WorldWideScience

Sample records for annealed dilute systems

  1. Dynamics of ordering processes in annealed dilute systems: Island formation, vacancies at domain boundaries, and compactification

    DEFF Research Database (Denmark)

    Shah, Peter Jivan; Mouritsen, Ole G.

    1990-01-01

    The dynamics of the ordering processes in two-dimensional lattice models with annealed vacancies and nonconserved order parameter is studied as a function of temperature and vacancy concentration by means of Monte Carlo temperature-quenching simulations. The models are Ising antiferromagnets...... with couplings leading to twofold-degenerate as well as fourfold-degenerate ordering. The models are quenched into a phase-separation region, which makes it possible for both types of ordering to observe the following scenario of ordering processes: (i) early-time nucleation and growth of ordered domains, (ii...

  2. Helium dilution refrigeration system

    Science.gov (United States)

    Roach, P.R.; Gray, K.E.

    1988-09-13

    A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

  3. Effective field treatment of the annealed bond-dilute transverse Ising model

    International Nuclear Information System (INIS)

    Silva, P.R.; Sa Barreto, F.C. de

    1983-01-01

    The dilution of the spin-1/2 transverse Ising Model is studied by means of an effective field type treatment based on an extension of Callen's relation to the present model. The thermodynamics of the diluted model is obtained and the results are shown to be an improvement over the standard mean field treatment. The results are also compared with the Monte Carlo calculation for the spin-infinite transverse Ising Model. (Author) [pt

  4. Optimization Via Open System Quantum Annealing

    Science.gov (United States)

    2016-01-07

    be solved by a quantum evolution from a strong transverse field to a spin glass Hamiltonian (also known as quantum annealing or QA). We have...reduced to Quadratic Unconstrained Binary Optimization (QUBO), which can be solved by a quantum evolution from a strong transverse field to a spin...Excellence grant for Education , Research and Engineering: The number of undergraduates funded by your agreement who graduated during this period and

  5. Kinetic Monte Carlo simulation of nanostructural evolution under post-irradiation annealing in dilute FeMnNi

    Energy Technology Data Exchange (ETDEWEB)

    Chiapetto, M. [SCK-CEN, Nuclear Materials Science Institute, Mol (Belgium); Unite Materiaux et Transformations (UMET), UMR 8207, Universite de Lille 1, ENSCL, Villeneuve d' Ascq (France); Becquart, C.S. [Unite Materiaux et Transformations (UMET), UMR 8207, Universite de Lille 1, ENSCL, Villeneuve d' Ascq (France); Laboratoire commun EDF-CNRS, Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Domain, C. [EDF R and D, Departement Materiaux et Mecanique des Composants, Les Renardieres, Moret sur Loing (France); Laboratoire commun EDF-CNRS, Etude et Modelisation des Microstructures pour le Vieillissement des Materiaux (EM2VM) (France); Malerba, L. [SCK-CEN, Nuclear Materials Science Institute, Mol (Belgium)

    2015-01-01

    Post-irradiation annealing experiments are often used to obtain clearer information on the nature of defects produced by irradiation. However, their interpretation is not always straightforward without the support of physical models. We apply here a physically-based set of parameters for object kinetic Monte Carlo (OKMC) simulations of the nanostructural evolution of FeMnNi alloys under irradiation to the simulation of their post-irradiation isochronal annealing, from 290 to 600 C. The model adopts a ''grey alloy'' scheme, i.e. the solute atoms are not introduced explicitly, only their effect on the properties of point-defect clusters is. Namely, it is assumed that both vacancy and SIA clusters are significantly slowed down by the solutes. The slowing down increases with size until the clusters become immobile. Specifically, the slowing down of SIA clusters by Mn and Ni can be justified in terms of the interaction between these atoms and crowdions in Fe. The results of the model compare quantitatively well with post-irradiation isochronal annealing experimental data, providing clear insight into the mechanisms that determine the disappearance or re-arrangement of defects as functions of annealing time and temperature. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. A simple approximation method for dilute Ising systems

    International Nuclear Information System (INIS)

    Saber, M.

    1996-10-01

    We describe a simple approximate method to analyze dilute Ising systems. The method takes into consideration the fluctuations of the effective field, and is based on a probability distribution of random variables which correctly accounts for all the single site kinematic relations. It is shown that the simplest approximation gives satisfactory results when compared with other methods. (author). 12 refs, 2 tabs

  7. Automated spike preparation system for Isotope Dilution Mass Spectrometry (IDMS)

    International Nuclear Information System (INIS)

    Maxwell, S.L. III; Clark, J.P.

    1990-01-01

    Isotope Dilution Mass Spectrometry (IDMS) is a method frequently employed to measure dissolved, irradiated nuclear materials. A known quantity of a unique isotope of the element to be measured (referred to as the ''spike'') is added to the solution containing the analyte. The resulting solution is chemically purified then analyzed by mass spectrometry. By measuring the magnitude of the response for each isotope and the response for the ''unique spike'' then relating this to the known quantity of the ''spike'', the quantity of the nuclear material can be determined. An automated spike preparation system was developed at the Savannah River Site (SRS) to dispense spikes for use in IDMS analytical methods. Prior to this development, technicians weighed each individual spike manually to achieve the accuracy required. This procedure was time-consuming and subjected the master stock solution to evaporation. The new system employs a high precision SMI Model 300 Unipump dispenser interfaced with an electronic balance and a portable Epson HX-20 notebook computer to automate spike preparation

  8. Position of Effective Spins Induced by Dilution in Two-Dimensional Spin-Peierls Systems

    Science.gov (United States)

    Yasuda, Chitoshi; Miyara, Shouta

    2018-01-01

    The site- and bond-dilution effects of the nonmagnetic ground state of a two-dimensional S = 1/2 antiferromagnetic Heisenberg model, coupled with the lattice distortions on a square lattice, are investigated by performing quantum Monte Carlo simulations. In the nondiluted system, a phase diagram parameterized by the interchain interaction and the elastic constant is obtained, and the values of the lattice distortions in the dimerized phase are evaluated precisely. In the diluted system, we compare two ground-state energies assuming two patterns of lattice distortions with magnetic moments (effective spins) induced near the diluted parts and induced at the midpoint between the diluted parts. As a result, we find that it is difficult to induce effective spins near diluted parts for large elastic constants, small interchain interactions, and large concentrations of dilution.

  9. Chiral-glass transition in a diluted dipolar-interaction Heisenberg system

    International Nuclear Information System (INIS)

    Zhang Kaicheng; Liu Guibin; Zhu Yan

    2011-01-01

    Recently, numerical simulations reveal that a spin-glass transition can occur in the three-dimensional diluted dipolar system. By defining the chirality of triple spins in a diluted dipolar Heisenberg spin glass, we study the chiral ordering in the system using parallel tempering algorithm and heat bath method. The finite-size scaling analysis reveals that the system undergoes a chiral-glass transition at finite temperature. - Highlights: → We define the chirality in a diluted dipolar Heisenberg system. → The system undergoes a chiral-glass transition at finite temperature. → We extract the critical exponents of the chiral-glass transition.

  10. 30 CFR 36.49 - Tests of exhaust-gas dilution system.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests of exhaust-gas dilution system. 36.49 Section 36.49 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING... carbon dioxide, carbon monoxide, oxides of nitrogen, and aldehydes in the diluted exhaust shall be below...

  11. Replica bounds for diluted non-Poissonian spin systems

    International Nuclear Information System (INIS)

    Franz, Silvio; Leone, Michele; Toninelli, Fabio Lucio

    2003-01-01

    In this paper we extend replica bounds and free energy subadditivity arguments to diluted spin-glass models on graphs with arbitrary, non-Poissonian degree distribution. The new difficulties specific of this case are overcome introducing an interpolation procedure that stresses the relation between interpolation methods and the cavity method. As a byproduct we obtain self-averaging identities that generalize the Ghirlanda-Guerra ones to the multi-overlap case

  12. Open-System Quantum Annealing in Mean-Field Models with Exponential Degeneracy*

    Directory of Open Access Journals (Sweden)

    Kostyantyn Kechedzhi

    2016-05-01

    Full Text Available Real-life quantum computers are inevitably affected by intrinsic noise resulting in dissipative nonunitary dynamics realized by these devices. We consider an open-system quantum annealing algorithm optimized for such a realistic analog quantum device which takes advantage of noise-induced thermalization and relies on incoherent quantum tunneling at finite temperature. We theoretically analyze the performance of this algorithm considering a p-spin model that allows for a mean-field quasiclassical solution and, at the same time, demonstrates the first-order phase transition and exponential degeneracy of states, typical characteristics of spin glasses. We demonstrate that finite-temperature effects introduced by the noise are particularly important for the dynamics in the presence of the exponential degeneracy of metastable states. We determine the optimal regime of the open-system quantum annealing algorithm for this model and find that it can outperform simulated annealing in a range of parameters. Large-scale multiqubit quantum tunneling is instrumental for the quantum speedup in this model, which is possible because of the unusual nonmonotonous temperature dependence of the quantum-tunneling action in this model, where the most efficient transition rate corresponds to zero temperature. This model calculation is the first analytically tractable example where open-system quantum annealing algorithm outperforms simulated annealing, which can, in principle, be realized using an analog quantum computer.

  13. Reorganization Law and Dilution Threats in Different Financial Systems

    NARCIS (Netherlands)

    Hege, U.; Mella-Barral, P.

    2000-01-01

    In a market-based financial system, credit is held by dispersed creditors, and out-of-court renegotiation of debt is more likely to fail because of hold-out problems; in a bank-based system, out-of-court renegotiation stands good chances to succeed. Since out-of-court renegotiation is a substitute

  14. An on-line dilution system for spectrometry using an inductively coupled plasma source

    International Nuclear Information System (INIS)

    Moore, G.L.; Watson, A.E.; Humphries-Cuff, P.J.

    1982-01-01

    An on-line dilution system that uses a two-channel peristaltic pump to feed a GMK Babington type of nebulizer is described. By the use of a diluent containing the appropriate concentrations of acid, sodium, and internal standard element, which was fed at a constant rate to the nebulizer, the system produced analytical results that are not significantly different (less than 3 per cent relative) from those obtained with the normal dilution technique. However, a considerable saving in time is achieved, as well as a saving in the use of expensive reagents

  15. Long-range interactions in dilute granular systems

    NARCIS (Netherlands)

    Müller, M.K

    2008-01-01

    In this thesis, on purpose, we focussed on the most challenging, longest ranging potentials. We analyzed granular media of low densities obeying 1/r long-range interaction potentials between the granules. Such systems are termed granular gases and differ in their behavior from ordinary gases by

  16. Molecular alloy with diluted magnetic moments-molecular Kondo system.

    Science.gov (United States)

    Idobata, Yuki; Zhou, Biao; Kobayashi, Akiko; Kobayashi, Hayao

    2012-01-18

    [Ni(1-x)Cu(x)(tmdt)(2)] (tmdt = trimethylenetetrathiafulvalenedithiolate) was prepared for realizing molecular Kondo systems. Magnetic moments (S = (1)/(2)) are considered to exist at the central {CuS(4)} parts of Cu(tmdt)(2) molecules. The χT-versus-T curve of the system with x ≈ 0.15 showed a broad peak at ~10 K. The decrease in the χT value below 10 K is consistent with a singlet ground state, as expected for a Kondo system. However, in the system with x ≈ 0.27, the χT value decreased when the temperature was lowered to 2 K, indicating antiferromagnetic interactions between magnetic moments through π-d interactions. Although the susceptibility anomaly suggested that the π-d interactions become important at T K. However, the differential resistivity Δρ(T) = ρ(obs) - ρ(L)(T) showed a logarithmic resistivity increase at 8-20 K with decreasing temperature, where ρ(L)(T) is a fitted function of ρ(obs) obtained at T > 50 K that is considered to represent approximately the temperature dependence of the resistivity without spin scattering of the conduction electrons. © 2011 American Chemical Society

  17. Polymer filtration systems for dilute metal ion recovery

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

    1998-12-01

    Scientists at Los Alamos National Laboratory have developed a metal recovery system that meets the global treatment demands for all kinds of industrial and metal-processing streams. The Polymer Filtration (PF) System--a process that is easily operated and robust--offers metal-finishing businesses a convenient and inexpensive way to recover and recycle metal ions in-house, thus reducing materials costs, waste removal costs, and industrial liability. As a valuable economic and environmental asset, the PF System has been named a winner of a 1995 R and D 100 Award. These awards are presented annually by R and D Magazine to the one hundred most significant technical innovations of the year. The PF System is based on the use of water-soluble metal-binding polymers and on advanced ultrafiltration membranes. Customers for this technology will receive new soluble polymers, especially formulated for their waste stream, and the complete PF processing unit: a reaction reservoir, pumps, plumbing, controls, and the advanced ultrafiltration membranes, all in a skid mounted frame. Metal-bearing waste water is treated in the reaction reservoir, where the polymer binds with the metal ions under balanced acid/base conditions. The reservoir fluid is then pumped through the ultrafiltration system--a cartridge packed with ultrafiltration membranes shaped in hollow fibers. As the fluid travels inside the fiber, water and other small molecules--simple salts such as calcium and sodium, for example--pass through the porous membrane walls of the fibers and are discharged through the outlet as permeate. The polymer-bound metal, which is too large to pass through the pores, is both purified and concentrated inside the hollow fibers and is returned to the fluid reservoir for further waste water treatment.

  18. Homeopathic and high dilution preparations for pest management to tomato crop under organic production system

    OpenAIRE

    Modolon,Tatiani A; Boff,Pedro; Boff,Mari Inês C; Miquelluti,David José

    2012-01-01

    Tomato crops (Solanum lycopersicum) under conventional production system are constantly treated against pest and diseases, with organic synthetic pesticides that are used may cause serious disturbance to environment and human health. This research was carried out in order to study the effect of homeopathic and high dilution preparations on pests and diseases management of tomato crop under organic production system. Two experiments were conducted under field conditions and one in greenhouse. ...

  19. Cyclic Heating-Annealing and Boltzmann Distribution of Free Energies in a Spin-Glass System

    International Nuclear Information System (INIS)

    Zhou Haijun

    2007-01-01

    Ergodicity of a spin-glass is broken at low temperatures; the system is trapped in one of many ergodic configurational domains. Transitions between different ergodic domains are achievable through a heating-annealing procedure. If this experiment is repeated infinite times, all ergodic configurational domains will be visited with frequences that decreasing exponentially with their free energies. The mean free energy density of a spin-glass system on a random graph is calculated based on this free energy Boltzmann distribution in the present work, by means of the cavity approach.

  20. Prediction of two-dimensional diluted magnetic semiconductors: Doped monolayer MoS2 systems

    KAUST Repository

    Cheng, Yingchun

    2013-03-05

    Using first-principles calculations, we propose a two-dimensional diluted magnetic semiconductor: monolayer MoS2 doped by transition metals. Doping of transition metal atoms from the IIIB to VIB groups results in nonmagnetic states, since the number of valence electrons is smaller or equal to that of Mo. Doping of atoms from the VIIB to IIB groups becomes energetically less and less favorable. Magnetism is observed for Mn, Fe, Co, Zn, Cd, and Hg doping, while for the other dopants from these groups it is suppressed by Jahn-Teller distortions. Analysis of the binding energies and magnetic properties indicates that (Mo,X)S2 (X=Mn, Fe, Co, and Zn) are promising systems to explore two-dimensional diluted magnetic semiconductors.

  1. Effects of Dilution Systems in Olfactometry on the Recovery of Typical Livestock Odorants Determined by PTR-MS

    OpenAIRE

    Kasper, Pernille; Mannebeck, Dietmar; Oxbøl, Arne; Nygaard, Jens Vinge; Hansen, Michael Jørgen; Feilberg, Anders

    2017-01-01

    The present study provides an elaborate assessment of the performance of olfactometers in terms of odorant recovery for a selection of odorants emitted from livestock houses. The study includes three different olfactometer dilution systems, which have been in use at accredited odor laboratories. They consist of: (i) a custom-built olfactometer made of glass tubes, (ii) a TO8 olfactometer, and (iii) an Olfacton dilution system based on a mass flow controller. The odorants include hydrogen sulf...

  2. Insertable system for fast turnaround time microwave experiments in a dilution refrigerator.

    Science.gov (United States)

    Ong, Florian R; Orgiazzi, Jean-Luc; de Waard, Arlette; Frossati, Giorgio; Lupascu, Adrian

    2012-09-01

    Microwave experiments in dilution refrigerators are a central tool in the field of superconducting quantum circuits and other research areas. This type of experiments relied so far on attaching a device to the mixing chamber of a dilution refrigerator. The minimum turnaround time in this case is a few days as required by cooling down and warming up the entire refrigerator. We developed a new approach, in which a suitable sample holder is attached to a cold-insertable probe and brought in contact with transmission lines permanently mounted inside the cryostat. The total turnaround time is 8 h if the target temperature is 80 mK. The lowest attainable temperature is 30 mK. Our system can accommodate up to six transmission lines, with a measurement bandwidth tested from zero frequency to 12 GHz. This bandwidth is limited by low-pass components in the setup; we expect the intrinsic bandwidth to be at least 18 GHz. We present our setup, discuss the experimental procedure, and give examples of experiments enabled by this system. This new measurement method will have a major impact on systematic ultra-low temperature studies using microwave signals, including those requiring quantum coherence.

  3. Beam Halo on the LHC TCDQ Diluter System and Thermal Load on the Downstream Superconducting Magnets

    CERN Document Server

    Goddard, B; Presland, A; Redaelli, S; Robert-Démolaize, G; Sarchiapone, L; Weiler, T; Weterings, W

    2006-01-01

    The moveable single-jawed graphite TCDQ diluter must be positioned very close to the circulating LHC beam in order to prevent damage to downstream components in the event of an unsynchronised beam abort. A two-jawed graphite TCS.IR6 collimator forms part of the TCDQ system. The requirement to place the jaws close to the beam means that the system can intercept a substantial beam halo load. Initial investigations indicated a worryingly high heat load on the Q4 coils. This paper presents the updated load cases, shielding and simulation geometry, and the results of simulations of the energy deposition in the TCDQ system and in the downstream superconducting Q4 magnet. The implications for the operation of the LHC are discussed.

  4. Sewage Treatment Systems of Cruise Ships and The Parameters Affect on Dilution of Effluent at Sea

    Directory of Open Access Journals (Sweden)

    Volkan ŞAHİN

    2015-11-01

    Full Text Available Cruise ships play an inevitable role in tourism sector across the world. Increasing in cruise ship tourism accompanies with significant environmental problems. Due to both size of cruise ships and the amount of passengers and consumables, cruise ships have a great potential for producing considerable amounts of wastes. Various types of wastes are produced in cruise ships depending on the daily consumptions of these wastes. Sewage, which consists mainly the toilet wastes, is the most important problem. Sewage contains various types of heavy metal, chemicals and pathogens that have harmful effects on marine species and ecosystem. Many national and international regulations and conventions are established in order to prevent the harmful effects of wastes. Studies on preventing and minimizing ship-related pollution contribute to both developing new waste management systems and forming new procedures for removing the wastes in both ship and port. In this study, Marine Sanitation Device (MSD and Advanced Wastewater Treatment (AWT and treatment procedures are investigated. ‘Dilution factor’ obtained by theoretical and experimental studies is explained in detail and variation of dilution factor depending on ship dimensions and velocity is investigated.

  5. A cryogen-free dilution refrigerator based Josephson qubit measurement system

    Science.gov (United States)

    Tian, Ye; Yu, H. F.; Deng, H.; Xue, G. M.; Liu, D. T.; Ren, Y. F.; Chen, G. H.; Zheng, D. N.; Jing, X. N.; Lu, Li; Zhao, S. P.; Han, Siyuan

    2012-03-01

    We develop a small-signal measurement system on cryogen-free dilution refrigerator which is suitable for superconducting qubit studies. Cryogen-free refrigerators have several advantages such as less manpower for system operation and large sample space for experiment, but concern remains about whether the noise introduced by the coldhead can be made sufficiently low. In this work, we demonstrate some effective approaches of acoustic isolation to reduce the noise impact. The electronic circuit that includes the current, voltage, and microwave lines for qubit coherent state measurement is described. For the current and voltage lines designed to have a low pass of dc-100 kHz, we show that the measurements of Josephson junction's switching current distribution with a width down to 1 nA, and quantum coherent Rabi oscillation and Ramsey interference of the superconducting qubit can be successfully performed.

  6. An interactive system for creating object models from range data based on simulated annealing

    International Nuclear Information System (INIS)

    Hoff, W.A.; Hood, F.W.; King, R.H.

    1997-01-01

    In hazardous applications such as remediation of buried waste and dismantlement of radioactive facilities, robots are an attractive solution. Sensing to recognize and locate objects is a critical need for robotic operations in unstructured environments. An accurate 3-D model of objects in the scene is necessary for efficient high level control of robots. Drawing upon concepts from supervisory control, the authors have developed an interactive system for creating object models from range data, based on simulated annealing. Site modeling is a task that is typically performed using purely manual or autonomous techniques, each of which has inherent strengths and weaknesses. However, an interactive modeling system combines the advantages of both manual and autonomous methods, to create a system that has high operator productivity as well as high flexibility and robustness. The system is unique in that it can work with very sparse range data, tolerate occlusions, and tolerate cluttered scenes. The authors have performed an informal evaluation with four operators on 16 different scenes, and have shown that the interactive system is superior to either manual or automatic methods in terms of task time and accuracy

  7. Nonequilibrium spin transport through a diluted magnetic semiconductor quantum dot system with noncollinear magnetization

    International Nuclear Information System (INIS)

    Ma, Minjie; Jalil, Mansoor Bin Abdul; Tan, Seng Gee

    2013-01-01

    The spin-dependent transport through a diluted magnetic semiconductor quantum dot (QD) which is coupled via magnetic tunnel junctions to two ferromagnetic leads is studied theoretically. A noncollinear system is considered, where the QD is magnetized at an arbitrary angle with respect to the leads’ magnetization. The tunneling current is calculated in the coherent regime via the Keldysh nonequilibrium Green’s function (NEGF) formalism, incorporating the electron–electron interaction in the QD. We provide the first analytical solution for the Green’s function of the noncollinear DMS quantum dot system, solved via the equation of motion method under Hartree–Fock approximation. The transport characteristics (charge and spin currents, and tunnel magnetoresistance (TMR)) are evaluated for different voltage regimes. The interplay between spin-dependent tunneling and single-charge effects results in three distinct voltage regimes in the spin and charge current characteristics. The voltage range in which the QD is singly occupied corresponds to the maximum spin current and greatest sensitivity of the spin current to the QD magnetization orientation. The QD device also shows transport features suitable for sensor applications, i.e., a large charge current coupled with a high TMR ratio. - Highlights: ► The spin polarized transport through a diluted magnetic quantum dot is studied. ► The model is based on the Green’s function and the equation of motion method.► The charge and spin currents and tunnel magnetoresistance (TMR) are investigated. ► The system is suitable for current-induced spin-transfer torque application. ► A large tunneling current and a high TMR are possible for sensor application.

  8. Different approaches to analyze the dipolar interaction effects on diluted and concentrated granular superparamagnetic systems

    Energy Technology Data Exchange (ETDEWEB)

    Moscoso-Londoño, O., E-mail: omoscoso@ifi.unicamp.br [Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas (UNICAMP), CEP13083-859 Campinas, São Paulo (Brazil); Tancredi, P. [Laboratorio de Sólidos Amorfos, INTECIN, Facultad de Ingeniería, Universidad de Buenos Aires (UBA), CONICET, C1063ACV Buenos Aires (Argentina); Muraca, D. [Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas (UNICAMP), CEP13083-859 Campinas, São Paulo (Brazil); Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC (UFABC), Av. Dos Estados, 5001, Santo André, SP (Brazil); Mendoza Zélis, P.; Coral, D.; Fernández van Raap, M.B. [Instituto de Física, Universidad Nacional de La Plata (UNLP), CONICET, CC.67, 1900 La Plata, Buenos Aires (Argentina); Wolff, U.; Neu, V.; Damm, C. [IFW Dresden, Leibniz Institute for Solid State and Materials Research, Dresden, Helmholtzstrasse 20, 01069 Dresden (Germany); Oliveira, C.L.P. de [Instituto de Física, Universidade de São Paulo, São Paulo 05314970 (Brazil); Pirota, K.R. [Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas (UNICAMP), CEP13083-859 Campinas, São Paulo (Brazil); and others

    2017-04-15

    Controlled magnetic granular materials with different concentrations of magnetite nanoparticles immersed in a non-conducting polymer matrix were synthesized and, their macroscopic magnetic observables analyzed in order to advance towards a better understanding of the magnetic dipolar interactions and its effects on the obtained magnetic parameters. First, by means of X-ray diffraction, transmission electron microscopy, small angle X-ray scattering and X-ray absorption fine structure an accurate study of the structural properties was carried out. Then, the magnetic properties were analyzed by means of different models, including those that consider the magnetic interactions through long-range dipolar forces as: the Interacting Superparamagnetic Model (ISP) and the Vogel-Fulcher law (V-F). In systems with larger nanoparticle concentrations, magnetic results clearly indicate that the role played by the dipolar interactions affects the magnetic properties, giving rise to obtaining magnetic and structural parameters without physical meaning. Magnetic parameters as the effective anisotropic constant, magnetic moment relaxation time and mean blocking temperature, extracted from the application of the ISP model and V-F Law, were used to simulate the zero-field-cooling (ZFC) and field-cooling curves (FC). A comparative analysis of the simulated, fitted and experimental ZFC/FC curves suggests that the current models depict indeed our dilute granular systems. Notwithstanding, for concentrated samples, the ISP model infers that clustered nanoparticles are being interpreted as single entities of larger magnetic moment and volume, effect that is apparently related to a collective and complex magnetic moment dynamics within the cluster. - Highlights: • Nanoparticle architecture into matrices determines the composite magnetic response. • Magnetically diluted or compacted systems are useful to study magnetism at nanoscale. • Particle aggregation into the matrices was examined

  9. Buffer layer annealing effects on the magnetization reversal process in Pd/Co/Pd systems

    Energy Technology Data Exchange (ETDEWEB)

    Fassatoui, A., E-mail: Fassatouiaymen@Hotmail.com [LMOP: LR99ES17, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, 2092 (Tunisia); Belhi, R. [LMOP: LR99ES17, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, 2092 (Tunisia); Vogel, J. [Institut Néel (CNRS and Université Grenoble Alpes), 25 rue des Martyrs, B. P. 166, Grenoble cedex 9, 38042 (France); Abdelmoula, K. [LMOP: LR99ES17, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, 2092 (Tunisia)

    2016-12-15

    We have investigated the effect of annealing the buffer layer on the magnetization reversal behavior in Pd/Co/Pd thin films using magneto-optical Kerr microscopy. It was found that annealing the buffer layer at 150 °C for 1 h decreases the coercivity and increases the saturation magnetization and the effective magnetic anisotropy constant. This study also shows that the annealing induces a change of the magnetization reversal from a mixed nucleation and domain wall propagation process to one dominated by domain wall propagation. This result demonstrates that the main effect of annealing the buffer layer is to decrease the domain wall pinning in the Co layer, favoring the domain wall propagation mode. - Highlights: • The buffer layer surface morphology changes upon annealing of the buffer layer. • The coercivity decreases while the saturation magnetization and the effective anisotropy increase with the annealing of the buffer layer. • The reversal process changes from a mixed nucleation and domain wall propagation process to one dominated by domain wall propagation when annealing the buffer layer.

  10. Microfluidic serial dilution ladder.

    Science.gov (United States)

    Ahrar, Siavash; Hwang, Michelle; Duncan, Philip N; Hui, Elliot E

    2014-01-07

    Serial dilution is a fundamental procedure that is common to a large number of laboratory protocols. Automation of serial dilution is thus a valuable component for lab-on-a-chip systems. While a handful of different microfluidic strategies for serial dilution have been reported, approaches based on continuous flow mixing inherently consume larger amounts of sample volume and chip real estate. We employ valve-driven circulatory mixing to address these issues and also introduce a novel device structure to store each stage of the dilution process. The dilution strategy is based on sequentially mixing the rungs of a ladder structure. We demonstrate a 7-stage series of 1 : 1 dilutions with R(2) equal to 0.995 in an active device area of 1 cm(2).

  11. Dynamics of open quantum systems by interpolation of von Neumann and classical master equations, and its application to quantum annealing

    Science.gov (United States)

    Kadowaki, Tadashi

    2018-02-01

    We propose a method to interpolate dynamics of von Neumann and classical master equations with an arbitrary mixing parameter to investigate the thermal effects in quantum dynamics. The two dynamics are mixed by intervening to continuously modify their solutions, thus coupling them indirectly instead of directly introducing a coupling term. This maintains the quantum system in a pure state even after the introduction of thermal effects and obtains not only a density matrix but also a state vector representation. Further, we demonstrate that the dynamics of a two-level system can be rewritten as a set of standard differential equations, resulting in quantum dynamics that includes thermal relaxation. These equations are equivalent to the optical Bloch equations at the weak coupling and asymptotic limits, implying that the dynamics cause thermal effects naturally. Numerical simulations of ferromagnetic and frustrated systems support this idea. Finally, we use this method to study thermal effects in quantum annealing, revealing nontrivial performance improvements for a spin glass model over a certain range of annealing time. This result may enable us to optimize the annealing time of real annealing machines.

  12. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1982-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices in which the device is rapidly heated to a temperature between 450 and 900 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. (author)

  13. Revisiting the dilution procedure used to manipulate microbial biodiversity in terrestrial systems.

    Science.gov (United States)

    Yan, Yan; Kuramae, Eiko E; Klinkhamer, Peter G L; van Veen, Johannes A

    2015-07-01

    It is hard to assess experimentally the importance of microbial diversity in soil for the functioning of terrestrial ecosystems. An approach that is often used to make such assessment is the so-called dilution method. This method is based on the assumption that the biodiversity of the microbial community is reduced after dilution of a soil suspension and that the reduced diversity persists after incubation of more or less diluted inocula in soil. However, little is known about how the communities develop in soil after inoculation. In this study, serial dilutions of a soil suspension were made and reinoculated into the original soil previously sterilized by gamma irradiation. We determined the structure of the microbial communities in the suspensions and in the inoculated soils using 454-pyrosequencing of 16S rRNA genes. Upon dilution, several diversity indices showed that, indeed, the diversity of the bacterial communities in the suspensions decreased dramatically, with Proteobacteria as the dominant phylum of bacteria detected in all dilutions. The structure of the microbial community was changed considerably in soil, with Proteobacteria, Bacteroidetes, and Verrucomicrobia as the dominant groups in most diluted samples, indicating the importance of soil-related mechanisms operating in the assembly of the communities. We found unique operational taxonomic units (OTUs) even in the highest dilution in both the suspensions and the incubated soil samples. We conclude that the dilution approach reduces the diversity of microbial communities in soil samples but that it does not allow accurate predictions of the community assemblage during incubation of (diluted) suspensions in soil. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. User's manual for the ARMLID (Argonne metallic lithium/isotopic dilution) tritium assay system

    International Nuclear Information System (INIS)

    Porges, K.G.; Bretscher, M.M.; Bennett, E.F.; DiIorio, G.; Mattas, R.F.; Lewandowski, E.F.

    1992-08-01

    The Argonne Metallic Lithium - Isotopic Dilution (ARMLID) system described in this report, originally developed at ANL for other purposes, was recently redeployed to measure the tritium production rate (TPR) in a series of US/Japanese collaborative fusion blanket integral experiments, involving large assemblies of fusion breeder blanket materials that were irradiated with a fusion neutron source at FNS/JAERI, Japan. Whereas previous uses of the ARMUD scheme involved just a few samples, its application infusion blanket TPR mapping called for large sample numbers per experiment, implying a commensurate scale of sample fabrication and encapsulation, on one hand, and tritium extraction and counting on the other hand. To shorten the time required for these various tasks, yet still yield reliable and accurate results, both the sample fabrication - encapsulation facility and the tritium extraction system had to be extensively revised from original versions that were designed for accuracy, but not necessarily for speed. The present report describes overall revisions in sufficient detail to serve as a User's Manual for this facility, and/or suggest how a new system might be put together. Either possibility may develop in the near future, in support of ITER design studies. Preliminary and partial descriptions of various aspects and features of the system were presented orally, in the course of annual ANL/JAERI/UCLA ''workshops'', over the last 34 years, as well as elsewhere

  15. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1981-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices is described in which the device is rapidly heated to a temperature between 450 and 600 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. The process may be enhanced by the application of optical radiation from a Xenon lamp. (author)

  16. La-NMR study on a La dilute system of PrPb{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Y; Sakai, H; Chudo, H; Kambe, S; Yasuoka, H [ASRC, Japan Atomic Energy Agency, Tokai, Naka, Ibaraki 319-1195 (Japan); Suzuki, H S [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Homma, Y; Aoki, D; Shiokawa, Y, E-mail: tokunaga.yo@jaea.go.j [IMR Tohoku University, Narita Oarai Higashiibaraki Ibaraki 311-1313 (Japan)

    2009-03-01

    We report the first {sup 139} La-NMR measurements on a La dilute system of PrPb{sub 3}. We have succeeded to detect {sup 139}La-NMR signal on a powder sample of Pr{sub 0.97}La{sub 0.03}Pb{sub 3} and extracted the temperature dependence of the Knight shift{sup 139}La K(T) in a temperature range between 1.5 and 220 K. K(T) has been found to maintain a linear relation with the bulk-susceptibility {sub chi}(T){sup bulk} in wide temperature range, except for a small deviation in the temperature region below 6 K. The slopes of the{sup 139} K vs nu{sup bulk} plots yield for the hyperfine coupling constants A{sub hf} the value 375 Oe/muB. From the NMR results, we discuss the effect of the La substitutions on microscopic magnetic properties of PrPb{sub 3}.

  17. A high current sinusoidal pulse generator for the diluter magnets of the LHC beam dump system

    CERN Document Server

    Vossenberg, Eugène B; Ducimetière, L; Schröder, G H

    2000-01-01

    CERN is constructing the Large Hadron Collider (LHC), a superconducting accelerator that will collide protons at a center of mass energy of 14 TeV. The two colliding beams will each store an energy of up to 540 MJ, which must be safely deposited within one beam revolution of 89 mu s on two external absorbers located about 700 m from the extraction points at the end of dedicated extraction tunnels. To avoid evaporation of the graphite absorber material by the very high energy density of the incident beams, the deposition area of the beams on the absorber front face will be increased. This is done by a pair of sinusoidally powered orthogonal magnet systems producing approximately an e-shape figure of about 35 mm diameter, with a minimum velocity of 10 mm/ mu s during the dumping process. The pulse generators of the horizontally and vertically deflecting diluter magnets are composed of capacitor banks, discharged by stacks of solid state closing switches. They are connected to the magnets by 28 m long low induct...

  18. A constant-volume rapid exhaust dilution system for motor vehicle particulate matter number and mass measurements.

    Science.gov (United States)

    Maricq, M Matti; Chase, Richard E; Xu, Ning; Podsiadlik, Diane H

    2003-10-01

    An improved version of the constant volume sampling (CVS) methodology that overcomes a number of obstacles that exist with the current CVS dilution tunnel system used in most diesel and gasoline vehicle emissions test facilities is presented. The key feature of the new sampling system is the introduction of dilution air immediately at the vehicle tailpipe. In the present implementation, this is done concentrically through a cylindrical air filter. Elimination of the transfer hose conventionally used to connect the tailpipe to the dilution tunnel significantly reduces the hydrocarbon and particulate matter (PM) storage release artifacts that can lead to wildly incorrect particle number counts and to erroneous filter-collected PM mass. It provides accurate representations of particle size distributions for diesel vehicles by avoiding the particle coagulation that occurs in the transfer hose. Furthermore, it removes the variable delay time that otherwise exists between the time that emissions exit the tailpipe and when they are detected in the dilution tunnel. The performance of the improved CVS system is examined with respect to diesel, gasoline, and compressed natural gas vehicles.

  19. Different approaches to analyze the dipolar interaction effects on diluted and concentrated granular superparamagnetic systems

    Science.gov (United States)

    Moscoso-Londoño, O.; Tancredi, P.; Muraca, D.; Mendoza Zélis, P.; Coral, D.; Fernández van Raap, M. B.; Wolff, U.; Neu, V.; Damm, C.; de Oliveira, C. L. P.; Pirota, K. R.; Knobel, M.; Socolovsky, L. M.

    2017-04-01

    Controlled magnetic granular materials with different concentrations of magnetite nanoparticles immersed in a non-conducting polymer matrix were synthesized and, their macroscopic magnetic observables analyzed in order to advance towards a better understanding of the magnetic dipolar interactions and its effects on the obtained magnetic parameters. First, by means of X-ray diffraction, transmission electron microscopy, small angle X-ray scattering and X-ray absorption fine structure an accurate study of the structural properties was carried out. Then, the magnetic properties were analyzed by means of different models, including those that consider the magnetic interactions through long-range dipolar forces as: the Interacting Superparamagnetic Model (ISP) and the Vogel-Fulcher law (V-F). In systems with larger nanoparticle concentrations, magnetic results clearly indicate that the role played by the dipolar interactions affects the magnetic properties, giving rise to obtaining magnetic and structural parameters without physical meaning. Magnetic parameters as the effective anisotropic constant, magnetic moment relaxation time and mean blocking temperature, extracted from the application of the ISP model and V-F Law, were used to simulate the zero-field-cooling (ZFC) and field-cooling curves (FC). A comparative analysis of the simulated, fitted and experimental ZFC/FC curves suggests that the current models depict indeed our dilute granular systems. Notwithstanding, for concentrated samples, the ISP model infers that clustered nanoparticles are being interpreted as single entities of larger magnetic moment and volume, effect that is apparently related to a collective and complex magnetic moment dynamics within the cluster.

  20. X-ray absorption spectroscopy of diluted system by undulator photon source and multi-element solid-state detector

    CERN Document Server

    Tanida, H

    2001-01-01

    In order to measure the extended X-ray absorption fine structure (EXAFS) spectrum of an ultra-diluted system, an optics and detector control system for a synchrotron radiation beamline is developed. The undulator gap width is continuously tuned to obtain the maximum X-ray photon flux during the energy scan for the EXAFS measurement. A piezoelectric translator optimizes the parallelism of the double crystal in a monochromator at each measurement point to compensate for mechanical errors of the monochromator, resulting in a smooth and intense X-ray photon flux during the measurement. For a detection of a weak fluorescence signal from diluted samples, a 19-element solid-state detector and digital signal processor are used. A K-edge EXAFS spectrum of iron in a myoglobin aqueous solution with a concentration of 5.58 parts per million was obtained by this system.

  1. Open-System Quantum Annealing in Mean-Field Models with Exponential Degeneracy

    Science.gov (United States)

    2016-08-25

    5355 (1998). [6] S. Geman and D. Geman, Stochastic Relaxation, Gibbs Distributions, and the Bayesian Restoration of Images , IEEE Trans. Pattern Anal...R. Martonak, E. Tosatti, and R. Car, Theory of Quantum Annealing of an Ising Spin Glass, Science 295, 2427 (2002). [12] V. Bapst, L. Foini, F...the Theory of Rydberg Atoms in External Fields, Rev. Mod. Phys. 65, 115 (1993). [19] S. A. Owerre and M. B. Paranjape, Macroscopic Quantum Tunneling

  2. Classical experiments in whole-body metabolism: open-circuit respirometry-diluted flow chamber, hood, or facemask systems.

    Science.gov (United States)

    Schoffelen, P F M; Plasqui, G

    2018-01-01

    For over two centuries, scientists have measured gas exchange in animals and humans and linked this to energy expenditure of the body. The aim of this review is to provide a comprehensive overview of open-circuit diluted flow indirect calorimetry and to help researchers to make the optimal choice for a certain system and its application. A historical perspective shows that 'open circuit diluted flow' is a technique first used in the 19th century and applicable today for room calorimeters, ventilated hood systems, and facemasks. Room calorimeters are a classic example of an open-circuit diluted flow system. The broadly applied ventilated hood calorimeters follow the same principle and can be classified as a derivative of these room calorimeters. The basic principle is that the subject breathes freely in a passing airflow that is fully captured and analyzed. Oxygen and CO 2 concentrations are measured in inlet ambient air and captured outlet air. The airflow, which is adapted depending on the application (e.g., rest versus exercise), is measured. For a room indirect calorimeter, the dilution in the large room volume is also taken into account, and this is the most complex application of this type of calorimeter. Validity of the systems can be tested by alcohol burns, gas infusions and by performing repeated measurements on subjects. Using the latter, the smallest CV (%) was found for repeated VO 2max tests (1.2%) with an SD of approximately 1 kJ min -1 . The smallest SD was found for sleeping metabolic rate (0.11 kJ min -1 ) with a CV (%) of 2.4%.

  3. Dilution Confusion: Conventions for Defining a Dilution

    Science.gov (United States)

    Fishel, Laurence A.

    2010-01-01

    Two conventions for preparing dilutions are used in clinical laboratories. The first convention defines an "a:b" dilution as "a" volumes of solution A plus "b" volumes of solution B. The second convention defines an "a:b" dilution as "a" volumes of solution A diluted into a final volume of "b". Use of the incorrect dilution convention could affect…

  4. PREFACE: Many-body correlations from dilute to dense nuclear systems

    Science.gov (United States)

    Otsuka, Takaharu; Urban, Michael; Yamada, Taiichi

    2011-09-01

    The International EFES-IN2P3 conference on "Many body correlations from dilute to dense nuclear systems" was held at the Institut Henri Poincaré (IHP), Paris, France, from 15-18 February 2011, on the occasion of the retirement of our colleague Peter Schuck. Correlations play a decisive role in various many-body systems such as nuclear systems, condensed matter and quantum gases. Important examples include: pairing correlations (Cooper pairs) which give rise to nuclear superfluidity (analogous to superconductivity in condensed matter); particle-hole (RPA) correlations in the description of the ground state beyond mean-field theory; clusters; and α-particle correlations in certain nuclei. Also, the nucleons themselves can be viewed as clusters of three quarks. During the past few years, researchers have started to study how the character of these correlations changes with the variation of the density. For instance, the Cooper pairs in dense matter can transform into a Bose-Einstein condensate (BEC) of true bound states at low density (this is the BCS-BEC crossover studied in ultracold Fermi gases). Similar effects play a role in neutron matter at low density, e.g., in the "neutron skin" of exotic nuclei. The α-cluster correlation becomes particularly important at lower density, such as in the excited states of some nuclei (e.g., the α-condensate-like structure in the Hoyle state of 12C) or in the formation of compact stars. In addition to nuclear physics, topics from astrophysics (neutron stars), condensed matter, and quantum gases were discussed in 48 talks and 19 posters, allowing the almost 90 participants from different communities to exchange their ideas, experiences and methods. The conference dinner took place at the Musée d'Orsay, and all the participants enjoyed the very pleasant atmosphere. One session of the conference was dedicated to the celebration of Peter's retirement. We would like to take this opportunity to wish Peter all the best and we hope

  5. A quantum annealing approach for fault detection and diagnosis of graph-based systems

    Science.gov (United States)

    Perdomo-Ortiz, A.; Fluegemann, J.; Narasimhan, S.; Biswas, R.; Smelyanskiy, V. N.

    2015-02-01

    Diagnosing the minimal set of faults capable of explaining a set of given observations, e.g., from sensor readouts, is a hard combinatorial optimization problem usually tackled with artificial intelligence techniques. We present the mapping of this combinatorial problem to quadratic unconstrained binary optimization (QUBO), and the experimental results of instances embedded onto a quantum annealing device with 509 quantum bits. Besides being the first time a quantum approach has been proposed for problems in the advanced diagnostics community, to the best of our knowledge this work is also the first research utilizing the route Problem → QUBO → Direct embedding into quantum hardware, where we are able to implement and tackle problem instances with sizes that go beyond previously reported toy-model proof-of-principle quantum annealing implementations; this is a significant leap in the solution of problems via direct-embedding adiabatic quantum optimization. We discuss some of the programmability challenges in the current generation of the quantum device as well as a few possible ways to extend this work to more complex arbitrary network graphs.

  6. Circuit design for multi-body interactions in superconducting quantum annealing systems with applications to a scalable architecture

    Science.gov (United States)

    Chancellor, N.; Zohren, S.; Warburton, P. A.

    2017-06-01

    Quantum annealing provides a way of solving optimization problems by encoding them as Ising spin models which are implemented using physical qubits. The solution of the optimization problem then corresponds to the ground state of the system. Quantum tunneling is harnessed to enable the system to move to the ground state in a potentially high non-convex energy landscape. A major difficulty in encoding optimization problems in physical quantum annealing devices is the fact that many real world optimization problems require interactions of higher connectivity, as well as multi-body terms beyond the limitations of the physical hardware. In this work we address the question of how to implement multi-body interactions using hardware which natively only provides two-body interactions. The main result is an efficient circuit design of such multi-body terms using superconducting flux qubits in which effective N-body interactions are implemented using N ancilla qubits and only two inductive couplers. It is then shown how this circuit can be used as the unit cell of a scalable architecture by applying it to a recently proposed embedding technique for constructing an architecture of logical qubits with arbitrary connectivity using physical qubits which have nearest-neighbor four-body interactions. It is further shown that this design is robust to non-linear effects in the coupling loops, as well as mismatches in some of the circuit parameters.

  7. Hydro-Thermal Scheduling by a Hybrid Evolutionary Programming—Simulated Annealing Method in a Large Power System

    Science.gov (United States)

    Nayak, Nimain Charan; Rajan, C. Christober Asir

    2010-10-01

    This Paper proposes a new hybrid algorithm for solving the Unit Commitment problem in Hydrothermal Power System using a hybrid Evolutionary Programming—Simulated Annealing method. The main objective of this project is to find the generation scheduling by committing the generating units such that the total operating cost can be minimized by satisfying both the forecasted load demand and various operating constraints of the generating units. It is a Global Optimization technique for solving Unit Commitment Problem, operates on a system, which is designed to encode each unit's operating schedule with regard to its minimum up/down time. In this method, the unit commitment schedule is coded as a string of symbols. An initial population of parent solutions is generated at random. Here the parents are obtained from a predefined set of solutions i.e. each and every solution is adjusted to meet the requirements. Then, random recommitment is carried out with respect to the unit's minimum down times. Simulated Annealing (SA) is a powerful optimization procedure that has been successfully applied to a number of combinatorial optimization problems. It avoids entrapment at local optimum by maintaining a short term memory of recently obtained solutions. Numerical results are shown comparing the cost solutions and computation time obtained by using the proposed hybrid method than conventional methods like Dynamic Programming, Lagrangian Relaxation.

  8. Comparison of haemolytic activity of tentacle-only extract from jellyfish Cyanea capillata in diluted whole blood and erythrocyte suspension: diluted whole blood is a valid test system for haemolysis study.

    Science.gov (United States)

    Wang, Qianqian; Xiao, Liang; He, Qian; Liu, Sihua; Zhang, Jing; Li, Yue; Zhang, Zhi; Nie, Fei; Guo, Yufeng; Zhang, Liming

    2012-11-01

    In this paper, we utilized two different test systems to compare the haemolysis of tentacle-only extract (TOE) devoid of nematocysts from jellyfish Cyanea capillata, the 1% whole blood and 0.45% erythrocyte suspension approximately with the same erythrocyte concentration from the blood samples of sheep, rabbit, mouse, rat and human, respectively. Without exception, the haemolytic activity of TOE was dose-dependent in both test systems from all the five kinds of blood samples, while it was generally stronger in erythrocyte suspension than that in diluted whole blood at the relatively high concentration of TOE. When various aliquots of plasma were added into the erythrocyte suspension test system, the haemolytic activity of TOE was declined with the plasma quantity increasing, and dropped to about 20% at the presence of two aliquots of plasma. If serum albumin of 0.5 mg/ml, approximately the same albumin content in 1% whole blood, was added into the erythrocyte suspension test system instead, the haemolysis of TOE was similarly inhibited. The effects of GSH, ascorbic acid and protease inhibitor on the haemolytic activity of TOE were detected in the erythrocyte suspension and diluted whole blood simultaneously, and the test results were coincident between the two systems. These results suggested that the inconsistency of TOE haemolysis between the erythrocyte suspension and diluted whole blood is a universal occurrence in the mammals, and blood plasma plays a dose-dependent protective role against haemolysis which may be due to serum albumin. Diluted whole blood is a valid and convenient test system for haemolysis study in vitro. Copyright © 2011 Elsevier GmbH. All rights reserved.

  9. Effects of Dilution Systems in Olfactometry on the Recovery of Typical Livestock Odorants Determined by PTR-MS.

    Science.gov (United States)

    Kasper, Pernille Lund; Mannebeck, Dietmar; Oxbøl, Arne; Nygaard, Jens Vinge; Hansen, Michael Jørgen; Feilberg, Anders

    2017-08-11

    The present study provides an elaborate assessment of the performance of olfactometers in terms of odorant recovery for a selection of odorants emitted from livestock houses. The study includes three different olfactometer dilution systems, which have been in use at accredited odor laboratories. They consist of: (i) a custom-built olfactometer made of glass tubes, (ii) a TO8 olfactometer, and (iii) an Olfacton dilution system based on a mass flow controller. The odorants include hydrogen sulfide, methanethiol, dimethyl sulfide, acetic acid, butanoic acid, propanoic acid, 3-methylbutanoic acid, 4-methylphenol, and trimethylamine. Furthermore, n -butanol, as the reference gas in the European standard for olfactometry, EN13725, was included. All measurements were performed in real time with proton-transfer-reaction mass spectrometry (PTR-MS). The results show that only dimethyl sulfide was almost completely recovered in all cases, while for the remaining compounds, the performance was found to vary significantly (from 0 to 100%) depending on the chemical properties of the compounds, the concentration levels, the pulse duration, and the olfactometer material. To elucidate the latter, the recovery in different locations of the TO8 olfactometer and in tubes of different materials, that is, poly-tetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), stainless steel and SilcoTek-coated steel, were tested. Significant saturation effects were observed when odorants were in contact with stainless steel.

  10. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  11. Optical Design of Dilute Nitride Quantum Wells Vertical Cavity Semiconductor Optical Amplifiers for Communication Systems

    Directory of Open Access Journals (Sweden)

    Faten A. Chaqmaqchee

    2016-04-01

    Full Text Available III-V semiconductors components such as Gallium Arsenic (GaAs, Indium Antimony (InSb, Aluminum Arsenic (AlAs and Indium Arsenic (InAs have high carrier mobilities and direct energy gaps. This is making them indispensable for today’s optoelectronic devices such as semiconductor lasers and optical amplifiers at 1.3 μm wavelength operation. In fact, these elements are led to the invention of the Gallium Indium Nitride Arsenic (GaInNAs, where the lattice is matched to GaAs for such applications. This article is aimed to design dilute nitride GaInNAs quantum wells (QWs enclosed between top and bottom of Aluminum (Gallium Arsenic Al(GaAs distributed bragg mirrors (DBRs using MATLAB® program. Vertical cavity semiconductor optical amplifiers (VCSOAs structures are based on Fabry Perot (FP method to design optical gain and bandwidth gain to be operated in reflection and transmission modes. The optical model gives access to the contact layer of epitaxial structure and the reflectivity for successive radiative modes, their lasing thresholds, emission wavelengths and optical field distributions in the laser cavity.

  12. INFLUENCE OF IMPULSE PHOTON ANNEALING ON STRUCTURE AND PHASE COMPOSITION OF THIN-FILMED SYSTEMS ON BASIS OF SILICON AND TRANSITION METALS

    Directory of Open Access Journals (Sweden)

    M. I. Markevich

    2013-01-01

    Full Text Available Methods of transmission electronic microscopy, electron diffraction, energy dispersive X-ray microanalysis have been used for investigations of element composition, regularities in structural and phase transmissions occurring in thin-filmed systems Si–Fe–Si and TiN–Ti–Si while using impulse photon annealing in terms of radiation energy density. Optimum parameters of impulse photon annealing for formation of β-FeSi2 and C54-TiSi2 thin films on silicon have been determined in the paper.

  13. H2 dilution effect in the Cat-CVD processes of the SiH4/NH3 system

    International Nuclear Information System (INIS)

    Ansari, S.G.; Umemoto, Hironobu; Morimoto, Takashi; Yoneyama, Koji; Izumi, Akira; Masuda, Atsushi; Matsumura, Hideki

    2006-01-01

    Gas-phase diagnostics in the catalytic chemical vapor deposition processes of the SiH 4 /NH 3 /H 2 system were carried out to examine the effect of H 2 dilution. The decomposition efficiency of NH 3 showed a sharp decrease with the introduction of a small amount of SiH 4 , but this decrease was recovered by the addition of H 2 when the NH 3 pressure was low. On the other hand, at higher NH 3 pressures, the decomposition efficiency showed a minor dependence on the H 2 partial pressure. The addition of SiH 4 to the NH 3 system decreases the H-atom density by one order of magnitude, but this decrease is also recovered by H 2 addition. H atoms produced from H 2 must re-activate the catalyzer surfaces poisoned by SiH 4 when the NH 3 pressure is low

  14. Survey of the chemical diffusion at infinite dilution in the nickel-plutonium and aluminium-uranium systems; Contribution a l'etude de l'heterodiffusion a dilution infinie systemes nickel-plutonium et aluminium-uranium

    Energy Technology Data Exchange (ETDEWEB)

    Blechet, J.J. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-09-01

    Solubility S{sub 0} and chemical diffusion coefficients D{sub PuNi} at infinite dilution of plutonium in nickel have been determined by autoradiography {alpha} in poly-phased system by the welded couples method: S{sub 0} varies from 40 to 80.10{sup -6} (atomic concentration) and D{sub PuNi} follows an Arrhenius law D = D{sub 0} exp (-Q/RT) with 0.03 cm{sup 2}/s < D{sub 0} < 1.6 cm{sup 2}/s and 46000 cal/mole < Q < 56000 cal/mole. Diffusion of uranium in aluminium have been carried out by fissiography using the thin layer method. Frequency factor lies between 0.01 and 3.1 cm{sup 2}/s and the activation energy lies between 24000 and 34000 cal/mole. (author) [French] La solubilite S{sub 0} et les coefficients de diffusion chimique D{sub PuNi}, a dilution infinie, du plutonium dans le nickel ont ete determines par autoradiographie {alpha} sur des couples soudes en systeme polyphase. Entre 1000 et 1125 deg. C. S{sub 0} varie de 40 a 80.10{sup -6} et D obeit a une loi d'ARRHENIUS (concentration atomique) D = D{sub 0} exp (-Q/RT) avec 0.03 cm{sup 2}s{sup -1} < D{sub 0} < 1.60 cm{sup 2}s{sup -1} 46000 calories par mole < Q < 56000 calories par mole. La diffusion de l'uranium dans l'aluminium a ete etudiee par fissiographie en utilisant la technique du depot mince. Le facteur de frequence est situe entre 0.01 et 3.1 cm{sup 2}s{sup -1} et l'energie d'activation entre 24000 et 34000 calories par mole. (auteur)

  15. Design of a scanning gate microscope for mesoscopic electron systems in a cryogen-free dilution refrigerator.

    Science.gov (United States)

    Pelliccione, M; Sciambi, A; Bartel, J; Keller, A J; Goldhaber-Gordon, D

    2013-03-01

    We report on our design of a scanning gate microscope housed in a cryogen-free dilution refrigerator with a base temperature of 15 mK. The recent increase in efficiency of pulse tube cryocoolers has made cryogen-free systems popular in recent years. However, this new style of cryostat presents challenges for performing scanning probe measurements, mainly as a result of the vibrations introduced by the cryocooler. We demonstrate scanning with root-mean-square vibrations of 0.8 nm at 3 K and 2.1 nm at 15 mK in a 1 kHz bandwidth with our design. Using Coulomb blockade thermometry on a GaAs/AlGaAs gate-defined quantum dot, we demonstrate an electron temperature of 45 mK.

  16. Evaluation of system requirements and standards development for thermal annealing of reactor pressure vessels. Progress report, March-September 1982

    International Nuclear Information System (INIS)

    Server, W.L.

    1983-03-01

    The material property data on thermal annealing of reactor-pressure-vessel steels have been reviewed. The most-critical materials are high copper welds; the data indicate that close to full recovery of Charpy V-notch properties can be realized by annealing at 850 0 F for 1 week (168 hours). However, the variability and sparcity of annealing recovery data dictate appropriate surveillance and experimental test programs. Of particular concern are the actual fracture-toughness changes and the differences between test- and power-reactor conditions. A survey of pressurized-water-reactor vendors, architect engineers, and consultants has been performed to assess the feasibility of performing a thermal-annealing cycle to restore the beltline material properties to their original state. This survey also addressed the issue of whether or not an actual annealing demonstration should be performed. It is the consensus view of the industry that in-situ reactor-vessel annealing can be done, but several areas still need to be studied and the American Society of Mechanical Engineers' Boiler and Pressure Vessel Code guidelines need to be defined

  17. On the metallic-like behaviour in dilute two dimensional systems

    International Nuclear Information System (INIS)

    Hamilton, A.R.; Simmons, M.Y.; University of Cambridge, Cambridge,; Pepper, M.; Ritchie, D.A.

    2000-01-01

    Full text: In the past five years numerous experimental studies of a wide variety of low disorder two dimensional (2D) semiconductor systems have revealed an unexpectedly large decrease in the resistance as the temperature is lowered from T ∼ 1 K, suggesting the existence of a 2D metal. Although numerous theories have been put forward to explain this metallic-like behaviour (which contradicts the expectations of one parameter scaling theory), its origins, and the question of whether it persists to T 0, are still subjects of great debate. Recent experiments have shown that despite the strong interactions (r s = 10) these systems still exhibit Fermi liquid behaviour, and that the drop in resistance with decreasing T is not quantum in origin. These results therefore argue against the existence of a true 2D metallic phase, and we now address the final remaining question - what then is the origin of the widely observed metallic-like drop in resistance in 2D systems? We present a study of the metallic behaviour in low density GaAs hole systems, and Si electron systems, close to the apparent 2D 'metal' -insulator transition. The strength of the metallic behaviour is shown to be almost independent of the symmetry of the confining potential, and is predominantly determined by the low temperature resistivity (i.e. by k F l). Furthermore in both material systems the fractional change in the conductivity depends only on T/T F , independent of the carrier density. Although the origins of the metallic behaviour remain unexplained, our results rule out interactions, the shape of the potential well and spin-orbit effects as possible causes

  18. Comparison of dilute chemical decontaminations of RAPS-2 full primary heat transport system

    International Nuclear Information System (INIS)

    Bhat, H.R.

