Classical and quantum analysis of one-dimensional velocity selection for ultracold atoms

International Nuclear Information System (INIS)

Fox, J K; Kim, H A; Mishra, S R; Myrskog, S H; Jofre, A M; Segal, L R; Kim, J B; Steinberg, A M

2005-01-01

We discuss a velocity selection technique for obtaining cold atoms, in which all atoms below a certain energy are spatially selected from the surrounding atom cloud. Velocity selection can in some cases be more efficient than other cooling techniques for the preparation of ultracold atom clouds in one dimension. With quantum mechanical and classical simulations and theory we present a scheme using a dipole force barrier to select the coldest atoms from a magnetically trapped atom cloud. The dipole and magnetic potentials create a local minimum which traps the coldest atoms. A unique advantage of this technique is the sharp cut-off in the velocity distribution of the sample of selected atoms. Such a non-thermal distribution should prove useful for a variety of experiments, including proposed studies of atomic tunnelling and scattering from quantum potentials. We show that when the rms size of the atom cloud is smaller than the local minimum in which the selected atoms are trapped, the velocity selection technique can be more efficient in one dimension than some common techniques such as evaporative cooling. For example, one simulation shows nearly 6% of the atoms retained at a temperature 100 times lower than the starting condition

Atom probe field ion microscopy and related topics: A bibliography 1993

Energy Technology Data Exchange (ETDEWEB)

Godfrey, R.D.; Miller, M.K.; Russell, K.F.

1994-10-01

This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included.

Atom probe field ion microscopy and related topics: A bibliography 1993

International Nuclear Information System (INIS)

Godfrey, R.D.; Miller, M.K.; Russell, K.F.

1994-10-01

This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included

Amplitudes and state parameters from ion- and atom-atom excitation processes

International Nuclear Information System (INIS)

Andersen, T.; Horsdal-Pedersen, E.

1984-01-01

This chapter examines single collisions between two atomic species, one of which is initially in a 1 S state (there is only one initial spin channel). The collisions are characterized by a definite scattering plane and a definite orientation. Topics considered include an angular correlation between scattered particles and autoionization electrons or polarized photons emitted from states excited in atomic collisions (photon emission, electron emission, selectivity excited target atoms), experimental methods for obtaining information on the alignment and orientation parameters of atoms or ions excited in specific collisions, results of experiments and numerical calculations (quasi-oneelectron systems, He + -He collisions, other collision systems), and future aspects and possible applications of the polarizedphoton, scattered-particle coincidence techniques to atomic spectroscopy

Pulsations in white dwarfs: Selected topics

Directory of Open Access Journals (Sweden)

Saio H.

2013-03-01

Full Text Available This paper presents a very brief overview of the observed properties of g-mode pulsations in variable white dwarfs. We then discuss a few selected topics: Excitation mechanisms (kappa- and convection- mechanisms, and briefly the effect of a strong magnetic field (∼ 1 MG on g-modes as recently found in a hot DQ (carbon-rich atmosphere white dwarf. In the discussion of excitation mechanisms, a simple interpretation for the convection mechanism is given.

Case studies in atomic collision physics

CERN Document Server

McDaniel, E W

1974-01-01

Case Studies in Atomic Physics III focuses on case studies on atomic and molecular physics, including atomic collisions, transport properties of electrons, ions, molecules, and photons, interaction potentials, spectroscopy, and surface phenomena. The selection first discusses detailed balancing in the time-dependent impact parameter method, as well as time-reversal in the impact parameter method and coupled state approximation. The text also examines the mechanisms of electron production in ion. Topics include measurement of doubly differential cross sections and electron spectra, direct Coul

Physics of quantum fluids. New trends and hot topics in atomic and polariton condensates

Energy Technology Data Exchange (ETDEWEB)

Bramati, Alberto [Paris Univ. (France). Laboratoire Kastler Brossel; Centre National de la Recherche Scientifique (CNRS), 75 - Paris (France); Modugno, Michele (eds.) [IKERBASQUE, Bilbao (Spain); Univ. del Pais Vasco, Bilbao (Spain). Dept. de Fisica Teorica e Historia de la Ciencia

2013-10-01

Provides an overview of the field of quantum fluids. Presents analogies and differences between polariton and atomic quantum fluids. With contributions from the major actors in the field. Explains a new type of quantum fluid with specific characteristics. The study of quantum fluids, stimulated by the discovery of superfluidity in liquid helium, has experienced renewed interest after the observation of Bose-Einstein condensation (BEC) in ultra-cold atomic gases and the observation a new type of quantum fluid with specific characteristics derived from its intrinsic out-of-equilibrium nature. The main objective of this book is to take a snapshot of the state-of-the-art of this fast moving field with a special emphasis on the hot topics and new trends. Bringing together the most active specialists of the two areas (atomic and polaritonic quantum fluids), we expect that this book will facilitate the exchange and the collaboration between these two communities working on subjects with very strong analogies.

Physics of quantum fluids new trends and hot topics in atomic and polariton condensates

CERN Document Server

Modugno, Michele

2013-01-01

The study of quantum fluids, stimulated by the discovery of superfluidity in liquid helium, has experienced renewed interest after the observation of Bose-Einstein condensation (BEC) in ultra-cold atomic gases and the observation a new type of quantum fluid with specific characteristics derived from its intrinsic out-of-equilibrium nature. The main objective of this book is to take a snapshot of the state-of-the-art of this fast moving field with a special emphasis on the hot topics and new trends. Bringing together the most active specialists of the two areas (atomic and polaritonic quantum fluids), we expect that this book will facilitate the exchange and the collaboration between these two communities working on subjects with very strong analogies.

Preface: Special Topic on Atomic and Molecular Layer Processing: Deposition, Patterning, and Etching

Science.gov (United States)

Engstrom, James R.; Kummel, Andrew C.

2017-02-01

Thin film processing technologies that promise atomic and molecular scale control have received increasing interest in the past several years, as traditional methods for fabrication begin to reach their fundamental limits. Many of these technologies involve at their heart phenomena occurring at or near surfaces, including adsorption, gas-surface reactions, diffusion, desorption, and re-organization of near-surface layers. Moreover many of these phenomena involve not just reactions occurring under conditions of local thermodynamic equilibrium but also the action of energetic species including electrons, ions, and hyperthermal neutrals. There is a rich landscape of atomic and molecular scale interactions occurring in these systems that is still not well understood. In this Special Topic Issue of The Journal of Chemical Physics, we have collected recent representative examples of work that is directed at unraveling the mechanistic details concerning atomic and molecular layer processing, which will provide an important framework from which these fields can continue to develop. These studies range from the application of theory and computation to these systems to the use of powerful experimental probes, such as X-ray synchrotron radiation, probe microscopies, and photoelectron and infrared spectroscopies. The work presented here helps in identifying some of the major challenges and direct future activities in this exciting area of research involving atomic and molecular layer manipulation and fabrication.

Quantum mechanics new approaches to selected topics

CERN Document Server

Lipkin, Harry Jeannot

1973-01-01

Acclaimed as ""excellent"" (Nature) and ""very original and refreshing"" (Physics Today), this collection of self-contained studies is geared toward advanced undergraduates and graduate students. Its broad selection of topics includes the Mössbauer effect, many-body quantum mechanics, scattering theory, Feynman diagrams, and relativistic quantum mechanics.Author Harry J. Lipkin, a well-known teacher at Israel's Weizmann Institute, takes an unusual approach by introducing many interesting physical problems and mathematical techniques at a much earlier point than in conventional texts. This meth

Efficient mass-selective three-photon ionization of zirconium atoms

Science.gov (United States)

Page, Ralph H.

1994-01-01

In an AVLIS process, .sup.91 Zr is selectively removed from natural zirconium by a three-step photoionization wherein Zr atoms are irradiated by a laser beam having a wavelength .lambda..sub.1, selectively raising .sup.91 Zr atoms to an odd-parity E.sub.1 energy level in the range of 16000-19000 cm.sup.-1, are irradiated by a laser beam having a wavelength .lambda..sub.2 to raise the atoms from an E.sub.l level to an even-parity E.sub.2 energy level in the range of 35000-37000 cm.sup.-1 and are irradiated by a laser beam having a wavelength .lambda..sub.3 to cause a resonant transition of atoms from an E.sub.2 level to an autoionizing level above 53506 cm.sup.-1. .lambda..sub.3 wavelengths of 5607, 6511 or 5756 .ANG. will excite a zirconium atom from an E.sub.2 energy state of 36344 cm.sup.-1 to an autoionizing level; a .lambda..sub.3 wavelength of 5666 .ANG. will cause an autoionizing transition from an E.sub.2 level of 36068 cm.sup.-1 ; and a .lambda. .sub.3 wavelength of 5662 .ANG. will cause an ionizing resonance of an atom at an E.sub.2 level of 35904 cm.sup.-1.

Selective photoionization of isotopic atoms with pulsed lasers

International Nuclear Information System (INIS)

Dai Changjian

1994-01-01

The dynamics of isotopically selective interactions between the radiation of three pulsed lasers and atoms with a four-levels scheme has been studied. Starting from the time-dependent Schroedinger equation with the rotating-wave approximation, authors applied Sylvester theorem to the dynamic equations associated with near-and off-resonant excitations, respectively. Authors obtained the explicit expressions for the four-levels occupation probabilities. The analytic treatment explored the properties of coherent oscillations occurred in the atomic excitation processes with intense monochromatic lasers. The conditions under which the population inversion takes place are derived from near-resonant excitations. The criteria to select the basic parameters of pulsed lasers involved in the process are also provided

Site-selective substitutional doping with atomic precision on stepped Al (111) surface by single-atom manipulation.

Science.gov (United States)

Chen, Chang; Zhang, Jinhu; Dong, Guofeng; Shao, Hezhu; Ning, Bo-Yuan; Zhao, Li; Ning, Xi-Jing; Zhuang, Jun

2014-01-01

In fabrication of nano- and quantum devices, it is sometimes critical to position individual dopants at certain sites precisely to obtain the specific or enhanced functionalities. With first-principles simulations, we propose a method for substitutional doping of individual atom at a certain position on a stepped metal surface by single-atom manipulation. A selected atom at the step of Al (111) surface could be extracted vertically with an Al trimer-apex tip, and then the dopant atom will be positioned to this site. The details of the entire process including potential energy curves are given, which suggests the reliability of the proposed single-atom doping method.

Selective excitation of atoms or molecules to high-lying states

International Nuclear Information System (INIS)

Ducas, T.W.

1978-01-01

This specification relates to the selective excitation of atoms or molecules to high lying states and a method of separating different isotopes of the same element by selective excitation of the isotopes. (U.K.)

History-Based Instruction Enriched with Various Sources of Situational Interest on the Topic of the Atom: the Effect on Students' Achievement and Interest

Science.gov (United States)

Pekdağ, Bülent; Azizoğlu, Nursen

2018-05-01

This study examines the effect of history-based instruction on the topic of the atom on students' academic achievement and their interest in the history of science, investigating as well the relationship between student interest and academic achievement. The sample of the study consisted of two groups of freshman students from an undergraduate elementary science teachers program. The same chemistry instructor taught the groups, which were randomly assigned as an experimental and a control group. The students in the control group received traditional teacher-centered instruction, while the experimental group students were taught the topic of the atom using history-based instruction enriched with various sources of situational interest such as novelty, autonomy, social involvement, and knowledge acquisition (NASK). Data gathering instruments were the Atom Achievement Test and the History of Science Interest Scale, administered to both of the groups before and after the instruction. The data were analyzed with the independent-samples t test, the paired-samples t test, and one-way ANCOVA statistical analysis. The results showed that the history-based instruction including NASK was more effective than traditional instruction in improving the students' learning of the subject of the atom as well as in stimulating and improving students' interest in the history of science. Further, students with high interest displayed significantly better achievement than students with low interest. The better learning of the topic of the atom was more pronounced in the case of students with a high interest in the history of science compared to students with moderate or low interest.

Descriptive Topology in Selected Topics of Functional Analysis

CERN Document Server

Kakol, J; Pellicer, Manuel Lopez

2011-01-01

"Descriptive Topology in Selected Topics of Functional Analysis" is a collection of recent developments in the field of descriptive topology, specifically focused on the classes of infinite-dimensional topological vector spaces that appear in functional analysis. Such spaces include Frechet spaces, (LF)-spaces and their duals, and the space of continuous real-valued functions C(X) on a completely regular Hausdorff space X, to name a few. These vector spaces appear in functional analysis in distribution theory, differential equations, complex analysis, and various other analytical set

Radio frequency selective addressing of localized atoms in a periodic potential

International Nuclear Information System (INIS)

Ott, H.; De Mirandes, E.; Ferlaino, F.; Roati, G.; Tuerck, V.; Modugno, G.; Inguscio, M.

2004-01-01

We study the localization and addressability of ultracold atoms in a combined parabolic and periodic potential. Such a potential supports the existence of localized stationary states and we show that applying a radio frequency field allows us to selectively address atoms in these states. This method is used to measure the energy and momentum distribution of the atoms in the localized states. We also discuss possible extensions of this scheme to address and manipulate atoms in single lattice sites

The future of atomic energy; TOPICAL

International Nuclear Information System (INIS)

Fermi, E.

1946-01-01

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

The site selection law and the anti-atom movement

International Nuclear Information System (INIS)

Haefner, Daniel

2015-01-01

The anti atom movement has reached many of their political claims with the German nuclear power phaseout. At the same time the government has regained the interpretive dominance with the in radioactive waste management with the new search for possible final repository sites. He anti-atom movement refuses most parts of the actual law but cannot abdicate from the responsibility of the process of site selection. The contribution shows using three actual research approaches that such a convergence is probable to occur in the future. A cooperation of anti-atom movement and the government is of high probability in the long term, but is not necessarily identical to a political acceptance.

Atomic and Molecular Data and their Applications★

Science.gov (United States)

Drake, Gordon W. F.; Yoon, Jung-Sik; Kato, Daiji; Karwasz, Grzegorz

2018-03-01

This topical issue on Atomic and molecular data and their applications was motivated by the 10th International Conference on Atomic and Molecular Data (ICAMDATA 2016), which was held from September 26 to 29, 2016 in Gunsan, Republic of Korea. The topics of this issue reflect those of the conference program. The scientific papers in the topical issue cover the fields of atomic and molecular structure, radiative transitions, scattering processes, data base development, and the applications of atomic and molecular data to plasma modeling. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, and Grzegorz Karwasz.

Velocity selection for ultra-cold atoms using bimodal mazer cavity

International Nuclear Information System (INIS)

Irshad, A.; Qamar, S.

2009-04-01

In this paper, we discuss the velocity selection of ultra-cold three-level atoms in Λ configuration using a micromazer. Our model is the same as discussed by Arun et al., for mazer action in a bimodal cavity. We have shown that significantly narrowed velocity distribution of ultra-cold atoms can be obtained in this system due to the presence of dark states. (author)

The site selection law and the anti-atom movement; Das Standortauswahlgesetz und die Anti-Atom-Bewegung

Energy Technology Data Exchange (ETDEWEB)

Haefner, Daniel

2015-07-01

The anti atom movement has reached many of their political claims with the German nuclear power phaseout. At the same time the government has regained the interpretive dominance with the in radioactive waste management with the new search for possible final repository sites. He anti-atom movement refuses most parts of the actual law but cannot abdicate from the responsibility of the process of site selection. The contribution shows using three actual research approaches that such a convergence is probable to occur in the future. A cooperation of anti-atom movement and the government is of high probability in the long term, but is not necessarily identical to a political acceptance.

Selected topics in magnetism

CERN Document Server

Gupta, L C

1993-01-01

Part of the ""Frontiers in Solid State Sciences"" series, this volume presents essays on such topics as spin fluctuations in Heisenberg magnets, quenching of spin fluctuations by high magnetic fields, and kondo effect and heavy fermions in rare earths amongst others.

The energy dependence of selective hydrogen atom abstraction by H(D) atoms in the photolysis of neopentane - ethane mixtures at 77 K

International Nuclear Information System (INIS)

Miyazaki, T.; Fueki, K.

1980-01-01

Selective hydrogen - atom - abstraction reaction by H or D atom has been studied in a neo C 5 H 12 - C 2 H 6 (less than 1 mol %) mixture at 77 K by ESR spectroscopy. The H (or D) atom produced by the photolysis of HI (or DI) reacts with neo - C 2 H 12 and C 2 H 6 to form neo - C 5 H 11 and C 2 H 5 radicals. In order to obtain H atoms with different kinetic energies, the photolysis was performed with different lights of 313, 254 and 229 nm. The selective formation of the C 2 H 5 radical by the reaction of the H (or D) atom with C 2 H 6 becomes more effective with the decrease in the energy of the H (or D) atom. The formation of the neo - C 5 H 11 radical by the reaction of the H (or D) atom with neo - C 2 H 12 becomes more effective with the increase in the energy of the H (or D) atom. (A.R.H.) [pt

5. All-Russian (international) scientific conference. Physicochemical processes during selection of atoms and molecules. Collection of reports

International Nuclear Information System (INIS)

Baranov, V.Yu.; Kolesnikov, Yu.A.

2000-01-01

The materials of the 5. All-Russian (international) scientific conference: Physicochemical processes during selection of atoms and molecules, are presented. The conference took place in Zvenigorod, 2-6 October, 2000. A wide range of items connected with uranium enrichment, selection of atoms and molecules by isotopic composition: laser methods, ion cyclotron-resonance method, are discussed. The selection of molecules and atoms by rectification and chemical isotopic exchange methods, the selection in the field of centrifugal forces are treated. The questions of search for the new advanced methods for selection of atoms and molecules were discussed at the conference, the problems of radioisotope production were represented. The subject matter of the use of stable isotopes and radionuclides is demonstrated widely. The subjects connected with experimental and engineering equipment for selection of atoms and molecules are embodied in the paper [ru

Single-Atom Catalyst of Platinum Supported on Titanium Nitride for Selective Electrochemical Reactions.

Science.gov (United States)

Yang, Sungeun; Kim, Jiwhan; Tak, Young Joo; Soon, Aloysius; Lee, Hyunjoo

2016-02-05

As a catalyst, single-atom platinum may provide an ideal structure for platinum minimization. Herein, a single-atom catalyst of platinum supported on titanium nitride nanoparticles were successfully prepared with the aid of chlorine ligands. Unlike platinum nanoparticles, the single-atom active sites predominantly produced hydrogen peroxide in the electrochemical oxygen reduction with the highest mass activity reported so far. The electrocatalytic oxidation of small organic molecules, such as formic acid and methanol, also exhibited unique selectivity on the single-atom platinum catalyst. A lack of platinum ensemble sites changed the reaction pathway for the oxygen-reduction reaction toward a two-electron pathway and formic acid oxidation toward direct dehydrogenation, and also induced no activity for the methanol oxidation. This work demonstrates that single-atom platinum can be an efficient electrocatalyst with high mass activity and unique selectivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Strategies for Finding and Selecting an Ideal Thesis or Dissertation Topic: A Review of Literature

Science.gov (United States)

Lei, Simon A.

2009-01-01

Choosing an ideal master's thesis or doctoral dissertation topic is probably one of the most important decisions students will make while in graduate school. Some graduate students may spend a year or even longer looking for potential topics before finally selecting one for their thesis or dissertation. There are a number of successful strategies…

Modern atomic physics

CERN Document Server

Natarajan, Vasant

2015-01-01

Much of our understanding of physics in the last 30-plus years has come from research on atoms, photons, and their interactions. Collecting information previously scattered throughout the literature, Modern Atomic Physics provides students with one unified guide to contemporary developments in the field. After reviewing metrology and preliminary material, the text explains core areas of atomic physics. Important topics discussed include the spontaneous emission of radiation, stimulated transitions and the properties of gas, the physics and applications of resonance fluorescence, coherence, cooling and trapping of charged and neutral particles, and atomic beam magnetic resonance experiments. Covering standards, a different way of looking at a photon, stimulated radiation, and frequency combs, the appendices avoid jargon and use historical notes and personal anecdotes to make the topics accessible to non-atomic physics students. Written by a leader in atomic and optical physics, this text gives a state-of-the...

Atoms - molecules - nuclei. Vol. 1

International Nuclear Information System (INIS)

Otter, G.; Honecker, R.

1993-01-01

This first volume covers the following topics: Wave-particle dualism, classical atomic physics; the Schroedinger equation, angular momentum in quantum physics, one-electron atoms and many-electron atoms with atomic structure, atomic spectra, exotic atoms, influence of electric and magnetic fields

Selectivity and coherence for photoexcitation of atoms

International Nuclear Information System (INIS)

Dai Changjian

1995-01-01

The results of both analytic and numerical treatments of the four-level Schroedinger equation are displayed. Transition Probabilities to various states for the cases of on-resonance and off-resonance are calculated. Dependences of probability on time and on characteristics of laser fields are investigated. Selectivity and coherence of the interaction between monochromatic laser fields and isotopic atom are examined. The conditions under which the population inversion takes place derived from the analytic solutions are confirmed

Materials selection for long life in LEO: a critical evaluation of atomic oxygen testing with thermal atom systems

International Nuclear Information System (INIS)

Koontz, S.L.; Kuminecz, J.; Leger, L.; Nordine, P.

1988-01-01

The use of thermal atom test methods as a materials selection and screening technique for low-Earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined to be in thermal atom environments are compared to those observed in LEO and in high quality LEO simulations. Reaction efficiencies measured in a new type of thermal atom apparatus are one-hundredth to one-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of 8 in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain specific thermal test environments can be used as reliable materials screening tools. Using thermal atom methods to predict material lifetime in LEO requires direct calibration of the method against LEO data or high quality simulation data for each material

Atoms

International Nuclear Information System (INIS)

Fuchs, Alain; Villani, Cedric; Guthleben, Denis; Leduc, Michele; Brenner, Anastasios; Pouthas, Joel; Perrin, Jean

2014-01-01

Completed by recent contributions on various topics (atoms and the Brownian motion, the career of Jean Perrin, the evolution of atomic physics since Jean Perrin, relationship between scientific atomism and philosophical atomism), this book is a reprint of a book published at the beginning of the twentieth century in which the author addressed the relationship between atomic theory and chemistry (molecules, atoms, the Avogadro hypothesis, molecule structures, solutes, upper limits of molecular quantities), molecular agitation (molecule velocity, molecule rotation or vibration, molecular free range), the Brownian motion and emulsions (history and general features, statistical equilibrium of emulsions), the laws of the Brownian motion (Einstein's theory, experimental control), fluctuations (the theory of Smoluchowski), light and quanta (black body, extension of quantum theory), the electricity atom, the atom genesis and destruction (transmutations, atom counting)

Selected topics on data and databases

International Nuclear Information System (INIS)

Ralchenko, Y.

2001-01-01

Dr. Ralchenko reviewed atomic data activities at the WIS Plasma Laboratory. Physical sputtering yields over the broad energy range for fusion is presented. Collisional database including electron and heavy particle projectiles was completed. Quantum-mechanical calculations for the process of Stark broadening of atomic spectral lines are continued. Systems considered include data for Be-like ions and lithium-like ions

Selected topics on data and databases

Energy Technology Data Exchange (ETDEWEB)

Ralchenko, Y [Weizmann Institute of Science, Rehovot (Israel)

2001-12-01

Dr. Ralchenko reviewed atomic data activities at the WIS Plasma Laboratory. Physical sputtering yields over the broad energy range for fusion is presented. Collisional database including electron and heavy particle projectiles was completed. Quantum-mechanical calculations for the process of Stark broadening of atomic spectral lines are continued. Systems considered include data for Be-like ions and lithium-like ions.

Selected topics in special nuclear materials safeguard system design

International Nuclear Information System (INIS)

King, L.L.; Thatcher, C.D.; Clarke, J.D.; Rodriguez, M.P.

1991-01-01

During the past two decades the improvements in circuit integration have given rise to many new applications in digital processing technology by continuously reducing the unit cost of processing power. Along with this increase in processing power a corresponding decrease in circuit volume has been achieved. Progress has been so swift that new classes of applications become feasible every 2 or 3 years. This is especially true in the application of proven new technology to special nuclear materials (SNM) safeguard systems. Several areas of application were investigated in establishing the performance requirements for the SNM safeguard system. These included the improvements in material control and accountability and surveillance by using multiple sensors to continuously monitor SNM inventory within the selected value(s); establishing a system architecture to provide capabilities needed for present and future performance requirements; and limiting operating manpower exposure to radiation. This paper describes two selected topics in the application of state-of-the-art, well-proven technology to SNM safeguard system design

Uncondensed atoms in the regime of velocity-selective coherent population trapping

International Nuclear Information System (INIS)

Il’ichov, L. V.; Tomilin, V. A.

2016-01-01

We consider the model of a Bose condensate in the regime of velocity-selective coherent population trapping. As a result of interaction between particles, some fraction of atoms is outside the condensate, remaining in the coherent trapping state. These atoms are involved in brief events of intense interaction with external resonant electromagnetic fields. Intense induced and spontaneous transitions are accompanied by the exchange of momenta between atoms and radiation, which is manifested as migration of atoms in the velocity space. The rate of such migration is calculated. A nonlinear kinetic equation for the many-particle statistical operator for uncondensed atoms is derived under the assumption that correlations of atoms with different momenta are insignificant. The structure of its steady-state solution leads to certain conclusions about the above-mentioned migration pattern taking the Bose statistics into consideration. With allowance for statistical effects, we derive nonlinear integral equations for frequencies controlling the migration. The results of numerical solution of these equations are represented in the weak interatomic interaction approximation.

4. All-Russian (international) scientific conference. Physicochemical processes during selection of atoms and molecules. Collection of reports

International Nuclear Information System (INIS)

Baranov, V.Yu.; Kolesnikov, Yu.A.

1999-01-01

The reports of the 4. All-Russian (international) scientific conference: Physicochemical processes during selection of atoms and molecules, are presented. The conference took place in Zvenigorod, 4-8 October, 1999. Contents of the reports are the following: laser isotope separation of molecules and atoms; isotopic selection of molecules and atoms in the field of centrifugal forces; selection of molecules by means of rectification and isotopic exchange methods; separation of isotopes by ion cyclotron-resonance method, in electric discharge and electromagnetic field; change in physical properties of substances which variation of their natural isotopic composition; use of isotopes in pharmacy preparation; status of experimental and diagnostic technique; certain promising methods of selection of atoms and molecules. The problems of laser separation of uranium isotopes, separation of carbon isotopes by multi-photon selective dissociation are discussed. The procedures permitting production of isotopes with high concentration and efficiency are developed [ru

Selected topics in grand unification

International Nuclear Information System (INIS)

Seckel, D.

1983-01-01

This dissertation is a collection of four pieces of research dealing with grand unification. The topics are neutron oscillation, CP violation, magnetic monopole abundance and distribution in neutron stars, and a proposal for an inflationary cosmology driven by stress-energy in domain walls

Topics relating to atomic collisions in dilute Bose-Einstein condensates

International Nuclear Information System (INIS)

Roberts, David C.

2002-01-01

In this thesis, we investigate various aspects of applications and limitations arising from atomic collisions in dilute Bose-Einstein condensates. First, we investigate the relative particle number squeezing produced in the excited states of a dilute condensate at zero temperature using stimulated light scattering. We show that a modest number of relative number squeezed particles can be achieved when atoms, produced in pairs through collisions in the condensate, are scattered out by their interaction with the lasers. This squeezing is optimal when the momentum is larger than the inverse healing length. This modest number of relative number squeezed particles has the potential to be amplified in four-wave-mixing experiments. We study the limitations on the relative number squeezing between photons and atoms coupled out from a homogeneous Bose-Einstein condensate. We consider the coupling between the translational atomic states by two photon Bragg processes, one of the photon modes involved in the Bragg process being in a coherent state, and the other initially unpopulated. We start with an interacting condensate at zero temperature and compute the time evolution for the system. We discuss how collisions between the atoms and photon rescattering affect the degree of squeezing which may be reached in such experiments. We investigate the limitations arising from atomic collisions on the storage and delay times of probe pulses in EIT experiments. We find that the atomic collisions can be described by an effective decay rate that limits storage and delay times. We calculate the momentum and temperature dependence of the decay rate and find that it is necessary to excite atoms to a particular momentum depending on temperature and spacing of the energy levels involved in order to minimize the decoherence effects of atomic collisions. Finally, we propose a method to probe states in the Mott insulator regime produced from a condensate in an optical lattice. We consider a

Measurement of collisional self broadening of atomic resonance lines in selective reflection experiment

International Nuclear Information System (INIS)

Papoyan, A.V.

1998-01-01

A method is developed to measure directly the collisional self broadening rate for a dense atomic vapor from selective reflection spectra. Experimental realization for the atomic D 1 and D 2 resonance lines of Rb confirms a validity of the proposed technique. The deflection of experimentally measured values is not more than 20% from theoretically predicted ones in the atomic number density range of 7· 10 16 - 7· 10 17 cm - 3 . 10 refs

Area-selective atomic layer deposition of platinum using photosensitive polyimide

NARCIS (Netherlands)

Vervuurt, R.H.J.; Sharma, A.; Jiao, Y.; Kessels, W.M.M.; Bol, A.A.

