WorldWideScience

Sample records for atomic energy control

  1. Atomic energy

    CERN Multimedia

    1996-01-01

    Interviews following the 1991 co-operation Agreement between the Department of Atomic Energy (DAE) of the Government of India and the European Organization for Nuclear Research (CERN) concerning the participation in the Large Hadron Collider Project (LHC) . With Chidambaram, R, Chairman, Atomic Energy Commission and Secretary, Department of Atomic Energy, Department of Atomic Energy (DAE) of the Government of India and Professor Llewellyn-Smith, Christopher H, Director-General, CERN.

  2. Energy from the Atom.

    Science.gov (United States)

    Smith, Patricia L.

    This curriculum guide was written to supplement fifth and sixth grade science units on matter and energy. It was designed to provide more in-depth material on the atom. The first part, "Teacher Guide," contains background information, biographical sketches of persons in the history of nuclear energy, vocabulary, answer sheets, management sheets…

  3. Quality assurance and quality control programme in the Personal Dosimetry Department of the Greek Atomic Energy Commission.

    Science.gov (United States)

    Kamenopoulou, V; Drikos, G; Carinou, E; Papadomarkaki, E; Askounis, P; Kyrgiakou, H; Kefalonitis, N

    2002-01-01

    A quality assurance (QA) and quality control (QC) programme was applied to the personal monitoring department (TLD based) of the Greek Atomic Energy Commission (GAEC). This programme was designed according to the recommendations of international bodies such as the International Organization for Standardization (ISO), the International Electrotechnical Commission (IEC), the International Atomic Energy Agency (IAEA) and the European Commission (CEC). This paper deals with the presentation of the QA/QC programme which includes administrative data and information, technical checking of the equipment, acceptance tests of new equipment and dosemeters, issuing and processing of the dosemeters, dose evaluation, record keeping and reporting, traceability and reproducibility, handling of complaints, internal reviews and external audits.

  4. High-energy atomic physics

    CERN Document Server

    Drukarev, Evgeny G

    2016-01-01

    This self-contained text introduces readers to the field of high-energy atomic physics - a new regime of photon-atom interactions in which the photon energies significantly exceed the atomic or molecular binding energies, and which opened up with the recent advent of new synchrotron sources. From a theoretical point of view, a small-parameter characteristic of the bound system emerged, making it possible to perform analytic perturbative calculations that can in turn serve as benchmarks for more powerful numerical computations. The first part of the book introduces readers to the foundations of this new regime and its theoretical treatment. In particular, the validity of the small-parameter perturbation expansion and of the lowest-order approximation is critically reviewed. The following chapters then apply these insights to various atomic processes, such as photoionization as a many-body problem, dominant mechanisms for the production of ions at higher energies, Compton scattering and ionization accompanied b...

  5. Atomic Batteries: Energy from Radioactivity

    OpenAIRE

    Kumar, Suhas

    2015-01-01

    With alternate, sustainable, natural sources of energy being sought after, there is new interest in energy from radioactivity, including natural and waste radioactive materials. A study of various atomic batteries is presented with perspectives of development and comparisons of performance parameters and cost. We discuss radioisotope thermal generators, indirect conversion batteries, direct conversion batteries, and direct charge batteries. We qualitatively describe their principles of operat...

  6. Atoms for pest control

    Energy Technology Data Exchange (ETDEWEB)

    Lindquist, D.A. (Joint FAO/IAEA Div. of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Vienna (Austria)) (and others)

    1984-06-01

    Insects cause losses estimated at between 8% and 20% of total production of crops and livestock throughout the world. With the aim of developing technologies which can reduce such losses, the Insect and Pest Control Section of the Joint FAO/IAEA Division actively sponsors projects and conducts research through the Entomology Section of the Agricultural Biotechnology Laboratory at Seibersdorf. In its work, the Section has placed considerable emphasis on the Sterile Insect Technique (SIT). This technique involves the sterilization and release of large numbers of insects of the target species into the area where control is to be achieved. There, the sterile insects mate with the fertile wild insects, which produce no progeny: the technique is thus a highly specific form of ''birth control''. It is being used against a number of pest species in several countries.

  7. A Quantum Model of Atoms (the Energy Levels of Atoms).

    Science.gov (United States)

    Rafie, Francois

    2001-01-01

    Discusses the model for all atoms which was developed on the same basis as Bohr's model for the hydrogen atom. Calculates the radii and the energies of the orbits. Demonstrates how the model obeys the de Broglie's hypothesis that the moving electron exhibits both wave and particle properties. (Author/ASK)

  8. International Atomic Energy Agency specialists meeting on experience in ageing, maintenance, and modernization of instrumentation and control systems for improving nuclear power plant availability

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This report presents the proceedings of the Specialist`s Meeting on Experience in Aging, Maintenance and Modernization of Instrumentation and Control Systems for Improving Nuclear Power Plant Availability that was held at the Ramada Inn in Rockville, Maryland on May 5--7, 1993. The Meeting was presented in cooperation with the Electric Power Research Institute, Oak Ridge National Laboratory and the International Atomic Energy Agency. There were approximately 65 participants from 13 countries at the Meeting. Individual reports have been cataloged separately.

  9. Atomic energy levels and Grotrian diagrams

    CERN Document Server

    Bashkin, Stanley

    1975-01-01

    Atomic Energy Levels and Grotrian Diagrams, Volume I: Hydrogen I - Phosphorus XV presents diagrams of various elements that show their energy level and electronic transitions. The book covers the first 15 elements according to their atomic number. The text will be of great use to researchers and practitioners of fields such as astrophysics that requires pictorial representation of the energy levels and electronic transitions of elements.

  10. Ultrasound control modelization at the Atomic Energy Commission; La modelisation du controle par ultrasons au commissariat a l`energie atomique

    Energy Technology Data Exchange (ETDEWEB)

    Calmon, P.; Lecoeur-Taibi, I.; Lhemery, A. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes et Systemes Avances

    1995-10-01

    The Champ-Sons code (for the ultrasonic field modelization) and of the Mephisto code (prediction of the ultrasonic echography from the a priori knowledge of the controlled piece and of the encountered defects) are presented with three applications: pipes with inner or outer cracks, rocket tank fuel with a welded joint and PWR pressure vessel with an irregular coating. (A.B.). 7 refs., 4 figs.

  11. A History of the Atomic Energy Commission

    Science.gov (United States)

    Buck, Alice L.

    1983-07-01

    This pamphlet traces the history of the US Atomic Energy Commission's twenty-eight year stewardship of the Nation's nuclear energy program, from the signing of the Atomic Energy Act on August 1, 1946 to the signing of the Energy Reorganization Act on October 11, 1974. The Commission's early concentration on the military atom produced sophisticated nuclear weapons for the Nation's defense and made possible the creation of a fleet of nuclear submarines and surface ships. Extensive research in the nuclear sciences resulted in the widespread application of nuclear technology for scientific, medical and industrial purposes, while the passage of the Atomic Energy Act of 1954 made possible the development of a nuclear industry, and enabled the United States to share the new technology with other nations.

  12. Why? The nuclear and atomic energy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwangwoong

    2009-01-15

    This book is a science comic book for students in elementary school, which contains energy and life such as our body and energy, animal and energy, plant and energy, kinetic energy, potential energy and the principle of the conservation of energy in the first part. The second part explains fossil fuel like coal, petroleum and natural gas. Next it deals with electric power, nuclear energy such as atom and molecule, nuclear fusion and energy for future like solar cell and black hole power plant.

  13. Energy Wave Model of Atom

    Institute of Scientific and Technical Information of China (English)

    伍细如

    2015-01-01

    proton emits energy wave, electron could sits any position away from nucleus, but be the most stable just when it sits at the trough of energy wave, and this position accords with Bohr radius and Schr?dinger equation.

  14. The Future of Atomic Energy

    Science.gov (United States)

    Fermi, E.

    1946-05-27

    There is definitely a technical possibility that atomic power may gradually develop into one of the principal sources of useful power. If this expectation will prove correct, great advantages can be expected to come from the fact that the weight of the fuel is almost negligible. This feature may be particularly valuable for making power available to regions of difficult access and far from deposits of coal. It also may prove a great asset in mobile power units for example in a power plant for ship propulsion. On the negative side there are some technical limitations to be applicability of atomic power of which perhaps the most serious is the impossibility of constructing light power units; also there will be some peculiar difficulties in operating atomic plants, as for example the necessity of handling highly radioactive substances which will necessitate, at least for some considerable period, the use of specially skilled personnel for the operation. But the chief obstacle in the way of developing atomic power will be the difficulty of organizing a large scale industrial development in an internationally safe way. This presents actually problems much more difficult to solve than any of the technical developments that are necessary, It will require an unusual amount of statesmanship to balance properly the necessity of allaying the international suspicion that arises from withholding technical secrets against the obvious danger of dumping the details of the procedures for an extremely dangerous new method of warfare on a world that may not yet be prepared to renounce war. Furthermore, the proper balance should be found in the relatively short time that will elapse before the 'secrets' will naturally become open knowledge by rediscovery on part of the scientists and engineers of other countries.

  15. Low Energy Atomic Photodesorption from Organic Coatings

    Directory of Open Access Journals (Sweden)

    Alessandro Lucchesini

    2016-10-01

    Full Text Available Organic coatings have been widely used in atomic physics during the last 50 years because of their mechanical properties, allowing preservation of atomic spins after collisions. Nevertheless, this did not produce detailed insight into the characteristics of the coatings and their dynamical interaction with atomic vapors. This has changed since the 1990s, when their adsorption and desorption properties triggered a renewed interest in organic coatings. In particular, a novel class of phenomena produced by non-destructive light-induced desorption of atoms embedded in the coating surface was observed and later applied in different fields. Nowadays, low energy non-resonant atomic photodesorption from organic coatings can be considered an almost standard technique whenever large densities of atomic vapors or fast modulation of their concentration are required. In this paper, we review the steps that led to this widespread diffusion, from the preliminary observations to some of the most recent applications in fundamental and applied physics.

  16. The mean excitation energy of atomic ions

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Oddershede, Jens; Sabin, John R.

    2015-01-01

    A method for calculation of the mean excitation energies of atomic ions is presented, making the calculation of the energy deposition of fast ions to plasmas, warm, dense matter, and complex biological systems possible. Results are reported to all ions of helium, lithium, carbon, neon, aluminum...

  17. The Harnessed Atom: Nuclear Energy & Electricity.

    Science.gov (United States)

    Department of Energy, Washington, DC. Nuclear Energy Office.

    This document is part of a nuclear energy curriculum designed for grades six through eight. The complete kit includes a written text, review exercises, activities for the students, and a teachers guide. The 19 lessons in the curriculum are divided into four units including: (1) "Energy and Electricity"; (2) "Understanding Atoms and Radiation"; (3)…

  18. ATOMIZATION CAUSED BY BOTTOM FLOW ENERGY DISSIPATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bottom flow energy dissipation is one of the common energydissipation methods for flood-releasing structures with high water head. Measures of this energy dissipation depend mainly on the turbulent action of hydraulic jump.In this paper, the physical process and the calculating methods of the atomization caused by bottom flow energy dissipation were studied, the computation models of atomization quantity for the self-aerated flow in overflow and hydraulic jump regions are presented, and the main results are of theoretical and practical significance for the hydraulic and electric engineering.

  19. Atomic Force Controlled Capillary Electrophoresis

    Science.gov (United States)

    Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham

    2010-03-01

    Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.

  20. Atomic orbital self-energy and electronegativity

    CERN Document Server

    Ribeiro, Mauro

    2016-01-01

    In this work, atomic calculations were performed within the local-density and generalized-gradient approximations of exchange and correlation density functionals within density-functional theory to provide accurate periodic trends of first ionization energies and electron affinities of the atomic series from hydrogen to xenon. Electronegativities were determined directly from Mulliken's formula and were shown to be equivalently calculated rather by using Slater-Janak's transition state or by calculating the electrostatic self-energies of the orbitals involved in the transition to ions. Finally, comparisons were made with other theoretical and experimental results, including Mulliken-Jaff\\'e's electronegativity scale.

  1. Probing Dark Energy with Atom Interferometry

    CERN Document Server

    Burrage, Clare; Hinds, E A

    2015-01-01

    Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

  2. Atomic Interferometry Test of Dark Energy

    CERN Document Server

    Brax, Philippe

    2016-01-01

    Atomic interferometry can be used to probe dark energy models coupled to matter. We consider the constraints coming from recent experimental results on models generalising the inverse power law chameleons such as $f(R)$ gravity in the large curvature regime, the environmentally dependent dilaton and symmetrons. Using the tomographic description of these models, we find that only symmetrons with masses smaller than the dark energy scale can be efficiently tested. In this regime, the resulting constraints complement the bounds from the E\\"otwash experiment and exclude small values of the symmetron self-coupling.

  3. Atomic displacement energy in amorphous compounds

    Science.gov (United States)

    Sanditov, D. S.; Mashanov, A. A.

    2016-12-01

    Atomic displacement energy Δɛe in multicomponent sheet and lead-silicate glasses is calculated from the free activation energy of a viscous flow. The value of Δɛe is shown to remain constant in a rather wide range of temperatures in the glass transition region. Satisfactory agreement with calculations of Δɛe using the current formula incorporating the glass transition temperature and the fluctuation volume fraction frozen at this temperature is obtained. The validity of the above formula not only at the glass transition temperature but also in the temperature region adjacent to it is confirmed.

  4. On the energy of electric field in hydrogen atom

    OpenAIRE

    Kornyushin, Yuri

    2009-01-01

    It is shown that hydrogen atom is a unique object in physics having negative energy of electric field, which is present in the atom. This refers also to some hydrogen-type atoms: hydrogen anti-atom, atom composed of proton and antiproton, and positronium.

  5. Atomic Mass and Nuclear Binding Energy for F-35 (Fluorine)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume A `Nuclei with Z = 1 - 54' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope F-35 (Fluorine, atomic number Z = 9, mass number A = 35).

  6. Ground Levels and Ionization Energies for the Neutral Atoms

    Science.gov (United States)

    SRD 111 Ground Levels and Ionization Energies for the Neutral Atoms (Web, free access)   Data for ground state electron configurations and ionization energies for the neutral atoms (Z = 1-104) including references.

  7. Precision Control of Cold Rubidium Atoms

    Science.gov (United States)

    Nic Chormaic, Síle; Deasy, Kieran; Morrissey, Michael; Shortt, Brian; Yarovitskiy, Alexander

    2005-10-01

    Research interest in designing sources of cold atoms has significantly increased during the past 10 years with the development of suitable laser sources for magneto-optical trapping and the further mastering of evaporative cooling in order to achieve Bose-Einstein condensation. The magneto-optical trap is now viewed as a standard research facility worldwide and has opened up many exciting research directions in atomic physics. One area of interest is that of combining spherical microcavities with cold atomic sources in order to achieve efficient photon exchange between the cavity and atom for further understandings of cavity quantum electrodynamics. This could eventually lead to atom entanglement via photon exchange, which would have implications for quantum logic design. However, initial attempts to achieve such interactions have been hindered by inadequate control and manipulation of the cold atom source. Here, we present work on designing and building an ultra-stable source of magneto-optically cooled rubidium atoms with a temperature in the tens of μK range. We present a suitable experimental arrangement including details on the ultra-high vacuum chamber, the laser systems being used, and the source of rubidium vapor. We discuss some future directions for the research, including diffraction of atoms from gratings and micron-sized objects and parameter control of the atom cloud.

  8. 32 CFR 2400.4 - Atomic Energy Material.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Atomic Energy Material. 2400.4 Section 2400.4... General Provisions § 2400.4 Atomic Energy Material. Nothing in this Regulation supersedes any requirement made by or under the Atomic Energy act of 1954, as amended. “Restricted Data” and...

  9. Atom-interferometry constraints on dark energy

    CERN Document Server

    Hamilton, Paul; Haslinger, Philipp; Simmons, Quinn; Müller, Holger; Khoury, Justin

    2015-01-01

    If dark energy---which drives the accelerated expansion of the universe---consists of a new light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity. There has, however, been much theoretical progress in developing theories with screening mechanisms, which can evade detection by suppressing forces in regions of high density, such as the laboratory. One prominent example is the chameleon field. We reduce the effect of this screening mechanism by probing the chameleon with individual atoms rather than bulk matter. Using a cesium matter-wave interferometer near a spherical mass in an ultra-high vacuum chamber, we constrain a wide class of dynamical dark energy theories. Our experiment excludes a range of chameleon theories that reproduce the observed cosmic acceleration.

  10. Laser controlled atom source for optical clocks

    Science.gov (United States)

    Kock, Ole; He, Wei; Świerad, Dariusz; Smith, Lyndsie; Hughes, Joshua; Bongs, Kai; Singh, Yeshpal

    2016-11-01

    Precision timekeeping has been a driving force in innovation, from defining agricultural seasons to atomic clocks enabling satellite navigation, broadband communication and high-speed trading. We are on the verge of a revolution in atomic timekeeping, where optical clocks promise an over thousand-fold improvement in stability and accuracy. However, complex setups and sensitivity to thermal radiation pose limitations to progress. Here we report on an atom source for a strontium optical lattice clock which circumvents these limitations. We demonstrate fast (sub 100 ms), cold and controlled emission of strontium atomic vapours from bulk strontium oxide irradiated by a simple low power diode laser. Our results demonstrate that millions of strontium atoms from the vapour can be captured in a magneto-optical trap (MOT). Our method enables over an order of magnitude reduction in scale of the apparatus. Future applications range from satellite clocks testing general relativity to portable clocks for inertial navigation systems and relativistic geodesy.

  11. Feedback Control of MEMS to Atoms

    CERN Document Server

    Shapiro, Benjamin

    2012-01-01

    Feedback Control of MEMS to Atoms illustrates the use of control and control systems as an essential part of functioning integrated miniaturized systems. The book is organized according to the dimensional scale of the problem, starting with microscale systems and ending with atomic-scale systems. Similar to macroscale machines and processes, control systems can play a major role in improving the performance of micro- and nanoscale systems and in enabling new capabilities that would otherwise not be possible. The majority of problems at these scales present many new challenges that go beyond the current state-of-the-art in control theory and engineering. This is a result of the multidisciplinary nature of micro/nanotechnology, which requires the merging of control engineering with physics, biology and chemistry. This book: Shows how the utilization of feedback control in nanotechnology instrumentation can yield results far better than passive systems can Discusses the application of control systems to problems...

  12. Atom-Interferometry Constraints on Dark Energy

    Science.gov (United States)

    Mueller, Holger

    2016-03-01

    If dark energy is a light scalar field, it might interact with normal matter. The interactions, however, are suppressed in some leading models, which are thus compatible with current cosmological observations as well as solar-system and laboratory studies. Such suppression typically relies on the scalar's interaction with macroscopic amounts of ordinary matter, but can be bypassed by studying the interaction with individual particles. Using an atom interferometer, we have placed tight constraints on so-called chameleon models, ruling out interaction parameters βM > 4 ×104 . This limit is improved by 2.5 orders of magnitude relative to previous experiments. We have already increased the sensitivity of our interferometer hundredfold and are expecting a new constraint soon. Purpose-built experiments in the lab or on the international space station will completely close the gap and rule out out chameleons and other theories, such as axions, dark photons, symmetrons or f (R) gravity.

  13. Controlling a d-level atom in a cavity

    Energy Technology Data Exchange (ETDEWEB)

    Keyl, Michael [TU Muenchen, Fakultaet Mathematik, 85748 Garching (Germany)

    2016-07-01

    In this talk we discuss quantum control theory for a d-level atom in a cavity. The atom is described by a Graph Γ with energy levels as vertices and edges e as allowed transitions. For each such e the atom interacts (via a Jaynes-Cummings like interaction term) with a different mode of the cavity. We consider controllability of the overall system (i.e. atom and cavity) under the assumption that all atom-cavity interactions can be switched on and off individually and that the atom itself is fully controllable. Our main tools are symmetry based arguments recently introduced for the discussion of the two-level case. The basic idea is to divide the control Hamiltonians into two sets. One which is invariant under the action of an Abelian symmetry group G and a second set which breaks this symmetry. We will discuss how the group G and its action are related to the graph Γ and its fundamental groupoid, and how these structure can be used to prove full controllability - at least if Γ is acyclic. For Graphs containing cycles the situation is more difficult and the universal covering graph has to be used. We demonstrate this, using the fully connected graph on three vertices as an example.

  14. Atomic Mass and Nuclear Binding Energy for Ra-226 (Radium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides atomic mass, mass excess, nuclear binding energy, nucleon separation energies, Q-values, and nucleon residual interaction parameters for atomic nuclei of the isotope Ra-226 (Radium, atomic number Z = 88, mass number A = 226).

  15. Quickening nature's pulse: atomic agriculture at the International Atomic Energy Agency.

    Science.gov (United States)

    Hamblin, Jacob Darwin

    2015-01-01

    Mutation breeders in the 1960s seemed poised to use atomic energy to speed up mutation rates in plants in order to develop new crop varieties, for the benefit of all people. Although skepticism had slowed this work in the United States, the International Atomic Energy Agency (IAEA) nurtured the scientific field, its community of experts, and an imagined version of the future that put humans in control of their destiny. The IAEA acted as a center of dissemination and support for experts and ideas even when they had fallen from favor elsewhere. Through the lens of the IAEA, plant breeding bore the appearance of a socially progressive, ultra-modern science destined to alleviate population pressures. Administrators at the IAEA also were desperate for success stories, hoping to highlight mutation plant breeding as a potential solution to the world's ills. The community of mutation plant breeders gained a lifeline from the consistent clarion call from the Vienna-based agency to use atomic energy to understand the natural world and quicken its pulse with radioisotopes.

  16. A liquid drop model for embedded atom method cluster energies

    Science.gov (United States)

    Finley, C. W.; Abel, P. B.; Ferrante, J.

    1996-01-01

    Minimum energy configurations for homonuclear clusters containing from two to twenty-two atoms of six metals, Ag, Au, Cu, Ni, Pd, and Pt have been calculated using the Embedded Atom Method (EAM). The average energy per atom as a function of cluster size has been fit to a liquid drop model, giving estimates of the surface and curvature energies. The liquid drop model gives a good representation of the relationship between average energy and cluster size. As a test the resulting surface energies are compared to EAM surface energy calculations for various low-index crystal faces with reasonable agreement.

  17. Determination of Atomic Data Pertinent to the Fusion Energy Program

    Energy Technology Data Exchange (ETDEWEB)

    Reader, J.

    2013-06-11

    We summarize progress that has been made on the determination of atomic data pertinent to the fusion energy program. Work is reported on the identification of spectral lines of impurity ions, spectroscopic data assessment and compilations, expansion and upgrade of the NIST atomic databases, collision and spectroscopy experiments with highly charged ions on EBIT, and atomic structure calculations and modeling of plasma spectra.

  18. Optimal control of complex atomic quantum systems

    Science.gov (United States)

    van Frank, S.; Bonneau, M.; Schmiedmayer, J.; Hild, S.; Gross, C.; Cheneau, M.; Bloch, I.; Pichler, T.; Negretti, A.; Calarco, T.; Montangero, S.

    2016-10-01

    Quantum technologies will ultimately require manipulating many-body quantum systems with high precision. Cold atom experiments represent a stepping stone in that direction: a high degree of control has been achieved on systems of increasing complexity. However, this control is still sub-optimal. In many scenarios, achieving a fast transformation is crucial to fight against decoherence and imperfection effects. Optimal control theory is believed to be the ideal candidate to bridge the gap between early stage proof-of-principle demonstrations and experimental protocols suitable for practical applications. Indeed, it can engineer protocols at the quantum speed limit – the fastest achievable timescale of the transformation. Here, we demonstrate such potential by computing theoretically and verifying experimentally the optimal transformations in two very different interacting systems: the coherent manipulation of motional states of an atomic Bose-Einstein condensate and the crossing of a quantum phase transition in small systems of cold atoms in optical lattices. We also show that such processes are robust with respect to perturbations, including temperature and atom number fluctuations.

  19. Solar and Geothermal Energy: New Competition for the Atom

    Science.gov (United States)

    Carter, Luther J.

    1974-01-01

    Describes new emphasis on research into solar and geothermal energy resources by governmental action and recent legislation and the decreased emphasis on atomic power in supplementing current energy shortages. (BR)

  20. Books on Atomic Energy for Adults and Children

    Energy Technology Data Exchange (ETDEWEB)

    None

    1969-01-01

    This booklet contains two lists of atomic energy books, one for students and one for adults. The student list has grade annotations. The lists are not all-inclusive but comprise selected basic books on atomic energy and closely related subjects.

  1. Positronium-alkali atom scattering at medium energies

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Ajoy [Laban Hrad Vidyapith, AD-369, Salt Lake City, Kolkata 700 064 (India); Basu, Arindam [Department of Physics, Maheshtala College, Chandannagar, South 24 Parganas, Kolkata 700 140 (India); Sarkar, Nirmal K [Sodepur Chandrachur Vidyapith, 1, Desh Bandhu Nagar, Sodepur, 743 174 (India); Sinha, Prabal K [Department of Physics, Bangabasi College, 19, Raj Kumar Chakravorty Sarani, Kolkata 700 009 (India)

    2004-04-28

    We investigate the scattering of orthopositronium (o-Ps) atom off different atomic alkali targets (Na to Cs) at low and medium energies (up to 120 eV). Projectile-elastic and target-elastic close-coupling models have been employed to investigate the systems in addition to the static-exchange model. Elastic, excitation and total cross sections have been reported for all four systems. The magnitude of the alkali excitation cross section increases with increasing atomic number of the target atom while the position of the peak value shifts towards lower incident energies. The magnitudes of the Ps excitation and ionization cross sections increase steadily with atomic number with no change in the peak position. The reported results show regular behaviour with increasing atomic number of the target atom. Scattering parameters for the Ps-Rb and Ps-Cs systems are being reported for the first time.

  2. Atomic level spatial variations of energy states along graphene edges.

    Science.gov (United States)

    Warner, Jamie H; Lin, Yung-Chang; He, Kuang; Koshino, Masanori; Suenaga, Kazu

    2014-11-12

    The local atomic bonding of carbon atoms around the edge of graphene is examined by aberration-corrected scanning transmission electron microscopy (STEM) combined with electron energy loss spectroscopy (EELS). High-resolution 2D maps of the EELS combined with atomic resolution annular dark field STEM images enables correlations between the carbon K-edge EELS and the atomic structure. We show that energy states of graphene edges vary across individual atoms along the edge according to their specific C-C bonding, as well as perpendicular to the edge. Unique spectroscopic peaks from the EELS are assigned to specific C atoms, which enables unambiguous spectroscopic fingerprint identification for the atomic structure of graphene edges with unprecedented detail.

  3. Energy spectrum of fermionized bosonic atoms in optical lattices

    Institute of Scientific and Technical Information of China (English)

    Jiurong Han; Haichao Zhang; Yuzhu Wang

    2005-01-01

    We investigate the energy spectrum of fermionized bosonic atoms, which behave very much like spinless noninteracting fermions, in optical lattices by means of the perturbation expansion and the retarded Green's function method. The results show that the energy spectrum splits into two energy bands with single-occupation; the fermionized bosonic atom occupies nonvanishing energy state and left hole has a vanishing energy at any given momentum, and the system is in Mott-insulating state with a energy gap.Using the characteristic of energy spectra we obtained a criterion with which one can judge whether the Tonks-Girardeau (TG) gas is achieved or not.

  4. Atom-Role-Based Access Control Model

    Science.gov (United States)

    Cai, Weihong; Huang, Richeng; Hou, Xiaoli; Wei, Gang; Xiao, Shui; Chen, Yindong

    Role-based access control (RBAC) model has been widely recognized as an efficient access control model and becomes a hot research topic of information security at present. However, in the large-scale enterprise application environments, the traditional RBAC model based on the role hierarchy has the following deficiencies: Firstly, it is unable to reflect the role relationships in complicated cases effectively, which does not accord with practical applications. Secondly, the senior role unconditionally inherits all permissions of the junior role, thus if a user is under the supervisor role, he may accumulate all permissions, and this easily causes the abuse of permission and violates the least privilege principle, which is one of the main security principles. To deal with these problems, we, after analyzing permission types and role relationships, proposed the concept of atom role and built an atom-role-based access control model, called ATRBAC, by dividing the permission set of each regular role based on inheritance path relationships. Through the application-specific analysis, this model can well meet the access control requirements.

  5. Streaming current of a rotary atomizer for energy harvesting

    NARCIS (Netherlands)

    Nguyen, Trieu; Boer, de H.; Tran, T.; Berg, van den A.; Eijkel, J.C.T.; Zengerle, R.

    2013-01-01

    We present the experimental results of an energy conversion system based on a rotary atomizer and the streaming current phenomenon. The advantage of using a rotary atomizer instead of a channel or membrane micropore as in conventional pressure-driven approached is that the centrifugal force exerted

  6. Energy scaling of cold atom-atom-ion three-body recombination

    CERN Document Server

    Krükow, Artjom; Härter, Arne; Denschlag, Johannes Hecker; Pérez-Ríos, Jesús; Greene, Chris H

    2015-01-01

    We study three-body recombination of Ba$^+$ + Rb + Rb in the mK regime where a single $^{138}$Ba$^{+}$ ion in a Paul trap is immersed into a cloud of ultracold $^{87}$Rb atoms. We measure the energy dependence of the three-body rate coefficient $k_3$ and compare the results to the theoretical prediction, $k_3 \\propto E_{\\textrm{col}}^{-3/4}$ where $E_{\\textrm{col}}$ is the collision energy. We find agreement if we assume that the non-thermal ion energy distribution is determined by at least two different micro-motion induced energy scales. Furthermore, using classical trajectory calculations we predict how the median binding energy of the formed molecules scales with the collision energy. Our studies give new insights into the kinetics of an ion immersed into an ultracold atom cloud and yield important prospects for atom-ion experiments targeting the s-wave regime.

  7. Determination of Surface Exciton Energies by Velocity Resolved Atomic Desorption

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Wayne P.; Joly, Alan G.; Beck, Kenneth M.; Sushko, Petr V.; Shluger, Alexander L.

    2004-08-20

    We have developed a new method for determining surface exciton band energies in alkali halides based on velocity-resolved atomic desorption (VRAD). Using this new method, we predict the surface exciton energies for K1, KBr, KC1, and NaC1 within +0.15 eV. Our data, combined with the available EELS data for alkali fluorides, demonstrate a universal linear correlation with the inverse inter-atomic distance in these materials. The results suggest that surface excitons exist in all alkali halides and their excitation energies can be predicted from the known bulk exciton energies and the obtained correlation plot.

  8. An informational approach about energy and temperature in atoms

    Science.gov (United States)

    Flores-Gallegos, N.

    2016-08-01

    In this letter, we introduce new definitions of energy and temperature based on the information theory model, and we show that our definition of informational energy is related to the kinetic energy of the Thomas-Fermi model, meanwhile the definition of informational temperature proposed, permit identify 'hot' and 'cold' zones of an atom, such zones are related to the changes in the local electron energy wherein the chemical and physical changes can occur; informational temperature also can reproduce the shell structure of an atom.

  9. CPT Magnetometer with Atomic Energy Level Modulation

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-Bin; DU Run-Chang; LIU Chao-Yang; GU Si-Hong

    2008-01-01

    We propose and experimentally investigate a coherent population trapping state based magnetometer prototype with87 Rb atoms.Through modulating Zeeman sublevels with an ac magnetic field,not only a phase sensitive detection scheme suitable for miniature magnetometer is realized,but also the detection resolution of magnetic field intensity could be improved by a factor of two.Our study result indicates that it is a promising low power consumption miniature sensitive low magnetic field sensor offering spatially resolved measurement at the sub-millimetre level.

  10. Two atoms scattering at low and cold energies

    Indian Academy of Sciences (India)

    Hasi Ray

    2014-12-01

    A modified static-exchange model is developed to study the collision of an atom with another atom. It includes the effect of long-range dipole–dipole van der Waals interaction between two atoms in addition to the exact effect of short-range force due to Coulomb exchange between two system electrons. Both these interactions dominate at colder energies. The system is treated as a four-centre problem in the centre-of-mass frame. The present ab-initio model is useful to study the two-atomic collisions at low energies, as well as cold energies. The new code is applied to study the scattering of positronium (Ps) by hydrogen (H), both in their ground states.

  11. Chameleon dark energy and atom interferometry

    Science.gov (United States)

    Elder, Benjamin; Khoury, Justin; Haslinger, Philipp; Jaffe, Matt; Müller, Holger; Hamilton, Paul

    2016-08-01

    Atom interferometry experiments are searching for evidence of chameleon scalar fields with ever-increasing precision. As experiments become more precise, so too must theoretical predictions. Previous work has made numerous approximations to simplify the calculation, which in general requires solving a three-dimensional nonlinear partial differential equation. This paper calculates the chameleonic force using a numerical relaxation scheme on a uniform grid. This technique is more general than previous work, which assumed spherical symmetry to reduce the partial differential equation to a one-dimensional ordinary differential equation. We examine the effects of approximations made in previous efforts on this subject and calculate the chameleonic force in a setup that closely mimics the recent experiment of Hamilton et al. Specifically, we simulate the vacuum chamber as a cylinder with dimensions matching those of the experiment, taking into account the backreaction of the source mass, its offset from the center, and the effects of the chamber walls. Remarkably, the acceleration on a test atomic particle is found to differ by only 20% from the approximate analytical treatment. These results allow us to place rigorous constraints on the parameter space of chameleon field theories, although ultimately the constraint we find is the same as the one we reported in Hamilton et al. because we had slightly underestimated the size of the vacuum chamber. This computational technique will continue to be useful as experiments become even more precise and will also be a valuable tool in optimizing future searches for chameleon fields and related theories.

  12. Chameleon Dark Energy and Atom Interferometry

    CERN Document Server

    Elder, Benjamin; Haslinger, Philipp; Jaffe, Matt; Müller, Holger; Hamilton, Paul

    2016-01-01

    Atom interferometry experiments are searching for evidence of chameleon scalar fields with ever-increasing precision. As experiments become more precise, so too must theoretical predictions. Previous work has made numerous approximations to simplify the calculation, which in general requires solving a 3-dimensional nonlinear partial differential equation (PDE). In this paper, we introduce a new technique for calculating the chameleonic force, using a numerical relaxation scheme on a uniform grid. This technique is more general than previous work, which assumed spherical symmetry to reduce the PDE to a 1-dimensional ordinary differential equation (ODE). We examine the effects of approximations made in previous efforts on this subject, and calculate the chameleonic force in a set-up that closely mimics the recent experiment of Hamilton et al. Specifically, we simulate the vacuum chamber as a cylinder with dimensions matching those of the experiment, taking into account the backreaction of the source mass, its o...

  13. Seeking to Improve Low Energy Neutral Atom Detection in Space

    Science.gov (United States)

    Shappirio, M.; Coplan, M.; Chornay, D.; Collier, M.; Herrero, F.; Ogilvie, K.; Williams, E.

    2007-01-01

    The detection of energetic neutral atoms allows for the remote examination of the interactions between plasmas and neutral populations in space. Before these neutral atoms can be measured, they must first be converted to ions. For the low energy end of this spectrum, interaction with a conversion surface is often the most efficient method to convert neutrals into ions. It is generally thought that the most efficient surfaces are low work functions materials. However, by their very nature, these surfaces are highly reactive and unstable, and therefore are not suitable for space missions where conditions cannot be controlled as they are in a laboratory. We therefore are looking to optimize a stable surface for conversion efficiency. Conversion efficiency can be increased either by changing the incident angle of the neutral particles to be grazing incidence and using stable surfaces with high conversion efficiencies. We have examined how to increase the angle of incidence from -80 degrees to -89 degrees, while maintaining or improving the total active conversion surface area without increasing the overall volume of the instrument. We are developing a method to micro-machine silicon, which will reduce the volume to surface area ratio by a factor of 60. We have also examined the material properties that affect the conversion efficiency of the surface for stable surfaces. Some of the parameters we have examined are work function, smoothness, and bond structure. We find that for stable surfaces, the most important property is the smoothness of the surface.

  14. Positron impact ionization of atomic hydrogen at low energies

    Indian Academy of Sciences (India)

    K Chakrabarti

    2001-04-01

    Low energy positron impact ionization of atomic hydrogen is studies theoretically using the hyperspherical partial wave method of Das [1] in constant 12, equal energy sharing geometry. The TDCS reveal considerable differences in physics compared to electron impact ionization under the same geometry.

  15. An atomic clockwork using phase dependent energy shifts

    CERN Document Server

    De Munshi, D; Mukherjee, M

    2011-01-01

    A frequency stabilized laser referenced to an unperturbed atomic two level system acts as the most accurate clock with femtosecond clock ticks. For any meaningful use, a Femtosecond Laser Frequency Comb (FLFC) is used to transfer the atomic clock accuracy to electronically countable nanosecond clock ticks. Here we propose an alternative clockwork based on the phenomenon that when an atomic system is slowly evolved in a cyclic path, the atomic energy levels gather some phase called the geometric phase. This geometric phase dependent energy shift has been used here to couple the two frequency regimes in a phase coherent manner. It has also been shown that such a technique can be implemented experimentally, bypassing the highly involved setup of a FLFC.

  16. Population coherent control of Rydberg potassium atom via adiabatic passage

    Institute of Scientific and Technical Information of China (English)

    Jiang Li-Juan; Zhang Xian-Zhou; Jia Guang-Rui; Zhang Yong-Hui; Xia Li-Hua

    2013-01-01

    The time-dependent multilevel approach (TDMA) and B-spline expansion technique are used to study the coherent population transfer between the quantum states of a potassium atom by a single frequency-chirped microwave pulse.The Rydberg potassium atom energy levels of n =6-15,l =0-5 states in zero field are calculated and the results are in good agreement with other theoretical values.The time evolutions of the population transfer of the six states from n =70 to n =75 in different microwave fields are obtained.The results show that the coherent control of the population transfer from the lower states to the higher ones can be accomplished by optimizing the microwave pulse parameters.

  17. General engineering ethics and multiple stress of atomic energy engineering

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kunihiko [Shibaura Inst. of Tech., Tokyo (Japan)

    1999-08-01

    The factors, by which the modern engineering ethics has been profoundly affected, were classified to three categories, namely mental blow, the destruction of human function and environment damage. The role of atomic energy engineering in the ethic field has been shown in the first place. It is pointed out that it has brought about the mental blow by the elucidation of universal truth and discipline and the functional disorder by the power supply. However, the direct effect of radiation to the human kinds is only a part of the stresses comparing to the accumulation of the social stress which should be taken into account of by the possibility of disaster and the suspicion of the atomic energy politics. An increase in the multiple stresses as well as the restriction of criticism will place obstacles on the promotion of atomic energy. (author)

  18. Atomic coherence control on the entanglement of two atoms in two-photon processes

    Institute of Scientific and Technical Information of China (English)

    Hu Yao-Hua; Fang Mao-Fa; Wu Qin

    2007-01-01

    Considering two identical two-level atoms interacting with a single-mode thermal field through two-photon processes, this paper studies the atomic coherence control on the entanglement between two two-level atoms, and finds that the entanglement is greatly enhanced due to the initial atomic coherence. The results show that the entanglement can be manipulated by changing the initial parameters of the system, such as the superposition coefficients and the relative phases of the initial atomic coherent state and the mean photon number of the cavity field.

  19. Automatic generation of reaction energy databases from highly accurate atomization energy benchmark sets.

    Science.gov (United States)

    Margraf, Johannes T; Ranasinghe, Duminda S; Bartlett, Rodney J

    2017-03-31

    In this contribution, we discuss how reaction energy benchmark sets can automatically be created from arbitrary atomization energy databases. As an example, over 11 000 reaction energies derived from the W4-11 database, as well as some relevant subsets are reported. Importantly, there is only very modest computational overhead involved in computing >11 000 reaction energies compared to 140 atomization energies, since the rate-determining step for either benchmark is performing the same 140 quantum chemical calculations. The performance of commonly used electronic structure methods for the new database is analyzed. This allows investigating the relationship between the performances for atomization and reaction energy benchmarks based on an identical set of molecules. The atomization energy is found to be a weak predictor for the overall usefulness of a method. The performance of density functional approximations in light of the number of empirically optimized parameters used in their design is also discussed.

  20. Understanding Atomic Structure: Is There a More Direct and Compelling Connection between Atomic Line Spectra and the Quantization of an Atom's Energy?

    Science.gov (United States)

    Rittenhouse, Robert C.

    2015-01-01

    The "atoms first" philosophy, adopted by a growing number of General Chemistry textbook authors, places greater emphasis on atomic structure as a key to a deeper understanding of the field of chemistry. A pivotal concept needed to understand the behavior of atoms is the restriction of an atom's energy to specific allowed values. However,…

  1. Correlated energy transfer between two ultracold atomic species

    Science.gov (United States)

    Krönke, Sven; Knörzer, Johannes; Schmelcher, Peter

    2015-05-01

    We study a single atom as an open quantum system, which is initially prepared in a coherent state of low energy and oscillates in a one-dimensional harmonic trap through an interacting ensemble of NA bosons, held in a displaced trap [arXiv:1410.8676]. The non-equilibrium quantum dynamics of the total system is simulated by means of an ab-initio method, giving us access to all properties of the open system and its finite environment. In this talk, we focus on unraveling the interplay of energy exchange and correlations between the subsystems, which are coupled in such a spatio-temporally localized manner. We show that an inter-species interaction-induced level splitting accelerates the energy transfer between the atomic species for larger NA, which becomes less complete at the same time. System-environment correlations prove to be significant except for times when the excess energy distribution among the subsystems is highly imbalanced. These correlations result in incoherent energy transfer processes, which accelerate the early energy donation of the single atom. By analyzing correlations between intra-subsystem excitations, certain energy transfer channels are shown to be (dis-)favored depending on the instantaneous direction of transfer.

  2. Non—conservation of energy arising from atomic dipole interactions and its effects on light field and coupled atoms

    Institute of Scientific and Technical Information of China (English)

    DongChuan-Hua

    2003-01-01

    The interactions between coulpled atoms and a single mode of a quantized electromagnetic field, which involve the terms originating from the dipole interactions, are discussed. In the usual Jaynes-Cummings model for coupled atoms, the terms of non-conservation of energy originating from dipole interactions are neglected, however, we take them into consideration in this paper. The effects of these terms on the evolutions of quantum statistic properties and squeezing of the field, the squeezing of atomic dipole moments and atomic population inversion are investigated. It has been shown that the coupling between atoms modulates these evolutions of fields and atoms. The terms of non-conservation of energy affect these evolutions of field and atoms slightly. They also have effects on the squeezing of the field, the squeezing of atomic dipole and atomic population inversions. The initial states of atoms also affect these properties.

  3. Non-conservation of energy arising from atomic dipole interactions and its effects on light field and coupled atoms

    Institute of Scientific and Technical Information of China (English)

    董传华

    2003-01-01

    The interactions between coupled atoms and a single mode of a quantized electromagnetic field, which involve the terms originating from the dipole interactions, are discussed. In the usual Jaynes Cummings model for coupled atoms,the terms of non-conservation of energy originating from dipole interactions are neglected, however, we take them into consideration in this paper. The effects of these terms on the evolutions of quantum statistic properties and squeezing of the field, the squeezing of atomic dipole moments and atomic population inversion are investigated. It has been shown that the coupling between atoms modulates these evolutions of fields and atoms. The terms of non-conservation of energy affect these evolutions of fields and atoms slightly. They also have effects on the squeezing of the field, the squeezing of atomic dipole and atomic population inversions. The initial states of atoms also affect these properties.

  4. Correlation Between Energy Transfer Rate and Atomization Energy of Some Trinitro Aromatic Explosive Molecules

    Institute of Scientific and Technical Information of China (English)

    Su-hong Ge; Xin-lu Cheng; Zheng-lai Liu; Xiang-dong Yang; Fang-fang Dong

    2008-01-01

    An assumptive theoretical relationship is suggested to describe the property of molecular atomization energy and energy transfer rate in the initiation of explosions. To investigate the relationship between atomization energy and energy transfer rate, the number of doorway modes of explosives is estimated by the theory of Dlott and Fayer in which the rate is proportional to the number of normal mode vibrations. It was evaluated frequencies of normal mode vibrations of eight molecules by means of density functional theory (DFT) at the b3p86/6-31G(d,p) level. It is found that the number of doorway modes shows a linear correlation to the atomization energies of the molecules, which were also calculated by means of the same method. A mechanism of this correlation is discussed. It is also noted that in those explosives with similar molecular structure and molecular weight, the correlation between the atomization energy and the number of doorway modes is higher.

  5. Corrections to the Nonrelativistic Ground Energy of a Helium Atom

    Institute of Scientific and Technical Information of China (English)

    段一士; 刘玉孝; 张丽杰

    2004-01-01

    Considering the nuclear motion, we present the nonrelativistic ground energy of a helium atom by using a simple effective variational wavefunction with a flexible parameter k. Based on the result, the relativistic and radiative corrections to the nonrelativistic Hamiltonian are discussed. The high precision value of the helium ground energy is evaluated to be -2.90338 a.u. With the relative error 0.00034%.

  6. Estimation of correlation energy for excited-states of atoms

    CERN Document Server

    Hemanadhan, M

    2014-01-01

    The correlation energies of various atoms in their excited-states are estimated by modelling the Coulomb hole following the previous work by Chakravorty and Clementi. The parameter in the model is fixed by making the corresponding Coulomb hole to satisfy the exact constraint of charge neutrality.

  7. A Bibliography of Basic Books on Atomic Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1974-01-01

    This booklet lists selected commercially published books for the general public on atomic energy and closely related subjects. Books for young readers have school grade annotations.This booklet contains an author index, a title index, and a list of publishers’ addresses.

  8. Delegation from the Pakistan Atomic Energy Commission (PAEC)

    CERN Multimedia

    Patrice Loiez

    2002-01-01

    L. to r.: Dr Hafeez Hoorani (NCP) and Dr Michel Della Negra, Spokesman, CMS experiment with a delegation from the Pakistan Atomic Energy Commission: Mr Saeed Ahmed, Director SES, PAEC, Mr Muhammad Naeem, Director PWI and Mr Javed Iqleem, Deputy Chairman PAEC visiting the CMS magnet assembly hall at Point 5.

  9. Scientists credit `Atoms for Peace' for progress on energy, security

    CERN Multimedia

    Jones, D

    2003-01-01

    "Fifty years after President Eisenhower unveiled his plan for developing peaceful uses for nuclear fission, the scientific advances spawned by his Atoms for Peace program have made possible major advances in energy and national security, a panel of physicists said last week" (1 page).

  10. Atomic switches: atomic-movement-controlled nanodevices for new types of computing

    Directory of Open Access Journals (Sweden)

    Takami Hino, Tsuyoshi Hasegawa, Kazuya Terabe, Tohru Tsuruoka, Alpana Nayak, Takeo Ohno and Masakazu Aono

    2011-01-01

    Full Text Available Atomic switches are nanoionic devices that control the diffusion of metal cations and their reduction/oxidation processes in the switching operation to form/annihilate a metal atomic bridge, which is a conductive path between two electrodes in the on-state. In contrast to conventional semiconductor devices, atomic switches can provide a highly conductive channel even if their size is of nanometer order. In addition to their small size and low on-resistance, their nonvolatility has enabled the development of new types of programmable devices, which may achieve all the required functions on a single chip. Three-terminal atomic switches have also been developed, in which the formation and annihilation of a metal atomic bridge between a source electrode and a drain electrode are controlled by a third (gate electrode. Three-terminal atomic switches are expected to enhance the development of new types of logic circuits, such as nonvolatile logic. The recent development of atomic switches that use a metal oxide as the ionic conductive material has enabled the integration of atomic switches with complementary metal-oxide-semiconductor (CMOS devices, which will facilitate the commercialization of atomic switches. The novel characteristics of atomic switches, such as their learning and photosensing abilities, are also introduced in the latter part of this review.

  11. Multipolar electrostatics for proteins: atom-atom electrostatic energies in crambin.

    Science.gov (United States)

    Yuan, Yongna; Mills, Matthew J L; Popelier, Paul L A

    2014-02-15

    Accurate electrostatics necessitates the use of multipole moments centered on nuclei or extra point charges centered away from the nuclei. Here, we follow the former alternative and investigate the convergence behavior of atom-atom electrostatic interactions in the pilot protein crambin. Amino acids are cut out from a Protein Data Bank structure of crambin, as single amino acids, di, or tripeptides, and are then capped with a peptide bond at each side. The atoms in the amino acids are defined through Quantum Chemical Topology (QCT) as finite volume electron density fragments. Atom-atom electrostatic energies are computed by means of a multipole expansion with regular spherical harmonics, up to a total interaction rank of L = ℓA+ ℓB + 1 = 10. The minimum internuclear distance in the convergent region of all the 15 possible types of atom-atom interactions in crambin that were calculated based on single amino acids are close to the values calculated from di and tripeptides. Values obtained at B3LYP/aug-cc-pVTZ and MP2/aug-cc-pVTZ levels are only slightly larger than those calculated at HF/6-31G(d,p) level. This convergence behavior is transferable to the well-known amyloid beta polypeptide Aβ1-42. Moreover, for a selected central atom, the influence of its neighbors on its multipole moments is investigated, and how far away this influence can be ignored is also determined. Finally, the convergence behavior of AMBER becomes closer to that of QCT with increasing internuclear distance.

  12. Born-Oppenheimer approximation of quantized cavity-atom system and localization control of atomic tunneling

    Institute of Scientific and Technical Information of China (English)

    孙昌璞

    1995-01-01

    The generalized Born-Oppenheimer approximation theory is applied to the localization control of state tunneling of a two-level atom in a cavity field with single mode. The nonadiabatic effect of tunneling of atomic chiral states in coherent cavity field is analyzed quantitatively and the condition for realizing localization is given strictly. Besides, the influence of variation in temperature on tunneling of atomic state is discussed.

  13. [Constant scaled-energy spectroscopy of Rydberg atoms in a static electric field].

    Science.gov (United States)

    Cao, Jun-wen; Liu, Xiao-jun; Zhao, Zhi; Zhan, Ming-sheng

    2002-02-01

    In the past years, scaled energy spectroscopy is under active investigation because this method can simplify the analysis of atomic spectra in the external field based on classic mechanics. A fully computer-controlled experimental system to study the constant scaled-energy spectroscopy was established and described in this paper. The excitation energy E and the strength of the external electric field F were controlled synchronously to keep the scaled-energy epsilon = E/square root of F constant. With this system, constant scaled-energy spectra of Strontium Rydberg atoms at epsilon = -3.0 in a static electric field were successfully recorded for the first time, and the recurrence spectra were obtained by a Fourier transform.

  14. Degrees of controllability for quantum systems and application to atomic systems

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, S.G.; Solomon, A.I. [Quantum Processes Group, Open University, Milton Keynes (United Kingdom)]. E-mails: S.G.Schirmer@open.ac.uk; A.I.Solomon@open.ac.uk; Leahy, J.V. [Department of Mathematics and Institute of Theoretical Science, University of Oregon, Eugene, OR (United States)]. E-mail: leahy@math.uoregon.edu

    2002-05-10

    Precise definitions for different degrees of controllability for quantum systems are given, and necessary and sufficient conditions for each type of controllability are discussed. The results are applied to determine the degree of controllability for various atomic systems with degenerate energy levels and transition frequencies. (author)

  15. Atomic Layer Deposition of Bismuth Vanadates for Solar Energy Materials.

    Science.gov (United States)

    Stefik, Morgan

    2016-07-07

    The fabrication of porous nanocomposites is key to the advancement of energy conversion and storage devices that interface with electrolytes. Bismuth vanadate, BiVO4 , is a promising oxide for solar water splitting where the controlled fabrication of BiVO4 layers within porous, conducting scaffolds has remained a challenge. Here, the atomic layer deposition of bismuth vanadates is reported from BiPh3 , vanadium(V) oxytriisopropoxide, and water. The resulting films have tunable stoichiometry and may be crystallized to form the photoactive scheelite structure of BiVO4 . A selective etching process was used with vanadium-rich depositions to enable the synthesis of phase-pure BiVO4 after spinodal decomposition. BiVO4 thin films were measured for photoelectrochemical performance under AM 1.5 illumination. The average photocurrents were 1.17 mA cm(-2) at 1.23 V versus the reversible hydrogen electrode using a hole-scavenging sulfite electrolyte. The capability to deposit conformal bismuth vanadates will enable a new generation of nanocomposite architectures for solar water splitting.

  16. Single-atom quantum control of macroscopic mechanical oscillators

    Science.gov (United States)

    Bariani, F.; Otterbach, J.; Tan, Huatang; Meystre, P.

    2014-01-01

    We investigate a hybrid electromechanical system consisting of a pair of charged macroscopic mechanical oscillators coupled to a small ensemble of Rydberg atoms. The resonant dipole-dipole coupling between an internal atomic Rydberg transition and the mechanics allows cooling to its motional ground state with a single atom despite the considerable mass imbalance between the two subsystems. We show that the rich electronic spectrum of Rydberg atoms, combined with their high degree of optical control, paves the way towards implementing various quantum-control protocols for the mechanical oscillators.

  17. Atomic Energy Levels with QED and Contribution of the Screened Self-Energy

    OpenAIRE

    Bigot, Eric-Olivier Le; Indelicato, Paul

    2000-01-01

    We present an introduction to the principles behind atomic energy level calculations with Quantum Electrodynamics (QED) and the two-time Green's function method; this method allows one to calculate an effective Hamiltonian that contains all QED effects and that can be used to predict QED Lamb shifts of degenerate, quasidegenerate and isolated atomic levels.

  18. Study on the fine control of atoms by coherent interaction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jae Min; Rho, S. P.; Park, H. M.; Lee, K. S.; Rhee, Y. J.; Yi, J. H.; Jeong, D. Y.; Jung, E. C.; Choe, A. S.; Lee, J. M

    1998-01-01

    The basic research on the control of atoms using the coherent interaction, such as the development of the generator of the thermal atomic beam with high directionality, the photodeflection of atomic beam and the coherent excitation of atoms, has been performed. Yb atomic beam with small divergence was generated and the deflection mechanism of the atomic beam was studied by using a broad band dye laser and a narrow band laser. It has been proved that the single mode dye laser with narrow bandwidth was suitable for deflection of atoms but the frequency locking system was indispensable. And the apparatus for intermodulated optogalvanic (IMOG) experiment was developed and the high resolution optogalvanic spectroscopy was studied for laser frequency stabilization. (author). 74 refs., 1 tab., 26 figs

  19. The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Uruguay: development of tissues quality control and quality management system in the National Multi-Tissue Bank of Uruguay.