    2000-01-01

    First ever attempt to decontaminate a full primary system of an Indian PHWR was carried out at Rajasthan Atomic Power Station Unit -2 (RAPS-2) in August 1992. The decontamination factors obtained were moderate. The second attempt to decontaminate the same system was made in February 1996 with a different formulation. The decontamination factors obtained were lesser than the earlier attempt. The details of the two campaigns and their relative merits and demerits are discussed. Some more studies are required to be done before further implementation of the picolonic acid/ascorbic acid formulation. The 1992 attempt was with picolinic acid and ascorbic acid whereas the 1996 attempt was with EDTA + citric acid + ascorbic Acid (EAC ) formulation. A number of lessons were learnt from the first campaign and the improvements were applied during the subsequent decontamination campaigns at Madras Atomic Power station. The total iron removed and various radio nuclides removed are also detailed in the paper. Picolonic acid and ascorbic acid is a better formulation for decontamination of full PHT systems of Indian PHWRs. Use of EAC formulation generates a lot of crud which settles in narrow clearances. Picolonic Acid/Ascorbic Acid formulation does not generate any crud. Decontamination using a single cycle of the picolonic acid/ascorbic acid formulation is more effective than the decontamination using three cycles of EAC formulation. (author)

  19. Electronic annealing Fermi operator expansion for DFT calculations on metallic systems

    Science.gov (United States)

    Aarons, Jolyon; Skylaris, Chris-Kriton

    2018-02-01

    Density Functional Theory (DFT) calculations with computational effort which increases linearly with the number of atoms (linear-scaling DFT) have been successfully developed for insulators, taking advantage of the exponential decay of the one-particle density matrix. For metallic systems, the density matrix is also expected to decay exponentially at finite electronic temperature and linear-scaling DFT methods should be possible by taking advantage of this decay. Here we present a method for DFT calculations at finite electronic temperature for metallic systems which is effectively linear-scaling (O(N)). Our method generates the elements of the one-particle density matrix and also finds the required chemical potential and electronic entropy using polynomial expansions. A fixed expansion length is always employed to generate the density matrix, without any loss in accuracy by the application of a high electronic temperature followed by successive steps of temperature reduction until the desired (low) temperature density matrix is obtained. We have implemented this method in the ONETEP linear-scaling (for insulators) DFT code which employs local orbitals that are optimised in situ. By making use of the sparse matrix machinery of ONETEP, our method exploits the sparsity of Hamiltonian and density matrices to perform calculations on metallic systems with computational cost that increases asymptotically linearly with the number of atoms. We demonstrate the linear-scaling computational cost of our method with calculation times on palladium nanoparticles with up to ˜13 000 atoms.

  20. Electronic annealing Fermi operator expansion for DFT calculations on metallic systems.

    Science.gov (United States)

    Aarons, Jolyon; Skylaris, Chris-Kriton

    2018-02-21

    Density Functional Theory (DFT) calculations with computational effort which increases linearly with the number of atoms (linear-scaling DFT) have been successfully developed for insulators, taking advantage of the exponential decay of the one-particle density matrix. For metallic systems, the density matrix is also expected to decay exponentially at finite electronic temperature and linear-scaling DFT methods should be possible by taking advantage of this decay. Here we present a method for DFT calculations at finite electronic temperature for metallic systems which is effectively linear-scaling (O(N)). Our method generates the elements of the one-particle density matrix and also finds the required chemical potential and electronic entropy using polynomial expansions. A fixed expansion length is always employed to generate the density matrix, without any loss in accuracy by the application of a high electronic temperature followed by successive steps of temperature reduction until the desired (low) temperature density matrix is obtained. We have implemented this method in the ONETEP linear-scaling (for insulators) DFT code which employs local orbitals that are optimised in situ. By making use of the sparse matrix machinery of ONETEP, our method exploits the sparsity of Hamiltonian and density matrices to perform calculations on metallic systems with computational cost that increases asymptotically linearly with the number of atoms. We demonstrate the linear-scaling computational cost of our method with calculation times on palladium nanoparticles with up to ∼13 000 atoms.

  1. Radionuclide interaction with clays in dilute and heavily compacted systems: a critical review.

    Science.gov (United States)

    Miller, Andrew W; Wang, Yifeng

    2012-02-21

    Given the unique properties of clays (i.e., low permeability and high ion sorption/exchange capacity), clays or clay formations have been proposed either as an engineered material or as a geologic medium for nuclear waste isolation and disposal. A credible evaluation of such disposal systems relies on the ability to predict the behavior of these materials under a wide range of thermal-hydrological-mechanical-chemical (THMc) conditions. Current model couplings between THM and chemical processes are simplistic and limited in scope. This review focuses on the uptake of radionuclides onto clay materials as controlled by mineral composition, structure, and texture (e.g., pore size distribution), and emphasizes the connections between sorption chemistry and mechanical compaction. Variable uptake behavior of an array of elements has been observed on various clays as a function of increasing compaction due to changes in pore size and structure, hydration energy, and overlapping electric double layers. The causes for this variability are divided between "internal" (based on the fundamental structure and composition of the clay minerals) and "external" (caused by a force external to the clay). New techniques need to be developed to exploit known variations in clay mineralogy to separate internal from external effects.

  2. Genetic Algorithm Based Simulated Annealing Method for Solving Unit Commitment Problem in Utility System

    Science.gov (United States)

    Rajan, C. Christober Asir

    2010-10-01

    The objective of this paper is to find the generation scheduling such that the total operating cost can be minimized, when subjected to a variety of constraints. This also means that it is desirable to find the optimal generating unit commitment in the power system for the next H hours. Genetic Algorithms (GA's) are general-purpose optimization techniques based on principles inspired from the biological evolution using metaphors of mechanisms such as neural section, genetic recombination and survival of the fittest. In this, the unit commitment schedule is coded as a string of symbols. An initial population of parent solutions is generated at random. Here, each schedule is formed by committing all the units according to their initial status ("flat start"). Here the parents are obtained from a pre-defined set of solution's i.e. each and every solution is adjusted to meet the requirements. Then, a random recommitment is carried out with respect to the unit's minimum down times. And SA improves the status. A 66-bus utility power system with twelve generating units in India demonstrates the effectiveness of the proposed approach. Numerical results are shown comparing the cost solutions and computation time obtained by using the Genetic Algorithm method and other conventional methods.

  3. L-Edge X-ray Absorption Spectroscopy of Dilute Systems Relevant to Metalloproteins Using an X-ray Free-Electron Laser

    NARCIS (Netherlands)

    Mitzner, Rolf; Rehanek, Jens; Kern, Jan; Gul, Sheraz; Hattne, Johan; Taguchi, Taketo; Alonso-Mori, Roberto; Tran, Rosalie; Weniger, Christian; Schroeder, Henning; Quevedo, Wilson; Laksmono, Hartawan; Sierra, Raymond G.; Han, Guangye; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Kubicek, Katharina; Schreck, Simon; Kunnus, Kristjan; Brzhezinskaya, Maria; Firsov, Alexander; Minitti, Michael P.; Turner, Joshua J.; Moeller, Stefan; Sauter, Nicholas K.; Bogan, Michael J.; Nordlund, Dennis; Schlotter, William F.; Messinger, Johannes; Borovik, Andrew; Techert, Simone; de Groot, Frank M. F.|info:eu-repo/dai/nl/08747610X; Foehlisch, Alexander; Erko, Alexei; Bergmann, Uwe; Yachandra, Vittal K.; Wernet, Philippe; Yano, Junko

    2013-01-01

    L-edge spectroscopy of 3d transition metals provides important electronic structure information and has been used in many fields. However, the use of this method for studying dilute aqueous systems, such as metalloenzymes, has not been prevalent because of severe radiation damage and the lack of

  4. Effect of the dilution factor on 18FDG and Na18F samples for bacterial endotoxin test using PTS (portable test system)

    International Nuclear Information System (INIS)

    Silveira, Marina B.; Costa, Flavia M.; Ferreira, Soraya Z.

    2011-01-01

    18 FDG and Na 18 F are radiopharmaceuticals produced as sterile solutions suitable for intravenous administration, which must contain no more than 175 EV/V. The most commonly used approach to detect endotoxins is the gelclot technique that requires 60 minutes for results. For radiopharmaceuticals containing short-life radionuclides, such as 18 F, there is an increasing interest for faster quality control methods. FDA licensed the Endosafe, PTS, a kinetic chromogenic endotoxin detection system that takes about 15 minutes for results. As other techniques, PTS test is susceptible to interferences which can be solved by product dilution. The aim of this study was to establish the best dilution of 18 FDG and Na 18 F for PTS analysis. Two different dilution factors for 18 FDG and 1:10 for Na 18 F were essayed: 1:10 and 1:100. 18 FDG and Na 18 solutions were prepared by the addition of LAL reagent water. Considering the assay acceptance criteria, the best dilution factor was 1:100 for 18 FDG and 1:10 for Na 18 F. The recovery of the product positive control was 98-12% for 18 FDG 1:100 and 104-120% for Na 18 F 1:10, which were, in both cases, within the specification (50-200%) and very close to 100%. Results obtained with these dilution studies were important to establish the most appropriate and non-interfering dilution factor for 18 FDG and Na 18 F routine endotoxin test. (author)

  5. Enhancement of the electrical characteristics of MOS capacitors by reducing the organic content of H{sub 2}O-diluted Spin-On-Glass based oxides

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Joel, E-mail: jmolina@inaoep.mx [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico); Munoz, Ana; Torres, Alfonso; Landa, Mauro; Alarcon, Pablo; Escobar, Manuel [National Institute of Astrophysics, Optics and Electronics, Electronics Department, Luis Enrique Erro 1, PO BOX 51 and 216, Tonantzintla, Puebla 72000 (Mexico)

    2011-10-25

    In this work, the physical, chemical and electrical properties of Metal-Oxide-Semiconductor (MOS) capacitors with Spin-On-Glass (SOG)-based thin films as gate dielectric have been investigated. Experiments of SOG diluted with two different solvents (2-propanol and deionized water) were done in order to reduce the viscosity of the SOG solution so that thinner films (down to {approx}20 nm) could be obtained and their general characteristics compared. Thin films of SOG were deposited on silicon by the sol-gel technique and they were thermally annealed using conventional oxidation furnace and Rapid Thermal Processing (RTP) systems within N{sub 2} ambient after deposition. SOG dilution using non-organic solvents like deionized water and further annealing (at relatively high temperatures {>=}450 deg. C) are important processes intended to reduce the organic content of the films. Fourier-Transform Infrared (FTIR) Spectroscopy results have shown that water-diluted SOG films have a significant reduction in their organic content after increasing annealing temperature and/or dilution percentage when compared to those of undiluted SOG films. Both current-voltage (I-V) and capacitance-voltage (C-V) measurements show better electrical characteristics for SOG-films diluted in deionized water compared to those diluted in 2-propanol (which is an organic solvent). The electrical characteristics of H{sub 2}O-diluted SOG thin films are very similar to those obtained from high quality thermal oxides so that their application as gate dielectrics in MOS devices is promising. Finally, it has been demonstrated that by reducing the organic content of SOG-based thin films, it is possible to obtain MOS devices with better electrical properties.

  6. Forward osmosis membrane modular configurations for osmotic dilution of seawater by forward osmosis and reverse osmosis hybrid system.

    Science.gov (United States)

    Kim, Jung Eun; Phuntsho, Sherub; Ali, Syed Muztuza; Choi, Joon Young; Shon, Ho Kyong

    2018-01-01

    This study evaluates various options for full-scale modular configuration of forward osmosis (FO) process for osmotic dilution of seawater using wastewater for simultaneous desalination and water reuse through FO-reverse osmosis (RO) hybrid system. Empirical relationship obtained from one FO membrane element operation was used to simulate the operational performances of different FO module configurations. The main limiting criteria for module operation is to always maintain the feed pressure higher than the draw pressure throughout the housing module for safe operation without affecting membrane integrity. Experimental studies under the conditions tested in this study show that a single membrane housing cannot accommodate more than four elements as the draw pressure exceeds the feed pressure. This then indicates that a single stage housing with eight elements is not likely to be practical for safe FO operation. Hence, six different FO modular configurations were proposed and simulated. A two-stage FO configuration with multiple housings (in parallel) in the second stage using same or larger spacer thickness reduces draw pressure build-up as the draw flow rates are reduced to half in the second stage thereby allowing more than four elements in the second stage housing. The loss of feed pressure (pressure drop) and osmotic driving force in the second stage are compensated by operating under the pressure assisted osmosis (PAO) mode, which helps enhance permeate flux and maintains positive pressure differences between the feed and draw chamber. The PAO energy penalty is compensated by enhanced permeate throughput, reduced membrane area, and plant footprint. The contribution of FO/PAO to total energy consumption was not significant compared to post RO desalination (90%) indicating that the proposed two-stage FO modular configuration is one way of making the FO full-scale operation practical for FO-RO hybrid system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Criticality experiments: analysis, evaluation, and programs. 8. Prompt Neutron Decay Constants in Uranium Diluted with Matrix Material Systems

    International Nuclear Information System (INIS)

    Sanchez, Rene; Loaiza, David; Brunson, Glenn

    2001-01-01

    Rossi-Alpha measurements were performed on uranium diluted with matrix material systems to determine the prompt neutron decay constants. These constants represent an eigenvalue characteristic of these particular critical assemblies, which can be experimentally measured by the Rossi-Alpha or pulse neutron source techniques and calculated by a deterministic or Monte Carlo method. In the measurements presented in this paper, highly enriched foils diluted in various X/ 235 U ratios with polyethylene and SiO 2 , and polyethylene and aluminum were assembled to a high multiplication, and the prompt neutron decay constants were obtained by the Rossi-Alpha technique. The uranium diluted with matrix material experiments were fueled with highly enriched uranium foils. The average dimensions of the bare foils were 22.86 cm squared and 0.00762 cm thick. The foils were laminated with plastic sheets to reduce the amount of airborne contamination. Each foil weighed ∼70 g. The diluent material consisted of SiO 2 , or 6061 aluminum plates, which were embedded into polyethylene plates. The SiO 2 and aluminum plates were 22.86 cm square and 0.64 cm thick. The polyethylene plates were 39.12 cm square and 1.91 cm thick. Each polyethylene plate had a central recess whose dimensions were 22.86 cm by 22.86 cm by 0.64 cm deep and was used to accommodate the SiO 2 , or aluminum plates as well as the uranium foils. There were eight 39.12-cm-squared by 2.54-cm-thick high density polyethylene plates that form the top and bottom reflectors (four at the top and four at the bottom). Also, one of the polyethylene plates located in the center of the assembly had holes drilled in a radial direction to accommodate neutron detectors. Four 3 He detectors were placed in this plate. The 3 He detectors were 1.27 cm in diameter and ∼15 cm long. Rossi-Alpha measurements were performed at several subcritical separations for both experiments. The data were collected with a type I time analyzer (PATRM

  8. Identification of differentially expressed genes using an annealing control primer system in stage III serous ovarian carcinoma

    International Nuclear Information System (INIS)

    Kim, Yun-Sook; Hwan Do, Jin; Bae, Sumi; Bae, Dong-Han; Shick Ahn, Woong

    2010-01-01

    Most patients with ovarian cancer are diagnosed with advanced stage disease (i.e., stage III-IV), which is associated with a poor prognosis. Differentially expressed genes (DEGs) in stage III serous ovarian carcinoma compared to normal tissue were screened by a new differential display method, the annealing control primer (ACP) system. The potential targets for markers that could be used for diagnosis and prognosis, for stage III serous ovarian cancer, were found by cluster and survival analysis. The ACP-based reverse transcriptase polymerase chain reaction (RT PCR) technique was used to identify DEGs in patients with stage III serous ovarian carcinoma. The DEGs identified by the ACP system were confirmed by quantitative real-time PCR. Cluster analysis was performed on the basis of the expression profile produced by quantitative real-time PCR and survival analysis was carried out by the Kaplan-Meier method and Cox proportional hazards multivariate model; the results of gene expression were compared between chemo-resistant and chemo-sensitive groups. A total of 114 DEGs were identified by the ACP-based RT PCR technique among patients with stage III serous ovarian carcinoma. The DEGs associated with an apoptosis inhibitory process tended to be up-regulated clones while the DEGs associated with immune response tended to be down-regulated clones. Cluster analysis of the gene expression profile obtained by quantitative real-time PCR revealed two contrasting groups of DEGs. That is, a group of genes including: SSBP1, IFI6 DDT, IFI27, C11orf92, NFKBIA, TNXB, NEAT1 and TFG were up-regulated while another group of genes consisting of: LAMB2, XRCC6, MEF2C, RBM5, FOXP1, NUDCP2, LGALS3, TMEM185A, and C1S were down-regulated in most patients. Survival analysis revealed that the up-regulated genes such as DDAH2, RNase K and TCEAL2 might be associated with a poor prognosis. Furthermore, the prognosis of patients with chemo-resistance was predicted to be very poor when genes such

  9. Development and characterization of dilutable self-microemulsifying premicroemulsion systems (SMEPMS as templates for preparation of nanosized particulates

    Directory of Open Access Journals (Sweden)

    Lin SF

    2013-09-01

    Full Text Available Shen-Fu Lin,1 Ying-Chen Chen,2 Hsiu-O Ho,2 Wei-Yu Huang,2 Ming-Thau Sheu,2,3 Der-Zen Liu1,4 1Graduate Institute of Biomedical Materials and Tissue Engineering, College of Oral Medicine, 2School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan; 3Clinical Research Center and Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan; 4Center for General Education, Hsuan Chuang University, Hsinchu, Taiwan Abstract: The utilization of self-microemulsifying premicroemulsion systems (SMEPMS as templates for preparing poorly water-soluble compounds in the nanosized range represents a promising strategy. Fenofibrate was formulated with n-butyl L-lactate, Tween 80, and a number of cosurfactants (ethanol, 1-propanol, and PEG 600, diluted with the water phase (either water or saccharide solution and then subjected to a freeze-drying (FD process to obtain SMEPMS nanosized particulates. Results demonstrated that the particle size after resuspension of these FD SMEPMS nanosized particulates in water was too large, so the addition of saccharide solutions (lactose, mannitol, glucose, sucrose, and trehalose as the solid carrier to prevent particles from aggregating seemed to be necessary and workable due to steric hindrance and repulsion. However, instability of these resuspended FD nanosized particulates after 30–90 minutes still occurred, and the addition of 0.5% sodium lauryl sulfate in the resuspending medium was able to retard the aggregation and maintain the particle size within the nano-range. Evaluation by scanning electron microscopy and X-ray powder diffraction also confirmed the results. It was concluded that using an SMEPMS formulation with PEG 600 as the cosurfactant, and in the presence of a suitable saccharide as an anticaking agent and FD process were able to produce fenofibrate nanoparticles. Keywords: fenofibrate, saccharides, freeze-drying, nanoparticles

  10. Bayesian analysis of systems with random chemical composition: renormalization-group approach to Dirichlet distributions and the statistical theory of dilution.

    Science.gov (United States)

    Vlad, Marcel Ovidiu; Tsuchiya, Masa; Oefner, Peter; Ross, John

    2002-01-01

    We investigate the statistical properties of systems with random chemical composition and try to obtain a theoretical derivation of the self-similar Dirichlet distribution, which is used empirically in molecular biology, environmental chemistry, and geochemistry. We consider a system made up of many chemical species and assume that the statistical distribution of the abundance of each chemical species in the system is the result of a succession of a variable number of random dilution events, which can be described by using the renormalization-group theory. A Bayesian approach is used for evaluating the probability density of the chemical composition of the system in terms of the probability densities of the abundances of the different chemical species. We show that for large cascades of dilution events, the probability density of the composition vector of the system is given by a self-similar probability density of the Dirichlet type. We also give an alternative formal derivation for the Dirichlet law based on the maximum entropy approach, by assuming that the average values of the chemical potentials of different species, expressed in terms of molar fractions, are constant. Although the maximum entropy approach leads formally to the Dirichlet distribution, it does not clarify the physical origin of the Dirichlet statistics and has serious limitations. The random theory of dilution provides a physical picture for the emergence of Dirichlet statistics and makes it possible to investigate its validity range. We discuss the implications of our theory in molecular biology, geochemistry, and environmental science.

  11. Determination of performance criteria of safety systems in a nuclear power plant via simulated annealing optimization method

    International Nuclear Information System (INIS)

    Jung, Woo Sik

    1993-02-01

    This study presents and efficient methodology that derives design alternatives and performance criteria of safety functions/systems in commercial nuclear power plants. Determination of design alternatives and intermediate-level performance criteria is posed as a reliability allocation problem. The reliability allocation is performed for determination of reliabilities of safety functions/systems from top-level performance criteria. The reliability allocation is a very difficult multi objective optimization problem (MOP) as well as a global optimization problem with many local minima. The weighted Chebyshev norm (WCN) approach in combination with an improved Metropolis algorithm of simulated annealing is developed and applied to the reliability allocation problem. The hierarchy of probabilistic safety criteria (PSC) may consist of three levels, which ranges from the overall top level (e.g., core damage frequency, acute fatality and latent cancer fatality) through the interlnediate level (e.g., unavailiability of safety system/function) to the low level (e.g., unavailability of components, component specifications or human error). In order to determine design alternatives of safety functions/systems and the intermediate-level PSC, the reliability allocation is performed from the top-level PSC. The intermediated level corresponds to an objective space and the top level is related to a risk space. The reliability allocation is performed by means of a concept of two-tier noninferior solutions in the objective and risk spaces within the top-level PSC. In this study, two kinds of towtier noninferior solutions are defined: intolerable intermediate-level PSC and desirable design alternatives of safety functions/systems that are determined from Sets 1 and 2, respectively. Set 1 is obtained by maximizing simultaneously not only safety function/system unavailabilities but also risks. Set 1 reflects safety function/system unavailabilities in the worst case. Hence, the

  12. Effect of Side Chain Functional Group on Interactions in Ionic Liquid Systems: Insights from Infinite Dilution Thermodynamic Data.

    Science.gov (United States)

    Paduszyński, Kamil; Królikowska, Marta

    2017-11-02

    Measurements of infinite dilution activity coefficients of 48 molecular solutes (including alkanes, alkenes, alkynes, aromatics, ethers, alcohols, water, ketones, pyridine, thiophene, acetonitrile, and 1-nitropropane) in two ionic liquids (ILs), namely, 1-(2-hydroxyethyl)-3-methylimidazolium dicyanamide and 1-(2-chloroethyl)-3-methylimidazolium dicyanamide, are reported in the temperature range from T = 308.15 to 358.15 K. Comparative analysis of an effect of OH/Cl substitution of terminal carbon in side chains of imidazolium cations is presented and discussed in terms of different types of intermolecular forces acting between ILs and solutes. The new data also are confronted to those published previously for a "plain" counterpart of the studied ILs, namely, 1-ethyl-3-methylimidazolium dicyanamide. Infinite dilution capacity and selectivity of the studied ILs are presented to evaluate them as separating agents in extraction of aromatics from alkanes and sulfur compounds from alkanes. Three modeling approaches, namely, linear solvation energy relationship (LSER), regular solution theory, and conductor-like screening model for real solvents (COSMO-RS), are tested for their capabilities of capturing the substitution effects detected experimentally.

  13. Simulated annealing model of acupuncture

    Science.gov (United States)

    Shang, Charles; Szu, Harold

    2015-05-01

    The growth control singularity model suggests that acupuncture points (acupoints) originate from organizers in embryogenesis. Organizers are singular points in growth control. Acupuncture can cause perturbation of a system with effects similar to simulated annealing. In clinical trial, the goal of a treatment is to relieve certain disorder which corresponds to reaching certain local optimum in simulated annealing. The self-organizing effect of the system is limited and related to the person's general health and age. Perturbation at acupoints can lead a stronger local excitation (analogous to higher annealing temperature) compared to perturbation at non-singular points (placebo control points). Such difference diminishes as the number of perturbed points increases due to the wider distribution of the limited self-organizing activity. This model explains the following facts from systematic reviews of acupuncture trials: 1. Properly chosen single acupoint treatment for certain disorder can lead to highly repeatable efficacy above placebo 2. When multiple acupoints are used, the result can be highly repeatable if the patients are relatively healthy and young but are usually mixed if the patients are old, frail and have multiple disorders at the same time as the number of local optima or comorbidities increases. 3. As number of acupoints used increases, the efficacy difference between sham and real acupuncture often diminishes. It predicted that the efficacy of acupuncture is negatively correlated to the disease chronicity, severity and patient's age. This is the first biological - physical model of acupuncture which can predict and guide clinical acupuncture research.

  14. Energy Saving in Industrial Annealing Furnaces

    Directory of Open Access Journals (Sweden)

    Fatma ÇANKA KILIÇ

    2018-03-01

    Full Text Available In this study, an energy efficiency studies have been carried out in a natural gas-fired rolling mill annealing furnace of an industrial establishment. In this context, exhaust gas from the furnace has been examined in terms of waste heat potential. In the examinations that have been made in detail; waste heat potential was found as 3.630,31 kW. Technical and feasibility studies have been carried out to realize electricity production through an Organic Rankine Cycle (ORC system for evaluating the waste heat potential of the annealing furnace. It has been calculated that 1.626.378,88 kWh/year of electricity can be generated by using the exhaust gas waste heat of the annealing furnace through an ORC system to produce electric energy with a net efficiency of 16%. The financial value of this energy was determined as 436.032,18 TL/year and the simple repayment period of the investment was 8,12 years. Since the annealing period of the annealing furnace is 2800 hours/year, the investment has not been found to be feasible in terms of the feasibility studies. However, the investment suitability can be assured when the annealing furnace is operating at full capacity for 8,000 hours or more annually.

  15. Microstructural evolution and adhesion of thin coatings in the Be-C-O and Be-W-O systems under annealing

    International Nuclear Information System (INIS)

    Mateus, R.; Alves, E.; Porosnicu, C.; Lungu, C.P.

    2016-01-01

    During reactor operation chemical composition of exposed surfaces will evolve over time due to erosion, re-deposition and heat-load events. The main materials considered for plasma facing components (PFC) in the reactor chamber will be beryllium and tungsten. From the present work we conclude that this option will highly mitigate the re-emission of co-deposits to the main plasma compared with previous carbon wall machines. The experiment was carried out by analysing Be, C and W layers deposited on pure Be, graphite and W plates after annealing in vacuum up to 1073 K. In the Be-C-O system, the formation of beryllium carbide and beryllium oxide is enhanced at temperatures higher than 873 K, leading to strong delamination of the films. In opposition, the formation of intermetallics in the Be-W-O system mitigates the occurrence of these events and recovers the delaminated zones. (author)

  16. Comparison of the Cathra Repliscan II, the AutoMicrobic system Gram-Negative General Susceptibility-Plus Card, and the Micro-Media System Fox Panel for dilution susceptibility testing of gram-negative bacilli.

    Science.gov (United States)

    Reiber, N E; Kelly, M T; Latimer, J M; Tison, D L; Hysmith, R M

    1985-06-01

    A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San Jose, Calif.) in determining MICs of 12 antibiotics for 200 gram-negative bacilli. Of the 200 strains tested, 12 isolates did not grow in one of the three systems. The 188 remaining organisms included 158 members of the family Enterobacteriaceae, 20 Pseudomonas spp., 5 Acinetobacter sp., 3 Aeromonas spp., and 2 Vibrio spp. A total of 2,256 organism-antibiotic combinations were analyzed for each system. An MIC was considered correct if two of the three systems were in agreement. When disagreements occurred, correct MICs were determined by the standard agar dilution method. With this criterion, overall agreements of the Cathra Repliscan II system, AutoMicrobic system, and Micro-Media Fox Panel system were 94.7, 94.9, and 95.5%, respectively. Tetracycline (20%), nitrofurantoin (20%), and ampicillin (16%) accounted for 56% of the discrepancies observed. These results indicate that all three systems perform with a high degree of accuracy for susceptibility testing of gram-negative bacilli.

  17. Application of dual-anneal diffusion multiples to the effective study of phase diagrams and phase transformations in the Fe–Cr–Ni system

    International Nuclear Information System (INIS)

    Cao, Siwei; Zhao, Ji-Cheng

    2015-01-01

    A dual-anneal diffusion multiple (DADM) approach is developed for effective determination of intermediate-temperature phase diagrams that are critical to the establishment of reliable thermodynamic databases. A large amount of phase equilibrium data was obtained from DADMs to construct the Fe–Cr–Ni isothermal sections at 1200, 900, 800 and 700 °C. The DADM approach is also a systematic and effective way to study phase precipitation from wide ranges of compositions, thus generating rich atlases of microstructures induced by various transformations. The results from this study indicate that the body-centered cubic to sigma phase transformation in the Fe–Cr–Ni system took place initially through a massive transformation mechanism

  18. Dilute phosphoric acid-catalysed hydrolysis of municipal bio-waste wood shavings using autoclave parr reactor system.

    Science.gov (United States)

    Orozco, Angela M; Al-Muhtaseb, Ala'a H; Albadarin, Ahmad B; Rooney, David; Walker, Gavin M; Ahmad, Mohammad N M

    2011-10-01

    The visibility of using municipal bio-waste, wood shavings, as a potential feedstock for ethanol production was investigated. Dilute acid hydrolysis of wood shavings with H₃PO₄ was undertaken in autoclave parr reactor. A combined severity factor (CSF) was used to integrate the effects of hydrolysis times, temperature and acid concentration into a single variable. Xylose concentration reached a maximum value of 17 g/100 g dry mass corresponding to a yield of 100% at the best identified conditions of 2.5 wt.% H₃PO₄, 175 °C and 10 min reaction time corresponding to a CSF of 1.9. However, for glucose, an average yield of 30% was obtained at 5 wt.% H₃PO₄, 200 °C and 10 min. Xylose production increased with increasing temperature and acid concentration, but its transformation to the degradation product furfural was also catalysed by those factors. The maximum furfural formed was 3 g/100 g dry mass, corresponding to the 24% yield. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Impact of pretreatment with dilute sulfuric acid under moderate temperature on hydrolysis of corn stover with two enzyme systems.

    Science.gov (United States)

    Tai, Chao; Keshwani, Deepak

    2014-03-01

    Pretreatment of corn stover with dilute sulfuric acid at moderate temperature was investigated, and glucan digestibility by Cellic CTec2 and Celluclast on the pretreated biomass was compared. Pretreatments were carried out from 60 to 180 min at the temperature from 105 to 135 °C, with acid concentrations ranging from 0.5 to 2% (w/v). Significant portion of xylan was removed during pretreatment, and the glucan digestibility by CTec2 was significantly better than that by Celluclast in all cases. Analysis showed that glucan digestibility by both two enzymes correlated directly with the extent of xylan removal in pretreatment. Confidence interval was built to give a more precise range of glucan conversion and to test the significant difference among pretreatment conditions. Response surface model was built to obtain the optimal pretreatment condition to achieve high glucan conversion after enzymatic hydrolysis. Considering the cost and energy savings, the optimal pretreatment condition of 1.75% acid for 160 min at 135 °C was determined, and glucan conversion can achieve the range from 72.86 to 76.69% at 95% confidence level after enzymatic hydrolysis, making total glucan recovery up to the range from 89.42 to 93.25%.

  20. Effective enzymatic in situ saccharification of bamboo shoot shell pretreated by dilute alkalic salts sodium hypochlorite/sodium sulfide pretreatment under the autoclave system.

    Science.gov (United States)

    Chong, Gang-Gang; He, Yu-Cai; Liu, Qiu-Xiang; Kou, Xiao-Qin; Huang, Xiao-Jun; Di, Jun-Hua; Ma, Cui-Luan

    2017-10-01

    In this study, dilute alkali salts (0.6% NaClO, 0.067% Na 2 S) pretreatment at 10% sulfidity under the autoclave system at 120°C for 40min was used for pretreating bamboo shoot shell (BSS). Furthermore, FT-IR, XRD and SEM were employed to characterize the changes in the cellulose structural characteristics (porosity, morphology, and crystallinity) of the pretreated BSS solid residue. After 72h, the reducing sugars and glucose from the enzymatic in situ hydrolysis of 50g/L pretreated BSS in dilute NaClO/Na 2 S media could be obtained at 31.11 and 20.32g/L, respectively. Finally, the obtained BSS-hydrolysates containing alkalic salt NaClO/Na 2 S resulted in slightly negative effects on the ethanol production. Glucose in BSS-hydrolysates was fermented from 20.0 to 0.17g/L within 48h, and an ethanol yield of 0.41g/g glucose, which represents 80.1% of the theoretical yield, was obtained. This study provided an effective strategy for potential utilization of BSS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

    Diluted pollens would have many uses by the tree breeder. Dilutions would be particularly advantageous in making many controlled pollinations with a limited amount of pollen. They also would be useful in artificial mass pollinations of orchards or single trees. Diluted pollens might help overcome troublesome genetic barriers to crossing. Feasibility o,f using diluted...

  2. Continuously operating dilution refrigerator with adsorption pumps

    International Nuclear Information System (INIS)

    Majdanov, V.A.; Mikhin, N.P.; Omelaenko, N.F.; Rudavskij, Eh.Ya.; Rybalko, A.S.; Chagovets, V.K.; Mikheev, V.A.

    1994-01-01

    The main parts and performance of two versions of the continuously operating dilution refrigerator with an adsorption pumping system dedicated to physical investigations at ultralow temperatures are described. Compared to conventional dilution refrigerators these versions are more compact, economic and more vibration proof. This type of dilution refrigerator allows a single shot operation to be realized. The minimum temperature reached in a single continuous heat exchanger refrigerator is 18 mK for a continuous operation and 5 - 8 mK for a single shot are. On addition of four discrete heat exchangers, the minimum temperature for continuous operation reduces down to 8 mK

  3. Electrokinetic investigations on the system polystyrene/aqueous electrolyte solution : verification of model theories on dilute and concentrated dispersions

    NARCIS (Netherlands)

    Put, van der A.G.

    1980-01-01

    This thesis presents a systematic experimental and theoretical study on electrokinetic and electroconducting properties of disperse systems. The increasing interest in transport processes through charged porous systems has recently brought about a corresponding growth of models and theories since

  4. Application of the coupled code system KIKO3D/ATHLET to the boron dilution transients in VVER-440 Type NPP

    International Nuclear Information System (INIS)

    Hegyi, G.; Kereszturi, A.; Trosztel, I.

    2003-01-01

    The transient caused by a perturbation of boron concentration and coolant temperature at the inlet of a Russian developed reactor (VVER-440) is reanalysed as a part of the modernisation (introduction of a new type profiled fuel) and power upgrading (up to 108 %) project. This task is one of the basis cases to be investigated in the safety analysis of the pressurized water reactor (PWR) and the criteria of Anticipated Operational Occurrences (AOO) have to be fulfilled for it. First detailed planning calculations were performed with the thermal hydraulic system code ATHLET and neutron physical code system KARATE-440 to find out the appropriate initial parameter set taking into account the active safety system of the NPP. Finally the most reactive case is analysed by the KIKO3D/ATHLET coupled system code. Whereas the investigation is done for safety analysis, conservative assumptions are imposed on reactivity characteristics. Moreover at the core inlet no-mixing is supposed from the unaffected loops. The presented calculations show, how the coupled code system with a detailed description of plant functions and core behaviour can help to understand better the local phenomena in the study of a potential risk of dilution accident, as it offers the possibility to evaluate the plant safety in a more realistic and versatile manner. (author)

  5. Effect of annealing temperature on the structural–microstructural and ...

    Indian Academy of Sciences (India)

    In order to get good quality reproducible films of Tl : HTSC system, we have studied the different annealing conditions to finally achieve the optimized annealing condition. In the present investigation, Tl–Ca–Ba–Cu–O superconducting films have been prepared on YSZ (100) and MgO (100) single crystal substrates via ...

  6. Traffic Flow Optimization Using a Quantum Annealer

    Directory of Open Access Journals (Sweden)

    Florian Neukart

    2017-12-01

    Full Text Available Quantum annealing algorithms belong to the class of metaheuristic tools, applicable for solving binary optimization problems. Hardware implementations of quantum annealing, such as the quantum processing units (QPUs produced by D-Wave Systems, have been subject to multiple analyses in research, with the aim of characterizing the technology’s usefulness for optimization and sampling tasks. In this paper, we present a real-world application that uses quantum technologies. Specifically, we show how to map certain parts of a real-world traffic flow optimization problem to be suitable for quantum annealing. We show that time-critical optimization tasks, such as continuous redistribution of position data for cars in dense road networks, are suitable candidates for quantum computing. Due to the limited size and connectivity of current-generation D-Wave QPUs, we use a hybrid quantum and classical approach to solve the traffic flow problem.

  7. Semantic search via concept annealing

    Science.gov (United States)

    Dunkelberger, Kirk A.

    2007-04-01

    Annealing, in metallurgy and materials science, is a heat treatment wherein the microstructure of a material is altered, causing changes in its properties such as strength and hardness. We define concept annealing as a lexical, syntactic, and semantic expansion capability (the removal of defects and the internal stresses that cause term- and phrase-based search failure) coupled with a directed contraction capability (semantically-related terms, queries, and concepts nucleate and grow to replace those originally deformed by internal stresses). These two capabilities are tied together in a control loop mediated by the information retrieval precision and recall metrics coupled with intuition provided by the operator. The specific representations developed have been targeted at facilitating highly efficient and effective semantic indexing and searching. This new generation of Find capability enables additional processing (i.e. all-source tracking, relationship extraction, and total system resource management) at rates, precisions, and accuracies previously considered infeasible. In a recent experiment, an order magnitude reduction in time to actionable intelligence and nearly three orderss magnitude reduction in false alarm rate was achieved.

  8. A Compact Safe Cold-Start (CS2) System for Scramjets using Dilute Triethylaluminum Fuel Mixtures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the cold-start requirements of scramjet engines by developing a safe, energy-dense, and low volume hydrocarbon fuel conditioning system based...

  9. A Compact Safe Cold-Start (CS2) System for Scramjets using Dilute Triethylaluminum Fuel Mixtures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal leverages a highly successful Phase 1 feasibility effort to further develop a system that satisfies the cold-start requirements of scramjet engines....

  10. A Compact Safe Cold-Start (CS2) System for Scramjets using Dilute Triethylaluminum Fuel Mixtures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the cold-start requirements of scramjet engines by developing a safe, energy-dense, and low volume hydrocarbon fuel conditioning system based...

  11. A Compact Safe Cold-Start (CS2) System for Scramjets using Dilute Triethylaluminum Fuel Mixtures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal leverages a highly successful Phase 1 feasibility effort to further develop a system that satisfies the cold-start requirements of scramjet engines....

  12. Multi-Channel Auto-Dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Barr, Jonathan L.

    2009-04-23

    Geological sequestration has the potential capacity and longevity to significantly decrease the amount of anthropogenic CO2 introduced into the atmosphere by combustion of fossil fuels such as coal. Effective sequestration, however, requires the ability to verify the integrity of the reservoir and ensure that potential leakage rates are kept to a minimum. Moreover, understanding the pathways by which CO2 migrates to the surface is critical to assessing the risks and developing remediation approaches. Field experiments, such as those conducted at the Zero Emissions Research and Technology (ZERT) project test site in Bozeman, Montana, require a flexible CO2 monitoring system that can accurately and continuously measure soil-surface CO2 fluxes for multiple sampling points at concentrations ranging from background levels to several tens of percent. To meet this need, PNNL is developing a multi-port battery-operated system capable of both spatial and temporal monitoring of CO2 at concentrations from ambient to at least 150,000 ppmv. This report describes the system components (sampling chambers, measurement and control system, and power supply) and the results of a field test at the ZERT site during the late summer and fall of 2008. While the system performed well overall during the field test, several improvements to the system are suggested for implementation in FY2009.

  13. GPU accelerated population annealing algorithm

    Science.gov (United States)

    Barash, Lev Yu.; Weigel, Martin; Borovský, Michal; Janke, Wolfhard; Shchur, Lev N.

    2017-11-01

    Population annealing is a promising recent approach for Monte Carlo simulations in statistical physics, in particular for the simulation of systems with complex free-energy landscapes. It is a hybrid method, combining importance sampling through Markov chains with elements of sequential Monte Carlo in the form of population control. While it appears to provide algorithmic capabilities for the simulation of such systems that are roughly comparable to those of more established approaches such as parallel tempering, it is intrinsically much more suitable for massively parallel computing. Here, we tap into this structural advantage and present a highly optimized implementation of the population annealing algorithm on GPUs that promises speed-ups of several orders of magnitude as compared to a serial implementation on CPUs. While the sample code is for simulations of the 2D ferromagnetic Ising model, it should be easily adapted for simulations of other spin models, including disordered systems. Our code includes implementations of some advanced algorithmic features that have only recently been suggested, namely the automatic adaptation of temperature steps and a multi-histogram analysis of the data at different temperatures. Program Files doi:http://dx.doi.org/10.17632/sgzt4b7b3m.1 Licensing provisions: Creative Commons Attribution license (CC BY 4.0) Programming language: C, CUDA External routines/libraries: NVIDIA CUDA Toolkit 6.5 or newer Nature of problem: The program calculates the internal energy, specific heat, several magnetization moments, entropy and free energy of the 2D Ising model on square lattices of edge length L with periodic boundary conditions as a function of inverse temperature β. Solution method: The code uses population annealing, a hybrid method combining Markov chain updates with population control. The code is implemented for NVIDIA GPUs using the CUDA language and employs advanced techniques such as multi-spin coding, adaptive temperature

  14. In situ optical absorption spectroscopy of annealing behaviours of quench-deposited films in the binary system CsI- PbI{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, S; Amaya, K; Saito, T [Research Centre for Development of the Far-Infrared Region, Fukui University, Bunkyo, Fukui (Japan)

    2003-02-19

    We have investigated annealing behaviours of quench-deposited films of the binary CsI-PbI{sub 2} system by in situ optical absorption spectroscopy. Various films composed of multiple crystalline phases of CsPbI{sub 3} and/or Cs{sub 4}PbI{sub 6} as well as of CsI and/or PbI{sub 2} are obtained, depending on the mixing ratio of the CsI and PbI{sub 2}. It is difficult to prepare films purely composed of a single CsPbI{sub 3} or Cs{sub 4}PbI{sub 6} phase alone. However, it is possible to obtain films where crystallites of either CsPbI{sub 3} or Cs{sub 4}PbI{sub 6} coexist with the CsI phase. Using such films, we measure the fundamental optical absorption spectrum of CsPbI{sub 3} and Cs{sub 4}PbI{sub 6} for the first time. Cs{sub 4}PbI{sub 6} exhibits stronger oscillator-like absorption compared to CsPbI{sub 3}, due to the localized nature of both the Pb 6s and 6p states.

  15. Morphology of interior interfaces in dilute nitride III/V material systems; Morphologie innerer Grenzflaechen in verduennt stickstoffhaltigen III/V-Materialsystemen

    Energy Technology Data Exchange (ETDEWEB)

    Oberhoff, S.

    2007-12-03

    This study aims to clarify structure formation processes in dilute N-containing III/V-based material systems, using highly selective etching methods and subsequent atomic force microscopy (AFM) to expose and analyse interior interfaces. In the first part of this study it was directly proved for the first time that adding Sb during growth interruption inhibits the GI-induced structural phase transition and reduces the diffusivity on GaAs and (GaIn)(NAs) surfaces. However, applying Sb during GI does not affect the driving force of the structural phase transition. Therefore a fundamental analysis about the incorporation of Sb into GaAs, Ga(NAs) and (GaIn)(NAs) was carried out in the second part of the study. Using a combination of high resolution X-ray diffraction, transmission electron microscopy and SIMS measurements, it was verified that incorporating Sb into (GaIn)(NAs) causes an increase of the In content and a decrease of the N content. In the third part of the study, novel etching methods for the GaP-based material system Ga(NAsP) are introduced which provide the opportunity to analyse structure formation processes on interior interfaces in this material system by AFM. (orig.)

  16. Conversion of organic solid waste to hydrogen and methane by two-stage fermentation system with reuse of methane fermenter effluent as diluting water in hydrogen fermentation.

    Science.gov (United States)

    Jung, Kyung-Won; Moon, Chungman; Cho, Si-Kyung; Kim, Sang-Hyoun; Shin, Hang-Sik; Kim, Dong-Hoon

    2013-07-01

    In this study, a two-stage system converting organic solid waste (food waste+sewage sludge) to H2 and CH4 was operated. In the first stage of dark fermentative hydrogen production (DFHP), a recently proposed method that does not require external inoculum, was applied. In the second stage, anaerobic sequencing batch reactor (ASBR) and an up-flow anaerobic sludge blanket reactor (UASBr) were followed to treat H2 fermenter effluent. (H2+CH4-ASBR) system showed better performance in terms of total biogas conversion (78.6%), while higher biogas production rate (2.03 L H2/Lsystem/d, 1.96 L CH4/Lsystem/d) was achieved in (H2+CH4-UASBr) system. To reduce the alkali addition requirement in DFHP process, CH4 fermenter effluent was tested as a diluting water. Both the ASBR and UASBr effluent was effective to keep the pH above 6 without CH4 production. In case of using ASBR effluent, H2 production dropped by 15%, but alkali addition requirement was reduced by 50%. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Interaction-driven versus disorder-driven transport in ultra-dilute GaAs two-dimensional hole systems

    Science.gov (United States)

    Huang, Jian; Pfeiffer, L. N.; West, K. W.

    2012-02-01

    It is well-known that the insulating behavior in the two-dimensional metal-to-insulator transition demonstrates a finite temperature conduction via hopping. Recently, however, some very strongly interacting higher purity two-dimensional electron systems at temperatures T->0 demonstrate certain nonactivated insulating behaviors that are absent in more disordered systems. Through measuring in dark the T-dependence of the conductivity of ultra-high quality 2D holes with charge densities down to 7x10^8 cm-2, an approximate power-law behavior is identified. Moreover, for the lowest charge densities, the exponent exhibits a linearly decreasing density-dependence which suggests an interaction-driven nature. Such an electron state is fragile to even a slight increase of disorder which causes a crossover from nonactivated to activated conduction. The non-activated conduction may well be an universal interaction-driven signature of an electron state of strongly correlated (semiquantum) liquid.

  18. Application of the reference method isotope dilution gas chromatography mass spectrometry (ID/GC/MS) to establish metrological traceability for calibration and control of blood glucose test systems.

    Science.gov (United States)

    Andreis, Elisabeth; Küllmer, Kai; Appel, Matthias

    2014-05-01

    Self-monitoring of blood glucose (BG) by means of handheld BG systems is a cornerstone in diabetes therapy. The aim of this article is to describe a procedure with proven traceability for calibration and evaluation of BG systems to guarantee reliable BG measurements. Isotope dilution gas chromatography mass spectrometry (ID/GC/MS) is a method that fulfills all requirements to be used in a higher-order reference measurement procedure. However, this method is not applicable for routine measurements because of the time-consuming sample preparation. A hexokinase method with perchloric acid (PCA) sample pretreatment is used in a measurement procedure for such purposes. This method is directly linked to the ID/GC/MS method by calibration with a glucose solution that has an ID/GC/MS-determined target value. BG systems are calibrated with whole blood samples. The glucose levels in such samples are analyzed by this ID/GC/MS-linked hexokinase method to establish traceability to higher-order reference material. For method comparison, the glucose concentrations in 577 whole blood samples were measured using the PCA-hexokinase method and the ID/GC/MS method; this resulted in a mean deviation of 0.1%. The mean deviation between BG levels measured in >500 valid whole blood samples with BG systems and the ID/GC/MS was 1.1%. BG systems allow a reliable glucose measurement if a true reference measurement procedure, with a noninterrupted traceability chain using ID/GC/MS linked hexokinase method for calibration of BG systems, is implemented. Systems should be calibrated by means of a traceable and defined measurement procedure to avoid bias. © 2014 Diabetes Technology Society.

  19. Radiation annealing in cuprous oxide

    DEFF Research Database (Denmark)

    Vajda, P.

    1966-01-01

    Experimental results from high-intensity gamma-irradiation of cuprous oxide are used to investigate the annealing of defects with increasing radiation dose. The results are analysed on the basis of the Balarin and Hauser (1965) statistical model of radiation annealing, giving a square-root relati......Experimental results from high-intensity gamma-irradiation of cuprous oxide are used to investigate the annealing of defects with increasing radiation dose. The results are analysed on the basis of the Balarin and Hauser (1965) statistical model of radiation annealing, giving a square...

  20. Finite-time thermodynamics and simulated annealing

    International Nuclear Information System (INIS)

    Andresen, B.

    1989-01-01

    When the general, global optimization technique simulated annealing was introduced by Kirkpatrick et al. (1983), this mathematical algorithm was based on an analogy to the statistical mechanical behavior of real physical systems like spin glasses, hence the name. In the intervening span of years the method has proven exceptionally useful for a great variety of extremely complicated problems, notably NP-problems like the travelling salesman, DNA sequencing, and graph partitioning. Only a few highly optimized heuristic algorithms (e.g. Lin, Kernighan 1973) have outperformed simulated annealing on their respective problems (Johnson et al. 1989). Simulated annealing in its current form relies only on the static quantity 'energy' to describe the system, whereas questions of rate, as in the temperature path (annealing schedule, see below), are left to intuition. We extent the connection to physical systems and take over further components from thermodynamics like ensemble, heat capacity, and relaxation time. Finally we refer to finite-time thermodynamics (Andresen, Salomon, Berry 1984) for a dynamical estimate of the optimal temperature path. (orig.)

  1. Gluconeogenesis from labeled carbon: estimating isotope dilution

    International Nuclear Information System (INIS)

    Kelleher, J.K.

    1986-01-01

    To estimate the rate of gluconeogenesis from steady-state incorporation of labeled 3-carbon precursors into glucose, isotope dilution must be considered so that the rate of labeling of glucose can be quantitatively converted to the rate of gluconeogenesis. An expression for the value of this isotope dilution can be derived using mathematical techniques and a model of the tricarboxylic acid (TCA) cycle. The present investigation employs a more complex model than that used in previous studies. This model includes the following pathways that may affect the correction for isotope dilution: 1) flux of 3-carbon precursor to the oxaloacetate pool via acetyl-CoA and the TCA cycle; 2) flux of 4- or 5-carbon compounds into the TCA cycle; 3) reversible flux between oxaloacetate (OAA) and pyruvate and between OAA and fumarate; 4) incomplete equilibrium between OAA pools; and 5) isotope dilution of 3-carbon tracers between the experimentally measured pool and the precursor for the TCA-cycle OAA pool. Experimental tests are outlined which investigators can use to determine whether these pathways are significant in a specific steady-state system. The study indicated that flux through these five pathways can significantly affect the correction for isotope dilution. To correct for the effects of these pathways an alternative method for calculating isotope dilution is proposed using citrate to relate the specific activities of acetyl-CoA and OAA

  2. Influence of alloying and secondary annealing on anneal hardening ...

    Indian Academy of Sciences (India)

    Unknown

    Influence of alloying and secondary annealing on anneal hardening effect at sintered copper alloys. SVETLANA NESTOROVIC. Technical Faculty Bor, University of Belgrade, Bor, Yugoslavia. MS received 11 February 2004; revised 29 October 2004. Abstract. This paper reports results of investigation carried out on sintered ...

  3. Simultaneous photometric determination of albumin and total protein in animal blood plasma employing a multicommutated flow system to carried out on line dilution and reagents solutions handling

    Science.gov (United States)

    Luca, Gilmara C.; Reis, Boaventura F.

    2004-02-01

    An automatic flow procedure for the simultaneous determination of albumin and total protein in blood plasma samples is proposed. The flow network comprised a set of three-way solenoid valves assembled to implement the multicommutation. The flow set up was controlled by means of a computer equipped with an electronic interface card which running a software wrote in QUICKBASIC 4.5 performed on line programmed dilution to allow the determination of both albumin and total protein in blood plasma. The photometric methods based on Bromocresol Green and Biuret reagents were selected for determination of albumin and total protein, respectively. Two LEDs based photometers coupled together the flow cells were employed as detector. After the adjustment of the operational parameters the proposed system presented the following features: an analytical throughput of 45 sample processing per hour for two analytes; relative standard deviations of 1.5 and 0.8% ( n=10) for a typical sample presenting 34 g l -1 albumin and 90 g l -1 total protein, respectively; linear responses ranging from 0 to 15 g l -1 albumin ( r=0.998) and total protein ( r=0.999); sample and reagents consumption, 140 μl serum solution, 0.015 mg VBC and 0.432 mg CuSO 4 per determination, respectively. Applying the paired t-test between results obtained using the proposed system and reference methods no significant difference at 95 and 90% confidence level for albumin and total protein, respectively, were observed.

  4. DOE's annealing prototype demonstration projects

    International Nuclear Information System (INIS)

    Warren, J.; Nakos, J.; Rochau, G.

    1997-01-01

    One of the challenges U.S. utilities face in addressing technical issues associated with the aging of nuclear power plants is the long-term effect of plant operation on reactor pressure vessels (RPVs). As a nuclear plant operates, its RPV is exposed to neutrons. For certain plants, this neutron exposure can cause embrittlement of some of the RPV welds which can shorten the useful life of the RPV. This RPV embrittlement issue has the potential to affect the continued operation of a number of operating U.S. pressurized water reactor (PWR) plants. However, RPV material properties affected by long-term irradiation are recoverable through a thermal annealing treatment of the RPV. Although a dozen Russian-designed RPVs and several U.S. military vessels have been successfully annealed, U.S. utilities have stated that a successful annealing demonstration of a U.S. RPV is a prerequisite for annealing a licensed U.S. nuclear power plant. In May 1995, the Department of Energy's Sandia National Laboratories awarded two cost-shared contracts to evaluate the feasibility of annealing U.S. licensed plants by conducting an anneal of an installed RPV using two different heating technologies. The contracts were awarded to the American Society of Mechanical Engineers (ASME) Center for Research and Technology Development (CRTD) and MPR Associates (MPR). The ASME team completed its annealing prototype demonstration in July 1996, using an indirect gas furnace at the uncompleted Public Service of Indiana's Marble Hill nuclear power plant. The MPR team's annealing prototype demonstration was scheduled to be completed in early 1997, using a direct heat electrical furnace at the uncompleted Consumers Power Company's nuclear power plant at Midland, Michigan. This paper describes the Department's annealing prototype demonstration goals and objectives; the tasks, deliverables, and results to date for each annealing prototype demonstration; and the remaining annealing technology challenges

  5. A posteriori determination of the useful data range for small-angle scattering experiments on dilute monodisperse systems

    Directory of Open Access Journals (Sweden)

    Petr V. Konarev

    2015-05-01

    Full Text Available Small-angle X-ray and neutron scattering (SAXS and SANS experiments on solutions provide rapidly decaying scattering curves, often with a poor signal-to-noise ratio, especially at higher angles. On modern instruments, the noise is partially compensated for by oversampling, thanks to the fact that the angular increment in the data is small compared with that needed to describe adequately the local behaviour and features of the scattering curve. Given a (noisy experimental data set, an important question arises as to which part of the data still contains useful information and should be taken into account for the interpretation and model building. Here, it is demonstrated that, for monodisperse systems, the useful experimental data range is defined by the number of meaningful Shannon channels that can be determined from the data set. An algorithm to determine this number and thus the data range is developed, and it is tested on a number of simulated data sets with various noise levels and with different degrees of oversampling, corresponding to typical SAXS/SANS experiments. The method is implemented in a computer program and examples of its application to analyse the experimental data recorded under various conditions are presented. The program can be employed to discard experimental data containing no useful information in automated pipelines, in modelling procedures, and for data deposition or publication. The software is freely accessible to academic users.

  6. A posteriori determination of the useful data range for small-angle scattering experiments on dilute monodisperse systems.

    Science.gov (United States)

    Konarev, Petr V; Svergun, Dmitri I

    2015-05-01

    Small-angle X-ray and neutron scattering (SAXS and SANS) experiments on solutions provide rapidly decaying scattering curves, often with a poor signal-to-noise ratio, especially at higher angles. On modern instruments, the noise is partially compensated for by oversampling, thanks to the fact that the angular increment in the data is small compared with that needed to describe adequately the local behaviour and features of the scattering curve. Given a (noisy) experimental data set, an important question arises as to which part of the data still contains useful information and should be taken into account for the interpretation and model building. Here, it is demonstrated that, for monodisperse systems, the useful experimental data range is defined by the number of meaningful Shannon channels that can be determined from the data set. An algorithm to determine this number and thus the data range is developed, and it is tested on a number of simulated data sets with various noise levels and with different degrees of oversampling, corresponding to typical SAXS/SANS experiments. The method is implemented in a computer program and examples of its application to analyse the experimental data recorded under various conditions are presented. The program can be employed to discard experimental data containing no useful information in automated pipelines, in modelling procedures, and for data deposition or publication. The software is freely accessible to academic users.

  7. Radiation annealing in cuprous oxide

    DEFF Research Database (Denmark)

    Vajda, P.

    1966-01-01

    Experimental results from high-intensity gamma-irradiation of cuprous oxide are used to investigate the annealing of defects with increasing radiation dose. The results are analysed on the basis of the Balarin and Hauser (1965) statistical model of radiation annealing, giving a square...

  8. Inward cholesterol gradient of the membrane system in P. falciparum-infected erythrocytes involves a dilution effect from parasite-produced lipids

    Directory of Open Access Journals (Sweden)

    Fuyuki Tokumasu

    2014-05-01

    Full Text Available Plasmodium falciparum (Pf infection remodels the human erythrocyte with new membrane systems, including a modified host erythrocyte membrane (EM, a parasitophorous vacuole membrane (PVM, a tubulovesicular network (TVN, and Maurer's clefts (MC. Here we report on the relative cholesterol contents of these membranes in parasitized normal (HbAA and hemoglobin S-containing (HbAS, HbAS erythrocytes. Results from fluorescence lifetime imaging microscopy (FLIM experiments with a cholesterol-sensitive fluorophore show that membrane cholesterol levels in parasitized erythrocytes (pRBC decrease inwardly from the EM, to the MC/TVN, to the PVM, and finally to the parasite membrane (PM. Cholesterol depletion of pRBC by methyl-β-cyclodextrin treatment caused a collapse of this gradient. Lipid and cholesterol exchange data suggest that the cholesterol gradient involves a dilution effect from non-sterol lipids produced by the parasite. FLIM signals from the PVM or PM showed little or no difference between parasitized HbAA vs HbS-containing erythrocytes that differed in lipid content, suggesting that malaria parasites may regulate the cholesterol contents of the PVM and PM independently of levels in the host cell membrane. Cholesterol levels may affect raft structures and the membrane trafficking and sorting functions that support Pf survival in HbAA, HbAS and HbSS erythrocytes.

