Kim, Do-Hyang; Eckert, Jürgen; Lee, Min-Ha

    2015-01-01

    We present investigations on the plastic deformation behavior of a brittle bulk amorphous alloy by simple uniaxial compressive loading at room temperature. A patterning is possible by cold-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homogenous flow without the need for thermal energy or shaping at elevated temperatures. The experimental evidence suggests that there is an inconsistency between macroscopic plasticity and deformability of an amorphous alloy. Moreover, imprinting of specific geometrical features on Cu foil and Zr-based metallic glass is represented by using the patterned bulk amorphous alloy as a die. These results demonstrate the ability of amorphous alloys or metallic glasses to precisely replicate patterning features onto both conventional metals and the other amorphous alloys. Our work presents an avenue for avoiding the embrittlement of amorphous alloys associated with thermoplastic forming and yields new insight the forming application of bulk amorphous alloys at room temperature without using heat treatment. PMID:26563908

  18. Imprinting bulk amorphous alloy at room temperature.

    PubMed

    Kim, Song-Yi; Park, Eun-Soo; Ott, Ryan T; Lograsso, Thomas A; Huh, Moo-Young; Kim, Do-Hyang; Eckert, Jürgen; Lee, Min-Ha

    2015-01-01

    We present investigations on the plastic deformation behavior of a brittle bulk amorphous alloy by simple uniaxial compressive loading at room temperature. A patterning is possible by cold-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homogenous flow without the need for thermal energy or shaping at elevated temperatures. The experimental evidence suggests that there is an inconsistency between macroscopic plasticity and deformability of an amorphous alloy. Moreover, imprinting of specific geometrical features on Cu foil and Zr-based metallic glass is represented by using the patterned bulk amorphous alloy as a die. These results demonstrate the ability of amorphous alloys or metallic glasses to precisely replicate patterning features onto both conventional metals and the other amorphous alloys. Our work presents an avenue for avoiding the embrittlement of amorphous alloys associated with thermoplastic forming and yields new insight the forming application of bulk amorphous alloys at room temperature without using heat treatment. PMID:26563908

  19. TEM-simulation of amorphous carbon films: influence of supercell packaging.

    PubMed

    Schultrich, H; Schultrich, B

    2001-07-01

    Recent developments in thin film technology allow to prepare deliberately amorphous carbon films with structures widely varying between graphite-like (sp2) and diamond-like (sp3) atomic bonds. This leads to amorphous structures with correspondingly varying densities. By periodically changing deposition conditions, nanometer multilayers may be prepared consisting of carbon layers of different density. Simulation of the electron microscopic imaging allows to differentiate between such real structural details (on the nanometer scale) and artefacts induced by the imaging procedure. But it must be assured that the modeled structure reflects the real one with sufficient accuracy. Thorough comparison of different simulation strategies shows that for the adequate simulation of TEM imaging of amorphous materials, the thickness of the layer with independently distributed atoms has to exceed a certain limit. Then, the statistical scattering of the randomly distributed atoms will be averaged. Otherwise, if the model of the transmission electron microscopy sample is constructed as iteration of thin identical supercells, the superposition of scattering waves with constant phase differences results in enhanced local fluctuations burying the multilayer structure. For thicker packages of supercells with independent random distributions, the effect of statistical atomic arrangements is more and more leveled off. Hence, nanometer structures based on regions with different density will be visible more distinctively in the random background. For carbon, this critical thickness amounts to about 4 nm. This is of special importance for the visualization of nanoscaled heterogeneities like multilayers or nanotube-like inclusions in amorphous matrices. PMID:11419873

  20. Amorphous rare earth magnet powders

    SciTech Connect

    Sellers, C.H.; Branagan, D.J.; Hyde, T.A.; Lewis, L.H.; Panchanathan, V.

    1996-08-01

    Gas atomization (GA) processing does not generally have a high enough cooling rate to produce the initial amorphous microstructure needed to obtain optimal magnetic properties in RE{sub 2}Fe{sub 14}B alloys. Phase separation and an underquenched microstructure result from detrimental {alpha}-Fe precipitation, and the resulting magnetic domain structure is very coarse. Additionally, there is a dramatic dependence of the magnetic properties on the cooling rate (and therefore the particle size) and the powders can be sensitive to environmental degradation. Alloy compositions designed just for GA (as opposed to melt spinning) are necessary to produce an amorphous structure that can be crystallized to result in a fine structure with magnetic properties which are independent of particle size. The addition of titanium and carbon to the melt has been found to change the solidification process sufficiently to result in an ``overquenched`` state in which most of the powder size fractions have an amorphous component. Crystallization with a brief heat treatment produces a structure which has improved magnetic properties, in part due to the ability to use compositions with higher Fe contents without {alpha}-Fe precipitation. Results from magnetometry, magnetic force microscopy, and x-ray analyses will be used to contrast the microstructure, domain structure, and magnetic properties of this new generation of amorphous powders with their multiphase predecessors.

  1. Model for amorphous aggregation processes

    NASA Astrophysics Data System (ADS)

    Stranks, Samuel D.; Ecroyd, Heath; van Sluyter, Steven; Waters, Elizabeth J.; Carver, John A.; von Smekal, Lorenz

    2009-11-01

    The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first applications of the model, we have tested it against experimental turbidimetry data of three proteins relevant to the wine industry and biochemistry, namely, thaumatin, a thaumatinlike protein, and α -lactalbumin. The model is very robust and describes amorphous experimental data to a high degree of accuracy. Details about the aggregation process, such as shape parameters of the aggregates and rate constants, can also be extracted.

  2. Tandem junction amorphous silicon solar cells

    DOEpatents

    Hanak, Joseph J.

    1981-01-01

    An amorphous silicon solar cell has an active body with two or a series of layers of hydrogenated amorphous silicon arranged in a tandem stacked configuration with one optical path and electrically interconnected by a tunnel junction. The layers of hydrogenated amorphous silicon arranged in tandem configuration can have the same bandgap or differing bandgaps.

  3. Electromagnetic response of buried cylindrical structures for line current excitation

    NASA Astrophysics Data System (ADS)

    Pajewski, Lara; Ponti, Cristina

    2013-04-01

    The Cylindrical-Wave Approach (CWA) rigorously solves, in the spectral domain, the electromagnetic forward scattering by a finite set of buried two-dimensional perfectly-conducting or dielectric objects [1]-[2]. In this technique, the field scattered by underground objects is represented in terms of a superposition of cylindrical waves. Use is made of the plane-wave spectrum [1] to take into account the interaction of such waves with the planar interface between air and soil, and between different layers eventually present in the ground [3]. Obstacles of general shape can be simulated through the CWA with good results, by using a suitable set of small circular-section cylinders [4]. Recently, we improved the CWA by facing the fundamental problem of losses in the ground [5]: this is of significant importance in remote-sensing applications, since real soils often have complex permittivity and conductivity, and sometimes also a complex permeability. While in previous works concerning the CWA a monochromatic or pulsed plane-wave incident field was considered, in the present work a different source of scattering is present: a cylindrical wave radiated by a line source. Such a source is more suitable to model the practical illumination field used in GPR surveys. The electric field radiated by the line current is expressed by means of a first-kind Hankel function of 0-th order. The theoretical solution to the scattering problem is developed for both dielectric and perfectly-conducting cylinders buried in a dielectric half-space. The approach is implemented in a Fortran code; an accurate numerical evaluation of the involved spectral integrals is performed, the highly-oscillating behavior of the homogeneous waves is correctly followed and evanescent contributions are taken into account. The electromagnetic field scattered in both air and ground can be obtained, in near- and far-field regions, for arbitrary radii and permittivity of the buried cylinders, as well as for

  4. New Screw Design for Securing Buried Distractors Usefulness and Ease of Removal.

    PubMed

    Fariña, Rodrigo; Hinojosa, Andrés; Sánchez, Martín; Olate, Sergio

    2015-07-01

    There are 2 types of distraction devices for mandibular distraction: buried and external. The advantage of buried devices is the stability, but the difficulty in removing the screws is the greatest disadvantage. To resolve this problem, an osteosynthesis screw (Fariña Screw) has been designed, which greatly facilitates its removal when buried distractors are used. PMID:26102540

  5. 49 CFR 193.2629 - External corrosion control: buried or submerged components.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: buried or submerged... corrosion control: buried or submerged components. (a) Each buried or submerged component that is subject to external corrosive attack must be protected from external corrosion by— (1) Material that has been...

  6. 49 CFR 193.2629 - External corrosion control: buried or submerged components.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: buried or submerged... corrosion control: buried or submerged components. (a) Each buried or submerged component that is subject to external corrosive attack must be protected from external corrosion by— (1) Material that has been...

  7. 49 CFR 193.2629 - External corrosion control: buried or submerged components.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: buried or submerged... corrosion control: buried or submerged components. (a) Each buried or submerged component that is subject to external corrosive attack must be protected from external corrosion by— (1) Material that has been...

  8. 49 CFR 193.2629 - External corrosion control: buried or submerged components.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: buried or submerged... corrosion control: buried or submerged components. (a) Each buried or submerged component that is subject to external corrosive attack must be protected from external corrosion by— (1) Material that has been...

  9. 49 CFR 193.2629 - External corrosion control: buried or submerged components.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: buried or submerged... corrosion control: buried or submerged components. (a) Each buried or submerged component that is subject to external corrosive attack must be protected from external corrosion by— (1) Material that has been...

  10. In situ grouting of buried transuranic waste with polyacrylamide

    SciTech Connect

    Spalding, B.P.; Lee, S.Y.; Farmer, C.D.; Hyder, L.K.; Supaokit, P.

    1987-01-01

    This project is a demonstration and evaluation of the in situ hydrologic stabilization of buried transuranic waste at a humid site via grout injection. Two small trenches, containing buried transuranic waste, were filled with 34.000 L of polyacrylamide grout. Initial field results have indicated that voids within the trenches were totally filled by the grout and that the intratrench hydraulic conductivity was reduced to below field-measurable values. No evidence of grout constituents were observed in twelve perimeter groundwater monitoring wells indicating that grout was contained completely within the two trenches. Polyacrylamide grout was selected for field demonstration over the polyacrylate grout due to its superior performance in laboratory degradation studies. Also supporting the selection of polyacrylamide was the difficulty in controlling the set time of the acrylate polymerization. Based on preliminary degradation monitoring, the polyacrylamide was estimated to have a microbiological half-life of 362 years in the test soil. 15 refs., 9 figs., 12 tabs.

  11. Field test plan: Buried waste technologies, Fiscal Year 1995

    SciTech Connect

    Heard, R.E.; Hyde, R.A.; Engleman, V.S.; Evans, J.D.; Jackson, T.W.

    1995-06-01

    The US Department of Energy, Office of Technology Development, supports the applied research, development, demonstration, testing, and evaluation of a suite of advanced technologies that, when integrated with commercially available baseline technologies, form a comprehensive remediation system for the effective and efficient remediation of buried waste. The Fiscal Year 1995 effort is to deploy and test multiple technologies from four functional areas of buried waste remediation: site characterization, waste characterization, retrieval, and treatment. This document is the basic operational planning document for the deployment and testing of the technologies that support the field testing in Fiscal Year 1995. Discussed in this document are the scope of the tests; purpose and objective of the tests; organization and responsibilities; contingency plans; sequence of activities; sampling and data collection; document control; analytical methods; data reduction, validation, and verification; quality assurance; equipment and instruments; facilities and utilities; health and safety; residuals management; and regulatory management.

  12. Continuum soil modeling in the static analysis of buried structures

    SciTech Connect

    Julyk, L.J.; Marlow, R.S.; Moore, C.J.; Day, J.P.; Dyrness, A.D.

    1993-10-01

    Soil loading traditionally has been modeled as a hydrostatic pressure, a practice acceptable for many design applications. In the analyses of buried structure with predictive goals, soil compliance and load redistribution in the presence of soil plasticity are important factors to consider in determining the appropriate response of the structure. In the analysis of existing buried waste-storage tanks at the US Department of Energy`s Hanford Site, three soil-tank interaction modeling considerations are addressed. First, the soil interacts with the tank as the tank expands and contracts during thermal cycles associated with changes in the heat generated by the waste material as a result of additions and subtractions of the waste. Second, the soil transfers loads from the surface to the tank and provides support by resisting radial displacement of the tank haunch. Third, conventional finite-element mesh development causes artificial stress concentrations in the soil associated with differential settlement.

  13. Burying flowlines and cables in 186-m water

    SciTech Connect

    Cameron, G.

    1983-07-01

    UDI Group Ltd. and British Petroleum Development Ltd. have developed a 30-ton remote controlled seabed vehicle. The vehicle was built with the expressed purpose of burying the 35 km of flowlines for the remote wellheads on the Magnus field in 186-m of water, in order to increase thermal insulation of pipelines and to produce a greater degree of physical protection against damage from fishing gear, etc. During the 1981 trials, it was decided to carry out further development of the system for simultaneous laying and burial of the control umbilicals required for the remote wellhead controls on Magnus. For this work, it was necessary for each control umbilical to be positioned alongside its respective flowline along the route between the wellhead and the platform. At the platform end of the route, the flowlines and umbilicals are densely concentrated, and accuracy is required in the laying and burying of the umbilicals.

  14. Aeromagnetic Expression of Buried Basaltic Volcanoes Near Yucca Mountain, Nevada

    USGS Publications Warehouse

    O'Leary, D. W.; Mankinen, E.A.; Blakely, R.J.; Langenheim, V.E.; Ponce, D.A.

    2002-01-01

    A high-resolution aeromagnetic survey has defined a number of small dipolar anomalies indicating the presence of magnetic bodies buried beneath the surface of Crater Flat and the Amargosa Desert. Results of potential-field modeling indicate that isolated, small-volume, highly magnetic bodies embedded within the alluvial deposits of both areas produce the anomalies. Their physical characteristics and the fact that they tend to be aligned along major structural trends provide strong support for the hypothesis that the anomalies reflect buried basaltic volcanic centers. Other, similar anomalies are identified as possible targets for further investigation. High-resolution gravity and ground-magnetic surveys, perhaps along with drilling sources of selected anomalies and radiometric age determinations, can provide valuable constraints in estimating potential volcanic hazard to the potential nuclear waste repository at Yucca Mountain.

  15. Schedule optimization for IR detection of buried targets

    NASA Astrophysics Data System (ADS)

    Derzko, Zenon; Eylander, John B.; Broach, J. Thomas

    2012-06-01

    Schedule optimization of air platforms for IR sensors is a priority because of 1) the time sensitive nature of the IR detection of buried targets, 2) limited air platform assets, and 3) limited bandwidth for live-feed video. Scheduling optimization for airborne IR sensors depends on transient meteorological predictions, transient soil properties, target type and depth. This work involves using predictions from the Weather Research and Forecasting (WRF) model, a regional weather model, as input to the Countermine Computational Test Bed (CTB), a 3D finite element model that accounts for coupled heat and moisture transfer in soil and targets. The result is a continuous 2-day optimized schedule for airborne IR assets. In this paper, a 2-day optimized schedule for an airborne IR sensor asset is demonstrated for a single geographical location with a buried target. Transient physical surface and subsurface soil temperatures are presented as well as the phase-shifted, transient thermal response of the target.

  16. Common causes of material degradation in buried piping

    SciTech Connect

    Jenkins, C.F.

    1997-01-20

    Buried pipe may fail for innumerable reasons. Causes can be mechanical damage/breakage, chemically initiated corrosion, or a combination. Failures may originate either internally or externally on the pipe. They may be related to flaws in the design, to excessive or unanticipated internal pressure or ground level loading, and/or to poor or uncertain installation practice. Or the pipe may simply ``wear out`` in service. Steel is strong and very forgiving in underground applications, especially with regard to backfill. However, soil support developed through densification or compaction is critical for brittle concrete and vitrified clay tile pipe, and is very important for cast iron and plastic pipe. Chemistry of the soil determines whether or not it will enhance corrosion or other types of degradation. Various causes and mechanisms for deterioration of buried pipe are indicated. Some peculiarities of the different materials of construction are characterized. Repair methods and means to circumvent special problems are described.

  17. Technology Solutions Case Study: Buried and Encapsulated Ducts, Jacksonville, Florida

    SciTech Connect

    2013-11-01

    Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation; specifically for use in humid climates.

  18. Buried Porous Silicon-Germanium Layers in Monocrystalline Silicon Lattices

    NASA Technical Reports Server (NTRS)

    Fathauer, Robert W. (Inventor); George, Thomas (Inventor); Jones, Eric W. (Inventor)

    1998-01-01

    Monocrystalline semiconductor lattices with a buried porous semiconductor layer having different chemical composition is discussed and monocrystalline semiconductor superlattices with a buried porous semiconductor layers having different chemical composition than that of its monocrystalline semiconductor superlattice are discussed. Lattices of alternating layers of monocrystalline silicon and porous silicon-germanium have been produced. These single crystal lattices have been fabricated by epitaxial growth of Si and Si-Ge layers followed by patterning into mesa structures. The mesa structures are strain etched resulting in porosification of the Si-Ge layers with a minor amount of porosification of the monocrystalline Si layers. Thicker Si-Ge layers produced in a similar manner emitted visible light at room temperature.

  19. FY-94 buried waste integrated demonstration program report

    SciTech Connect

    Not Available

    1994-11-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a multitude of advanced technologies. These technologies are being integrated to form a comprehensive remediation system for the effective and efficient remediation of buried waste. These efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER/WM) needs and objectives. This document summarizes previous demonstrations and describes the FY-94 BWID technology development and demonstration activities. Sponsored by the DOE Office of Technology Development (OTD), BWID works with universities and private industry to develop these technologies, which are being transferred to the private sector for use nationally and internationally. A public participation policy has been established to provide stakeholders with timely and accurate information and meaningful opportunities for involvement in the technology development and demonstration process.

  20. Vertical Bipolar Charge Plasma Transistor with Buried Metal Layer

    PubMed Central

    Nadda, Kanika; Kumar, M. Jagadesh

    2015-01-01

    A self-aligned vertical Bipolar Charge Plasma Transistor (V-BCPT) with a buried metal layer between undoped silicon and buried oxide of the silicon-on-insulator substrate, is reported in this paper. Using two-dimensional device simulation, the electrical performance of the proposed device is evaluated in detail. Our simulation results demonstrate that the V-BCPT not only has very high current gain but also exhibits high BVCEO · fT product making it highly suitable for mixed signal high speed circuits. The proposed device structure is also suitable for realizing doping-less bipolar charge plasma transistor using compound semiconductors such as GaAs, SiC with low thermal budgets. The device is also immune to non-ideal current crowding effects cropping up at high current densities. PMID:25597295

  1. Prediction of the TNT signature from buried UXO/landmines

    SciTech Connect

    Webb, S.W.; Phelan, J.M.; Finsterle, S.A.; Pruess, K.

    1998-06-01

    The detection and removal of buried unexploded ordnance (UXO) and landmines is one of the most important problems facing the world today. Numerous detection strategies are being developed, including infrared, electrical conductivity, ground-penetrating radar, and chemical sensors. Chemical sensors rely on the detection of TNT molecules, which are transported from buried UXO/landmines by advection and diffusion in the soil. As part of this effort, numerical models are being developed to predict TNT transport in soils including the effect of precipitation and evaporation. Modifications will be made to TOUGH2 for application to the TNT chemical sensing problem. Understanding the fate and transport of TNT in the soil will affect the design, performance and operation of chemical sensors by indicating preferred sensing strategies.

  2. Amorphous metal-organic frameworks.

    PubMed

    Bennett, Thomas D; Cheetham, Anthony K

    2014-05-20

    Crystalline metal-organic frameworks (MOFs) are porous frameworks comprising an infinite array of metal nodes connected by organic linkers. The number of novel MOF structures reported per year is now in excess of 6000, despite significant increases in the complexity of both component units and molecular networks. Their regularly repeating structures give rise to chemically variable porous architectures, which have been studied extensively due to their sorption and separation potential. More recently, catalytic applications have been proposed that make use of their chemical tunability, while reports of negative linear compressibility and negative thermal expansion have further expanded interest in the field. Amorphous metal-organic frameworks (aMOFs) retain the basic building blocks and connectivity of their crystalline counterparts, though they lack any long-range periodic order. Aperiodic arrangements of atoms result in their X-ray diffraction patterns being dominated by broad "humps" caused by diffuse scattering and thus they are largely indistinguishable from one another. Amorphous MOFs offer many exciting opportunities for practical application, either as novel functional materials themselves or facilitating other processes, though the domain is largely unexplored (total aMOF reported structures amounting to under 30). Specifically, the use of crystalline MOFs to detect harmful guest species before subsequent stress-induced collapse and guest immobilization is of considerable interest, while functional luminescent and optically active glass-like materials may also be prepared in this manner. The ion transporting capacity of crystalline MOFs might be improved during partial structural collapse, while there are possibilities of preparing superstrong glasses and hybrid liquids during thermal amorphization. The tuning of release times of MOF drug delivery vehicles by partial structural collapse may be possible, and aMOFs are often more mechanically robust than

  3. Investigation of guided waves propagation in pipe buried in sand

    SciTech Connect

    Leinov, Eli; Cawley, Peter; Lowe, Michael J.S.

    2014-02-18

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

  4. Quantitation of buried contamination by use of solvents

    NASA Technical Reports Server (NTRS)

    Pappas, S. P.; Hsiao, P.; Hill, L. W.

    1973-01-01

    A method for determining the quantity of buried contamination using solvents is presented. A nonsporocidal method with which high spore recoveries are achievable from silicone coatings and potting compounds was developed. An extension of the method to silicon potting compound RTV 60 is reported. It is stated that spores remain viable during chemical curing of silicone potting compounds and more than ninety percent of the spore population is recoverable by amine dissolution and proper plating techniques.

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

    SciTech Connect

    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.

  6. Detection of buried objects using reflected GNSS signals

    NASA Astrophysics Data System (ADS)

    Notarpietro, Riccardo; De Mattia, Salvatore; Campanella, Maurizio; Pei, Yuekun; Savi, Patrizia

    2014-12-01

    The use of reflected Global Navigation Satellite System (GNSS) signals for sensing the Earth has been growing rapidly in recent years. This technique is founded on the basic principle of detecting GNSS signals after they have been reflected off the Earth's surface and using them to determine the properties of the reflecting surface remotely. This is the so-called GNSS reflectometry (GNSS-R) technique. In this paper, a new application regarding the detection of metallic buried objects is analyzed and it is validated through several experimental campaigns. Although the penetration depth of GNSS signals into the ground is not optimal and depends on the soil moisture, GNSS signals can likely interact approximately with the first 10 cm of the ground and therefore can be reflected back by any metallic object buried on the first terrain layer. A very light and low-cost GNSS receiver prototype based on a software-defined radio approach was developed. This receiver can be used as a payload on board small drones or unmanned aerial systems to detect metallic objects (mines or other explosive devices). A signal processing tool based on an open-loop GNSS signal acquisition strategy was developed. The results of two experiments which show the possibility of using GNSS-R signals to detect buried metallic objects and to provide an estimate of their dimensions are discussed.

  7. Buried Waste Integrated Demonstration FY-95 Deployment Plan

    SciTech Connect

    Stacey, D.E.

    1995-03-01

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the U.S. Department of Energy Office of Technology Development. BWID supports the applied research, development, demonstration, testing, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. The FY-95 effort will fund 24 technologies in five areas of buried waste site remediation: site characterization, waste characterization, retrieval, treatment, and containment/stabilization. Ten of these technologies will take part in the integrated field demonstration that will take place at the Idaho National Engineering Laboratory (INEL) facilities in the summer of 1995. This document is the basic operational planning document for deployment of all BWID projects funded in FY-95. Discussed in this document are the BWID preparations for the INEL integrated field demonstration, INEL research and development (R&D) demonstrations, non-INEL R&D demonstrations, and office research and technical review meetings. Each project will have a test plan detailing the specific procedures, objectives, and tasks of the test. Therefore, information that is specific to testing each technology is intentionally limited in this document.

  8. FY-95 technology catalog. Technology development for buried waste remediation

    SciTech Connect

    1995-10-01

    The US Department of Energy`s (DOE) Buried Waste Integrated Demonstration (BWID) program, which is now part of the Landfill Stabilization Focus Area (LSFA), supports applied research, development, demonstration, and evaluation of a multitude of advanced technologies dealing with underground radioactive and hazardous waste remediation. These innovative technologies are being developed as part of integrated comprehensive remediation systems for the effective and efficient remediation of buried waste sites throughout the DOE complex. These efforts are identified and coordinated in support of Environmental Restoration (EM-40) and Waste Management (EM-30) needs and objectives. Sponsored by the DOE Office of Technology Development (EM-50), BWID and LSFA work with universities and private industry to develop technologies that are being transferred to the private sector for use nationally and internationally. This report contains the details of the purpose, logic, and methodology used to develop and demonstrate DOE buried waste remediation technologies. It also provides a catalog of technologies and capabilities with development status for potential users. Past FY-92 through FY-94 technology testing, field trials, and demonstrations are summarized. Continuing and new FY-95 technology demonstrations also are described.

  9. Buried-euxenic-basin model sets Tarim basin potential

    SciTech Connect

    Hsu, K.J. )

    1994-11-28

    The Tarim basin is the largest of the three large sedimentary basins of Northwest China. The North and Southwest depressions of Tarim are underlain by thick sediments and very thin crust. The maximum sediment thickness is more than 15 km. Of the several oil fields of Tarim, the three major fields were discovered during the last decade, on the north flank of the North depression and on the Central Tarim Uplift. The major targets of Tarim, according to the buried-euxenic-basin model, should be upper Paleozoic and lower Mesozoic reservoirs trapping oil and gas condensates from lower Paleozoic source beds. The paper describes the basin and gives a historical perspective of exploration activities and discoveries. It then explains how this basin can be interpreted by the buried-euxenic-basin model. The buried-euxenic-basin model postulates four stages of geologic evolution: (1) Sinian and early Paleozoic platform sedimentation on relic arcs and deep-marine sedimentation in back-arc basins in Xinjiang; (2) Late Paleozoic foreland-basin sedimentation in north Tarim; (3) Mesozoic and Paleogene continental deposition, subsidence under sedimentary load; and (4) Neogene pull-apart basin, wrench faulting and extension.

  10. Degradation of carbohydrates and lignins in buried woods

    USGS Publications Warehouse

    Hedges, J.I.; Cowie, G.L.; Ertel, J.R.; James, Barbour R.; Hatcher, P.G.

    1985-01-01

    Spruce, alder, and oak woods deposited in coastal sediments were characterized versus their modern counterparts by quantification of individual neutral sugars and lignin-derived phenols as well as by scanning electron microscopy, 13C NMR, and elemental analysis. The buried spruce wood from a 2500 yr old deposit was unaltered whereas an alder wood from the same horizon and an oak wood from an open ocean sediment were profoundly degraded. Individual sugar and lignin phenol analyses indicate that at least 90 and 98 wt% of the initial total polysaccharides in the buried alder and oak woods, respectively, have been degraded along with 15-25 wt% of the lignin. At least 75% of the degraded biopolymer has been physically lost from these samples. This evidence is supported by the SEM, 13C NMR and elemental analyses, all of which indicate selective loss of the carbohydrate moiety. The following order of stability was observed for the major biochemical constituents of both buried hardwoods: vanillyl and p-hydroxyl lignin structural units > syringyl lignin structural units > pectin > ??-cellulose > hemicellulose. This sequence can be explained by selective preservation of the compound middle lamella regions of the wood cell walls. The magnitude and selectivity of the indicated diagenetic reactions are sufficient to cause major changes in the chemical compositions of wood-rich sedimentary organic mixtures and to provide a potentially large in situ nutrient source. ?? 1985.

  11. Exoelectron analysis of amorphous silicon

    NASA Astrophysics Data System (ADS)

    Dekhtyar, Yu. D.; Vinyarskaya, Yu. A.

    1994-04-01

    The method based on registration of photothermostimulated exoelectron emission (PTSE) is used in the proposed new field of investigating the structural defects in amorphous silicon (a-Si). This method can be achieved if the sample under investigation is simultaneously heated and illuminated by ultraviolet light. The mechanism of PTSE from a-Si has been studied in the case of a hydrogenized amorphous silicon (a-Si:H) film grown by glow discharge method. The electronic properties and annealing of defects were analyzed in the study. It has been shown from the results that the PTSE from a-Si:H takes place as a prethreshold single-photon external photoeffect. The exoemission spectroscopy of a-Si:H was shown to be capable in the study of thermally and optically stimulated changes in the electronic structure of defects, their annealing, as well as diffusion of atomic particles, such as hydrogen.

  12. Uranium incorporation into amorphous silica.

    PubMed

    Massey, Michael S; Lezama-Pacheco, Juan S; Nelson, Joey M; Fendorf, Scott; Maher, Kate

    2014-01-01

    High concentrations of uranium are commonly observed in naturally occurring amorphous silica (including opal) deposits, suggesting that incorporation of U into amorphous silica may represent a natural attenuation mechanism and promising strategy for U remediation. However, the stability of uranium in opaline silicates, determined in part by the binding mechanism for U, is an important factor in its long-term fate. U may bind directly to the opaline silicate matrix, or to materials such as iron (hydr)oxides that are subsequently occluded within the opal. Here, we examine the coordination environment of U within opaline silica to elucidate incorporation mechanisms. Precipitates (with and without ferrihydrite inclusions) were synthesized from U-bearing sodium metasilicate solutions, buffered at pH ∼ 5.6. Natural and synthetic solids were analyzed with X-ray absorption spectroscopy and a suite of other techniques. In synthetic amorphous silica, U was coordinated by silicate in a double corner-sharing coordination geometry (Si at ∼ 3.8-3.9 Å) and a small amount of uranyl and silicate in a bidentate, mononuclear (edge-sharing) coordination (Si at ∼ 3.1-3.2 Å, U at ∼ 3.8-3.9 Å). In iron-bearing synthetic solids, U was adsorbed to iron (hydr)oxide, but the coordination environment also contained silicate in both edge-sharing and corner-sharing coordination. Uranium local coordination in synthetic solids is similar to that of natural U-bearing opals that retain U for millions of years. The stability and extent of U incorporation into opaline and amorphous silica represents a long-term repository for U that may provide an alternative strategy for remediation of U contamination. PMID:24984107

  13. Visual Observations of the Amorphous-Amorphous Transition in H2O Under Pressure.

    PubMed

    Mishima, O; Takemura, K; Aoki, K

    1991-10-18

    The vapor-deposited low-density amorphous phase of H(2)O was directly compressed at 77 kelvin with a diamond-anvil cell, and the boundary between the low-density amorphous phase and the high-density amorphous phase was observed while the sample was warmed under compression. The transition from the low-density amorphous phase to the high-density amorphous phase was distinct and reversible in an apparently narrow pressure range at approximately 130 to approximately 150 kelvin, which provided experimental evidence for polymorphism in amorphous H(2)O. PMID:17742228

  14. Nature of the AX center participating persistent photoconductivity effect in As-doped p-ZnO

    NASA Astrophysics Data System (ADS)

    Jeong, T. S.; Yu, J. H.; Mo, H. S.; Kim, T. S.; Youn, C. J.; Hong, K. J.

    2013-08-01

    The possible nature of metastable capture centers giving rise to persist photoconductivity (PPC) effect in As-doped p-ZnO was investigated using the photoluminescence result. Through the plot of log σph vs. 1/T and temperature-dependent PPC-decay process, the metastable trapping centers were extracted to be 15.1, 178.2, 180.6, and 291.9 meV. The shallow level of 15.1 meV was related to the binding energy of the neutral acceptor bound exciton. Also, the deep levels of 178.2 and 180.6 meV were caused by complex acceptor states of AsZn-2VZn located at 185 meV above the edge of the valence band. Furthermore, the trapping center of 291.9 meV was corresponded to the hole capture barrier of VZn located at 300 meV above the valence band. Therefore, these trapping centers were deeply related to the AX centers originating the native defects due to VZn or defect complexes of the As-implanted dopant in ZnO. Also, these defects, induced by the metastable AX centers, were concluded to be responsible for the PPC effect.

  15. Structural Modelling of Two Dimensional Amorphous Materials

    NASA Astrophysics Data System (ADS)

    Kumar, Avishek

    The continuous random network (CRN) model of network glasses is widely accepted as a model for materials such as vitreous silica and amorphous silicon. Although it has been more than eighty years since the proposal of the CRN, there has not been conclusive experimental evidence of the structure of glasses and amorphous materials. This has now changed with the advent of two-dimensional amorphous materials. Now, not only the distribution of rings but the actual atomic ring structure can be imaged in real space, allowing for greater charicterization of these types of networks. This dissertation reports the first work done on the modelling of amorphous graphene and vitreous silica bilayers. Models of amorphous graphene have been created using a Monte Carlo bond-switching method and MD method. Vitreous silica bilayers have been constructed using models of amorphous graphene and the ring statistics of silica bilayers has been studied.

  16. Narrow band gap amorphous silicon semiconductors

    DOEpatents

    Madan, A.; Mahan, A.H.

    1985-01-10

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  17. Amorphous silicon solar cell allowing infrared transmission

    DOEpatents

    Carlson, David E.

    1979-01-01

    An amorphous silicon solar cell with a layer of high index of refraction material or a series of layers having high and low indices of refraction material deposited upon a transparent substrate to reflect light of energies greater than the bandgap energy of the amorphous silicon back into the solar cell and transmit solar radiation having an energy less than the bandgap energy of the amorphous silicon.

  18. Amorphous powders for inhalation drug delivery.

    PubMed

    Chen, Lan; Okuda, Tomoyuki; Lu, Xiang-Yun; Chan, Hak-Kim

    2016-05-01

    For inhalation drug delivery, amorphous powder formulations offer the benefits of increased bioavailability for poorly soluble drugs, improved biochemical stability for biologics, and expanded options of using various drugs and their combinations. However, amorphous formulations usually have poor physicochemical stability. This review focuses on inhalable amorphous powders, including the production methods, the active pharmaceutical ingredients and the excipients with a highlight on stabilization of the particles. PMID:26780404

  19. Reflection Seismic Imaging of Buried Valleys, Onshore Denmark

    NASA Astrophysics Data System (ADS)

    Lykke-Andersen, H.; Jørgensen, F.; Nørmark, E.

    The steadily increasing demands for securing supplies of clean groundwater have in recent years led to the adoption of reflection seismics in the family of geophysical methods used for groundwater research in Denmark. Buried valleys- often some km wide and a few hundred metres deep - have proved to be important sites for deeply seated, well protected groundwater reservoirs. It is a well known fact that the structure of buried valleys is complicated. With their potential for generation of relatively high resolution images of depositional and tectonic structures, reflection seismics have be- come a valuable supplement to the traditional resistivity methods in the study of buried valleys. Reflection seismic is an expensive method compared to other methods in use for groundwater research; therefore, careful selection of profile locations is mandatory. A practice has developed where selection of locations are based on mapping results obtained by resistivity methods. Results obtained by dynamite and vibrator sources are presented. Experience shows that the quality of the two data types is comparable. Vertical resolution better than ca. 10 m can be obtained, but the bandwidth of data is variable. In areas where non-(water) saturated shallow sediments are present; the bandwidth may be strongly reduced. Depth penetration down to at least one km is normally obtained. The seismic data are tied to wells by means of vertical seismic profiles in exploratory wells. Results are presented to illustrate: 1) potentials and limi- tations of the method and 2) a number of valleys with different types of valley-fill and relationships with the substratum. The genesis of the valleys will be briefly discussed.

  20. A Large Buried Felsic Component in the Ancient Martian Crust?

    NASA Astrophysics Data System (ADS)

    Baratoux, D.; Monnereau, M.; Samuel, H.; Michaut, C.; Wieczorek, M. A.; Garcia, R.

    2014-12-01

    A new range of crustal density values for Mars was calculated from the major element chemistry of Martian meteorites
(3100 - 3700 kg/m3), igneous rocks at Gusev crater (3100 - 3600 kg/m3) and from the surface concentration of Fe, Al, Ca, Si, and K measured by the Gamma-Ray Spectrometer (GRS) (3250 - 3450 kg/m3) (Baratoux et al., 2014). Whereas a dense basaltic crust would be compatible with the moment of inertia factor of Mars, its thickness would exceed 100 km. Such a thick crust is not compatible with the geoid-to-topography ratios in the highlands, and would be unstable and prone to basal flow and/or crustal delamination. An alternative possibility is the existence of a buried light felsic or anorthositic component. A low-density crustal component in the highlands would be consistent with an isostatic compensation associated with a difference in elevation between the two hemispheres of Mars. This alternative is reinforced in the context of the findings of felsic or anorthositic material from visible/NIR spectroscopy (Carter and Poulet, 2013, Wray et al. 2013), and the identification of feldspar-rich rocks at Gale crater (Sautter et al., 2014), whereas felsic lithologies were already identified by Pathfinder. The recently identified outcrops could be either remnants of an ancient anorthositic crust or the result of local igneous differentiation of plutonic bodies. The latter interpretation is currently preferred as early Mars conditions should not be compatible with the formation of a plagioclase floatation crust (Elkins-Tanton et al., 2005). However, in light of the geophysical and petrological constraints discussed above, and given the absence of abundant light material at the surface, we advocate for the existence of a buried anorthositic crustal component that has been largely buried by volcanic material of basaltic composition in the late Noachian or Hesperian eras. Implications regarding the magma ocean scenario for Mars will be discussed.

  1. Ion-implanted planar-buried-heterostructure diode laser

    DOEpatents

    Brennan, Thomas M.; Hammons, Burrell E.; Myers, David R.; Vawter, Gregory A.

    1991-01-01

    A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding layer 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an ion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

  2. Explosive fluid transmitted shock method for mining deeply buried coal

    DOEpatents

    Archibald, Paul B.

    1976-06-22

    A method for recovering coal from deeply buried deposits comprising drilling a hole down into a coal seam, filling the hole with water, and periodically detonating an explosive charge at the bottom of the water-filled hole. The water transmits the explosive shock wave to the face of the coal seam, thereby fracturing and dislodging the coal. The resulting suspension of loose coal in water is then pumped to the surface where the coal is recovered and the water is recycled to the mining operation.