    Science.gov (United States)

    Alvarez, I; Morales Pedraza, Jorge; Saldías, M C; Pérez Campos, H; Wodowóz, O; Acosta, María; Vicentino, W; Silva, W; Rodríguez, G; Machín, D; Alvarez, O

    2009-05-01

    BNOT was created and regulated in 1977 and started its operation in 1978 according to the Decree No. 86/1977. By the Decree 248/005 is transformed in the National Institute of Donation and Transplantation of Cells, Tissues and Organs (Instituto Nacional de Donación y Trasplante de Células, Tejidos y Organos--INDT). The organisation has been operating within the State University Medical School and the Public Health Secretary and it is the governmental organisation responsible for the regulation, policy and management of donation and transplantation in Uruguay. By the Decree 160/2006 is responsible for human cells and tissues regulation too. The participation of the INDT in the IAEA program facilitated the introduction of the radiation sterilisation technique for the first time in the country. The radiation sterilisation of tissues processed by INDT (ex BNOT), was initially carried out in the 60 Cobalt Industrial Plant in the National Atomic Energy Commission of Argentina and now is carried out in INDT, using a Gamma Cell 220 Excel, which was provided by the IAEA through the national project URU/7/005. The results of the implementation of tissues, quality control and quality management system, are showed.

  20. Nano Electronics on Atomically Controlled van der Waals Quantum Heterostructures

    Science.gov (United States)

    2015-03-30

    Final 3. DATES COVERED (From - To) 14 Aug 13 to 13 Feb 15 4. TITLE AND SUBTITLE Nano Electronics on Atomically Controlled van der Waals...OMB control number. 1. REPORT DATE 14 MAY 2015 2. REPORT TYPE Final 3. DATES COVERED 14-08-2013 to 13-02-2015 4. TITLE AND SUBTITLE Nano ...AOARD Grant 134122 “ Nano Electronics on Atomically Controlled van der Waals Quantum Heterostructures” 3/30/2015 Name of Principal

  1. Atomic switch: atom/ion movement controlled devices for beyond von-neumann computers.

    Science.gov (United States)

    Hasegawa, Tsuyoshi; Terabe, Kazuya; Tsuruoka, Tohru; Aono, Masakazu

    2012-01-10

    An atomic switch is a nanoionic device that controls the diffusion of metal ions/atoms and their reduction/oxidation processes in the switching operation to form/annihilate a conductive path. Since metal atoms can provide a highly conductive channel even if their cluster size is in the nanometer scale, atomic switches may enable downscaling to smaller than the 11 nm technology node, which is a great challenge for semiconductor devices. Atomic switches also possess novel characteristics, such as high on/off ratios, very low power consumption and non-volatility. The unique operating mechanisms of these devices have enabled the development of various types of atomic switch, such as gap-type and gapless-type two-terminal atomic switches and three-terminal atomic switches. Novel functions, such as selective volatile/nonvolatile, synaptic, memristive, and photo-assisted operations have been demonstrated. Such atomic switch characteristics can not only improve the performance of present-day electronic systems, but also enable development of new types of electronic systems, such as beyond von- Neumann computers.

  2. Plasma screening effects on the energies of hydrogen atom

    Energy Technology Data Exchange (ETDEWEB)

    Soylu, A. [Department of Physics, Nigde University, 51240 Nigde (Turkey)

    2012-07-15

    A more general exponential cosine screened Coulomb potential is used for the first time to investigate the screening effects on the hydrogen atom in plasmas. This potential is examined for four different cases that correspond to four different type potentials when the different parameters are used in the potential within the framework of the well-known asymptotic iteration method. By solving the corresponding the radial Schroedinger equation with the screened and exponential cosine screened Coulomb potentials and comparing the obtained energy eigenvalues with the results of other studies, the applicability of the method to this kind of plasma physics problem is shown. The energy values of more general exponential cosine screened Coulomb potential are presented for various parameters in the potential. One of the advantages of the present potential is that it exhibits stronger screening effect than that of the exponential cosine screened Coulomb potential and it is also reduced to screened Coulomb and exponential cosine screened Coulomb as well as Coulomb potentials for special values of parameters. The parameters in the potential would be useful to model screening effects which cause an increase or decrease in the energy values of hydrogen atom in both Debye and quantum plasmas and in this manner this potential would be useful for the investigations of the atomic structure and collisions in plasmas.

  3. Scattering of low-energy neutrinos on atomic shells

    Energy Technology Data Exchange (ETDEWEB)

    Babič, Andrej [Dept. of Dosimetry and Application of Ionizing Radiation, Czech Technical University, 115 19 Prague, Czech Rep. (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University, 128 00 Prague (Czech Republic); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Šimkovic, Fedor [Institute of Experimental and Applied Physics, Czech Technical University, 128 00 Prague (Czech Republic); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Department of Nuclear Physics and Biophysics, Comenius University, 842 48 Bratislava (Slovakia)

    2015-10-28

    We present a derivation of the total cross section for inelastic scattering of low-energy solar neutrinos and reactor antineutrinos on bound electrons, resulting in a transition of the electron to an excited state. The atomic-shell structure of various chemical elements is treated in terms of a nonrelativistic approximation. We estimate the interaction rates for modern neutrino detectors, in particular the Borexino and GEMMA experiments. We establish that in these experiments the effect can be safely neglected, but it could be accessible to future large-volume neutrino detectors with low energy threshold.

  4. Study on the fine control of atoms by coherent interaction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jae Min; Rho, S. P.; Park, H. M.; Lee, K. S.; Rhee, Y. J.; Yi, J. H.; Jeong, D. Y.; Ko, K. H.; Lee, J. M.; Kim, M.K

    2000-01-01

    Study on one dimensional atom cooling and trapping process which is basic to the development of atom manipulation technology has been performed. A Zeeman slower has been designed and manufactured for efficient cooling of atoms. The speed of atoms finally achieved is as slow as 15 m/s with proper cooling conditions. By six circularly-polarized laser beams and quadrupole magnetic field, the atoms which have been slowed down by zeeman slower have been trapped in a small spatial region inside MOT. The higher the intensity of the slowing laser is the more is the number of atoms slowed and the maximum number of atoms trapped has been 10{sup 8}. The atoms of several tens of {mu}K degree have been trapped by controlling the intensity of trapping laser and intensity gradient of magnetic field. EIT phenomena caused by atomic coherent interaction has been studied for the development of atom optical elements. For the investigation of the focusing phenomena induced by the coherent interaction, experimental measurements and theoretical analysis have been performed. Spatial dependency of spectrum and double distribution signal of coupling laser have been obtained. The deflection of laser beams utilizing the EIT effects has also been considered. (author)

  5. Controllable Magnetic Focusing of Cold Atoms on a Chip

    Institute of Scientific and Technical Information of China (English)

    LIU Yang; YUN Min; YIN Jian-Ping

    2006-01-01

    @@ We propose a new lens scheme to focus cold atoms by using a controllable inhomogeneous magnetic field from a square current-carrying wire fabricated on a chip. The spatial distributions of the magnetic field are calculated, and the results show that the generated magnetic field is a two-dimensional (2D) quadrupole one and can be used to focus cold atoms or a cold atomic beam. The dynamic processes of cold atoms passing through our square wire layout and its focusing properties are studied by using Monte Carlo simulations. Our study shows that the atomic clouds can be focused effectively by our magnetic lens scheme, and the focal lengthof the atomic lens and its radius of focused spot can be continuously changed by adjusting the current in the wires.

  6. Importance of Atomic Contacts in Vibrational Energy Flow in Proteins.

    Science.gov (United States)

    Kondoh, Masato; Mizuno, Misao; Mizutani, Yasuhisa

    2016-06-02

    Vibrational energy flow in proteins was studied by monitoring the time-resolved anti-Stokes ultraviolet resonance Raman scattering of three myoglobin mutants in which a Trp residue substitutes a different amino acid residue near heme. The anti-Stokes Raman intensities of the Trp residue in the three mutants increased with similar rates after depositing excess vibrational energy at heme, despite the difference in distance between heme and each substituted Trp residue along the main chain of the protein. This indicates that vibrational energy is not transferred through the main chain of the protein but rather through atomic contacts between heme and the Trp residue. Distinct differences were observed in the amplitude of the band intensity change between the Trp residues at different positions, and the amplitude of the band intensity change exhibits a correlation with the extent of exposure of the Trp residue to solvent water. This correlation indicates that atomic contacts between an amino acid residue and solvent water play an important role in vibrational energy flow in a protein.

  7. Quantum Control nd Measurement of Spins in Cold Atomic Gases

    Science.gov (United States)

    Deutsch, Ivan

    2014-03-01

    Spins are natural carriers of quantum information given their long coherence time and our ability to precisely control and measure them with magneto-optical fields. Spins in cold atomic gases provide a pristine environment for such quantum control and measurement, and thus this system can act as a test-bed for the development of quantum simulators. I will discuss the progress my group has made in collaboration with Prof. Jessen, University of Arizona, to develop the toolbox for this test-bed. Through its interactions with rf and microwave magnetic fields, whose waveforms are designed through optimal control techniques, we can implement arbitrary unitary control on the internal hyperfine spins of cesium atoms, a 16 dimensional Hilbert space (isomorphic to 4 qubits). Control of the collective spin of the ensemble of many atoms is performed via the mutual coupling of the atomic ensemble to a mode of the electromagnetic field that acts as a quantum data bus for entangling atoms with one another. Internal spin control can be used to enhance the entangling power of the atom-photon interface. Finally, both projective and weak-continuous measurements can be performed to tomograhically reconstruct quantum states and processes.

  8. Features of Low Energy Classical Bremsstrahlung From Neutral Atoms.

    Science.gov (United States)

    Florescu, A.; Obolensky, O. I.; Pratt, R. H.

    2002-05-01

    We study classical bremsstrahlung from neutral atoms and investigate the features characteristic for the low incident energy region. These features include oscillations in the energy dependence of the bremsstrahlung cross section and structures in the asymmetry parameter of radiation. We use soft-photon limit results to elucidate the physical origins of the features. We show that there is a correspondence between classical and quantum results [1]. In both cases the features result from the suppression of contributions to the radiation from certain angular momenta at certain energies. In quantum mechanics this corresponds to zeroes in certain radiation matrix elements. In the classical case the lack of contribution from some interval of angular momentum is caused by behaviors of elastic electron scattering in screened potentials. [1] A. Florescu, O. I. Obolensky, C. D. Shaffer, and R. H. Pratt 2001 AIP Conference Proceedings 576, 60-64.

  9. Positron-Lithium Atom and Electron-Lithium Atom Scattering Systems at Intermediate and High Energies

    Institute of Scientific and Technical Information of China (English)

    K. Ratnavelu; S. Y. Ng

    2006-01-01

    @@ The coupled-channel optical method is used to study positron scattering by atomic lithium at energies ranging from the ionization threshold to 60 eV. The present method simultaneously treats the target channels and the positronium (Ps) channels in the coupled-channel method together with the continuum effects via an ab-initio optical potential. Ionization, elastic and inelastic cross sections in target channels, and the total cross section are also reported and compared with other theoretical and experimental data. A comparative study with the corresponding electron-lithium data is also reported.

  10. Embedded atom calculations of unstable stacking fault energies and surface energies in intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, D. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Zhou, S.J. [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Vailhe, C.; Mutasa, B.; Panova, J. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States)

    1997-01-01

    We performed embedded atom method calculations on surface energies and unstable stacking fault energies for a series of intermetallics for which interatomic potentials of the embedded atom type have recently been developed. These results were analyzed and applied to the prediction of relative ductility of these materials using the various current theories. Series of alloys with the B2 ordered structure were studied, and the results were compared to those in pure body-centered cubic (bcc) Fe. Ordered compounds with L1{sub 2} and L1{sub 0} structures based on the face-centered cubic (fcc) lattice were also studied. It was found that there is a correlation between the values of the antiphase boundary (APB) energies in B2 alloys and their unstackable stacking fault energies. Materials with higher APB energies tend to have higher unstable stacking fault energies, leading to an increased tendency to brittle fracture. {copyright} {ital 1997 Materials Research Society.}

  11. Many-body approximations for atomic binding energies

    CERN Document Server

    Schuster, Micah D; Staker, Joshua T

    2011-01-01

    We benchmark three approximations for the many-body problem -- the Hartree-Fock, projected Hartree-Fock, and random phase approximations -- against full numerical configuration-interaction calculations of the electronic structure of atoms, from Li through to Ne. Each method uses exactly the same input, i.e., the same single-particle basis and Coulomb matrix elements, so any differences are strictly due to the approximation itself. Although it consistently overestimates the ground state binding energy, the random phase approximation has the smallest overall errors; furthermore, we suggest it may be useful as a method for efficient optimization of single-particle basis functions.

  12. Particle beam technology for control of atomic-bonding state in materials

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Junzo [Kyoto Univ. (Japan). Faculty of Engineering

    1997-03-01

    The atomic-bonding state in materials can be controlled through `kinetic bonding` process by energetic particle beams which have a sufficient atomic kinetic energy. In order to clarify the `kinetic bonding` process the negative-ion beam deposition is considered as an ideal method because the negative ion has no additional active energies. Sputter type heavy negative-ion sources can be used for this purpose. Carbon films prepared by carbon negative-ion beam deposition have a strong dependency of the film properties on ion beam kinetic energy and have a quite high thermal conductivity which is comparable to that of the IIb diamond at a kinetic energy of 50-100 eV/atom. It suggests that new or metastable materials could be formed through the `kinetic bonding` process. Negative-ion beams can also be used for ion implantation, in which charging problems are perfectly reduced. (author)

  13. A solar energy controller

    Energy Technology Data Exchange (ETDEWEB)

    Laurentiu, A.

    1981-05-30

    A simplified design of a flat solar energy collector with an absorber made from plastic, and a housing stamped from polyethylene with a thermal insulation layer made from porous plastic is patented. The thermal insulation layer is also stamped out as a hole part in the necessary shape. A transparency made from transparent plastic in the form of a cover is applied to the housing. The cover has edges that attach to the vertical walls of the housing. In order to improve the seal of the internal area of the collector, the edges of the transparency fit into the gap between the vertical walls of the housing and the attachment piece on the walls. The collector is characterized by simplicity in assembly and low cost.

  14. Adiabatic control of atomic dressed states for transport and sensing

    Science.gov (United States)

    Cooper, N. R.; Rey, A. M.

    2015-08-01

    We describe forms of adiabatic transport that arise for dressed-state atoms in optical lattices. Focusing on the limit of weak tunnel-coupling between nearest-neighbor lattice sites, we explain how adiabatic variation of optical dressing allows control of atomic motion between lattice sites: allowing adiabatic particle transport in a direction that depends on the internal state, and force measurements via spectroscopic preparation and readout. For uniformly filled bands these systems display topologically quantized particle transport. An implementation of the dressing scheme using optical transitions in alkaline-earth atoms is discussed as well as its favorable features for precise force sensing.

  15. ASTROPHYSICS. Atom-interferometry constraints on dark energy.

    Science.gov (United States)

    Hamilton, P; Jaffe, M; Haslinger, P; Simmons, Q; Müller, H; Khoury, J

    2015-08-21

    If dark energy, which drives the accelerated expansion of the universe, consists of a light scalar field, it might be detectable as a "fifth force" between normal-matter objects, in potential conflict with precision tests of gravity. Chameleon fields and other theories with screening mechanisms, however, can evade these tests by suppressing the forces in regions of high density, such as the laboratory. Using a cesium matter-wave interferometer near a spherical mass in an ultrahigh-vacuum chamber, we reduced the screening mechanism by probing the field with individual atoms rather than with bulk matter. We thereby constrained a wide class of dark energy theories, including a range of chameleon and other theories that reproduce the observed cosmic acceleration.

  16. The role of correlation in the ground state energy of confined helium atom

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, N. [Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, 09340 México Distrito Federal (Mexico)

    2014-01-14

    We analyze the ground state energy of helium atom confined by spherical impenetrable walls, and the role of the correlation energy in the total energy. The confinement of an atom in a cavity is one way in which we can model the effect of the external pressure on an atom. The calculations of energy of the system are carried out by the variational method. We find that the correlation energy remains almost constant for a range values of size of the boxes analyzed.

  17. Model based control of dynamic atomic force microscope.

    Science.gov (United States)

    Lee, Chibum; Salapaka, Srinivasa M

    2015-04-01

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H(∞) control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments.

  18. Model based control of dynamic atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chibum [Department of Mechanical System Design Engineering, Seoul National University of Science and Technology, Seoul 139-743 (Korea, Republic of); Salapaka, Srinivasa M., E-mail: salapaka@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2015-04-15

    A model-based robust control approach is proposed that significantly improves imaging bandwidth for the dynamic mode atomic force microscopy. A model for cantilever oscillation amplitude and phase dynamics is derived and used for the control design. In particular, the control design is based on a linearized model and robust H{sub ∞} control theory. This design yields a significant improvement when compared to the conventional proportional-integral designs and verified by experiments.

  19. Controlled long-range interactions between Rydberg atoms and ions

    Science.gov (United States)

    Secker, T.; Gerritsma, R.; Glaetzle, A. W.; Negretti, A.

    2016-07-01

    We theoretically investigate trapped ions interacting with atoms that are coupled to Rydberg states. The strong polarizabilities of the Rydberg levels increase the interaction strength between atoms and ions by many orders of magnitude, as compared to the case of ground-state atoms, and may be mediated over micrometers. We calculate that such interactions can be used to generate entanglement between an atom and the motion or internal state of an ion. Furthermore, the ion could be used as a bus for mediating spin-spin interactions between atomic spins in analogy to much employed techniques in ion-trap quantum simulation. The proposed scheme comes with attractive features as it maps the benefits of the trapped-ion quantum system onto the atomic one without obviously impeding its intrinsic scalability. No ground-state cooling of the ion or atom is required and the setup allows for full dynamical control. Moreover, the scheme is to a large extent immune to the micromotion of the ion. Our findings are of interest for developing hybrid quantum information platforms and for implementing quantum simulations of solid-state physics.

  20. Controlled long-range interactions between Rydberg atoms and ions

    CERN Document Server

    Secker, Thomas; Glaetzle, Alexander W; Negretti, Antonio

    2016-01-01

    We theoretically investigate trapped ions interacting with atoms that are coupled to Rydberg states. The strong polarizabilities of the Rydberg levels increases the interaction strength between atoms and ions by many orders of magnitude, as compared to the case of ground state atoms, and may be mediated over micrometers. We calculate that such interactions can be used to generate entanglement between an atom and the motion or internal state of an ion. Furthermore, the ion could be used as a bus for mediating spin-spin interactions between atomic spins in analogy to much employed techniques in ion trap quantum simulation. The proposed scheme comes with attractive features as it maps the benefits of the trapped ion quantum system onto the atomic one without obviously impeding its intrinsic scalability. No ground state cooling of the ion or atom is required and the setup allows for full dynamical control. Moreover, the scheme is to a large extent immune to the micromotion of the ion. Our findings are of interest...

  1. Effect of external energy on atomic, crystalline and powder characteristics of antimony and bismuth powders

    Indian Academy of Sciences (India)

    Vikram V Dabhade; Rama Mohan R Tallapragada; Mahendra Kumar Trivedi

    2009-10-01

    Next to atoms and molecules the powders are the smallest state of matter available in high purities and large quantities. The effect of any external energy on the shape, morphology and structure can thus be studied with relative ease. The present investigation deals with the effect of a non-contact external energy on the powders of antimony and bismuth. The characteristics of powders treated by external energy are compared with the as received powders (control). The average particle sizes, 50 and 99, the sizes below which 99% of the particles are present showed significant increase and decrease indicating that the energy had caused deformation and fracture as if the powders have been subjected to high energy milling. To be able to understand the reasons for these changes the powders are characterized by techniques such as X-ray diffraction (XRD), surface area determination (BET), thermal analytical techniques such as DTA–DTG, DSC–TGA and SDTA and scanning electron microscopy (SEM). The treated powder samples exhibited remarkable changes in the powder characteristics at all structural levels starting from polycrystalline particles, through single crystal to atoms. The external energy had changed the lattice parameters of the unit cell which in turn changed the crystallite size and density. The lattice parameters are then used to compute the weight and effective nuclear charge of the atom which showed significant variation. It is speculated that the external energy is acting on the nucleus through some reversible weak interaction of larger cross section causing changes in the proton to neutron ratios. Thus the effect is felt by all the atoms, and hence the unit cell, single crystal grain and grain boundaries. The stresses generated in turn may have caused deformation or fracture of the weak interfaces such as the crystallite and grain boundaries.

  2. Control of Solar Energy Systems

    CERN Document Server

    Camacho, Eduardo F; Rubio, Francisco R; Martínez, Diego

    2012-01-01

    Control of Solar Energy Systems details the main solar energy systems, problems involved with their control, and how control systems can help in increasing their efficiency.  After a brief introduction to the fundamental concepts associated with the use of solar energy in both photovoltaic and thermal plants, specific issues related to control of solar systems are embarked upon. Thermal energy systems are then explored in depth, as well as  other solar energy applications such as solar furnaces and solar refrigeration systems. Problems of variable generation profile and of the contribution of many solar plants to the same grid system are considered with the necessary integrated and supervisory control solutions being discussed. The text includes material on: ·         A comparison of basic and advanced control methods for parabolic troughs from PID to nonlinear model-based control; ·         solar towers and solar tracking; ·         heliostat calibration, characterization and off...

  3. Physics and Its Multiple Roles in the International Atomic Energy Agency

    Science.gov (United States)

    Massey, Charles D.

    2017-01-01

    The IAEA is the world's centre for cooperation in the nuclear field. It was set up as the world's ``Atoms for Peace'' organization in 1957 within the United Nations family. The Agency works with its Member States and multiple partners worldwide to promote the safe, secure and peaceful use of nuclear technologies. Three main areas of work underpin the IAEA's mission: Safety and Security, Science and Technology, and Safeguards and Verification. To carry out its mission, the Agency is authorized to encourage and assist research on, and development and practical application of, atomic energy for peaceful uses throughout the world; foster the exchange of scientific and technical information on peaceful uses of atomic energy; and encourage the exchange of training of scientists and experts in the field of peaceful uses of atomic energy. Nowadays, nuclear physics and nuclear technology are applied in a great variety of social areas, such as power production, medical diagnosis and therapies, environmental protection, security control, material tests, food processing, waste treatments, agriculture and artifacts analysis. This presentation will cover the role and practical application of physics at the IAEA, and, in particular, focus on the role physics has, and will play, in nuclear security.

  4. Isotope Effects in Low Energy Ion-Atom Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Havener, Charles C [ORNL; Seely, D. G. [Albion College; Thomas, J. D. [University of Toledo, Toledo, OH; Kvale, Thomas Jay [University of Toledo, Toledo, OH

    2009-01-01

    Isotope effects for charge transfer processes have recently received increased attention. The ion-atom merged-beams apparatus at Oak Ridge National Laboratory is used to measure charge transfer for low energy collisions of multi-charged ions with H and D and is therefore well suited to investigate isotope effects. The apparatus has been relocated and upgraded to accept high velocity beams from the 250 kV High Voltage Platform at the Multi-Charged Ion Research Facility. The intense higher velocity multi-charged ion beams allow, for the first time, measurements with both H and D from keV/u down to meV/u collision energies in the center-of-mass frame. When charge transfer occurs at relatively large inter-nuclear distances (via radial couplings) the ion-induced dipole attraction can lead to trajectory effects, causing differences in the charge transfer cross sections for H and D. A strong isotope effect (nearly a factor of two) has been observed in the cross section for Si4+ + H(D) below 0.1 eV/u. However, little or no difference is observed for N2+ + H(D). Recently, strong effects have been predicted for the fundamental system He2+ + H(D,T) at collision energies below 200 eV/u where charge transfer occurs primarily through united-atom rotational coupling. We are currently exploring systems where rotational coupling is important and isotopic differences in the cross section can be observed.

  5. Controlling the dynamics of a single atom in lateral atom manipulation.

    Science.gov (United States)

    Stroscio, Joseph A; Celotta, Robert J

    2004-10-01

    We studied the dynamics of a single cobalt (Co) atom during lateral manipulation on a copper (111) surface in a low-temperature scanning tunneling microscope. The Co binding site locations were revealed in a detailed image that resulted from lateral Co atom motion within the trapping potential of the scanning tip. Random telegraph noise, corresponding to the Co atom switching between hexagonal close-packed (hcp) and face-centered cubic (fcc) sites, was seen when the tip was used to try to position the Co atom over the higher energy hcp site. Varying the probe tip height modified the normal copper (111) potential landscape and allowed the residence time of the Co atom in these sites to be varied. At low tunneling voltages (less than approximately 5 millielectron volts), the transfer rate between sites was independent of tunneling voltage, current, and temperature. At higher voltages, the transfer rate exhibited a strong dependence on tunneling voltage, indicative of vibrational heating by inelastic electron scattering.

  6. Controlling the Multiport Nature of Bragg Diffraction in Atom Interferometry

    CERN Document Server

    Parker, Richard H; Estey, Brian; Zhong, Weicheng; Huang, Eric; Müller, Holger

    2016-01-01

    Bragg diffraction has been used in atom interferometers because it allows signal enhancement through multiphoton momentum transfer and suppression of systematics by not changing the internal state of atoms. Its multi-port nature, however, can lead to parasitic interferometers, allows for intensity-dependent phase shifts in the primary interferometers, and distorts the ellipses used for phase extraction. We study and suppress these unwanted effects. Specifically, phase extraction by ellipse fitting and the resulting systematic phase shifts are calculated by Monte Carlo simulations. Phase shifts arising from the thermal motion of the atoms are controlled by spatial selection of atoms and an appropriate choice of Bragg intensity. In these simulations, we found that Gaussian Bragg pulse shapes yield the smallest systematic shifts. Parasitic interferometers are suppressed by a "magic" Bragg pulse duration. The sensitivity of the apparatus was improved by the addition of AC Stark shift compensation, which permits d...

  7. Energy from the Atom. A Basic Teaching Unit on Energy. Revised.

    Science.gov (United States)

    McDermott, Hugh, Ed.; Scharmann, Larry, Ed.

    Recommended for grades 9-12 social studies and/or physical science classes, this 4-8 day unit focuses on four topics: (1) the background and history of atomic development; (2) two common types of nuclear reactors (boiling water and pressurized water reactors); (3) disposal of radioactive waste; and (4) the future of nuclear energy. Each topic…

  8. Basic DTU Wind Energy controller

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig; Henriksen, Lars Christian

    This report contains a description and documentation, including source code, of the basic DTU Wind Energy controller applicable for pitch-regulated, variable speed wind turbines. The controller features both partial and full load operation capabilities as well as switching mechanisms ensuring...

  9. An atomic empire a technical history of the rise and fall of the British atomic energy programme

    CERN Document Server

    Hill, C N

    2013-01-01

    Britain was the first country to exploit atomic energy on a large scale, and at its peak in the mid-1960s, it had generated more electricity from nuclear power than the rest of the world combined.The civil atomic energy programme grew out of the military programme which produced plutonium for atomic weapons. In 1956, Calder Hall power station was opened by the Queen. The very next year, one of the early Windscale reactors caught fire and the world's first major nuclear accident occurred.The civil programme ran into further difficulty in the mid-1960s and as a consequence of procrastination in

  10. Chaotic Energy Hopping in Bidirectionally Kicked Rydberg Atoms

    Science.gov (United States)

    Burke, Korana; Mitchell, Kevin; Ye, Shuzhen; Dunning, F. Barry

    2012-06-01

    A highly excited (n 306) quasi one-dimensional Rydberg atom exposed to periodic alternating external electric field pulses exhibits chaotic behavior. Time evolution of this system is governed by a geometric structure of phase space called a homoclinic tangle and its turnstile. The turnstile is responsible for organizing chaotic ionization. We present and explain the results from an experiment designed to probe the structure of the phase space turnstile. We create time-independent Rydberg wave packets, subject them to alternating electric field kicks, and measure the ionization fraction. We present the behavior of the ionization fraction as a function of the applied kick strength and show that this behavior is directly connected to the size and shape of the underlying turnstile. For short kicking periods the ionization fraction as a function of the applied kick strength exhibits step-function-like behavior that changes into s-shape behavior for large kicking periods. Next we use the geometric structure of phase space to design a short pulse sequence that quickly and efficiently transfers electronic wave packet from a high energy state to a much lower energy state. Finally, we show how the phase space geometry influences the efficiency of the transport between energy states.

  11. Atomic Energy of Canada Limited annual report 2000-2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This is the annual report of the Atomic Energy of Canada Limited for the year ending March 31, 2001 and summarizes the activities of AECL during the period 2000-2001. The activities covered in this report include the CANDU reactor business, with progress being reported in the construction of two CANDU 6 reactors for the Qinshan CANDU project in China, the anticipated completion of Cernavoda unit 2, the completion of spent fuel storage at Cernavoda unit 1 in Romania, as well as the service business with New Brunswick Power, Ontario Power Generation, Bruce Power and Hydro Quebec in the refurbishment of operating, CANDU reactors. In the R and D programs discussions continue on funding for the Canadian Neutron Facility for Materials Research (CNF) and progress on the Maple medical isotope reactor.

  12. Atomic Energy of Canada Limited annual report 1999-2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This is the annual report of the Atomic Energy of Canada Limited for the year ending March 31, 2000, and summarizes the activities of AECL during the period 1999-2000. The activities covered in this report include the CANDU reactor business, with the completion of the Wolsong unit 4 in the Republic of Korea, progress in the construction of two CANDU reactors for the Qinshan CANDU project in China, as well as the service business with Ontario Power Generation in the rehabilitation and life extension of operating CANDU reactors. In the R and D programs there is on-going effort towards the next generation of reactor technologies for CANDU nuclear power plants, discussions continue on the funding for the Canadian Neutron Facility for materials research (CNF) and progress being made on the Maple medical isotope reactor.

  13. Nonlinear control techniques for an atomic force microscope system

    Institute of Scientific and Technical Information of China (English)

    Yongchun FANG; Matthew FEEMSTER; Darren DAWSON; Nader M.JALILI

    2005-01-01

    Two nonlinear control techniques are proposed for an atomic force microscope system.Initially,a learning-based control algorithm is developed for the microcantilever-sample system that achieves asymptotic cantilever tip tracking for periodic trajectories.Specifically,the control approach utilizes a learning-based feedforward term to compensate for periodic dynamics and high-gain terms to account for non-periodic dynamics.An adaptive control algorithm is then developed to achieve asymptotic cantilever tip tracking for bounded tip trajectories despite uncertainty throughout the system parameters.Simulation results are provided to illustrate the efficacy and performance of the control strategies.

  14. Control of inhomogeneous atomic ensembles of hyperfine qudits

    DEFF Research Database (Denmark)

    Mischuck, Brian Edward; Merkel, Seth T.; Deutsch, Ivan H.

    2012-01-01

    We study the ability to control d-dimensional quantum systems (qudits) encoded in the hyperfine spin of alkali-metal atoms through the application of radio- and microwave-frequency magnetic fields in the presence of inhomogeneities in amplitude and detuning. Such a capability is essential...

  15. Controlled Creation of Spatial Superposition States for Single Atoms

    CERN Document Server

    Deasy, K; Chormaic, S N; Gong, S; Jin, S; Niu, Y; Busch, Th.

    2006-01-01

    We present a method for the controlled and robust generation of spatial superposition states of single atoms in micro-traps. Using a counter-intuitive positioning sequence for the individual potentials and appropriately chosen trapping frequencies, we show that it is possible to selectively create two different orthogonal superposition states, which can in turn be used for quantum information purposes.

  16. Controlling Rydberg atom excitations in dense background gases

    CERN Document Server

    Liebisch, Tara Cubel; Engel, Felix; Nguyen, Huan; Balewski, Jonathan; Lochead, Graham; Böttcher, Fabian; Westphal, Karl M; Kleinbach, Kathrin S; Schmid, Thomas; Gaj, Anita; Löw, Robert; Hofferberth, Sebastian; Pfau, Tilman; Pérez-Ríos, Jesús; Greene, Chris H

    2016-01-01

    We discuss the density shift and broadening of Rydberg spectra measured in cold, dense atom clouds in the context of Rydberg atom spectroscopy done at room temperature, dating back to the experiments of Amaldi and Segr\\`e in 1934. We discuss the theory first developed in 1934 by Fermi to model the mean-field density shift and subsequent developments of the theoretical understanding since then. In particular, we present a model whereby the density shift is calculated using a microscopic model in which the configurations of the perturber atoms within the Rydberg orbit are considered. We present spectroscopic measurements of a Rydberg atom, taken in a Bose-Einstein condensate (BEC) and thermal clouds with densities varying from $5\\times10^{14}\\textrm{cm}^{-3}$ to $9\\times10^{12}\\textrm{cm}^{-3}$. The density shift measured via the spectrum's center of gravity is compared with the mean-field energy shift expected for the effective atom cloud density determined via a time of flight image. Lastly, we present calcul...

  17. Controlled manipulation of nanoparticles with an atomic force microscope

    Science.gov (United States)

    Junno, T.; Deppert, K.; Montelius, L.; Samuelson, L.

    1995-06-01

    We report on the application of the atomic force microscope (AFM) to manipulate and position nanometer-sized particles with nanometer precision. The technique, which can be regarded as a nanometer-scale analogy to atomic level manipulation with the scanning tunneling microscope, allowed us to form arbitrary nanostructures, under ambient conditions, by controlled manipulation of individual 30 nm GaAs particles. A whole new set of nanodevices can be fabricated particle-by-particle for studies of quantum effects and single electron tunneling. We also demonstrate a method, based on the AFM manipulation, to determine the true lateral dimensions of nano-objects, in spite of the tip-sample convolution.

  18. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  19. The impact of atomic precision measurements in high energy physics

    OpenAIRE

    Casalbuoni, Roberto

    2000-01-01

    In this talk I discuss the relevance of atomic physics in understanding some important questions about elementary particle physics. A particular attention is devoted to atomic parity violation measurements which seem to suggest new physics beyond the Standard Model. Atomic physics might also be relevant in discovering possible violations of the CPT symmetry.

  20. A study on the improvement of the legal system concerning Korean Atomic Energy Act

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Il Un; Jung, Jong Hak; Kim, Jae Ho; Moon, Jong Wook; Kim, In Sub [Chungnam National Univ., Taejon (Korea, Republic of)

    1998-03-15

    Cause-effect analysis, adjustment, and generalization of the current atomic energy act are contents of this research. These are to be based on the legal theory. Analysis of the current atomic energy act from the viewpoint of constitutional law and administrative law. Review of the other domestic legal systems which have similar problems as the atomic energy act has. Inquiry about the operation of nuclear legal systems of foreign nations.

  1. Quantum optical circulator controlled by a single chirally coupled atom

    Science.gov (United States)

    Scheucher, Michael; Hilico, Adèle; Will, Elisa; Volz, Jürgen; Rauschenbeutel, Arno

    2016-12-01

    Integrated nonreciprocal optical components, which have an inherent asymmetry between their forward and backward propagation direction, are key for routing signals in photonic circuits. Here, we demonstrate a fiber-integrated quantum optical circulator operated by a single atom. Its nonreciprocal behavior arises from the chiral interaction between the atom and the transversally confined light. We demonstrate that the internal quantum state of the atom controls the operation direction of the circulator and that it features a strongly nonlinear response at the single-photon level. This enables, for example, photon number–dependent routing and novel quantum simulation protocols. Furthermore, such a circulator can in principle be prepared in a coherent superposition of its operational states and may become a key element for quantum information processing in scalable integrated optical circuits.

  2. Atomic Energy Act and Related Legislation. Environmental Guidance Program Reference Book: Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    1992-09-01

    This report presents information related to the Atomic Energy Act and related legislation. Sections are presented pertaining to legislative history and statutes, implementing regulations, and updates.

  3. Energy corrugation in atomic-scale friction on graphite revisited by molecular dynamics simulations

    Science.gov (United States)

    Sun, Xiao-Yu; Qi, Yi-Zhou; Ouyang, Wengen; Feng, Xi-Qiao; Li, Qunyang

    2016-08-01

    Although atomic stick-slip friction has been extensively studied since its first demonstration on graphite, the physical understanding of this dissipation-dominated phenomenon is still very limited. In this work, we perform molecular dynamics (MD) simulations to study the frictional behavior of a diamond tip sliding over a graphite surface. In contrast to the common wisdom, our MD results suggest that the energy barrier associated lateral sliding (known as energy corrugation) comes not only from interaction between the tip and the top layer of graphite but also from interactions among the deformed atomic layers of graphite. Due to the competition of these two subentries, friction on graphite can be tuned by controlling the relative adhesion of different interfaces. For relatively low tip-graphite adhesion, friction behaves normally and increases with increasing normal load. However, for relatively high tip-graphite adhesion, friction increases unusually with decreasing normal load leading to an effectively negative coefficient of friction, which is consistent with the recent experimental observations on chemically modified graphite. Our results provide a new insight into the physical origins of energy corrugation in atomic scale friction.

  4. Energy corrugation in atomic-scale friction on graphite revisited by molecular dynamics simulations

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yu Sun; Yi-Zhou Qi; Wengen Ouyang; Xi-Qiao Feng; Qunyang Li

    2016-01-01

    Although atomic stick–slip friction has been extensively studied since its first demonstration on graphite, the physical understanding of this dissipation-dominated phenomenon is still very limited. In this work, we perform molecular dynamics (MD) simulations to study the frictional behavior of a diamond tip sliding over a graphite surface. In contrast to the common wisdom, our MD results suggest that the energy barrier associated lateral sliding (known as energy corrugation) comes not only from interaction between the tip and the top layer of graphite but also from interactions among the deformed atomic layers of graphite. Due to the competi-tion of these two subentries, friction on graphite can be tuned by controlling the relative adhesion of different interfaces. For relatively low tip-graphite adhesion, friction behaves nor-mally and increases with increasing normal load. However, for relatively high tip-graphite adhesion, friction increases unusually with decreasing normal load leading to an effec-tively negative coefficient of friction, which is consistent with the recent experimental observations on chemically modified graphite. Our results provide a new insight into the physical origins of energy corrugation in atomic scale friction.

  5. Electrode surface engineering by atomic layer deposition: A promising pathway toward better energy storage

    KAUST Repository

    Ahmed, Bilal

    2016-04-29

    Research on electrochemical energy storage devices including Li ion batteries (LIBs), Na ion batteries (NIBs) and supercapacitors (SCs) has accelerated in recent years, in part because developments in nanomaterials are making it possible to achieve high capacities and energy and power densities. These developments can extend battery life in portable devices, and open new markets such as electric vehicles and large-scale grid energy storage. It is well known that surface reactions largely determine the performance and stability of electrochemical energy storage devices. Despite showing impressive capacities and high energy and power densities, many of the new nanostructured electrode materials suffer from limited lifetime due to severe electrode interaction with electrolytes or due to large volume changes. Hence control of the surface of the electrode material is essential for both increasing capacity and improving cyclic stability of the energy storage devices.Atomic layer deposition (ALD) which has become a pervasive synthesis method in the microelectronics industry, has recently emerged as a promising process for electrochemical energy storage. ALD boasts excellent conformality, atomic scale thickness control, and uniformity over large areas. Since ALD is based on self-limiting surface reactions, complex shapes and nanostructures can be coated with excellent uniformity, and most processes can be done below 200. °C. In this article, we review recent studies on the use of ALD coatings to improve the performance of electrochemical energy storage devices, with particular emphasis on the studies that have provided mechanistic insight into the role of ALD in improving device performance. © 2016 Elsevier Ltd.

  6. Controlled state-to-state atom-exchange reaction in an ultracold atom-dimer mixture

    CERN Document Server

    Rui, Jun; Liu, Lan; Zhang, De-Chao; Liu, Ya-Xiong; Nan, Jue; Zhao, Bo; Pan, Jian-Wei

    2016-01-01

    Ultracold molecules offer remarkable opportunities to study chemical reactions at nearly zero temperature. Although significant progresses have been achieved in exploring ultracold bimolecular reactions, the investigations are usually limited to measurements of the overall loss rates of the reactants. Detection of the reaction products will shed new light on understanding the reaction mechanism and provide a unique opportunity to study the state-to-state reaction dynamics. Here we report on the direct observation of an exoergic atom-exchange reaction in an ultracold atom-dimer mixture. Both the atom and molecule products are observed and the quantum states are characterized. By changing the magnetic field, the reaction can be switched on or off, and the reaction rate can be controlled. The reaction is efficient and we have measured a state-to-state reaction rate of up to $1.1(3)\\times10^{-9}$cm$^{3}/$s from the time evolution of the reactants and products. Our work represents the realization of a controlled q...

  7. AtomDB and PyAtomDB: Atomic Data and Modelling Tools for High Energy and Non-Maxwellian Plasmas

    Science.gov (United States)

    Foster, Adam; Smith, Randall K.; Brickhouse, Nancy S.; Cui, Xiaohong

    2016-04-01

    The release of AtomDB 3 included a large wealth of inner shell ionization and excitation data allowing accurate modeling of non-equilibrium plasmas. We describe the newly calculated data and compare it to published literature data. We apply the new models to existing supernova remnant data such as W49B and N132D. We further outline progress towards AtomDB 3.1, including a new energy-dependent charge exchange cross sections.We present newly developed models for the spectra of electron-electron bremsstrahlung and those due to non-Maxwellian electron distributions.Finally, we present our new atomic database access tools, released as PyAtomDB, allowing powerful use of the underlying fundamental atomic data as well as the spectral emissivities.

  8. Triggering the atomic layers control of hexagonal boron nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yangxi [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Zhang, Changrui, E-mail: crzhang12@gmail.com [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Li, Bin [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Jiang, Da; Ding, Guqiao; Wang, Haomin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China); Xie, Xiaoming, E-mail: xmxie@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050 (China)

    2014-09-15

    Highlights: • Thickness of h-BN films can be controlled from double atomic layers to over ten atomic layers by adjusting the CVD parameters, quite different from the reported thickness control of up to tens of nanometers. (The interlayer distance of h-BN is 0.333 nm.) • Growth mechanisms of h-BN are discussed, especially for bilayer h-BN films. • Both epitaxial growth and diffusion-segregation process are involved in the synthesis of bilayer h-BN films. - Abstract: In this work, we report the successful synthesis of large scale hexagonal boron nitride films with controllable atomic layers. The films are grown on thin nickel foils via ambient pressure chemical vapor deposition with borazine as the precursor. The atomic layers of h-BN films can be controlled in a narrow range by adjusting growth time and the cooling rates. Transmission electron microscope results shows the h-BN films exhibit high uniformity and good crystalline. X-ray photoelectron spectroscopy shows the B/N elemental ratio is about 1.01. The h-BN films exhibit a pronounced deep ultraviolet absorption at 203.0 nm with a large optical band gap of 6.02 ± 0.03 eV. The results suggest potential applications of h-BN films in deep ultraviolet and dielectric materials. Growth mechanisms of h-BN films with thickness control are discussed, especially when the synthesized h-BN films after a higher cooling rate show an in-plane rotation angle between bilayers. Both epitaxial growth and diffusion-segregation process are involved in the synthesis of bilayer h-BN films.

  9. Fountain pen nanochemistry: Atomic force control of chrome etching

    Science.gov (United States)

    Lewis, Aaron; Kheifetz, Yuri; Shambrodt, Efim; Radko, Anna; Khatchatryan, Edward; Sukenik, Chaim

    1999-10-01

    In this report we demonstrate a general method for affecting chemical reactions with a high degree of spatial control that has potentially wide applicability in science and technology. Our technique is based on complexing the delivery of liquid or gaseous materials through a cantilevered micropipette with an atomic force microscope that is totally integrated into a conventional optical microscope. Controlled etching of chrome is demonstrated without detectable effects on the underlying glass substrate. This simple combination allows for the nanometric spatial control of the whole world of chemical reactions in defined regions of surfaces. Applications of the technique in critical areas such as mask repair are likely.

  10. Basic DTU Wind Energy controller

    Energy Technology Data Exchange (ETDEWEB)

    Hartvig Hansen, M.; Henriksen, Lars Christian

    2013-01-15

    This report contains a description and documentation, including source code, of the basic DTU Wind Energy controller applicable for pitch-regulated, variable speed wind turbines. The controller features both partial and full load operation capabilities as well as switching mechanisms ensuring smooth switching between the two modes of operation. The partial and full load controllers are both based on classical proportional-integral control theory as well as additional filters such as an optional drive train damper and a notch filter mitigating the influence of rotor speed dependent variations in the feedback. The controller relies on generator speed as the primary feedback sensor. Additionally, the reference generator power is used as a feedback term to smoothen the switching between partial and full load operation. Optionally, a low-pass filtered wind speed measurement can be used for wind speed dependent minimum blade pitch in partial load operation. The controller uses the collective blade pitch angle and electromagnetic generator torque to control the wind turbine. In full load operation a feedback term from the collective blade pitch angle is used to schedule the gains of the proportional-integral controller to counter the effects of changing dynamics of the wind turbine for different wind speeds. Blade pitch servo and generator models are not included in this controller and should be modeled separately, if they are to be included in the simulations. (Author)

  11. Tritium handling experience at Atomic Energy of Canada Limited

    Energy Technology Data Exchange (ETDEWEB)

    Suppiah, S.; McCrimmon, K.; Lalonde, S.; Ryland, D.; Boniface, H.; Muirhead, C.; Castillo, I. [Atomic Energy of Canad Limited - AECL, Chalk River Laboratories, Chalk River, ON (Canada)

    2015-03-15

    Canada has been a leader in tritium handling technologies as a result of the successful CANDU reactor technology used for power production. Over the last 50 to 60 years, capabilities have been established in tritium handling and tritium management in CANDU stations, tritium removal processes for heavy and light water, tritium measurement and monitoring, and understanding the effects of tritium on the environment. This paper outlines details of tritium-related work currently being carried out at Atomic Energy of Canada Limited (AECL). It concerns the CECE (Combined Electrolysis and Catalytic Exchange) process for detritiation, tritium-compatible electrolysers, tritium permeation studies, and tritium powered batteries. It is worth noting that AECL offers a Tritium Safe-Handling Course to national and international participants, the course is a mixture of classroom sessions and hands-on practical exercises. The expertise and facilities available at AECL is ready to address technological needs of nuclear fusion and next-generation nuclear fission reactors related to tritium handling and related issues.

  12. Control of quantum magnets by atomic exchange bias.

    Science.gov (United States)

    Yan, Shichao; Choi, Deung-Jang; Burgess, Jacob A J; Rolf-Pissarczyk, Steffen; Loth, Sebastian

    2015-01-01

    Mixing of discretized states in quantum magnets has a radical impact on their properties. Managing this effect is key for spintronics in the quantum limit. Magnetic fields can modify state mixing and, for example, mitigate destabilizing effects in single-molecule magnets. The exchange bias field has been proposed as a mechanism for localized control of individual nanomagnets. Here, we demonstrate that exchange coupling with the magnetic tip of a scanning tunnelling microscope provides continuous tuning of spin state mixing in an individual nanomagnet. By directly measuring spin relaxation time with electronic pump-probe spectroscopy, we find that the exchange interaction acts analogously to a local magnetic field that can be applied to a specific atom. It can be tuned in strength by up to several tesla and cancel external magnetic fields, thereby demonstrating the feasibility of complete control over individual quantum magnets with atomically localized exchange coupling.

  13. Atomic-Scale Control of Electron Transport through Single Molecules

    DEFF Research Database (Denmark)

    Wang, Y. F.; Kroger, J.; Berndt, R.;

    2010-01-01

    Tin-phthalocyanine molecules adsorbed on Ag(111) were contacted with the tip of a cryogenic scanning tunneling microscope. Orders-of-magnitude variations of the single-molecule junction conductance were achieved by controllably dehydrogenating the molecule and by modifying the atomic structure...... of the surface electrode. Nonequilibrium Green's function calculations reproduce the trend of the conductance and visualize the current flow through the junction, which is guided through molecule-electrode chemical bonds....

  14. Fast and Accurate Modeling of Molecular Atomization Energies with Machine Learning

    CERN Document Server

    Rupp, Matthias; Müller, Klaus-Robert; von Lilienfeld, O Anatole

    2011-01-01

    We introduce a machine learning model to predict atomization energies of a diverse set of organic molecules, based on nuclear charges and atomic positions only. The problem of solving the molecular Schr\\"odinger equation is mapped onto a non-linear statistical regression problem of reduced complexity. Regression models are trained on and compared to atomization energies computed with hybrid density-functional theory. Cross-validation over more than seven thousand small organic molecules yields a mean absolute error of ~10 kcal/mol. Applicability is demonstrated for the prediction of molecular atomization potential energy curves.

  15. Level-energy-dependent mean velocities of excited tungsten atoms sputtered by krypton-ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Nogami, Keisuke; Sakai, Yasuhiro; Mineta, Shota [Department of Physics, Toho University, Miyama, Funabashi, Chiba 274-8510 (Japan); Kato, Daiji; Murakami, Izumi [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan and Department of Fusion Science, School of Physical Sciences, SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 (Japan); Sakaue, Hiroyuki A. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Kenmotsu, Takahiro [Department of Biomedical Engineering, Faculty of Life and Medical Sciences, Doshisha University, Tatara-Miyakodani, Kyotanabe, Kyoto 610-0394 (Japan); Furuya, Kenji [Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Motohashi, Kenji, E-mail: motohashi@toyo.jp [Department of Biomedical Engineering, Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan and Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 (Japan)

    2015-11-15

    Visible emission spectra were acquired from neutral atoms sputtered by 35–60 keV Kr{sup +} ions from a polycrystalline tungsten surface. Mean velocities of excited tungsten atoms in seven different 6p states were also obtained via the dependence of photon intensities on the distance from the surface. The average velocities parallel to the surface normal varied by factors of 2–4 for atoms in the different 6p energy levels. However, they were almost independent of the incident ion kinetic energy. The 6p-level energy dependence indicated that the velocities of the excited atoms were determined by inelastic processes that involve resonant charge exchange.

  16. SIMULATION OF THE ATOMIZED FLOW BY SLIT TYPE BUCKET ENERGY DISSIPATOR

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-he; DUAN Hong-dong

    2005-01-01

    Slit type bucket is one kind of flip bucket for energy dissipation generally used in the hydraulic project.In this paper the atomized flow produced behind this energy dissipator is analyzed, a numerical model for the aerated jet considering air entrainment and air resistance force is suggested, and simulation of the rain resulted by the atomized flow is also discussed.Furthermore, the prototype observation data for the atomized flow of Dongjiang Hydropower Station is used to verify the model suggested.

  17. Energy shift of H-atom electrons due to Gibbons-Hawking thermal bath

    CERN Document Server

    Pardy, Miroslav

    2016-01-01

    The electromagnetic shift of energy levels of H-atom electrons is determined by calculating an electron coupling to the Gibbons-Hawking electromagnetic field thermal bath. Energy shift of electrons in H-atom is determined in the framework of the non-relativistic quantum mechanics.

  18. Double-electron capture by highly-ionized atoms isolated at very low energy

    Science.gov (United States)

    Fogwell Hoogerheide, Shannon; Dreiling, Joan M.; Sahiner, Arda; Tan, Joseph N.

    2016-05-01

    Charge exchange with background gases, also known as electron capture processes, is important in the study of comets, controlled fusion energy, anti-matter atoms, and proposed one-electron ions in Rydberg states. However, there are few experiments in the very low energy regime that could be useful for further theoretical development. At NIST, highly-charged ions extracted from an electron-beam ion trap can be isolated with energy state. Analysis using a system of rate equations yields information about the ion cloud expansion and single-electron capture rates. A substantial amount of double-electron capture is also observed. We present the relative rates and discuss the error budget. SFH and JMD were funded by National Research Council Research Associateship Awards during some of this work.

  19. Recent Development of Advanced Electrode Materials by Atomic Layer Deposition for Electrochemical Energy Storage.

    Science.gov (United States)

    Guan, Cao; Wang, John

    2016-10-01

    Electrode materials play a decisive role in almost all electrochemical energy storage devices, determining their overall performance. Proper selection, design and fabrication of electrode materials have thus been regarded as one of the most critical steps in achieving high electrochemical energy storage performance. As an advanced nanotechnology for thin films and surfaces with conformal interfacial features and well controllable deposition thickness, atomic layer deposition (ALD) has been successfully developed for deposition and surface modification of electrode materials, where there are considerable issues of interfacial and surface chemistry at atomic and nanometer scale. In addition, ALD has shown great potential in construction of novel nanostructured active materials that otherwise can be hardly obtained by other processing techniques, such as those solution-based processing and chemical vapor deposition (CVD) techniques. This review focuses on the recent development of ALD for the design and delivery of advanced electrode materials in electrochemical energy storage devices, where typical examples will be highlighted and analyzed, and the merits and challenges of ALD for applications in energy storage will also be discussed.

  20. Wireless embedded control system for atomically precise manufacturing

    KAUST Repository

    Khan, Yasser

    2011-04-01

    This paper will explore the possibilities of implementing a wireless embedded control system for atomically precise manufacturing. The manufacturing process, similar to Scanning Tunneling Microscopy, takes place within an Ultra High Vacuum (UHV) chamber at a pressure of 10-10 torr. In order to create vibration isolation, and to keep internal noise to a minimum, a wireless link inside the UHV chamber becomes essential. We present a MATLAB simulation of the problem, and then demonstrate a hardware scheme between a Gumstix computer and a Linux based laptop for controlling nano-manipulators with three degrees of freedom. © 2011 IEEE.

  1. Controlled Reactions between Ultracold Alkali and Metastable Helium Atoms

    CERN Document Server

    Flores, Adonis Silva; Knoop, Steven

    2016-01-01

    In an ultracold, optically trapped mixture of $^{87}$Rb and metastable triplet $^4$He atoms we have studied trap loss for different spin-state combinations, for which interspecies Penning ionization is the main two-body loss process. We observe long trapping lifetimes for the purely quartet spin-state combination, indicating strong suppression of Penning ionization loss by at least two orders of magnitude. For the other spin-mixtures we observe short lifetimes that depend linearly on the doublet character of the entrance channel. We compare the extracted loss rate coefficient with recent predictions of multichannel quantum-defect theory for reactive collisions involving a strong exothermic loss channel and find near-universal loss for doublet scattering. Our work demonstrates control of reactive collisions by internal atomic state preparation, which also implies magnetic field tunability.

  2. Resonant optical control of the spin of a single Cr atom in a quantum dot

    Science.gov (United States)

    Lafuente-Sampietro, A.; Utsumi, H.; Boukari, H.; Kuroda, S.; Besombes, L.

    2017-01-01

    A Cr atom in a semiconductor host carries a localized spin with an intrinsic large spin to strain coupling, which is particularly promising for the development of hybrid spin-mechanical systems and coherent mechanical spin driving. We demonstrate here that the spin of an individual Cr atom inserted in a semiconductor quantum dot can be controlled optically. We first show that a Cr spin can be prepared by resonant optical pumping. Monitoring the time dependence of the intensity of the resonant fluorescence of the quantum dot during this process permits us to probe the dynamics of the optical initialization of the Cr spin. Using this initialization and readout technique we measured a Cr spin relaxation time at T =5 K in the microsecond range. We finally demonstrate that, under a resonant single-mode laser field, the energy of any spin state of an individual Cr atom can be independently tuned by using the optical Stark effect.