  9. Intelligent medical image processing by simulated annealing

    International Nuclear Information System (INIS)

    Ohyama, Nagaaki

    1992-01-01

    Image processing is being widely used in the medical field and already has become very important, especially when used for image reconstruction purposes. In this paper, it is shown that image processing can be classified into 4 categories; passive, active, intelligent and visual image processing. These 4 classes are explained at first through the use of several examples. The results show that the passive image processing does not give better results than the others. Intelligent image processing, then, is addressed, and the simulated annealing method is introduced. Due to the flexibility of the simulated annealing, formulated intelligence is shown to be easily introduced in an image reconstruction problem. As a practical example, 3D blood vessel reconstruction from a small number of projections, which is insufficient for conventional method to give good reconstruction, is proposed, and computer simulation clearly shows the effectiveness of simulated annealing method. Prior to the conclusion, medical file systems such as IS and C (Image Save and Carry) is pointed out to have potential for formulating knowledge, which is indispensable for intelligent image processing. This paper concludes by summarizing the advantages of simulated annealing. (author)

  10. Defect annealing in Mn/Fe-implanted TiO2(rutile)

    CERN Document Server

    Gunnlaugsson, H P; Masenda, H; Mølholt, T E; Johnston, K; Bharuth-Ram, K; Gislason, H; Langouche, G; Naidoo, D; Ólafsson, S; Svane, A; Weyer, G

    2014-01-01

    A study of the annealing processes and charge state of dilute Fe in rutile TiO2 single crystals was performed in the temperature range 143-662 K, utilizing online 57Fe emission Mossbauer spectroscopy following low concentrations ( 350 K.

  11. Standard dilution analysis.

    Science.gov (United States)

    Jones, Willis B; Donati, George L; Calloway, Clifton P; Jones, Bradley T

    2015-02-17

    Standard dilution analysis (SDA) is a novel calibration method that may be applied to most instrumental techniques that will accept liquid samples and are capable of monitoring two wavelengths simultaneously. It combines the traditional methods of standard additions and internal standards. Therefore, it simultaneously corrects for matrix effects and for fluctuations due to changes in sample size, orientation, or instrumental parameters. SDA requires only 200 s per sample with inductively coupled plasma optical emission spectrometry (ICP OES). Neither the preparation of a series of standard solutions nor the construction of a universal calibration graph is required. The analysis is performed by combining two solutions in a single container: the first containing 50% sample and 50% standard mixture; the second containing 50% sample and 50% solvent. Data are collected in real time as the first solution is diluted by the second one. The results are used to prepare a plot of the analyte-to-internal standard signal ratio on the y-axis versus the inverse of the internal standard concentration on the x-axis. The analyte concentration in the sample is determined from the ratio of the slope and intercept of that plot. The method has been applied to the determination of FD&C dye Blue No. 1 in mouthwash by molecular absorption spectrometry and to the determination of eight metals in mouthwash, wine, cola, nitric acid, and water by ICP OES. Both the accuracy and precision for SDA are better than those observed for the external calibration, standard additions, and internal standard methods using ICP OES.

  12. Dynamical Frustration in ANNNI Model and Annealing

    Science.gov (United States)

    Sen, Parongama; Das, Pratap K.

    Simulated annealing is usually applied to systems with frustration, like spin glasses and optimisation problems, where the energy landscape is complex with many spurious minima. There are certain other systems, however, which have very simple energy landscape picture and ground states, but still the system fails to reach its ground state during a energy-lowering dynamical process. This situation corresponds to "dynamical frustration ". We have specifically considered the case of the axial next nearest neighbour (ANNNI) chain, where such a situation is encountered. In Sect. II, we elaborate the notion of dynamic frustration with examples and in Sect. III, the dynamics in ANNNI model is discussed in detail. The results of application of the classical and quantum annealing are discussed in Sects. IV and V. Summary and some concluding comments are given in the last section.

  13. An automatic versatile system integrating solid-phase extraction with ultra-high performance liquid chromatography-tandem mass spectrometry using a dual-dilution strategy for direct analysis of auxins in plant extracts.

    Science.gov (United States)

    Zhong, Qisheng; Qiu, Xiongxiong; Lin, Caiyong; Shen, Lingling; Huo, Yin; Zhan, Song; Yao, Jinting; Huang, Taohong; Kawano, Shin-ichi; Hashi, Yuki; Xiao, Langtao; Zhou, Ting

    2014-09-12

    An automatic versatile system which integrated solid phase extraction (SPE) with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. Diverse commercial SPE columns can be used under an ambient pressure in this online system realized by a dual-dilution strategy. The first dilution enabled the direct injection of complex samples with minimal pretreatment, and the second dilution realized direct introduction of large volume of strong eluent into the UHPLC column without causing peak broadening or distortion. In addition, a post-column compensation mode was also designed for the matrix-effects evaluation. The features of the online system were systematically investigated, including the dilution effect, the capture of desorption solution, the column-head stacking effect and the system recovery. Compared with the offline UHPLC system, this online system showed significant advantages such as larger injection volume, higher sensitivity, shorter analysis time and better repeatability. The feasibility of the system was demonstrated by the direct analysis of three auxins from different plant tissues, including leaves of Dracaena sanderiana, buds and petals of Bauhinia. Under the optimized conditions, the whole analysis procedure took only 7min. All the correlation coefficients were greater than 0.9987, the limits of detection and the limits of quantitation were in the range of 0.560-0.800ng/g and 1.80-2.60ng/g, respectively. The recoveries of the real samples ranged from 61.0 to 117%. Finally, the post-column compensation mode was applied and no matrix-effects were observed under the analysis conditions. The automatic versatile system was rapid, sensitive and reliable. We expect this system could be extended to other target analytes in complex samples utilizing diverse SPE columns. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Desynchronization in diluted neural networks

    International Nuclear Information System (INIS)

    Zillmer, Ruediger; Livi, Roberto; Politi, Antonio; Torcini, Alessandro

    2006-01-01

    The dynamical behavior of a weakly diluted fully inhibitory network of pulse-coupled spiking neurons is investigated. Upon increasing the coupling strength, a transition from regular to stochasticlike regime is observed. In the weak-coupling phase, a periodic dynamics is rapidly approached, with all neurons firing with the same rate and mutually phase locked. The strong-coupling phase is characterized by an irregular pattern, even though the maximum Lyapunov exponent is negative. The paradox is solved by drawing an analogy with the phenomenon of 'stable chaos', i.e., by observing that the stochasticlike behavior is 'limited' to an exponentially long (with the system size) transient. Remarkably, the transient dynamics turns out to be stationary

  15. Dilution refrigeration with multiple mixing chambers

    International Nuclear Information System (INIS)

    Coops, G.M.

    1981-01-01

    A dilution refrigerator is an instrument to reach temperatures in the mK region in a continuous way. The temperature range can be extended and the cooling power can be enlarged by adding an extra mixing chamber. In this way we obtain a double mixing chamber system. In this thesis the theory of the multiple mixing chamber is presented and tested on its validity by comparison with the measurements. Measurements on a dilution refrigerator with a circulation rate up to 2.5 mmol/s are also reported. (Auth.)

  16. Population annealing: Theory and application in spin glasses

    OpenAIRE

    Wang, Wenlong; Machta, Jonathan; Katzgraber, Helmut G.

    2015-01-01

    Population annealing is an efficient sequential Monte Carlo algorithm for simulating equilibrium states of systems with rough free energy landscapes. The theory of population annealing is presented, and systematic and statistical errors are discussed. The behavior of the algorithm is studied in the context of large-scale simulations of the three-dimensional Ising spin glass and the performance of the algorithm is compared to parallel tempering. It is found that the two algorithms are similar ...

  17. Computational Bottlenecks of Quantum Adiabatic Annealing

    Science.gov (United States)

    Knysh, Sergey

    2015-03-01

    Quantum annealing in a transverse field with rate dΓ / dt inversely proportional to the system size N suppresses non-adiabatic transitions for fully connected spin glass such as the Sherrington-Kirpatrick (SK) model at the quantum critical point. This alone is not sufficient to ensure that the problem is solvable in polynomial time. I conjecture the appearance of small gaps associated with macroscopic tunneling events deep in the spin glass phase. This effect is demonstrated rigorously for the annealing of a toy model that shares a set of crtical exponents with SK model: Hopfield network with two Gaussian patterns. It presents with 0 . 15 lnN additional bottlenecks with gaps that scale as a stretched exponential exp[-c (NΓ) 3 / 4]. Further, I extend the analysis to the ρ-landscapes model (random energy model with correlations) which more faithfully represents real spin glasses.

  18. Applications of 15N-isotopic dilution techniques to study the recovery of nitrogen fertilizer in the soil and plant uptake in wheat cropping system

    International Nuclear Information System (INIS)

    Rouanet, Juan Luis; Godoy, Alejandra; Montenegro, Adolfo; Mera, Mario; Uribe, Hamil; Pino, Ines; Parada, Ana Maria; Nario, Adriana

    1999-01-01

    Soil erosion is a major concern of the Chilean Ministry of Agriculture, which supports actions to develop new approaches in order to decrease the loss of this fragile natural resource and to promote sustainable production systems. This study, based on the management of biological, chemical and physical characteristics of the soil, was aimed to save nitrogen fertilizer. Nitrogen fertilization is the most costly production factor in wheat cropping systems on Ultisols, one of the most eroded soil types in southern Chile. A field experiment was undertaken on a Ultisol (''Buenos Aires'' Farm) at Imperial, IX Region, during 1997 and 1998, in order to assess the nitrogen and water use efficiency by a wheat crop (cv. Dalcahue-INIA) under alternative soil tillage systems. 15 N-isotopic dilution techniques allowed determining aspects of plant nutrition, nitrogen and water movement in the soil, processes not evaluated so far under these conditions. A strip-plot field layout with four replications was used , with soil tillage systems (traditional, burning/no-till, and no burning/no-till) as the main plots and crop successions (wheat-lupin-wheat and lupin-wheat-oat) as the subplots (30 m-2). In each subplot, a microplot (1m-2 ) was delimited. N fertilizer in the form of urea was added on subplots, except the microplot, at the rate of 150 kg N ha-1. 15N-labelled urea at c. 10 atom % excess, at the rate of 150 kg N ha-1, was added to the microplots. The fertilizer was split three times, 10% at planting, 45% at tillering and 45% jointing stage. No significant differences were found for wheat grain yield among tillage treatments. N fertilizer recovery by the wheat crop was 43%, and 56% on the nitrogen found in plants was derived from soil. No significant differences for these proportions were found among treatments. Although the wheat crop did not respond to tillage treatments in terms of 15N recovery, the physiological nitrogen use efficiency, or grain production per unit of

  19. Influence of alloying and secondary annealing on anneal hardening ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. This paper reports results of investigation carried out on sintered copper alloys (Cu, 8 at%; Zn,. Ni, Al and Cu–Au with 4 at%Au). The alloys were subjected to cold rolling (30, 50 and 70%) and annealed isochronally up to recrystallization temperature. Changes in hardness and electrical conductivity were fol-.

  20. Management of the Bohunice RPVs annealing procedures

    International Nuclear Information System (INIS)

    Repka, M.

    1994-01-01

    The program of annealing regeneration procedure of RPVs units 1 and 2 of NPP V-1 (EBO) realization in the year 1993, is the topic of this paper. In the paper the following steps are described in detail: the preparation works, the annealing procedure realization schedule and safety management: starting with zero conditions, assembling of annealing apparatus, annealing procedure, cooling down and disassembling procedure of annealing apparatus. At the end the programs of annealing of both RPVs including the dosimetry measurements are discussed and evaluated. (author). 3 figs

  1. Integrated solutions for atmosphere production and control when annealing thermal exchanger tubes

    International Nuclear Information System (INIS)

    Chaffotte, Florent; Pinte, Gilles; Bockel-Macal, Savine; Bruchet, Pierre

    2012-01-01

    After having outlined and described the role of the atmosphere for tube annealing processes (carbon exchanges, gas phase interactions, carbon transfer at the metal-gas interface, carbon diffusion within tubes, parameters affecting oxidation), this article presents different solutions aimed at the production of atmospheres for tube annealing: nitrogen-diluted endothermic atmosphere, or nitrogen-hydrogen atmospheres. It discusses how this atmosphere must be selected. It presents different solutions for the control of these atmospheres: control of carbon potential, or control of the carbon flow. The benefits of such a control are illustrated by an example where tubes are processed in a continuous oven equipped with rollers heated by radiating tubes

  2. Pulsed Laser Annealing of Carbon

    Science.gov (United States)

    Abrahamson, Joseph P.

    This dissertation investigates laser heating of carbon materials. The carbon industry has been annealing carbon via traditional furnace heating since at least 1800, when Sir Humphry Davy produced an electric arc with carbon electrodes made from carbonized wood. Much knowledge has been accumulated about carbon since then and carbon materials have become instrumental both scientifically and technologically. However, to this day the kinetics of annealing are not known due to the slow heating and cooling rates of furnaces. Additionally, consensus has yet to be reached on the cause of nongraphitizability. Annealing trajectories with respect to time at temperature are observed from a commercial carbon black (R250), model graphitizable carbon (anthracene coke) and a model nongraphitizable carbon (sucrose char) via rapid laser heating. Materials were heated with 1064 nm and 10.6 im laser radiation from a Q-switched Nd:YAG laser and a continuous wave CO2 laser, respectively. A pulse generator was used reduce the CO2 laser pulse width and provide high temporal control. Time-temperature-histories with nanosecond temporal resolution and temperature reproducibility within tens of degrees Celsius were determined by spectrally resolving the laser induced incandescence signal and applying multiwavelength pyrometry. The Nd:YAG laser fluences include: 25, 50, 100, 200, 300, and 550 mJ/cm2. The maximum observed temperature ranged from 2,400 °C to the C2 sublimation temperature of 4,180 °C. The CO2 laser was used to collect a series of isothermal (1,200 and 2,600 °C) heat treatments versus time (100 milliseconds to 30 seconds). Laser heated samples are compared to furnace annealing at 1,200 and 2,600 °C for 1 hour. The material transformation trajectory of Nd:YAG laser heated carbon is different than traditional furnace heating. The traditional furnace annealing pathway is followed for CO2 laser heating as based upon equivalent end structures. The nanostructure of sucrose char

  3. Morphological, thermal and annealed microhardness ...

    Indian Academy of Sciences (India)

    Unknown

    blended with sugarcane bagasse which showed good me- chanical properties when investigated by SEM, thermal gravimetric analysis (TGA), DSC and tensile testing (Chiel- lini et al 2001). An increase in the engineering yield stress was observed, with a decline in tensile impact strength. With DSC on annealing, a small ...

  4. Morphological, thermal and annealed microhardness ...

    Indian Academy of Sciences (India)

    The present paper reports the preparation of full IPNs of gelatin and polyacrylonitrile. Various compositions of gluteraldehyde crosslinked gelatin and N,N′-methylene-bis-acrylamide crosslinked PAN were characterized by SEM and DSC techniques. The IPNs were also thermally pretreated by the annealing process.

  5. Partially Annealed Disorder and Collapse of Like-Charged Macroions

    Science.gov (United States)

    Mamasakhlisov, Yevgeni S.; Naji, Ali; Podgornik, Rudolf

    2008-11-01

    Charged systems with partially annealed charge disorder are investigated using field-theoretic and replica methods. Charge disorder is assumed to be confined to macroion surfaces surrounded by a cloud of mobile neutralizing counterions in an aqueous solvent. A general formalism is developed by assuming that the disorder is partially annealed (with purely annealed and purely quenched disorder included as special cases), i.e., we assume in general that the disorder undergoes a slow dynamics relative to fast-relaxing counterions making it possible thus to study the stationary-state properties of the system using methods similar to those available in equilibrium statistical mechanics. By focusing on the specific case of two planar surfaces of equal mean surface charge and disorder variance, it is shown that partial annealing of the quenched disorder leads to renormalization of the mean surface charge density and thus a reduction of the inter-plate repulsion on the mean-field or weak-coupling level. In the strong-coupling limit, charge disorder induces a long-range attraction resulting in a continuous disorder-driven collapse transition for the two surfaces as the disorder variance exceeds a threshold value. Disorder annealing further enhances the attraction and, in the limit of low screening, leads to a global attractive instability in the system.

  6. Sorption-cooled continuous miniature dilution refrigeration for astrophysical applications

    Science.gov (United States)

    May, Andrew J.; Calisse, Paolo G.; Coppi, Gabriele; Haynes, Vic; Martinis, Lorenzo; McCulloch, Mark A.; Melhuish, Simon J.; Piccirillo, Lucio

    2016-07-01

    A progress report is provided on the development of a tiltable continuous miniature dilution refrigerator and associated 3He/4He sorption coolers. These systems are currently being developed to provide sub-Kelvin cooling of the bolometer arrays for several ground- and balloon-based experiments which aim to measure the polarization of the Cosmic Microwave Background (QUBIC, LSPE and POLARBEAR-2). The novel tiltable miniaturised system benefits from a lack of external circulation pumps and a mechanically simple design. The condenser of the twin-pumped recirculating diluter is cooled continuously by two 3He/4He sorption coolers. The sorption pumps are operated by convective heat switches. The dilution unit features a thermally separated mixing chamber, still and step heat exchangers. The designs and analyses of both the sorption coolers and the diluter are reported; both systems have been manufactured and are presently under test.

  7. Prevention of uncontrolled boron dilution

    International Nuclear Information System (INIS)

    Sere, J. L.

    1997-01-01

    The paper presents a synthesis of the global analysis of uncontrolled boron dilution risk performed by (European Consortium Mochovce (EUCOM) in the frame of Safety Measures RC 01 and AA 11. Recommendation for additional improvements (mainly I and C interlocks or inhibition) are presented. (author)

  8. Dilution Refrigeration of Multi-Ton Cold Masses

    CERN Document Server

    Wikus, P; CERN. Geneva

    2007-01-01

    Dilution refrigeration is the only means to provide continuous cooling at temperatures below 250 mK. Future experiments featuring multi-ton cold masses require a new generation of dilution refrigeration systems, capable of providing a heat sink below 10 mK at cooling powers which exceed the performance of present systems considerably. This thesis presents some advances towards dilution refrigeration of multi-ton masses in this temperature range. A new method using numerical simulation to predict the cooling power of a dilution refrigerator of a given design has been developed in the framework of this thesis project. This method does not only allow to take into account the differences between an actual and an ideal continuous heat exchanger, but also to quantify the impact of an additional heat load on an intermediate section of the dilute stream. In addition, transient behavior can be simulated. The numerical model has been experimentally verified with a dilution refrigeration system which has been designed, ...

  9. Rapid Thermal annealing of silicon layers amorphized by ion implantation

    International Nuclear Information System (INIS)

    Hasenack, C.M.

    1986-01-01

    The recrystallization behavior and the supression mechanisms of the residual defects of silicon layers amorphized by ion implantation, were investigated. The samples were annealed with the aid of a rapid thermal annealing (RTA) system at temperature range from 850 to 1200 0 C, and annealing time up to 120 s. Random and aligned Rutherford backscattering spectroscopy were used to analyse the samples. Similarities in the recrystallization behavior for layers implanted with ions of the same chemical groups such as As or Sb; Ge, Sn or Pb, In or Ga, are observed. The results show that the effective supression of resisual defects of the recrystallired layers is vinculated to the redistribution of impurities via thermal diffusion. (author) [pt

  10. Adiabatic quantum computation and quantum annealing theory and practice

    CERN Document Server

    McGeoch, Catherine C

    2014-01-01

    Adiabatic quantum computation (AQC) is an alternative to the better-known gate model of quantum computation. The two models are polynomially equivalent, but otherwise quite dissimilar: one property that distinguishes AQC from the gate model is its analog nature. Quantum annealing (QA) describes a type of heuristic search algorithm that can be implemented to run in the ``native instruction set'''' of an AQC platform. D-Wave Systems Inc. manufactures {quantum annealing processor chips} that exploit quantum properties to realize QA computations in hardware. The chips form the centerpiece of a nov

  11. Uranium determination by isotopic dilution

    International Nuclear Information System (INIS)

    Lucas, M.

    1978-01-01

    The method of determination by isotopic dilution is reviewed. The method principle is outlined with emphasis on sample preparation and on tracer solution preparation and calibration. The validity conditions of the method are defined for both high uranium concentrations and trace determination, the detection limit being around 0.1 ppb. The main advantages of the method are its selectivity, very high sensitivity and precision. The main fields of application are nuclear industry, geochronology and isotopic geochemistry [fr

  12. Plutonium determination by isotope dilution

    International Nuclear Information System (INIS)

    Lucas, M.

    1980-01-01

    The principle is to add to a known amount of the analysed solution a known amount of a spike solution consisting of plutonium 242. The isotopic composition of the resulting mixture is then determined by surface ionization mass spectrometry, and the plutonium concentration in the solution is deduced, from this measurement. For irradiated fuels neutronic studies or for fissile materials balance measurements, requiring the knowledge of the ratio U/Pu or of concentration both uranium and plutonium, it is better to use the double spike isotope dilution method, with a spike solution of known 233 U- 242 Pu ratio. Using this method, the ratio of uranium to plutonium concentration in the irradiated fuel solution can be determined without any accurate measurement of the mixed amounts of sample and spike solutions. For fissile material balance measurements, the uranium concentration is determined by using single isotope dilution, and the plutonium concentration is deduced from the ratio Pu/U and U concentration. The main advantages of isotope dilution are its selectivity, accuracy and very high sensitivity. The recent improvements made to surface ionization mass spectrometers have considerably increased the precision of the measurements; a relative precision of about 0.2% to 0.3% is obtained currently, but it could be reduced to 0.1%, in the future, with a careful control of the experimental procedures. The detection limite is around 0.1 ppb [fr

  13. Mechanical properties of electron-beam-melted molybdenum and dilute molybdenum-rhenium alloys

    Science.gov (United States)

    Klopp, W. D.; Witzke, W. R.

    1972-01-01

    A study of molybdenum and three dilute molybdenum-rhenium alloys was undertaken to determine the effects of rhenium on the low temperature ductility and other mechanical properties of molybdenum. Alloys containing 3.9, 5.9, and 7.7 atomic percent rhenium exhibited lower ductile-brittle transition temperatures than did the unalloyed molybdenum. The maximum improvement in the annealed condition was observed for molybdenum - 7.7 rhenium, which had a ductile-brittle transition temperature approximately 200 C (360 F) lower than that for unalloyed molybdenum. Rhenium additions also increased the low and high temperature tensile strengths and the high temperature creep strength of molybdenum. The mechanical behavior of dilute molybdenum-rhenium alloys is similar to that observed for dilute tungsten-rhenium alloys.

  14. Quantum annealing for combinatorial clustering

    Science.gov (United States)

    Kumar, Vaibhaw; Bass, Gideon; Tomlin, Casey; Dulny, Joseph

    2018-02-01

    Clustering is a powerful machine learning technique that groups "similar" data points based on their characteristics. Many clustering algorithms work by approximating the minimization of an objective function, namely the sum of within-the-cluster distances between points. The straightforward approach involves examining all the possible assignments of points to each of the clusters. This approach guarantees the solution will be a global minimum; however, the number of possible assignments scales quickly with the number of data points and becomes computationally intractable even for very small datasets. In order to circumvent this issue, cost function minima are found using popular local search-based heuristic approaches such as k-means and hierarchical clustering. Due to their greedy nature, such techniques do not guarantee that a global minimum will be found and can lead to sub-optimal clustering assignments. Other classes of global search-based techniques, such as simulated annealing, tabu search, and genetic algorithms, may offer better quality results but can be too time-consuming to implement. In this work, we describe how quantum annealing can be used to carry out clustering. We map the clustering objective to a quadratic binary optimization problem and discuss two clustering algorithms which are then implemented on commercially available quantum annealing hardware, as well as on a purely classical solver "qbsolv." The first algorithm assigns N data points to K clusters, and the second one can be used to perform binary clustering in a hierarchical manner. We present our results in the form of benchmarks against well-known k-means clustering and discuss the advantages and disadvantages of the proposed techniques.

  15. Loviisa Unit One: Annealing - healing

    Energy Technology Data Exchange (ETDEWEB)

    Kohopaeae, J.; Virsu, R. [ed.; Henriksson, A. [ed.

    1997-11-01

    Unit 1 of the Loviisa nuclear powerplant was annealed in connection with the refuelling outage in the summer of 1996. This type of heat treatment restored the toughness properties of the pressure vessel weld, which had been embrittled be neutron radiation, so that it is almost equivalent to a new weld. The treatment itself was an ordinary metallurgical procedure that took only a few days. But the material studies that preceded it began over fifteen years ago and have put IVO at the forefront of world-wide expertise in the area of radiation embrittlement

  16. Simulated annealing with constant thermodynamic speed

    International Nuclear Information System (INIS)

    Salamon, P.; Ruppeiner, G.; Liao, L.; Pedersen, J.

    1987-01-01

    Arguments are presented to the effect that the optimal annealing schedule for simulated annealing proceeds with constant thermodynamic speed, i.e., with dT/dt = -(v T)/(ε-√C), where T is the temperature, ε- is the relaxation time, C ist the heat capacity, t is the time, and v is the thermodynamic speed. Experimental results consistent with this conjecture are presented from simulated annealing on graph partitioning problems. (orig.)

  17. Keystream Generator Based On Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Ayad A. Abdulsalam

    2011-01-01

    Full Text Available Advances in the design of keystream generator using heuristic techniques are reported. A simulated annealing algorithm for generating random keystream with large complexity is presented. Simulated annealing technique is adapted to locate these requirements. The definitions for some cryptographic properties are generalized, providing a measure suitable for use as an objective function in a simulated annealing algorithm, seeking randomness that satisfy both correlation immunity and the large linear complexity. Results are presented demonstrating the effectiveness of the method.

  18. Neutron scattering study of dilute supercritical solutions

    International Nuclear Information System (INIS)

    Cochran, H.D.; Wignall, G.D.; Shah, V.M.; Londono, J.D.; Bienkowski, P.R.

    1994-01-01

    Dilute solutions in supercritical solvents exhibit interesting microstructures that are related to their dramatic macroscopic behavior. In typical attractive solutions, solutes are believed to be surrounded by clusters of solvent molecules, and solute molecules are believed to congregate in the vicinity of one another. Repulsive solutions, on the other hand, exhibit a local region of reduced solvent density around the solute with solute-solute congregation. Such microstructures influence solubility, partial molar volume, reaction kinetics, and many other properties. We have undertaken to observe these interesting microstructures directly by neutron scattering experiments on dilute noble gas systems including Ar. The three partial structure factors for such systems and the corresponding pair correlation functions can be determined by using the isotope substitution technique. The systems studied are uniquely suited for our objectives because of the large coherent neutron scattering length of the isotope 36 Ar and because of the accurate potential energy functions that are available for use in molecular simulations and theoretical calculations to be compared with the scattering results. We will describe our experiment, the unique apparatus we have built for it, and the neutron scattering results from our initial allocations of beam time. We will also describe planned scattering experiments to follow those with noble gases, including study of long-chain molecules in supercritical solvents. Such studies will involve hydrocarbon mixtures with and without deuteration to provide contrast

  19. Synthesis of dilute magnetic semiconductors by ion implantation

    International Nuclear Information System (INIS)

    Braunstein, G.H.; Dresselhaus, G.; Withrow, S.P.

    1986-01-01

    We have synthesized layers of CdMnTe by implantation of Mn into CdTe. Samples of CdTe have been implanted with Mn ions of 60 keV energy to fluences in the range 1 x 10 13 cm -2 to 2 x 10 16 cm -2 resulting in local concentrations of up to 10% at the maximum of the Mn distribution. Rutherford backscattering-channeling analysis has been used to study the radiation damage after implantation and after subsequent rapid thermal annealing (RTA). These experiments reveal that RTA for 15 sec at a temperature T greater than or equal to 700 0 C results in the complete recovery of the lattice order, without affecting the stoichiometry of CdTe. Photoluminescence (PL) measurements of a sample showing complete annealing reveal an increase in the band gap corresponding to the synthesis of very dilute (x approx. = 0.004) Cd/sub 1-x/Mn/sub x/Te. A shift of the excitonic PL peak to lower energies is observed when a magnetic field H less than or equal to 1T is applied. These measurements provide clear evidence for the synthesis of a DMS by ion implantation of Mn into CdTe

  20. External validation of aminoglycoside models used in web calculators and clinical decision support systems after laboratory conversion to serum creatinine isotope dilution mass spectrometry assay.

    Science.gov (United States)

    Wolowich, William R; Steinberg, Jennifer G

    2012-04-01

    Models to predict gentamicin t(½) from serum creatinine (SCr) estimated creatinine clearance (CrCl) are currently being incorporated into smart-device applications and clinical decision support modules without external validation. The aim of this study was to determine whether such models remain viable after conversion to isotope dilution mass spectrometry (IDMS) SCr assay. This study analyzed data from retrospective reviews of the medical records of nonobese adults receiving the aminoglycoside gentamicin and having ≥2 evaluable serum gentamicin concentrations after laboratory IDMS SCr conversion, from January 2008 to August 2009, at a tertiary care hospital in Florida. A literature search found a number of cited aminoglycoside models. This group of models was classified as group 1. The World Wide Web was also searched for the term aminoglycoside dosing calculators, with 6 models found and referred to as group 2. Predictive performance measures were used to compare the model results with the t(½) calculated from gentamicin concentrations using the Nelder-Mead algorithm. The records of 39 patients met the inclusion criteria (23 men, 16 women; age range, 18-86 years; range of estimated CrCl, 55-115 mL/min) and provided the "gold standard" aminoglycoside t(½). A gentamicin t(½) was predicted from several published models (group 1) and from other models used in online smart-device applications (group 2) and clinical decision modules. The median (interquartile range) root mean square errors were 0.48 (0.44 to 0.65) and 0.48 (0.45 to 0.70) hours from group-1 and -2 models, respectively. The median mean relative prediction errors were 9% (-14% to +13%) and 11% (+1% to +21%) from groups 1 and 2. The median mean absolute prediction errors were 21% (19% to 28%) and 21% (20% to 30%) from groups 1 and 2. Adjusting SCr by +20% improved the predictive ability in 3 of 12 cited models and in 5 of 6 models used in applications. Models to predict gentamicin t(½) should be

  1. Forgot your password: Correlation dilution

    OpenAIRE

    Medard, Muriel; Makhdoumi Kakhaki, Ali; Calmon, Flavio du Pin

    2015-01-01

    We consider the problem of diluting common randomness from correlated observations by separated agents. This problem creates a new framework to study statistical privacy, in which a legitimate party, Alice, has access to a random variable X, whereas an attacker, Bob, has access to a random variable Y dependent on X drawn from a joint distribution p[subscript X,Y]. Alice's goal is to produce a non-trivial function of her available information that is uncorrelated with (has small correlation wi...

  2. A miniaturized plastic dilution refrigerator

    International Nuclear Information System (INIS)

    Bindilatti, V.; Oliveira, N.F.Jr.; Martin, R.V.; Frossati, G.

    1996-01-01

    We have built and tested a miniaturized dilution refrigerator, completely contained (still, heat exchanger and mixing chamber) inside a plastic (PVC) tube of 10 mm diameter and 170 mm length. With a 25 cm 2 CuNi heat exchanger, it reached temperatures below 50 mK, for circulation rates below 70 μmol/s. The cooling power at 100 mK and 63 μmol/s was 45 μW. The experimental space could accommodate samples up to 6 mm in diameter. (author)

  3. Coupled Quantum Fluctuations and Quantum Annealing

    Science.gov (United States)

    Hormozi, Layla; Kerman, Jamie

    We study the relative effectiveness of coupled quantum fluctuations, compared to single spin fluctuations, in the performance of quantum annealing. We focus on problem Hamiltonians resembling the the Sherrington-Kirkpatrick model of Ising spin glass and compare the effectiveness of different types of fluctuations by numerically calculating the relative success probabilities and residual energies in fully-connected spin systems. We find that for a small class of instances coupled fluctuations can provide improvement over single spin fluctuations and analyze the properties of the corresponding class. Disclaimer: This research was funded by ODNI, IARPA via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  4. Direct Immersion Annealing of Block Copolymer Thin Films

    Science.gov (United States)

    Karim, Alamgir

    We demonstrate ordering of thin block copolymer (BCP) films via direct immersion annealing (DIA) at enhanced rate leading to stable morphologies. The BCP films are immersed in carefully selected mixtures of good and marginal solvents that can impart enhanced polymer mobility, while inhibiting film dissolution. DIA is compatible with roll-to-roll assembly manufacturing and has distinct advantages over conventional thermal annealing and batch processing solvent-vapor annealing methods. We identify three solvent composition-dependent BCP film ordering regimes in DIA for the weakly interacting polystyrene -poly(methyl methacrylate) (PS -PMMA) system: rapid short range order, optimal long-range order, and a film instability regime. Kinetic studies in the ``optimal long-range order'' processing regime as a function of temperature indicate a significant reduction of activation energy for BCP grain growth compared to oven annealing at conventional temperatures. An attractive feature of DIA is its robustness to ordering other BCP (e.g. PS-P2VP) and PS-PMMA systems exhibiting spherical, lamellar and cylindrical ordering. Inclusion of nanoparticles in these films at high concentrations and fast ordering kinetics study with neutron reflectivity and SANS will be discussed. This is (late) Contributed Talk Abstract for Dillon Medal Symposium at DPOLY - discussed with DPOLY Chair Dvora Perahia.

  5. High-temperature laser annealing for thin film polycrystalline silicon solar cell on glass substrate

    Science.gov (United States)

    Chowdhury, A.; Schneider, J.; Dore, J.; Mermet, F.; Slaoui, A.

    2012-06-01

    Thin film polycrystalline silicon films grown on glass substrate were irradiated with an infrared continuous wave laser for defects annealing and/or dopants activation. The samples were uniformly scanned using an attachment with the laser system. Substrate temperature, scan speed and laser power were varied to find suitable laser annealing conditions. The Raman spectroscopy and Suns- V oc analysis were carried out to qualify the films quality after laser annealing. A maximum enhancement of the open circuit voltage V oc of about 100 mV is obtained after laser annealing of as-grown polysilicon structures. A strong correlation was found between the full width half maximum of the Si crystalline peak and V oc. It is interpreted as due to defects annealing as well as to dopants activation in the absorbing silicon layer. The maximum V oc reached is 485 mV after laser treatment and plasma hydrogenation, thanks to defects passivation.

  6. Understanding the microwave annealing of silicon

    Directory of Open Access Journals (Sweden)

    Chaochao Fu

    2017-03-01

    Full Text Available Though microwave annealing appears to be very appealing due to its unique features, lacking an in-depth understanding and accurate model hinder its application in semiconductor processing. In this paper, the physics-based model and accurate calculation for the microwave annealing of silicon are presented. Both thermal effects, including ohmic conduction loss and dielectric polarization loss, and non-thermal effects are thoroughly analyzed. We designed unique experiments to verify the mechanism and extract relevant parameters. We also explicitly illustrate the dynamic interaction processes of the microwave annealing of silicon. This work provides an in-depth understanding that can expedite the application of microwave annealing in semiconductor processing and open the door to implementing microwave annealing for future research and applications.

  7. Reduction of two-dimensional dilute Ising spin glasses

    Science.gov (United States)

    Boettcher, Stefan; Hartmann, Alexander K.

    2005-07-01

    The recently proposed reduction method is applied to the Edwards-Anderson model on bond-diluted square lattices. In combination with a graph-theoretical matching algorithm, this allows us to calculate numerically exact ground states of large systems. Low-temperature domain-wall excitations are studied to determine the stiffness exponent y2 . A value of y2=-0.281(3) is found, consistent with previous results obtained on undiluted lattices. This comparison demonstrates the validity of the reduction method for bond-diluted spin systems and provides strong support for similar studies proclaiming accurate results for stiffness exponents in dimensions d=3,…,7 .

  8. Computer registration of radioactive indicator-dilution curves.

    Science.gov (United States)

    Shepherd, A P; Perry, M A; Alexander, G M; Granger, D N; Riedel, G L; Kvietys, P R; Franke, C P

    1983-12-01

    A system is described for recording indicator-dilution curves produced by gamma radiation-emitting tracers. The system consists of a flow-through cuvette in a well counter, appropriate commercially available gamma radiation-detecting equipment, an Apple II computer, and a two-channel pulse-counting interface of our own design. With the counting interface and the software described here, an investigator can simultaneously record two indicator-dilution curves produced by gamma emitters. Instead of having to wait hours or days for results, the investigator can watch the data being recorded and display the results in graphic form almost immediately after each injection.

  9. Competitive annealing of multiple DNA origami: formation of chimeric origami

    International Nuclear Information System (INIS)

    Majikes, Jacob M; Nash, Jessica A; LaBean, Thomas H

    2016-01-01

    Scaffolded DNA origami are a robust tool for building discrete nanoscale objects at high yield. This strategy ensures, in the design process, that the desired nanostructure is the minimum free energy state for the designed set of DNA sequences. Despite aiming for the minimum free energy structure, the folding process which leads to that conformation is difficult to characterize, although it has been the subject of much research. In order to shed light on the molecular folding pathways, this study intentionally frustrates the folding process of these systems by simultaneously annealing the staple pools for multiple target or parent origami structures, forcing competition. A surprising result of these competitive, simultaneous anneals is the formation of chimeric DNA origami which inherit structural regions from both parent origami. By comparing the regions inherited from the parent origami, relative stability of substructures were compared. This allowed examination of the folding process with typical characterization techniques and materials. Anneal curves were then used as a means to rapidly generate a phase diagram of anticipated behavior as a function of staple excess and parent staple ratio. This initial study shows that competitive anneals provide an exciting way to create diverse new nanostructures and may be used to examine the relative stability of various structural motifs. (paper)

  10. Analysis of boron dilution in a four-loop PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.G.; Sha, W.T. [Argonne National Lab., IL (United States)

    1995-03-01

    Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four-loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant is at hot standby and the reactor coolant system has been heated to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated and a sensitivity study is performed to assess the accuracy of the numerical modeling of the geometry of the reactor coolant system.

  11. Programação da produção em sistemas flow shop utilizando um método heurístico híbrido algoritmo genético-simulated annealing Production scheduling in flow shop systems by using a hybrid genetic algorithm-simulated annealing heuristic

    Directory of Open Access Journals (Sweden)

    Walther Rogério Buzzo

    2000-12-01

    Full Text Available Este artigo trata do problema de programação de tarefas flow shop permutacional. Diversos métodos heurísticos têm sido propostos para tal problema, sendo que um dos tipos de método consiste em melhorar soluções iniciais a partir de procedimentos de busca no espaço de soluções, tais como Algoritmo Genético (AG e Simulated Annealing (SA. Uma idéia interessante que tem despertado gradativa atenção refere-se ao desenvolvimento de métodos heurísticos híbridos utilizando Algoritmo Genético e Simulated Annealing. Assim, o objetivo é combinar as técnicas de tal forma que o procedimento resultante seja mais eficaz do que qualquer um dos seus componentes isoladamente. Neste artigo é apresentado um método heurístico híbrido Algoritmo Genético-Simulated Annealing para minimizar a duração total da programação flow shop permutacional. Com o propósito de avaliar a eficácia da hibridização, o método híbrido é comparado com métodos puros AG e SA. Os resultados obtidos a partir de uma experimentação computacional são apresentados.This paper deals with the Permutation Flow Shop Scheduling problem. Many heuristic methods have been proposed for this scheduling problem. A class of such heuristics finds a good solution by improving initial sequences for the jobs through search procedures on the solution space as Genetic Algorithm (GA and Simulated Annealing (SA. A promising approach for the problem is the formulation of hybrid metaheuristics by combining GA and SA techniques so that the consequent procedure is more effective than either pure GA or SA methods. In this paper we present a hybrid Genetic Algorithm-Simulated Annealing heuristic for the minimal makespan flow shop sequencing problem. In order to evaluate the effectiveness of the hybridization we compare the hybrid heuristic with both pure GA and SA heuristics. Results from computational experience are presented.

  12. Precision Laser Annealing of Focal Plane Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); DeRose, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Starbuck, Andrew Lea [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verley, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jenkins, Mark W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    We present results from laser annealing experiments in Si using a passively Q-switched Nd:YAG microlaser. Exposure with laser at fluence values above the damage threshold of commercially available photodiodes results in electrical damage (as measured by an increase in photodiode dark current). We show that increasing the laser fluence to values in excess of the damage threshold can result in annealing of a damage site and a reduction in detector dark current by as much as 100x in some cases. A still further increase in fluence results in irreparable damage. Thus we demonstrate the presence of a laser annealing window over which performance of damaged detectors can be at least partially reconstituted. Moreover dark current reduction is observed over the entire operating range of the diode indicating that device performance has been improved for all values of reverse bias voltage. Additionally, we will present results of laser annealing in Si waveguides. By exposing a small (<10 um) length of a Si waveguide to an annealing laser pulse, the longitudinal phase of light acquired in propagating through the waveguide can be modified with high precision, <15 milliradian per laser pulse. Phase tuning by 180 degrees is exhibited with multiple exposures to one arm of a Mach-Zehnder interferometer at fluence values below the morphological damage threshold of an etched Si waveguide. No reduction in optical transmission at 1550 nm was found after 220 annealing laser shots. Modeling results for laser annealing in Si are also presented.

  13. Cylinder packing by simulated annealing

    Directory of Open Access Journals (Sweden)

    M. Helena Correia

    2000-12-01

    Full Text Available This paper is motivated by the problem of loading identical items of circular base (tubes, rolls, ... into a rectangular base (the pallet. For practical reasons, all the loaded items are considered to have the same height. The resolution of this problem consists in determining the positioning pattern of the circular bases of the items on the rectangular pallet, while maximizing the number of items. This pattern will be repeated for each layer stacked on the pallet. Two algorithms based on the meta-heuristic Simulated Annealing have been developed and implemented. The tuning of these algorithms parameters implied running intensive tests in order to improve its efficiency. The algorithms developed were easily extended to the case of non-identical circles.Este artigo aborda o problema de posicionamento de objetos de base circular (tubos, rolos, ... sobre uma base retangular de maiores dimensões. Por razões práticas, considera-se que todos os objetos a carregar apresentam a mesma altura. A resolução do problema consiste na determinação do padrão de posicionamento das bases circulares dos referidos objetos sobre a base de forma retangular, tendo como objetivo a maximização do número de objetos estritamente posicionados no interior dessa base. Este padrão de posicionamento será repetido em cada uma das camadas a carregar sobre a base retangular. Apresentam-se dois algoritmos para a resolução do problema. Estes algoritmos baseiam-se numa meta-heurística, Simulated Annealling, cuja afinação de parâmetros requereu a execução de testes intensivos com o objetivo de atingir um elevado grau de eficiência no seu desempenho. As características dos algoritmos implementados permitiram que a sua extensão à consideração de círculos com raios diferentes fosse facilmente conseguida.

  14. The United States’ European Phased Adaptive Approach Missile Defense System: Defending Against Iranian Missile Threats Without Diluting the Russian Deterrent

    Science.gov (United States)

    2015-01-01

    km/s burnout velocity) located in Deveselu as part of the EPAA Phase 1 Aegis Ashore site were able to kinematically engage minimum energy trajectory...deterrent. After the New Strategic Arms Reduction Treaty was signed in 2010, Russia refused to engage in further nuclear arms control talks with...defense system, Russian officials began to express concern that Phase 4 of the EPAA system—in which SM-3 IIB interceptors (with a burnout velocity of

  15. Analysis of boron dilution in a four-loop PWR

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J.G.; Sha, W.T.

    1995-12-31

    Thermal mixing and boron dilution in a pressurized water reactor were analyzed with COMMIX codes. The reactor system was the four loop Zion reactor. Two boron dilution scenarios were analyzed. In the first scenario, the plant is in cold shutdown and the reactor coolant system has just been filled after maintenance on the steam generators. To flush the air out of the steam generator tubes, a reactor coolant pump (RCP) is started, with the water in the pump suction line devoid of boron and at the same temperature as the coolant in the system. In the second scenario, the plant is at hot standby and the reactor coolant system has been heated up to operating temperature after a long outage. It is assumed that an RCP is started, with the pump suction line filled with cold unborated water, forcing a slug of diluted coolant down the downcomer and subsequently through the reactor core. The subsequent transient thermal mixing and boron dilution that would occur in the reactor system is simulated for these two scenarios. The reactivity insertion rate and the total reactivity are evaluated.

  16. Optimization of a water resource system expansion using the Genetic Algorithm and Simulated Annealing methods; Optimizacion de la expansion de un sistema de recursos hidricos utilizados las metodologias del algoritmo genetico y el recocido simulado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Camacho, Enrique; Andreu Alvarez, Joaquin [Universidad Politecnica de Valencia (Spain)

    2001-06-01

    Two numerical procedures, based on the Genetic Algorithm (GA) and the Simulated Annealing (SA), are developed to solve the problem of the expansion of capacity of a water resource system. The problem was divided into two subproblems: capital availability and operation policy. Both are optimisation-simulation models, the first one is solved by means of the GA and SA, in each case, while the second one is solved using the Out-of-kilter algorithm (OKA), in both models. The objective function considers the usual benefits and costs in this kind of systems, such as irrigation and hydropower benefits, costs of dam construction and system maintenance. The strength and weakness of both models are evaluated by comparing their results with those obtained with the branch and bound technique, which was classically used to solve this kind of problems. [Spanish] Un par de metodos numericos fundamentados en dos tecnicas de busqueda globales. Algoritmos Genetico (AG) y Recocido Simulado (RS), son desarrollados para resolver el problema de expansion de capacidad de un sistema de recursos hidricos. La estrategia ha sido dividir al problema en dos subproblemas: el de disponibilidad de capital y el de la politica de operacion. Ambos modelos son de optimizacion-simulacion, el primero se realiza mediante los algoritmos del RS y el AG en cada caso, en tanto que el segundo lleva a cabo a traves del algoritmo del Out-of-kilter (AOK) en los dos modelos. La funcion objetivo con que se trabaja considera los beneficios y costos mas comunes en este tipo de sistema, tales como beneficios por riego, por hidroelectricidad y costos de construccion de los embalses y mantenimiento del sistema. La potencia y debilidades delos dos modelos se evaluan mediante la comparacion con los resultados obtenidos a traves de una de las tecnicas mas usadas en este tipo de problemas: la de ramificacion y acotacion.

  17. High field Moessbauer study of dilute Ir-(Fe) alloys

    International Nuclear Information System (INIS)

    Takabatake, Toshiro; Mazaki, Hiromasa; Shinjo, Teruya.

    1981-01-01

    The magnetic behavior of very dilute Fe impurities in Ir has been studied by means of Moessbauer measurement in external fields up to 80 kOe at 4.2 K. The saturation hyperfine field increases in proportion to the external field up to the maximum magnetic field available. This means that for a localized spin fluctuation system IrFe, the effective magnetic moment associated with Fe impurities is induced in proportion to the external field. No anomalous spectrum was observed with a very dilute sample (--10 ppm 57 Co), indicating that the interaction between impurities is responsible for the anomalous spectrum previously observed with a less homogeneous sample. (author)

  18. Thermal diffusion in dilute nanofluids investigated by photothermal interferometry

    International Nuclear Information System (INIS)

    Philip, J; Nisha, M R

    2010-01-01

    We have carried out a theoretical analysis of the dependence of the particle mass fraction on the thermal diffusivity of dilute suspensions of nanoparticles in liquids (dilute nanofluids). The analysis takes in to account adsorption of an ordered layer of solvent molecules around the nanoparticles. It is found that thermal diffusivity decreases with mass fraction for sufficiently small particle sizes. Beyond a critical particle size thermal diffusivity begins to increase with mass fraction for the same system. The results have been verified experimentally by measuring the thermal diffusivity of dilute suspensions of TiO 2 nanoparticles dispersed in polyvinyl alcohol (PVA) medium. The effect is attributed to Kapitza resistance of thermal waves in the medium.

  19. Moderate Dilution of Copper Slag by Natural Gas

    Science.gov (United States)

    Zhang, Bao-jing; Zhang, Ting-an; Niu, Li-ping; Liu, Nan-song; Dou, Zhi-he; Li, Zhi-qiang

    2018-01-01

    To enable use of copper slag and extract the maximum value from the contained copper, an innovative method of reducing moderately diluted slag to smelt copper-containing antibacterial stainless steel is proposed. This work focused on moderate dilution of copper slag using natural gas. The thermodynamics of copper slag dilution and ternary phase diagrams of the slag system were calculated. The effects of blowing time, temperature, matte settling time, and calcium oxide addition were investigated. The optimum reaction conditions were identified to be blowing time of 20 min, reaction temperature of 1250°C, settling time of 60 min, CaO addition of 4% of mass of slag, natural gas flow rate of 80 mL/min, and outlet pressure of 0.1 MPa. Under these conditions, the Fe3O4 and copper contents of the residue were 7.36% and 0.50%, respectively.

  20. Interventions in Early Mathematics: Avoiding Pollution and Dilution.

    Science.gov (United States)

    Sarama, Julie; Clements, Douglas H

    2017-01-01

    Although specific interventions in early mathematics have been successful, few have been brought to scale successfully, especially across the challenging diversity of populations and contexts in the early childhood system in the United States. In this chapter, we analyze a theoretically based scale-up model for early mathematics that was designed to avoid the pollution and dilution that often plagues efforts to achieve broad success. We elaborate the theoretical framework by noting the junctures that are susceptible to dilution or pollution. Then we expatiate the model's guidelines to describe specifically how they were designed and implemented to mitigate pollution and dilution. Finally, we provide evidence regarding the success of these efforts. © 2017 Elsevier Inc. All rights reserved.

  1. Pd-based alloy nanoclusters in ion-implanted silica: Formation and stability under thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Battaglin, G.; Cattaruzza, E.; De Marchi, G.; Gonella, F.; Mattei, G. E-mail: mattei@padova.infm.it; Maurizio, C.; Mazzoldi, P.; Parolin, M.; Sada, C.; Calliari, I

    2002-05-01

    In this work we report on the formation and stability under thermal annealing of Pd-Cu and Pd-Ag alloy nanoclusters obtained by sequential ion implantation in silica. The role of the annealing atmosphere on the alloy cluster formation and stability is investigated. A comparison is made with similar alloy-based systems obtained by sequential ion implantation in silica of Au-Ag or Au-Cu followed by annealing under similar conditions, in order to evidence the peculiar effect of the various metals in controlling the alloy evolution and/or decomposition.

  2. Annealing temperature dependence of exchange bias in BiFeO3/CoFe bilayers

    Science.gov (United States)

    Yu, T.; Naganuma, H.; Wang, W. X.; Ando, Y.; Han, X. F.

    2012-04-01

    BiFeO3/CoFe bilayers with different BiFeO3 (BFO) crystalities were fabricated by chemical solution deposition and sputtering method. Exchange bias has been successfully induced in these bilayers by post-annealing. The annealing temperature dependence of exchange bias as well as coercivity was investigated. Two kinds of annealing temperature dependence behaviors were observed. It is found that, similar to the conventional antiferromagnet/ferromagnet system, the temperature dependence of exchange bias is dominated by direct interface coupling, and the crystality of BFO has no profound effect on exchange bias.

  3. Electronic defect levels in continuous wave laser annealed silicon metal oxide semiconductor devices

    Science.gov (United States)

    Cervera, M.; Garcia, B. J.; Martinez, J.; Garrido, J.; Piqueras, J.

    1988-09-01

    The effect of laser treatment on the bulk and interface states of the Si-SiO2 structure has been investigated. The annealing was performed prior to the gate metallization using a continuous wave Ar+ laser. For low laser powers the interface state density seems to decrease slightly in comparison with untreated samples. However, for the highest irradiating laser powers a new bulk level at 0.41 eV above the valence band with concentrations up to 1015 cm-3 arises probably due to the electrical activation of the oxygen diluted in the Czochralski silicon. Later postmetallization annealings reduce the interface state density to values in the 1010 cm-2 eV-1 range but leave the concentration of the 0.41-eV center nearly unchanged.

  4. Synthesis of copper nanoparticles in a fluoropolymer matrix by annealing in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Safonov, Alexey, E-mail: safonov@itp.nsc.ru [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation); Sulyaeva, Veronica [Nikolaev Institute of Inorganic Chemistry SB RAS, Lavrentyev Ave. 3, 630090, Novosibirsk (Russian Federation); Timoshenko, Nikolay; Starinskiy, Sergey [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation)

    2017-07-12

    In this paper, a method for synthesizing copper nanoparticles in a fluoropolymer matrix is proposed which prevents the reduction in the plasmonic properties due to the oxidation of the metal. The basic idea of the proposed method of nanoparticle synthesis is to anneal of thin metal film coated with a thin layer of fluoropolymer. The morphology and optical properties of the resulting composites were determined. The optical properties remained unchanged after several months of storage under standard conditions. - Highlights: • The copper-fluoropolymer composites are obtained by a combination of GJD and HWCVD. • The annealing of thin Cu film covered with fluoropolymer leads to formation of NPs. • The dilution of the localized surface plasmon resonance due to oxidation was analyzed. • The plasmonic properties of the Cu NPs are saved in the fluoropolymer matrix. • The fluoropolymer matrix prevents oxidation of metal NPs.

  5. Coherence and stiffness of spin waves in diluted ferromagnets

    Czech Academy of Sciences Publication Activity Database

    Turek, Ilja; Kudrnovský, Josef; Drchal, Václav

    2016-01-01

    Roč. 94, č. 17 (2016), č. článku 174447. ISSN 2469-9950 R&D Projects: GA ČR GA15-13436S Institutional support: RVO:68081723 ; RVO:68378271 Keywords : spin waves * diluted ferromagnets * disordered systems Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.836, year: 2016

  6. Exactly soluble diluted random one-dimensional lattices

    NARCIS (Netherlands)

    Nieuwenhuizen, Th.M.

    1984-01-01

    Exact solutions for the characteristic function, which determines the density of states and inverse localization length, and one-particle Green function are presented for a class of lattice models with diluted randomness. (Examples are: harmonic, electronic, relaxation and X-Y spin systems.) With

  7. The Kolmogorov -Sinai entropy for dilute gases in equilibrium

    NARCIS (Netherlands)

    van Beijeren, H.; Dorfman, J.R.; Posch, H.A.; Dellago, Ch.

    1997-01-01

    We consider the density expansion of the Kolmogorov-Sinai (KS) entropy per particle for a dilute gas in equilibrium, and use methods from the kinetic theory of gases to compute the leading term. For an equilibrium system, the KS entropy hKS is the sum of all of the positive Lyapunov exponents

  8. Use of an Eductor to Reliably Dilute a Plutonium Solution

    International Nuclear Information System (INIS)

    Steimke, J.L.

    1999-01-01

    Savannah River Site (SRS) in South Carolina is dissolving Pu239 scrap, which is a legacy from the production of nuclear weapons materials, and will later convert it into oxide form to stabilize it. An eductor has been used to both dilute and transfer a plutonium containing solution between tanks. Eductors have the advantages of simplicity and no moving parts. Reliable control of dilution is important because the geometry of the receiving tank could potentially allow a nuclear criticality. Dilution factor was to have been controlled by the appropriate choice of flow restrictor in the line between the plutonium solution tank and the eductor. However, dilution factors measured for liquid transfers with different flow restrictors showed unexpected trends, causing concern that the process was not well understood. As a result, the performance of the eductor and associated piping were analyzed using a mathematical model. The one dimensional, two phase model accounted for eductor performance and for air and vapor coming out of solution at low pressures. The unexpected trends were shown to be the result of variations in viscosities and densities of both the plutonium solution and the nitric acid solution used as both the motive fluid and diluent. The model agreed well with existing data and was then used to make pre-test predictions of flows for four solution transfers with good agreement. This provided confidence that the eductor system was a reliable method for obtaining specified dilution factors. Based on model results, recommendations were made and implemented for the operation of the eductor transfer system. One unexpected result of the analysis was the observation that slow corrosion inside the eductor is increasing the dilution factor, which is a conservative trend

  9. Enthalpy relaxation and annealing effect in polystyrene.

    Science.gov (United States)

    Sakatsuji, Waki; Konishi, Takashi; Miyamoto, Yoshihisa

    2013-07-01

    The effects of thermal history on the enthalpy relaxation in polystyrene are studied by differential scanning calorimetry. The temperature dependence of the specific heat in the liquid and the glassy states, that of relaxation time, and the exponent of the Kohlrausch-Williams-Watts function are determined by measurements of the thermal response against sinusoidal temperature variation. A phenomenological model equation previously proposed to interpret the memory effect in the frozen state is applied to the enthalpy relaxation and the evolution of entropy under a given thermal history is calculated. The annealing below the glass transition temperature produces two effects on enthalpy relaxation: the decay of excess entropy with annealing time in the early stage of annealing and the increase in relaxation time due to physical aging in the later stage. The crossover of these effects is reflected in the variation of temperature of the maximum specific heat observed in the heating process after annealing and cooling.

  10. Annealing behavior of high permeability amorphous alloys

    International Nuclear Information System (INIS)

    Rabenberg, L.

    1980-06-01

    Effects of low temperature annealing on the magnetic properties of the amorphous alloy Co 71 4 Fe 4 6 Si 9 6 B 14 4 were investigated. Annealing this alloy below 400 0 C results in magnetic hardening; annealing above 400 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

  11. Global warming: Temperature estimation in annealers

    Directory of Open Access Journals (Sweden)

    Jack Raymond

    2016-11-01

    Full Text Available Sampling from a Boltzmann distribution is NP-hard and so requires heuristic approaches. Quantum annealing is one promising candidate. The failure of annealing dynamics to equilibrate on practical time scales is a well understood limitation, but does not always prevent a heuristically useful distribution from being generated. In this paper we evaluate several methods for determining a useful operational temperature range for annealers. We show that, even where distributions deviate from the Boltzmann distribution due to ergodicity breaking, these estimates can be useful. We introduce the concepts of local and global temperatures that are captured by different estimation methods. We argue that for practical application it often makes sense to analyze annealers that are subject to post-processing in order to isolate the macroscopic distribution deviations that are a practical barrier to their application.

  12. Microstructural evolution and pitting resistance of annealed lean duplex stainless steel UNS S32304

    International Nuclear Information System (INIS)

    Zhang Ziying; Han Dong; Jiang Yiming; Shi Chong; Li Jin

    2012-01-01

    Highlights: ► The relationship between pitting corrosion resistance and annealing temperature for UNS S32304 was systemically studied. ► The specimens annealed at 1080 °C for 1 h, quenched in water exhibit the best pitting corrosion resistance. ► The relationship between microstructural evolution and pitting resistance of annealed UNS S32304 was discussed in detail. ► The pitting corrosion resistance is consistent with pitting resistance equivalent number of weaker phase for UNS S32304 alloy. - Abstract: The effect of annealing temperature in the range from 1000 to 1200 °C on the pitting corrosion behavior of duplex stainless steel UNS S32304 was investigated by the potentiodynamic polarization and potentiostatic critical pitting temperature techniques. The microstructural evolution and pit morphologies were studied using a scanning electron microscopy with energy dispersive X-ray spectroscopy. The results demonstrated that the nucleation of metastable pits transformed from austenite phase to ferrite phase with the increasing annealing temperature. As the annealing temperature increased, the pitting corrosion resistance firstly increased and then decreased. The highest pitting corrosion resistance was obtained at 1080 °C with the highest critical pitting temperature value and pitting nucleation resistance. The results could be well explained by the microstructural evolution of ferrite and austenite phases induced by annealing treatment.