  3. Low-Frequency Electromagnetic Backscatter from Buried Tunnels

    SciTech Connect

    Casey, K; Pao, H

    2006-06-21

    This progress report is submitted under a contract between the Special Project Office of DARPA and Lawrence Livermore National Laboratory. The Project Manager at DARPA is Dr. Michael Zatman. Our purpose under this contract is to investigate interactions between electromagnetic waves and a class of buried targets located in multilayered media with rough interfaces. In this report, we investigate three preliminary problems. In each case our specific goal is to understand various aspects of the electromagnetic wave interaction mechanisms with targets in layered media. The first problem, discussed in Section 2, is that of low-frequency electromagnetic backscattering from a tunnel that is cut into a lossy dielectric half-space. In this problem, the interface between the upper (free space) region and the lower (ground) region is smooth. The tunnel is assumed to be a cylindrical free-space region of infinite extent in its axial direction and with a diameter that is small in comparison to the free-space wavelength. Because its diameter is small, the tunnel can be modeled as a buried ''wire'' described by an equivalent impedance per unit length. In Section 3 we extend the analysis to include a statistically rough interface between the air and ground regions. The interface is modeled as a random-phase screen. Such a screen reduces the coherent power in a plane wave that is transmitted through it, scattering some of the total power into an incoherent field. Our analysis of this second problem quantifies the reduction in the coherent power backscattered from the buried tunnel that is caused by the roughness of the air-ground interface. The problem of low-frequency electromagnetic backscattering from two buried tunnels, parallel to each other but at different locations in the ground, is considered in Section 4. In this analysis, we wish to determine the conditions under which the presence of more than one tunnel can be detected via backscattering. Section 5 concludes the report

  4. Approximation functions for airblast environments from buried charges

    SciTech Connect

    Reichenbach, H.; Behrens, K.; Kuhl, A.L.

    1993-11-01

    In EMI report E 1/93, ``Airblast Environments from Buried HE-Charges,`` fit functions were used for the compact description of blastwave parameters. The coefficients of these functions were approximated by means of second order polynomials versus DOB. In most cases, the agreement with the measured data was satisfactory; to reduce remaining noticeable deviations, an approximation by polygons (i.e., piecewise-linear approximation) was used instead of polynomials. The present report describes the results of the polygon approximation and compares them to previous data. We conclude that the polygon representation leads to a better agreement with the measured data.

  5. Technology status report: In situ vitrification applied to buried wastes

    SciTech Connect

    Thompson, L.E.; Bates, S.O.; Hansen, J.E.

    1992-09-01

    This document is a technical status report on In Situ Vitrification (ISV) as applied to buried waste; the report takes both technical and institutional concerns into perspective. The ISV process involves electrically melting such contaminated solid media as soil, sediment, sludge, and mill tailings. The resultant product is a high-quality glass-and-crystalline waste form that possesses high resistance to corrosion and leaching and is capable of long-term environmental exposure without significant degradation. The process also significantly reduces the volume of the treated solid media due to the removal of pore spaces in the soil.

  6. Polarization lidar measurements of honeybees for locating buried landmines

    NASA Astrophysics Data System (ADS)

    Shaw, Joseph A.; Seldomridge, Nathan L.; Dunkle, Dustin L.; Nugent, Paul W.; Spangler, Lee H.; Churnside, James H.; Wilson, James W.; Bromenshenk, Jerry J.; Henderson, Colin B.

    2005-08-01

    A polarization-sensitive lidar was used to detect honeybees trained to locate buried landmines by smell. Lidar measurements of bee location agree reasonably well with maps of chemical plume strength and bee density determined by visual and video counts, indicating that the bees are preferentially located near the explosives and that the lidar identifies the locations of higher bee concentration. The co-polarized lidar backscatter signal is more effective than the cross-polarized signal for bee detection. Laboratory measurements show that the depolarization ratio of scattered light is near zero for bee wings and up to approximately thirty percent for bee bodies.

  7. Remote Excavation System technology evaluation report: Buried Waste Robotics Program

    SciTech Connect

    Not Available

    1993-09-01

    This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the system and discussed the procedures used to conduct the tests.

  8. Defensive burying in rodents: ethology, neurobiology and psychopharmacology.

    PubMed

    De Boer, Sietse F; Koolhaas, Jaap M

    2003-02-28

    Defensive burying refers to the typical rodent behavior of displacing bedding material with vigorous treading-like movements of their forepaws and shoveling movements of their heads directed towards a variety of noxious stimuli that pose a near and immediate threat, such as a wall-mounted electrified shock-prod. Since its introduction 25 years ago by Pinel and Treit [J. Comp. Physiol. Psychol. 92 (1978) 708], defensive (shock-prod) burying has been the focus of a considerable amount of research effort delineating the methodology/ethology, psychopharmacology and neurobiology of this robust and species-specific active avoidance or coping response. The present review gives a summary of this research with special reference to the behavioral (face and construct) and pharmacological (predictive) validity of the shock-prod burying test as an animal model for human anxiety. Emphasis is also placed on some recent modifications of the paradigm that may increase its utility and reliability as to individual differences in expressed emotional coping responses and sensitivity to pharmacological treatments. Overall, the behavioral and physiological responses displayed in the shock-prod paradigm are expressions of normal and functionally adaptive coping patterns and the extremes of either active (i.e., burying) or passive (i.e., freezing) forms of responding in this test cannot simply be regarded as inappropriate, maladaptive or pathological. For this reason, the shock-prod paradigm is not an animal model for anxiety disorder or for any other psychiatric disease, but instead possesses a high degree of face and construct validity for normal and functionally adaptive human fear and anxious apprehension. However, the apparent good pharmacological validation (predictive validity) of this test reinforces the view that normal and pathological anxiety involves, at least partly, common neurobiological substrates. Therefore, this paradigm is not only suitable for screening potential

  9. Elastic Phase Response of Silica Nanoparticles Buried in Soft Matter

    SciTech Connect

    Tetard, Laurene; Passian, Ali; Lynch, Rachel M; Voy, Brynn H; Shekhawat, Gajendra; Dravid, Vinayak; Thundat, Thomas George

    2008-01-01

    Tracking the uptake of nanomaterials by living cells is an important component in assessing both potential toxicity and in designing future materials for use in vivo. We show that the difference in the local elasticity at the site of silica (SiO{sub 2}) nanoparticles confined within a macrophage enables functional ultrasonic interactions. By elastically exciting the cell, a phase perturbation caused by the buried SiO{sub 2} nanoparticles was detected and used to map the subsurface populations of nanoparticles. Localization and mapping of stiff chemically synthesized silica nanoparticles within the cellular structures of a macrophage are important in basic as well as applied studies.

  10. The thermal regime around buried submarine high-voltage cables

    NASA Astrophysics Data System (ADS)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-08-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine high-voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70 °C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near-surface sediments are poorly understood. We present temperature measurements from a 2-D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments-coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m2) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples to measure the time-dependent 2-D temperature distributions. The observed and corresponding Finite Element Method simulations of the steady state heat flow regimes and normalized radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10 °C up to 40 cm from the source of 60 °C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between cf. 20 and 36 °C above ambient, with >10 °C heat increases occurring over a metre from the source of 55 °C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (cf. 7 °C) operating temperatures and reaching temperatures of up to 18 °C above ambient at a metre from the source at surface temperatures of only 18 °C. These findings are important for the surrounding near

  11. The thermal regime around buried submarine high voltage cables

    NASA Astrophysics Data System (ADS)

    Emeana, C. J.; Hughes, T. J.; Dix, J. K.; Gernon, T. M.; Henstock, T. J.; Thompson, C. E. L.; Pilgrim, J. A.

    2016-05-01

    The expansion of offshore renewable energy infrastructure and the need for trans-continental shelf power transmission require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70°C and are typically buried 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the heat flow pattern and potential effects on the sedimentary environments around such anomalously high heat sources in the near surface sediments are poorly understood. We present temperature measurements from a 2D laboratory experiment representing a buried submarine HV cable, and identify the thermal regimes generated within typical unconsolidated shelf sediments-coarse silt, fine sand and very coarse sand. We used a large (2 × 2.5 m) tank filled with water-saturated spherical glass beads (ballotini) and instrumented with a buried heat source and 120 thermocouples, to measure the time-dependent 2D temperature distributions. The observed and corresponding Finite Element Method (FEM) simulations of the steady state heat flow regimes, and normalised radial temperature distributions were assessed. Our results show that the heat transfer and thus temperature fields generated from submarine HV cables buried within a range of sediments are highly variable. Coarse silts are shown to be purely conductive, producing temperature increases of >10°C up to 40 cm from the source of 60°C above ambient; fine sands demonstrate a transition from conductive to convective heat transfer between c. 20°C and 36°C above ambient, with >10°C heat increases occurring over a metre from the source of 55°C above ambient; and very coarse sands exhibit dominantly convective heat transfer even at very low (c. 7°C) operating temperatures and reaching temperatures of up to 18°C above ambient at a metre from the source at surface temperatures of only 18°C. These findings are important for the surrounding near surface

  12. Ancient buried submarine trough, northwest Gulf of Mexico

    USGS Publications Warehouse

    Berryhill, H.L., Jr.

    1981-01-01

    A large buried submarine trough crosses the seaward margin of the continental shelf off the southwest coast of Louisiana. Original length was about 90 km, and width at the shelf edge was 16 km. Maximum eroded depth may have been as much as 305 m. Seismic characteristics of the prograded fill indicate cyclically repeated sequences of retrogressive deltaic and partly slumped sediments overlain by well-layered transgressive deposits. Slumping was increasingly prevalent toward the shelf edge. The cyclic sequences indicate that the trough was a passageway for large volumes of sediment onto the continental slope during several stages of lowered sea level. ?? 1981 A.M. Dowden, Inc.

  13. Plasma Deposition of Amorphous Silicon

    NASA Technical Reports Server (NTRS)

    Calcote, H. F.

    1982-01-01

    Strongly adhering films of silicon are deposited directly on such materials as Pyrex and Vycor (or equivalent materials) and aluminum by a non-equilibrium plasma jet. Amorphous silicon films are formed by decomposition of silicon tetrachloride or trichlorosilane in the plasma. Plasma-jet technique can also be used to deposit an adherent silicon film on aluminum from silane and to dope such films with phosphorus. Ability to deposit silicon films on such readily available, inexpensive substrates could eventually lead to lower cost photovoltaic cells.

  14. Preparation of amorphous sulfide sieves

    DOEpatents

    Siadati, Mohammad H.; Alonso, Gabriel; Chianelli, Russell R.

    2006-11-07

    The present invention involves methods and compositions for synthesizing catalysts/porous materials. In some embodiments, the resulting materials are amorphous sulfide sieves that can be mass-produced for a variety of uses. In some embodiments, methods of the invention concern any suitable precursor (such as thiomolybdate salt) that is exposed to a high pressure pre-compaction, if need be. For instance, in some cases the final bulk shape (but highly porous) may be same as the original bulk shape. The compacted/uncompacted precursor is then subjected to an open-flow hot isostatic pressing, which causes the precursor to decompose and convert to a highly porous material/catalyst.

  15. Technology needs for remediation: Hanford and other DOE sites. Buried Waste Integrated Demonstration Program

    SciTech Connect

    Stapp, D.C.

    1993-01-01

    Technologies are being developed under the Buried Waste Integrated Demonstration (BWID) program to facilitate remediation of the US Department of Energy`s (DOE) buried and stored low-level radioactive, transuranic (TRU), and mixed radioactive and hazardous buried wastes. The BWID program is being coordinated by the Idaho National Engineering Laboratory (INEL) in southeastern Idaho, a DOE site that has large volumes of buried radioactive wastes. The program is currently focusing its efforts on the problems at INEL`s Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC). As specific technologies are successfully demonstrated, they will be available for transfer to applications at other DOE buried waste sites. The purpose of this study is to present buried waste technology needs that have been identified for DOE sites other than INEL.

  16. Laser surface treatment of amorphous metals

    NASA Astrophysics Data System (ADS)

    Katakam, Shravana K.

    Amorphous materials are used as soft magnetic materials and also as surface coatings to improve the surface properties. Furthermore, the nanocrystalline materials derived from their amorphous precursors show superior soft magnetic properties than amorphous counter parts for transformer core applications. In the present work, laser based processing of amorphous materials will be presented. Conventionally, the nanocrystalline materials are synthesized by furnace heat treatment of amorphous precursors. Fe-based amorphous/nanocrystalline materials due to their low cost and superior magnetic properties are the most widely used soft magnetic materials. However, achieving nanocrystalline microstructure in Fe-Si-B ternary system becomes very difficult owing its rapid growth rate at higher temperatures and sluggish diffusion at low temperature annealing. Hence, nanocrystallization in this system is achieved by using alloying additions (Cu and Nb) in the ternary Fe-Si-B system. Thus, increasing the cost and also resulting in reduction of saturation magnetization. laser processing technique is used to achieve extremely fine nanocrystalline microstructure in Fe-Si-B amorphous precursor. Microstructure-magnetic Property-laser processing co-relationship has been established for Fe-Si-B ternary system using analytical techniques. Laser processing improved the magnetic properties with significant increase in saturation magnetization and near zero coercivity values. Amorphous materials exhibit excellent corrosion resistance by virtue of their atomic structure. Fe-based amorphous materials are economical and due to their ease of processing are of potential interest to synthesize as coatings materials for wear and corrosion resistance applications. Fe-Cr-Mo-Y-C-B amorphous system was used to develop thick coatings on 4130 Steel substrate and the corrosion resistance of the amorphous coatings was improved. It is also shown that the mode of corrosion depends on the laser processing

  17. Note: Laser ablation technique for electrically contacting a buried implant layer in single crystal diamond

    SciTech Connect

    Ray, M. P.; Baldwin, J. W.; Butler, J. E.; Pate, B. B.; Feygelson, T. I.

    2011-05-15

    The creation of thin, buried, and electrically conducting layers within an otherwise insulating diamond by annealed ion implantation damage is well known. Establishing facile electrical contact to the shallow buried layer has been an unmet challenge. We demonstrate a new method, based on laser micro-machining (laser ablation), to make reliable electrical contact to a buried implant layer in diamond. Comparison is made to focused ion beam milling.

  18. Beam and shell modes of buckling of buried pipes induced by compressive ground failure

    SciTech Connect

    Chiou, Y.J.; Chi, S.Y.

    1995-12-31

    The buckling of buried pipeline induced by compressive ground failure was investigated. Both the beam mode of buckling and local shell mode of buckling, and their interactions were studied. The pipeline response was analyzed numerically. The results agree qualitatively with past researches and possess satisfactory comparisons with actual case histories. The relations of critical buried depth versus ratio of pipe diameter to thickness for buried pipe with different imperfections and various soil foundations were established.

  19. Studies of hydrogenated amorphous silicon

    SciTech Connect

    Bishop, S G; Carlos, W E

    1984-07-01

    This report discusses the results of probing the defect structure and bonding of hydrogenated amorphous silicon films using both nuclear magnetic resonance (NMR) and electron spin resonance (ESR). The doping efficiency of boron in a-Si:H was found to be less than 1%, with 90% of the boron in a threefold coordinated state. On the other hand, phosphorus NMR chemical shift measurements yielded a ration of threefold to fourfold P sites of roughly 4 to 1. Various resonance lines were observed in heavily boron- and phosphorus-doped films and a-SiC:H alloys. These lines were attributed to band tail states on twofold coordinated silicon. In a-SiC:H films, a strong resonance was attributed to dangling bonds on carbon atoms. ESR measurements on low-pressure chemical-vapor-deposited (LPCVD) a-Si:H were performed on samples. The defect density in the bulk of the films was 10/sup 17//cc with a factor of 3 increase at the surface of the sample. The ESR spectrum of LPCVD-prepared films was not affected by prolonged exposure to strong light. Microcrystalline silicon samples were also examined. The phosphorus-doped films showed a strong signal from the crystalline material and no resonance from the amorphous matrix. This shows that phosphorus is incorporated in the crystals and is active as a dopant. No signal was recorded from the boron-doped films.

  20. Ductile crystalline-amorphous nanolaminates.

    PubMed

    Wang, Yinmin; Li, Ju; Hamza, Alex V; Barbee, Troy W

    2007-07-01

    It is known that the room-temperature plastic deformation of bulk metallic glasses is compromised by strain softening and shear localization, resulting in near-zero tensile ductility. The incorporation of metallic glasses into engineering materials, therefore, is often accompanied by complete brittleness or an apparent loss of useful tensile ductility. Here we report the observation of an exceptional tensile ductility in crystalline copper/copper-zirconium glass nanolaminates. These nanocrystalline-amorphous nanolaminates exhibit a high flow stress of 1.09 +/- 0.02 GPa, a nearly elastic-perfectly plastic behavior without necking, and a tensile elongation to failure of 13.8 +/- 1.7%, which is six to eight times higher than that typically observed in conventional crystalline-crystalline nanolaminates (<2%) and most other nanocrystalline materials. Transmission electron microscopy and atomistic simulations demonstrate that shear banding instability no longer afflicts the 5- to 10-nm-thick nanolaminate glassy layers during tensile deformation, which also act as high-capacity sinks for dislocations, enabling absorption of free volume and free energy transported by the dislocations; the amorphous-crystal interfaces exhibit unique inelastic shear (slip) transfer characteristics, fundamentally different from those of grain boundaries. Nanoscale metallic glass layers therefore may offer great benefits in engineering the plasticity of crystalline materials and opening new avenues for improving their strength and ductility. PMID:17592136

  1. Preliminary observations of arthropods associated with buried carrion on Oahu.

    PubMed

    Rysavy, Noel M; Goff, M Lee

    2015-03-01

    Several studies in Hawaii have focused on arthropod succession and decomposition patterns of surface remains, but the current research presents the first study to focus on shallow burials in this context. Three domestic pig carcasses (Sus scrofa L.) were buried at the depths of 20-40 cm in silty clay loam soil on an exposed ridge on the leeward side of the volcanically formed Koolau Mountain Range. One carcass was exhumed after 3 weeks, another after 6 weeks, and the last carcass was exhumed after 9 weeks. An inventory of arthropod taxa present on the carrion and in the surrounding soil and observations pertaining to decomposition were recorded at each exhumation. The longer the carrion was buried, the greater the diversity of arthropod species that were recovered from the remains. Biomass loss was calculated to be 49% at the 3-week interval, 56% at the 6-week interval, and 59% at the 9-week interval. PMID:25413711

  2. Effect of magnetite on GPR for detection of buried landmines

    NASA Astrophysics Data System (ADS)

    van Dam, Remke L.; Borchers, Brian; Hendrickx, Jan M. H.

    2006-05-01

    Ferrimagnetic minerals such as magnetite and maghaemite can affect ground-penetrating radar (GPR) signals. This may lead to false alarms and missed targets when surveying for the detection of buried landmines and unexploded ordnance (UXO). In most field situations ferrimagnetic mineral content is too low to affect GPR wave behavior. However, in soils and sedimentary material with magnetite-rich parent material large concentrations of magnetite can be found. This paper is a first systematic experimental effort to study the effects of large concentrations of magnetite for GPR detection of subsurface targets. We study the effects of (i) different homogeneous mixtures of magnetite and quartz sand and (ii) magnetite concentrated in layers (placer deposits), on the propagation behavior of GPR waves and reflection characteristics of steel and plastic balls. The balls are buried in homogeneous mixtures of magnetite and quartz sand and below a layer of pure magnetite. Important observations include that the simulated placer deposits did have a large effect on the detectability of balls below the placer deposits and that homogeneous mixtures had no significant effect.

  3. Sensor System Fo4r Buried Waste Containment Sites

    DOEpatents

    Smith, Ann Marie; Gardner, Bradley M.; Kostelnik, Kevin M.; Partin, Judy K.; Lancaster, Gregory D.; Pfeifer, Mary Catherine

    2003-11-18

    A sensor system for a buried waste containment site having a bottom wall barrier and sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

  4. Sensor System Fo4r Buried Waste Containment Sites

    DOEpatents

    Smith, Ann Marie; Gardner, Bradley M.; Kostelnik, Kevin M.; Partin, Judy K.; Lancaster, Gregory D.; Pfeifer, Mary Catherine

    2005-09-27

    A sensor system for a buried waste containment site having a bottom wall barrier and/or sidewall barriers, for containing hazardous waste. The sensor system includes one or more sensor devices disposed in one or more of the barriers for detecting a physical parameter either of the barrier itself or of the physical condition of the surrounding soils and buried waste, and for producing a signal representing the physical parameter detected. Also included is a signal processor for receiving signals produced by the sensor device and for developing information identifying the physical parameter detected, either for sounding an alarm, displaying a graphic representation of a physical parameter detected on a viewing screen and/or a hard copy printout. The sensor devices may be deployed in or adjacent the barriers at the same time the barriers are deployed and may be adapted to detect strain or cracking in the barriers, leakage of radiation through the barriers, the presence and leaking through the barriers of volatile organic compounds, or similar physical conditions.

  5. Full-scale retrieval of simulated buried transuranic waste

    SciTech Connect

    Valentich, D.J.

    1993-09-01

    This report describes the results of a field test conducted to determine the effectiveness of using conventional type construction equipment for the retrieval of buried transuranic (TRU) waste. A cold (nonhazardous and nonradioactive) test pit (1,100 yd{sup 3} volume) was constructed with boxes and drums filled with simulated waste materials, such as metal, plastic, wood, concrete, and sludge. Large objects, including truck beds, tanks, vaults, pipes, and beams, were also placed in the pit. These materials were intended to simulate the type of wastes found in TRU buried waste pits and trenches. A series of commercially available equipment items, such as excavators and tracked loaders outfitted with different end effectors, were used to remove the simulated waste. Work was performed from both the abovegrade and belowgrade positions. During the demonstration, a number of observations, measurements, and analyses were performed to determine which equipment was the most effective in removing the waste. The retrieval rates for the various excavation techniques were recorded. The inherent dust control capabilities of the excavation methods used were observed. The feasibility of teleoperating reading equipment was also addressed.

  6. Sum frequency generation vibrational spectroscopic studies on buried heterogeneous biointerfaces.

    PubMed

    Zhang, Chi; Jasensky, Joshua; Leng, Chuan; Del Grosso, Chelsey; Smith, Gary D; Wilker, Jonathan J; Chen, Zhan

    2014-05-01

    A sum frequency generation (SFG) vibrational micro-spectroscopy system was developed to examine buried heterogeneous biointerfaces. A compact optical microscope was constructed with total-internal reflection (TIR) SFG geometry to monitor the tightly focused SFG laser spots on interfaces, providing the capability of selectively probing different regions on heterogeneous biointerfaces. The TIR configuration ensures and enhances the SFG signal generated only from the sample/substrate interfacial area. As an example for possible applications in biointerfaces studies, the system was used to probe and compare buried interfacial structures of different biological samples attached to underwater surfaces. We studied the interface of a single mouse oocyte on a silica prism to demonstrate the feasibility of tracing and studying a single live cell and substrate interface using SFG. We also examined the interface between a marine mussel adhesive plaque and a CaF2 substrate, showing the removal of interface-bonded water molecules. This work also paves the way for future integration of other microscopic techniques such as TIR-fluorescence microscopy or nonlinear optical imaging with SFG spectroscopy for multimodal surface or interface studies. PMID:24784085

  7. Helmet-mounted uncooled FPA camera for buried object detection

    NASA Astrophysics Data System (ADS)

    Miller, John L.; Duvoisin, Herbert A., III; Wiltsey, George

    1997-08-01

    Software neural nets hosted on a parallel processor can analyze input from an IR imager to evaluate the likelihood of a buried object. However, it is only recently that low weight, staring LWIR sensors have become available in uncooled formats at sensitivities that provide enough information for useful man-portable helmet mounted applications. The images from the IR are presented to a human user through a see-through display after processing and highlighting by a neural net housed in a fanny-pack. This paper describes the phenomenology of buried object detection in the infrared, the neural net based image processing, the helmet mounted IR sensor and the ergonomics of mounting a sensor to head gear. The maturing and commercialization of uncooled focal plane arrays and high density electronics enables lightweight, low cost, small camera packages that can be integrated with hard hats and military helmets. The head gear described has a noise equivalent delta temperature (NEDT) of less than 50 milliKelvin, consumes less than 10 watts and weighs about 1.5 kilograms.

  8. Buried Impact Basins and the Earliest History of Mars

    NASA Technical Reports Server (NTRS)

    Frey, H. V.

    2003-01-01

    The "Quasi-Circular Depressions" (QCDs) seen in MOLA data which have little or no visible appearance in image data have been interpreted as buried impact basins on Mars. These have important implications for the age of the lowland crust, what mechanisms could produce the crustal dichotomy, and the existence of crust older than the oldest observed surface units on Mars. A global survey of large QCDs using high resolution MOLA data now available has provided further details of the earliest history of Mars. The lowlands are of Early Noachian age, slightly younger than the buried highlands and definitely older than the exposed highland surface. A depopulation of large visible basins at diameters 800 to 1300 km suggests some global scale event early in martian history, maybe related to the formation of the lowlands and/or the development of Tharsis. A suggested early disappearance of the global magnetic field can be placed within a temporal sequence of formation of the very largest impact basins.

  9. Buried structure for increasing fabrication performance of micromaterial by electromigration

    NASA Astrophysics Data System (ADS)

    Kimura, Yasuhiro; Saka, Masumi

    2016-06-01

    The electromigration (EM) technique is a physical synthetic growth method for micro/nanomaterials. EM causes atomic diffusion in a metal line by high-density electron flows. The intentional control of accumulation and relaxation of atoms by EM can lead to the fabrication of a micro/nanomaterial. TiN passivation has been utilized as a component of sample in the EM technique. Although TiN passivation can simplify the cumbersome processes for preparing the sample, the leakage of current naturally occurs because of the conductivity of TiN as a side effect and decreases the performance of micro/nanomaterial fabrication. In the present work, we propose a buried structure, which contributes to significantly decreasing the current for fabricating an Al micromaterial by confining the current flow in the EM technique. The fabrication performance was evaluated based on the threshold current for fabricating an Al micromaterial using the buried structure and the previous structure with the leakage of current.

  10. Centrifuge modeling of buried continuous pipelines subjected to normal faulting

    NASA Astrophysics Data System (ADS)

    Moradi, Majid; Rojhani, Mahdi; Galandarzadeh, Abbas; Takada, Shiro

    2013-03-01

    Seismic ground faulting is the greatest hazard for continuous buried pipelines. Over the years, researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method. The lack of well-documented field case histories of pipeline failure from seismic ground faulting and the cost and complicated facilities needed for full-scale experimental simulation mean that a centrifuge-based method to determine the behavior of pipelines subjected to faulting is best to verify numerical approaches. This paper presents results from three centrifuge tests designed to investigate continuous buried steel pipeline behavior subjected to normal faulting. The experimental setup and procedure are described and the recorded axial and bending strains induced in a pipeline are presented and compared to those obtained via analytical methods. The influence of factors such as faulting offset, burial depth and pipe diameter on the axial and bending strains of pipes and on ground soil failure and pipeline deformation patterns are also investigated. Finally, the tensile rupture of a pipeline due to normal faulting is investigated.

  11. Stabilization of ancient organic matter in deep buried paleosols

    NASA Astrophysics Data System (ADS)

    Marin-Spiotta, E.; Chaopricha, N. T.; Mueller, C.; Diefendorf, A. F.; Plante, A. F.; Grandy, S.; Mason, J. A.

    2012-12-01

    Buried soils representing ancient surface horizons can contain large organic carbon reservoirs that may interact with the atmosphere if exposed by erosion, road construction, or strip mining. Paleosols in long-term depositional sites provide a unique opportunity for studying the importance of different mechanisms on the persistence of organic matter (OM) over millennial time-scales. We report on the chemistry and bioavailability of OM stored in the Brady soil, a deeply buried (7 m) paleosol in loess deposits of southwestern Nebraska, USA. The Brady Soil developed 9,000-13,500 years ago during a time of warming and drying. The Brady soil represents a dark brown horizon enriched in C relative to loess immediately above and below. Spanning much of the central Great Plains, this buried soil contains large C stocks due to the thickness of its A horizon (0.5 to 1 m) and wide geographic extent. Our research provides a unique perspective on long-term OM stabilization in deep soils using multiple analytical approaches. Soils were collected from the Brady soil A horizon (at 7 m depth) and modern surface A horizons (0-15 cm) at two sites for comparison. Soils were separated by density fractionation using 1.85 g ml-1 sodium polytungstate into: free particulate organic matter (fPOM) and aggregate-occluded (oPOM) of two size classes (large: >20 μm, and small: < 20 μm). The remaining dense fraction was separated into sand, silt, and clay size fractions. The distribution and age of C among density and particle-size fractions differed between surface and Brady soils. We isolated the source of the characteristic dark coloring of the Brady soil to the oPOM-small fraction, which also contained 20% of the total organic C pool in the Brady soil. The oPOM-small fraction and the bulk soil in the middle of the Brady A horizon had 14C ages of 10,500-12,400 cal yr BP, within the time that the soil was actively forming at the land surface. Surface soils showed modern ages. Lipid analyses of

  12. Analyses of SRS waste glass buried in granite in Sweden and salt in the United States

    SciTech Connect

    Williams, J.P. ); Wicks, G.G. ); Clark, D.E. ); Lodding, A.R. )

    1991-01-01

    Simulated Savannah River Site (SRS) waste glass forms have been buried in the granite geology of the Stirpa mine in Sweden for two years. Analyses of glass surfaces provided a measure of the performance of the waste glasses as a function of time. Similar SRS waste glass compositions have also been buried in salt at the WIPP facility in Carlsbad, New Mexico for a similar time period. Analyses of the SRS waste glasses buried in-situ in granite will be presented and compared to the performance of these same compositions buried in salt at WIPP.

  13. Analyses of SRS waste glass buried in granite in Sweden and salt in the United States

    SciTech Connect

    Williams, J.P.; Wicks, G.G.; Clark, D.E.; Lodding, A.R.

    1991-12-31

    Simulated Savannah River Site (SRS) waste glass forms have been buried in the granite geology of the Stirpa mine in Sweden for two years. Analyses of glass surfaces provided a measure of the performance of the waste glasses as a function of time. Similar SRS waste glass compositions have also been buried in salt at the WIPP facility in Carlsbad, New Mexico for a similar time period. Analyses of the SRS waste glasses buried in-situ in granite will be presented and compared to the performance of these same compositions buried in salt at WIPP.

  14. Fluorination of amorphous thin-film materials with xenon fluoride

    DOEpatents

    Weil, R.B.

    1987-05-01

    A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

  15. Fluorination of amorphous thin-film materials with xenon fluoride

    DOEpatents

    Weil, Raoul B.

    1988-01-01

    A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

  16. Method of making amorphous metal composites

    DOEpatents

    Byrne, Martin A.; Lupinski, John H.

    1982-01-01

    The process comprises placing an amorphous metal in particulate form and a low molecular weight (e.g., 1000-5000) thermosetting polymer binder powder into a container, mixing these materials, and applying heat and pressure to convert the mixture into an amorphous metal composite.

  17. Electron tunnelling into amorphous germanium and silicon.

    NASA Technical Reports Server (NTRS)

    Smith, C. W.; Clark, A. H.

    1972-01-01

    Measurements of tunnel conductance versus bias, capacitance versus bias, and internal photoemission were made in the systems aluminum-oxide-amorphous germanium and aluminium-oxide-amorphous silicon. A function was extracted which expresses the deviation of these systems from the aluminium-oxide-aluminium system.

  18. Electron beam recrystallization of amorphous semiconductor materials

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.

    1968-01-01

    Nucleation and growth of crystalline films of silicon, germanium, and cadmium sulfide on substrates of plastic and glass were investigated. Amorphous films of germanium, silicon, and cadmium sulfide on amorphous substrates of glass and plastic were converted to the crystalline condition by electron bombardment.

  19. Imprinting bulk amorphous alloy at room temperature

    DOE PAGESBeta

    Kim, Song-Yi; Park, Eun-Soo; Ott, Ryan T.; Lograsso, Thomas A.; Huh, Moo-Young; Kim, Do-Hyang; Eckert, Jürgen; Lee, Min-Ha

    2015-11-13

    We present investigations on the plastic deformation behavior of a brittle bulk amorphous alloy by simple uniaxial compressive loading at room temperature. A patterning is possible by cold-plastic forming of the typically brittle Hf-based bulk amorphous alloy through controlling homogenous flow without the need for thermal energy or shaping at elevated temperatures. The experimental evidence suggests that there is an inconsistency between macroscopic plasticity and deformability of an amorphous alloy. Moreover, imprinting of specific geometrical features on Cu foil and Zr-based metallic glass is represented by using the patterned bulk amorphous alloy as a die. These results demonstrate the abilitymore » of amorphous alloys or metallic glasses to precisely replicate patterning features onto both conventional metals and the other amorphous alloys. In conclusion, our work presents an avenue for avoiding the embrittlement of amorphous alloys associated with thermoplastic forming and yields new insight the forming application of bulk amorphous alloys at room temperature without using heat treatment.« less

  20. Structure, thermodynamics, and crystallization of amorphous hafnia

    NASA Astrophysics Data System (ADS)

    Luo, Xuhui; Demkov, Alexander A.

    2015-09-01

    We investigate theoretically amorphous hafnia using the first principles melt and quench method. We identify two types of amorphous structures of hafnia. Type I and type II are related to tetragonal and monoclinic hafnia, respectively. We find type II structure to show stronger disorder than type I. Using the phonon density of states, we calculate the specific heat capacity for type II amorphous hafnia. Using the nudged elastic band method, we show that the averaged transition barrier between the type II amorphous hafnia and monoclinic phase is approximately 0.09 eV/HfO2. The crystallization temperature is estimated to be 421 K. The calculations suggest an explanation for the low thermal stability of amorphous hafnia.

  1. Solid-state diffusion in amorphous zirconolite

    SciTech Connect

    Yang, C.; Dove, M. T.; Trachenko, K.; Zarkadoula, E.; Todorov, I. T.; Geisler, T.; Brazhkin, V. V.

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  2. Neutron irradiation induced amorphization of silicon carbide

    SciTech Connect

    Snead, L.L.; Hay, J.C.

    1998-09-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 {times} 10{sup 25} n/m{sup 2}. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density ({minus}10.8%), elastic modulus as measured using a nanoindentation technique ({minus}45%), hardness as measured by nanoindentation ({minus}45%), and standard Vickers hardness ({minus}24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C.

  3. Structure, thermodynamics, and crystallization of amorphous hafnia

    SciTech Connect

    Luo, Xuhui; Demkov, Alexander A.

    2015-09-28

    We investigate theoretically amorphous hafnia using the first principles melt and quench method. We identify two types of amorphous structures of hafnia. Type I and type II are related to tetragonal and monoclinic hafnia, respectively. We find type II structure to show stronger disorder than type I. Using the phonon density of states, we calculate the specific heat capacity for type II amorphous hafnia. Using the nudged elastic band method, we show that the averaged transition barrier between the type II amorphous hafnia and monoclinic phase is approximately 0.09 eV/HfO{sub 2}. The crystallization temperature is estimated to be 421 K. The calculations suggest an explanation for the low thermal stability of amorphous hafnia.

  4. Amorphization of Ti1- x Mn x

    NASA Astrophysics Data System (ADS)

    Chu, B.-L.; Chen, C.-C.; Perng, T.-P.

    1992-08-01

    Three amorphous Ti1- x Mn x alloy powders, with x = 0.4, 0.5, and 0.6, were prepared by mechanical alloying (MA) of the elemental powders in a high-energy ball mill. The amorphous powders were characterized by X-ray diffraction (XRD) and high-resolution transmission elec- tron microscopy (HRTEM). The crystallization temperatures for these alloys detected by dif- ferential scanning calorimetry (DSC) varied from 769 to 830 K. The calculated enthalpies of mixing in these amorphous phases are relatively small compared with those for other Ti-base binary alloys. The criteria for solid-state amorphization reaction are examined. It is suggested that the kinetics of nucleation and growth favors the formation of the amorphous phases and the supply of atoms for nucleation and growth is predominantly through the defective regions induced by MA.

  5. Lunar Radar Scattering from Near-Surface Buried Crater Ejecta

    NASA Astrophysics Data System (ADS)

    Thompson, T. W.; Ustinov, E. A.; Heggy, E.

    2009-12-01

    The Apollo 15, 16, and 17 core tubes show that the uppermost few meters of the lunar regolith are interlaced layers of a fine grained powders and blocky crater ejecta. The layers of crater ejecta have dielectric constants in the range of 7-9 while the fine-grained powders has dielectric constant on the order of 2.7. These differences in dielectric constant, in turn, create radar reflections that are both refracted and reflected back through the space-regolith interface. Note that for a dielectric constant of 2.7 for the lunar regolith, radio waves incident on the lunar surface at the angle of 30-degrees from the normal will propagate in the regolith at an angle of 18-degrees. At the limb, radio waves incident on the lunar surface at an angle near 90-degrees from the normal will propagate in the regolith at an angle of about 37-degrees. These angles are within the range where radar backscatter is in the quasi-specular regime. When these buried crater ejecta layers are modeled using Hagfors’ formulation (Hagfors, 1963), echo powers match the behavior observed for average lunar backscatter at centimeter wavelengths for higher (30° to 90°) angles of incidence. In addition, Hagfors et al. (1965) conducted an experiment where the Moon was illuminated at 23-cm wavelength with circular polarization and the differences were observed in orthogonal linear polarizations. Modeling of these observations and assuming again that the buried crater ejecta scatter in a quasi-specular manner, echo differences in horizontal and vertical linear polarizations are in relatively good agreement with the observations. The data from Chandrayaan Mini-RF radar, which operated at S-Band (13cm) wavelength, and the Lunar Reconnaissance Orbiter (LRO) Mini-RF radar, which is operating at S-Band and X-Band (4-cm) wavelengths, provide an opportunity for a new examination of whether radar backscatter from buried crater ejecta behaves like a quasi-specular scatter. These radars reproduce the

  6. Locomotion of Amorphous Surface Robots

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T. (Inventor)

    2016-01-01

    An amorphous robot includes a compartmented bladder containing fluid, a valve assembly, and an outer layer encapsulating the bladder and valve assembly. The valve assembly draws fluid from a compartment(s) and discharges the drawn fluid into a designated compartment to displace the designated compartment with respect to the surface. Another embodiment includes elements each having a variable property, an outer layer that encapsulates the elements, and a control unit. The control unit energizes a designated element to change its variable property, thereby moving the designated element. The elements may be electromagnetic spheres with a variable polarity or shape memory polymers with changing shape and/or size. Yet another embodiment includes an elongated flexible tube filled with ferrofluid, a moveable electromagnet, an actuator, and a control unit. The control unit energizes the electromagnet and moves the electromagnet via the actuator to magnetize the ferrofluid and lengthen the flexible tube.