2016-01-01

Area-selective atomic layer deposition (AS-ALD) of platinum (Pt) was studied using photosensitive polyimide as a masking layer. The polyimide films were prepared by spin-coating and patterned using photolithography. AS-ALD of Pt using poly(methyl-methacrylate) (PMMA) masking layers was used as a

Predictive Validity of an Empirical Approach for Selecting Promising Message Topics: A Randomized-Controlled Study

Science.gov (United States)

Lee, Stella Juhyun; Brennan, Emily; Gibson, Laura Anne; Tan, Andy S. L.; Kybert-Momjian, Ani; Liu, Jiaying; Hornik, Robert

2016-01-01

Several message topic selection approaches propose that messages based on beliefs pretested and found to be more strongly associated with intentions will be more effective in changing population intentions and behaviors when used in a campaign. This study aimed to validate the underlying causal assumption of these approaches which rely on cross-sectional belief–intention associations. We experimentally tested whether messages addressing promising themes as identified by the above criterion were more persuasive than messages addressing less promising themes. Contrary to expectations, all messages increased intentions. Interestingly, mediation analyses showed that while messages deemed promising affected intentions through changes in targeted promising beliefs, messages deemed less promising also achieved persuasion by influencing nontargeted promising beliefs. Implications for message topic selection are discussed. PMID:27867218

Experiments on state selection and Penning ionisation with fast metastable rare gas atoms

International Nuclear Information System (INIS)

Kroon, J.P.C.

1985-01-01

This thesis describes experiments with metastable He/Ne atoms. The experiments are performed in a crossed beam machine. Two different sources are used for the production of metastable atoms: a source for the production of metastable atoms in the thermal energy range and a hollow cathode arc for the production of metastable atoms in the superthermal energy range (1-7 eV). The progress made in the use of the hollow cathode arc is described as well as the experimental set-up. The rare gas energy-level diagram is characterized by two metastable levels. By optical pumping it is possible to select a single metastable level, both for He and Ne. For the case of He this is done by a recently built He quenchlamp which selectively quenches the metastable 2 1 S level population. In the thermal energy range the quenching is complete; in the superthermal energy range the 2 1 S level population is only partly quenched. For the optical pumping of Ne* atoms a cw dye laser is used. New experiments have been started on the measurement, in a crossed beam machine, of the fluorescence caused by inelastic collisions where metastable atoms are involved. The He* + Ne system is used as a pilot study for these experiments. The He-Ne laser is based on this collision system. (Auth.)

Optically polarized atoms understanding light-atom interactions

CERN Document Server

Auzinsh, Marcis; Rochester, Simon M

2010-01-01

This book is addressed at upper-level undergraduate and graduate students involved in research in atomic, molecular, and optical Physics. It will also be useful to researchers practising in this field. It gives an intuitive, yet sufficiently detailed and rigorous introduction to light-atom interactions with a particular emphasis on the symmetry aspects of the interaction, especially those associated with the angular momentum of atoms and light. The book will enable readers to carryout practical calculations on their own, and is richly illustrated with examples drawn from current research topic

Freshman Health Topics

Science.gov (United States)

Hovde, Karen

2011-01-01

This article examines a cluster of health topics that are frequently selected by students in lower division classes. Topics address issues relating to addictive substances, including alcohol and tobacco, eating disorders, obesity, and dieting. Analysis of the topics examines their interrelationships and organization in the reference literature.…

Theory of many-electron atoms. Selected papers

International Nuclear Information System (INIS)

Jucys, A.P.

1978-01-01

Selected papers of the founder of contemporary theoretical physics in Lithuania Adolfas Jucys on the theory of many-electron atoms and their spectra are presented, as well as a complete bibliography of his scientific works, a brief biographical essay and description of his scientific and social activities, reminiscences of other scientists about him. In these papers such questions are considered: Fock's self-consistent field in different approximations, various problems of the many-configurational approximation, incomplete separation of variables, expanded calculation method, application of nonorthogonal radial orbitals, method of irreducible tensor operators, graphical representation of the matrix elements and a number of other problems

Melting of size-selected gallium clusters with 60-183 atoms.

Science.gov (United States)

Pyfer, Katheryne L; Kafader, Jared O; Yalamanchali, Anirudh; Jarrold, Martin F

2014-07-10

Heat capacities have been measured as a function of temperature for size-selected gallium cluster cations with between 60 and 183 atoms. Almost all clusters studied show a single peak in the heat capacity that is attributed to a melting transition. The peaks can be fit by a two-state model incorporating only fully solid-like and fully liquid-like species, and hence no partially melted intermediates. The exceptions are Ga90(+), which does not show a peak, and Ga80(+) and Ga81(+), which show two peaks. For the clusters with two peaks, the lower temperature peak is attributed to a structural transition. The melting temperatures for clusters with less than 50 atoms have previously been shown to be hundreds of degrees above the bulk melting point. For clusters with more than 60 atoms the melting temperatures decrease, approaching the bulk value (303 K) at around 95 atoms, and then show several small upward excursions with increasing cluster size. A plot of the latent heat against the entropy change for melting reveals two groups of clusters: the latent heats and entropy changes for clusters with less than 94 atoms are distinct from those for clusters with more than 93 atoms. This observation suggests that a significant change in the nature of the bonding or the structure of the clusters occurs at 93-94 atoms. Even though the melting temperatures are close to the bulk value for the larger clusters studied here, the latent heats and entropies of melting are still far from the bulk values.

Exponential Improvement in Photon Storage Fidelities Using Subradiance and “Selective Radiance” in Atomic Arrays

Directory of Open Access Journals (Sweden)

A. Asenjo-Garcia

2017-08-01

Full Text Available A central goal within quantum optics is to realize efficient, controlled interactions between photons and atomic media. A fundamental limit in nearly all applications based on such systems arises from spontaneous emission, in which photons are absorbed by atoms and then rescattered into undesired channels. In typical theoretical treatments of atomic ensembles, it is assumed that this rescattering occurs independently, and at a rate given by a single isolated atom, which in turn gives rise to standard limits of fidelity in applications such as quantum memories for light or photonic quantum gates. However, this assumption can in fact be dramatically violated. In particular, it has long been known that spontaneous emission of a collective atomic excitation can be significantly suppressed through strong interference in emission between atoms. While this concept of “subradiance” is not new, thus far the techniques to exploit the effect have not been well understood. In this work, we provide a comprehensive treatment of this problem. First, we show that in ordered atomic arrays in free space, subradiant states acquire an elegant interpretation in terms of optical modes that are guided by the array, which only emit due to scattering from the ends of the finite system. We also go beyond the typically studied regime of a single atomic excitation and elucidate the properties of subradiant states in the many-excitation limit. Finally, we introduce the new concept of “selective radiance.” Whereas subradiant states experience a reduced coupling to all optical modes, selectively radiant states are tailored to simultaneously radiate efficiently into a desired channel while scattering into undesired channels is suppressed, thus enabling an enhanced atom-light interface. We show that these states naturally appear in chains of atoms coupled to nanophotonic structures, and we analyze the performance of photon storage exploiting such states. We find

Pt Single Atoms Embedded in the Surface of Ni Nanocrystals as Highly Active Catalysts for Selective Hydrogenation of Nitro Compounds.

Science.gov (United States)

Peng, Yuhan; Geng, Zhigang; Zhao, Songtao; Wang, Liangbing; Li, Hongliang; Wang, Xu; Zheng, Xusheng; Zhu, Junfa; Li, Zhenyu; Si, Rui; Zeng, Jie

2018-06-13

Single-atom catalysts exhibit high selectivity in hydrogenation due to their isolated active sites, which ensure uniform adsorption configurations of substrate molecules. Compared with the achievement in catalytic selectivity, there is still a long way to go in exploiting the catalytic activity of single-atom catalysts. Herein, we developed highly active and selective catalysts in selective hydrogenation by embedding Pt single atoms in the surface of Ni nanocrystals (denoted as Pt 1 /Ni nanocrystals). During the hydrogenation of 3-nitrostyrene, the TOF numbers based on surface Pt atoms of Pt 1 /Ni nanocrystals reached ∼1800 h -1 under 3 atm of H 2 at 40 °C, much higher than that of Pt single atoms supported on active carbon, TiO 2 , SiO 2 , and ZSM-5. Mechanistic studies reveal that the remarkable activity of Pt 1 /Ni nanocrystals derived from sufficient hydrogen supply because of spontaneous dissociation of H 2 on both Pt and Ni atoms as well as facile diffusion of H atoms on Pt 1 /Ni nanocrystals. Moreover, the ensemble composed of the Pt single atom and nearby Ni atoms in Pt 1 /Ni nanocrystals leads to the adsorption configuration of 3-nitrostyrene favorable for the activation of nitro groups, accounting for the high selectivity for 3-vinylaniline.

Theory and applications of atomic and ionic polarizabilities

International Nuclear Information System (INIS)

Mitroy, J; Safronova, M S; Clark, Charles W

2010-01-01

Atomic polarization phenomena impinge upon a number of areas and processes in physics. The dielectric constant and refractive index of any gas are examples of macroscopic properties that are largely determined by the dipole polarizability. When it comes to microscopic phenomena, the existence of alkaline-earth anions and the recently discovered ability of positrons to bind to many atoms are predominantly due to the polarization interaction. An imperfect knowledge of atomic polarizabilities is presently looming as the largest source of uncertainty in the new generation of optical frequency standards. Accurate polarizabilities for the group I and II atoms and ions of the periodic table have recently become available by a variety of techniques. These include refined many-body perturbation theory and coupled-cluster calculations sometimes combined with precise experimental data for selected transitions, microwave spectroscopy of Rydberg atoms and ions, refractive index measurements in microwave cavities, ab initio calculations of atomic structures using explicitly correlated wavefunctions, interferometry with atom beams and velocity changes of laser cooled atoms induced by an electric field. This review examines existing theoretical methods of determining atomic and ionic polarizabilities, and discusses their relevance to various applications with particular emphasis on cold-atom physics and the metrology of atomic frequency standards. (topical review)

Theory and applications of atomic and ionic polarizabilities

Energy Technology Data Exchange (ETDEWEB)

Mitroy, J [School of Engineering, Charles Darwin University, Darwin NT 0909 (Australia); Safronova, M S [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Clark, Charles W, E-mail: jxm107@rsphysse.anu.edu.a, E-mail: msafrono@udel.ed, E-mail: charles.clark@nist.go [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, MD 20899-8410 (United States)

2010-10-28

Atomic polarization phenomena impinge upon a number of areas and processes in physics. The dielectric constant and refractive index of any gas are examples of macroscopic properties that are largely determined by the dipole polarizability. When it comes to microscopic phenomena, the existence of alkaline-earth anions and the recently discovered ability of positrons to bind to many atoms are predominantly due to the polarization interaction. An imperfect knowledge of atomic polarizabilities is presently looming as the largest source of uncertainty in the new generation of optical frequency standards. Accurate polarizabilities for the group I and II atoms and ions of the periodic table have recently become available by a variety of techniques. These include refined many-body perturbation theory and coupled-cluster calculations sometimes combined with precise experimental data for selected transitions, microwave spectroscopy of Rydberg atoms and ions, refractive index measurements in microwave cavities, ab initio calculations of atomic structures using explicitly correlated wavefunctions, interferometry with atom beams and velocity changes of laser cooled atoms induced by an electric field. This review examines existing theoretical methods of determining atomic and ionic polarizabilities, and discusses their relevance to various applications with particular emphasis on cold-atom physics and the metrology of atomic frequency standards. (topical review)

Towards Non-prescriptive Issues: a Teaching Framework for Selecting Marketing Dissertation Topics

OpenAIRE

Horan, Conor

2006-01-01

There is a significant absence in academic literature, textbooks and practical teaching tools for advising or guiding student learning, in a practical non-prescriptive manner, toward topic selection and development. Prescriptive or rational approaches, taken by many research methods textbooks, are not adequate or sufficient when teaching this important first stage in the research process. Non-prescriptive approaches describing manageable steps should be researched more to fill this pedagogic ...

Atomic Physics 16: Sixteenth International Conference on Atomic Physics. Proceedings

International Nuclear Information System (INIS)

Baylis, W.E.; Drake, G.W.

1999-01-01

These proceedings represent papers presented at the 16th International Conference on Atomic Physics held in Windsor, Ontario, Canada, in August, 1998. The topics discussed included a wide array of subjects in atomic physics such as atom holography, alignment in atomic collisions, coulomb-interacting particles, muon experiments, x-rays from comets, atomic electron collisions in intense laser fields, spectroscopy of trapped ions, and Bose-Einstein condensates. This conference represents the single most important meeting world wide on fundamental advances in atomic physics. There were 30 papers presented at the conference,out of which 4 have been abstracted for the Energy, Science and Technology database

Atomic physics

International Nuclear Information System (INIS)

Anon.

1976-01-01

Research activities in atomic physics at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: experiments on stored ions; test for parity violation in neutral weak currents; energy conservation and astrophysics; atomic absorption spectroscopy, atomic and molecular detectors; theoretical studies of quantum electrodynamics and high-z ions; atomic beam magnetic resonance; radiative decay from the 2 3 Po, 2 levels of helium-like argon; quenching of the metastable 2S/sub 1/2/ state of hydrogen-like argon in an external electric field; and lifetime of the 2 3 Po level of helium-like krypton

Quark-gluon plasma (Selected Topics)

International Nuclear Information System (INIS)

Zakharov, V. I.

2012-01-01

Introductory lectures to the theory of (strongly interacting) quark-gluon plasma given at the Winter School of Physics of ITEP (Moscow, February 2010). We emphasize theoretical issues highlighted by the discovery of the low viscosity of the plasma. The topics include relativistic hydrodynamics, manifestations of chiral anomaly in hydrodynamics, superfluidity, relativistic superfluid hydrodynamics, effective stringy scalars, holographic models of Yang-Mills theories.

Proceedings of the first topical meeting on Asian network for accelerator-driven systems and nuclear transmutation technology

International Nuclear Information System (INIS)

Sasa, Toshinobu

2016-03-01

The first topical meeting on Asian Network for Accelerator-driven System (ADS) and Nuclear Transmutation Technology (NTT) was held on 26-27 October 2015 at the J-PARC Center, Japan Atomic Energy Agency, Japan. The topical meeting was an optional one in-between the regular meeting, which is held in every two years. Instead of the regular meetings, which cover all research fields for ADS and NTT, such as accelerator, spallation target, subcritical reactor, fuel, and material, the topical meeting is focused on a specific topic to make technical discussions more deeply. In this meeting, the technology for lead-bismuth eutectic alloy was selected, as it was one of the hot issues in the world, and the topic was deeply discussed by specialists in Asian countries. This report summarizes all presentation materials discussed in the meeting. (author)

A Molecular Dynamics of Cold Neutral Atoms Captured by Carbon Nanotube Under Electric Field and Thermal Effect as a Selective Atoms Sensor.

Science.gov (United States)

Santos, Elson C; Neto, Abel F G; Maneschy, Carlos E; Chen, James; Ramalho, Teodorico C; Neto, A M J C

2015-05-01

Here we analyzed several physical behaviors through computational simulation of systems consisting of a zig-zag type carbon nanotube and relaxed cold atoms (Rb, Au, Si and Ar). These atoms were chosen due to their different chemical properties. The atoms individually were relaxed on the outside of the nanotube during the simulations. Each system was found under the influence of a uniform electric field parallel to the carbon nanotube and under the thermal effect of the initial temperature at the simulations. Because of the electric field, the cold atoms orbited the carbon nanotube while increasing the initial temperature allowed the variation of the radius of the orbiting atoms. We calculated the following quantities: kinetic energy, potential energy and total energy and in situ temperature, molar entropy variation and average radius of the orbit of the atoms. Our data suggest that only the action of electric field is enough to generate the attractive potential and this system could be used as a selected atoms sensor.

The ENTRIA project. Selected disciplinary and interdisciplinary research topics

International Nuclear Information System (INIS)

Roehlig, Klaus-Juergen; Hocke, Peter; Walther, Clemens

2015-01-01

ENTRIA (''Disposal Options for Radioactive Residues: Interdisciplinary Analyses and Development of Evaluation Principles'', www.entria.de) is a joint research project carried out by twelve departments and institutes from German universities and major research institutions and one partner from Switzerland. It is financed by the German Ministry of Education and Research (BMBF). Scientists representing natural sciences, civil engineering, philosophy, law, social and political sciences, and technology assessment carry out disciplinary and interdisciplinary research addressing three options to manage especially high-level radioactive waste: - Final disposal in deep geological formations without any arrangements for retrieval, - disposal in deep geological formations with arrangements for monitoring and retrieval, and - (prolonged) surface (or near-surface) storage. In the paper, the following selected research topics - both disciplinary and interdisciplinary - are briefly introduced in order to provide an impression of the project scope: - Surface storage, - reference concepts for emplacement in deep geological formations with retrievability and monitoring, - radiation exposure and justification of measures, - interdisciplinary perspectives on dose limits, - comparative studies on nuclear waste governance, - nuclear waste governance in Switzerland, - public involvement and the German Site Selection Act, and - citizens' jury.

Accelerating atomic orbital-based electronic structure calculation via pole expansion and selected inversion

International Nuclear Information System (INIS)

Lin, Lin; Yang, Chao; Chen, Mohan; He, Lixin

2013-01-01

We describe how to apply the recently developed pole expansion and selected inversion (PEXSI) technique to Kohn–Sham density function theory (DFT) electronic structure calculations that are based on atomic orbital discretization. We give analytic expressions for evaluating the charge density, the total energy, the Helmholtz free energy and the atomic forces (including both the Hellmann–Feynman force and the Pulay force) without using the eigenvalues and eigenvectors of the Kohn–Sham Hamiltonian. We also show how to update the chemical potential without using Kohn–Sham eigenvalues. The advantage of using PEXSI is that it has a computational complexity much lower than that associated with the matrix diagonalization procedure. We demonstrate the performance gain by comparing the timing of PEXSI with that of diagonalization on insulating and metallic nanotubes. For these quasi-1D systems, the complexity of PEXSI is linear with respect to the number of atoms. This linear scaling can be observed in our computational experiments when the number of atoms in a nanotube is larger than a few hundreds. Both the wall clock time and the memory requirement of PEXSI are modest. This even makes it possible to perform Kohn–Sham DFT calculations for 10 000-atom nanotubes with a sequential implementation of the selected inversion algorithm. We also perform an accurate geometry optimization calculation on a truncated (8, 0) boron nitride nanotube system containing 1024 atoms. Numerical results indicate that the use of PEXSI does not lead to loss of the accuracy required in a practical DFT calculation. (paper)

A hybrid polarization-selective atomic sensor for radio-frequency field detection with a passive resonant-cavity field amplifier

OpenAIRE

Anderson, David A.; Paradis, Eric G.; Raithel, Georg

2018-01-01

We present a hybrid atomic sensor that realizes radio-frequency electric field detection with intrinsic field amplification and polarization selectivity for robust high-sensitivity field measurement. The hybrid sensor incorporates a passive resonator element integrated with an atomic vapor cell that provides amplification and polarization selectivity for detection of incident radio-frequency fields. The amplified intra-cavity radio-frequency field is measured by atoms using a quantum-optical ...

Progress in atomic spectroscopy

International Nuclear Information System (INIS)

Beyer, H.J.; Kleinpoppen, H.

1984-01-01

This book presents reviews by leading experts in the field covering areas of research at the forefront of atomic spectroscopy. Topics considered include the k ordering of atomic structure, multiconfiguration Hartree-Fock calculations for complex atoms, new methods in high-resolution laser spectroscopy, resonance ionization spectroscopy (inert atom detection), trapped ion spectroscopy, high-magnetic-field atomic physics, the effects of magnetic and electric fields on highly excited atoms, x rays from superheavy collision systems, recoil ion spectroscopy with heavy ions, investigations of superheavy quasi-atoms via spectroscopy of electron rays and positrons, impact ionization by fast projectiles, and amplitudes and state parameters from ion- and atom-atom excitation processes

Nuclear and atomic physics at one gigaflop

International Nuclear Information System (INIS)

Bottcher, C.; Strayer, J.B.

1989-01-01

A three-day workshop on problems in atomic and nuclear physics which depend on and are, at present, severely limited by access to supercomputing at effective rates of one gigaflop or more, was held at Oak Ridge, Tennessee, April 14-16, 1988. The participants comprised researchers from universities, industries and laboratories in the United States and Europe. In this volume are presented talks from that meeting on atomic and nuclear physics topics and on modern parallel processing concepts and hardware. The physics topics included strong fields in atomic and nuclear physics, the role of quarks in nuclear physics, the nuclear few-body problem, relativistic descriptions of heavy-ion collisions, nuclear hydrodynamics, Monte Carlo techniques for many-body problems, precision calculation of atomic QED effects, classical simulation of atomic processes, atomic structure, atomic many-body perturbation theory, quantal studies of small and large molecular systems, and multi-photon atomic and molecular problems

Human-competitive automatic topic indexing

CERN Document Server

Medelyan, Olena

2009-01-01

Topic indexing is the task of identifying the main topics covered by a document. These are useful for many purposes: as subject headings in libraries, as keywords in academic publications and as tags on the web. Knowing a document’s topics helps people judge its relevance quickly. However, assigning topics manually is labor intensive. This thesis shows how to generate them automatically in a way that competes with human performance. Three kinds of indexing are investigated: term assignment, a task commonly performed by librarians, who select topics from a controlled vocabulary; tagging, a popular activity of web users, who choose topics freely; and a new method of keyphrase extraction, where topics are equated to Wikipedia article names. A general two-stage algorithm is introduced that first selects candidate topics and then ranks them by significance based on their properties. These properties draw on statistical, semantic, domain-specific and encyclopedic knowledge. They are combined using a machine learn...

Plasmas applied atomic collision physics, v.2

CERN Document Server

Barnett, C F

1984-01-01

Applied Atomic Collision Physics, Volume 2: Plasmas covers topics on magnetically confined plasmas. The book starts by providing the history of fusion research and describing the various approaches in both magnetically and inertially confined plasmas. The text then gives a general discussion of the basic concepts and properties in confinement and heating of a plasma. The theory of atomic collisions that result in excited quantum states, particularly highly ionized impurity atoms; and diverse diagnostic topics such as emission spectra, laser scattering, electron cyclotron emission, particle bea

The Effects of Topic Familiarity, Author Expertise, and Content Relevance on Norwegian Students' Document Selection: A Mixed Methods Study

Science.gov (United States)

McCrudden, Matthew T.; Stenseth, Tonje; Bråten, Ivar; Strømsø, Helge I.

2016-01-01

This mixed methods study investigated the extent to which author expertise and content relevance were salient to secondary Norwegian students (N = 153) when they selected documents that pertained to more familiar and less familiar topics. Quantitative results indicated that author expertise was more salient for the less familiar topic (nuclear…

Section of Atomic Collisions

International Nuclear Information System (INIS)

Berenyi, D.; Biri, S.; Gulyas, L.; Juhasz, Z.; Kover, A.; Orban, A.; Palinkas, J.; Papp, T.; Racz, R.; Ricz, S.

2009-01-01

The Section of Atomic Collisions is a research unit with extended activity in the field of atomic and molecular physics. Starting from the study of atomic processes at the beamlines of nuclear physics accelerators in the seventies, our research community became one of the centers of fundamental research in Atomki. We also have a strong connection to materials sciences especially along the line of electron and ion spectroscopy methods. Our present activity covers a wide range of topics from atomic collision mechanisms of fundamental interest, to the complex interactions of electrons, ions, photons and antiparticles with atoms, molecules, surfaces, and specific nanostructures. In the last few years, an increasing fraction of our present topics has become relevant for applications, e.g., molecular collision studies for the radiation therapy methods of tumors, or ion-nanostructure interactions for the future construction of small ion-focusing elements. Our section belongs to the Division of Atomic Physics. The other unit of the Division is the Section of Electron Spectroscopy and Materials Sciences. There are traditionally good connections and a strong collaboration between the groups of the two sections in many fields. From the very beginning of our research work in atomic collisions, external collaborations were of vital importance for us. We regularly organize international workshops in the field of fast ion-atom collisions and related small conferences in Debrecen from 1981. Recently, we organized the Conference on Radiation Damage in Biomolecular Systems (RADAM 2008, Debrecen), and coorganized the Conference on Elementary Processes in Atomic Systems (CEPAS 2008, Cluj). We have access to several large scale facilities in Europe within the framework of formal and informal collaborations. The next themes are in this article: Forward electron emission from energetic atomic collisions; Positron-atom collisions; Photon-atom interactions; Interference effects in electron

Selected Topics in International Special Education.

Science.gov (United States)

Kelly, Nancy

2002-01-01

This article provides information on special education topics on the international front. Information is presented on projects that evaluated early intervention programs, a life-centered career education program in the Philippines, a Peruvian vocational program for individuals with severe disabilities, and special classes for children with…

Selected topics from classical bacterial genetics.

Science.gov (United States)

Raleigh, Elisabeth A; Elbing, Karen; Brent, Roger

2002-08-01

Current cloning technology exploits many facts learned from classical bacterial genetics. This unit covers those that are critical to understanding the techniques described in this book. Topics include antibiotics, the LAC operon, the F factor, nonsense suppressors, genetic markers, genotype and phenotype, DNA restriction, modification and methylation and recombination.

Atomic and molecular science with synchrotron radiation

International Nuclear Information System (INIS)

1989-01-01

This paper discusses the following topics: electron correlation in atoms; atomic innershell excitation and decay mechanisms; timing experiments; x-ray scattering; properties of ionized species; electronic properties of actinide atoms; total photon-interaction cross sections; and molecular physics. 66 refs

AHRQ series paper 3: identifying, selecting, and refining topics for comparative effectiveness systematic reviews: AHRQ and the effective health-care program.

Science.gov (United States)

Whitlock, Evelyn P; Lopez, Sarah A; Chang, Stephanie; Helfand, Mark; Eder, Michelle; Floyd, Nicole

2010-05-01

This article discusses the identification, selection, and refinement of topics for comparative effectiveness systematic reviews within the Agency for Healthcare Research and Quality's Effective Health Care (EHC) program. The EHC program seeks to align its research topic selection with the overall goals of the program, impartially and consistently apply predefined criteria to potential topics, involve stakeholders to identify high-priority topics, be transparent and accountable, and continually evaluate and improve processes. A topic prioritization group representing stakeholder and scientific perspectives evaluates topic nominations that fit within the EHC program (are "appropriate") to determine how "important" topics are as considered against seven criteria. The group then judges whether a new comparative effectiveness systematic review would be a duplication of existing research syntheses, and if not duplicative, if there is adequate type and volume of research to conduct a new systematic review. Finally, the group considers the "potential value and impact" of a comparative effectiveness systematic review. As the EHC program develops, ongoing challenges include ensuring the program addresses truly unmet needs for synthesized research because national and international efforts in this arena are uncoordinated, as well as engaging a range of stakeholders in program decisions while also achieving efficiency and timeliness.

Isotope-abundance variations and atomic weights of selected elements: 2016 (IUPAC Technical Report)

Science.gov (United States)

Coplen, Tyler B.; Shrestha, Yesha

2016-01-01

There are 63 chemical elements that have two or more isotopes that are used to determine their standard atomic weights. The isotopic abundances and atomic weights of these elements can vary in normal materials due to physical and chemical fractionation processes (not due to radioactive decay). These variations are well known for 12 elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine, and thallium), and the standard atomic weight of each of these elements is given by IUPAC as an interval with lower and upper bounds. Graphical plots of selected materials and compounds of each of these elements have been published previously. Herein and at the URL http://dx.doi.org/10.5066/F7GF0RN2, we provide isotopic abundances, isotope-delta values, and atomic weights for each of the upper and lower bounds of these materials and compounds.

Automatic selection of atomic fingerprints and reference configurations for machine-learning potentials

Science.gov (United States)

Imbalzano, Giulio; Anelli, Andrea; Giofré, Daniele; Klees, Sinja; Behler, Jörg; Ceriotti, Michele

2018-06-01

Machine learning of atomic-scale properties is revolutionizing molecular modeling, making it possible to evaluate inter-atomic potentials with first-principles accuracy, at a fraction of the costs. The accuracy, speed, and reliability of machine learning potentials, however, depend strongly on the way atomic configurations are represented, i.e., the choice of descriptors used as input for the machine learning method. The raw Cartesian coordinates are typically transformed in "fingerprints," or "symmetry functions," that are designed to encode, in addition to the structure, important properties of the potential energy surface like its invariances with respect to rotation, translation, and permutation of like atoms. Here we discuss automatic protocols to select a number of fingerprints out of a large pool of candidates, based on the correlations that are intrinsic to the training data. This procedure can greatly simplify the construction of neural network potentials that strike the best balance between accuracy and computational efficiency and has the potential to accelerate by orders of magnitude the evaluation of Gaussian approximation potentials based on the smooth overlap of atomic positions kernel. We present applications to the construction of neural network potentials for water and for an Al-Mg-Si alloy and to the prediction of the formation energies of small organic molecules using Gaussian process regression.