  3. Coherently controlling Raman-induced grating in atomic media

    CERN Document Server

    Arkhipkin, V G; Timofeev, I V

    2015-01-01

    We consider dynamically controllable periodic structures, called Raman induced gratings, in three- and four-level atomic media, resulting from Raman interaction in a standing-wave pump. These gratings are due to periodic spatial modulation of the Raman nonlinearity and fundamentally differ from the ones based on electromagnetically induced transparency. The transmission and reflection spectra of such gratings can be simultaneously amplified and controlled by varying the pump field intensity. It is shown that a transparent medium with periodic spatial modulation of the Raman gain can be opaque near the Raman resonance and yet at the same time it can be a non-linear amplifying mirror. We also show that spectral properties of the Raman induced grating can be controlled with the help of an additional weak control field.

  4. Atomic mean excitation energies for stopping powers from local plasma oscillator strengths

    Science.gov (United States)

    Wilson, J. W.; Xu, Y. J.; Chang, C. K.; Kamaratos, E.

    1984-01-01

    The stopping of a charged particle by isolated atoms is investigated theoretically using an 'atomic plasma' model in which atomic oscillator strengths are replaced by the plasma frequency spectrum. The plasma-frequency correction factor for individual electron motion proposed by Pines (1953) is incorporated, and atomic mean excitation energies are calculated for atoms through Sr. The results are compared in a graph with those obtained theoretically by Inokuti et al. (1978, 1981) and Dehmer et al. (1975) and with the experimental values compiled by Seltzer and Berger (1982): good agreement is shown.

  5. Observation of a power-law energy distribution in atom-ion hybrid system

    Science.gov (United States)

    Meir, Ziv; Akerman, Nitzan; Sikorsky, Tomas; Ben-Shlomi, Ruti; Dallal, Yehonatan; Ozeri, Roee

    2016-05-01

    Understanding atom-ion collision dynamics is at the heart of the growing field of ultra-cold atom-ion physics. The naive picture of a hot ion sympathetically-cooled by a cold atomic bath doesn't hold due to the time dependent potentials generated by the ion Paul trap. The energy scale of the atom-ion system is determined by a combination of the atomic bath temperature, the ion's excess micromotion (EMM) and the back action of the atom-ion attraction on the ion's position in the trap. However, it is the position dependent ion's inherent micromotion which acts as an amplifier for the ion's energy during random consecutive collisions. Due to this reason, the ion's energy distribution deviates from Maxwell-Boltzmann (MB) characterized by an exponential tail to one with power-law tail described by Tsallis q-exponential function. Here we report on the observation of a strong deviation from MB to Tsallis energy distribution of a trapped ion. In our experiment, a ground-state cooled 88 Sr+ ion is immersed in an ultra-cold cloud of 87 Rb atoms. The energy scale is determined by either EMM or solely due to the back action on the ion position during a collision with an atom in the trap. Energy distributions are obtained using narrow optical clock spectroscopy.

  6. Energy Spectra of the Confined Atoms Obtained by Using B-Splines

    Institute of Scientific and Technical Information of China (English)

    SHI Ting-Yun; BAO Cheng-Guang; LI Bai-Wen

    2001-01-01

    We have calculated the energy spectra of one- and two-electron atoms (ions) centered in an impenetrable spherical box by variational method with B-splines as basis functions. Accurate results are obtained for both large and small radii of confinement. The critical box radius of confined hydrogen atom is also calculated to show the usefulness of our method. A partial energy degeneracy in confined hydrogen atom is found when the radius of spherical box is equal to the distance at which a node of single-node wavefunctions of free hydrogen atom is located.

  7. Theoretical study of atoms by the electronic kinetic energy density and stress tensor density

    CERN Document Server

    Nozaki, Hiroo; Tachibana, Akitomo

    2016-01-01

    We analyze the electronic structure of atoms in the first, second and third periods using the electronic kinetic energy density and stress tensor density, which are local quantities motivated by quantum field theoretic consideration, specifically the rigged quantum electrodynamics. We compute the zero surfaces of the electronic kinetic energy density, which we call the electronic interfaces, of the atoms. We find that their sizes exhibit clear periodicity and are comparable to the conventional atomic and ionic radii. We also compute the electronic stress tensor density and its divergence, tension density, of the atoms, and discuss how their electronic structures are characterized by them.

  8. Excitation and charge transfer in low-energy hydrogen atom collisions with neutral atoms: Theory, comparisons, and application to Ca

    CERN Document Server

    Barklem, Paul S

    2016-01-01

    A theoretical method for the estimation of cross sections and rates for excitation and charge transfer processes in low-energy hydrogen atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent interactions in the neutral atom-hydrogen atom system, is presented. The calculation of potentials and non-adiabatic radial couplings using the method is demonstrated. The potentials are used together with the multi-channel Landau-Zener model to calculate cross sections and rate coefficients. The main feature of the method is that it employs asymptotically exact atomic wavefunctions, which can be determined from known atomic parameters. The method is applied to Li+H, Na+H, and Mg+H collisions, and the results compare well with existing detailed full-quantum calculations. The method is applied to the astrophysically important problem of Ca+H collisions, and rate coefficients are calculated for temperatures in the range 1000-20000 K.

  9. Alternate Funding Sources for the International Atomic Energy Agency

    Energy Technology Data Exchange (ETDEWEB)

    Toomey, Christopher; Wyse, Evan T.; Kurzrok, Andrew J.; Swarthout, Jordan M.

    2012-09-04

    Since 1957, the International Atomic Energy Agency (IAEA) has worked to ensure the safe and responsible promotion of nuclear technology throughout the world. The IAEA operates at the intersection of the Nuclear Nonproliferation Treaty’s (NPT) fourth and third articles, which guarantee Parties to the Treaty the right to peaceful uses of nuclear technology, provided those activities are placed under safeguards verified by the IAEA. However, while the IAEA has enjoyed substantial success and prestige in the international community, there is a concern that its resources are being stretched to a point where it may no longer be possible to execute its multifaceted mission in its entirety. As noted by the Director General (DG) in 2008, demographics suggest that every aspect of the IAEA’s operations will be in higher demand due to increasing reliance on non-carbon-based energy and the concomitant nonproliferation, safety, and security risks that growth entails. In addition to these nuclear energy concerns, the demand for technical developmental assistance in the fields of food security, resource conservation, and human health is also predicted to increase as the rest of the world develops. Even with a 100% value-for-money rating by the U.S. Office of Management and Budget (OMB) and being described as an “extraordinary bargain” by the United Nations Secretary-General’s High-level Panel on Threats, Challenges and Change, real budget growth at the Agency has been limited to zero-real growth for a better part of the last two decades. Although the 2012 regular budget (RB) received a small increase for most programs, the 2013 RB has been set at zero-real growth. As a result, the IAEA has had to defer infrastructure investments, which has hindered its ability to provide the public goods its Members seek, decreased global security and development opportunities, and functionally transformed the IAEA into a charity, dependent on extrabudgetary (EB) contributions to sustain

  10. Control of inhomogeneous atomic ensembles of hyperfine qudits

    CERN Document Server

    Mischuck, Brian E; Deutsch, Ivan H

    2011-01-01

    We study the ability to control d-dimensional quantum systems (qudits) encoded in the hyperfine spin of alkali-metal atoms through the application of radio- and microwave-frequency magnetic fields in the presence of inhomogeneities in amplitude and detuning. Such a capability is essential to the design of robust pulses that mitigate the effects of experimental uncertainty and also for application to tomographic addressing of particular members of an extended ensemble. We study the problem of preparing an arbitrary state in the Hilbert space from an initial fiducial state. We prove that inhomogeneous control of qudit ensembles is possible based on a semi-analytic protocol that synthesizes the target through a sequence of alternating rf and microwave-driven SU(2) rotations in overlapping irreducible subspaces. Several examples of robust control are studied, and the semi-analytic protocol is compared to a brute force, full numerical search. For small inhomogeneities, < 1%, both approaches achieve average fide...

  11. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    Energy Technology Data Exchange (ETDEWEB)

    Vos, M. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Marmitt, G. G. [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra ACT (Australia); Instituto de Fisica da Universidade Federal do Rio Grande do Sul, Avenida Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Finkelstein, Y. [Nuclear Research Center — Negev, Beer-Sheva 84190 (Israel); Moreh, R. [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2015-09-14

    Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.

  12. Resonance interaction energy between two accelerated identical atoms in a coaccelerated frame and the Unruh effect

    CERN Document Server

    Zhou, Wenting; Rizzuto, Lucia

    2016-01-01

    We investigate the resonance interaction energy between two uniformly accelerated identical atoms, interacting with the scalar field or the electromagnetic field in the vacuum state, in the reference frame coaccelerating with the atoms. We assume that one atom is excited and the other in the ground state, and that they are prepared in their correlated symmetric or antisymmetric state. Using perturbation theory, we separate, at the second order in the atom-field coupling, the contributions of vacuum fluctuations and radiation reaction field to the energy shift of the interacting system. We show that only the radiation reaction term contributes to the resonance interaction between the two atoms, while Unruh thermal fluctuations, related to the vacuum fluctuations contribution, do not affect the resonance interatomic interaction. We also show that the resonance interaction between two uniformly accelerated atoms, recently investigated in the comoving (locally inertial) frame, can be recovered in the coaccelerate...

  13. Two-Pulse Atomic Coherent Control (2PACC) Spectroscopy of Eley-Rideal Reactions. An Application of an Atom Laser

    CERN Document Server

    Jorgensen, S F; Jorgensen, Solvejg; Kosloff, Ronnie

    2003-01-01

    A spectroscopic application of the atom laser is suggested. The spectroscopy termed 2PACC employs the coherent properties of matter-waves from a two pulse atom laser. These waves are employed to control a gas-surface chemical recombination reaction. The method is demonstrated for an Eley-Rideal reaction of a hydrogen or alkali atom-laser pulse where the surface target is an adsorbed hydrogen atom. The reaction yields either a hydrogen or alkali hydride molecule. The desorbed gas phase molecular yield and its internal state is shown to be controlled by the time and phase delay between two atom-laser pulses. The calculation is based on solving the time-dependent Schrodinger equation in a diabatic framework. The probability of desorption which is the predicted 2PACC signal has been calculated as a function of the pulse parameters.

  14. Interactions of satellite-speed helium atoms with satellite surfaces. 2: energy distributions of reflected helium atoms. [7000 m/s

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S.M.; Knuth, E.L.

    1976-04-01

    Energy transfer in collisions of satellite-speed (7,000 m/s) helium atoms with a cleaned 6061-T6 satellite-type aluminum surface was investigated by use of the molecular-beam technique. The amount of energy transferred was determined from the measured energy of the molecular-beam and the measured spatial and energy distributions of the reflected atoms. Spatial distributions of helium atoms scattered from a 6061-T6 aluminum surface were measured. The scattering pattern exhibits a prominent backscattering, probably due to the gross surface roughness and/or the relative lattice softness of the aluminum surface. Energy distributions of reflected helium atoms from the same surface were measured for six different incidence angles. For each incidence angle, distributions were measured at approximately sixty scattering positions. At a given scattering position, the energy spectra of the reflected helium atoms and the background gas were obtained by use of the retarding-field energy analyzer. (auth)

  15. Field ionization of free helium atoms: Correlation between the kinetic energy of ionized atoms and probability of their field ionization

    Energy Technology Data Exchange (ETDEWEB)

    Piskur, J.; Borg, L. [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Stupnik, A.; Leisch, M. [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Ernst, W.E. [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Holst, B. [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria)], E-mail: bodil@cantab.net

    2008-05-15

    In this paper the correlation between the kinetic energy of helium atoms and the probability of field ionization is investigated by exploiting the narrow velocity distribution of supersonic molecular beams. Field ionization measurements were carried out on supersonic helium beams at 298 K and 95 K corresponding to energies of about 65 meV and 20 meV, respectively, for the individual atoms. The field ionization was performed with a tungsten tip, radius of curvature 12 nm, kept at room temperature. The ionization probability was found to increase by about a factor 10 when the beam was cooled from 298 K to 95 K. The results presented in this paper are of importance for improving the understanding of field ionization and for the development of a new detector for helium and other molecular beams.

  16. Field ionization of free helium atoms: Correlation between the kinetic energy of ionized atoms and probability of their field ionization

    Science.gov (United States)

    Piskur, J.; Borg, L.; Stupnik, A.; Leisch, M.; Ernst, W. E.; Holst, B.

    2008-05-01

    In this paper the correlation between the kinetic energy of helium atoms and the probability of field ionization is investigated by exploiting the narrow velocity distribution of supersonic molecular beams. Field ionization measurements were carried out on supersonic helium beams at 298 K and 95 K corresponding to energies of about 65 meV and 20 meV, respectively, for the individual atoms. The field ionization was performed with a tungsten tip, radius of curvature 12 nm, kept at room temperature. The ionization probability was found to increase by about a factor 10 when the beam was cooled from 298 K to 95 K. The results presented in this paper are of importance for improving the understanding of field ionization and for the development of a new detector for helium and other molecular beams.

  17. The Scales of Time, Length, Mass, Energy, and Other Fundamental Physical Quantities in the Atomic World and the Use of Atomic Units in Quantum Mechanical Calculations

    Science.gov (United States)

    Teo, Boon K.; Li, Wai-Kee

    2011-01-01

    This article is divided into two parts. In the first part, the atomic unit (au) system is introduced and the scales of time, space (length), and speed, as well as those of mass and energy, in the atomic world are discussed. In the second part, the utility of atomic units in quantum mechanical and spectroscopic calculations is illustrated with…

  18. Experimental evidence of the decrease of kinetic energy of hadrons in passing through atomic nuclei

    Science.gov (United States)

    Strugalski, Z.

    1985-01-01

    Hadrons with kinetic energies higher than the pion production threshold lose their kinetic energies monotonically in traversing atomic nuclei, due to the strong interactions in nuclear matter. This phenomenon is a crude analogy to the energy loss of charged particles in their passage through materials. Experimental evidence is presented.

  19. Nonlinear control of chaotic walking of atoms in an optical lattice

    OpenAIRE

    Yu, Argonov V.; Prants, S.V.

    2007-01-01

    Centre-of-mass atomic motion in an optical lattice near the resonance is shown to be a chaotic walking due to the interplay between coherent internal atomic dynamics and spontaneous emission. Statistical properties of chaotic atomic motion can be controlled by the single parameter, the detuning between the atomic transition frequency and the laser frequency. We derive a Fokker-Planck equation in the energetic space to describe the atomic transport near the resonance and demonstrate numericall...

  20. Mr Parvez Butt, Chairman of the Atomic Energy Commission (PAEC), Pakistan

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    Photo 01: Mr. Parvez Butt, Chairman Pakistan Atomic Energy Commission (standing 4th from left) with his delegation and ATLAS team standing in front of the Barrel Supports manufactured in HMC3 - Pakistan.

  1. Adiabatic Charge Control in a Single Donor Atom Transistor

    CERN Document Server

    Prati, Enrico; Cocco, Simone; Petretto, Guido; Fanciulli, Marco

    2010-01-01

    A Silicon quantum device containing a single Arsenic donor and an electrostatic quantum dot in parallel is realized in a nanometric field effect transistor. The different coupling capacitances of the donor and the quantum dot with the control and the back gates determine a relative rigid shift of their energy spectrum as a function of the back gate voltage, causing the crossing of the energy levels. We observe the sequential tunneling through the $D^{2-}$ and the $D^{3-}$ energy levels of the donor at 4.2 K, ordinarily hidden at high temperature as they lie above the conduction band edge of Silicon. The exchange coupling of the localized electrons is controlled in the anticrossing region by moving one electron from the donor to the quantum dot site and \\textit{viceversa}, in order to realize physical qubits for quantum information processing.

  2. On modal energy in civil structural control

    Institute of Scientific and Technical Information of China (English)

    Miao PANG; Tie-jiong LOU; Ming ZHAO

    2008-01-01

    A new control strategy based on modal energy criterion is proposed to demonstrate the effectiveness of the control system in reducing structural earthquake responses. The modal control algorithm combining LQR (linear quadratic regulator) control algorithm is adopted in the discrete time-history analysis. The various modal energy forms are derived by definition of the generalized absolute displacement vector. A preliminary numerical study of the effectiveness of this control strategy is carried out on a 20-storey framed steel structural model. The controlled performance of the model is studied from the perspectives of both response and modal energy. Results show that the modal energy-based control strategy is very effective in reducing structural responses as well as in consuming a large amount of modal energy, while augmentation of additional generalized control force corresponding to the modes that contain little modal energy is unnecessary, as it does little help to improve the controlled structural performance.

  3. The energy control; La maitrise de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-15

    Because of strong constraints, the energy control has not been a priority of the public choices. With the market liberalization, the framework of the energy control is modified. But the new program became not sufficient. This study aims to present the necessary new policy of the energy control, which must be integrated in the attitudes and must imply the local government. (A.L.B.)

  4. The industrial development of atomic energy; Le developpement industriel de l'energie atomique

    Energy Technology Data Exchange (ETDEWEB)

    Kowarski, L. [Commissariat a l' Energie Atomique, Paris (France). Centre d' Etudes Nucleaires

    1955-07-01

    Countries with large stock of fissile material and producing large quantity of nuclear pure {sup 235}U and {sup 239}Pu are able to allocate part of the stock to non military research. For countries with low stock of fissile material, all the stock is allocated to military research. An economical and technical solution has to be find to dedicate a part of fissile material to non military research and develop the atomic energy industry. It stated the industrial and economical problems and in particular the choice between the use of enriched fuel with high refining cost or depleted fuel with low production cost. It discusses of four possible utilizations of the natural resources: reactors functioning with pure fissile material ({sup 235}U or {sup 239}Pu) or concentrated material ({sup 235}U mixed with small quantities of {sup 238}U after an incomplete isotopic separation), breeder reactors functioning with enriched material mixed with {sup 238}U or Thorium placed in an appropriate spatial distribution to allow neutrons beam to activate {sup 238}U or Thorium with the regeneration of fissile material in {sup 239}Pu, reactors using natural uranium or low enriched uranium can also produce Plutonium with less efficiency than breeder reactors and the last solution being the use of natural uranium with the only scope of energy production and no production of secondary fissile material. The first class using pure fissile material has a low energy efficiency and is used only by large fissile material stock countries to accumulate energy in small size fuel for nuclear engines researches for submarines and warships. The advantage of the second class of reactors, breeder reactors, is that they produce energy and plutonium. Two type of breeder reactor are considered: breeder reactor using pure fissile material and {sup 238}U or breeder reactor using the promising mixture of pure fissile material and Thorium. Different projects are in phase of development in United States, England

  5. Virial theorem in the Kohn-Sham density-functional theory formalism: accurate calculation of the atomic quantum theory of atoms in molecules energies.

    Science.gov (United States)

    Rodríguez, Juan I; Ayers, Paul W; Götz, Andreas W; Castillo-Alvarado, F L

    2009-07-14

    A new approach for computing the atom-in-molecule [quantum theory of atoms in molecule (QTAIM)] energies in Kohn-Sham density-functional theory is presented and tested by computing QTAIM energies for a set of representative molecules. In the new approach, the contribution for the correlation-kinetic energy (T(c)) is computed using the density-functional theory virial relation. Based on our calculations, it is shown that the conventional approach where atomic energies are computed using only the noninteracting part of the kinetic energy might be in error by hundreds of kJ/mol.

  6. "Pseudo-invariant Eigen-operator" Method for Deriving Energy-Gap of an Atom-Cavity Jaynes-Cummings Hamiltonian with Atomic Centre-of-Mass Motion

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-Yi; TANG Xu-Bing

    2006-01-01

    Using the "Pseudo-invariant eigen-operator" method we find the energy-gap of the Jaynes-Cummings Hamiltonian model of an atom-cavity system. This model takes the atomic centre-of-mass motion into account. The supersymmetric structure is involved in the Hamiltonian of an atom-cavity system. By selecting suitable supersymmetric generators and using supersymmetric transformation the Hamiltonian is diagonalized and energy eigenvectors are obtained.

  7. Scaled-energy spectroscopy of a |M|=1 Rydberg barium atom in an electric field

    Institute of Scientific and Technical Information of China (English)

    Wang Lei; Quan Wei; Shen Li; Yang Hai-Feng; Shi Ting-Yun; Liu Xiao-Jun; Liu Hong-Ping; Zhan Ming-Sheng

    2009-01-01

    We observe strong energy-dependent quantum defects in the scaled-energy Stark spectra for |M|=1 Rydberg states of barium atoms at three scaled energies: ε= -2.000, ε= -2.500 and ε=-3.000. In an attempt to explain the observations, theoretical calculations of closed orbit theory based on a model potential including core effect are performed for non-hydrogenic atoms. While such a potential has been uniformly successful for alkali atoms with a single valence electron, it fails to match experimental results for barium atoms in the 6snp Rydberg states with two valence electrons. Our study points out that this discrepancy is due to the strong perturbation from the 5d8p state, which voids the simple approximation for constant quantum defects of principle quantum number n.

  8. Matter, energy, and heat transfer in a classical ballistic atom pump.

    Science.gov (United States)

    Byrd, Tommy A; Das, Kunal K; Mitchell, Kevin A; Aubin, Seth; Delos, John B

    2014-11-01

    A ballistic atom pump is a system containing two reservoirs of neutral atoms or molecules and a junction connecting them containing a localized time-varying potential. Atoms move through the pump as independent particles. Under certain conditions, these pumps can create net transport of atoms from one reservoir to the other. While such systems are sometimes called "quantum pumps," they are also models of classical chaotic transport, and their quantum behavior cannot be understood without study of the corresponding classical behavior. Here we examine classically such a pump's effect on energy and temperature in the reservoirs, in addition to net particle transport. We show that the changes in particle number, of energy in each reservoir, and of temperature in each reservoir vary in unexpected ways as the incident particle energy is varied.

  9. A Combination of the Work Formalism for Exchange with an Optimized Correlation Energy Functional for Atoms

    Science.gov (United States)

    Cordero, N. A.; Sen, K. D.; Alonso, J. A.; Balbás, L. C.

    1995-09-01

    The Harbola-Sahni formalism for the exchange potential of many-electron systems gives extremely accurate total energies for atoms (the energies are practically indistinguishable from the Hartree-Fock energies). We combine here this formalism with the usual density functional prescription for the correlation potential, using a recently developed optimized local correlation functional (Gritsenko O.V. et al., Phys. Rev. A 47 (1993) 1811). Numerical tests carried out for several closed shell atoms and ions indicate that the results preserve the accuracy of the exchange-only calculations. We expect the same behavior to hold true for large molecules and atomic clusters. However, similar tests for the He, Be and Ne isoelectronic series indicate that the optimized local correlation functional is not valid for highly ionized atoms.

  10. Atom probe tomography simulations and density functional theory calculations of bonding energies in Cu3Au

    KAUST Repository

    Boll, Torben

    2012-10-01

    In this article the Cu-Au binding energy in Cu3Au is determined by comparing experimental atom probe tomography (APT) results to simulations. The resulting bonding energy is supported by density functional theory calculations. The APT simulations are based on the Müller-Schottky equation, which is modified to include different atomic neighborhoods and their characteristic bonds. The local environment is considered up to the fifth next nearest neighbors. To compare the experimental with simulated APT data, the AtomVicinity algorithm, which provides statistical information about the positions of the neighboring atoms, is applied. The quality of this information is influenced by the field evaporation behavior of the different species, which is connected to the bonding energies. © Microscopy Society of America 2012.

  11. Optical-bistability-enabled control of resonant light transmission for an atom-cavity system

    Science.gov (United States)

    Sawant, Rahul; Rangwala, S. A.

    2016-02-01

    The control of light transmission through a standing-wave Fabry-Pérot cavity containing atoms is theoretically and numerically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained. The response of the intracavity intensity to an intersecting beam on atomic resonance is understood in the presence of stationary atoms (closed system) and nonstatic atoms (open system) in the cavity. The nonstatic system of atoms is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, which corresponds to a thermal environment where atoms are moving in and out of the cavity mode volume. The control behavior with three- and two-level atomic systems is also studied, and the rich physics arising out of these systems for closed and open atomic systems is discussed. The solutions to the models are used to interpret the steady-state and transient behavior observed by Sharma et al. [Phys. Rev. A 91, 043824 (2015)], 10.1103/PhysRevA.91.043824.

  12. Cavity-assisted measurement and coherent control of collective atomic spin oscillators

    CERN Document Server

    Kohler, Jonathan; Schreppler, Sydney; Stamper-Kurn, Dan M

    2016-01-01

    We demonstrate continuous measurement and coherent control of the collective spin of an atomic ensemble undergoing Larmor precession in a high-finesse optical cavity. The coupling of the precessing spin oscillator to the cavity field yields phenomena similar to those observed in cavity optomechanics, including cavity amplification, damping, and optical spring shifts. These effects arise from autonomous optical feedback onto the atomic spin dynamics, conditioned by the cavity spectrum. We use this feedback to stabilize the spin in either its high- or low-energy state, where it achieves a steady-state temperature in equilibrium with measurement back-action. We measure the effective spin temperature from the asymmetry between the Stokes and anti-Stokes sidebands and show that, for sufficiently large Larmor frequency, such a feedback-stabilized spin ensemble remains in a nearly pure quantum state, in spite of continuous interaction with the probe field.

  13. Disposal of radioactive wastes arising in the United Kingdom from the peaceful uses of atomic energy

    CERN Document Server

    Bryant, P M

    1971-01-01

    This paper describes United Kingdom policy in relation to radioactive waste and summarises the relevant legislation ad methods of control. Data are given on the amounts of radioactivity discharged as waste from establishments of the United Kingdom Atomic Energy Authority, the nuclear power stations operated by the Electricity Generating Boards and other users of radioactive materials. Studies of the behaviour of radioactivity in the environment are reported with particular reference to food chains and other potential sources of irradiation of the public. The results of environmental monitoring are presented and estimates are made of radiation doses received by individual members of the public and larger population groups as a result of waste disposal. It is concluded that the doses received are all within the appropriate limits recommended by the International Commission on Radiological Protection, and in most cases are trivial.

  14. Determining Nuclear Fingerprints: Glove Boxes, Radiation Protection, and the International Atomic Energy Agency.

    Science.gov (United States)

    Rentetzi, Maria

    2017-03-15

    In a nuclear laboratory, a glove box is a windowed, sealed container equipped with two flexible gloves that allow the user to manipulate nuclear materials from the outside in an ostensibly safe environment. As a routine laboratory device, it invites neglect from historians and storytellers of science. Yet, since especially the Gulf War, glove boxes have put the interdependence of science, diplomacy, and politics into clear relief. Standing at the intersection of history of science and international history, technological materials and devices such as the glove box can provide penetrating insight into the role of international diplomatic organizations to the global circulation and control of scientific knowledge. The focus here is on the International Atomic Energy Agency.

  15. Energy Management Controls. Course Syllabus.

    Science.gov (United States)

    Bergen County Vocational-Technical High School, Hackensack, NJ.

    This course is one of four in a solar systems and energy management program developed by the Bergen County Vocational-Technical Schools to help tradespeople (heating, ventilation, and air conditioning; mechanics; plumbers; and electricians) to develop an awareness of alternate energy sources and to gain skills in the areas of solar installations…

  16. Developing the World's Digital Collection on Peaceful Uses of Atomic Energy.

    Science.gov (United States)

    Levine, Emil

    1997-01-01

    Discusses the developers/development, maintainers, and users of the digital collection on peaceful uses of nuclear energy, produced by the International Nuclear Information System (INIS) of the International Atomic Energy Agency (IAEA). Sensitive to users in both developing and highly developed countries, this system provides closer linkage…

  17. 76 FR 56242 - Duke Energy Carolinas, LLC; Southern Nuclear Operating Company; Establishment of Atomic Safety...

    Science.gov (United States)

    2011-09-12

    ... Energy Carolinas, LLC; Southern Nuclear Operating Company; Establishment of Atomic Safety and Licensing...: Duke Energy Carolinas, LLC, (William States Lee III Nuclear Station, Units 1 and 2), Docket Nos. 52-018... From the Federal Register Online via the Government Publishing Office NUCLEAR...

  18. Using Density Functional Theory (DFT) for the Calculation of Atomization Energies

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The calculation of atomization energies using density functional theory (DFT), using the B3LYP hybrid functional, is reported. The sensitivity of the atomization energy to basis set is studied and compared with the coupled cluster singles and doubles approach with a perturbational estimate of the triples (CCSD(T)). Merging the B3LYP results with the G2(MP2) approach is also considered. It is found that replacing the geometry optimization and calculation of the zero-point energy by the analogous quantities computed using the B3LYP approach reduces the maximum error in the G2(MP2) approach. In addition to the 55 G2 atomization energies, some results for transition metal containing systems will also be presented.

  19. Controlling interactions between highly-magnetic atoms with Feshbach resonances

    CERN Document Server

    Kotochigova, Svetlana

    2014-01-01

    This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic $^7$S$_3$ chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on Dysprosium and Erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

  20. Chain-branching control of the atomic structure of alkanethiol-based gold-sulfur interfaces.

    Science.gov (United States)

    Wang, Yun; Chi, Qijin; Zhang, Jingdong; Hush, Noel S; Reimers, Jeffrey R; Ulstrup, Jens

    2011-09-28

    Density functional theory structure calculations at 0 K and simulations at 300 K of observed high-resolution in situ scanning tunneling microscopy (STM) images reveal three different atomic-interface structures for the self-assembled monolayers (SAMs) of three isomeric butanethiols on Au(111): direct binding to the Au(111) surface without pitting, binding to adatoms above a regular surface with extensive pitting, and binding to adatoms with local surface vacancies and some pitting. Thermal motions are shown to produce some observed STM features, with a very tight energy balance controlling the observed structures. Variation of the degree of substitution on the α carbon is found to significantly change the relative energies for interaction of the different types of adatom structures with the surface, while the nature of the surface cell, controlled primarily by inter-adsorbate steric interactions, controls substrate reorganization energies and adsorbate distortion energies. Most significantly, by manipulating these features, chemical control of the adsorbate can produce stable interfaces with surface pitting eliminated, providing new perspectives for technological applications of SAMs.

  1. Two-dimensional sub-half-wavelength atom localization via controlled spontaneous emission.

    Science.gov (United States)

    Wan, Ren-Gang; Zhang, Tong-Yi

    2011-12-05

    We propose a scheme for two-dimensional (2D) atom localization based on the controlled spontaneous emission, in which the atom interacts with two orthogonal standing-wave fields. Due to the spatially dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the resulting spontaneously emission spectrum. The phase sensitive property of the atomic system leads to quenching of the spontaneous emission in some regions of the standing-waves, which significantly reduces the uncertainty in the position measurement of the atom. We find that the frequency measurement of the emitted light localizes the atom in half-wavelength domain. Especially the probability of finding the atom at a particular position can reach 100% when a photon with certain frequency is detected. By increasing the Rabi frequencies of the driving fields, such 2D sub-half-wavelength atom localization can acquire high spatial resolution.

  2. A Novel Controllable Beam Splitter for Guided Atoms

    Institute of Scientific and Technical Information of China (English)

    刘南春; 高伟建; 印建平

    2003-01-01

    We propose a novel atomic beamsplitter for guided atoms composed of a U-shaped current carrying conductor and an additional bias magnetic field, and study the dynamic process of atomic beam splitting in the beamsplitter by Monte Carlo simulations. Our study shows that the splitting ratio of the beamsplitter can be continuously adjusted from 0 to 1by changing the additional bias field. In addition, the transverse temperature of guided atoms at the outlets of the beamsplitter are also estimated and explained qualitatively.

  3. Nuclear Energy: It is Time to Revitalize the Peaceful Atom

    Science.gov (United States)

    2011-03-16

    levels of poisonous hydrogen sulfide . Base load electricity is required twenty four hours a day. Wind power is intermittent. The sun does not shine at...dependence on foreign oil by producing hydrogen for use in fuel cells and synthetic liquid fuels.57 Nuclear energy is bad for the environment. Nuclear

  4. LOW ENERGY BEAM-GAS SPECTROSCOPY OF HIGHLY IONISED ATOMS

    OpenAIRE

    Desesquelles, J.; DENIS A.; Druetta, M.; Martin, S.

    1989-01-01

    Features of low energy beam-gas spectroscopic source are reviewed and compared to those of other light sources. Measurement techniques are surveyed. They include the study of wavelength of heavy multiply charged ions in visible and u.v. ranges from normal excited states, doubly excited states, high n levels and doubly excited Rydberg levels.

  5. Laser spectroscopy of the antiprotonic helium atom – its energy levels and state lifetimes

    CERN Document Server

    Hidetoshi, Yamaguchi

    2003-01-01

    The antiprotonic atom is a three-body exotic system consisting of an antiproton, an electron and a helium nucleus. Its surprising longevity was found and has been studied for more than 10 years. In this work, transition energies and lifetimes of this exotic atom were systematically studied by using the antiproton beam of AD(Antiproton Decelerator) facility at CERN, with an RFQ antiproton decelerator, a narrow-bandwidth laser, Cerenkov counters with fast-response photomultiplier tubes, and cryogenic helium target systems. Thirteen transition energies were determined with precisions of better than 200 ppb by a laser spectroscopy method, together with the elimination of the shift effect caused by collisions with surrounding atoms. Fifteen lifetimes (decay rates) of short-lived states were determined from the time distributions of the antiproton-annihilation signals and the resonance widths of the atomic spectral lines. The relation between the magnitude of the decay rates and the transition multipolarity was inv...

  6. Bayesian feedback control of a two-atom spin-state in an atom-cavity system

    CERN Document Server

    Brakhane, Stefan; Kampschulte, Tobias; Martinez-Dorantes, Miguel; Reimann, René; Yoon, Seokchan; Widera, Artur; Meschede, Dieter

    2012-01-01

    We experimentally demonstrate real-time feedback control of the joint spin-state of two neutral Caesium atoms inside a high finesse optical cavity. The quantum states are discriminated by their different cavity transmission levels. A Bayesian update formalism is used to estimate state occupation probabilities as well as transition rates. We stabilize the balanced two-atom mixed state, which is deterministically inaccessible, via feedback control and find very good agreement with Monte-Carlo simulations. On average, the feedback loops achieves near optimal conditions by steering the system to the target state marginally exceeding the time to retrieve information about its state.

  7. The energy profiles of atomic conformational transition intermediates of adenylate kinase.

    Science.gov (United States)

    Feng, Yaping; Yang, Lei; Kloczkowski, Andrzej; Jernigan, Robert L

    2009-11-15

    The elastic network interpolation (ENI) (Kim et al., Biophys J 2002;83:1620-1630) is a computationally efficient and physically realistic method to generate conformational transition intermediates between two forms of a given protein. However it can be asked whether these calculated conformations provide good representatives for these intermediates. In this study, we use ENI to generate conformational transition intermediates between the open form and the closed form of adenylate kinase (AK). Based on C(alpha)-only intermediates, we construct atomic intermediates by grafting all the atoms of known AK structures onto the C(alpha) atoms and then perform CHARMM energy minimization to remove steric conflicts and optimize these intermediate structures. We compare the energy profiles for all intermediates from both the CHARMM force-field and from knowledge-based energy functions. We find that the CHARMM energies can successfully capture the two energy minima representing the open AK and closed AK forms, while the energies computed from the knowledge-based energy functions can detect the local energy minimum representing the closed AK form and show some general features of the transition pathway with a somewhat similar energy profile as the CHARMM energies. The combinatorial extension structural alignment (Shindyalov et al., 1998;11:739-747) and the k-means clustering algorithm are then used to show that known PDB structures closely resemble computed intermediates along the transition pathway.

  8. van der Waals energy under strong atom-field coupling in doped carbon nanotubes

    OpenAIRE

    Bondarev, Igor; Lambin, Philippe

    2004-01-01

    Using a unified macroscopic QED formalism, we derive an integral equation for the van der Waals energy of a two-level atomic system near a carbon nanotube. The equation is valid for both strong and weak atom-vacuum-field coupling. By solving it numerically, we demonstrate the inapplicability of weak-coupling-based van der Waals interaction models in a close vicinity of the nanotube surface.

  9. van der Waals energy under strong atom field coupling in doped carbon nanotubes

    Science.gov (United States)

    Bondarev, I. V.; Lambin, Ph.

    2004-10-01

    Using a unified macroscopic QED formalism, we derive an integral equation for the van der Waals energy of a two-level atomic system near a carbon nanotube. The equation is valid for both strong and weak atom-vacuum-field coupling. By solving it numerically, we demonstrate the inapplicability of weak-coupling-based van der Waals interaction models in a close vicinity of the nanotube surface.

  10. Direct measurement of desorption and diffusion energies of O and N atoms physisorbed on amorphous surfaces

    CERN Document Server

    Minissale, Marco; Dulieu, François

    2016-01-01

    Physisorbed atoms on the surface of interstellar dust grains play a central role in solid state astrochemistry. Their surface reactivity is one source of the observed molecular complexity in space. In experimental astrophysics, the high reactivity of atoms also constitutes an obstacle to measuring two of the fundamental properties in surface physics, namely desorption and diffusion energies, and so far direct measurements are non-existent for O and N atoms. We investigated the diffusion and desorption processes of O and N atoms on cold surfaces in order to give boundary conditions to astrochemical models. Here we propose a new technique for directly measuring the N- and O-atom mass signals. Including the experimental results in a simple model allows us to almost directly derive the desorption and diffusion barriers of N atoms on amorphous solid water ice (ASW) and O atoms on ASW and oxidized graphite. We find a strong constraint on the values of desorption and thermal diffusion energy barriers. The measured b...

  11. Implementation of dose management system at radiation protection board of Ghana Atomic Energy Commission.

    Science.gov (United States)

    Hasford, F; Amoako, J K; Darko, E O; Emi-Reynolds, G; Sosu, E K; Otoo, F; Asiedu, G O

    2012-01-01

    The dose management system (DMS) is a computer software developed by the International Atomic Energy Agency for managing data on occupational exposure to radiation sources and intake of radionuclides. It is an integrated system for the user-friendly storage, processing and control of all existing internal and external dosimetry data. The Radiation Protection Board (RPB) of the Ghana Atomic Energy Commission has installed, customised, tested and using the DMS as a comprehensive DMS to improve personnel and area monitoring in the country. Personnel dose records from the RPBs database from 2000 to 2009 are grouped into medical, industrial and education/research sectors. The medical sector dominated the list of monitored institutions in the country over the 10-y period representing ∼87 %, while the industrial and education/research sectors represent ∼9 and ∼4 %, respectively. The number of monitored personnel in the same period follows a similar trend with medical, industrial and education/research sectors representing ∼74, ∼17 and ∼9 %, respectively. Analysis of dose data for 2009 showed that there was no instance of a dose above the annual dose limit of 20 mSv, however, 2.7 % of the exposed workers received individual annual doses >1 mSv. The highest recorded individual annual dose and total collective dose in all sectors were 4.73 mSv and 159.84 man Sv, respectively. Workers in the medical sector received higher individual doses than in the other two sectors, and average dose per exposed worker in all sectors is 0.25 mSv.

  12. German atomic energy law in the international framework. Proceedings. Deutsches Atomenergierecht im internationalen Rahmen. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, N. (Goettingen Univ. (Germany). Inst. fuer Voelkerrecht) (ed.)

    1992-01-01

    The regional conference was devoted to the legal problems that ensue from German reunification against the background of the integration of German atomic energy law within international law. The elements of national atomic energy legislation required by international law and recent developments in international nuclear liability law were discussed from different perspectives. The particular problems of the application of the German Atomic Energy Act in the 5 new Laender (the territories of the former GDR) were presented and discussed, namely: The continued validity of old licences issued by the GDR; practical legal problems connected with the construction of nuclear power plants in the 5 new Laender; the legal issues connected with the final repository for radioactive wastes at Morsleben; and the new developments in radiation protection law following from the Unification Treaty and the new ICRP recommendations. All 14 lectures have been abstracted and indexed individually. (orig.).

  13. Nuclear Safeguards and the International Atomic Energy Agency

    Science.gov (United States)

    1995-04-01

    Control and Disarmament McLean, VA AecBurton F. Judson Agency David Dorn Consultant Washington, DC United Nations Special Los Gatos , CA Henry Sokolski...admitted to conducting nuclear activities safeguards are willing to cede additional soy - there. If the request for such a "special inspec- ereignty to

  14. Energy monitoring and control Systems - which one

    Energy Technology Data Exchange (ETDEWEB)

    Agase, H.D.

    1980-01-01

    Considering the high cost and general limitations of energy supplies, there is no better source of energy than simple conservation. It is the cheapest, the safest and the most productive alternative available today. This overview of Energy Monitoring and Control System types, and what to consider in their selection, will relate to conservation and significant dollar savings potential to the user.

  15. Calculation of the surface energy of fcc metals with modified embedded-atom method

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian-Min; Ma Fei; Xu Ke-Wei

    2004-01-01

    The surface energies for 38 surfaces of fcc metals Cu, Ag, Au, Ni, Pd, Pt, Al, Pb, Rh and Ir have been calculated by using the modified embedded-atom method. The results show that, for Cu, Ag, Ni, Al, Pb and Ir, the average values of the surface energies are very close to the polycrystalline experimental data. For all fcc metals, as predicted, the close-packed (111) surface has the lowest surface energy. The surface energies for the other surfaces increase linearly with increasing angle between the surfaces (hkl) and (111). This can be used to estimate the relative values of the surface energy.

  16. Inquiries about awareness and knowledge of children and pupils on the concept related with atomic energy

    Energy Technology Data Exchange (ETDEWEB)

    Atobe, Kozo; Kobayashi, T.; Matukawa, Tokuo; Honda, Makoto; Awata, Takaaki; Fukuoka, Noboru [Naruto University of Education, Naruto, Tokushima (Japan); Okada, Moritami [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst; Nakagawa, Masuo [Faculty of Education, Kagawa University, Takamatsu, Kagawa (Japan)

    2001-01-01

    There is almost no chance to learn about the words (atomic energy), (radioactivity) and (radiation) in the middle and/or high school educations in Japan, because physics is one of the options in the high school curriculum, and 80-90% of students do not like to choose physics. This inquires aim to know the level of their knowledge on energy resources, atomic energy, radioactivity, radiation, and information sources on their related knowledge. Inquiries are made for the middle and high school students in Tokushima and Tsuruga. There are coal power plants in Tokushima, while atomic power plants in Tsuruga. Fossils energy gets the highest points in Tokushima, while Atomic energy gets the highest points in Tsuruga for a present-day energy source. Solar energy sources get the highest point as a promising 21st century energy source in both prefectures, especially for female students. Radioactivity reminds them of words atomic bomb, disease, injury, and harmful, those give very negative images. Radiation reminds them of words roentgen, radiation therapy, x-ray, and hospital use, those designate a sort of plus-image. More than 50 to 60% of them obtained their knowledge from mass media, particularly, television. In addition, less than a few % of them can give any scientific description about these words. As a whole, authors can say that the students have got a certain concept for these words from information of mass media. Meanwhile the school education has approximately no effect on the formation of their concept. Authors are giving some advises and recommendations for the school education and mass media in Japan. (Y. Tanaka)

  17. Self-energy and interaction energy of stacking fault in fcc metals calculated by embedded-atom method

    Institute of Scientific and Technical Information of China (English)

    何刚; 戎咏华; 徐祖耀

    2000-01-01

    The stacking fault energies of five fcc metals (Cu, Ag, Au, Ni and Al) with various quan-tivalences have been calculated by embedded-atom method (EAM). It indicated that the stacking fault energy is mainly determined by the metallic bond-energy and the lattice constant. Thus, monovalent fcc metals should have different stacking fault energies, contrary to Attree’s conclusion. The interaction energy between stacking faults one I 111 I layer apart in a fcc metal is found to be 1/40-1/250 of its self-energy, while it becomes zero when the two stacking faults are two layers apart. The twin energy is just half of the energy of intrinsic stacking fault energy without the consideration of lattice relaxation and the energy of a single intrinsic stacking fault is almost the same as that of extrinsic stacking fault, which are consistent with the results from the calculation of Lennard-Jones force between atoms, but differ from Attree’s result.

  18. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    Science.gov (United States)

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  19. Wavefunction and energy of the 1s22sns configuration in a beryllium atom

    Institute of Scientific and Technical Information of China (English)

    Huang Shi-Zhong; Ma Kun; Yu Jia-Ming; Liu Fen

    2008-01-01

    A new set of trial functions for 1s22sns configurations in a beryllium atom is suggested.A Mathematica program baaed on the variational method is developed to calculate the wavefunctions and energies of 1s22sns (n=3-6)configurations in a beryllium atom.Non-relativistic energy,polarization correction and relativistic correction which include mass correction,one- and two-body Darwin corrections,spin-spin contact interaction and orbit-orbit interaction,are calculated respectively.The results are in good agreement with experimental data.

  20. Mr. Ansar Shamsi, Member Finance, Mr. Malik Adalat Khan, Director Finance, Pakistan Atomic Energy Commission

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    Photo 01: Mr Ansar Shamsi, Member Finance, Pakistan Atomic Energy Commission (centre), visiting the ATLAS Tile Calorimeter in building 191 with, from left to right, Mr Syed Shaukat Hussain, Pakistan Mission in Geneva and Dr Peter Jenni, ATLAS Spokesperson. Photo 02: Mr Ansar Shamsi, Member Finance, Pakistan Atomic Energy Commission (2nd form left), visiting the ATLAS Tile Calorimeter in building 191 with, from left to right, Mr Syed Shaukat Hussain, Pakistan Mission in Geneva; Dr Peter Jenni, ATLAS Spokesperson; Dr David Jacobs and Dr Philip Bryant, Joint Pakistan-CERN Committee.

  1. Progression of Technology Education for Atomic Energy Engineering in Tsuyama National College of Technology

    Science.gov (United States)

    Kato, Manabu; Kobayashi, Toshiro; Okada, Tadashi; Sato, Makoto; Sasai, Yuji; Konishi, Daijiro; Harada, Kanji; Taniguchi, Hironari; Toya, Hideaki; Inada, Tomomi; Sori, Hitoshi; Yagi, Hideyuki

    This paper describes the achievements of a program in which technology education is provided to cultivate practical core engineers for low-level radiation. It was made possible by means of (1) an introductory education program starting at an early age and a continuous agenda throughout college days and (2) regional collaboration. First, with regard to the early-age introductory education program and the continuous education agenda, the subjects of study related to atomic energy or nuclear engineering were reorganized as “Subjects related to Atomic Power Education” for all grades in all departments. These subjects were included in the syllabus and the student guide book, emphasizing a continuous and consistent policy throughout seven-year college study, including the five-year system and additional two-year advanced course. Second, to promote practical education, the contents of lectures, experiments, and internships were enriched and realigned in collaboration with the Japan Atomic Energy Agency, Okayama University and The Cyugoku Electric Power Co., Inc. In addition to the expansion and rearrangement of atomic power education, research on atomic power conducted for graduation thesis projects were undertaken to enhance the educational and research activities. In consequence, it has been estimated that there is now a total of fourteen subject areas in atomic energy technology, more than eight-hundred registered students in the department, and thirteen members of the teaching staff related to atomic energy technology. Furthermore, the “Tsuyama model” is still being developed. This program was funded by the Ministry of Education, Culture, Sports, Science and Technology.

  2. Automatic control algorithm effects on energy production

    Science.gov (United States)

    Mcnerney, G. M.

    1981-01-01

    A computer model was developed using actual wind time series and turbine performance data to simulate the power produced by the Sandia 17-m VAWT operating in automatic control. The model was used to investigate the influence of starting algorithms on annual energy production. The results indicate that, depending on turbine and local wind characteristics, a bad choice of a control algorithm can significantly reduce overall energy production. The model can be used to select control algorithms and threshold parameters that maximize long term energy production. The results from local site and turbine characteristics were generalized to obtain general guidelines for control algorithm design.

  3. Molecules Near Absolute Zero and External Field Control of Atomic and Molecular Dynamics

    CERN Document Server

    Krems, R V

    2005-01-01

    This article reviews the current state of the art in the field of cold and ultracold molecules and demonstrates that chemical reactions, inelastic collisions and dissociation of molecules at subKelvin temperatures can be manipulated with external electric or magnetic fields. The creation of ultracold molecules may allow for spectroscopy measurements with extremely high precision and tests of fundamental symmetries of nature, quantum computation with molecules as qubits, and controlled chemistry. The probability of chemical reactions and collisional energy transfer can be very large at temperatures near zero Kelvin. The collision energy of ultracold atoms and molecules is much smaller than perturbations due to interactions with external electric or magnetic fields available in the laboratory. External fields may therefore be used to induce dissociation of weakly bound molecules, stimulate forbidden electronic transitions, suppress the effect of centrifugal barriers in outgoing reaction channels or tune Feshbac...

  4. The international atom: evolution of radiation control programs.

    Science.gov (United States)

    Bradley, F J

    2002-07-01

    Under the Atoms for Peace program, Turkey received a one MWt swimming pool reactor in 1962 that initiated a health physics program for the reactor and a Radiation Control Program (RCP) for the country's use of ionizing radiation. Today, over 13,000 radiation workers, concentrated in the medical field, provide improved medical care with 6,200 x-ray units, including 494 CAT scanners, 222 radioimmunoassay (RIA) labs and 42 radiotherapy centers. Industry has a large stake in the safe use of ionizing radiation with over 1,200 x-ray and gamma radiography and fluoroscopic units, 2,500 gauges in automated process control and five irradiators. A 48-person RCP staff oversees this expanded radiation use. One incident involving a spent 3.3 TBq (88 Ci) 60Co source resulted in 10 overexposures but no fatalities. Taiwan received a 1.6 MWt swimming pool reactor in 1961 and rapidly applied nuclear technology to the medical and industrial fields. Today, there are approximately 24,000 licensed radiation workers in nuclear power field, industry, medicine and academia. Four BWRs and two PWRs supply about 25% of the island's electrical power needs. One traumatic event galvanized the RCP when an undetermined amount of 60Co was accidentally incorporated into reinforcing bars, which in turn were incorporated into residential and commercial buildings. Public exposures were estimated to range up to 15 mSv (1.3 rem) per annum. There were no reported ill effects, except possibly psychological, to date. The RCP now has instituted stringent control measures to ensure radiation-free dwellings and work places. Albania's RCP is described as it evolved since 1972. Regulations were promulgated which followed the IAEA Basic Safety Standards of that era. With 525 licenses and 600 radiation workers, the problem was not in the regulations per se but in their enforcement. The IAEA helped to upgrade the RCP as the economy evolved from one that was centrally planned economy to a free market economy. As this

  5. Atomically modified thin interface in metal-dielectric hetero-integrated systems: control of electronic properties

    Science.gov (United States)

    Iida, Kenji; Nobusada, Katsuyuki

    2017-04-01

    We have performed first-principles studies of the electronic properties of Cu-diamond hetero-integrated systems, particularly placing emphasis on elucidating the effects of surface modification of diamond with H or O. It is found that the electronic properties crucially depend on the chemical compositions of the modified atomically thin interface region. The local density of states (LDOS) of the H-terminated diamond moiety near the Cu surface exhibits a clearly different distribution from that near the vacuum region, whereas the LDOS of the O-terminated diamond is almost independent of the Cu deposition. In other words, the effects of the electronic interactions between Cu and diamond on the electronic properties in the interface region are readily controlled by surface modification with only one atomic (i.e. H or O) layer. Electric field (EF) effects on the Cu-diamond systems also strongly depend on the electronic details, i.e. atomistic modification in the interface regions. In particular, at the interface between the H-terminated diamond moiety and the vacuum region, its conduction band energy is strongly affected by an applied EF much more than the valence band energy; that is, the band gap can be varied with an applied EF. The band gap variation is found to be attributed to an atomistic level difference in the spatial extension of the valence and conduction bands and thus is not explained with a macroscopic band diagram model. It has been demonstrated that the electronic properties of hetero-integrated systems are described and controlled well by carefully designing atomically thin interface regions.

  6. International Atomic Energy Agency intercomparison of ion beam analysis software

    Science.gov (United States)

    Barradas, N. P.; Arstila, K.; Battistig, G.; Bianconi, M.; Dytlewski, N.; Jeynes, C.; Kótai, E.; Lulli, G.; Mayer, M.; Rauhala, E.; Szilágyi, E.; Thompson, M.

    2007-09-01

    Ion beam analysis (IBA) includes a group of techniques for the determination of elemental concentration depth profiles of thin film materials. Often the final results rely on simulations, fits and calculations, made by dedicated codes written for specific techniques. Here we evaluate numerical codes dedicated to the analysis of Rutherford backscattering spectrometry, non-Rutherford elastic backscattering spectrometry, elastic recoil detection analysis and non-resonant nuclear reaction analysis data. Several software packages have been presented and made available to the community. New codes regularly appear, and old codes continue to be used and occasionally updated and expanded. However, those codes have to date not been validated, or even compared to each other. Consequently, IBA practitioners use codes whose validity, correctness and accuracy have never been validated beyond the authors' efforts. In this work, we present the results of an IBA software intercomparison exercise, where seven different packages participated. These were DEPTH, GISA, DataFurnace (NDF), RBX, RUMP, SIMNRA (all analytical codes) and MCERD (a Monte Carlo code). In a first step, a series of simulations were defined, testing different capabilities of the codes, for fixed conditions. In a second step, a set of real experimental data were analysed. The main conclusion is that the codes perform well within the limits of their design, and that the largest differences in the results obtained are due to differences in the fundamental databases used (stopping power and scattering cross section). In particular, spectra can be calculated including Rutherford cross sections with screening, energy resolution convolutions including energy straggling, and pileup effects, with agreement between the codes available at the 0.1% level. This same agreement is also available for the non-RBS techniques. This agreement is not limited to calculation of spectra from particular structures with predetermined

  7. Energy, Carbon-emission and Financial Savings from Thermostat Control

    Energy Technology Data Exchange (ETDEWEB)

    Blasing, T J [ORNL; Schroeder, Dana [University of Georgia, Athens, GA

    2013-08-01

    Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67.

  8. Free energy for a damped cold atom in SU(2) non-Abelian gauge potentials

    Science.gov (United States)

    Guingarey, Issoufou; Avossevou, Gabriel Y. H.

    2017-03-01

    Our main aim in this work is to find out the exact formula of the equilibrium free energy for a cold atom subjected to a harmonic potential in the background of an artificial non-Abelian uniform magnetic field and linearly coupled to a heat bath. The heat bath consists of a collection of independent quantum harmonic oscillators, while its interaction with the cold atom is modeled in terms of bilinear coupling between the coordinate variables of the cold atom and the oscillators. The main thermodynamic properties of such a system are modified in comparison with the Abelian case. For a non-Abelian magnetic field generated from the laser methods employing degenerate dark states, we evaluate the effect of the non-Abelian dynamics on the magnetic moment of the cold atom.