  7. Locomotion of Amorphous Surface Robots

    NASA Technical Reports Server (NTRS)

    Bradley, Arthur T. (Inventor)

    2014-01-01

    An amorphous robot includes a compartmented bladder containing fluid, a valve assembly, and an outer layer encapsulating the bladder and valve assembly. The valve assembly draws fluid from a compartment(s) and discharges the drawn fluid into a designated compartment to displace the designated compartment with respect to the surface. Another embodiment includes elements each having a variable property, an outer layer that encapsulates the elements, and a control unit. The control unit energizes a designated element to change its variable property, thereby moving the designated element. The elements may be electromagnetic spheres with a variable polarity or shape memory polymers with changing shape and/or size. Yet another embodiment includes an elongated flexible tube filled with ferrofluid, a moveable electromagnet, an actuator, and a control unit. The control unit energizes the electromagnet and moves the electromagnet via the actuator to magnetize the ferrofluid and lengthen the flexible tube.

  8. Large-Diameter Visible and Buried Impact Basins on Mars: Implications for age of the Highlands and (Buried) Lowlands and Turn-off of the Global Magnetic Field

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.

    2003-01-01

    The global populations of visible and buried impact basins less than 200 km diameter revealed by high resolution gridded MOLA indicate: (a) a small (approx. 10) number of very large basins (D=1300-3000km), most of which have remained visible over martian history; (b) a much larger population of smaller basins (D=200-800 km) with many more buried than visible (on images); (c) a depletion of visible basins at intermediate diameters which may be a signature of some global-scale event (formation of the lowlands? origin of Tharsis?); and (d) a crater retention age for the buried lowlands greater than that of the visible highlands but less than that of the total (visible + buried) highlands. Crustal magnetic anomalies are generally not present in the interiors of the largest basins with two exceptions: these two (which appear to be the oldest) may predate the demise of the global magnetic field.

  9. Polarity inversion and coupling of laser beam induced current in As-doped long-wavelength HgCdTe infrared detector pixel arrays: Experiment and simulation

    NASA Astrophysics Data System (ADS)

    Hu, W. D.; Chen, X. S.; Ye, Z. H.; Chen, Y. G.; Yin, F.; Zhang, B.; Lu, W.

    2012-10-01

    In this paper, experimental results of polarity inversion and coupling of laser beam induced current for As-doped long-wavelength HgCdTe pixel arrays grown on CdZnTe are reported. Models for the p-n junction transformation are proposed and demonstrated using numerical simulations. Simulation results are shown to be in agreement with the experimental results. It is found that the deep traps induced by ion implantation are very sensitive to temperature, resulting in a decrease of the quasi Fermi level in the implantation region in comparison to that in the Hg interstitials diffusion and As-doped regions. The Hg interstitial diffusion, As-doping amphoteric behavior, ion implantation damage traps, and the mixed conduction, are key factors for inducing the polarity reversion, coupling, and junction broadening at different temperatures. The results provide the near room-temperature HgCdTe photovoltaic detector with a reliable reference on the junction reversion and broadening around implanted regions, as well as controlling the n-on-p junction for very long wavelength HgCdTe infrared detector pixels.

  10. Radargrams of Buried Basin from Two Adjacent Orbits

    NASA Technical Reports Server (NTRS)

    2005-01-01

    These two radargrams from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) show echoes from an approximately 250-kilometer (155-mile) diameter circular structure below the surface of Mars. The circular structure is interpreted to be a buried impact basin.

    In two orbits spaced about 50 kilometers (31 miles) apart, MARSIS detected a series of arc-shaped reflectors that have no apparent source in the surface topography or geology. In the lower image, a linear reflector nearly parallel to the surface is seen embedded in the arcs. This reflection may be coming from the floor of the basin. The time delay to the linear reflector suggests a depth of 1.5 to 2.5 kilometers (0.9 to 1.6 miles).

    MARSIS is an instrument on the European Space Agency's Mars Express orbiter. NASA and the Italian Space Agency jointly funded the instrument.

  11. Buried Waste Integrated Demonstration: Selection of potential demonstration locations

    SciTech Connect

    Arrenholz, D.A.; Knight, J.L.

    1991-11-01

    The first step towards identifying primary Buried Waste Integrated Demonstration locations is the selection of potential demonstration sites within the Subsurface Disposal Area. The sites selected are Pits 4, 5, 6, and 9, containing transuranic waste of Rocky Flats origin, the Acid Pit, and Pad A. The criteria and methodology for selection of these sites, as well as a description of the wastes present in each area, are included in this report. At a later date, technology-specific demonstration locations will be selected from these six potential sites. The selected locations will be used as necessary to demonstrate technologies whose potential abilities may be optimal on waste forms present at these identified locations.

  12. Measure Guideline: Buried and/or Encapsulated Ducts

    SciTech Connect

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license.

  13. Smooth plains deformation in a buried crater of Mercury

    NASA Astrophysics Data System (ADS)

    Lopez, V.; Ruiz, J.; Vazquez, A.

    2012-09-01

    The surface of Mercury shows different kinds of tectonics landforms, mostly indicating surface contraction [1,2]. Compressional features include lobate scarps, wrinkle ridges, and high relief ridges, which are different manifestations of thrust faults, depending on, for example, deep angle of faulting and type of surface geology [3-5]. Also, there are evidences of long-wavelengh topography variations, affecting to the northern smooth plains and Caloris basin, which could also be the expression of contraction (and maybe large scale folding) related to the cooling of Mercury [6]. In this work we focus on the deformation in an area centered in the equator comprising a buried crater affected by two different sets of tectonic features.

  14. Solid state television camera (CCD-buried channel)

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The development of an all solid state television camera, which uses a buried channel charge coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array is utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control (i.e., ALC and AGC) techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.

  15. Structure of ancient buried wood from Phyllocladus trichomanoides

    SciTech Connect

    Attalla, M.I.; Serra, R.G.; Vassallo, A.M.; Wilson, M.A.

    1988-01-01

    Trees of the fossil gymnosperm Phyllocladus trichomanoides were buried by a volcanic eruption at Taupo, New Zealand about 2000 years ago. Three samples of fossil heartwood and fossil sapwood from this tree have been studied by /sup 13/C solid-state nuclear magnetic resonance (NMR) techniques including dipolar dephasing. The spectra of sapwood contain more resonances from carbohydrates at 66 and 75 ppm whereas the spectra of heartwood contain significantly more signal from methoxyl and other lignin derived carbons. Values obtained for the fraction of aromatic carbon that is protonated in the samples fa are of the order of 0.50, in good agreement with that expected for a lignin-based, mainly guaiacyl structure. In addition to estimating fa dipolar dephasing appears to be useful in accentuating differences in methoxyl content between heartwood and sapwood.

  16. Retrieval of Shape Characteristics for Buried Objects with GPR Monitoring

    NASA Astrophysics Data System (ADS)

    Soldovieri, F.; Comite, D.; Galli, A.; Valerio, G.; Barone, P. M.; Lauro, S. E.; Mattei, E.; Pettinelli, E.

    2012-04-01

    Information retrieval on the location and the geometrical features (dimensions and shape) of buried objects is of fundamental importance in geosciences areas involving environmental protection, mine clearance, archaeological investigations, space and planetary exploration, and so forth. Among the different non-invasive sensing techniques usually employed to achieve this kind of information, those based on ground-penetrating-radar (GPR) instruments are well-established and suitable to the mentioned purposes [1]. In this context, our interest in the present work is specifically focused on testing the potential performance of typical GPR instruments by means of appropriate data processing. It will be shown in particular to what extent the use of a suitable "microwave tomographic approach" [2] is able to furnish a shape estimation of the targets, possibly recognizing different kinds of canonical geometries, even having reduced cross sections and in critical conditions, where the scatterer size is comparable with resolution limits imposed by the usual measurement configurations. Our study starts by obtaining the typical "direct" information from the GPR techniques that is the scattered field in subsurface environments under the form of radargrams. In order to get a wide variety of scenarios for the operating conditions, this goal is achieved by means of two different and independent approaches [3]. One approach is based on direct measurements through an experimental laboratory setup: commercial GPR instruments (typically bistatic configurations operating around 1 GHz frequency range) are used to collect radargram profiles by investigating an artificial basin filled of liquid and/or granular materials (sand, etc.), in which targets (having different constitutive parameters, shape, and dimensions) can be buried. The other approach is based on numerical GPR simulations by means of a commercial CAD electromagnetic tool (CST), whose suitable implementation and data

  17. Enhanced buried UXO detection via GPR/EMI data fusion

    NASA Astrophysics Data System (ADS)

    Masarik, Matthew P.; Burns, Joseph; Thelen, Brian T.; Kelly, Jack; Havens, Timothy C.

    2016-05-01

    This paper investigates the enhancements to detection of buried unexploded ordinances achieved by combining ground penetrating radar (GPR) data with electromagnetic induction (EMI) data. Novel features from both the GPR and the EMI sensors are concatenated as a long feature vector, on which a non-parametric classifier is then trained. The classifier is a boosting classifier based on tree classifiers, which allows for disparate feature values. The fusion algorithm was applied to a government-provided dataset from an outdoor testing site, and significant performance enhancements were obtained relative to classifiers trained solely on the GPR or EMI data. It is shown that the performance enhancements come from a combination of improvements in detection and in clutter rejection.

  18. Surface acoustic wave devices as passive buried sensors

    NASA Astrophysics Data System (ADS)

    Friedt, J.-M.; Rétornaz, T.; Alzuaga, S.; Baron, T.; Martin, G.; Laroche, T.; Ballandras, S.; Griselin, M.; Simonnet, J.-P.

    2011-02-01

    Surface acoustic wave (SAW) devices are currently used as passive remote-controlled sensors for measuring various physical quantities through a wireless link. Among the two main classes of designs—resonator and delay line—the former has the advantage of providing narrow-band spectrum informations and hence appears compatible with an interrogation strategy complying with Industry-Scientific-Medical regulations in radio-frequency (rf) bands centered around 434, 866, or 915 MHz. Delay-line based sensors require larger bandwidths as they consists of a few interdigitated electrodes excited by short rf pulses with large instantaneous energy and short response delays but is compatible with existing equipment such as ground penetrating radar (GPR). We here demonstrate the measurement of temperature using the two configurations, particularly for long term monitoring using sensors buried in soil. Although we have demonstrated long term stability and robustness of packaged resonators and signal to noise ratio compatible with the expected application, the interrogation range (maximum 80 cm) is insufficient for most geology or geophysical purposes. We then focus on the use of delay lines, as the corresponding interrogation method is similar to the one used by GPR which allows for rf penetration distances ranging from a few meters to tens of meters and which operates in the lower rf range, depending on soil water content, permittivity, and conductivity. Assuming propagation losses in a pure dielectric medium with negligible conductivity (snow or ice), an interrogation distance of about 40 m is predicted, which overcomes the observed limits met when using interrogation methods specifically developed for wireless SAW sensors, and could partly comply with the above-mentioned applications. Although quite optimistic, this estimate is consistent with the signal to noise ratio observed during an experimental demonstration of the interrogation of a delay line buried at a depth of 5

  19. Location of Buried Mineshafts and Adits Using Reconnaissance Geophysical Methods

    NASA Astrophysics Data System (ADS)

    Culshaw, Martin; Donnelly, Laurance; McCann, David

    Britain has a long history of mining activity, which stretches back some 3000 years to the excavation of flint in East Anglia. The legacy of this long period of activity is the presence of many buried mineshafts and adits, whose location is often unknown precisely and in many cases not even recorded in historical mining records. As has been shown by Donnelly et al (2003) the discovery of a mineshaft in an area of housing development can have a profound effect on property values in its vicinity. Hence, urgent action must be taken to establish at the site investigation stage of a development to determine whether any mineshafts are present at the site so that remedial action can be taken before construction commences. A study of historical information and the drilling may well enable the developer to locate any suspected mineshafts and adits on his site. However, the use of geophysical reconnaissance methods across the whole site may well provide sufficient information to simplify the drilling programme and reduce its cost to a minimum. In this paper a number of rapid reconnaissance geophysical methods are described and evaluated in terms of their success in the location of buried mineshafts and adits. It has shown that a combination of ground conductivity and magnetic surveys provides a most effective approach on open sites in greenfield and brownfield areas. Ground penetrating radar and micro-gravity surveys have proved to be a valuable approach in urban areas where the use of many geophysical methods is prevented by the presence of various types of cultural noise. On a regional scale the infrared thermography method is being increasingly used but care must be taken to overcome certain environmental difficulties. The practical use of all these geophysical methods in the field is illustrated by a number of appropriate case histories.

  20. Quantification of surface amorphous content using dispersive surface energy: the concept of effective amorphous surface area.

    PubMed

    Brum, Jeffrey; Burnett, Daniel

    2011-09-01

    We investigate the use of dispersive surface energy in quantifying surface amorphous content, and the concept of effective amorphous surface area is introduced. An equation is introduced employing the linear combination of surface area normalized square root dispersive surface energy terms. This equation is effective in generating calibration curves when crystalline and amorphous references are used. Inverse gas chromatography is used to generate dispersive surface energy values. Two systems are investigated, and in both cases surface energy data collected for physical mixture samples comprised of amorphous and crystalline references fits the predicted response with good accuracy. Surface amorphous content of processed lactose samples is quantified using the calibration curve, and interpreted within the context of effective amorphous surface area. Data for bulk amorphous content is also utilized to generate a thorough picture of how disorder is distributed throughout the particle. An approach to quantifying surface amorphous content using dispersive surface energy is presented. Quantification is achieved by equating results to an effective amorphous surface area based on reference crystalline, and amorphous materials. PMID:21725707

  1. Amorphous metallic films in silicon metallization systems

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.; Kattelus, H.; So, F.

    1984-01-01

    The general objective was to determine the potential of amorphous metallic thin films as a means of improving the stability of metallic contacts to a silicon substrate. The specific objective pursued was to determine the role of nitrogen in the formation and the resulting properties of amorphous thin-film diffusion barriers. Amorphous metallic films are attractive as diffusion barriers because of the low atomic diffusivity in these materials. Previous investigations revealed that in meeting this condition alone, good diffusion barriers are not necessarily obtained, because amorphous films can react with an adjacent medium (e.g., Si, Al) before they recrystallize. In the case of a silicon single-crystalline substrate, correlation exists between the temperature at which an amorphous metallic binary thin film reacts and the temperatures at which the films made of the same two metallic elements react individually. Amorphous binary films made of Zr and W were investigated. Both react with Si individually only at elevated temperatures. It was confirmed that such films react with Si only above 700 C when annealed in vacuum for 30 min. Amorphous W-N films were also investigated. They are more stable as barriers between Al and Si than polycrystalline W. Nitrogen effectively prevents the W-Al reaction that sets in at 500 C with polycrystalline W.

  2. Crystalline to amorphous transformation in silicon

    SciTech Connect

    Cheruvu, S.M.

    1982-09-01

    In the present investigation, an attempt was made to understand the fundamental mechanism of crystalline-to-amorphous transformation in arsenic implanted silicon using high resolution electron microscopy. A comparison of the gradual disappearance of simulated lattice fringes with increasing Frenkel pair concentration with the experimental observation of sharp interfaces between crystalline and amorphous regions was carried out leading to the conclusion that when the defect concentration reaches a critical value, the crystal does relax to an amorphous state. Optical diffraction experiments using atomic models also supported this hypothesis. Both crystalline and amorphous zones were found to co-exist with sharp interfaces at the atomic level. Growth of the amorphous fraction depends on the temperature, dose rate and the mass of the implanted ion. Preliminary results of high energy electron irradiation experiments at 1.2 MeV also suggested that clustering of point defects occurs near room temperature. An observation in a high resolution image of a small amorphous zone centered at the core of a dislocation is presented as evidence that the nucleation of an amorphous phase is heterogeneous in nature involving clustering or segregation of point defects near existing defects.

  3. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Examination of buried... Requirements for Corrosion Control § 192.459 External corrosion control: Examination of buried pipeline when... portion must be examined for evidence of external corrosion if the pipe is bare, or if the coating...

  4. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: Examination of buried... Requirements for Corrosion Control § 192.459 External corrosion control: Examination of buried pipeline when... portion must be examined for evidence of external corrosion if the pipe is bare, or if the coating...

  5. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Examination of buried... Requirements for Corrosion Control § 192.459 External corrosion control: Examination of buried pipeline when... portion must be examined for evidence of external corrosion if the pipe is bare, or if the coating...

  6. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Examination of buried... Requirements for Corrosion Control § 192.459 External corrosion control: Examination of buried pipeline when... portion must be examined for evidence of external corrosion if the pipe is bare, or if the coating...

  7. 49 CFR 192.459 - External corrosion control: Examination of buried pipeline when exposed.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Examination of buried... Requirements for Corrosion Control § 192.459 External corrosion control: Examination of buried pipeline when... portion must be examined for evidence of external corrosion if the pipe is bare, or if the coating...

  8. Broadband infrared electro-optic modulator having a buried microstrip network

    NASA Technical Reports Server (NTRS)

    Cheo, Peter K. (Inventor); Gilden, Meyer (Inventor)

    1987-01-01

    A microwave infrared modulator having a novel three dimensional structure is presented. The modulator includes a waveguide and metal base with a dielectric wafer buried therebetween. The buried wafer allows for conventional microstrip structures to be employed with larger microstrip electrode dimensions than would otherwise be possible.

  9. Numerical Modeling of Mechanical Behavior for Buried Steel Pipelines Crossing Subsidence Strata

    PubMed Central

    Han, C. J.

    2015-01-01

    This paper addresses the mechanical behavior of buried steel pipeline crossing subsidence strata. The investigation is based on numerical simulation of the nonlinear response of the pipeline-soil system through finite element method, considering large strain and displacement, inelastic material behavior of buried pipeline and the surrounding soil, as well as contact and friction on the pipeline-soil interface. Effects of key parameters on the mechanical behavior of buried pipeline were investigated, such as strata subsidence, diameter-thickness ratio, buried depth, internal pressure, friction coefficient and soil properties. The results show that the maximum strain appears on the outer transition subsidence section of the pipeline, and its cross section is concave shaped. With the increasing of strata subsidence and diameter-thickness ratio, the out of roundness, longitudinal strain and equivalent plastic strain increase gradually. With the buried depth increasing, the deflection, out of roundness and strain of the pipeline decrease. Internal pressure and friction coefficient have little effect on the deflection of buried pipeline. Out of roundness is reduced and the strain is increased gradually with the increasing of internal pressure. The physical properties of soil have a great influence on the mechanical properties of buried pipeline. The results from the present study can be used for the development of optimization design and preventive maintenance for buried steel pipelines. PMID:26103460

  10. 75 FR 32313 - Specifications and Drawings for Construction Direct Buried Plant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Executive Order 12372'' (50 FR 47034), advising that USDA Rural Development Utilities Programs loans and... Rural Utilities Service 7 CFR Part 1755 Specifications and Drawings for Construction Direct Buried Plant... Construction of Direct Buried Plant (Form 515a). The revised specification will include new construction...

  11. Contribution to classification of buried objects based on acoustic impedance matching.

    PubMed

    Stepanić, J; Wüstenberg, H; Krstelj, V; Mrasek, H

    2003-03-01

    Determination of material the buried objects are made of could contribute significantly to their recognition, or classification. This is important in detecting buried antipersonnel landmines within the context of humanitarian demining, as well as in a variety of other applications. In this article the concept has been formulated of the approach to buried object's material determination starting with ultrasonic impulse propagation analysis in a particular testing set configuration. The impulse propagates through a characterized transfer material in such a way that a part of it, a reflected wave, carries the information about the buried object's surface material acoustic impedance. The limit of resolution capability is theoretically analyzed and experimentally evaluated and the influencing factors described. Among these, the contact between clean surfaces of the transfer material and buried object is emphasized. PMID:12565075

  12. Image restoration techniques using Compton backscatter imaging for the detection of buried land mines

    NASA Astrophysics Data System (ADS)

    Wehlburg, Joseph C.; Keshavmurthy, Shyam P.; Watanabe, Yoichi; Dugan, Edward T.; Jacobs, Alan M.

    1995-06-01

    Earlier landmine imaging systems used two collimated detectors to image objects. These systems had difficulty in distinguishing between surface features and buried features. Using a combination of collimated and uncollimated detectors in a Compton backscatter imaging (CBI) system, allows the identification of surface and buried features. Images created from the collimated detectors contain information about the surface and the buried features, while the uncollimated detectors respond (approximately 80%) to features on the surface. The analysis of surface features are performed first, then these features can be removed and the buried features can be identified. Separation of the surface and buried features permits the use of a globbing algorithm to define regions of interest that can then be quantified [area, Y dimension, X dimension, and center location (xo, yo)]. Mine composition analysis is also possible because of the properties of the four detector system. Distinguishing between a pothole and a mine, that was previously very difficult, can now be easily accomplished.

  13. Buried topography of Utopia, Mars - Persistence of a giant impact depression

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.

    1989-01-01

    Knobs, partially buried craters, ring fractures, and some mesas permit a qualitative determination of the topography buried beneath younger northern plains materials. These features are widely distributed in the Utopia area but are absent in a large, roughly circular region centered at about 48 deg N, 240 deg W. This implies the existence of a circular depression about 3300 km in diameter buried beneath Utopia Planitia that is interpreted to represent the central part of a very large impact basin. The presence of buried curved massifs around part of this depression, and a roughly coincident mascon, lend further support. Present topography, areal geology, and paleotopography of buried surfaces all point to the persistence of this major depression for almost the entire history of Mars.

  14. Fast evaluation of Sommerfeld integrals for EM scattering and radiation by three-dimensional buried objects

    SciTech Connect

    Cui, T.J.; Chew, W.C.

    1999-03-01

    This paper presents a fast method for electromagnetic scattering and radiation problems pertinent to three-dimensional (3-D) buried objects. In this approach, a new symmetrical form of the Green`s function is derived, which can reduce the number of Sommerfeld integrals involved in the buried objects problem. The integration along steepest descent paths and leading-order approximations are introduced to evaluate these Sommerfeld integrals, which can greatly accelerate the computation. Based on the fast evaluation of Sommerfeld integrals, the radiation of an arbitrarily oriented electric dipole buried in a half space is first analyzed and computed. Then, the scattering by buried dielectric objects and conducting objects is considered using the method of moments (MOM). Numerical results show that the fast method can save tremendous CPU time in radiation and scattering problems involving buried objects.

  15. Latent ion tracks in amorphous silicon

    SciTech Connect

    Bierschenk, Thomas; Giulian, Raquel; Afra, Boshra; Rodriguez, Matias D; Schauries, D; Mudie, Stephen; Pakarinen, Olli H; Djurabekova, Flyura; Nordlund, Kai; Osmani, Orkhan; Medvedev, Nikita; Rethfield, Baerbel; Ridgway, Mark C; Kluth, Patrick

    2013-01-01

    We present experimental evidence for the formation of ion tracks in amorphous Si induced by swift heavy ion irradiation. An underlying core-shell structure consistent with remnants of a high density liquid structure was revealed by small-angle x-ray scattering and molecular dynamics simulations. Ion track dimensions dier for as-implanted and relaxed Si as attributed to dierent microstructures and melting temperatures. The identication and characterisation of ion tracks in amorphous Si yields new insight into mechanisms of damage formation due to swift heavy ion irradiation in amorphous semiconductors.

  16. Method of producing hydrogenated amorphous silicon film

    DOEpatents

    Wiesmann, Harold J.

    1980-01-01

    This invention relates to hydrogenated amorphous silicon produced by thermally decomposing silane (SiH.sub.4) or other gases comprising H and Si, from a tungsten or carbon foil heated to a temperature of about 1400.degree.-1600.degree. C., in a vacuum of about 10.sup.-6 to 19.sup.-4 torr, to form a gaseous mixture of atomic hydrogen and atomic silicon, and depositing said gaseos mixture onto a substrate independent of and outside said source of thermal decomposition, to form hydrogenated amorphous silicon. The presence of an ammonia atmosphere in the vacuum chamber enhances the photoconductivity of the hydrogenated amorphous silicon film.

  17. Peculiarities of Vibration Characteristics of Amorphous Ices

    NASA Astrophysics Data System (ADS)

    Gets, Kirill V.; Subbotin, Oleg S.; Belosludov, Vladimir R.

    2012-03-01

    Dynamic properties of low (LDA), high (HDA) and very high (VHDA) density amorphous ices were investigated within the approach based on Lattice Dynamics simulations. In this approach, we assume that the short-range molecular order mainly determines the dynamic and thermodynamic properties of amorphous ices. Simulation cell of 512 water molecules with periodical boundary conditions and disordering allows us to study dynamical properties and dispersion curves in the Brillouin zone of pseudo-crystal. Existence of collective phenomena in amorphous ices which is usual for crystals but anomalous for disordered phase was confirmed in our simulations. Molecule amplitudes of delocalized (collective) as well as localized vibrations have been considered.

  18. Structural relaxation of amorphous silicon carbide.

    PubMed

    Ishimaru, Manabu; Bae, In-Tae; Hirotsu, Yoshihiko; Matsumura, Syo; Sickafus, Kurt E

    2002-07-29

    We have examined amorphous structures of silicon carbide (SiC) using both transmission electron microscopy and a molecular-dynamics approach. Radial distribution functions revealed that amorphous SiC contains not only heteronuclear (Si-C) bonds but also homonuclear (Si-Si and C-C) bonds. The ratio of heteronuclear to homonuclear bonds was found to change upon annealing, suggesting that structural relaxation of the amorphous SiC occurred. Good agreement was obtained between the simulated and experimentally measured radial distribution functions. PMID:12144449

  19. The effect of immersion time on burying depth of the bivalve Macoma balthica (Tellinidae)

    NASA Astrophysics Data System (ADS)

    de Goeij, Petra; Honkoop, Pieter J. C.

    2002-03-01

    As a characteristic buried tellinid bivalve, Macoma balthica has a long inhalent siphon that enables it to feed in two different ways: deposit and suspension feeding. To deposit feed efficiently on benthic microalgae, Macoma has to live close to the sediment surface, where it can graze an extensive surface area, but is within reach of many predators. Individuals that are more safely buried at a greater depth can only suspension feed, or deposit feed from a small surface area. We expected local differences in burying depth on intertidal mudflats to be caused by differences in immersion time (i.e. time available for feeding, particularly suspension feeding), since immersion time has been shown experimentally to affect body condition positively, and since body condition and burying depth in Macoma are postively related in the field. To test this we experimentally manipulated immersion time, and followed changes in burying depth and body condition. In the experiments, longer immersion time went consistently with greater burying depth of Macoma and higher body condition. On a transect in the western Wadden Sea, the deepest Macoma were indeed found at the intertidal level with the longest immersion time, but these were at that time not the animals with the highest body condition. Within each locality, however, body condition was positively correlated with burying depth. The experimental data and the within-locality data support the hypothesis that longer immersion time may influence burying depth through body condition. However, the fact that between-locality differences in burying depth seemed to be consistently related to immersion time, but not to body condition, indicates that body condition alone does not explain place-to-place variation in burying depth.

  20. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    DOEpatents

    Farmer, Joseph C.; Wong, Frank M. G.; Haslam, Jeffery J.; Yang, Nancy; Lavernia, Enrique J.; Blue, Craig A.; Graeve, Olivia A.; Bayles, Robert; Perepezko, John H.; Kaufman, Larry; Schoenung, Julie; Ajdelsztajn, Leo

    2009-11-17

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  1. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    DOEpatents

    Farmer, Joseph C.; Wong, Frank M.G.; Haslam, Jeffery J.; Yang, Nancy; Lavernia, Enrique J.; Blue, Craig A.; Graeve, Olivia A.; Bayles, Robert; Perepezko, John H.; Kaufman, Larry; Schoenung, Julie; Ajdelsztajn, Leo

    2014-07-15

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  2. Amorphization of Silicon Carbide by Carbon Displacement

    SciTech Connect

    Devanathan, Ram; Gao, Fei; Weber, William J.

    2004-05-10

    We have used molecular dynamics simulations to examine the possibility of amorphizing silicon carbide (SiC) by exclusively displacing C atoms. At a defect generation corresponding to 0.2 displacements per atom, the enthalpy surpasses the level of melt-quenched SiC, the density decreases by about 15%, and the radial distribution function shows a lack of long-range order. Prior to amorphization, the surviving defects are mainly C Frenkel pairs (67%), but Si Frenkel pairs (18%) and anti-site defects (15%) are also present. The results indicate that SiC can be amorphized by C sublattice displacements. Chemical short-range disorder, arising mainly from interstitial production, plays a significant role in the amorphization.

  3. Amorphous Semiconductor Thin Films, an Introduction

    SciTech Connect

    Martin, Peter M.

    2003-12-01

    The field of amorphous semiconductors is so large that I cannot do it justice, but I hope this short column gives you some insight into the properties and materials available, and the issues involved.

  4. Ion-beam amorphization of semiconductors: A physical model based on the amorphous pocket population

    SciTech Connect

    Mok, K.R.C.; Jaraiz, M.; Martin-Bragado, I.; Rubio, J.E.; Castrillo, P.; Pinacho, R.; Barbolla, J.; Srinivasan, M.P.

    2005-08-15

    We introduce a model for damage accumulation up to amorphization, based on the ion-implant damage structures commonly known as amorphous pockets. The model is able to reproduce the silicon amorphous-crystalline transition temperature for C, Si, and Ge ion implants. Its use as an analysis tool reveals an unexpected bimodal distribution of the defect population around a characteristic size, which is larger for heavier ions. The defect population is split in both size and composition, with small, pure interstitial and vacancy clusters below the characteristic size, and amorphous pockets with a balanced mixture of interstitials and vacancies beyond that size.

  5. In situ observation of amorphous-amorphous apparently first-order phase transition in zeolites

    NASA Astrophysics Data System (ADS)

    Ovsyuk, Nikolay; Goryainov, Sergei

    2006-09-01

    In this letter, the authors present the observation of the phase transition between low-density amorphous (LDA) and high-density amorphous (HDA) zeolites using a high pressure Raman spectroscopy. It is found that this transition is apparently of the first order and occurs with a silicon coordination rise. It is shown that the Raman spectra of the LDA-HDA phase transitions in zeolites and in silicon are almost identical, suggesting a generality of amorphous-amorphous transformations both in simple substances and in complex polyatomic materials with tetrahedral configurations.

  6. Amorphous Phases on the Surface of Mars

    NASA Technical Reports Server (NTRS)

    Rampe, E. B.; Morris, R. V.; Ruff, S. W.; Horgan, B.; Dehouck, E.; Achilles, C. N.; Ming, D. W.; Bish, D. L.; Chipera, S. J.

    2014-01-01

    Both primary (volcanic/impact glasses) and secondary (opal/silica, allophane, hisingerite, npOx, S-bearing) amorphous phases appear to be major components of martian surface materials based on orbital and in-situ measurements. A key observation is that whereas regional/global scale amorphous components include altered glass and npOx, local scale amorphous phases include hydrated silica/opal. This suggests widespread alteration at low water-to-rock ratios, perhaps due to snow/ice melt with variable pH, and localized alteration at high water-to-rock ratios. Orbital and in-situ measurements of the regional/global amorphous component on Mars suggests that it is made up of at least three phases: npOx, amorphous silicate (likely altered glass), and an amorphous S-bearing phase. Fundamental questions regarding the composition and the formation of the regional/global amorphous component(s) still remain: Do the phases form locally or have they been homogenized through aeolian activity and derived from the global dust? Is the parent glass volcanic, impact, or both? Are the phases separate or intimately mixed (e.g., as in palagonite)? When did the amorphous phases form? To address the question of source (local and/or global), we need to look for variations in the different phases within the amorphous component through continued modeling of the chemical composition of the amorphous phases in samples from Gale using CheMin and APXS data. If we find variations (e.g., a lack of or enrichment in amorphous silicate in some samples), this may imply a local source for some phases. Furthermore, the chemical composition of the weathering products may give insight into the formation mechanisms of the parent glass (e.g., impact glasses contain higher Al and lower Si [30], so we might expect allophane as a weathering product of impact glass). To address the question of whether these phases are separate or intimately mixed, we need to do laboratory studies of naturally altered samples made

  7. Amorphous silicon-tellurium alloys

    NASA Astrophysics Data System (ADS)

    Shufflebotham, P. K.; Card, H. C.; Kao, K. C.; Thanailakis, A.

    1986-09-01

    Amorphous silicon-tellurium alloy thin films were fabricated by coevaporation over the composition range of 0-82 at. % Te. The electronic and optical properties of these films were systematically investigated over this same range of composition. The optical gap of these films was found to decrease monotonically with increasing Te content. Conduction near room temperature was due to extended state conduction, while variable range hopping dominated below 250 K. The incorporation of Te in concentrations of less than 1 at. % was found to produce an increase in the density of localized states at the Fermi level and a decrease in the activation energy. This was attributed to the Te being incorporated as a substitutional, fourfold coordinated, double donor in a-Si. At approximately 60 at. % Te, a decrease in the density of localized states at the Fermi level, and an increase in the activation energy and photoresponse was indicated. This was attributed to the possible formation of a less defective a-Si:Te compound.

  8. Ductile crystalline–amorphous nanolaminates

    PubMed Central

    Wang, Yinmin; Li, Ju; Hamza, Alex V.; Barbee, Troy W.

    2007-01-01

    It is known that the room-temperature plastic deformation of bulk metallic glasses is compromised by strain softening and shear localization, resulting in near-zero tensile ductility. The incorporation of metallic glasses into engineering materials, therefore, is often accompanied by complete brittleness or an apparent loss of useful tensile ductility. Here we report the observation of an exceptional tensile ductility in crystalline copper/copper–zirconium glass nanolaminates. These nanocrystalline–amorphous nanolaminates exhibit a high flow stress of 1.09 ± 0.02 GPa, a nearly elastic-perfectly plastic behavior without necking, and a tensile elongation to failure of 13.8 ± 1.7%, which is six to eight times higher than that typically observed in conventional crystalline–crystalline nanolaminates (<2%) and most other nanocrystalline materials. Transmission electron microscopy and atomistic simulations demonstrate that shear banding instability no longer afflicts the 5- to 10-nm-thick nanolaminate glassy layers during tensile deformation, which also act as high-capacity sinks for dislocations, enabling absorption of free volume and free energy transported by the dislocations; the amorphous–crystal interfaces exhibit unique inelastic shear (slip) transfer characteristics, fundamentally different from those of grain boundaries. Nanoscale metallic glass layers therefore may offer great benefits in engineering the plasticity of crystalline materials and opening new avenues for improving their strength and ductility. PMID:17592136

  9. Structure of Amorphous Titania Nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Chen, B.; Banfield, J. F.; Waychunas, G. A.

    2008-12-01

    Ultrafine (2 - 3 nm) titania (TiO2) nanoparticles show only diffuse scattering by both conventional powder x-ray diffraction and electron diffraction. We used synchrotron wide-angle x-ray scattering (WAXS) to probe the atomic correlations in this amorphous material. The atomic pair-distribution function (PDF) derived from Fourier transform of the WAXS data was used for reverse Monte Carlo (RMC) simulations of the atomic structure of the small nanoparticles. Molecular dynamics simulations were used to generate input structures for the RMC. X-ray absorption spectroscopy (XAS) simulations were used to screen candidate structures obtained from the RMC. The structure model that best describes both the WAXS and XAS data consists of particles with a highly distorted shell and a small strained anatase-like crystalline core. The average coordination number of Ti is 5.3 and the Ti-O bond length peaks at 1.940 Å. Relative to bulk titania, the reduction of the coordination number is primarily due to the truncation of the Ti-O octahedra at the titania nanoparticle surface, and the shortening of the Ti-O bond length is due to bond contraction in the distorted shell. Core-shell structures in ultrafine nanoparticles may be common in many materials (e.g. ZnS).

  10. A Magnetic Sensor with Amorphous Wire

    PubMed Central

    He, Dongfeng; Shiwa, Mitsuharu

    2014-01-01

    Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/√Hz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor. PMID:24940865

  11. Tests Of Amorphous-Silicon Photovoltaic Modules

    NASA Technical Reports Server (NTRS)

    Ross, Ronald G., Jr.

    1988-01-01

    Progress in identification of strengths and weaknesses of amorphous-silicon technology detailed. Report describes achievements in testing reliability of solar-power modules made of amorphous-silicon photovoltaic cells. Based on investigation of modules made by U.S. manufacturers. Modules subjected to field tests, to accelerated-aging tests in laboratory, and to standard sequence of qualification tests developed for modules of crystalline-silicon cells.

  12. Amorphous Carbon-Boron Nitride Nanotube Hybrids

    NASA Technical Reports Server (NTRS)

    Kim, Jae Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor); Lin, Yi (Inventor); Connell, John (Inventor)

    2016-01-01

    A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.

  13. Wear Resistant Amorphous and Nanocomposite Steel Coatings

    SciTech Connect

    Branagan, Daniel James; Swank, William David; Haggard, Delon C; Fincke, James Russell; Sordelet, D.