Momentum distributions of selected rare-gas atoms probed by intense femtosecond laser pulses

DEFF Research Database (Denmark)

Abu-Samha, Mahmoud; Madsen, Lars Bojer

2011-01-01

We provide a direct comparison between numerical and experimental (Rudenko et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 L407) photoelectron momentum distributions in strong-field ionization of selected rare-gas atoms (He, Ne and Ar), probed by femtosecond linearly polarized laser pulses. The cal......We provide a direct comparison between numerical and experimental (Rudenko et al 2004 J. Phys. B: At. Mol. Opt. Phys. 37 L407) photoelectron momentum distributions in strong-field ionization of selected rare-gas atoms (He, Ne and Ar), probed by femtosecond linearly polarized laser pulses....... The calculations are performed by solving the time-dependent Schrödinger equation within the single-active-electron approximation, and focal-volume effects are taken into account by appropriately averaging the results. The resulting momentum distributions are in quantitative agreement with the experimental...

Selected topics of fluid mechanics

Science.gov (United States)

Kindsvater, Carl E.

1958-01-01

the Euler, Froude, Reynolds, Weber, and Cauchy numbers are defined as essential tools for interpreting and using experimental data. The derivations of the energy and momentum equations are treated in detail. One-dimensional equations for steady nonuniform flow are developed, and the restrictions applicable to the equations are emphasized. Conditions of uniform and gradually varied flow are discussed, and the origin of the Chezy equation is examined in relation to both the energy and the momentum equations. The inadequacy of all uniform-flow equations as a means of describing gradually varied flow is explained. Thus, one of the definitive problems of river hydraulics is analyzed in the light of present knowledge. This report is the outgrowth of a series of short schools conducted during the spring and summer of 1953 for engineers of the Surface Water Branch, Water Resources Division, U. S. Geological Survey. The topics considered are essentially the same as the topics selected for inclusion in the schools. However, in order that they might serve better as a guide and outline for informal study, the arrangement of the writer's original lecture notes has been considerably altered. The purpose of the report, like the purpose of the schools which inspired it, is to build a simple but strong framework of the fundamentals of fluid mechanics. It is believed that this framework is capable of supporting a detailed analysis of most of the practical problems met by the engineers of the Geological Survey. It is hoped that the least accomplishment of this work will be to inspire the reader with the confidence and desire to read more of the recent and current technical literature of modern fluid mechanics.

ORNL R and D on advanced small and medium power reactors: selected topics

International Nuclear Information System (INIS)

White, J.D.; Trauger, D.B.

1989-01-01

From 1984-1985, ORNL studied several innovative small and medium power nuclear concepts with respect to viability. Criteria for assessment of market attractiveness were developed and are described here. Using these criteria and descriptions of selected advanced reactor concepts, an assessment of their projected market viability in the time period 2000-2010 was made. All of these selected concepts could be considered as having the potential for meeting the criteria but, in most cases, considerable R and D would be required to reduce uncertainties. This work and later studies of safety and licensing of advanced, passively safe reactor concepts by ORNL are described. The results of these studies are taken into account in most of the current (FY 1989) work at ORNL on advanced reactors. A brief outline of this current work is given. One of the current R and D efforts at ORNL which addresses the operability and safety of advanced reactors is the Advanced Controls Program. Selected topics from this Program are described

ORNL R and D on advanced small and medium power reactors: Selected topics

International Nuclear Information System (INIS)

White, J.D.; Trauger, D.B.

1988-01-01

From 1984-1985, ORNL studied several innovative small and medium power nuclear concepts with respect to viability. Criteria for assessment of market attractiveness were developed and are described here. Using these criteria and descriptions of selected advanced reactor concepts, and assessment of their projected market viability in the time period 2000-2010 was made. All of these selected concepts could be considered as having the potential for meeting the criteria but, in most cases, considerable RandD would be required to reduce uncertainties. This work and later studies of safety and licensing of advanced, passively safe reactor concepts by ORNL are described. The results of these studies are taken into account in most of the current (FY 1989) work at ORNL on advanced reactors. A brief outline of this current work is given. One of the current RandD efforts at ORNL which addresses the operability and safety of advanced reactors is the Advanced Controls Program. Selected topics from this Program are described. 13 refs., 1 fig

Laser stabilisation for velocity-selective atomic absorption

NARCIS (Netherlands)

Meijer, H.A.J.; Meulen, H.P. van der; Ditewig, F.; Wisman, C.J.; Morgenstern, R.

1987-01-01

A relatively simple method is described for stabilising a dye laser at a frequency ν = ν0 + νc in the vicinity of an atomic resonance frequency ν0. The Doppler effect is exploited by looking for atomic fluorescence when a laser beam is crossed with an atomic beam at certain angles αi. Absolute

Topics in gravitation and gauge fields

International Nuclear Information System (INIS)

Leen, T.K.

1982-01-01

The theoretical studies presented here address three distinct topics. The first deals with quantum-mechanical effects of classical gravitational radiation. Specifically, the use of the interstellar medium itself as a remote quantum-mechanical detector of gravitational waves is investigated. This study is motivated by the presumed existence of atomic hydrogen in the vicinity of astrophysical sources of gravitational radiation. Space-time curvature produces uniquely identifiable shifts in atomic hydrogen energy levels. The oscillating level shifts induced by a passing gravitational wave could conceivably be detected spectroscopically. Accordingly the level shifts for both low-lying and highly excited states of single electron atoms immersed in gravitational radiation have been studied. The second two topics deal with the theory of quantized fields on curved space-times. In the first of these studies, a naive model of cosmological baryon synthesis is examined. The model incorporates a hard CP violation as well as a baryon (and lepton) non-conserving interaction and is thus capable of generating an excess of matter over antimatter. The time dependent background geometry of the early universe drives the interaction producing net excess of baryon/lepton pairs. In the final topic, the question of renormalizability of non-Abelian gauge fields theories in a general curved space-time is addressed. All modern theories of elementary particle physics are gauge theories and one would like to know if their perturbative expansions continue to be well defined (i.e. renormalizable) on curved backgrounds. In general, one is interested in knowing if field theories renormalizable in Minkowski space remain so in a general curved space-time

Development of selective photoionization spectroscopy technology - Development of a computer program to calculate selective ionization of atoms with multistep processes

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Soon; Nam, Baek Il [Myongji University, Seoul (Korea, Republic of)

1995-08-01

We have developed computer programs to calculate 2-and 3-step selective resonant multiphoton ionization of atoms. Autoionization resonances in the final continuum can be put into account via B-Spline basis set method. 8 refs., 5 figs. (author)

Affinity between information retrieval system and search topic

International Nuclear Information System (INIS)

Ebinuma, Yukio

1979-01-01

Ten search profiles are tested on the INIS system at the Japan Atomic Energy Research Institute. The results are plotted on recall-precision chart ranging from 100% recall to 100% precision. The curves are not purely systems-dependent nor search-dependent, and are determined substantially by the ''affinity'' between the system and the search topic. The curves are named ''Affinity curves of search topics with information retrieval systems'', and hence retrieval affinity factors are derived. They are obtained not only for individual search topics but also for averages in the system. By such a quantitative examination, the difference of affinity among search topics in a given system, that of the same search topic among various systems, and that of systems to the same group of search topics can be compared reasonably. (author)

Atomic excitation and recombination in external fields

International Nuclear Information System (INIS)

Nayfeh, M.H.; Clark, C.W.

1985-01-01

This volume offers a timely look at Rydberg states of atoms in external fields and dielectronic recombination. Each topic provides authoritative coverage, presents a fresh account of a flourishing field of current atomic physics and introduces new opportunities for discovery and development. Topics considered include electron-atom scattering in external fields; observations of regular and irregular motion as exemplified by the quadratic zeeman effect and other systems; Rydberg atoms in external fields and the Coulomb geometry; crossed-field effects in the absorption spectrum of lithium in a magnetic field; precise studies of static electric field ionization; widths and shapes of stark resonances in sodium above the saddle point; studies of electric field effects and barium autoionizing resonances; autoionization and dielectronic recombination in plasma electric microfields; dielectronic recombination measurements on multicharged ions; merged beam studies of dielectronic recombination; Rydberg atoms and dielectronic recombination in astrophysics; and observations on dielectronic recombination

Quantum trajectories in elastic atom-surface scattering: threshold and selective adsorption resonances.

Science.gov (United States)

Sanz, A S; Miret-Artés, S

2005-01-01

The elastic resonant scattering of He atoms off the Cu(117) surface is fully described with the formalism of quantum trajectories provided by Bohmian mechanics. Within this theory of quantum motion, the concept of trapping is widely studied and discussed. Classically, atoms undergo impulsive collisions with the surface, and then the trapped motion takes place covering at least two consecutive unit cells. However, from a Bohmian viewpoint, atom trajectories can smoothly adjust to the equipotential energy surface profile in a sort of sliding motion; thus the trapping process could eventually occur within one single unit cell. In particular, both threshold and selective adsorption resonances are explained by means of this quantum trapping considering different space and time scales. Furthermore, a mapping between each region of the (initial) incoming plane wave and the different parts of the diffraction and resonance patterns can be easily established, an important issue only provided by a quantum trajectory formalism. (c) 2005 American Institute of Physics.

Atomic layer deposition overcoating: tuning catalyst selectivity for biomass conversion.

Science.gov (United States)

Zhang, Hongbo; Gu, Xiang-Kui; Canlas, Christian; Kropf, A Jeremy; Aich, Payoli; Greeley, Jeffrey P; Elam, Jeffrey W; Meyers, Randall J; Dumesic, James A; Stair, Peter C; Marshall, Christopher L

2014-11-03

The terraces, edges, and facets of nanoparticles are all active sites for heterogeneous catalysis. These different active sites may cause the formation of various products during the catalytic reaction. Here we report that the step sites of Pd nanoparticles (NPs) can be covered precisely by the atomic layer deposition (ALD) method, whereas the terrace sites remain as active component for the hydrogenation of furfural. Increasing the thickness of the ALD-generated overcoats restricts the adsorption of furfural onto the step sites of Pd NPs and increases the selectivity to furan. Furan selectivities and furfural conversions are linearly correlated for samples with or without an overcoating, though the slopes differ. The ALD technique can tune the selectivity of furfural hydrogenation over Pd NPs and has improved our understanding of the reaction mechanism. The above conclusions are further supported by density functional theory (DFT) calculations. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of an alternating current plasma as an element selective atomic emission detector for high-resolution capillary gas chromatography and as a source for atomic absorption and atomic emission spectrometry

Science.gov (United States)

Ombaba, Jackson M.

This thesis deals with the construction and evaluation of an alternating current plasma (ACP) as an element-selective detector for high resolution capillary gas chromatography (GC) and as an excitation source for atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). The plasma, constrained in a quartz discharge tube at atmospheric pressure, is generated between two copper electrodes and utilizes helium as the plasma supporting gas. The alternating current plasma power source consists of a step-up transformer with a secondary output voltage of 14,000 V at a current of 23 mA. The device exhibits a stable signal because the plasma is self-seeding and reignites itself every half cycle. A tesla coil is not required to commence generation of the plasma if the ac voltage applied is greater than the breakdown voltage of the plasma-supporting gas. The chromatographic applications studied included the following: (1) the separation and selective detection of the organotin species, tributyltin chloride (TBT) and tetrabutyltin (TEBT), in environmental matrices including mussels (Mvutilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienyl manganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer (common room humidifier) was utilized as a sample introduction device for aqueous solutions when the ACP was employed as an atomization source for atomic absorption spectrometry and as an excitation source for atomic emission spectrometry. Plasma diagnostic parameters studied include spatial electron number density across the discharge tube, electronic, excitation and ionization temperatures. Interference studies both in absorption and emission modes were also considered. Figures of merits of selected elements both in absorption and emission modes are reported. The evaluation of a computer-aided optimization program, Drylab GC, using

Applied atomic collision physics. Vol. 2

International Nuclear Information System (INIS)

Barnett, C.F.; Harrison, M.F.A.

1984-01-01

This volume brings together papers on atomic processes that have been important in fusion research during the past 30 years. Topics include: Atomic radiation from low density plasma; Properties of magnetically confined plasmas in tokomaks; Diagnostics and; Heating by energetic particles. Each chapter includes references

Precision measurement with atom interferometry

International Nuclear Information System (INIS)

Wang Jin

2015-01-01

Development of atom interferometry and its application in precision measurement are reviewed in this paper. The principle, features and the implementation of atom interferometers are introduced, the recent progress of precision measurement with atom interferometry, including determination of gravitational constant and fine structure constant, measurement of gravity, gravity gradient and rotation, test of weak equivalence principle, proposal of gravitational wave detection, and measurement of quadratic Zeeman shift are reviewed in detail. Determination of gravitational redshift, new definition of kilogram, and measurement of weak force with atom interferometry are also briefly introduced. (topical review)

Selected papers on analysis and related topics

CERN Document Server

2008-01-01

This volume contains translations of papers that originally appeared in the Japanese journal Sūgaku. The papers range over a variety of topics, including operator algebras, analysis, and statistics. This volume is suitable for graduate students and research mathematicians interested in analysis and its applications.

Atomic and molecular sciences

International Nuclear Information System (INIS)

Lane, N.F.

1989-01-01

The theoretical atomic and molecular physics program at Rice University addresses basic questions about the collision dynamics of electrons, atoms, ions and molecules, emphasizing processes related to possible new energy technologies and other applications. The program focuses on inelastic collision processes that are important in understanding energy and ionization balance in disturbed gases and plasmas. Emphasis is placed on systems and processes where some experimental information is available or where theoretical results may be expected to stimulate new measurements. Examples of current projects include: excitation and charge-transfer processes; orientation and alignment of excited states following collisions; Rydberg atom collisions with atoms and molecules; Penning ionization and ion-pair formation in atom-atom collisions; electron-impact ionization in dense, high-temperature plasmas; electron-molecule collisions; and related topics

Atomic energy law after the opt-out. Alive and fascinating. Report about the 14th German atomic energy law symposium 2012

International Nuclear Information System (INIS)

Leidinger, Tobias

2013-01-01

Atomic energy law remains a living, fascinating subject matter. Nearly 200 participants were convinced of this impression at the 14 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 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 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 transparency

Speciation analysis of arsenic by selective hydride generation- cryotrapping-atomic fluorescence spectrometry with flame-in-gas- shield atomizer: Achieving extremely low detection limits with inexpensive instrumentation

Czech Academy of Sciences Publication Activity Database

Musil, Stanislav; Matoušek, Tomáš; Currier, J. M.; Stýblo, M.; Dědina, Jiří

2014-01-01

Roč. 86, č. 20 (2014), s. 10422-10428 ISSN 0003-2700 R&D Projects: GA ČR GA14-23532S; GA MŠk LH12040 Institutional support: RVO:68081715 Keywords : speciation analysis of arsenic * selective hydride generation * flame-in-gas-shield atomizer * cryotrapping-atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014

Grand unification and gravity - selected topics

International Nuclear Information System (INIS)

Zee, A.

1981-09-01

The material given here was presented in lectures delivered at the 4th Kyoto Summer Institute on Grand Unification and Related Topics. It consists of six sections. The sections are: the family problem, fermion mass hierarchy, maximal local symmetry, operator analysis of new physics, dynamically generated gravity, and Kaluza theory and grand unification. The last section contains a (hopefully) pedagogical introduction to Kaluza theory. For pedagogical completeness, several appendices reviewing some elementary notions of differential geometry have been added

Cancer in atomic bomb survivors

International Nuclear Information System (INIS)

Shigematsu, I.; Kagan, A.

1986-01-01

This book presents information on the following topics: sampling of atomic bomb survivors and method of cancer detection in Hiroshima and Nagasaki; atomic bomb dosimetry for epidemiological studies of survivors in Hiroshima and Nagasaki; tumor and tissue registries in Hiroshima and Nagasaki; the cancer registry in Nagasaki, with atomic bomb survivor data, 1973-1977; cancer mortality; methods for study of delayed health effects of a-bomb radiation; experimental radiation carcinogenesis in rodents; leukemia, multiple myeloma, and malignant lymphoma; cancer of the thyroid and salivary glands; malignant tumors in atomic bomb survivors with special reference to the pathology of stomach and lung cancer; colorectal cancer among atomic bomb survivors; breast cancer in atomic bomb survivors; and ovarian neoplasms in atomic bomb survirors

COMPREHENSIVE ANALYSIS OF BIOLOGICALLY RELEVANT ARSENICALS BY PH-SELECTIVE HYDRIDE GENERATION-ATOMIC ABSORPTION SPECTROMETRY

Science.gov (United States)

A method based on pH-selective generation and separation of arsines is commonly used for analysis of inorganic, methylated, and dimethylated trivalent and pentavalent arsenicals by hydride generation-atomic absorption spectrometry (HG-AAS). We have optimized this method to pe...

Topical problems in the implementation of Atomic Energy Law

International Nuclear Information System (INIS)

Basse, H.

1983-01-01

The German Symposium on Atomic Energylaw, a discussion circle of law and various opinious in the field of nuclear energy, is 10 years old and has in the meanwhile become an institution. The 7th meeting again had an impressive scientific level as far as the speeches, and discussions were concerned. (orig.) [de

State-selective charge transfer cross sections for light ion impact of atomic hydrogen

Energy Technology Data Exchange (ETDEWEB)

Schultz, D. R. [University of North Texas; Stancil, Phillip C. [University of Georgia, Athens; Havener, C. C. [Oak Ridge National Laboratory (ORNL)

2015-01-01

Owing to the utility of diagnosing plasma properties such as impurity concentration and spatial distribution, and plasma temperature and rotation, by detection of photon emission following capture of electrons from atomic hydrogen to excited states of multiply charged ions, new calculations of state-selective charge transfer involving light ions have been carried out using the atomic orbital close-coupling and the classical trajectory Monte Carlo methods. By comparing these with results of other approaches applicable in a lower impact energy regime, and by benchmarking them using key experimental data, knowledge of the cross sections can be made available across the range parameters needed by fusion plasma diagnostics.

Experimental evidence of state-selective charge transfer in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Chan, George C.-Y.; Hieftje, Gary M.

2004-01-01

State-selective charge-transfer behavior was observed for Fe, Cr, Mn and Cu in inductively coupled plasma (ICP)-atomic emission spectrometry. Charge transfer from Ar + to Fe, Cr and Mn is state-selective because of inefficient collisional mixing of the quasiresonant charge-transfer energy levels with nearby levels. This low efficiency is the consequence of differences in electronic configuration of the core electrons. The reason for state-selective charge-transfer behavior to Cu is not clear, although a tentative explanation based on efficiency of intramultiplet and intermultiplet mixing for this special case is offered

The IAEA's WorldAtom Internet site: International news and information services

International Nuclear Information System (INIS)

Kyd, D.R.

2000-01-01

The International Atomic Energy Agency (IAEA) provides news and public information services via the Internet through its WorldAtom home page. The page is accessible at www.iaea.org/worldatom. Following are brief highlights of the items available on the site by clicking Press Centre, Reference Centre, or other links: Daily Press Review: Summaries of selected news items pertaining to global nuclear developments and the IAEA's work are provided each day, drawing upon a wide range of global media sources. IAEA NewsBriefs: Regularly featured are updates about IAEA activities related to areas of safety, technology transfer, and nuclear safeguards. Meetings and training courses: News about IAEA-sponsored symposia, seminars, and other meetings, as well as information about international meetings on atomic energy sponsored by other organizations, are updated on a daily basis. Press releases and statements: All IAEA press releases and media advisories since 1995 are accessible on the site. Topical and feature pages: In-depth coverage and links to information resources within and outside the IAEA are regularly given to selected topics of high international interest involving the IAEA. IAEA publications: listings and overviews of IAEA technical reports, safety standards, and other publications are updated as they are issued. Scientific and technical information: WorldAtom includes links (Reference Centre) to the International Nuclear Information System, IAEA's extensive bibliographic database of references and resources, to the nuclear database, and to departmental pages at IAEA that focus on IAEA programs and activities. IAEA documents: Electronic versions of official IAEA documents are added as they are issued. These documents include the texts and status lists of international conventions under IAEA auspices; IAEA information circulars to member states; IAEA annual reports (since 1995); and background reports and documents for the IAEA General Conference related to

Atomic processes relevant to polarization plasma spectroscopy

International Nuclear Information System (INIS)

Fujimoto, T.; Koike, F.; Sakimoto, K.; Okasaka, R.; Kawasaki, K.; Takiyama, K.; Oda, T.; Kato, T.

1992-04-01

When atoms (ions) are excited anisotropically, polarized excited atoms are produced and the radiation emitted by these atoms is polarized. From the standpoint of plasma spectroscopy research, we review the existing data for various atomic processes that are related to the polarization phenomena. These processes are: electron impact excitation, excitation by atomic and ionic collisions, photoexcitation, radiative recombination and bremsstrahlung. Collisional and radiative relaxation processes of atomic polarization follow. Other topics included are: electric-field measurement, self alignment, Lyman doublet intensity ratio, and magnetic-field measurement of the solar prominence. (author)

Decay of long-lived autoionization atomic states in atom collisions

International Nuclear Information System (INIS)

Krakov, B.G.

1994-01-01

Radiationless decay of long-lived autoionization states of helium atoms in atom collisions is investigated. It is shown that the states may decay in atom collisions due to softening of the selection rules

Lectures on the mathematics of quantum mechanics II selected topics

CERN Document Server

Dell'Antonio, Gianfausto

2016-01-01

The first volume (General Theory) differs from most textbooks as it emphasizes the mathematical structure and mathematical rigor, while being adapted to the teaching the first semester of an advanced course in Quantum Mechanics (the content of the book are the lectures of courses actually delivered.). It differs also from the very few texts in Quantum Mechanics that give emphasis to the mathematical aspects because this book, being written as Lecture Notes, has the structure of lectures delivered in a course, namely introduction of the problem, outline of the relevant points, mathematical tools needed, theorems, proofs. This makes this book particularly useful for self-study and for instructors in the preparation of a second course in Quantum Mechanics (after a first basic course). With some minor additions it can be used also as a basis of a first course in Quantum Mechanics for students in mathematics curricula. The second part (Selected Topics) are lecture notes of a more advanced course aimed at giving th...

On-line atomic data access

Energy Technology Data Exchange (ETDEWEB)

Schultz, D.R. [Oak Ridge National Lab., TN (United States); Nash, J.K. [Lawrence Livermore National Lab., CA (United States)

1996-04-01

The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser- produced plasma research, and plasma processing. Modern computer database and communications technology nables this data to be placed on-line and obtained by users of the Internet. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

Theoretical atomic physics

CERN Document Server

Friedrich, Harald

2017-01-01

This expanded and updated well-established textbook contains an advanced presentation of quantum mechanics adapted to the requirements of modern atomic physics. It includes topics of current interest such as semiclassical theory, chaos, atom optics and Bose-Einstein condensation in atomic gases. In order to facilitate the consolidation of the material covered, various problems are included, together with complete solutions. The emphasis on theory enables the reader to appreciate the fundamental assumptions underlying standard theoretical constructs and to embark on independent research projects. The fourth edition of Theoretical Atomic Physics contains an updated treatment of the sections involving scattering theory and near-threshold phenomena manifest in the behaviour of cold atoms (and molecules). Special attention is given to the quantization of weakly bound states just below the continuum threshold and to low-energy scattering and quantum reflection just above. Particular emphasis is laid on the fundamen...

Diagnosing Students’ conception on atomic structure using open ended questions

Science.gov (United States)

Fitriza, Z.; Gazali, F.

2018-05-01

This study aims to diagnose students’ conception on atomic structure concepts using open ended questions. For this reason, a 7 items of assay test was administered to 135 senior high school students from different schools in West Sumatera. The data were collected using a an open ended test which is covering the concept used in the topic Atomic Structure. The open ended test of students’ conceptual was developed to identify the alternative conceptions that student might have regarding the concepts in Atomic Structure, to measure the level of students’ conceptions, and the way of students’ thinking concerning the concepts. The results showed that students find difficulties about some concepts of Atomic structure such as atom, atomic model, electron configuration, period and group.The result of this study illuminated the concepts to be underlined in developing teaching and learning approach concerning the topic of Atomic Structure.

Trapped atoms along nanophotonic resonators

Science.gov (United States)

Fields, Brian; Kim, May; Chang, Tzu-Han; Hung, Chen-Lung

2017-04-01

Many-body systems subject to long-range interactions have remained a very challenging topic experimentally. Ultracold atoms trapped in extreme proximity to the surface of nanophotonic structures provides a dynamic system combining the strong atom-atom interactions mediated by guided mode photons with the exquisite control implemented with trapped atom systems. The hybrid system promises pair-wise tunability of long-range interactions between atomic pseudo spins, allowing studies of quantum magnetism extending far beyond nearest neighbor interactions. In this talk, we will discuss our current status developing high quality nanophotonic ring resonators, engineered on CMOS compatible optical chips with integrated nanostructures that, in combination with a side illuminating beam, can realize stable atom traps approximately 100nm above the surface. We will report on our progress towards loading arrays of cold atoms near the surface of these structures and studying atom-atom interaction mediated by photons with high cooperativity.

High-magnetic field atomic physics

International Nuclear Information System (INIS)

Gay, J.C.

1984-01-01

This chapter discusses both the traditional developments of Zeeman techniques at strong fields and the fundamental concepts of diamagnetism. Topics considered include historical aspects, the production of high fields, the atom in a magnetic field (Hamiltonian and symmetries, the various magnetic regimes in atomic spectra), applications of the Zeeman effect at strong B fields, the Landau regime for loosely bound particles, theoretical concepts of atomic diamagnetism, and the ultra-high-field regime and quantum electrodynamics. It is concluded that the wide implications of the problem of the strongly magnetized hydrogen atom in various domains of physics and its conceptual importance concerning theoretical methods of classical and quantum mechanics justify the experimental and theoretical efforts in atomic physics

Quantum Electronics for Atomic Physics

CERN Document Server

Nagourney, Warren

2010-01-01

Quantum Electronics for Atomic Physics provides a course in quantum electronics for researchers in atomic physics. The book covers the usual topics, such as Gaussian beams, cavities, lasers, nonlinear optics and modulation techniques, but also includes a number of areas not usually found in a textbook on quantum electronics. It includes such practical matters as the enhancement of nonlinear processes in a build-up cavity, impedance matching into a cavity, laser frequencystabilization (including servomechanism theory), astigmatism in ring cavities, and atomic/molecular spectroscopic techniques

PREFACE: CEWQO Topical Issue CEWQO Topical Issue

Science.gov (United States)

Bozic, Mirjana; Man'ko, Margarita

2009-09-01

This topical issue of Physica Scripta collects selected peer-reviewed contributions based on invited and contributed talks and posters presented at the 15th Central European Workshop on Quantum Optics (CEWQO) which took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu). On behalf of the whole community took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu, cewqo08.phy.bg.ac.yu). On behalf of the whole community of the workshop, we thank the referees for their careful reading and useful suggestions which helped to improve all of the submitted papers. A brief description of CEWQO The Central European Workshop on Quantum Optics is a series of conferences started informally in Budapest in 1992. Sometimes small events transform into important conferences, as in the case of CEWQO. Professor Jozsef Janszky, from the Research Institute of Solid State Physics and Optics, is the founder of this series. Margarita Man'ko obtained the following information from Jozsef Janszky during her visit to Budapest, within the framework of cooperation between the Russian and Hungarian Academies of Sciences in 2005. He organized a small workshop on quantum optics in Budapest in 1992 with John Klauder as a main speaker. Then, bearing in mind that a year before Janszky himself was invited by Vladimir Buzek to give a seminar on the same topic in Bratislava, he decided to assign the name 'Central European Workshop on Quantum Optics', considering the seminar in Bratislava to be the first workshop and the one in Budapest the second. The third formal workshop took place in Bratislava in 1993 organized by Vladimir Buzek, then in 1994 (Budapest, by Jozsef Janszky), 1995 and 1996 (Budmerice, Slovakia, by Vladimir Buzek), 1997 (Prague, by Igor Jex), 1999 (Olomouc, Czech Republic, by Zdenek Hradil), 2000 (Balatonfüred, Hungary, by Jozsef Janszky ), 2001 (Prague, by Igor Jex), 2002 (Szeged, Hungary, by Mihaly Benedict), 2003 (Rostock,Germany, by Werner Vogel and

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

International Nuclear Information System (INIS)

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

2011-01-01

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. (topical review)

Sixteenth International Conference on the physics of electronic and atomic collisions

Energy Technology Data Exchange (ETDEWEB)

Dalgarno, A.; Freund, R.S.; Lubell, M.S.; Lucatorto, T.B. (eds.)

1989-01-01

This report contains abstracts of papers on the following topics: photons, electron-atom collisions; electron-molecule collisions; electron-ion collisions; collisions involving exotic species; ion- atom collisions, ion-molecule or atom-molecule collisions; atom-atom collisions; ion-ion collisions; collisions involving rydberg atoms; field assisted collisions; collisions involving clusters and collisions involving condensed matter.

Sixteenth International Conference on the physics of electronic and atomic collisions

International Nuclear Information System (INIS)

Dalgarno, A.; Freund, R.S.; Lubell, M.S.; Lucatorto, T.B.