  9. Computational model for noncontact atomic force microscopy: energy dissipation of cantilever.

    Science.gov (United States)

    Senda, Yasuhiro; Blomqvist, Janne; Nieminen, Risto M

    2016-09-21

    We propose a computational model for noncontact atomic force microscopy (AFM) in which the atomic force between the cantilever tip and the surface is calculated using a molecular dynamics method, and the macroscopic motion of the cantilever is modeled by an oscillating spring. The movement of atoms in the tip and surface is connected with the oscillating spring using a recently developed coupling method. In this computational model, the oscillation energy is dissipated, as observed in AFM experiments. We attribute this dissipation to the hysteresis and nonconservative properties of the interatomic force that acts between the atoms in the tip and sample surface. The dissipation rate strongly depends on the parameters used in the computational model.

  10. A simple nonbinary scattering model applicable to atomic collisions is crystals at 1ow energies

    DEFF Research Database (Denmark)

    Andersen, Hans Henrik; Sigmund, Peter

    1966-01-01

    Presents the solution of a special scattering problem which may be important in the theory of slowing-down of atomic particles in crystals. A projectile moves along the centre axis of a regular ring of n equal atoms which are free and do not interact with each other. The interaction between...... the projectile and each ring atom is described by a Born-Mayer potential, and the scattering is assumed to be elastic and governed by the classical equations of motion. Because of symmetry, the problem can be reduced to plane motion of a particle in a potential of elliptic symmetry. The elliptic force field...... the asymptotic velocities of the ring atoms as well as the energy loss of the projectile. Furthermore, it can be decided whether the projectile is reflected by the ring. Both the feasibility of assumptions specifying the problem and the validity of different approximations made in the transformation from...

  11. Piezoelectric energy harvesting computer controlled test bench

    Science.gov (United States)

    Vázquez-Rodriguez, M.; Jiménez, F. J.; de Frutos, J.; Alonso, D.

    2016-09-01

    In this paper a new computer controlled (C.C.) laboratory test bench is presented. The patented test bench is made up of a C.C. road traffic simulator, C.C. electronic hardware involved in automating measurements, and test bench control software interface programmed in LabVIEW™. Our research is focused on characterizing electronic energy harvesting piezoelectric-based elements in road traffic environments to extract (or "harvest") maximum power. In mechanical to electrical energy conversion, mechanical impacts or vibrational behavior are commonly used, and several major problems need to be solved to perform optimal harvesting systems including, but no limited to, primary energy source modeling, energy conversion, and energy storage. It is described a novel C.C. test bench that obtains, in an accurate and automatized process, a generalized linear equivalent electrical model of piezoelectric elements and piezoelectric based energy store harvesting circuits in order to scale energy generation with multiple devices integrated in different topologies.

  12. Quantum State Control of Trapped Atomic and Molecular Ions

    Science.gov (United States)

    Seck, Christopher M.

    Full quantum control of a molecule would have a significant impact in molecular coherent control (alignment and orientation) and ultracold and quantum chemistry, quantum computing and simulation as well as hybrid quantum devices, and precision spectroscopy of importance to fundamental physics research. Precision spectroscopy of even simple diatomic molecules offers the possibility of uncovering physics beyond the standard model, specifically time variation of the proton-to-electron mass ratio, which is currently constrained by astronomical molecular observations at the 10-16 1/yr level and laboratory atomic measurements at the 10-17 1/yr level. To achieve this level of measurement and to avoid the complications of diatomic structure on traditional spectroscopy methods, molecular quantum logic spectroscopy (mQLS) will be the spectroscopy technique of choice. We discuss development of in-house external-cavity diode laser (ECDL) systems and improvements to the Libbrecht-Hall circuit, which is a well-known, low-noise current driver for narrow-linewidth diode lasers. However, as the current approaches the maximum set limit, the noise in the laser current increases dramatically. This behavior is documented and simple circuit modifications to alleviate this issue are explored. We cool trapped AlH+ molecules to their ground rotational-vibrational quantum state using an electronically-exciting broadband laser to simultaneously drive cooling resonances from many different rotational levels. We demonstrate rotational cooling on the 140(20) ms timescale from room temperature to 3.8 K, with the ground state population increasing from 3% to 95.4%. Since QLS does not require the high gate fidelities usually associated with quantum computation and quantum simulation, it is possible to make simplifying choices in ion species and quantum protocols at the expense of some fidelity. We demonstrate sideband cooling and motional state detection protocols for 138Ba+ of sufficient fidelity

  13. Probing the energy flow in Bessel light beams using atomic photoionization

    Science.gov (United States)

    Surzhykov, A.; Seipt, D.; Fritzsche, S.

    2016-09-01

    The growing interest in twisted light beams also requires a better understanding of their complex internal structure. Particular attention is currently being given to the energy circulation in these beams as usually described by the Poynting vector field. In the present study we propose to use the photoionization of alkali-metal atoms as a probe process to measure (and visualize) the energy flow in twisted light fields. Such measurements are possible since the angular distribution of photoelectrons, emitted from a small atomic target, appears sensitive to and is determined by the local direction of the Poynting vector. To illustrate the feasibility of the proposed method, detailed calculations were performed for the ionization of sodium atoms by nondiffractive Bessel beams.

  14. Hydrogen atom wave function and eigen energy in the Rindler space

    Science.gov (United States)

    Dai, De-Chang

    2016-10-01

    We study the hydrogen atom eigenstate energy and wave function in the Rindler space. The probability distribution is tilted because the electric field of the nucleus is no longer spherically symmetric. The hydrogen atom therefore cannot be treated exactly in the same way as what it is in an inertial frame. We also find that if the external force accelerates only the nucleus and then the nucleus accelerates its surrounding electrons through electromagnetic force, the electrons can tunnel through the local energy gap and split the hydrogen atom into an ion. This is similar to what one expects from the Stark effect. However, the critical acceleration is about 3 ×1022 m /s2. It is well beyond the gravitational acceleration on a regular star surface.

  15. Hydrogen atom wave function and eigen energy in the Rindler space

    CERN Document Server

    Dai, De-Chang

    2016-01-01

    We study the hydrogen atom eigenstate energy and wave function in the Rindler space. The probability distribution is tilted because the electric field of the nucleus is no longer spherically symmetric. The hydrogen atom therefore cannot be treated exactly in the same way as what it is in an inertial frame. We also find that if the external force accelerates only the nucleus and then the nucleus accelerates its surrounding electrons through electromagnetic force, the electrons can tunnel through the local energy gap and split the hydrogen atom into an ion. This is similar to what one expects from the Stark effect. However, the critical acceleration is about $3\\times 10^{22} m/s^2$. It is well beyond the gravitational acceleration on a regular star surface.

  16. Nuclear energy in the service of biomedicine: the U.S. Atomic Energy Commission's radioisotope program, 1946-1950.

    Science.gov (United States)

    Creager, Angela N H

    2006-01-01

    The widespread adoption of radioisotopes as tools in biomedical research and therapy became one of the major consequences of the "physicists' war" for postwar life science. Scientists in the Manhattan Project, as part of their efforts to advocate for civilian uses of atomic energy after the war, proposed using infrastructure from the wartime bomb project to develop a government-run radioisotope distribution program. After the Atomic Energy Bill was passed and before the Atomic Energy Commission (AEC) was formally established, the Manhattan Project began shipping isotopes from Oak Ridge. Scientists and physicians put these reactor-produced isotopes to many of the same uses that had been pioneered with cyclotron-generated radioisotopes in the 1930s and early 1940s. The majority of early AEC shipments were radioiodine and radiophosphorus, employed to evaluate thyroid function, diagnose medical disorders, and irradiate tumors. Both researchers and politicians lauded radioisotopes publicly for their potential in curing diseases, particularly cancer. However, isotopes proved less successful than anticipated in treating cancer and more successful in medical diagnostics. On the research side, reactor-generated radioisotopes equipped biologists with new tools to trace molecular transformations from metabolic pathways to ecosystems. The U.S. government's production and promotion of isotopes stimulated their consumption by scientists and physicians (both domestic and abroad), such that in the postwar period isotopes became routine elements of laboratory and clinical use. In the early postwar years, radioisotopes signified the government's commitment to harness the atom for peace, particularly through contributions to biology, medicine, and agriculture.

  17. Kinetic-energy matrix elements for atomic Hylleraas-CI wave functions.

    Science.gov (United States)

    Harris, Frank E

    2016-05-28

    Hylleraas-CI is a superposition-of-configurations method in which each configuration is constructed from a Slater-type orbital (STO) product to which is appended (linearly) at most one interelectron distance rij. Computations of the kinetic energy for atoms by this method have been difficult due to the lack of formulas expressing these matrix elements for general angular momentum in terms of overlap and potential-energy integrals. It is shown here that a strategic application of angular-momentum theory, including the use of vector spherical harmonics, enables the reduction of all atomic kinetic-energy integrals to overlap and potential-energy matrix elements. The new formulas are validated by showing that they yield correct results for a large number of integrals published by other investigators.

  18. Using Uncertainty Principle to Find the Ground-State Energy of the Helium and a Helium-like Hookean Atom

    Science.gov (United States)

    Harbola, Varun

    2011-01-01

    In this paper, we accurately estimate the ground-state energy and the atomic radius of the helium atom and a helium-like Hookean atom by employing the uncertainty principle in conjunction with the variational approach. We show that with the use of the uncertainty principle, electrons are found to be spread over a radial region, giving an electron…

  19. DNA Free Energy Landscapes and RNA Nano-Self-Assembly Using Atomic Force Microscopy

    Science.gov (United States)

    Frey, Eric William

    There is an important conceptual lesson which has long been appreciated by those who work in biophysics and related interdisciplinary fields. While the extraordinary behavior of biological matter is governed by its detailed atomic structure and random fluctuations, and is therefore difficult to predict, it can nevertheless be understood within simplified frameworks. Such frameworks model the system as consisting of only one or a few components, and model the behavior of the system as the occupation of a single state out of a small number of states available. The emerging widespread application of nanotechnology, such as atomic force microscopy (AFM), has expanded this understanding in eye-opening new levels of detail by enabling nano-scale control, measurement, and visualization of biological molecules. This thesis describes two independent projects, both of which illuminate this understanding using AFM, but which do so from very different perspectives. The organization of this thesis is as follows. Chapter 1 begins with an experimental background and introduction to AFM, and then describes our setup in both single-molecule manipulation and imaging modes. In Chapter 2, we describe the first project, the motivation for which is to extend methods for the experimental determination of the free energy landscape of a molecule. This chapter relies on the analysis of single-molecule manipulation data. Chapter 3 describes the second project, the motivation for which is to create RNA-based nano-structures suitable for future applications in living mammalian cells. This chapter relies mainly on imaging. Chapters 2 and 3 can thus be read and understood separately.

  20. Local group modes and the dynamics of intramolecular energy transfer across a heavy atom

    OpenAIRE

    Lopez, Vicente; Fairen, Victor; Lederman, Steven M.; Marcus, R.A

    1986-01-01

    The dynamics of energy transfer is discussed for a model system in which two ligands are separated by a heavy atom. Numerical and analytical results are given for the case that each ligand is a CC. In the quasiperiodic regime, the dynamics are interpreted using perturbation theory. Local group modes involved in an intramolecular energy localization which can occur in this regime are identified. An approximate separation of the primarily ligand–ligand motions from the primarily ligand–metal–li...

  1. An extension of the Eisberg-Resnick treatment for electron energies in many-electron atoms

    Science.gov (United States)

    Whitaker, M. A. B.; Bennett, I.

    1989-03-01

    Eisberg and Resnick present a simple argument for the energy of an electron in a multielectron atom using the concept of shielding from electrons in inner shells. The results of such a treatment are unfortunately confined so as to be out of range of experimental values. Here, the effect of electrons in outer shells is included, and, in the nonrelativistic region, energies are obtained for electrons in the first and second shells in reasonable agreement with experiment.

  2. The regularities of the Rydberg energy levels of many-valence electron atom Al

    Institute of Scientific and Technical Information of China (English)

    郑能武; 孙育杰

    2000-01-01

    Within the scheme of the weakest bound electron potential model theory, the concept of spectral-level-like series is presented by reasonably classifying the Rydberg energy level of atom Al. Based on this concept, the regularities of the Rydberg energy levels are systematically studied. The deviations of the calculated values from the experimental values are generally about several percent of 1 cm, which is of high accuracy.

  3. Energy Levels in Helium and Neon Atoms by an Electron-Impact Method.

    Science.gov (United States)

    Taylor, N.; And Others

    1981-01-01

    Electronic energy levels in noble gas atoms may be determined with a simple teaching apparatus incorporating a resonance potentials tube in which the electron beam intensity is held constant. The resulting spectra are little inferior to those obtained by more elaborate electron-impact methods and complement optical emission spectra. (Author/SK)

  4. Electromagnetic separation of stable isotopes at the Institute of Atomic Energy, Academia Sinica

    Science.gov (United States)

    Ming-da, Hua; Gong-pan, Li; Shi-jun, Su; Nai-feng, Mao; Hung-yung, Lu

    1981-07-01

    For almost 20 years the Institute of Atomic Energy, Academia Sinica has been separating stable isotopes of the elements by electromagnetic separators and supplying these materials to research work in many fields of our country. In this article we shall attempt to outline the growth of the effort and describe the present situation.

  5. Saturation of Energy Levels in Analytical Atomic Fluorescence Spectrometry. II. Experimental.

    Science.gov (United States)

    1981-01-30

    RESEARCH Contract N14-76-C-0838 Task Ao. NR 051-622 TECHNICAL REPORT NO. 34 SATURATION OF ENERGY LEVELS IN ANALYTICAL ATOMIC FLUORESCENCE SPECTROMETRY II...an assumption which is valid only if the daral o’l of 111, cxcilIatio n pulse is mucl ) longer than the fluorescence life- time of the tjaii!,ition

  6. Molecular markers predicting radiotherapy response: report and recommendations from an International Atomic Energy Agency technical meeting.

    NARCIS (Netherlands)

    West, C.M.; McKay, M.J.; Holscher, T.; Baumann, M.; Stratford, I.J.; Bristow, R.G.; Iwakawa, M.; Imai, T.; Zingde, S.M.; Anscher, M.S.; Bourhis, J.; Begg, A.C.; Haustermans, K.; Bentzen, S.M.; Hendry, J.H.

    2005-01-01

    PURPOSE: There is increasing interest in radiogenomics and the characterization of molecular profiles that predict normal tissue and tumor radioresponse. A meeting in Amsterdam was organized by the International Atomic Energy Agency to discuss this topic on an international basis. METHODS AND MATERI

  7. A New Method for the Atomic Ground-State Energy in the Screened Coulomb Potential

    Institute of Scientific and Technical Information of China (English)

    YU Peng-Peng; GUO Hua

    2001-01-01

    The new method proposed recently by Friedberg,Lee and Zhao is applied to the derivation of the atomic ground-state energy with the inclusion of the screening effect.The present results are compared with those obtained in the pure Coulomb potential and by the variational approach.The overall good results are obtained with this new method.``

  8. Climate Control Using Nuclear Energy

    CERN Document Server

    Modgil, Moninder Singh

    2008-01-01

    We examine implications of anthropogenic low pressure regions, - created by injecting heat from nuclear reactors, into atmosphere. We suggest the possibility that such artificially generated low pressure regions, near hurricanes could disrupt their growth, path, and intensity. This method can also create controlled tropical stroms, which lead to substantial rainfall in arid areas, such as - (1)Sahara desert, (2) Australian interior desert, and (3) Indian Thar desert. A simple vortex suction model is developed to study, effect on atmospheric dynamics, by such a nuclear heat injection system.

  9. Controller reduction by preserving impulse response energy

    Science.gov (United States)

    Craig, Roy R., Jr.; Su, Tzu-Jeng

    1989-01-01

    A model order reduction algorithm based on a Krylov recurrence formulation is developed to reduce order of controllers. The reduced-order controller is obtained by projecting the full-order LQG controller onto a Krylov subspace in which either the controllability or the observability grammian is equal to the identity matrix. The reduced-order controller preserves the impulse response energy of the full-order controller and has a parameter-matching property. Two numerical examples drawn from other controller reduction literature are used to illustrate the efficacy of the proposed reduction algorithm.

  10. Non-destructive Faraday imaging of dynamically controlled ultracold atoms

    DEFF Research Database (Denmark)

    Gajdacz, Miroslav; Pedersen, Poul Lindholm; Mørch, Troels

    2013-01-01

    We describe an easily implementable method for non-destructive measurements of ultracold atomic clouds based on dark field imaging of spatially resolved Faraday rotation. The signal-to-noise ratio is analyzed theoretically and, in the absence of experimental imperfections, the sensitivity limit...... is found to be identical to other conventional dispersive imaging techniques. The dependence on laser detuning, atomic density, and temperature is characterized in a detailed comparison with theory. Due to low destructiveness, spatially resolved images of the same cloud can be acquired up to 2000 times...

  11. Discrete Energies of a Weakly Outcoupled Atom Laser Beam Outside the Bose–Einstein Condensate Region

    Directory of Open Access Journals (Sweden)

    Teguh Budi Prayitno

    2014-12-01

    Full Text Available We consider the possibility of a discrete set of energies of a weakly outcoupled atom laser beam to the homogeneous Schrödinger equation with anisotropic harmonic trap in Cartesian coordinates outside the Bose–Einstein condensate region. This treatment is used because working in the cylindrical coordinates is not really possible, even though we implement the cigar-shaped trap case. The Schrödinger equation appears to replace a set of two-coupled Gross– Pitaevskii equations by enabling the weak-coupling assumption. This atom laser can be produced in a simple way that only involves extracting the atoms in a condensate from by using the radio frequency field. We initially present the relation between condensates as sources and atom laser as an output by exploring the previous work of Riou et al. in the case of theoretical work for the propagation of atom laser beams. We also show that even though the discrete energies are obtained by means of an approaching harmonic oscillator, degeneracy is only available in two states because of the anisotropic external potential

  12. Control of Energy Regeneration for Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yi; MAO Xiao-jian; LI Li-ming; ZHUO Bn

    2008-01-01

    To extend electric vehicle (EV) running distance, the vehicle energy regeneration (ER) method and vehicle control strategy were designed based on the original vehicle braking system. The ER principle of direct current (DC) brushless motor was studied, the motor mathematical model and PI control method with torque close-loop were built. This control method was applied to pure EV and the real road tests were evaluated.The ER control does not make any significant uncomfortable influence brake feeling and can save about 10% battery energy based on 3 times economic commission for Europe (ECE) driving cycles.

  13. DEVELOPMENT OF ATOM-ECONOMICAL CATALYTIC PATHWAYS FOR CONVERSIONS OF SYNGAS TO ENERGY LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    MAHAJAN,D.; WEGRZYN,J.E.; LEE,T.; GUREVICH,M.

    1999-03-01

    The subject of catalytic syngas conversions to fuels and chemicals is well studied (1--3). But globally, the recent focus is on development of technologies that offer an economical route to desired products (4). Economical transport of natural gas from remote locations and within clathrate hydrates is of continuing interest at Brookhaven National Laboratory (BNL). Under this project, a Liquid Phase Low Temperature (LPLT) concept is being applied to attain highly efficient transformations of natural-gas derived syngas to specific products. Furthermore, a more precise term ``Atom Economy'' has been recently introduced by Trost to describe development of highly efficient homogeneously catalyzed synthesis of organic molecules (5). Taken from reference 5, the term ``Atom Economy'' is defined as maximizing the number of atoms of all raw materials that end up in the product with any other reactant required on in catalytic amount. For application to methane transformations that may involve one or more steps, atom economy of each of these steps is critical. The authors, therefore, consider atom-economy synonymous with overall energy efficiency of a process. This paper describes potential liquid products from catalytic syngas conversions, i.e. gas to liquids (GTL) technologies and process considerations that are necessary for economical transport of natural gas. As such, the present study defines an atom-economical standard to directly compare competing GTL technologies.

  14. Graphene as a flexible template for controlling magnetic interactions between metal atoms

    Science.gov (United States)

    Lee, Sungwoo; Kim, Dongwook; Robertson, Alex W.; Yoon, Euijoon; Hong, Suklyun; Ihm, Jisoon; Yu, Jaejun; Warner, Jamie H.; Lee, Gun-Do

    2017-03-01

    Metal-doped graphene produces magnetic moments that have potential application in spintronics. Here we use density function theory computational methods to show how the magnetic interaction between metal atoms doped in graphene can be controlled by the degree of flexure in a graphene membrane. Bending graphene by flexing causes the distance between two substitutional Fe atoms covalently bonded in graphene to gradually increase and these results in the magnetic moment disappearing at a critical strain value. At the critical strain, a carbon atom can enter between the two Fe atoms and blocks the interaction between relevant orbitals of Fe atoms to quench the magnetic moment. The control of interactions between doped atoms by exploiting the mechanical flexibility of graphene is a unique approach to manipulating the magnetic properties and opens up new opportunities for mechanical-magnetic 2D device systems.

  15. Optical bistability enabled control of resonant light transmission for an atom-cavity system

    CERN Document Server

    Sawant, Rahul

    2015-01-01

    The control of light transmission through a Fabry-Perot cavity containing atoms is theoretically investigated, when the cavity mode beam and an intersecting control beam are both close to specific atomic resonances. A four-level atomic system is considered and its interaction with the cavity mode is studied by solving for the time dependent cavity field and atomic state populations. The conditions for optical bistability of the atom-cavity system are obtained in steady state limit. For an ensemble of atoms in the cavity mode, the response of the intra-cavity light intensity to the intersecting resonant beam is understood for stationary atoms (closed system) and non-static atoms (open system). The open system is modelled by adjusting the atomic state populations to represent the exchange of atoms in the cavity mode, with the thermal environment. The solutions to the model are used to qualitatively explain the observed steady state and transient behaviour of the light in the cavity mode, in Sharma et. al. [1]. ...

  16. Controlling quantum coherence of atom laser by light with strong strength

    Institute of Scientific and Technical Information of China (English)

    JING; Hui(景辉); GE; Molin(葛墨林); GE; Molin(葛墨林)

    2002-01-01

    A new method for controlling the quantum coherence of atom laser by applying input light with strong strength is presented within the framework of quantum dynamical theory. Unlike the case of rotating wave approximation(RWA), we show that the non-classical properties, such as sub-Poisson distribution and quadrature squeezed effect, can appear in the output atom laser beam with time. By choosing suitable initial RF phase, a steady and brighter output of squeezed coherent atom laser is also available.

  17. The role of thermal energy accommodation and atomic recombination probabilities in low pressure oxygen plasmas

    Science.gov (United States)

    Gibson, Andrew Robert; Foucher, Mickaël; Marinov, Daniil; Chabert, Pascal; Gans, Timo; Kushner, Mark J.; Booth, Jean-Paul

    2017-02-01

    Surface interaction probabilities are critical parameters that determine the behaviour of low pressure plasmas and so are crucial input parameters for plasma simulations that play a key role in determining their accuracy. However, these parameters are difficult to estimate without in situ measurements. In this work, the role of two prominent surface interaction probabilities, the atomic oxygen recombination coefficient γ O and the thermal energy accommodation coefficient α E in determining the plasma properties of low pressure inductively coupled oxygen plasmas are investigated using two-dimensional fluid-kinetic simulations. These plasmas are the type used for semiconductor processing. It was found that α E plays a crucial role in determining the neutral gas temperature and neutral gas density. Through this dependency, the value of α E also determines a range of other plasma properties such as the atomic oxygen density, the plasma potential, the electron temperature, and ion bombardment energy and neutral-to-ion flux ratio at the wafer holder. The main role of γ O is in determining the atomic oxygen density and flux to the wafer holder along with the neutral-to-ion flux ratio. It was found that the plasma properties are most sensitive to each coefficient when the value of the coefficient is small causing the losses of atomic oxygen and thermal energy to be surface interaction limited rather than transport limited.

  18. Circular dichroism in free-free transitions of high energy electron-atom scattering

    CERN Document Server

    Cionga, Aurelia; Zloh, Gabriela; 10.1103/PhysRevA.62.063406

    2013-01-01

    We consider high energy electron scattering by hydrogen atoms in the presence of a laser field of moderate power and higher frequencies. If the field is a superposition of a linearly and a circularly polarized laser beam in a particular configuration, then we can show that circular dichroism in two photon transitions can be observed not only for the differential but also for the integrated cross sections, provided the laser-dressing of the atomic target is treated in second order perturbation theory and the coupling between hydrogenic bound and continuum states is involved.

  19. Construction of the energy matrix for complex atoms. Part VI: Core polarization effects

    Science.gov (United States)

    Elantkowska, Magdalena; Ruczkowski, Jarosław; Dembczyński, Jerzy

    2016-12-01

    The continuation of series of papers concerning the construction of the energy matrix for complex atoms is presented. The second-order perturbation theory contributions originating from core polarization effects in the hyperfine structure are considered. Fifteen new formulae for angular coefficients of core polarization parameters are given. The complete set of corrections up to the second-order perturbation theory was taken into account and the accuracy of the wave functions in the intermediate coupling scheme, on the example of the lanthanum atom, was checked.

  20. Effective atomic numbers, electron densities and kinetic energy released in matter of vitamins for photon interaction

    Science.gov (United States)

    Shantappa, A.; Hanagodimath, S. M.

    2014-01-01

    Effective atomic numbers, electron densities of some vitamins (Retinol, Riboflavin, Niacin, Biotin, Folic acid, Cobalamin, Phylloquinone and Flavonoids) composed of C, H, O, N, Co, P and S have been calculated for total and partial photon interactions by the direct method for energy range 1 keV-100 GeV by using WinXCOM and kinetic energy released in matter (Kerma) relative to air is calculated in energy range of 1 keV-20 MeV. Change in effective atomic number and electron density with energy is calculated for all photon interactions. Variation of photon mass attenuation coefficients with energy are shown graphically only for total photon interaction. It is observed that change in mass attenuation coefficient with composition of different chemicals is very large below 100 keV and moderate between 100 keV and 10 MeV and negligible above 10 MeV. Behaviour of vitamins is almost indistinguishable except biotin and cobalamin because of large range of atomic numbers from 1(H) to 16 (S) and 1(H) to 27(Co) respectively. K a value shows a peak due to the photoelectric effect around K-absorption edge of high- Z constituent of compound for biotin and cobalamin.

  1. Quasiclassical approach to high-energy QED processes in strong laser and atomic fields

    CERN Document Server

    Di Piazza, A

    2012-01-01

    An approach, based on the use of the quasiclassical Green's function, is developed for investigating high-energy quantum electrodynamical processes in combined strong laser and atomic fields. Employing an operator technique, we derive the Green's function of the Dirac equation in an arbitrary plane wave and a localized potential. Then, we calculate the total cross section of high-energy electron-positron photoproduction in an atomic field of arbitrary charge number (Bethe-Heitler process) in the presence of a strong laser field. It is shown that the laser field substantially modifies the cross section at already available incoming photon energies and laser parameters. This makes it feasible to observe the analogous effect in a laser field of the Landau-Pomeranchuk-Migdal effect for the Bethe-Heitler process.

  2. Quantum control of ultra-cold atoms: uncovering a novel connection between two paradigms of quantum nonlinear dynamics

    DEFF Research Database (Denmark)

    Wang, Jiao; Mouritzen, Anders Sørrig; Gong, Jiangbin

    2009-01-01

    .e. the kicked rotor model and the kicked Harper model, is established. In particular, it is shown that Hofstadter's butterfly quasi-energy spectrum in periodically driven quantum systems may soon be realized experimentally, with the effective Planck constant tunable by varying the time delay between two...... sequences of control fields. Extensions of this study are also discussed. The results are intended to open up a new generation of cold-atom experiments of quantum nonlinear dynamics....

  3. Watching the dynamics of electrons and atoms at work in solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Canton, S. E.; Zhang, X.; Liu, Y.; Zhang, J.; Pápai, M.; Corani, A.; Smeigh, A. L.; Smolentsev, G.; Attenkofer, K.; Jennings, G.; Kurtz, C. A.; Li, F.; Harlang, T.; Vithanage, D.; Chabera, P.; Bordage, A.; Sun, L.; Ott, S.; Wärnmark, K.; Sundström, V.

    2015-07-06

    The photochemical reactions performed by transition metal complexes have been proposed as viable routes towards solar energy conversion and storage into other forms that can be conveniently used in our everyday applications. In order to develop efficient materials, it is necessary to identify, characterize and optimize the elementary steps of the entire process on the atomic scale. To this end, we have studied the photoinduced electronic and structural dynamics in two heterobimetallic ruthenium–cobalt dyads, which belong to the large family of donor–bridge–acceptor systems. Using a combination of ultrafast optical and X-ray absorption spectroscopies, we can clock the light-driven electron transfer processes with element and spin sensitivity. In addition, the changes in local structure around the two metal centers are monitored. These experiments show that the nature of the connecting bridge is decisive for controlling the forward and the backward electron transfer rates, a result supported by quantum chemistry calculations. More generally, this work illustrates how ultrafast optical and X-ray techniques can disentangle the influence of spin, electronic and nuclear factors on the intramolecular electron transfer process. Finally, some implications for further improving the design of bridged sensitizer-catalysts utilizing the presented methodology are outlined.

  4. The Russian Federation's Ministry of Atomic Energy: Programs and Developments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Craig M.

    2000-07-24

    The Ministry of Atomic Energy of the Russian Federation (Minatom) is one of Russia's largest and most influential federal bodies. Throughout 1999 its head, Yevgeny Adamov, has worked to increase the Ministry's commercial competitiveness by consolidating redundant facilities and tightening control over subsidiary organizations. Economic difficulties and budget constraints, however, have hindered Minatom's ability to achieve many of its programs and goals. As a result, the Ministry has continued, renewed or initiated contracts with several countries possessing questionable commitments to nonproliferation and has sought to expand its role in international nuclear waste management and spent fuel reprocessing in order to raise new sources of revenue. While many of these programs are not likely to come to fruition, others raise significant nonproliferation and environmental concerns. This paper reviews select programs driving Minatom's efforts to raise funds, comments on their potential viability, and highlights areas likely to be of particular concern for the United States over the next three to five years.

  5. Watching the dynamics of electrons and atoms at work in solar energy conversion.

    Science.gov (United States)

    Canton, S E; Zhang, X; Liu, Y; Zhang, J; Pápai, M; Corani, A; Smeigh, A L; Smolentsev, G; Attenkofer, K; Jennings, G; Kurtz, C A; Li, F; Harlang, T; Vithanage, D; Chabera, P; Bordage, A; Sun, L; Ott, S; Wärnmark, K; Sundström, V

    2015-01-01

    The photochemical reactions performed by transition metal complexes have been proposed as viable routes towards solar energy conversion and storage into other forms that can be conveniently used in our everyday applications. In order to develop efficient materials, it is necessary to identify, characterize and optimize the elementary steps of the entire process on the atomic scale. To this end, we have studied the photoinduced electronic and structural dynamics in two heterobimetallic ruthenium-cobalt dyads, which belong to the large family of donor-bridge-acceptor systems. Using a combination of ultrafast optical and X-ray absorption spectroscopies, we can clock the light-driven electron transfer processes with element and spin sensitivity. In addition, the changes in local structure around the two metal centers are monitored. These experiments show that the nature of the connecting bridge is decisive for controlling the forward and the backward electron transfer rates, a result supported by quantum chemistry calculations. More generally, this work illustrates how ultrafast optical and X-ray techniques can disentangle the influence of spin, electronic and nuclear factors on the intramolecular electron transfer process. Finally, some implications for further improving the design of bridged sensitizer-catalysts utilizing the presented methodology are outlined.

  6. Investigation of energy thresholds of atomic and cluster sputtering of some elements under ion bombardment

    CERN Document Server

    Atabaev, B G; Lifanova, L F

    2002-01-01

    Threshold energies of sputtering of negative cluster ions from the Si(111) surface were measured at bombardment by Cs sup + , Rb sup + , and Na sup + ions with energy of 0.1-3.0 keV. These results are compared with the calculations of the similar thresholds by Bohdansky etc. formulas (3) for clusters Si sub n sup - and Cu sub n sup - with n=(1-5) and also for B, C, Al, Si, Fe, Cu atoms. Threshold energies of sputtering for the above elements were also estimated using the data from (5). Satisfactory agreement between the experimental and theoretical results was obtained. (author)

  7. Japan Returns to Atom. Current Status and Prospects of the Japanese Nuclear Energy

    Directory of Open Access Journals (Sweden)

    Łukasz Tolak

    2015-12-01

    Full Text Available In a year and a half after the events of March 2011, Japan excluded all their nuclear reactors, returning to fossil fuels as a basis in the energy field. The shock associated with nuclear disaster seemed to indicate an ultimate end of Japanese adventure with the atom. The situation has, however, significantly changed during the last several months, and the first nuclear reactor connected again to the electric network, is a proof of the change of the energy policy. The article aims to identify the current state of knowledge on the future of nuclear energy in the Japanese energy sector and adjustments proposed in the future energy mix. At the same time, it is an attempt to analyze the reasons that led the current Government of Prime Minister Abe to take very unpopular decisions to return to nuclear energy.

  8. Safety precautions in atomic pile control (1962); Securite dans le controle des piles atomiques (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Furet, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    We have been led to study the problem of safety in atomic pile control as a result of our participation on the one hand in the planning of C.E.A. atomic piles, and on the other hand in the pile safety sub omission considering atomic pile safety of operational or planned C.E.A. piles. We have thus had to consider the wishes occurring in piles during their operation and also their behaviour in the dynamic state The present work deals mainly with the importance of intrinsic safety devices, with the influence of reactivity variations on the power fluctuations during accidental operation, and with the development of robust and reliable safety appliances. The starting p accident has been especially studied both for low-flux piles where a compromise is necessary between the response time of the safety appliances and the statistical fluctuations and for high lux piles where xenon poisoning has an effect on the lower limit of the velocity of reactivity liberation. The desirability has been stressed of automation as a safety factor in atomic pile control. The details required for an understanding of the diagrams of the apparatus are given. (author) [French] Nous avons aborde le probleme de la securite dans le controle des piles atomiques a la suite de notre participation d'une part aux avant rojets de piles atomiques du CE.A. et d'autre part a l'examen au sein de la sous ommission de surete des piles, de la securite des piles du CE.A. en fonctionnement ou en projet. Nous avons ete amenes a nous interesser alors aux risques encourus par les piles pendant leur fonctionnement et par la meme a leur comportement en regime dynamique. Ce travail traite principalement de l'importance des securites intrinseques, de l'influence des variations de reactivite sur les evolutions de puissance en regime d'accident et du developpement d'appareillages de securite robustes et de fonctionnement tres sur. L'accident de demarrage a ete particulierement

  9. Robust Control of Laddermill Wind Energy System

    NARCIS (Netherlands)

    Podgaets, A.R.; Ockels, W.J.

    2007-01-01

    Laddermill flight control problem with closed loop is considered in this paper. Laddermill is an alternative concept for energy production using high altitude kites. The kites have been simulated as rigid bodies and the cable as a thin elastic line. Euler angles and cable speed are controls. Flight

  10. Energy efficient control of a refrigeration plant

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Larsen, Lars F. S.

    2009-01-01

    of of a nonlinear controller. The stability of the proposed method is validated theoretically by Lyapunov analysis and experimental results shows the performance of the system for a wide range of operating points. The method is compared to a conventional method based on a thermostatic superheat controller...... and the methods are evaluated with respect to energy efficiency....

  11. Discrete control of resonant wave energy devices.

    Science.gov (United States)

    Clément, A H; Babarit, A

    2012-01-28

    Aiming at amplifying the energy productive motion of wave energy converters (WECs) in response to irregular sea waves, the strategies of discrete control presented here feature some major advantages over continuous control, which is known to require, for optimal operation, a bidirectional power take-off able to re-inject energy into the WEC system during parts of the oscillation cycles. Three different discrete control strategies are described: latching control, declutching control and the combination of both, which we term latched-operating-declutched control. It is shown that any of these methods can be applied with great benefit, not only to mono-resonant WEC oscillators, but also to bi-resonant and multi-resonant systems. For some of these applications, it is shown how these three discrete control strategies can be optimally defined, either by analytical solution for regular waves, or numerically, by applying the optimal command theory in irregular waves. Applied to a model of a seven degree-of-freedom system (the SEAREV WEC) to estimate its annual production on several production sites, the most efficient of these discrete control strategies was shown to double the energy production, regardless of the resource level of the site, which may be considered as a real breakthrough, rather than a marginal improvement.

  12. Scheme for Deterministic BSM-Free Controlled Teleportation of Unknown Atomic States

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    We propose a controlled scheme for teleportation of an arbitrary one or two atomic state via a driven QED cavity. The scheme does not involve the joint Bell-state-measurement BSM and the probability of successful teleportation is 1. We show that the original atomic state cannot be perfectly restored by the receiver without all the agents collaborate and classical communication.

  13. Control of atomic transition rates via laser light shaping

    CERN Document Server

    Jauregui, R

    2015-01-01

    A modular systematic analysis of the feasibility of modifying atomic transition rates by tailoring the electromagnetic field of an external coherent light source is presented. The formalism considers both the center of mass and internal degrees of freedom of the atom, and all properties of the field: frequency, angular spectrum, and polarization. General features of recoil effects for internal forbidden transitions are discussed. A comparative analysis of different structured light sources is explicitly worked out. It includes spherical waves, Gaussian beams, Laguerre-Gaussian beams, and propagation invariant beams with closed analytical expressions. It is shown that increments in the order of magnitude of the transition rates for Gaussian and Laguerre-Gaussian beams, with respect to those obtained in the paraxial limit, requires waists of the order of the wavelength, while propagation invariant modes may considerably enhance transition rates under more favorable conditions. For transitions that can be natura...

  14. Study on the fine control of atoms by coherent interaction

    Energy Technology Data Exchange (ETDEWEB)

    Min, Han Jae; Rho, S. P.; Park, H. M.; Lee, K. S.; Rhee, Y. J.; Yi, J. H.; Jeong, D. Y.; Jung, E. C.; Choe, A. S.; Lee, J. M

    1999-01-01

    The doppler-free saturation spectroscopy of Na atoms has been performed and the proper conditions for the frequency stabilization of narrow band cw dye lasers, which was used as laser sources for the laser cooling and trapping, have been obtained as follows : a) optimum pressure of a Na vapor cell: 10 mTorr b) intensity of a pump laser : a few {mu}W c) intensity of a probe laser : 1/10 of that of a pump laser. EIT (Electromagnetically Induced Transparency) generated by coherent laser-atom interactions was investigated experimentally and analyzed theoretically. The absorption of a probe laser could be remarkably reduced more than 90 % due to EIT effect. The EIT spectrum as narrow as 6 MHz which is even narrower than the natural linewidth of an excited state could be obtained under proper conditions.

  15. Optical meta-atom for localization of light with quantized energy

    CERN Document Server

    Lannebère, Sylvain

    2015-01-01

    The capacity to confine light into a small region of space is of paramount importance in many areas of modern science. Here, we suggest a mechanism to store a quantized "bit" of light - with a very precise amount of energy - in an open core-shell plasmonic structure ("meta-atom") with a nonlinear optical response. Notwithstanding the trapped light state is embedded in the radiation continuum, its lifetime is not limited by the radiation loss. Interestingly, it is shown that the interplay between the nonlinear response and volume plasmons enables breaking fundamental reciprocity restrictions, and coupling very efficiently an external light source to the meta-atom. The collision of an incident optical pulse with the meta-atom may be used to release the trapped radiation "bit".

  16. Dynamics of Finite Energy Airy Beams Carrying Orbital Angular Momentum in Multilevel Atomic Vapors

    Science.gov (United States)

    Wu, Zhenkun; Wang, Shun; Hu, Weifei; Gu, Yuzong

    2016-10-01

    We numerically investigate the dynamics of inward circular finite-energy Airy beams carrying different orbital angular momentum (OAM) numbers in a close-Λ three-level atomic vapor with the electromagnetically induced transparency (EIT) window. We report that due to the EIT induced by the microwave field, the transverse intensity distribution properties of Airy beam can be feasibly manipulated and modulated through adjusting OAM numbers l and the frequency detuning, as well as the propagation distance, in the multi-level atomic systems. What's more, the rotation of the beam also can be observed with different positions in atomic ensembles. The investigation may provide a useful tool for studying particle manipulation, signal processing and propagation in graded-index (GRIN) fibers.

  17. Atom beam triangulation of organic layers at 100 meV normal energy: self-assembled perylene on Ag(110) at room temperature

    CERN Document Server

    Kalashnyk, Nataliya

    2015-01-01

    The controlled growth of organic layer on surface is still awaiting for an on-line reliable monitoring that would allow improvement of its quality. We show here that the self-assembly of the perylene monolayer deposited on Ag(110) at room temperature can be tracked with low energy atoms in a regime where the energy perpendicular to the layer is less than 0.1 eV preventing damage to the layer. The image processing required for this triangulation technique with atoms is described in details.

  18. Advanced Energy Harvesting Control Schemes for Marine Renewable Energy Devices

    Energy Technology Data Exchange (ETDEWEB)

    McEntee, Jarlath [Ocean Renewable Power Company, Portland, ME (United States); Polagye, Brian [Ocean Renewable Power Company, Portland, ME (United States); Fabien, Brian [Ocean Renewable Power Company, Portland, ME (United States); Thomson, Jim [Ocean Renewable Power Company, Portland, ME (United States); Kilcher, Levi [Ocean Renewable Power Company, Portland, ME (United States); Marnagh, Cian [Ocean Renewable Power Company, Portland, ME (United States); Donegan, James [Ocean Renewable Power Company, Portland, ME (United States)

    2016-03-31

    The Advanced Energy Harvesting Control Schemes for Marine Renewable Energy Devices (Project) investigated, analyzed and modeled advanced turbine control schemes with the objective of increasing the energy harvested by hydrokinetic turbines in turbulent flow. Ocean Renewable Power Company (ORPC) implemented and validated a feedforward controller to increase power capture; and applied and tested the controls on ORPC’s RivGen® Power Systems in Igiugig, Alaska. Assessments of performance improvements were made for the RivGen® in the Igiugig environment and for ORPC’s TidGen® Power System in a reference tidal environment. Annualized Energy Production (AEP) and Levelized Cost of Energy (LCOE) improvements associated with implementation of the recommended control methodology were made for the TidGen® Power System in the DOE reference tidal environment. System Performance Advancement (SPA) goals were selected for the project. SPA targets were to improve Power to Weight Ratio (PWR) and system Availability, with the intention of reducing Levelized Cost of Electricity (LCOE). This project focused primarily reducing in PWR. Reductions in PWR of 25.5% were achieved. Reductions of 20.3% in LCOE were achieved. This project evaluated four types of controllers which were tested in simulation, emulation, a laboratory flume, and the field. The adaptive Kω2 controller performs similarly to the non-adaptive version of the same controller and may be useful in tidal channels where the mean velocity is continually evolving. Trends in simulation were largely verified through experiments, which also provided the opportunity to test assumptions about turbine responsiveness and control resilience to varying scales of turbulence. Laboratory experiments provided an essential stepping stone between simulation and implementation on a field-scale turbine. Experiments also demonstrated that using “energy loss” as a metric to differentiate between well-designed controllers operating at

  19. Atomic Structure Control of Silica Thin Films on Pt(111)

    KAUST Repository

    Crampton, Andrew S

    2015-05-27

    Metal oxide thin films grown on metal single crystals are commonly used to model heterogeneous catalyst supports. The structure and properties of thin silicon dioxide films grown on metal single crystals have only recently been thoroughly characterized and their spectral properties well established. We report the successful growth of a three- dimensional, vitreous silicon dioxide thin film on the Pt(111) surface and reproduce the closed bilayer structure previously reported. The confirmation of the three dimensional nature of the film is unequivocally shown by the infrared absorption band at 1252 cm−1. Temperature programmed desorption was used to show that this three-dimensional thin film covers the Pt(111) surface to such an extent that its application as a catalyst support for clusters/nanoparticles is possible. The growth of a three-dimensional film was seen to be directly correlated with the amount of oxygen present on the surface after the silicon evaporation process. This excess of oxygen is tentatively attributed to atomic oxygen being generated in the evaporator. The identification of atomic oxygen as a necessary building block for the formation of a three-dimensional thin film opens up new possibilities for thin film growth on metal supports, whereby simply changing the type of oxygen enables thin films with different atomic structures to be synthesized. This is a novel approach to tune the synthesis parameters of thin films to grow a specific structure and expands the options for modeling common amorphous silica supports under ultra high vacuum conditions.

  20. Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic Atomization

    Science.gov (United States)

    Okawa, Hirokazu; Nishi, Kentaro; Shindo, Dai; Kawamura, Youhei

    2012-07-01

    The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 µm), green tuff (6 µm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without.

  1. Whither the legal control of nuclear energy?

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Peter [Leicester School of Law (United Kingdom). Environmental Law Unit

    1995-12-31

    International nuclear trade is governed by the regime of legal control of nuclear energy, nuclear materials, knowledge of nuclear processes and weapons. Nuclear trade is under pinned by international agreements concerning physical protection and safeguards, the control of nuclear weapons, the protection of nuclear materials from terrorist action and third part liability. The political and geographical boundary changes of the past two years have significantly altered the background against which this regime has developed. Such changes have affected nuclear trade. The paper summarised the legal control of nuclear energy between States, identifies the areas of change which may affect this regime and the consequences for international trade. Conclusions are drawn as to the development of the international legal control of nuclear energy. (author). 21 refs.

  2. Coherent control of atoms and diatomic molecules with shaped ultrashort pulses; Manipulation coherente d'atomes et de molecules diatomiques avec des impulsions mises en forme

    Energy Technology Data Exchange (ETDEWEB)

    Degert, J

    2002-12-15

    This thesis deals with the theoretical and experimental study of coherent control of atomic and molecular systems with shaped pulses. At first, we present several experiments of control of coherent transients in rubidium. These transients appear when a two-level system is excited by a perturbative chirped pulse, and are characterized by oscillations in the excited state population. For a strong chirp, we show that a phase step in the spectrum modifies the phase of the oscillations. Then, by direct analogy with Fresnel zone lens, we conceive a chirped pulse with a highly modulated amplitude, allowing to suppress destructive contributions to the population transfer. In a second set of experiments, we focus on quantum path interferences in two-photon transitions excited by linearly chirped pulses. Owing to the broad bandwidth of ultrashort pulses, sequential and direct excitation paths contribute to the excited state population. Oscillations resulting from interferences between these two paths are observed in atomic sodium. Moreover, we show that they are observable whatever the sign of chirp. Theoretically, we study the control of the predissociation of a benchmark diatomic molecule: NaI. Predissociation leads to matter wave interferences in the fragments distribution. First, we show that a suitably chosen probe pulse allows the observation of theses interferences. Next, using a sequence of control pulse inducing electronic transition, we demonstrate the possibility to manipulate fragment energy distribution. (author)

  3. Controllability of wind energy; Regelbaarheid van windenergie

    Energy Technology Data Exchange (ETDEWEB)

    Brand, A. [ECN Wind Energy, Petten (Netherlands)

    2012-02-15

    First, an explanation is offered as to why the controllability of wind energy is limited. Then the capacity adjustment at farm level is outlined and various control targets are discussed. Finally the current and future wind farm control systems are discussed. [Dutch] Eerst wordt uitgelegd waarom windenergie beperkt regelbaar is. Daarna volgt een schets van vermogensregeling op parkniveau en passeren verschillende regeldoelstellingen de revue. Tenslotte komen de huidige en de toekomstige windparkregelingen aan de orde.

  4. Visualizing the large-$Z$ scaling of the kinetic energy density of atoms

    CERN Document Server

    Cancio, Antonio C

    2016-01-01

    The scaling of neutral atoms to large $Z$, combining periodicity with a gradual trend to homogeneity, is a fundamental probe of density functional theory, one that has driven recent advances in understanding both the kinetic and exchange-correlation energies. Although research focus is normally upon the scaling of energies, insights can also be gained from energy densities. We visualize the scaling of the positive-definite kinetic energy density (KED) in closed-shell atoms, in comparison to invariant quantities based upon the gradient and Laplacian of the density. We notice a striking fit of the KED within the core of any atom to a gradient expansion using both the gradient and the Laplacian, appearing as an asymptotic limit around which the KED oscillates. The gradient expansion is qualitatively different from that derived from first principles for a slowly-varying electron gas and is correlated with a nonzero Pauli contribution to the KED near the nucleus. We propose and explore orbital-free meta-GGA models...

  5. Spatial assignment of symmetry adapted perturbation theory interaction energy components: The atomic SAPT partition.

    Science.gov (United States)

    Parrish, Robert M; Sherrill, C David

    2014-07-28

    We develop a physically-motivated assignment of symmetry adapted perturbation theory for intermolecular interactions (SAPT) into atom-pairwise contributions (the A-SAPT partition). The basic precept of A-SAPT is that the many-body interaction energy components are computed normally under the formalism of SAPT, following which a spatially-localized two-body quasiparticle interaction is extracted from the many-body interaction terms. For electrostatics and induction source terms, the relevant quasiparticles are atoms, which are obtained in this work through the iterative stockholder analysis (ISA) procedure. For the exchange, induction response, and dispersion terms, the relevant quasiparticles are local occupied orbitals, which are obtained in this work through the Pipek-Mezey procedure. The local orbital atomic charges obtained from ISA additionally allow the terms involving local orbitals to be assigned in an atom-pairwise manner. Further summation over the atoms of one or the other monomer allows for a chemically intuitive visualization of the contribution of each atom and interaction component to the overall noncovalent interaction strength. Herein, we present the intuitive development and mathematical form for A-SAPT applied in the SAPT0 approximation (the A-SAPT0 partition). We also provide an efficient series of algorithms for the computation of the A-SAPT0 partition with essentially the same computational cost as the corresponding SAPT0 decomposition. We probe the sensitivity of the A-SAPT0 partition to the ISA grid and convergence parameter, orbital localization metric, and induction coupling treatment, and recommend a set of practical choices which closes the definition of the A-SAPT0 partition. We demonstrate the utility and computational tractability of the A-SAPT0 partition in the context of side-on cation-π interactions and the intercalation of DNA by proflavine. A-SAPT0 clearly shows the key processes in these complicated noncovalent interactions, in

  6. Precision control of magneto-optically cooled rubidium atoms (Invited Paper)

    Science.gov (United States)

    Nic Chormaic, S.; Yarovitskiy, A.; Shortt, B.; Deasy, K.; Morrissey, M.

    2005-06-01

    Research interest in designing sources of cold atoms has significantly increased during the past ten years with the development of suitable laser sources for magneto-optical trapping and the further mastering of evaporative cooling in order to achieve Bose-Einstein condensation. The magneto-optical trap is now viewed as a standard research facility worldwide and has opened up many new exciting research directions in atomic physics. One area of interest is that of combining spherical microcavities with cold atomic sources in order to achieve efficient photon exchange between the cavity and atom for further understandings of cavity quantum electrodynamics. This could eventually lead to atom entanglement via photon exchange which would have implications for quantum logic design. However, initial attempts to achieve such interactions have been hindered by inadequate control and manipulation of the cold atom source. Here, we present work on designing and building an ultra-stable source of magneto-optically cooled rubidium atoms with a temperature in the tens of microKelvin range. We discuss the different cooling mechanisms involved in the process and present a suitable experimental arrangement including details on the ultra-high vacuum chamber, the laser systems being used and the source of rubidium vapour. Finally, we discuss some future direction for the research including the diffraction of atoms from gratings and micron-sized objects and the parameter control of the cloud of atoms.

  7. Flash Atomization: A New Concept to Control Combustion Instability in Water-Injected Gas Turbines

    Directory of Open Access Journals (Sweden)

    Vishwas Iyengar

    2012-01-01

    Full Text Available The objective of this work is to explore methods to reduce combustor rumble in a water-injected gas turbine. Attempts to use water injection as a means to reduce NOX emissions in gas turbines have been largely unsuccessful because of increased combustion instability levels. This pulsation causes chronic fretting, wear, and fatigue that damages combustor components. Of greater concern is that liberated fragments could cause extensive damage to the turbine section. Combustion instability can be tied to the insufficient atomization of injected water; large water droplets evaporate non-uniformly that lead to energy absorption in chaotic pulses. Added pulsation is amplified by the combustion process and acoustic resonance. Effervescent atomization, where gas bubbles are injected, is beneficial by producing finely atomized droplets; the gas bubbles burst as they exit the nozzles creating additional energy to disperse the liquid. A new concept for effervescent atomization dubbed “flash atomization” is presented where water is heated to just below its boiling point in the supply line so that some of it will flash to steam as it leaves the nozzle. An advantage of flash atomization is that available heat energy can be used rather than mechanical energy to compress injection gas for conventional effervescent atomization.

  8. Calculations of Self-diffusion Activation Energies for Alkaline Metals With Embedded Atom Method

    Institute of Scientific and Technical Information of China (English)

    欧阳义芳; 张邦维; 廖树帜

    1994-01-01

    Calculations were performed for the self-diffusion activation energies of monovacancy and both formation and binding energies of divacancies for alkaline metals Li, Na, K, Rb, Cs using the embedded atom method (EAM) model for bcc transition metals developed by the authors recently. The aim of the paper is to extend the application of the new model, to compare the calculated values for self-diffusion with the experimental data and those of previous calculations, and to discuss the intrinsic characteristic of self-diffusion in alkaline metals. The calculated monovacancy migration energies and activation energies are in excellent agreement with experimental data, and the calculated divacancy migration and activation energies are in good agreement with the experimental values available.

  9. U.S. Radioecology Research Programs of the Atomic Energy Commission in the 1950s

    Energy Technology Data Exchange (ETDEWEB)

    Reichle, D.E.

    2004-01-12

    This report contains two companion papers about radiological and environmental research that developed out of efforts of the Atomic Energy Commission in the late 1940s and the 1950s. Both papers were written for the Joint U.S.-Russian International Symposium entitled ''History of Atomic Energy Projects in the 1950s--Sociopolitical, Environmental, and Engineering Lessons Learned,'' which was hosted by the International Institute for Applied Systems Analysis in Laxemberg, Austria, in October 1999. Because the proceedings of this symposium were not published, these valuable historic reviews and their references are being documented as a single ORNL report. The first paper, ''U.S. Radioecology Research Programs Initiated in the 1950s,'' written by David Reichle and Stanley Auerbach, deals with the formation of the early radioecological research programs at the U.S. Atomic Energy Commission's nuclear production facilities at the Clinton Engineering Works in Oak Ridge, Tennessee; at the Hanford Plant in Richland, Washington; and at the Savannah River Plant in Georgia. These early radioecology programs were outgrowths of the environmental monitoring programs at each site and eventually developed into the world renowned National Laboratory environmental program sponsored by the Office of Biological and Environmental Research of the U.S. Department of Energy. The original version of the first paper was presented by David Reichle at the symposium. The second paper, ''U.S. Atomic Energy Commission's Environmental Research Programs Established in the 1950s,'' summarizes all the environmental research programs supported by the U.S. Atomic Energy Commission in the 1950s and discusses their present-day legacies. This paper is a modified, expanded version of a paper that was published in September 1997 in a volume commemorating the 50th anniversary symposium of the U.S. Department of Energy's Office of

  10. Phase-controlled atom-photon entanglement in a three-level ∧-type closed-loop atomic system

    Institute of Scientific and Technical Information of China (English)

    Ali Mortezapour; Zeinab Kordi; Mohammad Mahmoudi

    2013-01-01

    We study the entanglement of dressed atom and its spontaneous emission in a three-level A-type closed-loop atomic system in a multi-photon resonance condition and beyond it.It is shown that the von Neumann entropy in such a system is phase-dependent,and it can be controlled by either the intensity or relative phase of applied fields.It is demonstrated that for the special case of the Rabi frequency of applied fields,the system is disentangled.In addition,we take into account the effect of Doppler broadening on the entanglement and it is found that a suitable choice of laser propagation direction allows us to obtain the steady state degree of entanglement (DEM) even in the presence of the Doppler effect.