    2001-10-01

    In this article, amorphous and nanocomposite thermally deposited steel coatings have been formed by using both plasma and high-velocity oxy-fuel (HVOF) spraying techniques. This was accomplished by developing a specialized iron-based composition with a low critical cooling rate (?104 K/s) for metallic glass formation, processing the alloy by inert gas atomization to form micron-sized amorphous spherical powders, and then spraying the classified powder to form coatings. A primarily amorphous structure was formed in the as-sprayed coatings, independent of coating thickness. After a heat treatment above the crystallization temperature (568°C), the structure of the coatings self-assembled (i.e., devitrified) into a multiphase nanocomposite microstructure with 75 to 125 nm grains containing a distribution of 20 nm second-phase grain-boundary precipitates. Vickers microhardness testing revealed that the amorphous coatings were very hard (10.2 to 10.7 GPa), with further increases in hardness after devitrification (11.4 to 12.8 GPa). The wear characteristics of the amorphous and nanocomposite coatings were determined using both two-body pin-on-disk and three-body rubber wheel wet-slurry sand tests. The results indicate that the amorphous and nanocomposite steel coatings are candidates for a wide variety of wear-resistant applications.

  14. Amorphous boron nitride at high pressure

    NASA Astrophysics Data System (ADS)

    Durandurdu, Murat

    2016-06-01

    The pressure-induced phase transformation in hexagonal boron nitrite and amorphous boron nitrite is studied using ab initio molecular dynamics simulations. The hexagonal-to-wurtzite phase transformation is successfully reproduced in the simulation with a transformation mechanism similar to one suggested in experiment. Amorphous boron nitrite, on the other hand, gradually transforms to a high-density amorphous phase with the application of pressure. This phase transformation is irreversible because a densified amorphous state having both sp3 and sp2 bonds is recovered upon pressure release. The high-density amorphous state mainly consists of sp3 bonds and its local structure is quite similar to recently proposed intermediate boron nitrite phases, in particular tetragonal structure (P42/mnm), rather than the known the wurtzite or cubic boron nitrite due to the existence of four membered rings and edge sharing connectivity. On the basis of this finding we propose that amorphous boron nitrite might be best candidate as a starting structure to synthesize the intermediate phase(s) at high pressure and temperature (probably below 800 °C) conditions.

  15. Buried Object Detection Method Using Optimum Frequency Range in Extremely Shallow Underground

    NASA Astrophysics Data System (ADS)

    Sugimoto, Tsuneyoshi; Abe, Touma

    2011-07-01

    We propose a new detection method for buried objects using the optimum frequency response range of the corresponding vibration velocity. Flat speakers and a scanning laser Doppler vibrometer (SLDV) are used for noncontact acoustic imaging in the extremely shallow underground. The exploration depth depends on the sound pressure, but it is usually less than 10 cm. Styrofoam, wood (silver fir), and acrylic boards of the same size, different size styrofoam boards, a hollow toy duck, a hollow plastic container, a plastic container filled with sand, a hollow steel can and an unglazed pot are used as buried objects which are buried in sand to about 2 cm depth. The imaging procedure of buried objects using the optimum frequency range is given below. First, the standardized difference from the average vibration velocity is calculated for all scan points. Next, using this result, underground images are made using a constant frequency width to search for the frequency response range of the buried object. After choosing an approximate frequency response range, the difference between the average vibration velocity for all points and that for several points that showed a clear response is calculated for the final confirmation of the optimum frequency range. Using this optimum frequency range, we can obtain the clearest image of the buried object. From the experimental results, we confirmed the effectiveness of our proposed method. In particular, a clear image of the buried object was obtained when the SLDV image was unclear.

  16. Geological characteristics in buried coalfields synthetically using remote sensing and non-remote sensing information

    NASA Astrophysics Data System (ADS)

    Dai, Shifeng; Wang, Silong; Liu, Yurong

    1998-08-01

    With the rapid development of coal industry in China, the emphasis of the geological exploration has been changed from the exposed area to the buried area. Because of the limitation of the geological condition and the exploration methods, it is very difficult to study the geological phenomena in buried coalfield. To the coal geologists in China, to search an effective and practical method has been the important tackle key problem for recent years. In this paper, the authors discussed the characteristics of remote sensing technology in the geological study, and the forming mechanism of remote sensing information in the buried area from the view of agrology and physics, so the important academic evidences were offered for the geological study using remote sensing image in the buried coalfield. The characteristics of the non-remote sensing information, the geophysics information and the basal geological information, were also introduced in the study of buried geological bodies. The authors expounded the general processing method in the investigation of buried geological bodies using remote sensing and non-remote sensing information. At last, the probable distribution area of buried igneous rocks, in Huaibei coalfield in China, were successfully forecasted synthetically using the remote sensing, and non-remote sensing information.

  17. Bedrock mapping of buried valley networks using seismic reflection and airborne electromagnetic data

    NASA Astrophysics Data System (ADS)

    Oldenborger, G. A.; Logan, C. E.; Hinton, M. J.; Pugin, A. J.-M.; Sapia, V.; Sharpe, D. R.; Russell, H. A. J.

    2016-05-01

    In glaciated terrain, buried valleys often host aquifers that are significant groundwater resources. However, given the range of scales, spatial complexity and depth of burial, buried valleys often remain undetected or insufficiently mapped. Accurate and thorough mapping of bedrock topography is a crucial step in detecting and delineating buried valleys and understanding formative valley processes. We develop a bedrock mapping procedure supported by the combination of seismic reflection data and helicopter time-domain electromagnetic data with water well records for the Spiritwood buried valley aquifer system in Manitoba, Canada. The limited spatial density of water well bedrock observations precludes complete depiction of the buried valley bedrock topography and renders the water well records alone inadequate for accurate hydrogeological model building. Instead, we leverage the complementary strengths of seismic reflection and airborne electromagnetic data for accurate local detection of the sediment-bedrock interface and for spatially extensive coverage, respectively. Seismic reflection data are used to define buried valley morphology in cross-section beneath survey lines distributed over a regional area. A 3D model of electrical conductivity is derived from inversion of the airborne electromagnetic data and used to extrapolate buried valley morphology over the entire survey area. A spatially variable assignment of the electrical conductivity at the bedrock surface is applied to different features of the buried valley morphology identified in the seismic cross-sections. Electrical conductivity is then used to guide construction of buried valley shapes between seismic sections. The 3D locus of points defining each morphological valley feature is constructed using a path optimization routine that utilizes deviation from the assigned electrical conductivities as the cost function. Our resulting map represents a bedrock surface of unprecedented detail with more

  18. Of mice and marbles: Novel perspectives on burying behavior as a screening test for psychiatric illness.

    PubMed

    Wolmarans, De Wet; Stein, Dan J; Harvey, Brian H

    2016-06-01

    Burying forms part of the normal behavioral routine of rodents, although its expression is species-specific. However, it has been suggested that aberrant burying behavior, of which marble-burying (MB) is an example, may represent neophobic and/or compulsive-like behavior. In the present investigation, we assessed MB in an established animal model of obsessive-compulsive disorder (OCD)-namely, spontaneous stereotypy in the deer mouse-to establish whether high (H) stereotypy is associated with neophobia and/or another compulsive endophenotype, i.e. MB, as compared to nonstereotypical (N) controls. A three-trial, one-zone MB test was performed over three consecutive evenings both before and after chronic treatment with high-dose (50 mg/kg/day) oral escitalopram. Neophobia was measured via the number of marbles buried during the first pre- and posttreatment MB trials, and compulsive-like behavior via the number of marbles buried over all pre- and posttreatment MB trials. The data from the present study support earlier findings that burying is a normal behavioral routine (inherent burying behavior, IBB) that is expressed by all deer mice, irrespective of stereotypical cohort, and is not associated with either neophobia or compulsiveness. Indeed, chronic escitalopram treatment, which is similarly effective in treating clinical anxiety and OCD, as well as in attenuating H behavior, failed to influence IBB. Although 11 % of the animals presented with a unique burying endophenotype (high burying behavior), escitalopram also failed to attenuate said behavior, necessitating further investigation as to its relevance. In conclusion, MB cannot be regarded as a measure of anxiety-like or compulsive behavior in the deer mouse model of OCD. PMID:26920212

  19. The Low Frequency Aeroacoustics of Buried Nozzle Systems

    NASA Astrophysics Data System (ADS)

    Taylor, M. V.; Crighton, D. G.; Cargill, A. M.

    1993-05-01

    A simplified model of a "buried nozzle" aeroengine system is considered. The primary flow issues into a co-annular flow within a mixing chamber, and then the co-annular flow issues into the ambient medium from a secondary nozzle. Within the mixing chamber only fine scale mixing takes place, and shear layers within the mixing chamber and downstream of the secondary nozzle are assumed to sustain large scale instability waves. Excitation of this system is provided by low frequency plane waves, incident from upstream on the primary nozzle (and emanating from combustion processes in the hot core of an aeroengine). The response of this system, in the acoustic far field and in the mixing chamber, is obtained analytically from the asymptotic solution, at low frequency, of model sub-problems the solutions of which determine the wave reflection and transmission processes at the primary and secondary nozzles. In these sub-problems the shear layers are represented by vortex sheets and the nozzle walls by semi-infinite circular ducts, with Kutta conditions imposed on the unsteady flow at the primary and secondary nozzle lips. Analytical descriptions are given of the various wave modes (quasi-plane acoustic waves, and instability waves localized on the primary and secondary shear layers), of the acoustic field strength and directivity (essentially monopole, dipole and quadrupole fields), and of the conditions under which near-resonant response may occur, with large amplitudes of the perturbations in the mixing chamber and in the acoustic field.

  20. Colossal optical transmission through buried metal gratings (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Roberts, Christopher M.; Liu, Runyu; Zhao, Xiang; Yu, Lan; Li, Xiuling; Wasserman, Daniel M.; Podolskiy, Viktor A.

    2015-09-01

    In Extraordinary Optical Transmission (EOT), a metallic film perforated with an array of [periodic] apertures exhibits transmission over 100% normalized to the total aperture area, at selected frequencies. EOT devices have potential applications as optical filters and as couplers in hybrid electro-optic contacts/devices. Traditional passive extraordinary optical transmission structures, typically demonstrate un-normalized transmission well below 50%, and are typically outperformed by simpler thin-film techniques. To overcome these limitations, we demonstrate a new breed of extraordinary optical transmission devices, by "burying" an extraordinary optical transmission grating in a dielectric matrix via a metal-assisted-chemical etching process. The resulting structure is an extraordinary optical transmission grating on top of a dielectric substrate with dielectric nano-pillars extruded through the grating apertures. These structures not only show significantly enhanced peak transmission when normalized to the open area of the metal film, but more importantly, peak transmission greater than that observed from the bare semiconductor surface. The structures were modeled using three-dimensional rigorous coupled wave analysis and characterized experimentally by Fourier transform infrared reflection and transmission spectroscopy, and the good agreement between the two has been demonstrated. The drastic enhancement of light transmission in our structures originates from structuring of high-index dielectric substrate, with pillars effectively guiding light through metal apertures.

  1. Buried Mesozoic rift basins of Moroccan Atlantic continental margin

    SciTech Connect

    Mohamed, N.; Jabour, H.; El Mostaine, M.

    1995-08-01

    The Atlantic continental margin is the largest frontier area for oil and gas exploration in Morocco. Most of the activity has been concentrated where Upper Jurassic carbonate rocks have been the drilling objectives, with only one significant but non commercial oil discovery. Recent exploration activities have focused on early Mesozoic Rift basins buried beneath the post-rift sediments of the Middle Atlantic coastal plain. Many of these basins are of interest because they contain fine-grained lacustrine rocks that have sufficient organic richness to be classified as efficient oil prone source rock. Location of inferred rift basins beneath the Atlantic coastal plain were determined by analysis of drilled-hole data in combination with gravity anomaly and aeromagnetic maps. These rift basins are characterized by several half graben filled by synrift sediments of Triassic age probably deposited in lacustrine environment. Coeval rift basins are known to be present in the U.S. Atlantic continental margin. Basin modeling suggested that many of the less deeply bored rift basins beneath the coastal plain are still within the oil window and present the most attractive exploration targets in the area.

  2. The Panther Mountain circular structure, a possible buried meteorite crater

    NASA Technical Reports Server (NTRS)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    1992-01-01

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  3. The Challenging Buried Bumper Syndrome after Percutaneous Endoscopic Gastrostomy

    PubMed Central

    Afifi, Ibrahim; Zarour, Ahmad; Al-Hassani, Ammar; Peralta, Ruben; El-Menyar, Ayman; Al-Thani, Hassan

    2016-01-01

    Buried bumper syndrome (BBS) is a rare complication developed after percutaneous endoscopic gastrostomy (PEG). We report a case of a 38-year-old male patient who sustained severe traumatic brain injury that was complicated with early BBS after PEG tube insertion. On admission, bedside PEG was performed, and 7 days later the patient developed signs of sepsis with rapid progression to septic shock and acute kidney injury. Abdominal CT scan revealed no collection or leakage of the contrast, but showed malpositioning of the tube bumper at the edge of the stomach and not inside of it. Diagnostic endoscopy revealed that the bumper was hidden in the posterolateral part of the stomach wall forming a tract inside of it, which confirmed the diagnosis of BBS. The patient underwent laparotomy with a repair of the stomach wall perforation, and the early postoperative course was uneventful. Acute BBS is a rare complication of PEG tube insertion which could be manifested with severe complications such as pressure necrosis, peritonitis and septic shock. Early identification is the mainstay to prevent such complications. Treatment selection is primarily guided by the presenting complications, ranging from simple endoscopic replacement to surgical laparotomy. PMID:27462190

  4. Whole-field digital vibrometer system for buried landmine detection

    NASA Astrophysics Data System (ADS)

    Lal, Amit; Hess, Cecil; Scott, Eddie; Dang, Michael; Nichols, Robert

    2005-06-01

    Previous results have shown the potential of acoustic-to-seismic coupling with Laser Doppler Vibrometry for the detection of buried landmines. An important objective of the present technology is to improve the spatial resolution and the speed of the measurement. In this paper, MetroLaser reports on a whole-field digital vibrometer (WDV) that measures an entire one meter area with sub-centimeter spatial resolution in just a few seconds. The WDV is based on a dual-pulsed laser such that each pulse illuminates a one meter area on the ground, and the temporal separation between the two laser pulses can be adjusted to match the ground excitation frequency. By sweeping this excitation frequency, a displacement map of the ground at each frequency can be quickly generated. In addition, an innovative speckle repositioning strategy allows for movement of the measurement platform at reasonable speeds while still obtaining measurements with interferometric precision. This paper describes the WDV instrument and presents preliminary experimental results obtained with this system. This research is being supported by the U.S. Army RDECOM CERDEC NVESD under Contract W909MY04-C-0004.

  5. Buried threat detection using a handheld ground penetrating radar system

    NASA Astrophysics Data System (ADS)

    Knox, Mary; Torrione, Peter; Collins, Leslie; Morton, Kenneth

    2015-05-01

    In this work, we explore the efficacy of two buried threat detectors on handheld data. The first algorithm is an energy-based algorithm, which computes how anomalous a given A-scan measurement after it is normalized according to its local statistics. It is based on a commonly used prescreener for the Husky Mounted Detection System (HMDS). In the HMDS setting measurements are sampled on a crosstrack-downtrack grid, and sequential measurements are at neighboring downtrack locations. In contrast, in the handheld setting sequential scans are often taken at neighboring crosstrack locations, and neighboring downtrack locations can be hundreds of scans away. In order to include both downtrack and crosstrack information, we compute local statistics over a much larger area than in the HMDS setting. The second algorithm is a shape-based algorithm. Shape Invariant Feature Transform (SIFT) features, which capture the gradient distributions of local patches, are extracted and used to train a non-linear Support Vector Machine (SVM). We found that in terms of AUC, the SIFT-SVM algorithm results in a 2.2% absolute improvement over the energy-based algorithm, with the greatest gains seen at lower false alarm rates.

  6. The Panther Mountain circular structure, a possible buried meteorite crater

    NASA Astrophysics Data System (ADS)

    Isachsen, Y. W.; Wright, S. F.; Revetta, F. A.; Duneen, R. J.

    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon.

  7. Measure Guideline: Buried and/or Encapsulated Ducts

    SciTech Connect

    Shapiro, C.; Zoeller, W.; Mantha, P.

    2013-08-01

    Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

  8. Thermal processing system concepts and considerations for RWMC buried waste

    SciTech Connect

    Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

    1992-02-01

    This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

  9. Soil drying characteristics around a buried heated pipe

    SciTech Connect

    Murphy, W.E.; Miller, B.D.; Felton, G.K.

    1995-11-01

    Research on ground coupled heat pumps began in the late 1940s, but they became commercially available only in the 1980s. The system components are off-the-shelf items used in other applications, but the ground heat exchanger is unique for each installation. Ground heat transfer is complicated by soil porosity and the many variables needed to characterize soil properties. Another complication is the coupling of the heat and mass transfers. A finite difference numerical model was developed for a horizontal buried pipe where the heat and mass transfer relationships in the unsaturated porous soil were fully accounted for. The comparison of predicted temperature profiles and controlled laboratory measurements produced significant deviations after several days from the start of the test. These differences were likely due to the underprediction by the model of the moisture movement away from the pipe. Nearly complete drying out of the soil around the pipe was predicted by the model and was observed experimentally. The primary difficulty in obtaining good agreement with experimental results over all time periods was due to soil physical property variation with moisture content.

  10. Climate-mediated cooperation promotes niche expansion in burying beetles

    PubMed Central

    Sun, Syuan-Jyun; Rubenstein, Dustin R; Chen, Bo-Fei; Chan, Shih-Fan; Liu, Jian-Nan; Liu, Mark; Hwang, Wenbe; Yang, Ping-Shih; Shen, Sheng-Feng

    2014-01-01

    The ability to form cooperative societies may explain why humans and social insects have come to dominate the earth. Here we examine the ecological consequences of cooperation by quantifying the fitness of cooperative (large groups) and non-cooperative (small groups) phenotypes in burying beetles (Nicrophorus nepalensis) along an elevational and temperature gradient. We experimentally created large and small groups along the gradient and manipulated interspecific competition with flies by heating carcasses. We show that cooperative groups performed as thermal generalists with similarly high breeding success at all temperatures and elevations, whereas non-cooperative groups performed as thermal specialists with higher breeding success only at intermediate temperatures and elevations. Studying the ecological consequences of cooperation may not only help us to understand why so many species of social insects have conquered the earth, but also to determine how climate change will affect the success of these and other social species, including our own. DOI: http://dx.doi.org/10.7554/eLife.02440.001 PMID:24842999

  11. Detecting buried explosive hazards with handheld GPR and deep learning

    NASA Astrophysics Data System (ADS)

    Besaw, Lance E.

    2016-05-01

    Buried explosive hazards (BEHs), including traditional landmines and homemade improvised explosives, have proven difficult to detect and defeat during and after conflicts around the world. Despite their various sizes, shapes and construction material, ground penetrating radar (GPR) is an excellent phenomenology for detecting BEHs due to its ability to sense localized differences in electromagnetic properties. Handheld GPR detectors are common equipment for detecting BEHs because of their flexibility (in part due to the human operator) and effectiveness in cluttered environments. With modern digital electronics and positioning systems, handheld GPR sensors can sense and map variation in electromagnetic properties while searching for BEHs. Additionally, large-scale computers have demonstrated an insatiable appetite for ingesting massive datasets and extracting meaningful relationships. This is no more evident than the maturation of deep learning artificial neural networks (ANNs) for image and speech recognition now commonplace in industry and academia. This confluence of sensing, computing and pattern recognition technologies offers great potential to develop automatic target recognition techniques to assist GPR operators searching for BEHs. In this work deep learning ANNs are used to detect BEHs and discriminate them from harmless clutter. We apply these techniques to a multi-antennae, handheld GPR with centimeter-accurate positioning system that was used to collect data over prepared lanes containing a wide range of BEHs. This work demonstrates that deep learning ANNs can automatically extract meaningful information from complex GPR signatures, complementing existing GPR anomaly detection and classification techniques.

  12. Detection of Buried Human Remains Using Bioreporter Fluorescence

    SciTech Connect

    Vass, A. Dr.; Singleton, G. B.

    2001-10-01

    The search for buried human remains is a difficult, laborious and time-consuming task for law enforcement agencies. This study was conducted as a proof of principle demonstration to test the concept of using bioreporter microorganisms as a means to cover large areas in such a search. These bioreporter microorganisms are affected by a particular component of decaying organic matter that is distinct from decaying vegetation. The diamino compounds cadaverine and putrescine were selected as target compounds for the proof-of-principle investigation, and a search for microorganisms and genes that are responsive to either of these compounds was conducted. One recombinant clone was singled out for characterization based on its response to putrescine. The study results show that small concentrations of putrescine increased expression from this bioreporter construct. Although the level of increase was small (making it difficult to distinguish the signal from background), the results demonstrate the principle that bioreporters can be used to detect compounds resulting from decaying human remains and suggest that a wider search for target compounds should be conducted.

  13. Strong and Tough Layered Nanocomposites with Buried Interfaces.

    PubMed

    Chen, Ke; Tang, Xuke; Yue, Yonghai; Zhao, Hewei; Guo, Lin

    2016-04-26

    In nacre, the excellent mechanical properties of materials are highly dependent on their intricate hierarchical structures. However, strengthening and toughening effects induced by the buried inorganic-organic interfaces actually originate from various minerals/ions with small amounts, and have not drawn enough attention yet. Herein, we present a typical class of artificial nacres, fabricated by graphene oxide (GO) nanosheets, carboxymethylcellulose (CMC) polymer, and multivalent cationic (M(n+)) ions, in which the M(n+) ions cross-linking with plenty of oxygen-containing groups serve as the reinforcing "evocator", working together with other cooperative interactions (e.g., hydrogen (H)-bonding) to strengthen the GO/CMC interfaces. When compared with the pristine GO/CMC paper, the cross-linking strategies dramatically reinforce the mechanical properties of our artificial nacres. This special reinforcing effect opens a promising route to strengthen and toughen materials to be applied in aerospace, tissue engineering, and wearable electronic devices, which also has implication for better understanding of the role of these minerals/ions in natural materials for the mechanical improvement. PMID:27070962

  14. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy

    SciTech Connect

    Oberbeck, Lars; Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y. E-mail: michelle.simmons@unsw.edu.au; Schofield, Steven R.; Curson, Neil J. E-mail: michelle.simmons@unsw.edu.au

    2014-06-23

    We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.

  15. Pannus Is the New Prepuce? Penile Cancer in a Buried Phallus

    PubMed Central

    Manwaring, Jared; Vourganti, Srinivas; Nikolavsky, Dmitriy; Valente, Alfredo L.; Byler, Timothy

    2015-01-01

    Two males presented to our urology department with complaints of bleeding and malodor from buried phallus within a suprapubic fat pad. Although both men had neonatal circumcisions, advanced penile carcinoma was found in both men. Formal penectomies showed high grade, poorly differentiated squamous cell carcinoma invading the corporal bodies and urethra. Buried penis represents a difficulty in early detection of suspicious lesions but may also provide an environment susceptible to poor hygiene and subsequent chronic inflammation. Patients with buried penis may be at a higher risk for development of invasive penile cancer and may benefit from regular and thorough genital exams. PMID:26446361

  16. Consecutively Preparing D-Xylose, Organosolv Lignin, and Amorphous Ultrafine Silica from Rice Husk

    PubMed Central

    Zhang, Hongxi; Ding, Xuefeng; Wang, Zichen; Zhao, Xu

    2014-01-01

    Rice husk is an abundant agricultural by-product reaching the output of 80 million tons annually in the world. The most common treatment method of rice husk is burning or burying, which caused serious air pollution and resource waste. In order to solve this problem, a new method is proposed to comprehensively utilize the rice husk in this paper. Firstly, the D-xylose was prepared from the semicellulose via dilute acid hydrolysis. Secondly, the lignin was separated via organic solvent pulping from the residue. Finally, the amorphous ultrafine silica was prepared via pyrolysis of the residue produced in the second process. In this way, the three main contents of rice husk (semicellulose, lignin, and silica) are consecutively converted to three fine chemicals, without solid waste produced. The yields of D-xylose and organosolv lignin reach 58.2% and 58.5%, respectively. The purity and specific surface of amorphous ultrafine silica reach 99.92% and 225.20 m2/g. PMID:25140120

  17. Consecutively preparing d-xylose, organosolv lignin, and amorphous ultrafine silica from rice husk.

    PubMed

    Zhang, Hongxi; Ding, Xuefeng; Wang, Zichen; Zhao, Xu

    2014-01-01

    Rice husk is an abundant agricultural by-product reaching the output of 80 million tons annually in the world. The most common treatment method of rice husk is burning or burying, which caused serious air pollution and resource waste. In order to solve this problem, a new method is proposed to comprehensively utilize the rice husk in this paper. Firstly, the D-xylose was prepared from the semicellulose via dilute acid hydrolysis. Secondly, the lignin was separated via organic solvent pulping from the residue. Finally, the amorphous ultrafine silica was prepared via pyrolysis of the residue produced in the second process. In this way, the three main contents of rice husk (semicellulose, lignin, and silica) are consecutively converted to three fine chemicals, without solid waste produced. The yields of D-xylose and organosolv lignin reach 58.2% and 58.5%, respectively. The purity and specific surface of amorphous ultrafine silica reach 99.92% and 225.20 m(2)/g. PMID:25140120

  18. Electrons and phonons in amorphous semiconductors

    NASA Astrophysics Data System (ADS)

    Prasai, Kiran; Biswas, Parthapratim; Drabold, D. A.

    2016-07-01

    The coupling between lattice vibrations and electrons is one of the central concepts of condensed matter physics. The subject has been deeply studied for crystalline materials, but far less so for amorphous and glassy materials, which are among the most important for applications. In this paper, we explore the electron-lattice coupling using current tools of a first-principles computer simulation. We choose three materials to illustrate the phenomena: amorphous silicon (a-Si), amorphous selenium (a-Se) and amorphous gallium nitride (a-GaN). In each case, we show that there is a strong correlation between the localization of electron states and the magnitude of thermally induced fluctuations in energy eigenvalues obtained from the density-functional theory (i.e. Kohn–Sham eigenvalues). We provide a heuristic theory to explain these observations. The case of a-GaN, a topologically disordered partly ionic insulator, is distinctive compared to the covalent amorphous examples. Next, we explore the consequences of changing the charge state of a system as a proxy for tracking photo-induced structural changes in the materials. Where transport is concerned, we lend insight into the Meyer–Neldel compensation rule and discuss a thermally averaged Kubo–Greenwood formula as a means to estimate electrical conductivity and especially its temperature dependence. We close by showing how the optical gap of an amorphous semiconductor can be computationally engineered with the judicious use of Hellmann–Feynman forces (associated with a few defect states) using molecular dynamics simulations. These forces can be used to close or open an optical gap, and identify a structure with a prescribed gap. We use the approach with plane-wave density functional methods to identify a low-energy amorphous phase of silicon including several coordination defects, yet with a gap close to that of good quality a-Si models.

  19. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    DOEpatents

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  20. Detection of Buried Empty Lunar Lava Tubes Using GRAIL Gravity Data

    NASA Astrophysics Data System (ADS)

    Sood, R.; Chappaz, L.; Melosh, H. J.; Howell, K. C.; Blair, D. M.; Milbury, C.

    2015-10-01

    GRAIL gravity data is used to detect buried empty lunar lava tubes that are of interest as possible habitation sites safe from cosmic radiation and micrometeorite impacts. Regions in the maria with known skylights and sinuous rilles are investigated.

  1. Building America Top Innovations 2013 Profile – Buried and Encapsulated Ducts

    SciTech Connect

    none,

    2013-09-01

    In this innovation profile, CARB research shows HVAC ducts that are encapsulated in closed-cell spray foam and buried in blown insulation in a vented attic meet the code requirements for ducts in conditioned space.

  2. [Super-low-frequency spectrum analysis for buried faults in coalfield].

    PubMed

    Chen, Li; Qin, Qi-Ming; Zhen, Guang-Wei; Wang, Nan; Bai, Yan-Bing; Chen, Chao

    2013-08-01

    Based on the super-low-frequency (SLF) electromagnetic detection technology, the advanced detection for the buried fault in the coalfield is still at the exploratory stage, while the technology has a strong practical significance for production and design of the coal mine. Firstly, in this paper, the SLF electromagnetic detection signals were collected in study area. Spectrum analysis of SLF signal by wavelet transform can remove high-frequency noise. Secondly, the profile of the measuring line across the fault was analyzed and interpreted geologically. Accordingly SLF spectrum characteristics of the buried fault could be researched. Finally, combined with the geological and seismic data, the characteristics and distribution of fault structures can be verified in the mining area. The results show that: the buried fault could be detected quickly and effectively by SLF electromagnetic detection Hence, SLF electromagnetic detection technology is an effective method for buried fault detection. PMID:24159862

  3. Potential of bioremediation for buried oil removal in beaches after an oil spill.

    PubMed

    Pontes, Joana; Mucha, Ana P; Santos, Hugo; Reis, Izabela; Bordalo, Adriano; Basto, M Clara; Bernabeu, Ana; Almeida, C Marisa R

    2013-11-15

    Bioremediation potential for buried oil removal, an application still lacking thorough research, was assessed in a specifically designed system in which an artificially contaminated oil layer of sand was buried in a sand column subjected to tidal simulation. The efficiency of biostimulation (BS, fertilizer addition) and bioaugmentation (BA, inoculation of pre-stimulated indigenous hydrocarbon-degrading microorganisms plus fertilizer) compared to natural attenuation was tested during a 180-day experimental period. The effect of BA was evident after 60 days (degradation of hydrocarbons reached 80%). BS efficacy was revealed only after 120 days. Microorganisms and nutrients added at the top of the sand column were able to reach the buried oil layer and contributed to faster oil elimination, an important feature for effective bioremediation treatments. Therefore, autochthonous BA with suitable nutritive conditions results in faster oil-biodegradation, appears to be a cost-effective methodology for buried oil remediation and contributes to the recovery of oil-impacted areas. PMID:24054785

  4. Buried-Hill discoveries of the Damintun depression in north China

    SciTech Connect

    Tong XiaoGuang; Huang Zuan )

    1991-04-01

    Several buried-hill oil fields recently have been found in the Damintun depression. All the buried hills except one consist of Archean metamorphic rocks. Of these, the Dongshenpu buried hill is the largest. The metamorphic rocks have no original porosity but have secondary porosity, such as weathering fractures, structural fractures, brecciated pores, secondary corrosion pores, and secondary replacement pores. Fractures, especially structural fractures, form the only migration passages and main reservoir spaces for hydrocarbons in the buried hill. Crude oil comes from Paleogene continental source rocks and is very waxy. Based on the interpretation of log data, the porosity averages 3.24%. According to calculations using pressure build-up curves, the effective permeability averages 0.140 {mu}m{sup 2}.

  5. DRAINAGE PIPE DETECTOR: GROUND PENETRATING RADAR SHOWS PROMISE IN LOCATING BURIED SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the more frustrating problems confronting farmers and land improvement contractors in the Midwestern United States involves locating buried agricultural drainage pipes. Conventional geophysical methods, particularly ground penetrating radar (GPR), presently being used for environmental and co...

  6. Slow dissolution behaviour of amorphous capecitabine.

    PubMed

    Meulenaar, Jelte; Beijnen, Jos H; Schellens, Jan H M; Nuijen, Bastiaan

    2013-01-30

    In this article, we report the anomalous dissolution behaviour of amorphous capecitabine. In contrast to what is expected from thermodynamic theory, amorphous capecitabine dissolves significantly slower compared to its crystalline counterpart. Our experiments show that this is due to the "gelling" properties of amorphous capecitabine in an aqueous environment. The "gel", which is immediately formed upon contact with water, entraps the capecitabine and significantly slows down its dissolution. This "gelling" property is hypothesized to be related to the low glass transition temperature (Tg 19°C) of amorphous capecitabine, resulting in an instant collapse ("gelling") in an aqueous environment. From IR and DSC analysis it is shown that this collapsed capecitabine is remarkably stable and does not recrystallize upon an increased water content or temperature. This highly reproducible dissolution behaviour can be applied in the development of a sustained release dosage form as substantially less sustained release excipient is required in order to attain the desired release profile. As capecitabine is a high-dosed drug, this is highly favourable in view of the size and thus clinical feasibility of the final dosage form. Currently, we are developing and clinically testing a sustained release formulation making use of amorphous capecitabine and its remarkable dissolution behaviour. PMID:23219704

  7. SURVIVAL OF AMORPHOUS WATER ICE ON CENTAURS

    SciTech Connect

    Guilbert-Lepoutre, Aurelie

    2012-10-01

    Centaurs are believed to be Kuiper Belt objects in transition between Jupiter and Neptune before possibly becoming Jupiter family comets. Some indirect observational evidence is consistent with the presence of amorphous water ice in Centaurs. Some of them also display a cometary activity, probably triggered by the crystallization of the amorphous water ice, as suggested by Jewitt and this work. Indeed, we investigate the survival of amorphous water ice against crystallization, using a fully three-dimensional thermal evolution model. Simulations are performed for varying heliocentric distances and obliquities. They suggest that crystallization can be triggered as far as 16 AU, though amorphous ice can survive beyond 10 AU. The phase transition is an efficient source of outgassing up to 10-12 AU, which is broadly consistent with the observations of the active Centaurs. The most extreme case is 167P/CINEOS, which barely crystallizes in our simulations. However, amorphous ice can be preserved inside Centaurs in many heliocentric distance-obliquity combinations, below a {approx}5-10 m crystallized crust. We also find that outgassing due to crystallization cannot be sustained for a time longer than 10{sup 4}-10{sup 4} years, leading to the hypothesis that active Centaurs might have recently suffered from orbital changes. This could be supported by both observations (although limited) and dynamical studies.

  8. Amorphous silicon detectors in positron emission tomography

    SciTech Connect

    Conti, M. Lawrence Berkeley Lab., CA ); Perez-Mendez, V. )

    1989-12-01

    The physics of the detection process is studied and the performances of different Positron Emission Tomography (PET) system are evaluated by theoretical calculation and/or Monte Carlo Simulation (using the EGS code) in this paper, whose table of contents can be summarized as follows: a brief introduction to amorphous silicon detectors and some useful equation is presented; a Tantalum/Amorphous Silicon PET project is studied and the efficiency of the systems is studied by Monte Carlo Simulation; two similar CsI/Amorphous Silicon PET projects are presented and their efficiency and spatial resolution are studied by Monte Carlo Simulation, light yield and time characteristics of the scintillation light are discussed for different scintillators; some experimental result on light yield measurements are presented; a Xenon/Amorphous Silicon PET is presented, the physical mechanism of scintillation in Xenon is explained, a theoretical estimation of total light yield in Xenon and the resulting efficiency is discussed altogether with some consideration of the time resolution of the system; the amorphous silicon integrated electronics is presented, total noise and time resolution are evaluated in each of our applications; the merit parameters {epsilon}{sup 2}{tau}'s are evaluated and compared with other PET systems and conclusions are drawn; and a complete reference list for Xenon scintillation light physics and its applications is presented altogether with the listing of the developed simulation programs.

  9. Crystallization of amorphous Zr-Be alloys

    NASA Astrophysics Data System (ADS)

    Golovkova, E. A.; Surkov, A. V.; Syrykh, G. F.

    2015-02-01

    The thermal stability and structure of binary amorphous Zr100 - x Be x alloys have been studied using differential scanning calorimetry and neutron diffraction over a wide concentration range (30 ≤ x ≤ 65). The amorphous alloys have been prepared by rapid quenching from melt. The studied amorphous system involves the composition range around the eutectic composition with boundary phases α-Zr and ZrBe2. It has been found that the crystallization of alloys with low beryllium contents ("hypoeutectic" alloys with x ≤ 40) proceeds in two stages. Neutron diffraction has demonstrated that, at the first stage, α-Zr crystallizes and the remaining amorphous phase is enriched to the eutectic composition; at the second stage, the alloy crystallizes in the α-Zr and ZrBe2 phases. At higher beryllium contents ("hypereutectic" alloys), one phase transition of the amorphous phase to a mixture of the α-Zr and ZrBe2 phases has been observed. The concentration dependences of the crystallization temperature and activation energy have been revealed.