1989-01-01

This report contains abstracts of papers on the following topics: photons, electron-atom collisions; electron-molecule collisions; electron-ion collisions; collisions involving exotic species; ion- atom collisions, ion-molecule or atom-molecule collisions; atom-atom collisions; ion-ion collisions; collisions involving rydberg atoms; field assisted collisions; collisions involving clusters and collisions involving condensed matter

Annual report 1983 of the section 'Karl Schoenherrstr. 3' (formerly 'Institute of Atomic Physics') of the 'Institute of Experimentalphysics' at the Leopold Franzens University, Innsbruck, Austria

International Nuclear Information System (INIS)

Howorka, F.; Maerk, T.D.; Lindinger, W.

1983-01-01

The research topics in the institute were 1) State selected ion neutral interactions. 2) Vibrational temperature of ions. 3) Interstellar molecular synthesis. 4) Radiation damage in solids. 5) Excitation in ion-molecule and ion-atom collisions. 6) Hollow-cathode discharges. (Author)

Parity non-conservation in atoms

International Nuclear Information System (INIS)

Barkov, L.M.

1982-01-01

The parity non-conservation discovered in particle physics in 1959 has consequences on the behaviour of atoms illuminated by light of circular polarization. The theoretical treatments of this topic and recent experimental test of detecting the effects of parity non-conservation on atomic physics are listed, reviewed and illustrated. The main experimental results and limits are summarized. Proposed future experiments are discussed. (D.Gy.)

Selected topical agents used in Traditional Chinese Medicine in the treatment of minor injuries- a review

Directory of Open Access Journals (Sweden)

Ping Chung eLEUNG

2016-02-01

Full Text Available Topical medicinal patches have been popular for the treatment of minor injuries like sprains and avulsions. Other inflammatory conditions like chronic musculo-tendinous pain and or fasciitis are also taken care of by local ointments or rubs. In the oriental communities, medicinal herbs frequently form the major components of the patches.In spite of the lack of scientific evidence of efficacy, the popularity of such traditional application persists for centuries.In this era of evidence-based clinical treatment, there is an urgent need to look into this traditional practice. The purpose should include a scientific verification of the efficacy of the practice, and once proven, further explorations would be indicated to bring the practice to a higher level.A system of comprehensive exploration was proposed and practiced in the past years to fulfill the aspiration. The research consisted of four areas:(1Identification of the suitable medicinal herbs for the topical study;(2Study of the biological activities of the selected herbs, concentrating on the areas of anti-inflammation, anti-oxidation, angiogenesis and cellular proliferation;(3Study on the transcutaneous transport of the chemicals of the selected herbs to deeper tissues; and(4Pilot clinical studies on common superficial inflammatory musculo-skeletal conditions to give objective clinical evidences to the topical applications.Five herbs were identified as suitable candidates of study. They were put into relevant laboratory platforms and were proven to be anti-oxidant, anti-inflammatory and pro-angiogenic. Three of the herbs were prepared as topical patches with an enhancer and used to treat three common ailments in pilot clinical trials, viz., plantar fasciitis, undisplaced metatarsal fracture and tendonitis of the wrist (de-Quervain’s disease and the elbow (Tennis elbow. The clinical results of the pilot studies were very positive.It is therefore concluded that further explorations are

Atomic cluster collisions

Science.gov (United States)

Korol, Andrey V.; Solov'yov, Andrey

2013-01-01

Atomic cluster collisions are a field of rapidly emerging research interest by both experimentalists and theorists. The international symposium on atomic cluster collisions (ISSAC) is the premier forum to present cutting-edge research in this field. It was established in 2003 and the most recent conference was held in Berlin, Germany in July of 2011. This Topical Issue presents original research results from some of the participants, who attended this conference. This issues specifically focuses on two research areas, namely Clusters and Fullerenes in External Fields and Nanoscale Insights in Radiation Biodamage.

Scattering of highly excited atoms

International Nuclear Information System (INIS)

Raith, W.

1980-01-01

Experimental methods to excite atomic beams into Rydberg states and the first results of collision experiments with such beams are reported. For further information see hints under relevant topics. (orig.) [de

Symposium on atomic spectroscopy (SAS-83): abstracts and program

International Nuclear Information System (INIS)

1983-09-01

Abstracts of papers given at the symposium are presented. Session topics include: Rydbergs, optical radiators, and planetary atoms; highly ionized atoms; ultraviolet radiation; theory, ion traps, and laser cooling; beam foil; and astronomy

Licensing topical report: application of probabilistic risk assessment in the selection of design basis accidents

International Nuclear Information System (INIS)

Houghton, W.J.

1980-06-01

A probabilistic risk assessment (PRA) approach is proposed to be used to scrutinize selection of accident sequences. A technique is described in this Licensing Topical Report to identify candidates for Design Basis Accidents (DBAs) utilizing the risk assessment results. As a part of this technique, it is proposed that events with frequencies below a specified limit would not be candidates. The use of the methodology described is supplementary to the traditional, deterministic approach and may result, in some cases, in the selection of multiple failure sequences as DBAs; it may also provide a basis for not considering some traditionally postulated events as being DBAs. A process is then described for selecting a list of DBAs based on the candidates from PRA as supplementary to knowledge and judgments from past licensing practice. These DBAs would be the events considered in Chapter 15 of Safety Analysis Reports of high-temperature gas-cooled reactors

The Mystery of Matter, World of the Atom Series.

Science.gov (United States)

Pollard, William G.

This booklet is one in the "World of the Atome Series" for junior high school students and their teachers. It describes the fascinating story of the search for the key to the structure of matter. These topics are reviewed: the chemical atom of the 19th century, the planetary atom, the wave atom, inside the elementary particles, and the mystery of…

Fundamentals in hadronic atom theory

CERN Document Server

Deloff, A

2003-01-01

Hadronic atoms provide a unique laboratory for studying hadronic interactions essentially at threshold. This text is the first book-form exposition of hadronic atom theory with emphasis on recent developments, both theoretical and experimental. Since the underlying Hamiltonian is a non-self-adjoined operator, the theory goes beyond traditional quantum mechanics and this book covers topics that are often glossed over in standard texts on nuclear physics. The material contained here is intended for the advanced student and researcher in nuclear, atomic or elementary-particle physics. A good know

Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

International Nuclear Information System (INIS)

Cho, Young Joon; Shin, Woong-Chul; Chang, Hyo Sik

2014-01-01

Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al 2 O 3 , we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al 2 O 3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al 2 O 3 film. • Ozone-based Al 2 O 3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

Atomic collisions related to atomic laser isotope separation

International Nuclear Information System (INIS)

Shibata, Takemasa

1995-01-01

Atomic collisions are important in various places in atomic vapor laser isotope separation (AVLIS). At a vaporization zone, many atomic collisions due to high density have influence on the atomic beam characteristics such as velocity distribution and metastable states' populations at a separation zone. In the separation zone, a symmetric charge transfer between the produced ions and the neutral atoms may degrade selectivity. We have measured atomic excitation temperatures of atomic beams and symmetric charge transfer cross sections for gadolinium and neodymium. Gadolinium and neodymium are both lanthanides. Nevertheless, results for gadolinium and neodymium are very different. The gadolinium atom has one 5d electron and neodymium atom has no 5d electron. It is considered that the differences are due to existence of 5d electron. (author)

Atoms in Astronomy.

Science.gov (United States)

Blanchard, Paul A.

This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. A Basic Topics section discusses atomic structure, emphasizing states of matter at high temperature and spectroscopic analysis of light from the stars. A section…

Physics of atoms and molecules

International Nuclear Information System (INIS)

Bransden, B.H.; Joachain, C.J.

1983-01-01

This book presents a unified account of the physics of atoms and molecules at a level suitable for second- and third-year undergraduate students of physics and physical chemistry. Following a brief historical introduction to the subject the authors outline the ideas and approximation methods of quantum mechanics to be used later in the book. Six chapters look at the structure of atoms and the interactions between atoms and electromagnetic radiation. The authors then move on to describe the structure of molecules and molecular spectra. Three chapters deal with atomic collisions, the scattering of electrons by atoms and the scattering of atoms by atoms. The concluding chapter considers a few of the many important applications of atomic physics within astrophysics, laser technology, and nuclear fusion. Problems are given at the end of each chapter, with hints at the solutions in an appendix. Other appendices include various special topics and derivations together with useful tables of units. (author)

Methods of selection and training of personnel for the Rajasthan atomic power station

International Nuclear Information System (INIS)

Sarma, M.S.R.; Wagadarikar, V.K.

1975-01-01

Personnel selected to work in a nuclear electric generating station rarely have the necessary knowledge and experience in all the related fields. A station can be operated and maintained and at the same time radiation doses absorbed by station personnel can be kept to a minimum only if the operating personnel are familiar with, and can be used for, all phases of station operation and the maintainers have more than one skill or trade. More technical knowledge and more diversified skills, in addition to those required in other industries, are needed because of the nature of the nuclear reactor and the associated radiation environment and high automation. A training programme has been developed at the Nuclear Training Centre (NTC) near the Rajasthan Atomic Power Station (RAPS), Kota, India, to cater to the needs of the operation and maintenance personnel for nuclear power stations including the Madras Atomic Power Station. This programme has been in operation for the last five years. The paper describes the method of recruitment/selection of various categories of personnel and the method of training them to meet the job requirements. (author)

Low-energy positron interactions with atoms and molecules

International Nuclear Information System (INIS)

Surko, C M; Gribakin, G F; Buckman, S J

2005-01-01

This paper is a review of low-energy positron interactions with atoms and molecules. Processes of interest include elastic scattering, electronic and vibrational excitation, ionization, positronium formation and annihilation. An overview is presented of the currently available theoretical and experimental techniques to study these phenomena, including the use of trap-based positron beam sources to study collision processes with improved energy resolution. State-resolved measurements of electronic and vibrational excitation cross sections and measurement of annihilation rates in atoms and molecules as a function of incident positron energy are discussed. Where data are available, comparisons are made with analogous electron scattering cross sections. Resonance phenomena, common in electron scattering, appear to be less common in positron scattering. Possible exceptions include the sharp onsets of positron-impact electronic and vibrational excitation of selected molecules. Recent energy-resolved studies of positron annihilation in hydrocarbons containing more than a few carbon atoms provide direct evidence that vibrational Feshbach resonances underpin the anomalously large annihilation rates observed for many polyatomic species. We discuss open questions regarding this process in larger molecules, as well as positron annihilation in smaller molecules where the theoretical picture is less clear. (topical review)

Ninth international symposium on hot atom chemistry. Abstracts

International Nuclear Information System (INIS)

1977-01-01

Abstracts of the papers presented at the Symposium are compiled. The topics considered were chemical dynamics of high energy reactions, hot atom chemistry in organic compounds of tritium, nitrogen, oxygen, and halogens, theory and chemical dynamics of hot atom reactions as determined by beam studies, solid state reactions of recoil atoms and implanted ions, hot atom chemistry in energy-related research, hot atom chemistry in inorganic compounds of oxygen and tritium, hot positronium chemistry, applied hot atom chemistry in labelling, chemical effects of radioactive decay, decay-induced reactions and excitation labelling, physical methods in hot atom chemistry, and hot atom reactions in radiation and stratospheric chemistry

Atomic T-violation: A biased history

International Nuclear Information System (INIS)

Sandars, P.G.H.

1991-01-01

This article reviews the history of atomic T-violation from a personal point of view. Considerable emphasis is put on the early edm work which was much encouraged by the interest shown by Art Rich. The present generation of beautiful experiments is described more briefly. We end with a short introduction to the new topic of T not P violation in atoms

The Elusive Neutrino, Understanding the Atom Series.

Science.gov (United States)

Bernstein, Jeremy

This booklet is one of the booklets in the "Understanding the Atom Series" published by the U. S. Atomic Energy Commission for high school science teachers and their students. The discovery of the neutrino and the research involving this important elementary particle of matter is discussed. The introductory section reviews topics basic…

Selected topics on the nonrelativistic diagram technique

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Narodetskij, I.M.

1983-01-01

The construction of the diagrams describing various processes in the four-particle systems is considered. It is shown that these diagrams, in particular the diagrams corresponding to the simple mechanisms often used in nuclear and atomic reaction theory, are readily obtained from the Faddeev-Yakubovsky equations. The covariant four-dimensional formalism of nonrelativistic Feynman graphs and its connection to the three-dimensional graph technique are briefly discussed

Atoms in astronomy

Science.gov (United States)

Blanchard, P. A.

1976-01-01

Aspects of electromagnetic radiation and atomic physics needed for an understanding of astronomical applications are explored. Although intended primarily for teachers, this brochure is written so that it can be distributed to students if desired. The first section, Basic Topics, is suitable for a ninth-grade general science class; the style is simple and repetitive, and no mathematics or physics background is required. The second section, Intermediate and Advanced Topics, requires a knowledge of the material in the first section and assumes a generally higher level of achievement and motivation on the part of the student. These latter topics might fit well into junior-level physics, chemistry, or earth-science courses. Also included are a glossary, a list of references and teaching aids, class exercises, and a question and answer section.

Study of the selective abstration reaction of the hydrogen atom in the radiolysis and photolysis of alkane mixture at 77 K

International Nuclear Information System (INIS)

Guedes, S.M.L.

1979-01-01

The occurence of the selective abstraction reaction of the solute hydrogen atom by hydrogen atom produced during radiolysis or photolysis of the systems such as neopentane/cyclo-hexane/HI, neopentane/2,3 dimethylbutane, n-pentane/HI/cyclo-hexane and cyclo-hexane/HI/n-pentane, at 77 K is studied. Experiments have been undertaken on the kinetics nature of the active species, the H atom, during radiolysis and photolysis of the neopentane/cyclo-hexane/HI system at 77 K, presenting competitive reactions. Studies have also been made on the occurrence of the selective abstraction reaction in inverted systems, in which the concentrations of the components of a system are so much altered that the solute becomes the solvent and vice-versa, in the other system. By means of photolysis at 77 K, it has been observed that for the two systems constitued by the cyclo-hexane and n-pentane the selective abstraction reaction occurs. However, for radiolysis of that same two systems it has been observed that only the hydrogen atom abstraction reaction corresponding to the solvent occurs. (Author) [pt

Thermally stable single atom Pt/m-Al2O3 for selective hydrogenation and CO oxidation

KAUST Repository

Zhang, Zailei

2017-07-27

Single-atom metal catalysts offer a promising way to utilize precious noble metal elements more effectively, provided that they are catalytically active and sufficiently stable. Herein, we report a synthetic strategy for Pt single-atom catalysts with outstanding stability in several reactions under demanding conditions. The Pt atoms are firmly anchored in the internal surface of mesoporous Al2O3, likely stabilized by coordinatively unsaturated pentahedral Al3+ centres. The catalyst keeps its structural integrity and excellent performance for the selective hydrogenation of 1,3-butadiene after exposure to a reductive atmosphere at 200 °C for 24 h. Compared to commercial Pt nanoparticle catalyst on Al2O3 and control samples, this system exhibits significantly enhanced stability and performance for n-hexane hydro-reforming at 550 °C for 48 h, although agglomeration of Pt single-atoms into clusters is observed after reaction. In CO oxidation, the Pt single-atom identity was fully maintained after 60 cycles between 100 and 400 °C over a one-month period.

Advances in atomic, molecular, and optical physics

CERN Document Server

Bederson, Benjamin

1993-01-01

Advances in Atomic, Molecular, and Optical Physics, established in 1965, continues its tradition of excellence with Volume 32, published in honor of Founding Editor Sir David Bates upon his retirement as editorof the series. This volume presents reviews of topics related to the applications of atomic and molecular physics to atmospheric physics and astrophysics.

Selection rule engineering of forbidden transitions of a hydrogen atom near a nanogap

Science.gov (United States)

Kim, Hyunyoung Y.; Kim, Daisik S.

2018-01-01

We perform an analytical study on the allowance of forbidden transitions for a hydrogen atom placed near line dipole sources, mimicking light emanating from a one-dimensional metallic nanogap. It is shown that the rapid variation of the electric field vector, inevitable in the near zone, completely breaks the selection rule of Δl=±1. While the forbidden transitions between spherically symmetric S states, such as 2S to 1S or 3S to 1S (Δl=0), are rather robust against selection rule breakage, Δl=±2 transitions such as between 3D and 1S or 3D and 2S states are very vulnerable to the spatial variation of the perturbing electric field. Transitions between 2S and 3D states are enhanced by many orders of magnitude, aided by the quadratic nature of both the perturbing Hamiltonian and D wavefunctions. The forbidden dipole moment, which approaches one Bohr radius times the electric charge in the vicinity of the gap, can be written in a simple closed form owing to the one-dimensional nature of our gap. With large enough effective volume together with the symmetric nature of the excited state wavefunctions, our work paves way towards atomic physics application of infinitely long nanogaps.

Development of new methods in modern selective organic synthesis: preparation of functionalized molecules with atomic precision

International Nuclear Information System (INIS)

Ananikov, V P; Khemchyan, L L; Ivanova, Yu V; Dilman, A D; Levin, V V; Bukhtiyarov, V I; Sorokin, A M; Prosvirin, I P; Romanenko, A V; Simonov, P A; Vatsadze, S Z; Medved'ko, A V; Nuriev, V N; Nenajdenko, V G; Shmatova, O I; Muzalevskiy, V M; Koptyug, I V; Kovtunov, K V; Zhivonitko, V V; Likholobov, V A

2014-01-01

The challenges of the modern society and the growing demand of high-technology sectors of industrial production bring about a new phase in the development of organic synthesis. A cutting edge of modern synthetic methods is introduction of functional groups and more complex structural units into organic molecules with unprecedented control over the course of chemical transformation. Analysis of the state-of-the-art achievements in selective organic synthesis indicates the appearance of a new trend — the synthesis of organic molecules, biologically active compounds, pharmaceutical substances and smart materials with absolute selectivity. Most advanced approaches to organic synthesis anticipated in the near future can be defined as 'atomic precision' in chemical reactions. The present review considers selective methods of organic synthesis suitable for transformation of complex functionalized molecules under mild conditions. Selected key trends in the modern organic synthesis are considered including the preparation of organofluorine compounds, catalytic cross-coupling and oxidative cross-coupling reactions, atom-economic addition reactions, methathesis processes, oxidation and reduction reactions, synthesis of heterocyclic compounds, design of new homogeneous and heterogeneous catalytic systems, application of photocatalysis, scaling up synthetic procedures to industrial level and development of new approaches to investigation of mechanisms of catalytic reactions. The bibliography includes 840 references

Atom Skimmers and Atom Lasers Utilizing Them

Science.gov (United States)

Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

2005-01-01

Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

Uncertainty estimates for theoretical atomic and molecular data

International Nuclear Information System (INIS)

Chung, H-K; Braams, B J; Bartschat, K; Császár, A G; Drake, G W F; Kirchner, T; Kokoouline, V; Tennyson, J

2016-01-01

Sources of uncertainty are reviewed for calculated atomic and molecular data that are important for plasma modeling: atomic and molecular structures and cross sections for electron-atom, electron-molecule, and heavy particle collisions. We concentrate on model uncertainties due to approximations to the fundamental many-body quantum mechanical equations and we aim to provide guidelines to estimate uncertainties as a routine part of computations of data for structure and scattering. (topical review)

Atoms in dense plasmas

International Nuclear Information System (INIS)

More, R.M.

1987-01-01

This paper covers some aspects of the theory of atomic processes in dense plasmas. Because the topic is very broad, a few general rules which give useful guidance about the typical behavior of dense plasmas have been selected. These rules are illustrated by semiclassical estimates, scaling laws and appeals to more elaborate calculations. Included in the paper are several previously unpublished results including a new mechanism for electron-ion heat exchange (section II), and an approximate expression for oscillator-strengths of highly charged ions (section V). However the main emphasis is not upon practical formulas but rather on questions of fundamental theory, the structural ingredients which must be used in building a model for plasma events. What are the density effects and how does one represent them? Which are most important? How does one identify an incorrect theory? The general rules help to answer these questions. 106 references, 23 figures, 2 tables

Selective Deflection of Polarized Light Via Coherently Driven Four-Level Atoms in a Double-Λ Configuration

International Nuclear Information System (INIS)

Guo Yu

2010-01-01

We study the interaction of a weak probe field, having two circular polarized components, i.e., σ - and σ + polarization, with an optically dense medium of four-level atoms in a double-Λ configuration, which is mediated by the electromagnetically induced transparency with a polarized control light with spatially inhomogeneous profile. We analyse the deflection of the polarized probe light and we find that we can selectively determine which circular component will be deflected after the polarized probe light enters the atom medium via adjusting the polarization and detuning of the control field. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Catalysis by nonmetals rules for catalyst selection

CERN Document Server

Krylov, Oleg V

1970-01-01

Catalysis by Non-metals: Rules of Catalyst Selection presents the development of scientific principles for the collection of catalysts. It discusses the investigation of the mechanism of chemosorption and catalysis. It addresses a series of properties of solid with catalytic activity. Some of the topics covered in the book are the properties of a solid and catalytic activity in oxidation-reduction reactions; the difference of electronegativities and the effective charges of atoms; the role of d-electrons in the catalytic properties of a solid; the color of solids; and proton-acid and proton-ba

Single-atom catalysts for CO2 electroreduction with significant activity and selectivity improvements.

Science.gov (United States)

Back, Seoin; Lim, Juhyung; Kim, Na-Young; Kim, Yong-Hyun; Jung, Yousung

2017-02-01

A single-atom catalyst (SAC) has an electronic structure that is very different from its bulk counterparts, and has shown an unexpectedly high specific activity with a significant reduction in noble metal usage for CO oxidation, fuel cell and hydrogen evolution applications, although physical origins of such performance enhancements are still poorly understood. Herein, by means of density functional theory (DFT) calculations, we for the first time investigate the great potential of single atom catalysts for CO 2 electroreduction applications. In particular, we study a single transition metal atom anchored on defective graphene with single or double vacancies, denoted M@sv-Gr or M@dv-Gr, where M = Ag, Au, Co, Cu, Fe, Ir, Ni, Os, Pd, Pt, Rh or Ru, as a CO 2 reduction catalyst. Many SACs are indeed shown to be highly selective for the CO 2 reduction reaction over a competitive H 2 evolution reaction due to favorable adsorption of carboxyl (*COOH) or formate (*OCHO) over hydrogen (*H) on the catalysts. On the basis of free energy profiles, we identified several promising candidate materials for different products; Ni@dv-Gr (limiting potential U L = -0.41 V) and Pt@dv-Gr (-0.27 V) for CH 3 OH production, and Os@dv-Gr (-0.52 V) and Ru@dv-Gr (-0.52 V) for CH 4 production. In particular, the Pt@dv-Gr catalyst shows remarkable reduction in the limiting potential for CH 3 OH production compared to any existing catalysts, synthesized or predicted. To understand the origin of the activity enhancement of SACs, we find that the lack of an atomic ensemble for adsorbate binding and the unique electronic structure of the single atom catalysts as well as orbital interaction play an important role, contributing to binding energies of SACs that deviate considerably from the conventional scaling relation of bulk transition metals.

Selected Topics on Mass Transport in Gas-solid Interactions

DEFF Research Database (Denmark)

Somers, Marcel A.J.

2004-01-01

The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion-controlled d......The present article is a short review containing examples of the role of mass transport in the solid state during gas-solid interactions. Examples are taken from the authors' research on the interaction of carbon and/or nitrogen with iron-based metals. Topics dealt with are diffusion...... on the kinetics of phenomena in the solid state. Various experimental techniques were applied to investigate these phenomena; it is however beyond the scope of the present article to treat experimental conditions in detail. The interested reader is referred to the original work for in depth discussions...

5. International workshop on autoionization phenomena in atoms. Abstracts

International Nuclear Information System (INIS)

Balashov, V.V.

1995-01-01

Summaries of the reports presented at the 5 International Workshop on Autoionization Phenomena in Atoms (Dubna, 12-14 December 1995). The main topics of these 53 reports are the following ones: photoexcitation of autoionizing states in atoms and ions, autoionization in electron-atom collisions, autoionization in heavy particle collisions, coincidence experiments in autoionization studies, investigations of autoionizing states with lasers and wave functions and decay characteristics of autoionizing states

Atomic profits, no thanks

International Nuclear Information System (INIS)

Bartels, W.; Dietrich, K.; Moeller, H.; Speier, C.

1980-01-01

The authors deal with the following topics: The secret of nuclear energy; the atom programmes of Bonn; on some arguments of the present nuclear energy discussion; how socialist countries solve the problems of nuclear energy. From the socialist point of view they discuss sociological, ideological and moral reasons for a peaceful utilization of nuclear energy. Nevertheless they refuse Bonn's atom programme because the high finance's interests concerning profit and power make it a danger. The biggest danger is said to lie in the creation of a plutonium-industry and the militaristic abuse which would be connected with it. The socialist way of utilizing atomic energy is seen by them as a way with a high feeling of responsibility towards all people and towards a guaranteed energy supply. (HSCH) [de

Topical Research: Africa.

Science.gov (United States)

Lynn, Karen

This lesson plan can be used in social studies, language arts, or library research. The instructional objective is for students to select a topic of study relating to Africa, write a thesis statement, collect information from media sources, and develop a conclusion. The teacher may assign the lesson for written or oral evaluation. The teacher…

Atom probe field ion microscopy and related topics: A bibliography 1992

Energy Technology Data Exchange (ETDEWEB)

Russell, K.F.; Godfrey, R.D.; Miller, M.K.

1993-12-01

This bibliography contains citations of books, conference proceedings, journals, and patents published in 1992 on the following types of microscopy: atom probe field ion microscopy (108 items); field emission microscopy (101 items); and field ion microscopy (48 items). An addendum of 34 items missed in previous bibliographies is included.

Selected topics in high temperature chemistry defect chemistry of solids

CERN Document Server

Johannesen, Ø

2013-01-01

The properties of materials at high temperature play a vital role in their processing and practical use. The real properties of materials at elevated temperatures are very often governed by defects in their structure. Lattice defects may consist of point defects like vacancies, interstitial atoms or substituted atoms. These classes are discussed in general and specifically for oxides, nitrides, carbides and sulfides. Defect aggregates, shear structures and adaptive structures are also described. Special attention is paid to hydrogen defects which seem to play an important role in several mater

International bulletin on atomic and molecular data for fusion. No. 49

International Nuclear Information System (INIS)

Botero, J.

1995-06-01

This issue of the bulletin provides atomic and molecular data references relevant to fusion research and technology. In part 1 the indexation of the papers is provided separately for (i) structure and spectra, (ii) atomic and molecular collisions, and (iii) surface interactions. Part 2 contains the bibliographic data for the above-listed topics and brief bibliographic lists for the following topics: (a) fusion research of general interest, (b) high energy laser- and beam-matter interaction, (c) bibliographic and numerical data collections, and (d) interaction of atomic particles with fields. Moreover, the creation of the Atomic and Molecular Data Information System (AMDIS) is announced by the IAEA. AMDIS contains three main parts: the Atomic and Molecular Bibliographic Data System (AMBDAS), the numerical database of recommended and evaluated atomic, molecular and plasma-surface interaction data ALADDIN and an electronic bulletin board with information regarding data needs, meetings and programs of the IAEA Atomic and Molecular Data Unit. AMDIS may be reached via INTERNET. For information on how to access AMDIS, an electronic mail inquiry can be sent (address: ''pms'' followed by the usual ''at'' symbol followed by ''ripcrs01.iaea.or.at'')

5. All-Russian (international) scientific conference. Physicochemical processes during selection of atoms and molecules. Program of the conference and summary of reports

International Nuclear Information System (INIS)

2000-01-01

The materials of the 5. All-Russian (international) scientific conference: Physicochemical processes during selection of atoms and molecules, are presented. The conference took place in Zvenigorod, 2-6 October, 2000. A wide range of items connected with uranium enrichment, selection of atoms and molecules by isotopic composition: laser methods, ion cyclotron-resonance method, are discussed. The paper contains the reports about harnessing radionuclides and stable isotopes in medicine and as a means of diagnostics. The results of investigation into modern and advanced technology for isotope separation are outlined. The selection of molecules by means of rectification methods and chemical isotope exchange are discussed [ru

Theory of many-electron atoms. Selected papers. Teoriya mnogoehlektronnykh atomov. Izbrannye trudy

Energy Technology Data Exchange (ETDEWEB)

Jucys, A P

1978-01-01

Selected papers of the founder of contemporary theoretical physics in Lithuania Adolfas Jucys on the theory of many-electron atoms and their spectra are presented, as well as a complete bibliography of his scientific works, a brief biographical essay and description of his scientific and social activities, reminiscences of other scientists about him. In these papers such questions are considered: Fock's self-consistent field in different approximations, various problems of the many-configurational approximation, incomplete separation of variables, expanded calculation method, application of nonorthogonal radial orbitals, method of irreducible tensor operators, graphical representation of the matrix elements and a number of other problems.

Interviews concerning topical questions in nuclear technology

International Nuclear Information System (INIS)

Segatz, U.; Schatz, A.; Stephany, M.; Michaelis, H.