  13. PERBANDINGAN KINERJA ALGORITMA GENETIKA DAN SIMULATED ANNEALING UNTUK MASALAH MULTIPLE OBJECTIVE PADA PENJADWALAN FLOWSHOP

    Directory of Open Access Journals (Sweden)

    I Gede Agus Widyadana

    2002-01-01

    Full Text Available The research is focused on comparing Genetics algorithm and Simulated Annealing in the term of performa and processing time. The main purpose is to find out performance both of the algorithm to solve minimizing makespan and total flowtime in a particular flowshop system. Performances of the algorithms are found by simulating problems with variation of jobs and machines combination. The result show the Simulated Annealing is much better than the Genetics up to 90%. The Genetics, however, only had score in processing time, but the trend that plotted suggest that in problems with lots of jobs and lots of machines, the Simulated Annealing will run much faster than the Genetics. Abstract in Bahasa Indonesia : Penelitian ini difokuskan pada pembandingan algoritma Genetika dan Simulated Annealing ditinjau dari aspek performa dan waktu proses. Tujuannya adalah untuk melihat kemampuan dua algoritma tersebut untuk menyelesaikan problem-problem penjadwalan flow shop dengan kriteria minimasi makespan dan total flowtime. Kemampuan kedua algoritma tersebut dilihat dengan melakukan simulasi yang dilakukan pada kombinasi-kombinasi job dan mesin yang berbeda-beda. Hasil simulasi menunjukan algoritma Simulated Annealing lebih unggul dari algoritma Genetika hingga 90%, algoritma Genetika hanya unggul pada waktu proses saja, namun dengan tren waktu proses yang terbentuk, diyakini pada problem dengan kombinasi job dan mesin yang banyak, algoritma Simulated Annealing dapat lebih cepat daripada algoritma Genetika. Kata kunci: Algoritma Genetika, Simulated Annealing, flow shop, makespan, total flowtime.

  14. Structural relaxation in annealed hyperquenched basaltic glasses

    DEFF Research Database (Denmark)

    Guo, Xiaoju; Mauro, John C.; Potuzak, M.

    2012-01-01

    The enthalpy relaxation behavior of hyperquenched (HQ) and annealed hyperquenched (AHQ) basaltic glass is investigated through calorimetric measurements. The results reveal a common onset temperature of the glass transition for all the HQ and AHQ glasses under study, indicating that the primary...... relaxation is activated at the same temperature regardless of the initial departure from equilibrium. The analysis of secondary relaxation at different annealing temperatures provides insights into the enthalpy recovery of HQ glasses....

  15. Irradiation embrittlement and optimisation of annealing

    International Nuclear Information System (INIS)

    1993-01-01

    This conference is composed of 30 papers grouped in 6 sessions related to the following themes: neutron irradiation effects in pressure vessel steels and weldments used in PWR, WWER and BWR nuclear plants; results from surveillance programmes (irradiation induced damage and annealing processes); studies on the influence of variations in irradiation conditions and mechanisms, and modelling; mitigation of irradiation effects, especially through thermal annealing; mechanical test procedures and specimen size effects

  16. Cost effectiveness of dilute chemical decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.; Weyman, G.D.

    The basic principles of dilute chemical decontamination are described, as well as the method of application. Methods of computing savings in radiation dose and costs are presented, with results from actual experience and illustrative examples. It is concluded that dilute chemical decontamination is beneficial in many cases. It reduces radiation exposure of workers, saves money, and simplifies maintenance work

  17. Storm Sewage Dilution in Smaller Streams

    DEFF Research Database (Denmark)

    Larsen, Torben; Vestergaard, Kristian

    1987-01-01

    A numerical model has been used to show how dilution in smaller streams can be effected by unsteady hydraulic conditions caused by a storm sewage overflow.......A numerical model has been used to show how dilution in smaller streams can be effected by unsteady hydraulic conditions caused by a storm sewage overflow....

  18. Boosting quantum annealer performance via sample persistence

    Science.gov (United States)

    Karimi, Hamed; Rosenberg, Gili

    2017-07-01

    We propose a novel method for reducing the number of variables in quadratic unconstrained binary optimization problems, using a quantum annealer (or any sampler) to fix the value of a large portion of the variables to values that have a high probability of being optimal. The resulting problems are usually much easier for the quantum annealer to solve, due to their being smaller and consisting of disconnected components. This approach significantly increases the success rate and number of observations of the best known energy value in samples obtained from the quantum annealer, when compared with calling the quantum annealer without using it, even when using fewer annealing cycles. Use of the method results in a considerable improvement in success metrics even for problems with high-precision couplers and biases, which are more challenging for the quantum annealer to solve. The results are further enhanced by applying the method iteratively and combining it with classical pre-processing. We present results for both Chimera graph-structured problems and embedded problems from a real-world application.

  19. Nanocrystalline magnetic materials obtained by flash annealing

    Directory of Open Access Journals (Sweden)

    Murakami R.K.

    1999-01-01

    Full Text Available The aim of the present work was to produce enhanced-remanence nanocrystalline magnetic material by crystallizing amorphous or partially amorphous Pr4.5Fe77B18.5 alloys by the flash annealing process, also known as the dc-Joule heating process, and to determine the optimal conditions for obtaining good magnetic coupling between the magnetic phases present in this material. Ribbons of Pr4.5Fe77B18.5 were produced by melt spinning and then annealed for 10-30 s at temperatures 500 - 640 °C by passing current through the sample to develop the enhanced-remanence nanocrystalline magnetic material. These materials were studied by X-ray diffraction, differential thermal analysis and magnetic measurements. Coercivity increases of up to 15% were systematically observed in relation to furnace-annealed material. Two different samples were carefully examined: (i a sample annealed at 600 °C which showed the highest coercive field Hc and remanence ratio Mr/Ms and (ii a sample annealed at 520 °C which showed phase separation in the second quadrant demagnetization curve. Our results are in agreement with other studies which show that flash annealing improves the magnetic properties of some amorphous ferromagnetic ribbons.

  20. VOC destruction by water diluted hydrogen mild combustion.

    Science.gov (United States)

    Sabia, P; Romeo, F; de Joannon, M; Cavaliere, A

    2007-06-01

    This study represents a preliminary numerical evaluation of the effect of steam dilution and hydrogen addition on the oxidation of formaldehyde and benzene, chosen as representative of the volatile organic compounds (VOC), in mild condition by evaluating the autoignition time and the steady state attainment. These parameters are important in the design of thermal VOC destruction plants since they influence the abatement efficiency and, therefore, the plant dimension. It has come out that, in comparison with the system diluted in nitrogen, steam induces lower autoignition times and, on the other hand, longer times for the attainment of the steady state. In contrast, for very high water content the autoignition time slightly increases. In particular results have shown that is possible to identify an optimum value of steam content that allows for the attainment of the steady state condition by the lowest residence time. Hydrogen addition to systems diluted in nitrogen promotes the oxidation reactions and anticipates the steady state condition. In steam diluted systems hydrogen delays the autoignition of the mixtures even though anticipates the attainment of the complete destruction of the VOC. The rate of production analysis has showed that the H(2)/O(2) reactions, that promote the ignition and the destruction of VOC, are sensibly modified by the presence of water and hydrogen.

  1. Annealed Demon Algorithms Solving the Environmental / Economic Dispatch Problem

    Directory of Open Access Journals (Sweden)

    Aristidis VLACHOS

    2013-06-01

    Full Text Available This paper presents an efficient and reliable Annealed Demon (AD algorithm for the Environmental/Economic Dispatch (EEB problem. The EED problem is a multi-objective non-linear optimization problem with constraints. This problem is one of the fundamentals issues in power system operation. The system of generation associates thermal generators and emissions which involves sulphur oxides (SO2 and nitrogen oxides (NOx. The aim is to minimize total fuel cost of the system and control emission. The proposed AD algorithm is applied for EED of a simple power system.

  2. Nickel silicide formation using multiple-pulsed laser annealing

    International Nuclear Information System (INIS)

    Setiawan, Y.; Lee, P. S.; Pey, K. L.; Wang, X. C.; Lim, G. C.; Chow, F. L.

    2007-01-01

    The effect of multiple-pulsed laser irradiation on Ni silicide formation in Ni(Ti)/Si system was studied. A layered structure consisting of both crystalline NiSi 2 and Ni-rich Ni-Si amorphous phases with a protective TiO x overlayer was formed after five-pulsed laser annealing at 0.4 J cm -2 . Different solidification velocities caused by a variation in the atomic concentration across the melt have led to the formation of this layered structure. On the other hand, by increasing the number of laser pulses, a continuous layer of polycrystalline NiSi was obtained after a 20-pulsed laser annealing at 0.3 J cm -2 laser fluence. Its formation is attributed to a better elemental mixing which occurred during subsequent pulses. Enhancement of surface absorption and remelting of the phases formed is proposed as the mechanism governing the continuous NiSi layer formation

  3. Origin of reverse annealing effect in hydrogen-implanted silicon

    Energy Technology Data Exchange (ETDEWEB)

    Di, Zengfeng [Los Alamos National Laboratory; Nastasi, Michael A [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory

    2009-01-01

    In contradiction to conventional damage annealing, thermally annealed H-implanted Si exhibits an increase in damage or reverse annealing behavior, whose mechanism has remained elusive. On the basis of quantitative high resolution transmission electron microscopy combined with channeling Rutherford backscattering analysis, we conclusively elucidate that the reverse annealing effect is due to the nucleation and growth of hydrogen-induce platelets. Platelets are responsible for an increase in the height and width the channeling damage peak following increased isochronal anneals.

  4. Ferromagnetism in diluted magnetic semiconductor heterojunction systems

    Czech Academy of Sciences Publication Activity Database

    Lee, B.; Jungwirth, Tomáš; MacDonald, A. H.

    2002-01-01

    Roč. 17, - (2002), s. 393-403 ISSN 0268-1242 R&D Projects: GA ČR GA202/98/0085; GA MŠk OC P5.10 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferromagnetic semiconductors * heterostructures Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.241, year: 2002

  5. Standard Guide for In-Service Annealing of Light-Water Moderated Nuclear Reactor Vessels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This guide covers the general procedures to be considered for conducting an in-service thermal anneal of a light-water moderated nuclear reactor vessel and demonstrating the effectiveness of the procedure. The purpose of this in-service annealing (heat treatment) is to improve the mechanical properties, especially fracture toughness, of the reactor vessel materials previously degraded by neutron embrittlement. The improvement in mechanical properties generally is assessed using Charpy V-notch impact test results, or alternatively, fracture toughness test results or inferred toughness property changes from tensile, hardness, indentation, or other miniature specimen testing (1). 1.2 This guide is designed to accommodate the variable response of reactor-vessel materials in post-irradiation annealing at various temperatures and different time periods. Certain inherent limiting factors must be considered in developing an annealing procedure. These factors include system-design limitations; physical constrain...

  6. Extended band anti-crossing model for dilute bismides

    Science.gov (United States)

    Hader, J.; Badescu, S. C.; Bannow, L. C.; Moloney, J. V.; Johnson, S. R.; Koch, S. W.

    2018-02-01

    Bandstructure properties of dilute bismide bulk systems are calculated using density functional theory. An extended band anti-crossing model is introduced to fit the obtained results. Using these as inputs for a fully microscopic many-body theory, absorption and photoluminescence spectra are computed for bulk and quantum-well systems. Comparison to experimental results identifies the applicability range of the new anti-crossing model.

  7. Modeling, Growth and Characterization of III-V and Dilute Nitride Antimonide Materials and Solar Cells

    Science.gov (United States)

    Maros, Aymeric

    III-V multijunction solar cells have demonstrated record efficiencies with the best device currently at 46 % under concentration. Dilute nitride materials such as GaInNAsSb have been identified as a prime choice for the development of high efficiency, monolithic and lattice-matched multijunction solar cells as they can be lattice-matched to both GaAs and Ge substrates. These types of cells have demonstrated efficiencies of 44% for terrestrial concentrators, and with their upright configuration, they are a direct drop-in product for today's space and concentrator solar panels. The work presented in this dissertation has focused on the development of relatively novel dilute nitride antimonide (GaNAsSb) materials and solar cells using plasma-assisted molecular beam epitaxy, along with the modeling and characterization of single- and multijunction solar cells. Nitrogen-free ternary compounds such as GaInAs and GaAsSb were investigated first in order to understand their structural and optical properties prior to introducing nitrogen. The formation of extended defects and the resulting strain relaxation in these lattice-mismatched materials is investigated through extensive structural characterization. Temperature- and power-dependent photoluminescence revealed an inhomogeneous distribution of Sb in GaAsSb films, leading to carrier localization effects at low temperatures. Tuning of the growth parameters was shown to suppress these Sb-induced localized states. The introduction of nitrogen was then considered and the growth process was optimized to obtain high quality GaNAsSb films lattice-matched to GaAs. Near 1-eV single-junction GaNAsSb solar cells were produced. The best devices used a p-n heterojunction configuration and demonstrated a current density of 20.8 mA/cm2, a fill factor of 64 % and an open-circuit voltage of 0.39 V, corresponding to a bandgap-voltage offset of 0.57 V, comparable with the state-of-the-art for this type of solar cells. Post-growth annealing

  8. Development of fast heating electron beam annealing setup for ultra high vacuum chamber.

    Science.gov (United States)

    Das, Sadhan Chandra; Majumdar, Abhijit; Katiyal, Sumant; Shripathi, T; Hippler, R

    2014-02-01

    We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10(-6) mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 ºC of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C.

  9. Nuclear techniques of analysis in diamond synthesis and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, D. N.; Prawer, S.; Gonon, P.; Walker, R.; Dooley, S.; Bettiol, A.; Pearce, J. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Nuclear techniques of analysis have played an important role in the study of synthetic and laser annealed diamond. These measurements have mainly used ion beam analysis with a focused MeV ion beam in a nuclear microprobe system. A variety of techniques have been employed. One of the most important is nuclear elastic scattering, sometimes called non-Rutherford scattering, which has been used to accurately characterise diamond films for thickness and composition. This is possible by the use of a database of measured scattering cross sections. Recently, this work has been extended and nuclear elastic scattering cross sections for both natural boron isotopes have been measured. For radiation damaged diamond, a focused laser annealing scheme has been developed which produces near complete regrowth of MeV phosphorus implanted diamonds. In the laser annealed regions, proton induced x-ray emission has been used to show that 50 % of the P atoms occupy lattice sites. This opens the way to produce n-type diamond for microelectronic device applications. All these analytical applications utilize a focused MeV microbeam which is ideally suited for diamond analysis. This presentation reviews these applications, as well as the technology of nuclear techniques of analysis for diamond with a focused beam. 9 refs., 6 figs.

  10. Nuclear techniques of analysis in diamond synthesis and annealing

    International Nuclear Information System (INIS)

    Jamieson, D. N.; Prawer, S.; Gonon, P.; Walker, R.; Dooley, S.; Bettiol, A.; Pearce, J.

    1996-01-01

    Nuclear techniques of analysis have played an important role in the study of synthetic and laser annealed diamond. These measurements have mainly used ion beam analysis with a focused MeV ion beam in a nuclear microprobe system. A variety of techniques have been employed. One of the most important is nuclear elastic scattering, sometimes called non-Rutherford scattering, which has been used to accurately characterise diamond films for thickness and composition. This is possible by the use of a database of measured scattering cross sections. Recently, this work has been extended and nuclear elastic scattering cross sections for both natural boron isotopes have been measured. For radiation damaged diamond, a focused laser annealing scheme has been developed which produces near complete regrowth of MeV phosphorus implanted diamonds. In the laser annealed regions, proton induced x-ray emission has been used to show that 50 % of the P atoms occupy lattice sites. This opens the way to produce n-type diamond for microelectronic device applications. All these analytical applications utilize a focused MeV microbeam which is ideally suited for diamond analysis. This presentation reviews these applications, as well as the technology of nuclear techniques of analysis for diamond with a focused beam. 9 refs., 6 figs

  11. Isotopic dilution requirements for 233U criticality safety in processing and disposal facilities

    International Nuclear Information System (INIS)

    Elam, K.R.; Forsberg, C.W.; Hopper, C.M.; Wright, R.Q.

    1997-11-01

    The disposal of excess 233 U as waste is being considered. Because 233 U is a fissile material, one of the key requirements for processing 233 U to a final waste form and disposing of it is to avoid nuclear criticality. For many processing and disposal options, isotopic dilution is the most feasible and preferred option to avoid nuclear criticality. Isotopic dilution is dilution of fissile 233 U with nonfissile 238 U. The use of isotopic dilution removes any need to control nuclear criticality in process or disposal facilities through geometry or chemical composition. Isotopic dilution allows the use of existing waste management facilities, that are not designed for significant quantities of fissile materials, to be used for processing and disposing of 233 U. The amount of isotopic dilution required to reduce criticality concerns to reasonable levels was determined in this study to be ∼ 0.66 wt% 233 U. The numerical calculations used to define this limit consisted of a homogeneous system of silicon dioxide (SiO 2 ), water (H 2 O), 233 U, and depleted uranium (DU) in which the ratio of each component was varied to determine the conditions of maximum nuclear reactivity. About 188 parts of DU (0.2 wt% 235 U) are required to dilute 1 part of 233 U to this limit in a water-moderated system with no SiO 2 present. Thus, for the US inventory of 233 U, several hundred metric tons of DU would be required for isotopic dilution

  12. Deterministic quantum annealing expectation-maximization algorithm

    Science.gov (United States)

    Miyahara, Hideyuki; Tsumura, Koji; Sughiyama, Yuki

    2017-11-01

    Maximum likelihood estimation (MLE) is one of the most important methods in machine learning, and the expectation-maximization (EM) algorithm is often used to obtain maximum likelihood estimates. However, EM heavily depends on initial configurations and fails to find the global optimum. On the other hand, in the field of physics, quantum annealing (QA) was proposed as a novel optimization approach. Motivated by QA, we propose a quantum annealing extension of EM, which we call the deterministic quantum annealing expectation-maximization (DQAEM) algorithm. We also discuss its advantage in terms of the path integral formulation. Furthermore, by employing numerical simulations, we illustrate how DQAEM works in MLE and show that DQAEM moderate the problem of local optima in EM.

  13. Minimal coital dilution in Accra, Ghana.

    Science.gov (United States)

    Jenness, Samuel M; Biney, Adriana A E; Ampofo, William K; Nii-Amoo Dodoo, Francis; Cassels, Susan

    2015-05-01

    Coital dilution, the reduction in the coital frequency per partner when an additional ongoing partner is added, may reduce the transmission potential of partnership concurrency for HIV and other sexually transmitted infections. Empirical estimates of dilution, especially dilution of sexual acts unprotected by condoms, are needed to inform prevention research. Sexually active adults in Accra, Ghana were recruited in a multistage household probability sample. Degree (number of ongoing partners), total acts, and unprotected acts were measured retrospectively for each month in the past year through an event history calendar. Random-effects negative binomial models estimated the association between degree and coital frequency. Compared with person-months with a single partner (monogamy), 2.06 times as many total acts and 1.94 times as many unprotected acts occurred in months with 2 partners. In months with 3 partners, 2.90 times as many total acts and 2.39 times as many unprotected acts occurred compared with monogamous months. Total acts but not unprotected acts also declined with partnership duration. No dilution was observed for total acts with up to 3 concurrent partners, but a small amount of dilution was observed for unprotected acts for months with multiple concurrencies. This suggests moderate selective condom use in months with multiple concurrencies. The implications of the observed dilution for future HIV transmission must be investigated with mathematical models.

  14. Thermal annealing of tilted fiber Bragg gratings

    Science.gov (United States)

    González-Vila, Á.; Rodríguez-Cobo, L.; Mégret, P.; Caucheteur, C.; López-Higuera, J. M.

    2016-05-01

    We report a practical study of the thermal decay of cladding mode resonances in tilted fiber Bragg gratings, establishing an analogy with the "power law" evolution previously observed on uniform gratings. We examine how this process contributes to a great thermal stability, even improving it by means of a second cycle slightly increasing the annealing temperature. In addition, we show an improvement of the grating spectrum after annealing, with respect to the one just after inscription, which suggests the application of this method to be employed to improve saturation issues during the photo-inscription process.

  15. Hardening by annealing: insights from different alloys

    International Nuclear Information System (INIS)

    Renk, O; Pippan, R; Hohenwarter, A; Schuh, B; Li, J H

    2015-01-01

    In contrast to the general notion about the annealing behavior of coarse grained materials, hardening phenomena in nanocrystalline materials can occur. Although the phenomena have already been recognized several years ago, the mechanisms behind are still controversially discussed. For example, the influence of solutes segregated to grain boundaries on the strengthening mechanism is unclear. We present a combination of atom probe tomography and mechanical data to reveal the role of segregations to the strengthening. The results show that despite large modifications of the boundary chemistry the mechanical behavior remains widely unaffected. Additionally, it will be shown that hardening upon annealing can only occur below a material-specific grain size threshold value. (paper)

  16. Modular annealing apparatus for in situ reactor vessel annealing and related method of assembly

    International Nuclear Information System (INIS)

    Bau, F.I.; Mavretish, R.S.

    1992-01-01

    This patent describes a method for annealing a nuclear reactor vessel in a containment building. It comprises pre-fabricating a plurality of heater segments at a location outside the containment building; transporting the plurality of heater segments to the containment building; removing the core and internals and storing same; installing temporary shielding for the stored internals; introducing each of the plurality of heater segments through an equipment hatch in the containment building; assembling the plurality of heater segments to form an annealing apparatus; and annealing the reactor vessel

  17. Calculation of Weighted Geometric Dilution of Precision

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2013-01-01

    Full Text Available To achieve high accuracy in wireless positioning systems, both accurate measurements and good geometric relationship between the mobile device and the measurement units are required. Geometric dilution of precision (GDOP is widely used as a criterion for selecting measurement units, since it represents the geometric effect on the relationship between measurement error and positioning determination error. In the calculation of GDOP value, the maximum volume method does not necessarily guarantee the selection of the optimal four measurement units with minimum GDOP. The conventional matrix inversion method for GDOP calculation demands a large amount of operation and causes high power consumption. To select the subset of the most appropriate location measurement units which give the minimum positioning error, we need to consider not only the GDOP effect but also the error statistics property. In this paper, we employ the weighted GDOP (WGDOP, instead of GDOP, to select measurement units so as to improve the accuracy of location. The handheld global positioning system (GPS devices and mobile phones with GPS chips can merely provide limited calculation ability and power capacity. Therefore, it is very imperative to obtain WGDOP accurately and efficiently. This paper proposed two formations of WGDOP with less computation when four measurements are available for location purposes. The proposed formulae can reduce the computational complexity required for computing the matrix inversion. The simpler WGDOP formulae for both the 2D and the 3D location estimation, without inverting a matrix, can be applied not only to GPS but also to wireless sensor networks (WSN and cellular communication systems. Furthermore, the proposed formulae are able to provide precise solution of WGDOP calculation without incurring any approximation error.

  18. Effective critical behaviour of diluted Heisenberg-like magnets

    OpenAIRE

    Dudka, M.; Folk, R.; Holovatch, Yu.; Ivaneiko, D.

    2005-01-01

    In agreement with the Harris criterion, asymptotic critical exponents of three-dimensional (3d) Heisenberg-like magnets are not influenced by weak quenched dilution of non-magnetic component. However, often in the experimental studies of corresponding systems concentration- and temperature-dependent exponents are found with values differing from those of the 3d Heisenberg model. In our study, we use the field--theoretical renormalization group approach to explain this observation and to calcu...

  19. Moessbauer-spectroscopic study of structure and magnetism of the exchange-coupled layer systems Fe/FeSn{sub 2}, and Fe/FeSi/Si and the ion-implanted diluted magnetic semiconductor SiC(Fe); Moessbauerspektroskopische Untersuchung von Struktur und Magnetismus der austauschgekoppelten Schichtsysteme Fe/FeSn{sub 2} und Fe/FeSi/Si und des ionenimplantierten verduennten magnetischen Halbleiters SiC(Fe)

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, Frank

    2009-07-07

    In line with this work the structural and magnetic properties of the exchange coupled layered systems Fe/FeSn{sub 2} and Fe/FeSi/Si and of the Fe ion implanted diluted magnetic semiconductor (DMS) SiC(Fe) were investigated. The main measuring method was the isotope selective {sup 57}Fe conversion electron Moessbauer spectroscopy (CEMS), mostly in connection with the {sup 57}Fe tracer layer technique, in a temperature range from 4.2 K to 340 K. Further measurement techniques were X-ray diffraction (XRD), electron diffraction (LEED, RHEED), SQUID magnetometry and FMR (Ferromagnetic Resonance). In the first part of this work the properties of thin AF FeSn{sub 2}(001) films and of the exchange-bias system Fe/FeSn{sub 2}(001) on InSb(001) were investigated. With the application of {sup 57}Fe-tracer layers and CEMS both the Fe-spin structure and the temperature dependence of the magnetic hyperfine field (B{sub hf}) of FeSn{sub 2} could be examined. The evaporation of Fe films on the FeSn{sub 2} films produced in the latter ones a high perpendicular spin component at the Fe/FeSn{sub 2} interface. In some distance from the interface the Fe spins rotate back into the sample plane. Furthermore {sup 57}Fe-CEMS provided a correlation between the absolute value of the exchange field vertical stroke He vertical stroke and the amount of magnetic defects within the FeSn{sub 2}. Temperature dependent CEMS-measurements yielded informations about the spin dynamics within the AF. The transition temperatures T{sub B}{sup *}, which were interpreted as superparamagnetic blocking temperatures, obtain higher values compared to the temperatures T{sub B} of the exchange-bias effect, obtained with magnetometry measurements. The second part of this work deals with the indirect exchange coupling within Fe/FeSi/Si/FeSi/Fe multilayers and FeSi diffusion barriers. The goal was to achieve Fe free Si interlayers. The CEMS results show that starting from a thickness of t{sub FeSi}=10-12 A of the

  20. Influence of Intercritical Annealing Temperature on Mechanical ...

    African Journals Online (AJOL)

    The fracture surfaces of the impact test samples were examined using the scanning electron microscope (SEM). Micros structural evolution of the samples was also examined with an optical microscope. The results showed that all the evaluated mechanical properties were improved by intercritical annealing, with the ...

  1. influence of intercritical annealing temperature on mechanical

    African Journals Online (AJOL)

    User

    Keywords: intercritical annealing, dual phase steel, mechanical properties, microstructure. 1. INTRODUCTION. Steel, is world's most “advanced” material. It is the most widely used engineering material, essentially due to the fact that it can be manufactured at very competitive cost in large quantities to very precise.

  2. Thermal annealing in neutron-irradiated tribromobenzenes

    DEFF Research Database (Denmark)

    Siekierska, K.E.; Halpern, A.; Maddock, A. G.

    1968-01-01

    The distribution of 82Br among various products in neutron-irradiated isomers of tribromobenzene has been investigated, and the effect of thermal annealing examined. Reversed-phase partition chromatography was employed for the determination of radioactive organic products, and atomic bromine...

  3. Compositional evolution of Pd-based nanoclusters under thermal annealing in ion implanted SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mattei, G. E-mail: mattei@padova.infm.it; Battaglin, G.; Bello, V.; Cattaruzza, E.; De Julian, C.; De Marchi, G.; Maurizio, C.; Mazzoldi, P.; Parolin, M.; Sada, C

    2004-06-01

    Sequential ion implantation has been used to synthesize Pd-based alloy nanoclusters in SiO{sub 2}. Three systems have been investigated (PdCu, PdAg and PdFe) in terms of nanocluster formation and stability under thermal annealing. In particular, we focused on the role played by the annealing atmosphere. A comparison is made with similar alloy-based systems obtained by sequential ion implantation in silica of Au-Ag or Au-Cu followed by annealing under similar conditions. Strong similarities have been found in the compositional evolution of Pd-based and Au-based nanoclusters.

  4. Impacts of Biodiesel Fuel Blends Oil Dilution on Light-Duty Diesel Engine Operation

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, M. J.; Alleman, T. L.; Luecke, J.; McCormick, R. L.

    2009-08-01

    Assesses oil dilution impacts on a diesel engine operating with a diesel particle filter, NOx storage, a selective catalytic reduction emission control system, and a soy-based 20% biodiesel fuel blend.

  5. Scalable effective-temperature reduction for quantum annealers via nested quantum annealing correction

    Science.gov (United States)

    Vinci, Walter; Lidar, Daniel A.

    2018-02-01

    Nested quantum annealing correction (NQAC) is an error-correcting scheme for quantum annealing that allows for the encoding of a logical qubit into an arbitrarily large number of physical qubits. The encoding replaces each logical qubit by a complete graph of degree C . The nesting level C represents the distance of the error-correcting code and controls the amount of protection against thermal and control errors. Theoretical mean-field analyses and empirical data obtained with a D-Wave Two quantum annealer (supporting up to 512 qubits) showed that NQAC has the potential to achieve a scalable effective-temperature reduction, Teff˜C-η , with 0 learning applications. Since we demonstrate that NQAC achieves error correction via a reduction of the effective-temperature of the quantum annealing device, our results address the problem of the "temperature scaling law for quantum annealers," which requires the temperature of quantum annealers to be reduced as problems of larger sizes are attempted to be solved.

  6. Mössbauer Studies of dilute Magnetic Semiconductors

    CERN Multimedia

    Gislason, H P; Debernardi, A; Dlamini, W B

    2002-01-01

    The recent discovery of (dilute) magnetic semiconductors with wide band gaps, e.g. GaN, ZnO and other oxides, having Curie temperatures, T$_{\\textrm{c}}$, well above room temperature, has prompted extraordinary experimental and theoretical efforts to understand, control and exploit this unexpected finding not least in view of the obvious potential of such materials for the fabrication of "spin-(elec)tronic" or magneto-optic devices. Ferromagnetism (FM) was achieved mostly by doping with dilute 3d transition metal impurities, notably Mn, Fe, and Co (in \\% concentrations), during growth or by subsequent ion implantation. However, it is fair to state that experimentally the conditions for the occurrence of ferro-, antiferro- or paramagnetism with these impurities are not yet controlled as generally at least two conflicting forms of magnetism or none have been reported for each system - albeit often produced by different techniques. Theory is challenged as "conventional" models seem to fail and no generally accep...

  7. Exchange bias in diluted-antiferromagnet/antiferromagnet bilayers

    International Nuclear Information System (INIS)

    Mao, Zhongquan; Zhan, Xiaozhi; Chen, Xi

    2015-01-01

    The hysteresis-loop properties of a diluted-antiferromagnetic (DAF) layer exchange coupling to an antiferromagnetic (AF) layer are investigated by means of numerical simulations. Remarkable loop shift and coercivity enhancement are observed in such DAF/AF bilayers, while they are absent in the uncoupled DAF single layer. The influences of pinned domains, dilution, cooling field and DAF layer thickness on the loop shift are investigated systematically. The result unambiguously confirms an exchange bias (EB) effect in the DAF/AF bilayers. It also reveals that the EB effect originates from the pinned AF domains within the DAF layer. In contrast to conventional EB systems, frozen uncompensated spins are not found at the interface of the AF pinning layer. (paper)

  8. Diluted magnetic semiconductor nanowires exhibiting magnetoresistance

    Science.gov (United States)

    Yang, Peidong [El Cerrito, CA; Choi, Heonjin [Seoul, KR; Lee, Sangkwon [Daejeon, KR; He, Rongrui [Albany, CA; Zhang, Yanfeng [El Cerrito, CA; Kuykendal, Tevye [Berkeley, CA; Pauzauskie, Peter [Berkeley, CA

    2011-08-23

    A method for is disclosed for fabricating diluted magnetic semiconductor (DMS) nanowires by providing a catalyst-coated substrate and subjecting at least a portion of the substrate to a semiconductor, and dopant via chloride-based vapor transport to synthesize the nanowires. Using this novel chloride-based chemical vapor transport process, single crystalline diluted magnetic semiconductor nanowires Ga.sub.1-xMn.sub.xN (x=0.07) were synthesized. The nanowires, which have diameters of .about.10 nm to 100 nm and lengths of up to tens of micrometers, show ferromagnetism with Curie temperature above room temperature, and magnetoresistance up to 250 Kelvin.

  9. Characterizing storm water dispersion and dilution from small coastal streams

    Science.gov (United States)

    Romero, Leonel; Siegel, David A.; McWilliams, James C.; Uchiyama, Yusuke; Jones, Charles

    2016-06-01

    Characterizing the dispersion and dilution of storm water from small coastal creeks is important for understanding the importance of land-derived subsidies to nearby ecosystems and the management of anthropogenic pollutants. In Southern California, creek runoff is episodic, intense, and short-lived while the plumes are buoyant, all of which make the field sampling of freshwater plumes challenging. Numerical modeling offers a viable way to characterize these systems. The dilution and dispersion of freshwater from two creeks that discharge into the Santa Barbara Channel, California is investigated using Regional Ocean Modeling System (ROMS) simulations with a horizontal resolution of 100 m. Tight coupling is found among precipitation, hydrologic discharge, wind forcing, and submesoscale flow structures which all contribute to plume evolution. During flooding, plumes are narrow and attached to the coast, due to downwelling/onshore wind forcing and intense vorticity filaments lying parallel to the shelf. As the storm passes, the winds typically shift to offshore/upwelling favorable conditions and the plume is advected offshore which enhances its dilution. Plumes reach the bottom nearshore while they form thin layers a few meters thick offshore. Dilution field of passive tracers released with the runoff is strongly anisotropic with stronger cross-shelf gradients than along-shelf. Dispersion analysis of statistical moments of the passive tracer distribution results in scale-dependent diffusivities consistent with the particle-pair analysis of Romero et al. (). Model validation, the roles of submesoscale processes, and wind forcing on plume evolution and application to ecological issues and marine resource management are discussed.

  10. Tailoring magnetic properties of multicomponent layered structure via current annealing in FePd thin films.

    Science.gov (United States)

    Cialone, Matteo; Celegato, Federica; Coïsson, Marco; Barrera, Gabriele; Fiore, Gianluca; Shvab, Ruslan; Klement, Uta; Rizzi, Paola; Tiberto, Paola

    2017-11-30

    Multicomponent layered systems with tailored magnetic properties were fabricated via current annealing from homogeneous Fe 67 Pd 33 thin films, deposited via radio frequency sputtering on Si/SiO2 substrates from composite target. To promote spontaneous nano-structuring and phase separation, selected samples were subjected to current annealing in vacuum, with a controlled oxygen pressure, using various current densities for a fixed time and, as a consequence, different phases and microstructures were obtained. In particular, the formation of magnetite in different amount was observed beside other iron oxides and metallic phases. Microstructures and magnetic properties evolution as a function of annealing current were studied and interpreted with different techniques. Moreover, the temperature profile across the film thickness was modelled and its role in the selective oxidation of iron was analysed. Results show that is possible to topologically control the phases formation across the film thickness and simultaneously tailor the magnetic properties of the system.

  11. Analyzing the uncorrected error of dilution water demand for the dilution biochemical oxygen demand method.

    Science.gov (United States)

    Chiang, Chow F; Wu, Yeong S; Young, James C

    2004-01-01

    Dilution water demand (DWD) can cause a positive error when the dilution biochemical oxygen demand (BOD) method is used. Dilution water demand may be attributed to oxidation of organic impurities in the dilution water and nitrification of ammonia added as a nutrient. To minimize the error associated with these sources, the standard BOD method requires that DWD be less than 0.2 mg/L in 5 days and does not allow correction for DWD when calculating test results. This study derives a set of theoretical equations to analyze the uncorrected errors with and without seeding. The authors concluded that DWD can be completely corrected if seeded dilution water is used for the sample dilution. When seeding individual bottles, the uncorrected error approaches 8.3 to approximately 8.8% at a 5-day depletion of 2 mg/L for a typical secondary effluent. Tests without seeding show an almost 1% higher uncorrected error than seeded tests. The analysis also suggests that these errors can be effectively reduced to less than 3% when the 5-day depletion approaches 6 mg/L. even for 5-day biochemical oxygen demand concentrations exceeding I x 10(4) mg/L. Further analysis indicates that, if not inhibited, the ammonium added to dilution water as a nutrient may contribute additional error due to nitrification.

  12. Dilute Oxygen Combustion Phase I Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, H.M.; Riley, M.F.; Kobayashi, H.

    1997-10-31

    A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions

  13. Dilute oxygen combustion. Phase I report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NO{sub x}) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NO{sub x} through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NO{sub x} production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature ({approximately}1366 K) oxidant (7-27% O{sub 2} vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d{sup +} scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d{sup +} scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW ({approximately}0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric

  14. Quantifying dilution caused by execution efficiency

    Directory of Open Access Journals (Sweden)

    Taís Renata Câmara

    Full Text Available Abstract In open pit mining, dilution is not always a factor systematically analyzed and calculated. Often it is only an adjusted number, for example, calculated or even empirically determined for a certain operational condition perpetuating along time in the form of a constant applied to calculating reserves or mine planning in attendance of audit requirements. Dilution and loss are factors that should be always considered for tonnage and grade estimates. These factors are always associated and can be determined considering several particularities of the deposit and the operation itself. In this study, a methodology was determined to identify blocks adjacent to the blocks previously planned to be mined. Thus, it is possible to estimate the dilution caused by poor operating efficiency, taking into account the inability of the equipment to perfectly remove each block, respecting its limits. Mining dilution is defined as the incorporation of waste material to ore due to the operational incapacity to efficiently separate the materials during the mining process, considering the physical processes, and the operating and geometric configurations of the mining with the equipment available.

  15. Dilution of whisky - the molecular perspective.

    Science.gov (United States)

    Karlsson, Björn C G; Friedman, Ran

    2017-08-17

    Whisky is distilled to around 70% alcohol by volume (vol-%) then diluted to about 40 vol-%, and often drunk after further slight dilution to enhance its taste. The taste of whisky is primarily associated with amphipathic molecules, such as guaiacol, but why and how dilution enhances the taste is not well understood. We carried out computer simulations of water-ethanol mixtures in the presence of guaiacol, providing atomistic details on the structure of the liquid mixture. We found that guaiacol is preferentially associated with ethanol, and, therefore, primarily found at the liquid-air interface in mixtures that contain up to 45 vol-% of ethanol. At ethanol concentrations of 59 vol-% or higher, guaiacol is increasingly surrounded by ethanol molecules and is driven to the bulk. This indicates that the taste of guaiacol in the whisky would be enhanced upon dilution prior to bottling. Our findings may apply to other flavour-giving amphipathic molecules and could contribute to optimising the production of spirits for desired tastes. Furthermore, it sheds light on the molecular structure of water-alcohol mixtures that contain small solutes, and reveals that interactions with the water may be negligible already at 89 vol-% of ethanol.

  16. Osmosis is not driven by water dilution.

    Science.gov (United States)

    Kramer, Eric M; Myers, David R

    2013-04-01

    There is a misconception among plant scientists that osmosis is driven by the tendency of solutes to dilute water. In this opinion article, we discuss the quantitative and qualitative failures of this view, and go on to review the correct kinetic picture of osmosis as it appears in physics textbooks. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Dilution kicker for the SPS beam dump

    CERN Multimedia

    1974-01-01

    In order to reduce thermal stress on the SPS dump material, the fast-ejected beam was swept horizontally across the dump. This was done with the "dilution kicker" MKDH, still in use at the time of writing. The person on the left is Manfred Mayer. See also 7404072X.

  18. Variational approach to the dilute Bose gas

    NARCIS (Netherlands)

    Bijlsma, M.; Stoof, H.T.C.

    1997-01-01

    We study the weakly interacting Bose gas in both two and three dimensions using a variational approach. In particular we construct the thermodynamic potential of the gas to within ladder approximation and find by minimization an accurate mean-field description of the dilute Bose gas. Using

  19. Atomic displacements in bcc dilute alloys

    Indian Academy of Sciences (India)

    We present here a systematic investigation of the atomic displacements in bcc transition metal (TM) dilute alloys. We have calculated the atomic displacements in bcc (V, Cr, Fe, Nb, Mo, Ta and W) transition metals (TMs) due to 3d, 4d and 5d TMs at the substitutional site using the Kanzaki lattice static method. Wills and ...

  20. Liquid volumes measurements by isotopic dilution

    International Nuclear Information System (INIS)

    Herrera M, J.M.

    1981-01-01

    By the nuclear technique, isotopic dilution industrial liquid volumes may be measured in large size recipients of irregular shapes using radiotracers. In the present work laboratory and pilot test are made with 2 radiotracers for optimizing the technique and later done on an industrial scale, obtaining a maximum deviation of +-2%, some recommendations are given to improve the performance of the technique. (author)

  1. Dilution kicker for the SPS beam dump

    CERN Multimedia

    1974-01-01

    In order to reduce thermal stress on the SPS dump material, the fast-ejected beam was swept horizontally across the dump. This was done with the "dilution kicker" MKDH, still in use at the time of writing. See also 7402051X.

  2. Atomic displacements in bcc dilute alloys

    Indian Academy of Sciences (India)

    Abstract. We present here a systematic investigation of the atomic displacements in bcc transition metal (TM) dilute alloys. We have calculated the atomic displacements in bcc. (V, Cr, Fe, Nb, Mo, Ta and W) transition metals (TMs) due to 3d, 4d and 5d TMs at the substitutional site using the Kanzaki lattice static method.

  3. Sulfuric Acid and Water: Paradoxes of Dilution

    Science.gov (United States)

    Leenson, I. A.

    2004-01-01

    On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

  4. Simulated annealing algorithm for optimal capital growth

    Science.gov (United States)

    Luo, Yong; Zhu, Bo; Tang, Yong

    2014-08-01

    We investigate the problem of dynamic optimal capital growth of a portfolio. A general framework that one strives to maximize the expected logarithm utility of long term growth rate was developed. Exact optimization algorithms run into difficulties in this framework and this motivates the investigation of applying simulated annealing optimized algorithm to optimize the capital growth of a given portfolio. Empirical results with real financial data indicate that the approach is inspiring for capital growth portfolio.

  5. Reduced-Complexity Deterministic Annealing for Vector Quantizer Design

    Directory of Open Access Journals (Sweden)

    Ortega Antonio

    2005-01-01

    Full Text Available This paper presents a reduced-complexity deterministic annealing (DA approach for vector quantizer (VQ design by using soft information processing with simplified assignment measures. Low-complexity distributions are designed to mimic the Gibbs distribution, where the latter is the optimal distribution used in the standard DA method. These low-complexity distributions are simple enough to facilitate fast computation, but at the same time they can closely approximate the Gibbs distribution to result in near-optimal performance. We have also derived the theoretical performance loss at a given system entropy due to using the simple soft measures instead of the optimal Gibbs measure. We use thederived result to obtain optimal annealing schedules for the simple soft measures that approximate the annealing schedule for the optimal Gibbs distribution. The proposed reduced-complexity DA algorithms have significantly improved the quality of the final codebooks compared to the generalized Lloyd algorithm and standard stochastic relaxation techniques, both with and without the pairwise nearest neighbor (PNN codebook initialization. The proposed algorithms are able to evade the local minima and the results show that they are not sensitive to the choice of the initial codebook. Compared to the standard DA approach, the reduced-complexity DA algorithms can operate over 100 times faster with negligible performance difference. For example, for the design of a 16-dimensional vector quantizer having a rate of 0.4375 bit/sample for Gaussian source, the standard DA algorithm achieved 3.60 dB performance in 16 483 CPU seconds, whereas the reduced-complexity DA algorithm achieved the same performance in 136 CPU seconds. Other than VQ design, the DA techniques are applicable to problems such as classification, clustering, and resource allocation.

  6. A simple deep monitoring well dilution technique.

    Science.gov (United States)

    Rogiers, Bart; Labat, Serge; Gedeon, Matej; Vandersteen, Katrijn

    2015-04-01

    Well dilution techniques are well known and studied as one of the basic techniques to quantify groundwater fluxes. A typical well dilution test consists of the injection of a tracer, a mixing mechanism (e.g. water circulation with a pump) to achieve a homogeneous concentration distribution within the well, and monitoring of the evolution of tracer concentration with time. An apparent specific discharge can be obtained from such a test, and when details on the well construction are known, it can be converted into a specific discharge representative of the undisturbed aquifer. For deep wells however, the injection of tracer becomes less practical and the use of pumps for circulating and mixing the water becomes problematic. This is due to the limited pressure that common pumps can endure at the outlet, as well as the large volume of water that makes it difficult to achieve a homogeneous concentration, and the impracticalities of getting a lot of equipment to large depths in very small monitoring wells. Injection and monitoring of tracer at a specific depth omits several of the problems with deep wells. We present a very simple device that can be used to perform a dilution test at a specific depth in deep wells. The injection device consists of a PVC tube with a detachable rubber seal at its bottom. To minimize disturbance of the water column in the well, we integrated an EC sensor in this injection device, which enables us to use demineralized water or dissolved salts as a tracer. Once at the target depth, the PVC tube is retracted and the EC sensor and tracer become subject to groundwater flow. The device was tested on a shallow well, on which different types of dilution tests were performed. The results of the other tests agree well with the injection tube results. Finally, the device was used to perform a dilution test in a deep well in order to demonstrate the feasibility of the approach.

  7. High Temperature Annealing Studies on the Piezoelectric Properties of Thin Aluminum Nitride Films

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, R.; Pagan, V.R.; Kabulski, A.; Kuchibhatla, S.; Harman, J.; Kasarla, K.R.; Rodak, L.E.; Hensel, J.P.; Famouri, P.; Korakakis, D.

    2008-01-01

    A Rapid Thermal Annealing (RTA) system was used to anneal sputtered and MOVPE-grown Aluminum Nitride (AlN) thin films at temperatures up to 1000°C in ambient and controlled environments. According to Energy Dispersive X-Ray Analysis (EDAX), the films annealed in an ambient environment rapidly oxidize after five minutes at 1000°C. Below 1000°C the films oxidized linearly as a function of annealing temperature which is consistent with what has been reported in literature [1]. Laser Doppler Vibrometry (LDV) was used to measure the piezoelectric coefficient, d33, of these films. Films annealed in an ambient environment had a weak piezoelectric response indicating that oxidation on the surface of the film reduces the value of d33. A high temperature furnace has been built that is capable of taking in-situ measurements of the piezoelectric response of AlN films. In-situ d33 measurements are recorded up to 300°C for both sputtered and MOVPE-grown AlN thin films. The measured piezoelectric response appears to increase with temperature up to 300°C possibly due to stress in the film.

  8. High Temperature Annealing Studies on the Piezoelectric Properties of Thin Aluminum Nitride Films

    Energy Technology Data Exchange (ETDEWEB)

    R. Farrell; V. R. Pagan; A. Kabulski; Sridhar Kuchibhatl; J. Harman; K. R. Kasarla; L. E. Rodak; P. Famouri; J. Peter Hensel; D. Korakakis

    2008-05-01

    A Rapid Thermal Annealing (RTA) system was used to anneal sputtered and MOVPE grown Aluminum Nitride (AlN) thin films at temperatures up to 1000°C in ambient and controlled environments. According to Energy Dispersive X-Ray Analysis (EDAX), the films annealed in an ambient environment rapidly oxidize after five minutes at 1000°C. Below 1000°C the films oxidized linearly as a function of annealing temperature which is consistent with what has been reported in literature [1]. Laser Doppler Vibrometry (LDV) was used to measure the piezoelectric coefficient, d33, of these films. Films annealed in an ambient environment had a weak piezoelectric response indicating that oxidation on the surface of the film reduces the value of d33. A high temperature furnace has been built that is capable of taking in-situ measurements of the piezoelectric response of AlN films. In-situ d33 measurements are recorded up to 300°C for both sputtered and MOVPE-grown AlN thin films. The measured piezoelectric response appears to increase with temperature up to 300°C possibly due to stress in the film.

  9. Thermal annealing response following irradiation of a CMOS imager for the JUICE JANUS instrument

    Science.gov (United States)

    Lofthouse-Smith, D.-D.; Soman, M. R.; Allanwood, E. A. H.; Stefanov, K. D.; Holland, A. D.; Leese, M.; Turne, P.

    2018-03-01

    ESA's JUICE (JUpiter ICy moon Explorer) spacecraft is an L-class mission destined for the Jovian system in 2030. Its primary goals are to investigate the conditions for planetary formation and the emergence of life, and how does the solar system work. The JANUS camera, an instrument on JUICE, uses a 4T back illuminated CMOS image sensor, the CIS115 designed by Teledyne e2v. JANUS imager test campaigns are studying the CIS115 following exposure to gammas, protons, electrons and heavy ions, simulating the harsh radiation environment present in the Jovian system. The degradation of 4T CMOS device performance following proton fluences is being studied, as well as the effectiveness of thermal annealing to reverse radiation damage. One key parameter for the JANUS mission is the Dark current of the CIS115, which has been shown to degrade in previous radiation campaigns. A thermal anneal of the CIS115 has been used to accelerate any annealing following the irradiation as well as to study the evolution of any performance characteristics. CIS115s have been irradiated to double the expected End of Life (EOL) levels for displacement damage radiation (2×1010 protons, 10 MeV equivalent). Following this, devices have undergone a thermal anneal cycle at 100oC for 168 hours to reveal the extent to which CIS115 recovers pre-irradiation performance. Dark current activation energy analysis following proton fluence gives information on trap species present in the device and how effective anneal is at removing these trap species. Thermal anneal shows no quantifiable change in the activation energy of the dark current following irradiation.

  10. Relaxation of enthalpy fluctuations during sub-T(g) annealing of glassy selenium.

    Science.gov (United States)

    Gulbiten, Ozgur; Mauro, John C; Lucas, Pierre

    2013-06-28

    The relaxation behavior of glass is influenced by the presence of dynamical heterogeneities, which lead to an intrinsically non-monotonic decay of fluctuations in density and enthalpy during isothermal annealing. This is apparently a universal feature of fragile glass forming systems associated with localized spatial variations in relaxation time. Here we present direct experimental observation of the nonmonotonic evolution of enthalpy fluctuations in glassy selenium annealed near room temperature. The nonmonotonic change in the distribution of enthalpy fluctuations measured by heat capacity spectroscopy offers direct evidence for the presence of dynamical heterogeneity in this glass. An enthalpy landscape model of selenium is then used to simulate annealing under identical conditions. The simulation results closely follow the evolution of enthalpy fluctuations observed experimentally. The close match between model and experiment demonstrate that enthalpy and density fluctuations are sources of dynamical heterogeneities in glassy materials.

  11. Annealing of GaN under high pressure of nitrogen

    CERN Document Server

    Porowski, S; Kolesnikov, D; Lojkowski, W; Jager, V; Jäger, W; Bogdanov, V; Suski, T; Krukowski, S

    2002-01-01

    Gallium nitride, aluminum nitride and indium nitride are basic materials for blue optoelectronic devices. The essential part of the technology of these devices is annealing at high temperatures. Thermodynamic properties of the Ga-N system and their consequences to application of high nitrogen pressure for the annealing of GaN based materials are summarized. The diffusion of Zn, Mg and Au in high dislocation density heteroepitaxial GaN/Al sub 2 O sub 3 layers will be compared with the diffusion in dislocation-free GaN single crystals and homoepitaxial layers. It will be shown that high dislocation density can drastically change the diffusion rates, which strongly affects the performance of nitride devices. Inter-diffusion of Al, Ga and In in AlGaN/GaN and InGaN/GaN quantum well (QW) structures will be also considered. It will be shown that in contrast to stability of metal contacts, which is strongly influenced by dislocations, the inter-diffusion of group III atoms in QW structures is not affected strongly by...

  12. 3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

    Science.gov (United States)

    Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

    2014-01-01

    3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

  13. Dynamic Dilution Effects in Polymeric Networks

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard; Sommer-Larsen, Peter; Hassager, Ole

    2006-01-01

    The relaxation processes occurring in slightly and well-entangled polydimetylsiloxane ( PDMS) networks are investigated. Swelling experiments are performed in order to determine the sol fractions. The low-frequency linear rheology of the two types of networks reveal two significant relaxation pro...... by the change in the amount of dangling arms and solubles with stoichiometry. The star arm relaxation is suppressed by washing out the sol fraction which is seen as a clear example of the dynamic dilution effect arising from the small amount of non-reactive PDMS....... processes, namely the reptation of linear species within the network and the arm withdrawal process of star arms in the sol fraction and of dangling single-chain ends attached to the network. The relaxation spectra are influenced by the stoichiometry to a large extent due to dynamic dilution effects caused...

  14. Dilute nanoemulsions via separation of satellite droplets.

    Science.gov (United States)

    Deen, Shad; Sajjadi, Shahriar

    2013-10-01

    A facile method is suggested for fabrication of dilute nanoemulsions. In a typical emulsification process, drops are usually accompanied by off-grade satellite droplets. The size of these satellite droplets ranges from hundreds of nanometers to above microns. Experiments were carried out to assess the possibility of separation of nanodrops from macroemulsions made via a conventional method in order to produce nanoemulsions. A low-power homogenizer was used to produce parent emulsions which were then injected from the bottom to a glass column containing water and allowed to cream. By monitoring drops remaining in the bottom of the column, it is clearly shown how progressively smaller they become with time yielding eventually dilute nanoemulsions. The average diameter of drops reduced to 100 nm when oil with high viscosity was used. The concentration of resulting nanoemulsions increased with increasing viscosity and ratio of the disperse phase of parent emulsions. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Determination of diffusion coefficients of various livestock antibiotics in water at infinite dilution

    Science.gov (United States)

    Soriano, Allan N.; Adamos, Kristoni G.; Bonifacio, Pauline B.; Adornado, Adonis P.; Bungay, Vergel C.; Vairavan, Rajendaran

    2017-11-01

    The fate of antibiotics entering the environment raised concerns on the possible effect of antimicrobial resistance bacteria. Prediction of the fate and transport of these particles are needed to be determined, significantly the diffusion coefficient of antibiotic in water at infinite dilution. A systematic determination of diffusion coefficient of antibiotic in water at infinite dilution of five different kinds of livestock antibiotics namely: Amtyl, Ciprotyl, Doxylak Forte, Trisullak, and Vetracin Gold in the 293.15 to 313.15 K temperature range are reported through the use of the method involving the electrolytic conductivity measurements. A continuous stirred tank reactor is utilized to measure the electrolytic conductivities of the considered systems. These conductivities are correlated by using the Nernst-Haskell equation to determine the infinite dilution diffusion coefficient. Determined diffusion coefficients are based on the assumption that in dilute solution, these antibiotics behave as strong electrolyte from which H+ cation dissociate from the antibiotic's anion.

  16. Isotope dilution analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.; Lesny, J.; Korenova, Z.; Klas, J.; Klehr, E.H.

    1986-01-01

    Isotope dilution analysis has been used for the determination of several trace elements - especially metals - in a variety of environmental samples, including aerosols, water, soils, biological materials and geological materials. Variations of the basic concept include classical IDA, substoichiometric IDA, and more recently, sub-superequivalence IDA. Each variation has its advantages and limitations. A periodic chart has been used to identify those elements which have been measured in environmental samples using one or more of these methods. (author)

  17. The Effect of Vacuum Annealing of Magnetite and Zero-Valent Iron Nanoparticles on the Removal of Aqueous Uranium

    Directory of Open Access Journals (Sweden)

    R. A. Crane

    2013-01-01

    Full Text Available As-formed and vacuum annealed zero-valent iron nanoparticles (nano-Fe0 and magnetite nanoparticles (nano-Fe3O4 were tested for the removal of uranium from carbonate-rich mine water. Nanoparticles were introduced to batch systems containing the mine water under oxygen conditions representative of near-surface waters, with a uranyl solution studied as a simple comparator system. Despite the vacuum annealed nano-Fe0 having a 64.6% lower surface area than the standard nano-Fe0, similar U removal (>98% was recorded during the initial stages of reaction with the mine water. In contrast, ≤15% U removal was recorded for the mine water treated with both as-formed and vacuum annealed nano-Fe3O4. Over extended reaction periods (>1 week, appreciable U rerelease was recorded for the mine water solutions treated using nano-Fe0, whilst the vacuum annealed material maintained U at <50 μg L−1 until 4 weeks reaction. XPS analysis of reacted nanoparticulate solids confirmed the partial chemical reduction of UVI to UIV in both nano-Fe0 water treatment systems, but with a greater amount of UIV detected on the vacuum annealed particles. Results suggest that vacuum annealing can enhance the aqueous reactivity of nano-Fe0 and, for waters of complex chemistry, can improve the longevity of aqueous U removal.

  18. Quantitative determination of the solidus line in the dilute limit of succinonitrile-camphor alloys

    Science.gov (United States)

    Mota, F. L.; Fabietti, L. M.; Bergeon, N.; Strutzenberg, L. L.; Karma, A.; Billia, B.; Trivedi, R.

    2016-08-01

    Different phase diagram measurements for succinonitrile-camphor alloys to date have yielded different values of the solute partition coefficient and the freezing range of the alloy. These parameters are critical to model solidification microstructure evolution. New measurements are made to precisely characterize the dilute limit of the succinonitrile-camphor phase diagram using thin-sample directional solidification experiments where convection is negligible, so that solute transport in the melt is purely diffusive, and the temperature gradient is constant in time. These results are confirmed through complementary measurements by differential scanning calorimetry and isothermal annealing. Possible measurement uncertainties in previously measured solidus lines are discussed. Experimental results were further confirmed using a boundary layer model of transient planar interface dynamics.

  19. Thermodynamics of dilute gases: application to submonolayer He films

    International Nuclear Information System (INIS)

    Vetrovec, M.B.; Carneiro, G.M.

    1979-01-01

    The thermodynamic properties of submonolayer He films are calculated. Expressions are first obtained for the thermodynamic properties of dilute systems of particles interacting through a short range potential taking into account binary interactions between the particles. These expressions are exact in the limit n→0, n being the particle number density, and are valid at all temperatures. At high temperatures these expressions are reduced to those obtained using the virial expansion truncated after the second term. These expressions are next applied to He in two dimensions and the results compared with experiment and with previous calculations [pt

  20. Thermodynamics of the superfluid dilute Bose gas with disorder

    International Nuclear Information System (INIS)

    Lopatin, A.V.; Vinokur, V.M.