  11. Electrical energy consumption control apparatuses and electrical energy consumption control methods

    Science.gov (United States)

    Hammerstrom, Donald J.

    2012-09-04

    Electrical energy consumption control apparatuses and electrical energy consumption control methods are described. According to one aspect, an electrical energy consumption control apparatus includes processing circuitry configured to receive a signal which is indicative of current of electrical energy which is consumed by a plurality of loads at a site, to compare the signal which is indicative of current of electrical energy which is consumed by the plurality of loads at the site with a desired substantially sinusoidal waveform of current of electrical energy which is received at the site from an electrical power system, and to use the comparison to control an amount of the electrical energy which is consumed by at least one of the loads of the site.

  12. Electronic torsional sound in linear atomic chains: chemical energy transport at 1000 km/s

    CERN Document Server

    Kurnosov, Arkady A; Maksymov, Andrii A; Burin, Alexander L

    2016-01-01

    We investigate entirely electronic torsional vibrational modes in linear cumulene chains. The carbon nuclei of a cumulene are positioned along the primary axis so they can participate only in transverse and longitudinal motions. However, the interatomic electronic clouds behave as a torsion spring with remarkable torsional stiffness. The collective dynamics of these clouds can be described in terms of electronic vibrational quanta, which we name torsitons. It is shown that the group velocity of the wavepacket of torsitons is much higher than the typical speed of sound, because of the small mass of participating electrons compared to the atomic mass. For the same reason the maximum energy of the torsitons in cumulenes is as high as a few electronvolts, while the minimum possible energy is evaluated as a few hundred wavenumbers and this minimum is associated with asymmetry of zero point atomic vibrations. Molecular systems for experimental evaluation of the predictions are proposed.

  13. Atomic Energy Act (AtG) and subordinate legislation. Collections. 33. ed.; Atomgesetz mit Verordnungen. Textsammlung

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, Eberhard (ed.)

    2014-07-01

    The 33rd edition of the present statute book contains the Site Selection Law (StandAG) of 25 July 2013, which specifies the procedure for selecting sites for final disposal of high-level radioactive wastes, and the Law on the Establishment of a Federal Office for Disposal of Radioactive Wastes, promulgated as Art. 3 of the Site Selection Law. Some regulations of the StandAG already took effect on 27 July 2013, while others are to be enacted on 1 January 2014 along with amendments to the Atomic Energy Law, the Schedule of Costs to the Atomic Energy Law and the Law on Environmental Impact Assessments that result from the StandAG. The new edition also includes legislative amendments that were passed after the publication of the previous edition, namely those to the Food Irradiation Ordinance, the Law on the Establishment of the Federal Radiation Protection Office and to relevant regulations of the Criminal Code.

  14. Formation of nanostructures on HOPG surface in presence of surfactant atom during low energy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan, M., E-mail: ranjanm@ipr.res.in; Joshi, P.; Mukherjee, S.

    2016-07-15

    Low energy ions beam often develop periodic patterns on surfaces under normal or off-normal incidence. Formation of such periodic patterns depends on the substrate material, the ion beam parameters, and the processing conditions. Processing conditions introduce unwanted contaminant atoms, which also play strong role in pattern formation by changing the effective sputtering yield of the material. In this work we have analysed the effect of Cu, Fe and Al impurities introduced during low energy Ar{sup +} ion irradiation on HOPG substrate. It is observed that by changing the species of foreign atoms the surface topography changes drastically. The observed surface topography is co-related with the modified sputtering yield of HOPG. Presence of Cu and Fe amplify the effective sputtering yield of HOPG, so that the required threshold for the pattern formation is achieved with the given fluence, whereas Al does not lead to any significant change in the effective yield and hence no pattern formation occurs.

  15. Energy Optimal Control of Induction Motor Drives

    DEFF Research Database (Denmark)

    Abrahamsen, Flemming

    This thesis deals with energy optimal control of small and medium-size variable speed induction motor drives for especially Heating, Ventilation and Air-Condition (HVAC) applications. Optimized efficiency is achieved by adapting the magnetization level in the motor to the load, and the basic...... purpose is demonstrate how this can be done for low-cost PWM-VSI drives without bringing the robustness of the drive below an acceptable level. Four drives are investigated with respect to energy optimal control: 2.2 kW standard and high-efficiency motor drives, 22 kW and 90 kW standard motor drives....... The method has been to make extensive efficiency measurements within the specified operating area with optimized efficiency and with constant air-gap flux, and to establish reliable converter and motor loss models based on those measurements. The loss models have been used to analyze energy optimal control...

  16. Scaled-Down Moderator Circulation Test Facility at Korea Atomic Energy Research Institute

    OpenAIRE

    2016-01-01

    Korea Atomic Energy Research Institute (KAERI) started the experimental research on moderator circulation as one of a the national research and development programs from 2012. This research program includes the construction of the moderator circulation test (MCT) facility, production of the validation data for self-reliant computational fluid dynamics (CFD) tools, and development of optical measurement system using the particle image velocimetry (PIV). In the present paper we introduce the sc...

  17. Protein structure prediction by all-atom free-energy refinement

    Directory of Open Access Journals (Sweden)

    Wenzel Wolfgang

    2007-03-01

    Full Text Available Abstract Background The reliable prediction of protein tertiary structure from the amino acid sequence remains challenging even for small proteins. We have developed an all-atom free-energy protein forcefield (PFF01 that we could use to fold several small proteins from completely extended conformations. Because the computational cost of de-novo folding studies rises steeply with system size, this approach is unsuitable for structure prediction purposes. We therefore investigate here a low-cost free-energy relaxation protocol for protein structure prediction that combines heuristic methods for model generation with all-atom free-energy relaxation in PFF01. Results We use PFF01 to rank and cluster the conformations for 32 proteins generated by ROSETTA. For 22/10 high-quality/low quality decoy sets we select near-native conformations with an average Cα root mean square deviation of 3.03 Å/6.04 Å. The protocol incorporates an inherent reliability indicator that succeeds for 78% of the decoy sets. In over 90% of these cases near-native conformations are selected from the decoy set. This success rate is rationalized by the quality of the decoys and the selectivity of the PFF01 forcefield, which ranks near-native conformations an average 3.06 standard deviations below that of the relaxed decoys (Z-score. Conclusion All-atom free-energy relaxation with PFF01 emerges as a powerful low-cost approach toward generic de-novo protein structure prediction. The approach can be applied to large all-atom decoy sets of any origin and requires no preexisting structural information to identify the native conformation. The study provides evidence that a large class of proteins may be foldable by PFF01.

  18. Precision X-ray spectroscopy of kaonic atoms as a probe of low-energy kaon-nucleus interaction

    CERN Document Server

    Shi, H; Beer, G; Bellotti, G; Berucci, C; Bragadireanu, A M; Bosnar, D; Cargnelli, M; Curceanu, C; Butt, A D; d'Uffizi, A; Fiorini, C; Ghio, F; Guaraldo, C; Hayano, R S; Iliescu, M; Ishiwatari, T; Iwasaki, M; Sandri, P Levi; Marton, J; Okada, S; Pietreanu, D; Piscicchia, K; Vidal, A Romero; Sbardella, E; Scordo, A; Sirghi, D L; Sirghi, F; Tatsuno, H; Doce, O Vazquez; Widmann, E; Zmeskal, J

    2016-01-01

    In the exotic atoms where one atomic $1s$ electron is replaced by a $K^{-}$, the strong interaction between the $K^{-}$ and the nucleus introduces an energy shift and broadening of the low-lying kaonic atomic levels which are determined by only the electromagnetic interaction. By performing X-ray spectroscopy for Z=1,2 kaonic atoms, the SIDDHARTA experiment determined with high precision the shift and width for the $1s$ state of $K^{-}p$ and the $2p$ state of kaonic helium-3 and kaonic helium-4. These results provided unique information of the kaon-nucleus interaction in the low energy limit.

  19. Energy Efficiency of Distributed Environmental Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, H. Ezzat; Isik, Can; Dannenhoffer, John F. III

    2011-02-23

    In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant

  20. Wind energy systems control engineering design

    CERN Document Server

    Garcia-Sanz, Mario

    2012-01-01

    IntroductionBroad Context and MotivationConcurrent Engineering: A Road Map for EnergyQuantitative Robust ControlNovel CAD Toolbox for QFT Controller DesignOutline Part I: Advanced Robust Control Techniques: QFT and Nonlinear SwitchingIntroduction to QFTQuantitative Feedback TheoryWhy Feedback? QFT OverviewInsight into the QFT TechniqueBenefits of QFTMISO Analog QFT Control SystemIntroductionQFT Method (Single-Loop MISO System)Design Procedure OutlineMinimum-Phase System Performance SpecificationsJ LTI Plant ModelsPlant Templates of P?(s), P( j_i )Nominal PlantU-Contour (Stability Bound)Trackin

  1. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  2. Atomically thick bismuth selenide freestanding single layers achieving enhanced thermoelectric energy harvesting.

    Science.gov (United States)

    Sun, Yongfu; Cheng, Hao; Gao, Shan; Liu, Qinghua; Sun, Zhihu; Xiao, Chong; Wu, Changzheng; Wei, Shiqiang; Xie, Yi

    2012-12-19

    Thermoelectric materials can realize significant energy savings by generating electricity from untapped waste heat. However, the coupling of the thermoelectric parameters unfortunately limits their efficiency and practical applications. Here, a single-layer-based (SLB) composite fabricated from atomically thick single layers was proposed to optimize the thermoelectric parameters fully. Freestanding five-atom-thick Bi(2)Se(3) single layers were first synthesized via a scalable interaction/exfoliation strategy. As revealed by X-ray absorption fine structure spectroscopy and first-principles calculations, surface distortion gives them excellent structural stability and a much increased density of states, resulting in a 2-fold higher electrical conductivity relative to the bulk material. Also, the surface disorder and numerous interfaces in the Bi(2)Se(3) SLB composite allow for effective phonon scattering and decreased thermal conductivity, while the 2D electron gas and energy filtering effect increase the Seebeck coefficient, resulting in an 8-fold higher figure of merit (ZT) relative to the bulk material. This work develops a facile strategy for synthesizing atomically thick single layers and demonstrates their superior ability to optimize the thermoelectric energy harvesting.

  3. The International Atomic Energy Agency's activities in radiation medicine and cancer: promoting global health through diplomacy.

    Science.gov (United States)

    Deatsch-Kratochvil, Amanda N; Pascual, Thomas Neil; Kesner, Adam; Rosenblatt, Eduardo; Chhem, Rethy K

    2013-02-01

    Global health has been an issue of seemingly low political importance in comparison with issues that have direct bearing on countries' national security. Recently, health has experienced a "political revolution" or a rise in political importance. Today, we face substantial global health challenges, from the spread of infectious disease, gaps in basic maternal and child health care, to the globalization of cancer. A recent estimate states that the "overall lifetime risk of developing cancer (both sexes) is expected to rise from more than one in three to one in two by 2015." These issues pose significant threats to international health security. To successfully combat these grave challenges, the international community must embrace and engage in global health diplomacy, defined by scholars Thomas Novotny and Vicanne Adams as a political activity aimed at improving global health, while at the same time maintaining and strengthening international relations. The IAEA (International Atomic Energy Agency) is an international organization with a unique mandate to "accelerate and enlarge the contribution of atomic energy to peace, health, and prosperity throughout the world." This article discusses global health diplomacy, reviews the IAEA's program activities in human health by focusing on radiation medicine and cancer, and the peaceful applications of atomic energy within the context of global health diplomacy.

  4. Simulation of Flywheel Energy Storage System Controls

    Science.gov (United States)

    Truong, Long V.; Wolff, Frederick J.; Dravid, Narayan

    2001-01-01

    This paper presents the progress made in the controller design and operation of a flywheel energy storage system. The switching logic for the converter bridge circuit has been redefined to reduce line current harmonics, even at the highest operating speed of the permanent magnet motor-generator. An electromechanical machine model is utilized to simulate charge and discharge operation of the inertial energy in the flywheel. Controlling the magnitude of phase currents regulates the rate of charge and discharge. The resulting improvements are demonstrated by simulation.

  5. A New Determination of the Binding Energy of Atomic Oxygen on Dust Grain Surfaces: Experimental Results and Simulations

    CERN Document Server

    He, Jiao; Hopkins, Tyler; Vidali, Gianfranco; Kaufman, Michael J

    2015-01-01

    The energy to desorb atomic oxygen from an interstellar dust grain surface, $E_{\\rm des}$, is an important controlling parameter in gas-grain models; its value impacts the temperature range over which oxygen resides on a dust grain. However, no prior measurement has been done of the desorption energy. We report the first direct measurement of $E_{\\rm des}$ for atomic oxygen from dust grain analogs. The values of $E_{\\rm des}$ are $1660\\pm 60$~K and $1850\\pm 90$~K for porous amorphous water ice and for a bare amorphous silicate film, respectively, or about twice the value previously adopted in simulations of the chemical evolution of a cloud. We use the new values to study oxygen chemistry as a function of depth in a molecular cloud. For $n=10^4$ cm$^{-3}$ and $G_0$=10$^2$ ($G_0$=1 is the average local interstellar radiation field), the main result of the adoption of the higher oxygen binding energy is that H$_2$O can form on grains at lower visual extinction $A_{\\rm V}$, closer to the cloud surface. A higher ...

  6. Control and automation, and energy system engineering

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tai-hoon [Hannam Univ., Daejeon (Korea, Republic of); Adeli, Hojjat [Ohio State Univ., Columbus, OH (United States); Stoica, Adrian [Jet Propulsion Laboratory, Pasadena, CA (United States); Kang, Byeong-Ho (eds.) [Tasmania Univ., Hobart, TAS (Australia)

    2011-07-01

    This book comprises selected papers of the International Conferences, CA and CES3 2011, held as Part of the Future Generation Information Technology Conference, FGIT 2011, in Conjunction with GDC 2011, Jeju Island, Korea, in December 2011. The papers presented were carefully reviewed and selected from numerous submissions and focused on the various aspects of control and automation, and circuits, control, communication, electricity, electronics, energy, system, signal and simulation. (orig.)

  7. Pollution Control Guidance for Geothermal Energy Development

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, Robert P.

    1978-06-01

    This report summarizes the EPA regulatory approach toward geothermal energy development. The state of knowledge is described with respect to the constituents of geothermal effluents and emissions, including water, air, solid wastes, and noise. Pollutant effects are discussed. Pollution control technologies that may be applicable are described along with preliminary cost estimates for their application. Finally discharge and emission limitations are suggested that may serve as interim guidance for pollution control during early geothermal development.

  8. X-ray energies of circular transitions and electrons screening in kaonic atoms

    CERN Document Server

    Santos, J P; Desclaux, J P; Indelicato, P J; Parente, F; Indelicato, Paul; ccsd-00002661, ccsd

    2004-01-01

    The QED contribution to the energies of the circular (n,l=n-1), 2 ≤ n ≤ 19 transitions have been calculated for several kaonic atoms throughout the periodic table, using the current world average kaon mass. Calculations were done in the framework of the Klein-Gordon equation, with finite nuclear size and all-order Uelhing vacuum polarization corrections, as well as Kallen and Sabry and Wichmann and Kroll corrections. These energy level values are compared with other computed values. The circular transition energies are compared with available measured and theoretical transition energy. Electron screening is evaluated using a Dirac-Fock model for the electronic part of the wave function. The effect of electronic wavefunction correlation is evaluated for the first time.

  9. Stacking fault energy in FCC plutonium with multiple reference states in the modified embedded atom method

    Science.gov (United States)

    Valone, S. M.; Baskes, M. I.; Rudin, S. P.

    2012-03-01

    Basic concepts from the multi-reference state formalism for determining the functions for the modified embedded atom method (MEAM) are adopted to modeling elemental plutonium (Pu). In the case of elemental Pu, the focus is on the background electron density. Here we utilize a portion of the formalism that determines the structure of the background density necessary to capture correct phase ordering between fcc and ideal hcp crystal structures. The critical information comes from cold curves, that is the energy/volume relationships, for these phases. Practically speaking, the energy difference between these two phases determines the stacking fault energy of the material. At the same time, the simple monoclinic phase of elemental Pu also becomes higher in energy at the equilibrium volume of the fcc phase. The new model is based on first-principles electronic structure calculations and captures the basic phase ordering of those calculations.

  10. Entangled Radiation through an Atomic Reservoir Controlled by Coherent Population Trapping

    Institute of Scientific and Technical Information of China (English)

    Li Qian; ZHONG Wen-Xue; HU Xiang-Ming

    2008-01-01

    We show that it is possible to generate Einstein-Podolsky-Rosen (EPR) entangled radiation using an atomic reservoir controlled by coherent population trapping. A beam of three-level atoms is initially prepared in nearcoherent population trapping (CPT) state and acts as a long-lived coherence-controlled reservoir. Four-wave mixing leads to amplification of cavity modes resonant with Rabi sidebands of the atomic dipole transitions. The cavity modes evolve into an EPR state, whose degree of entanglement is controlled by the intensities and the frequencies of the driving fields. This scheme uses the long-lived CPT coherence and is robust against spontaneous emission of the atomic beam. At the same time, this scheme is implemented in a one-step procedure, not in a two-step procedure as was required in Phys. Rev. Lett. 98 (2007) 240401.

  11. ELENA MCP detector: absolute efficiency measurement for low energy neutral atoms

    Science.gov (United States)

    Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

    2012-04-01

    MicroChannel plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section)which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (EMEFISTO facility of the Physical Institute of University of Bern (CH), measurements on three different type of MCPs coating have been performed providing the behaviors of MCP detection efficiency in the range 10eV-1keV. Outcomes from such measurements are here discussed.

  12. A Responsive Battery with Controlled Energy Release.

    Science.gov (United States)

    Wang, Xiaopeng; Gao, Jian; Cheng, Zhihua; Chen, Nan; Qu, Liangti

    2016-11-14

    A new type of responsive battery with the fascinating feature of pressure perceptibility has been developed, which can spontaneously, timely and reliably control the power outputs (e.g., current and voltage) in response to pressure changes. The device design is based on the structure of the Zn-air battery, in which graphene-coated sponge serves as pressure-sensitive air cathode that endows the whole system with the capability of self-controlled energy release. The responsive batteries exhibit superior battery performance with high open-circuit voltage (1.3 V), and competitive areal capacity of 1.25 mAh cm(-2) . This work presents an important move towards next-generation intelligent energy storage devices with energy management function.

  13. Interference and dynamics of light from a distance-controlled atom pair in an optical cavity

    CERN Document Server

    Neuzner, Andreas; Morin, Olivier; Ritter, Stephan; Rempe, Gerhard

    2016-01-01

    Interference is central to quantum physics and occurs when indistinguishable paths exist, like in a double-slit experiment. Replacing the two slits with two single atoms introduces optical non-linearities for which nontrivial interference phenomena are predicted. Their observation, however, has been hampered by difficulties in preparing the required atomic distribution, controlling the optical phases and detecting the faint light. Here we overcome all of these experimental challenges by combining an optical lattice for atom localisation, an imaging system with single-site resolution, and an optical resonator for light steering. We observe resonator-induced saturation of resonance fluorescence for constructive interference of the scattered light and nonzero emission with huge photon bunching for destructive interference. The latter is explained by atomic saturation and photon pair generation. Our experimental setting is scalable and allows one to realize the Tavis-Cummings model for any number of atoms and pho...

  14. Advanced Energy Harvesting Control Schemes for Marine Renewable Energy Devices

    Energy Technology Data Exchange (ETDEWEB)

    McEntee, Jarlath [Ocean Renewable Power Company, Portland, ME (United States); Polagye, Brian [Ocean Renewable Power Company, Portland, ME (United States); Fabien, Brian [Ocean Renewable Power Company, Portland, ME (United States); Thomson, Jim [Ocean Renewable Power Company, Portland, ME (United States); Kilcher, Levi [Ocean Renewable Power Company, Portland, ME (United States); Marnagh, Cian [Ocean Renewable Power Company, Portland, ME (United States); Donegan, James [Ocean Renewable Power Company, Portland, ME (United States)

    2016-03-31

    The Advanced Energy Harvesting Control Schemes for Marine Renewable Energy Devices (Project) investigated, analyzed and modeled advanced turbine control schemes with the objective of increasing the energy harvested by hydrokinetic turbines in turbulent flow. Ocean Renewable Power Company (ORPC) implemented and validated a feedforward controller to increase power capture; and applied and tested the controls on ORPC’s RivGen® Power Systems in Igiugig, Alaska. Assessments of performance improvements were made for the RivGen® in the Igiugig environment and for ORPC’s TidGen® Power System in a reference tidal environment. Annualized Energy Production (AEP) and Levelized Cost of Energy (LCOE) improvements associated with implementation of the recommended control methodology were made for the TidGen® Power System in the DOE reference tidal environment. System Performance Advancement (SPA) goals were selected for the project. SPA targets were to improve Power to Weight Ratio (PWR) and system Availability, with the intention of reducing Levelized Cost of Electricity (LCOE). This project focused primarily reducing in PWR. Reductions in PWR of 25.5% were achieved. Reductions of 20.3% in LCOE were achieved. This project evaluated four types of controllers which were tested in simulation, emulation, a laboratory flume, and the field. The adaptive Kω2 controller performs similarly to the non-adaptive version of the same controller and may be useful in tidal channels where the mean velocity is continually evolving. Trends in simulation were largely verified through experiments, which also provided the opportunity to test assumptions about turbine responsiveness and control resilience to varying scales of turbulence. Laboratory experiments provided an essential stepping stone between simulation and implementation on a field-scale turbine. Experiments also demonstrated that using “energy loss” as a metric to differentiate between well-designed controllers operating at

  15. Low energy neutral atom imaging on the Moon with the SARA instrument aboard Chandrayaan-1 mission

    Indian Academy of Sciences (India)

    Anil Bhardwaj; Stas Barabash; Yoshifumi Futaana; Yoichi Kazama; Kazushi Asamura; David McCann; R Sridharan; Mats Holmstrom; Peter Wurz; Rickard Lundin

    2005-12-01

    This paper reports on the Sub-keV Atom Reflecting Analyzer (SARA)experiment that will be flown on the first Indian lunar mission Chandrayaan-1.The SARA is a low energy neutral atom (LENA)imaging mass spectrometer,which will perform remote sensing of the lunar surface via detection of neutral atoms in the energy range from 10 eV to 3 keV from a 100 km polar orbit.In this report we present the basic design of the SARA experiment and discuss various scientific issues that will be addressed.The SARA instrument consists of three major subsystems:a LENA sensor (CENA),a solar wind monitor (SWIM),and a digital processing unit (DPU).SARA will be used to image the solar wind –surface interaction to study primarily the surface composition and surface magnetic anomalies and associated mini-magnetospheres.Studies of lunar exosphere sources and space weathering on the Moon will also be attempted.SARA is the first LENA imaging mass spectrometer of its kind to be flown on a space mission.A replica of SARA is planned to fly to Mercury onboard the BepiColombo mission.

  16. Correlation energies beyond the random-phase approximation: ISTLS applied to spherical atoms and ions

    CERN Document Server

    Gould, Tim

    2012-01-01

    The inhomogeneous Singwi, Tosi, Land and Sjolander (ISTLS) correlation energy functional of Dobson, Wang and Gould [PRB {\\bf 66} 081108(R) (2008)] has proved to be excellent at predicting correlation energies in semi-homogeneous systems, showing promise as a robust `next step' fifth-rung functional by using dynamic correlation to go beyond the limitations of the direct random-phase approximation (dRPA), but with similar numerical scaling with system size. In this work we test the functional on fourteen spherically symmetric, neutral and charged atomic systems and find it gives excellent results (within 2mHa/$e^-$ except Be) for the absolute correlation energies of the neutral atoms tested, and good results for the ions (within 4mHa/$e^-$). In all cases it performs better than the dRPA. When combined with the previous successes, these new results point to the ISTLS functional being a prime contender for high-accuracy, benchmark DFT correlation energy calculations.

  17. Atomic energy law after the opt-out. Alive and fascinating. Report about the 14{sup th} German atomic energy law symposium 2012; Atomrecht nach dem Ausstieg. Lebendig und spannend. Tagungsbericht 14. Deutsches Atomrechtssymposium 2012

    Energy Technology Data Exchange (ETDEWEB)

    Leidinger, Tobias [Gleiss Lutz Rechtsanwaelte, Duesseldorf (Germany)

    2013-01-15

    Atomic energy law remains a living, fascinating subject matter. Nearly 200 participants were convinced of this impression at the 14{sup th} German Atomic Energy Law Symposium held in Berlin on November 19-20, 2012. Under the scientific chairmanship of Professor Dr. Martin Burgi, Ludwig Maximilian University of Munich, the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), after an interruption of 5 years, again organized a scientific conference about practice-related topics of atomic energy and radiation protection law. Atomic energy law once again proved to be a reference area for sophisticated issues of constitutional law and administrative law above and beyond its technical confines. The agenda of the 14{sup th} German Atomic Energy Law Symposium featured a broad spectrum of topics ranging from backfitting of nuclear power plants to European atomic energy and radiation protection law, to challenges facing national legal systems in the execution of atomic energy law, to legal issues connected with decommissioning and waste management, and on to the topical subject of finding a repository site. The 14{sup th} German Atomic Energy Law Symposium, on the whole, again demonstrated that an open discourse between science and practice is able to furnish important contributions to the implementation of laws in a balanced way rooted in practice. Especially the contributions dealing with the independence of public authorities and their organization, the doctrine of the reservation of functions of the executive branch, and planning by laws contain additional provisions able to influence the continued development of administrative law also above and beyond atomic energy law. The BMU also referred to a decision just heard from Brussels to the effect that a new European Safety Directive would be published as early as in 2013. As a consequence of the nuclear stress tests conducted EU-wide, the Directive is to lay down provisions about

  18. Internal Spin Control, Squeezing and Decoherence in Ensembles of Alkali Atomic Spins

    Science.gov (United States)

    Norris, Leigh Morgan

    Large atomic ensembles interacting with light are one of the most promising platforms for quantum information processing. In the past decade, novel applications for these systems have emerged in quantum communication, quantum computing, and metrology. Essential to all of these applications is the controllability of the atomic ensemble, which is facilitated by a strong coupling between the atoms and light. Non-classical spin squeezed states are a crucial step in attaining greater ensemble control. The degree of entanglement present in these states, furthermore, serves as a benchmark for the strength of the atom-light interaction. Outside the broader context of quantum information processing with atomic ensembles, spin squeezed states have applications in metrology, where their quantum correlations can be harnessed to improve the precision of magnetometers and atomic clocks. This dissertation focuses upon the production of spin squeezed states in large ensembles of cold trapped alkali atoms interacting with optical fields. While most treatments of spin squeezing consider only the case in which the ensemble is composed of two level systems or qubits, we utilize the entire ground manifold of an alkali atom with hyperfine spin f greater than or equal to 1/2, a qudit. Spin squeezing requires non-classical correlations between the constituent atomic spins, which are generated through the atoms' collective coupling to the light. Either through measurement or multiple interactions with the atoms, the light mediates an entangling interaction that produces quantum correlations. Because the spin squeezing treated in this dissertation ultimately originates from the coupling between the light and atoms, conventional approaches of improving this squeezing have focused on increasing the optical density of the ensemble. The greater number of internal degrees of freedom and the controllability of the spin-f ground hyperfine manifold enable novel methods of enhancing squeezing. In

  19. Experimental realization of real-time feedback-control of single-atom arrays

    Science.gov (United States)

    Kim, Hyosub; Lee, Woojun; Ahn, Jaewook

    2016-05-01

    Deterministic loading of neutral atoms on particular locations has remained a challenging problem. Here we show, in a proof-of-principle experimental demonstration, that such deterministic loading can be achieved by rearrangement of atoms. In the experiment, cold rubidium atom were trapped by optical tweezers, which are the hologram images made by a liquid-crystal spatial light modulator (LC-SLM). After the initial occupancy was identified, the hologram was actively controlled to rearrange the captured atoms on to unfilled sites. For this, we developed a new flicker-free hologram algorithm that enables holographic atom translation. Our demonstration show that up to N=9 atoms were simultaneously moved in the 2D plane with the movable degrees of freedom of 2N=18 and the fidelity of 99% for single-atom 5- μm translation. It is hoped that our in situ atom rearrangement becomes useful in scaling quantum computers. Samsung Science and Technology Foundation [SSTF-BA1301-12].

  20. An Apparatus for the Measurement of Various Scattering Processes in Intermediate Energy, Ion - Atom Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Kvale, T. J.; Seely, D. G.

    1998-07-01

    This paper summarizes the main features of an apparatus constructed at the University of Toledo for the study of various scattering processes in intermediate energy, ion - atom collisions. The main purpose of this facility is to provide experimental data which serve as benchmarks to test current scattering theories for those processes. Recent measurements of single electron detachment (SED) and double electron detachment (DED) total cross sections for 5-50 keV H{sup -} ions incident on noble gases and for 10-50 keV H{sup -} ions incident on CH{sub 4} molecules were conducted in this laboratory. As a result of an analysis of the scattered beam growth curves, information about other charge-changing cross sections in the hydrogen-atom (molecule) collision systems were obtain, as well.

  1. Software development agreement between CERN and the Indian Department of Atomic Energy

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The development and prototyping work for the LHC computing facility is being organised as a project that includes many scientific institutes and industrial partners, coordinated by CERN. The project is nicknamed LCG (after LHC Computing Grid). Addendum No. 1 to the Protocol dated 24/09/02 to the 1991 co-operation agreement between CERN and the Department of Atomic Energy (DAE) of the Government of India defines the collaboration between CERN and DAE on software development for the LCG Prototype Project. Photo 01: Signing the addendum are G. Govindrajan (left), Director of the Electronics and Instrumentation Group at the Bhabha Atomic Research Centre, Mumbai, India and Dr. Hans Hoffmann, CERN Director for Technology Transfer and for Scientific Computing. Looking on are Christoph Eck (far left), resource manager of the LCG Project and Les Robertson, LCG Project Leader. Photo 02: (left to right) Christoph Eck, resource manager of the LCG Project; G. Govindrajan, Director of the Electronics and Instrumentation G...

  2. Software development agreement between CERN and the Indian Department of Atomic Energy

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The development and prototyping work for the LHC computing facility is being organised as a project that includes many scientific institutes and industrial partners, coordinated by CERN. The project is nicknamed LCG (after LHC Computing Grid). Addendum No. 1 to the Protocol dated 24/09/02 to the 1991 co-operation agreement between CERN and the Department of Atomic Energy (DAE) of the Government of India defines the collaboration between CERN and DAE on software development for the LCG Prototype Project. Signing the addendum are G. Govindrajan (left), Director of the Electronics and Instrumentation Group at the Bhabha Atomic Research Centre, Mumbai, India and Dr. Hans Hoffmann, CERN Director for Technology Transfer and for Scientific Computing.

  3. Demystifying Introductory Chemistry. Part 4: An Approach to Reaction Thermodynamics through Enthalpies, Entropies, and Free Energies of Atomization.

    Science.gov (United States)

    Spencer, James N.; And Others

    1996-01-01

    Presents an alternative approach to teaching reaction thermodynamics in introductory chemistry courses using calculations of enthalpies, entropies, and free energies of atomization. Uses a consistent concept, that of decomposition of a compound to its gaseous atoms, to discuss not only thermodynamic parameters but also equilibrium and…

  4. 78 FR 56944 - Strata Energy, Inc. (Ross In Situ Recovery Uranium Project); Notice of Atomic Safety and...

    Science.gov (United States)

    2013-09-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Strata Energy, Inc. (Ross In Situ Recovery Uranium Project); Notice of Atomic Safety and Licensing Board Reconstitution Pursuant to 10 CFR 2.313(c) and 2.321(b), the Atomic Safety and Licensing...

  5. Development and Applications for the Remote Controllable Atomic Force Microscope

    Science.gov (United States)

    Fornaro, P.; Guggisberg, M.; Gyalog, T.; Wattinger, Ch.; Meyer, E.; Güntherodt, H.-J.

    2003-12-01

    We present a fully remote controllable AFM, featuring a motorized four-axis sample stage. The low cost robotics allows a fast and accurate change of pre-defined positions. Due to the software interface the instrument can be programmed to perform sequences of measurements. This allows the automated acquisition of large scale high resolution images. The instrument can be controlled and monitored from various locations using a standard network interface.

  6. Nutrients, satiety, and control of energy intake.

    Science.gov (United States)

    Tremblay, Angelo; Bellisle, France

    2015-10-01

    In the context of the worldwide epidemic of obesity affecting men and women of all ages, it is important to understand the mechanisms that control human appetite, particularly those that allow the adjustment of energy intake to energy needs. Satiety is one important psycho-biological mechanism whose function is to inhibit intake following the ingestion of a food or a beverage. According to the classical theories of appetite control, satiety is influenced by macronutrient intake and/or metabolism. Satiety also seems to be modified by micronutrients, non-nutrients, and some bioactive food constituents. Under optimal conditions, satiety should be well connected with hunger and satiation in a way that spontaneously leads to a close match between energy intake and expenditures. However, the current obesity epidemic suggests that dysfunctions often affect satiety and energy intake. In this regard, this paper presents a conceptual integration that hopefully will help health professionals address satiety issues and provide the public with informed advice to facilitate appetite control.

  7. On the combination of a low energy hydrogen atom beam with a cold multipole ion trap

    Energy Technology Data Exchange (ETDEWEB)

    Borodi, Gheorghe

    2008-12-09

    The first part of the activities of this thesis was to develop a sophisticated ion storage apparatus dedicated to study chemical processes with atomic hydrogen. The integration of a differentially pumped radical beam source into an existing temperature variable 22- pole trapping machine has required major modifications. Since astrophysical questions have been in the center of our interest, the introduction first gives a short overview of astrophysics and -chemistry. The basics of ion trapping in temperature variable rf traps is well-documented in the literature; therefore, the description of the basic instrument (Chapter 2) is kept rather short. Much effort has been put into the development of an intense and stable source for hydrogen atoms the kinetic energy of which can be changed. Chapter 3 describes this module in detail with emphasis on the integration of magnetic hexapoles for guiding the atoms and special treatments of the surfaces for reducing H-H recombination. Due to the unique sensitivity of the rf ion trapping technique, this instrument allows one to study a variety of reactions of astrochemical and fundamental interest. The results of this work are summarized in Chapter 4. Reactions of CO{sub 2}{sup +} with hydrogen atoms and molecules have been established as calibration standard for in situ determination of H and H{sub 2} densities over the full temperature range of the apparatus (10 K-300 K). For the first time, reactions of H- and D-atoms with the ionic hydrocarbons CH{sup +}, CH{sub 2}{sup +}, and CH{sub 4}{sup +} have been studied at temperatures of interstellar space. A very interesting, not yet fully understood collision system is the interaction of protonated methane with H. The outlook presents some ideas, how to improve the new instrument and a few reaction systems are mentioned which may be studied next. (orig.)

  8. Dorsomedial hypothalamic NPY and energy balance control.

    Science.gov (United States)

    Bi, Sheng; Kim, Yonwook J; Zheng, Fenping

    2012-12-01

    Neuropeptide Y (NPY) is a potent hypothalamic orexigenic peptide. Within the hypothalamus, Npy is primarily expressed in the arcuate nucleus (ARC) and the dorsomedial hypothalamus (DMH). While the actions of ARC NPY in energy balance control have been well studied, a role for DMH NPY is still being unraveled. In contrast to ARC NPY that serves as one of downstream mediators of actions of leptin in maintaining energy homeostasis, DMH NPY is not under the control of leptin. Npy gene expression in the DMH is regulated by brain cholecystokinin (CCK) and other yet to be identified molecules. The findings of DMH NPY overexpression or induction in animals with increased energy demands and in certain rodent models of obesity implicate a role for DMH NPY in maintaining energy homeostasis. In support of this view, adeno-associated virus (AAV)-mediated overexpression of NPY in the DMH causes increases in food intake and body weight and exacerbates high-fat diet-induced hyperphagia and obesity. Knockdown of NPY in the DMH via AAV-mediated RNAi ameliorates hyperphagia, obesity and glucose intolerance of Otsuka Long-Evans Tokushima Fatty rats in which DMH NPY overexpression has been proposed to play a causal role. NPY knockdown in the DMH also prevents high-fat diet-induced hyperphagia, obesity and impaired glucose homeostasis. A detailed examination of actions of DMH NPY reveals that DMH NPY specifically affects nocturnal meal size and produces an inhibitory action on within meal satiety signals. In addition, DMH NPY modulates energy expenditure likely through affecting brown adipocyte formation and thermogenic activity. Overall, the recent findings provide clear evidence demonstrating critical roles for DMH NPY in energy balance control, and also imply a potential role for DMH NPY in maintaining glucose homeostasis.

  9. Control of light trapping in a large atomic system by a static magnetic field

    CERN Document Server

    Skipetrov, S E; Havey, M D

    2016-01-01

    We propose to control light trapping in a large ensemble of cold atoms by an external, static magnetic field. For an appropriate choice of frequency and polarization of the exciting pulse, the field is expected to speed up the fluorescence of a dilute atomic system but can significantly slow it down in a dense ensemble. The slowing down of fluorescence is due to the excitation of spatially localized collective atomic states that appear only under a strong magnetic field and have exponentially long lifetimes. The control of fluorescence by the magnetic field may be of interest for use in future quantum-information processing devices. It also paves a way towards the experimental observation of the disorder-induced localization of light in cold atomic systems.

  10. Electromagnetically induced transparency and controllable group velocity in a five-level atomic system

    Institute of Scientific and Technical Information of China (English)

    Lihui Jin; Shangqing Gong; Yueping Niu; Shiqi Jin

    2006-01-01

    @@ The optical properties of a five-level atomic system composed of a A-type four-level atomic and a tripod four-level atomic systems are investigated. It is found that the behaviors of electromagnetically induced transparency (EIT) and group velocity can be controlled by choosing appropriate parameters with the interacting dark resonances. In particular, when all the fields are on resonance, the slow light at the symmetric transparency windows with a much broader EIT width is obtained by tuning the intensity of the coupling field in comparison with its sub-system, which provides potential applications in quantum storage and retrieval of light.

  11. Controllable Persistent Atom Current of Bose-Einstein Condensates in an Optical Lattice Ring

    Institute of Scientific and Technical Information of China (English)

    ZHENG Gong-Ping; LIANG Jiu-Qing

    2005-01-01

    In this paper the macroscopic quantum state of Bose-Einstein condensates in optical lattices is studied by solving the periodic Gross-Pitaevskii equation in one-dimensional geometry. It is shown that an exact solution seen to be a travelling wave of excited macroscopic quantum states resultes in a persistent atom current, which can be controlled by adjusting of the barrier height of the optical periodic potential. A critical condition to generate the travelling wave is demonstrated and we moreover propose a practical experiment to realize the persistent atom current in a toroidal atom waveguide.

  12. Interference control of nonlinear excitation in a multi-atom cavity quantum electrodynamics system.

    Science.gov (United States)

    Yang, Guoqing; Tan, Zheng; Zou, Bichen; Zhu, Yifu

    2014-12-01

    We show that by manipulating quantum interference in a multi-atom cavity quantum electrodynamics (CQED) system, the nonlinear excitation of the cavity-atom polariton can be resonantly enhanced while the linear excitation is suppressed. Under the appropriate conditions, it is possible to selectively enhance or suppress the polariton excitation with two free-pace laser fields. We report on an experiment with cold Rb atoms in an optical cavity and present experimental results that demonstrate such interference control of the CQED excitation and its direct application to studies of all-optical switching and cross-phase modulation of the cavity-transmitted light.

  13. Jaynes-Cummings model with a collective atomic mode

    OpenAIRE

    Zheng, Shi-Biao

    2012-01-01

    We study the dynamics of a single control atom and an atomic sample interacting with a nonresonant cavity mode. The control atom is driven by an auxiliary classical field. Under certain conditions, the coherent energy exchange between the control atom and the atomic sample induced by the cavity mode is described by the Jaynes-Cummings model. The idea provides a possibility for quantum-state engineering and reconstruction for collective atomic modes.

  14. Controlling energy landscapes with correlations between minima

    CERN Document Server

    Pusuluri, Sai Teja; Mehta, Pankaj; Castillo, Horacio Emilio

    2016-01-01

    Neural network models have been used to construct energy landscapes for modeling biological phenomena, in which the minima of the landscape correspond to memory patterns stored by the network. Here, we show that dynamic properties of those landscapes, such as the sizes of the basins of attraction and the density of stable and metastable states, depend strongly on the correlations between the memory patterns and can be altered by introducing hierarchical structures. Our findings suggest dynamic features of energy landscapes can be controlled by choosing the correlations between patterns

  15. Solar energy control system. [temperature measurement

    Science.gov (United States)

    Currie, J. R. (Inventor)

    1981-01-01

    A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.

  16. Energy Efficiency of Distributed Environmental Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, H. Ezzat; Isik, Can; Dannenhoffer, John F. III

    2011-02-23

    In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant

  17. A model for energy transfer in collisions of atoms with highly excited molecules.

    Science.gov (United States)

    Houston, Paul L; Conte, Riccardo; Bowman, Joel M

    2015-05-21

    A model for energy transfer in the collision between an atom and a highly excited target molecule has been developed on the basis of classical mechanics and turning point analysis. The predictions of the model have been tested against the results of trajectory calculations for collisions of five different target molecules with argon or helium under a variety of temperatures, collision energies, and initial rotational levels. The model predicts selected moments of the joint probability distribution, P(Jf,ΔE) with an R(2) ≈ 0.90. The calculation is efficient, in most cases taking less than one CPU-hour. The model provides several insights into the energy transfer process. The joint probability distribution is strongly dependent on rotational energy transfer and conservation laws and less dependent on vibrational energy transfer. There are two mechanisms for rotational excitation, one due to motion normal to the intermolecular potential and one due to motion tangential to it and perpendicular to the line of centers. Energy transfer is found to depend strongly on the intermolecular potential and only weakly on the intramolecular potential. Highly efficient collisions are a natural consequence of the energy transfer and arise due to collisions at "sweet spots" in the space of impact parameter and molecular orientation.

  18. Role of low-energy ion irradiation in the formation of an aluminum germanate layer on a germanium substrate by radical-enhanced atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Yukio, E-mail: y-fukuda@rs.suwa.tus.ac.jp; Yamada, Daichi; Yokohira, Tomoya; Yanachi, Kosei [Tokyo University of Science, Suwa, 5000-1 Toyohira, Chino, Nagano 391-0292 (Japan); Yamamoto, Chiaya; Yoo, Byeonghak; Sato, Tetsuya [University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511 (Japan); Yamanaka, Junji [University of Yamanashi, 7-32 Miyamae, Kofu, Yamanashi 400-8511 (Japan); Takamatsu, Toshiyuki [SST Inc., 989-6 Shimadadai, Yachiyo, Chiba 276-0004 (Japan); Okamoto, Hiroshi [Hirosaki University, 3 Bunkyo, Hirosaki 036-8561 (Japan)

    2016-03-15

    Radical-enhanced atomic layer deposition uses oxygen radicals generated by a remote microwave-induced plasma as an oxidant to change the surface reactions of the alternately supplied trimethylaluminum precursor and oxygen radicals on a Ge substrate, which leads to the spontaneous formation of an aluminum germanate layer. In this paper, the effects that low-energy ions, supplied from a remote microwave plasma to the substrate along with the oxygen radicals, have on the surface reactions were studied. From a comparative study of aluminum oxide deposition under controlled ion flux irradiation on the deposition surface, it was found that the ions enhance the formation of the aluminum germanate layer. The plasma potential measured at the substrate position by the Langmuir probe method was 5.4 V. Assuming that the kinetic energy of ions arriving at the substrate surface is comparable to that gained by this plasma potential, such ions have sufficient energy to induce exchange reactions of surface-adsorbed Al atoms with the underlying Ge atoms without causing significant damage to the substrate. This ion-induced exchange reaction between Al and Ge atoms is inferred to be the background kinetics of the aluminum germanate formation by radical-enhanced atomic layer deposition.

  19. Evaluation of atomic electron binding energies for Monte Carlo particle transport

    CERN Document Server

    Pia, Maria Grazia; Batic, Matej; Begalli, Marcia; Kim, Chan Hyeong; Quintieri, Lina; Saracco, Paolo

    2011-01-01

    A survey of atomic binding energies used by general purpose Monte Carlo systems is reported. Various compilations of these parameters have been evaluated; their accuracy is estimated with respect to experimental data. Their effects on physics quantities relevant to Monte Carlo particle transport are highlighted: X-ray fluorescence emission, electron and proton ionization cross sections, and Doppler broadening in Compton scattering. The effects due to different binding energies are quantified with respect to experimental data. The results of the analysis provide quantitative ground for the selection of binding energies to optimize the accuracy of Monte Carlo simulation in experimental use cases. Recommendations on software design dealing with these parameters and on the improvement of data libraries for Monte Carlo simulation are discussed.

  20. Channel adaptive rate control for energy optimization

    Institute of Scientific and Technical Information of China (English)

    BLANCH Carolina; POLLIN Sofie; LAFRUIT Gauthier; EBERLE Wolfgang

    2006-01-01

    Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.

  1. APPLICATION OF CORRELATION—POLARIZA TION POTENTIAL TO THE LOW—ENERGY ELECTRON SCATTERING WITH ATOMS AND MOLECULES

    Institute of Scientific and Technical Information of China (English)

    Zhijie; JianminYuan

    1990-01-01

    Applicability of the correlation potential,which is currently used in the local density functional theory,to the low-energy electron-atom and molecule scattering is investigated with some examples of scattering processes.

  2. Surface Magnetism of Cobalt Nanoislands Controlled by Atomic Hydrogen.

    Science.gov (United States)

    Park, Jewook; Park, Changwon; Yoon, Mina; Li, An-Ping

    2017-01-11

    Controlling the spin states of the surface and interface is key to spintronic applications of magnetic materials. Here, we report the evolution of surface magnetism of Co nanoislands on Cu(111) upon hydrogen adsorption and desorption with the hope of realizing reversible control of spin-dependent tunneling. Spin-polarized scanning tunneling microscopy reveals three types of hydrogen-induced surface superstructures, 1H-(2 × 2), 2H-(2 × 2), and 6H-(3 × 3), with increasing H coverage. The prominent magnetic surface states of Co, while being preserved at low H coverage, become suppressed as the H coverage level increases, which can then be recovered by H desorption. First-principles calculations reveal the origin of the observed magnetic surface states by capturing the asymmetry between the spin-polarized surface states and identify the role of hydrogen in controlling the magnetic states. Our study offers new insights into the chemical control of magnetism in low-dimensional systems.

  3. Coherent-feedback Quantum Control with Cold Atomic Spins

    Science.gov (United States)

    2012-08-27

    Coherent Feedback Control," GRC on Physics Research and Education, Mt. Holyoke College, August 2011 H. Mabuchi, "Design and analysis of autonomous...technique for compensation of tensor coupling effects in polarization spectroscopy of dense Cesium clouds , based on dual-wavelength probing with

  4. Minimum energy control and optimal-satisfactory control of Boolean control network

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fangfei, E-mail: li_fangfei@163.com; Lu, Xiwen

    2013-12-09

    In the literatures, to transfer the Boolean control network from the initial state to the desired state, the expenditure of energy has been rarely considered. Motivated by this, this Letter investigates the minimum energy control and optimal-satisfactory control of Boolean control network. Based on the semi-tensor product of matrices and Floyd's algorithm, minimum energy, constrained minimum energy and optimal-satisfactory control design for Boolean control network are given respectively. A numerical example is presented to illustrate the efficiency of the obtained results.

  5. New atomic energy law - international and national developments. Proceedings; Neues Atomenergierecht - internationale und nationale Entwicklungen. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, N. [ed.] [Goettingen Univ. (Germany). Inst. fuer Voelkerrecht

    1995-12-31

    Two of the working sessions of the meeting were devoted to aspects of international atomic energy law; the international character of the meeting was also reflected by the home countries of the members of the panel discussion concluding the working sessions. There was substantial reason to put emphasis on the international dimension of the topics discussed. In June 1994, the Nuclear Safety Convention had been signed in Vienna by diplomatic representatives of the signatory countries, and this Convention marks a signpost in the history of international atomic energy law. At the time the meeting was held, negotiations for improving the international nuclear lability law, which had been dragging on since 1989, had come to a stalemate. The meeting offered a suitable forum for taking a scientific approach to tackle the complex problems involved in reshaping the law on nuclear safety and nuclear liability. The third working session of the meeting has been discussing topics relating to the implementation of the German Atomgesetz (Atomic Energy Act). (orig./HP) [Deutsch] Zwei der Arbeitssitzungen waren Fragen des internationalen Atomenergierechts gewidmet; auch die Zusammensetzung der Teilnehmer des abschliessenden Rundtischgespraechs wiesen die internationalen Aspekte als den Schwerpunkt der Veranstaltung aus. Fuer diese Gewichtung bestand begruendeter Anlass. Im Juni 1994 hatte eine diplomatische Konferenz in Wien die sogenannte Nukleare Sicherheitskonvention verabschiedet, die einen Meilenstein in der Entwicklung des internationalen Atomrechts darstellt. Die bereits seit 1989 andauernden Verhandlungen zur Verbesserung des internationalen Atomhaftungsrechts fanden sich zur Zeit der Tagung in einer krisenhaften Situation. Dies bot Anlass zur wissenschaftlichen Aufarbeitung der Komplexe nukleare Sicherheit und Atomhaftungsrecht. In einer dritten Arbeitssitzung wurden aktuelle Themen aus dem Bereich des Vollzugs des Atomgesetzes eroertert. (orig./HP)

  6. Atomic-powered democracy: Policy against politics in the quest for American nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.W.

    1993-01-01

    This dissertation focuses on the relationship of American nuclear energy to democracy. It examines whether the nuclear policy processes have furthered the legitimacy-government accountability and citizen participation-which the democratic institutes are based. Nuclear policy and its institutions have placed severe limitations on democratic practices. Contravened democracy is seen most clearly in the decoupling of policy from politics. Decoupling refers to the weakening of institutional linkages between citizens and government, and to the erosion of the norms that ground liberal democracy. Decoupling is manifested in policy centralization, procedural biases, technical rationality, and the spatial displacement of conflict. Decoupling has normative implications: While federal accountability was limited and citizen participation was shackled, other major groups enjoyed privileged access to policy making. The decoupling of nuclear policy from politics arose within the context of US liberal-democratic capitalism. The federal government pursued its own goals of defense and world leadership. Yet, it was not structurally autonomous from the hegemony of the political-economic context. Economically, the Atomic Energy Act did not permit federal agencies to directly invest in power plant construction, and did not authorize them to commercially generate electricity. Private industry was structurally placed to domesticate the atom. Politically, the liberal-democratic system hampered an unquestioning pursuit of atomic energy. Federal institutions have been forced to heed some of the anti-nuclear concerns. The pervasive influence of the US political economy on nuclear policy has come to transgress democracy. Nuclear power's growth faltered during the 1970s. The political and economic constraints on federal actions have limited the means available to revive a becalmed nuclear industry; this has exerted strong pressure on federal institutions to decouple policy from

  7. ELENA MCP detector: absolute detection efficiency for low-energy neutral atoms

    Science.gov (United States)

    Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J. A.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

    2012-09-01

    Microchannel Plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission of ESA to Mercury to be launched in 2015. ELENA is a Time of Flight (TOF) sensor, based on a novel concept using an ultra-sonic oscillating shutter (Start section), which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop detector. The scientific objective of ELENA is to detect energetic neutral atoms in the range 10 eV - 5 keV, within 76° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the plasma environment and the planet’s surface, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles released from the surface, via solar wind-induced ion sputtering (MEFISTO facility of the Physical Institute of the University of Bern (CH), measurements on three different types of MCP (with and without coating) have been performed providing the detection efficiencies in the energy range 10eV - 1keV. Outcomes from such measurements are discussed here.

  8. Application of an excited state LDA exchange energy functional for the calculation of transition energy of atoms within time-independent density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Shamim, Md; Harbola, Manoj K, E-mail: sami@iitk.ac.i, E-mail: mkh@iitk.ac.i [Department of Physics, Indian Institute of Technology, Kanpur 208 016 (India)

    2010-11-14

    Transition energies of a new class of excited states (two-gap systems) of various atoms are calculated in time-independent density functional formalism by using a recently proposed local density approximation exchange energy functional for excited states. It is shown that the excitation energies calculated with this functional compare well with those calculated with exact exchange theories.

  9. Adaptive control of solar energy collector systems

    CERN Document Server

    Lemos, João M; Igreja, José M

    2014-01-01

    This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts

  10. The University of Rochester Atomic Energy Project quarterly report, April 1, 1950--June 30, 1950

    Energy Technology Data Exchange (ETDEWEB)

    Blair, H.A.

    1950-12-31

    This quarterly progress report gives an overview of the University of Rochester Atomic Energy Project for April 1, 1950 thru June 30, 1950. Sections included are entitled (1) Biological Effects of External Radiation (X-rays and gamma rays), (2) Biological Effects of External Radiation (Infra-red and ultraviolet), (3) Biological effects of radioactive materials (polonium, radon, thoron, and miscellaneous project materials), (4) Uranium, (5) Beryllium, (7) thorium, (8) fluoride, (9) zirconium, (10) special materials, (11) Isotopes, (12) Outside services, (12) Project health, (13) Health physics, (14) Special Clinical Service, and (15) Instrumentation (Spectroscopy, electron microscopy, x-ray and nuclear radiation detectors, x-ray diffraction, and electronics).

  11. Atomic layer epitaxy of hematite on indium tin oxide for application in solar energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, Alex B.; Riha, Shannon; Guo, Peijun; Emery, Jonathan D.

    2016-07-12

    A method to provide an article of manufacture of iron oxide on indium tin oxide for solar energy conversion. An atomic layer epitaxy method is used to deposit an uncommon bixbytite-phase iron (III) oxide (.beta.-Fe.sub.2O.sub.3) which is deposited at low temperatures to provide 99% phase pure .beta.-Fe.sub.2O.sub.3 thin films on indium tin oxide. Subsequent annealing produces pure .alpha.-Fe.sub.2O.sub.3 with well-defined epitaxy via a topotactic transition. These highly crystalline films in the ultra thin film limit enable high efficiency photoelectrochemical chemical water splitting.