1978-01-01

On the occasion of the Nuclex meeting, October 3-7, 1978, Basle/Switzerland, the editorial department of 'Atom und Strom' questioned some leading scientists in nuclear technology on particularly relevant topics. The following subjects were discussed: - How long can we do without nuclear energy, - Modern technology for nuclear power plants, - Nuclear fuel cycle and environment, - Nuclear energy and European Communities, - Nuclear energy and its risks (reflections on incidents). (orig./UA) [de

Regularization theory for ill-posed problems selected topics

CERN Document Server

Lu, Shuai

2013-01-01

Thismonograph is a valuable contribution to thehighly topical and extremly productive field ofregularisationmethods for inverse and ill-posed problems. The author is an internationally outstanding and acceptedmathematicianin this field. In his book he offers a well-balanced mixtureof basic and innovative aspects.He demonstrates new,differentiatedviewpoints, and important examples for applications. The bookdemontrates thecurrent developments inthe field of regularization theory,such as multiparameter regularization and regularization in learning theory. The book is written for graduate and PhDs

Spectroscopy, Understanding the Atom Series.

Science.gov (United States)

Hellman, Hal

This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

Densification behavior of gas and water atomized 316L stainless steel powder during selective laser melting

Science.gov (United States)

Li, Ruidi; Shi, Yusheng; Wang, Zhigang; Wang, Li; Liu, Jinhui; Jiang, Wei

2010-04-01

The densification during selective laser melting (SLM) process is an important factor determining the final application of SLM-part. In the present work, the densifications under different processing conditions were investigated and the densification mechanisms were elucidated. It was found that the higher laser power, lower scan speed, narrower hatch spacing and thinner layer thickness could enable a much smoother melting surface and consequently a higher densification. The gas atomized powder possessed better densification than water atomized powder, due to the lower oxygen content and higher packing density of gas atomized powder. A large number of regular-shaped pores can be generated at a wider hatch spacing, even if the scanning track is continuous and wetted very well. The densification mechanisms were addressed and the methods for building dense metal parts were also proposed as follows: inhibiting the balling phenomenon, increasing the overlap ratio of scanning tracks and reducing the micro-cracks.

Proceedings of the 8th topical meeting on nuclear code development

International Nuclear Information System (INIS)

1993-03-01

The 8th Topical Meeting on Nuclear Code Development, organized by Committee on Reactor Physics and Nuclear Codes Committee of Japan Atomic Energy Research Institute (JAERI), was held at Tokai Research Establishment of JAERI, on 11th and 12th of November, 1992. In the meeting, 14 papers were presented on the topics of (1) the next generation nuclear reactor design system and (2) advances of the nuclear fuel reprocessing safety analysis codes. These papers are compiled in this proceedings. (author)

International meeting 'Selected topics on nuclear methods for non-nuclear applications'. Proceedings

International Nuclear Information System (INIS)

Stoyanov, Ch.

2007-01-01

The volume includes the presentations given on the International Meeting 'Selected Topics on Nuclear Methods for Non-nuclear Applications'. The meeting was organized by the Project CECOA. The Project 'CEnter for COoerative Activities' (CECOA) of the Institute for Nuclear Research and Nuclear Energy (INRNE) of Bulgarian Academy of Sciences is part of the Program 'Creating of Infrastructure' of Bulgarian Ministry of Science and Education. The CECOA-project unifies the groups of INRNE doing research in the field of nuclear methods. Four Laboratories of INRNE are members of CECOA-project: Moessbauer Spectroscopy and Low Radioactivity Measurements, High-Resolution Gamma-Spectroscopy, Neutron Methods in Condensed Matter, Neutron Optics and Structure Analysis. Taking into account the leading role of education on nuclear physics the Project includes program devoted to the training on nuclear physics. The presented volume contains 23 contributed papers. The contributions are separated in 6 sections. The section 'Nano technology' includes 5 papers. The activity in this field within the Project reveals the collaboration with other Institutes of Bulgarian Academy of Sciences as well as large international contacts. The section 'Radioecology and Radioactive Waste' is two fold. Part of the contributions of the section manifests the connection of the CECOA with small enterprises. The contacts are on the level of common projects concerning the investigations, remediation and release of radioactively contaminated terrain, soils, water, buildings and materials around the former uranium processing industry. Another part of the section is devoted to the application of nuclear methods to the treatment of radioactive waste produced by nuclear power stations. The section 'Neutron Physics' reveals the activity within the Project connected with the study of new materials using polarized neutrons and neutron diffraction methods. The section 'Nuclear Physics' is an introduction to some

The effect of topic selection on writing fluency among Japanese high school students

Directory of Open Access Journals (Sweden)

Sarah Lin Lubold

2016-01-01

Full Text Available Written fluency and fluency building activities have been shown to promote linguistic choice and student voice development, increased ability to express ideas using complex grammatical structures and greater intrinsic motivation in English language learners. Since the 1970’s, process-oriented writing has been emphasized, yielding an amplified focus on meaning of student content over linguistic form precision. Current research of writing fluency must delve deeper into questions of student ownership of topic and the outcomes for low-risk activities that support fluency practice and encourage confidence building in students. The purpose of this replication study is to further explore previous findings on the effects of topic selection on writing fluency for high school English as foreign language learners. Building off of the work of Bonzo (2008, this study focused on a timed, non-graded writing activity administered to groups of Japanese engineering students in three departments: mechanical, electrical, and global engineering. The six subsequent samples for each participating student were analyzed using online text-analysis for total and unique word counts, providing data used to perform a t-test. Responses to bi-lingual student questionnaires, with prompts on self-perceived written English ability, self-efficacy and strategies for success while writing, provided additional insight into the facets of fluency. The results of these writing sessions offer both confirmation of and contrast to Bonzo’s original work, demonstrate increased student meaning making, and support the use of free writing activities in English language classrooms as a means by which student written fluency may be improved.

Laser guiding of cold atoms in photonic crystals

International Nuclear Information System (INIS)

Tarasishin, A V; Magnitskiy, Sergey A; Shuvaev, V A; Zheltikov, Aleksei M

2000-01-01

The possibility of using photonic crystals with a lattice defect for the laser guiding of cold atoms is analysed. We have found a configuration of a photonic-crystal lattice and a defect ensuring the distribution of a potential in the defect mode of the photonic crystal allowing the guiding of cold atoms along the defect due to the dipole force acting on atoms. Based on quantitative estimates, we have demonstrated that photonic crystals with a lattice defect permit the guiding of atoms with much higher transverse temperatures and a much higher transverse localisation degree than in the case of hollow-core fibres. (laser applications and other topics in quantum electronics)

A concise course on the theory of classical liquids basics and selected topics

CERN Document Server

Santos, Andrés

2016-01-01

This short primer offers non-specialist readers a concise, yet comprehensive introduction to the field of classical fluids – providing both fundamental information and a number of selected topics to bridge the gap between the basics and ongoing research. In particular, hard-sphere systems represent a favorite playground in statistical mechanics, both in and out of equilibrium, as they represent the simplest models of many-body systems of interacting particles, and at higher temperature and densities they have proven to be very useful as reference systems for real fluids. Moreover, their usefulness in the realm of soft condensed matter has become increasingly recognized – for instance, the effective interaction among (sterically stabilized) colloidal particles can be tuned to almost perfectly match the hard-sphere model. These lecture notes present a brief, self-contained overview of equilibrium statistical mechanics of classical fluids, with special applications to both the structural and thermodynamic pr...

International bulletin on atomic and molecular data for fusion. No. 47

International Nuclear Information System (INIS)

Botero, J.

1993-12-01

This bulletin, published by the IAEA, provides atomic and molecular data references relevant to fusion research and technology. In part I the indexation of the papers is provided separately for (i) structure and spectra, (ii) atomic and molecular collisions, and (iii) surface interactions. Part II contains the bibliographic data for the above-listed topics and for high-energy laser and beam-matter interaction of atomic particles with fields. Also included are sections on atomic and molecular data needs for fusion research and on news about ALADDIN (A Labelled Atomic Data INterface) and evaluated data bases

Atomic and solid state physics with the 14UD

International Nuclear Information System (INIS)

Newton, C.S.

1975-02-01

The use of energetic heavy ions in atomic and solid state physics is discussed. Topics that are discussed include: 1) Properties of excited ions, 2) radiation damage studies by channeling, 3) energy loss of ions and range measurements, 4) oscillating effects in channeling, 5) x-ray production in solids, 6) coherence effects in channeling and 7) formation of united atoms. (author)

Identifying Topics in Microblogs Using Wikipedia.

Science.gov (United States)

Yıldırım, Ahmet; Üsküdarlı, Suzan; Özgür, Arzucan

2016-01-01

Twitter is an extremely high volume platform for user generated contributions regarding any topic. The wealth of content created at real-time in massive quantities calls for automated approaches to identify the topics of the contributions. Such topics can be utilized in numerous ways, such as public opinion mining, marketing, entertainment, and disaster management. Towards this end, approaches to relate single or partial posts to knowledge base items have been proposed. However, in microblogging systems like Twitter, topics emerge from the culmination of a large number of contributions. Therefore, identifying topics based on collections of posts, where individual posts contribute to some aspect of the greater topic is necessary. Models, such as Latent Dirichlet Allocation (LDA), propose algorithms for relating collections of posts to sets of keywords that represent underlying topics. In these approaches, figuring out what the specific topic(s) the keyword sets represent remains as a separate task. Another issue in topic detection is the scope, which is often limited to specific domain, such as health. This work proposes an approach for identifying domain-independent specific topics related to sets of posts. In this approach, individual posts are processed and then aggregated to identify key tokens, which are then mapped to specific topics. Wikipedia article titles are selected to represent topics, since they are up to date, user-generated, sophisticated articles that span topics of human interest. This paper describes the proposed approach, a prototype implementation, and a case study based on data gathered during the heavily contributed periods corresponding to the four US election debates in 2012. The manually evaluated results (0.96 precision) and other observations from the study are discussed in detail.

Regulatory cross-cutting topics for fuel cycle facilities.

Energy Technology Data Exchange (ETDEWEB)

Denman, Matthew R.; Brown, Jason; Goldmann, Andrew Scott; Louie, David

2013-10-01

This report overviews crosscutting regulatory topics for nuclear fuel cycle facilities for use in the Fuel Cycle Research & Development Nuclear Fuel Cycle Evaluation and Screening study. In particular, the regulatory infrastructure and analysis capability is assessed for the following topical areas: Fire Regulations (i.e., how applicable are current Nuclear Regulatory Commission (NRC) and/or International Atomic Energy Agency (IAEA) fire regulations to advance fuel cycle facilities) Consequence Assessment (i.e., how applicable are current radionuclide transportation tools to support risk-informed regulations and Level 2 and/or 3 PRA) While not addressed in detail, the following regulatory topic is also discussed: Integrated Security, Safeguard and Safety Requirement (i.e., how applicable are current Nuclear Regulatory Commission (NRC) regulations to future fuel cycle facilities which will likely be required to balance the sometimes conflicting Material Accountability, Security, and Safety requirements.)

Spin-selective depopulation of triplet sublevels in rapidly rotating triplet exciplexes detected by a heavy-atom-induced magnetic field effect

OpenAIRE

Steiner, Ulrich

1980-01-01

A mechanism is presented explaining a reported heavy-atom-induced magnetic field effect as a consequence of non-equilibrium triplet sublevel population in an intermediate exciplex. The triplet exciplex spin polarization is induced by sub-level-selective intersystem crossing from the exciplex triplet to its singlet ground state and is decreased by an external magnetic field. The theory accounts almost quantitatively for the observed influence of magnetic field strength and heavy-atom substitue...

Non-steroidal topical immunomodulators provide skin-selective, self-limiting treatment in atopic dermatitis

NARCIS (Netherlands)

Bos, Jan D.

2003-01-01

Topical corticosteroids are the mainstay of treatment for atopic dermatitis; however, their clinical utility is limited by potential side effects. Recently, the steroid-free topical immunomodulators; tacrolimus ointment and pimecrolimus cream have become available. These agents provide effective

Atomic and molecular theory

International Nuclear Information System (INIS)

Inokuti, Mitio.

1990-01-01

The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs

Atomic and molecular theory

Energy Technology Data Exchange (ETDEWEB)

Inokuti, Mitio.

1990-01-01

The multifaceted role of theoretical physics in understanding the earliest stages of radiation action is discussed. Scientific topics chosen for the present discourse include photoabsorption, electron collisions, and ionic collisions, and electron transport theory, Connections of atomic and molecular physics with condensed-matter physics are also discussed. The present article includes some historical perspective and an outlook for the future. 114 refs., 3 figs.

Basic atomic interactions of accelerated heavy ions in matter atomic interactions of heavy ions

CERN Document Server

Tolstikhina, Inga; Winckler, Nicolas; Shevelko, Viacheslav

2018-01-01

This book provides an overview of the recent experimental and theoretical results on interactions of heavy ions with gaseous, solid and plasma targets from the perspective of atomic physics. The topics discussed comprise stopping power, multiple-electron loss and capture processes, equilibrium and non-equilibrium charge-state fractions in penetration of fast ion beams through matter including relativistic domain. It also addresses mean charge-states and equilibrium target thickness in ion-beam penetrations, isotope effects in low-energy electron capture, lifetimes of heavy ion beams, semi-empirical formulae for effective cross sections. The book is intended for researchers and graduate students working in atomic, plasma and accelerator physics.

Two-photon emission and multiphoton absorption by atoms

International Nuclear Information System (INIS)

Mu, X.

1988-01-01

This thesis consists of investigations of two problems concerning photon-atom interactions. The first topic deals with two-photon transitions in atomic inner shells. An independent-particle model has been used to describe the two-photon transitions between different inner-shell electron states. The first relativistic self-consistent-field calculation of these transition rates in Ag, Mo, and Xe has been carried out. The theoretical results are compared with recent measurements. Good agreement with measured rates is found except in some cases where more reliable experiments still need to be done. The second topic is multiphoton multiionization of atoms. The maximum entropy principle has been employed in this theoretical investigation. A detailed statistical analysis of measured ionic charge distributions produced in strong laser pulses has been carried out. The results of this analysis indicates that the charge-state distribution is a Poissonian, rather than the binomial which prevails under infrared radiation, and hence that ionization occurs stepwise during the pulse. This result is shown to be consistent with experimental data

Resonance ionization spectroscopy: Counting noble gas atoms

International Nuclear Information System (INIS)

Hurst, G.S.; Payne, M.G.; Chen, C.H.; Willis, R.D.; Lehmann, B.E.; Kramer, S.D.

1981-01-01

The purpose of this paper is to describe new work on the counting of noble gas atoms, using lasers for the selective ionization and detectors for counting individual particles (electrons or positive ions). When positive ions are counted, various kinds of mass analyzers (magnetic, quadrupole, or time-of-flight) can be incorporated to provide A selectivity. We show that a variety of interesting and important applications can be made with atom-counting techniques which are both atomic number (Z) and mass number (A) selective. (orig./FKS)

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

Progress in radiopharmacology 3. Selected topics. Fortschritte in der Radiopharmakologie 3

Energy Technology Data Exchange (ETDEWEB)

Cox, P H [ed.

1982-01-01

Three selected topics: Brain, Kidney and Endocrinology were dealt with in depth by invited speakers together with original work submitted in poster form. The session on renal diseases provided some interesting original data concerning the evaluation of renal circulation using Xenon which was complemented by reviews of the reagents available to study glomerular and tubule function. A comparison of biodistribution data on reagents for scintigraphy led to the conclusion that although Tc DMSA shows the highest degree of concentration in the renal cortex the characteristics of Tc glucoheptonate give a better visualization of the organ. A new reagent Aprotinin was introduced which shows a high affinity for the renal cortex, no liver or spleen uptake and an extremely low urinary excretion. These characteristics may prove to be of great value both in evaluating relative renal function and in the detection of space occupying lesions. The presentations on Brain demonstrated the value of positron emission studies for the elucidation of function. The criteria for the use of Tc/sup 99m/ DMSA labelling kits for cisternography are discussed. The s0206on on Endocrinology includes some new approaches such as thallium uptake in thyroid carcinoma, iodine-131 dosimetry in therapy and the effect of generators on technetium uptake in the thyroid. (Auth.)

Selected Topics on Managing Complexity and Information Systems Engineering: Editorial Introduction to Issue 8 of CSIMQ

Directory of Open Access Journals (Sweden)

Peter Forbrig

2016-10-01

Full Text Available Business process models greatly contribute to analyze and understand the activities of enterprises. However, it is still a challenge to cope with the complexity of systems specifications and their requirements. This issue of the journal of Complex Systems Informatics and Modeling (CSIMQ presents papers that discuss topics on managing complexity and information systems engineering. The papers are extended versions of selected papers from the workshop on Continuous Requirements Engineering held at the requirements engineering conference REFSQ 2016 in Gothenburg, the workshop on Managed Complexity held at the business informatics conference BIR 2016 in Prague, and the CAiSE 2016 Forum held in Ljubljana.

Annual progress report for atomic and nuclear research with accelerators and fusion related atomic physics. Reporting period, October 1, 1974--September 30, 1975

International Nuclear Information System (INIS)

1975-10-01

Topics covered include: laboratory operation and development; atomic collision cross sections in gases; ionization cross sections in thin solid materials; experimental impact-parameter dependent probabilities for k-shell vacancy production by fast heavy-ion projectiles; x-ray spectroscopy with high energy ions; atomic lifetime measurements; polarization studies of ion-induced x rays; theoretical spectra in ion-induced reactions; theoretical atomic cross section calculations; search for heavy-ion resonances; lifetimes of low energy states in 21 Ne; nuclear scattering and reactions; and trace element analysis

Identifying Topics in Microblogs Using Wikipedia.

Directory of Open Access Journals (Sweden)

Ahmet Yıldırım

Full Text Available Twitter is an extremely high volume platform for user generated contributions regarding any topic. The wealth of content created at real-time in massive quantities calls for automated approaches to identify the topics of the contributions. Such topics can be utilized in numerous ways, such as public opinion mining, marketing, entertainment, and disaster management. Towards this end, approaches to relate single or partial posts to knowledge base items have been proposed. However, in microblogging systems like Twitter, topics emerge from the culmination of a large number of contributions. Therefore, identifying topics based on collections of posts, where individual posts contribute to some aspect of the greater topic is necessary. Models, such as Latent Dirichlet Allocation (LDA, propose algorithms for relating collections of posts to sets of keywords that represent underlying topics. In these approaches, figuring out what the specific topic(s the keyword sets represent remains as a separate task. Another issue in topic detection is the scope, which is often limited to specific domain, such as health. This work proposes an approach for identifying domain-independent specific topics related to sets of posts. In this approach, individual posts are processed and then aggregated to identify key tokens, which are then mapped to specific topics. Wikipedia article titles are selected to represent topics, since they are up to date, user-generated, sophisticated articles that span topics of human interest. This paper describes the proposed approach, a prototype implementation, and a case study based on data gathered during the heavily contributed periods corresponding to the four US election debates in 2012. The manually evaluated results (0.96 precision and other observations from the study are discussed in detail.

Cern academic training programme 2011: Selected Topics in the Physics of Heavy Ion Collisions

CERN Multimedia

PH Department

2011-01-01

LECTURE SERIES 14, 15 & 16 March 2011 Selected Topics in the Physics of Heavy Ion Collisions 11:00-12:00 - Bldg. 222-R-001 - Filtration Plant In these lectures, I discuss some classes of measurements accessible in heavy ion collisions at the LHC. How can these observables be measured, to what extent can they be calculated, and what do they tell us about the dense mesoscopic system created during the collision? In the first lecture, I shall focus in particular on measurements that constrain the spatio-temporal picture of the collisions and that measure centrality, orientations and extensions. In the subsequent lectures, I then discuss on how classes of measurements allow one to characterize collective phenomena, and to what extent these measurements can constrain the properties of matter produced in heavy ion collisions. Organiser: Maureen Prola-Tessaur/PH-EDU  

Selected topics in phenomenology of the standard model

International Nuclear Information System (INIS)

Roberts, R.G.

1991-01-01

These lectures cover some aspects of phenomenology of topics in high energy physics which advertise the success of the standard model in dealing with a wide variety of experimental data. First we begin with a look at deep inelastic scattering. This tells us about the structure of the nucleon, which is understood in terms of the SU(3) gauge theory of QCD, which then allows the information on quark and gluon distributions to be carried over to other 'hard' processes such as hadronic production of jets. Recent data on electroweak processes can estimate the value of Sin 2 θw to a precision where the inclusion of radiative corrections allow bounds to be made on the mass of the top quark. Electroweak effects arise in e + e - collisions, but we first present a review of the recent history of this topic within the context of QCD. We bring the subject up to date with a look at the physics at (or near) the Z pole where the measurement of asymmetries can give more information. We look at the conventional description of quark mixing by the CKM matrix and see how the mixing parameters are systematically being extracted from a variety of reactions and decays. In turn, the values can be used to set bounds on the top quark mass. The matter of CP violation in weak interactions is addressed within the context of the standard model, recent data on ε'/ε being the source of current excitement. Finally, we at the theoretical description and experimental efforts to search for the top quark. (author)

Atomic energy review

International Nuclear Information System (INIS)

1971-01-01

The ATOMIC ENERGY REVIEW (AER), a periodical started in 1963 in accordance with the recommendation made by the Scientific Advisory Committee, is now preparing for its tenth year of publication. The journal appears quarterly (ca 900 pages/year) and occasionally has special issues and supplements. From 1963 to 1971 AER developed into an important international high-standard scientific journal which keeps scientists in Member States informed on progress in various fields of nuclear energy. The Agency's specific role of helping 'developing countries to further their science and education' is reflected in the publication policy of the journal. The subject scope of AER, which was determined at the journal's inception, is very broad. It covers topics in experimental and theoretical physics, nuclear electronics and equipment, physics and technology of reactors and reactor materials and fuels, radio-chemistry, and industrial, medical and other uses of radioisotopes. In other words, almost any subject related to the peaceful application of nuclear energy can qualify for inclusion. Specifically, at any particular time the selection criteria for topics are influenced by the Agency's current programme and interests. AER carries comprehensive review articles, critical state-of-the-art and current awareness surveys, and reports on the important meetings organized or sponsored by the Agency. The following four subsections gradually became necessary to do justice to this variety of material: 'Reviews' proper, 'Current Research and Development', 'Special Item' and 'Conferences and Symposia'. Apart from the conference reports, one hundred and twenty-five reviews, almost all of which were published in English to make them accessible to a wide public, have so far been published

Laser-induced fluorescence line narrowing in atomic vapors

International Nuclear Information System (INIS)

Meier, T.; Schuessler, H.A.

1983-01-01

The use of highly monochromatic light allows the selective excitation of atoms in vapors if excitation and detection of the fluorescence is carried out collinearly. The atoms capable of absorbing light then form an atomic beam of well defined velocity along the direction of the laser beam, but no velocity selection occurs perpendicular to it. The potential of the technique for Doppler-free atomic spectroscopy and for the study of excited atom collisions is demonstrated using the Na D 1 line as an example

Topical antibiotics as a major contextual hazard toward bacteremia within selective digestive decontamination studies: a meta-analysis.

Science.gov (United States)

Hurley, James C

2014-12-31

Among methods for preventing pneumonia and possibly also bacteremia in intensive care unit (ICU) patients, Selective Digestive Decontamination (SDD) appears most effective within randomized concurrent controlled trials (RCCT's) although more recent trials have been cluster randomized. However, of the SDD components, whether protocolized parenteral antibiotic prophylaxis (PPAP) is required, and whether the topical antibiotic actually presents a contextual hazard, remain unresolved. The objective here is to compare the bacteremia rates and patterns of isolates in SDD-RCCT's versus the broader evidence base. Bacteremia incidence proportion data were extracted from component (control and intervention) groups decanted from studies investigating antibiotic (SDD) or non-antibiotic methods of VAP prevention and summarized using random effects meta-analysis of study and group level data. A reference category of groups derived from purely observational studies without any prevention method under study provided a benchmark incidence. Within SDD RCCTs, the mean bacteremia incidence among concurrent component groups not exposed to PPAP (27 control; 17.1%; 13.1-22.1% and 12 intervention groups; 16.2%; 9.1-27.3%) is double that of the benchmark bacteremia incidence derived from 39 benchmark groups (8.3; 6.8-10.2%) and also 20 control groups from studies of non-antibiotic methods (7.1%; 4.8 - 10.5). There is a selective increase in coagulase negative staphylococci (CNS) but not in Pseudomonas aeruginosa among bacteremia isolates within control groups of SDD-RCCT's versus benchmark groups with data available. The topical antibiotic component of SDD presents a major contextual hazard toward bacteremia against which the PPAP component partially mitigates.

Theoretical treatment of electron capture and excitation in two-electron system ion-atom, atom-atom collisions at low to intermediate energy

International Nuclear Information System (INIS)

Kimura, M.

1986-01-01

A review of various theoretical treatments which have been used to study electron-capture and excitation processes in two-electron-system ion-atom, atom-atom collisions at low to intermediate energy is presented. Advantages as well as limitations associated with these theoretical models in application to practical many-electron ion-atom, atom-atom collisions are specifically pointed out. Although a rigorous theoretical study of many-electron systems has just begun so that reports of theoretical calculations are scarce to date in comparison to flourishing experimental activities, some theoretical results are of great interest and provide important information for understanding collision dynamics of the system which contains many electrons. Selected examples are given for electron capture in a multiply charged ion-He collision, ion-pair formation in an atom-atom collision and alignment and orientation in a Li + + He collision. (Auth.)

Influence of number of topics, topic duration, and curricular focus on biology achievement of Population 3 TIMSS countries

Science.gov (United States)

Hodges, Eddie Louis

The purposes of this study were to determine if a relationship exists between biology achievement and (1) number of topics, (2) topic duration, (3) curricular focus, and (4) science achievement using TIMSS data from Population 3---the final year of secondary school. Students included in this study were subsets of the 55,675 students from 22 countries who participated in the science literacy portion of TIMSS at the Population 3 level (IEA, 1997). The sample included in this study for the four research questions were comprised of between (1) 17,769 and 37,794 students from 15 countries, (2) 17,769 and 37,794 students from 15 countries, (3) 21,715 and 46,458 students from 18 countries, and (4) 19,518 and 46,458 students from 18 countries, respectively. A Pearson's product moment correlation was used to determine whether a relationship exists between the number of biology topics addressed by intended national science curricula and mean student achievement on selected items by country. No statistically significant correlation was found by country between biology achievement and number of topics. To determine whether a relationship exists between the topic duration of biology topics addressed by released, biology-oriented, Population 3 Science Literacy items and student achievement on those items, a Pearson's product moment correlation was also used. A statistically significant correlation between biology achievement and topic duration for only one topic (Interdependence of Life) was found at the .05 level of significance. A possible relationship between the degree of curricular focus of Population 3 TIMSS countries and student achievement on selected items by country was evaluated using a Pearson's product moment correlation. No statistically significant correlation by country between biology achievement and degree of curricular focus was found. A Pearson's product moment correlation was used to determine whether a relationship exists between science literacy

Selective hydrogen atom abstraction by hydrogen atoms in photolysis of cyclohexane-normal pentane mixtures at 77 K

International Nuclear Information System (INIS)

Miyazaky, T.; Guedes, S.M.L.; Andrade e Silva, L.G. de; Fernandes, L.

1977-01-01

The reaction of H atoms, produced by the photolysis of HI, has been studied in c-C 6 H 12 -n-C 5 H 12 mixtures at 77K. H atoms in c-C 6 H 12 matrix react more effectively with solute n-C 5 H 12 than solvent c-C 6 H 12 , while H atoms in n-C 5 H 12 matrix react more effectively with solute c-C 6 H 12 than solvent n-C 5 H 12 [pt

Polarization, alignment, and orientation in atomic collisions

CERN Document Server

Andersen, Nils

2017-01-01

This book covers polarization, alignment, and orientation effects in atomic collisions induced by electron, heavy particle, or photon impact. The first part of the book presents introductory chapters on light and particle polarization, experimental and computational methods, and the density matrix and state multipole formalism. Examples and exercises are included. The second part of the book deals with case studies of electron impact and heavy particle excitation, electron transfer, impact ionization, and autoionization. A separate chapter on photo-induced processes by new-generation light sources has been added. The last chapter discusses related topics and applications. Part III includes examples of charge clouds and introductory summaries of selected seminal papers of tutorial value from the early history of the field (1925 – 1975). The book is a significant update to the previous (first) edition, particularly in experimental and computational methods, the inclusion of key results obtained during the pas...

Atomic and molecular spectroscopy basic concepts and applications

CERN Document Server

Kakkar, Rita

2015-01-01

Spectroscopy is the study of electromagnetic radiation and its interaction with solid, liquid, gas and plasma. It is one of the widely used analytical techniques to study the structure of atoms and molecules. The technique is also employed to obtain information about atoms and molecules as a result of their distinctive spectra. The fast-spreading field of spectroscopic applications has made a noteworthy influence on many disciplines, including energy research, chemical processing, environmental protection and medicine. This book aims to introduce students to the topic of spectroscopy. The author has avoided the mathematical aspects of the subject as far as possible; they appear in the text only when inevitable. Including topics such as time-dependent perturbation theory, laser action and applications of Group Theory in interpretation of spectra, the book offers a detailed coverage of the basic concepts and applications of spectroscopy.