    2002-01-01

    We generalize the Beliaev-Popov diagrammatic technique for the problem of interacting dilute Bose gas with weak disorder. Averaging over disorder is implemented by the replica method. The low-energy asymptotic form of the Green function confirms that the low-energy excitations of the superfluid dirty-boson system are sound waves with velocity renormalized by the disorder and additional dissipation due to the impurity scattering. We find the thermodynamic potential and the superfluid density at any temperature below the superfluid transition temperature (but outside the Ginzburg region) and derive the phase diagram in temperature vs disorder plane

  1. Study of annealing effects in In–Sb bilayer thin films

    Indian Academy of Sciences (India)

    TECS

    torr. The optical transmission spectra of as deposited and annealed films have been carried out at room temperature. The variation in optical band gap with thickness was also observed. Rutherford back scattering and X-ray diffraction analysis confirms mixing of bilayer system. The transverse I–V characteristic shows mixing ...

  2. Interference Alignment Using Variational Mean Field Annealing

    DEFF Research Database (Denmark)

    Badiu, Mihai Alin; Guillaud, Maxime; Fleury, Bernard Henri

    2014-01-01

    We study the problem of interference alignment in the multiple-input multiple- output interference channel. Aiming at minimizing the interference leakage power relative to the receiver noise level, we use the deterministic annealing approach to solve the optimization problem. In the corresponding...... for interference alignment. We also show that the iterative leakage minimization algorithm by Gomadam et al. and the alternating minimization algorithm by Peters and Heath, Jr. are instances of our method. Finally, we assess the performance of the proposed algorithm through computer simulations....

  3. Simulated annealing for tensor network states

    International Nuclear Information System (INIS)

    Iblisdir, S

    2014-01-01

    Markov chains for probability distributions related to matrix product states and one-dimensional Hamiltonians are introduced. With appropriate ‘inverse temperature’ schedules, these chains can be combined into a simulated annealing scheme for ground states of such Hamiltonians. Numerical experiments suggest that a linear, i.e., fast, schedule is possible in non-trivial cases. A natural extension of these chains to two-dimensional settings is next presented and tested. The obtained results compare well with Euclidean evolution. The proposed Markov chains are easy to implement and are inherently sign problem free (even for fermionic degrees of freedom). (paper)

  4. Binary Sparse Phase Retrieval via Simulated Annealing

    Directory of Open Access Journals (Sweden)

    Wei Peng

    2016-01-01

    Full Text Available This paper presents the Simulated Annealing Sparse PhAse Recovery (SASPAR algorithm for reconstructing sparse binary signals from their phaseless magnitudes of the Fourier transform. The greedy strategy version is also proposed for a comparison, which is a parameter-free algorithm. Sufficient numeric simulations indicate that our method is quite effective and suggest the binary model is robust. The SASPAR algorithm seems competitive to the existing methods for its efficiency and high recovery rate even with fewer Fourier measurements.

  5. Molecular analysis of two mouse dilute locus deletion mutations: Spontaneous dilute lethal20J and radiation-induced dilute prenatal lethal Aa2 alleles

    International Nuclear Information System (INIS)

    Strobel, M.C.; Seperack, P.K.; Copeland, N.G.; Jenkins, N.A.

    1990-01-01

    The dilute (d) coat color locus of mouse chromosome 9 has been identified by more than 200 spontaneous and mutagen-induced recessive mutations. With the advent of molecular probes for this locus, the molecular lesion associated with different dilute alleles can be recognized and precisely defined. In this study, two dilute mutations, dilute-lethal20J (dl20J) and dilute prenatal lethal Aa2, have been examined. Using a dilute locus genomic probe in Southern blot analysis, we detected unique restriction fragments in dl20J and Aa2 DNA. Subsequent analysis of these fragments showed that they represented deletion breakpoint fusion fragments. DNA sequence analysis of each mutation-associated deletion breakpoint fusion fragment suggests that both genomic deletions were generated by nonhomologous recombination events. The spontaneous dl20J mutation is caused by an interstitial deletion that removes a single coding exon of the dilute gene. The correlation between this discrete deletion and the expression of all dilute-associated phenotypes in dl20J homozygotes defines the dl20J mutation as a functional null allele of the dilute gene. The radiation-induced Aa2 allele is a multilocus deletion that, by complementation analysis, affects both the dilute locus and the proximal prenatal lethal-3 (pl-3) functional unit. Molecular analysis of the Aa2 deletion breakpoint fusion fragment has provided access to a previously undefined gene proximal to d. Initial characterization of this new gene suggests that it may represent the genetically defined pl-3 functional unit

  6. Implantation annealing in GaAs by incoherent light

    International Nuclear Information System (INIS)

    Davies, D.E.; Ryan, T.G.; Soda, K.J.; Comer, J.J.

    1983-01-01

    Implanted GaAs has been successfully activated through concentrating the output of quartz halogen lamps to anneal in times of the order of 1 sec. The resulting layers are not restricted by the reduced mobilities and thermal instabilities of laser annealed GaAs. Better activation can be obtained than with furnace annealing but this generally requires maximum temperatures >= 1050degC. (author)

  7. Influence of Different Annealing Ambients on the Properties of Zinc Sulfide Prepared by Atomic Layer Deposition

    Science.gov (United States)

    Yoo, Dongjun; Heo, Seung Chan; Choi, Moon Suk; Kim, Dohyung; Chung, Chulwon; Choi, Hag Young; Jeon, Hyeongtag; Choi, Changhwan

    2013-10-01

    The effects of different post annealing ambients (vacuum, O2, and H2S gases) on the chemical, structural, and optical properties of zinc sulfide (ZnS) thin films prepared by atomic layer deposition (ALD) were investigated. Diethylzinc [DEZ, Zn(C2H5)2] and H2S gas were used as precursor and reactant gas, respectively. Compared to as-deposited 50-nm-thick ZnS film, the optical energy band gap (Eg) of ZnS annealed under vacuum and H2S conditions increased from 3.73 to 3.85 eV, while it decreased down to 3.23 eV for the O2 annealing case. The change in the Eg of the thicker ZnS is similar to that of the thinner ZnS case. This behavior is related to the change in the Zn to S ratio. The vacuum and H2S anneals increases the Zn/S ratio, leading to higher Zn interstitial defects or S vacancy sites in the films. X-ray diffraction analysis reveals that ZnS thin film has a preferred orientation of hexagonal wurtizte (002) and cubic zinc blend (111) at ˜28.2°, and its grain size changes in a range from 18.79 to 28.14 nm after annealing. However, for O2 annealing, the patterns of both the newly formed ZnO phase and the reduced ZnS phase appear at 34.04°. This result suggests that change in the composition and crystal structure during the process significantly affects the optical properties of ZnS thin film, which should be taken into consideration in searching for an alternative buffer layer for Cu2InGaSe(S)4 (CIGS) thin film solar cell systems.

  8. Microstructural study of annealed gold-silicon thin films under nanoindentation

    International Nuclear Information System (INIS)

    Lee, W.-S.; Fong, F.-J.

    2008-01-01

    The mechanical properties of as-deposited Au/Si thin films indented to depths of 1000 nm are measured using a nanoindentation technique. The microstructural evolution of the as-deposited indented specimens and specimens annealed at temperatures of 250, 350 and 450 deg. C, respectively, are examined via transmission electron microscopy (TEM). The initial deposited thin film system is a composite structure consisting of a 500 nm Au thin film, a 5 nm Cr adhesive layer and a Si(1 0 0) substrate. The Au thin film has a polycrystalline structure, while both the Cr adhesive layer and the Si substrate have a single crystal state. The experimental nanoindentation results for the as-deposited specimens show that the loading curves are continuous and smooth. However, a pop-out feature is observed in the unloading curves. Furthermore, a pile-up of the thin film material is observed around the edges of the indentation. By contrast, a total recovery of the plastic zones in the indentation site takes place in the annealed specimens. TEM observations show that the microstructural evolution of the thin films within the indentation zone is strongly dependent on the annealing temperature. In the case of the as-deposited specimens, the indentation pressure induces a chain-like island structure and a distorted crystalline structure within the indentation zone. However, in the specimens annealed at temperatures of 250 and 350 deg. C, respectively, the microstructure of the indentation zone changes from a distorted crystalline structure to an amorphous phase as a result of the plastic deformation induced during indentation. The pop-out event observed in the unloading curve of the as-deposited specimens is also thought to be related to a similar amorphous transformation. At an annealing temperature of 450 deg. C, the microstructure contains both amorphous phase and crystalline eutectic phase. The formation of eutectic phase is the result of a higher annealing temperature and a greater

  9. Benefits of Intercritical Annealing in Quenching and Partitioning Steel

    Science.gov (United States)

    Wang, X.; Liu, L.; Liu, R. D.; Huang, M. X.

    2018-03-01

    Compared to the quenching and partitioning (Q&P) steel produced by full austenization annealing, the Q&P steel produced by the intercritical annealing shows a similar ultimate tensile stress but a larger tensile ductility. This property is attributable to the higher volume fraction and the better mechanical stability of the retained austenite after the intercritical annealing. Moreover, intercritical annealing produces more ferrite and fewer martensite phases in the microstructure, making an additional contribution to a higher work hardening rate and therefore a better tensile ductility.

  10. Magnetic field annealing for improved creep resistance

    Science.gov (United States)

    Brady, Michael P.; Ludtka, Gail M.; Ludtka, Gerard M.; Muralidharan, Govindarajan; Nicholson, Don M.; Rios, Orlando; Yamamoto, Yukinori

    2015-12-22

    The method provides heat-resistant chromia- or alumina-forming Fe-, Fe(Ni), Ni(Fe), or Ni-based alloys having improved creep resistance. A precursor is provided containing preselected constituents of a chromia- or alumina-forming Fe-, Fe(Ni), Ni(Fe), or Ni-based alloy, at least one of the constituents for forming a nanoscale precipitate MaXb where M is Cr, Nb, Ti, V, Zr, or Hf, individually and in combination, and X is C, N, O, B, individually and in combination, a=1 to 23 and b=1 to 6. The precursor is annealed at a temperature of 1000-1500.degree. C. for 1-48 h in the presence of a magnetic field of at least 5 Tesla to enhance supersaturation of the M.sub.aX.sub.b constituents in the annealed precursor. This forms nanoscale M.sub.aX.sub.b precipitates for improved creep resistance when the alloy is used at service temperatures of 500-1000.degree. C. Alloys having improved creep resistance are also disclosed.

  11. Superplasticity of Annealed H13 Steel

    Directory of Open Access Journals (Sweden)

    Zhenxin Duan

    2017-07-01

    Full Text Available H13 steel is a widely used hot work die material. A new type of hot working method is imperative to develop complex and precise dies. In this paper, the heat treatment of H13 steel (AISI was carried out by annealing, the final structure is a point or spherical pearlite, and the grain size is about 30–40 μm. The tensile properties of the annealed microstructure were investigated at 650, 750, and 850 °C with the strain rates of 1 × 10−3 s−1, 5 × 10−4 s−1, and 1 × 10−4 s−1. The tensile fracture and microstructure were analyzed by SEM and HREM. The results show that the tensile samples reach superplasticity at the strain rate of 1 × 10−4 s−1 in the temperature range of 750–850 °C. When the temperature is 850 °C, the maximum elongation rate reaches 112.5%. This demonstrates the possibility of making superplastic forming molds. During the tensile process, the refined M23C6 and other high hardness carbides which are dispersed uniformly in the matrix, effectively inhibits grain growth and hinders dislocation movement, leading to the improvement of plasticity.

  12. Mean Field Analysis of Quantum Annealing Correction.

    Science.gov (United States)

    Matsuura, Shunji; Nishimori, Hidetoshi; Albash, Tameem; Lidar, Daniel A

    2016-06-03

    Quantum annealing correction (QAC) is a method that combines encoding with energy penalties and decoding to suppress and correct errors that degrade the performance of quantum annealers in solving optimization problems. While QAC has been experimentally demonstrated to successfully error correct a range of optimization problems, a clear understanding of its operating mechanism has been lacking. Here we bridge this gap using tools from quantum statistical mechanics. We study analytically tractable models using a mean-field analysis, specifically the p-body ferromagnetic infinite-range transverse-field Ising model as well as the quantum Hopfield model. We demonstrate that for p=2, where the phase transition is of second order, QAC pushes the transition to increasingly larger transverse field strengths. For p≥3, where the phase transition is of first order, QAC softens the closing of the gap for small energy penalty values and prevents its closure for sufficiently large energy penalty values. Thus QAC provides protection from excitations that occur near the quantum critical point. We find similar results for the Hopfield model, thus demonstrating that our conclusions hold in the presence of disorder.

  13. Superplasticity of Annealed H13 Steel.

    Science.gov (United States)

    Duan, Zhenxin; Pei, Wen; Gong, Xuebo; Chen, Hua

    2017-07-28

    H13 steel is a widely used hot work die material. A new type of hot working method is imperative to develop complex and precise dies. In this paper, the heat treatment of H13 steel (AISI) was carried out by annealing, the final structure is a point or spherical pearlite, and the grain size is about 30-40 μm. The tensile properties of the annealed microstructure were investigated at 650, 750, and 850 °C with the strain rates of 1 × 10 -3 s -1 , 5 × 10 -4 s -1 , and 1 × 10 -4 s -1 . The tensile fracture and microstructure were analyzed by SEM and HREM. The results show that the tensile samples reach superplasticity at the strain rate of 1 × 10 -4 s -1 in the temperature range of 750-850 °C. When the temperature is 850 °C, the maximum elongation rate reaches 112.5%. This demonstrates the possibility of making superplastic forming molds. During the tensile process, the refined M 23 C₆ and other high hardness carbides which are dispersed uniformly in the matrix, effectively inhibits grain growth and hinders dislocation movement, leading to the improvement of plasticity.

  14. A coherent quantum annealer with Rydberg atoms

    Science.gov (United States)

    Glaetzle, A. W.; van Bijnen, R. M. W.; Zoller, P.; Lechner, W.

    2017-06-01

    There is a significant ongoing effort in realizing quantum annealing with different physical platforms. The challenge is to achieve a fully programmable quantum device featuring coherent adiabatic quantum dynamics. Here we show that combining the well-developed quantum simulation toolbox for Rydberg atoms with the recently proposed Lechner-Hauke-Zoller (LHZ) architecture allows one to build a prototype for a coherent adiabatic quantum computer with all-to-all Ising interactions and, therefore, a platform for quantum annealing. In LHZ an infinite-range spin-glass is mapped onto the low energy subspace of a spin-1/2 lattice gauge model with quasi-local four-body parity constraints. This spin model can be emulated in a natural way with Rubidium and Caesium atoms in a bipartite optical lattice involving laser-dressed Rydberg-Rydberg interactions, which are several orders of magnitude larger than the relevant decoherence rates. This makes the exploration of coherent quantum enhanced optimization protocols accessible with state-of-the-art atomic physics experiments.

  15. MEDICAL STAFF SCHEDULING USING SIMULATED ANNEALING

    Directory of Open Access Journals (Sweden)

    Ladislav Rosocha

    2015-07-01

    Full Text Available Purpose: The efficiency of medical staff is a fundamental feature of healthcare facilities quality. Therefore the better implementation of their preferences into the scheduling problem might not only rise the work-life balance of doctors and nurses, but also may result into better patient care. This paper focuses on optimization of medical staff preferences considering the scheduling problem.Methodology/Approach: We propose a medical staff scheduling algorithm based on simulated annealing, a well-known method from statistical thermodynamics. We define hard constraints, which are linked to legal and working regulations, and minimize the violations of soft constraints, which are related to the quality of work, psychic, and work-life balance of staff.Findings: On a sample of 60 physicians and nurses from gynecology department we generated monthly schedules and optimized their preferences in terms of soft constraints. Our results indicate that the final value of objective function optimized by proposed algorithm is more than 18-times better in violations of soft constraints than initially generated random schedule that satisfied hard constraints.Research Limitation/implication: Even though the global optimality of final outcome is not guaranteed, desirable solutionwas obtained in reasonable time. Originality/Value of paper: We show that designed algorithm is able to successfully generate schedules regarding hard and soft constraints. Moreover, presented method is significantly faster than standard schedule generation and is able to effectively reschedule due to the local neighborhood search characteristics of simulated annealing.

  16. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method

    International Nuclear Information System (INIS)

    Garcia, M. R.; Perez, M. M.

    1979-01-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs

  17. The phase diagrams of the site-diluted spin-1/2 Ising superlattice

    International Nuclear Information System (INIS)

    Saber, A.; Essaoudi, I.; Ainane, A.; Dujardin, F.; Saber, M.; Stebe, B.

    1998-08-01

    Using the effective field theory with a probability distribution technique that accounts for the single-site spin correlations, the critical behavior of a diluted spin-1/2 Ising superlattice consisting of two different ferromagnet materials is examined. The critical temperature of the system is studied as a function of the thickness of the constituents in a unit cell, the concentration of magnetic atoms, and the exchange interactions in each material. It is shown that the properties of the diluted system are different from those of the corresponding pure system. (author)

  18. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem

    2015-01-01

    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  19. Deuterium and oxygen-18 isotope dilution spaces in normal adults

    International Nuclear Information System (INIS)

    Wong, W.; Cochran, W.; Lee, L.; Klish, W.; Klein, P.

    1986-01-01

    In light of the limited series of published comparison the authors have determined the deuterium and oxygen-18 isotope dilution spaces in 10 normal subjects, 5 males and 5 females. Labeled water was administered orally at doses of 40 mg deuterium oxide and 60 mg oxygen-18 per kg of body weight. One predose blood sample and six hourly postdose blood samples were collected from each subject. Aliquots of plasma water were reduced directly to hydrogen gas with zinc shot in individual quartz reaction vessels and 2 H/ 1 H isotope ratios were determined by gas-isotope-ratio mass spectrometry (GIRMS). 18 O/ 16 O isotope ratios were determined after plasma samples were equilibrated with CO 2 in an isotope exchange system. Both 2 H- and 18 O-labeled water attained isotopic equilibrium in plasma within 3 hr after administration. The deuterium dilution spaces in males and females were 56.4 +/- 2.1% (mean +/- SD) and 55.9 +/- 0.9% of body weight, respectively, while the 18 O dilution spaces constituted 54.1 +/- 1.85% and 53.30 +/- 1.30%. The deuterium spaces were larger than the 18 O spaces by 4.55 +/- 0.56% in men and 4.78 +/- 1.63% in women and were significant at P < 0.01. These results compare with values of 3.81 +/- 2.66% for males (n = 6) and 1.10 +/- 2.67% for females (n = 2) previously reported by Schoeller et al

  20. Analyses of PWR boron dilution consequences with the Arrotta code

    International Nuclear Information System (INIS)

    Johanson, E.; Cheng, H.W.; Sehgal, B.R.

    1998-03-01

    During the past few years, major attention has been paid to analyzing the issue of reactivity initiated accidents (RIAs), of which the boron dilution event is of very special interest to the countries having pressurized water reactors (PWRs) in their nuclear power delivery systems. The scenario considered is that if an inadvertent accumulation of boron free water in one loop during reactor startup operations of a PWR and the inadvertent startup of the reactor coolant pump (RCP) in the loop. This could then lead to a rapid boron dilution in the core, which can in turn give rise to a power excursion. This report is devoted to studying the potential physical and thermal hydraulic consequences of a slug of diluted coolant entering the core after one RCP start under a couple of postulated cases. The severity of the consequences of such a scenario is primarily determined by the amount of positive reactivity insertion, and they are also related to the reactivity insertion rate. Therefore, in the report, detailed calculations and analyses have been carried out from case to case by using the well-known space-time kinetics code, ARROTTA. As a result, the spatial distribution for nodal power, fuel enthalpy, fuel temperature and clad outside temperature as well as the change in core reactivity, total core power and peak fuel temperature can be provided. In general, the maximum fuel enthalpy, peak fuel temperature, and clad outside temperature, for all the cases considered in the report, do not exceed their respective routine safety limitations because of the strong Doppler effect and moderator temperature feedback, except if the safety limitations on fuel enthalpy addition for high burnup fuel are drastically reduced

  1. Subcloning Dt40 by limiting dilution.

    Science.gov (United States)

    Buerstedde, Jean-Marie

    2006-01-01

    Subcloning by limited dilution can be used to derive clonally related cell populations from a heterogeneous DT40 cell culture. For example, if one suspects that a drug resistant population may represent the progeny of more than one transfectant, the protocol can be used to isolate genetically homogeneous mutant clones. Other uses are the excision of floxed DNA sequences after Cre recombinase expression or fluctuation analysis to determine mutation rates (see Protocols 'Excision of floxed-DNA sequences by transient induction of Mer-Cre-Mer' and 'Analysis of sIgM expression by FACS').

  2. Confluence Model or Resource Dilution Hypothesis?

    DEFF Research Database (Denmark)

    Jæger, Mads

    Studies on family background often explain the negative effect of sibship size on educational attainment by one of two theories: the Confluence Model (CM) or the Resource Dilution Hypothesis (RDH). However, as both theories – for substantively different reasons – predict that sibship size should...... to identify a unique RDH effect on educational attainment. Using sibling data from the Wisconsin Longitudinal Study (WLS) and a random effect Instrumental Variable model, I find that in addition to having a negative effect on cognitive ability, sibship size also has a strong negative effect on educational...

  3. Evolution of Zr/Hf/Zr trilayers during annealing studied by RBS

    International Nuclear Information System (INIS)

    Kling, A.; Soares, J.C.

    2010-01-01

    The Zr/Hf system is highly interesting due its various applications, e.g. formation of amorphous ternary alloys, superconductive properties and production of gate oxide layers with high dielectric coefficients by oxidation of Zr/Hf multilayers. In this work Zr/Hf/Zr trilayers with an individual layer thickness of approximately 50 nm were deposited by electron gun evaporation on a substrate consisting of silicon covered by a micrometer thick thermal oxide layer. Samples were subjected to annealing procedures at 500 and 1200 o C in flowing air atmosphere to promote oxidation and Zr/Hf interdiffusion effects. RBS studies of the as-deposited and annealed samples were performed at the van-de-Graaff accelerator of ITN using He + and H + beams with energies between 2.0 and 2.525 MeV in order to study compositional changes induced by the heat treatment. In the case of low-temperature annealing the layer system appears, besides the oxidation process starting from the surface, to be stable. On the other hand, high-temperature annealing leads to an asymmetric Hf-diffusion into the surface and interior Zr-layer provoked by anomalous diffusion due to a phase transition in Zr accompanied by an almost complete oxidation of the layer structure Oxygen and metal depth distributions obtained by RBS in the as-deposited and treated samples are provided.

  4. Dissipative environment may improve the quantum annealing performances of the ferromagnetic p -spin model

    Science.gov (United States)

    Passarelli, G.; De Filippis, G.; Cataudella, V.; Lucignano, P.

    2018-02-01

    We investigate the quantum annealing of the ferromagnetic p -spin model in a dissipative environment (p =5 and p =7 ). This model, in the large-p limit, codifies Grover's algorithm for searching in an unsorted database [L. K. Grover, Proceedings of the 28th Annual ACM Symposium on Theory of Computing (ACM, New York, 1996), pp. 212-219]. The dissipative environment is described by a phonon bath in thermal equilibrium at finite temperature. The dynamics is studied in the framework of a Lindblad master equation for the reduced density matrix describing only the spins. Exploiting the symmetries of our model Hamiltonian, we can describe many spins and extrapolate expected trends for large N and p . While at weak system-bath coupling the dissipative environment has detrimental effects on the annealing results, we show that in the intermediate-coupling regime, the phonon bath seems to speed up the annealing at low temperatures. This improvement in the performance is likely not due to thermal fluctuation but rather arises from a correlated spin-bath state and persists even at zero temperature. This result may pave the way to a new scenario in which, by appropriately engineering the system-bath coupling, one may optimize quantum annealing performances below either the purely quantum or the classical limit.

  5. Nano-mechanical Behaviour and Mmicrostructural Evolution of Cu/Si Thin Films at Different Annealing Temperatures

    Directory of Open Access Journals (Sweden)

    Woei-Shyan Lee

    2012-07-01

    Full Text Available This study investigates the nano-mechanical properties of as-deposited Cu/Si thin films indented to a depth of 2000 nm using a nanoindentation technique. Cu films with a thickness of 1800 nm are deposited on (100 silicon substrates and the indented specimens are then annealed at temperatures of 160℃ and 210℃, respectively, using rapid thermal annealing (RTA technique. The results show that the hardness and Young’s modulus of the Cu/Si thin films have maximum values of 0.82 GPa and 95 GPa, respectively. The TEM observations show that the specimens annealed at a temperature of 160℃, the amorphous nature of the microstructure within the indented zone is maintained. However, annealed at a higher temperature of 210℃, the indentation affected zone consists of Copper silicide (η-Cu3Si precipitates are observed in the annealed specimens. Overall, the results presented in this study confirm that the annealing temperature has a significant effect on the formation of η-Cu3Si in nanoindented Cu/Si thin-film systems.

  6. The effects of different heat treatment annealing on structural properties of LaFe11.5Si1.5 compound

    Science.gov (United States)

    Norizan, Yang Nurhidayah Asnida; Din, Muhammad Faiz Md; Zamri, Wan Fathul Hakim W.; Hashim, Fakroul Ridzuan; Jusoh, Mohd Taufik; Rahman, Mohd Rashid Abdul

    2018-02-01

    The cubic NaZn13-type LaFe13-xSix based compounds have been studied systematically and has become one of the most interesting systems for exploring large MCE. Its magnetic properties are strongly doping dependent and provides many of advantage compare to other as magnetic materials for magnetic refrigerator application. In other to produce high quality of cubic NaZn13-type structure, the structural properties of LaFe11.5Si1.5 compounds annealed at different temperature have been investigated. The LaFe11.5Si1.5 compounds was prepared by arc melting and annealed at two different heat treatment which are 1323 K for 14 days and 1523 K for 4 hour. The powder X-ray diffraction (XRD) shows that a short time and high temperature annealing process has benefits for the formation of the NaZn13-type phase compared to a long time and low temperature annealing process. This is shown by the weight fraction of cubic NaZn13- type structure increases from 80% for low temperature annealing to 83% for high temperature annealing. At the same time, high temperature annealing increase the main structure and decrease the impurity (α-Fe and LaFeSi). Furthermore, it can be clearly seen in the Rietveld refinement results that the lattice parameter is increase at the high temperature annealing because of more cubic NaZn13 is formed at higher temperature.

  7. Investigation of annealing-treatment on structural and optical ...

    Indian Academy of Sciences (India)

    Administrator

    This conforms to the results already reported by Moustaghfir et al (2003). A higher annealing tempera- ture enhances the formation of larger and more closely packed crystals. The increase of the refractive index with increasing annealing temperature can be partly attributed to improvement in film quality with the reduction in.

  8. Effect of isochronal annealing on phase transformation studies of ...

    Indian Academy of Sciences (India)

    Abstract. The effect of isochronal annealing on the phase transformation in iron oxide nanoparticles is reported in this work. Iron oxide nanoparticles were successfully synthesized using an ash supported technique followed by annealing for 2 h at various temperatures between 300 and 700◦C. It was observed using X-ray ...

  9. Effect of annealing treatment on optical properties and ...

    Indian Academy of Sciences (India)

    2018-03-28

    Mar 28, 2018 ... C. UV–visible spectrophotometer showed that the annealing treatment of the first WO3 layer enhanced the transparency of films in the visible region. The innovations of the present study have been based on the annealing of the films and finding an optimum thickness for the Ag film at 12–14 nm.

  10. Effect of heat moisture treatment and annealing on physicochemical ...

    African Journals Online (AJOL)

    Red sorghum starch was physically modified by annealing and heat moisture treatment. The swelling power and solubility increased with increasing temperature range (60-90°), while annealing and heatmoisture treatment decreased swelling power and solubility of starch. Solubility and swelling were pH dependent with ...

  11. Simulated annealing approach for solving economic load dispatch ...

    African Journals Online (AJOL)

    user

    Abstract. This paper presents Simulated Annealing (SA) algorithm for optimization inspired by the process of annealing in ... Various classical optimization techniques were used to solve the ELD problem, for example: lambda iteration approach, ...... Research of fuzzy self-adaptive immune algorithm and its application.

  12. Effect of isochronal annealing on phase transformation studies of ...

    Indian Academy of Sciences (India)

    The effect of isochronal annealing on the phase transformation in iron oxide nanoparticles is reported in this work. Iron oxide nanoparticles were successfully synthesized using an ash supported technique followed by annealing for 2 h at various temperatures between 300 and 700° C. It was observed using X-ray diffraction ...

  13. Effect of annealing process of iron powder on magnetic properties ...

    Indian Academy of Sciences (India)

    Administrator

    The amplitude permeability and magnetic loss of the cores reached the maximum and minimum values, respectively. The magnetic loss of the cores was separated into hysteresis loss and eddy current loss by Stoppels Method which were decreased by the annealing process. Keywords. Reduced iron powders; annealing ...

  14. A note on simulated annealing to computer laboratory scheduling ...

    African Journals Online (AJOL)

    Simulated Annealing algorithm is used in solving real life problem of Computer Laboratory scheduling in order to maximize the use of scarce and insufficient resources. KEY WORDS: Simulated Annealing (SA), Computer Laboratory Scheduling, Statistical Thermodynamics, Energy Function, and Heuristic etc. Global Jnl of ...

  15. Response of neutron-irradiated RPV steels to thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1997-03-01

    One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels.

  16. Improvements in or relating to laser annealed electronic devices

    International Nuclear Information System (INIS)

    Barraclough, K.G.; Cullis, A.G.; Webber, H.C.

    1981-01-01

    A method of producing laser annealed electronic devices is described. The technique involves irradiating semiconductor material such as silicon or germanium to produce a neutron transmuted semiconductor material and laser annealing a selected region or regions in a slice of the transmuted material to a sub-micron depth. (U.K.)

  17. Effect of annealing on magnetic properties and silicide formation at ...

    Indian Academy of Sciences (India)

    coercivity decreases and remanence increases. The values of remanence of pristine Co/Si and annealed at 300°C are. 0⋅80 and 0⋅98, respectively. 3.3 AFM measurement. Morphological changes of silicide surface during high temperature annealing have been investigated by AFM in terms of the RMS surface roughness.

  18. Stored energy and annealing behavior of heavily deformed aluminium

    DEFF Research Database (Denmark)

    Kamikawa, Naoya; Huang, Xiaoxu; Kondo, Yuka

    2012-01-01

    are quantified such as boundary spacing, misorientation angle and dislocation density for 99.99% aluminium deformed by accumulative roll-bonding to a strain of 4.8. Two different annealing processes have been applied; (i) one-step annealing for 0.5 h at 100-400°C and (ii) two-step annealing for 6 h at 175°C......It has been demonstrated in previous work that a two-step annealing treatment, including a low-temperature, long-time annealing and a subsequent high-temperature annealing, is a promising route to control the microstructure of a heavily deformed metal. In the present study, structural parameters...... followed by 0.5 h annealing at 200-600°C, where the former treatment leads to discontinuous recrystallization and the latter to uniform structural coarsening. This behavior has been analyzed in terms of the relative change during annealing of energy stored as elastic energy in the dislocation structure...

  19. Capsize of polarization in dilute photonic crystals.

    Science.gov (United States)

    Gevorkian, Zhyrair; Hakhoumian, Arsen; Gasparian, Vladimir; Cuevas, Emilio

    2017-11-29

    We investigate, experimentally and theoretically, polarization rotation effects in dilute photonic crystals with transverse permittivity inhomogeneity perpendicular to the traveling direction of waves. A capsize, namely a drastic change of polarization to the perpendicular direction is observed in a one-dimensional photonic crystal in the frequency range 10 ÷ 140 GHz. To gain more insights into the rotational mechanism, we have developed a theoretical model of dilute photonic crystal, based on Maxwell's equations with a spatially dependent two dimensional inhomogeneous dielectric permittivity. We show that the polarization's rotation can be explained by an optical splitting parameter appearing naturally in Maxwell's equations for magnetic or electric fields components. This parameter is an optical analogous of Rashba like spin-orbit interaction parameter present in quantum waves, introduces a correction to the band structure of the two-dimensional Bloch states, creates the dynamical phase shift between the waves propagating in the orthogonal directions and finally leads to capsizing of the initial polarization. Excellent agreement between theory and experiment is found.

  20. Angular filter refractometry analysis using simulated annealing.

    Science.gov (United States)

    Angland, P; Haberberger, D; Ivancic, S T; Froula, D H

    2017-10-01

    Angular filter refractometry (AFR) is a novel technique used to characterize the density profiles of laser-produced, long-scale-length plasmas [Haberberger et al., Phys. Plasmas 21, 056304 (2014)]. A new method of analysis for AFR images was developed using an annealing algorithm to iteratively converge upon a solution. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on the minimization of the χ 2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in an average uncertainty in the density profile of 5%-20% in the region of interest.

  1. Inferring hierarchical clustering structures by deterministic annealing

    International Nuclear Information System (INIS)

    Hofmann, T.; Buhmann, J.M.

    1996-01-01

    The unsupervised detection of hierarchical structures is a major topic in unsupervised learning and one of the key questions in data analysis and representation. We propose a novel algorithm for the problem of learning decision trees for data clustering and related problems. In contrast to many other methods based on successive tree growing and pruning, we propose an objective function for tree evaluation and we derive a non-greedy technique for tree growing. Applying the principles of maximum entropy and minimum cross entropy, a deterministic annealing algorithm is derived in a meanfield approximation. This technique allows us to canonically superimpose tree structures and to fit parameters to averaged or open-quote fuzzified close-quote trees

  2. Annealing effects on cathodoluminescence of zircon

    Science.gov (United States)

    Tsuchiya, Y.; Nishido, H.; Noumi, Y.

    2011-12-01

    U-Pb zircon dating (e. g., SHRIMP) is an important tool to interpret a history of the minerals at a micrometer-scale, where cathodoluminescence (CL) imaging allows us to recognize internal zones and domains with different chemical compositions and structural disorder at high spatial resolution. The CL of zircon is attributed by various types of emission centers, which are extrinsic ones such as REE impurities and intrinsic ones such as structural defects. Metamictization resulted from radiation damage to the lattice by alpha particles from the decay of U and Th mostly causes an effect on the CL features of zircon as a defect center. However, slightly radiation-damaged zircon, which is almost nondetectable by XRD, has not been characterized using CL method. In this study, annealing effects on CL of zircon has been investigated to clarify a recovery process of the damaged lattice at low radiation dose. A single crystal of zircon from Malawi was selected for CL measurements. It contains HfO2: 2.30 w.t %, U: 241 ppm and Th: 177 ppm. Two plate samples perpendicular to c and a axes were prepared for annealing experiments during 12 hours from room temperature to 1400 degree C. Color CL images were captured using a cold-cathode microscope (Luminoscope: Nuclide ELM-3R). CL spectral measurements were conducted using an SEM (JEOL: JSM-5410) combined with a grating monochromator (Oxford: Mono CL2) to measure CL spectra ranging from 300 to 800 nm in 1 nm steps with a temperature controlled stage. The dispersed CL was collected by a photoncounting method using a photomultiplier tube (Hamamatsu: R2228) and converted to digital data. All CL spectra were corrected for the total instrumental response. Spectral analysis reveals an anisotropy of the CL emission bands related to intrinsic defect center in blue region, radiation-induced defect center from 500 to 700 nm, and trivalent Dy impurity center at 480 and 580 nm, but their relative intensities are almost constant. CL on the

  3. Efficiency of quantum vs. classical annealing in nonconvex learning problems.

    Science.gov (United States)

    Baldassi, Carlo; Zecchina, Riccardo

    2018-02-13

    Quantum annealers aim at solving nonconvex optimization problems by exploiting cooperative tunneling effects to escape local minima. The underlying idea consists of designing a classical energy function whose ground states are the sought optimal solutions of the original optimization problem and add a controllable quantum transverse field to generate tunneling processes. A key challenge is to identify classes of nonconvex optimization problems for which quantum annealing remains efficient while thermal annealing fails. We show that this happens for a wide class of problems which are central to machine learning. Their energy landscapes are dominated by local minima that cause exponential slowdown of classical thermal annealers while simulated quantum annealing converges efficiently to rare dense regions of optimal solutions. Copyright © 2018 the Author(s). Published by PNAS.

  4. Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem ...

    African Journals Online (AJOL)

    Blast Movement Monitoring (BMM) system is a new method of determining material movement during blasting in order to minimise ore loss, dilution and sometimes misclassification. The BMM system was introduced at AngloGold Ashanti Iduapriem (AAIL) Mine in the first quarter of 2013 as a result of reconciliation ...

  5. Large-deviation theory for diluted Wishart random matrices

    Science.gov (United States)

    Castillo, Isaac Pérez; Metz, Fernando L.

    2018-03-01

    Wishart random matrices with a sparse or diluted structure are ubiquitous in the processing of large datasets, with applications in physics, biology, and economy. In this work, we develop a theory for the eigenvalue fluctuations of diluted Wishart random matrices based on the replica approach of disordered systems. We derive an analytical expression for the cumulant generating function of the number of eigenvalues IN(x ) smaller than x ∈R+ , from which all cumulants of IN(x ) and the rate function Ψx(k ) controlling its large-deviation probability Prob[IN(x ) =k N ] ≍e-N Ψx(k ) follow. Explicit results for the mean value and the variance of IN(x ) , its rate function, and its third cumulant are discussed and thoroughly compared to numerical diagonalization, showing very good agreement. The present work establishes the theoretical framework put forward in a recent letter [Phys. Rev. Lett. 117, 104101 (2016), 10.1103/PhysRevLett.117.104101] as an exact and compelling approach to deal with eigenvalue fluctuations of sparse random matrices.

  6. The influence of annealing temperature on the strength of TRISO coated particles

    Energy Technology Data Exchange (ETDEWEB)

    Rooyen, I.J. van, E-mail: Isabel.vanrooyen@pbmr.co.z [Pebble Bed Modular Reactor (Pty) Ltd., 1279 Mike Crawford Avenue, Centurion (South Africa); Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Neethling, J.H. [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Rooyen, P.M. van [Pebble Bed Modular Reactor (Pty) Ltd., 1279 Mike Crawford Avenue, Centurion (South Africa)

    2010-07-31

    The integrity of the Pebble Bed Modular Reactor (PBMR) fuel, and specifically the SiC layer system of the Tristructural Isotropic (TRISO) coated particle (CP), namely inner pyrolytic carbon, silicon carbide and outer pyrolytic carbon (I-PyC-SiC-O-PyC), determines the containment of fission products. The PBMR fuel consists of TRISO coated particles (CPs) embedded in a graphite matrix. One of the characterization techniques investigated by PBMR is the determination of strength of CPs. It is a well known metallurgical fact that temperature, amongst many other parameters, may influence the strength of a material. A recently developed method for measuring the strength of the TRISO coated particles was used and is briefly described in this article. The advantages of this method are demonstrated by the comparison of strength measurements of five experimental PBMR CP batches as a function of annealing temperature. Significant modification of strength after annealing was measured with increased temperature within the range 1000-2100 {sup o}C. The interesting feature of decreasing standard deviation of the strength with increasing temperature will also be discussed with a possible explanation. A significant difference in coated particle strength is also demonstrated for two CP batches with layer thickness on the extremities of the SiC layer thickness specification. The effect of long duration annealing on these strength values will also be demonstrated by comparing results from 1 h to 100 h annealing periods of coated particles at a temperature of 1600 {sup o}C.

  7. GPU-Accelerated Population Annealing Algorithm: Frustrated Ising Antiferromagnet on the Stacked Triangular Lattice

    Directory of Open Access Journals (Sweden)

    Borovský Michal

    2016-01-01

    Full Text Available The population annealing algorithm is a novel approach to study systems with rough free-energy landscapes, such as spin glasses. It combines the power of simulated annealing, Boltzmann weighted differential reproduction and sequential Monte Carlo process to bring the population of replicas to the equilibrium even in the low-temperature region. Moreover, it provides a very good estimate of the free energy. The fact that population annealing algorithm is performed over a large number of replicas with many spin updates, makes it a good candidate for massive parallelism. We chose the GPU programming using a CUDA implementation to create a highly optimized simulation. It has been previously shown for the frustrated Ising antiferromagnet on the stacked triangular lattice with a ferromagnetic interlayer coupling, that standard Markov Chain Monte Carlo simulations fail to equilibrate at low temperatures due to the effect of kinetic freezing of the ferromagnetically ordered chains. We applied the population annealing to study the case with the isotropic intra- and interlayer antiferromagnetic coupling (J2/|J1| = −1. The reached ground states correspond to non-magnetic degenerate states, where chains are antiferromagnetically ordered, but there is no long-range ordering between them, which is analogical with Wannier phase of the 2D triangular Ising antiferromagnet.

  8. Direct comparison of quantum and simulated annealing on a fully connected Ising ferromagnet

    Science.gov (United States)

    Wauters, Matteo M.; Fazio, Rosario; Nishimori, Hidetoshi; Santoro, Giuseppe E.

    2017-08-01

    We compare the performance of quantum annealing (QA, through Schrödinger dynamics) and simulated annealing (SA, through a classical master equation) on the p -spin infinite range ferromagnetic Ising model, by slowly driving the system across its equilibrium, quantum or classical, phase transition. When the phase transition is second order (p =2 , the familiar two-spin Ising interaction) SA shows a remarkable exponential speed-up over QA. For a first-order phase transition (p ≥3 , i.e., with multispin Ising interactions), in contrast, the classical annealing dynamics appears to remain stuck in the disordered phase, while we have clear evidence that QA shows a residual energy which decreases towards zero when the total annealing time τ increases, albeit in a rather slow (logarithmic) fashion. This is one of the rare examples where a limited quantum speedup, a speedup by QA over SA, has been shown to exist by direct solutions of the Schrödinger and master equations in combination with a nonequilibrium Landau-Zener analysis. We also analyze the imaginary-time QA dynamics of the model, finding a 1 /τ2 behavior for all finite values of p , as predicted by the adiabatic theorem of quantum mechanics. The Grover-search limit p (odd )=∞ is also discussed.

  9. Annealing effect on structural and optical properties of chemical bath deposited MnS thin film

    Energy Technology Data Exchange (ETDEWEB)

    Ulutas, Cemal, E-mail: cemalulutas@hakkari.edu.tr [Faculty of Education, Hakkari Universty, 30000, Hakkari (Turkey); Gumus, Cebrail [Faculty of Science and Letters, Cukurova University, 01330, Adana (Turkey)

    2016-03-25

    MnS thin film was prepared by the chemical bath deposition (CBD) method on commercial microscope glass substrate deposited at 30 °C. The as-deposited film was given thermal annealing treatment in air atmosphere at various temperatures (150, 300 and 450 °C) for 1 h. The MnS thin film was characterized by using X-ray diffraction (XRD), UV-vis spectrophotometer and Hall effect measurement system. The effect of annealing temperature on the structural, electrical and optical properties such as optical constants of refractive index (n) and energy band gap (E{sub g}) of the film was determined. XRD measurements reveal that the film is crystallized in the wurtzite phase and changed to tetragonal Mn{sub 3}O{sub 4} phase after being annealed at 300 °C. The energy band gap of film decreased from 3.69 eV to 3.21 eV based on the annealing temperature.

  10. Improving Simulated Annealing by Replacing Its Variables with Game-Theoretic Utility Maximizers

    Science.gov (United States)

    Wolpert, David H.; Bandari, Esfandiar; Tumer, Kagan

    2001-01-01

    The game-theory field of Collective INtelligence (COIN) concerns the design of computer-based players engaged in a non-cooperative game so that as those players pursue their self-interests, a pre-specified global goal for the collective computational system is achieved as a side-effect. Previous implementations of COIN algorithms have outperformed conventional techniques by up to several orders of magnitude, on domains ranging from telecommunications control to optimization in congestion problems. Recent mathematical developments have revealed that these previously developed algorithms were based on only two of the three factors determining performance. Consideration of only the third factor would instead lead to conventional optimization techniques like simulated annealing that have little to do with non-cooperative games. In this paper we present an algorithm based on all three terms at once. This algorithm can be viewed as a way to modify simulated annealing by recasting it as a non-cooperative game, with each variable replaced by a player. This recasting allows us to leverage the intelligent behavior of the individual players to substantially improve the exploration step of the simulated annealing. Experiments are presented demonstrating that this recasting significantly improves simulated annealing for a model of an economic process run over an underlying small-worlds topology. Furthermore, these experiments reveal novel small-worlds phenomena, and highlight the shortcomings of conventional mechanism design in bounded rationality domains.

  11. Improving Simulated Annealing by Recasting it as a Non-Cooperative Game

    Science.gov (United States)

    Wolpert, David; Bandari, Esfandiar; Tumer, Kagan

    2001-01-01

    The game-theoretic field of COllective INtelligence (COIN) concerns the design of computer-based players engaged in a non-cooperative game so that as those players pursue their self-interests, a pre-specified global goal for the collective computational system is achieved "as a side-effect". Previous implementations of COIN algorithms have outperformed conventional techniques by up to several orders of magnitude, on domains ranging from telecommunications control to optimization in congestion problems. Recent mathematical developments have revealed that these previously developed game-theory-motivated algorithms were based on only two of the three factors determining performance. Consideration of only the third factor would instead lead to conventional optimization techniques like simulated annealing that have little to do with non-cooperative games. In this paper we present an algorithm based on all three terms at once. This algorithm can be viewed as a way to modify simulated annealing by recasting it as a non-cooperative game, with each variable replaced by a player. This recasting allows us to leverage the intelligent behavior of the individual players to substantially improve the exploration step of the simulated annealing. Experiments are presented demonstrating that this recasting improves simulated annealing by several orders of magnitude for spin glass relaxation and bin-packing.

  12. Criteria for the evaluation of a dilute decontamination demonstration

    International Nuclear Information System (INIS)

    FitzPatrick, V.F.; Divine, J.R.; Hoenes, G.R.; Munson, L.F.; Card, C.J.

    1981-12-01

    This document provides the prerequisite technical information required to evaluate and/or develop a project to demonstrate the dilute chemical decontamination of the primary coolant system of light water reactors. The document focuses on five key areas: the basis for establishing programmatic prerequisites and the key decision points that are required for proposal evaluation and/or RFP (Request for Proposal) issuance; a technical review of the state-of-the-art to identify the potential impacts of a reactor's primary-system decontamination on typical BWR and PWR plants; a discussion of the licensing, recertification, fuel warranty, and institutional considerations and processes; a preliminary identification and development of the selection criteria for the reactor and the decontamination process; and a preliminary identification of further research and development that might be required

  13. A Study of Satelite Navigation, Dilution of Precision , and Positionig Techniques for use on and Around the Moon

    National Research Council Canada - National Science Library

    MacNicol, John

    2002-01-01

    .... Dilution of precision is the figure of merit used to determine if a candidate lunar satellite navigation system can meet accuracy specifications based on a given satellite constellation and the measurement types used...

  14. Simulation of the diffusion of implanted impurities in silicon structures at the rapid thermal annealing

    International Nuclear Information System (INIS)

    Komarov, F.F.; Komarov, A.F.; Mironov, A.M.; Makarevich, Yu.V.; Miskevich, S.A.; Zayats, G.M.

    2011-01-01

    Physical and mathematical models and numerical simulation of the diffusion of implanted impurities during rapid thermal treatment of silicon structures are discussed. The calculation results correspond to the experimental results with a sufficient accuracy. A simulation software system has been developed that is integrated into ATHENA simulation system developed by Silvaco Inc. This program can simulate processes of the low-energy implantation of B, BF 2 , P, As, Sb, C ions into the silicon structures and subsequent rapid thermal annealing. (authors)

  15. Homeopathic and high dilution preparations for pest management to tomato crop under organic production system Manejo fitossanitário do tomateiro com uso de preparados homeopáticos e altas diluições sob sistema orgânico de produção

    Directory of Open Access Journals (Sweden)

    Tatiani A Modolon

    2012-03-01

    Full Text Available Tomato crops (Solanum lycopersicum under conventional production system are constantly treated against pest and diseases, with organic synthetic pesticides that are used may cause serious disturbance to environment and human health. This research was carried out in order to study the effect of homeopathic and high dilution preparations on pests and diseases management of tomato crop under organic production system. Two experiments were conducted under field conditions and one in greenhouse. All of them in randomized block design with the cultivar Santa Cruz Kada. The treatments consisted of homeopathic preparations Staphysagria, Arsenicum album, Sulphur, Arnica montana, high dilution preparations of Solanum lycopersicum and Solanum aculeatissimum, at the decimal (DH or centesimal (CH scale of hahnemanian high dilution. Bordeaux mixture, cupric preparation, and Bacillus thuringiensis were also included in weight doses. The preparation Arnica montana 12DH increased the tomato yield under field conditions. The damage incidence of small borer was efficiently reduced with applications of Sulphur 12CH that equalling to B. thuringiensis. The same treatment did not reduce the large borers. B. thuringiensis reduced also the septoria leaf spot incidence in the field. In greenhouse, the high dilution preparation of tomato at 12DH completely suppressed the septoria leaf spot and drastically reduced the same disease at 24DH. The homeopathic and high dilution preparations have the potential to be effective on replacing pesticides that are used on tomato, and could be suitable to fill legal requirement for organic production system.O tomateiro (Solanum lycopersicum sob sistema de produção convencional está constantemente sujeito a pragas e doenças, os pesticidas orgânicos sintéticos que são usados podem causar graves perturbações ao meio ambiente e à saúde humana. O objetivo deste trabalho foi avaliar o efeito de preparados homeopáticos e altas

  16. Dilution effects on ultrafine particle emissions from Euro 5 and Euro 6 diesel and gasoline vehicles

    Science.gov (United States)

    Louis, Cédric; Liu, Yao; Martinet, Simon; D'Anna, Barbara; Valiente, Alvaro Martinez; Boreave, Antoinette; R'Mili, Badr; Tassel, Patrick; Perret, Pascal; André, Michel

    2017-11-01

    Dilution and temperature used during sampling of vehicle exhaust can modify particle number concentration and size distribution. Two experiments were performed on a chassis dynamometer to assess exhaust dilution and temperature on particle number and particle size distribution for Euro 5 and Euro 6 vehicles. In the first experiment, the effects of dilution (ratio from 8 to 4 000) and temperature (ranging from 50 °C to 150 °C) on particle quantification were investigated directly from tailpipe for a diesel and a gasoline Euro 5 vehicles. In the second experiment, particle emissions from Euro 6 diesel and gasoline vehicles directly sampled from the tailpipe were compared to the constant volume sampling (CVS) measurements under similar sampling conditions. Low primary dilutions (3-5) induced an increase in particle number concentration by a factor of 2 compared to high primary dilutions (12-20). Low dilution temperatures (50 °C) induced 1.4-3 times higher particle number concentration than high dilution temperatures (150 °C). For the Euro 6 gasoline vehicle with direct injection, constant volume sampling (CVS) particle number concentrations were higher than after the tailpipe by a factor of 6, 80 and 22 for Artemis urban, road and motorway, respectively. For the same vehicle, particle size distribution measured after the tailpipe was centred on 10 nm, and particles were smaller than the ones measured after CVS that was centred between 50 nm and 70 nm. The high particle concentration (≈106 #/cm3) and the growth of diameter, measured in the CVS, highlighted aerosol transformations, such as nucleation, condensation and coagulation occurring in the sampling system and this might have biased the particle measurements.

  17. Retrieval properties of diluted attractor neural networks

    Science.gov (United States)

    Rodrigues Neto, C.; Fontanari, J. F.

    1996-06-01

    We investigate the dependence of the retrieval properties of the pseudo-inverse and optimal attractor neural networks on the fraction of stored patterns 0305-4470/29/12/012/img1, the temperature T and the margin parameter 0305-4470/29/12/012/img2. Phase diagrams in the full space of parameters are presented in the regime of extreme dilution, i.e. when the connectivity C satisfies the condition 0305-4470/29/12/012/img3, where N is the number of neurons. Furthermore, we study analytically the neighbourhood of a stored pattern for both models by calculating the average fraction of unstable sites 0305-4470/29/12/012/img4 in a pattern that differs by d sites from a given stored pattern. This analysis may shed light on the properties of the basins of attraction of the stored patterns.

  18. Critical exponents for diluted resistor networks.

    Science.gov (United States)

    Stenull, O; Janssen, H K; Oerding, K

    1999-05-01

    An approach by Stephen [Phys. Rev. B 17, 4444 (1978)] is used to investigate the critical properties of randomly diluted resistor networks near the percolation threshold by means of renormalized field theory. We reformulate an existing field theory by Harris and Lubensky [Phys. Rev. B 35, 6964 (1987)]. By a decomposition of the principal Feynman diagrams, we obtain diagrams which again can be interpreted as resistor networks. This interpretation provides for an alternative way of evaluating the Feynman diagrams for random resistor networks. We calculate the resistance crossover exponent phi up to second order in epsilon=6-d, where d is the spatial dimension. Our result phi=1+epsilon/42+4epsilon(2)/3087 verifies a previous calculation by Lubensky and Wang, which itself was based on the Potts-model formulation of the random resistor network.

  19. Mechanisms of urine concentration and dilution (1961)

    International Nuclear Information System (INIS)

    Morel, F.; Guinnebault, M.

    1961-01-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [fr

  20. Disorder effects in diluted ferromagnetic semiconductors

    Science.gov (United States)

    Bouzerar, G.; Kudrnovský, J.; Bruno, P.

    2003-11-01

    Carrier induced ferromagnetism in diluted III-V semiconductor (DMS) is analyzed within a two-step approach. First, within a single site coherent-potential approximation formalism, we calculate the element resolved averaged Green’s function of the itinerant carrier. Then using a generalized RKKY formula we evaluate the Mn-Mn long-range exchange integrals and the Curie temperature as a function of the exchange parameter, magnetic impurity concentration, and carrier density. The effect of a proper treatment of the disorder which includes all single-site multiple scattering appears to play a crucial role. The standard RKKY calculation which neglects disorder, strongly underestimates the Curie temperature and is inappropriate to describe magnetism in DMS. It is also shown that an antiferromagnetic exchange favors higher Curie temperature.

  1. Calculation of inherent boron dilution scenarios

    International Nuclear Information System (INIS)

    Kereszturi, A.; Toth, E.L.; Telbisz, M.; Trosztel, I.

    1999-01-01

    Two inherent boron dilution scenarios have been investigated in the frame of the PH2.08 PHARE project supported by the EC[1]. The Small Break LOCA (SBLOCA) initiating event was investigated by the SMABRE[2] and ATHLET[3] codes, while the SMATRA[4] code was used for the study of an ATWS initiating event. The results show that in case of SBLOCA slug formation is possible if the operator starts to cool down the secondary loop but the slug does not enter the core because it is removed by the Low Pressure Safety Injection. In case of ATWS, it was concluded that the maximum void fraction in the hot leg remained below 95% and that there was sufficient water in the two-phase flow to prevent formation of un borated slugs. Furthermore at the time the condensation of steam was already impossible in the steam generators because of drying out. (Authors)

  2. Water Metabolism of Walruses by Isotope Dilution

    DEFF Research Database (Denmark)

    Acquarone, M.; Born, E. W.; Chwalibog, A.

    was sampled via an epidural catheter, at regular intervals, for up to seven hours after the initial enrichment to assess isotope equilibration in the body water pools. Five individuals returned to the haul-out after feeding trips of varying duration (158±86 hr, 44-287 hr) where they were immobilized again......In August 2000, the hydrogen isotope dilution method was used on 7 adult male Atlantic walruses (Odobenus rosmarus rosmarus) (weight: 1197±148 kg, mean±SD, range 1013-1508 kg) at a terrestrial haul-out in Northeastern Greenland to determine their body water pool sizes and body water turnover rates....... During immobilization by use of etorphine HCl (reversed with diprenorphine HCl), a first blood sample was taken to measure background isotope levels. The animals were then enriched with deuterium oxide by infusion into the epidural vein. During recovery, while the animals were still on the beach, blood...

  3. Guideline on Isotope Dilution Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, Amy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-19

    Isotope dilution mass spectrometry is used to determine the concentration of an element of interest in a bulk sample. It is a destructive analysis technique that is applicable to a wide range of analytes and bulk sample types. With this method, a known amount of a rare isotope, or ‘spike’, of the element of interest is added to a known amount of sample. The element of interest is chemically purified from the bulk sample, the isotope ratio of the spiked sample is measured by mass spectrometry, and the concentration of the element of interest is calculated from this result. This method is widely used, although a mass spectrometer required for this analysis may be fairly expensive.

  4. The changes of ADI structure during high temperature annealing

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2010-01-01

    Full Text Available The results of structure investigations of ADI during it was annealing at elevated temperature are presented. Ductile iron austempered at temperature 325oC was then isothermally annealed 360 minutes at temperature 400, 450, 500 and 550oC. The structure investigations showed that annealing at these temperatures caused substantial structure changes and thus essential hardness decrease, which is most useful property of ADI from point of view its practical application. Degradation advance of the structure depends mainly on annealing temperature, less on the time of the heat treatment. It was concluded that high temperature annealing caused precipitation of Fe3C type carbides, which morphology and distribution depend on temperature. In case of 400oC annealing the carbides precipitates inside bainitic ferrite lath in specific crystallographic planes and partly at the grain boundaries. The annealing at the temperature 550oC caused disappearing of characteristic for ADI needle or lath – like morphology, which is replaced with equiaxed grains. In this case Fe3C carbides take the form very fine precipitates with spheroidal geometry.

  5. Grain coarsening mechanism of Cu thin films by rapid annealing

    International Nuclear Information System (INIS)

    Sasajima, Yasushi; Kageyama, Junpei; Khoo, Khyoupin; Onuki, Jin

    2010-01-01

    Cu thin films have been produced by an electroplating method using nominal 9N anode and nominal 6N CuSO 4 .5H 2 O electrolyte. Film samples were heat-treated by two procedures: conventional isothermal annealing in hydrogen atmosphere (abbreviated as H 2 annealing) and rapid thermal annealing with an infrared lamp (abbreviated as RTA). After heat treatment, the average grain diameters and the grain orientation distributions were examined by electron backscattering pattern analysis. The RTA samples (400 o C for 5 min) have a larger average grain diameter, more uniform grain distribution and higher ratio of (111) orientation than H 2 annealed samples (400 o C for 30 min). This means that RTA can produce films with coarser and more uniformly distributed grains than H 2 annealing within a short time, i.e. only a few minutes. To clarify the grain coarsening mechanism, grain growth by RTA was simulated using the phase field method. The simulated grain diameter reaches its maximum at a heating rate which is the same order as that in the actual RTA experiment. The maximum grain diameter is larger than that obtained by H 2 annealing with the same annealing time at the isothermal stage as in RTA. The distribution of the misorientation was analyzed which led to a proposed grain growth model for the RTA method.

  6. Rapid and long-term gamma-radiation annealing in low-dropout voltage regulators

    Directory of Open Access Journals (Sweden)

    Vukić Vladimir Đ.