  10. Amorphous Silicon Based Neutron Detector

    SciTech Connect

    Xu, Liwei

    2004-12-12

    Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield using low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: · High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; · Various single-junction and double junction detector devices have been fabricated; · The detector devices fabricated have been systematically tested and analyzed. · Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies

  11. FOREWORD: Special section on electromagnetic characterization of buried obstacles

    NASA Astrophysics Data System (ADS)

    Lesselier, Dominique; Chew, Weng Cho

    2004-12-01

    This Inverse Problems special section on electromagnetic characterization of buried obstacles contains a selection of 14 invited papers, involving 41 authors and 19 research groups worldwide. (Though this section consists of invited papers, the standard refereeing procedures of Inverse Problems have been rigorously observed.) We do not claim to have reached all the high-level researchers in the field, but we believe that we have made a fair attempt. As illustrated by the variety of contributions included, the aim of this special section is to address theoretical and practical inversion problems (and the solutions thereof) that arise in the field of electromagnetic characterization of obstacles (artificial or natural) buried on the Earth or in planetary subsoil. Civil and military engineering, archaeological and environmental issues are typically among those within the scope of the investigation. An example is the characterization of a single (or multiple) obstacle(s) located near the interface or at shallow depths via electromagnetic means operating within relevant frequency bands. However, we also welcomed novel and thought-provoking investigations, even though their direct application to the real world, or even to laboratory-controlled settings, may still be far off. Within this general mathematical and applied framework, the submitted papers focused on a combination of theoretical, computational and experimental developments. They either reviewed the most recent advances in a particular area of research or were an original and specialized contribution. Let us now take the opportunity to remind the readers that this special section harks back (in addition to sharing some common contributors) to two special sections already published in the journal which possessed the same flavour of wave-field inversion and its many applications. They were `Electromagnetic imaging and inversion of the Earth's subsurface', which was published in October 2000 (volume 16, issue 5

  12. Nutrition, hormones and life history in burying beetles.

    PubMed

    Trumbo, Stephen T; Robinson, Gene E

    2004-05-01

    Nutrition, hormones and the allocation of physiological resources are intricately related. To investigate these inter-relationships in female burying beetles (Nicrophorus spp.), we examined the effect of diet quality on juvenile hormone (JH) levels and reproduction, and the effect of JH supplementation on reproduction and resistance to starvation. Nicrophorus orbicollis adult females fed a less preferred mealworm larvae diet gained less body mass, had smaller ovaries and had lower titers of JH in their hemolymph than females fed a preferred blowfly diet. When presented a carcass for breeding, females on a less preferred diet oviposited 33% fewer eggs, and eggs were of 18% less mass. Females on the less preferred diet also took longer to begin oviposition as indicated indirectly by the time when their eggs hatched. To investigate the effects of JH, independent of nutrition, JH was topically applied to single and paired females of Nicrophorus tomentosus. When presented a carcass, JH-treated paired females oviposited more eggs (28%-year 1, 44%-year 2) than control females, and also showed a trend toward faster oviposition. JH supplementation had a greater effect on single females. JH treatment increased the proportion of single females attempting reproduction (at least one viable larva), increased the number of eggs (69%-year 1, 123%-year 2), and increased the proportion of females ovipositing early. In separate experiments, treatment with JH or a JH analog negatively affected resistance to starvation in three species. Treatment with JH reduced starvation survival by 10.3% days in N. tomentosus females. Treatment with the JH analog methoprene reduced starvation survival 17.8% in N. orbicollis females and by 18% in Ptomascopus morio females. These results suggest that JH has positive and negative effects on different components of life history. PMID:15121451

  13. Buried bumper syndrome: A complication of percutaneous endoscopic gastrostomy

    PubMed Central

    Cyrany, Jiri; Rejchrt, Stanislav; Kopacova, Marcela; Bures, Jan

    2016-01-01

    Percutaneous endoscopic gastrostomy (PEG) is a widely used method of nutrition delivery for patients with long-term insufficiency of oral intake. The PEG complication rate varies from 0.4% to 22.5% of cases, with minor complications being three times more frequent. Buried bumper syndrome (BBS) is a severe complication of this method, in which the internal fixation device migrates alongside the tract of the stoma outside the stomach. Excessive compression of tissue between the external and internal fixation device of the gastrostomy tube is considered the main etiological factor leading to BBS. Incidence of BBS is estimated at around 1% (0.3%-2.4%). Inability to insert, loss of patency and leakage around the PEG tube are considered to be a typical symptomatic triad. Gastroscopy is indicated in all cases in which BBS is suspected. The depth of disc migration in relation to the lamina muscularis propria of the stomach is critical for further therapy and can be estimated by endoscopic or transabdominal ultrasound. BBS can be complicated by gastrointestinal bleeding, perforation, peritonitis, intra-abdominal and abdominal wall abscesses, or phlegmon, and these complications can lead to fatal outcomes. The most important preventive measure is adequate positioning of the external bolster. A conservative approach should be applied only in patients with high operative risk and dismal prognosis. Choice of the method of release is based on the type of the PEG set and depth of disc migration. A disc retained inside the stomach and completely covered by the overgrowing tissue can be released using some type of endoscopic dissection technique (needle knife, argon plasma coagulation, or papillotome through the cannula). Proper patient selection and dissection of the overgrowing tissue are the major determinants for successful endoscopic therapy. A disc localized out of the stomach (lamina muscularis propria) should be treated by a surgeon. PMID:26811611

  14. Review of Concrete Biodeterioration in Relation to Buried Nuclear Waste

    SciTech Connect

    Turick, C; Berry, C.

    2012-10-15

    Long-term storage of low level radioactive material in below ground concrete disposal units (DUs) (Saltstone Disposal Facility) is a means of depositing wastes generated from nuclear operations of the U.S. Department of Energy. Based on the currently modeled degradation mechanisms, possible microbial induced effects on the structural integrity of buried low level wastes must be addressed. Previous international efforts related to microbial impacts on concrete structures that house low level radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the recent research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete vaults housing stored wastes and the wastes themselves. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources like components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The results of this review suggest that microbial activity in Saltstone, (grouted low level radioactive waste) is unlikely due to very high pH and osmotic pressure. Biodegradation of the concrete vaults housing the radioactive waste however, is a possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Results from this review point to parameters to focus on for modeling activities and also, possible options for mitigation that would minimize concrete biodegradation. In addition, key chemical components that drive microbial

  15. FOREWORD: Special section on electromagnetic characterization of buried obstacles

    NASA Astrophysics Data System (ADS)

    Lesselier, Dominique; Chew, Weng Cho

    2004-12-01

    This Inverse Problems special section on electromagnetic characterization of buried obstacles contains a selection of 14 invited papers, involving 41 authors and 19 research groups worldwide. (Though this section consists of invited papers, the standard refereeing procedures of Inverse Problems have been rigorously observed.) We do not claim to have reached all the high-level researchers in the field, but we believe that we have made a fair attempt. As illustrated by the variety of contributions included, the aim of this special section is to address theoretical and practical inversion problems (and the solutions thereof) that arise in the field of electromagnetic characterization of obstacles (artificial or natural) buried on the Earth or in planetary subsoil. Civil and military engineering, archaeological and environmental issues are typically among those within the scope of the investigation. An example is the characterization of a single (or multiple) obstacle(s) located near the interface or at shallow depths via electromagnetic means operating within relevant frequency bands. However, we also welcomed novel and thought-provoking investigations, even though their direct application to the real world, or even to laboratory-controlled settings, may still be far off. Within this general mathematical and applied framework, the submitted papers focused on a combination of theoretical, computational and experimental developments. They either reviewed the most recent advances in a particular area of research or were an original and specialized contribution. Let us now take the opportunity to remind the readers that this special section harks back (in addition to sharing some common contributors) to two special sections already published in the journal which possessed the same flavour of wave-field inversion and its many applications. They were `Electromagnetic imaging and inversion of the Earth's subsurface', which was published in October 2000 (volume 16, issue 5

  16. Seismic fragility analysis of buried steel piping at P, L, and K reactors

    SciTech Connect

    Wingo, H.E.

    1989-10-01

    Analysis of seismic strength of buried cooling water piping in reactor areas is necessary to evaluate the risk of reactor operation because seismic events could damage these buried pipes and cause loss of coolant accidents. This report documents analysis of the ability of this piping to withstand the combined effects of the propagation of seismic waves, the possibility that the piping may not behave in a completely ductile fashion, and the distortions caused by relative displacements of structures connected to the piping.

  17. A process for ensuring regulatory compliance at the INEL`s buried waste integrated demonstrations

    SciTech Connect

    Cannon, P.G.; Watson, L.R.; Blacker, P.B.

    1993-03-01

    The Buried Waste Integrated Demonstration Program is funded by the Department of Energy Office of Technology Development. The mission of this Integrated Demonstration is to identify, evaluate, and demonstrate a suite of innovative technologies for the remediation of radioactive and hazardous waste buried throughout the DOE complex between 1950 and 1970. The program approach to development of a long-range strategy for improving buried waste remediation capabilities is to combine systems analysis with already identified remediation needs for DOE complex buried waste. The systems analysis effort has produced several configuration options (a top-level block diagram of a cradle-to-grave remediation system) capable of remediating the transuranic-contaminated waste pits and trenches at the Idaho National Engineering Laboratory. Technologies for demonstration are selected using three criteria: (a) the ability to satisfy a specific buried waste need, (b) the ability to satisfy functional and operational requirements defined for functional sub-elements in a configuration option, and (c) performance against Comprehensive Environmental Restoration and Compensation Liability Act selection criteria, such as effectiveness, implementability, and cost. Early demonstrations experienced problems with missed requirements, prompting the Buried Waste Integrated Demonstration Program Office to organize a Corrective Action Team to identify the cause and recommend corrective actions. The result of this team effort is the focus of this paper.

  18. Experimental Studies about Transient Characteristics of a Deeply Buried Grounding Electrode and a Grounding Mesh

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuo; Yanagawa, Shunichi; Sekioka, Shozo

    When lightning strikes the tower of a cellular phone base station or other such facilities, power and communication equipments in the vicinity of the tower may suffer extensive damages due to the lightning current flowing backward from the grounding system of the tower. The use of a deeply buried grounding electrode has been proposed recently to suppress such back flow current and a potential rise in the vicinity of the tower. The deeply buried grounding electrode is a bare conductor buried deep in the ground that is connected to a lightning rod on the ground by an insulated wire. When lightning strikes the lightning rod, the lightning current is directed to the electrode from which it diffuses to the ground. The deeply buried grounding electrodes have been installed in cellular phone base stations and other such facilities to solve such problems caused by the back flow current and the potential rise. A grounding mesh is usually laid around such base stations as a grounding system for the facilities on the ground. Therefore, it is important to understand the interactions between the deeply buried grounding electrode and the grounding mesh. In this study, experiments on the interactions between a grounding mesh and a deeply buried grounding electrode have been carried out. Additionally, the transient characteristics of the mesh grounding have researched.

  19. Cannabidiol reverses the mCPP-induced increase in marble-burying behavior.

    PubMed

    Nardo, Mirella; Casarotto, Plinio C; Gomes, Felipe V; Guimarães, Francisco S

    2014-10-01

    Cannabidiol (CBD), one of the main components of Cannabis sp., presents clinical and preclinical anxiolytic properties. Recent results using the marble-burying test (MBT) suggest that CBD can also induce anticompulsive-like effects. Meta-chloro-phenyl-piperazine (mCPP) is a nonspecific serotonergic agonist (acting mainly at 5HT1A, 5HT2C and 5HT1D receptors) reported to increase symptoms in OCD patients and block the anticompulsive-like effect of serotonin reuptake inhibitors (SRIs) in animal models. The aim of this study was to investigate the interference of CBD on mCPP effects in repetitive burying. Administration of mCPP showed dual effects in the MBT, increasing the number of buried marbles at lower (0.1 mg/kg) while decreasing it at higher doses (1 mg/kg), an effect not related to a general increase in anxiety-like behavior. As found previously, CBD (30 mg/kg) and the positive control fluoxetine (FLX; 10 mg/kg) decreased burying behavior without changing general exploratory activity. A similar effect was found when subeffective doses of CBD (15 mg/kg) and FLX (3 mg/kg) were administered together. These subeffective doses alone were also able to block mCPP-induced repetitive burying. The results, in addition to reinforcing a possible anticompulsive effect of CBD, also suggest that mCPP-induced repetitive burying could be a useful test for the screening of compounds with presumed anticompulsive properties. PMID:24118015

  20. Imaging of Au nanoparticles deeply buried in polymer matrix by various atomic force microscopy techniques.

    PubMed

    Kimura, Kuniko; Kobayashi, Kei; Matsushige, Kazumi; Yamada, Hirofumi

    2013-10-01

    Recently, some papers reported successful imaging of subsurface features using atomic force microscopy (AFM). Some theoretical studies have also been presented, however the imaging mechanisms are not fully understood yet. In the preceeding papers, imaging of deeply buried nanometer-scale features has been successful only if they were buried in a soft matrix. In this paper, subsurface features (Au nanoparticles) buried in a soft polymer matrix were visualized. To elucidate the imaging mechanisms, various AFM techniques; heterodyne force microscopy, ultrasonic atomic force microscopy (UAFM), 2nd-harmonic UAFM and force modulation microscopy (FMM) were employed. The particles buried under 960 nm from the surface were successfully visualized which has never been achieved. The results elucidated that it is important for subsurface imaging to choose a cantilever with a suitable stiffness range for a matrix. In case of using the most suitable cantilever, the nanoparticles were visualized using every technique shown above except for FMM. The experimental results suggest that the subsurface features buried in a soft matrix with a depth of at least 1 µm can affect the local viscoelasticity (mainly viscosity) detected as the variation of the amplitude and phase of the tip oscillation on the surface. This phenomenon presumably makes it possible to visualize such deeply buried nanometer-scale features in a soft matrix. PMID:23770541

  1. Progestogens and Estrogen Influence Impulsive Burying and Avoidant Freezing Behavior of Naturally Cycling and Ovariectomized Rats

    PubMed Central

    Llaneza, Danielle C.; Frye, Cheryl A.

    2009-01-01

    Steroid hormones, progesterone and estradiol, may influence approach and/or anxiety behavior. Female rats in behavioral estrus, have elevated levels of these steroid hormones and demonstrate more approach and less anxiety behavior than do diestrous rats. Ovariectomy obviates these cyclic variations and systemic progesterone and/or estrogen replacement can enhance approach and anti-anxiety behavior. However, the role of progesterone and/or estrogen in mediating impulsive, avoidant and/or fear behaviors requires further investigation. We hypothesized that if progesterone and/or estrogen influences impulsivity and/or fear then rats in behavioral estrus would demonstrate less impulsive behavior in a burying task and freezing behavior in a conditioned fear task than will diestrous rats. Ovariectomized rats administered progesterone and/or estrogen would show less impulsive burying and freezing behaviors than will vehicle-administered rats. Experiment 1: Naturally cycling rats were tested in marble burying or conditioned fear when they were in behavioral estrus or diestrus. Experiment 2: Ovariectomized rats were administered progesterone, estrogen or vehicle, then tested in marble burying or conditioned fear. Results of Experiment 1 show rats in behavioral estrus demonstrate less impulsive burying and less freezing behavior than diestrous rats. Results of Experiment 2 show administration of progesterone or both estrogen and progesterone decreases impulsive burying and each decrease freezing behavior compared to vehicle. Thus, progesterone and/or estrogen may mediate impulsive and/or avoidant behavior. PMID:19447128

  2. Distinct microbial communities associated with buried soils in the Siberian tundra

    NASA Astrophysics Data System (ADS)

    Gittel, Antje; Bárta, Jiří; Kohoutová, Iva; Mikutta, Robert; Owens, Sarah; Gilbert, Jack; Schnecker, Jörg; Wild, Birgit; Hannisdal, Bjarte; Maerz, Joeran; Lashchinskiy, Nikolay; Čapek, Petr; Šantrůčková, Hana; Gentsch, Norman; Shibistova, Olga; Guggenberger, Georg; Richter, Andreas; Torsvik, Vigdis; Schleper, Christa; Urich, Tim

    2014-05-01

    Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze-thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes.

  3. Amorphous metallic films in silicon metallization systems

    NASA Technical Reports Server (NTRS)

    So, F.; Kolawa, E.; Nicolet, M. A.

    1985-01-01

    Diffusion barrier research was focussed on lowering the chemical reactivity of amorphous thin films on silicon. An additional area of concern is the reaction with metal overlays such as aluminum, silver, and gold. Gold was included to allow for technology transfer to gallium arsenide PV cells. Amorphous tungsten nitride films have shown much promise. Stability to annealing temperatures of 700, 800, and 550 C were achieved for overlays of silver, gold, and aluminum, respectively. The lower results for aluminum were not surprising because there is an eutectic that can form at a lower temperature. It seems that titanium and zirconium will remove the nitrogen from a tungsten nitride amorphous film and render it unstable. Other variables of research interest were substrate bias and base pressure during sputtering.

  4. Transverse and longitudinal vibrations in amorphous silicon

    NASA Astrophysics Data System (ADS)

    Beltukov, Y. M.; Fusco, C.; Tanguy, A.; Parshin, D. A.

    2015-12-01

    We show that harmonic vibrations in amorphous silicon can be decomposed to transverse and longitudinal components in all frequency range even in the absence of the well defined wave vector q. For this purpose we define the transverse component of the eigenvector with given ω as a component, which does not change the volumes of Voronoi cells around atoms. The longitudinal component is the remaining orthogonal component. We have found the longitudinal and transverse components of the vibrational density of states for numerical model of amorphous silicon. The vibrations are mostly transverse below 7 THz and above 15 THz. In the frequency interval in between the vibrations have a longitudinal nature. Just this sudden transformation of vibrations at 7 THz from almost transverse to almost longitudinal ones explains the prominent peak in the diffusivity of the amorphous silicon just above 7 THz.

  5. Amorphous/epitaxial superlattice for thermoelectric application

    NASA Astrophysics Data System (ADS)

    Ishida, Akihiro; Thao, Hoang Thi Xuan; Shibata, Mamoru; Nakashima, Seisuke; Tatsuoka, Hirokazu; Yamamoto, Hidenari; Kinoshita, Yohei; Ishikiriyama, Mamoru; Nakamura, Yoshiaki

    2016-08-01

    An amorphous/epitaxial superlattice system is proposed for application to thermoelectric devices, and the superlattice based on a PbGeTeS system was prepared by the alternate deposition of PbS and GeTe using a hot wall epitaxy technique. The structure was analyzed by high-resolution transmission electron microscopy (HRTEM) and X-ray analysis, and it was found that the superlattice consists of an epitaxial PbTe-based layer and a GeS-based amorphous layer by the reconstruction of the constituents. A reduction in thermal conductivity due to the amorphous/epitaxial system was confirmed by a 2ω method. Electrical and thermoelectric properties were measured for the samples.

  6. Measuring strain distributions in amorphous materials

    NASA Astrophysics Data System (ADS)

    Poulsen, Henning F.; Wert, John A.; Neuefeind, Jörg; Honkimäki, Veijo; Daymond, Mark

    2005-01-01

    A number of properties of amorphous materials including fatigue, fracture and component performance are governed by the magnitude of strain fields around inhomogeneities such as inclusions, voids and cracks. At present, localized strain information is only available from surface probes such as optical or electron microscopy. This is unfortunate because surface and bulk characteristics in general differ. Hence, to a large extent, the assessment of strain distributions relies on untested models. Here we present a universal diffraction method for characterizing bulk stress and strain fields in amorphous materials and demonstrate its efficacy by work on a material of current interest in materials engineering: a bulk metallic glass. The macroscopic response is shown to be less stiff than the atomic next-neighbour bonds because of structural rearrangements at the scale of 4-10 Å. The method is also applicable to composites comprising an amorphous matrix and crystalline inclusions.

  7. IUE observations of amorphous hot galaxies

    NASA Technical Reports Server (NTRS)

    Lamb, S. A.; Hjellming, M. S.; Gallagher, J. S., III; Hunter, D. A.

    1985-01-01

    Blue amorphous galaxies are star-forming, irregularlike systems which lack the spatially distinct OB stellar groups that are characteristic of most late-type galaxies. In order to better understand the nature of star-formation processes in these unusual galaxies, short-wavelength IUE spectra of the amorphous galaxies NGC 1705 and NGC 1800 have been obtained. It is found that NGC 1705 contains a normal mix of OB stars, which is consistent with the nearly constant recent star-formation rate inferred from new optical data. NGC 1800 is likely to have similar properties, and blue galaxies with amorphous structures thus do not show evidence for anomalies in stellar populations. The UV spectra of these galaxies and a variety of other hot extragalactic stellar systems in fact have similar characteristics, which suggests OB stellar populations are often homogeneous in their properties.

  8. Enthalpy of crystallization of amorphous yttrium oxide

    SciTech Connect

    Reznitskii, L.A.

    1988-02-01

    Measurements have been made on the enthalpies of crystallization of amorphous Fe/sub 2/O/sub 3/ and Y/sub 3/Fe/sub 5/O/sub 12/ from amorphous Fe/sub 2/O/sub 3/ and Y/sub 2/O/sub 3/ as determined by the DSC method. The heat of crystallization for Y/sub 2/O/sub 3am/ does not make itself felt on the heating thermogram, in contrast to that for Fe/sub 2/O/sub 3/, evidently because it is spread out over a wide temperature range, so it is difficult to measure. One can combine thermochemical equations to calculate the enthalpy of crystallization for amorphous yttrium oxide as ..delta..H = -24.9 kJ/mole.

  9. The Phagocytosis and Toxicity of Amorphous Silica

    PubMed Central

    Costantini, Lindsey M.; Gilberti, Renée M.; Knecht, David A.

    2011-01-01

    Background Inhalation of crystalline silica is known to cause an inflammatory reaction and chronic exposure leads to lung fibrosis and can progress into the disease, silicosis. Cultured macrophages bind crystalline silica particles, phagocytose them, and rapidly undergo apoptotic and necrotic death. The mechanism by which particles are bound and internalized and the reason particles are toxic is unclear. Amorphous silica has been considered to be a less toxic form, but this view is controversial. We compared the uptake and toxicity of amorphous silica to crystalline silica. Methodology/Principal Findings Amorphous silica particles are phagocytosed by macrophage cells and a single internalized particle is capable of killing a cell. Fluorescent dextran is released from endo-lysosomes within two hours after silica treatment and Caspase-3 activation occurs within 4 hours. Interestingly, toxicity is specific to macrophage cell lines. Other cell types are resistant to silica particle toxicity even though they internalize the particles. The large and uniform size of the spherical, amorphous silica particles allowed us to monitor them during the uptake process. In mCherry-actin transfected macrophages, actin rings began to form 1-3 minutes after silica binding and the actin coat disassembled rapidly following particle internalization. Pre-loading cells with fluorescent dextran allowed us to visualize the fusion of phagosomes with endosomes during internalization. These markers provided two new ways to visualize and quantify particle internalization. At 37°C the rate of amorphous silica internalization was very rapid regardless of particle coating. However, at room temperature, opsonized silica is internalized much faster than non-opsonized silica. Conclusions/Significance Our results indicate that amorphous and crystalline silica are both phagocytosed and both toxic to mouse alveolar macrophage (MH-S) cells. The pathway leading to apoptosis appears to be similar in both

  10. Cooling of hot electrons in amorphous silicon

    SciTech Connect

    Vanderhaghen, R.; Hulin, D.; Cuzeau, S.; White, J.O.

    1997-07-01

    Measurements of the cooling rate of hot carriers in amorphous silicon are made with a two-pump, one-probe technique. The experiment is simulated with a rate-equation model describing the energy transfer between a population of hot carriers and the lattice. An energy transfer rate proportional to the temperature difference is found to be consistent with the experimental data while an energy transfer independent of the temperature difference is not. This contrasts with the situation in crystalline silicon. The measured cooling rates are sufficient to explain the difficulty in observing avalanche effects in amorphous silicon.

  11. Ion bombardment and disorder in amorphous silicon

    SciTech Connect

    Sidhu, L.S.; Gaspari, F.; Zukotynski, S.

    1997-07-01

    The effect of ion bombardment during growth on the structural and optical properties of amorphous silicon are presented. Two series of films were deposited under electrically grounded and positively biased substrate conditions. The biased samples displayed lower growth rates and increased hydrogen content relative to grounded counterparts. The film structure was examined using Raman spectroscopy. The transverse optic like phonon band position was used as a parameter to characterize network order. Biased samples displayed an increased order of the amorphous network relative to grounded samples. Furthermore, biased samples exhibited a larger optical gap. These results are correlated and attributed to reduced ion bombardment effects.

  12. Amorphous Insulator Films With Controllable Properties

    NASA Technical Reports Server (NTRS)

    Alterovitz, Samuel A.; Warner, Joseph D.; Liu, David C.; Pouch, John J.

    1987-01-01

    In experiments described in report, amorphous hydrogenated carbon films grown at room temperature by low-frequency plasma deposition, using methane or butane gas. Films have unique array of useful properties; (a) adhere to wide variety of materials; (b) contain only carbon and hydrogen; (c) smooth and free of pinholes; (d) resistant to attack by moisture and chemicals; and (e) have high electric-breakdown strength and electrical resistivity. Two of optical properties and hardness of this film controlled by deposition conditions. Amorphous a-C:H and BN films used for hermetic sealing and protection of optical, electronic, magnetic, or delicate mechanical systems, and for semiconductor field dielectrics.

  13. Short range order in amorphous polycondensates

    SciTech Connect

    Lamers, C.; Richter, D.; Schweika, W.; Batoulis, J.; Sommer, K.; Cable, J.W.; Shapiro, S.M.

    1992-12-01

    The static coherent structure factors S(Q) of the polymer glass Bisphenol-A-Polycarbonate and its chemical variation Bisphenol-A- Polyctherkctone- both in differently deuterated versions- have been measured by spin polarized neutron scattering. The method of spin polarization analysis provided an experimental separation of coherent and incoherent scattering and a reliable intensity calibration. Results are compared to structure factors calculated for model structures which were obtained by ``amorphous cell`` computer simulations. In general reasonable agreement is found between experiment and simulation; however, certain discrepancies hint at an insufficient structural relaxation in the amorphous cell method. 15 refs, 1 fig, 1 tab.

  14. Superhydrophobic amorphous carbon/carbon nanotube nanocomposites

    NASA Astrophysics Data System (ADS)

    Han, Z. J.; Tay, B. K.; Shakerzadeh, M.; Ostrikov, K.

    2009-06-01

    Superhydrophobic amorphous carbon/carbon nanotube nanocomposites are fabricated by plasma immersion ion implantation with carbon nanotube forests as a template. The microstructure of the fabricated nanocomposites shows arrays of carbon nanotubes capped with amorphous carbon nanoparticles. Contact angle measurements show that both advancing and receding angles close to 180° can be achieved on the nanocomposites. The fabrication here does not require patterning of carbon nanotubes or deposition of conformal coatings with low surface energy, which are usually involved in conventional approaches for superhydrophobic surfaces. The relationship between the observed superhydrophobicity and the unique microstructure of the nanocomposites is discussed.

  15. Production feature of soft magnetic amorphous alloys

    NASA Astrophysics Data System (ADS)

    Tyagunov, A. G.; Baryshev, E. E.; Shmakova, K. Yu

    2016-06-01

    Methods for making nanocrystalline alloys have been discussed. Temperature dependences of the surface tension (σ), electric resistivity (ρ), magnetic susceptibility (χ) and kinematic viscosity (ν) have been obtained. Comparison of the properties of amorphous ribbons obtained by the pilot and serial technologies has been conducted. Science-based technology of multi-component alloy smelting makes it possible to prepare equilibrium smelt, the structure of which has a significant effect on the properties of the amorphous ribbon before spinning and kinetics of its crystallization has been offered.

  16. Nanoindentation-induced amorphization in silicon carbide

    NASA Astrophysics Data System (ADS)

    Szlufarska, Izabela; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya

    2004-07-01

    The nanoindentation-induced amorphization in SiC is studied using molecular dynamics simulations. The load-displacement response shows an elastic shoulder followed by a plastic regime consisting of a series of load drops. Analyses of bond angles, local pressure, and shear stress, and shortest-path rings show that these drops are related to dislocation activities under the indenter. We show that amorphization is driven by coalescence of dislocation loops and that there is a strong correlation between load-displacement response and ring distribution.

  17. EXAFS Studies of Amorphous MoGe

    NASA Astrophysics Data System (ADS)

    Boyce, J. B.; Carter, W. L.; Geballe, T. H.; Claeson, T.

    1982-06-01

    Extended X-ray Absorption Fine Structure of amorphous and crystalline Mo-Ge samples sputter deposited on glass or kapton substrates was studied. Small local distortions were found in a substitutional b.c.c. Mo rich sample. A coordination in the range 5-7 and Ge-Mo distance of 2.65 A were estimated for an amorphous, intermediate composition Mo-Ge sample. The lack of superconductivity of some samples deposited on kapton was correlated to the presence of oxygen in the material.

  18. Thermal conductivity of sputtered amorphous Ge films

    SciTech Connect

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka

    2014-02-15

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids.

  19. New Amorphous Silicon Alloy Systems

    NASA Astrophysics Data System (ADS)

    Kapur, Mridula N.

    1990-01-01

    The properties of hydrogenated amorphous silicon (a-Si:H) have been modified by alloying with Al, Ga and S respectively. The Al and Ga alloys are in effect quaternary alloys as they were fabricated in a carbon-rich discharge. The alloys were prepared by the plasma assisted chemical vapor deposition (PACVD) method. This method has several advantages, the major one being the relatively low defect densities of the resulting materials. The PACVD system used to grow the alloy films was designed and constructed in the laboratory. It was first tested with known (a-Si:H and a-Si:As:H) materials. Thus, it was established that device quality alloy films could be grown with the home-made PACVD setup. The chemical composition of the alloys was characterized by secondary ion mass spectrometry (SIMS), and electron probe microanalysis (EPMA). The homogeneous nature of hydrogen distribution in the alloys was established by SIMS depth profile analysis. A quantitative analysis of the bulk elemental content was carried out by EPMA. The analysis indicated that the alloying element was incorporated in the films more efficiently at low input gas concentrations than at the higher concentrations. A topological model was proposed to explain the observed behavior. The optical energy gap of the alloys could be varied in the 0.90 to 1.92 eV range. The Al and Ga alloys were low band gap materials, whereas alloying with S had the effect of widening the energy gap. It was observed that although the Si-Al and Si-Ga alloys contained significant amounts of C and H, the magnitude of the energy gap was determined by the metallic component. The various trends in optical properties could be related to the binding characteristics of the respective alloy systems. A quantitative explanation of the results was provided by White's tight binding model. The dark conductivity-temperature dependence of the alloys was examined. A linear dependence was observed for the Al and Ga systems. Electronic conduction in

  20. Two species/nonideal solution model for amorphous/amorphous phase transitions

    SciTech Connect

    Moynihan, C.T.

    1997-12-31

    A simple macroscopic thermodynamic model for first order transitions between two amorphous phases in a one component liquid is reviewed, augmented and evaluated. The model presumes the existence in the liquid of two species, whose concentrations are temperature and pressure dependent and which form a solution with large, positive deviations from ideality. Application of the model to recent data indicates that water can undergo an amorphous/amorphous phase transition below a critical temperature T{sub c} of 217K and above a critical pressure P{sub c} of 380 atm.

  1. MCNP Modeling Results for Location of Buried TRU Waste Drums

    NASA Astrophysics Data System (ADS)

    Steinman, D. K.; Schweitzer, J. S.

    2006-05-01

    In the 1960's, fifty-five gallon drums of TRU waste were buried in shallow pits on remote U.S. Government facilities such as the Idaho National Engineering Laboratory (now split into the Idaho National Laboratory and the Idaho Completion Project [ICP]). Subsequently, it was decided to remove the drums and the material that was in them from the burial pits and send the material to the Waste Isolation Pilot Plant in New Mexico. Several technologies have been tried to locate the drums non-intrusively with enough precision to minimize the chance for material to be spread into the environment. One of these technologies is the placement of steel probe holes in the pits into which wireline logging probes can be lowered to measure properties and concentrations of material surrounding the probe holes for evidence of TRU material. There is also a concern that large quantities of volatile organic compounds (VOC) are also present that would contaminate the environment during removal. In 2001, the Idaho National Engineering and Environmental Laboratory (INEEL) built two pulsed neutron wireline logging tools to measure TRU and VOC around the probe holes. The tools are the Prompt Fission Neutron (PFN) and the Pulsed Neutron Gamma (PNG), respectively. They were tested experimentally in surrogate test holes in 2003. The work reported here estimates the performance of the tools using Monte-Carlo modelling prior to field deployment. A MCNP model was constructed by INEEL personnel. It was modified by the authors to assess the ability of the tools to predict quantitatively the position and concentration of TRU and VOC materials disposed around the probe holes. The model was used to simulate the tools scanning the probe holes vertically in five centimetre increments. A drum was included in the model that could be placed near the probe hole and at other locations out to forty-five centimetres from the probe-hole in five centimetre increments. Scans were performed with no chlorine in the

  2. Reconstruction of buried objects embedded in circular opaque structures

    NASA Astrophysics Data System (ADS)

    Persico, Raffaele; Gennarelli, Gianluca; Soldovieri, Francesco

    2014-05-01

    This contribution deals with the ground penetrating radar imaging of targets embedded in a visually opaque circular structure. The problem has practical relevance in civil engineering and archeological prospections, where structures of interest such as columns or pillars may have to be inspected in non-invasive way in order to detect the possible presence of anomalies (e.g. cracks, water infiltrations, and so on). In this framework, we investigate the possibility to inspect the circular region of interest thanks to a radar system composed by two antennas that are in contact with the structure and rotate simultaneously around it in order to illuminate and measure the field scattered by buried objects from multiple directions. Two different measurement strategies are examined. The first one is the multimonostatic configuration where the backscattered signal is collected by the transmitting antenna itself, as it moves along the circular observation line. The second acquisition strategy is the multibistatic one, with the transmitting and receiving antennas shifted by a constant angular offset of ninety degrees as they move around the column. From the mathematical viewpoint, the imaging problem is formulated as a linear inverse scattering one holding under Born approximation [1]. Furthermore, the Green's function of a homogeneous medium [2] is used to simplify the evaluation of the kernel of the integral equation. The inverse problem is then solved via the Truncated Singular Value Decomposition algorithm [3] in order to obtain a regularized solution. Tomographic reconstructions based on full-wave synthetic data generated by the Finite Difference Time Domain code GPRmax2D [4] are shown to assess the effectiveness of the reconstruction process. REFERENCES [1] W. C. Chew, Waves and fields in inhomogeneous media, IEEE Press, 1995. [2] R. F. Harrington, Time harmonic electromagnetic waves, McGraw-Hill, New York, USA, 1961. [3] M. Bertero and P. Boccacci, Introduction to

  3. Amorphization and nanocrystallization of silcon under shock compression

    SciTech Connect

    Remington, B. A.; Wehrenberg, C. E.; Zhao, S.; Hahn, E. N.; Kad, B.; Bringa, E. M.; Meyers, M. A.

    2015-11-06

    High-power, short-duration, laser-driven, shock compression and recovery experiments on [001] silicon unveiled remarkable structural changes above a pressure threshold. Two distinct amorphous regions were identified: (a) a bulk amorphous layer close to the surface and (b) amorphous bands initially aligned with {111} slip planes. Further increase of the laser energy leads to the re-crystallization of amorphous silicon into nanocrystals with high concentration of nano-twins. This amorphization is produced by the combined effect of high magnitude hydrostatic and shear stresses under dynamic shock compression. Shock-induced defects play a very important role in the onset of amorphization. Calculations of the free energy changes with pressure and shear, using the Patel-Cohen methodology, are in agreement with the experimental results. Molecular dynamics simulation corroborates the amorphization, showing that it is initiated by the nucleation and propagation of partial dislocations. As a result, the nucleation of amorphization is analyzed qualitatively by classical nucleation theory.

  4. Inverted amorphous silicon solar cell utilizing cermet layers

    DOEpatents

    Hanak, Joseph J.

    1979-01-01

    An amorphous silicon solar cell incorporating a transparent high work function metal cermet incident to solar radiation and a thick film cermet contacting the amorphous silicon opposite to said incident surface.

  5. Amorphization of embedded Cu nanocrystals by ion irradiation

    NASA Astrophysics Data System (ADS)

    Johannessen, B.; Kluth, P.; Llewellyn, D. J.; Foran, G. J.; Cookson, D. J.; Ridgway, M. C.

    2007-02-01

    While bulk crystalline elemental metals cannot be amorphized by ion irradiation in the absence of chemical impurities, the authors demonstrate that finite-size effects enable the amorphization of embedded Cu nanocrystals. The authors form and compare the atomic-scale structure of the polycrystalline, nanocrystalline, and amorphous phases, present an explanation for the extreme sensitivity to irradiation exhibited by nanocrystals, and show that low-temperature annealing is sufficient to return amorphized material to the crystalline form.

  6. Plasma deposition of amorphous metal alloys

    DOEpatents

    Hays, A.K.

    1979-07-18

    Amorphous metal alloy coatings are plasma-deposited by dissociation of vapors of organometallic compounds and metalloid hydrides in the presence of a reducing gas, using a glow discharge. Tetracarbonylnickel, phosphine, and hydrogen constitute a typical reaction mixture of the invention, yielding a NiPC alloy.

  7. Plasma deposition of amorphous metal alloys

    DOEpatents

    Hays, Auda K.

    1986-01-01

    Amorphous metal alloy coatings are plasma-deposited by dissociation of vapors of organometallic compounds and metalloid hydrides in the presence of a reducing gas, using a glow discharge. Tetracarbonylnickel, phosphine, and hydrogen constitute a typical reaction mixture of the invention, yielding a NiPC alloy.

  8. Ion-assisted recrystallization of amorphous silicon

    NASA Astrophysics Data System (ADS)

    Priolo, F.; Spinella, C.; La Ferla, A.; Rimini, E.; Ferla, G.

    1989-12-01

    Our recent work on ion-beam-assisted epitaxial growth of amorphous Si layers on single crystal substrates is reviewed. The planar motion of the crystal-amorphous interface was monitored in situ, during irradiations, by transient reflectivity measurements. This technique allows the measurement of the ion-induced growth rate with a very high precision. We have observed that this growth rate scales linearly with the number of displacements produced at the crystal-amorphous interface by the impinging ions. Moreover the regrowth onto <100> oriented substrates is a factor of ≈ 4 faster with respect to that on <111> substrates. Impurities dissolved in the amorphous layer influence the kinetics of recrystallization. For instance, dopants such as As, B and P enhance the ion-induced growth rate while oxygen has the opposite effect. The dependence of the rate on impurity concentration is however less strong with respect to pure thermal annealing. For instance, an oxygen concentration of 1 × 1021 / cm3 decreases the ion-induced growth rate by a factor of ≈ 3; this same concentration would have decreased the rate of pure thermal annealing by more than 4 orders of magnitude. The reduced effects of oxygen during ion-beam crystallization allow the regrowth of deposited Si layers despite the presence of a high interfacial oxygen content. The process is investigated in detail and its possible application to the microelectronic technology is discussed.