Topics in clinical oncology. 15

International Nuclear Information System (INIS)

Cepcek, P.

1987-12-01

The monograph comprising primarily papers on topical subjects of oncology and cancer research, contains also a selection of papers presented at the 2. Congress of the Czechoslovak Society of Nuclear Medicine and Radiation Hygiene. Seven papers were selected on behalf of their subject related to clinical oncology. All of them were iputted in INIS; five of them deal with the scintiscanning of the skeleton of cancer patients, one with radioimmunodetection of tumors, and one with radionuclide lymphography. (A.K.)

Topical Nasal Anesthesia in Flexible Bronchoscopy--A Cross-Over Comparison between Two Devices.

Directory of Open Access Journals (Sweden)

Thomas Fuehner

Full Text Available Topical airway anesthesia is known to improve tolerance and patient satisfaction during flexible bronchoscopy (FB. Lidocaine is commonly used, delivered as an atomized spray. The current study assesses safety and patient satisfaction for nasal anesthesia of a new atomization device during outpatient bronchoscopy in lung transplant recipients.Using a prospective, non-blinded, cross-over design, patients enrolled between 01-10-2014 and 24-11-2014 received 2% lidocaine using the standard reusable nasal atomizer (CRNA. Those enrolled between 25-11-2014 and 30-01-2015, received a disposable intranasal mucosal atomization device (DIMAD. After each procedure, the treating physician, their assistant and the patient independently rated side-effects and satisfaction, basing their responses on visual analogue scales (VAS. At their next scheduled bronchoscopy during the study period, patients then received the alternative atomizer. Written consent was obtained prior to the first bronchoscopy, and the study approved by the institutional ethics committee.Of the 252 patients enrolled between 01-10-2014 and 30-01-2015, 80 (32% received both atomizers. Physicians reported better efficacy (p = 0.001 and fewer side effects (p< = 0.001 for DIMAD in patients exposed to both procedures. Among patients with one visit, physicians and their assistants reported improved efficacy (p = 0.018, p = 0.002 and fewer side effects (p< = 0.001, p = 0.029 for the disposable atomizer, whereas patients reported no difference in efficacy or side effects (p = 0.72 and p = 0.20. No severe adverse events were noted. The cost of the reusable device was 4.08€ per procedure, compared to 3.70€ for the disposable device.Topical nasal anesthesia via a disposable intranasal mucosal atomization device (DIMAD offers comparable safety and patient comfort, compared to conventional reusable nasal atomizers (CRNA in lung transplant recipients. Procedural costs were reduced by 0.34€ per

Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions

International Nuclear Information System (INIS)

1987-01-01

The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume

No advantages in terms of safety. 'Energy in a Dialog' about the 'Final disposal site selection law'

International Nuclear Information System (INIS)

Anon.

2013-01-01

The current legislative process for the site selection law (StandAG) was topic of the DAtF event 'Energy in a Dialog' on 6 June 2013 in Berlin: 'Is the path the goal: purpose and results of the site selection law'. The President of the German Atomic Forum (DAtF), Dr. Ralf Gldner, moderated the discussion with Prof. Dr. Ortwin Renn of the University of Stuttgart and the CEO of the Gesellschaft fuer Nuklear-Service (GNS), Hannes Wimmer. The opportunities and risks of a new site search for high-level radioactive waste were the main topics. Professor Renn summarized some findings to conditions of acceptance perceived in connection with industrial projects. Dr. Wimmer said in his keynote that social acceptance for site selection for a repository must be maintained for a long time. During the ensuing discussion, a common understanding was evident on some aspects of the topic. This is especially true for a limitation of the new location search method in terms of its objective. As a realistic objective to determine a secure suitable site was considered instead of a 'best' location proposed by the new law. (orig.)

Atom history, from intuitive ideas to reality

International Nuclear Information System (INIS)

Radvanyi, P.

2007-01-01

This book gathers the ground scientific texts that have stood out as milestones in the way scientists have built their understanding of the atom over centuries. From the very intuitive ideas of Greek philosophers to the most recent results on ultra-cold atoms, via the discovery of natural radioactivity or the existence of the neutron, about 55 articles written by prestigious physicists have been organized into 16 chapters. Each chapter being dedicated to a topic such as molecules, spectroscopy, electrons, X-rays, atom mass, artificial radioactivity..., begins with a commentary that draws the scientific context of that time, describes the links between the articles and highlights the importance of the discoveries. (A.C.)

Antimatter atoms

International Nuclear Information System (INIS)

Anon.

1996-01-01

In january 1996, CERN broadcasted the information of the creation of nine anti-hydrogen atoms, observed through disintegration products. The experimental facility was CERN LEAR ring. An antiproton beam scattered a xenon jet, and the resulting antimatter was first selected by its insensitivity to beam bending magnets. Their disintegration was detected in thin NaI detectors, in which the anti-atoms are at once deprived from their positron. Then, magnetic and time-of-flight spectrometers are used. (D.L.)

Elementary Atom Interaction with Matter

OpenAIRE

Mrowczynski, Stanislaw

1998-01-01

The calculations of the elementary atom (the Coulomb bound state of elementary particles) interaction with the atom of matter, which are performed in the Born approximation, are reviewed. We first discuss the nonrelativistic approach and then its relativistic generalization. The cross section of the elementary atom excitation and ionization as well as the total cross section are considered. A specific selection rule, which applies for the atom formed as positronium by particle-antiparticle pa...

Calcium Atom Trap for Atom Trap Mass Spectrometer

Energy Technology Data Exchange (ETDEWEB)

Ko, Kwang Hoon; Park, Hyun Min; Han, Jae Min; Kim, Taek Soo; Cha, Yong Ho; Lim, Gwon; Jeong, Do Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Trace isotope analysis has been an important role in science, archaeological dating, geology, biology and nuclear industry. Artificially produced fission products such as Sr-90, Cs-135 and Kr-85 can be released to the environment when nuclear accident occurs and the reprocessing factory operates. Thus, the analysis of them has been of interest in nuclear industry. But it is difficult to detect them due to low natural abundance less then 10-10. The ultra-trace radio isotopes have been analyzed by the radio-chemical method, accelerator mass spectrometer, and laser based method. The radiochemical method has been used in the nuclear industry. But this method has disadvantages of long measurement time for long lived radioisotopes and toxic chemical process for the purification. The accelerator mass spectrometer has high isotope selectivity, but the system is huge and it has the isobar effects. The laser based method, such as RIMS (Resonance Ionization Mass Spectrometry) is a basically isobar-effect free method. Recently, ATTA (Atom Trap Trace Analysis), one of the laser based method, has been successfully demonstrated sufficient isotope selectivity with small system size. It has been applied for the detection of Kr-81 and Kr-85. However, it is not suitable for real sample detection, because it requires steady atomic beam generation during detection and is not allowed simultaneous detection of other isotopes. Therefore, we proposed the coupled method of Atom Trap and Mass Spectrometer. It consists of three parts, neutral atom trap, ionization and mass spectrometer. In this paper, we present the demonstration of the magneto-optical trap of neutral calcium. We discuss the isotope selective characteristics of the MOT (Magneto Optical Trap) of calcium by the fluorescence measurement. In addition, the frequency stabilization of the trap beam will be presented

Atomic and molecular physics of controlled thermonuclear fusion

International Nuclear Information System (INIS)

Joachain, C.J.; Post, D.E.

1983-01-01

This book attempts to provide a comprehensive introduction to the atomic and molecular physics of controlled thermonuclear fusion, and also a self-contained source from which to start a systematic study of the field. Presents an overview of fusion energy research, general principles of magnetic confinement, and general principles of inertial confinement. Discusses the calculation and measurement of atomic and molecular processes relevant to fusion, and the atomic and molecular physics of controlled thermonuclear research devices. Topics include recent progress in theoretical methods for atomic collisions; current theoretical techniques for electron-atom and electronion scattering; experimental aspects of electron impact ionization and excitation of positive ions; the theory of charge exchange and ionization by heavy particles; experiments on electron capture and ionization by multiply charged ions; Rydberg states; atomic and molecular processes in high temperature, low-density magnetically confined plasmas; atomic processes in high-density plasmas; the plasma boundary region and the role of atomic and molecular processes; neutral particle beam production and injection; spectroscopic plasma diagnostics; and particle diagnostics for magnetic fusion experiments

Advances in atomic spectroscopy

CERN Document Server

Sneddon, J

1997-01-01

This series describes selected advances in the area of atomic spectroscopy. It is primarily intended for the reader who has a background in atmoic spectroscopy; suitable to the novice and expert. Although a widely used and accepted method for metal and non-metal analysis in a variety of complex samples, Advances in Atomic Spectroscopy covers a wide range of materials. Each Chapter will completely cover an area of atomic spectroscopy where rapid development has occurred.

Design of Offshore Wind Turbine Support Structures: Selected topics in the field of geotechnical engineering

DEFF Research Database (Denmark)

Bakmar, Christian LeBlanc

.D. thesis was to enable low-cost and low-risk support structures to be designed in order to improve the economic feasibility of future offshore wind farms. The research work was divided in the following four selected research topics in the field of geotechnical engineering, relating to the monopile......Breaking the dependence on fossil fuels offers many opportunities for strengthened competitiveness, technological development and progress. Offshore wind power is a domestic, sustainable and largely untapped energy resource that provides an alternative to fossil fuels, reduces carbon emissions......, and decreases the economic and supply risks associated with reliance on imported fuels. Today, the modern offshore wind turbine offers competitive production prices for renewable energy and is therefore a key technology in achieving the energy and climate goals of the future. The overall aim of this Ph...

Area-selective atomic layer deposition of platinum using photosensitive polyimide.

Science.gov (United States)

Vervuurt, René H J; Sharma, Akhil; Jiao, Yuqing; Kessels, Wilhelmus Erwin M M; Bol, Ageeth A

2016-10-07

Area-selective atomic layer deposition (AS-ALD) of platinum (Pt) was studied using photosensitive polyimide as a masking layer. The polyimide films were prepared by spin-coating and patterned using photolithography. AS-ALD of Pt using poly(methyl-methacrylate) (PMMA) masking layers was used as a reference. The results show that polyimide has excellent selectivity towards the Pt deposition, after 1000 ALD cycles less than a monolayer of Pt is deposited on the polyimide surface. The polyimide film could easily be removed after ALD using a hydrogen plasma, due to a combination of weakening of the polyimide resist during Pt ALD and the catalytic activity of Pt traces on the polyimide surface. Compared to PMMA for AS-ALD of Pt, polyimide has better temperature stability. This resulted in an improved uniformity of the Pt deposits and superior definition of the Pt patterns. In addition, due to the absence of reflow contamination using polyimide the nucleation phase during Pt ALD is drastically shortened. Pt patterns down to 3.5 μm were created with polyimide, a factor of ten smaller than what is possible using PMMA, at the typical Pt ALD processing temperature of 300 °C. Initial experiments indicate that after further optimization of the polyimide process Pt features down to 100 nm should be possible, which makes AS-ALD of Pt using photosensitive polyimide a promising candidate for patterning at the nanoscale.

Proceedings of fifth international topical meeting on nuclear thermal hydraulics, operations and safety

International Nuclear Information System (INIS)

1997-01-01

The fifth international topical meeting on nuclear thermohydraulics, operations and safety was convened in Beijing in April 14-18, 1997. The topical meeting was sponsored by the Chinese Nuclear Society and cosponsored by American Nuclear Society, Atomic Energy Society of Japan, American Society of Mechanical Engineers, Canada Nuclear Society, Korean Nuclear Society, Mexican Nuclear Society, Nuclear Society of Slovenia and Spanish Nuclear Society. There were 262 articles were published in the meeting. They are related nuclear power thermohydraulics, operations and safety

Atoms, radiation, and radiation protection

International Nuclear Information System (INIS)

Turner, J.E.

1986-01-01

This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection

Graphene oxide/metal nanocrystal multilaminates as the atomic limit for safe and selective hydrogen storage.

Science.gov (United States)

Cho, Eun Seon; Ruminski, Anne M; Aloni, Shaul; Liu, Yi-Sheng; Guo, Jinghua; Urban, Jeffrey J

2016-02-23

Interest in hydrogen fuel is growing for automotive applications; however, safe, dense, solid-state hydrogen storage remains a formidable scientific challenge. Metal hydrides offer ample storage capacity and do not require cryogens or exceedingly high pressures for operation. However, hydrides have largely been abandoned because of oxidative instability and sluggish kinetics. We report a new, environmentally stable hydrogen storage material constructed of Mg nanocrystals encapsulated by atomically thin and gas-selective reduced graphene oxide (rGO) sheets. This material, protected from oxygen and moisture by the rGO layers, exhibits exceptionally dense hydrogen storage (6.5 wt% and 0.105 kg H2 per litre in the total composite). As rGO is atomically thin, this approach minimizes inactive mass in the composite, while also providing a kinetic enhancement to hydrogen sorption performance. These multilaminates of rGO-Mg are able to deliver exceptionally dense hydrogen storage and provide a material platform for harnessing the attributes of sensitive nanomaterials in demanding environments.

Mathematics++ selected topics beyond the basic courses

CERN Document Server

Kantor, Ida; Šámal, Robert

2015-01-01

Mathematics++ is a concise introduction to six selected areas of 20th century mathematics providing numerous modern mathematical tools used in contemporary research in computer science, engineering, and other fields. The areas are: measure theory, high-dimensional geometry, Fourier analysis, representations of groups, multivariate polynomials, and topology. For each of the areas, the authors introduce basic notions, examples, and results. The presentation is clear and accessible, stressing intuitive understanding, and it includes carefully selected exercises as an integral part. Theory is comp

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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Atomic physics made clear

International Nuclear Information System (INIS)

Meinhold, H.

1980-01-01

This book is a popular introduction into the foundations of atomic physics und quantum mechanics. Starting from some phenomenological concepts Bohr's model and the construction of the periodic system regarding the shell structure of atoms are introduced. In this framework the selection rules and magnetic moments of atomic electrons are considered. Finally the wave-particle dualism is considered. In the appendix some mathematical methods are described which are useful for a deeper penetration into the considered ideas. (HSI)

Atomic spectroscopy sympsoium, Gaithersburg, Maryland, September 23--26, 1975

International Nuclear Information System (INIS)

1975-01-01

Abstracts of one hundred papers given at the conference are presented along with the conference program and an author index. Session topics include: highly ionized atoms; laser spectroscopy and hyperfine structure; complex spectra; laser spectroscopy, radiation theory; theory of highly ionized atoms and analysis of plasmas; plasma spectroscopy, line strengths; spectral analysis, instrumentation, reference wavelengths; beam foil spectroscopy, line strengths, energy levels; absorption spectroscopy, autoionization, and related theory; and spectral analysis, instrumentation, and VUV physics

Sixth meeting of the ITPA Topical Group on Diagnostics

International Nuclear Information System (INIS)

Donne, A.J.H.; Costley, A.E.

2004-01-01

The Sixth Meeting of the International Tokamak Physics Activities (ITPA) Topical Group (TG) on Diagnostics was held at JAERI, Naka from 19-21 February 2004. This meeting was combined with a Progress Meeting on ITER/BPX (burning plasma experiment) relevant diagnostic developments on-going in Japan. For the first time, ITPA members from China, as well as observers from South Korea, attended. In addition, an associated sub-meeting was held at General Atomics, San Diego, 23-24 April, immediately after the 15th Topical Conference on High Temperature Plasma Diagnostics. At the sub-meeting a special one-day session was devoted to issues related to beam-aided spectroscopy. In total more than 50 participants attended the meetings and all ITER partners were represented. The key topics reviewed and discussed at the TG meeting were: (i) the overall status of diagnostics developments for ITER, (ii) the progress in the research on the designated high priority topics, (iii) the progress with some key ITER/BPX-relevant diagnostic developments ongoing in the ITPA participant laboratories, (iv) the progress and plans for the work of the specialist working groups, (v) the status and plans for the International Diagnostic Database

Atomic energy in its repercussions on life and health. [In French

Energy Technology Data Exchange (ETDEWEB)

1956-01-01

The papers given at the July 1955 conference in Paris on the dangers of atomic energy and radiation are presented. The topics discussed include the dangers inherent in atomic equipment, the radioactive effects of atomic explosions, a review of the analyses made in Japan of the radioactive ash from the March 1954 Bikini explosions, long distance propagation and characteristics of the radioactive particles emitted in atomic explosions, eventual influences of atomic explosions on evolution, radioactivity in air and rain, radioactive clouds, meteorological effects of atomic explosions, a general review of the biological effects of ionizing radiation, medical problems posed by the immediate effects of atomic explosions, cataracts received from explosions or research in atomic energy, atomic radiation and aquatic life, biological danger from powders emitting ..beta.. rays, effect of weak doses of radiation, ionizing radiation and the gases in atomic industry, and therapy for radiolesions.

Isotopic separation of 235U and 238U in an atomic beam with selective two-step photo-ionisation

International Nuclear Information System (INIS)

Boehm, H.D.V.

1977-01-01

The present work gives a report on investigations on isotope separation of 235 U and 238 U by means of selective two-stage photo-ionization on atomic uranium. An atomic beam of sufficient particle density was produced by dissociation of URe 2 in an electron beam heated tungsten furnace at a temperature of 2.500 k. A continuously operated rhodamin-69 dye laser with a maximum output of 120 mW and about 50 mHz band width in one-made operation was used for selective excitation from the ground state. From this state of excitation, ionization resulted achieving a light power of 1.8 W below 3030 A in the reaction volume. The measured separation factors show that the laser method enables the enrichment of uranium to the required valve of three or more percent 235 U for light water reactors in a single separation step. The hyperfine structure could be considerably better resolved compared to earlier investigations, so that it was possible for the first time to identify and measure hitherto unobserved weak components. (orig.) [de

The contaminated Western Hero and other madness during the Atomic Age

International Nuclear Information System (INIS)

Herzog, Rudolph

2012-01-01

The book on mad activities during the Atomic Age includes the following topics: The second most hazardous invention in all time; the red bomb; the story on the tactic nuclear war; the contaminated Western hero or how the bomb came to Alaska; swords into plowshares; the apocalypse machine; flying reactors; how safe is safe?; atomic Australia; nuclear medicine on wrong ways; broken arrows.

Immunomodulation and safety of topical calcineurin inhibitors for the treatment of atopic dermatitis.

Science.gov (United States)

Hultsch, Thomas; Kapp, Alexander; Spergel, Jonathan

2005-01-01

Atopic dermatitis (AD) is a chronic or chronically relapsing inflammatory skin condition that primarily affects children. Topical corticosteroids have been the mainstay of treatment since the late 1950s. While providing excellent short-term efficacy, topical corticosteroid usage is limited by potential adverse effects, including impairment of the function and viability of Langerhans cells/dendritic cells. The recently introduced topical calcineurin inhibitors pimecrolimus cream 1% (Elidel) and tacrolimus ointment 0.03 and 0.1% (Protopic) exhibit a more selective mechanism of action and do not affect Langerhans cells/dendritic cells. For the immune system of young children 'learning' to mount a balanced Th1/Th2 response, this selective effect has particular benefits. In clinical experience, topical calcineurin inhibitors have been shown to be a safe and effective alternative to topical corticosteroids in almost 7 million patients (>5 million on pimecrolimus; >1.7 million on tacrolimus). Topical pimecrolimus is primarily used in children with mild and moderate AD, whereas tacrolimus is used preferentially in more severe cases. None of the topical calcineurin inhibitors have been associated with systemic immunosuppression-related malignancies known to occur following long-term sustained systemic immunosuppression with oral immunosuppressants (e.g., tacrolimus, cyclosporine A, and corticosteroids) in transplant patients. Preclinical and clinical data suggest a greater skin selectivity and larger safety margin for topical pimecrolimus. (c) 2005 S. Karger AG, Basel

Important atomic physics issues for ion beam fusion

International Nuclear Information System (INIS)

Bangerter, R.O.

1985-01-01

This paper suggests several current atomic physics questions important to ion beam fusion. Among the topics discussed are beam transport, beam-target interaction, and reactor design. The major part of the report is discussion concerning areas of research necessary to better understand beam-target interactions

Influence of the atomic structure on the quantum state of sputtered Ir atoms

International Nuclear Information System (INIS)

Bastiaansen, J.; Philipsen, V.; Lievens, P.; Silverans, R.E.; Vandeweert, E.

2004-01-01

The probability of the ejection of a neutral atom in a specific quantum state after keV-ion beam sputtering is often interpreted in terms of the interaction between the atomic states of the escaping atom and the electronic states of the solid. In this work, we examined this interplay in the sputtering of iridium as this element has--unlike the elements employed in previous investigations--a complex atomic structure due to strong configuration interactions. Double-resonant two-photon laser ionization is used to probe the sputtered Ir atoms yielding information about the probability for an ejected atom to populate a specific atomic state and its escape velocity. The qualitative features of the corresponding population partition and state-selective velocity distributions show the influence of the excitation energy and the electronic structure of the different atomic states. A comparison is made between the experimental data and predictions from the resonant electron transfer description

CANAS '01 - Colloquium analytical atomic spectroscopy; CANAS '01 - Colloquium Analytische Atomspektroskopie. Programm. Kurzfassungen der Vortraege und Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The main topics of the meeting on analytical atom spectroscopy were: optical atom spectrometry, x-ray fluorescence analysis, absorption spectroscopy, icp mass spectroscopy, trace analysis, sampling, sample preparation and quality assurance.

Vertical versus Lateral Two-Dimensional Heterostructures: On the Topic of Atomically Abrupt p/n-Junctions.

Science.gov (United States)

Zhou, Ruiping; Ostwal, Vaibhav; Appenzeller, Joerg

2017-08-09

The key appeal of two-dimensional (2D) materials such as graphene, transition metal dichalcogenides (TMDs), or phosphorene for electronic applications certainly lies in their atomically thin nature that offers opportunities for devices beyond conventional transistors. It is also this property that makes them naturally suited for a type of integration that is not possible with any three-dimensional (3D) material, that is, forming heterostructures by stacking dissimilar 2D materials together. Recently, a number of research groups have reported on the formation of atomically sharp p/n-junctions in various 2D heterostructures that show strong diode-type rectification. In this article, we will show that truly vertical heterostructures do exhibit much smaller rectification ratios and that the reported results on atomically sharp p/n-junctions can be readily understood within the framework of the gate and drain voltage response of Schottky barriers that are involved in the lateral transport.

TRACE ANALYSIS BY LASER-EXCITED ATOMIC FLUORESCENCE WITH ATOMIZATION IN A PULSED PLASMA

OpenAIRE

Lunyov , O.; Oshemkov , S.; Petrov , A.

1991-01-01

The possibilities of plasma atomization for laser fluorescence trace analysis are discussed. Pulsed hot hollow cathode discharge was used for analysis of solutions and powdered samples. The high voltage spark and laser-induced breakdown (laser spark) were used as atomizers of metal-containing atmospheric aerosols. Detection limits were improved by means of temporal background selection.

US Support Program Topical Meetings 1999 to 2008

Energy Technology Data Exchange (ETDEWEB)

Pepper,S.

2008-06-10

In 1999, the International Safeguards Project Office began organizing topical workshops to explore technical issues facing the International Atomic Energy Agency's Department of Safeguards. Representatives from IAEA member states including the United States, national laboratories and companies were invited to the workshops to discuss the technical issues. In some cases professional facilitators were hired to lead the discussions and in some cases business gaming techniques were employed. Since 1999, the following topics have been addressed Data Communication Technologies (1999), Information Security (2000), Design and Testing for High Reliability (2001), Standardization and Integration of Unattended and Remote Monitoring Systems (2002), Roadmapping: Surveillance (2003), IAEA Seals Technology Roadmapping Workshop (2004), Turning Information Into Knowledge (2004), Safeguards Tools of the Future (2005), and Advanced Sensors for Safeguards (2007). This paper will review the scope of the workshops and summarize their results.

Proceedings of the workshop on opportunities for atomic physics using slow, highly-charged ions

Energy Technology Data Exchange (ETDEWEB)

1987-01-01

The study of atomic physics with highly-charged ions is an area of intense activity at the present time because of a convergence of theoretical interest and advances in experimental techniques. The purpose of the Argonne ''Workshop on Opportunities for Atomic Physics Using Slow, Highly-Charged Ions'' was to bring together atomic, nuclear, and accelerator physicists in order to identify what new facilities would be most useful for the atomic physics community. The program included discussion of existing once-through machines, advanced ion sources, recoil ion techniques, ion traps, and cooler rings. One of the topics of the Workshop was to discuss possible improvement to the ANL Tandem-Linac facility (ATLAS) to enhance the capability for slowing down ions after they are stripped to a high-charge state (the Accel/Decel technique). Another topic was the opportunity for atomic physics provided by the ECR ion source which is being built for the Uranium Upgrade of ATLAS. 18 analytics were prepared for the individual papers in this volume.

Request for Support for the Conference on Super Intense Laser Atom Physics

International Nuclear Information System (INIS)

Todd Ditmire

2004-01-01

The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions

International bulletin on atomic and molecular data for fusion. No. 52

Energy Technology Data Exchange (ETDEWEB)

Stephens, J A [ed.

1997-08-01

This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics.

International bulletin on atomic and molecular data for fusion. No. 52

International Nuclear Information System (INIS)

Stephens, J.A.

1997-08-01

This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics

Nuclear γ-ray spectroscopy of cool free atoms

International Nuclear Information System (INIS)

Rivlin, Lev A

1999-01-01

Consideration is given to the capabilities of gamma-ray spectroscopy of the nuclei of free neutral atoms cooled employing modern laser light-pressure techniques. This spectroscopy is comparable with the Mossbauer spectroscopy in respect of the expected resolving power. (laser applications and other topics in quantum electronics)

Laser Control of Atoms and Molecules

CERN Document Server

Letkhov, V S

2007-01-01

This text treats laser light as a universal tool to control matter at the atomic and molecular level, one of the most exciting applications of lasers. Lasers can heat matter, cool atoms to ultra-low temperatures where they show quantum collective behaviour, and can act selectively on specific atoms and molecules for their detection and separation.

Critical pathway studies for selected radionuclides. Part of a coordinated programme on environmental monitoring for radiological protection in Asia and the Far East

International Nuclear Information System (INIS)

Bhat, I.S.

1980-04-01

The programme carried out critical pathway studies for selected radionuclides ( 60 Co, 63 Ni, 59 Fe, 54 Mn, sup(110m)Ag, 106 Ru and 144 Ce) and assessed population exposure in the vicinity of Tarapur Atomic Power Station. The following topics are covered under the programme. (i) Demographic study of dietary habits and consumption data for Tarapur population. (ii) Concentration and accumulation of radionuclides in food products. (iii) Determination of radionuclides in sea water, silt, marine algae and marine organisms at Tarapur Atomic Power Station (TAPS) Site. (iv) Behaviour of radionuclides released to marine environment. (v) Evaluation of critical exposure pathway. (vi) Population exposure in the vicinity of Tarapur Atomic Power Station

Accurate atom-mapping computation for biochemical reactions.

Science.gov (United States)

Latendresse, Mario; Malerich, Jeremiah P; Travers, Mike; Karp, Peter D

2012-11-26

The complete atom mapping of a chemical reaction is a bijection of the reactant atoms to the product atoms that specifies the terminus of each reactant atom. Atom mapping of biochemical reactions is useful for many applications of systems biology, in particular for metabolic engineering where synthesizing new biochemical pathways has to take into account for the number of carbon atoms from a source compound that are conserved in the synthesis of a target compound. Rapid, accurate computation of the atom mapping(s) of a biochemical reaction remains elusive despite significant work on this topic. In particular, past researchers did not validate the accuracy of mapping algorithms. We introduce a new method for computing atom mappings called the minimum weighted edit-distance (MWED) metric. The metric is based on bond propensity to react and computes biochemically valid atom mappings for a large percentage of biochemical reactions. MWED models can be formulated efficiently as Mixed-Integer Linear Programs (MILPs). We have demonstrated this approach on 7501 reactions of the MetaCyc database for which 87% of the models could be solved in less than 10 s. For 2.1% of the reactions, we found multiple optimal atom mappings. We show that the error rate is 0.9% (22 reactions) by comparing these atom mappings to 2446 atom mappings of the manually curated Kyoto Encyclopedia of Genes and Genomes (KEGG) RPAIR database. To our knowledge, our computational atom-mapping approach is the most accurate and among the fastest published to date. The atom-mapping data will be available in the MetaCyc database later in 2012; the atom-mapping software will be available within the Pathway Tools software later in 2012.

Classical trajectory perspective of atomic ionization in strong laser fields. Semiclassical modeling

International Nuclear Information System (INIS)

Liu, Jie

2014-01-01

Dealing with timely and interesting issues in strong laser physics. Illustrates complex strong field atomic ionization with the simple semiclassical model of classical trajectory perspective for the first time. Provides a theoretical model that can be used to account for recent experiments. The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers in the field of laser physics, atom molecule physics and theoretical physics. Dr. Jie Liu is a professor of Institute of Applied Physics and Computational Mathematics, China and Peking University.

Resources for Topics in Nursing.

Science.gov (United States)

Riordan, Dale B.