    2017-01-01

    Full Text Available Samples of four types of low-dropout voltage regulators, with both serial pnp and npn transistors, were examined in room-temperature isothermal gamma radiation annealing. After uninterrupted exposure to a total ionising dose of 500 Gy, biased and loaded voltage regulators were examined in room-temperature annealing within the first 30 minutes after the exposure. Beside the on-line measurement of output voltage and quiescent current during the thirty-minute period immediately after irradiation, also results were procured after 10-year room-temperature spontaneous recovery. Data obtained during the irradiation and rapid annealing were fitted with linear, exponential, and power-law regression functions. A simple procedure was proposed, based on the quiescent current annealing factor, for the quick estimation of the integrated voltage regulator's radiation sensitivity during the post-irradiation isothermal annealing. In order to estimate the circuit's radiation sensitivity, immediately after irradiation, tested devices have to be left in the same operating conditions as during the exposure. If a clear trend of the quiescent current recovery can be observed, further examinations have to be implemented to estimate if a circuit is acceptably radiation-tolerant. If no recovery trend can be observed within the first hour after irradiation, or even further degradation is noticed, then the examined voltage regulator is a radiation-sensitive device and cannot be used in radiation environments. The described procedure is based on the macroscopic effects of the radiation-induced charge-trapping in field oxides and interfaces. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 171007: Physical and functional effects of the interaction of radiation with electrical and biological systems

  7. Effect of Annealing Temperature on the Water Contact Angle of PVD Hard Coatings.

    Science.gov (United States)

    Yang, Yu-Sen; Cho, Ting-Pin

    2013-08-07

    Various PVD (physical vapor deposition) hard coatings including nitrides and metal-doped diamond-like carbons (Me-DLC) were applied in plastic injection and die-casting molds to improve wear resistance and reduce sticking. In this study, nitrides hcp-AlN (hexagonal close-packed AlN), Cr₂N, (CrAl)₂N) and Me-DLC (Si-DLC and Cr-DLC) coatings were prepared using a closed field unbalanced magnetron reactive sputtering system. The coatings were annealed in air for 2 h at various temperatures, after which the anti-sticking properties were assessed using water contact angle (WCA) measurements. The as-deposited hcp-AlN, Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior and exhibit respective WCAs of 119°, 106° and 101°. The as-deposited Si-DLC and Cr-DLC coatings exhibit hydrophilic behavior and exhibit respective WCAs of 74° and 88°. The annealed Cr₂N and (CrAl)₂N coatings exhibit hydrophobic behavior with higher WCAs, while the annealed hcp-AlN, Si-DLC and Cr-DLC coatings are hydrophilic. The increased WCA of the annealed Cr₂N and (CrAl)₂N coatings is related to their crystal structure and increased roughness. The decreased WCA of the annealed hcp-AlN, Si-DLC and Cr-DLC coatings is related to their crystal structures and has little correlation with roughness.

  8. Effect of Annealing Temperature on the Water Contact Angle of PVD Hard Coatings

    Science.gov (United States)

    Yang, Yu-Sen; Cho, Ting-Pin

    2013-01-01

    Various PVD (physical vapor deposition) hard coatings including nitrides and metal-doped diamond-like carbons (Me-DLC) were applied in plastic injection and die-casting molds to improve wear resistance and reduce sticking. In this study, nitrides hcp-AlN (hexagonal close-packed AlN), Cr2N, (CrAl)2N) and Me-DLC (Si-DLC and Cr-DLC) coatings were prepared using a closed field unbalanced magnetron reactive sputtering system. The coatings were annealed in air for 2 h at various temperatures, after which the anti-sticking properties were assessed using water contact angle (WCA) measurements. The as-deposited hcp-AlN, Cr2N and (CrAl)2N coatings exhibit hydrophobic behavior and exhibit respective WCAs of 119°, 106° and 101°. The as-deposited Si-DLC and Cr-DLC coatings exhibit hydrophilic behavior and exhibit respective WCAs of 74° and 88°. The annealed Cr2N and (CrAl)2N coatings exhibit hydrophobic behavior with higher WCAs, while the annealed hcp-AlN, Si-DLC and Cr-DLC coatings are hydrophilic. The increased WCA of the annealed Cr2N and (CrAl)2N coatings is related to their crystal structure and increased roughness. The decreased WCA of the annealed hcp-AlN, Si-DLC and Cr-DLC coatings is related to their crystal structures and has little correlation with roughness. PMID:28811440

  9. Effect of Annealing Temperature on the Water Contact Angle of PVD Hard Coatings

    Directory of Open Access Journals (Sweden)

    Yu-Sen Yang

    2013-08-01

    Full Text Available Various PVD (physical vapor deposition hard coatings including nitrides and metal-doped diamond-like carbons (Me-DLC were applied in plastic injection and die-casting molds to improve wear resistance and reduce sticking. In this study, nitrides hcp-AlN (hexagonal close-packed AlN, Cr2N, (CrAl2N and Me-DLC (Si-DLC and Cr-DLC coatings were prepared using a closed field unbalanced magnetron reactive sputtering system. The coatings were annealed in air for 2 h at various temperatures, after which the anti-sticking properties were assessed using water contact angle (WCA measurements. The as-deposited hcp-AlN, Cr2N and (CrAl2N coatings exhibit hydrophobic behavior and exhibit respective WCAs of 119°, 106° and 101°. The as-deposited Si-DLC and Cr-DLC coatings exhibit hydrophilic behavior and exhibit respective WCAs of 74° and 88°. The annealed Cr2N and (CrAl2N coatings exhibit hydrophobic behavior with higher WCAs, while the annealed hcp-AlN, Si-DLC and Cr-DLC coatings are hydrophilic. The increased WCA of the annealed Cr2N and (CrAl2N coatings is related to their crystal structure and increased roughness. The decreased WCA of the annealed hcp-AlN, Si-DLC and Cr-DLC coatings is related to their crystal structures and has little correlation with roughness.

  10. Annealed Scaling for a Charged Polymer

    International Nuclear Information System (INIS)

    Caravenna, F.; Hollander, F. den; Pétrélis, N.; Poisat, J.

    2016-01-01

    This paper studies an undirected polymer chain living on the one-dimensional integer lattice and carrying i.i.d. random charges. Each self-intersection of the polymer chain contributes to the interaction Hamiltonian an energy that is equal to the product of the charges of the two monomers that meet. The joint probability distribution for the polymer chain and the charges is given by the Gibbs distribution associated with the interaction Hamiltonian. The focus is on the annealed free energy per monomer in the limit as the length of the polymer chain tends to infinity. We derive a spectral representation for the free energy and use this to prove that there is a critical curve in the parameter plane of charge bias versus inverse temperature separating a ballistic phase from a subballistic phase. We show that the phase transition is first order. We prove large deviation principles for the laws of the empirical speed and the empirical charge, and derive a spectral representation for the associated rate functions. Interestingly, in both phases both rate functions exhibit flat pieces, which correspond to an inhomogeneous strategy for the polymer to realise a large deviation. The large deviation principles in turn lead to laws of large numbers and central limit theorems. We identify the scaling behaviour of the critical curve for small and for large charge bias. In addition, we identify the scaling behaviour of the free energy for small charge bias and small inverse temperature. Both are linked to an associated Sturm-Liouville eigenvalue problem. A key tool in our analysis is the Ray-Knight formula for the local times of the one-dimensional simple random walk. This formula is exploited to derive a closed form expression for the generating function of the annealed partition function, and for several related quantities. This expression in turn serves as the starting point for the derivation of the spectral representation for the free energy, and for the scaling theorems

  11. Dilution in a Dense Bottom Jet in Cross Currents

    DEFF Research Database (Denmark)

    Petersen, O.; Larsen, Torben

    1998-01-01

    A 3-dimensional numerical model describing the dilution in the near field around dense vertical jets in a cross flow is formulated and validated against laboratory experiments. The validation shows that the model reproduces the flow pattern well, though the dilution is underestimated by 20......%. The model is applied to a case study where the dilution from two vertical jets at an angle in shallow water is described. It is demonstrated that a 20% increase in dilution is possible. It is concluded that the model may become a valuable tool in diffusor design....

  12. 21 CFR 866.2500 - Microtiter diluting and dispensing device.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2500... a mechanical device intended for medical purposes to dispense or serially dilute very small...

  13. The phase diagram of annealed Ge(111)/Ga

    DEFF Research Database (Denmark)

    Molinàs-Mata, P.; Böhringer, M.; Artacho, E.

    1995-01-01

    A study of the annealed phases of Ge(111)/Ga for coverages above 0.05 ML is presented. The surfaces are investigated by low-energy electron diffraction, scanning tunneling microscopy, and partly by photoemission and surface X-ray diffraction using synchrotron radiation. For Ga coverages beyond 0.......05 ML and up to about 2 ML and annealing temperatures higher than 500 degrees C four different phases appear. They all can be characterized as being discommensurate. Surprisingly, no commensurate superstructure appears on annealed Ge(111)/Ga....

  14. Structural study of conventional and bulk metallic glasses during annealing

    International Nuclear Information System (INIS)

    Pineda, E.; Hidalgo, I.; Bruna, P.; Pradell, T.; Labrador, A.; Crespo, D.

    2009-01-01

    Metallic glasses with conventional glass-forming ability (Al-Fe-Nd, Fe-Zr-B, Fe-B-Nb compositions) and bulk metallic glasses (Ca-Mg-Cu compositions) were studied by synchrotron X-ray diffraction during annealing throughout glass transition and crystallization temperatures. The analysis of the first diffraction peak position during the annealing process allowed us to follow the free volume change during relaxation and glass transition. The structure factor and the radial distribution function of the glasses were obtained from the X-ray measurements. The structural changes occurred during annealing are analyzed and discussed.

  15. Anisotropic annealing of fission fragments in synthetic quartz

    CERN Document Server

    Sawamura, T; Narita, M

    1999-01-01

    A study on the thermal annealing behavior of fission fragments in synthetic quartz crystals was performed for application of synthetic quartz to track detectors under high temperature circumstances: x-, y-, and z-cut quartz plates were exposed to fission fragments from sup 2 sup 5 sup 2 Cf and were annealed up to 750 deg. C. It was found that track retention depended on the crystallographic structure: the annealing temperature, where the number of etched tracks was sharply reduced, was 550 deg. C for the x- and y-cut plates and 750 deg. C for z-cut plates. Track sizes decrease and disperse with reductions in the track retention.

  16. Effect of dilution rate on productivity of continuous bacteriophage production in cellstat.

    Science.gov (United States)

    Nabergoj, Dominik; Kuzmić, Nina; Drakslar, Benjamin; Podgornik, Aleš

    2018-04-01

    Ability to efficiently propagate high quantities of bacteriophages (phages) is of great importance considering higher phage production needs in the future. Continuous production of phages could represent an interesting option. In our study, we tried to elucidate the effect of dilution rate on productivity of continuous production of phages in cellstat. As a model system, a well-studied phage T4 and Escherichia coli K-12 as a host were used. Experiments where physiology of bacteria was changing with dilution rate of cellstat and where bacterial physiology was kept constant were performed. For both setups there exists an optimal dilution rate when maximal productivity is achieved. Experimentally obtained values of phage concentration and corresponding productivity were compared with mathematical model predictions, and good agreement was obtained for both types of experiments. Analysis of mathematical model coefficients revealed that latent period and burst size to dilution rate coefficient mostly affect optimum dilution rate and productivity. Due to high sensitivity, it is important to evaluate phage growth parameters carefully, to run cellstat under optimal productivity.

  17. A scaling approach for fluid mixing in rapid boron-dilution transients

    International Nuclear Information System (INIS)

    Gavrilas, Mirela; Palazov, Vesselin

    1999-01-01

    The issue of rapid-boron dilution transients has been investigated for a decade with few definitive conclusions. The potential reactivity insertion that would result from the transport of a boron-dilute slug to the core region depends on the spatial and temporal concentration of neutron poison in the fluid that penetrates the core. Difficulties in assessing the consequences of a boron-dilution transient lie in the diversity of postulated on-set scenarios, and in the large dependence of the resulting reactivity insertion on plant conditions and geometric features. The University of Maryland (UM) 2 x 4 Thermohydraulic Loop Facility is collecting code validation data for rapid boron-dilution transients. The data has to be representative of the prototype. scaling thus becomes an important consideration. The mixing of the boron-dilute slug with the highly borated coolant present in the primary system is advective-diffusive. Therefore, the scaling approach involves extracting relevant parameters from the advection-diffusion equation. The dimensionless numbers that govern mixing are shown to be the Strouhal and Schmidt numbers. They have to be considered simultaneously to properly scale the flow in the model facility. A closer investigation of the relation between these two numbers reveals that, for fully developed turbulent flows, matching only one of these numbers is sufficient. This conclusion is substantiated by experimental results from Vattenfall. (author)

  18. Effects of Extreme Dilutions of Apis mellifica Preparations on Gene Expression Profiles of Human Cells

    Directory of Open Access Journals (Sweden)

    Elisabetta Bigagli

    2016-01-01

    Full Text Available Gene expression analysis has been employed in the past to test the effects of high dilutions on cell systems. However, most of the previous studies were restricted to the investigation of few dilutions, making it difficult to explore underlying mechanisms of action. Using whole-genome transcriptomic analysis, we investigated the effects of a wide range of Apis mellifica dilutions on gene expression profiles of human cells. RWPE-1 cells, a nonneoplastic adult human epithelial prostate cell line, were exposed to Apis mellifica preparations (3C, 5C, 7C, 9C, 12C, 15C, and 30C or to the reference solvent solutions for 24 hours; nonexposed cells were also checked for gene expression variations. Our results showed that even the most diluted solutions retained the ability to trigger significant variations in gene expression. Gene pathway analysis revealed consistent variations in gene expression induced by Apis mellifica when compared to nonexposed reference cells but not to reference solvent solutions. Since the effects of Apis Mellifica at extreme dilutions did not show dose–effect relationships, the biological or functional interpretation of these results remains uncertain.

  19. Two-body correlation functions in dilute nuclear matter

    International Nuclear Information System (INIS)

    Isayev, A A

    2006-01-01

    Finding the distinct features of the crossover from the regime of large overlapping Cooper pairs to the limit of non-overlapping pairs of fermions (Shafroth pairs) in multicomponent Fermi systems remains one of the actual problems in a quantum many-body theory. Here this transition is studied by calculating the two-body density, spin and isospin correlation functions in dilute asymmetric nuclear matter. It is shown that criterion of the crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting in the change of the sign of the density correlation function at low momentum transfer, fails to describe correctly the density-driven BEC-BCS transition at finite isospin asymmetry or finite temperature. As an unambiguous signature of the BEC-BCS transition, there can be used the presence (BCS regime) or absence (BEC regime) of the singularity in the momentum distribution of the quasiparticle density of states

  20. Radiation damage and annealing in plutonium tetrafluoride

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, Kaylyn; Casella, Amanda; Sinkov, Sergey; Sweet, Lucas; McNamara, Bruce; Delegard, Calvin; Jevremovic, Tatjana

    2017-12-01

    Plutonium tetrafluoride that was separated prior to 1966 at the Hanford Site in Washington State was analyzed at the Pacific Northwest National Laboratory (PNNL) in 2015 and 2016. The plutonium tetrafluoride, as received, was an off-normal color and considering the age of the plutonium, there were questions about the condition of the material. These questions had to be answered in order to determine the suitability of the material for future use or long-term storage. Therefore, Thermogravimetric/Differential Thermal Analysis and X-ray Diffraction evaluations were conducted to determine the plutonium’s crystal structure, oxide content, and moisture content; these analyses reported that the plutonium was predominately amorphous and tetrafluoride, with an oxide content near ten percent. Freshly fluorinated plutonium tetrafluoride is known to be monoclinic. During the initial Thermogravimetric/Differential Thermal analyses, it was discovered that an exothermic event occurred within the material near 414°C. X-ray Diffraction analyses were conducted on the annealed tetrafluoride. The X-ray Diffraction analyses indicated that some degree of recrystallization occurred in conjunction with the 414°C event. The following commentary describes the series of Thermogravimetric/Differential Thermal and X-ray Diffraction analyses that were conducted as part of this investigation at PNNL, in collaboration with the University of Utah Nuclear Engineering Program.

  1. Ethanol fermentation of a diluted molasses medium by Saccharomyces cerevisiae immobilized on chrysotile

    Directory of Open Access Journals (Sweden)

    Monte Alegre Ranulfo

    2003-01-01

    Full Text Available In this work, the catalytic role of chrysotile support on the acceleration of alcoholic fermentation under non-aseptic conditions by Saccharomyces cerevisiae was investigated. The fermentation medium employed consisted only of diluted sugar-cane molasses. In the batch fermentations process with immobilized yeasts, the initial rate of CO2 production increased roughly 27 % during the first 30 minutes, compared to systems containing no chrysotile. A study of continuous alcoholic fermentation with chrysotile in the reactor bed showed a higher ethanol production rate at the different dilution rates investigated compared to similar fermentations without chrysotile.

  2. Prototype Repository. Tracer dilution tests during operation phase, test campaign 3

    Energy Technology Data Exchange (ETDEWEB)

    Harrstroem, Johan; Andersson, Peter (Geosigma AB (Sweden))

    2010-05-15

    The Prototype Repository project is focused on testing and demonstrating the function of the SKB deep repository system. The third tracer dilution campaign during the Prototype Repository operation period was performed in January 2010. The purpose was to estimate the groundwater flows and hydraulic gradients in the boreholes vicinity and will function as a reference for comparison with results from modeling and prior assumptions. The test campaign consisted of tracer dilution tests in 13 different borehole sections. Each test consisted of approximately 15-55 min tracer injection time and about 1-3 days dilution test time depending on the transmissivity of the test section. The data interpretation also included estimates of the local hydraulic gradients in the vicinity of the borehole sections

  3. Dilute Surfactant Methods for Carbonate Formations

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2006-02-01

    There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

  4. Continuous Flow Aquatic Toxicity Testing Using Dilution Water by Reverse Osmosis

    Science.gov (United States)

    1979-04-01

    AMRL-TR-79-25 CONTINUOUS FLOW AQUATIC TOXICOLOGY TESTING USING DILUTION WATER BY REVERSE OSMOSIS J. W. FISHtER R. C INMAN M. A. HAGERMAN C. B. HARRAH...showing construction design. 8 DISCUSSION This system was designed for limited xise in an aquatic toxicology laboratory. The floor space and water quality

  5. A novel He3-He4 dilution refrigerator with superfluid He4 circulation

    International Nuclear Information System (INIS)

    Severijns, A.P.

    1980-01-01

    A novel dilution refrigerator system is proposed, which offers the potentiality of very high circulation rates. The design of this refrigerator is described and the construction and performance of a prototype are discussed. He 4 is circulated by means of a multi-stage thermomechanical or fountain pump, which can build up high fountain pressures. (author)

  6. Sin nombre virus and rodent species diversity: a test of the dilution and amplification hypotheses.

    Science.gov (United States)

    Clay, Christine A; Lehmer, Erin M; Jeor, Stephen St; Dearing, M Denise

    2009-07-31

    Species diversity is proposed to greatly impact the prevalence of pathogens. Two predominant hypotheses, the "Dilution Effect" and the "Amplification Effect", predict divergent outcomes with respect to the impact of species diversity. The Dilution Effect predicts that pathogen prevalence will be negatively correlated with increased species diversity, while the Amplification Effect predicts that pathogen prevalence will be positively correlated with diversity. For many host-pathogen systems, the relationship between diversity and pathogen prevalence has not be empirically examined. We tested the Dilution and Amplification Effect hypotheses by examining the prevalence of Sin Nombre virus (SNV) with respect to diversity of the nocturnal rodent community. SNV is directly transmitted primarily between deer mice (Peromyscus maniculatus). Using mark-recapture sampling in the Spring and Fall of 2003-2005, we measured SNV prevalence in deer mice at 16 landscape level sites (3.1 hectares each) that varied in rodent species diversity. We explored several mechanisms by which species diversity may affect SNV prevalence, including reduced host density, reduced host persistence, the presence of secondary reservoirs and community composition. We found a negative relationship between species diversity and SNV prevalence in deer mice, thereby supporting the Dilution Effect hypothesis. Deer mouse density and persistence were lower at sites with greater species diversity; however, only deer mouse persistence was positively correlated with SNV prevalence. Pinyon mice (P. truei) may serve as dilution agents, having a negative effect on prevalence, while kangaroo rats (Dipodomys ordii), may have a positive effect on the prevalence of SNV, perhaps through effects on deer mouse behavior. While previous studies on host-pathogen systems have found patterns of diversity consistent with either the Dilution or Amplification Effects, the mechanisms by which species diversity influences

  7. Solvent vapor annealing of an insoluble molecular semiconductor

    KAUST Repository

    Amassian, Aram

    2010-01-01

    Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

  8. Structural changes during annealing of GaInAsN

    International Nuclear Information System (INIS)

    Kurtz, Sarah; Webb, J.; Gedvilas, L.; Friedman, D.; Geisz, J.; Olson, J.; King, R.; Joslin, D.; Karam, N.

    2001-01-01

    The alloy GaInAsN has great potential as a lower-band-gap material lattice matched to GaAs, but there is little understanding of what causes its poor optoelectronic properties and why these improve with annealing. This study provides information about the structural changes that occur when GaInAsN is annealed. The Fourier transform infrared spectra exhibit two primary features: a triplet at ∼470 cm-1 (Ga--N stretch) and two or three bands at ∼3100 cm-1 (N--H stretch). The change in the Ga--N stretch absorption can be explained if the nitrogen environment is converted from NGa 4 to NInGa 3 after annealing. The N--H stretch is also changed after annealing, implying a second, and unrelated, structural change

  9. Performance of two different quantum annealing correction codes

    Science.gov (United States)

    Mishra, Anurag; Albash, Tameem; Lidar, Daniel A.

    2016-02-01

    Quantum annealing is a promising approach for solving optimization problems, but like all other quantum information processing methods, it requires error correction to ensure scalability. In this work, we experimentally compare two quantum annealing correction (QAC) codes in the setting of antiferromagnetic chains, using two different quantum annealing processors. The lower-temperature processor gives rise to higher success probabilities. The two codes differ in a number of interesting and important ways, but both require four physical qubits per encoded qubit. We find significant performance differences, which we explain in terms of the effective energy boost provided by the respective redundantly encoded logical operators of the two codes. The code with the higher energy boost results in improved performance, at the expense of a lower-degree encoded graph. Therefore, we find that there exists an important trade-off between encoded connectivity and performance for quantum annealing correction codes.

  10. Compatible topologies and parameters for NMR structure determination of carbohydrates by simulated annealing

    OpenAIRE

    Feng, Yingang

    2017-01-01

    The use of NMR methods to determine the three-dimensional structures of carbohydrates and glycoproteins is still challenging, in part because of the lack of standard protocols. In order to increase the convenience of structure determination, the topology and parameter files for carbohydrates in the program Crystallography & NMR System (CNS) were investigated and new files were developed to be compatible with the standard simulated annealing protocols for proteins and nucleic acids. Recalculat...

  11. Phase diagram of 2D Hubbard model by simulated annealing mean field approximation

    International Nuclear Information System (INIS)

    Kato, Masaru; Kitagaki, Takashi

    1991-01-01

    In order to investigate the stable magnetic structure of the Hubbard model on a square lattice, we utilize the dynamical simulated annealing method which proposed by R. Car and M. Parrinello. Results of simulations on a 10 x 10 lattice system with 80 electrons under assumption of collinear magnetic structure that the most stable state is incommensurate spin density wave state with periodic domain wall. (orig.)

  12. Stochastic search in structural optimization - Genetic algorithms and simulated annealing

    Science.gov (United States)

    Hajela, Prabhat

    1993-01-01

    An account is given of illustrative applications of genetic algorithms and simulated annealing methods in structural optimization. The advantages of such stochastic search methods over traditional mathematical programming strategies are emphasized; it is noted that these methods offer a significantly higher probability of locating the global optimum in a multimodal design space. Both genetic-search and simulated annealing can be effectively used in problems with a mix of continuous, discrete, and integer design variables.

  13. Simulated annealing image reconstruction for positron emission tomography

    International Nuclear Information System (INIS)

    Sundermann, E.; Lemahieu, I.; Desmedt, P.

    1994-01-01

    In Positron Emission Tomography (PET) images have to be reconstructed from moisy projection data. The noise on the PET data can be modeled by a Poison distribution. In this paper, we present the results of using the simulated annealing technique to reconstruct PET images. Various parameter settings of the simulated annealing algorithm are discussed and optimized. The reconstructed images are of good quality and high contrast, in comparison to other reconstruction techniques. (authors)

  14. Far-infrared spectroscopy of thermally annealed tungsten silicide films

    International Nuclear Information System (INIS)

    Amiotti, M.; Borghesi, A.; Guizzetti, G.; Nava, F.; Santoro, G.

    1991-01-01

    The far-infrared transmittance spectrum of tungsten silicide has been observed for the first time. WSi 2 polycrystalline films were prepared by coevaporation and chemical-vapour deposition on silicon wafers, and subsequently thermally annealed at different temperatures. The observed structures are interpreted, on the basis of the symmetry properties of the crystal, such as infrared-active vibrational modes. Moreover, the marked lineshape dependence on annealing temperature enables this technique to analyse the formation of the solid silicide phases

  15. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate wettability. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  16. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-07-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases IFT with a minimum at about 0.2 M. Addition of surfactant decreases IFT further. In the absence of surfactant the minerals are oil-wet after aging with crude oil. Addition of surfactant solution decreases the contact angle to intermediate-wet for many surfactants and water-wet for one surfactant. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Plans for the next quarter include conducting core adsorption, phase behavior, wettability and mobilization studies.

  17. Dilute antiferromagnetism in magnetically doped phosphorene

    Directory of Open Access Journals (Sweden)

    Andrew Allerdt

    2017-11-01

    Full Text Available We study the competition between Kondo physics and indirect exchange on monolayer black phos-phorous using a realistic description of the band structure in combination with the density matrixrenormalization group (DMRG method. The Hamiltonian is reduced to a one-dimensional problemvia an exact canonical transformation that makes it amenable to DMRG calculations, yielding exactresults that fully incorporate the many-body physics. We find that a perturbative description of theproblem is not appropriate and cannot account for the slow decay of the correlations and the completelack of ferromagnetism. In addition, at some particular distances, the impurities decouple formingtheir own independent Kondo states. This can be predicted from the nodes of the Lindhard function.Our results indicate a possible route toward realizing dilute anti-ferromagnetism in phosphorene. Received: 19 September 2017, Accepted: 12 October 2017; Edited by: K. Hallberg; DOI: http://dx.doi.org/10.4279/PIP.090008 Cite as: A Allerdt, A E Feiguin, Papers in Physics 9, 090008 (2017

  18. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty

    2003-01-01

    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have acquired field oil and core samples and field brine compositions from Marathon. We have conducted preliminary adsorption and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Receding contact angles increase with surfactant adsorption. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  19. Dilution in Transition Zone between Rising Plumes and Surface Plumes

    DEFF Research Database (Denmark)

    Larsen, Torben

    2004-01-01

    The papers presents some physical experiments with the dilution of sea outfall plumes with emphasize on the transition zone where the relative fast flowing vertical plume turns to a horizontal surface plume following the slow sea surface currents. The experiments show that a considerable dilution...

  20. The dilute random field Ising model by finite cluster approximation

    International Nuclear Information System (INIS)

    Benyoussef, A.; Saber, M.

    1987-09-01

    Using the finite cluster approximation, phase diagrams of bond and site diluted three-dimensional simple cubic Ising models with a random field have been determined. The resulting phase diagrams have the same general features for both bond and site dilution. (author). 7 refs, 4 figs

  1. Nonthermal plasma assisted photocatalytic oxidation of dilute benzene

    Indian Academy of Sciences (India)

    to utilize the UV light for photocatalytic decomposition of chlorinated VOCs.23. Benzene, a commonly used industrial solvent, whose abatement under dilute concentrations (<1000 ppm) may not be economical by conventional techniques. The present study was aimed at the total oxidation of dilute benzene in a DBD reactor.

  2. Behaviour of humic-bentonite aggregates in diluted suspensions ...

    African Journals Online (AJOL)

    Formation and disaggregation of micron-size aggregates in a diluted suspension made up of HSs and bentonite (B) were studied by tracing distribution of aggregate sizes and their counts in freshly prepared and aged suspensions, and at high (10 000) and low (1.0) [HS]/[B] ratios. Diluted HSB suspensions are unstable ...

  3. Near-wall molecular ordering of dilute ionic liquids

    NARCIS (Netherlands)

    Jitvisate, Monchai; Seddon, James Richard Thorley

    2017-01-01

    The interfacial behavior of ionic liquids promises tunable lubrication as well as playing an integral role in ion diffusion for electron transfer. Diluting the ionic liquids optimizes bulk parameters, such as electric conductivity, and one would expect dilution to disrupt the near-wall molecular

  4. Enhancement of surface magnetism due to bulk bond dilution

    International Nuclear Information System (INIS)

    Tsallis, C.; Sarmento, E.F.; Albuquerque, E.L. de

    1985-01-01

    Within a renormalization group scheme, the phase diagram of a semi-infinite simple cubic Ising ferromagnet is discussed, with arbitrary surface and bulk coupling constants, and including possible dilution of the bulk bonds. It is obtained that dilution makes easier the appearance of surface magnetism in the absence of bulk magnetism. (Author) [pt

  5. Effect of dietary dilution of energy and nutrients during different ...

    African Journals Online (AJOL)

    A completely randomized design was conducted to evaluate the effect of dietary dilution of energy and nutrients during different growing periods on compensatory growth of Ross broilers. Four replicant pens were assigned per seven treatments. Chicks in each treatment received concentrated and diluted diets in different ...

  6. Conventional treatment planning optimization using simulated annealing

    International Nuclear Information System (INIS)

    Morrill, S.M.; Langer, M.; Lane, R.G.

    1995-01-01

    Purpose: Simulated annealing (SA) allows for the implementation of realistic biological and clinical cost functions into treatment plan optimization. However, a drawback to the clinical implementation of SA optimization is that large numbers of beams appear in the final solution, some with insignificant weights, preventing the delivery of these optimized plans using conventional (limited to a few coplanar beams) radiation therapy. A preliminary study suggested two promising algorithms for restricting the number of beam weights. The purpose of this investigation was to compare these two algorithms using our current SA algorithm with the aim of producing a algorithm to allow clinically useful radiation therapy treatment planning optimization. Method: Our current SA algorithm, Variable Stepsize Generalized Simulated Annealing (VSGSA) was modified with two algorithms to restrict the number of beam weights in the final solution. The first algorithm selected combinations of a fixed number of beams from the complete solution space at each iterative step of the optimization process. The second reduced the allowed number of beams by a factor of two at periodic steps during the optimization process until only the specified number of beams remained. Results of optimization of beam weights and angles using these algorithms were compared using a standard cadre of abdominal cases. The solution space was defined as a set of 36 custom-shaped open and wedged-filtered fields at 10 deg. increments with a target constant target volume margin of 1.2 cm. For each case a clinically-accepted cost function, minimum tumor dose was maximized subject to a set of normal tissue binary dose-volume constraints. For this study, the optimized plan was restricted to four (4) fields suitable for delivery with conventional therapy equipment. Results: The table gives the mean value of the minimum target dose obtained for each algorithm averaged over 5 different runs and the comparable manual treatment

  7. Thermalization, Freeze-out, and Noise: Deciphering Experimental Quantum Annealers

    Science.gov (United States)

    Marshall, Jeffrey; Rieffel, Eleanor G.; Hen, Itay

    2017-12-01

    By contrasting the performance of two quantum annealers operating at different temperatures, we address recent questions related to the role of temperature in these devices and their function as "Boltzmann samplers." Using a method to reliably calculate the degeneracies of the energy levels of large-scale spin-glass instances, we are able to estimate the instance-dependent effective temperature from the output of annealing runs. Our results corroborate the "freeze-out" picture which posits two regimes, one in which the final state corresponds to a Boltzmann distribution of the final Hamiltonian with a well-defined "effective temperature" determined at a freeze-out point late in the annealing schedule, and another regime in which such a distribution is not necessarily expected. We find that the output distributions of the annealers do not, in general, correspond to a classical Boltzmann distribution for the final Hamiltonian. We also find that the effective temperatures at different programing cycles fluctuate greatly, with the effect worsening with problem size. We discuss the implications of our results for the design of future quantum annealers to act as more-effective Boltzmann samplers and for the programing of such annealers.

  8. Optimization using quantum mechanics: quantum annealing through adiabatic evolution

    International Nuclear Information System (INIS)

    Santoro, Giuseppe E; Tosatti, Erio

    2006-01-01

    We review here some recent work in the field of quantum annealing, alias adiabatic quantum computation. The idea of quantum annealing is to perform optimization by a quantum adiabatic evolution which tracks the ground state of a suitable time-dependent Hamiltonian, where 'ℎ' is slowly switched off. We illustrate several applications of quantum annealing strategies, starting from textbook toy-models-double-well potentials and other one-dimensional examples, with and without disorder. These examples display in a clear way the crucial differences between classical and quantum annealing. We then discuss applications of quantum annealing to challenging hard optimization problems, such as the random Ising model, the travelling salesman problem and Boolean satisfiability problems. The techniques used to implement quantum annealing are either deterministic Schroedinger's evolutions, for the toy models, or path-integral Monte Carlo and Green's function Monte Carlo approaches, for the hard optimization problems. The crucial role played by disorder and the associated non-trivial Landau-Zener tunnelling phenomena is discussed and emphasized. (topical review)

  9. Effect of annealing treatments on photoluminescence and charge storage mechanism in silicon-rich SiNx:H films

    Directory of Open Access Journals (Sweden)

    Sahu Bhabani

    2011-01-01

    Full Text Available Abstract In this study, a wide range of a-SiNx:H films with an excess of silicon (20 to 50% were prepared with an electron-cyclotron resonance plasma-enhanced chemical vapor deposition system under the flows of NH3 and SiH4. The silicon-rich a-SiNx:H films (SRSN were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties. A strong visible photoluminescence (PL at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C. The possible origins of the PL are briefly discussed. The authors have succeeded in the formation of amorphous Si quantum dots with an average size of about 3 to 3.6 nm by varying excess amount of Si and annealing temperature. Electrical properties have been investigated on Al/Si3N4/SRSN/SiO2/Si structures by capacitance-voltage and conductance-voltage analysis techniques. A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices.

  10. Annealing temperature dependence of magnetic properties of CoFeB/MgO stacks on different buffer layers

    Science.gov (United States)

    Watanabe, Kyota; Fukami, Shunsuke; Sato, Hideo; Ikeda, Shoji; Matsukura, Fumihiro; Ohno, Hideo

    2017-08-01

    We investigate the annealing temperature dependence of the magnetic properties of CoFeB/MgO stacks with different buffer materials (Mo, Ta, and W). For Mo and W, bcc-crystalline and amorphous-like films are prepared by changing the deposition conditions. A relatively small saturation magnetization is maintained after annealing up to 400 °C for the samples with bcc-W, bcc-Mo, and amorphous-like Mo buffers. A small variation in magnetic dead layer thickness with annealing is observed for the samples with bcc-crystalline buffer layers. The interfacial anisotropy is found to mainly depend on the element of the buffer layer used regardless of its crystalline structure, and is larger for the samples with W and Mo buffers than those with Ta buffer. The sample with bcc-Mo buffer shows the highest robustness against annealing among the studied systems. We give a systematic picture based on the thermochemistry that can reasonably explain the observed buffer layer dependence of the variations in magnetic properties with annealing.

  11. Thermal annealing and pressure effects on BaFe2-xCoxAs2 single crystals.

    Science.gov (United States)

    Shin, Dongwon; Jung, Soon-Gil; Prathiba, G; Seo, Soonbeom; Choi, Ki-Young; Kim, Kee Hoon; Park, Tuson

    2017-11-26

    We investigate the pressure and thermal annealing effects on BaFe2-xCoxAs2 (Co-Ba122) single crystals with x = 0.1 and 0.17 via electrical transport measurements. The thermal annealing treatment not only enhances the superconducting transition temperature (Tc) from 9.6 to 12.7 K for x = 0.1 and from 18.1 to 21.0 K for x = 0.17, but also increases the antiferromagnetic transition temperature (TN). Simultaneous enhancement of Tc and TN by the thermal annealing treatment indicates that thermal annealing could substantially improve the quality of the Co-doped Ba122 samples. Interestingly, Tc of the Co-Ba122 compounds shows a scaling behavior with a linear dependence on the resistivity value at 290 K, irrespective of tuning parameters, such as chemical doping, pressure, and thermal annealing. These results not only provide an effective way to access the intrinsic properties of the BaFe2As2 system, but also may shed a light on designing new materials with higher superconducting transition temperature. © 2017 IOP Publishing Ltd.

  12. Thermal annealing and pressure effects on BaFe2-xCoxAs2single crystals.

    Science.gov (United States)

    Shin, Dongwon; Jung, Soon-Gil; Prathiba, G; Seo, Soonbeom; Choi, Ki-Young; Kim, Kee Hoon; Park, Tuson

    2017-12-08

    We investigate the pressure and thermal annealing effects on BaFe 2-x Co x As 2 (Co-Ba122) single crystals with x  =  0.1 and 0.17 via electrical transport measurements. The thermal annealing treatment not only enhances the superconducting transition temperature (T c ) from 9.6 to 12.7 K for x  =  0.1 and from 18.1 to 21.0 K for x  =  0.17, but also increases the antiferromagnetic transition temperature (T N ). Simultaneous enhancement of T c and T N by the thermal annealing treatment indicates that thermal annealing could substantially improve the quality of the Co-doped Ba122 samples. Interestingly, T c of the Co-Ba122 compounds shows a scaling behavior with a linear dependence on the resistivity value at 290 K, irrespective of tuning parameters such as chemical doping, pressure, and thermal annealing. These results not only provide an effective way to access the intrinsic properties of the BaFe 2 As 2 system, but may also shed a light on designing new materials with higher superconducting transition temperature.

  13. Effects of Annealing on the Martensitic Transformation of Ni-Based Ferromagnetic Shape Memory Heusler Alloys and Nanoparticles

    Directory of Open Access Journals (Sweden)

    Tina Fichtner

    2015-03-01

    Full Text Available We report on the effects of annealing on the martensitic phase transformation in the Ni-based Heusler system: Mn50Ni40Sn10 and Mn50Ni41Sn9 powder and Co50Ni21Ga32 nanoparticles. For the powdered Mn50Ni40Sn10 and Mn50Ni41Sn9 alloys, structural and magnetic measurements reveal that post-annealing decreases the martensitic transformation temperatures and increases the transition hysteresis. This might be associated with a release of stress in the Mn50Ni40Sn10 and Mn50Ni41Sn9 alloys during the annealing process. However, in the case of Co50Ni21Ga32 nanoparticles, a reverse phenomenon is observed. X-ray diffraction analysis results reveal that the as-prepared Co50Ni21Ga32 nanoparticles do not show a martensitic phase at room temperature. Post-annealing followed by ice quenching, however, is found to trigger the formation of the martensitic phase. The presence of the martensitic transition is attributed to annealing-induced particle growth and the stress introduced during quenching.

  14. Efficacy comparison between simple mixed-dilution and simple mid-dilution on-line hemodiafiltration techniques: a crossover study.

    Science.gov (United States)

    Susantitaphong, Paweena; Tiranathanagul, Khajohn; Katavetin, Pisut; Hanwiwatwong, Orawadee; Wittayalertpanya, Supeecha; Praditpornsilpa, Kearkiat; Tungsanga, Kriang; Eiam-Ong, Somchai

    2012-12-01

    Mid-dilution and mixed-dilution on-line hemodiafiltration (OL-HDF) techniques are innovated to overcome the limitations of two standard techniques including predilution and postdilution. Unfortunately, the head-to-head comparisons between these two novel techniques in the same study are still limited. Moreover, the original mid-dilution and mixed-dilution OL-HDF need special dialyzers and special machines. In the present study, simple mid-dilution and simple mixed-dilution OL-HDF were settled with the aim for clinical use in general hemodialysis (HD) centers. The efficacies of uremic toxins removal between both modalities were measured and compared. This prospective randomized crossover study was conducted on 12 stable HD patients undergoing simple mixed-dilution and simple mid-dilution OL-HDF techniques. HD prescriptions were similar in both techniques. The dialysis efficacies were determined by calculating small- (urea, creatinine, and phosphate) and middle-molecule (beta-2 microglobulin [β2M]) removal. Moreover, potential complications such as high transmembrane pressure (TMP) and protein loss were also observed. Simple mixed-dilution OL-HDF provided significantly greater clearances of urea, creatinine, and β2M when compared with the simple mid-dilution OL-HDF techniques. Phosphate clearances in both techniques were comparable. In addition, TMP and dialysate albumin loss were not different. There were no intradialytic complications in both techniques. Simple mixed-dilution OL-HDF could provide greater efficacy for small- and middle-molecule clearances and acceptable potential risks, while phosphate removal is comparable. © 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  15. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    International Nuclear Information System (INIS)

    Sugiharto; Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-01-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  16. Radiotracer Dilution Method for Mercury Inventory Study in Electrolytic Cells

    Science.gov (United States)

    Sugiharto, Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul; Santoso, Sigit Budi; Abidin, Zainal; Santoso, Gatot Budi

    2010-06-01

    Purpose of the experiment is to demonstrate feasibility the use of radiotracer to measure weight of mercury in electrolytic cells of soda industry. The weight of mercury in each cell of the plant is designed approximately 1700 kg. Radiotracer is prepared by mixing 203 Hg radioactive mercury with 2400 g of inactive mercury in a bath. The respective precisely weighted mercury aliquots to be injected into the cells are prepared by pouring approximately 130 g of radioactive mercury taken from the bath into 13 standard vials, in accordance with the number of the cells tested. Four standard references prepared by further dilution of ±2 g active mercury taken from the bath to obtain the dilution factors range of 12,000 to 20,000 from which the calibration graph is constructed. The injection process is conducting by pouring the radioactive mercury from aliquots into the flowing mercury at the inlet side of the cell and allows them to mix thoroughly. It is assumed that the mass of the radiotracer injected into a closed system remains constant, at least during the period of the test. From this experiment it was observed that the mixing time is two days after injection of radioactive mercury. The inactive mercury in each electrolytic cell calculated by the radiotracer method is of the range 1351.529 kg to 1966.354 kg with maximum error (95% confidence) is 1.52 %. The accuracy of measurement of the present method is better than gravimetric one which accounts 4 % of error on average.

  17. Formation of oxygen related donors in step-annealed CZ–silicon

    Indian Academy of Sciences (India)

    The effect of step-annealing necessitated by the difficulties being faced in the long duration annealing treatments to be given to CZ–silicon has been studied. One pre-anneal of 10 h followed by annealing of 10 h causes a decrease in the absorption coefficient for carbon (c). Oxygen and carbon both accelerate thermal ...

  18. Rapid hardening induced by electric pulse annealing in nanostructured pure aluminum

    DEFF Research Database (Denmark)

    Zeng, Wei; Shen, Yao; Zhang, Ning

    2012-01-01

    Nanostructured pure aluminum was fabricated by heavy cold-rolling and then subjected to recovery annealing either by applying electric pulse annealing or by traditional air furnace annealing. Both annealing treatments resulted in an increase in yield strength due to the occurrence of a “dislocation...

  19. Solubilization of tea seed oil in a food-grade water-dilutable microemulsion.

    Directory of Open Access Journals (Sweden)

    Lingli Deng

    Full Text Available Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.. The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase ( 45% water along the dilution line.

  20. Effect of CO2 dilution on combustion and emissions characteristics of the hydrogen-enriched gasoline engine

    International Nuclear Information System (INIS)

    Wang, Shuofeng; Ji, Changwei; Zhang, Bo; Cong, Xiaoyu; Liu, Xiaolong

    2016-01-01

    CO 2 (Carbon dioxide) dilution is a feasible way for controlling NOx (Nitrogen oxides) emissions and loads of the internal combustion engines. This paper investigated the effect of CO 2 dilution on the combustion and emissions characteristics of a hydrogen-enriched gasoline engine. The experiment was conducted on a 1.6 L spark-ignition engine with electronically controlled hydrogen and gasoline injection systems. At two hydrogen volume fractions of 0 and 3%, the CO 2 volume fraction in the intake was gradually increased from 0 to 4%. The fuel-air mixtures were kept at the stoichiometric. The experimental results demonstrated that brake mean effective pressure of the gasoline engine was quickly reduced after adopting CO 2 dilution. Comparatively, Bmep (Brake mean effective pressure) of the 3% hydrogen-enriched engine was gently decreased with the increase of CO 2 dilution level. Thermal efficiency of the 3% hydrogen-enriched gasoline engine was raised under properly increased CO 2 dilution levels. However, thermal efficiency of the pure gasoline engine was generally dropped after the CO 2 dilution. The addition of hydrogen could shorten flame development and propagation durations under CO 2 diluent conditions for the gasoline engine. Increasing CO 2 fraction in the intake caused the dropped NOx and raised HC (Hydrocarbon) emissions. Increasing hydrogen fraction in the intake could effectively reduce HC emissions under CO 2 diluent conditions. - Highlights: • CO 2 dilution reduces cooling loss and NOx of H 2 -enriched gasoline engines. • H 2 -blended gasoline engine gains better efficiency after CO 2 dilution. • CoVimep of H 2 -blended gasoline engine is kept at low level after CO 2 addition. • CO 2 dilution has small effect on reducing Bmep of H 2 -blended gasoline engine.

  1. The dilution effect on the extinction of wall diffusion flame

    Directory of Open Access Journals (Sweden)

    Ghiti Nadjib

    2014-12-01

    Full Text Available The dynamic process of the interaction between a turbulent jet diffusion methane flame and a lateral wall was experimentally studied. The evolution of the flame temperature field with the Nitrogen dilution of the methane jet flame was examined. The interaction between the diffusion flame and the lateral wall was investigated for different distance between the wall and the central axes of the jet flame. The dilution is found to play the central role in the flame extinction process. The flame response as the lateral wall approaches from infinity and the increasing of the dilution rate make the flame extinction more rapid than the flame without dilution, when the nitrogen dilution rate increase the flame temperature decrease.

  2. Studies of core response in local boron dilution accidents

    International Nuclear Information System (INIS)

    Siltanen, P.; Antila, M.

    1995-01-01

    During the past few years major attention has been given to analyzing the possibilities and potential consequences of a slug of diluted water entering the core of the WWER-440 reactors in Loviisa. Suitable countermeasures have already been implemented to reduce the probability of external inhomogeneous dilution. Inhomogeneous dilution scenarios with their high reactivity disturbance potential were not included in the original safe analyses. The presentation concentrates on typical dilution scenarios. Results of potential consequences in the core are presented for three typical dilution scenarios for the hot reactor condition. The calculations have been performed using the 3-dimensional dynamic core model HEXTRAN coupled with the circuit model SMABRE. The principles of the new preventive automation recently implemented at Loviisa NPS are also described. (7 refs., 6 figs.)

  3. Kredsløbsmonitorering med lithium dilution cardiac output-systemet

    DEFF Research Database (Denmark)

    Christiansen, Christian; Hostrup, Anette; Tønnesen, Else

    2008-01-01

    The lithium dilution cardiac output (LiDCO) system measures cardiac output beat-to-beat with high precision. The system is based on an arterial pulse power analysis which is calibrated every eight hours with a small non-pharmacological dose of lithium. The system is minimally invasive; it require...... only a peripheral arterial catheter and a venous access. Dynamic parameters for early goal-directed therapy are also provided. Udgivelsesdato: 2008-Feb-11...

  4. Asymptotic Behavior of a Chemostat Model with Stochastic Perturbation on the Dilution Rate

    Directory of Open Access Journals (Sweden)

    Chaoqun Xu

    2013-01-01

    Full Text Available We present a stochastic simple chemostat model in which the dilution rate was influenced by white noise. The long time behavior of the system is studied. Mainly, we show how the solution spirals around the washout equilibrium and the positive equilibrium of deterministic system under different conditions. Furthermore, the sufficient conditions for persistence in the mean of the stochastic system and washout of the microorganism are obtained. Numerical simulations are carried out to support our results.

  5. SU-F-BRD-13: Quantum Annealing Applied to IMRT Beamlet Intensity Optimization

    International Nuclear Information System (INIS)

    Nazareth, D; Spaans, J

    2014-01-01

    Purpose: We report on the first application of quantum annealing (QA) to the process of beamlet intensity optimization for IMRT. QA is a new technology, which employs novel hardware and software techniques to address various discrete optimization problems in many fields. Methods: We apply the D-Wave Inc. proprietary hardware, which natively exploits quantum mechanical effects for improved optimization. The new QA algorithm, running on this hardware, is most similar to simulated annealing, but relies on natural processes to directly minimize the free energy of a system. A simple quantum system is slowly evolved into a classical system, representing the objective function. To apply QA to IMRT-type optimization, two prostate cases were considered. A reduced number of beamlets were employed, due to the current QA hardware limitation of ∼500 binary variables. The beamlet dose matrices were computed using CERR, and an objective function was defined based on typical clinical constraints, including dose-volume objectives. The objective function was discretized, and the QA method was compared to two standard optimization Methods: simulated annealing and Tabu search, run on a conventional computing cluster. Results: Based on several runs, the average final objective function value achieved by the QA was 16.9 for the first patient, compared with 10.0 for Tabu and 6.7 for the SA. For the second patient, the values were 70.7 for the QA, 120.0 for Tabu, and 22.9 for the SA. The QA algorithm required 27–38% of the time required by the other two methods. Conclusion: In terms of objective function value, the QA performance was similar to Tabu but less effective than the SA. However, its speed was 3–4 times faster than the other two methods. This initial experiment suggests that QA-based heuristics may offer significant speedup over conventional clinical optimization methods, as quantum annealing hardware scales to larger sizes

  6. The effect of annealing time in oxygen flux on the electric properties of the Ru(Sr{sub 2-x}Ca {sub x})GdCu{sub 2}O{sub 8{+-}}{sub z} system with 0.0 < x < 2.0, prepared at ambient pressure

    Energy Technology Data Exchange (ETDEWEB)

    Abatal, M. [IIM-UNAM, AP 70-360, 04510 Mexico D.F. (Mexico); Chavira, E. [IIM-UNAM, AP 70-360, 04510 Mexico D.F. (Mexico)]. E-mail: chavira@servidor.unam.mx; Filippini, C. [LEPES-CNRS, 25 Ave. des Martyrs, BP 166, 38048 Grenoble (France); Garcia-Vazquez, V. [IF-LRT, BUAP, AP J-48, 72570 Puebla, Pue. (Mexico); Perez, J.C. [IF-LRT, BUAP, AP J-48, 72570 Puebla, Pue. (Mexico); Tholence, J.L. [LEPES-CNRS, 25 Ave. des Martyrs, BP 166, 38048 Grenoble (France); Noel, H. [LCSIM, Ave. General Leclerc, 35042 Renne (France)

    2005-08-01

    A solid-state reaction method for synthesis of Ru(Sr{sub 2-x}Ca {sub x})GdCu{sub 2}O{sub 8{+-}}{sub z} system within the composition range of 0.0 < x < 2.0, at ambient pressure and within the range of 960-1070 deg, C is reported. The temperature interval for the preparation of the solid solution is determined by differential thermal analysis (DTA) in air. A solid solution is shown to exist up to x = 0.1, with a crystalline structure that is isomorphous to RuSr{sub 2}GdCu{sub 2}O{sub 8} (Ru-1212) compound observed by X-ray powder diffraction (XRD). The studies by the scanning electron microscopy (SEM) technique gives a particle size around 1-6 {mu}m. The results of transmission electron microscopy (TEM) studies confirm the tetragonal unit cell of Ru(Sr{sub 2-x}Ca {sub x})GdCu{sub 2}O{sub 8{+-}}{sub z} system. The temperature dependence of the electrical resistivity of the samples annealed in oxygen flux for 12 and 41 h, respectively at T = 960 deg, C shows a semiconductor behavior.

  7. Structure Formation in Semi-Dilute Polymer Solution during Electrospinning

    Science.gov (United States)

    Zussman, Eyal; Paley, Yakov; Arinstein, Arkadii; Shuster, Kim

    2012-02-01

    In our recent work it was shown that longitudinal stretching of electrospun highly entangled semi-dilute polymer solution caused by jet hydrodynamic forces, transforms the topological network to an almost fully-stretched state within less than 1 mm from the jet start (PRE, 2011). Further evolution of the polymer network is related to a disentanglement of polymer chains and transformation of the topological network structure. As was sown by Malkin et al., (Rheol. Acta, 2011) high deformation rate of a topological polymer network, results in reptations of macromolecules caused by uncompensated local forces, whereas Brownian motion effect is negligible. Based on this conclusion, we examine the disentanglement process, using a mechanical pulley-block system assembled from multiple pulleys suspended by elastic springs, and taut string connecting two blocks. Each pulley corresponds to a topological knot; the taut string corresponds to a reptated chain; the springs correspond to surrounded polymer chains; and the blocks correspond to local deformation force. It turned out that the system is sensitive to system parameters. The pulleys can approach each other and the string stops to move. Such a behavior corresponds to formation of bundle of knots of entangled chains. In other conditions, the string continuously moves while the pulleys did not approach each other which corresponds to disentanglement of polymer chains. These experiments clarify the disentanglement kinetics in rapid-deformed polymer system.

  8. Atomic retention and near infrared photoluminescence from PbSe nanocrystals fabricated by sequential ion implantation and electron beam annealing

    International Nuclear Information System (INIS)

    Carder, D.A.; Markwitz, A.; Reeves, R.J.; Kennedy, J.; Fang, F.

    2013-01-01

    Nanocrystals of PbSe have been fabricated in a silicon dioxide matrix by sequential low energy ion implantation followed by an electron beam annealing step. Transmission electron microscopy reveals PbSe nanocrystals with typical sizes between 3 and 10 nm in the sub-surface region. Rutherford Backscattering Spectrometry has been used to study the total atomic retention, as a function of implanted atoms, following annealing. Photoluminescence was observed in various samples, at 4 K, as a broad peak between 1.4 and 2.0 μm, with observation of a dependence of the peak wavelength on annealing temperature. Room temperature photoluminescence was observed for samples with a high retention of implanted atoms, demonstrating the importance of nanocrystal density for achieving ambient temperature emission in these systems

  9. Multilevel resistance in ZnO nanowire memristors enabled by hydrogen annealing treatment

    Directory of Open Access Journals (Sweden)

    Sunghun Lee

    2016-12-01

    Full Text Available In non-volatile memory technology, various attempts to overcome both technology and physical limits have led to development of neuromorphic devices like memristors. Moreover, multilevel resistance and the potential for enhanced memory capability has attracted much attention. Here, we report memristive characteristics and multilevel resistance in a hydrogen annealed ZnO nanowire device. We find that the memristive behavior including negative differential resistance arises from trapped electrons in an amorphous ZnO interfacial layer at the injection electrode that is formed following hydrogen annealing. Furthermore, we demonstrate that it is possible to control electrons trapping and detrapping by the controlled application of voltage pulses to establish a multilevel memory. These results could pave the way for multifunctional memory device technology such as the artificial neuromorphic system.

  10. Registration of range data using a hybrid simulated annealing and iterative closest point algorithm

    Energy Technology Data Exchange (ETDEWEB)

    LUCK,JASON; LITTLE,CHARLES Q.; HOFF,WILLIAM

    2000-04-17

    The need to register data is abundant in applications such as: world modeling, part inspection and manufacturing, object recognition, pose estimation, robotic navigation, and reverse engineering. Registration occurs by aligning the regions that are common to multiple images. The largest difficulty in performing this registration is dealing with outliers and local minima while remaining efficient. A commonly used technique, iterative closest point, is efficient but is unable to deal with outliers or avoid local minima. Another commonly used optimization algorithm, simulated annealing, is effective at dealing with local minima but is very slow. Therefore, the algorithm developed in this paper is a hybrid algorithm that combines the speed of iterative closest point with the robustness of simulated annealing. Additionally, a robust error function is incorporated to deal with outliers. This algorithm is incorporated into a complete modeling system that inputs two sets of range data, registers the sets, and outputs a composite model.

  11. Ionic liquids behave as dilute electrolyte solutions

    Science.gov (United States)

    Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

    2013-01-01

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

  12. Note: Improving long-term stability of hot-wire anemometer sensors by means of annealing.

    Science.gov (United States)

    Lundström, H

    2015-08-01

    Annealing procedures for hot-wire sensors of platinum and platinum-plated tungsten have been investigated experimentally. It was discovered that the two investigated sensor metals behave quite differently during the annealing process, but for both types annealing may improve long-term stability considerably. Measured drift of sensors both without and with prior annealing is presented. Suggestions for suitable annealing temperatures and times are given.

  13. Results of Waste Transfer and Back-Dilution in Tanks 241-SY-101 and 241-SY-102

    Energy Technology Data Exchange (ETDEWEB)

    LA Mahoney; ZI Antoniak; WB Barton; JM Conner; NW Kirch; CW Stewart; BE Wells

    2000-07-26

    This report chronicles the process of remediation of the flammable gas hazard in Tank 241-SY-101 (SY-101) by waste transfer and back-dilution from December 18, 1999 through April 2, 2000. A brief history is given of the development of the flammable gas retention and release hazard in this tank, and the transfer and dilution systems are outlined. A detailed narrative of each of the three transfer and dilution campaigns is given to provide structure for the balance of the report. Details of the behavior of specific data are then described, including the effect of transfer and dilution on the waste levels in Tanks SY-101 and SY-102, data from strain gauges on equipment suspended from the tank dome, changes in waste configuration as inferred from neutron and gamma logs, headspace gas concentrations, waste temperatures, and the mixerpump operating performance. Operating data and performance of the transfer pump in SY-101 are also discussed.

  14. Results of Waste Transfer and Back-Dilution in Tanks 241-SY-101 and 241-SY-102

    International Nuclear Information System (INIS)

    Mahoney, L.A.; Antoniak, Z.I.; Barton, W.B.; Conner, J.M.; Kirch, N.W.; Stewart, C.W.; Wells, B.E.

    2000-01-01

    This report chronicles the process of remediation of the flammable gas hazard in Tank 241-SY-101 (SY-101) by waste transfer and back-dilution from December 18, 1999 through April 2, 2000. A brief history is given of the development of the flammable gas retention and release hazard in this tank, and the transfer and dilution systems are outlined. A detailed narrative of each of the three transfer and dilution campaigns is given to provide structure for the balance of the report. Details of the behavior of specific data are then described, including the effect of transfer and dilution on the waste levels in Tanks SY-101 and SY-102, data from strain gauges on equipment suspended from the tank dome, changes in waste configuration as inferred from neutron and gamma logs, headspace gas concentrations, waste temperatures, and the mixerpump operating performance. Operating data and performance of the transfer pump in SY-101 are also discussed

  15. Dewetting of Epitaxial Silver Film on Silicon by Thermal Annealing

    Science.gov (United States)

    Sanders, Charlotte E.; Kellogg, Gary L.; Shih, C.-K.