  9. Athermal nonlinear elastic constants of amorphous solids.

    PubMed

    Karmakar, Smarajit; Lerner, Edan; Procaccia, Itamar

    2010-08-01

    We derive expressions for the lowest nonlinear elastic constants of amorphous solids in athermal conditions (up to third order), in terms of the interaction potential between the constituent particles. The effect of these constants cannot be disregarded when amorphous solids undergo instabilities such as plastic flow or fracture in the athermal limit; in such situations the elastic response increases enormously, bringing the system much beyond the linear regime. We demonstrate that the existing theory of thermal nonlinear elastic constants converges to our expressions in the limit of zero temperature. We motivate the calculation by discussing two examples in which these nonlinear elastic constants play a crucial role in the context of elastoplasticity of amorphous solids. The first example is the plasticity-induced memory that is typical to amorphous solids (giving rise to the Bauschinger effect). The second example is how to predict the next plastic event from knowledge of the nonlinear elastic constants. Using the results of our calculations we derive a simple differential equation for the lowest eigenvalue of the Hessian matrix in the external strain near mechanical instabilities; this equation predicts how the eigenvalue vanishes at the mechanical instability and the value of the strain where the mechanical instability takes place. PMID:20866874

  10. Athermal nonlinear elastic constants of amorphous solids

    NASA Astrophysics Data System (ADS)

    Karmakar, Smarajit; Lerner, Edan; Procaccia, Itamar

    2010-08-01

    We derive expressions for the lowest nonlinear elastic constants of amorphous solids in athermal conditions (up to third order), in terms of the interaction potential between the constituent particles. The effect of these constants cannot be disregarded when amorphous solids undergo instabilities such as plastic flow or fracture in the athermal limit; in such situations the elastic response increases enormously, bringing the system much beyond the linear regime. We demonstrate that the existing theory of thermal nonlinear elastic constants converges to our expressions in the limit of zero temperature. We motivate the calculation by discussing two examples in which these nonlinear elastic constants play a crucial role in the context of elastoplasticity of amorphous solids. The first example is the plasticity-induced memory that is typical to amorphous solids (giving rise to the Bauschinger effect). The second example is how to predict the next plastic event from knowledge of the nonlinear elastic constants. Using the results of our calculations we derive a simple differential equation for the lowest eigenvalue of the Hessian matrix in the external strain near mechanical instabilities; this equation predicts how the eigenvalue vanishes at the mechanical instability and the value of the strain where the mechanical instability takes place.

  11. Metal electrode for amorphous silicon solar cells

    DOEpatents

    Williams, Richard

    1983-01-01

    An amorphous silicon solar cell having an N-type region wherein the contact to the N-type region is composed of a material having a work function of about 3.7 electron volts or less. Suitable materials include strontium, barium and magnesium and rare earth metals such as gadolinium and yttrium.

  12. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Kaplan, S.N.; Perez-Mendez, V.

    1992-05-26

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n-type, intrinsic, p-type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography. 18 figs.

  13. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Kaplan, Selig N.; Perez-Mendez, Victor

    1992-01-01

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n type, intrinsic, p type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography.

  14. The Electronic Structure of Amorphous Carbon Nanodots.

    PubMed

    Margraf, Johannes T; Strauss, Volker; Guldi, Dirk M; Clark, Timothy

    2015-06-18

    We have studied hydrogen-passivated amorphous carbon nanostructures with semiempirical molecular orbital theory in order to provide an understanding of the factors that affect their electronic properties. Amorphous structures were first constructed using periodic calculations in a melt/quench protocol. Pure periodic amorphous carbon structures and their counterparts doped with nitrogen and/or oxygen feature large electronic band gaps. Surprisingly, descriptors such as the elemental composition and the number of sp(3)-atoms only influence the electronic structure weakly. Instead, the exact topology of the sp(2)-network in terms of effective conjugation defines the band gap. Amorphous carbon nanodots of different structures and sizes were cut out of the periodic structures. Our calculations predict the occurrence of localized electronic surface states, which give rise to interesting effects such as amphoteric reactivity and predicted optical band gaps in the near-UV/visible range. Optical and electronic gaps display a dependence on particle size similar to that of inorganic colloidal quantum dots. PMID:25731776

  15. Novel As-doped, As and N-codoped carbon nanotubes as highly active and durable electrocatalysts for O2 reduction in alkaline medium

    NASA Astrophysics Data System (ADS)

    Liu, Ziwu; Li, Meng; Wang, Fang; Wang, Quan-De

    2016-02-01

    To develop more efficient metal-free cathode electrocatalysts for fuel cells, novel arsenic (As)-doped, As and N-codoped carbon nanotubes are synthesized by chemical vapor deposition in this work. The as-prepared As-containing carbon nanotubes exhibit significantly enhanced activity and long-term durability for the oxygen reduction reaction (ORR) in alkaline medium, indicating that the doping of As or codoping As with other heteroatoms into carbon matrix could improve the ORR activity of carbon materials due to the changes in electronic and physical properties of carbon nanotubes evidenced by density functional theory calculations. Moreover, As-containing carbon nanotubes also display much better methanol tolerance, showing a good potential application for future fuel cells.

  16. Molecular dynamics simulation of amorphous indomethacin.

    PubMed

    Xiang, Tian-Xiang; Anderson, Bradley D

    2013-01-01

    Molecular dynamics (MD) simulations have been conducted using an assembly consisting of 105 indomethacin (IMC) molecules and 12 water molecules to investigate the underlying dynamic (e.g., rotational and translational diffusivities and conformation relaxation rates) and structural properties (e.g., conformation, hydrogen-bonding distributions, and interactions of water with IMC) of amorphous IMC. These properties may be important in predicting physical stability of this metastable material. The IMC model was constructed using X-ray diffraction data with the force-field parameters mostly assigned by analogy with similar groups in Amber-ff03 and atomic charges calculated with the B3LYP/ccpVTZ30, IEFPCM, and RESP models. The assemblies were initially equilibrated in their molten state and cooled through the glass transition temperature to form amorphous solids. Constant temperature dynamic runs were then carried out above and below the T(g) (i.e., at 600 K (10 ns), 400 K (350 ns), and 298 K (240 ns)). The density (1.312 ± 0.003 g/cm(3)) of the simulated amorphous solid at 298 K was close to the experimental value (1.32 g/cm(3)) while the estimated T(g) (384 K) was ~64 degrees higher than the experimental value (320 K) due to the faster cooling rate. Due to the hindered rotation of its amide bond, IMC can exist in different diastereomeric states. Different IMC conformations were sufficiently sampled in the IMC melt or vapor, but transitions occurred rarely in the glass. The hydrogen-bonding patterns in amorphous IMC are more complex in the amorphous state than in the crystalline polymorphs. Carboxylic dimers that are dominant in α- and γ-crystals were found to occur at a much lower probability in the simulated IMC glasses while hydrogen-bonded IMC chains were more easily identified patterns in the simulated amorphous solids. To determine molecular diffusivity, a novel analytical method is proposed to deal with the non-Einsteinian behavior, in which the temporal

  17. Strain relaxation in buried strained layers by mixture of single and dipolar dislocation arrays

    NASA Astrophysics Data System (ADS)

    Jin, Z.; Yang, S.; Ma, C.; Liu, S.

    1999-06-01

    The strain relaxation in buried strained layers is investigated using an elastic continuum model. The mixture of single dislocations residing at the substrate/strained layer interface (lower interface) and dipolar dislocations in which one is at the lower interface and the other at the strained layer/capping layer interface (upper interface), is proposed. In the mixture, the dislocation distributions are denoted by a parameter which is the ratio of the density of misfit dislocations at the upper interface to that at the lower interface. In a buried strained layer, relaxation of mean strain occurs by introduction of two orthogonal arrays of mixture of single and dipolar dislocations. Considering both the free surface and interactions between dislocations, the total elastic energy per unit area of buried strained layer containing two orthogonal arrays of mixture of single and dipolar dislocations is calculated. The energy is dependent on the misfit dislocation distributions. On energy minimization considerations, the expression of the misfit dislocation distributions in a buried strained layer with arbitrary strain relaxation and capping layer thickness is derived. It is demonstrated that the strain is initially relaxed by the single misfit dislocations and relaxed by the mixture of single and dipolar misfit dislocations in the final stage of strain relaxation in many buried layers of practical interest.

  18. Role and development of soil parameters for seismic responses of buried lifelines

    SciTech Connect

    Wang, L.R.L.

    1983-01-01

    Buried lifelines, e.g. oil, gas, water and sewer pipelines have been damaged heavily in recent earthquakes such as 1971 San Fernando Earthquake, in U.S.A., 1976 Tangshan Earthquake, in China, and 1978 MiyagiKen-Oki Earthquake, in Japan, among others. Researchers on the seismic performance of these buried lifelines have been initiated in the United States and many other countries. Various analytical models have been proposed. However, only limited experimental investigations are available. The sources of earthquake damage to buried lifelines include landslide, tectonic uplift-subsidence, soil liquefaction, fault displacement and ground shaking (effects of wave propagation). This paper is concerned with the behavior of buried lifeline systems subjected to surface faulting and ground shaking. The role and development of soil parameters that significantly influence the seismic responses are discussed. The scope of this paper is to examine analytically the influence of various soil and soilstructure interaction parameters to the seismic responses of buried pipelines, to report the currently available physical data of these and related parameters for immediate applications, and to describe the experiments to obtain additional information on soil resistant characteristics to longitudinal pipe motions.

  19. Analytical model of LDMOS with a single step buried oxide layer

    NASA Astrophysics Data System (ADS)

    Yuan, Song; Duan, Baoxing; Cao, Zhen; Guo, Haijun; Yang, Yintang

    2016-09-01

    In this paper, a two-dimensional analytical model is established for the Single-Step Buried Oxide SOI structure proposed by the authors. Based on the two-dimensional Poisson equation, the analytic expression of the surface electric field and potential distributions for the device is achieved. In the SBOSOI (Single-Step Buried Oxide Silicon On Insulator) structure, the buried oxide layer thickness changes stepwise along the drift region, and the electric field in the oxide layer also varies with the different buried oxide layer thickness. These variations will modulate the surface electric field distribution through the electric field modulation effects, which makes the surface electric field distribution more uniform. As a result, the breakdown voltage of the device is improved by 60% compared with the conventional SOI structure. To verify the accuracy of the analytical model, the device simulation software ISE TCAD is utilized, the analytical values are in good agreement with the simulation results by the simulation software. The results verified the established two-dimensional analytical model for SBOSOI structure is valid, and it also illustrates the breakdown voltage enhancement by the electric field modulation effect sufficiently. The established analytical models will provide the physical and mathematical basis for further analysis of the new power devices with the patterned buried oxide layer.

  20. Kelvin probe characterization of buried graphitic microchannels in single-crystal diamond

    SciTech Connect

    Bernardi, E. Battiato, A.; Olivero, P.; Vittone, E.; Picollo, F.

    2015-01-14

    In this work, we present an investigation by Kelvin Probe Microscopy (KPM) of buried graphitic microchannels fabricated in single-crystal diamond by direct MeV ion microbeam writing. Metal deposition of variable-thickness masks was adopted to implant channels with emerging endpoints and high temperature annealing was performed in order to induce the graphitization of the highly-damaged buried region. When an electrical current was flowing through the biased buried channel, the structure was clearly evidenced by KPM maps of the electrical potential of the surface region overlying the channel at increasing distances from the grounded electrode. The KPM profiling shows regions of opposite contrast located at different distances from the endpoints of the channel. This effect is attributed to the different electrical conduction properties of the surface and of the buried graphitic layer. The model adopted to interpret these KPM maps and profiles proved to be suitable for the electronic characterization of buried conductive channels, providing a non-invasive method to measure the local resistivity with a micrometer resolution. The results demonstrate the potential of the technique as a powerful diagnostic tool to monitor the functionality of all-carbon graphite/diamond devices to be fabricated by MeV ion beam lithography.

  1. Kelvin probe characterization of buried graphitic microchannels in single-crystal diamond

    NASA Astrophysics Data System (ADS)

    Bernardi, E.; Battiato, A.; Olivero, P.; Picollo, F.; Vittone, E.

    2015-01-01

    In this work, we present an investigation by Kelvin Probe Microscopy (KPM) of buried graphitic microchannels fabricated in single-crystal diamond by direct MeV ion microbeam writing. Metal deposition of variable-thickness masks was adopted to implant channels with emerging endpoints and high temperature annealing was performed in order to induce the graphitization of the highly-damaged buried region. When an electrical current was flowing through the biased buried channel, the structure was clearly evidenced by KPM maps of the electrical potential of the surface region overlying the channel at increasing distances from the grounded electrode. The KPM profiling shows regions of opposite contrast located at different distances from the endpoints of the channel. This effect is attributed to the different electrical conduction properties of the surface and of the buried graphitic layer. The model adopted to interpret these KPM maps and profiles proved to be suitable for the electronic characterization of buried conductive channels, providing a non-invasive method to measure the local resistivity with a micrometer resolution. The results demonstrate the potential of the technique as a powerful diagnostic tool to monitor the functionality of all-carbon graphite/diamond devices to be fabricated by MeV ion beam lithography.

  2. Control of diffusion of implanted boron in preamorphized Si: Elimination of interstitial defects at the amorphous-crystal interface

    NASA Astrophysics Data System (ADS)

    Roth, E. G.; Holland, O. W.; Thomas, D. K.

    1999-02-01

    Transient-enhanced diffusion (TED) during thermal annealing of ion-implanted B in Si is well established and attributed to the ion-induced, excess interstitials. On the other hand, the mechanism to account for TED of B in preamorphized (PA) Si remains unclear. Enhanced diffusion of the B persists in regrown layers even though the ion-induced interstitial defects responsible for TED in B+-only implanted Si are eliminated following regrowth. To test the hypothesis that TED in PA Si results from the "excess" interstitial-type defects below the amorphous-crystalline (a-c) interface, a buried PA layer has been recrystallized from the surface inward to the SiO2 interface of silicon-on-insulator material to eliminate all possible sources of excess interstitials. The effect on B diffusion and the role of the residual interstitial-type defects will be discussed.

  3. Fabricating amorphous silicon solar cells by varying the temperature _of the substrate during deposition of the amorphous silicon layer

    DOEpatents

    Carlson, David E.

    1982-01-01

    An improved process for fabricating amorphous silicon solar cells in which the temperature of the substrate is varied during the deposition of the amorphous silicon layer is described. Solar cells manufactured in accordance with this process are shown to have increased efficiencies and fill factors when compared to solar cells manufactured with a constant substrate temperature during deposition of the amorphous silicon layer.

  4. GPR investigations in galleries buried inside a karstified limestone formation

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-04-01

    A large scientific program of geophysical investigations is presently performed inside the Low-Noise Underground Laboratory (Laboratoire Souterrain à Bas Bruit / LSBB, Rustrel, France) which is an decomissioned underground missile control center, buried in a karstified limestone formation. One of the goals of this project is the understanding of the water circulation inside the structure. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity. The dip is around 25 degrees and vertical faults locally affect the structure. The studied zone is located in south-eastern France (Provence) and is characterized by a mediterranean climate with long dry periods and strong, short events of rain. This phenomenon induces large variations of water content within the karstified limestone from dry to saturated conditions. Analysis of the spatial and temporal variations of the water flow in a karstified limestones needs to define the geological context and the adequate geophysical methods. GPR offers a good tradeoff between resolution and ease of use on one hand and investigation depth on the other hand. We present some GPR profiles which have been acquired in April 2008 after a quite long and strong period of rain, inducing a complete water saturation inside the karstified massif. We used several RAMAC shielded antennas from 100 to 500 MHz. The longest profile is around 600 m long, with a 20 cm spacing, running from a raw to a concrete gallery. These data sets are characterized by a very good signal to noise ratio and a signal penetration, up to 18 meters. Signal processing includes very low frequency filtering, amplitude compensation, keeping lateral relative attenuation and ringing suppression. Final sections includes migration and time to depth conversion or depth migration. The estimated

  5. Defect-induced solid state amorphization of molecular crystals

    NASA Astrophysics Data System (ADS)

    Lei, Lei; Carvajal, Teresa; Koslowski, Marisol

    2012-04-01

    We investigate the process of mechanically induced amorphization in small molecule organic crystals under extensive deformation. In this work, we develop a model that describes the amorphization of molecular crystals, in which the plastic response is calculated with a phase field dislocation dynamics theory in four materials: acetaminophen, sucrose, γ-indomethacin, and aspirin. The model is able to predict the fraction of amorphous material generated in single crystals for a given applied stress. Our results show that γ-indomethacin and sucrose demonstrate large volume fractions of amorphous material after sufficient plastic deformation, while smaller amorphous volume fractions are predicted in acetaminophen and aspirin, in agreement with experimental observation.

  6. Method and apparatus for increasing resistance of bipolar buried layer integrated circuit devices to single-event upsets

    NASA Technical Reports Server (NTRS)

    Zoutendyk, John A. (Inventor)

    1991-01-01

    Bipolar transistors fabricated in separate buried layers of an integrated circuit chip are electrically isolated with a built-in potential barrier established by doping the buried layer with a polarity opposite doping in the chip substrate. To increase the resistance of the bipolar transistors to single-event upsets due to ionized particle radiation, the substrate is biased relative to the buried layer with an external bias voltage selected to offset the built-in potential just enough (typically between about +0.1 to +0.2 volt) to prevent an accumulation of charge in the buried-layer-substrate junction.

  7. Atomic-scale disproportionation in amorphous silicon monoxide.

    PubMed

    Hirata, Akihiko; Kohara, Shinji; Asada, Toshihiro; Arao, Masazumi; Yogi, Chihiro; Imai, Hideto; Tan, Yongwen; Fujita, Takeshi; Chen, Mingwei

    2016-01-01

    Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regions. Nevertheless, the direct experimental observation is still missing. Here we report the amorphous structure characterized by angstrom-beam electron diffraction, supplemented by synchrotron X-ray scattering and computer simulations. In addition to the theoretically predicted amorphous silicon and silicon-dioxide clusters, suboxide-type tetrahedral coordinates are detected by angstrom-beam electron diffraction at silicon/silicon-dioxide interfaces, which provides compelling experimental evidence on the atomic-scale disproportionation of amorphous silicon monoxide. Eventually we develop a heterostructure model of the disproportionated silicon monoxide which well explains the distinctive structure and properties of the amorphous material. PMID:27172815

  8. The Structure and Properties of Amorphous Indium Oxide

    PubMed Central

    2015-01-01

    A series of In2O3 thin films, ranging from X-ray diffraction amorphous to highly crystalline, were grown on amorphous silica substrates using pulsed laser deposition by varying the film growth temperature. The amorphous-to-crystalline transition and the structure of amorphous In2O3 were investigated by grazing angle X-ray diffraction (GIXRD), Hall transport measurement, high resolution transmission electron microscopy (HRTEM), electron diffraction, extended X-ray absorption fine structure (EXAFS), and ab initio molecular dynamics (MD) liquid-quench simulation. On the basis of excellent agreement between the EXAFS and MD results, a model of the amorphous oxide structure as a network of InOx polyhedra was constructed. Mechanisms for the transport properties observed in the crystalline, amorphous-to-crystalline, and amorphous deposition regions are presented, highlighting a unique structure–property relationship. PMID:25678743

  9. Atomic-scale disproportionation in amorphous silicon monoxide

    PubMed Central

    Hirata, Akihiko; Kohara, Shinji; Asada, Toshihiro; Arao, Masazumi; Yogi, Chihiro; Imai, Hideto; Tan, Yongwen; Fujita, Takeshi; Chen, Mingwei

    2016-01-01

    Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regions. Nevertheless, the direct experimental observation is still missing. Here we report the amorphous structure characterized by angstrom-beam electron diffraction, supplemented by synchrotron X-ray scattering and computer simulations. In addition to the theoretically predicted amorphous silicon and silicon-dioxide clusters, suboxide-type tetrahedral coordinates are detected by angstrom-beam electron diffraction at silicon/silicon-dioxide interfaces, which provides compelling experimental evidence on the atomic-scale disproportionation of amorphous silicon monoxide. Eventually we develop a heterostructure model of the disproportionated silicon monoxide which well explains the distinctive structure and properties of the amorphous material. PMID:27172815

  10. Atomic-scale disproportionation in amorphous silicon monoxide

    NASA Astrophysics Data System (ADS)

    Hirata, Akihiko; Kohara, Shinji; Asada, Toshihiro; Arao, Masazumi; Yogi, Chihiro; Imai, Hideto; Tan, Yongwen; Fujita, Takeshi; Chen, Mingwei

    2016-05-01

    Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regions. Nevertheless, the direct experimental observation is still missing. Here we report the amorphous structure characterized by angstrom-beam electron diffraction, supplemented by synchrotron X-ray scattering and computer simulations. In addition to the theoretically predicted amorphous silicon and silicon-dioxide clusters, suboxide-type tetrahedral coordinates are detected by angstrom-beam electron diffraction at silicon/silicon-dioxide interfaces, which provides compelling experimental evidence on the atomic-scale disproportionation of amorphous silicon monoxide. Eventually we develop a heterostructure model of the disproportionated silicon monoxide which well explains the distinctive structure and properties of the amorphous material.

  11. Characterization of Poly-Amorphous Indomethacin by Terahertz Spectroscopy

    NASA Astrophysics Data System (ADS)

    Otsuka, Makoto; Nishizawa, Jun-ichi; Fukura, Naomi; Sasaki, Tetsuo

    2012-09-01

    Since the stability of amorphous solids of pharmaceuticals differs depending on the method of preparation, there are several solid-state chemical structures in amorphous solids, which like poly-amorphous solids might have different characteristics the same as in crystalline solids. However, it is not easy to identify the differences in solid-state characteristics between amorphous solids using conventional analytical methods, such as powder X-ray diffraction analysis, since all of the poly-amorphous solids had similar halo X-ray diffraction patterns. However, terahertz spectroscopy can distinguish the amorphous solids of indomethacin with different physicochemical properties, and is expected to provide a rapid and non-destructive qualitative analysis for the solid materials, it would be useful for the qualitative evaluation of amorphous solids in the pharmaceutical industry.

  12. Characterization of Poly-Amorphous Indomethacin by Terahertz Spectroscopy

    NASA Astrophysics Data System (ADS)

    Otsuka, Makoto; Nishizawa, Jun-ichi; Fukura, Naomi; Sasaki, Tetsuo

    2012-05-01

    Since the stability of amorphous solids of pharmaceuticals differs depending on the method of preparation, there are several solid-state chemical structures in amorphous solids, which like poly-amorphous solids might have different characteristics the same as in crystalline solids. However, it is not easy to identify the differences in solid-state characteristics between amorphous solids using conventional analytical methods, such as powder X-ray diffraction analysis, since all of the poly-amorphous solids had similar halo X-ray diffraction patterns. However, terahertz spectroscopy can distinguish the amorphous solids of indomethacin with different physicochemical properties, and is expected to provide a rapid and non-destructive qualitative analysis for the solid materials, it would be useful for the qualitative evaluation of amorphous solids in the pharmaceutical industry.

  13. Characterization of the Marquez Dome buried impact crater using gravity and magnetic data

    NASA Technical Reports Server (NTRS)

    Wong, A. M.; Reid, A. M.; Hall, S. A.; Sharpton, V. L.

    1993-01-01

    The buried impact crater, Marquez Dome, located in Leon County in east central Texas, is an approximately 15 km diameter structure whose central uplift is now partially exposed due to headward erosion of the post-impact cover. The central uplift is approximately 3 km in diameter and the rocks within it have been uplifted more than 1200 m above their regional level. The crater rim remains buried and previous attempts to determine its location have had to rely on seismic reflection data and geologic well logs. These attempts have been somewhat successful in mapping the extent of the disturbed zone around Marquez Dome, but more limited in their ability to image the shallow buried rim. In an attempt to define accurately the whole Marquez Dome structure and assist in the selection of drilling sites, a geophysical investigation involving gravity and magnetic data over the central uplift and the surrounding area has been undertaken.

  14. Buried-hill discoveries in Damintan depression of North China basin

    SciTech Connect

    Xiaoguang, T.; Zuan, H.

    1988-01-01

    The Damintan fault depression is about 20 km west of Shenyang, Liaoning Province, North China, and is a small Tertiary continental depression, covering only about 800 km/sup 2/. In the depression, the Tertiary system unconformably overlies upper-middle Proterozoic sedimentary rocks and Archean metamorphic rocks. The Tertiary system is up to 6,600 m in thickness. Source rocks are in the third and fourth members of the Eocens Shahejie Formation. Buried-hill traps were formed in Proterozoic carbonates and metamorphic rocks of the Archean. Fault block, stratigraphic, and lithologic traps also occur in sandstones of the Shahejie Formation, especially in those of the third member. Several buried-hill-drape traps occur in the depression. The various types of oil pole in each buried-hill-drape trap constitute a complex hydrocarbon accumulation zone. A series of oil fields have been found in the depression. The crude oil is characterized by high wax content and high pour point.

  15. A "watch window" technique for monitoring buried free jejunum flaps during circumferential pharyngolaryngectomy reconstruction.

    PubMed

    Li, Quan; Zhang, Xin-Rui; Liu, Xue-Kui; Zhang, Zhi-Gang; Liu, Wei-Wei; Li, Hao; Guo, Zhu-Ming

    2012-07-01

    The free jejunum flap approach is the optimal option for circumferential pharyngolaryngectomy reconstruction. In this study, we designed a "watch window" for monitoring buried free jejunum flaps, thereby allowing us to assess graft viability. From 2007 to 2011, 14 patients with hypopharyngeal cancer underwent circumferential pharyngolaryngectomy that was reconstructed using a free jejunum flap at the Sun Yat-sen University Cancer Centre. During the closing of the neck incision, a "watch window" was designed for postoperative monitoring. Two patients experienced thrombosis of the pedicle. One was detected early and successfully rescued by removal of the thrombosis, the other one managed with a second free jejunum flap. The success rate of the buried flaps was 92.9%. No pharyngocutaneous fistulas or strictures occurred. All patients eventually resumed oral feeding and swallowing. The "watch window" technique for monitoring buried free jejunum flaps is simple, reliable and useful for finding vascular problems. Level of evidence Case series. PMID:22116384

  16. Buried penis: An unrecognized risk factor in the development of invasive penile cancer

    PubMed Central

    Abdulla, Alym; Daya, Dean; Pinthus, Jehonathan; Davies, Timothy

    2012-01-01

    One of the documented benefits of neonatal circumcision is protection against invasive penile cancer. To date there have been a handful of published cases of invasive penile cancer in men circumcised as neonates. We report a case of a 73-year-old man, with a history of neonatal circumcision with no evidence of previous human papillomavirus exposure, who developed a buried penis secondary to obesity. He was diagnosed with Grade 2, pT3N0 squamous cell carcinoma of the penis. This report suggests that buried penis may pose a risk factor for the development of penile cancer despite the protective effects of neonatal circumcision. Thus periodic examination of a buried penis is warranted even in patients with no risk factors for penile cancer. A review of the literature is provided. PMID:23093645

  17. Atomic friction at exposed and buried graphite step edges: Experiments and simulations

    SciTech Connect

    Ye, Zhijiang; Martini, Ashlie

    2015-06-08

    The surfaces of layered materials such as graphite exhibit step edges that affect friction. Step edges can be exposed, where the step occurs at the outmost layer, or buried, where the step is underneath another layer of material. Here, we study friction at exposed and buried step edges on graphite using an atomic force microscope (AFM) and complementary molecular dynamics simulations of the AFM tip apex. Exposed and buried steps exhibit distinct friction behavior, and the friction on either step is affected by the direction of sliding, i.e., moving up or down the step, and the bluntness of the tip. These trends are analyzing in terms of the trajectory of the AFM tip as it moves over the step, which is a convolution of the topography of the surface and the tip shape.

  18. Acoustic identification of buried underwater unexploded ordnance using a numerically trained classifier (L).

    PubMed

    Bucaro, Joseph A; Waters, Zachary J; Houston, Brian H; Simpson, Harry J; Sarkissian, Angie; Dey, Saikat; Yoder, Timothy J

    2012-12-01

    Using a finite element-based structural acoustics code, simulations were carried out for the acoustic scattering from an unexploded ordnance rocket buried in the sediment under 3 m of water. The simulation treated 90 rocket burial angles in steps of 2°. The simulations were used to train a generative relevance vector machine (RVM) algorithm for identifying rockets buried at unknown angles in an actual water/sediment environment. The trained RVM algorithm was successfully tested on scattering measurements made in a sediment pool facility for six buried targets including the rocket at 90°, 120°, and 150°, a boulder, a cinderblock, and a cinderblock rolled 45° about its long axis. PMID:23231093

  19. Evaluation of the graphite electrode DC arc furnace for the treatment of INEL buried wastes

    SciTech Connect

    Surma, J.E.; Freeman, C.J.; Powell, T.D.; Cohn, D.R.; Smatlak, D.L.; Thomas, P.; Woskov, P.P.; Hamilton, R.A.; Titus, C.H.; Wittle, J.K.

    1993-06-01

    The past practices of DOE and its predecessor agencies in burying radioactive and hazardous wastes have left DOE with the responsibility of remediating large volumes of buried wastes and contaminated soils. The Buried Waste Integrated Demonstration (BWID), has chosen to evaluate treatment of buried wastes at the Idaho National Engineering Laboratory (INEL). Because of the characteristics of the buried wastes, the potential for using high-temperature thermal treatment technologies is being evaluated. The soil-waste mixture at INEL, when melted or vitrified, produces a glass/ceramic referred to as iron-enriched basalt (IEB). One potential problem with producing the IEB material is the high melting temperature of the waste and soil (1,400-1,600{degrees}C). One technology that has demonstrated capabilities to process high melting point materials is the plasma arc heated furnace. A three-party program was initiated and the program involved testing an engineering-scale DC arc furnace to gain preliminary operational and waste processibility information. It also included the design, fabrication, and evaluation of a second-generation, pilot-scale graphite electrode DC arc furnace. Widely ranging simulants of INEL buried waste were prepared and processed in the Mark I furnace. The tests included melting of soils with metals, sludges, combustibles, and simulated drums. Very promising results in terms of waste product quality, volume reduction, heating efficiency, and operational reliability and versatility were obtained. The results indicate that the graphite electrode DC arc technology would be very well suited for treating high melting point wastes such as those found at INEL. The graphite electrode DC arc furnace has been demonstrated to be very simple, yet effective, with excellent prospects for remote or semi-remote operation.

  20. Radar Detections of Buried Supraglacial Lakes Across the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Koenig, L.; Lampkin, D. J.; Montgomery, L.; Hamilton, S.; Joseph, C.; Moustafa, S.; Panzer, B.; Casey, K.; Paden, J. D.; Leuschen, C.; Gogineni, S.

    2014-12-01

    Surface melt over the Greenland Ice Sheet (GrIS) is increasing and estimated to account for half or more of the total mass loss. Little, however, is known about the hydrologic pathways that route surface melt within the ice sheet. Radar imaging provides a tool to investigate the englacial water storage and pathways across the GrIS. Here, we present data from the Center for Remote Sensing of Ice Sheets' radars flown by NASA's Operation IceBridge (OIB). OIB flights occur in the spring, before significant GrIS melt. The airborne radar echograms collected in the supraglacial lake regions show a unique attenuation signal attributed to over-winter storage of water, referred to here as buried lakes. The Snow Radar (~2-8 Ghz), that images the top 10's of meters of the ice sheet at high vertical resolution in the snow/firn (~4 cm), is used to map the spatial extent and depth of the retained water along OIB flight lines from 2009-2012. The buried lakes are distributed extensively around the margin of the GrIS. The subsurface water can persist through multiple winters and is, on average, ~4.2 + 0.4 m below the surface. Most buried lakes have no visible surface expression at the time of overflight but the few buried lakes that are visible have a unique visible signature associated with a darker blue color where subsurface water is located. The volume of retained water in the buried lakes is small compared to the total mass loss from the GrIS but the water will have important implications locally for the development of the englacial hydrologic network, ice temperature profiles and glacial dynamics. The buried lakes represent a year-round source of meltwater in the GrIS englacial hydrologic system.

  1. Physical Modelling on Detecting Buried Object Using Electrical Resistivity Imaging (ERI)

    NASA Astrophysics Data System (ADS)

    Hazreek, Z. A. M.; Nizam, Z. M.; Azhar, A. T. S.; Aziman, M.; Shaylinda, M. Z. N.

    2016-07-01

    This study focused on the evaluation of electrical resistivity method (ERM) for buried object detection and its relationship due to the different stiffness of material. In the past, the conventional method to detect the buried structure was face some limitation due to the time and cost. For example, previous approach related to the trial and error excavation has always expose to some risky outcome due to the uncertainties of the buried object location. Hence, this study introduced an alternative technique with particular reference to resistivity method to detect and evaluate the buried object with different strength of stiffness. The experiment was performed based on field miniature model (small scale study) using soil trial embankment made by lateritic soil and various concrete cube strengths (grade 20, 25 and 30) representing buried object with different conditions. 2D electrical resistivity test (electrical resistivity imaging) was perform using ABEM Terrameter SAS4000 during the data acquisition while the raw data was process using RES2DINV software. It was found that the electrical resistivity method was able to detect the buried concrete structures targeted based on the contrast of the electrical resistivity image produced. Moreover, three different strength of concrete cube were able to be differentiated based on the electrical resistivity values (ERV) obtained. This study found that the ERV of concrete cube for grade 20, 25 and 30 were 170 Ωm, 227 Ωm and 503 Ωm, respectively. Hence, this study shows that the ERV has a strong relationship with different stiffness of material thus applicable to be a useful alternative tool in underground structure detection.

  2. Distinct microbial communities associated with buried soils in the Siberian tundra

    PubMed Central

    Gittel, Antje; Bárta, Jiří; Kohoutová, Iva; Mikutta, Robert; Owens, Sarah; Gilbert, Jack; Schnecker, Jörg; Wild, Birgit; Hannisdal, Bjarte; Maerz, Joeran; Lashchinskiy, Nikolay; Čapek, Petr; Šantrůčková, Hana; Gentsch, Norman; Shibistova, Olga; Guggenberger, Georg; Richter, Andreas; Torsvik, Vigdis L; Schleper, Christa; Urich, Tim

    2014-01-01

    Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze–thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition and thus have a crucial role in SOM accumulation in buried soils. We surveyed the microbial community structure in cryoturbated soils from nine soil profiles in the northeastern Siberian tundra using high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. We found that bacterial abundances in buried topsoils were as high as in unburied topsoils. In contrast, fungal abundances decreased with depth and were significantly lower in buried than in unburied topsoils resulting in remarkably low fungal to bacterial ratios in buried topsoils. Fungal community profiling revealed an associated decrease in presumably ectomycorrhizal (ECM) fungi. The abiotic conditions (low to subzero temperatures, anoxia) and the reduced abundance of fungi likely provide a niche for bacterial, facultative anaerobic decomposers of SOM such as members of the Actinobacteria, which were found in significantly higher relative abundances in buried than in unburied topsoils. Our study expands the knowledge on the microbial community structure in soils of Northern latitude permafrost regions, and attributes the delayed decomposition of SOM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which bacterial decomposers are able to act as their functional substitutes. PMID:24335828

  3. Reversibility and criticality in amorphous solids

    PubMed Central

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A.; Lookman, Turab

    2015-01-01

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning' transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaotic behaviour and why chaotic motion is not possible in pinned systems. These findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched. PMID:26564783

  4. Reversibility and criticality in amorphous solids.

    PubMed

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A; Lookman, Turab

    2015-01-01

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a 'front depinning' transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaotic behaviour and why chaotic motion is not possible in pinned systems. These findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched. PMID:26564783

  5. Reversibility and criticality in amorphous solids

    SciTech Connect

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A.; Lookman, Turab

    2015-11-13

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning’ transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaotic behaviour and why chaotic motion is not possible in pinned systems. As a result, these findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched.

  6. Reversibility and criticality in amorphous solids

    DOE PAGESBeta

    Regev, Ido; Weber, John; Reichhardt, Charles; Dahmen, Karin A.; Lookman, Turab

    2015-11-13

    The physical processes governing the onset of yield, where a material changes its shape permanently under external deformation, are not yet understood for amorphous solids that are intrinsically disordered. Here, using molecular dynamics simulations and mean-field theory, we show that at a critical strain amplitude the sizes of clusters of atoms undergoing cooperative rearrangements of displacements (avalanches) diverges. We compare this non-equilibrium critical behaviour to the prevailing concept of a ‘front depinning’ transition that has been used to describe steady-state avalanche behaviour in different materials. We explain why a depinning-like process can result in a transition from periodic to chaoticmore » behaviour and why chaotic motion is not possible in pinned systems. As a result, these findings suggest that, at least for highly jammed amorphous systems, the irreversibility transition may be a side effect of depinning that occurs in systems where the disorder is not quenched.« less

  7. Application of amorphous brush-plated

    NASA Astrophysics Data System (ADS)

    Zheng, M.; Zhu, Y.; Zheng, Z.

    1994-02-01

    The results obtained during industrial trials have shown that the service life of hot work dies can be increased by 33 to 180% using the brush plating technique to prepare amorphous coatings. The coatings possess a much higher hardness, lower friction coefficient at room and elevated temperatures, good scale resistance in addition to higher surface finish, compared to uncoated dies, and thus improve the tribological performance of the dies. In this work, a study of the crystallization process, its kinetics, and the hardness variations of the coatings has been made. According to the data obtained, it can be considered that the main reason for the success of amorphous brush-plated coatings is that, during the operation, crystallization and precipitation takes place instantaneously, which results in a strong secondary hardening effect, thus leading to an increase in the red hardness of the surface layers of dies, therefore ensuring higher thermal wear resistance of the dies.

  8. Amorphous wires in displacement sensing techniques

    NASA Astrophysics Data System (ADS)

    Hristoforou, E.; Niarchos, D.

    1992-10-01

    In this paper, a new displacement sensor is proposed which is based on the magnetostrictive delay line technique (MDL). Due to this technique, the displacement of a moving magnet at either the acoustic stress point of origin or the detecting coil can be sensed, due to the change of the peak value of the output voltage. This sensor uses the recently developed FeSiB and FeCoCrSiB amorphous wires. Reported results show a linear response for defined regions of displacement, and a monotonic one for the case of the 125 μm FeSiB wires. It is also shown that this sensor arrangement can be used for fabrication of displacement distribution integrated sensors. Finally, it is shown that use of amorphous wires makes the repeatability of the response of the sensor as accurate as 0.6% without using hardware or software calibration.

  9. Surface modified amorphous ribbon based magnetoimpedance biosensor.

    PubMed

    Kurlyandskaya, Galina V; Fal Miyar, Vanessa

    2007-04-15

    Magnetoimpedance (MI) changes due to surface modification of the sensitive element caused by human urine, were studied with the aim of creating a robust biosensor working on a principle of electrochemical magnetoimpedance spectroscopy. A biosensor prototype with an as-quenched amorphous ribbon sensitive element was designed and calibrated for a frequency range of 0.5-10 MHz at a current intensity of 60 mA. Measurements as a function of the exposure time were made both in a regime where chemical surface modification and MI measurements were separated as well as in a regime where they were done simultaneously. The MI variation was explained by the change of the surface magnetic anisotropy. It was shown that the magnetoimpedance effect can be successfully employed as a new option to probe the electric features of the Fe(5)Co(70)Si(15)B(10) amorphous ribbon magnetic electrode surface modified by human urine. PMID:16914305

  10. New transformations between crystalline and amorphous ice

    NASA Technical Reports Server (NTRS)

    Hemley, R. J.; Chen, L. C.; Mao, H. K.