This guide is intended to help the user become familiar with a selected group of reference tools and resources which are useful in nursing education and practice. It is important for students to use the correct medical or scientific terminology, understand the scope of a topic, and then utilize the tools necessary to research subjects of interest.…

Chemistry {ampersand} Materials Science progress report summary of selected research and development topics, FY97

Energy Technology Data Exchange (ETDEWEB)

Newkirk, L.

1997-12-01

This report contains summaries of research performed in the Chemistry and Materials Science division. Topics include Metals and Ceramics, High Explosives, Organic Synthesis, Instrument Development, and other topics.

Gas lasers applied atomic collision physics, v.3

CERN Document Server

McDaniel, E W

1982-01-01

Applied Atomic Collision Physics, Volume 3: Gas Lasers describes the applications of atomic collision physics in the development of many types of gas lasers. Topics covered range from negative ion formation in gas lasers to high-pressure ion kinetics and relaxation of molecules exchanging vibrational energy. Ion-ion recombination in high-pressure plasmas is also discussed, along with electron-ion recombination in gas lasers and collision processes in chemical lasers.Comprised of 14 chapters, this volume begins with a historical summary of gas laser developments and an overview of the basic ope

Tracking topic birth and death in LDA.

Energy Technology Data Exchange (ETDEWEB)

Wilson, Andrew T.; Robinson, David Gerald

2011-09-01

Most topic modeling algorithms that address the evolution of documents over time use the same number of topics at all times. This obscures the common occurrence in the data where new subjects arise and old ones diminish or disappear entirely. We propose an algorithm to model the birth and death of topics within an LDA-like framework. The user selects an initial number of topics, after which new topics are created and retired without further supervision. Our approach also accommodates many of the acceleration and parallelization schemes developed in recent years for standard LDA. In recent years, topic modeling algorithms such as latent semantic analysis (LSA)[17], latent Dirichlet allocation (LDA)[10] and their descendants have offered a powerful way to explore and interrogate corpora far too large for any human to grasp without assistance. Using such algorithms we are able to search for similar documents, model and track the volume of topics over time, search for correlated topics or model them with a hierarchy. Most of these algorithms are intended for use with static corpora where the number of documents and the size of the vocabulary are known in advance. Moreover, almost all current topic modeling algorithms fix the number of topics as one of the input parameters and keep it fixed across the entire corpus. While this is appropriate for static corpora, it becomes a serious handicap when analyzing time-varying data sets where topics come and go as a matter of course. This is doubly true for online algorithms that may not have the option of revising earlier results in light of new data. To be sure, these algorithms will account for changing data one way or another, but without the ability to adapt to structural changes such as entirely new topics they may do so in counterintuitive ways.

Eleventh Arab Conference on the Peaceful Uses of Atomic Energy

International Nuclear Information System (INIS)

Nasr, N.

2012-01-01

The Arab conference on the peaceful uses of atomic energy is an important station where Arab researchers and scientists meet to present the results of their scientific and applied research activities, to exchange views, experiences and knowledge and to strengthen the bonds of cooperation among them. Under this framework, the Arab Atomic Energy Agency organized the eleventh Arab conference on the peaceful uses of atomic energy in cooperation with the Ministry of Science and Communications of the Republic of Sudan and the Sudan Atomic Energy Commission in Khartoum city during the period of 23-27 December 2012. The sessions of the conference included scientific papers, in addition to specialized lectures on topics of particular importance in the field of peaceful applications of atomic energy followed by panel discussions.

Doctoral Dissertation Topics in Education: Do They Align with Critical Issues?

Directory of Open Access Journals (Sweden)

Ethan J Allen

2016-11-01

Full Text Available American society faces complex educational issues which impact many facets of its national interests. Institutions of higher education are granting doctoral degrees to educational leaders, but it is not known to what extent their dissertation topics are aligned with both longstanding and critical issues in education. Using a theoretical framework synthesizing Paul and Elder’s critical thinking model and Kuhlthau’s information seeking process, this study examines a set of education doctoral dissertation topical selections and categorizes them by general themes in relationship to many of the recognized educational issues in the United States. Investigators categorized dissertations from four departments within the College of Education of their home institution. The dataset, retrieved from ProQuest Dissertations and Theses Global, consisted of 231 documents published between 2005 and 2014. Through an inter-rater process examining dissertation titles, abstracts, and keywords, the dissertations were assigned critical issue themes culled from nine editions of a college text, and then categorized under a broader topical scheme situated within a well-used educational research website. Findings indicated that most dissertations concentrated in studies that researched problems and issues within schools. Further, some of the issues considered longstanding were not studied by dissertation authors within the sample. For example, privatization of schools and classroom discipline and justice were not selected for study. Findings also suggest new directions for those responsible for dissertation supervision and topic selection. The study adds to the literature on dissertation topic selection that addresses existing educational issues.

Topics in mathematical and applied statistics

NARCIS (Netherlands)

Pas, van der S.L.

2017-01-01

This thesis is composed of papers on four topics: Bayesian theory for the sparse normal means problem, specifically for the horseshoe prior (Chapters 1-3), Bayesian theory for community detection (Chapter 4), nested model selection (Chapter 5), and the application of competing risk methods in the

The role of international atomic energy agency in maintaining nuclear safety competence

International Nuclear Information System (INIS)

Aro, I.; Mazour, T.

2000-01-01

This paper provides information how International Atomic Energy Agency can assist Member States in maintaining and developing nuclear safety competence. The topics covered include the development of safety standards, organisation of nuclear safety related conferences, provision of safety reviews, organisation of training courses and topical workshops and publication of training related documents. Usefulness of these activities for competence development is discussed. (author)

Energy levels of muonic atoms

International Nuclear Information System (INIS)

Borie, E.; Rinker, G.A.

1982-01-01

The theory of muonic atoms is a complex and highly developed combination of nuclear physics, atomic physics, and quantum electrodynamics. Perhaps nowhere else in microscopic physics are such diverse branches so intimately intertwined and yet readily available for precise experimental verification or rejection. In the present review we summarize and discuss all of the most important components of muonic atom theory, and show in selected cases how this theory meets experimental measurements

Enhancing atom densities in solid hydrogen by isotopic substitution

International Nuclear Information System (INIS)

Collins, G.W.; Souers, P.C.; Mapoles, E.R.; Magnotta, F.

1991-01-01

Atomic hydrogen inside solid H 2 increases the energy density by 200 MegaJoules/m 3 , for each percent mole fraction stored. How many atoms can be stored in solid hydrogen? To answer this, we need to know: (1) how to produce and trap hydrogen atoms in solid hydrogen, (2) how to keep the atoms from recombining into the ground molecular state, and (3) how to measure the atom density in solid hydrogen. Each of these topics will be addressed in this paper. Hydrogen atoms can be trapped in solid hydrogen by co-condensing atoms and molecules, external irradiation of solid H 2 , or introducing a radioactive impurity inside the hydrogen lattice. Tritium, a heavy isotope of hydrogen, is easily condensed as a radioactive isotopic impurity in solid H 2 . Although tritium will probably not be used in future rockets, it provides a way of applying a large, homogenious dose to solid hydrogen. In all of the data presented here, the atoms are produced by the decay of tritium and thus knowing how many atoms are produced from the tritium decay in the solid phase is important. 6 refs., 6 figs

Atomic Layer Etching of Silicon to Solve ARDE-Selectivity-Profile-Uniformity Trade-Offs

Science.gov (United States)

Wang, Mingmei; Ranjan, Alok; Ventzek, Peter; Koshiishi, Akira

2014-10-01

With shrinking critical dimensions, dry etch faces more and more challenges. Minimizing each of aspect ratio dependent etching (ARDE), bowing, undercut, selectivity, and within die uniformly across a wafer are met by trading off one requirement against another. At the root of the problem is that roles radical flux, ion flux and ion energy play may be both good and bad. Increasing one parameter helps meeting one requirement but hinders meeting the other. Self-limiting processes like atomic layer etching (ALE) promise a way to escape the problem of balancing trade-offs. ALE was realized in the mid-1990s but the industrial implementation has been slow. In recent years interest in ALE has revived. We present how ARDE, bowing/selectivity trade-offs may be overcome by varying radical/ion ratio, byproduct re-deposition. We overcome many of the practical implementation issues associated with ALE by precise passivation process control. The Monte Carlo Feature Profile Model (MCFPM) is used to illustrate realistic scenarios built around an Ar/Cl2 chemistry driven etch of Si masked by SiO2. We demonstrate that ALE can achieve zero ARDE and infinite selectivity. Profile control depends on careful management of the ion energies and angles. For ALE to be realized in production environment, tight control of IAD is a necessary. Experimental results are compared with simulation results to provide context to the work.

Lecture Notes on Topics in Accelerator Physics

International Nuclear Information System (INIS)

Chao, Alex W.

2002-01-01

These are lecture notes that cover a selection of topics, some of them under current research, in accelerator physics. I try to derive the results from first principles, although the students are assumed to have an introductory knowledge of the basics. The topics covered are: (1) Panofsky-Wenzel and Planar Wake Theorems; (2) Echo Effect; (3) Crystalline Beam; (4) Fast Ion Instability; (5) Lawson-Woodward Theorem and Laser Acceleration in Free Space; (6) Spin Dynamics and Siberian Snakes; (7) Symplectic Approximation of Maps; (8) Truncated Power Series Algebra; and (9) Lie Algebra Technique for nonlinear Dynamics. The purpose of these lectures is not to elaborate, but to prepare the students so that they can do their own research. Each topic can be read independently of the others

Lecture Notes on Topics in Accelerator Physics

Energy Technology Data Exchange (ETDEWEB)

Chao, Alex W.

2002-11-15

These are lecture notes that cover a selection of topics, some of them under current research, in accelerator physics. I try to derive the results from first principles, although the students are assumed to have an introductory knowledge of the basics. The topics covered are: (1) Panofsky-Wenzel and Planar Wake Theorems; (2) Echo Effect; (3) Crystalline Beam; (4) Fast Ion Instability; (5) Lawson-Woodward Theorem and Laser Acceleration in Free Space; (6) Spin Dynamics and Siberian Snakes; (7) Symplectic Approximation of Maps; (8) Truncated Power Series Algebra; and (9) Lie Algebra Technique for nonlinear Dynamics. The purpose of these lectures is not to elaborate, but to prepare the students so that they can do their own research. Each topic can be read independently of the others.

Topics and topic prominence in two sign languages

NARCIS (Netherlands)

Kimmelman, V.

2015-01-01

In this paper we describe topic marking in Russian Sign Language (RSL) and Sign Language of the Netherlands (NGT) and discuss whether these languages should be considered topic prominent. The formal markers of topics in RSL are sentence-initial position, a prosodic break following the topic, and

Graph-based Techniques for Topic Classification of Tweets in Spanish

Directory of Open Access Journals (Sweden)

Hector Cordobés

2014-03-01

Full Text Available Topic classification of texts is one of the most interesting challenges in Natural Language Processing (NLP. Topic classifiers commonly use a bag-of-words approach, in which the classifier uses (and is trained with selected terms from the input texts. In this work we present techniques based on graph similarity to classify short texts by topic. In our classifier we build graphs from the input texts, and then use properties of these graphs to classify them. We have tested the resulting algorithm by classifying Twitter messages in Spanish among a predefined set of topics, achieving more than 70% accuracy.

16. International Conference on Atomic Collisions in Solids. Book of abstracts

Energy Technology Data Exchange (ETDEWEB)

Paul, H; Bauer, P; Semrad, D [ed.; Johannes Kepler Univ., Linz (Austria). Inst. fuer Experimentalphysik

1996-12-31

In this conference book of abstracts the following topics are treated: The interaction of atomic, molecular or ion beams with surfaces of solid metals and crystals, scattering and collisions, ion bombardment, ion channeling, energy losses and charge exchange, thin films, secondary emission, the Auger effect, sputtering of particles and atomic and molecular clusters. Thereby not only experimental results are presented but also computerized simulation methods are applied. (Suda).

16. International Conference on Atomic Collisions in Solids. Book of abstracts

International Nuclear Information System (INIS)

Paul, H.; Bauer, P.; Semrad, D.

1995-01-01

In this conference book of abstracts the following topics are treated: The interaction of atomic, molecular or ion beams with surfaces of solid metals and crystals, scattering and collisions, ion bombardment, ion channeling, energy losses and charge exchange, thin films, secondary emission, the Auger effect, sputtering of particles and atomic and molecular clusters. Thereby not only experimental results are presented but also computerized simulation methods are applied. (Suda)

Applications of beam-foil spectroscopy to atomic collisions in solids

Science.gov (United States)

Sellin, I. A.

1976-01-01

Some selected papers presented at the Fourth International Conference on Beam-Foil Spectroscopy, whose results are of particular pertinence to ionic collision phenomena in solids, are reviewed. The topics discussed include solid target effects and means of surmounting them in the measurement of excited projectile ion lifetimes for low-energy heavy element ions; the electron emission accompanying the passage of heavy particles through solid targets; the collision broadening of X rays emitted from 100 keV ions moving in solids; residual K-shell excitation in chlorine ions penetrating carbon; comparison between 40 MeV Si on gaseous SiH4 targets at 300 mtorr and 40 MeV Si on Al; and the emergent surface interaction in beam-foil spectroscopy. A distinct overlap of interests between the sciences of beam-foil spectroscopy and atomic collisions in solids is pointed out.

Topics in current aerosol research (part2)

CERN Document Server

Hidy, G M

1972-01-01

Topics in Current Aerosol Research, Part 2 contains some selected articles in the field of aerosol study. The chosen topics deal extensively with the theory of diffusiophoresis and thermophoresis. Also covered in the book is the mathematical treatment of integrodifferential equations originating from the theory of aerosol coagulation. The book is the third volume of the series entitled International Reviews in Aerosol Physics and Chemistry. The text offers significant understanding of the methods employed to develop a theory for thermophoretic and diffusiophoretic forces acting on spheres in t

[Presentation of the "physical handicap" topic in six selected children's books--a critical analysis].

Science.gov (United States)

Flottmeyer, L; Fries, A

1993-05-01

Since the late 60s, reality-oriented books for children and young people have increasingly turned to subject-matters and issues involving social/societal criticism, among them the theme of "being disabled". In the discussion on the degree to which media, and books in particular, do affect children's attitudes and socialization, it has been underlined that media take effect in the development of specific attitudinal patterns and behavioural dispositions in those cases where the recipient has not already formed a "completed" opinion of the topic at hand. This in particular is true in children of primary school age, and above all relates to their view of the disabled person. Six selected children's books were reviewed critically, based on a catalogue of criteria permitting coverage of as wide as spectrum as possible of "physical disability" and allied subjects. Summarizing, it is noted that the books reviewed do give children the opportunity, and partly in an excellent manner, of gaining insights into the situation of disabled persons. The potential for didactical treatment in primary classrooms is pointed out.

Hydride generation – in-atomizer collection of Pb in a quartz trap-and-atomizer device for atomic absorption spectrometry – an interference study

Energy Technology Data Exchange (ETDEWEB)

Novotný, Pavel [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic); High School in Hořice, Husova 1414, 508 01 Hořice (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno (Czech Republic)

2013-01-01

Interferences of selected hydride forming elements (As, Sb, Bi, Se and Sn) on lead determination by hydride generation atomic absorption spectrometry were extensively studied in both on-line atomization and preconcentration (collection) modes. The commonly used on-line atomization mode was found free of significant interferences, whereas strong interference from Bi was observed when employing the preconcentration mode with plumbane collection in a quartz trap-and-atomizer device. Interference of Bi seems to take place in the preconcentration step. Interference of Bi in the collection mode cannot be reduced by increased hydrogen radical amount in the trap and/or the atomizer. - Highlights: ► Interference study on Pb determination by in-atomizer trapping was performed for the first time. ► Bi was found as a severe interferent in the preconcentration mode (Pb:Bi ratio 1:100). ► No interference was found in the on-line atomization (no preconcentration). ► Bi interference occurs during preconcentration.

2nd International School of Physics of Exotic Atoms "Ettore Majorana"

CERN Document Server

Duclos, J; Fiorentini, Giovanni; Torelli, Gabriele; Exotic atoms : fundamental interactions and structure of matter

1980-01-01

The second course of the International School on the Physics of Exotic Atoms took place at the "Ettore Majorana" Center for Scien­ tific Culture, Erice, Sicily, during the period from March 25 to April 5, 1979. It was attended by 40 participants from 23 insti­ tutes in 8 countries. The purpose of the course was to review the various aspects of the physics of exotic atoms, with particular emphasis on the re­ sults obtained in the last two years, i.e., after the first course of the School (Erice, April 24-30, 1977). The course dealt with two main topics, A) Exotic atoms and fundamental interactions and B) Applications to the study of the structure of matter. One of the aims of the course was to offer an opportunity for the exchange of experiences between scientists working in the two fields. In view of this, the lectures in the morning discussed the more general arguments in a common session, whereas the more specialized topics were treated in the afternoon, in two parallel sections. Section A was or...

CANAS '01 - Colloquium analytical atomic spectroscopy; CANAS '01 - Colloquium Analytische Atomspektroskopie. Programm. Kurzfassungen der Vortraege und Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The main topics of the meeting on analytical atom spectroscopy were: optical atom spectrometry, x-ray fluorescence analysis, absorption spectroscopy, icp mass spectroscopy, trace analysis, sampling, sample preparation and quality assurance.

PREFACE: International Symposium on (e,2e), Double Photoionization and Related Topics & 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions

Science.gov (United States)

Martin, Nicholas L. S.; deHarak, Bruno A.

2010-01-01

From 30 July to 1 August 2009, over a hundred scientists from 18 countries attended the International Symposium on (e,2e), Double Photoionization and Related Topics and the 15th International Symposium on Polarization and Correlation in Electronic and Atomic Collisions which were held at the W T Young Library of the University of Kentucky, USA. Both conferences were satellite meetings of the XXVI International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC) held in Kalamazoo, Michigan, USA, 21-28 July 2009. These symposia covered a broad range of experimental and theoretical topics involving excitation, ionization (single and multiple), and molecular fragmentation, of a wide range of targets by photons and charged particles (polarized and unpolarized). Atomic targets ranged from hydrogen to the heavy elements and ions, while molecular targets ranged from H2 to large molecules of biological interest. On the experimental front, cold target recoil ion momentum spectroscopy (COLTRIMS), also known as the Reaction Microscope because of the complete information it gives about a wide variety of reactions, is becoming commonplace and has greatly expanded the ability of researchers to perform previously inaccessible coincidence experiments. Meanwhile, more conventional spectrometers are also advancing and have been used for increasingly sophisticated and exacting measurements. On the theoretical front great progress has been made in the description of target states, and in the scattering calculations used to describe both simple and complex reactions. The international nature of collaborations between theorists and experimentalists is exemplified by, for example, the paper by Ren et al which has a total of 13 authors of whom the experimental group of six is from Heidelberg, Germany, one theoretical group is from Australia, with the remainder of the theoreticians coming from several different institutions in the United States. A total of 52 invited talks and

A history of the Atomic Energy Control Board

International Nuclear Information System (INIS)

Sims, G.H.E.

1980-07-01

Topics covered include the pre-history of the AECB, its creation, early operations and evolution, its relations with nuclear research, the uranium industry, and the nuclear power industry, its involvement with transportation and safeguards, and some current problems. The focus is on the Atomic Energy Control Act and regulations derived from the act

Detection of single atoms by resonance ionization spectroscopy

International Nuclear Information System (INIS)

Hurst, G.S.

1986-01-01

Rutherford's idea for counting individual atoms can, in principle, be implemented for nearly any type of atom, whether stable or radioactive, by using methods of resonance ionization. With the RIS technique, a laser is tuned to a wavelength which will promote a valence electron in a Z-selected atom to an excited level. Additional resonance or nonresonance photoabsorption steps are used to achieve nearly 100% ionization efficiencies. Hence, the RIS process can be saturated for the Z-selected atoms; and since detectors are available for counting either single electrons or positive ions, one-atom detection is possible. Some examples are given of one-atom detection, including that of the noble gases, in order to show complementarity with AMS methods. For instance, the detection of 81 Kr using RIS has interesting applications for solar neutrino research, ice-cap dating, and groundwater dating. 39 refs., 7 figs., 2 tabs

International bulletin on atomic and molecular data for fusion. No. 54-55

International Nuclear Information System (INIS)

Stephens, J.A.

1998-12-01

This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In the first part the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, polarizabilities, electric moments, interatomic potentials), (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions), and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). There are also chapters with beam-matter interactions and data on interactions of atomic particles with fields. In the second Part contains the bibliographic data, essentially for the above listed topics

OpenMPI and ExxonMobil Topics

Energy Technology Data Exchange (ETDEWEB)

Hjelm, Nathan Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pritchard, Howard Porter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-09

These are a series of slides for a presentation for ExxonMobil's visit to Los Alamos National Laboratory. Topics covered are: Open MPI - The Release Story, MPI-3 RMA in Open MPI, MPI dynamic process management and Open MPI, and new options with CLE 6. Open MPI RMA features are: since v2.0.0 full support for the MPI-3.1 specification, support for non-contiguous datatypes, support for direct use of the RDMA capabilities of high performance networks (Cray Gemini/Aries, Infiniband), starting in v2.1.0 will have support for using network atomic operations for MPI_Fetch_and_op and MPI_Compare_and_swap, tested with MPI_THREAD_MULTIPLE.

Atomic crystals resistive switching memory

International Nuclear Information System (INIS)

Liu Chunsen; Zhang David Wei; Zhou Peng

2017-01-01

Facing the growing data storage and computing demands, a high accessing speed memory with low power and non-volatile character is urgently needed. Resistive access random memory with 4F 2 cell size, switching in sub-nanosecond, cycling endurances of over 10 12 cycles, and information retention exceeding 10 years, is considered as promising next-generation non-volatile memory. However, the energy per bit is still too high to compete against static random access memory and dynamic random access memory. The sneak leakage path and metal film sheet resistance issues hinder the further scaling down. The variation of resistance between different devices and even various cycles in the same device, hold resistive access random memory back from commercialization. The emerging of atomic crystals, possessing fine interface without dangling bonds in low dimension, can provide atomic level solutions for the obsessional issues. Moreover, the unique properties of atomic crystals also enable new type resistive switching memories, which provide a brand-new direction for the resistive access random memory. (topical reviews)

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

1999-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics.

International bulletin on atomic and molecular data for fusion. No. 48

International Nuclear Information System (INIS)

1994-10-01

This bulletin provides atomic and molecular data references relevant to thermonuclear fusion research and technology. In part I the indexing of the papers is given separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; interatomic potentials), (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy particle collisions), and (iii) surface interactions (sputtering, surface damage, blistering, flaking, arcing, chemical reactions). Part II contains the bibliographic data for the above listed topics and for plasma composition and impurities, plasma heating, cooling and fuelling, high energy laser- and beam- matter interaction, bibliographic and numerical data collections, and on interaction of atomic particles with fields. Also included are sections on atomic and molecular data needs for fusion research and on news about ALADDIN (A Labelled Atomic Data Interface) and evaluated-data bases

International bulletin on atomic and molecular data for fusion. Nos. 50-51

International Nuclear Information System (INIS)

Botero, J.; Stephens, J.A.

1996-10-01

This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, polarizabilities, electric moments, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics

Laser spectroscopy and laser isotope separation of atomic gadolinium

International Nuclear Information System (INIS)

Chen, Y. W.; Yamanaka, C.; Nomaru, K.; Kou, K.; Niki, H.; Izawa, Y.; Nakai, S.

1994-01-01

Atomic vapor laser isotope separation (AVLIS) is a process which uses intense pulsed lasers to selectively photoionize one isotopic species of a chemical element, after which these ions are extracted electromagnetically. The AVLIS has several advantages over the traditional methods based on the mass difference, such as high selectivity, low energy consumption, short starting time and versatility to any atoms. The efforts for atomic vapor laser isotope separation at ILT and ILE, Osaka University have been concentrated into the following items: 1) studies on laser spectroscopy and laser isotope separation of atomic gadolinium, 2) studies on interaction processes including coherent dynamics, propagation effects and atom-ion collision in AVLIS system, 3) development of laser systems for AVLIS. In this paper, we present experimental results on the laser spectroscopy and laser isotope separation of atomic gadolinium.

Atomic Layer Deposition of Electron Selective SnOx and ZnO Films on Mixed Halide Perovskite: Compatibility and Performance.

Science.gov (United States)

Hultqvist, Adam; Aitola, Kerttu; Sveinbjörnsson, Kári; Saki, Zahra; Larsson, Fredrik; Törndahl, Tobias; Johansson, Erik; Boschloo, Gerrit; Edoff, Marika

2017-09-06

The compatibility of atomic layer deposition directly onto the mixed halide perovskite formamidinium lead iodide:methylammonium lead bromide (CH(NH 2 ) 2 , CH 3 NH 3 )Pb(I,Br) 3 (FAPbI 3 :MAPbBr 3 ) perovskite films is investigated by exposing the perovskite films to the full or partial atomic layer deposition processes for the electron selective layer candidates ZnO and SnO x . Exposing the samples to the heat, the vacuum, and even the counter reactant of H 2 O of the atomic layer deposition processes does not appear to alter the perovskite films in terms of crystallinity, but the choice of metal precursor is found to be critical. The Zn precursor Zn(C 2 H 5 ) 2 either by itself or in combination with H 2 O during the ZnO atomic layer deposition (ALD) process is found to enhance the decomposition of the bulk of the perovskite film into PbI 2 without even forming ZnO. In contrast, the Sn precursor Sn(N(CH 3 ) 2 ) 4 does not seem to degrade the bulk of the perovskite film, and conformal SnO x films can successfully be grown on top of it using atomic layer deposition. Using this SnO x film as the electron selective layer in inverted perovskite solar cells results in a lower power conversion efficiency of 3.4% than the 8.4% for the reference devices using phenyl-C 70 -butyric acid methyl ester. However, the devices with SnO x show strong hysteresis and can be pushed to an efficiency of 7.8% after biasing treatments. Still, these cells lacks both open circuit voltage and fill factor compared to the references, especially when thicker SnO x films are used. Upon further investigation, a possible cause of these losses could be that the perovskite/SnO x interface is not ideal and more specifically found to be rich in Sn, O, and halides, which is probably a result of the nucleation during the SnO x growth and which might introduce barriers or alter the band alignment for the transport of charge carriers.

A Discourse Perspective of Topic-prominence in Chinese EFL Learners’ Interlanguage

Directory of Open Access Journals (Sweden)

Shaopeng Li

2014-07-01

Full Text Available The present study aims to investigate the general characteristics of topic-prominent typological interlanguage development of Chinese learners of English in terms of acquiring subject-prominent English structures from the discourse perspective. We have selected as the research target “topic chain” which is the main topic-prominent structure in Chinese discourse and “zero anaphora” which is the most common topic anaphor of topic chain. Topic structures mainly appear in Chinese discourse in the form of “topic chain” (Wang, 2002; 2004. Actually, in the event of a topic chain, research on topic structures should go into the typical range of discourse. Two important findings were yielded by the present study. First, the characteristics of Chinese topic chain are transferrable to the interlanguage of Chinese EFL learners, thus resulting in overgeneralization of zero anaphora; second, interlanguage discourse of Chinese EFL learners reflects the characteristics of a second language acquisition process from topic-prominence to subject-prominence, thus lending support to the discourse transfer hypothesis.

Advanced technologies and atomic energy

International Nuclear Information System (INIS)

1995-01-01

The expert committee on the research 'Application of advanced technologies to nuclear power' started the activities in fiscal year 1994 as one of the expert research committees of Atomic Energy Society of Japan. The objective of its foundation is to investigate the information on the advanced technologies related to atomic energy and to promote their practice. In this fiscal year, the advanced technologies in the fields of system and safety, materials and measurement were taken up. The second committee meeting was held in March, 1995. In this report, the contents of the lectures at the committee meeting and the symposium are compiled. The topics in the symposium were the meaning of advanced technologies, the advanced technologies and atomic energy, human factors and control and safety systems, robot technology and microtechnology, and functionally gradient materials. Lectures were given at two committee meetings on the development of atomic energy that has come to the turning point, the development of advanced technologies centering around ULSI, the present problems of structural fine ceramics and countermeasures of JFCC, the material analysis using laser plasma soft X-ray, and the fullerene research of advanced technology development in Power Reactor and Nuclear Fuel Development Corporation. (K.I.)

Controlling the atom

International Nuclear Information System (INIS)

Mazuzan, G.T.; Walker, J.S.