  12. Current and anticipated uses of thermal hydraulic codes at the Japan Atomic Energy Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Akimoto, Hajime; Kukita; Ohnuki, Akira [Japan Atomic Energy Research Institute, Ibaraki (Japan)

    1997-07-01

    The Japan Atomic Energy Research Institute (JAERI) is conducting several research programs related to thermal-hydraulic and neutronic behavior of light water reactors (LWRs). These include LWR safety research projects, which are conducted in accordance with the Nuclear Safety Commission`s research plan, and reactor engineering projects for the development of innovative reactor designs or core/fuel designs. Thermal-hydraulic and neutronic codes are used for various purposes including experimental analysis, nuclear power plant (NPP) safety analysis, and design assessment.

  13. Scaled-energy spectroscopy of helium \\|M\\|=1 Rydberg atoms in a static electric field

    Science.gov (United States)

    Kips, Annemieke; Vassen, Wim; Hogervorst, Wim; Dando, Paul A.

    1998-10-01

    We present scaled-energy spectra on helium Rydberg atoms in a static electric field. \\|M\\|=1 states were studied in excitation from the 2 1S0 metastable state. Spectra were recorded for ɛ=-2.940(4), ɛ=-2.350(4), both below the saddle point, and ɛ=-1.760(4), above the saddle point. Closed-orbit theory was applied to interpret the spectra. A recent extension to closed-orbit theory, incorporating core effects, was used. This significantly improved agreement between experiment and theory.

  14. X-alpha calculation of transition energies in multiply ionized atoms

    Science.gov (United States)

    Ringers, D. A.; Chen, M. H.

    1974-01-01

    It is shown that the accuracy of calculations can be improved if appropriate (different) values of alpha are used for each configuration. Alternatively, the Slater Transition state can be used, wherein a total energy difference is related to a difference in single electron eigenvalues. By a series expansion, the value of alpha for an excited configuration can be related to its value for the ground state configuration. The terms Delta alpha (delta Epsilon/delta alpha) exhibit a similar dependence on atomic number as the ground state values of alpha. Results of sample calculations are reported and compared with experiment.

  15. Energy landscape investigation by wavelet transform analysis of atomic force spectroscopy data in a biorecognition experiment.

    Science.gov (United States)

    Bizzarri, Anna Rita

    2016-01-01

    Force fluctuations recorded in an atomic force spectroscopy experiment, during the approach of a tip functionalized with biotin towards a substrate charged with avidin, have been analyzed by a wavelet transform. The observation of strong transient changes only when a specific biorecognition process between the partners takes place suggests a drastic modulation of the force fluctuations when biomolecules recognize each other. Such an analysis allows to investigate the peculiar features of a biorecognition process. These results are discussed in connection with the possible role of energy minima explored by biomolecules during the biorecognition process.

  16. Real-time study of the adiabatic energy loss in an atomic collision with a metal cluster.

    Science.gov (United States)

    Baer, Roi; Siam, Nidal

    2004-10-01

    Gas-phase hydrogen atoms are accelerated towards metallic surfaces in their vicinity. As it approaches the surface, the velocity of an atom increases and this motion excites the metallic electrons, causing energy loss to the atom. This dissipative dynamics is frequently described as atomic motion under friction, where the friction coefficient is obtained from ab initio calculations assuming a weak interaction and slow atom. This paper tests the aforementioned approach by comparing to a real-time Ehrenfest molecular dynamics simulation of such a process. The electrons are treated realistically using standard approximations to time-dependent density functional theory. We find indeed that the electronic excitations produce a friction-like force on the atom. However, the friction coefficient strongly depends on the direction of the motion of the atom: it is large when the atom is moving towards the cluster and much smaller when the atom is moving away. It is concluded that a revision of the model for energy dissipation at metallic surfaces, at least for clusters, may be necessary.

  17. Controlling Atomic, Solid-State and Hybrid Systems for Quantum Information Processing

    Science.gov (United States)

    2013-09-04

    determines the energy scale of the associated many-body atomic states (Buluta and Nori , 2009; Yi et al., 2008; Leung et al., 2012; Lewenstein et al., 2012...Botter, S. Schreppler, T. Purdy, N. Brahms, and D. Stamper-Kurn. Nature, 488:476, 2012. I. Buluta and F. Nori . Science, 326:108, 2009. T. Busch, B.G

  18. Atomic data for controlled fusion research. Volume IV. Spectroscopic data for iron

    Energy Technology Data Exchange (ETDEWEB)

    Wiese, W.L. (ed.)

    1985-02-01

    Comprehensive spectroscopic data tables are presented for all ions of Fe. Tables of ionization potentials, wave lengths of spectral lines, atomic energy levels, and transition probabilities are given which were excerpted from general critical compilations. All utilized compilations are less than five years old and include data on electric dipole as well as magnetic dipole transitions.

  19. Enhanced creation of dispersive monolayer phonons in Xe/Pt(111) by inelastic helium atom scattering at low energies

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Bruch, Ludwig Walter

    2007-01-01

    Conditions likely to lead to enhanced inelastic atomic scattering that creates shear horizontal (SH) and longitudinal acoustic (LA) monolayer phonons are identified, specifically examining the inelastic scattering of He-4 atoms by a monolayer solid of Xe/Pt(111) at incident energies of 2-25 me...... an absorbing potential at large distance. The times now extend to beyond 100 ps and enable a clarification of processes involving transient trapping of the He atoms. The wave packet is made more monochromatic by significantly increasing the spatial width of the initial Gaussian shape. The narrower energy...

  20. Low-energy electron elastic scattering from Os atom: New electron affinity

    Science.gov (United States)

    Felfli, Z.; Kiros, F.; Msezane, A. Z.

    2013-05-01

    Bilodeau and Haugan measured the binding energies (BEs) of the ground state and the excited state of the Os- ion to be 1.07780(12) eV and 0.553(3) eV, respectively. These values are consistent with those calculated in. Here our investigation, using the recent complex angular momentum methodology wherein is embedded the crucial electron-electron correlations and the vital core polarization interaction, has found that the near threshold electron-Os elastic scattering total cross section (TCS) is characterized by three stable bound states of the Os- ion formed as resonances during the slow electron collision, with BEs of 1.910 eV, 1.230 eV and 0.224 eV. The new extracted electron affinity (EA) value from the TCS of 1.910 eV for the Os atom is significantly different from that measured in. Our calculated elastic differential cross sections (DCSs) also yield the relevant BEs for the ground and the two excited states of the Os- ion. The complex characteristic resonance structure in the TCS for the Os atom is ideal for catalysis, but makes it difficult to execute the Wigner threshold law in describing the threshold detachment behavior of complex atoms and extracting the reliable attendant EAs. Supported by U.S. DOE, AFOSR and CAU CFNM, NSF-CREST Program.

  1. A Terrestrial Search for Dark Contents of the Vacuum, Such as Dark Energy, Using Atom Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Adler, Ronald J.; /Stanford U., HEPL /San Francisco State U.; Muller, Holger; /UC, Berkeley; Perl, Martin L.; /KIPAC, Menlo Park /SLAC

    2012-06-11

    We describe the theory and first experimental work on our concept for searching on earth for the presence of dark contents of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but which might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong nongravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO. The paper concludes with a projection that a future search of this nature might be carried out using an atom interferometer in an orbiting satellite. The laboratory apparatus is now being constructed.

  2. Magnetizabilities of relativistic hydrogenlike atoms in some arbitrary discrete energy eigenstates

    CERN Document Server

    Stefańska, Patrycja

    2016-01-01

    We present the results of numerical calculations of magnetizability ($\\chi$) of the relativistic one-electron atoms with a pointlike, spinless and motionless nuclei of charge $Ze$. Exploiting the analytical formula for $\\chi$ recently derived by us [P. Stefa{\\'n}ska, 2015], valid for an arbitrary discrete energy eigenstate, we have found the values of the magnetizability for the ground state and for the first and the second set of excited states (i.e.: $2s_{1/2}$, $2p_{1/2}$, $2p_{3/2}$, $3s_{1/2}$, $3p_{1/2}$, $3p_{3/2}$, $3d_{3/2}$, and $3d_{5/2}$) of the Dirac one-electron atom. The results for ions with the atomic number $1 \\leqslant Z \\leqslant 137$ are given in 14 tables. The comparison of the numerical values of magnetizabilities for the ground state and for each states belonging to the first set of excited states of selected hydrogenlike ions, obtained with the use of two different values of the fine-structure constant, i.e.: $\\alpha^{-1}=137.035 999 139$ (CODATA 2014) and $\\alpha^{-1}=137.035 999 074...

  3. Digitalisation in atomic pile control (1962); La digitalisation dans le controle des piles atomiques (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Furet, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    A brief survey is first given of the general theorems of Boodle's algebra and of sequence systems using D.A. Huffmans theory. Some indications are then given concerning the setting-up and the operation of digital computers and also of the principal codes used in digital techniques. It is then shown how digitalisation in atomic pile control makes it possible to use new techniques having the following advantages in particular: greater working safety, a higher degree of centralisation, and suppression of the linear elements. A few examples are given of the application of these techniques to control, particularly with respect to the measurement of the neutronic power and of the period and also of course, to the treatment of the data and the sequence automatisms. The advantage of using digital techniques in the shutdown channels is also examined. Finally a review is given of the technology and the viability of the control devices used. (author) [French] On rappelle d'abord ici les theoremes generaux de l'algebre de Boole et des systemes a sequences en s'appuyant sur la theorie de D.A. Huffmann. On donne ensuite quelques indications sur l'agencement et le fonctionnement des calculateurs digitaux ainsi que les principaux codes utilises dans les techniques digitales. On montre alors comment la digitalisation dans le controle des piles atomiques permet d'utiliser de nouvelles techniques presentant principalement les avantages suivants: securite de fonctionnement plus grande, centralisation plus elevee et suppression des elements lineaires. Un certain nombre d'exemples sont donnes sur l'application de ces techniques au controle, particulierement en ce qui concerne la mesure de la puissance neutronique, de la periode et aussi bien entendu du traitement des informations et des automatismes a sequences. On analyse aussi l'avantage de l'utilisation des techniques digitales dans les chaines de securite. Enfin, un apercu est donne

  4. Efficient polarization insensitive complex wavefront control using Huygens' metasurfaces based on dielectric resonant meta-atoms

    CERN Document Server

    Chong, Katie E; Staude, Isabelle; James, Anthony; Dominguez, Jason; Liu, Sheng; Subramania, Ganapathi S; Decker, Manuel; Neshev, Dragomir N; Brener, Igal; Kivshar, Yuri S

    2016-01-01

    Subwavelength-thin metasurfaces have shown great promises for the control of optical wavefronts, thus opening new pathways for the development of efficient flat optics. In particular, Huygens' metasurfaces based on all-dielectric resonant meta-atoms have already shown a huge potential for practical applications with their polarization insensitivity and high transmittance efficiency. Here, we experimentally demonstrate a polarization insensitive holographic Huygens' metasurface based on dielectric resonant meta-atoms capable of complex wavefront control at telecom wavelengths. Our metasurface produces a hologram image in the far-field with 82% transmittance efficiency and 40% imaging efficiency. Such efficient complex wavefront control shows that Huygens' metasurfaces based on resonant dielectric meta-atoms are a big step towards practical applications of metasurfaces in wavefront design related technologies, including computer-generated holograms, ultra-thin optics, security and data storage devices.

  5. Control of light trapping in a large atomic system by a static magnetic field

    Science.gov (United States)

    Skipetrov, S. E.; Sokolov, I. M.; Havey, M. D.

    2016-07-01

    We propose to control light trapping in a large ensemble of cold atoms by an external, static magnetic field. For an appropriate choice of frequency and polarization of the exciting pulse, the field is expected to speed up the fluorescence of a dilute atomic system. In a dense ensemble, the field does not affect the early-time superradiant signal but amplifies intensity oscillations at intermediate times and induces a very slow, nonexponential long-time decay. The slowing down of fluorescence is due to the excitation of spatially localized collective atomic states that appear only under a strong magnetic field and have exponentially long lifetimes. Our results therefore pave a way towards experimental observation of the disorder-induced localization of light in cold atomic systems.

  6. Concept of effective atomic number and effective mass density in dual-energy X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bonnin, Anne, E-mail: annebonnin@free.fr [ESRF, 6 Jules Horowitz, F-38073 Grenoble Cedex (France); LVA, Vibrations and Acoustic Laboratory, INSA-Lyon, Université de Lyon, F-69621 Villeurbanne Cedex (France); Duvauchelle, Philippe, E-mail: philippe.duvauchelle@insa-lyon.fr [LVA, Vibrations and Acoustic Laboratory, INSA-Lyon, Université de Lyon, F-69621 Villeurbanne Cedex (France); Kaftandjian, Valérie [LVA, Vibrations and Acoustic Laboratory, INSA-Lyon, Université de Lyon, F-69621 Villeurbanne Cedex (France); Ponard, Pascal [Thales Electron Devices SAS, 2 Rue Marcel Dassault, BP23 78141 Vélizy, Villacoublay Cedex (France)

    2014-01-01

    This paper focuses on dual-energy X-ray computed tomography and especially the decomposition of the measured attenuation coefficient in a mass density and atomic number basis. In particular, the concept of effective atomic number is discussed. Although the atomic number is well defined for chemical elements, the definition of an effective atomic number for any compound is not an easy task. After reviewing different definitions available in literature, a definition related to the method of measurement and X-ray energy, is suggested. A new concept of effective mass density is then introduced in order to characterize material from dual-energy computed tomography. Finally, this new concept and definition are applied on a simulated case, focusing on explosives identification in luggage.

  7. Self-Energy Correction to the Two-Photon Decay Width in Hydrogenlike Atoms

    CERN Document Server

    Jentschura, U D

    2004-01-01

    We investigate the gauge invariance of the leading logarithmic radiative correction to the two-photon decay width in hydrogenlike atoms. It is shown that an effective treatment of the correction using a Lamb-shift "potential" leads to equivalent results in both the length as well as the velocity gauges provided all relevant correction terms are taken into account. Specifically, the relevant radiative corrections are related to the energies that enter into the propagator denominators, to the Hamiltonian, to the wave functions, and to the energy conservation condition that holds between the two photons; the form of all of these effects is different in the two gauges, but the final result is shown to be gauge invariant, as it should be. Although the actual calculation only involves integrations over nonrelativistic hydrogenic Green functions, the derivation of the leading logarithmic correction can be regarded as slightly more complex than that of other typical logarithmic terms. The dominant radiative correctio...

  8. Atomic structure of "multilayer silicene" grown on Ag(111): Dynamical low energy electron diffraction analysis

    Science.gov (United States)

    Kawahara, Kazuaki; Shirasawa, Tetsuroh; Lin, Chun-Liang; Nagao, Ryo; Tsukahara, Noriyuki; Takahashi, Toshio; Arafune, Ryuichi; Kawai, Maki; Takagi, Noriaki

    2016-09-01

    We have investigated the atomic structure of the "multilayer silicene" grown on the Ag(111) single crystal surface by using low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). We measured the intensity of the LEED spot as a function of the incident electron energy (I-V curve) and analyzed the I-V curve using a dynamical LEED theory. We have found that the Si(111)(√{ 3} ×√{ 3})-Ag model well reproduces the I-V curve whereas the models consisting of the honeycomb structure of Si do not. The bias dependence of the STM image of multilayer silicene agrees with that of the Si(111)(√{ 3} ×√{ 3})-Ag reconstructed surface. Consequently, we have concluded that the multilayer silicene grown on Ag(111) is identical to the Si(111)(√{ 3} ×√{ 3})-Ag reconstructed structure.

  9. Geothermal research and development program of the US Atomic Energy Commission

    Science.gov (United States)

    Werner, L. B.

    1974-01-01

    Within the overall federal geothermal program, the Atomic Energy Commission has chosen to concentrate on development of resource utilization and advanced research and technology as the areas most suitable to the expertise of its staff and that of the National Laboratories. The Commission's work in geothermal energy is coordinated with that of other agencies by the National Science Foundation, which has been assigned lead agency by the Office of Management and Budget. The objective of the Commission's program, consistent with the goals of the total federal program is to facilitate, through technological advancement and pilot plant operations, achievement of substantial commercial production of electrical power and utilization of geothermal heat by the year 1985. This will hopefully be accomplished by providing, in conjunction with industry, credible information on the economic operation and technological reliability of geothermal power and use of geothermal heat.

  10. Solution of the Energy Level of Hydrogen-Like Atom for the Debye Shidlding Potential

    Institute of Scientific and Technical Information of China (English)

    HUXian-Quan; HUWen-Jiang; 等

    2002-01-01

    The first-order revision and the approximation analytical formula of the energy levels for hydrogen-like atoms under the condition of Debye shielding potential are achieved by means of the Rayleigh-Schroedinger perturbation theory.meanwhile,the corresponding recurrence relations are obtained from the use of the solution of power series,Based on the above solutions and with the use of energy consistent method the equivalent value of second-order reversion under the condition of Debye shielding potential is produced as well and the esult is compared with the data obtained by the numerical method.Besides,the critical bond-state and corresponding cut-off conditions are discussed.

  11. Charge-state-dependent energy loss of slow ions. II. Statistical atom model

    Science.gov (United States)

    Wilhelm, Richard A.; Möller, Wolfhard

    2016-05-01

    A model for charge-dependent energy loss of slow ions is developed based on the Thomas-Fermi statistical model of atoms. Using a modified electrostatic potential which takes the ionic charge into account, nuclear and electronic energy transfers are calculated, the latter by an extension of the Firsov model. To evaluate the importance of multiple collisions even in nanometer-thick target materials we use the charge-state-dependent potentials in a Monte Carlo simulation in the binary collision approximation and compare the results to experiment. The Monte Carlo results reproduce the incident charge-state dependence of measured data well [see R. A. Wilhelm et al., Phys. Rev. A 93, 052708 (2016), 10.1103/PhysRevA.93.052708], even though the experimentally observed charge exchange dependence is not included in the model.

  12. Localized description of surface energy gap effects in the resonant charge exchange between atoms and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias-Garcia, A; Garcia, Evelina A; Goldberg, E C, E-mail: aiglesiasg@santafe-conicet.gov.ar [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC-CONICET-UNL), Gueemes 3450, CC91, (S3000GLN) Santa Fe (Argentina)

    2011-02-02

    The resonant charge exchange between atoms and surfaces is described by considering a localized atomistic view of the solid within the Anderson model. The presence of a surface energy gap is treated within a simplified tight-binding model of the solid, and a proper calculation of the Hamiltonian terms based on a LCAO expansion of the solid eigenstates is performed. It is found that interference terms jointly with a surface projected gap maximum at the {Gamma} point and the Fermi level inside it, lead to hybridization widths negligible around the Fermi level. This result can explain experimental observations related to long-lived adsorbate states and anomalous neutral fractions of low energy ions in alkali/Cu(111) systems.

  13. Imaging the heliosphere using neutral atoms from solar wind energy down to 15 eV

    Energy Technology Data Exchange (ETDEWEB)

    Galli, A.; Wurz, P. [Physics Institute, University of Bern, Bern 3012 (Switzerland); Fuselier, S. A.; McComas, D. J. [Southwest Research Institute, San Antonio, TX 78228 (United States); Bzowski, M.; Sokół, J. M.; Kubiak, M. A. [Space Research Centre, Polish Academy of Sciences, Warsaw 00-716 (Poland); Möbius, E. [University of New Hampshire, Durham, NH 03824 (United States)

    2014-11-20

    We study the spatial and temporal distribution of hydrogen energetic neutral atoms (ENAs) from the heliosheath observed with the IBEX-Lo sensor of the Interstellar Boundary EXplorer (IBEX) from solar wind energies down to the lowest available energy (15 eV). All available IBEX-Lo data from 2009 January until 2013 June were included. The sky regions imaged when the spacecraft was outside of Earth's magnetosphere and when the Earth was moving toward the direction of observation offer a sufficient signal-to-noise ratio even at very low energies. We find that the ENA ribbon—a 20° wide region of high ENA intensities—is most prominent at solar wind energies whereas it fades at lower energies. The maximum emission in the ribbon is located near the poles for 2 keV and closer to the ecliptic plane for energies below 1 keV. This shift is an evidence that the ENA ribbon originates from the solar wind. Below 0.1 keV, the ribbon can no longer be identified against the globally distributed ENA signal. The ENA measurements in the downwind direction are affected by magnetospheric contamination below 0.5 keV, but a region of very low ENA intensities can be identified from 0.1 keV to 2 keV. The energy spectra of heliospheric ENAs follow a uniform power law down to 0.1 keV. Below this energy, they seem to become flatter, which is consistent with predictions. Due to the subtraction of local background, the ENA intensities measured with IBEX agree with the upper limit derived from Lyα observations.

  14. Interactions and low energy collisions between an alkali ion and an alkali atom of different nucleus

    CERN Document Server

    Rakshit, Arpita; Berriche, Hamid; Deb, Bimalendu

    2015-01-01

    We study theoretically interaction potentials and low energy collisions between different alkali atoms and alkali ions. Specifically, we consider systems like X + Y$^{+}$, where X(Y$^{+})$ is either Li(Cs$^+$) or Cs((Li$^+$), Na(Cs$^+$) or Cs(Na$^+$) and Li(Rb$^+$) or Rb(Li$^+$). We calculate the molecular potentials of the ground and first two excited states of these three systems using pseudopotential method and compare our results with those obtained by others. We calculate ground-state scattering wave functions and cross sections of these systems for a wide range of energies. We find that, in order to get convergent results for the total scattering cross sections for energies of the order $1$ K, one needs to take into account at least 60 partial waves. In the low energy limit ($< 1 \\mu$K), elastic scattering cross sections exhibit Wigner law threshold behavior while in the high energy limit the cross sections go as $E^{-1/3}$. We discuss qualitatively the possibilities of forming cold molecular ion by ...

  15. Intelligent energy management control for independent microgrid

    Indian Academy of Sciences (India)

    T BOGARAJ; J KANAKARAJ

    2016-07-01

    This work presents a new adaptive scheme for energy management in an independent microgrid.The proposed energy management system has been developed to manage the utilization of power among the hybrid resources and energy storage system in order to supply the load requirement based on multi-agent system (MAS) concept and predicted renewable powers and load powers. Auto regressive moving average models have been developed for predicting the wind speed, atmospheric temperature, irradiation, and connected loads. The structure proposed in this paper includes renewable sources as primary source and storage system as secondary source. A wind generator and solar PV array system together acts as primary source, which supplies power to the local load most of the time in this energy management strategy. When they fail to meet the load demand, the secondary source present in the system will assist the primary source and help to attain the goal of satisfying load demand without interruption. If the primary source and secondary source together are not able to meet the load demand then load shedding will be executed according to the priority set. Thus the developed MAS algorithm co-ordinates the hybrid system components and achieves energy management among renewableenergy sources, storage units, and load under varying environmental conditions and varying loads. STATCOM based compensation has been implemented to balance the reactive power demand and to mitigate the voltage fluctuations and harmonics on the AC bus. The proposed microgrid has been simulated with MAS concept in Matlab/Simulink environment. The results presented in this paper show cases the effectiveness of the proposed energy management controller.

  16. Incorporating the nuclear vibrational energies into the -atom in molecules- analysis: An analytical study

    CERN Document Server

    Gharabaghi, Masumeh

    2016-01-01

    The orthodox quantum theory of atoms in molecules (QTAIM) is based on the clamped nucleus paradigm and working solely with the electronic wavefunctions, so unable to include nuclear vibrations in the AIM analysis. On the other hand, the recently extended version of the QTAIM, called the multi-component QTAIM (MC-QTAIM), incorporates both electrons and quantum nuclei, i.e. those nuclei treated as quantum waves instead of clamped point charges, into the AIM analysis using non-adiabatic wavefunctions. Thus, the MC-QTAIM is the natural framework to incorporate the role of nuclear vibrations into the AIM analysis. In this study, within the context of the MC-QTAIM, the formalism of including nuclear vibrational energy in the atomic basin energy is developed in detail and its contribution is derived analytically using the recently proposed non-adiabatic Hartree product nuclear wavefunction. It is demonstrated that within the context of this wavefunction the quantum nuclei may be conceived pseudo-adiabatically as qua...

  17. Pairwise energies for polypeptide coarse-grained models derived from atomic force fields

    Science.gov (United States)

    Betancourt, Marcos R.; Omovie, Sheyore J.

    2009-05-01

    The energy parametrization of geometrically simplified versions of polypeptides, better known as polypeptide or protein coarse-grained models, is obtained from molecular dynamics and statistical methods. Residue pairwise interactions are derived by performing atomic-level simulations in explicit water for all 210 pairs of amino acids, where the amino acids are modified to closer match their structure and charges in polypeptides. Radial density functions are computed from equilibrium simulations for each pair of residues, from which statistical energies are extracted using the Boltzmann inversion method. The resulting models are compared to similar potentials obtained by knowledge based methods and to hydrophobic scales, resulting in significant similarities in spite of the model simplicity. However, it was found that glutamine, asparagine, lysine, and arginine are more attractive to other residues than anticipated, in part, due to their amphiphilic nature. In addition, equally charged residues appear more repulsive than expected. Difficulties in the calculation of knowledge based potentials and hydrophobicity scale for these cases, as well as sensitivity of the force field to polarization effects are suspected to cause this discrepancy. It is also shown that the coarse-grained model can identify native structures in decoy databases nearly as well as more elaborate knowledge based methods, in spite of its resolution limitations. In a test conducted with several proteins and corresponding decoys, the coarse-grained potential was able to identify the native state structure but not the original atomic force field.

  18. Intrinsic Resolution of Molecular Electronic Wave Functions and Energies in Terms of Quasi-atoms and Their Interactions.

    Science.gov (United States)

    West, Aaron C; Schmidt, Michael W; Gordon, Mark S; Ruedenberg, Klaus

    2017-02-09

    A general intrinsic energy resolution has been formulated for strongly correlated wave functions in the full molecular valence space and its subspaces. The information regarding the quasi-atomic organization of the molecular electronic structure is extracted from the molecular wave function without introducing any additional postulated model state wave functions. To this end, the molecular wave function is expressed in terms of quasi-atomic molecular orbitals, which maximize the overlap between subspaces of the molecular orbital space and the free-atom orbital spaces. As a result, the molecular wave function becomes the superposition of a wave function representing the juxtaposed nonbonded quasi-atoms and a wave function describing the interatomic electron migrations that create bonds through electron sharing. The juxtaposed nonbonded quasi-atoms are shown to consist of entangled quasi-atomic states from different atoms. The binding energy is resolved as a sum of contributions that are due to quasi-atom formation, quasiclassical electrostatic interactions, and interatomic interferences caused by electron sharing. The contributions are further resolved according to orbital interactions. The various transformations that generate the analysis are determined by criteria that are independent of the working orbital basis used for calculating the molecular wave function. The theoretical formulation of the resolution is quantitatively validated by an application to the C2 molecule.

  19. Conference on Nuclear Energy and Science for the 21st Century: Atoms for Peace Plus Fifty - Washington, D.C., October 2003

    Energy Technology Data Exchange (ETDEWEB)

    Pfaltzgraff, Robert L [Institute for Foreign Policy Analysis

    2006-10-22

    This conference's focus was the peaceful uses of the atom and their implications for nuclear science, energy security, nuclear medicine and national security. The conference also provided the setting for the presentation of the prestigious Enrico Fermi Prize, a Presidential Award which recognizes the contributions of distinguished members of the scientific community for a lifetime of exceptional achievement in the science and technology of nuclear, atomic, molecular, and particle interactions and effects. An impressive group of distinguished speakers addressed various issues that included: the impact and legacy of the Eisenhower Administration’s “Atoms for Peace” concept, the current and future role of nuclear power as an energy source, the challenges of controlling and accounting for existing fissile material, and the horizons of discovery for particle or high-energy physics. The basic goal of the conference was to examine what has been accomplished over the past fifty years as well as to peer into the future to gain insights into what may occur in the fields of nuclear energy, nuclear science, nuclear medicine, and the control of nuclear materials.

  20. A novel controllable double-layer magnetic lattice with cold atoms

    Institute of Scientific and Technical Information of China (English)

    Min Yun; Jianping Yin

    2005-01-01

    We propose a novel array of controllable double-well magnetic microtraps for cold atoms by using an array of square current-carrying wires and two additional bias magnetic fields. Arrays of double layer magnetooptical traps (MOTs) and Ioffe traps can be constructed by using same wire configurations and different currents and bias fields. Furthermore, the array of double-well magnetic microtraps can be continuously evolved as an array of single-well magnetic microtraps by reducing the currents in the wires. Our study shows that our scheme can be used to realize a controllable double-layer magnetic lattice with cold atoms, to form array of Bose-Einstein condensations (BECs), or to study atom interference, and so on.

  1. Observing Planets and Small Bodies in Sputtered High Energy Atom (SHEA) Fluxes

    Science.gov (United States)

    Milillo, A.; Orsini, S.; Hsieh, K. C.; Baragiola, R.; Fama, M.; Johnson, R.; Mura, A.; Plainaki, Ch.; Sarantos, M.; Cassidy, T. A.; DeAngelis, E; Desai, M.; Goldstein, R.; Lp, W.-H.; Killen, R.; Livi, S.

    2012-01-01

    The evolution of the surfaces of bodies unprotected by either strong magnetic fields or thick atmospheres in the Solar System is caused by various processes, induced by photons, energetic ions and micrometeoroids. Among these processes, the continuous bombardment of the solar wind or energetic magnetospheric ions onto the bodies may significantly affect their surfaces, with implications for their evolution. Ion precipitation produces neutral atom releases into the exosphere through ion sputtering, with velocity distribution extending well above the particle escape limits. We refer to this component of the surface ejecta as sputtered high-energy atoms (SHEA). The use of ion sputtering emission for studying the interaction of exposed bodies (EB) with ion environments is described here. Remote sensing in SHEA in the vicinity of EB can provide mapping of the bodies exposed to ion sputtering action with temporal and mass resolution. This paper speculates on the possibility of performing remote sensing of exposed bodies using SHEA The evolution of the surfaces of bodies unprotected by either strong magnetic fields or thick atmospheres in the Solar System is caused by various processes, induced by photons, energetic ions and micrometeoroids. Among these processes, the continuous bombardment of the solar wind or energetic magnetospheric ions onto the bodies may significantly affect their surfaces, with implications for their evolution. Ion precipitation produces neutral atom releases into the exosphere through ion sputtering, with velocity distribution extending well above the particle escape limits. We refer to this component of the surface ejecta as sputtered high-energy atoms (SHEA). The use of ion sputtering emission for studying the interaction of exposed bodies (EB) with ion environments is described here. Remote sensing in SHEA in the vicinity of EB can provide mapping of the bodies exposed to ion sputtering action with temporal and mass resolution. This paper

  2. Background report for the formerly utilized Manhattan Engineer District/Atomic Energy Commission sites program

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    The Department of Energy is conducting a program to determine radiological conditions at sites formerly used by the Army Corps of Engineers' Manhattan Engineer District and the Atomic Energy Commission in the early years of nuclear energy development. Also included in the program are sites used in the Los Alamos plutonium development program and the Trinity atomic bomb test site. Materials, equipment, buildings, and land became contaminated, primarily with naturally occurring radioactive nuclides. They were later decontaminated in accordance with the standards and survey methods in use at that time. Since then, however, radiological criteria, and proposed guidelines for release of such sites for unrestricted use have become more stringent as research on the effects of low-level radiation has progressed. In addition, records documenting some of these decontamination efforts cannot be found, and the final radiological conditions of the sites could not be adequately determined from the records. As a result, the Formerly Utilized Sites Program was initiated in 1974 to identify these formerly used sites and to reevaluate their radiological status. This report covers efforts through June 1980 to determine the radiological status of sites for which the existing conditions could not be clearly defined. Principal contractor facilities and associated properties have already been identified and activities are continuing to identify additional sites. Any new sites located will probably be subcontractor facilities and areas used for disposal of contractor waste or equipment; however, only limited information regarding this equipment and material has been collected to date. As additional information becomes available, supplemental reports will be published.

  3. 10 CFR 8.2 - Interpretation of Price-Anderson Act, section 170 of the Atomic Energy Act of 1954.

    Science.gov (United States)

    2010-01-01

    ... upon the legislative history, stated that the problem of a reactor accident in the United States... Atomic Energy Act of 1954. 8.2 Section 8.2 Energy NUCLEAR REGULATORY COMMISSION INTERPRETATIONS § 8.2... caused outside the United States by a nuclear incident occurring within the United States. (b)...

  4. Dependence of the atomic energy levels on a superstrong magnetic field with account of a finite nucleus radius and mass

    Science.gov (United States)

    Godunov, S. I.; Vysotsky, M. I.

    2013-06-01

    The influence of the finiteness of the proton radius and mass on the energies of a hydrogen atom and hydrogenlike ions in a superstrong magnetic field is studied. The finiteness of the nucleus size pushes the ground energy level up leading to a nontrivial dependence of the value of the critical nucleus charge on the external magnetic field.

  5. A new exact quantum mechanical rovibrational kinetic energy operator for penta-atomic systems in internal coordinates

    Institute of Scientific and Technical Information of China (English)

    陈光巨; 李玉学

    1999-01-01

    The concrete molecule-fixed (MF) kinetic energy operator for penta-atomic molecules is expressed in terms of the parameterδ, the matrix element G?, and angular momentum operator (?). The applications of the operator are also discussed. Finally, a general compact form of kinetic energy operator suitable for calculating the rovibrational spectra of polyatomie molecules is presented.

  6. Influence on electron energy loss spectroscopy of the niobium-substituted uranium atom: A density functional theory study

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We present the electronic structure and electron energy loss spectroscopy (EELS) for uranium, niobium and U3Nb in which uranium is substituted by niobium. Comparing the electronic structures and optical properties for uranium, niobium and U3Nb, we found that when niobium atom replaces uranium atom in the center lattice, density of state (DOS) of U3Nb shifts downward to low energy. Niobium affects DOS forfand d electrons more than that for p and s electrons. U3Nb is similar to uranium for the electronic energy loss spectra.

  7. Precise atomic-scale investigations of material sputtering process by light gas ions in pre-threshold energy region

    CERN Document Server

    Suvorov, A L

    2002-01-01

    Foundation and prospects of the new original technique of the sputtering yield determination of electro-conducting materials and sub-atomic layers on their surface by light gas ions the pre-threshold energy region (from 10 to 500 eV) are considered. The technique allows to identify individual surface vacancies, i.e., to count individual sputtered atoms directly. A short review of the original results obtained by using the developed techniques is given. Data are presented and analyzed concerning energy thresholds of the sputtering onset and energy dependences of sputtering yield in the threshold energy region for beryllium, tungsten, tungsten oxide, alternating tungsten-carbon layers, three carbon materials as well as for sub-atomic carbon layers on surface of certain metals at their bombardment by hydrogen, deuterium and/or helium ions

  8. Controlling the atom. The beginnings of nuclear regulation 1946--1962

    Energy Technology Data Exchange (ETDEWEB)

    Mazuzan, G.T.; Walker, J.S.

    1997-08-01

    This book traces the early history of nuclear power regulation in the US. It focuses on the Atomic Energy Commission (AEC), the federal agency that until 1975 was primarily responsible for planning and carrying out programs to protect public health and safety from the hazards of the civilian use of nuclear energy. It also describes the role of other groups that figured significantly in the development of regulatory policies, including the congressional Joint Committee on Atomic Energy, federal agencies other than the AEC, state governments, the nuclear industry, and scientific organizations. And it considers changes in public perceptions of and attitudes toward atomic energy and the dangers of radiation exposure. The context in which regulatory programs evolved is a rich and complex mixture of political, legislative, legal, technological, scientific, and administrative history. The basic purpose of this book is to provide the Nuclear Regulatory Commission (NRC), which inherited responsibility for nuclear safety after Congress disbanded the AEC, and the general public with information on the historical antecedents and background of regulatory issues.

  9. Architecture for Combined Energy and Attitude Control System

    OpenAIRE

    Ibrahim M. Mehedi; Renuganth Varatharajoo; Harlisya Harun; Mohd N. Filipski

    2005-01-01

    Combining the energy and attitude control system is a feasible technology for small satellites to improve the space missions. In this Combined Energy and Attitude Control System (CEACS) a double rotating flywheel is used to replace the conventional battery for energy storage as well as to control the attitude of an earth oriented satellite. Each flywheel is to be controlled in the torque mode. The energy and attitude inputs for the flywheels' control architecture are also ...

  10. A Cost-Effective Atomic Force Microscope for Undergraduate Control Laboratories

    Science.gov (United States)

    Jones, C. N.; Goncalves, J.

    2010-01-01

    This paper presents a simple, cost-effective and robust atomic force microscope (AFM), which has been purposely designed and built for use as a teaching aid in undergraduate controls labs. The guiding design principle is to have all components be open and visible to the students, so the inner functioning of the microscope has been made clear to…

  11. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne;

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve...

  12. Collisions of low-energy antiprotons and protons with atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Luehr, Armin

    2010-02-18

    Antiproton (anti p) collisions have evolved to a powerful tool for the testing of dynamic electron correlations in atoms and molecules. While advances in the understanding of anti p collisions with the simplest one- and two-electron atoms, H and He, have been achieved experiment and theory did not agree for low-energy anti p+He collisions (<40 keV), stimulating a vivid theoretical activity. On the other hand, only very few theoretical anti p studies can be found considering molecular as well as other atomic targets, in contrast to proton (p) collisions. This is in particular true for anti p impacts on H{sub 2} despite its fundamental role in representing the simplest two-electron molecule. The obtained results may be useful for the anti p experiments at CERN (e.g., antihydrogen production) and in particular for the facility design of low-energy anti p storage rings (e.g., at FLAIR) where a precise knowledge of the anti p interaction with the dominant residual-gas molecule H{sub 2} is needed. In this work a nonperturbative, time-dependent numerical approach is developed which describes ionization and excitation of atoms or molecules by either anti p or p impact based on the impact-parameter method. A spectral close-coupling method is employed for solving the time-dependent Schroedinger equation in which the scattering wave function is expanded in (effective) one- or two-electron eigenstates of the target. This includes for the first time a full two-electron, two-center description of the H{sub 2} molecule in anti p collisions. The radial part of the one-electron eigenstates is expanded in B splines while the two-electron basis is obtained with a configurationinteraction approach. Calculations are performed for anti p collisions with H, H{sub 2}{sup +}, and H{sub 2} as well as with He and alkali-metal atoms Li, Na, K, and Rb. Additionally, data are obtained for p collisions with H{sub 2}, Li, Na, and K. The developed method is tested and validated by detailed

  13. Energy Saving by the Idle Engine Controller

    Energy Technology Data Exchange (ETDEWEB)

    Editor [Korea Energy Management Corporation, Yongin (Korea)

    2001-03-01

    The high energy price facing up to $30 per barrel is the cost increasing factor that brings a deathblow to the domestic transportation industry, so it is serious to practice the energy saving in order to overcome such a situation. Transportation industry once got the great effect from the promotion for a light car, the improvement of auto structure, and the induction to economical driving way. According to the recent survey on drivers, however, the rate of the respondents that replied on the survey as 'in cases of stopping or parking for 1 minute, turn off the engine.' was just 14%, 86% of respondents did not have any consciousness of the problem about the idle operation. The Government has been promoting the legalization of the restriction to prevent an idle operation and enacting 'An Act of Idle Regulation in a Specific Area' and 'A Rule of Idle Restriction in a General Area'. An idle operation, which is one of the biggest factors in excessive consumption of oil as well as an air pollutant, should eradicate by self-participation. However, because an idle operation is conducted by unconsciousness, the development of an automatic controller is required for the restriction of unnecessary energy consumption. 1 fig., 4 tabs.

  14. Heteronanojunctions with atomic size control using a lab-on-chip electrochemical approach with integrated microfluidics.

    Science.gov (United States)

    Lunca Popa, P; Dalmas, G; Faramarzi, V; Dayen, J F; Majjad, H; Kemp, N T; Doudin, B

    2011-05-27

    A versatile tool for electrochemical fabrication of heteronanojunctions with nanocontacts made of a few atoms and nanogaps of molecular spacing is presented. By integrating microfluidic circuitry in a lab-on-chip approach, we keep control of the electrochemical environment in the vicinity of the nanojunction and add new versatility for exchanging and controlling the junction's medium. Nanocontacts made of various materials by successive local controlled depositions are demonstrated, with electrical properties revealing sizes reaching a few atoms only. Investigations on benchmark molecular electronics material, trapped between electrodes, reveal the possibility to create nanogaps of size matching those of molecules. We illustrate the interest of a microfluidic approach by showing that exposure of a fabricated molecular junction to controlled high solvent flows can be used as a reliability criterion for the presence of molecular entities in a gap.

  15. Open-Loop Control in Quantum Optics: Two-Level Atom in Modulated Optical Field

    CERN Document Server

    Saifullah, Sergei

    2008-01-01

    The methods of mathematical control theory are widely used in the modern physics, but still they are less popular in quantum science. We will discuss the aspects of control theory, which are the most useful in applications to the real problems of quantum optics. We apply this technique to control the behavior of the two-level quantum particles (atoms) in the modulated external optical field in the frame of the so called "semi classical model", where quantum two-level atomic system (all other levels are neglected) interacts with classical electromagnetic field. In this paper we propose a simple model of feedforward (open-loop) control for the quantum particle system, which is a basement for further investigation of two-level quantum particle in the external one-dimensional optical field.

  16. High-performance laser power feedback control system for cold atom physics

    Institute of Scientific and Technical Information of China (English)

    Bo Lu; Thibault Vogt; Xinxing Liu; Xiaoji Zhou; Xuzong Chen

    2011-01-01

    @@ A laser power feedback control system that features fast response,large-scale performance,low noise,and excellent stability is presented.Some essential points used for optimization are described.Primary optical lattice experiments are given as examples to show the performance of this system.With these performance characteristics,the power control system is useful for applications in cold atom physics and precision measurements.%A laser power feedback control system that features fast response, large-scale performance, low noise, and excellent stability is presented. Some essential points used for optimization are described. Primary optical lattice experiments are given as examples to show the performance of this system. With these performance characteristics, the power control system is useful for applications in cold atom physics and precision measurements.

  17. Energy Landscape of Alginate-Epimerase Interactions Assessed by Optical Tweezers and Atomic Force Microscopy.

    Directory of Open Access Journals (Sweden)

    Armend Gazmeno Håti

    Full Text Available Mannuronan C-5 epimerases are a family of enzymes that catalyze epimerization of alginates at the polymer level. This group of enzymes thus enables the tailor-making of various alginate residue sequences to attain various functional properties, e.g. viscosity, gelation and ion binding. Here, the interactions between epimerases AlgE4 and AlgE6 and alginate substrates as well as epimerization products were determined. The interactions of the various epimerase-polysaccharide pairs were determined over an extended range of force loading rates by the combined use of optical tweezers and atomic force microscopy. When studying systems that in nature are not subjected to external forces the access to observations obtained at low loading rates, as provided by optical tweezers, is a great advantage since the low loading rate region for these systems reflect the properties of the rate limiting energy barrier. The AlgE epimerases have a modular structure comprising both A and R modules, and the role of each of these modules in the epimerization process were examined through studies of the A- module of AlgE6, AlgE6A. Dynamic strength spectra obtained through combination of atomic force microscopy and the optical tweezers revealed the existence of two energy barriers in the alginate-epimerase complexes, of which one was not revealed in previous AFM based studies of these complexes. Furthermore, based on these spectra estimates of the locations of energy transition states (xβ, lifetimes in the absence of external perturbation (τ0 and free energies (ΔG# were determined for the different epimerase-alginate complexes. This is the first determination of ΔG# for these complexes. The values determined were up to 8 kBT for the outer barrier, and smaller values for the inner barriers. The size of the free energies determined are consistent with the interpretation that the enzyme and substrate are thus not tightly locked at all times but are able to relocate

  18. Status of contamination monitoring in radiation activities of National Atomic Energy Agency (NAEA) in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Suhariyono, Gatot [National Atomic Energy Agency, Jakarta (Indonesia)

    1997-06-01

    National Atomic Energy Agency (NAEA) or Badan Tenaga Atom Nasional (BATAN) is a non departmental governmental agency, headed by a Director General who is directly responsible to the President. Center for Standardization and Radiation Safety Research (CSRSR) is one of the research centers within the deputy for the assessment of nuclear science and technology of the NAEA. The main task of the CSRSR is to implement research and development program, development and services in the field of radiation safety, standardization, dosimetry, radiation health as well as the application of nuclear techniques in medicine, according to the policy confirmed by the director general of BATAN. Task of radiation protection division is to set up programs and to develop radiation protection, personal monitoring system and radiation level of the working areas and their surroundings as well as dose limitation system, to carry out technical up grading of radiation protection officials skill and to help coping with radiation accident. The key factor on contamination monitoring is to reduce human error and mechanical failures. These problems can be achieved to the highest degree by developing knowledge and skill of staffs via trainings or courses on contamination and decontamination, so that they are hoped to become trained and qualified staffs. (G.K.)

  19. A terrestrial search for dark contents of the vacuum, such as dark energy, using atom interferometry

    CERN Document Server

    Adler, Ronald J; Perl, Martin L

    2011-01-01

    We describe the theory and first experimental work on our concept for searching on earth for the presence of dark content of the vacuum (DCV) using atom interferometry. Specifically, we have in mind any DCV that has not yet been detected on a laboratory scale, but might manifest itself as dark energy on the cosmological scale. The experimental method uses two atom interferometers to cancel the effect of earth's gravity and diverse noise sources. It depends upon two assumptions: first, that the DCV possesses some space inhomogeneity in density, and second that it exerts a sufficiently strong non-gravitational force on matter. The motion of the apparatus through the DCV should then lead to an irregular variation in the detected matter-wave phase shift. We discuss the nature of this signal and note the problem of distinguishing it from instrumental noise. We also discuss the relation of our experiment to what might be learned by studying the noise in gravitational wave detectors such as LIGO.The paper concludes ...

  20. Greatly enhanced intensity-difference squeezing via energy-level modulations in hot atomic media

    CERN Document Server

    Zhang, Da; Zhang, Zhaoyang; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

    2016-01-01

    Narrow-band intensity-difference squeezing (IDS) beams have important applications in quantum metrology and quantum information. The best way to generate narrow-band IDS is to employ parametrically-amplified (PA) four-wave mixing (FWM) process in high-gain atomic media. Such IDS can be further enhanced by cascading multiple PA-FWM processes in separate atomic media. The complicated experimental setup, added losses and mechanical stability can limit the wide uses of such scheme in practical applications. Here, we show that by modulating/dressing the internal energy level(s) with additional laser(s), the degree of original IDS can be substantially increased. With an initial IDS of $-4.0\\pm0.1$ dB using PA-non-degenerate-FWM process in a three-level $\\Lambda$-type configuration, the degree of IDS can be enhanced to $-7.0\\pm0.1$ dB/$-8.1\\pm0.1$ dB when we use one/two laser beam(s) to modulate the involved ground/excited state(s). Our results show a low-loss, robust and efficient way to produce high degree of IDS ...

  1. Lyman- photodissociation of CH3CFCl2 (HCFC-141b): Quantum yield and translational energy of hydrogen atoms

    Indian Academy of Sciences (India)

    Almuth Laeuter; Hans-Robert Volpp; Jai P Mittal; Rajesh K Vatsa

    2007-07-01

    The collision-free, room temperature gas-phase photodissociation dynamics of CH3CFCl2 (HCFC-141b) was studied using Lyman- laser radiation (121.6 nm) by the laser photolysis/laserinduced fluorescence `pump/probe’ technique. Lyman- radiation was used both to photodissociate the parent molecule and to detect the nascent H atom products via (22P → 12S) laser-induced fluorescence. Absolute H atom quantum yield, H = (0.39 ± 0.09) was determined by calibration method in which CH4 photolysis at 121.6 nm was used as a reference source of well-defined H atom concentrations. The line shapes of the measured H atom Doppler profiles indicate a Gaussian velocity distribution suggesting the presence of indirect H atom formation pathways in the Lyman- photodissociation of CH3CFCl2. The average kinetic energy of H atoms calculated from Doppler profiles was found to be T(lab) = (50 ± 3) kJ/mol. The nearly statistical translational energy together with the observed Maxwell-Boltzmann velocity distribution indicates that for CH3CFCl2 the H atom forming dissociation process comes closer to the statistical limit.

  2. Controlling steady-state and dynamical properties of atomic optical bistability

    CERN Document Server

    Joshi, Amitabh

    2012-01-01

    This book provides a comprehensive introduction to the theoretical and experimental studies of atomic optical bistability and multistability, and their dynamical properties in systems with two- and three-level inhomogeneously-broadened atoms inside an optical cavity. By making use of the modified linear absorption and dispersion, as well as the greatly enhanced nonlinearity in the three-level electromagnetically induced transparency system, the optical bistablity and efficient all-optical switching can be achieved at relatively low laser powers, which can be well controlled and manipulated. Un

  3. Magnetic-field-mediated coupling and control in hybrid atomic-nanomechanical systems

    CERN Document Server

    Tretiakov, A

    2016-01-01

    Magnetically coupled hybrid quantum systems enable robust quantum state control through Landau-Zener transitions. Here, we show that an ultracold atomic sample coupled to a nanomechanical resonator via oscillating magnetic fields can be used to cool the resonator's mechanical motion, to measure the mechanical temperature, and to enable entanglement of these mesoscopic objects. We calculate the expected coupling for both permanent-magnet and current-conducting nanostring resonators and describe how this hybridization is attainable using recently developed fabrication techniques, including SiN nanostrings and atom chips.

  4. Molecular Dynamics Study on Interfacial Energy and Atomic Structure of Ag/Ni and Cu/Ni Heterophase System

    Institute of Scientific and Technical Information of China (English)

    Haijiang LIU; Shaoqing WANG; An DU; Caibei ZHANG

    2004-01-01

    The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those containing the (111) plane have the lowest energies, which is in agreement with the experiments. Comparing surface energy with interracial energy, it is found the order of the interfacial energies of Ag/Ni and Cu/Ni containing the planes fall in the same order as solid-vapor surface energies of Ag, Cu and Ni. In this MD simulation, the relaxed atomic structure and dislocation network of (110)Ag||(110)Ni interface are coincident to HREM observations.

  5. Latitude, Energy, and Time Variations of Energetic Neutral Atom Spectral indices Measured by IBEX

    Science.gov (United States)

    Desai, Mihir; Heerikhuisen, Jacob; McComas, David; Funsten, Herbert; Pogorelov, Nikolai; Zank, Gary; Schwadron, Nathan; Fuselier, Stephen; Allegrini, Frederic; Dayeh, Maher A.

    2016-07-01

    We investigate the latitude, energy, and time variations of the globally distributed 0.5-6 keV energetic neutral atom (ENA) spectra measured by the Interstellar Boundary Explorer (IBEX) during the first 5 years of the mission. Our previous results based on the first 3 years of IBEX observations showed that the ENA spectral indices at the two lowest energies (0.89 and 1.47 keV) exhibit no clear trend with ecliptic latitude θ, while those at ˜2.29 and ˜3.41 keV exhibit a clear latitudinal pattern; flatter spectra occur above 60° latitude and steeper spectra occur within ±30° of the equator. While these results confirmed the previously reported latitudinal organization of the ENA spectra and their remarkable similarity to that of the solar wind (SW) speed observed by Ulysses in the inner heliosphere, we also showed that, unlike previous reports, the ˜0.5-6 keV globally distributed ENA spectral indices could not be represented as single power laws over much of the sky, and that they depend on energy and latitude. In this paper we extend the above results to include years 4 and 5 of IBEX observations and investigate if the spectral indices vary as a function of time. Finally, we discuss implications of our results on models and simulations that seek to map the IBEX ENA observations back to the latitudinal profile of the SW speed structure observed in the inner heliosphere.

  6. Testing the validity of the International Atomic Energy Agency (IAEA) safety culture model.

    Science.gov (United States)

    López de Castro, Borja; Gracia, Francisco J; Peiró, José M; Pietrantoni, Luca; Hernández, Ana

    2013-11-01

    This paper takes the first steps to empirically validate the widely used model of safety culture of the International Atomic Energy Agency (IAEA), composed of five dimensions, further specified by 37 attributes. To do so, three independent and complementary studies are presented. First, 290 students serve to collect evidence about the face validity of the model. Second, 48 experts in organizational behavior judge its content validity. And third, 468 workers in a Spanish nuclear power plant help to reveal how closely the theoretical five-dimensional model can be replicated. Our findings suggest that several attributes of the model may not be related to their corresponding dimensions. According to our results, a one-dimensional structure fits the data better than the five dimensions proposed by the IAEA. Moreover, the IAEA model, as it stands, seems to have rather moderate content validity and low face validity. Practical implications for researchers and practitioners are included.

  7. Solid Hydrogen Experiments for Atomic Propellants: Particle Formation Energy and Imaging Analyses

    Science.gov (United States)

    Palaszewski, Bryan

    2002-01-01

    This paper presents particle formation energy balances and detailed analyses of the images from experiments that were conducted on the formation of solid hydrogen particles in liquid helium during the Phase II testing in 2001. Solid particles of hydrogen were frozen in liquid helium and observed with a video camera. The solid hydrogen particle sizes and the total mass of hydrogen particles were estimated. The particle formation efficiency is also estimated. Particle sizes from the Phase I testing in 1999 and the Phase II testing in 2001 were similar. Though the 2001 testing created similar particles sizes, many new particle formation phenomena were observed. These experiment image analyses are one of the first steps toward visually characterizing these particles and it allows designers to understand what issues must be addressed in atomic propellant feed system designs for future aerospace vehicles.

  8. Scaled-Down Moderator Circulation Test Facility at Korea Atomic Energy Research Institute

    Directory of Open Access Journals (Sweden)

    Hyoung Tae Kim

    2016-01-01

    Full Text Available Korea Atomic Energy Research Institute (KAERI started the experimental research on moderator circulation as one of a the national research and development programs from 2012. This research program includes the construction of the moderator circulation test (MCT facility, production of the validation data for self-reliant computational fluid dynamics (CFD tools, and development of optical measurement system using the particle image velocimetry (PIV. In the present paper we introduce the scaling analysis performed to extend the scaling criteria suitable for reproducing thermal-hydraulic phenomena in a scaled-down CANDU- (CANada Deuterium Uranium- 6 moderator tank, a manufacturing status of the 1/4 scale moderator tank. Also, preliminary CFD analysis results for the full-size and scaled-down moderator tanks are carried out to check whether the moderator flow and temperature patterns of both the full-size reactor and scaled-down facility are identical.

  9. Cell Evolutionary Algorithm: a New Optimization Method on Ground-State Energy of the Atomic

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The purpose of this paper is to present a new general approach to solve ground-state energies of the double-electron systems in a uniform magnetic field, in which the basic element of evolution is the set in the solution space, rather than the point. The paper defines the Cell Evolutionary Algorithm, which imple-ments such a view of the evolution mechanism. First, the optimal set in which the optimal solution may be ob-tained. Then this approach applies the embedded search method to get the optimal solution. We tested this approach on the atomic structure, and the results show that it can improve not only the efficiency but also the accuracy of the calculations as it relates to this specific problem.