    2013-03-01

    It has been shown that noble metals can grow epitaxially on semiconducting and insulating substrates, despite being a non-wetting system: low temperature deposition followed by room temperature annealing leads to atomically flat film morphology. However, the resulting metastable films are vulnerable to dewetting, which has limited their utility for applications under ambient conditions. The physics of this dewetting is of great interest but little explored. We report on an investigation of the dewetting of epitaxial Ag(111) films on Si(111) and (100). Low energy electron microscopy (LEEM) shows intriguing evolution in film morphology and crystallinity, even at temperatures below 100oC. On the basis of these findings, we can begin to draw compelling inferences about film-substrate interaction and the kinetics of dewetting. Financial support is from NSF, DGE-0549417 and DMR-0906025. This work was performed, in part, at the Center for Integrated Nanotechnologies, User Facility operated for the U.S. DOE Office of Science. Sandia National Lab is managed and operated by Sandia Corp., a subsidiary of Lockheed Martin Corp., for the U.S. DOE's National Nuclear Security Administration under DE-AC04-94AL85000.

  16. Finding a Hadamard matrix by simulated annealing of spin vectors

    Science.gov (United States)

    Bayu Suksmono, Andriyan

    2017-05-01

    Reformulation of a combinatorial problem into optimization of a statistical-mechanics system enables finding a better solution using heuristics derived from a physical process, such as by the simulated annealing (SA). In this paper, we present a Hadamard matrix (H-matrix) searching method based on the SA on an Ising model. By equivalence, an H-matrix can be converted into a seminormalized Hadamard (SH) matrix, whose first column is unit vector and the rest ones are vectors with equal number of -1 and +1 called SH-vectors. We define SH spin vectors as representation of the SH vectors, which play a similar role as the spins on Ising model. The topology of the lattice is generalized into a graph, whose edges represent orthogonality relationship among the SH spin vectors. Starting from a randomly generated quasi H-matrix Q, which is a matrix similar to the SH-matrix without imposing orthogonality, we perform the SA. The transitions of Q are conducted by random exchange of {+, -} spin-pair within the SH-spin vectors that follow the Metropolis update rule. Upon transition toward zeroth energy, the Q-matrix is evolved following a Markov chain toward an orthogonal matrix, at which the H-matrix is said to be found. We demonstrate the capability of the proposed method to find some low-order H-matrices, including the ones that cannot trivially be constructed by the Sylvester method.

  17. Concurrent laser welding and annealing exploiting robotically manipulated optical fibers

    Science.gov (United States)

    Abdullah, Hussein A.; Siddiqui, Rafiq A.

    2002-12-01

    Present investigation reports on the effects of incorporating pre- and post-heating on the mechanical properties of laser-welded joints, in normal air condition. Two common types of steels, i.e. mild steel, and stainless steel were welded with Lumonic's MS 830 Nd 3+:YAG laser machine, with an output capacity of 400 W. Due to the low integrated energy input required for laser welded joints, the welded region are often cooled too rapidly via conduction to the surrounding material and atmosphere, which leads to hardness discontinuities in the fusion and heat affected zone. The effects of in-process laser annealing on the mechanical properties and microstructure of laser-welded joints are important in any manufacturing operation. To improve the poor weld characteristics, this work investigates the use of automated dual-beam delivery system to implement a pre- or post-heating technique, simultaneously with the welding process. The results show that proper selection of the control parameters for the pre- or post-heating can reduce the hardness of the weld significantly and improve the welded joints mechanical properties, such as higher tensile strength and better durability.

  18. Liquid nitrogen enhancement of partially annealed fission tracks in glass

    International Nuclear Information System (INIS)

    Pilione, L.J.; Gold, D.P.

    1976-01-01

    It is known that the number density of fission tracks in solids is reduced if the sample is heated before chemical etching, and the effect of annealing must be allowed for before an age can be assigned to the sample. The extent of annealing can be determined by measuring the reduction of track parameters (diameter and/or length) and comparison with unannealed tracks. Correct ages can be obtained by careful calibration studies of track density reduction against track diameter or length reduction at different annealing temperatures and times. For crystallised minerals, however, the resulting correction techniques are not generally valid. In the experimental work described glass samples were partially annealed and then immersed in liquid N 2 for various periods, and it was shown that the properties of the glass and the track parameters could be altered so as to observe tracks that would normally be erased by annealing. The results of track density measurements against liquid N 2 immersion times are shown graphically. A gain of about 40% was achieved after 760 hours immersion time. The size of the tracks was not noticeably affected by the immersion. It was thought that thermal shock might be the cause of the track enhancement, but it was found that repeated immersion for about 2 hours did not lead to an increase in track density. Other studies suggest that the mechanism that erases the tracks through annealing may be partially reversed when the temperature of the sample is significantly lowered for a sufficient length of time. Further work is under way to find whether or not the process of enhancement is a reversal of the annealing process. Similar enhancement effects using liquid N 2 have been observed for d-particle tracks in polycarbonate detectors. (U.K.)

  19. Effective potential study of the Diluted Antiferromagnet in a Field

    Science.gov (United States)

    Yllanes, David; Fernandez, L. A.; Martin-Mayor, V.

    2011-03-01

    We present a numerical study of the three-dimensional Diluted Antiferromagnet in a Field (DAFF), one of the experimental realizations of the Random Field Ising Model. We work in a constrained ensemble (tethered ensemble) where the Helmholtz effective potential is featured, rather than the free energy. Our method cures the problem of a strong violation of self-averaging, thus allowing us to compute the correlation length for systems sizes up to L = 32 . This quantity, when measured in units of the lattice size, is independent of the system size at the critical point, a strong indication of a second-order phase transition. This scale invariance allows us to apply finite-size scaling in the form of Nightingale's phenomenological renormalization. We obtain accurate estimates of the critical exponents. Since our method reconstructs the effective potential, we can also compute accurately the hyperscaling violation exponent. We perform as well an investigation of the geometrical properties of the instanton-like configurations, namely, the minimal cost configurations joining the two ordered phases. This study sheds light on previous claims of a first-order phase transition in this system.

  20. Weighted Geometric Dilution of Precision Calculations with Matrix Multiplication

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2015-01-01

    Full Text Available To enhance the performance of location estimation in wireless positioning systems, the geometric dilution of precision (GDOP is widely used as a criterion for selecting measurement units. Since GDOP represents the geometric effect on the relationship between measurement error and positioning determination error, the smallest GDOP of the measurement unit subset is usually chosen for positioning. The conventional GDOP calculation using matrix inversion method requires many operations. Because more and more measurement units can be chosen nowadays, an efficient calculation should be designed to decrease the complexity. Since the performance of each measurement unit is different, the weighted GDOP (WGDOP, instead of GDOP, is used to select the measurement units to improve the accuracy of location. To calculate WGDOP effectively and efficiently, the closed-form solution for WGDOP calculation is proposed when more than four measurements are available. In this paper, an efficient WGDOP calculation method applying matrix multiplication that is easy for hardware implementation is proposed. In addition, the proposed method can be used when more than exactly four measurements are available. Even when using all-in-view method for positioning, the proposed method still can reduce the computational overhead. The proposed WGDOP methods with less computation are compatible with global positioning system (GPS, wireless sensor networks (WSN and cellular communication systems.

  1. Weighted geometric dilution of precision calculations with matrix multiplication.

    Science.gov (United States)

    Chen, Chien-Sheng

    2015-01-05

    To enhance the performance of location estimation in wireless positioning systems, the geometric dilution of precision (GDOP) is widely used as a criterion for selecting measurement units. Since GDOP represents the geometric effect on the relationship between measurement error and positioning determination error, the smallest GDOP of the measurement unit subset is usually chosen for positioning. The conventional GDOP calculation using matrix inversion method requires many operations. Because more and more measurement units can be chosen nowadays, an efficient calculation should be designed to decrease the complexity. Since the performance of each measurement unit is different, the weighted GDOP (WGDOP), instead of GDOP, is used to select the measurement units to improve the accuracy of location. To calculate WGDOP effectively and efficiently, the closed-form solution for WGDOP calculation is proposed when more than four measurements are available. In this paper, an efficient WGDOP calculation method applying matrix multiplication that is easy for hardware implementation is proposed. In addition, the proposed method can be used when more than exactly four measurements are available. Even when using all-in-view method for positioning, the proposed method still can reduce the computational overhead. The proposed WGDOP methods with less computation are compatible with global positioning system (GPS), wireless sensor networks (WSN) and cellular communication systems.

  2. Specific heat in diluted magnetic semiconductor quantum ring

    Science.gov (United States)

    Babanlı, A. M.; Ibragimov, B. G.

    2017-11-01

    In the present paper, we have calculated the specific heat and magnetization of a quantum ring of a diluted magnetic semiconductor (DMS) material in the presence of magnetic field. We take into account the effect of Rashba spin-orbital interaction, the exchange interaction and the Zeeman term on the specific heat. We have calculated the energy spectrum of the electrons in diluted magnetic semiconductor quantum ring. Moreover we have calculated the specific heat dependency on the magnetic field and Mn concentration at finite temperature of a diluted magnetic semiconductor quantum ring.

  3. Automated isotope dilution liquid chromatography-tandem mass spectrometry with on-line dilution and solid phase extraction for the measurement of cortisol in human serum sample.

    Science.gov (United States)

    Kawaguchi, Migaku; Eyama, Sakae; Takatsu, Akiko

    2014-08-05

    A candidate reference measurement procedure involving automated isotope dilution coupled with liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) with on-line dilution and solid phase extraction (SPE) has been developed and critically evaluated. We constructed the LC-MS/MS with on-line dilution and SPE system. An isotopically labelled internal standard, cortisol-d4, was added to serum sample. After equilibration, the methanol was added to the sample, and deproteination was performed. Then, the sample was applied to the LC-MS/MS system. The limit of detection (LOD) and limit of quantification (LOQ) were 0.2 and 1ngg(-1), respectively. Excellent precision was obtained with within-day variation (RSD) of 1.9% for ID-LC-MS/MS analysis (n=6). This method, which demonstrates simple, easy, good accuracy, high precision, and is free from interferences from structural analogues, qualifies as a reference measurement procedure. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. High pressure annealing of Europium implanted GaN

    KAUST Repository

    Lorenz, K.

    2012-02-09

    GaN epilayers were implanted with Eu to fluences of 1×10^13 Eu/cm2 and 1×10^15 Eu/cm2. Post-implant thermal annealing was performed in ultra-high nitrogen pressures at temperatures up to 1450 ºC. For the lower fluence effective structural recovery of the crystal was observed for annealing at 1000 ºC while optical activation could be further improved at higher annealing temperatures. The higher fluence samples also reveal good optical activation; however, some residual implantation damage remains even for annealing at 1450 ºC which leads to a reduced incorporation of Eu on substitutional sites, a broadening of the Eu luminescence lines and to a strongly reduced fraction of optically active Eu ions. Possibilities for further optimization of implantation and annealing conditions are discussed.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  5. Experimental quantum annealing: case study involving the graph isomorphism problem

    Science.gov (United States)

    Zick, Kenneth M.; Shehab, Omar; French, Matthew

    2015-01-01

    Quantum annealing is a proposed combinatorial optimization technique meant to exploit quantum mechanical effects such as tunneling and entanglement. Real-world quantum annealing-based solvers require a combination of annealing and classical pre- and post-processing; at this early stage, little is known about how to partition and optimize the processing. This article presents an experimental case study of quantum annealing and some of the factors involved in real-world solvers, using a 504-qubit D-Wave Two machine and the graph isomorphism problem. To illustrate the role of classical pre-processing, a compact Hamiltonian is presented that enables a reduced Ising model for each problem instance. On random N-vertex graphs, the median number of variables is reduced from N2 to fewer than N log2 N and solvable graph sizes increase from N = 5 to N = 13. Additionally, error correction via classical post-processing majority voting is evaluated. While the solution times are not competitive with classical approaches to graph isomorphism, the enhanced solver ultimately classified correctly every problem that was mapped to the processor and demonstrated clear advantages over the baseline approach. The results shed some light on the nature of real-world quantum annealing and the associated hybrid classical-quantum solvers. PMID:26053973

  6. Laser annealing heals radiation damage in avalanche photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jin Gyu [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); Anisimova, Elena; Higgins, Brendon L.; Bourgoin, Jean-Philippe [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Jennewein, Thomas [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada); Canadian Institute for Advanced Research, Quantum Information Science Program, Toronto, ON (Canada); Makarov, Vadim [University of Waterloo, Institute for Quantum Computing, Waterloo, ON (Canada); University of Waterloo, Department of Electrical and Computer Engineering, Waterloo, ON (Canada); University of Waterloo, Department of Physics and Astronomy, Waterloo, ON (Canada)

    2017-12-15

    Avalanche photodiodes (APDs) are a practical option for space-based quantum communications requiring single-photon detection. However, radiation damage to APDs significantly increases their dark count rates and thus reduces their useful lifetimes in orbit. We show that high-power laser annealing of irradiated APDs of three different models (Excelitas C30902SH, Excelitas SLiK, and Laser Components SAP500S2) heals the radiation damage and several APDs are restored to typical pre-radiation dark count rates. Of nine samples we test, six APDs were thermally annealed in a previous experiment as another solution to mitigate the radiation damage. Laser annealing reduces the dark count rates further in all samples with the maximum dark count rate reduction factor varying between 5.3 and 758 when operating at -80 C. This indicates that laser annealing is a more effective method than thermal annealing. The illumination power to reach these reduction factors ranges from 0.8 to 1.6 W. Other photon detection characteristics, such as photon detection efficiency, timing jitter, and afterpulsing probability, fluctuate but the overall performance of quantum communications should be largely unaffected by these variations. These results herald a promising method to extend the lifetime of a quantum satellite equipped with APDs. (orig.)

  7. On simulated annealing phase transitions in phylogeny reconstruction.

    Science.gov (United States)

    Strobl, Maximilian A R; Barker, Daniel

    2016-08-01

    Phylogeny reconstruction with global criteria is NP-complete or NP-hard, hence in general requires a heuristic search. We investigate the powerful, physically inspired, general-purpose heuristic simulated annealing, applied to phylogeny reconstruction. Simulated annealing mimics the physical process of annealing, where a liquid is gently cooled to form a crystal. During the search, periods of elevated specific heat occur, analogous to physical phase transitions. These simulated annealing phase transitions play a crucial role in the outcome of the search. Nevertheless, they have received comparably little attention, for phylogeny or other optimisation problems. We analyse simulated annealing phase transitions during searches for the optimal phylogenetic tree for 34 real-world multiple alignments. In the same way in which melting temperatures differ between materials, we observe distinct specific heat profiles for each input file. We propose this reflects differences in the search landscape and can serve as a measure for problem difficulty and for suitability of the algorithm's parameters. We discuss application in algorithmic optimisation and as a diagnostic to assess parameterisation before computationally costly, large phylogeny reconstructions are launched. Whilst the focus here lies on phylogeny reconstruction under maximum parsimony, it is plausible that our results are more widely applicable to optimisation procedures in science and industry. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Enhancing quantum annealing performance for the molecular similarity problem

    Science.gov (United States)

    Hernandez, Maritza; Aramon, Maliheh

    2017-05-01

    Quantum annealing is a promising technique which leverages quantum mechanics to solve hard optimization problems. Considerable progress has been made in the development of a physical quantum annealer, motivating the study of methods to enhance the efficiency of such a solver. In this work, we present a quantum annealing approach to measure similarity among molecular structures. Implementing real-world problems on a quantum annealer is challenging due to hardware limitations such as sparse connectivity, intrinsic control error, and limited precision. In order to overcome the limited connectivity, a problem must be reformulated using minor-embedding techniques. Using a real data set, we investigate the performance of a quantum annealer in solving the molecular similarity problem. We provide experimental evidence that common practices for embedding can be replaced by new alternatives which mitigate some of the hardware limitations and enhance its performance. Common practices for embedding include minimizing either the number of qubits or the chain length and determining the strength of ferromagnetic couplers empirically. We show that current criteria for selecting an embedding do not improve the hardware's performance for the molecular similarity problem. Furthermore, we use a theoretical approach to determine the strength of ferromagnetic couplers. Such an approach removes the computational burden of the current empirical approaches and also results in hardware solutions that can benefit from simple local classical improvement. Although our results are limited to the problems considered here, they can be generalized to guide future benchmarking studies.

  9. Efficient Embedding of Integer Programming Problems on Quantum Annealers

    Science.gov (United States)

    Venturelli, Davide; Trummer, Immanuel

    Quantum Annealers are being considered as a possible platform to solve challenging Integer Optimization Problems (IOP). Hard-coding an IOP as an Ising model onto an annealer is however no easy task due to the severe restrictions imposed mostly by the connectivity of the graph implemented by the hardware architecture, as it has widely discussed for the D-Wave machines. The current approaches employ graph minor embedding algorithms that require a significant overhead of resources (number of qubits, computing power) with respect to the number of logical variables in the IOP. This overhead is arguably the primary problems for practitioners of quantum annealing. We present a new method to deterministically embed an arbitrary IOP in a generic class of annealing chip layouts such that the asymptotic scaling beats all the current methods. It is shown on the latest D-Wave chips to allow programming of problems, relevant for database and space sciences, with approximately 5-10x more variables with respect to the published approaches. The method is efficient in the sense that a valid embedding can be computed at run-time in polynomial time. The discussed methods can inform the design of next-generation of quantum annealers.

  10. Reliability implications of defects in high temperature annealed Si/SiO2/Si structures

    International Nuclear Information System (INIS)

    Warren, W.L.; Fleetwood, D.M.; Shaneyfelt, M.R.; Winokur, P.S.; Devine, R.A.B.; Mathiot, D.; Wilson, I.H.; Xu, J.B.

    1994-01-01

    High-temperature post-oxidation annealing of poly-Si/SiO 2 /Si structures such as metal-oxide-semiconductor capacitors and metal-oxide-semiconductor field effect transistors is known to result in enhanced radiation sensitivity, increased 1/f noise, and low field breakdown. The authors have studied the origins of these effects from a spectroscopic standpoint using electron paramagnetic resonance (EPR) and atomic force microscopy. One result of high temperature annealing is the generation of three types of paramagnetic defect centers, two of which are associated with the oxide close to the Si/SiO 2 interface (oxygen-vacancy centers) and the third with the bulk Si substrate (oxygen-related donors). In all three cases, the origin of the defects may be attributed to out-diffusion of O from the SiO 2 network into the Si substrate with associated reduction of the oxide. The authors present a straightforward model for the interfacial region which assumes the driving force for O out-diffusion is the chemical potential difference of the O in the two phases (SiO 2 and the Si substrate). Experimental evidence is provided to show that enhanced hole trapping and interface-trap and border-trap generation in irradiated high-temperature annealed Si/SiO 2 /Si systems are all related either directly, or indirectly, to the presence of oxygen vacancies

  11. The Effect of Annealing on Nanothick Indium Tin Oxide Transparent Conductive Films for Touch Sensors

    Directory of Open Access Journals (Sweden)

    Shih-Hao Chan

    2015-01-01

    Full Text Available This study aims to discuss the sheet resistance of ultrathin indium tin oxide (ITO transparent conductive films during the postannealing treatment. The thickness of the ultrathin ITO films is 20 nm. They are prepared on B270 glass substrates at room temperature by a direct-current pulsed magnetron sputtering system. Ultrathin ITO films with high sheet resistance are commonly used for touch panel applications. As the annealing temperature is increased, the structure of the ultrathin ITO film changes from amorphous to polycrystalline. The crystalline of ultrathin ITO films becomes stronger with an increase of annealing temperature, which further leads to the effect of enhanced Hall mobility. A postannealing treatment in an atmosphere can enhance the optical transmittance owing to the filling of oxygen vacancies, but the sheet resistance rises sharply. However, a higher annealing temperature, above 250°C, results in a decrease in the sheet resistance of ultrathin ITO films, because more Sn ions become an effective dopant. An optimum sheet resistance of 336 Ω/sqr was obtained for ultrathin ITO films at 400°C with an average optical transmittance of 86.8% for touch sensor applications.

  12. Exponentially Biased Ground-State Sampling of Quantum Annealing Machines with Transverse-Field Driving Hamiltonians.

    Science.gov (United States)

    Mandrà, Salvatore; Zhu, Zheng; Katzgraber, Helmut G

    2017-02-17

    We study the performance of the D-Wave 2X quantum annealing machine on systems with well-controlled ground-state degeneracy. While obtaining the ground state of a spin-glass benchmark instance represents a difficult task, the gold standard for any optimization algorithm or machine is to sample all solutions that minimize the Hamiltonian with more or less equal probability. Our results show that while naive transverse-field quantum annealing on the D-Wave 2X device can find the ground-state energy of the problems, it is not well suited in identifying all degenerate ground-state configurations associated with a particular instance. Even worse, some states are exponentially suppressed, in agreement with previous studies on toy model problems [New J. Phys. 11, 073021 (2009)NJOPFM1367-263010.1088/1367-2630/11/7/073021]. These results suggest that more complex driving Hamiltonians are needed in future quantum annealing machines to ensure a fair sampling of the ground-state manifold.

  13. Thermal Annealing Reduces Geminate Recombination in TQ1:N2200 All-Polymer Solar Cells

    KAUST Repository

    Karuthedath, Safakath

    2018-03-27

    A combination of steady-state and time-resolved spectroscopic measurements is used to investigate the photophysics of the all-polymer bulk heterojunction system TQ1:N2200. Upon thermal annealing a doubling of the external quantum efficiency and an improved fill factor (FF) is observed, resulting in an increase in the power conversion efficiency. Carrier extraction is similar for both blends, as demonstrated by time-resolved electric-field-induced second harmonic generation experiments in conjunction with transient photocurrent studies, spanning the ps-µs time range. Complementary transient absorption spectroscopy measurements reveal that the different quantum efficiencies originate from differences in charge carrier separation and recombination at the polymer-polymer interface: in as-spun samples ~35 % of the charges are bound in interfacial charge-transfer states and recombine geminately, while this pool is reduced to ~7 % in thermally-annealed sample, resulting in higher short-circuit currents. Time-delayed collection field experiments demonstrate a field-dependent charge generation process in as-spun samples, which reduces the FF. In contrast, field-dependence of charge generation is weak in annealed films. While both devices exhibit significant non-geminate recombination competing with charge extraction, causing low FFs, our results demonstrate that the donor/acceptor interface in all-polymer solar cells can be favourably altered to enhance charge separation, without compromising charge transport and extraction.

  14. Influence of thermal annealing on microstructural, morphological, optical properties and surface electronic structure of copper oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Department of Physics, Nigde University, 51240 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Akgul, Guvenc, E-mail: guvencakgul@gmail.com [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Yildirim, Nurcan [Department of Physics Engineering, Ankara University, 06100 Ankara (Turkey); Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Unalan, Husnu Emrah [Department of Metallurgical and Materials Engineering, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey); Turan, Rasit [Department of Physics, Middle East Technical University, 06800 Ankara (Turkey); Center for Solar Energy Research and Applications, Middle East Technical University, 06800 Ankara (Turkey)

    2014-10-15

    In this study, effect of the post-deposition thermal annealing on copper oxide thin films has been systemically investigated. The copper oxide thin films were chemically deposited on glass substrates by spin-coating. Samples were annealed in air at atmospheric pressure and at different temperatures ranging from 200 to 600°C. The microstructural, morphological, optical properties and surface electronic structure of the thin films have been studied by diagnostic techniques such as X-ray diffraction (XRD), Raman spectroscopy, ultraviolet–visible (UV–VIS) absorption spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The thickness of the films was about 520 nm. Crystallinity and grain size was found to improve with annealing temperature. The optical bandgap of the samples was found to be in between 1.93 and 2.08 eV. Cupric oxide (CuO), cuprous oxide (Cu{sub 2}O) and copper hydroxide (Cu(OH){sub 2}) phases were observed on the surface of as-deposited and 600 °C annealed thin films and relative concentrations of these three phases were found to depend on annealing temperature. A complete characterization reported herein allowed us to better understand the surface properties of copper oxide thin films which could then be used as active layers in optoelectronic devices such as solar cells and photodetectors. - Highlights: • Effect of post-deposition annealing on copper oxide thin films was investigated. • Structural, optical, and electronic properties of the thin films were determined. • Oxidation states of copper oxide thin films were confirmed by XPS analysis. • Mixed phases of CuO and Cu{sub 2}O were found to coexist in copper oxide thin films.

  15. Evolution of the surface plasmon resonance of Au:TiO{sub 2} nanocomposite thin films with annealing temperature

    Energy Technology Data Exchange (ETDEWEB)

    Borges, J., E-mail: joelborges@fisica.uminho.pt [Universidade do Minho, Centro/Departamento de Física (Portugal); Buljan, M.; Sancho-Parramon, J.; Bogdanovic-Radovic, I.; Siketic, Z. [Rudjer Boskovic Institute (Croatia); Scherer, T.; Kübel, C. [Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility - KNMF (Germany); Bernstorff, S. [Elettra-Sincrotrone Trieste (Italy); Cavaleiro, A. [University of Coimbra, SEG-CEMUC, Mechanical Engineering Department (Portugal); Vaz, F.; Rolo, A. G. [Universidade do Minho, Centro/Departamento de Física (Portugal)

    2014-12-15

    This paper reports on the changes in the structural and morphological features occurring in a particular type of nanocomposite thin-film system, composed of Au nanoparticles (NPs) dispersed in a host TiO{sub 2} dielectric matrix. The structural and morphological changes, promoted by in-vacuum annealing experiments of the as-deposited thin films at different temperatures (ranging from 200 to 800 °C), resulted in a well-known localized surface plasmon resonance (LSPR) phenomenon, which gave rise to a set of different optical responses that can be tailored for a wide number of applications, including those for optical-based sensors. The results show that the annealing experiments enabled a gradual increase of the mean grain size of the Au NPs (from 2 to 23 nm), and changes in their distributions and separations within the dielectric matrix. For higher annealing temperatures of the as-deposited films, a broad size distribution of Au NPs was found (sizes up to 100 nm). The structural conditions necessary to produce LSPR activity were found to occur for annealing experiments above 300 °C, which corresponded to the crystallization of the gold NPs, with an average size strongly dependent on the annealing temperature itself. The main factor for the promotion of LSPR was the growth of gold NPs and their redistribution throughout the host matrix. On the other hand, the host matrix started to crystallize at an annealing temperature of about 500 °C, which is an important parameter to explain the shift of the LSPR peak position to longer wavelengths, i.e. a red-shift.

  16. Solving a Higgs optimization problem with quantum annealing for machine learning

    Science.gov (United States)

    Mott, Alex; Job, Joshua; Vlimant, Jean-Roch; Lidar, Daniel; Spiropulu, Maria

    2017-10-01

    The discovery of Higgs-boson decays in a background of standard-model processes was assisted by machine learning methods. The classifiers used to separate signals such as these from background are trained using highly unerring but not completely perfect simulations of the physical processes involved, often resulting in incorrect labelling of background processes or signals (label noise) and systematic errors. Here we use quantum and classical annealing (probabilistic techniques for approximating the global maximum or minimum of a given function) to solve a Higgs-signal-versus-background machine learning optimization problem, mapped to a problem of finding the ground state of a corresponding Ising spin model. We build a set of weak classifiers based on the kinematic observables of the Higgs decay photons, which we then use to construct a strong classifier. This strong classifier is highly resilient against overtraining and against errors in the correlations of the physical observables in the training data. We show that the resulting quantum and classical annealing-based classifier systems perform comparably to the state-of-the-art machine learning methods that are currently used in particle physics. However, in contrast to these methods, the annealing-based classifiers are simple functions of directly interpretable experimental parameters with clear physical meaning. The annealer-trained classifiers use the excited states in the vicinity of the ground state and demonstrate some advantage over traditional machine learning methods for small training datasets. Given the relative simplicity of the algorithm and its robustness to error, this technique may find application in other areas of experimental particle physics, such as real-time decision making in event-selection problems and classification in neutrino physics.

  17. Solving a Higgs optimization problem with quantum annealing for machine learning.

    Science.gov (United States)

    Mott, Alex; Job, Joshua; Vlimant, Jean-Roch; Lidar, Daniel; Spiropulu, Maria

    2017-10-18

    The discovery of Higgs-boson decays in a background of standard-model processes was assisted by machine learning methods. The classifiers used to separate signals such as these from background are trained using highly unerring but not completely perfect simulations of the physical processes involved, often resulting in incorrect labelling of background processes or signals (label noise) and systematic errors. Here we use quantum and classical annealing (probabilistic techniques for approximating the global maximum or minimum of a given function) to solve a Higgs-signal-versus-background machine learning optimization problem, mapped to a problem of finding the ground state of a corresponding Ising spin model. We build a set of weak classifiers based on the kinematic observables of the Higgs decay photons, which we then use to construct a strong classifier. This strong classifier is highly resilient against overtraining and against errors in the correlations of the physical observables in the training data. We show that the resulting quantum and classical annealing-based classifier systems perform comparably to the state-of-the-art machine learning methods that are currently used in particle physics. However, in contrast to these methods, the annealing-based classifiers are simple functions of directly interpretable experimental parameters with clear physical meaning. The annealer-trained classifiers use the excited states in the vicinity of the ground state and demonstrate some advantage over traditional machine learning methods for small training datasets. Given the relative simplicity of the algorithm and its robustness to error, this technique may find application in other areas of experimental particle physics, such as real-time decision making in event-selection problems and classification in neutrino physics.

  18. A study on the annealing characteristics of BAF for cold rolled steel strip

    International Nuclear Information System (INIS)

    Kim, Soon Kyung; Kim, Moon Kyung; Jeon, Eon Chan

    1998-01-01

    The cold spot temperature control system for BAF (Batch Annealing Furnace) has been established in order to reduce energy consumption to improve productivity and to stabilize the properties of products. We improved material quality, increased output, and decreased the annealing cost and homogeneous distribution of cold spot temperature in BAF. The introduction of H 2 instead of N 2 as atmospheric gas, combined with high convection in BAF, has resulted in a considerable increase in furnace efficiency and material quality. By the low density, high diffusibility, and reducing character of H 2 , a better heat transfer resulting in uniform material temperature and improved coil surface can be achieved. The results in this study are as follows; Heating time is reduced to one half by increasing the inflow rate of atmospheric gas and changing of atmospheric gas component from HNx(H 2 : 5%, N 2 : 95%) to Ax(H 2 : 75%, N 2 : 25%) gas. The annealing cycle time is also reduced to 2.7 times. In the case of HNx BAF the cold spot moved to the center after 32 hours of heating, while in the case of H 2 BAF it moved from the one-third position of the B coil inside to the center just after 12 hours of heating, resulting from a heat transfer increase to the radius direction. The temperature in this part is higher than any other parts when cooling. Soaking time at batch annealing cycle is decided by input coil width, and the time for quality homogenization of 1219 mm width coil must be longer by 2.0 hours than that of 914 mm width coil with the same coil weight at H 2 BAF, however, it is necessary to make 2.5 hours longer at HNx BAF

  19. Ab-initio calculations for dilute magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Belhadji, Brahim

    2008-03-03

    This thesis focusses on ab-initio calculations for the electronic structure and the magnetic properties of dilute magnetic semiconductors (DMS). In particular we aim at the understanding of the complex exchange interactions in these systems. Our calculations are based on density functional theory, being ideally suited for a description of the material specific properties of the considered DMS. Moreover we use the KKR Green function method in connection with the coherent potential approximation (CPA), which allows to include the random substitutional disorder in a mean field-like approximation for the electronic structure. Finally we calculate the exchange coupling constants J{sub ij} between two impurities in a CPA medium by using the Lichtenstein formula and from this calculate the Curie temperature by a numerically exact Monte Carlo method. Based on this analysis we found and investigated four different exchange mechanisms being of importance in DMS systems: Double exchange, p-d exchange, antiferromagnetic superexchanges, and ferromagnetic superexchange. A second topic we have investigated in this thesis is the pressure dependence of the exchange interactions and the Curie temperatures in (Ga,Mn)As and (In,Mn)As, using the LDA and the LDA+U approximations. Exact calculations of T{sub C} by Monte Carlo simulations show a somehow different behavior. (orig.)

  20. A Cold Cycle Dilution Refrigerator for Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The cold cycle dilution refrigerator is a continuous refrigerator capable of cooling to temperatures below 100 mK that makes use of a novel thermal magnetic pump....

  1. Heterogeneous and homogeneous nanoscale precipitation in dilute Cu-Co alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, A.L. [Department of Materials Science and Metallurgy, PUC-Rio, Rio de Janeiro (Brazil)], E-mail: anarocha@dcmm.puc-rio.br; Solorzano, I.G. [Department of Materials Science and Metallurgy, PUC-Rio, Rio de Janeiro (Brazil); Vander Sande, J.B. [Department of Materials Science and Engineering, MIT, Cambridge (United States)

    2007-09-15

    The precipitation behavior of dilute Cu-Co alloys under isothermal annealing has been investigated by means of transmission electron microscopy. The observations show that different mechanisms occur in the coherent and incoherent precipitation stages. Coherent homogeneous Co particles of about 15 nm in size are consistently observed from the early stages of precipitation. The coexistence of coherent nanoscale spherical precipitates together with incoherent microscale precipitates is observed at higher temperatures, above 600 deg. C, with the latter forming well-developed and faceted Co-rich crystals. In the heterogeneous decomposition mode, the development of discontinuous precipitation colonies consisting of regularly-spaced rod-like Co particles is observed. Upon further growth, these rods break down into chains of spherical particles which are thought to be formed as a consequence of Rayleigh instability. In addition, depending on the thermal conditions, the generation of domains on the order of 100 nm is observed within the matrix, which is constituted of large grains with average size of 100 {mu}m.

  2. Heterogeneous and homogeneous nanoscale precipitation in dilute Cu-Co alloys

    International Nuclear Information System (INIS)

    Rocha, A.L.; Solorzano, I.G.; Vander Sande, J.B.

    2007-01-01

    The precipitation behavior of dilute Cu-Co alloys under isothermal annealing has been investigated by means of transmission electron microscopy. The observations show that different mechanisms occur in the coherent and incoherent precipitation stages. Coherent homogeneous Co particles of about 15 nm in size are consistently observed from the early stages of precipitation. The coexistence of coherent nanoscale spherical precipitates together with incoherent microscale precipitates is observed at higher temperatures, above 600 deg. C, with the latter forming well-developed and faceted Co-rich crystals. In the heterogeneous decomposition mode, the development of discontinuous precipitation colonies consisting of regularly-spaced rod-like Co particles is observed. Upon further growth, these rods break down into chains of spherical particles which are thought to be formed as a consequence of Rayleigh instability. In addition, depending on the thermal conditions, the generation of domains on the order of 100 nm is observed within the matrix, which is constituted of large grains with average size of 100 μm

  3. Formability of Annealed Ni-Ti Shape Memory Alloy Sheet

    Science.gov (United States)

    Fann, K. J.; Su, J. Y.; Chang, C. H.

    2018-03-01

    Ni-Ti shape memory alloy has two specific properties, superelasiticity and shape memory effect, and thus is widely applied in diverse industries. To extend its application, this study attempts to investigate the strength and cold formability of its sheet blank, which is annealed at various temperatures, by hardness test and by Erichsen-like cupping test. As a result, the higher the annealing temperature, the lower the hardness, the lower the maximum punch load as the sheet blank fractured, and the lower the Erichsen-like index or the lower the formability. In general, the Ni-Ti sheet after annealing has an Erichsen-like index between 8 mm and 9 mm. This study has also confirmed via DSC that the Ni-Ti shape memory alloy possesses the austenitic phase and shows the superelasticity at room temperature.

  4. NRC assessment of the Department of Energy annealing demonstration project

    International Nuclear Information System (INIS)

    Jackson, D.A.; Malik, S.N.

    1997-01-01

    Thermal annealing is the only known method for mitigating the effects of neutron irradiation embrittlement in reactor pressure vessel (RPV) steels. In May 1996, the US Department of Energy (DOE) in conjunction with the American Society of Mechanical Engineers, Westinghouse, Cooperheat, Electric Power Research Institute (with participating utilities), Westinghouse Owner's Group, Consumers Power, Electricite' de France, Duquesne Light and the Central Research Institute of the Electric Power Industry (Japan) sponsored an annealing demonstration project (ADP) at Marble Hill. The Marble Hill Plant, located in Madison, Indiana, is a Westinghouse 4 loop design. The plant was nearly 70% completed when the project was canceled. Hence, the RPV was never irradiated. The paper will present highlights from the NRCs independent evaluation of the Marble Hill Annealing Demonstration Project

  5. Morphology and annealing kinetics of ion tracks in minerals

    Directory of Open Access Journals (Sweden)

    Ewing R. C.

    2012-10-01

    Full Text Available We have studied the morphology and annealing kinetics of ion tracks in Durango apatite using synchrotron small angle X-ray scattering. The non-destructive, artefact-free technique enables us to determine the track radii with a resolution of fractions of a nanometre. The tracks were generated using different heavy ions with energies between 185 MeV and 2.6 GeV. The track morphology is consistent with the formation of long cylindrical amorphous tracks. The annealing kinetics, measured by SAXS in combination with ex situ and in situ annealing experiments, suggests structural relaxation followed by recrystallisation of the damaged material. The measurement methodology shown here provides a new means for in-depth studies of ion-track formation in minerals under a wide variety of geological conditions.

  6. Molecular dynamics simulation of annealed ZnO surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Min, Tjun Kit; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technology, Multimedia University, Melaka Campus, 75450 Melaka (Malaysia)

    2015-04-24

    The effect of thermally annealing a slab of wurtzite ZnO, terminated by two surfaces, (0001) (which is oxygen-terminated) and (0001{sup ¯}) (which is Zn-terminated), is investigated via molecular dynamics simulation by using reactive force field (ReaxFF). We found that upon heating beyond a threshold temperature of ∼700 K, surface oxygen atoms begin to sublimate from the (0001) surface. The ratio of oxygen leaving the surface at a given temperature increases as the heating temperature increases. A range of phenomena occurring at the atomic level on the (0001) surface has also been explored, such as formation of oxygen dimers on the surface and evolution of partial charge distribution in the slab during the annealing process. It was found that the partial charge distribution as a function of the depth from the surface undergoes a qualitative change when the annealing temperature is above the threshold temperature.

  7. Mean field annealing approach to large residual-statics estimation

    Science.gov (United States)

    Cary, Peter W.; Upham, Warren

    1993-12-01

    We present a new method for solving the large residual-statics problem, called mean field annealing, which may be capable of overcoming some of the limitations of stochastic methods. Mean field annealing is a global-search method that is governed by a purely deterministic set of equations. The mean field annealing method approaches global optimization problems in a fundamentally different way from stochastic global-search methods. The mean field approach never samples individual trial solutions in model space. Instead, the mean field equations, which are solved at successively lower temperatures with a fixed-point method, involve solving for the probability distributions of each variable rather than solving for the variables themselves. The probability distribution of each variable is resolved separately by replacing all other variables that occur in the energy function by their expectation values.

  8. Doped ZnO nanowires obtained by thermal annealing.

    Science.gov (United States)

    Shan, C X; Liu, Z; Wong, C C; Hark, S K

    2007-02-01

    Doped ZnO nanowires were prepared in a very simple and inexpensive thermal annealing method using ZnSe nanowires as a precursor. As doped, P doped, and As/P codoped ZnO nanowires were obtained in this method. X-ray diffraction shows that the zincblende ZnSe nanowires were converted to doped wurtzite ZnO nanowires. The incorporation of the dopants was confirmed by energy dispersive X-ray spectroscopy. The doping concentration could be adjusted by changing the annealing temperature and duration. Scanning electron microscopy indicated that the morphology of the ZnSe nanowires was essentially retained after the annealing and doping process. Photoluminescence spectroscopy also verified the incorporation of the dopants into the nanowires.

  9. Phase annealing for the conditional simulation of spatial random fields

    Science.gov (United States)

    Hörning, S.; Bárdossy, A.

    2018-03-01

    Simulated annealing (SA) is a popular geostatistical simulation method as it provides great flexibility. In this paper possible problems of conditioning its realizations are discussed. A statistical test to recognize whether the observations are well embedded in their simulated neighborhood or not is developed. A new simulated annealing method, phase annealing (PA), is presented which makes it possible to avoid poor embedding of observations. PA is based on the Fourier representation of the spatial field. Instead of the individual pixel values, phases corresponding to different Fourier components are modified (i.e. shifted) in order to match prescribed statistics. The method treats neighborhoods together and thus avoids singularities at observation locations. It is faster than SA and can be used for the simulation of high resolution fields. Examples demonstrate the applicability of the method.

  10. Toward understanding dynamic annealing processes in irradiated ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael Thomas [Texas A & M Univ., College Station, TX (United States)

    2013-05-01

    High energy particle irradiation inevitably generates defects in solids. The ballistic formation and thermalization of the defect creation process occur rapidly, and are believed to be reasonably well understood. However, knowledge of the evolution of defects after damage cascade thermalization, referred to as dynamic annealing, is quite limited. Unraveling the mechanisms associated with dynamic annealing is crucial since such processes play an important role in the formation of stable postirradiation disorder in ion-beam-processing of semiconductors, and determines the “radiation tolerance” of many nuclear materials. The purpose of this dissertation is to further our understanding of the processes involved in dynamic annealing. In order to achieve this, two main tasks are undertaken.

  11. Chaotic Multiquenching Annealing Applied to the Protein Folding Problem

    Directory of Open Access Journals (Sweden)

    Juan Frausto-Solis

    2014-01-01

    Full Text Available The Chaotic Multiquenching Annealing algorithm (CMQA is proposed. CMQA is a new algorithm, which is applied to protein folding problem (PFP. This algorithm is divided into three phases: (i multiquenching phase (MQP, (ii annealing phase (AP, and (iii dynamical equilibrium phase (DEP. MQP enforces several stages of quick quenching processes that include chaotic functions. The chaotic functions can increase the exploration potential of solutions space of PFP. AP phase implements a simulated annealing algorithm (SA with an exponential cooling function. MQP and AP are delimited by different ranges of temperatures; MQP is applied for a range of temperatures which goes from extremely high values to very high values; AP searches for solutions in a range of temperatures from high values to extremely low values. DEP phase finds the equilibrium in a dynamic way by applying least squares method. CMQA is tested with several instances of PFP.

  12. Reduction of Annealing Times for Energy Conservation in Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Anthony D. Rollett; Hasso Weiland; Mohammed Alvi; Abhijit Brahme

    2005-08-31

    Carnegie Mellon University was teamed with the Alcoa Technical Center with support from the US Dept. of Energy (Office of Industrial Technology) and the Pennsylvania Technology Investment Authority (PTIA) to make processing of aluminum less costly and more energy efficient. Researchers in the Department of Materials Science and Engineering have investigated how annealing processes in the early stages of aluminum processing affect the structure and properties of the material. Annealing at high temperatures consumes significant amounts of time and energy. By making detailed measurements of the crystallography and morphology of internal structural changes they have generated new information that will provide a scientific basis for shortening processing times and consuming less energy during annealing.

  13. Phase Formation in the System ZrO2–LaO1.5–MnOx in Air and PO2B1 Pa After 500 h of Annealing at 12001 and 14001 deg.C

    DEFF Research Database (Denmark)

    Chatzichristodoulou, Christodoulos; Chen, Ming; Bowen, Jacob R.

    2010-01-01

    The phase relation in the ZrO2–LaO1.5–MnOx system has been experimentally determined at 1200° and 1400°C in air and at 1200°C in N2 (∼100 Pa). Tie lines between LaMnO3 and t-ZrO2 and between LaMnO3 and La2Zr2O7 are observed at 1200°C in air. The geometry of the phase diagram changes at 1400°C in ...

  14. Microstructural characterization of intercritically annealed low alloy PM steels

    International Nuclear Information System (INIS)

    Gueral, A.; Tekeli, S.

    2007-01-01

    In this study, the applicability of intercritical annealing heat treatment, which is usually practiced to high strength low alloy ingot steels (HSLA), to low alloy powder metallurgy (PM) processed steels was investigated. With this heat treatment, it was intended to produce a dual-phase steel structure (ferrite + martensite) in PM steel. The effect of various amount of graphite addition on microstructure was also examined. For these purposes, atomized iron powder (Ancorsteel 1000) was mixed with 0.3 and 0.5 wt% graphite powder. The mixed powders were cold pressed at 700 MPa with single action and sintered at 1120 deg. C for 30 min under pure argon gas atmosphere. Some of the sintered specimens were directly annealed at intercritical heat treatment temperatures of 724, 735 and 760 deg. C and rapidly water quenched. Through these heat treatments, ferrite + martensite microstructure with coarse grain size were produced. The other sintered specimens were first austenitized at 890 deg. C for 12 min before intercritically annealing and then rapidly water quenched to produce fully martensitic structure. These specimens with fully martensitic microstructure were subsequently annealed at intercritical annealing temperatures of 724, 735 and 760 deg. C and rapidly water quenched. Ferrite + martensite microstructure with fine grain size was obtained by this route. The experimental results showed that martensite volume fraction increased with increasing intercritical annealing temperature as well as increasing graphite content. It is thought that mechanical properties of PM steels can be controlled by these heat treatments which are an alternative to traditional heat treatments of quenching + tempering applied usually to PM steels

  15. Anisotropy evolution of nanoparticles under annealing: Benefits of isothermal remanent magnetization simulation

    Science.gov (United States)

    Tournus, Florent; Tamion, Alexandre; Hillion, Arnaud; Dupuis, Véronique

    2016-12-01

    Isothermal remanent magnetization (IRM) combined with Direct current demagnetization (DcD) are powerful tools to qualitatively study the interactions (through the Δm parameter) between magnetic particles in a granular media. For magnetic nanoparticles diluted in a matrix, it is possible to reach a regime where Δm is equal to zero, i.e. where interparticle interactions are negligible: one can then infer the intrinsic properties of nanoparticles through measurements on an assembly, which are analyzed by a combined fit procedure (based on the Stoner-Wohlfarth and Néel models). Here we illustrate the benefits of a quantitative analysis of IRM curves, for Co nanoparticles embedded in amorphous carbon (before and after annealing): while a large anisotropy increase may have been deduced from the other measurements, IRM curves provide an improved characterization of the nanomagnets intrinsic properties, revealing that it is in fact not the case. This shows that IRM curves, which only probe the irreversible switching of nanomagnets, are complementary to widely used low field susceptibility curves.

  16. Anisotropy evolution of nanoparticles under annealing: Benefits of isothermal remanent magnetization simulation

    International Nuclear Information System (INIS)

    Tournus, Florent; Tamion, Alexandre; Hillion, Arnaud; Dupuis, Véronique

    2016-01-01

    Isothermal remanent magnetization (IRM) combined with Direct current demagnetization (DcD) are powerful tools to qualitatively study the interactions (through the Δm parameter) between magnetic particles in a granular media. For magnetic nanoparticles diluted in a matrix, it is possible to reach a regime where Δm is equal to zero, i.e. where interparticle interactions are negligible: one can then infer the intrinsic properties of nanoparticles through measurements on an assembly, which are analyzed by a combined fit procedure (based on the Stoner–Wohlfarth and Néel models). Here we illustrate the benefits of a quantitative analysis of IRM curves, for Co nanoparticles embedded in amorphous carbon (before and after annealing): while a large anisotropy increase may have been deduced from the other measurements, IRM curves provide an improved characterization of the nanomagnets intrinsic properties, revealing that it is in fact not the case. This shows that IRM curves, which only probe the irreversible switching of nanomagnets, are complementary to widely used low field susceptibility curves.

  17. Effects of dissolved species on radiolysis of diluted seawater

    International Nuclear Information System (INIS)

    Hata, Kuniki; Hanawa, Satoshi; Kasahara, Shigeki; Motooka, Takafumi; Tsukada, Takashi; Muroya, Yusa; Yamashita, Shinichi; Katsumura, Yosuke

    2014-01-01

    Fukushima Daiichi Nuclear Power Plants (NPPs) experienced seawater injection into the cores and fuel pools as an emergent measure after the accident. After the accident, retained water has been continuously desalinized, and subsequently the concentration of chloride ion (Cl - ) has been kept at a lower level these days. These ions in seawater are known to affect water radiolysis, which causes the production of radiolytic products, such as hydrogen peroxide (H 2 O 2 ), molecular hydrogen (H 2 ) and molecular oxygen (O 2 ). However, the effects of dissolved ions relating seawater on the production of the stable radiolytic products are not well understood in the diluted seawater. To understand of the production behavior in diluted seawater under radiation, radiolysis calculations were carried out. Production of H 2 is effectively suppressed by diluting by up to vol10%. The concentrations of oxidants (H 2 O 2 and O 2 ) are also suppressed by dilution of dissolved species. The effect of oxidants on corrosion of materials is thought to be low when the seawater was diluted by less than 1 vol% by water. It is also shown that deaeration is one of the effective measure to suppress the concentrations of oxidants at a lower level for any dilution conditions. (author)

  18. Modernization of two gas-fired shaft annealing furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Barthof, G.; Porst, G.; Raczek, S.

    1986-04-01

    The objective was to modernize two existing shaft-type annealing furnaces used for the heat treatment of grey iron castings with the aim of reducing the consumption of gaseous fuel, minimize the formation of scale, decrease maintenance expense and apply more automatic control to the annealing process. This was to be achieved by an optimum combination of new types of construction materials and advanced firing and control equipment. The author describes the furnace in its condition prior to and after reconstruction. The operating results obtained after reconstruction were found to justify the costs incurred. The payback period is roughly one year.

  19. Dependence of boron cluster dissolution on the annealing ambient

    International Nuclear Information System (INIS)

    Radic, Ljubo; Lilak, Aaron D.; Law, Mark E.

    2002-01-01

    Boron is introduced into silicon via implantation to form p-type layers. This process creates damage in the crystal that upon annealing causes enhanced diffusion and clustering of the boron layer. Reactivation of the boron is not a well-understood process. In this letter we experimentally investigate the effect of the annealing ambient on boron reactivation kinetics. An oxidizing ambient which injects silicon interstitials is compared to an inert ambient. Contrary to published theory, an excess of interstitials does not accelerate the reactivation process

  20. A theoretical comparison of evolutionary algorithms and simulated annealing

    Energy Technology Data Exchange (ETDEWEB)

    Hart, W.E.

    1995-08-28

    This paper theoretically compares the performance of simulated annealing and evolutionary algorithms. Our main result is that under mild conditions a wide variety of evolutionary algorithms can be shown to have greater performance than simulated annealing after a sufficiently large number of function evaluations. This class of EAs includes variants of evolutionary strategie and evolutionary programming, the canonical genetic algorithm, as well as a variety of genetic algorithms that have been applied to combinatorial optimization problems. The proof of this result is based on a performance analysis of a very general class of stochastic optimization algorithms, which has implications for the performance of a variety of other optimization algorithm.

  1. Increased electrical conductivity of peptides through annealing process

    Directory of Open Access Journals (Sweden)

    Seok Daniel Namgung

    2017-08-01

    Full Text Available Biocompatible biologically occurring polymer is suggested as a component of human implantable devices since conventional inorganic materials are apt to trigger inflammation and toxicity problem within human body. Peptides consisting of aromatic amino acid, tyrosine, are chosen, and enhancement on electrical conductivity is studied. Annealing process gives rise to the decrease on resistivity of the peptide films and the growth of the carrier concentration is a plausible reason for such a decrease on resistivity. The annealed peptides are further applied to an active layer of field effect transistor, in which low on/off current ratio (∼10 is obtained.

  2. Effect of annealing on field emission properties of nanodiamond coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, C.X., E-mail: zhaicatty@126.co [School of Information Science and Technology, Northwest University, Xi' an 710127, Shaanxi (China); Yun, J.N.; Zhao, L.L.; Zhang, Z.Y.; Wang, X.W.; Chen, Y.Y. [School of Information Science and Technology, Northwest University, Xi' an 710127, Shaanxi (China)

    2011-03-01

    Field electron emission of detonation nanodiamond (ND) coated on a titanium substrate by electrophoretic deposition is investigated. It is found that thermal annealing can significantly improve the field emission properties of the ND layer, which can be mainly attributed to the formation of the TiC phase between diamond and Ti. The first-principles calculated results show that the formation of transition layers can lower the interface barrier and enhance the field electron emission of ND coating. Besides, the transformation of diamond to graphite after annealing has been revealed by Raman spectra. This transformation also benefits the electron emission enhancement.

  3. Crystallographic refinement by simulated annealing: Application to crambin

    International Nuclear Information System (INIS)

    Bruenger, A.T.; Yale Univ., New Haven, CT; Harvard Univ., Cambridge, MA; Karplus, M.; Petsko, G.A.

    1989-01-01

    A detailed description of the method of crystallographic refinement by simulated annealing is presented. To test the method, it has been applied to a 1.5 A resolution X-ray structure of crambin. The dependence of the success of the simulated annealing protocol with respect to the temperature of the heating stage is discussed. Optimal success is achieved at relatively high temperatures. Regardless of the protocol used, the molecular-dynamics refined structure always yields an improved R factor compared with restrained least-squares refinement without manual re-fitting. The differences between the various refined structures and the corresponding electron density maps are discussed. (orig.)

  4. Structural, topographical and magnetic evolution of RF-sputtered Fe-Ni alloy based thin films with thermal annealing

    International Nuclear Information System (INIS)

    Lisha, R; Geetha, P; Anantharaman, M R; Hysen, T; Avasthi, D K; Ramanujan, R V

    2014-01-01

    Metglas 2826 MB having a nominal composition of Fe 40 Ni 38 Mo 4 B 18 is an excellent soft magnetic material and finds application in sensors and memory heads. However, the thin-film forms of Fe 40 Ni 38 Mo 4 B 18 are seldom studied, although they are important in micro-electro-mechanical systems/nano-electro-mechanical systems devices. The stoichiometry of the film plays a vital role in determining the structural and magnetic properties of Fe 40 Ni 38 Mo 4 B 18 thin films: retaining the composition in thin films is a challenge. Thin films of 52 nm thickness were fabricated by RF sputtering technique on silicon substrate from a target of nominal composition of Fe 40 Ni 38 Mo 4 B 18 . The films were annealed at temperatures of 400 °C and 600 °C. The micro-structural studies of films using glancing x-ray diffractometer (GXRD) and transmission electron microscope (TEM) revealed that pristine films are crystalline with (FeNiMo) 23 B 6 phase. Atomic force microscope (AFM) images were subjected to power spectral density analysis to understand the probable surface evolution mechanism during sputtering and annealing. X-ray photoelectron spectroscopy (XPS) was employed to determine the film composition. The sluggish growth of crystallites with annealing is attributed to the presence of molybdenum in the thin film. The observed changes in magnetic properties were correlated with annealing induced structural, compositional and morphological changes. (papers)

  5. Rapid thermal annealing effects on the microstructure and the thermoelectric properties of electrodeposited Bi{sub 2}Te{sub 3} film

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Mohammad Mamunur [School of Electrical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 680-749 (Korea, Republic of); Cho, Kyung Ho [Agency for Defense Development, Yuseong P.O. Box 35-42, Daejeon 305-600 (Korea, Republic of); Chung, Gwiy-Sang, E-mail: gschung@ulsan.ac.kr [School of Electrical Engineering, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 680-749 (Korea, Republic of)

    2013-08-15

    Bismuth telluride thermoelectric films were prepared by galvanostatic process from 1 M nitric acid solution containing 8 mM Bi{sup 3+} and 8 mM HTeO{sub 2}{sup +}. Both the n and p-type films were deposited. The thermoelectric properties of the films were measured before and after the rapid thermal annealing treatment to observe the annealing effects on the as-deposited film. Post annealing treatment was carried out under Ar environment at 200–300 °C for 2–10 min duration. Annealing effects on microstructure were examined from X-Ray diffraction (XRD) patterns and Scanning Electron Microscopy images. Electrical transport properties were analyzed by Hall Effect measurement system. The analysis revealed that the carrier density decreased and the carrier mobility increased with the enhancing of annealing temperature and duration. The Seebeck coefficient and power factor were improved significantly after rapid annealing treatment for both n and p-type Bi{sub 2}Te{sub 3} films. For n-type Bi{sub 2}Te{sub 3} film, the Seebeck coefficient improved about three-fold (from −57 to −169.49 μV/K) and the power factor improved around six-fold (from 2.74 to 17.37 μW/K{sup 2} cm) after annealing. On the other hand, for p-type Bi{sub 2}Te{sub 3} film the Seebeck coefficient enhanced around three-fold (from 28 to 112.3 μV/K) and the power factor enhanced around two-fold (from 2.57 to 4.43 μW/K{sup 2} cm) after annealing.

  6. Quantifying dilution and amplification in a community of hosts for tick-borne pathogens.

    Science.gov (United States)

    Levi, Taal; Keesing, Felicia; Holt, Robert D; Barfield, Michael; Ostfeld, Richard S

    2016-03-01

    Recent controversy over whether biodiversity reduces disease risk (dilution effect) has focused on the ecology of Lyme disease, a tick-borne zoonosis. A criticism of the dilution effect is that increasing host species richness might amplify disease risk, assuming that total host abundance, and therefore feeding opportunities for ticks, increase with species richness. In contrast, a dilution effect is expected when poor quality hosts for ticks and pathogens (dilution hosts) divert tick blood meals away from competent hosts. Even if host densities are additive, the relationship between host density and tick encounters can be nonlinear if the number of ticks that encounter a host is a saturating function of host density, which occurs if ticks aggregate on the remaining hosts rather than failing to find a host before death. Both dilution and amplification are theoretical possibilities, and assessing which is more prevalent required detailed analyses of empirical systems. We used field data to explore the degree of tick redistribution onto fewer individuals with variation in intraspecific host density and novel data-driven models for tick dynamics to determine how changes in vertebrate community composition influence the density of nymphs infected with the Lyme bacterium. To be conservative, we allowed total host density to increase additively with species richness. Our long-term field studies found that larval and nymphal ticks redistribute onto fewer individuals as host densities decline, that a large proportion of nymphs and adults find hosts, and that mice and chipmunks feed a large proportion of nymphs. White-footed mice, eastern chipmunks, short-tailed shrews, and masked shrews were important amplification hosts that greatly increased the density of infected nymphs. Gray squirrels and Virginia opossums were important dilution hosts. Removing these two species increased the maximum number of larvae attached to amplification hosts by 57%. Raccoons and birds were

  7. Interpretation of microstructure evolution during self-annealing and thermal annealing of nanocrystalline electrodeposits—A comparative study

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2010-01-01

    Electrodeposition results in a non-equilibrium state of the as-deposited nanocrystalline microstructure, which evolves towards an energetically more favorable state as a function of time and/or temperature upon deposition. Real-time investigation of the evolving microstructure in copper, silver......-annealing kinetics of copper and silver electrodeposits as well as the annealing kinetics of electrodeposited nickel. Similarities and characteristic differences of the kinetics and mechanisms of microstructure evolution in the various electrodeposits are discussed and the experimental results are attempted...... and nickel electrodeposits was achieved by time-resolved X-ray diffraction line profile analysis and crystallographic texture analysis during room temperature storage and during isothermal annealing at elevated temperatures. These in-situ studies with unique time resolution allowed quantification of the self...