    1989-01-01

    High-pressure optical and spectroscopic techniques were used to obtain directly the ice I(h) - hda-ice transformation in a diamond-anvil cell, and the stability of the amorphous form is examined as functions of pressure and temperature. It is demonstrated that hda-ice transforms abruptly at 4 GPa and 77 K to a crystalline phase close in structure to orientationally disordered ice-VII and to a more highly ordered, ice-VIII-like structure at higher temperatures. This is the first time that an amorphous solid is observed to convert to a crystalline solid at low temperatures by compression alone. Phase transitions of this type may be relevant on icy planetary satellites, and there may also be implications for the high-pressure behavior of silica.

  11. Annealing behavior of high permeability amorphous alloys

    SciTech Connect

    Rabenberg, L.

    1980-06-01

    Effects of low temperature annealing on the magnetic properties of the amorphous alloy Co/sub 71/ /sub 4/Fe/sub 4/ /sub 6/Si/sub 9/ /sub 6/B/sub 14/ /sub 4/ were investigated. Annealing this alloy below 400/sup 0/C results in magnetic hardening; annealing above 400/sup 0/C but below the crystallization temperature results in magnetic softening. Above the crystallization temperature the alloy hardens drastically and irreversibly. Conventional and high resolution transmission electron microscopy were used to show that the magnetic property changes at low temperatures occur while the alloy is truly amorphous. By imaging the magnetic microstructures, Lorentz electron microscopy has been able to detect the presence of microscopic inhomogeneities in this alloy. The low temperature annealing behavior of this alloy has been explained in terms of atomic pair ordering in the presence of the internal molecular field. Lorentz electron microscopy has been used to confirm this explanation.

  12. Wear Resistant Amorphous and Nanocomposite Coatings

    SciTech Connect

    Racek, O

    2008-03-26

    Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.

  13. Thermoluminescence characteristics of hydrogenated amorphous zirconia

    NASA Astrophysics Data System (ADS)

    Montalvo, T. R.; Tenorio, L. O.; Nieto, J. A.; Salgado, M. B.; Estrada, A. M. S.; Furetta, C.

    2005-05-01

    This paper reports the experimental results concerning the thermoluminescent (TL) characteristics of hydrogenated amorphous zirconium oxide (a-Zr:H) powder prepared by the sol-gel method. The advantages of this method are the homogeneity and the purity of the gels associated with a relatively low sintering temperature. Hydrogenated amorphous powder was characterized by thermal analysis and X-ray diffraction. The main TL characteristics investigated were the TL response as a function of the absorbed dose, the reproducibility of the TL readings and the fading. The undoped a-Zr:H powder presents a TL glow curve with two peaks centered at 150 and 260 degrees C, respectively, after beta irradiation. The TL response a-Zr:H as a function of the absorbed dose showed a linear behavior over a wide range. The results presented open the possibility to use this material as a good TL dosimeter.

  14. Low-temperature relaxations in amorphous polyolefins

    NASA Technical Reports Server (NTRS)

    Hiltner, A.; Baer, E.; Martin, J. R.; Gillham, J. K.

    1974-01-01

    The dynamic mechanical relaxation behavior of two series of amorphous polyolefins, was investigated from 4.2 K to the glass transition. Most of the polymers show a damping maximum or plateau in the 40 to 50 K region. Various mechanisms which have been suggested for cryogenic relaxations in amorphous polymers are considered as they might relate to the polyolefins. Two secondary relaxation processes above 80 K are distinguished. A relaxation at about 160 K (beta) in the second and third member of each series is associated with restricted blackbone motion. This process requires a certain degree of chain flexibility since it is not observed in the first member of each series. A lower temperature process (gamma) is observed in each member of the second series and is attributed to motion of the ethyl side group.

  15. Chromic Mechanism in Amorphous WO3 Films

    SciTech Connect

    Zhang, J. G.; Benson, D. K.; Tracy, C. E.; Deb, S. K.; Czanderna, A. W.

    1997-06-01

    We propose a new model for the chromic mechanism in amorphous tungsten oxide films (WO3-y .cntdot. nH2O). This model not only explains a variety of seemingly conflicting experimental results reported in the literature that cannot be explained by existing models, it also has practical implications with respect to improving the coloring efficiency and durability of electrochromic devices. According to this model, a typical as-deposited tungsten oxide film has tungsten mainly in W6+ and W4+ states and can be represented as W6+(1-y) W4+(y)O(3-y) .cntdot. nH2O. The proposed chromic mechanism is based on the small polaron transition between the charge-induced W5+ state and the orignial W4+ state insteasd of the W5+ and W6+ states as suggested in previous models. The correlation between the electrochromic and photochromic behavior in amorphous tungsten oxide films is also discussed.

  16. Insulating behavior of an amorphous graphene membrane

    NASA Astrophysics Data System (ADS)

    Van Tuan, Dinh; Kumar, Avishek; Roche, Stephan; Ortmann, Frank; Thorpe, M. F.; Ordejon, Pablo

    2012-09-01

    We investigate the charge transport properties of planar amorphous graphene that is fully topologically disordered, in the form of sp2 threefold coordinated networks consisting of hexagonal rings but also including many pentagons and heptagons distributed in a random fashion. Using the Kubo transport methodology and the Lanczos method, the density of states, mean free paths, and semiclassical conductivities of such amorphous graphene membranes are computed. Despite a large increase in the density of states close to the charge neutrality point, all electronic properties are dramatically degraded, evidencing an Anderson insulating state caused by topological disorder alone. These results are supported by Landauer-Büttiker conductance calculations, which show a localization length as short as 5 nm.

  17. Germanium detector passivated with hydrogenated amorphous germanium

    DOEpatents

    Hansen, William L.; Haller, Eugene E.

    1986-01-01

    Passivation of predominantly crystalline semiconductor devices (12) is provided for by a surface coating (21) of sputtered hydrogenated amorphous semiconductor material. Passivation of a radiation detector germanium diode, for example, is realized by sputtering a coating (21) of amorphous germanium onto the etched and quenched diode surface (11) in a low pressure atmosphere of hydrogen and argon. Unlike prior germanium diode semiconductor devices (12), which must be maintained in vacuum at cryogenic temperatures to avoid deterioration, a diode processed in the described manner may be stored in air at room temperature or otherwise exposed to a variety of environmental conditions. The coating (21) compensates for pre-existing undesirable surface states as well as protecting the semiconductor device (12) against future impregnation with impurities.

  18. Dynamical models of hydrogenated amorphous silicon

    NASA Astrophysics Data System (ADS)

    Mousseau, Normand; Lewis, Laurent J.

    1991-04-01

    The results of our molecular-dynamics simulation of bulk hydrogenated amorphous silicon using empirical potentials are presented. More specifically, we discuss a dynamical procedure for incorporating hydrogen into a pure amorphous silicon matrix, which is derived from the concept of floating bonds put forward by Pantelides [Phys. Rev. Lett. 57, 2979 (1986)]. The structures resulting from this model are compared with those obtained with use of a static approach recently developed by us. This method exhibits considerable improvement over the previous one and, in particular, unambiguously reveals the strain-relieving role of hydrogen. While the former model leads to substantial overcoordination, the present one results in almost perfect tetrahedral bonding, with an average coordination number Z=4.03, the lowest value ever achieved using a Stillinger-Weber potential. The simulations are also used to calculate the vibrational densities of states, which are found to be in good accord with corresponding neutron-scattering measurements.

  19. Characterization of Amorphous Zinc Tin Oxide Semiconductors

    SciTech Connect

    Rajachidambaram, Jaana Saranya; Sanghavi, Shail P.; Nachimuthu, Ponnusamy; Shutthanandan, V.; Varga, Tamas; Flynn, Brendan T.; Thevuthasan, Suntharampillai; Herman, Gregory S.

    2012-06-12

    Amorphous zinc tin oxide (ZTO) was investigated to determine the effect of deposition and post annealing conditions on film structure, composition, surface contamination, and thin film transistor (TFT) device performance. X-ray diffraction results indicated that the ZTO films remain amorphous even after annealing to 600 °C. We found that the bulk Zn:Sn ratio of the sputter deposited films were slightly tin rich compared to the composition of the ceramic sputter target, and there was a significant depletion of zinc at the surface. X-ray photoelectron spectroscopy also indicated that residual surface contamination depended strongly on the sample post-annealing conditions where water, carbonate and hydroxyl species were absorbed to the surface. Electrical characterization of ZTO films, using TFT test structures, indicated that mobilities as high as 17 cm2/Vs could be obtained for depletion mode devices.

  20. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    SciTech Connect

    Allan, M.L.

    1996-06-01

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.

  1. Performance-Based Technology Selection Filter description report. INEL Buried Waste Integrated Demonstration System Analysis project

    SciTech Connect

    O`Brien, M.C.; Morrison, J.L.; Morneau, R.A.; Rudin, M.J.; Richardson, J.G.

    1992-05-01

    A formal methodology has been developed for identifying technology gaps and assessing innovative or postulated technologies for inclusion in proposed Buried Waste Integrated Demonstration (BWID) remediation systems. Called the Performance-Based Technology Selection Filter, the methodology provides a formalized selection process where technologies and systems are rated and assessments made based on performance measures, and regulatory and technical requirements. The results are auditable, and can be validated with field data. This analysis methodology will be applied to the remedial action of transuranic contaminated waste pits and trenches buried at the Idaho National Engineering Laboratory (INEL).

  2. Behavior of pipelines buried in SCP-improved ground during earthquakes

    SciTech Connect

    Fuchida, Kunihiko; Akiyoshi, Takashi; Hyodo, Takeshi

    1995-12-31

    Behavior of pipelines buried in the improved ground by sand compaction pile (SCP) and subjected to permanent ground displacement induced by liquefaction is investigated. Combining the programs for the simulation of SCP-improvement, the liquefaction analysis and the permanent ground displacement, the soil spring and the input ground displacement for the analysis of pipelines are evaluated. Results of numerical computations for the pipeline responses show that SCP ground improvement is effective to prevent soil liquefaction and reduce responses of pipeline buried in SCP-improved ground.

  3. Buried anode lithium thin film battery and process for forming the same

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Liu, Ping

    2004-10-19

    A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

  4. Buried waste integrated demonstration fiscal year 1992 close-out report

    SciTech Connect

    Cannon, P.G.; Kostelnik, K.M.; Owens, K.J.

    1993-02-01

    The mission of the Buried Waste Integrated Demonstration Program (BWID) is to support the development and demonstration of a suite of technologies that when integrated with commercially-available baseline technologies form a comprehensive remediation system for the effective and efficient remediation of buried waste disposed of throughout the US Department of Energy complex. To accomplish this mission of identifying technological solutions for remediation deficiencies, the Office of Technology Development initiated the BWID at the Idaho National Engineering Laboratory in fiscal year (FY)-91. This report summarizes the activities of the BWID Program during FY-92.

  5. Buried Anode Device Development: Cooperative Research and Development Final Report, CRADA Number CRD-11-451

    SciTech Connect

    Tenent, R.

    2015-03-01

    The possibility of a reflecting electrochromic device is very attractive, and the 'Buried Anode' architecture developed at NREL could yield such a device. The subject of this cooperative agreement will be the development and refinement of a Buried Anode device process. This development will require the active involvement of NREL and US e-Chromic personnel, and will require the use of NREL equipment as much as possible. When this effort is concluded, US e-Chromic will have enough information to construct a pilot production line, where further development can continue.

  6. Nanoscale Imaging of Buried Structures with Elemental Specificity Using Resonant X-Ray Diffraction Microscopy

    SciTech Connect

    Song, Changyong; Bergstrom, Raymond; Ramunno-Johnson, Damien; Jiang, Huaidong; Miao, Jianwei; Paterson, David; Jonge, Martin D. de; McNulty, Ian; Lee, Jooyoung; Wang, Kang L.

    2008-01-18

    We report the first demonstration of resonant x-ray diffraction microscopy for element specific imaging of buried structures with a pixel resolution of {approx}15 nm by exploiting the abrupt change in the scattering cross section near electronic resonances. We performed nondestructive and quantitative imaging of buried Bi structures inside a Si crystal by directly phasing coherent x-ray diffraction patterns acquired below and above the Bi M{sub 5} edge. We anticipate that resonant x-ray diffraction microscopy will be applied to element and chemical state specific imaging of a broad range of systems including magnetic materials, semiconductors, organic materials, biominerals, and biological specimens.

  7. A neutron diffraction study of amorphous boron

    NASA Astrophysics Data System (ADS)

    Delaplane, R. G.; Lundström, T.; Dahlborg, U.; Howells, W. S.

    1991-07-01

    The structure of amorphous boron has been studied with pulsed neutron diffraction techniques using the ISIS facilities at the Rutherford Appleton Laboratory. The experimental static structure factor S(Q) and radial distribution function support a structural model based on units of B12 icosahedra resembling those found in crystalline β-rhombohedral boron, but with a certain degree of disorder occurring in the linking between these subunits.

  8. Design Requirements for Amorphous Piezoelectric Polymers

    NASA Technical Reports Server (NTRS)

    Ounaies, Z.; Young, J. A.; Harrison, J. S.

    1999-01-01

    An overview of the piezoelectric activity in amorphous piezoelectric polymers is presented. The criteria required to render a polymer piezoelectric are discussed. Although piezoelectricity is a coupling between mechanical and electrical properties, most research has concentrated on the electrical properties of potentially piezoelectric polymers. In this work, we present comparative mechanical data as a function of temperature and offer a summary of polarization and electromechanical properties for each of the polymers considered.

  9. Synthesis of new amorphous metallic spin glasses

    DOEpatents

    Haushalter, Robert C.

    1988-01-01

    Amorphous metallic precipitates having the formula (M.sub.1).sub.a (M.sub.2).sub.b wherein M.sub.1 is at least one transition metal, M.sub.2 is at least one main group metal and the integers "a" and "b" provide stoichiometric balance; the precipitates having a degree of local order characteristic of chemical compounds from the precipitation process and useful electrical and mechanical properties.

  10. Synthesis of new amorphous metallic spin glasses

    DOEpatents

    Haushalter, Robert C.

    1986-01-01

    Amorphous metallic precipitates having the formula (M.sub.1).sub.a (M.sub.2).sub.b wherein M.sub.1 is at least one transition metal, M.sub.2 is at least one main group metal and the integers "a" and "b" provide stoichiometric balance; the precipitates having a degree of local order characteristic of chemical compounds from the precipitation process and useful electrical and mechanical properties.

  11. Synthesis of new amorphous metallic spin glasses

    DOEpatents

    Haushalter, R.C.

    1985-02-11

    Disclosed are: amorphous metallic precipitates having the formula (M/sub 1/)/sub a/(M/sub 2/)/sub b/ wherein M/sub 1/ is at least one transition metal, M/sub 2/ is at least one main group metal and the integers ''a'' and ''b'' provide stoichiometric balance; the precipitates having a degree of local order characteristic of chemical compounds from the precipitation process and useful electrical and mechanical properties.

  12. Marijuana as doping in sports.

    PubMed

    Campos, Daniel R; Yonamine, Mauricio; de Moraes Moreau, Regina L

    2003-01-01

    A high incidence of positive cases for cannabinoids, in analyses for doping control in sports, has been observed since the International Olympic Committee (IOC) included them in the 1989 list of prohibited drugs under the title of classes of prohibited substances in certain circumstances. Where the rules of sports federations so provide, tests are conducted for marijuana, hashish or any other cannabis product exposure by means of urinalysis of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (carboxy-THC) the main metabolite of delta-9-tetrahydrocannabinol (THC). Concentrations >15 ng/mL (cut-off value) in confirmatory analytical procedures are considered doping. Cannabis is an illicit drug in several countries and has received much attention in the media for its potential therapeutic uses and the efforts to legalise its use. Studies have demonstrated that the use of cannabinoids can reduce anxiety, but it does not have ergogenic potential in sports activities. An increase in heart rate and blood pressure, decline of cardiac output and reduced psychomotor activity are some of the pharmacological effects of THC that will determine a decrease in athletic performance. An ergolytic activity of cannabis products has been observed in athletes of several different sport categories. In Brazil, analyses for doping control in sports, performed in our laboratories, have detected positive cases for carboxy-THC in urine samples of soccer, volleyball, cycling and other athletes. It is our intention to discuss in this article some points that may discourage individuals from using cannabis products during sports activities, even in the so-called permitted circumstances defined by the IOC and some sports federations. PMID:12744713

  13. Superconducting state parameters of amorphous metals

    NASA Astrophysics Data System (ADS)

    Vora, Aditya M.

    2007-07-01

    The theoretical computation of the superconducting state parameters (SSP) viz; electron-phonon coupling strength λ, Coulomb pseudopotential μ∗, transition temperature TC, isotope effect exponent α and effective interaction strength N0V of some monovalent (Li, Na, K, Rb and Cs), divalent (Mg, Zn, Be, Cd and Hg) and polyvalent (In, Tl, Ga, Al, La, Sn, Pb, Ti, Zr, Th, Bi, Nb and W) amorphous metals have been carried out by well known Ashcroft’s empty core (EMC) model pseudopotential. We have employed here five different types of local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) to study the exchange and correlation effects on the present investigations. The SSP for Be, Cd, Ga, Al, La, Ti, Zr, Th, Nb and W amorphous metals are reported first time in the present study. A very strong influence of all the exchange and correlation functions is found in the present study. Our results are in fair agreement with other available theoretical as well as experimental data. A strong dependency of the SSP of amorphous metals on the valency Z is found.

  14. Shock induced crystallization of amorphous Nickel powders

    NASA Astrophysics Data System (ADS)

    Cherukara, Mathew; Strachan, Alejandro

    2015-06-01

    Recent experimental work has shown the efficacy of amorphous Ni/crystalline Al composites as energetic materials, with flame velocities twice that of a comparable crystalline Ni/crystalline Al system. Of further interest is the recrystallization mechanisms in the pure amorphous Ni powders, both thermally induced and mechanically induced. We present large-scale molecular dynamics simulations of shock-induced recrystallization in loosely packed amorphous Nickel powders. We study the time dependent nucleation and growth processes by holding the shocked samples at the induced pressures and temperatures for extended periods following the passage of the shock (up to 6 ns). We find that the nanostructure of the recrystallized Ni and time scales of recrystallization are dependent on the piston velocity. At low piston velocities, nucleation events are rare, leading to long incubation times and a relatively coarse nanostructure. At higher piston velocities, local variations in temperature due to jetting phenomena and void collapse, give rise to multiple nucleation events on time scales comparable to the passage of the shock wave, leading to the formation of a fine-grained nanostructure. Interestingly, we observe that the nucleation and growth process occurs in two steps, with the first nuclei crystallizing into the BCC structure, before evolving over time into the expected FCC structure. U.S. Defense Threat Reduction Agency, HDTRA1-10-1-0119 (Program Manager Suhithi Peiris).

  15. Multiple cell photoresponsive amorphous alloys and devices

    SciTech Connect

    Ovshinsky, S.R.; Adler, D.

    1990-01-02

    This patent describes an improved photoresponsive tandem multiple solar cell device. The device comprising: at least a first and second superimposed cell of various materials. The first cell being formed of a silicon alloy material. The second cell including an amorphous silicon alloy semiconductor cell body having an active photoresponsive region in which radiation can impinge to produce charge carriers, the amorphous cell body including at least one density of states reducing element. The element being fluorine. The amorphous cell body further including a band gap adjusting element therein at least in the photoresponsive region to enhance the radiation absorption thereof, the adjusting element being germanium: the second cell being a multi-layer body having deposited semiconductor layers of opposite (p and n) conductivity type; and the first cell being formed with the second cell in substantially direct Junction contact therebetween. The first and second cells designed to generate substantially matched currents from each cell from a light source directed through the first cell and into the second cell.

  16. Amorphous molybdenum silicon superconducting thin films

    SciTech Connect

    Bosworth, D. Sahonta, S.-L.; Barber, Z. H.; Hadfield, R. H.

    2015-08-15

    Amorphous superconductors have become attractive candidate materials for superconducting nanowire single-photon detectors due to their ease of growth, homogeneity and competitive superconducting properties. To date the majority of devices have been fabricated using W{sub x}Si{sub 1−x}, though other amorphous superconductors such as molybdenum silicide (Mo{sub x}Si{sub 1−x}) offer increased transition temperature. This study focuses on the properties of MoSi thin films grown by magnetron sputtering. We examine how the composition and growth conditions affect film properties. For 100 nm film thickness, we report that the superconducting transition temperature (Tc) reaches a maximum of 7.6 K at a composition of Mo{sub 83}Si{sub 17}. The transition temperature and amorphous character can be improved by cooling of the substrate during growth which inhibits formation of a crystalline phase. X-ray diffraction and transmission electron microscopy studies confirm the absence of long range order. We observe that for a range of 6 common substrates (silicon, thermally oxidized silicon, R- and C-plane sapphire, x-plane lithium niobate and quartz), there is no variation in superconducting transition temperature, making MoSi an excellent candidate material for SNSPDs.

  17. Phase transitions in biogenic amorphous calcium carbonate

    NASA Astrophysics Data System (ADS)

    Gong, Yutao

    Geological calcium carbonate exists in both crystalline phases and amorphous phases. Compared with crystalline calcium carbonate, such as calcite, aragonite and vaterite, the amorphous calcium carbonate (ACC) is unstable. Unlike geological calcium carbonate crystals, crystalline sea urchin spicules (99.9 wt % calcium carbonate and 0.1 wt % proteins) do not present facets. To explain this property, crystal formation via amorphous precursors was proposed in theory. And previous research reported experimental evidence of ACC on the surface of forming sea urchin spicules. By using X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron emission microscopy (PEEM), we studied cross-sections of fresh sea urchin spicules at different stages (36h, 48h and 72h after fertilization) and observed the transition sequence of three mineral phases: hydrated ACC → dehydrated ACC → biogenic calcite. In addition, we unexpectedly found hydrated ACC nanoparticles that are surrounded by biogenic calcite. This observation indicates the dehydration from hydrated ACC to dehydrated ACC is inhibited, resulting in stabilization of hydrated ACC nanoparticles. We thought that the dehydration was inhibited by protein matrix components occluded within the biomineral, and we designed an in vitro assay to test the hypothesis. By utilizing XANES-PEEM, we found that SM50, the most abundant occluded matrix protein in sea urchin spicules, has the function to stabilize hydrated ACC in vitro.

  18. Crystalline-amorphous transition in silicate perovskites

    SciTech Connect

    Hemmati, M.; Chizmeshya, A.; Wolf, G.H.; Poole, P.H.; Shao, J.; Angell, C.A.

    1995-06-01

    CaSiO{sub 3} and MgSiO{sub 3} perovskites are known to undergo solid-state crystal to amorphous transitions near ambient pressure when decompressed from their high-pressure stability fields. In order to elucidate the mechanistic aspects of this transition we have performed detailed molecular-dynamics simulations and lattice-dynamical calculations on model silicate perovskite systems using empirical rigid-ion pair potentials. In the simulations at low temperatures, the model perovskite systems transform under tension to a low-density glass composed of corner shared chains of tetrahedral silicon. The amorphization is initiated by a thermally activated step involving a soft polar optic mode in the perovskite phase at the Brillouin zone center. Progression of the system along this reaction coordinate triggers, in succession, multiple barrierless modes of instability ultimately producing a catastrophic decohesion of the lattice. An important intermediary along the reaction path is a crystalline phase where silicon is in a five-coordinate site and the alkaline-earth metal atom is in eightfold coordination. At the onset pressure, this transitory phase is itself dynamically unstable to a number of additional vibrational modes, the most relevant being those which result in transformation to a variety of tetrahedral chain silicate motifs. These results support the conjecture that stress-induced amorphization arises from the near simultaneous accessibility of multiple modes of instability in the highly metastable parent crystalline phase.

  19. Characterization of Amorphous and Co-Amorphous Simvastatin Formulations Prepared by Spray Drying.

    PubMed

    Craye, Goedele; Löbmann, Korbinian; Grohganz, Holger; Rades, Thomas; Laitinen, Riikka

    2015-01-01

    In this study, spray drying from aqueous solutions, using the surface-active agent sodium lauryl sulfate (SLS) as a solubilizer, was explored as a production method for co-amorphous simvastatin-lysine (SVS-LYS) at 1:1 molar mixtures, which previously have been observed to form a co-amorphous mixture upon ball milling. In addition, a spray-dried formulation of SVS without LYS was prepared. Energy-dispersive X-ray spectroscopy (EDS) revealed that SLS coated the SVS and SVS-LYS particles upon spray drying. X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) showed that in the spray-dried formulations the remaining crystallinity originated from SLS only. The best dissolution properties and a "spring and parachute" effect were found for SVS spray-dried from a 5% SLS solution without LYS. Despite the presence of at least partially crystalline SLS in the mixtures, all the studied formulations were able to significantly extend the stability of amorphous SVS compared to previous co-amorphous formulations of SVS. The best stability (at least 12 months in dry conditions) was observed when SLS was spray-dried with SVS (and LYS). In conclusion, spray drying of SVS and LYS from aqueous surfactant solutions was able to produce formulations with improved physical stability for amorphous SVS. PMID:26633346

  20. A comprehensive inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the INEL RWMC during the years 1984-2003, Volume 3

    SciTech Connect

    1995-05-01

    This is the third volume of this comprehensive report of the inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the Idaho National Engineering Laboratory. Appendix B contains a complete printout of contaminant inventory and other information from the CIDRA Database and is presented in volumes 2 and 3 of the report.

  1. A comprehensive inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the INEL RWMC during the years 1984-2003, Volume 2

    SciTech Connect

    1995-05-01

    This is the second volume of this comprehensive report of the inventory of radiological and nonradiological contaminants in waste buried or projected to be buried in the subsurface disposal area of the Idaho National Engineering Laboratory. Appendix B contains a complete printout of contaminant inventory and other information from the CIDRA Database and is presented in volumes 2 and 3 of the report.

  2. Characterizing Amorphous Silicates in Extraterrestrial Materials

    NASA Astrophysics Data System (ADS)

    Fu, X.; Wang, A.; Krawczynski, M. J.

    2015-12-01

    Amorphous silicates are common in extraterrestrial materials. They are seen in the matrix of carbonaceous chondrites as well as in planetary materials. Tagish Lake is one of the most primitive carbonaceous meteorites in which TEM and XRD analyses found evidence for poorly crystalline phyllosilicate-like species; Raman spectra revealed amorphous silicates with variable degree of polymerization and low crystallinity. On Mars, CheMin discovered amorphous phases in all analyzed samples, and poorly crystalline smectite in mudstone samples. These discoveries pose questions on the crystallinity of phyllosilicates found by remote sensing on Mars, which is directly relevant to aqueous alteration during geologic history of Mars. Our goal is to use spectroscopy to better characterize amorphous silicates. We use three approaches: (1) using silicate glasses synthesized with controlled chemistry to study the effects of silicate polymerization and (2) using phyllosilicates synthesized with controlled hydrothermal treatment to study the effect of crystallinity on vibrational spectroscopy, finally (3) to use the developed correlations in above two steps to study amorphous phases in meteorites, and those found in future missions to Mars. In the 1st step, silicate glasses were synthesized from pure oxides in a range of NBO/T ratios (from 0 to 4). Depending on the targeted NBO/T and composition of mixed oxides, temperatures for each experiment fell in a range from 1260 to 1520 °C, run for ~ 4 hrs. The melt was quenched in liquid N2 or water. Homogeneity of glass was checked under optical microscopy. Raman spectra were taken over 100 spots on small chips free of bubbles and crystals. We have observed that accompanying an increase of NBO/T, there is a strengthening and a position shift of the Raman peak near 1000 cm-1 (Si-Onon-bridging stretching mode), and the weakening of broad Raman peaks near 500 cm-1 (ring breathing mode) and 700cm-1 (Si-Obridging-Si mode). We are building the

  3. Investigations on silicon/amorphous-carbon and silicon/nanocrystalline palladium/ amorphous-carbon interfaces.

    PubMed

    Roy, M; Sengupta, P; Tyagi, A K; Kale, G B

    2008-08-01

    Our previous work revealed that significant enhancement in sp3-carbon content of amorphous carbon films could be achieved when grown on nanocrystalline palladium interlayer as compared to those grown on bare silicon substrates. To find out why, the nature of interface formed in both the cases has been investigated using Electron Probe Micro Analysis (EPMA) technique. It has been found that a reactive interface in the form of silicon carbide and/silicon oxy-carbide is formed at the interface of silicon/amorphous-carbon films, while palladium remains primarily in its native form at the interface of nanocrystalline palladium/amorphous-carbon films. However, there can be traces of dissolved oxygen within the metallic layer as well. The study has been corroborated further from X-ray photoelectron spectroscopic studies. PMID:19049221

  4. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... pipelines installed before August 1, 1971. 192.457 Section 192.457 Transportation Other Regulations Relating... submerged pipelines installed before August 1, 1971. (a) Except for buried piping at compressor, regulator, and measuring stations, each buried or submerged transmission line installed before August 1,...

  5. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective...

  6. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective...

  7. 49 CFR 192.455 - External corrosion control: Buried or submerged pipelines installed after July 31, 1971.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.455 External corrosion control: Buried or... against external corrosion, including the following: (1) It must have an external protective...

  8. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2)...

  9. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2)...

  10. 49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2)...

  11. Cadaver dog and handler team capabilities in the recovery of buried human remains in the southeastern United States.

    PubMed

    Lasseter, Alanna E; Jacobi, Keith P; Farley, Ricky; Hensel, Lee

    2003-05-01

    The detection of human remains that have been deliberately buried to escape detection is a problem for law enforcement. Sometimes the cadaver dog and handler teams are successful, while other times law enforcement and cadaver dog teams are frustrated in their search. Five field trials tested the ability of four cadaver dog and handler teams to detect buried human remains. Human and animal remains were buried in various forested areas during the summer months near Tuscaloosa, Alabama. The remains ranged in decomposition from fresh to skeletonized. Cadaver dogs detected with varying success: buried human remains at different stages of decomposition, buried human remains at different depths, and buried decomposed human and animal remains. The results from these trials showed that some cadaver dogs were able to locate skeletonized remains buried at a significant depth. Fresh and skeletonized remains were found equally by the cadaver dogs along with some caveats. Dog handlers affected the reliability of the cadaver dog results. Observations and videotape of the cadaver dogs during field trials showed that they were reliable in finding buried human remains. PMID:12762533

  12. Identification of donor deactivation centers in heavily As-doped Si using time-of-flight medium-energy ion scattering spectroscopy

    SciTech Connect

    Min, Won Ja; Park, Kyungsu; Yu, Kyu-Sang; Joo, Sungjung; Kim, Yong-Sung; Moon, Dae Won

    2015-10-07

    Electrically-inactive arsenic (As) complexes in silicon are investigated using time-of-flight medium-energy ion scattering spectroscopy. In heavily As-doped Si, the As atoms that are segregated in the Si interface region just below the SiO{sub 2} are found to be in interstitial forms (As{sub i}), while the As atoms in the bulk Si region are found to be in the substitutional form (As{sub Si}). Despite the substitutional form of As, most of the As are found to be electrically inactive in the bulk region, and we identify the As to be in the form of a 〈111〉-oriented As{sub Si}-Si-vacancy (As{sub Si}-V{sub Si}) complex. The As{sub i} atoms in the interface Si region are found to exist together with Si-interstitial atoms (Si{sub i}), suggesting that the As{sub i} atoms in the interface Si region accompany the Si{sub i} atoms.

  13. Low dose effects of a Withania somnifera extract on altered marble burying behavior in stressed mice

    PubMed Central

    Dey, Amitabha; Chatterjee, Shyam Sunder; Kumar, Vikas

    2016-01-01

    Aim: Withania somnifera root (WSR) extracts are often used in traditionally known Indian systems of medicine for prevention and cure of psychosomatic disorders. The reported experiment was designed to test whether low daily oral doses of such extracts are also effective in suppressing marble burying behavior in stressed mice or not. Materials and Methods: Groups of mice treated with 10, 20, or 40 mg/kg daily oral doses of WSR were subjected to a foot shock stress-induced hyperthermia test on the 1st, 5th, 7th, and 10th day of the experiment. On the 11th and 12th treatment days, they were subjected to marble burying tests. Stress response suppressing effects of low dose WSR were estimated by its effects on body weight and basal core temperature of animals during the course of the experiment. Results: Alterations in bodyweight and basal core temperature triggered by repeated exposures to foot shock stress were absent even in the 10 mg/kg/day WSR treated group, whereas the effectiveness of the extract in foot shock stress-induced hyperthermia and marble burying tests increased with its increasing daily dose. Conclusion: Marble burying test in stressed mice is well suited for identifying bioactive constituents of W. somnifera like medicinal plants with adaptogenic, anxiolytic and antidepressant activities, or for quantifying pharmacological interactions between them. PMID:27366354

  14. 75 FR 38042 - Specifications and Drawings for Construction of Direct Buried Plant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ..., at 75 FR 32313 regarding the request for comments on revising RUS Bulletin 1753F-150, Specifications... document FR Doc. 2010-12830 beginning on page 32313 in the issue of June 8, 2010, make the following... Construction of Direct Buried Plant AGENCY: Rural Utilities Service, USDA. ACTION: Proposed Rule;...

  15. Analytical model of LDMOS with a double step buried oxide layer

    NASA Astrophysics Data System (ADS)

    Yuan, Song; Duan, Baoxing; Cao, Zhen; Guo, Haijun; Yang, Yintang

    2016-09-01

    In this paper, a two-dimensional analytical model is established for the Buried Oxide Double Step Silicon On Insulator structure proposed by the authors. Based on the two-dimensional Poisson equation, the analytic expressions of the surface electric field and potential distributions for the device are achieved. In the BODS (Buried Oxide Double Step Silicon On Insulator) structure, the buried oxide layer thickness changes stepwise along the drift region, and the positive charge in the drift region can be accumulated at the corner of the step. These accumulated charge function as the space charge in the depleted drift region. At the same time, the electric field in the oxide layer also varies with the different drift region thickness. These variations especially the accumulated charge will modulate the surface electric field distribution through the electric field modulation effects, which makes the surface electric field distribution more uniform. As a result, the breakdown voltage of the device is improved by 30% compared with the conventional SOI structure. To verify the accuracy of the analytical model, the device simulation software ISE TCAD is utilized, the analytical values are in good agreement with the simulation results by the simulation software. That means the established two-dimensional analytical model for BODS structure is valid, and it also illustrates the breakdown voltage enhancement by the electric field modulation effect sufficiently. The established analytical models will provide the physical and mathematical basis for further analysis of the new power devices with the patterned buried oxide layer.

  16. Saqqar Impact Structure: A Buried 34 km Crater in Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Kenkmann, T.; Afifi, A. M.; Stewart, S. A.; Poelchau, M. H.; Cook, D. J.; Neville, A. S.

    2015-09-01

    We present evidence for an impact origin of a circular structure with an apparent diameter of 34 km, centered at 29°35’N, 38°42’E, which is partially buried under ~400 m of Cretaceous-Paleogene strata in the Nafud basin in NW Saudi Arabia.

  17. Buried Seed Banks as Indicators of Seed Output along an Altitudinal Gradient.

    ERIC Educational Resources Information Center

    Thompson, K.

    1985-01-01

    Study of buried seed banks (viable seeds deposited in the soil near parent plants) provides a relatively easy way of determining cumulative effects on seed production and species' altitudinal limits. Sites, methods, validity, interpretation, problems of collection on a mountain, and germination techniques are discussed. (Author/DH)

  18. Transformation of lignin in surface and buried soils of mountainous landscapes

    NASA Astrophysics Data System (ADS)

    Kovaleva, N. O.; Kovalev, I. V.

    2009-11-01

    The content and composition of the lignin phenols in plants and soils of vertical natural zones were studied in the Northern Caucasus region and Northwestern Tien Shan. Three types of lignin transformation were revealed: steppe, forest, and meadow ones. It was shown that the degree of oxidation of the biopolymer during the transformation of organic matter increased when going from the living plant tissues to humic acids in surface and buried soils. The portion of lignin fragments remained unchanged during the biopolymer transformation in the following series: plant tissues-falloff-litter-soil-humic acids-buried humic acids. It was also shown that the biochemical composition of the plants had a decisive effect on the structure of the humic acids in the soils. The quantitative analysis of the lignin phenols and the 13C NMR spectroscopy proved that the lignin in higher plants was involved in the formation of specific compounds of soil humus, including aliphatic and aromatic molecular fragments. The first analysis of the lignin content and composition in buried soils of different ages was performed, and an increase in the degree of oxidation of the lignin structures was revealed in the soil chronoseries. It was proposed to use the proportions of lignin phenols in surface and buried soils as diagnostic criteria of the vegetation types in different epochs.

  19. Boston's Historic Burying Grounds Initiative: An Innovative and Educational Public/Private Partnership.

    ERIC Educational Resources Information Center

    Tracy, Regina

    1988-01-01

    Discusses Boston's Historic Burying Ground Initiative, which was undertaken from a concern for public education. The public-private partnership is expected to take 10 years and six million dollars to restore the final resting places of figures such as Paul Revere, Samuel Adams, Robert Treat Paine, and the Mather family of Puritan ministers. (GEA)

  20. Dual-band, infrared buried mine detection using a statistical pattern recognition approach

    SciTech Connect

    Buhl, M.R.; Hernandez, J.E.; Clark, G.A.; Sengupta, S.K.

    1993-08-01

    The main objective of this work was to detect surrogate land mines, which were buried in clay and sand, using dual-band, infrared images. A statistical pattern recognition approach was used to achieve this objective. This approach is discussed and results of applying it to real images are given.