  10. Negotiating supranational rules - The genesis of the International Atomic Energy Agency Safeguards System

    Energy Technology Data Exchange (ETDEWEB)

    Forland, Astrid

    1998-12-31

    The object of this thesis is the evolution from 1954-56 up until the mid 1970s of the nuclear safeguards system administered by the International Atomic Energy Agency (IAEA) in Vienna. The evolution is traced not through the practical implementation of the safeguards system, but through the various multilateral negotiations through which it was created. The focus is on analysing the arguments advanced in the various negotiations, and the main objective is to single out the factors determining the result. The discussion is organised into the following chapters: (1) The statute of the IAEA, (2) The IAEA 1961 safeguard document (INFCIRC/26), (3) The IAEA 1965 safeguards document (INFCIRC/66), (4) The non-proliferation treaty, (5) NPT safeguards. 92 refs.

  11. Lifetime Measurements of $ \\pi ^+ \\pi ^- $ and $\\pi^{+-} K^{-+}$ Atoms to Test Low-Energy QCD Predictions

    CERN Multimedia

    Ponta, T C; Dumitriu, D E; Afanasyev, L; Zhabitskiy, M; Rykalin, V; Hons, Z; Schacher, J; Yazkov, V; Gerndt, J; Detraz, C C; Guaraldo, C; Dreossi, D; Smolik, J; Gorchakov, O; Nikitin, M; Dudarev, A; Kluson, J; Hansroul, M; Okada, K; Constantinescu, S; Kruglov, V; Komarov, V; Takeutchi, F; Tarta, P D; Kuptsov, A; Nemenov, L; Karpukhin, V; Shliapnikov, P; Brekhovskikh, V; Saborido silva, J J; Drijard, D; Rappazzo, G F; Pentia, M C; Gugiu, M M; Kruglova, L; Pustylnik, Z; Trojek, T; Vrba, T; Iliescu, M A; Duma, M; Ciocarlan, C; Kulikov, A; Ol'shevskiy, V; Ryazantsev, A; Chiba, M; Anania, A; Tarasov, A; Gritsay, K; Lapchine, V; Cechak, T; Lopez aguera, A

    2002-01-01

    %PS212 \\\\ \\\\ The proposed experiment aims to measure the lifetime of $ \\pi ^+ \\pi ^- $ atoms in the ground state with 10\\% precision, using the 24~GeV/c proton beam of the CERN Proton Synchrotron. As the value of the above lifetime of order 10$ ^- ^{1} ^{5} $s is dictated by a strong interaction at low energy, the precise measurement of this quantity enables to determine a combination of S-wave pion scattering lengths to 5\\%. Pion scattering lengths have been calculated in the framework of chiral perturbation theory and values predicted at the same level of accuracy have, up to now, never been confronted with accurate experimental data. Such a measurement would submit the understanding of chiral symmetry breaking of QCD to a crucial test.

  12. Energy of the Isolated Metastable Iron-Nickel FCC Nanocluster with a Carbon Atom in the Tetragonal Interstice.

    Science.gov (United States)

    Bondarenko, Natalya V; Nedolya, Anatoliy V

    2017-12-01

    The energy of the isolated iron-nickel nanocluster was calculated by molecular mechanics method using Lennard-Jones potential. The cluster included a carbon atom that drifted from an inside octahedral interstice to a tetrahedral interstice in [Formula: see text] direction and after that in direction to the surface. In addition, one of 14 iron atoms was replaced by a nickel atom, the position of which was changing during simulation.The energy of the nanocluster was estimated at the different interatomic distances. As a result of simulation, the optimal interatomic distances of Fe-Ni-C nanocluster was chosen for the simulation, in which height of the potential barrier was maximal and face-centered cubic (FCC) nanocluster was the most stable.It is shown that there were three main positions of a nickel atom that significantly affected nanocluster's energy.The calculation results indicated that position of the carbon atom in the octahedral interstice was more energetically favorable than tetrahedral interstice in the case of FCC nanocluster. On the other side, the potential barrier was smaller in the direction [Formula: see text] than in the direction .This indicates that there are two ways for carbon atom to drift to the surface of the nanocluster.

  13. Elemental mapping in achromatic atomic-resolution energy-filtered transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Forbes, B.D. [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Houben, L. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Mayer, J. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Central Facility for Electron Microscopy, RWTH Aachen University, D-52074 Aachen (Germany); Dunin-Borkowski, R.E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Gruenberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Allen, L.J., E-mail: lja@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

    2014-12-15

    We present atomic-resolution energy-filtered transmission electron microscopy (EFTEM) images obtained with the chromatic-aberration-corrected FEI Titan PICO at the Ernst-Ruska Centre, Jülich, Germany. We find qualitative agreement between experiment and simulation for the background-subtracted EFTEM images of the Ti–L{sub 2,3} and O–K edges for a specimen of SrTiO{sub 3} oriented down the [110] zone axis. The simulations utilize the transition potential formulation for inelastic scattering, which permits a detailed investigation of contributions to the EFTEM image. We find that energy-filtered images of the Ti–L{sub 2,3} and O–K edges are lattice images and that the background-subtracted core-loss maps may not be directly interpretable as elemental maps. Simulations show that this is a result of preservation of elastic contrast, whereby the qualitative details of the image are determined primarily by elastic, coherent scattering. We show that this effect places a constraint on the range of specimen thicknesses which could theoretically yield directly useful elemental maps. In general, interpretation of EFTEM images is ideally accompanied by detailed simulations. - Highlights: • Achromatic atomic-resolution EFTEM images were obtained for STO 〈110〉. • Simulations were in qualitative agreement with Ti–L{sub 2,3} and O–K edge maps. • The experimental EFTEM maps are not directly interpretable as elemental maps. • Image intensities are strongly determined by preservation of elastic contrast. • Interpretation of EFTEM images is ideally accompanied by detailed simulations.

  14. Proceedings of the second US Department of Energy environmental control symposium. Volume 2. Nuclear energy, conservation, and solar energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-01

    These proceedings document the presentations given at the Second Environmental Control Symposium. Symposium presentations highlighted environmental control activities which span the entire DOE. Volume II contains papers relating to: environmental control aspects of nuclear energy use and development; nuclear waste management; renewable energy sources; transportation and building conservation (fuel economy, gasohol, building standards, and industry); and geothermal energy, power transmission, and energy storage. (DMC)

  15. Energy storage system control strategies for power distribution systems

    Directory of Open Access Journals (Sweden)

    Areewan Kajorndech

    2015-03-01

    Full Text Available Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system in order to improve reliability and save energy costs by determining an optimal charging schedule of the energy storage system. Simulation results demonstrate the benefits of energy storage system applications under the different control strategies.

  16. Charge-transfer energy in closed-shell ion-atom interactions. [for H and Li ions in He

    Science.gov (United States)

    Alvarez-Rizzatti, M.; Mason, E. A.

    1975-01-01

    The importance of charge-transfer energy in the interactions between closed-shell ions and atoms is investigated. Ab initio calculations on H(plus)-He and Li(plus)-He are used as a guide for the construction of approximate methods for the estimation of the charge-transfer energy for more complicated systems. For many alkali ion-rate gas systems the charge-transfer energy is comparable to the induction energy in the region of the potential minimum, although for doubly charged alkaline-earth ions in rare gases the induction energy always dominates. Surprisingly, an empirical combination of repulsion energy plus asymptotic induction energy plus asymptotic dispersion energy seems to give a fair representation of the total interaction, especially if the repulsion energy is parameterized, despite the omission of any explicit charge-transfer contribution. More refined interaction models should consider the charge-transfer energy contribution.

  17. EIT-control of single-atom motion in an optical cavity

    CERN Document Server

    Kampschulte, Tobias; Manz, Sebastian; Martinez-Dorantes, Miguel; Reimann, René; Yoon, Seokchan; Meschede, Dieter; Bienert, Marc; Morigi, Giovanna

    2012-01-01

    We demonstrate cooling of the motion of a single atom confined by a dipole trap inside a high-finesse optical resonator. Cooling of the vibrational motion results from EIT-like interference in an atomic \\Lambda-type configuration, where one transition is strongly coupled to the cavity mode and the other is driven by an external control laser. Good qualitative agreement with the theoretical predictions is found for the explored parameter ranges. The role of the cavity in the cooling dynamics is confirmed by means of a direct comparison with EIT-cooling performed in the dipole trap in free space. These results set the basis to the realization of an efficient photonic interface based on single atoms.

  18. Ultrafast triggered transient energy storage by atomic layer deposition into porous silicon for integrated transient electronics

    Science.gov (United States)

    Douglas, Anna; Muralidharan, Nitin; Carter, Rachel; Share, Keith; Pint, Cary L.

    2016-03-01

    Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics.Here we demonstrate the first on-chip silicon-integrated rechargeable transient power source based on atomic layer deposition (ALD) coating of vanadium oxide (VOx) into porous silicon. A stable specific capacitance above 20 F g-1 is achieved until the device is triggered with alkaline solutions. Due to the rational design of the active VOx coating enabled by ALD, transience occurs through a rapid disabling step that occurs within seconds, followed by full dissolution of all active materials within 30 minutes of the initial trigger. This work demonstrates how engineered materials for energy storage can provide a basis for next-generation transient systems and highlights porous silicon as a versatile scaffold to integrate transient energy storage into transient electronics. Electronic supplementary information (ESI) available: (i) Experimental details for ALD and material fabrication, ellipsometry film thickness, preparation of gel electrolyte and separator, details for electrochemical measurements, HRTEM image of VOx coated porous silicon, Raman spectroscopy for VOx as-deposited as well as annealed in air for 1 hour at 450 °C, SEM and transient behavior dissolution tests of uniformly coated VOx on

  19. Adjustment of the Brazilian radioprotection standards to the safety principles of the International Atomic Energy Agency; Adequacao das normas brasileiras de radioprotecao aos principios fundamentais de seguranca da International Atomic Energy Agency

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S.; Py Junior, Delcy de A., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Grupo Multidisciplinar de Radioprotecao; Kelecom, Alphonse, E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (LARARA-PLS/GETA/UFF), Niteroi, RJ (Brazil). Grupo de Estudos em Temas Ambientais. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Pereira, Juliana R. de S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil)

    2013-07-01

    The International Atomic Energy Agency (IAEA) has a recommendation with 10 basic safety principles (Fundamental Safety Principles Safety Fundamentals series, number SF-1), which are: 1) Responsibility for safety; 2) Role for government; 3) Leadership and management for safety; 4) Justification of facilities and activities; 5) Optimization of protection; 6) Limitation of risk to individuals; 7) Protection of present and futures generations; 8) Prevention of accidents; 9) Emergency preparedness and response and 10) Protection actions to reduce existing or unregulated radiations risk. The aim of this study is to verify that the Brazilian standards of radiation protection meet the principles described above and how well suited to them. The analysis of the national radiation protection regulatory system, developed and deployed by the National Nuclear Energy Commission (CNEN), showed that out of the ten items, two are covered partially, the number 2 and 10. The others are fully met. The item 2 the fact that the regulatory body (CNEN) be stock controller of a large company in the sector put in check its independence as a regulatory body. In item 10 the Brazilian standard of radiation protection does not provide explicit resolution of environmental liabilities.

  20. Control Methods Utilizing Energy Optimizing Schemes in Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, L.S; Thybo, C.; Stoustrup, Jakob;

    2003-01-01

    The potential energy savings in refrigeration systems using energy optimal control has been proved to be substantial. This however requires an intelligent control that drives the refrigeration systems towards the energy optimal state. This paper proposes an approach for a control, which drives...

  1. Real-time and in situ monitoring of sputter deposition with RHEED for atomic layer controlled growth

    Directory of Open Access Journals (Sweden)

    J. P. Podkaminer

    2016-08-01

    Full Text Available Sputter deposition is a widely used growth technique for a large range of important material systems. Epitaxial films of carbides, nitrides, metals, oxides and more can all be formed during the sputter process which offers the ability to deposit smooth and uniform films from the research level up to an industrial scale. This tunable kinematic deposition process excels in easily adapting for a large range of environments and growth procedures. Despite the vast advantages, there is a significant lack of in situ analysis options during sputtering. In particular, the area of real time atomic layer control is severely deficient. Atomic layer controlled growth of epitaxial thin films and artificially layered superlattices is critical for both understanding their emergent phenomena and engineering novel material systems and devices. Reflection high-energy electron diffraction (RHEED is one of the most common in situ analysis techniques during thin film deposition that is rarely used during sputtering due to the effect of the strong permanent magnets in magnetron sputter sources on the RHEED electron beam. In this work we have solved this problem and designed a novel way to deter the effect of the magnets for a wide range of growth geometries and demonstrate the ability for the first time to have layer-by-layer control during sputter deposition by in situ RHEED.

  2. Real-time and in situ monitoring of sputter deposition with RHEED for atomic layer controlled growth

    Science.gov (United States)

    Podkaminer, J. P.; Patzner, J. J.; Davidson, B. A.; Eom, C. B.

    2016-08-01

    Sputter deposition is a widely used growth technique for a large range of important material systems. Epitaxial films of carbides, nitrides, metals, oxides and more can all be formed during the sputter process which offers the ability to deposit smooth and uniform films from the research level up to an industrial scale. This tunable kinematic deposition process excels in easily adapting for a large range of environments and growth procedures. Despite the vast advantages, there is a significant lack of in situ analysis options during sputtering. In particular, the area of real time atomic layer control is severely deficient. Atomic layer controlled growth of epitaxial thin films and artificially layered superlattices is critical for both understanding their emergent phenomena and engineering novel material systems and devices. Reflection high-energy electron diffraction (RHEED) is one of the most common in situ analysis techniques during thin film deposition that is rarely used during sputtering due to the effect of the strong permanent magnets in magnetron sputter sources on the RHEED electron beam. In this work we have solved this problem and designed a novel way to deter the effect of the magnets for a wide range of growth geometries and demonstrate the ability for the first time to have layer-by-layer control during sputter deposition by in situ RHEED.

  3. Coupling, controlling, and processing non-transversal photons with a single atom

    Science.gov (United States)

    Rauschenbeutel, Arno

    2014-05-01

    I will report on recent experimental investigations of the interaction between single rubidium atoms and light that is confined by continuous total internal reflection in a whispering-gallery-mode (WGM) bottle microresonator. These resonators offer the advantage of very long photon lifetimes in conjunction with near lossless in- and out-coupling of light via tapered fiber couplers. We discovered that the non-transversal polarization of WGMs fundamentally alters the physics of light-matter interaction. Taking advantage of this effect, we recently demonstrated switching of signals between two distinct optical fibers controlled by a single atom. Owing to the excellent optical properties of our bottle microresonator, the scheme yields high switching fidelities and low losses. Furthermore, we exploited the strong birefringence of the bottle microresonator and implemented a single-atom-controlled polarization flip of the light that is guided through the coupling fiber. And finally, we made use of the strong nonlinear response of the atom-resonator system and experimentally realized an optical Kerr nonlinearity at the level of single photon. Analyzing the transmitted light, we observe a nonlinear phase shift of π between the cases of one and of two photons passing the resonator. This phase shift leads to entanglement between previously independent fiber-guided photons, which we verify by performing a full quantum state tomography of the transmitted two-photon state.

  4. Fully differential cross sections for low to intermediate energy perpendicular plane ionization of xenon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Purohit, G., E-mail: ghanshyam.purohit@spsu.ac.in; Singh, P.; Patidar, V.

    2014-12-15

    Highlights: • We present triply differential cross section (TDCS) results for the perpendicular plane ionization of xenon atoms. • The TDCS has been calculated in the modified distorted wave Born approximation formalism. • The effects of target polarization and post collision interaction have also been included. • The polarization potential, higher order effects and PCI has been found to be useful in the description of TDCS. - Abstract: Triple differential cross section (TDCS) results are reported for the perpendicular plane ionization of Xe (5p) at incident electron energies 5 eV, 10 eV, 20 eV, and 40 eV above ionization potential. The modified distorted wave Born approximation formalism with first as well as the second order Born terms has been used to calculate the TDCS. Effects of target polarization and post collision interaction have also been included. We compare the (e, 2e) TDCS results of our calculation with the recent available experimental data and theoretical results and discuss the process contributing to structure seen in the differential cross section. It has been observed from the present study that the second order effect and target polarization make significant contribution in description of collision dynamics of xenon at the low and intermediate energy for the perpendicular emission of electrons.

  5. Survival probability and energy modification of hydrogen Energetic Neutral Atoms on their way from the termination shock to Earth orbit

    CERN Document Server

    Bzowski, M

    2008-01-01

    Contect: With the forthcoming launch of a NASA SMEX mission IBEX devoted to imaging of heliospheric interface by in-situ detection of Energetic Neutral Atoms (ENA) an important issue becomes recognizing of transport of these atoms from the termination shock of the solar wind to Earth orbit. Aims: Investigate modifications of energy and of survival probability of the H ENA detectable by IBEX (0.01 -- 6 keV) between the termination shock and Earth orbit taking into account the influence of the variable and anisotropic solar wind and solar EUV radiation. Methods: Energy change of the atoms is calculated by numerical simulations of orbits of the H ENA atoms from ~100 AU from the Sun down to Earth orbit, taking into account solar gravity and Lyman-$\\alpha$ radiation pressure, which is variable in time and depends on radial velocity of the atom. To calculate survival probabilities of the atoms against onization, a detailed 3D and time-dependent model of H ENA ionization based on observations of the solar wind and E...

  6. Controlled rephasing of single spin-waves in a quantum memory based on cold atoms

    Science.gov (United States)

    Farrera, Pau; Albrecht, Boris; Heinze, Georg; Cristiani, Matteo; de Riedmatten, Hugues; Quantum Photonics With Solids; Atoms Team

    2015-05-01

    Quantum memories for light allow a reversible transfer of quantum information between photons and long lived matter quantum bits. In atomic ensembles, this information is commonly stored in the form of single collective spin excitations (spin-waves). In this work we demonstrate that we can actively control the dephasing of the spin-waves created in a quantum memory based on a cold Rb87 atomic ensemble. The control is provided by an external magnetic field gradient, which induces an inhomogeneous broadening of the atomic hyperfine levels. We show that acting on this gradient allows to control the dephasing of individual spin-waves and to induce later a rephasing. The spin-waves are then mapped into single photons, and we demonstrate experimentally that the active rephasing preserves the sub-Poissonian statistics of the retrieved photons. Finally we show that this rephasing control enables the creation and storage of multiple spin-waves in different temporal modes, which can be selectively readout. This is an important step towards the implementation of a functional temporally multiplexed quantum memory for quantum repeaters. We acknowledge support from the ERC starting grant, the Spanish Ministry of Economy and Competitiveness, the Fondo Europeo de Desarrollo Regional, and the International PhD- fellowship program ``la Caixa''-Severo Ochoa @ICFO.

  7. Energy-based modelling and control of wind energy conversion system with DFIG

    Science.gov (United States)

    Song, H. H.; Qu, Y. B.

    2011-02-01

    Focusing on wind energy conversion system (WECS) at the doubly-fed induction generator (DFIG) control level, a novel control approach was proposed to optimise wind energy capture from consideration of physical nature and energy relationship. According to energy flowing, the WECS was divided into several multi-ports energy conversion subsystems, and the structure matrices of the subsystems were elaborately designed. Based on this, port-controlled Hamiltonian models of the subsystems were obtained, and energy-based control using the models was provided to realise the machine side and the grid side control objectives of the WECS. The approach was applied on a 2 MW WECS, and compared with classical proportional-integral (PI) controller using MATLAB/Simulink. The results show that the energy-based control not only fully satisfies both side control requirements, but also has more robust control performances for a turbulent wind than the PI control.

  8. Controlling residual hydrogen gas in mass spectra during pulsed laser atom probe tomography.

    Science.gov (United States)

    Kolli, R Prakash

    2017-01-01

    Residual hydrogen (H2) gas in the analysis chamber of an atom probe instrument limits the ability to measure H concentration in metals and alloys. Measuring H concentration would permit quantification of important physical phenomena, such as hydrogen embrittlement, corrosion, hydrogen trapping, and grain boundary segregation. Increased insight into the behavior of residual H2 gas on the specimen tip surface in atom probe instruments could help reduce these limitations. The influence of user-selected experimental parameters on the field adsorption and desorption of residual H2 gas on nominally pure copper (Cu) was studied during ultraviolet pulsed laser atom probe tomography. The results indicate that the total residual hydrogen concentration, HTOT, in the mass spectra exhibits a generally decreasing trend with increasing laser pulse energy and increasing laser pulse frequency. Second-order interaction effects are also important. The pulse energy has the greatest influence on the quantity HTOT, which is consistently less than 0.1 at.% at a value of 80 pJ.

  9. Determination of deposited flux and energy of sputtered tungsten atoms on every stages of transport in HiPIMS discharge

    Science.gov (United States)

    Desecures, M.; de Poucques, L.; Bougdira, J.

    2017-02-01

    A time-resolved tunable diode-laser (DL) induced fluorescence (TR-TDLIF) technique has been used to identify different populations of atoms (on different stages of transport) to determine their corresponding deposited energy and flux. The temporal dimension permits the splitting of the processes of sputtering during the discharge and particles transport in the post-discharge where atoms and flux velocity distribution functions (AVDF, FVDF) of each population were measured varying the discharge parameters (power, voltage, pressure, and distance from target). Tungsten (W) was chosen, being an interesting case in terms of sputtered atom transport, considering its weight which implies weak changes of directivity or energy transfer after collisions with the buffer gas. The high temporal and spectral resolutions of TR-TDLIF are the keys for the distinction of the atoms populations and the stage corresponding to the transition from the ballistic to diffusive regime of transport was observed for the first time and named quasi-diffusive regime. Thus, the ability to dissociate populations of atoms and to determine their deposited flux and energy may be of great interest to adjust film properties as desired for applications.

  10. Controlled Synthesis of Atomically Layered Hexagonal Boron Nitride via Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Juanjuan Liu

    2016-11-01

    Full Text Available Hexagonal boron nitrite (h-BN is an attractive material for many applications including electronics as a complement to graphene, anti-oxidation coatings, light emitters, etc. However, the synthesis of high-quality h-BN is still a great challenge. In this work, via controlled chemical vapor deposition, we demonstrate the synthesis of h-BN films with a controlled thickness down to atomic layers. The quality of as-grown h-BN is confirmed by complementary characterizations including high-resolution transition electron microscopy, atomic force microscopy, Raman spectroscopy and X-ray photo-electron spectroscopy. This work will pave the way for production of large-scale and high-quality h-BN and its applications as well.

  11. Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

    Directory of Open Access Journals (Sweden)

    Sakuma Y

    2006-01-01

    Full Text Available AbstractAn atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs. Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

  12. Energy storage system control strategies for power distribution systems

    OpenAIRE

    Areewan Kajorndech; Dulpichet Rerkpreedapong

    2015-01-01

    Energy storage systems have been widely employed to attain several benefits, such as reliability improvement, stabilization of power systems connected with renewable energy resources, economic benefits and etc. To achieve the above objectives, the appropriate and effective control strategies for energy storage systems are needed to be developed. This research proposes energy storage system control strategies for power distribution systems equipped with a limited size of energy storage system ...

  13. Design of Energy Efficient SMISMO-ELS Control Strategies

    DEFF Research Database (Denmark)

    Hansen, Anders Hedegaard; Pedersen, Henrik C.; Andersen, Torben Ole;

    2011-01-01

    Traditionally mechanical linked meter-in and meterout spool valves are used for velocity control of hydraulic differential cylinders. However with the demand for energy efficient systems the individual meter-in and meter-out valves draws massive attention. This paper propose an energy efficient...... actuator control and combines this with energy efficient system control. Finally energy neutral performance improvments are suggested for the subjacent actuator in an ELS system....

  14. Analysis of H atoms in a negative ion source plasma with the non-equilibrium electron energy distribution function.

    Science.gov (United States)

    Koga, S; Shibata, T; Terasaki, R; Kameyama, N; Hatayama, A; Bacal, M; Tsumori, K

    2012-02-01

    In negative ion sources for the neutral beam injection, it is important to calculate H atom flux onto the plasma grid (PG) surface for the evaluation of H(-) production on the PG surface. We have developed a neutral (H(2) molecules and H atoms) transport code. In the present study, the neutral transport code is applied to the analysis of the H(2) and H transport in a NIFS-R&D ion source in order to calculate the flux onto the PG surface. Taking into account non-equilibrium feature of the electron energy distribution function (EEDF), i.e., the fast electron component, we have done the neutral transport simulation. The results suggest that the precise evaluation of the EEDF, especially in the energy range 15 eV < E < 30 eV is important for the dissociation rate of H(2) molecules by the electron impact collision and the resultant H atom flux on the PG.

  15. Calculation of Energies of the Ground and Low Excited States of a Confined Helium Atom in a Spherical Parabolic Well

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    @@ Making use of the adiabatic hyperspherical approach, we report a calculation for the energy spectrum of the ground and low-excited states of the confined helium atom in a spherical parabolic well. We find that the energies of a spherical parabolic well are in good agreement with those of an impenetrable spherical box for the larger confined potential radius. However, the energy values of a spherical parabolic well are much lower than those of an impenetrable spherical box for small values of re. We also find that the confinement may cause accidental degeneracies between levels with different low-excited states and the inversion of the energy values.

  16. Using Concept Maps as Instructional Materials to Foster the Understanding of the Atomic Model and Matter-Energy Interaction

    Science.gov (United States)

    Aguiar, Joana G.; Correia, Paulo R. M.

    2016-01-01

    In this paper, we explore the use of concept maps (Cmaps) as instructional materials prepared by teachers, to foster the understanding of chemistry. We choose fireworks as a macroscopic event to teach basic chemical principles related to the Bohr atomic model and matter-energy interaction. During teachers' Cmap navigation, students can experience…

  17. Scaled-energy spectroscopy of helium vertical bar M vertical bar=1 Rydberg atoms in a static electric field

    NARCIS (Netherlands)

    Kips, A.; Vassen, W.; Hogervorst, W.; Dando, P.A.

    1998-01-01

    We present scaled-energy spectra on helium Rydberg atoms in a static electric field. /M/ = 1 states were studied in excitation from the 2 S-1(0) metastable state. Spectra were recorded for epsilon = -2.940(4), epsilon = -2.350(4), both below the saddle point, and epsilon = -1.760(4), above the saddl

  18. 77 FR 27113 - Export and Import of Nuclear Equipment and Material; Export of International Atomic Energy Agency...

    Science.gov (United States)

    2012-05-09

    ... / Wednesday, May 9, 2012 / Rules and Regulations#0;#0; ] NUCLEAR REGULATORY COMMISSION 10 CFR Part 110 RIN 3150-AJ04 Export and Import of Nuclear Equipment and Material; Export of International Atomic Energy Agency Safeguards Samples AGENCY: Nuclear Regulatory Commission. ACTION: Final rule. SUMMARY: The...

  19. Absolute measurement of the effective atomic number and the electron density by using dual-energy CT images

    Science.gov (United States)

    Kim, Dae-Hong; Lee, Won-Hyung; Jeon, Sung-Soo; Kim, Hee-Joung

    2012-12-01

    Material decomposition using dual-energy and material-selective techniques was performed using computed-tomography (CT)-generated reconstructed images. Previous work using the dual-energy method focused on extracting the effective atomic number and the electron density of materials to confirm the dosimetric accuracy in radiation therapy. Dual-energy methods mostly depend on the device generating the X-rays, such as a synchrotron, and on dose verification for radiation treatment planning. Information obtained from CT imaging is important both in diagnosis and in planning radiation therapy. In a clinical setting, CT images are usually displayed as Houndsfield units (HU), which are extracted from the attenuation coefficient of a material. The attenuation coefficient is calculated using the effective atomic number and the electron density of a material; thus, information expressed in HU can be converted into the effective atomic number and the electron density by using the dual-energy equation. This study was performed using realistic Xray spectra to differentiate between the contrast media and plaque in vascular images. Our results suggest that the effective atomic number and electron density are useful in distinguishing between two adjacent materials with similar HUs.

  20. Design of energy-based terrain following flight control system

    Science.gov (United States)

    Wang, Wei; Li, Aijun; Xie, Yanwu; Tan, Jian

    2006-11-01

    Historically, aircraft longitudinal control has been realized by means of two loops: flight path (the control variable is elevator displacement) and speed control (the control variable is propulsive thrust or engine power). Both the elevator and throttle control cause coupled altitude and speed response, which exerts negative effects on longitudinal flight performance of aircraft, especially for Terrain Following(TF) flight. Energy-based method can resolve coupled problem between flight speed and path by controlling total energy rate and energy distribution rate between elevator and throttle. In this paper, energy-based control method is applied to design a TF flight control system for controlling flight altitude directly. An error control method of airspeed and altitude is adopted to eliminate the stable error of the total energy control system when decoupling control. Pitch loop and pitch rate feedback loop are designed for the system to damp the oscillatory response produced by TF system. The TF flight control system structure diagram and an aircraft point-mass energy motion model including basic control loops are given and used to simulate decoupling performance of the TF fight control system. Simulation results show that the energy-based TF flight control system can decouple flight velocity and flight path angle, exactly follow planned flight path, and greatly reduce altitude error, which is between +10m and -8m.

  1. AN INTELLIGENT NEURO-FUZZY TERMINAL SLIDING MODE CONTROL METHOD WITH APPLICATION TO ATOMIC FORCE MICROSCOPE

    Directory of Open Access Journals (Sweden)

    Seied Yasser Nikoo

    2016-11-01

    Full Text Available In this paper, a neuro-fuzzy fast terminal sliding mode control method is proposed for controlling a class of nonlinear systems with bounded uncertainties and disturbances. In this method, a nonlinear terminal sliding surface is firstly designed. Then, this sliding surface is considered as input for an adaptive neuro-fuzzy inference system which is the main controller. A proportinal-integral-derivative controller is also used to asist the neuro-fuzzy controller in order to improve the performance of the system at the begining stage of control operation. In addition, bee algorithm is used in this paper to update the weights of neuro-fuzzy system as well as the parameters of the proportinal-integral-derivative controller. The proposed control scheme is simulated for vibration control in a model of atomic force microscope system and the results are compared with conventional sliding mode controllers. The simulation results show that the chattering effect in the proposed controller is decreased in comparison with the sliding mode and the terminal sliding mode controllers. Also, the method provides the advantages of fast convergence and low model dependency compared to the conventional methods.

  2. Control and Transfer of Entanglement between Two Atoms Driven by Classical Fields under Dressed-State Representation

    Science.gov (United States)

    Liao, Qing-Hong; Zhang, Qi; Xu, Juan; Yan, Qiu-Rong; Liu, Ye; Chen, An

    2016-06-01

    We have studied the dynamics and transfer of the entanglement of the two identical atoms simultaneously interacting with vacuum field by employing the dressed-state representation. The two atoms are driven by classical fields. The influence of the initial entanglement degree of two atoms, the coupling strength between the atom and the classical field and the detuning between the atomic transition frequency and the frequency of classical field on the entanglement and atomic linear entropy is discussed. The initial entanglement of the two atoms can be transferred into the entanglement between the atom and cavity field when the dissipation is neglected. The maximally entangled state between the atoms and cavity field can be obtained under some certain conditions. The time of disentanglement of two atoms can be controlled and manipulated by adjusting the detuning and classical driving fields. Moreover, the larger the cavity decay rate is, the more quickly the entanglement of the two atoms decays. Supported by National Natural Science Foundation of China under Grant Nos. 11247213, 61368002, 11304010, 11264030, 61168001, China Postdoctoral Science Foundation under Grant No. 2013M531558, Jiangxi Postdoctoral Research Project under Grant No. 2013KY33, the Natural Science Foundation of Jiangxi Province under Grant No. 20142BAB217001, the Foundation for Young Scientists of Jiangxi Province (Jinggang Star) under Grant No. 20122BCB23002, the Research Foundation of the Education Department of Jiangxi Province under Grant Nos. GJJ13051, GJJ13057, and the Graduate Innovation Special Fund of Nanchang University under Grant No. cx2015137

  3. Economic Model Predictive Control for Smart Energy Systems

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus

    Model Predictive Control (MPC) can be used to control the energy distribution in a Smart Grid with a high share of stochastic energy production from renewable energy sources like wind. Heat pumps for heating residential buildings can exploit the slow heat dynamics of a building to store heat...

  4. Improving dryer energy efficiency and controllability simultaneously by process modification

    NARCIS (Netherlands)

    Atuonwu, J.C.; Straten, van G.; Deventer, van H.C.; Boxtel, van A.J.B.

    2013-01-01

    This work establishes a relationship between dryer energy performance and controllability using energy balances and process resiliency analysis. It is shown that using the process gain matrix, the dryer energy efficiency can be reliably calculated with conditions for simultaneous controllability imp

  5. Controlling Single-Photon Transport along an Optical Waveguide by using a Three-Level Atom

    Institute of Scientific and Technical Information of China (English)

    TIAN Wei; CHEN Bin; XU Wei-Dong

    2012-01-01

    We theoretically investigate the single-photon transport properties in an optical waveguide embedded with a V-type three-level atom (VTLA) based on symmetric and asymmetric couplings between the photon and the VTLA.Our numerical results show that the transmission spectrum of the incident photon can be well controlled by virtue of both symmetric and asymmetric coupling interactions.A multifrequency photon attenuator is realized by controlling the asymmetric coupling interactions.Furthermore,the influences of dissipation of the VTLA for the realistic physical system on single-photon transport properties are also analyzed.

  6. Control of the higher eigenmodes of a microcantilever: Applications in atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Karvinen, K.S., E-mail: kai.karvinen@uon.edu.au; Moheimani, S.O.R.

    2014-02-01

    While conventional techniques in dynamic mode atomic force microscopy typically involve the excitation of the first flexural mode of a microcantilever, situations arise where the excitation of higher modes may result in image artefacts. Strong nonlinear coupling between the cantilever modes in liquid environments may result in image artefacts, limiting the accuracy of the image. Similar observations have been made in high-speed contact mode AFM. To address this issue, we propose the application of the modulated–demodulated control technique to attenuate problematic modes to eliminate the image artefacts. The modulated–demodulated control technique is a high-bandwidth technique, which is well suited to the control of next generation of high-speed cantilevers. In addition to potential improvements in image quality, a high-bandwidth controller may also find application in multifrequency AFM experiments. To demonstrate the high-bandwidth nature of the control technique, we construct an amplitude modulation AFM experiment in air utilizing low amplitude setpoints, which ensures that harmonic generation and nonlinear coupling of the modes result in image artefacts. We then utilize feedback control to highlight the improvement in image quality. Such a control technique appears extremely promising in high-speed atomic force microscopy and is likely to have direct application in AFM in liquids. - Highlights: • The excitation of higher eigenmodes can potentially affect the estimated surface topography resulting in image artefacts. • We demonstrated the application of modulated–demodulated control and elimination of image artefacts resulting from the coupling of two modes. • Modulated–demodulated control is well suited to the control of high-frequency resonant dynamics and may find application in liquid/multifrequency AFM experiments.

  7. Sampling and analysis plan for the former Atomic Energy Commission bus lot property

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, R.R.

    1998-07-01

    This sampling and analysis plan (SAP) presents the rationale and strategy for the sampling and analysis activities proposed in support of an initial investigation of the former Atomic Energy Commission (AEC) bus lot property currently owned by Battelle Memorial Institute. The purpose of the proposed sampling and analysis activity is to investigate the potential for contamination above established action levels. The SAP will provide defensible data of sufficient quality and quantity to support recommendations of whether any further action within the study area is warranted. To assist in preparing sampling plans and reports, the Washington State Department of Ecology (Ecology) has published Guidance on Sampling and Data Analysis Methods. To specifically address sampling plans for petroleum-contaminated sites, Ecology has also published Guidance for Remediation of Petroleum Contaminated Sites. Both documents were used as guidance in preparing this plan. In 1992, a soil sample was taken within the current study area as part of a project to remove two underground storage tanks (USTs) at Battelle`s Sixth Street Warehouse Petroleum Dispensing Station (Section 1.3). The results showed that the sample contained elevated levels of total petroleum hydrocarbons (TPH) in the heavy distillate range. This current study was initiated in part as a result of that discovery. The following topics are considered: the historical background of the site, current site conditions, previous investigations performed at the site, an evaluation based on the available data, and the contaminants of potential concern (COPC).

  8. Cooperation between the US and the USSR in the peaceful uses of atomic energy

    Energy Technology Data Exchange (ETDEWEB)

    Seaborg, G.T.

    1989-10-01

    The decade of the 1960's saw a marked expansion of cooperation between the United States and the Soviet Union for the peaceful uses of atomic energy. In my opinion, this development constituted one of the most encouraging elements in the international scene. Until 1955 contacts between American and Soviet nuclear scientists were virtually nonexistent, as indeed (after World War II) were US-USSR contacts in other fields except as required in formal intergovernmental relations. Then, in July 1955, the discussions of the Heads of Government meeting in Geneva led to the declaration of a policy with the following aims: to lower the barriers which now impede the interchange of information and ideas between our peoples; to lower the barriers which now impede the opportunities of people to travel anywhere in the world for peaceful, friendly purposes, so that all will have a chance to know each other face to face; and to create conditions which will encourage nations to increase the exchange of peaceful goods throughout the world. 8 figs.

  9. Cross sections for medium energy He ions scattered from Hf and Au atoms

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tomoaki, E-mail: t-nishi@hosei.ac.jp [Research Center of Ion Beam Technology and College of Engineering, Hosei University, Koganei, Tokyo 184-8584 (Japan); Mitsuhara, Kei; Visikovskiy, Anton; Kido, Yoshiaki [Department of Physics, Ritsumeikan University, Kusatsu, Shiga-ken 525-8577 (Japan)

    2012-06-01

    The elastic scattering cross sections for medium energy He ions incident on Ni, Hf and Au atoms were measured precisely using a toroidal electrostatic analyzer. We prepared the targets of Ni({approx}1 nm)/HfO{sub 2}(1.5 nm)/Si(0 0 1) and Ni({approx}1 nm)/Au({approx}0.5 nm)/Si(1 1 1) and performed in situ ion scattering measurement under ultrahigh vacuum condition. The absolute amounts of Ni, Hf and Au were determined by Rutherford backscattering using 1.5 MeV He ions at a scattering angle of 150 Degree-Sign . The scattering cross sections for Hf and Au were normalized by those for Ni to avoid the ambiguities of the number of incident particles, solid angle subtended by a detector, detection efficiency and the He{sup +} fractions for the emerging He ions from the surfaces. The results obtained are compared with the simple Lee-Hart formula and the calculated values using the Moliere and ZBL potentials and the potentials derived from the Hartree-Fock-Slater wave functions.

  10. Negotiating supranational rules. The genesis of the International Atomic Energy Agency safeguards system

    Energy Technology Data Exchange (ETDEWEB)

    Forland, A.

    1997-12-31

    The object of this study is the evolution from 1954-56 up until the mid-1970s of the nuclear safeguards system administered by the International Atomic Energy Agency (IAEA) in Vienna. The main aim of the study is not to describe the IAEA safeguards system as such. The focus will be on analysing the arguments advanced in the various negotiations, and the main objective will be to single out the factors determining the result. In the course of the time span under study two international treaties were negotiated which were decisive for the development of international nuclear safeguards. These were the IAEA Stature (1956) and the Non-Proliferation Treaty (1968). The Statue as well as the NPT contain articles on international nuclear safeguards. These articles limit themselves to spelling out the safeguards principles. It was thus left to the IAEA Board of Governors to develop the safeguards procedures in detail. Two IAEA safeguards documents were negotiated between 1959 and 1965 in order to implement the safeguards article of the Statue. The safeguards requirements of the NPT were spelled out in a new model agreement in 1972. 58 refs.

  11. Towards Establishing Capacity for Biological Dosimetry at Ghana Atomic Energy Commission

    Science.gov (United States)

    Achel, Daniel Gyingiri; Achoribo, Elom; Agbenyegah, Sandra; Adaboro, Rudolph M.; Donkor, Shadrack; Adu-Bobi, Nana A. K.; Agyekum, Akwasi A.; Akuamoa, Felicia; Tagoe, Samuel N.; Kyei, Kofi A.; Yarney, Joel; Serafin, Antonio; Akudugu, John M.

    2016-01-01

    The aim of this study was not only to obtain basic technical prerequisites for the establishment of capacity of biological dosimetry at the Ghana Atomic Energy Commission (GAEC) but also to stimulate interest in biological dosimetry research in Ghana and Sub-Saharan Africa. Peripheral blood from four healthy donors was exposed to different doses (0–6 Gy) of gamma rays from a radiotherapy machine and lymphocytes were subsequently stimulated, cultured, and processed according to standard protocols for 48–50 h. Processed cells were analyzed for the frequencies of dicentric and centric ring chromosomes. Radiation dose delivered to the experimental model was verified using GafChromic® EBT films in parallel experiments. Basic technical prerequisites for the establishment of capacity of biological dosimetry in the GAEC have been realized and expertise in the dicentric chromosome assay consolidated. We successfully obtained preliminary cytogenetic data for a dose-response relationship of the irradiated blood lymphocytes. The data strongly indicate the existence of significant linear (α) and quadratic (β) components and are consistent with those published for the production of chromosome aberrations in comparable absorbed dose ranges. PMID:28217279

  12. Fermi and Coulomb correlation effects upon the interacting quantum atoms energy partition

    CERN Document Server

    Ruiz, Isela; Holguín-Gallego, Fernando José; Francisco, Evelio; Pendás, Ángel Martín; Rocha-Rinza, Tomás

    2016-01-01

    The Interacting Quantum Atoms (IQA) electronic energy partition is an important method in the field of quantum chemical topology which has given important insights of different systems and processes in physical chemistry. There have been several attempts to include Electron Correlation (EC) in the IQA approach, for example, through DFT and Hartree-Fock/Coupled-Cluster (HF/CC) transition densities. This work addresses the separation of EC in Fermi and Coulomb correlation and its effect upon the IQA analysis by taking into account spin-dependent one- and two-electron matrices $D^{\\mathrm{HF/CC}}_{p\\sigma q \\sigma}$ and $d^{\\mathrm{HF/CC}}_{p\\sigma q\\sigma r\\tau s\\tau}$ wherein $\\sigma$ and $\\tau$ represent either of the $\\alpha$ and $\\beta$ spin projections. We illustrate this approach by considering BeH$_2$,BH, CN$^-$, HF, LiF, NO$^+$, LiH, H$_2$O$\\cdots$H$_2$O and C$_2$H$_2$, which comprise non-polar covalent, polar covalent, ionic and hydrogen bonded systems. The same and different spin contributions to ($i$...

  13. Energy: Systems for Control, Maintenance, and Storage. A Bibliography.

    Science.gov (United States)

    Thomas, Gerald, Comp.; McKane, Irving, Comp.

    This publication is a bibliography of available periodical literature on specific aspects of energy and today's technology. The Applied Science and Technology Indexes were searched for articles that related to these specific areas: (1) Energy control systems; (2) Maintenance of Energy Systems; and (3) Energy storage. The articles and papers…

  14. Control Methods Utilizing Energy Optimizing Schemes in Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, L.S; Thybo, C.; Stoustrup, Jakob;

    2003-01-01

    The potential energy savings in refrigeration systems using energy optimal control has been proved to be substantial. This however requires an intelligent control that drives the refrigeration systems towards the energy optimal state. This paper proposes an approach for a control, which drives...... the condenser pressure towards an optimal state. The objective of this is to present a feasible method that can be used for energy optimizing control. A simulation model of a simple refrigeration system will be used as basis for testing the control method....

  15. Controlling multi-wave mixing signals via photonic band gap of electromagnetically induced absorption grating in atomic media

    CERN Document Server

    Zhang, Yiqi; Yao, Xin; Zhang, Zhaoyang; Chen, Haixia; Zhang, Huaibin; Zhang, Yanpeng

    2013-01-01

    We experimentally demonstrate dressed multi-wave mixing (MWM) and the reflection of the probe beam due to electromagnetically induced absorption (EIA) grating can coexist in a five-level atomic ensemble. The reflection is derived from the photonic band gap (PBG) of EIA grating, which is much broader than the PBG of EIT grating. Therefore, EIA-type PBG can reflect more energy from probe than EIT-type PBG does, which can effectively affect the MWM signal. The EIA-type as well as EIT-type PBG can be controlled by multiple parameters including the frequency detunings, propagation angles and powers of the involved light fields. Also, the EIA-type PBG by considering both the linear and third-order nonlinear refractive indices is also investigated. The theoretical analysis agrees well with the experimental results. This investigation has potential applications in all-optical communication and information processing.

  16. Two-atom energy spectrum in a harmonic trap near a Feshbach resonance at higher partial waves

    Science.gov (United States)

    Suzuki, Akira; Liang, Yi; Bhaduri, Rajat K.

    2009-09-01

    Two atoms in an optical lattice may be made to interact strongly at higher partial waves near a Feshbach resonance. These atoms, under appropriate constraints, could be bosonic or fermionic. The universal l=2 energy spectrum for such a system, with a caveat, is presented in this paper and checked with the spectrum obtained by direct numerical integration of the Schrödinger equation. The results reported here extend those of Yip for p -wave resonance [S.-K. Yip, Phys. Rev. A 78, 013612 (2008)], while exploring the limitations of a universal expression for the spectrum for the higher partial waves.

  17. Survival probability and energy modification of hydrogen Energetic Neutral Atoms on their way from the termination shock to Earth orbit

    OpenAIRE

    Bzowski, M.

    2008-01-01

    Context: With the forthcoming launch of a NASA SMEX mission IBEX devoted to imaging of heliospheric interface by in-situ detection of Energetic Neutral Atoms (ENA) an important issue becomes recognizing of transport of these atoms from the termination shock of the solar wind to Earth orbit. Aims: Investigate modifications of energy and of survival probability of the H ENA detectable by IBEX (0.01 -- 6 keV) between the termination shock and Earth orbit taking into account the influence of the ...

  18. Coordinated Control of Wave Energy Converters Subject to Motion Constraints

    OpenAIRE

    2016-01-01

    In this paper, a generic coordinated control method for wave energy converters is proposed, and the constraints on motion amplitudes and the hydrodynamic interaction between converters are considered. The objective of the control problem is to maximize the energy converted from ocean waves, and this is achieved by coordinating the power take-off (PTO) damping of each wave energy converter in the frequency domain in each sea state. In a case study, a wave energy farm consisting of four convert...

  19. Instrumentation and control for fossil-energy processes

    Energy Technology Data Exchange (ETDEWEB)

    1982-09-01

    The 1982 symposium on instrumentation and control for fossil energy processes was held June 7 through 9, 1982, at Adam's Mark Hotel, Houston, Texas. It was sponsored by the US Department of Energy, Office of Fossil Energy; Argonne National Laboratory; and the Society for Control and Instrumentation of Energy Processes. Fifty-two papers have been entered individually into EDB and ERA; eleven papers had been entered previously from other sources. (LTN)

  20. The bungling giant : Atomic Energy Canada Limited and next-generation nuclear technology, 1980-1994

    Energy Technology Data Exchange (ETDEWEB)

    Slater, I.J

    2003-07-01

    From 1980-1994 Atomic Energy Canada Limited (AECL), the Crown Corporation responsible for the development of nuclear technology in Canada, ventured into the market for small-scale, decentralized power systems with the Slowpoke Energy System (SES), a 10MW nuclear reactor for space heating in urban and remote areas. The SES was designed to be 'passively' or 'inherently' safe, such that even the most catastrophic failure of the system would not result in a serious accident (e.g. a meltdown or an explosion). This Canadian initiative, a beneficiary of the National Energy Program, was the first and by far the most successful attempt at a passively safe, decentralized nuclear power system anywhere in the world. Part one uses archival documentation and interviews with project leaders to reconstruct the history of the SES. The standard explanations for the failure of the project, cheap oil, public resistance to the technology, and lack of commercial expertise, are rejected. Part two presents an alternative explanation for the failure of AECL to commercialize the SES. In short, technological momentum towards large-scale nuclear designs led to structural restrictions for the SES project. These restrictions manifested themselves internally to the company (e.g., marginalization of the SES) and externally to the company (e.g., licensing). In part three, the historical lessons of the SES are used to refine one of the central tenets of Popper's political philosophy, 'piecemeal social engineering.' Popper's presentation of the idea is lacking in detail; the analysis of the SES provides some empirical grounding for the concept. I argue that the institutions surrounding traditional nuclear power represent a form utopian social engineering, leading to consequences such as the suspension of civil liberties to guarantee security of the technology. The SES project was an example of a move from the utopian social engineering of large

  1. Best Tracking Performance under Plant Uncertainty and Control Energy Constraint

    Institute of Scientific and Technical Information of China (English)

    KONG Yi-gang; WANG Zhi-xin; WANG Jian-guo

    2007-01-01

    This paper has investigated best tracking performance for linear feedback control systems in the case that plant uncertainty and control effort need to be considered simultaneously. Firstly, an average integral square criterion of the tracking error and the plant input energy over a class of additive model errors is defined. Then, utilizing spectral factorization to minimize the performance index, we obtain an optimal controller design method, and furthermore study optimal tracking performance under plant uncertainty and control energy constraint. The results can be used to evaluate optimal average tracking performance and control energy in designing practical control systems.

  2. 氢原子能级与碱金属原子能级的比较研究%Comparative Studying of Hydrogen Atomic Energy Level and Alkali Metal Atomic Energy Level

    Institute of Scientific and Technical Information of China (English)

    王建伟; 蒲小芹

    2014-01-01

    The article by Bohr theory and The analysis of forces method, considered the interaction of different sit-uation, hydrogen atoms with alkali metal atomic energy level structure have been analyzed, and the numerical cal-culation, energy level diagram have been drawn out., Hydrogen energy and alkali metal atomic energy level were compared, by using the method of comparative study on the similarities and differences are found out.%运用玻尔理论及受力分析的方法,考虑相互作用的不同情况,分析了氢原子与碱金属原子能级结构,并进行了数值计算,画出了能级结构图。再运用比较研究的方法对氢原子能级与碱金属原子能级进行比较,找出其相同点及不同点。

  3. Dynamic modeling, simulation and control of energy generation

    CERN Document Server

    Vepa, Ranjan

    2013-01-01

    This book addresses the core issues involved in the dynamic modeling, simulation and control of a selection of energy systems such as gas turbines, wind turbines, fuel cells and batteries. The principles of modeling and control could be applied to other non-convention methods of energy generation such as solar energy and wave energy.A central feature of Dynamic Modeling, Simulation and Control of Energy Generation is that it brings together diverse topics in thermodynamics, fluid mechanics, heat transfer, electro-chemistry, electrical networks and electrical machines and focuses on their appli

  4. Noise-control needs in the developing energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Keast, D.N.

    1978-03-01

    The noise characteristics of existing energy conversion technologies, e.g., from obtaining and processing fossil fuels to power plants operations, and of developing energy technologies (wind, geothermal sources, solar energy or fusion systems) are discussed in terms of the effects of noise on humans, animals, structures, and equipment and methods for noise control. Regulations for noise control are described. Recommendations are made for further research on noise control and noise effects. (LCL)

  5. Atomic Spectral Methods for Ab Initio Molecular Electronic Energy Surfaces: Transitioning From Small-Molecule to Biomolecular-Suitable Approaches.

    Science.gov (United States)

    Mills, Jeffrey D; Ben-Nun, Michal; Rollin, Kyle; Bromley, Michael W J; Li, Jiabo; Hinde, Robert J; Winstead, Carl L; Sheehy, Jeffrey A; Boatz, Jerry A; Langhoff, Peter W

    2016-08-25

    Continuing attention has addressed incorportation of the electronically dynamical attributes of biomolecules in the largely static first-generation molecular-mechanical force fields commonly employed in molecular-dynamics simulations. We describe here a universal quantum-mechanical approach to calculations of the electronic energy surfaces of both small molecules and large aggregates on a common basis which can include such electronic attributes, and which also seems well-suited to adaptation in ab initio molecular-dynamics applications. In contrast to the more familiar orbital-product-based methodologies employed in traditional small-molecule computational quantum chemistry, the present approach is based on an "ex-post-facto" method in which Hamiltonian matrices are evaluated prior to wave function antisymmetrization, implemented here in the support of a Hilbert space of orthonormal products of many-electron atomic spectral eigenstates familiar from the van der Waals theory of long-range interactions. The general theory in its various forms incorporates the early semiempirical atoms- and diatomics-in-molecules approaches of Moffitt, Ellison, Tully, Kuntz, and others in a comprehensive mathematical setting, and generalizes the developments of Eisenschitz, London, Claverie, and others addressing electron permutation symmetry adaptation issues, completing these early attempts to treat van der Waals and chemical forces on a common basis. Exact expressions are obtained for molecular Hamiltonian matrices and for associated energy eigenvalues as sums of separate atomic and interaction-energy terms, similar in this respect to the forms of classical force fields. The latter representation is seen to also provide a long-missing general definition of the energies of individual atoms and of their interactions within molecules and matter free from subjective additional constraints. A computer code suite is described for calculations of the many-electron atomic eigenspectra and

  6. Experimental investigation on atomization and collecting efficiency of wind-spray dust controller and its parameters optimization

    Institute of Scientific and Technical Information of China (English)

    寇保福; 刘邱祖; 曹世宸; 胡晓禾; 李延峰; 王毅然; 赵波慧

    2015-01-01

    In order to enhance the atomization efficiency of atomizer, a new type of wind-spray dust controller combining the rotary-atomization and colliding broken of droplets was designed by the method of opening the water circulation within the blades. The experiment test for dust controller was conducted by adjusting the following parameters: rotating speed, diversion hole-exit diameter, and colliding tooth angle. Results show that the atomization efficiency increases firstly then decreases with them. And the optimal parameters are obtained with rotating speed 1500−2200 r/min, diversion hole-exit diameter 2−2.5 mm and colliding tooth angle 30°−40°, and under these conditions the corresponding atomization efficiencytops to 95%. Then, the atomization situation under the optimal parameters is held from the aspect of simulation internal flow field and the results of droplet size (30−80μm) are got, which indicates that the conclusion on the optimized parameters of dust controller is reasonable. The collecting efficiencies of different dust concentrations are determined, ranging from 85% to 98.4%, which shows that the designed dust controller can obtain a good atomizing effect and achieve well dustfall efficiency for the wetting dust control of coal mine.

  7. Experimental investigation on atomization and collecting efficiency of wind-spray dust controller and its parameters optimization

    Institute of Scientific and Technical Information of China (English)

    寇保福; 刘邱祖; 曹世宸; 胡晓禾; 李延峰; 王毅然; 赵波慧

    2015-01-01

    In order to enhance the atomization efficiency of atomizer, a new type of wind-spray dust controller combining the rotary-atomization and colliding broken of droplets was designed by the method of opening the water circulation within the blades. The experiment test for dust controller was conducted by adjusting the following parameters: rotating speed, diversion hole-exit diameter, and colliding tooth angle. Results show that the atomization efficiency increases firstly then decreases with them. And the optimal parameters are obtained with rotating speed 1500-2200 r/min, diversion hole-exit diameter 2-2.5 mm and colliding tooth angle 30°-40°, and under these conditions the corresponding atomization efficiency tops to 95%. Then, the atomization situation under the optimal parameters is held from the aspect of simulation internal flow field and the results of droplet size(30-80 μm) are got, which indicates that the conclusion on the optimized parameters of dust controller is reasonable. The collecting efficiencies of different dust concentrations are determined, ranging from 85% to 98.4%, which shows that the designed dust controller can obtain a good atomizing effect and achieve well dustfall efficiency for the wetting dust control of coal mine.