  8. Influence of Al concentration and annealing temperature on structural, optical, and electrical properties of Al co-doped ZnO thin films

    International Nuclear Information System (INIS)

    Gürbüz, Osman; Kurt, İsmail; Çalışkan, Serkan; Güner, Sadık

    2015-01-01

    Highlights: • RF magnetron sputtering technique seems to be very efficient method for fabrication of Al doped ZnO (AZO) films. • Long range single crystalline structure improves with annealing process. • Optical properties became much better after annealing process especially for the AZO films that include high Al concentration. • Much greater conductivity with increasing Al concentration and annealing process. • AZO films have potential applicability in spintronic devices. - Abstract: The pure ZnO and Al-doped ZnO (AZO) thin films (thickness: 200 nm) were prepared on both side polished silica (SiO 2 ) substrates via RF magnetron sputtering at room temperature by using 2.5 inches high-purity ZnO (99.9%) and Al (99.9%) targets. The samples were annealed at 300 °C, 400 °C and 500 °C for 45 min in N 2 ambient in quartz annealing furnace system, respectively. We investigated the effects of various Al concentrations and annealing treatment on the structural, electrical, and optical properties of films. The preferred crystallization was observed along c axis (single (0 0 2) diffraction peak) from substrate surface assigning the single crystalline Würtzite lattice for pure ZnO and AZO thin films. Although increasing Al concentration decreases the order of crystallization of as-grown films, annealing process increases the long range crystal order. The crystallite sizes vary between minimum 12.98 nm and maximum 20.79 nm for as-grown and annealed samples. The crystallite sizes decrease with increasing Al concentration but increase with increasing annealing temperature as general trend. The grain size and porosity of films change with annealing treatment. The smaller grains coalesce together to form larger grains for many films. However, a reverse behavior is seen for Al 2.23 ZnO and Al 12.30 ZnO samples. That is, Al concentration plays critical role as well as temperature on grain size. Low percent optical transmittance (T%) is observed due to higher Al

  9. Generation of extended states in diluted transmission lines with distribution of inductances according to Galois sequences: Hamiltonian map approach

    International Nuclear Information System (INIS)

    Lazo, E.; Humire, F.R.; Saavedra, E.

    2014-01-01

    We study the localization properties of diluted direct transmission lines, when we distribute two values of inductances L A and L B , according to the aperiodic Galois sequence. When we dilute the aperiodic Galois system with (d−1) inductances with constant L 0 value, we find d sub-bands and (d−1) gaps; here d is the period of the distribution of the Galois sequence in the diluted system. Under the condition L 0 ≈(L A ,L B ), we find a set of extended states for finite N d system size, which disappears when N d →∞. For the case L 0 ⪢(L A ,L B ), using the scaling behavior of the averaged participation number 〈D(ω)〉 and the scaling behavior of the averaged normalized participation number 〈ξ(ω)〉, we demonstrate the existence of extended states in the thermodynamic limit

  10. Vibrations on pulse tube based Dry Dilution Refrigerators for low noise measurements

    Science.gov (United States)

    Olivieri, E.; Billard, J.; De Jesus, M.; Juillard, A.; Leder, A.

    2017-06-01

    Dry Dilution Refrigerators (DDR) based on pulse tube cryo-coolers have started to replace Wet Dilution Refrigerators (WDR) due to the ease and low cost of operation. However these advantages come at the cost of increased vibrations, induced by the pulse tube. In this work, we present the vibration measurements performed on three different commercial DDRs. We describe in detail the vibration measurement system we assembled, based on commercial accelerometers, conditioner and DAQ, and examined the effects of the various damping solutions utilized on three different DDRs, both in the low and high frequency regions. Finally, we ran low temperature, pseudo-massive (30 and 250 g) germanium bolometers in the best vibration-performing system under study and report on the results.

  11. Vibrations on pulse tube based Dry Dilution Refrigerators for low noise measurements

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, E. [CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, 91405 Orsay (France); Billard, J.; De Jesus, M.; Juillard, A. [Univ Lyon, Université Lyon 1, CNRS/IN2P3, IPN-Lyon, F-69622 Villeurbanne (France); Leder, A. [Massachussets Institute of Technology, Laboratory for Nuclear Science, 77 Massachusetts Avenue Cambridge, MA 02139-4307 (United States)

    2017-06-21

    Dry Dilution Refrigerators (DDR) based on pulse tube cryo-coolers have started to replace Wet Dilution Refrigerators (WDR) due to the ease and low cost of operation. However these advantages come at the cost of increased vibrations, induced by the pulse tube. In this work, we present the vibration measurements performed on three different commercial DDRs. We describe in detail the vibration measurement system we assembled, based on commercial accelerometers, conditioner and DAQ, and examined the effects of the various damping solutions utilized on three different DDRs, both in the low and high frequency regions. Finally, we ran low temperature, pseudo-massive (30 and 250 g) germanium bolometers in the best vibration-performing system under study and report on the results.

  12. Certification of mercury in acrylonitrile butadiene styrene by using isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Hu Hai; Ma Liandi; Wei Chao; Zhou Tao; Wang Jun; Zhao Motian; Li Jinying

    2008-01-01

    Under the framework of a co-certification system for the development of Certified Reference Materials (CRMs) among China, Japan and Korea, the 1st co-certification campaign of mercury in acrylonitrile butadiene styrene (ABS) for Japanese CRMs was taken. In this campaign isotope dilution mass spectrometry (IDMS) was used. First, all abundances of Hg in spike 202 Hg, CRM and ABS were analyzed by MC-ICP-MS before the certification. Then the concentrations of 202 Hg and Hg in ABS were determined with IDMS by Q-ICP-MS. A new procedure to reduce memory effect was used. first, dilute with 5 μg/g Au solution for 1 min; then, 5 μg/g EDTA solution for 2 min. The results accord to each other very well and this implies that the co-certification system can run swimmingly. (authors)

  13. Effect of Added Surfactants on the Dynamic Interfacial Tension Behaviour of Alkaline/Diluted Heavy Crude Oil System Effet de l’ajout de tensioactifs sur le comportement dynamique de la tension interfaciale du système solution alcaline/brut dilué

    Directory of Open Access Journals (Sweden)

    Trabelsi S.

    2013-02-01

    Full Text Available This study has been undertaken to get a better understanding of the interactions between Enhanced Oil Recovery (EOR surfactants used in chemical flooding and in situ surfactants present in an heavy oil. We report an experimental study of dynamic Interfacial Tension (IFT behaviour of diluted heavy oil/surfactant enhanced-alkaline systems. The dynamic IFT was measured using pendant drop and spinning drop tensiometers. The dynamic IFT between diluted heavy oil and alkaline solution (pH 11 with no added surfactant increased sharply with time, which was attributed to the transfer of the in situ surfactant (produced by saponification of the acids groups present in the crude oil across the oil/water interface. The addition of Sodium Dodecyl Benzene Sulfonate (SDBS above the Critical Micellar Concentration (CMC ~ 0.002%, changed completely the dynamic IFT behaviour of the diluted heavy oil as the IFT strongly decreased and finally reached a plateau, of about 1.5 × 10-3 mN/m at a concentration of only 0.02%. We attributed the efficiency of SDBS to a synergistic effect between the in situ surfactant and the added surfactant that form a mixed interfacial monolayer, which is very efficient in decreasing the IFT to ultra low values and in resisting mass transfer across the oil/water interface. Cette étude a été réalisée pour mieux comprendre les interactions entre les tensioactifs utilisés pour la récupération assistée de pétrole et les tensioactifs in situ présents dans le brut. Nous expérimentons le comportement dynamique des tensions interfaciales (mesurées par les méthodes de goutte pendante et goutte tournante entre le brut lourd dilué et les solutions alcalines avec ajout de tensioactif. La tension interfaciale dynamique entre le brut dilué et une solution alcaline (pH 11 sans ajout de tensioactif croît fortement au cours du temps, cette augmentation est attribuée au transfert des tensioactifs in situ (produits par saponification des

  14. Sensitivity study on hydraulic well testing inversion using simulated annealing

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Shinsuke; Najita, J.; Karasaki, Kenzi

    1997-11-01

    For environmental remediation, management of nuclear waste disposal, or geothermal reservoir engineering, it is very important to evaluate the permeabilities, spacing, and sizes of the subsurface fractures which control ground water flow. Cluster variable aperture (CVA) simulated annealing has been used as an inversion technique to construct fluid flow models of fractured formations based on transient pressure data from hydraulic tests. A two-dimensional fracture network system is represented as a filled regular lattice of fracture elements. The algorithm iteratively changes an aperture of cluster of fracture elements, which are chosen randomly from a list of discrete apertures, to improve the match to observed pressure transients. The size of the clusters is held constant throughout the iterations. Sensitivity studies using simple fracture models with eight wells show that, in general, it is necessary to conduct interference tests using at least three different wells as pumping well in order to reconstruct the fracture network with a transmissivity contrast of one order of magnitude, particularly when the cluster size is not known a priori. Because hydraulic inversion is inherently non-unique, it is important to utilize additional information. The authors investigated the relationship between the scale of heterogeneity and the optimum cluster size (and its shape) to enhance the reliability and convergence of the inversion. It appears that the cluster size corresponding to about 20--40 % of the practical range of the spatial correlation is optimal. Inversion results of the Raymond test site data are also presented and the practical range of spatial correlation is evaluated to be about 5--10 m from the optimal cluster size in the inversion.

  15. Effects of annealing on the modification of 230-MeV Pb ion irradiated sapphire

    International Nuclear Information System (INIS)

    Song Yin; Wang Zhiguang; Zhan Chonghong; Yao Cunfeng; Zang Hang; Liu Chunbao; Zhou Lihong; Sheng Yanbin; Xie Erqing

    2007-01-01

    Al 2 O 3 crystal is rhombohedral in cell structure and belongs to the D 3d space group with ionic bond. Sapphire posseses a wide band gap optical material for its broad transmission spectrum from ultraviolet to visible and near-infrared (0.2-2μm). It can be applied in the field of optics, fusion reactors as an insulator, the diagnostic systems and for optical window. In irradiation environment of reactor, radiation damage by neutron affects material characteristic, even possible result in accident. Ion implanted and high energy heavy ion irradiation as a sort of new technology of the modification of material, its good controllable, high reiteration and well-proportioned distributing, it can changes the surface and interior structure of material. These are help to the simulation of Al 2 O 3 interior structure modification of certain neutron radiation. In the present work the photoluminescence (PL) character of Single crystal sapphire (Al 2 O 3 ) samples and irradiated at 320 K by 230-MeV Pb ions and subsequently annealed at 600 K, 900 K and 1100 K temperature was studied. The modification of structure and optical properties induced by ion irradiation were analyzed using PL and FTIR spectra. The PL measurements showed that luminescence peaks located at 390, 413, 450, and 564 nm appeared in irradiated samples. The luminescence peaks appeared at 360, 380, and 516 nm after annealed irradiation samples. The peak of 380 nm became very intensity after 600 K anneal and other peak vanish. The peak of 380 nm weaken at 900 K anneal and 516 nm peak start buildup, the peak of 390 nm vanished and 510 nm peak increase along with temperature at 1100 K. The Fourier Transform Infrared (FTIR) spectra showed a broadening of the absorption band between 460 cm -1 and 510 cm -1 indicating strongly damaged regions formed in the Al 2 O 3 samples and position shift of the absorption band in 1000-1300 cm -1 towards to high wavenumber. After annealing, the lower irradiation fluence's samples

  16. FEM, FIM and STM studies of Hf adsorption on W: the annealing effects

    International Nuclear Information System (INIS)

    Szczudlo, Z.; Trembulowicz, A.; Ciszewksi, A.

    2004-01-01

    Full text: Surface alloys have attracted much attention recently, and investigation of them is a growing research field. Laves intermetallic phase with the regular structure of C15 is formed for the Hf-W System. Space filling in Laves phases is higher than that in the close-packed structures of fcc and hcp metals, and obviously higher than in bcc W. The former studies showed no evidence for Hf dissolution in the substrate in the temperature range 300 - 1500 K, though some evidence was found of Hf dissolution in the range 1500 - 1700 K and a possible surface alloy formation. In the present work, Hf layers of various thickness were deposited on tungsten field emitter tips and on W(110) and W(100) oriented single crystals at room temperature under UHV conditions previous to gradual annealing from 700 - 2300 K. Topographical and structural changes caused by annealing have been studied by field electron microscopy (FEM), field ion microscopy FIM in the case of the tips and by scanning tunneling microscopy (STM) in the case of W(110) and W(100) single crystals. The FEM and FIM studies showed faceting around the and poles of tungsten caused by annealing of the hafnium adsorption layers as well as strong development of the W {110} planes. The STM studies revealed that Hf deposited at room temperature on W(110) accumulate mainly along the step edges of the substrate. Sometimes islands were formed on terraces. Sporadically there were wide unfilled trays or hollows in the flat adsorbate layer. Growth of an ordered adsorbate layer proceeds mainly by sticking the Hf atoms at a terrace edge of the substrate. After heating up to 1650 K contrast changes were observed indicating that kind of a surface alloy could be formed on some terraces, originating at terrace edges. The width of the terraces on which the alloy was formed increased to 40 - 60 nm. In the case of Hf adsorption on W(100) after annealing up to 1200 K small separate islands of the adsorbate were formed. Evidences of

  17. Modeling syngas-fired gas turbine engines with two dilutants

    Science.gov (United States)

    Hawk, Mitchell E.

    2011-12-01

    Prior gas turbine engine modeling work at the University of Wyoming studied cycle performance and turbine design with air and CO2-diluted GTE cycles fired with methane and syngas fuels. Two of the cycles examined were unconventional and innovative. The work presented herein reexamines prior results and expands the modeling by including the impacts of turbine cooling and CO2 sequestration on GTE cycle performance. The simple, conventional regeneration and two alternative regeneration cycle configurations were examined. In contrast to air dilution, CO2 -diluted cycle efficiencies increased by approximately 1.0 percentage point for the three regeneration configurations examined, while the efficiency of the CO2-diluted simple cycle decreased by approximately 5.0 percentage points. For CO2-diluted cycles with a closed-exhaust recycling path, an optimum CO2-recycle pressure was determined for each configuration that was significantly lower than atmospheric pressure. Un-cooled alternative regeneration configurations with CO2 recycling achieved efficiencies near 50%, which was approximately 3.0 percentage points higher than the conventional regeneration cycle and simple cycle configurations that utilized CO2 recycling. Accounting for cooling of the first two turbine stages resulted in a 2--3 percentage point reduction in un-cooled efficiency, with air dilution corresponding to the upper extreme. Additionally, when the work required to sequester CO2 was accounted for, cooled cycle efficiency decreased by 4--6 percentage points, and was more negatively impacted when syngas fuels were used. Finally, turbine design models showed that turbine blades are shorter with CO2 dilution, resulting in fewer design restrictions.

  18. Magnetic properties of a diluted transverse spin-1 Ising nanocube with a longitudinal crystal-field

    Science.gov (United States)

    El Hamri, M.; Bouhou, S.; Essaoudi, I.; Ainane, A.; Ahuja, R.

    2016-12-01

    In the present work, the effective field theory with correlations based on the probability distribution technique has been used to investigate the effect of the surface shell longitudinal cristal field on the magnetic properties of a diluted antiferromagnetic spin-1 Ising nanocube particle. This effect has also been studied on the hysteresis loops of the system. It is found that this parameter has a strong effect on the magnetization profiles, compensation temperature, coercive field and remanent magnetization.

  19. A cluster-bethe-lattice approach to spin-waves in dilute ferromagnets

    International Nuclear Information System (INIS)

    Salzberg, J.B.; Silva, C.E.T.G. da; Falicov, L.M.

    1975-01-01

    The spin-wave spectra of a dilute ferromagnet within the cluster-bethe-lattice approximation is studied. Short range order effects for the alloy are included. A study of finite size clusters connected at their edges to Bethe lattices of the same coordination number allows one to determine:(i) the stability condition for the magnetic system; (ii) the continuum spin-wave local density of states and (iii) the existence of localized states below and above the continuum states

  20. Ball milling and annealing of Co-50 at% W Powders

    CSIR Research Space (South Africa)

    Bolokang, AS

    2013-04-01

    Full Text Available annealing of unmilled compacts yielded metastable phases. Upon 10 and 20 h ball milling of Co-W powder, no alloying was obtained. Although milling did not yield significant crystal changes in W and Co ground state struc- tures, its effect is evident during...

  1. Thermal annealing of protocrystalline a-Si:H

    NARCIS (Netherlands)

    Muller, T.F.G.; Arendse, C.J.; Halindintwali, S.; Knoesen, D.; Schropp, R.E.I.

    2011-01-01

    It proves difficult to obtain a set of protocrystalline silicon materials with different characteristics from the same deposition chamber to study the exact nature of these transition region materials. Hot-wire deposited protocrystalline silicon was thus isochronically annealed at different

  2. Meta-Modeling by Symbolic Regression and Pareto Simulated Annealing

    NARCIS (Netherlands)

    Stinstra, E.; Rennen, G.; Teeuwen, G.J.A.

    2006-01-01

    The subject of this paper is a new approach to Symbolic Regression.Other publications on Symbolic Regression use Genetic Programming.This paper describes an alternative method based on Pareto Simulated Annealing.Our method is based on linear regression for the estimation of constants.Interval

  3. Effect of annealing process of iron powder on magnetic properties ...

    Indian Academy of Sciences (India)

    Iron powder magnetic cores are used as soft magnetic rotors, in micro special motors such as BS brake motors, refrigerator compressor motors and brushless servo motors. Heat treatment of iron powder played an important role in the magnetic properties and loss of the motor cores. After the annealing process, the cracks ...

  4. The effects of Mg incorporation and annealing temperature on the ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 88; Issue 2. The effects of Mg incorporation and annealing temperature on the physicochemical properties and antibacterial activity against {\\it Listeria monocytogenes} of ZnO nanoparticles. NIMA SHADAN ALI ABDOLAHZADEH ZIABARI RAFIEH MERAAT KAMYAR ...

  5. A Deterministic Annealing Approach to Clustering AIRS Data

    Science.gov (United States)

    Guillaume, Alexandre; Braverman, Amy; Ruzmaikin, Alexander

    2012-01-01

    We will examine the validity of means and standard deviations as a basis for climate data products. We will explore the conditions under which these two simple statistics are inadequate summaries of the underlying empirical probability distributions by contrasting them with a nonparametric, method called Deterministic Annealing technique

  6. Effect of annealing atmosphere on microstructure, optical and ...

    Indian Academy of Sciences (India)

    2018-02-05

    Feb 5, 2018 ... Indian Academy of Sciences https://doi.org/10.1007/s12034-017-1542-6. Effect of annealing atmosphere on microstructure, optical and electronic properties of spray-pyrolysed In-doped Zn(O,S) thin films. MARGI JANI, DHYEY RAVAL, RANJAN KUMAR PATI, INDRAJIT MUKHOPADHYAY and ABHIJIT RAY.

  7. Effect of annealing process of iron powder on magnetic properties ...

    Indian Academy of Sciences (India)

    Administrator

    Abstract. Iron powder magnetic cores are used as soft magnetic rotors, in micro special motors such as BS brake motors, refrigerator compressor motors and brushless servo motors. Heat treatment of iron powder played an important role in the magnetic properties and loss of the motor cores. After the annealing process,.

  8. Correction of measured multiplicity distributions by the simulated annealing method

    International Nuclear Information System (INIS)

    Hafidouni, M.

    1993-01-01

    Simulated annealing is a method used to solve combinatorial optimization problems. It is used here for the correction of the observed multiplicity distribution from S-Pb collisions at 200 GeV/c per nucleon. (author) 11 refs., 2 figs

  9. Effects of nitrogen annealing on surface structure, silicide formation ...

    Indian Academy of Sciences (India)

    pure) bulk cobalt which was held in water cooled copper cru- cibles. All the samples were coated with 50 Å of cobalt at a rate of 0·1 Å/s. The deposition rate was ... sivity and due to the resultant shortage in the cobalt atoms, monosilicides are formed instead of di-metal silicides. At annealing temperatures higher than 600.

  10. Hafnium implanted in iron 1. Lattice location and annealing behavior

    NARCIS (Netherlands)

    de Bakker, J.M.G.J.; Pleiter, F; Smulders, P.J M

    1993-01-01

    Perturbed angular correlation, Rutherford backscattering and channelling experiments were conducted to study the lattice location and annealing behaviour of 110 keV hafnium ions implanted into iron single crystals. It was found that a fraction of 11-25% of the implanted hafnium atoms are located at

  11. Self-Organization and Annealed Disorder in a Fracturing Process

    DEFF Research Database (Denmark)

    Caldarelli, Guido; Di Tolla, Francesco; Petri, Alberto

    1996-01-01

    We show that a vectorial model for inhomogeneous elastic media self-organizes under external stress. An onset of crack avalanches of every duration and length scale compatible with the lattice size is observed. The behavior is driven by the introduction of annealed disorder, i.e., by lowering the...

  12. Influence of degree of deformation in rolling on anneal hardening ...

    Indian Academy of Sciences (India)

    Unknown

    The hardness, strength and electrical conductivity were measured and X-ray and DSC analyses performed. Anneal hardening effect was observed in the alloy in the temperature range 180–300°C, followed by an increase in the electrical conductivity. The amount of strengthening increases with increasing degree of prior.

  13. Coupled Qubits for Next Generation Quantum Annealing: Improving Coherence

    Science.gov (United States)

    Weber, Steven; Samach, Gabriel; Hover, David; Rosenberg, Danna; Yoder, Jonilyn; Kim, David K.; Kerman, Andrew; Oliver, William D.

    Quantum annealing is an optimization technique which potentially leverages quantum tunneling to enhance computational performance. Existing quantum annealers use superconducting flux qubits with short coherence times, limited primarily by the use of large persistent currents. Here, we examine an alternative approach, using flux qubits with smaller persistent currents and longer coherence times. We demonstrate tunable coupling, a basic building-block for quantum annealing, between two such qubits. Furthermore, we characterize qubit coherence as a function of coupler setting and investigate the effect of flux noise in the coupler loop on qubit coherence. Our results provide insight into the available design space for next-generation quantum annealers with improved coherence. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA) and by the Assistant Secretary of Defense for Research & Engineering under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  14. Thermal annealing of femtosecond laser written structures in silica glass

    NARCIS (Netherlands)

    Witcher, J.J.; Reichman, W.B.; Fletcher, L.B.; Troy, N.W.; Krol, D.M.

    2013-01-01

    We have investigated the thermal stability of femtosecond laser modification inside fused silica. Raman and FL spectroscopy show that fs-laser induced non-bridging oxygen hole center (NBOHC) defects completely disappear at 300 °C, whereas changes in Si-O ring structures only anneal out after heat

  15. Embrittlement recovery due to annealing of reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

    1995-01-01

    The irradiation embrittlement of nuclear reactor pressure vessels (RPV) can be reduced by thermal annealing at temperatures higher than the normal operating conditions. The objective of this work was to analyze the pertinent data and develop quantitative models for estimating the recovery in 30 ft-lb (41 J) Charpy transition temperature and Charpy upper shelf energy due to annealing. An analysis data base was developed, reviewed for completeness and accuracy, and documented as part of this work. Models were developed based on a combination of statistical techniques, including pattern recognition and transformation analysis, and the current understanding of the mechanisms governing embrittlement and recovery. The quality of models fitted in this project was evaluated by considering both the Charpy annealing data used for fitting and a surrogate hardness data base. This work demonstrates that microhardness recovery is i good surrogate for shift recovery and that there is a high level of consistency between he observed annealing trends and fundamental models of embrittlement and recovery processes

  16. Embrittlement recovery due to annealing of reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Eason, E.D.; Wright, J.E.; Nelson, E.E.; Odette, G.R.; Mader, E.V.

    1998-01-01

    The irradiation embrittlement of nuclear reactor pressure vessels (RPV) can be reduced by thermal annealing at temperatures higher than the normal operating conditions. The objective of this work was to analyze the pertinent data and develop quantitative models for estimating the recovery in 41 J (30 ft-lb) Charpy transition temperature (TT) and Charpy upper shelf energy (USE) due to annealing. An analysis data base was developed, reviewed for completeness and accuracy, and documented as part of this work. Models were developed based on a combination of statistical techniques, including pattern recognition and transformation analysis, and the current understanding of the mechanisms governing embrittlement and recovery. The quality of models fitted in this project was evaluated by considering both the Charpy annealing data used for fitting and a surrogate hardness data base. This work demonstrates that microhardness recovery is a good surrogate for shift recovery and that there is a high level of consistency between the observed annealing trends and fundamental models of embrittlement and recovery processes. (orig.)

  17. Effect of annealing on phase transition in poly (vinylidene fluoride ...

    Indian Academy of Sciences (India)

    The -phase poly (vinylidene fluoride) (PVDF) films are usually prepared using dimethyl sulfoxide (DMSO) solvent, regardless of preparation temperature. Here we report the crystallization of both and -phase PVDF films by varying preparation temperature using DMSO solvent. The -phase PVDF films were annealed ...

  18. Influence of degree of deformation in rolling on anneal hardening ...

    Indian Academy of Sciences (India)

    Unknown

    Influence of degree of deformation in rolling on anneal hardening effect of a cast copper alloy. SVETLANA NESTOROVIC*, DESIMIR MARKOVIC and LJUBICA IVANIC. Technical Faculty Bor, University of Belgrade, Belgrade, Yugoslavia. MS received 15 May 2003. Abstract. This paper reports results of investigations carried ...

  19. The afforestation problem: a heuristic method based on simulated annealing

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1992-01-01

    This paper presents the afforestation problem, that is the location and design of new forest compartments to be planted in a given area. This optimization problem is solved by a two-step heuristic method based on simulated annealing. Tests and experiences with this method are also presented....

  20. Dielectric properties of plasma sprayed silicates subjected to additional annealing

    Czech Academy of Sciences Publication Activity Database

    Ctibor, Pavel; Sedláček, J.; Nevrlá, Barbara; Neufuss, Karel

    2017-01-01

    Roč. 10, č. 2 (2017), s. 105-114 ISSN 2008-2134 Institutional support: RVO:61389021 Keywords : Annealing * Dielectric properties * Plasma spraying * Silicates * Electrical properties * Insulators Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films http://pccc.icrc.ac.ir/Articles/1/18/990/

  1. Infrared absorption studies of the annealing of irradiated diamonds

    International Nuclear Information System (INIS)

    Woods, G.S.

    1984-01-01

    Natural (types Ia and IIa) and synthetic (type Ib) diamonds have been irradiated with energetic electrons and neutrons and then heated at temperatures up to 1400 deg C. Attendant changes in the infrared absorption spectra, especially above the Raman frequency (1332 cm -1 ), have been monitored. The most prominent absorption to develop in the infrared region proper, on annealing both type Ia and type Ib specimens, whether electron- or neutron-irradiated is the H1a line at 1450 cm -1 . Measurements taken of neutron-irradiated type Ia specimens show that the strength of this line is specimen-dependent, and that it is a linear function of radiation dose. Isochronal annealing studies show that the onset of the line occurs during heating at 250 deg C for type Ia specimens and at 650 deg C for type Ib specimens. The absorption begins to weaken during heating at 1100 deg C, but it is very persistent, surviving an anneal of 4 hours at 1400 deg C, albeit with diminished intensity. Three other weaker lines at 1438, 1358 and 1355 cm -1 develop with the 1450 cm -1 line, but differ from it and from each other in subsequent annealing behaviour. Other lines were observed; these are reported and discussed. (author)

  2. Effect of annealing atmosphere on microstructure, optical and ...

    Indian Academy of Sciences (India)

    61

    Effect of annealing atmosphere on microstructure, optical and electronic properties of spray pyrolysed indium doped Zn(O,S) thin films. Margi Jani1, DhyeyRaval1,Ranjan Kumar Pati1, Indrajit Mukhopadhyay1. andAbhijit Ray1*. 1Solar Research and Development Center, School of Solar Energy, PanditDeendayal.

  3. Property change during nanosecond pulse laser annealing of ...

    Indian Academy of Sciences (India)

    ... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 35; Issue 3. Property change during nanosecond pulse laser annealing of amorphous NiTi thin film. S K Sadrnezhaad Noushin Yasavol Mansoureh Ganjali Sohrab Sanjabi. Volume 35 Issue 3 June 2012 pp 357-364 ...

  4. Physical Mapping Using Simulated Annealing and Evolutionary Algorithms

    DEFF Research Database (Denmark)

    Vesterstrøm, Jacob Svaneborg

    2003-01-01

    Physical mapping (PM) is a method of bioinformatics that assists in DNA sequencing. The goal is to determine the order of a collection of fragments taken from a DNA strand, given knowledge of certain unique DNA markers contained in the fragments. Simulated annealing (SA) is the most widely used...

  5. Low temperature electron irradiation and annealing of pure cadmium

    International Nuclear Information System (INIS)

    Menendez, M.A.

    1979-01-01

    Cadmium after electron irradiation below 2 0 K, was studied and the damage production rate in Dc was found to be (4.13 +- .16) x 10 -26 Ωcm/(e - /cm 2 ) for irradiation with 2.5 MeV electrons at 1.5 0 K. New annealing peaks were observed at 1.825 0 K and at about 2 0 K with activation energies of (2.6 +- .1) x 10 -3 eV and (2.77 +- .34) x 10 -3 eV, respectively. The peak at about 2 0 K exhibits dose-dependence, but it is better described by first order kinetics; this peak is believed to correspond to the long-range migration of the self-interstitial, preferentially to impurities where they form clusters. It has been found that subthreshold irradiation results in the annealing of damage already present. This radiation annealing effect may be a contributing factor to the seesaw effect. Another physical process may contribute to the seesaw effect, namely, the trapping of interstitials at impurities and their subsequent detrapping during annealing

  6. Air atmosphere annealing effects on LSO:Ce crystal

    Czech Academy of Sciences Publication Activity Database

    Ding, D.; Feng, H.; Ren, G.; Nikl, Martin; Qin, L.; Pan, S.; Yang, F.

    2010-01-01

    Roč. 57, č. 3 (2010), s. 1272-1277 ISSN 0018-9499 R&D Projects: GA MŠk ME08034 Institutional research plan: CEZ:AV0Z10100521 Keywords : annealing * cerium * LSO * luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.519, year: 2010

  7. Property change during nanosecond pulse laser annealing of ...

    Indian Academy of Sciences (India)

    Property change during nanosecond pulse laser annealing of amorphous. NiTi thin film ... near equiatomic Ni/Ti composition to produce partially crystallized highly sensitive R-phase spots surrounded by amorphous regions. Scanning ... ratio, shape recovery, damping capacity, chemical resistance, biocompatibility and ...

  8. Thermal annealing and ionic abrasion in ZnTe

    International Nuclear Information System (INIS)

    Bensahel, D.

    1975-01-01

    Thermal annealing of the ZnTe crystal is studied first in order to obtain information on the aspect of the penetration profile. Ionic abrasion is then investigated to find out whether it produces the same effects as ionic implantation, especially for luminescence [fr

  9. Coalescence during annealing of quiescent immiscible polymer blends

    Czech Academy of Sciences Publication Activity Database

    Dimzoski, Bojan; Fortelný, Ivan; Šlouf, Miroslav; Nevoralová, Martina; Michálková, Danuše; Mikešová, Jana

    -, 011 (2011), s. 1-12 ISSN 1618-7229 R&D Projects: GA AV ČR IAA200500903 Institutional research plan: CEZ:AV0Z40500505 Keywords : coalescence * polymer blends * annealing Subject RIV: BJ - Thermodynamics Impact factor: 0.515, year: 2011 http://www.e-polymers.org/journal/papers/bdimzoski_010311.pdf

  10. Corrections to scaling in random resistor networks and diluted continuous spin models near the percolation threshold.

    Science.gov (United States)

    Janssen, Hans-Karl; Stenull, Olaf

    2004-02-01

    We investigate corrections to scaling induced by irrelevant operators in randomly diluted systems near the percolation threshold. The specific systems that we consider are the random resistor network and a class of continuous spin systems, such as the x-y model. We focus on a family of least irrelevant operators and determine the corrections to scaling that originate from this family. Our field theoretic analysis carefully takes into account that irrelevant operators mix under renormalization. It turns out that long standing results on corrections to scaling are respectively incorrect (random resistor networks) or incomplete (continuous spin systems).

  11. Magnetite and magnetite/silver core/shell nanoparticles with diluted magnet-like behavior

    International Nuclear Information System (INIS)

    Garza-Navarro, Marco; Torres-Castro, Alejandro; Gonzalez, Virgilio; Ortiz, Ubaldo; De la Rosa, Elder

    2010-01-01

    In the present work is reported the use of the biopolymer chitosan as template for the preparation of magnetite and magnetite/silver core/shell nanoparticles systems, following a two step procedure of magnetite nanoparticles in situ precipitation and subsequent silver ions reduction. The crystalline and morphological characteristics of both magnetite and magnetite/silver core/shell nanoparticles systems were analyzed by high resolution transmission electron microscopy (HRTEM) and nanobeam diffraction patterns (NBD). The results of these studies corroborate the core/shell morphology and the crystalline structure of the magnetite core and the silver shell. Moreover, magnetization temperature dependent, M(T), measurements show an unusual diluted magnetic behavior attributed to the dilution of the magnetic ordering in the magnetite and magnetite/silver core/shell nanoparticles systems. - Graphical abstract: Biopolymer chitosan was used as stabilization media to synthesize both magnetite and magnetite/silver core/shell nanoparticles. Results of HRTEM and NBD patterns confirm core/shell morphology of the obtained nanoparticles. It was found that the composites show diluted magnet-like behavior.

  12. 454-Pyrosequencing Analysis of Bacterial Communities from Autotrophic Nitrogen Removal Bioreactors Utilizing Universal Primers: Effect of Annealing Temperature

    Directory of Open Access Journals (Sweden)

    Alejandro Gonzalez-Martinez

    2015-01-01

    Full Text Available Identification of anaerobic ammonium oxidizing (anammox bacteria by molecular tools aimed at the evaluation of bacterial diversity in autotrophic nitrogen removal systems is limited by the difficulty to design universal primers for the Bacteria domain able to amplify the anammox 16S rRNA genes. A metagenomic analysis (pyrosequencing of total bacterial diversity including anammox population in five autotrophic nitrogen removal technologies, two bench-scale models (MBR and Low Temperature CANON and three full-scale bioreactors (anammox, CANON, and DEMON, was successfully carried out by optimization of primer selection and PCR conditions (annealing temperature. The universal primer 530F was identified as the best candidate for total bacteria and anammox bacteria diversity coverage. Salt-adjusted optimum annealing temperature of primer 530F was calculated (47°C and hence a range of annealing temperatures of 44–49°C was tested. Pyrosequencing data showed that annealing temperature of 45°C yielded the best results in terms of species richness and diversity for all bioreactors analyzed.

  13. The effect of humidity on annealing of polymer optical fibre bragg gratings

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Nielsen, Kristian; Bang, Ole

    2015-01-01

    The effect of humidity on annealing of PMMA based microstructured polymer optical fiber (mPOF) Bragg gratings is studied. Polymer optical fibers (POFs) are annealed in order to release stress formed during the fabrication process. Un-annealed fibers will have high hysteresis and low sensitivity...... to humidity, particularly when operated at high temperature. Typically annealing of PMMA POFs is done at 80oC in an oven with no humidity control and therefor at low humidity. The response to humidity of PMMA FBGs annealed at different levels of humidity at the same temperature has also been studied. PMMA...... FBGs annealed at high humidity have response with no hysteresis and an improved sensitivity which are independent of temperature compared to FBGs annealed at the same temperature but at lower humidity. In addition, PMMA FBG annealed at high humidity showed a permanent blue shift more than 200nm, which...

  14. Vapor-Liquid Equilibrium in Diluted Polymer plus Solvent Systems

    Czech Academy of Sciences Publication Activity Database

    Bogdanić, Grozdana; Wichterle, Ivan

    2011-01-01

    Roč. 56, č. 4 (2011), s. 1080-1083 ISSN 0021-9568 R&D Projects: GA ČR GA104/07/0444 Grant - others:MZOŠ(HR) 061-0000000-3029 Institutional research plan: CEZ:AV0Z40720504 Keywords : polymer * prediction * total pressure Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.693, year: 2011

  15. A probabilistic analysis of rapid boron dilution scenarios

    International Nuclear Information System (INIS)

    Kohut, P.; Diamond, D.J.

    1993-01-01

    A probabilistic and deterministic analysis of a rapid boron dilution scenario related to reactor restart was performed. The event is initiated by a loss of off-site power during the startup dilution process. The automatic restart of the charging pump in such cases may lead to the accumulation of a diluted slug of water in the lower plenum. The restart of the reactor coolant pumps may send the diluted slug through the core, adding sufficient reactivity to overcome the shutdown margin and cause a power excursion. The concern is that the power excursion is sufficient in certain circumstances to cause fuel damage. The estimated core damage frequency based on the scoping analysis is 1.0--3.0E-05/yr for the plants analyzed. These are relatively significant values when compared to desirable goals. The analysis contained assumptions related to plant specific design characteristics which may lead to non-conservative estimates. The most important conservative assumptions were that mixing of the injected diluted water is insignificant and that fuel damage occurs when the slug passes through the core

  16. Initial magnetic susceptibility of the diluted magnetopolymer elastic composites

    International Nuclear Information System (INIS)

    Borin, D.Yu.; Odenbach, S.

    2017-01-01

    In this work diluted magnetopolymer elastic composites based on magnetic microparticles are experimentally studied. Considered samples have varied concentration of the magnetic powder and different structural anisotropy. Experimental data on magnetic properties are accomplished by microstructural observations performed using X-Ray tomography. Influence of the particles amount and structuring effects on the initial magnetic susceptibility of the composites as well as the applicability of the Maxwell-Garnett approximation, which is widely used in considerations of magnetopolymer elastic composites, are evaluated. It is demonstrated that the approximation works well for diluted samples containing randomly distributed magnetic particles and for the diluted samples with chain-like structures oriented perpendicular to an externally applied field, while it fails to predict the susceptibility of the samples with structures oriented parallel to the field. Moreover, it is shown, that variation of the chains morphology does not significantly change the composite initial magnetic susceptibility. - Highlights: • The Maxwell-Garnet prediction works well for the diluted isotropic composites. • The Maxwell-Garnet prediction can be used for composites with structures oriented perpendicular to an applied field. • Chains oriented parallel to an applied field significantly increase the composite initial magnetic susceptibility. • The number and thickness of chains is not of the highest importance for the diluted composites. • The crucial reason of the observed effect is expected to be the demagnetisation factor of the chains.

  17. Non‐diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle

    2016-01-01

    Background The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non‐diluted seawater and diluted seawater, on nasal mucosa functional parameters. Methods For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non‐diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Results Non‐diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Conclusion Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non‐diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. PMID:27101776

  18. Non-diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline.

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle; de Gabory, Ludovic

    2016-10-01

    The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non-diluted seawater and diluted seawater, on nasal mucosa functional parameters. For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non-diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Non-diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non-diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. © 2016 The Authors International Forum of Allergy & Rhinology, published by ARSAAOA, LLC.

  19. The effect of boron dilution transient on the VVER-1000 reactor core using MCNP and COBRA-EN codes

    Energy Technology Data Exchange (ETDEWEB)

    Jafari, Naser; Talebi, Saeed [Amirkabir Univ. of Technology, Tehran Polytechnic (Iran, Islamic Republic of). Dept. of Energy Engineering and Physics

    2017-07-15

    In this paper, the effect of boron dilution transient, as a consequence of the malfunction of the boron control system, was investigated in a VVER-1000 reactor, and then an appropriate setpoint was determined for the actuation of the emergency protection system to the reactor shutdown. In order to simulate the boron dilution, first, the whole reactor core was simulated by MCNPX code to compute the radial and axial power distribution. Then, the COBRA-EN code was employed using calculated power distribution for analyzing the thermal-hydraulic of hot fuel assembly and for extracting the safety parameters. For the safe operation of the reactor, certain parameters must be in defined specified ranges. Comparison between our results and FSARs data shows that the present modeling provides a good prediction of boron dilution transient with the maximum relative difference about 4%.

  20. The effect of pre-annealing on the structural evolution and optical ...

    Indian Academy of Sciences (India)

    65

    Ag thin films of 5nm thickness were deposited on glass substrates by thermal evaporation. The films were divided into two sets out of which one set was not annealed and the other set was subjected to pre-annealing at 300oC for 2 hrs in air. The un-annealed and pre-annealed films were exposed to iodine vapours at room ...

  1. Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current

    DEFF Research Database (Denmark)

    Shayesteh, Maryam; O' Connell, Dan; Gity, Farzan

    2014-01-01

    In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical properties of phosphorus and Arsenic-doped n +/p junctions. Using LTA, high carrier...

  2. Electro-optical characteristics of indium tin oxide (ITO) films: effect of thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, D.V.; Salehi, A.; Aliyu, Y.H.; Bunce, R.W. [University of Wales College of Cardiff (United Kingdom). School of Electrical, Electronics and System Engineering

    1996-02-01

    The effect of thermal annealing on the electrical and optical characteristics of ITO films prepared by reactive sputtering and thermal evaporation have been studied. The effect of the thermal annealing is to improve the conductivity and the optical transmission in the shorter wavelength region. The conductivity of the films increases with annealing temperature, this behaviour is associated with grain growth in the film. (author)

  3. Nitrogen aggregation in Ib type synthetic diamonds at low pressure and high-temperature annealing

    International Nuclear Information System (INIS)

    Kazyuchits, N.M.; Rusetskij, M.S.; Latushko, Ya.I.; Kazyuchits, V.N.; Zajtsev, A.M.

    2015-01-01

    A new technique for annealing of diamonds at low pressure and high temperature (LPHT) is considered. The absorption spectra of synthetic Ib diamonds are given before and after annealing. This is evident from a comparison of the spectra that nitrogen aggregation process takes place at the LPHT annealing diamond. (authors)

  4. 78 FR 31577 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan

    Science.gov (United States)

    2013-05-24

    ...)] Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan Determination On the basis of the... reason of imports from Japan of diffusion-annealed, nickel-plated flat-rolled steel products, provided... diffusion-annealed, nickel-plated flat-rolled steel products from Japan. Accordingly, effective March 27...

  5. Calculation of local boron dilution accidents with the Hextran code

    International Nuclear Information System (INIS)

    Kyrki-Rajamaeki, R.; Stenius, T.

    1995-01-01

    Possibilities of Reactivity Initiated Accidents (RIA) due to local boron dilution slugs entering the core of PWRs have been widely studied in recent years. In Finland the main analysis tool for reactor dynamics RIA calculations has been the three dimensional HEXTRAN code which also includes full circuit models. Reliable calculation of propagating boron fronts is very difficult with standard numerical algorithms because numerical diffusion tends to smoothen the front. Thus the reactivity effect of the boron dilution can be significantly lowered and conservatism of the analyses cannot be guaranteed. In normal flow conditions this problem has been avoided in HEXTRAN analyses by simulating the dilution front directly to the core inlet. In natural circulation conditions there occurs significant numerical diffusion even during the propagation of boron front inside the core. Therefore a new hydraulics solution method PLIM (Piecewise Linear Interpolation Method) has been applied to HEXTRAN. Examples are given of analyses made with HEXTRAN in both flow conditions

  6. ERM booster vaccination of Rainbow trout using diluted bacterin

    DEFF Research Database (Denmark)

    Schmidt, Jacob Günther; Henriksen, Niels H.; Buchmann, Kurt

    2016-01-01

    under laboratory conditions extend the protection period. The present field study investigated the applicability of the method under practical farming conditions (freshwater earth ponds supplied by stream water). Primary immersion vaccination of trout (3–4 g) for 30 s in Y. ruckeri bacterin (diluted 1......Enteric Red Mouth Disease ERM caused by Yersinia ruckeri infection is associated with morbidity and mortality in salmonid farming but immersion vaccination of fry may confer some protection for a number of months. Revaccination of rainbow trout, even by use of diluted ERM immersion vaccine, can......:10) in April 2015 was followed 3 months later (July 2015) by 1 h bathing of rainbow trout in bacterin (diluted 1:650 or 1:1700) in order to evaluate if this time saving vaccination methodology can improve immunity and protection. Trout were subjected in farms to natural Y. ruckeri exposure in June and July...

  7. Particle Based Image Segmentation with Simulated Annealing

    NARCIS (Netherlands)

    Everts, M.H.; Bekker, H.; Jalba, A.C.; Roerdink, J.B.T.M.

    2007-01-01

    The Charged Particle Model (CPM) is a physically motivated deformable model for shape recovery and segmentation. It simulates a system of charged particles moving in an electric field generated from the input image, whose positions in the equilibrium state are used for curve or surface

  8. Dynamical Properties of a Diluted Dipolar-Interaction Heisenberg Spin Glass

    International Nuclear Information System (INIS)

    Zhang Kai-Cheng; Liu Yong; Chi Feng

    2014-01-01

    Up to now the chirality is seldom studied in the diluted spin glass although many investigations have been performed on the site-ordered Edwards—Anderson model. By simulation, we investigate the dynamical properties of both the spin-glass and the chiral-glass phases in a diluted dipolar system, which was manifested to have a spin-glass transition by recent numerical study. By scaling we find that both phases have the same aging behavior and closer aging parameter μ. Similarly, the domains grow in the same way and both phases have a closer barrier exponent Ψ. It means that both the spins and the chirality have the same dynamical properties and they may freeze at the same temperature. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. Sample Loading and Accelerated Cooling of Cryogen-free Dilution Refrigerators

    Science.gov (United States)

    Teleberg, G.; Matthews, A. J.; Batey, G.; Elford, J.

    2012-12-01

    We present results from system tests of top and bottom loading cryogen-free dilution refrigerators which enable cool-down times from room temperature to mK temperatures in 6 to 8 hours. The loading and unloading processes take only a few minutes to perform and the cooling procedure is fully automated. Sample temperatures of less than 10 mK have been achieved with up to 8 coaxial cables and 25 DC-wires connected to the sample holder. We also present cool-down tests of a beam line dilution refrigerator with a 35 kg mass installed on the mixing chamber. A heat pipe was developed to accelerate the cooling of large experimental payloads and the mass was cooled from room temperature to 30 mK in less than 28 hours.

  10. Dynamic Stresses in the LHC TCDS Diluter from 7 TeV Beam Loading

    CERN Document Server

    Goddard, B; Presland, A; Weterings, W

    2006-01-01

    In the event of an unsynchronised beam abort, the MSD extraction septum of the LHC beam dumping system is protected from damage by the TCDS diluter. The simultaneous constraints of obtaining sufficient beam dilution while ensuring the survival of the TCDS make the design difficult, with high thermally induced dynamic stresses occurring in the material needed to attenuate the particle showers induced by the primary beam impact. In this paper, full 3D simulations are described where the worst-case beam loading has been used to generate the local temperature rise and to follow the resulting time evolution of the mechanical stresses. The results and the accompanying design changes for the TCDS, to provide an adequate performance margin, are detailed.

  11. Asymptotically optimal purification and dilution of mixed qubit and Gaussian states

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, Peter; Guta, Madalin; Adesso, Gerardo [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2011-08-15

    Given an ensemble of mixed qubit states, it is possible to increase the purity of the constituent states using a procedure known as state purification. The reverse operation, which we refer to as dilution, produces a larger ensemble, while reducing the purity level of the systems. In this paper we find asymptotically optimal procedures for purification and dilution of an ensemble of independently and identically distributed mixed qubit states, for some given input and output purities and an asymptotic output rate. Our solution involves using the statistical tool of local asymptotic normality, which recasts the qubit problem in terms of attenuation and amplification of a single-mode displaced Gaussian state. Therefore, to obtain the qubit solutions, we must first solve the analogous problems in the Gaussian setup. We provide full solutions to all of the above for the (global) trace-norm figure of merit.

  12. Evaluation of two gas-dilution methods for instrument calibration

    Science.gov (United States)

    Evans, A., Jr.

    1977-01-01

    Two gas dilution methods were evaluated for use in the calibration of analytical instruments used in air pollution studies. A dual isotope fluorescence carbon monoxide analyzer was used as the transfer standard. The methods are not new but some modifications are described. The rotary injection gas dilution method was found to be more accurate than the closed loop method. Results by the two methods differed by 5 percent. This could not be accounted for by the random errors in the measurements. The methods avoid the problems associated with pressurized cylinders. Both methods have merit and have found a place in instrument calibration work.

  13. Test plan for tank 241-AN-104 dilution studies

    International Nuclear Information System (INIS)

    Herting, D.L.

    1998-01-01

    Tank 241-AN-104 (104-AN) has been identified as the one of the first tanks to be retrieved for low level waste pretreatment and immobilization. Retrieval of the tank waste will require dilution. Laboratory tests are needed to determine the amount and type of dilution required for safe retrieval and transfer of feed and to re-dissolve major soluble sodium salts while not precipitating out other salts. The proposed laboratory tests are described in this document. Tank 241-AN-104 is on the Hydrogen Watch List

  14. Introduction to the Physics of Diluted Magnetic Semiconductors

    CERN Document Server

    Gaj, Jan A

    2010-01-01

    The book deals with diluted magnetic semiconductors, a class of materials important to the emerging field of spintronics. In these materials semiconducting properties, both transport and optical, are influenced by the presence of magnetic ions. It concentrates on basic physical mechanisms (e.g. carrier-ion and ion-ion interactions) and resulting phenomena (e.g. magnetic polaron formation and spin relaxation). Introduction to the Physics of Diluted Magnetic Semiconductors is addressed to graduate-level and doctoral students and young researchers entering the field. The authors have been actively involved in the creation of this branch of semiconductor physics.

  15. Dynamics of dilute disordered models: A solvable case

    International Nuclear Information System (INIS)

    Semerjian, Guilhem; Cugliandolo, Leticia F.

    2003-09-01

    We study the dynamics of a dilute spherical model with two body interactions and random exchanges. We analyze the Langevin equations and we introduce a functional variational method to study generic dilute disordered models. A crossover temperature replaces the dynamic transition of the fully-connected limit. There are two asymptotic regimes, one determined by the central band of the spectral density of the interactions and a slower one determined by localized configurations on sites with high connectivity. We confront the behavior of this model to the one of real glasses. (author)

  16. Optimization of cord blood unit sterility testing: impact of dilution, analysis delay, and inhibitory substances.

    Science.gov (United States)

    Girard, Mélissa; Laforce-Lavoie, Audrey; de Grandmont, Marie Joëlle; Cayer, Marie-Pierre; Fournier, Diane; Delage, Gilles; Thibault, Louis

    2017-08-01

    Different methods are used by cord blood banks to prepare samples for sterility testing. Suboptimal methods can result in the release of contaminated products. In our organization, samples are prepared by diluting the final product in RPMI-1640 medium. In this work, we have compared our method with different approaches to verify whether optimization should be sought. Cord blood units (n = 6 units per bacterial strain) characterized to contain inhibitory substances or not were inoculated (10 colony-forming units/mL) with Streptococcus agalactiae, Staphylococcus epidermidis, Klebsiella pneumoniae, Escherichia coli, or Bacteroides fragilis. After plasma and red blood cell removal, stem cell concentrates were diluted in RPMI-1640, thioglycollate, or the unit's plasma. These products, as well as final product, plasma, and red blood cell fractions, were held from 0 to 72 hours at 20 to 24°C before inoculation in culture bottles and detection using the BacT/ALERT 3D system. Dilution of cell concentrates in RPMI-1640 allowed bacterial detection in 93.3% of noninhibitory cord blood samples after a 24-hour storage period. Thioglycollate medium better promoted bacterial growth in inhibitory cord blood samples that were held for 72 hours before testing (66.7%) compared with RPMI-1640 (45.0%). Less than 33% of all spiked plasma samples were detected by the BacT/ALERT 3D system. Diluting cord blood samples in culture medium containing bacterial growth promoting substances is a suitable option for sterility testing, whereas the use of plasma should be proscribed, because it might lead to false-negative results. Because inhibitory substances affect bacterial growth, inoculation of culture bottles should be done rapidly after sample preparation. © 2017 AABB.

  17. Verifying mixing in dilution tunnels How to ensure cookstove emissions samples are unbiased

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Daniel L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Caubel, Julien J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Sharon S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gadgil, Ashok J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-12-15

    A well-mixed diluted sample is essential for unbiased measurement of cookstove emissions. Most cookstove testing labs employ a dilution tunnel, also referred to as a “duct,” to mix clean dilution air with cookstove emissions before sampling. It is important that the emissions be well-mixed and unbiased at the sampling port so that instruments can take representative samples of the emission plume. Some groups have employed mixing baffles to ensure the gaseous and aerosol emissions from cookstoves are well-mixed before reaching the sampling location [2, 4]. The goal of these baffles is to to dilute and mix the emissions stream with the room air entering the fume hood by creating a local zone of high turbulence. However, potential drawbacks of mixing baffles include increased flow resistance (larger blowers needed for the same exhaust flow), nuisance cleaning of baffles as soot collects, and, importantly, the potential for loss of PM2.5 particles on the baffles themselves, thus biasing results. A cookstove emission monitoring system with baffles will collect particles faster than the duct’s walls alone. This is mostly driven by the available surface area for deposition by processes of Brownian diffusion (through the boundary layer) and turbophoresis (i.e. impaction). The greater the surface area available for diffusive and advection-driven deposition to occur, the greater the particle loss will be at the sampling port. As a layer of larger particle “fuzz” builds on the mixing baffles, even greater PM2.5 loss could occur. The micro structure of the deposited aerosol will lead to increased rates of particle loss by interception and a tendency for smaller particles to deposit due to impaction on small features of the micro structure. If the flow stream could be well-mixed without the need for baffles, these drawbacks could be avoided and the cookstove emissions sampling system would be more robust.

  18. Effect of field-annealing on magnetostriction and tunneling magnetoresistance of Co/AlOx/Co/IrMn junctions

    International Nuclear Information System (INIS)

    Chen, Y.-T.; Tseng, J.-Y.; Chang, C.C.; Liu, W.C.; Jang, Jason Shian-Ching

    2010-01-01

    The magnetostriction (λ s ) and tunneling magnetoresistance (TMR) of two Co/AlO x /Co/IrMn MTJ systems that were deposited on Si(1 0 0) and glass substrate were examined at RT and field-annealing with various thicknesses of AlO x . One structure was a Si(1 0 0)/Ta/Co/AlO x /Co/IrMn/Ta system, and the other was a glass/Co/AlO x /Co/IrMn system. The experimental results reveal that, in the Si(1 0 0)/Ta/Co/AlO x /Co/IrMn/Ta system, the ratio of TMR is maximal under the field-annealing condition, and is optimal at an AlO x thickness of 26 A as well as in the RT condition. EDS analysis demonstrates that, these results are related to the distribution of Co and O atoms, because the oxidation of AlO x is most extensive at a thickness of 26 A. In the glass/Co/AlO x /Co/IrMn system, λ s does not significantly vary under the RT condition; however, λ s is maximized (-20 ppm) by field-annealing at an AlO x thickness of 17 A. The abundance of Co and O in the system dominates the behavior of λ s , according to EDS analysis. Finally, the minimum value of λ s and the maximum ratio of TMR are -8 ppm and 60%, respectively, at an AlO x thickness of 26 A under the field-annealing condition.

  19. Conformation of Single Pentablock Ionomer Chains in Dilute Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Aryal, Dipak [Clemson Univ., SC (United States); Perahia, Dvora [Clemson Univ., SC (United States); Grest, Gary S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-04-01

    The conformation of single chain pentablock ionomers (A-B-C-B-A) containing randomly sulfonated polystyrene in the center block, tethered to poly-ethylene-r-propylene end-capped by poly-t-butyl styrene is studied in dilute solutions by molecular dynamics simulations. Multi-block copolymers offer a means to tailor several properties into one molecule, taking advantage of their rich phase diagram together with unique properties of specific blocks. For this pentablock the ionic block facilitates transport while the A and B components are incorporated for mechanical stability. The present study investigates the confirmation of a single chain of pentablock ionomer of molecular weight Mw ~ 50,000 g/mol and sulfonated polystyrene of the same molecular weight as that of the center block for six sulfonation fractions f from f=0.0-0.55. For the sulfonated systems Na+ counterions are included. Results for the equilibrium conformation of the chains and the three blocks in water and 1:1 mixture of cyclohexane and n-heptane are compared to simulations in implicit poor solvents with dielectric constants ε =1.0 and 77.73. In water, the pentablock is collapsed with sulfonated groups on the outer surface. As the sulfonation fraction f increases, the ionic, center block is increasingly segregated from the hydrophobic regions. In the 1:1 mixture of cyclohexane and heptane both the flexible and end blocks are swollen while the center ionic block is collasped for f>0, while for f=0 all blocks are swollen. In both implicit poor solvents the pentablock is collapsed into a nearly spherical shape for all f. The sodium counterions are dispersed widely throughout the simulation cell for both water and ε =77.73 whereas for ε =1.0 the counterions are largely condensed on the collapsed pentablock.

  20. Interactions between Zygosaccharomyces mellis and Wallemia sebi in diluted molasses.

    Science.gov (United States)

    Vindeløv, J; Arneborg, N

    2001-01-22

    The yeast Zygosaccharomyces mellis and the mould Wallemia sebi were isolated from the same sample of crystalline sugar. Interactions between these fungi were investigated using a diluted molasses medium (water activity 0.89, pH 6.0) as a model system for the syrup film covering the surface of moist crystalline sugar. Single and mixed cultures of Z. mellis and W. sebi were incubated at 25 degrees C for 400 h. Our results show that the growth of Z. mellis in single culture was limited by available glucose and fructose, and that W sebi was able to invert sucrose to glucose and fructose in both single and mixed culture. Furthermore, the presence of W. sebi in the mixed culture increased the maximum specific growth rate of Z. mellis from 0.074 to 0.19 h(-1) and the growth yield of Z. mellis from 7.3 x 10(6) to 5.4 x 10(7) cfu/ml. These results indicate that the ability of W. sebi to invert sucrose may stimulate the growth of Z. mellis. Finally, the presence of Z. mellis inhibited the ability of W. sebi to invert sucrose: W. sebi was able to invert 1.0 g sucrose/l per h in single culture but only 0.6 g sucrose/l per h in mixed culture. As predicted by Raoults law, this corresponded to a reduction in the water activity of the growth medium from 0.890 to 0.850 in single culture, and to 0.865 in mixed culture.