  1. Marble burying as a test of the delayed anxiogenic effects of acute immobilisation stress in mice.

    PubMed

    Kedia, Sonal; Chattarji, Sumantra

    2014-08-15

    A majority of rodent studies characterizing the anxiogenic effects of stress have utilized exploration-based models, such as the elevated plus-maze. An alternative strategy has relied on ethologically natural behavior such as defensive burying. One such paradigm, marble burying, has proven to be an effective behavioral assay of the anxiolytic effects of pharmacological manipulations, and of genetically modified mouse models. Relatively little, however, is known about the sensitivity of this test in assessing the anxiogenic effects of stress. Most of the earlier reports have examined the immediate, but not more long-term, effects of pharmacological or environmental manipulations in mice. Hence, we used the marble burying test to examine if acute immobilization stress leads to enhanced anxiety-like behavior in C57Bl/6 mice if the test is employed with a significant time delay. We find this test to be sensitive enough to detect the anxiogenic effects even 10 days after a single episode of 2-h immobilization stress. Our results suggest that the marble burying test could serve as a useful behavioral paradigm for not only estimating the gradual progression of the anxiogenic impact of stress over time, but also raises the possibility of using the temporal delay after stress to test the potential efficacy of post-stress interventions with anxiolytic drugs. PMID:24932962

  2. Method of making a nonplanar buried-heterostructure distributed-feedback laser

    SciTech Connect

    Dolan, G.J.; Logan, R.A.; Temkin, H.; Wilt, D.P.

    1987-10-27

    This patent describes a method for making a distributed feedback laser. The method comprises forming a buried heterostructure on a substrate by sequential deposition of layers including an active layer and a cladding layer. The method comprises producing a grating structure on a nonplanar surface of the cladding layer.

  3. Superior broadband antireflection from buried Mie resonator arrays for high-efficiency photovoltaics.

    PubMed

    Zhong, Sihua; Zeng, Yang; Huang, Zengguang; Shen, Wenzhong

    2015-01-01

    Establishing reliable and efficient antireflection structures is of crucial importance for realizing high-performance optoelectronic devices such as solar cells. In this study, we provide a design guideline for buried Mie resonator arrays, which is composed of silicon nanostructures atop a silicon substrate and buried by a dielectric film, to attain a superior antireflection effect over a broadband spectral range by gaining entirely new discoveries of their antireflection behaviors. We find that the buried Mie resonator arrays mainly play a role as a transparent antireflection structure and their antireflection effect is insensitive to the nanostructure height when higher than 150 nm, which are of prominent significance for photovoltaic applications in the reduction of photoexcited carrier recombination. We further optimally combine the buried Mie resonator arrays with micron-scale textures to maximize the utilization of photons, and thus have successfully achieved an independently certified efficiency of 18.47% for the nanostructured silicon solar cells on a large-size wafer (156 mm × 156 mm). PMID:25746848

  4. PROCESSING TECHNIQUES FOR DISCRIMINATION BETWEEN BURIED UXO AND CLUTTER USING MULTISENSOR ARRAY DATA

    EPA Science Inventory

    The overall objective of this project is to develop reliable techniques for discriminating between buried UXO and clutter using multisensor electromagnetic induction sensor array data. The basic idea is to build on existing research which exploits differences in shape between or...

  5. Field application of innovative grouting agents for in situ stabilization of buried waste sites

    SciTech Connect

    Loomis, G.G.; Farnsworth, R.K.

    1997-12-31

    This paper presents field applications for two innovative grouting agents that were used to in situ stabilize buried waste sites, via jet grouting. The two grouting agents include paraffin and a proprietary iron oxide based cement grout called TECT. These materials were tested in specially designed cold test pits that simulate buried transuranic waste at the Idaho National Engineering Laboratory (INEL). The field demonstrations were performed at the INEL in an area referred to as the Cold Test Pit, which is adjacent to the INEL Radioactive Waste Management Complex (RWMC). At the RWMC, 56,000 m{sup 3} of transuranic (TRU) waste is co-mingled with over 170,000 m{sup 3} of soil in shallow land burial. Improving the confinement of this waste is one of the options for final disposition of this waste. Using jet-grouting technology to inject these materials into the pore spaces of buried waste sites results in the creation of buried monolithic waste forms that simultaneously protect the waste from subsidence, while eliminating the migratory potential of hazardous and radioactive contaminants in the waste.

  6. Evaluating In Situ Treatment Technologies for Buried Mixed Waste Remediation at the INEEL

    SciTech Connect

    D.F. Nickelson; D.K. Jorgensen; J.J. Jessmore; R.A. Hyde; R.K. Farnsworth

    1999-02-01

    Mixed radioactive and hazardous wastes were buried at the Department of Energy's Idaho National Engineering and Environmental Laboratory (INEEL) Subsurface Disposal Area from 1952 to 1969. To begin the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remediation process for the Subsurface Disposal Area, the Environmental Protection Agency (EPA) added the INEEL to its National Priorities List in 1989. DOE's Office of Environmental Restoration is planning several CERCLA treatability studies of remedial technologies that will be evaluated for potential remediation of the buried waste in the Subsurface Disposal Area. This paper discusses the in situ treatability studies that will be performed, including in situ vitrification, in situ grouting, and in situ thermal desorption. The in situ treatability studies will be conducted on simulated and actual buried wastes at the INEEL in 1999 and 2000. Results from the treatability studies will provide substantial information on the feasibility, implementability, and cost of applying these technologies to the INEEL Subsurface Disposal Area. In addition, much of the treatability study data will be applicable to buried waste site remediation efforts across the DOE complex.

  7. Evaluating In Situ Treatment Technologies for Buried Mixed Waste Remediation at the INEEL

    SciTech Connect

    Jorgensen, Douglas Kay; Nickelson, David Frank; Nickelson, Reva Anne; Farnsworth, Richard Kent; Jessmore, James Joseph

    1999-03-01

    Mixed radioactive and hazardous wastes were buried at the Department of Energy’s Idaho National Engineering and Environmental Laboratory (INEEL) Subsurface Disposal Area from 1952 to 1969. To begin the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remediation process for the Subsurface Disposal Area, the Environmental Protection Agency (EPA) added the INEEL to its National Priorities List in 1989. DOE’s Office of Environmental Restoration is planning several CERCLA treatability studies of remedial technologies that will be evaluated for potential remediation of the buried waste in the Subsurface Disposal Area. This paper discusses the in situ treatability studies that will be performed, including in situ vitrification, in situ grouting, and in situ thermal desorption. The in situ treatability studies will be conducted on simulated and actual buried wastes at the INEEL in 1999 and 2000. Results from the treatability studies will provide substantial information on the feasibility, implementability, and cost of applying these technologies to the INEEL Subsurface Disposal Area. In addition, much of the treatability study data will be applicable to buried waste site remediation efforts across the DOE complex.

  8. Microwave remote sensing of physically buried objects in the Negev desert: Implications for subsurface Martian exploration

    NASA Astrophysics Data System (ADS)

    Daniels, Julian; Blumberg, Dan G.; Vulfson, Leonid D.; Kotlyar, Alex L.; Freiliker, Valentin; Ronen, Gefen; Ben-Asher, Jiftach

    2003-03-01

    We report the remote detection of a physically buried specular reflecting object using microwave radar at Ashalim in the northern region of the Negev desert, Israel. Such detection provides an important terrestrial analogy for the potential detection of specularly reflecting subsurfaces under the desiccated regolith on Mars, such as ground-ice and liquid water. At Ashalim, a scatterometer operating in the P-band (441 MHz, 68 cm) was mounted on a cherry picker truck at a height of 8 m and used to detect two triangular aluminum mesh reflectors (forming a one meter square area reflector) buried down to a depth of 8 cm in dry sand. The decrease in measured backscattered power with increasing burial depth of the reflector is clearly evident. The experimental results compare well with a theoretical model that incorporates radar absorption effects arising in the sandy subsurface layer and radar interference effects arising from phase differences between reflections from the surface and buried reflector. This experiment and the associated modeling approach is the first of a series of planned experiments, which we outline for the detection and the theoretical evaluation of buried reflectors using remote microwave and VHF radar. We identify many potential subject areas for subsurface remote sensing in the Martian domain, particularly groundwater/ground-ice.

  9. Influence of Population Density on Offspring Number and Size in Burying Beetles

    ERIC Educational Resources Information Center

    Rauter, Claudia M.

    2010-01-01

    This laboratory exercise investigates the influence of population density on offspring number and size in burying beetles. Students test the theoretical predictions that brood size declines and offspring size increases when competition over resources becomes stronger with increasing population density. Students design the experiment, collect and…

  10. Hypothesis about the function of membrane-buried proline residues in transport proteins.

    PubMed Central

    Brandl, C J; Deber, C M

    1986-01-01

    In a survey of the bilayer-spanning regions of integral membrane proteins, membrane-buried proline residues were found in nearly all transport proteins examined, whereas membrane-buried regions of nontransport proteins were largely devoid of intramembranous proline residues. When amino acids from the complete sequences of representative sets of transport and nontransport membrane proteins were analyzed for the distribution of proline residues between aqueous vs. membranous domains, proline was shown to be selectively excluded from membranous domains of the nontransport proteins, in accord with expectation from energetic and structural considerations. In contrast, proline residues in transport proteins were evenly distributed between aqueous and membranous domains, consistent with the notion that functional membrane-buried proline residues are selectively included in transport proteins. As cis peptide bonds involving proline arise in proteins and have been implicated in protein dynamic processes, the cis-trans isomerization of an Xaa-Pro peptide bond (Xaa = unspecified amino acid) buried within the membrane--and the resulting redirection of the protein chain--is proposed to provide the reversible conformational change requisite for the regulation (opening/closing) of a transport channel. Parallel to this function, the relatively negative character of the carbonyl groups of Xaa-Pro peptide bonds may promote their participation as intramembranous liganding sites for positive species in proton/cation transport processes. PMID:3456574

  11. Testosterone reduces cumulative burying in female Wistar rats with minimal participation of estradiol.

    PubMed

    Gutiérrez-García, Ana G; Contreras, Carlos M; Vásquez-Hernández, Diana I; Molina-Jiménez, Tania; Jacome-Jacome, Emma

    2009-10-01

    Testosterone exerts anxiolytic effects, but the participation of its aromatase metabolic product estradiol is controversial. Therefore, we used the defensive burying paradigm in female Wistar rats to explore testosterone's (1.0 mg/rat, s.c.) interactions with picrotoxin (a noncompetitive gamma-aminobutyric acid-A receptor [GABA(A)] antagonist; 1.0 mg/kg, i.p.), formestane (an aromatase inhibitor; 3.0 mg/rat, s.c.), and tamoxifen (an estrogen receptor-beta antagonist; 1.0 mg/kg, s.c.). Serum levels of testosterone, estradiol, and progesterone were determined in the same rats. Burying latency and locomotion did not significantly change. Systemic testosterone administration enhanced serum testosterone and estradiol levels and reduced defensive burying. This reduction in total burying was blocked by pretreatment with picrotoxin and tamoxifen, but not formestane. We conclude that testosterone produced anxiolytic-like effects in female rats that were mediated by actions at the GABA(A) receptor, with participation of the estradiol receptor-beta, rather than estradiol aromatization. PMID:19520107

  12. Bioelectrochemical denitrification on biocathode buried in simulated aquifer saturated with nitrate-contaminated groundwater.

    PubMed

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-08-01

    Nitrate contamination in aquifers has posed human health under high risk because people still rely on groundwater withdrawn from aquifers as drinking water and running water sources. These days, bioelectrochemical technologies have shown a great number of benefits for nitrate remediation via autotrophic denitrification in groundwater. This study tested the working possibility of a denitrifying biocathode when installed into a simulated aquifer. The reactors were filled with sand and synthetic groundwater at various ratios (10, 50, and 100 %) to clarify the effect of various biocathode states (not-buried, half-buried, and fully buried) on nitrate reduction rate and microbial communities. Decreases in specific nitrate reduction rates were found to be correlated with increases in sand/medium ratios. A specific nitrate reduction rate of 322.6 mg m(-2) day(-1) was obtained when the biocathode was fully buried in an aquifer. Microbial community analysis revealed slight differences in the microbial communities of biocathodes at various sand/medium ratios. Various coccus- and rod-shaped bacteria were found to contribute to bioelectrochemical denitrification including Thiobacillus spp. and Paracoccus spp. This study demonstrated that the denitrifying biocathode could work effectively in a saturated aquifer and confirmed the feasibility of in situ application of microbial electrochemical denitrification technology. PMID:27117152

  13. ENVIRONMENTAL IMPACTS TO THE CHEMICAL SIGNATURE EMANATING FROM BURIED UNEXPLODED ORDNANCE

    EPA Science Inventory

    The goal of locating buried UXO and landmines is a significant challenge to science and technology. Technology development efforts are under way to use chemical sensors that can discriminate inert ordnance and clutter from live munitions that continue to be a threat. However, t...

  14. Feasibility of fast neutron analysis for the detection of explosives buried in soil

    NASA Astrophysics Data System (ADS)

    Faust, A. A.; McFee, J. E.; Bowman, C. L.; Mosquera, C.; Andrews, H. R.; Kovaltchouk, V. D.; Ing, H.

    2011-12-01

    A commercialized thermal neutron analysis (TNA) sensor has been developed to confirm the presence of buried bulk explosives as part of a multi-sensor anti-tank landmine detection system. Continuing improvements to the TNA system have included the use of an electronic pulsed neutron generator that offers the possibility of applying fast neutron analysis (FNA) methods to improve the system's detection capability. This paper describes an investigation into the use of FNA as a complementary component in such a TNA system. The results of a modeling study using simple geometries and a full model of the TNA sensor head are presented, as well as preliminary results from an experimental associated particle imaging (API) system that supports the modeling study results. The investigation has concluded that the pulsed beam FNA approach would not improve the detection performance of a TNA system for landmine or buried IED detection in a confirmation role, and could not be made into a practical stand-alone detection system for buried anti-tank landmines. Detection of buried landmines and IEDs by FNA remains a possibility, however, through the use of the API technique.

  15. Road detection and buried object detection in elevated EO/IR imagery

    NASA Astrophysics Data System (ADS)

    Kennedy, Levi; Kolba, Mark P.; Walters, Joshua R.

    2012-06-01

    To assist the warfighter in visually identifying potentially dangerous roadside objects, the U.S. Army RDECOM CERDEC Night Vision and Electronic Sensors Directorate (NVESD) has developed an elevated video sensor system testbed for data collection. This system provides color and mid-wave infrared (MWIR) imagery. Signal Innovations Group (SIG) has developed an automated processing capability that detects the road within the sensor field of view and identifies potentially threatening buried objects within the detected road. The road detection algorithm leverages system metadata to project the collected imagery onto a flat ground plane, allowing for more accurate detection of the road as well as the direct specification of realistic physical constraints in the shape of the detected road. Once the road has been detected in an image frame, a buried object detection algorithm is applied to search for threatening objects within the detected road space. The buried object detection algorithm leverages textural and pixel intensity-based features to detect potential anomalies and then classifies them as threatening or non-threatening objects. Both the road detection and the buried object detection algorithms have been developed to facilitate their implementation in real-time in the NVESD system.

  16. 75 FR 59933 - Specifications and Drawings for Construction of Direct Buried Plant

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ...The Rural Utilities Service (RUS) is amending its regulations on Telecommunications Policies on Specifications, Acceptable Materials, and Standard Contract Forms, by revising RUS Bulletin 1753F-150, Specifications and Drawings for Construction of Direct Buried Plant (Form 515a). The revised specifications will include new construction units for Fiber-to-the-Home, remove redundant or outdated......

  17. A Large Buried Felsic/Anorthositic Component in the Ancient Martian Crust

    NASA Astrophysics Data System (ADS)

    Baratoux, D.; Monnereau, M.; Samuel, H.; Michaut, C.; Wieczorek, M. A.

    2014-11-01

    The density of the basaltic component of the martian crust is revised to values >3100 kg/m3 in light of new data. A buried light (feldic/anorthositic) component is required to explain the field of gravity. It possible origins are discussed.

  18. Remotely controlled vehicles and systems for integrated remediation of buried tru wastes

    SciTech Connect

    Tucker, H.J.; Ballantyne, J.; Rife, G.; Fung, P.

    1996-12-31

    This paper describes the design, implementation and testing of remotely controlled vehicle systems developed for cooperative retrieval and transportation of Transuranic (TRU) buried wastes. The systems described are for the control of a Remote Excavator (REMEX), a Self Guided Transfer Vehicle (SGTV), a Remotely Controlled Materials Handling System and a Virtual Environment for Remote Operations (VERO), using imaging by a 3D Laser Camera.

  19. Infrared emission from hydrogenated amorphous carbon and amorphous carbon grains in the interstellar medium

    NASA Technical Reports Server (NTRS)

    Duley, W. W.; Jones, A. P.; Taylor, S. D.; Williams, D. A.

    1993-01-01

    The correlations deduced by Boulanger et al. (1990) from IRAS maps of the Chamaeleon, Taurus and Ursa Major molecular cloud complexes are interpreted in terms of the evolutionary hydrogenated amorphous carbon model of interstellar dust. In particular, regions of relatively strong 12-micron emission may be regions where recently accreted carbon is being converted by ambient UV to small PAHs in situ. Regions of weak 12-micron emission are probably quiescent regions where carbon has been annealed to amorphous carbon. Observational consequences of these inferences are briefly described.

  20. Amorphous-silicon module hot-spot testing

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.

    1985-01-01

    Hot spot heating occurs when cell short-circuit current is lower than string operating current. Amorphous cell hot spot are tested to develop the techniques required for performing reverse bias testing of amorphous cells. Also, to quantify the response of amorphous cells to reverse biasing. Guidelines are developed from testing for reducing hot spot susceptibility of amorphous modules and to develop a qualification test for hot spot testing of amorphous modules. It is concluded that amorphous cells undergo hot spot heating similarly to crystalline cells. Comparison of results obtained with submodules versus actual modules indicate heating levels lower in actual modules. Module design must address hot spot testing and hot spot qualification test conducted on modules showed no instabilities and minor cell erosion.

  1. Thermal properties of amorphous/crystalline silicon superlattices.

    PubMed

    France-Lanord, Arthur; Merabia, Samy; Albaret, Tristan; Lacroix, David; Termentzidis, Konstantinos

    2014-09-01

    Thermal transport properties of crystalline/amorphous silicon superlattices using molecular dynamics are investigated. We show that the cross-plane conductivity of the superlattices is very low and close to the conductivity of bulk amorphous silicon even for amorphous layers as thin as ≃ 6 Å. The cross-plane thermal conductivity weakly increases with temperature which is associated with a decrease of the Kapitza resistance with temperature at the crystalline/amorphous interface. This property is further investigated considering the spatial analysis of the phonon density of states in domains close to the interface. Interestingly, the crystalline/amorphous superlattices are shown to display large thermal anisotropy, according to the characteristic sizes of elaborated structures. These last results suggest that the thermal conductivity of crystalline/amorphous superlattices can be phonon engineered, providing new directions for nanostructured thermoelectrics and anisotropic materials in thermal transport. PMID:25105883

  2. Formation of amorphous silicon by light ion damage

    SciTech Connect

    Shih, Y.C.

    1985-12-01

    Amorphization by implantation of boron ions (which is the lightest element generally used in I.C. fabrication processes) has been systematically studied for various temperatures, various voltages and various dose rates. Based on theoretical considerations and experimental results, a new amorphization model for light and intermediate mass ion damage is proposed consisting of two stages. The role of interstitial type point defects or clusters in amorphization is emphasized. Due to the higher mobility of interstitials out-diffusion to the surface particularly during amorphization with low energy can be significant. From a review of the idealized amorphous structure, diinterstitial-divacancy pairs are suggested to be the embryos of amorphous zones formed during room temperature implantation. The stacking fault loops found in specimens implanted with boron at room temperature are considered to be the origin of secondary defects formed during annealing.

  3. Validating Ancient Age of the Buried Floor of the Northern Lowlands, Mars

    NASA Technical Reports Server (NTRS)

    Buczkowski, D. L.; Frey, H. V.; Roark, J. H.; McGill, G. E.

    2004-01-01

    Hesperian and Amazonian plains units cover the northern lowlands but little is known about what this surface covers. Models for the creation of the lowlands and the dichotomy boundary implement mechanisms which vary from internal processes, such as plate tectonics or first-order mantle convection, to external processes, such as a single large impact or multiple impacts. Different models require different time scales for low-land formation; determining the age of the buried low-land surface would help constrain the formation models. The Mars Orbiting Laser Altimeter (MOLA) has yielded a high-precision, topographic gridded data set that reveals the presence of Quasi-Circular Depressions (QCDs) in both the southern highlands and the northern lowlands. Most of these roughly circular depressions have no corresponding visible structural feature on the surface. It is proposed that these QCDs are the surface representation of buried impact craters. Based on this assumption, cumulative number vs. diameter curves were constructed, which placed the age of the buried surface of the northern lowlands in the Early or pre-Noachian. A Noachian basement is supported by the remnants of large craters and multi-ring basins discovered in earlier research, but the QCDs provide the first evidence of this for the entire lowland. Constraining the age of the basement floor to the earliest Noachian, however, would require that the process that formed the northern lowlands either occurred in the early Noachian or involves removal of material from the bottom of the crust without destroying the previously formed craters to achieve the modeled crustal thinning. But can we establish that the QCDs do in fact represent buried impact craters, and thus validate an Early Noachian age for the buried lowland floor?

  4. Buried soils of Late Quaternary moraines of the Wind River Mountains, Wyoming

    SciTech Connect

    Dahms, D.E. . Geography Dept.)

    1992-01-01

    Buried soils occur on kettle floors of four Pinedale moraine catenas of the western Wind River Mountains of Wyoming. Radiocarbon ages from bulk samples of Ab horizons indicate the soils were buried during the mid-Holocene. Soils on kettle floors have silty A and Bw horizons that overlie buried A and B horizons that also formed in silt-rich sediments. Crests and backslope soils also have A and Bw horizons of sandy loam formed over 2BCb and 2Cb horizons of stony coarse loamy sand. Recent data show the silty textures of the A and B horizons are due to eolian silt and clay from the Green River Basin just west of the mountains. The buried soils appear to represent alternate periods of erosion and deposition on the moraines during the Holocene. The original soils developed on higher slopes of the moraines were eroded during the mid-Holocene and the 2BC and 2C horizons exposed at the surface. Eroded soil sediments were transported downslope onto the kettle floors. Following erosion, silt-rich eolian sediments accumulated on all surfaces and mixed with the BC and C horizons (the mixed loess of Shroba and Birkeland). The present surface soils developed within this silt-rich material. Stone lines often occur at the Bw-2BCb/2Cb boundary, and mark the depth to which the earlier soils were eroded. Thus, soil profiles at the four localities result from two periods of soil formation, interrupted by an interval of erosion during the mid-Holocene. Moraines of this study are adjacent to the Fremont Lake type area for the Pinedale glaciation of the Rocky Mountains. Buried soils in kettles of the moraines indicates the soil characteristics of the Pinedale type region are not necessarily due to continuous post-Pinedale development, but may result from more than one episode of soil formation.

  5. Significant role of structural fractures in Ren-Qiu buried-block oil field, eastern China

    SciTech Connect

    Fei, Q.; Xie-Pei, W.

    1983-03-01

    Ren-qui oil field is in a buried block of Sinian (upper Proterozoic) rocks located in the Ji-zhong depression of the western Bohai Bay basin in eastern China. The main reservoir consists of Sinian dolomite rocks. It is a fault block with a large growth fault on the west side which trends north-northeast with throws of up to 1 km (0.6 mi) or more. The source rocks for the oil are Paleogene age and overlie the Sinian dolomite rocks. The structural fractures are the main factor forming the reservoir of the buried-block oil field. Three structural lines, trending northeast, north-northeast, and northwest, form the regional netted fracture system. The north-northeast growth fault controlled the structural development of the buried block. The block was raised and eroded before the Tertiary sediments were deposited. In the Eocene Epoch, the Ji-zhong depression subsided, but the deposition, faulting, and related uplift of the block happened synchronously as the block was gradually submerged. At the same time, several horizontal and vertical karst zones were formed by the karst water along the netted structural fractures. The Eocene oil source rocks lapped onto the block and so the buried block, with many developed karst fractures, was surrounded by a great thickness of source rocks. As the growth fault developed, the height of the block was increased from 400 m (1300 ft) before the Oligocene to 1300 m (4250 ft) after. As the petroleum was generated, it migrated immediately into the karst fractures of the buried block along the growth fault. The karst-fractured block reservoir has an 800-m (2600-ft) high oil-bearing closure and good connections developed between the karst fractures.

  6. Carbon stored in peatlands formed by terrestrialization: the importance of buried lake sediments

    NASA Astrophysics Data System (ADS)

    Talbot, J.

    2015-12-01

    A lot of efforts have been made over the last few decades to quantify the amount of carbon stored in soils, including in peat-producing systems. Estimates of soil carbon storage at the landscape scale has to take into account all buried carbon pools, including deep-buried lake sediments found under many peatlands that formed by terrestrialization. To illustrate the importance of buried lake sediments in the overall carbon storage of a peatland site, we studied a small peat swamp located in Gatineau Park (Quebec, Canada), the Folly peatland (45°27'18.12"N 75°46'57.38''W). This 7 ha peatland developed from a small lake that appeared after the postglacial Champlain Sea receded from the region, about 12 200 years ago. Its development followed a classical terrestrialization sequence and its hydrology has been stable since peat inception. A profile of over 8.5 m of organic matter was collected at the site, of which 2.5 m is peat and the rest is composed of lake sediments (gyttja). With the exception of a few tephra layers, the organic matter content exceeds 75 % of dry weight for the entire profile. Although it constitutes only 30 % of the profile depth, peat contains 48 % of the buried carbon because of its higher bulk density, and peat carbon accumulated at a rate of 88 g C m-2 yr-1. Overall, the site carbon density (including buried lake sediments) is 172 kg C m-2, a value comparable to the carbon density of many peatlands with much deeper peat profiles. The implications of these findings are discussed in the context of global peatland carbon inventories and peatland biogeochemistry.

  7. Groundwater Flow Dynamic Simulations of a Buried Valley Aquifer Calibrated with Field and Remotely Sensed Data

    NASA Astrophysics Data System (ADS)

    Calderhead, A. I.; Hinton, M. J.; Logan, C. E.; Sharpe, D.; Russel, H. A.; Oldenborger, G. A.; Pugin, A.; Rivera, A.; Castellazzi, P.; Martel, R.

    2013-12-01

    Buried valleys are a common occurrence in the North American prairie landscape. They are often characterized as high yield sources of groundwater in regions where low yield shale and tills dominate the hydrogeological setting. Firstly, 3D conceptual and geological models have been generated and used as a basis for creating a 3D finite element groundwater flow model. Field data, including piezometric readings, base flow measurements, and soil moisture probe data were collected between 2011 and 2013 and are used for calibrating the flow model. Secondly, the study aims to improve the spatial discretization of recharge estimates and include these refined values in the flow model. A temporal series of C-band Radar data and several land surface models were compared with the soil moisture probe data from the Spiritwood buried valley aquifer. The radar backscatter was used to develop moisture estimates at the regional scale. These estimates were then input into the HELP multi-parameter recharge model with the aim of assisting in estimates of a spatial discretization for groundwater recharge. Preliminary groundwater simulation results, with uniform recharge, show good agreement with piezometer readings and measured base flow readings. The temporal series of C-band radar backscatter, moisture probe data, and land surface models show corresponding variations between October, 2011 and October, 2012. The high resolution and regional extent of the radar data has a high potential to help develop a better understanding of recharge patterns in buried valley settings. Integrating a temporal series of high-resolution data into conceptual and numerical model development will refine our mapping, understanding and assessment of buried valley aquifers. Future work will include incorporating the spatially variable recharge estimates into the 3D finite element flow model. Additionally, various interpretations of the geological model will be tested to determine the extent, if any, that a

  8. Polyamorphous transition in amorphous fullerites C{sub 70}

    SciTech Connect

    Borisova, P. A.; Agafonov, S. S.; Glazkov, V. P.; D'yakonova, N. P.; Somenkov, V. A.

    2011-12-15

    Samples of amorphous fullerites C{sub 70} have been obtained by mechanical activation (grinding in a ball mill). The structure of the samples has been investigated by neutron and X-ray diffraction. The high-temperature (up to 1200 Degree-Sign C) annealing of amorphous fullerites revealed a polyamorphous transition from molecular to atomic glass, which is accompanied by the disappearance of fullerene halos at small scattering angles. Possible structural versions of the high-temperature amorphous phase are discussed.

  9. Amorphous silicon/polycrystalline thin film solar cells

    SciTech Connect

    Ullal, H.S.

    1991-03-13

    An improved photovoltaic solar cell is described including a p-type amorphous silicon layer, intrinsic amorphous silicon, and an n-type polycrystalline semiconductor such as cadmium sulfide, cadmium zinc sulfide, zinc selenide, gallium phosphide, and gallium nitride. The polycrystalline semiconductor has an energy bandgap greater than that of the amorphous silicon. The solar cell can be provided as a single-junction device or a multijunction device.

  10. A Re-Examination of the Relative Ages of Mare-Filled Impact Basins on the Lunar Nearside from the Gravity Signatures of Buried Craters

    NASA Astrophysics Data System (ADS)

    Evans, A. J.; Soderblom, J. M.; Solomon, S. C.; Zuber, M. T.

    2015-05-01

    GRAIL gravity data have revealed more than 100 putative buried impact craters beneath the nearside maria. We use this population of buried craters to re-assess basin chronology and the impact crater density of the lunar nearside.

  11. Advances in amorphous and nanocrystalline materials

    NASA Astrophysics Data System (ADS)

    Hasegawa, Ryusuke

    2012-10-01

    A new amorphous alloy has been recently introduced which shows a saturation magnetic induction Bs of 1.64 T which is compared with Bs=1.57 T for a currently available Fe-based amorphous alloy and decreased magnetic losses. Such a combination is rare but can be explained in terms of induced magnetic anisotropy being reduced by the alloy's chemistry and its heat treatment. It has been found that the region of magnetization rotation in the new alloy is considerably narrowed, resulting in reduced exciting power in the magnetic devices utilizing the material. Efforts to increase Bs also have been made for nanocrystalline alloys. For example, a nanocrystalline alloy having a composition of Fe80.5Cu1.5Si4B14 shows Bs exceeding 1.8 T. The iron loss at 50 Hz and at 1.6 T induction in a toroidal core of this material is 0.46 W/kg which is 2/3 that of a grain-oriented silicon steel. At 20 kHz/0.2 T excitation, the iron loss is about 60% of that in an Fe-based amorphous alloy which is widely used in power electronics. Another example is a Fe85Si2B8P4Cu1 nanocrystalline alloy with a Bs of 1.8 T, which is reported to exhibit a magnetic core loss of about 0.2 W/kg at 50 Hz and at 1.5 T induction. This article is a review of these new developments and their impacts on energy efficient magnetic devices.

  12. Structure and dynamics of amorphous water ice

    NASA Technical Reports Server (NTRS)

    Laufer, D.; Kochavi, E.; Bar-Nun, A.; Owen, T. (Principal Investigator)

    1987-01-01

    Further insight into the structure and dynamics of amorphous water ice, at low temperatures, was obtained by trapping in it Ar, Ne, H2, and D2. Ballistic water-vapor deposition results in the growth of smooth, approximately 1 x 0.2 micrometer2, ice needles. The amorphous ice seems to exist in at least two separate forms, at T < 85 K and at 85 < T < 136.8 K, and transform irreversibly from one form to the other through a series of temperature-dependent metastable states. The channels formed by the water hexagons in the ice are wide enough to allow the free penetration of H2 and D2 into the ice matrix even in the relatively compact cubic ice, resulting in H2-(D2-) to-ice ratios (by number) as high as 0.63. The larger Ar atoms can penetrate only into the wider channels of amorphous ice, and Ne is an intermediate case. Dynamic percolation behavior explains the emergence of Ar and Ne (but not H2 and D2) for the ice, upon warming, in small and big gas jets. The big jets, each containing approximately 5 x 10(10) atoms, break and propel the ice needles. Dynamic percolation also explains the collapse of the ice matrix under bombardment by Ar , at a pressure exceeding 2.6 dyn cm-2, and the burial of huge amounts of gas inside the collapsed matrix, up to an Ar-to-ice of 3.3 (by number). The experimental results could be relevant to comets, icy satellites, and icy grain mantles in dense interstellar clouds.

  13. Rapid Annealing Of Amorphous Hydrogenated Carbon

    NASA Technical Reports Server (NTRS)

    Alterovitz, Samuel A.; Pouch, John J.; Warner, Joseph D.

    1989-01-01

    Report describes experiments to determine effects of rapid annealing on films of amorphous hydrogenated carbon. Study represents first efforts to provide information for applications of a-C:H films where rapid thermal processing required. Major finding, annealing causes abrupt increase in absorption and concomitant decrease in optical band gap. Most of change occurs during first 20 s, continues during longer annealing times. Extend of change increases with annealing temperature. Researchers hypothesize abrupt initial change caused by loss of hydrogen, while gradual subsequent change due to polymerization of remaining carbon into crystallites or sheets of graphite. Optical band gaps of unannealed specimens on silicon substrates lower than those of specimens on quartz substrates.

  14. Deuterium in crystalline and amorphous silicon

    SciTech Connect

    Borzi, R.; Ma, H.; Fedders, P.A.; Leopold, D.J.; Norberg, R.E.; Boyce, J.B.; Johnson, N.M.; Ready, S.E.; Walker, J.

    1997-07-01

    The authors report deuteron magnetic resonance (DMR) measurements on aged deuterium-implanted single crystal n-type silicon and comparisons with amorphous silicon spectra. The sample film was prepared six years ago by deuteration from a-D{sub 2} plasma and evaluated by a variety of experimental methods. Deuterium has been evolving with time and the present DMR signal shows a smaller deuteron population. A doublet from Si-D configurations along (111) has decreased more than have central molecular DMR components, which include 47 and 12 kHz FWHM gaussians. Transient DMR magnetization recoveries indicate spin lattice relaxation to para-D{sub 2} relaxation centers.

  15. Mechanism for hydrogen diffusion in amorphous silicon

    SciTech Connect

    Biswas, R.; Li, Q.; Pan, B.C.; Yoon, Y.

    1998-01-01

    Tight-binding molecular-dynamics calculations reveal a mechanism for hydrogen diffusion in hydrogenated amorphous silicon. Hydrogen diffuses through the network by successively bonding with nearby silicons and breaking their Si{endash}Si bonds. The diffusing hydrogen carries with it a newly created dangling bond. These intermediate transporting states are densely populated in the network, have lower energies than H at the center of stretched Si{endash}Si bonds, and can play a crucial role in hydrogen diffusion. {copyright} {ital 1998} {ital The American Physical Society}

  16. Magnetron-Sputtered Amorphous Metallic Coatings

    NASA Technical Reports Server (NTRS)

    Thakoor, A. P.; Mehra, M.; Khanna, S. K.

    1985-01-01

    Amorphous coatings of refractory metal/metalloid-based alloys deposited by magnetron sputtering provide extraordinary hardness and wear resistance. Sputtering target fabricated by thoroughly mixing powders of tungsten, rhenium, and boron in stated proportions and pressing at 1,200 degrees C and 3,000 lb/in. to second power (21 MPa). Substrate lightly etched by sputtering before deposition, then maintained at bias of - 500 V during initial stages of film growth while target material sputtered onto it. Argon gas at pressure used as carrier gas for sputter deposition. Coatings dense, pinhole-free, extremely smooth, and significantly resistant to chemical corrosion in acidic and neutral aqueous environments.

  17. Fabrication and characterization of amorphous silica nanostructures

    NASA Astrophysics Data System (ADS)

    Jin, Lei; Wang, Jianbo; Cao, Guangyi; Choy, Wallace C. H.

    2008-06-01

    Large-scale amorphous silica nanostructures, including nanowires, nanotubes and flowerlike nanowire bunches depending on the position, have been fabricated on silicon wafer through a cheap route under the assistance of gold and germanium. Accompanying the observation of blue-green light emission, comprehensive micro-structural characterization reveals that the growth of nanostructures is catalyzed only by gold whereas the final morphology of nanostructures depends on the location to germanium ball. Au 2Si, a compound of gold and silicon, is also disclosed as an intermediate state during the catalysis. Correspondingly, a growth scheme is proposed based on the experimental results and the vapor-liquid-solid mechanism.

  18. Self-Diffusion in Amorphous Silicon

    NASA Astrophysics Data System (ADS)

    Strauß, Florian; Dörrer, Lars; Geue, Thomas; Stahn, Jochen; Koutsioubas, Alexandros; Mattauch, Stefan; Schmidt, Harald

    2016-01-01

    The present Letter reports on self-diffusion in amorphous silicon. Experiments were done on 29Si/natSi heterostructures using neutron reflectometry and secondary ion mass spectrometry. The diffusivities follow the Arrhenius law in the temperature range between 550 and 700 °C with an activation energy of (4.4 ±0.3 ) eV . In comparison with single crystalline silicon the diffusivities are tremendously higher by 5 orders of magnitude at about 700 °C , which can be interpreted as the consequence of a high diffusion entropy.

  19. Radiation resistance studies of amorphous silicon films

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.; Payson, J. Scott

    1989-01-01

    Hydrogenated amorphous silicon thin films were irradiated with 2.00 MeV helium ions using fluences ranging from 1E11 to 1E15 cm(-2). The films were characterized using photothermal deflection spectroscopy and photoconductivity measurements. The investigations show that the radiation introduces sub-band-gap states 1.35 eV below the conduction band and the states increase supralinearly with fluence. Photoconductivity measurements suggest the density of states above the Fermi energy is not changing drastically with fluence.

  20. Amorphous computing: examples, mathematics and theory.

    PubMed

    Stark, W Richard

    2013-01-01

    The cellular automata model was described by John von Neumann and his friends in the 1950s as a representation of information processing in multicellular tissue. With crystalline arrays of cells and synchronous activity, it missed the mark (Stark and Hughes, BioSystems 55:107-117, 2000). Recently, amorphous computing, a valid model for morphogenesis in multicellular information processing, has begun to fill the void. Through simple examples and elementary mathematics, this paper begins a computation theory for this important new direction. PMID:23946719