  8. Controlling the magnetic field sensitivity of atomic clock states by microwave dressing

    CERN Document Server

    Sárkány, L; Hattermann, H; Fortágh, J

    2014-01-01

    We demonstrate control of the differential Zeeman shift between clock states of ultracold rubidium atoms by means of non-resonant microwave dressing. Using the dc-field dependence of the microwave detuning, we suppress the first and second order differential Zeeman shift in magnetically trapped $^{87}$Rb atoms. By dressing the state pair 5S$_{1/2} F= 1, m_F = -1$ and $F= 2, m_F = 1$, a residual frequency spread of <0.1 Hz in a range of 100 mG around a chosen magnetic offset field can be achieved. This is one order of magnitude smaller than the shift of the bare states at the magic field of the Breit-Rabi parabola. We further identify double magic points, around which the clock frequency is insensitive to fluctuations both in the magnetic field and the dressing Rabi frequency. The technique is compatible with chip-based cold atom systems and allows the creation of clock and qubit states with reduced sensitivity to magnetic field noise.

  9. Impact of Atomic Structure on Absolute Energy Levels of Methylammonium Lead Iodide Perovskite

    Science.gov (United States)

    Choi, Joshua

    2015-03-01

    There has been a staggeringly rapid increase in the photovoltaic performance of methylammonium lead iodide (MAPbI3) perovskite - greater than 19 percent solar cell power conversion efficiency has been reported in less than five years since the first report in 2009. Despite the progress in device performance, structure-property relationships in MAPbI3 are still poorly understood. I will present our recent findings on the impact of changing the Pb-I bond length and Pb-I-Pb bond angle on the electronic structure of MAPbI3. By using the combination of temperature dependent X-ray scattering, ultraviolet photoelectron spectroscopy, absorbance and PL spectroscopy, we show that the energy levels of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) shift in the same direction as MAPbI3 goes through tetragonal-to-cubic structural phase transition wherein the rotational angle of PbI6 octahedra is the order parameter of the transition. Our experimental results are corroborated by density functional theory calculations which show that the lattice expansion and bond angle distortion cause different degree of orbital overlap between the Pb and I atoms and the anti-bonding orbital nature of both HOMO and LUMO results in the same direction of their shift. Moreover, through pair distribution function analysis of X-ray scattering, we discovered that the majority of MAPbI3 in thin film solar cell layer has highly disordered structure with a coherence range of only 1.4 nm. The nanostructuring correlates with a blueshift of the absorption onset and increases the photoluminescence. Our results underscore the importance of understanding the structure-property relationships in order to improve the device performance of metal-organic perovskites.

  10. Advances in the production of isotopes and radiopharmaceuticals at the Atomic Energy Corporation of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Louw, P.A.; De Villiers, W.Y.Z.; Jarvis, N.V. [Atomic Energy Corporation of South Africa Ltd, Pretoria (South Africa)

    1997-10-01

    The Atomic Energy Corporation of South Africa Ltd (AEC) owns and operates the 20 MW research reactor, SAFARI-1. Utilisation of the reactor has in recent years changed from research and materials testing to the production of isotopes. The most important breakthrough achieved in recent years is the production of high quality fission 99Mo. This has been produced routinely since April 1993 and supplied to clients across the world. A capability for the reliable production of 1000 Ci of 99Mo per week (calibrated for six days after production) has been proven. The AEC has also established facilities to produce its own 99mTc generators together with a most of radiopharmaceutical kits for diagnostic nuclear medicine purposes. The production of {sup 153}Sm and {sup 131}I (tellurium oxide route) has been operational for many years. Applications include therapeutic radiopharmaceuticals such as {sup 153}Sm-EDTMP for bone cancer pain palliation, {sup 13`}I-Lipiodol for liver cancer and {sup 131}I capsules for thyroid treatment. Facilities for the production of other isotopes such as {sup 131}I (from fission), {sup 32}P and {sup 35}S are in various stages of completion. Extensive analytical methods and equipment have been developed and are routinely used to certify the quality of exported isotopes. Irradiation and encapsulation of {sup 192}Ir is also performed routinely at the AEC. Modern facilities allow for the production of isotopes such as {sup 131}Ba and {sup 140}La on an ad hoc basis. Quality assurance procedures based on ISO9000 were developed for all aspects of the production of the various isotopes. Documentation, such as Drug Master Files, required by authorities in various countries has also been submitted and accepted 15 refs., 1 tab., 2 figs.

  11. Nuclear nonproliferation and safety: Challenges facing the International Atomic Energy Agency

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The Chairman of the Senate Committee on Govermental Affairs asked the United States General Accounting Office (GAO) to review the safeguards and nuclear power plant safety programs of the International Atomic Energy Agency (IAEA). This report examines (1) the effectiveness of IAEA`s safeguards program and the adequacy of program funding, (2) the management of U.S. technical assistance to the IAEA`s safeguards program, and (3) the effectiveness of IAEA`s program for advising United Nations (UN) member states about nuclear power plant safety and the adequacy of program funding. Under its statute and the Treaty on the Non-Proliferation of Nuclear Weapons, IAEA is mandated to administer safeguards to detect diversions of significant quantities of nuclear material from peaceful uses. Because of limits on budget growth and unpaid contributions, IAEA has had difficulty funding the safeguards program. IAEA also conducts inspections of facilities or locations containing declared nuclear material, and manages a program for reviewing the operational safety of designated nuclear power plants. The U.S. technical assistance program for IAEA safeguards, overseen by an interagency coordinating committee, has enhanced the agency`s inspection capabilities, however, some weaknesses still exist. Despite financial limitations, IAEA is meeting its basic safety advisory responsibilities for advising UN member states on nuclear safety and providing requested safety services. However, IAEA`s program for reviewing the operational safety of nuclear power plants has not been fully effective because the program is voluntary and UN member states have not requested IAEA`s review of all nuclear reactors with serious problems. GAO believes that IAEA should have more discretion in selecting reactors for review.

  12. Instrumentation and Control for Fossil-Energy Processes

    Science.gov (United States)

    Mark, A., Jr.

    1984-01-01

    Instrumentation and control requirements for fossil-energy processes discussed in working document. Published to foster advancement of instrumentation and control technology by making equipment suppliers and others aware of specifications, needs, and potential markets.

  13. An evaluation of exchange-correlation functionals for the calculations of the ionization energies for atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Segala, Maximiliano [Universidade Estadual do Rio Grande do Sul, Rua Oscar Matzembacher 475, 96760-000, Tapes, RS (Brazil); Chong, Delano P. [Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, B.C., V6T 1Z1 (Canada)], E-mail: chong@chem.ubc.ca

    2009-04-15

    In this paper, ionization energies of gas-phase atoms and molecules are calculated by energy-difference method and by approximate transition-state models with density functional theory (DFT). To determine the best functionals for ionization energies, we first study the H to Ar atoms. An approximation is used in which the electron density is first obtained from Kohn-Sham computations with an exchange-correlation potential V{sub xc} known as statistical average of orbital potentials (SAOP), after which the energy is computed from that density with 59 different exchange-correlation energy functionals E{sub xc}. For the 18 atoms, the best E{sub xc} functional providing an average absolute deviation (AAD) of only 0.110 eV is one known as the Krieger-Chen-Iafrate-Savin functional modified by Krieger, Chen, Iafrate, and Kurth, if one uses the spin-polarized spherical atom description. On the other hand, if one imposes the condition of integer-electrons, the best functional is the Becke 1997 functional modified by Wilson, Bradley, and Tozer, with an AAD of 0.107 eV, while several other functionals perform almost as well. For molecules, we can achieve an accuracy of AAD = 0.21 eV for valence VIPs of nonperhalo molecules with {delta}E(V{sub xc} = SAOP;PBE0) using integer-electron description. For perhalo molecules our best approach is {delta}E(V{sub xc} from either E{sub xc} or SAOP;mPW1PW) with full symmetry to obtain an AAD = 0.24 eV.

  14. Optical control of resonant light transmission for an atom-cavity system

    CERN Document Server

    Sharma, Arijit; Sawant, Rahul V; Sheikholeslami, G; Budker, D; Rangwala, S A

    2015-01-01

    We demonstrate the manipulation of transmitted light through an optical Fabry-Perot cavity, built around a spectroscopy cell containing enriched rubidium vapor. Light resonant with the $^{87}$Rb D$_{2}$ ($F=2/F=1$) $\\leftrightarrow F'$ manifold, is controlled by transverse intersection of the cavity mode by another resonant light beam. The cavity transmission can be suppressed or enhanced depending on the coupling of atomic states due to the intersecting beams. The extreme manifestation of cavity mode control is the precipitious destruction (negative logic switching) or buildup (positive logic switching) of the transmitted light intensity, on intersection of the transverse control beam with the cavity mode. Both the steady state and transient response are experimentally investigated. The mechanism behind the change in cavity transmission is discussed in brief.

  15. Correlation and contingency analysis of atom probe data: Diffusion-controlled dissolution of precipitates

    Energy Technology Data Exchange (ETDEWEB)

    Camus, E. (Hahn-Meitner-Institut Berlin GmbH (Germany)); Abromeit, C. (Hahn-Meitner-Institut Berlin GmbH (Germany))

    1994-05-01

    A statistical analysis of atom probe data is developed for evaluating the evolution of local composition fluctuations in concentrated alloys. The model allows the calculation of theoretical correlation and contingency coefficients for a presumed alloy microstructure taking into account the instrumental parameters, i.e. aperture size, block size and detector efficiency. A comparison of theoretical coefficients with those obtained from measured concentration profiles gives access to physically relevant parameters. The analysis is applied to the diffusion-controlled dissolution of spherical precipitates in the technical alloy Nimonic PE16 under ion irradiation. (orig.)

  16. State Feedback Control for Adjusting the Dynamic Behavior of a Piezoactuated Bimorph Atomic Force Microscopy Probe

    CERN Document Server

    Orun, Bilal; Basdogan, Cagatay; Guvenc, Levent

    2012-01-01

    We adjust the transient dynamics of a piezo-actuated bimorph Atomic Force Microscopy (AFM) probe using a state feedback controller. This approach enables us to adjust the quality factor and the resonance frequency of the probe simultaneously. First, we first investigate the effect of feedback gains on dynamic response of the probe and then show that the time constant of the probe can be reduced by reducing its quality factor and/or increasing its resonance frequency to reduce the scan error in tapping mode AFM.

  17. Optimal control of oscillation wave energy system using velocity premonition

    Institute of Scientific and Technical Information of China (English)

    CUI; Xiao

    2015-01-01

    Recently ocean wave energy draw much more attention for its widespread,abundant and highly energy flux density properties.Extracting energy from incident wave however,is limited for the random and unstable power input.Motion control for WEC is a promising method to improve the energy absorption and some practical applications are also verified such as latching control.In this paper,an active control strategy is proposed to achieve maximum energy capture.The mathematical description shows that the active control has the characteristic of anti-causal and the wave premonition is necessary for controller design.But the fact of premonition time horizon is still unclear.In this paper,the premonition nature is described mathematically based on hydrodynamic theory.Furthermore,a simulation is also performed to study the impacting of premonition time horizon on WEC’s properties and give a more insightful understanding of WEC active control.

  18. Refined Dummy Atom Model of Mg(2+) by Simple Parameter Screening Strategy with Revised Experimental Solvation Free Energy.

    Science.gov (United States)

    Jiang, Yang; Zhang, Haiyang; Feng, Wei; Tan, Tianwei

    2015-12-28

    Metal ions play an important role in the catalysis of metalloenzymes. To investigate metalloenzymes via molecular modeling, a set of accurate force field parameters for metal ions is highly imperative. To extend its application range and improve the performance, the dummy atom model of metal ions was refined through a simple parameter screening strategy using the Mg(2+) ion as an example. Using the AMBER ff03 force field with the TIP3P model, the refined model accurately reproduced the experimental geometric and thermodynamic properties of Mg(2+). Compared with point charge models and previous dummy atom models, the refined dummy atom model yields an enhanced performance for producing reliable ATP/GTP-Mg(2+)-protein conformations in three metalloenzyme systems with single or double metal centers. Similar to other unbounded models, the refined model failed to reproduce the Mg-Mg distance and favored a monodentate binding of carboxylate groups, and these drawbacks needed to be considered with care. The outperformance of the refined model is mainly attributed to the use of a revised (more accurate) experimental solvation free energy and a suitable free energy correction protocol. This work provides a parameter screening strategy that can be readily applied to refine the dummy atom models for metal ions.

  19. Hubbard model for ultracold bosonic atoms interacting via zero-point-energy-induced three-body interactions

    Science.gov (United States)

    Paul, Saurabh; Johnson, P. R.; Tiesinga, Eite

    2016-04-01

    We show that, for ultracold neutral bosonic atoms held in a three-dimensional periodic potential or optical lattice, a Hubbard model with dominant, attractive three-body interactions can be generated. In fact, we derive that the effect of pairwise interactions can be made small or zero starting from the realization that collisions occur at the zero-point energy of an optical lattice site and the strength of the interactions is energy dependent from effective-range contributions. We determine the strength of the two- and three-body interactions for scattering from van der Waals potentials and near Fano-Feshbach resonances. For van der Waals potentials, which for example describe scattering of alkaline-earth atoms, we find that the pairwise interaction can only be turned off for species with a small negative scattering length, leaving the 88Sr isotope a possible candidate. Interestingly, for collisional magnetic Feshbach resonances this restriction does not apply and there often exist magnetic fields where the two-body interaction is small. We illustrate this result for several known narrow resonances between alkali-metal atoms as well as chromium atoms. Finally, we compare the size of the three-body interaction with hopping rates and describe limits due to three-body recombination.

  20. A new method to measure electron density and effective atomic number using dual-energy CT images

    Science.gov (United States)

    Ramos Garcia, Luis Isaac; Pérez Azorin, José Fernando; Almansa, Julio F.

    2016-01-01

    The purpose of this work is to present a new method to extract the electron density ({ρ\\text{e}} ) and the effective atomic number (Z eff) from dual-energy CT images, based on a Karhunen-Loeve expansion (KLE) of the atomic cross section per electron. This method was used to calibrate a Siemens Definition CT using the CIRS phantom. The predicted electron density and effective atomic number using 80 kVp and 140 kVp were compared with a calibration phantom and an independent set of samples. The mean absolute deviations between the theoretical and calculated values for all the samples were 1.7 %  ±  0.1 % for {ρ\\text{e}} and 4.1 %  ±  0.3 % for Z eff. Finally, these results were compared with other stoichiometric method. The application of the KLE to represent the atomic cross section per electron is a promising method for calculating {ρ\\text{e}} and Z eff using dual-energy CT images.

  1. Model Predictive Control for Smart Energy Systems

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus

    load shifting capabilities of the units that adapts to the given price predictions. We furthermore evaluated control performance in terms of economic savings for different control strategies and forecasts. Chapter 5 describes and compares the proposed large-scale Aggregator control strategies....... Aggregators are assumed to play an important role in the future Smart Grid and coordinate a large portfolio of units. The developed economic MPC controllers interfaces each unit directly to an Aggregator. We developed several MPC-based aggregation strategies that coordinates the global behavior of a portfolio...

  2. Controlling Energy Demand in Mobile Computing Systems

    CERN Document Server

    Ellis, Carla

    2007-01-01

    This lecture provides an introduction to the problem of managing the energy demand of mobile devices. Reducing energy consumption, primarily with the goal of extending the lifetime of battery-powered devices, has emerged as a fundamental challenge in mobile computing and wireless communication. The focus of this lecture is on a systems approach where software techniques exploit state-of-the-art architectural features rather than relying only upon advances in lower-power circuitry or the slow improvements in battery technology to solve the problem. Fortunately, there are many opportunities to i

  3. First-Principles Molecular Dynamics Investigation of the Atomic-Scale Energy Transport: From Heat Conduction to Thermal Radiation

    CERN Document Server

    Ji, Pengfei

    2016-01-01

    First-principles molecular dynamics simulation based on a plane wave/pseudopotential implementation of density functional theory is adopted to investigate atomic scale energy transport for semiconductors (silicon and germanium). By imposing thermostats to keep constant temperatures of the nanoscale thin layers, initial thermal non-equilibrium between the neighboring layers is established under the vacuum condition. Models with variable gap distances with an interval of lattice constant increment of the simulated materials are set up and statistical comparisons of temperature evolution curves are made. Moreover, the equilibration time from non-equilibrium state to thermal equilibrium state of different silicon or/and germanium layers combinations are calculated. The results show significant distinctions of heat transfer under different materials and temperatures combinations. Further discussions on the equilibrium time are made to explain the simulation results. As the first work of the atomic scale energy tra...

  4. Estimation of length scale of RS II-$p$ braneworld model through perturbations in Helium's atom ground state energy

    CERN Document Server

    Garrido, Nephtali

    2012-01-01

    We put to the test an effective three-dimensional electrostatic potential, obtained effectively by considering an electrostatic source inside a (5+$p$)-dimensional braneworld scenario with $p$ compact and one infinite spacial extra dimensions in the RS II-$p$ model, for $p=1$ and $p=2$. This potential is regular at the source and matches the standard Coulomb potential outside a neighborhood. We use variational and perturbative approximation methods to calculate corrections to the ground energy of the Helium atom modified by this potential, by making use of a 6 and 39-parameter trial wave function of Hylleraas type for the ground state. These corrections to the ground-state energy are compared with experimental data for Helium atom in order to set bounds for the extra dimensions length scale. We find that these bounds are less restrictive than the ones obtained by Morales et. al. through a calculation using the Lamb shift in Hydrogen.

  5. Stereodynamical Origin of Anti-Arrhenius Kinetics: Negative Activation Energy and Roaming for a Four-Atom Reaction.

    Science.gov (United States)

    Coutinho, Nayara D; Silva, Valter H C; de Oliveira, Heibbe C B; Camargo, Ademir J; Mundim, Kleber C; Aquilanti, Vincenzo

    2015-05-07

    The OH + HBr → H2O + Br reaction, prototypical of halogen-atom liberating processes relevant to mechanisms for atmospheric ozone destruction, attracted frequent attention of experimental chemical kinetics: the nature of the unusual reactivity drop from low to high temperatures eluded a variety of theoretical efforts, ranking this one among the most studied four-atom reactions. Here, inspired by oriented molecular-beams experiments, we develop a first-principles stereodynamical approach. Thermalized sets of trajectories, evolving on a multidimensional potential energy surface quantum mechanically generated on-the-fly, provide a map of most visited regions at each temperature. Visualizations of rearrangements of bonds along trajectories and of the role of specific angles of reactants' mutual approach elucidate the mechanistic change from the low kinetic energy regime (where incident reactants reorient to find the propitious alignment leading to reaction) to high temperature (where speed hinders adjustment of directionality and roaming delays reactivity).

  6. Current mapping of low-energy (120 eV) helium and hydrogen irradiated tungsten by conductive atomic force microscopy

    Science.gov (United States)

    Fan, Hongyu; Endo, Takashi; Bi, Zhenghua; Yan, Weibin; Ohnuki, Somei; Yang, Qi; Ni, Weiyuan; Liu, Dongping

    2017-04-01

    Both conductive atomic force microscopy (CAFM) and transmission electron microscopy have been used to characterize the defects or He bubbles in low-energy (120 eV) H and He irradiated tungsten (W). By a comparative study, we find that the current mapping from CAFM is very sensitive in the detection of nanometer-sized defects in low-energy H and He irradiated W. Our calculation confirms that the resistance change in H and He irradiated W is strongly affected by the distance between atomic force microscopy tip and defects/He bubbles. CAFM can accurately detect defects/He bubbles in the W surface layer, however, it is infeasible to measure them in the deep layer (>20 nm), especially due to the existence of defects in the surface layer.

  7. Tumor radiosensitizers - current status of development of various approaches: Report of an International Atomic Energy Agency meeting

    DEFF Research Database (Denmark)

    Horsman, Michael Robert; Bohm, Lothar; Margison, Geoffrey P.

    2006-01-01

    PURPOSE: The International Atomic Energy Agency (IAEA) held a Technical Meeting of Consultants to (1) discuss a selection of relatively new agents, not those well-established in clinical practice, that operated through a variety of mechanisms to sensitize tumors to radiation and (2) to compare...... and contrast their tumor efficacy, normal tissue toxicity, and status of development regarding clinical application. The aim was to advise the IAEA as to which developing agent or class of agents would be worth promoting further, by supporting additional laboratory research or clinical trials...... and for clinical trials that would be suitable for industrialized countries, as well as trials that were considered more appropriate for developing countries.PURPOSE: The International Atomic Energy Agency (IAEA) held a Technical Meeting of Consultants to (1) discuss a selection of relatively new agents, not those...

  8. A study on environmental pollution control in energy field

    Energy Technology Data Exchange (ETDEWEB)

    Min, B.M.; Son, J.E.; Lee, H.K.; Choi, W.K.; Baek, I.H.; Lee, J.S. [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

    1995-12-01

    This report is contained such as following contents; Preparation of the stepwise pollution control strategies to reduce pollutants in energy field, which will be satisfy to tightened emission standard in the future. Analysis of the environmental pollution control technologies level, which related to energy field in domestic and other countries. Visualization of the reduction strategies of domestic carbon dioxide emission in energy field. And, discussion and proposal of the R and D program to improve the domestic environmental pollution control technologies in energy field. (author). 99 refs., 67 figs., 73 tabs.

  9. Controlling Atomic, Solid-State and Hybrid Systems for Quantum Information Processing

    Science.gov (United States)

    Gullans, Michael John

    Quantum information science involves the use of precise control over quantum systems to explore new technologies. However, as quantum systems are scaled up they require an ever deeper understanding of many-body physics to achieve the required degree of control. Current experiments are entering a regime which requires active control of a mesoscopic number of coupled quantum systems or quantum bits (qubits). This thesis describes several approaches to this goal and shows how mesoscopic quantum systems can be controlled and utilized for quantum information tasks. The first system we consider is the nuclear spin environment of GaAs double quantum dots containing two electrons. We show that the through appropriate control of dynamic nuclear polarization one can prepare the nuclear spin environment in three distinct collective quantum states which are useful for quantum information processing with electron spin qubits. We then investigate a hybrid system in which an optical lattice is formed in the near field scattering off an array of metallic nanoparticles by utilizing the plasmonic resonance of the nanoparticles. We show that such a system would realize new regimes of dense, ultra-cold quantum matter and can be used to create a quantum network of atoms and plasmons. Finally we investigate quantum nonlinear optical systems. We show that the intrinsic nonlinearity for plasmons in graphene can be large enough to make a quantum gate for single photons. We also consider two nonlinear optical systems based on ultracold gases of atoms. In one case, we demonstrate an all-optical single photon switch using cavity quantum electrodynamics (QED) and slow light. In the second case, we study few photon physics in strongly interacting Rydberg polariton systems, where we demonstrate the existence of two and three photon bound states and study their properties.

  10. Distributed-dispersed renewable energy systems and novel control strategies

    Science.gov (United States)

    Aljankawey, Abdualah S.

    Renewable green-energy systems are re-emerging as viable economic alternative sources of environmentally safe power generation in place of conventional fossil fuels. In terms of power quality and safety, this research investigates a number of renewable green-energy (wind, photovoltaic and fuel cells) interface schemes and control strategies that ensure maximum energy utilization, voltage and frequency stabilization and minimum impact on the host electric grid systems. The research key objectives are to study efficient and robust renewable energy converter schemes with associated control strategies and validate their operations for both stand-alone and electric utility grid interfacing. The research work investigates both stand-alone and grid connected renewable green-energy utilization schemes with a number of power electronic converter topologies and robust control schemes for both dispersed and hybrid renewable energy systems. Different sample study systems and control strategies are digitally simulated and fully validated using the MATLAB-Simulink-SimPower environment.

  11. Energy control strategy for parallel hydrostatic transmission hybrid vehicles

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; JIANG Ji-hai; WANG Xin

    2009-01-01

    Aimed at the relatively lower energy density and complicated coordinating operation between two power sources, a special energy control strategy is required to maximize the fuel saving potential. Then a new type of configuration for hydrostatic transmission hybrid vehicles (PHHV) and the selection criterion for impor-tant components are proposed. Based on the optimization of planet gear transmission ratio and the analysis of op-timal energy distribution for the proposed PHHV on a representative urban driving cycle, a fuzzy torque control strategy and a braking energy regeneration strategy are designed and developed to realize the real-time control of energy for the proposed PHHV. Simulation results demonstrate that the energy control strategy effectively im-proves the fuel economy of PHHV.

  12. Back-Influence of Molecular Motion on Energy Transfer in the Landau-Teller Model of Atom Molecule Scattering.

    Science.gov (United States)

    Pollak, Eli

    2016-07-21

    This year we celebrate the 80th anniversary of the Landau-Teller model for energy exchange in a collinear collision of an atom with a harmonic diatomic molecule. Even after 80 years though, the analytic theory to date has not included in it the back-influence of the oscillator's motion on the energy transfer between the approaching particle and the molecule. This is the topic of the present paper. The back-influence can be obtained by employing classical second-order perturbation theory. The second-order theory is used in both a classical and semiclassical context. Classically, analytic expressions are derived for the final phase and action of the diatom, after the collision. The energy loss of the atom is shown to decrease linearly with the increasing energy of the oscillator. The magnitude of this decrease is a direct consequence of the back-reaction of the oscillator on the translational motion. The qualitative result is universal, in the sense that it is not dependent on the details of the interaction of the atom with the oscillator. A numerical application to a model collision of an Ar atom with a Br2 diatom demonstrates the importance and accuracy of the second-order perturbation theory. The same results are then used to derive a second-order perturbation theory semiclassical expression for the quantum transition probability from initial vibrational state ni to final vibrational state nf of the oscillator. A comparison of the theory with exact quantum data is presented for a model collision of Br2 with a hydrogen molecule, where the hydrogen molecule is considered as a single approaching particle.

  13. Intelligent control of energy-saving power generation system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhiyuan; Zhang, Guoqing; Guo, Zhizhong [Harbin Institute of Technology, Harbin (China). Dept. of Electrical Engineering

    2013-07-01

    Highway power generation system which is environmentally friendly and sustainable provides an innovative method of energy conversion. It is also as a kind of city science and technology innovation, which has the characteristics of environmental protection and sustainable utilization. Making full use of vehicle impact speed control humps, we design a new kind of highway speed control humps combined with solar electric generation system integration. Developing green energy, energy saving and environment protection can be achieved.

  14. Collisions of electrons with hydrogen atoms I. Package outline and high energy code

    Science.gov (United States)

    Benda, Jakub; Houfek, Karel

    2014-11-01

    Being motivated by the applied researchers’ persisting need for accurate scattering data for the collisions of electrons with hydrogen atoms, we developed a computer package-Hex-that is designed to provide trustworthy results for all basic discrete and continuous processes within non-relativistic framework. The package consists of several computational modules that implement different methods, valid for specific energy regimes. Results of the modules are kept in a common database in the unified form of low-level scattering data (partial-wave T-matrices) and accessed by an interface program which is able to produce various derived quantities like e.g. differential and integral cross sections. This article is the first one of a series of articles that are concerned with the implementation and testing of the modules. Here we give an overview of their structure and present (a) the command-line interface program hex-db that can be also easily compiled into a derived code or used as a backend for a web-page form and (b) simple illustrative module specialized for high energies, hex-dwba, that implements distorted and plane wave Born approximation. Catalogue identifier: AETH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETH_v1_0.html Program obtainable from: CPC Program library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data etc.: 30367 No. of bytes in distributed program, including test data etc.: 232032 Distribution format: tar.gz Programming language: C++11 Operating system: Any system with a C++11 compiler (e.g. GCC 4.8.1; tested on OpenSUSE 13.1 and Windows 8). RAM: Test run 3 MiB. CPC Library Classification: 2.4 Electron scattering External libraries:GSL [49], FFTW3[52], SQLite3 [46]. All of the libraries are open-source and maintained. Nature of problem: Extraction of derived (observable) quantities from partial

  15. Doping of Semiconducting Atomic Chains

    Science.gov (United States)

    Toshishige, Yamada; Kutler, Paul (Technical Monitor)

    1997-01-01

    Due to the rapid progress in atom manipulation technology, atomic chain electronics would not be a dream, where foreign atoms are placed on a substrate to form a chain, and its electronic properties are designed by controlling the lattice constant d. It has been shown theoretically that a Si atomic chain is metallic regardless of d and that a Mg atomic chain is semiconducting or insulating with a band gap modified with d. For electronic applications, it is essential to establish a method to dope a semiconducting chain, which is to control the Fermi energy position without altering the original band structure. If we replace some of the chain atoms with dopant atoms randomly, the electrons will see random potential along the chain and will be localized strongly in space (Anderson localization). However, if we replace periodically, although the electrons can spread over the chain, there will generally appear new bands and band gaps reflecting the new periodicity of dopant atoms. This will change the original band structure significantly. In order to overcome this dilemma, we may place a dopant atom beside the chain at every N lattice periods (N > 1). Because of the periodic arrangement of dopant atoms, we can avoid the unwanted Anderson localization. Moreover, since the dopant atoms do not constitute the chain, the overlap interaction between them is minimized, and the band structure modification can be made smallest. Some tight-binding results will be discussed to demonstrate the present idea.

  16. Scattering of NH{sub 3} and ND{sub 3} with rare gas atoms at low collision energy

    Energy Technology Data Exchange (ETDEWEB)

    Loreau, J., E-mail: jloreau@ulb.ac.be [Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB) CP 160/09, 50 av. F.D. Roosevelt, 1050 Brussels (Belgium); Avoird, A. van der, E-mail: A.vanderAvoird@theochem.ru.nl [Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands)

    2015-11-14

    We present a theoretical study of elastic and rotationally inelastic collisions of NH{sub 3} and ND{sub 3} with rare gas atoms (He, Ne, Ar, Kr, Xe) at low energy. Quantum close-coupling calculations have been performed for energies between 0.001 and 300 cm{sup −1}. We focus on collisions in which NH{sub 3} is initially in the upper state of the inversion doublet with j = 1, k = 1, which is the most relevant in an experimental context as it can be trapped electrostatically and Stark-decelerated. We discuss the presence of resonances in the elastic and inelastic cross sections, as well as the trends in the inelastic cross sections along the rare gas series and the differences between NH{sub 3} and ND{sub 3} as a colliding partner. We also demonstrate the importance of explicitly taking into account the umbrella (inversion) motion of NH{sub 3} in order to obtain accurate scattering cross sections at low collision energy. Finally, we investigate the possibility of sympathetic cooling of ammonia using cold or ultracold rare gas atoms. We show that some systems exhibit a large ratio of elastic to inelastic cross sections in the cold regime, which is promising for sympathetic cooling experiments. The close-coupling calculations are based on previously reported ab initio potential energy surfaces for NH{sub 3}–He and NH{sub 3}–Ar, as well as on new, four-dimensional, potential energy surfaces for the interaction of ammonia with Ne, Kr, and Xe, which were computed using the coupled-cluster method and large basis sets. We compare the properties of the potential energy surfaces corresponding to the interaction of ammonia with the various rare gas atoms.

  17. A Computer-Controlled Classroom Model of an Atomic Force Microscope

    Science.gov (United States)

    Engstrom, Tyler A.; Johnson, Matthew M.; Eklund, Peter C.; Russin, Timothy J.

    2015-12-01

    The concept of "seeing by feeling" as a way to circumvent limitations on sight is universal on the macroscopic scale—reading Braille, feeling one's way around a dark room, etc. The development of the atomic force microscope (AFM) in 1986 extended this concept to imaging in the nanoscale. While there are classroom demonstrations that use a tactile probe to map the topography or some other property of a sample, the rastering of the probe over the sample is manually controlled, which is both tedious and potentially inaccurate. Other groups have used simulation or tele-operation of an AFM probe. In this paper we describe a teaching AFM with complete computer control to map out topographic and magnetic properties of a "crystal" consisting of two-dimensional arrays of spherical marble "atoms." Our AFM is well suited for lessons on the "Big Ideas of Nanoscale" such as tools and instrumentation, as well as a pre-teaching activity for groups with remote access AFM or mobile AFM. The principle of operation of our classroom AFM is the same as that of a real AFM, excepting the nature of the force between sample and probe.

  18. Hydration free energies using semiempirical quantum mechanical Hamiltonians and a continuum solvent model with multiple atomic-type parameters.

    Science.gov (United States)

    Anisimov, Victor M; Cavasotto, Claudio N

    2011-06-23

    To build the foundation for accurate quantum mechanical (QM) simulation of biomacromolecules in an aqueous environment, we undertook the optimization of the COnductor-like Screening MOdel (COSMO) atomic radii and atomic surface tension coefficients for different semiempirical Hamiltonians adhering to the same computational conditions recently followed in the simulation of biomolecular systems. This optimization was achieved by reproducing experimental hydration free energies of a set consisting of 507 neutral and 99 ionic molecules. The calculated hydration free energies were significantly improved by introducing a multiple atomic-type scheme that reflects different chemical environments. The nonpolar contribution was treated according to the scaled particle Claverie-Pierotti formalism. Separate radii and surface tension coefficient sets have been developed for AM1, PM3, PM5, and RM1 semiempirical Hamiltonians, with an average unsigned error for neutral molecules of 0.64, 0.66, 0.73, and 0.71 kcal/mol, respectively. Free energy calculation of each molecule took on average 0.5 s on a single processor. The new sets of parameters will enhance the quality of semiempirical QM calculations using COSMO in biomolecular systems. Overall, these results further extend the utility of QM methods to chemical and biological systems in the condensed phase.

  19. Fuzzy-Logic Subsumption Controller for Home Energy Management Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, Nathan; Johnson, Brian; Lundstrom, Blake

    2015-10-06

    Home Energy Management Systems (HEMS) are controllers that manage and coordinate the generation, storage, and loads in a home. These controllers are increasingly necessary to ensure that increasing penetrations of distributed energy resources are used effectively and do not disrupt the operation of the grid. In this paper, we propose a novel approach to HEMS design based on behavioral control methods, which do not require accurate models or predictions and are very responsive to changing conditions. We develop a proof-of-concept behavioral HEMS controller and show by simulation on an example home energy system that it capable of making context-dependent tradeoffs between goals under challenging conditions.

  20. Effects of RYGB on energy expenditure, appetite and glycemic control

    DEFF Research Database (Denmark)

    Schmidt, Julie Berg; Pedersen, Susie Dawn; Gregersen, Nikolaj Ture;

    2016-01-01

    the effect of RYGB on glycaemic control per se. Here, we investigated the effect of RYGB on EE, appetite, glycaemic control, and specific signalling molecules compared to a control group in comparable negative energy balance. Subjects/Methods:Obese normal glucose tolerant participants were randomized......Objectives: Increased energy expenditure (EE) has been proposed an important mechanism for weight loss following Roux-en-Y gastric bypass (RYGB). However, this has never been investigated in a controlled setting independent of changes in energy balance. Likewise, only few studies have investigated...

  1. Third-party protection and residual risk in Atomic Energy Act. On legally dogmatic classification of paragraph 7 Atomic Energy Act in the jurisprudence of the Federal Constitutional Law and Federal Administrative Court; Drittschutz und Restrisiko im Atomrecht. Zur rechtsdogmatischen Einordnung des paragraph 7d AtG in die Rechtsprechung des Bundesverfassungs- und des Bundesverwaltungsgerichts

    Energy Technology Data Exchange (ETDEWEB)

    Arndt, Hans-Wolfgang

    2012-03-15

    On 25th June 2009, the Council of the European Union has passed the directive 2009/71/EURATOM on a common framework for nuclear safety of nuclear installations. At first, the 12th Law amending the Atomic Energy Act supplements the Atomic Energy Act by regulations which implement the directive 2009/71/EURATIM into national law. In addition, paragraph 7 Atomic Energy Act introduces a new substantive obligation of the operators of nuclear power plants. The author of the contribution reports on whether paragraph 7 Atomic Energy Act provides additional nuclear protection or reduces the potential protection by law and jurisprudence.

  2. Control of degreening in postharvest green sour citrus fruit by electrostatic atomized water particles.

    Science.gov (United States)

    Yamauchi, Naoki; Takamura, Kohtaro; Shigyo, Masayoshi; Migita, Catharina Taiko; Masuda, Yukihiro; Maekawa, Tetsuya

    2014-08-01

    The effect of electrostatic atomized water particles (EAWP) on degreening of green sour citrus fruit during storage was determined. Superoxide anion and hydroxyl radicals included in EAWP were present on the surface of the fruit peel after the treatment. Hydrogen peroxide was formed from EAWP in an aqueous solution, which could indicate that a hydroxyl radical of EAWP turns to hydrogen peroxide in the fruit flavedo as well as in the aqueous solution. EAWP treatment effectively suppressed the degreening of green yuzu and Nagato-yuzukichi fruits during storage at 20°C. The enhancement in K+ ion leakage of both EAWP-treated fruits reduced in comparison with the control. In spite of EAWP treatment, total peroxide level in both fruits showed almost no changes during storage, suggesting that hydrogen peroxide formed by EAWP treatment could stimulate the activation of hydrogen peroxide scavenging system and control degreening of these fruits during storage.

  3. Energy Optimal Control Strategy of PHEV Based on PMP Algorithm

    Directory of Open Access Journals (Sweden)

    Tiezhou Wu

    2017-01-01

    Full Text Available Under the global voice of “energy saving” and the current boom in the development of energy storage technology at home and abroad, energy optimal control of the whole hybrid electric vehicle power system, as one of the core technologies of electric vehicles, is bound to become a hot target of “clean energy” vehicle development and research. This paper considers the constraints to the performance of energy storage system in Parallel Hybrid Electric Vehicle (PHEV, from which lithium-ion battery frequently charges/discharges, PHEV largely consumes energy of fuel, and their are difficulty in energy recovery and other issues in a single cycle; the research uses lithium-ion battery combined with super-capacitor (SC, which is hybrid energy storage system (Li-SC HESS, working together with internal combustion engine (ICE to drive PHEV. Combined with PSO-PI controller and Li-SC HESS internal power limited management approach, the research proposes the PHEV energy optimal control strategy. It is based on revised Pontryagin’s minimum principle (PMP algorithm, which establishes the PHEV vehicle simulation model through ADVISOR software and verifies the effectiveness and feasibility. Finally, the results show that the energy optimization control strategy can improve the instantaneity of tracking PHEV minimum fuel consumption track, implement energy saving, and prolong the life of lithium-ion batteries and thereby can improve hybrid energy storage system performance.

  4. Energy spectrum of the hydrogen atom in a space with one compactified extra dimension, R3 ×S1

    Science.gov (United States)

    Bureš, Martin

    2015-12-01

    We investigate the consequences of one extra compactified dimension for the energy spectrum of the non-relativistic hydrogen atom with a potential defined by Gauss' law, i.e. proportional to 1 /| x | 2 in non-compactified 4d space. The calculations were performed numerically by diagonalizing the Hamiltonian in two different sets of basis vectors. The energy levels and electron probability density are plotted as a function of the compactification radius. The occurrence of several physical effects is discussed and interpreted.

  5. Potential energy curves for the interaction of Ag(5s) and Ag(5p) with noble gas atoms

    CERN Document Server

    Loreau, J; Dalgarno, A

    2013-01-01

    We investigate the interaction of ground and excited states of a silver atom with noble gases (NG), including helium. Born-Oppenheimer potential energy curves are calculated with quantum chemistry methods and spin-orbit effects in the excited states are included by assuming a spin-orbit splitting independent of the internuclear distance. We compare our results with experimentally available spectroscopic data, as well as with previous calculations. Because of strong spin-orbit interactions, excited Ag-NG potential energy curves cannot be fitted to Morse-like potentials. We find that the labeling of the observed vibrational levels has to be shifted by one unit.

  6. The Russian Federation's Ministry of Atomic Energy: Programs and Developments

    Energy Technology Data Exchange (ETDEWEB)

    CM Johnson

    2000-07-24

    This paper reviews select programs driving the Ministry of Atomic Energy of the Russian Federation's (Minatom) efforts to raise funds, comments on their potential viability, and highlights areas likely to be of particular concern for the US over the next three to five years. The paper's findings are: (1) Despite numerous cabinet displacements throughout the Yeltsin administration, Yevgeny Adamov was reappointed Minister on four occasions. With Boris Yeltsin's January 1, 2000 resignation, Adamov's long-term position as the head of the Ministry is more tenuous, but he will likely retain his position until at least the March 2000 elections. Acting President Vladimir Putin is unlikely to reorganize his cabinet prior to that date and there are no signs that Putin is dissatisfied with Adamov's leadership of Minatom. (2) Adamov's chief priorities are downsizing Minatom's defense sector, increasing the oversight of subsidiary bodies by the central bureaucracy and consolidating commercial elements of the Ministry within an umbrella organization called Atomprom. (3) Viktor Mikhaylov, Adamov's predecessor and critic of his reform efforts, has been relieved of his duties as First Deputy Minister. While he retains his positions as Chief of the Science Councils and Chief Scientist at Arzamas-16, his influence on Minatom's direction is greatly diminished. Adamov will likely continue his efforts to further marginalize Mikhaylov in the coming year. (4) Securing extra-budgetary sources of income continues to be the major factor guiding Minatom's international business dealings. The Ministry will continue to aggressively promote the sale of nuclear technology abroad, often to countries with questionable nonproliferation commitments. (5) Given the financial difficulties in Russia and Minatom's client states, however, few nuclear development programs will come to fruition for a number of years, if ever. Nevertheless, certain

  7. Model Predictive Control of Buoy Type Wave Energy Converter

    DEFF Research Database (Denmark)

    Soltani, Mohsen N.; Sichani, Mahdi T.; Mirzaei, Mahmood

    2014-01-01

    The paper introduces the Wavestar wave energy converter and presents the implementation of model predictive controller that maximizes the power generation. The ocean wave power is extracted using a hydraulic electric generator which is connected to an oscillating buoy. The power generator...... is an additive device attached to the buoy which may include damping, stiffness or similar terms hence will affect the dynamic motion of the buoy. Therefore such a device can be seen as a closed-loop controller. The objective of the wave energy converter is to harvest as much energy from sea as possible....... This approach is then taken into account and an MPC controller is designed for a model wave energy converter and implemented on a numerical example. Further, the power outtake of this controller is compared to the optimal controller as an indicator of the performance of the designed controller....

  8. Triple differential cross section for the near threshold single ionization of helium atoms for equal energy sharing

    Energy Technology Data Exchange (ETDEWEB)

    Purohit, G., E-mail: ghanshyam.purohit@spsu.ac.in [Department of Physics, School of Engineering, Sir Padampat Singhania University, Bhatewar, Udaipur 313 601 (India); Singh, P. [Department of Physics, School of Engineering, Sir Padampat Singhania University, Bhatewar, Udaipur 313 601 (India); Dorn, A.; Ren, X. [Max Planck Institute for Nuclear Physics, 69117 Heidelberg (Germany); Patidar, V. [Department of Physics, School of Engineering, Sir Padampat Singhania University, Bhatewar, Udaipur 313 601 (India)

    2016-05-15

    Highlights: • Present paper describes electron impact single ionization of helium atoms near threshold. • This energy range provided challenges to theoretical models due to presence of several physical effects at low energies such as second order processes, PCI, polarization, etc. • Inclusion of second Born term and target polarization is helpful to analyze the measurements. • Present paper also describes usefulness of post collisional interaction in the collision dynamics at low energies. - Abstract: Low energy electron impact single ionization triple differential cross section (TDCS) results are reported for the helium atoms in the threshold regime at 1 eV, 3 eV and 5 eV excess energy. TDCSs are calculated in the doubly symmetric kinematics for the coplanar to perpendicular emission of electrons. Present attempt to calculate TDCS in the second Born approximation and treating target polarization and post collision interaction is helpful to analyze the available measurements. The second order processes, target polarization and post collision interaction (PCI) have been found to be significant in describing the trends of TDCS and helpful to produce reasonably good agreement with measurements.

  9. Control of energy flow in residential buildings; Energieflussregelung in Wohngebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Martin

    2011-07-01

    Energy systems in residential buildings are changing from monovalent, combustion based systems to multivalent systems containing technologies such as solar collectors, pellet boilers, heat pumps, CHP and multiple storages. Multivalent heat and electricity generation and additional storages raise the number of possible control signals in the system. This creates additional degrees of freedom regarding the choice of the energy converter and the instant of time for energy conversion. New functionality of controllers such as prioritisation of energy producers, optimization of electric self consumption and control of storages and energy feed-in are required. Within the scope of this thesis, new approaches for demand-driven optimal control of energy flows in multivalent building energy systems are developed and evaluated. The approaches are evaluated by means of system energy costs and operating emissions. For parametrisation of the controllers an easily understandable operating concept is developed. The energy flow controllers are implemented as a multi agent system (MAS) and a nonlinear model predictive controller (MPC). Proper functionality and stability are demonstrated in simulations of two example energy systems. In both example systems the MPC controller achieves less energy costs and operating emissions due to system wide global optimization and the more detailed system model within the controller. The multi agent approach turns out to perform better for systems with a huge number of components, e.g. in home automation and energy management systems. Due to the good performance of the reference control strategies, a significant reduction of energy costs and operating emissions is only possible with limitations. Systems for heat generation show only an especially low potential for optimization because of marginal variation ins heat production costs. The adaptation of the operation mode to user priorities, changing utilization characteristics and dynamic energy

  10. Third-order Douglas-Kroll self-consistent field energies for the neutral atoms H to Uuo.

    Science.gov (United States)

    Saito, Shiro L

    2009-02-21

    Third-order Douglas-Kroll self-consistent field (DK3-SCF) calculations with a finite-nucleus model were carried out for the neutral atoms H to Uuo, and DK3-SCF energies were obtained for them. The basis set used was the B-spline set. The parameters of the B-spline set were determined so as to reproduce the SQR-SCF limit energies given by Gaussian-type functions (GTFs). The SQR-SCF is a self-consistent field calculation with a simplified first-order Douglas-Kroll Hamiltonian (the "SQR" Hamiltonian) and can be carried out exactly with GTFs. The DK3-SCF energies given by this B-spline set should be highly accurate. A comparison is made with the DK3-SCF energies of Nakajima and Hirao [J. Chem. Phys. 116, 8270 (2002).

  11. Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

    Science.gov (United States)

    Paziresh, M.; Kingston, A. M.; Latham, S. J.; Fullagar, W. K.; Myers, G. M.

    2016-06-01

    Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073-2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127-135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260-1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (ρ) and

  12. Report of the US Department of Energy's team analyses of the Chernobyl-4 Atomic Energy Station accident sequence

    Energy Technology Data Exchange (ETDEWEB)

    1986-11-01

    In an effort to better understand the Chernobyl-4 accident of April 26, 1986, the US Department of Energy (DOE) formed a team of experts from the National Laboratories including Argonne National Laboratory, Brookhaven National Laboratory, Oak Ridge National Laboratory, and Pacific Northwest Laboratory. The DOE Team provided the analytical support to the US delegation for the August meeting of the International Atomic Energy Agency (IAEA), and to subsequent international meetings. The DOE Team has analyzed the accident in detail, assessed the plausibility and completeness of the information provided by the Soviets, and performed studies relevant to understanding the accident. The results of these studies are presented in this report.

  13. Nuclear energy and non proliferation. The role of the International Atomic Energy Agency; Energia nuclear y no proliferacion. El papel de la Organizacion Internacional de la Energia Atomica

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, J.; Rauf, T.

    2008-07-01

    This article discusses the role of the International Atomic Energy Agency (IAEA) in the prevention of the spread of nuclear weapons. The IAEA verifies States compliance with their non-proliferation commitments through the application of safeguards on their civilian nuclear programmes to ensure that they are being used solely for peaceful purposes. The IAEA safeguards have evolved in the course of five decades and have become an integral part of the international non-proliferation regime and the global security system. To continue to serve the international community, they need to continue to move with the times, especially in light of the renewed interest in nuclear energy. (Author)

  14. Quantum control of the hyperfine-coupled electron and nuclear spins in alkali-metal atoms

    Science.gov (United States)

    Merkel, Seth T.; Jessen, Poul S.; Deutsch, Ivan H.

    2008-08-01

    We study quantum control of the full hyperfine manifold in the ground-electronic state of alkali-metal atoms based on applied radio frequency and microwave fields. Such interactions should allow essentially decoherence-free dynamics and the application of techniques for robust control developed for NMR spectroscopy. We establish the conditions under which the system is controllable in the sense that one can generate an arbitrary unitary map on the system. We apply this to the case of Cs133 with its d=16 dimensional Hilbert space of magnetic sublevels in the 6S1/2 state, and design control wave forms that generate an arbitrary target state from an initial fiducial state. We develop a generalized Wigner function representation for this space consisting of the direct sum of two irreducible representations of SU(2), allowing us to visualize these states. The performance of different control scenarios is evaluated based on the ability to generate a high-fidelity operation in an allotted time with the available resources. We find good operating points commensurate with modest laboratory requirements.

  15. Aerial Measuring System (AMS)/Israel Atomic Energy Commission (IAEC) Joint Comparison Study Report

    Energy Technology Data Exchange (ETDEWEB)

    Wasiolek, P. [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Halevy, I. [Israel Atomic Energy Commission (IAEC), Yavne (Israel)

    2013-12-23

    Under the 13th Bilateral Meeting to Combat Nuclear Terrorism conducted on January 8–9, 2013, the committee approved the development of a cost-effective proposal to conduct a Comparison Study of the Aerial Measuring System (AMS) of the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA) and Israel Atomic Energy Commission (IAEC). The study was to be held at the Remote Sensing Laboratory (RSL), Nellis Air Force Base, Las Vegas, Nevada, with measurements at the Nevada National Security Site (NNSS). The goal of the AMS and the IAEC joint survey was to compare the responses of the two agencies’ aerial radiation detection systems to varied radioactive surface contamination levels and isotopic composition experienced at the NNSS, and the differing data processing techniques utilized by the respective teams. Considering that for the comparison both teams were using custom designed and built systems, the main focus of the short campaign was to investigate the impact of the detector size and data analysis techniques used by both teams. The AMS system, SPectral Advanced Radiological Computer System, Model A (SPARCS-A), designed and built by RSL, incorporates four different size sodium iodide (NaI) crystals: 1" × 1", 2" × 4" × 4", 2" × 4" ×16", and an “up-looking” 2" × 4" × 4". The Israel AMS System, Air RAM 2000, was designed by the IAEC Nuclear Research Center – Negev (NRCN) and built commercially by ROTEM Industries (Israel) and incorporates two 2" diameter × 2" long NaI crystals. The operational comparison was conducted at RSL-Nellis in Las Vegas, Nevada, during week of June 24–27, 2013. The Israeli system, Air RAM 2000, was shipped to RSL-Nellis and mounted together with the DOE SPARCS on a DOE Bell-412 helicopter for a series of aerial comparison measurements at local test ranges, including the Desert Rock Airport and Area 3 at the NNSS. A 4-person Israeli team from the IAEC NRCN supported the activity together with 11

  16. Calculations of Energy Losses due to Atomic Processes in Tokamaks with Applications to the ITER Divertor

    CERN Document Server

    Post, D; Clark, R E H; Putvinskaya, N

    1995-01-01

    Reduction of the peak heat loads on the plasma facing components is essential for the success of the next generation of high fusion power tokamaks such as the International Thermonuclear Experimental Reactor (ITER) 1 . Many present concepts for accomplishing this involve the use of atomic processes to transfer the heat from the plasma to the main chamber and divertor chamber walls and much of the experimental and theoretical physics research in the fusion program is directed toward this issue. The results of these experiments and calculations are the result of a complex interplay of many processes. In order to identify the key features of these experiments and calculations and the relative role of the primary atomic processes, simple quasi-analytic models and the latest atomic physics rate coefficients and cross sections have been used to assess the relative roles of central radiation losses through bremsstrahlung, impurity radiation losses from the plasma edge, charge exchange and hydrogen radiation losses f...

  17. Architecture for Combined Energy and Attitude Control System

    Directory of Open Access Journals (Sweden)

    Ibrahim M. Mehedi

    2005-01-01

    Full Text Available Combining the energy and attitude control system is a feasible technology for small satellites to improve the space missions. In this Combined Energy and Attitude Control System (CEACS a double rotating flywheel is used to replace the conventional battery for energy storage as well as to control the attitude of an earth oriented satellite. Each flywheel is to be controlled in the torque mode. The energy and attitude inputs for the flywheels' control architecture are also in the torque mode. All related mathematical representation along with the relevant transfer functions and the required numerical calculation are developed. The goals are to analyze the attitude performance with respect to the ideal and non-ideal test cases for a chosen reference mission.

  18. On the Coulomb corrections to the total cross section of the interaction of the $\\pi^{+}\\pi^{-}$ atom with ordinary atoms at high energy

    CERN Document Server

    Ivanov, D Yu

    1999-01-01

    The size of $\\pi^+\\pi^-$ atom in the low lying states is considerably smaller than the radius of atomic screening. Due to that we can neglect this screening calculating the contribution of multi-photon exchanges. We obtain the analytic formula for Coulomb corrections which works with a very good accuracy for the ground state of $\\pi^+\\pi^-$ atom.

  19. Energy Management Control Systems: Tools for Energy Savings and Environmental Protection

    Science.gov (United States)

    Zsebik, Albin; Zala, Laszlo F.

    2002-01-01

    The change in the price of energy has encouraged the increase of energy efficiency. This report will discuss a tool to promote energy efficiency in intelligent buildings, energy management control systems (EMCS). In addition to the online control of energy production, supply, and consumption, the function of the EMCS is to support short- and long-term planning of the system operation as well as to collect, store, and regularly evaluate operation data. The strategies behind planning and implementing the EMCS as well as the manipulating the resulting data are discussed in this report.

  20. Compressed Air Energy Storage System Control and Performance Assessment Using Energy Harvested Index

    Directory of Open Access Journals (Sweden)

    Hanif SedighNejad

    2014-01-01

    Full Text Available In this paper a new concept for control and performance assessment of compressed air energy storage (CAES systems in a hybrid energy system is introduced. The proposed criterion, based on the concept of energy harvest index (HEI, measures the capability of a storage system to capture renewable energy. The overall efficiency of the CAES system and optimum control and design from the technical and economic point of view is presented. A possible application of this idea is an isolated community with significant wind energy resource. A case study reveals the usefulness of the proposed criterion in design, control and implementation of a small CAES system in a hybrid power system (HPM for an isolated community. Energy harvested index and its effectiveness in increasing the wind penetration rate in the total energy production is discussed.