1984-01-01

The authors trace the early history of nuclear power regulation in the US. Focusing on the Atomic Energy Commission, they describe the role of other groups that figured in the development of regulatory policies, including the Congressional Joint Committee on Atomic Energy, other federal agencies, state governments, the nuclear industry, and scientific organizations. They consider changes in public perceptions of and attitudes toward atomic energy and the dangers of radiation exposure. The basic purpose of the book is to provide the Nuclear Regulatory Commission and the general public with information on the historical antecedents and background of regulatory issues so that there will be continuity in policy decisions. The book concludes with an annotated bibliography of selected references. 19 figures

Peringkasan Tweet Berdasarkan Trending Topic Twitter Dengan Pembobotan TF-IDF dan Single Linkage AngglomerativeHierarchical Clustering

Directory of Open Access Journals (Sweden)

Annisa Annisa

2016-10-01

Full Text Available Trending topic is a feature provided by twitter that informs something widely discussed by users in a particular time. The form of a trending topic is a hashtag and can be selected by clicking. However, the number of tweets for each trending topics can be very large, so it will be difficult if we want to know all the contents. So, in order to make easy when reading the topic, a small number of tweets can be selected as the main idea of the topic. In this study, we applied the Agglomerative Single Linkage Hierarchical Clustering by calculating the TF-IDF value for each word in advance. We used 100 trending topics, where each topic consists of 50 tweets in Indonesian. For testing, we provided 30 trending topics which consist of 2 until 9 sub-topics. The result is that each trending topics can be summarized into shorter text contains 2 until 9 tweets. We were able to summarize 1 trending topics exactly same as the topic summarized by human expert. However, the rest of topics corresponded partially with human expert.

The uses of atomic energy for the economic and social development in the German Democratic Republic

International Nuclear Information System (INIS)

1987-01-01

A report is given on the peaceful uses of atomic energy in the GDR. The following topics are discussed: (1) present state and prospects of the utilization of atomic energy in the GDR, (2) protection against the dangers from the use of atomic energy, (3) the GDR's share in international efforts to secure the peaceful uses and to further the development of atomic energy, and (4) conclusions for the enhancement of international cooperation in the peaceful uses of atomic energy. 2 tabs., 6 figs., and 23 color and 3 black-and-white plates are included

The ENTRIA project. Selected disciplinary and interdisciplinary research topics; Das ENTRIA-Projekt. Ausgewaehlte disziplinaere und interdisziplinaere Forschungsthemen

Energy Technology Data Exchange (ETDEWEB)

Roehlig, Klaus-Juergen [Technical Univ. Clausthal, Clausthal-Zellerfeld (Germany); Hocke, Peter [KIT Karlsruhe (Germany). Inst. for Technology Assessment and Systems Analysis; Smeddinck, Ulrich [Braunschweig Technical Univ. Braunschweig (Germany); Walther, Clemens [Hannover Univ. (Germany). Inst. for Radioecology and Radiation Protection

2015-07-01

ENTRIA (''Disposal Options for Radioactive Residues: Interdisciplinary Analyses and Development of Evaluation Principles'', www.entria.de) is a joint research project carried out by twelve departments and institutes from German universities and major research institutions and one partner from Switzerland. It is financed by the German Ministry of Education and Research (BMBF). Scientists representing natural sciences, civil engineering, philosophy, law, social and political sciences, and technology assessment carry out disciplinary and interdisciplinary research addressing three options to manage especially high-level radioactive waste: - Final disposal in deep geological formations without any arrangements for retrieval, - disposal in deep geological formations with arrangements for monitoring and retrieval, and - (prolonged) surface (or near-surface) storage. In the paper, the following selected research topics - both disciplinary and interdisciplinary - are briefly introduced in order to provide an impression of the project scope: - Surface storage, - reference concepts for emplacement in deep geological formations with retrievability and monitoring, - radiation exposure and justification of measures, - interdisciplinary perspectives on dose limits, - comparative studies on nuclear waste governance, - nuclear waste governance in Switzerland, - public involvement and the German Site Selection Act, and - citizens' jury.

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. Copyright © 2013 Wiley Periodicals, Inc.

Many-body dynamics with cold atoms and molecules in optical lattices

International Nuclear Information System (INIS)

Schachenmayer, J.

2012-01-01

Systems of cold atoms or molecules, trapped in a periodic potential formed from standing waves of laser light, provide an experimental possibility to study strongly correlated many-body lattice models, which are traditionally used in condensed matter physics. Due to the relatively weak energy scales in these ''optical lattices'' (next-neighbor tunneling energies are typically on the order of tens of Hertz), the time-scales of the dynamics in these systems is relatively slow and can be observed in experiments. Furthermore, the microscopic parameters of the models can be very well controlled by lattice laser intensities and external fields. Thus, optical lattices provide an excellent framework to study many-body quantum non-equilibrium dynamics, which on the theoretical level is the topic of this thesis. This thesis contains a study of many-body dynamics in optical lattices for both idealized isolated models and realistic models with imperfections. It is centered around four main topics: The first two topics are studies of coherent many-body dynamics. This contains explicitly: (i) an analysis of the possibility to dynamically prepare crystalline states of Rydberg atoms or polar molecules by adiabatically tuning laser parameters; and (ii) a study of the collapses and revivals of the momentum-distribution of a Bose-Einstein condensate with a fixed number of atoms, which is suddenly loaded into a deep optical lattice. The third main topic is entanglement and specifically the dynamical growth of entanglement between portions of an optical lattice in quench experiments. A method to create and measure large-scale entanglement is presented in this thesis. The fourth main topic addresses classical noise. Specifically, a system of atoms in an optical lattice, which is created from lasers with intensity fluctuations, is analyzed in this work. The noisy evolution of many-body correlation functions is studied and a method to cancel this noise in a realistic experimental setup is

Leukemia in atomic bomb survivors. 1. General observations. Leukemia in survivors of atomic bombing. Cytologic and biochemical studies on the granulocytes in early leukemia among atomic bomb survivors. Leukemogenic effects of ionizing radiation on atomic bomb survivors in Hiroshima City

Energy Technology Data Exchange (ETDEWEB)

Lange, R D; Moloney, W C; Yamawaki, Tokuso; Kastenbaum, M A

1959-01-01

This document contains 4 separate reports on leukemia in survivals of the atomic explosions in Hiroshima and Nagasaki. In the first report, observations on seventy-five established cases of leukemia occurring in people exposed to atomic bomb radiation are presented. These data indicate a great increase in the incidence of leukemia among atomic bomb survivors due to a single massive exposure to ionizing radiation. The leukemogenic effects of radiation are manifested equally in both sexes and at all age levels represented in this series. The striking preponderance of chronic myelogenous leukemia compared to chronic lymphatic leukemia has been noted in exposed individuals but it is pointed out that chronic lymphatic leukemia is comparatively rare among the Japanese. Cases of leukemia are still appearing in atomic bomb survivors. However, since 1950 there has been a steady decline in the number of cases. The second report consists of a review of all cases of leukemia referred to the ABCC from 1948 to April 1952, a total of 75 cases. In the third report, hematological and biochemical findings in separated leukocytes of four cases of preclinical myelogenous leukemia developing in atomic bomb survivors are described. The incidence of leukemia among survivors in Hiroshima is the topic of the fourth report. 38 references, 8 figures, 10 tables.

Strongly interacting photons and atoms

International Nuclear Information System (INIS)

Alge, W.

1999-05-01

This thesis contains the main results of the research topics I have pursued during the my PhD studies at the University of Innsbruck and partly in collaboration with the Institut d' Optique in Orsay, France. It is divided into three parts. The first and largest part discusses the possibility of using strong standing waves as a tool to cool and trap neutral atoms in optical cavities. This is very important in the field of nonlinear optics where several successful experiments with cold atoms in cavities have been performed recently. A discussion of the optical parametric oscillator in a regime where the nonlinearity dominates the evolution is the topic of the second part. We investigated mainly the statistical properties of the cavity output of the three interactive cavity modes. Very recently a system has been proposed which promises fantastic properties. It should exhibit a giant Kerr nonlinearity with negligible absorption thus leading to a photonic turnstile device based on cold atoms in cavity. We have shown that this model suffers from overly simplistic assumptions and developed several more comprehensive approaches to study the behavior of this system. Apart from the division into three parts of different contents the thesis is divided into publications, supplements and invisible stuff. The intention of the supplements is to reach researchers which work in related areas and provide them with more detailed information about the concepts and the numerical tools we used. It is written especially for diploma and PhD students to give them a chance to use the third part of our work which is actually the largest one. They consist of a large number of computer programs we wrote to investigate the behavior of the systems in parameter regions where no hope exists to solve the equations analytically. (author)

Excited-state imaging of cold atoms

NARCIS (Netherlands)

Sheludko, D.V.; Bell, S.C.; Vredenbregt, E.J.D.; Scholten, R.E.; Deshmukh, P.C.; Chakraborty, P.; Williams, J.F.

2007-01-01

We have investigated state-selective diffraction contrast imaging (DCI) of cold 85Rb atoms in the first excited (52P3/2) state. Excited-state DCI requires knowledge of the complex refractive index of the atom cloud, which was calculated numerically using a semi-classical model. The Autler-Townes

Selected Translated Abstracts of Chinese-Language Climate Change Publications; TOPICAL

International Nuclear Information System (INIS)

Cushman, R.M.; Burtis, M.D.

1999-01-01

This report contains English-translated abstracts of important Chinese-language literature concerning global climate change for the years 1995-1998. This body of literature includes the topics of adaptation, ancient climate change, climate variation, the East Asia monsoon, historical climate change, impacts, modeling, and radiation and trace-gas emissions. In addition to the biological citations and abstracts translated into English, this report presents the original citations and abstracts in Chinese. Author and title indexes are included to assist the reader in locating abstracts of particular interest

Proceedings of the Topical meeting on the reactor fuel performance - TopFuel 2012 Transactions

International Nuclear Information System (INIS)

2012-01-01

TopFuel is an annual topical meeting organised by ENS, the American Nuclear Society and the Atomic Energy Society of Japan. TopFuel's primary objective is to bring together leading specialists in the field from around the world to analyse advances in nuclear fuel management technology and to use the findings of the latest cutting-edge research to help manufacture the high performance nuclear fuels of today and tomorrow. Aim is to discuss the challenges facing the developers and manufacturers of new high-performance nuclear fuels - fuels that will help meet current and future energy demand and reduce man's over dependence upon CO 2 -emitting fossil fuels. The technical scope of Top Fuel 2012 includes all aspects of nuclear fuel from fuel rod to core design as well as manufacturing, performance in commercial and test reactors or on-going and future developments and trends. The meeting includes selectively front and/or back end issues that impact fuel designs and performance. (authors)

Shock wave dynamics derivatives and related topics

CERN Document Server

Emanuel, George

2012-01-01

"...this monograph develops an esoteric niche within shock wave theory. …treats shock waves from an analytical approach assuming perfect gas. Emanuel has made significant contributions to the theory of shock waves and has selected a number of topics that reflect those contributions."-Shock Waves, 2013.

Collision-produced atomic states

International Nuclear Information System (INIS)

Andersen, N.; Copenhagen Univ.

1988-01-01

The last 10-15 years have witnessed the development of a new, powerful class of experimental techniques for atomic collision studies, allowing partial or complete determination of the state of the atoms after a collision event, i.e. the full set of quantum-mechanical scattering amplitudes or - more generally - the density matrix describing the system. Evidently, such studies, involving determination of alignment and orientation parameters, provide much more severe tests of state-of-the-art scattering theories than do total or differential cross section measurements which depend on diagonal elements of the density matrix. The off-diagonal elements give us detailed information about the shape and dynamics of the atomic states. Therefore, close studies of collision-produced atomic states are currently leading to deeper insights into the fundamental physical mechanisms governing the dynamics of atomic collision events. The first part of the lectures deals with the language used to describe atomic states, while the second part presents a selection of recent results for model systems which display fundamental aspects of the collision physics in particularly instructive ways. I shall here restrict myself to atom-atom collisions. The discussion will be focused on states decaying by photon emission though most of the ideas can be easily modified to include electron emission as well. (orig./AH)

Electromagnetic transitions in the atom

International Nuclear Information System (INIS)

Ulehla, I.; Suk, M.; Trka, Z.

1990-01-01

Methods to achieve excitation of atoms are outlined and conditions necessary for the occurrence of electromagnetic transitions in the atomic shell are given. Radiative transitions between the energy states of the atom include stimulated absorption, spontaneous emission, and stimulated emission. Selection rules applying to the majority of observed transitions are given. The parity concept is explained. It is shown how the electromagnetic field and its interaction with the magnetic moment of the atom lead to a disturbance of the energy states of the atom and the occurrence of various electro-optical and magneto-optical phenomena. The Stark effect and electron spin resonance are described. X-rays and X-ray spectra, the Auger effect and the internal photoeffect are also dealt with. The principle of the laser is explained. (M.D.). 22 figs., 1 tab

European Group for Atomic Spectroscopy. Summaries of contributions, eleventh annual conference, Paris-Orsay, July 10-13, 1979

Energy Technology Data Exchange (ETDEWEB)

1979-07-01

Summaries are presented of talks given at the eleventh conference of the European group for atomic spectroscopy. Topics covered include: lifetimes; collisions; line shape; hyperfine structure; isotope shifts; saturation spectroscopy; Hanle effect; Rydberg levels; quantum beats; helium and helium-like atoms; metrology; and molecules. (GHT)

International bulletin on atomic and molecular data for fusion. No. 46

International Nuclear Information System (INIS)

Botero, J.

1993-06-01

The bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In Part I the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; interatomic potentials); (ii) atomic and molecular collisions (photon collisions; electron collisions; heavy-particle collisions; homonuclear sequences; isoelectronic sequences), and (iii) surface interactions (sputtering; chemical reactions; trapping and detrapping; surface damage; blistering, flaking; secondary electron emission). Part II contains the bibliographic data for the above listed topics and for high energy laser- and beam-matter interaction; interaction of atomic particles with fields. The atomic and molecular data needs in fusion research, as identified during the IAEA Consultants' Meeting on 'Atomic and Molecular Database for Hydrogen Recycling and Helium Exhaust from Fusion Reactors', June 1992, Vienna, are listed, covering (i) atomic and molecular collision processes, (ii) particle-surface interaction processes, and (iii) the status of data bases on atomic and molecular data and plasma-surface interactions. News on the ALADDIN (A labelled Atomic Data INterface) system is provided. Finally, a list of evaluated atomic and molecular data bases is provided

Introduction to liquid wall film atomization

Directory of Open Access Journals (Sweden)

Jícha Miroslav

2012-04-01

Full Text Available The objective of the article is an introduction to the theoretical study of atomization of droplets from the surface of a thin liquid film. The overview of basic principles of atomization prediction is complemented by the comparison of the calculations performed according to the selected approaches.

Atomic properties in hot plasmas from levels to superconfigurations

CERN Document Server

Bauche, Jacques; Peyrusse, Olivier

2015-01-01

This book is devoted to the calculation of hot-plasma properties which generally requires a huge number of atomic data. It is the first book that combines information on the details of the basic atomic physics and its application to atomic spectroscopy with the use of the relevant statistical approaches. Information like energy levels, radiative rates, collisional and radiative cross-sections, etc., must be included in equilibrium or non-equilibrium models in order to describe both the atomic-population kinetics and the radiative properties. From the very large number of levels and transitions involved in complex ions, some statistical (global) properties emerge. The book presents a coherent set of concepts and compact formulas suitable for tractable and accurate calculations. The topics addressed are: radiative emission and absorption, and a dozen of other collisional and radiative processes; transition arrays between level ensembles (configurations, superconfigurations); effective temperatures of configurat...

Exploring the Framing of Animal Farming and Meat Consumption: On the Diversity of Topics Used and Qualitative Patterns in Selected Demographic Contexts.

Science.gov (United States)

Nijland, Hanneke J; Aarts, Noelle; van Woerkum, Cees M J

2018-01-24

In various contexts, people talk about animal farming and meat consumption using different arguments to construct and justify their (non-)acceptability. This article presents the results of an in-depth qualitative inquiry into the content of and contextual patterns in the everyday-life framing regarding this issue, performed among consumers in various settings in two extremes in the European sphere: the Netherlands and Turkey. We describe the methodological steps of collecting, coding, and organizing the variety of encountered framing topics, as well as our search for symbolic convergence in groups of consumers from different selected demographic contexts (country, urban-rural areas, gender, age, and education level). The framing of animal farming and meat consumption in everyday-life is not a simple one-issue rational display of facts; people referred to a vast range of topics in the categories knowledge, convictions, pronounced behaviour, values, norms, interests, and feelings. Looking at framing in relation to the researched demographic contexts, most patterns were found on the level of topics; symbolic convergence in lines of reasoning and composite framing was less prominent in groups based on single demographic contexts than anticipated. An explanation for this lies in the complexity of frame construction, happening in relation with multiple interdependent contextual features.

Isolating and moving single atoms using silicon nanocrystals

Science.gov (United States)

Carroll, Malcolm S.

2010-09-07

A method is disclosed for isolating single atoms of an atomic species of interest by locating the atoms within silicon nanocrystals. This can be done by implanting, on the average, a single atom of the atomic species of interest into each nanocrystal, and then measuring an electrical charge distribution on the nanocrystals with scanning capacitance microscopy (SCM) or electrostatic force microscopy (EFM) to identify and select those nanocrystals having exactly one atom of the atomic species of interest therein. The nanocrystals with the single atom of the atomic species of interest therein can be sorted and moved using an atomic force microscope (AFM) tip. The method is useful for forming nanoscale electronic and optical devices including quantum computers and single-photon light sources.

Chain formation of metal atoms

DEFF Research Database (Denmark)

Bahn, Sune Rastad; Jacobsen, Karsten Wedel

2001-01-01

The possibility of formation of single-atomic chains by manipulation of nanocontacts is studied for a selection of metals (Ni, Pd, Pt, Cu, Ag, Au). Molecular dynamics simulations show that the tendency for chain formation is strongest for Au and Pt. Density functional theory calculations indicate...... that the metals which form chains exhibit pronounced many-atom interactions with strong bonding in low coordinated systems....

Selected topics on surface effects in fusion devices: neutral-beam injectors and beam-direct converters

International Nuclear Information System (INIS)

Kaminsky, M.

1978-01-01

Neutral-beam injectors are being used for the heating and fueling of plasmas in existing devices such as PLT (Princeton), ISX (Oak Ridge) and 2XIIB (Lawrence Livermore Laboratory) and will be used in devices such as TFTR (Princeton), MX (Livermore) and Doublet III (Gulf Atomic). For example, TFTR has been designed to receive a total of 20 MW of 120-keV deuterium atoms in pulses of 0.5-sec duration from 12 neutral beam injectors; for the MX experiment it is planned to inject a total of 750A (equivalent) of deuterium atoms with a mean energy of 56 keV in 0.5-sec pulses. The interaction of energetic deuterium atoms with exposed surfaces of device components such as beam dumps, beam-direct-convertors collectors, beam calorimeters, and armor plates, cause a variety of surface effects which affect deleteriously the operation of such devices. Some of the major effects will be discussed

Pre-service physics teachers' ideas on size, visibility and structure of the atom

International Nuclear Information System (INIS)

Uenlue, Pervin

2010-01-01

Understanding the atom gives the opportunity to both understand and conceptually unify the various domains of science, such as physics, chemistry, biology, astronomy and geology. Among these disciplines, physics teachers are expected to be particularly well educated in this topic. It is important that pre-service physics teachers know what sort of theories regarding the atom they will bring into their own classrooms. Six tasks were developed, comprising size, visibility and structure of the atom. These tasks carried out by pre-service physics teachers were examined by content analysis and six categories were determined. These are size, visibility, subatomic particles, atom models, electron orbit and electron features. Pre-service physics teachers' ideas about the atom were clarified under these categories.

New trends in atomic and molecular physics advanced technological applications

CERN Document Server

2013-01-01

The field of Atomic and Molecular Physics (AMP) has reached significant advances in high–precision experimental measurement techniques. The area covers a wide spectrum ranging from conventional to new emerging multi-disciplinary areas like physics of highly charged ions (HCI), molecular physics, optical science, ultrafast laser technology etc. This book includes the important topics of atomic structure, physics of atomic collision, photoexcitation, photoionization processes, Laser cooling and trapping, Bose Einstein condensation and advanced technology applications of AMP in the fields of astronomy , astrophysics , fusion, biology and nanotechnology. This book is useful for researchers, professors, graduate, post graduate and PhD students dealing with atomic and molecular physics. The book has a wide scope with applications in neighbouring fields like plasma physics, astrophysics, cold collisions, nanotechnology and future fusion energy sources like ITER (international Thermonuclear Experimental Reactor) To...

Activities of the JILA Atomic Collisions Cross Sections Data Center

International Nuclear Information System (INIS)

Gallagher, J.W.

1983-01-01

The JILA Atomic Collisions Cross Sections Data Center compiles, critically evaluates, and reviews cross sections and rates for low energy (<100 keV) collisions of electrons, photons, and heavy particles with atoms, ions, and simple molecules. Reports are prepared which provide easily accessible recommended data with error limits, list the fundamental literature related to specific topics, identify regions where data are missing, and point out inconsistencies in existing data. The general methodology used in producing evaluated compilations is described. Recently completed projects and work in progress are reported

Bibliography on atomic line shapes and shifts (June 1975 through June 1978). Interim report

International Nuclear Information System (INIS)

Fuhr, J.R.; Miller, B.J.; Martin, G.A.

1978-12-01

This is the third supplement to the NBS Special Publication 366, Bibliography on Atomic Line Shapes and Shifts (1889 through March 1972). It contains about 600 references and covers the literature from June 1975 through June 1978. As before, the bibliography contains five major parts: (1) All general interest papers are catalogued according to the broadening mechanisms (and, further, according to special topics under several of the mechanisms) and as to whether the work is a general theory, a general review, a table of profiles or parameters, a comment on existing work, a study of general experimental measurement techniques, or an experimental effort of general importance. Also included are selected papers on important applications of line broadening and on miscellaneous topics relating to atomic spectral line shapes and shifts. (2) In Part 2 all papers containing numerical data are ordered as to element, ionization stage, and broadening mechanism (in the case of foreign gas broadening the perturbing species are listed), and it is indicated whether the data are experimentally or theoretically derived. (3) While in the two preceding parts of the bibliography the references are listed for brevity by identification numbers only, in Part 3 all references are listed completely by journal, authors, and title and are generally arranged by year of publication and alphabetically by authors' names within the year. (4) This section contains a list of all authors and their papers. (5) A final section provides corrections or additions to the second supplement to the original bibliography

US Atomic Energy Law

International Nuclear Information System (INIS)

1981-01-01

This is a new volume follows in the series supplementing the volumes 11 and 12 published in 1965 and 1966, updating the collection of Federal Acts and Executive Orders of the President of the United States of America relating to atomic energy legislation. Since the publication of volumes 11 and 12, the US Atomic Energy Act of 1954 alone has been amended 25 times, mainly as a consequence of by the Nuclear Non-Proliferation Act and the Uranium Mill Tailings Radiation Control Act, both of 1978. The Atomic Energy Act of 1954 is supplemented by a selection of the most important Federal Acts, Executive Orders of the President and Resolutions of the Congress. (orig./HSCH) [de

Line emission processes in atomic and molecular shocks

International Nuclear Information System (INIS)

Shull, J.M.

1988-01-01

The review discusses the observations and theoretical models of interstellar shock waves in diffuse and molecular clouds. After summarizing the relevant gas dynamics, atomic, molecular and grain processes, and physics of radiative and magnetic precursors, the author describes observational diagnostics of shocks. This paper concludes with a discussion of two topics: unstable or non-steady shocks and thermal conduction in metal-rich shocks

Hiroshima. History and topicality of the atomic threat. Baseline material and information for education

International Nuclear Information System (INIS)

Verfuss, K.; Wunderer, H.

1995-01-01

Hiroshima is an important topic for education, not only in history and social sciences classes, but just as well for courses in German, ethics, religion, and in the natural sciences. The material has been compiled to serve as an information source both for specific subjects and for interdisciplinary approaches, and has been arranged in compliance with the didactic principles of multiperspective approach and controversial aspects. (orig.) [de

Composition and conductance distributions of single GeSi quantum rings studied by conductive atomic force microscopy combined with selective chemical etching.

Science.gov (United States)

Lv, Y; Cui, J; Jiang, Z M; Yang, X J

2013-02-15

Atomic force microscopy imaging combined with selective chemical etching is employed to quantitatively investigate three-dimensional (3D) composition distributions of single GeSi quantum rings (QRs). In addition, the 3D quantitative composition distributions and the corresponding conductance distributions are simultaneously obtained on the same single GeSi QRs by conductive atomic force microscopy combined with selective chemical etching, allowing us to investigate the correlations between the conductance and composition distributions of single QRs. The results show that the QRs' central holes have higher Ge content, but exhibit lower conductance, indicating that the QRs' conductance distribution is not consistent with their composition distribution. By comparing the topography, composition and conductance profiles of the same single QRs before and after different etching processes, it is found that the conductance distributions of GeSi QRs do not vary with the change of composition distribution. Instead, the QRs' conductance distributions are found to be consistent with their topographic shapes, which can be supposed to be due to the shape determined electronic structures.

Atomic physics at high brilliance synchrotron sources: Proceedings

International Nuclear Information System (INIS)

Berry, G.; Cowan, P.; Gemmell, D.

1994-08-01

This report contains papers on the following topics: present status of SPring-8 and the atomic physics undulator beamline; recent photoabsorption measurements in the rare gases and alkalis in the 3 to 15 keV proton energy region; atomic and molecular physics at LURE; experiments on atoms, ions and small molecules using the new generation of synchrotron radiation sources; soft x-ray fluorescence spectroscopy using tunable synchrotron radiation; soft x-ray fluorescence spectroscopy excited by synchrotron radiation: Inelastic and resonant scattering near threshold; outer-shell photoionization of ions; overview of the APS BESSRC beamline development; the advanced light source: Research opportunities in atomic and molecular physics; Photoionization of the Ba + ion by 4d shell excitation; decay dynamics of inner-shell excited atoms and molecules; absorption of atomic Ca, Cr, Mn and Cu; High-resolution photoelectron studies of resonant molecular photoionization; radiative and radiationless resonant raman scattering by synchrotron radiation; auger spectrometry of atoms and molecules; some thoughts of future experiments with the new generation of storage rings; Electron spectroscopy studies of argon K-shell excitation and vacancy cascades; ionization of atoms by high energy photons; ion coincidence spectroscopy on rare gas atoms and small molecules after photoexcitation at energies of several keV; an EBIS for use with synchrotron radiation photoionization of multiply charged ions and PHOBIS; gamma-2e coincidence measurements the wave of the future in inner-shell electron spectroscopy; recoil momentum spectroscopy in ion-atom and photon-atom collisions; a study of compton ionization of helium; future perspectives of photoionization studies at high photon energies; and status report on the advanced photon source. These papers have been cataloged separately elsewhere

Characterization data on the topical carrier DDC642

Directory of Open Access Journals (Sweden)

Eline Desmet

2016-06-01

Full Text Available This article contains original data, figures and methods used in the characterization of the liposomal carrier ‘DDC642’ for topical applications, described in “An elastic liposomal formulation for RNAi-based topical treatment of skin disorders: proof-of-concept in the treatment of psoriasis” (Desmet et al., 2016 [1]. Several elastic liposomal formulations have been evaluated for their ability to encapsulate and deliver RNA interference (RNAi molecules to cultured primary skin cells. The efficiency and effectiveness of these liposomes were compared to that of our previously characterized liposomes, the ‘SECosomes’ (SEC (Geusens et al., 2010 [2]. After selection of a potential superior carrier, based on encapsulation and transfection efficiency data (Desmet et al., 2016 [1], the selected DDC642 liposomes were characterized more in-depth. Herein, a detailed characterization of the DDC642 liposome and RNAi-loaded lipoplexes is given, including the matching protocols.

Two Selected Topics Involving Theory and Applications of Infinite Arrays of Microstrip Elements

National Research Council Canada - National Science Library

Targonski, Stephen

1995-01-01

.... The first topic, the effect of random positioning errors on the input impedance of an infinite array of printed dipoles, utilizes the infinite array solution to gain insight into the reduction...

Photocarcinogenicity of selected topically applied dermatological drugs: calcineurin inhibitors, corticosteroids, and vitamin D analogs

Directory of Open Access Journals (Sweden)

Catharina Margrethe Lerche

2010-09-01

Full Text Available Topical therapies constitute the mainstay of dermatological treatments for skin disorders, such as atopic dermatitis, contact dermatitis, psoriasis, or acne. Since some of these diseases are often chronic, treatment duration may last for years and may even last the patient’s entire lifetime. Obviously, such long-term therapy may raise safety concerns, which also include the potential photocarcinogenic effect. Most patients are exposed to ultraviolet radiation (UVR during leisure, work, vacations, or in tanning beds. Additionally, the patients may receive UVR via UVB phototherapy or psoralens plus UVA radiation (PUVA. The use of immunosuppressant’s, such as corticosteroids and calcineurin inhibitors, has markedly increased. Patients with skin diseases have benefited from both systemic and topical treatment of both new and established drugs. The issue of a black box warning by the US Food and Drug Administration has increased concerns about photocarcinogenesis, which raises the question: “Are these drugs safe?” This review focuses on the mechanism of action and photocarcinogenic potential of commonly used topical treatments, such as corticosteroids, calcineurin inhibitors, and vitamin D analogs.

Two-dimensional gold nanostructures with high activity for selective oxidation of carbon–hydrogen bonds

KAUST Repository

Wang, Liang

2015-04-22

Efficient synthesis of stable two-dimensional (2D) noble metal catalysts is a challenging topic. Here we report the facile synthesis of 2D gold nanosheets via a wet chemistry method, by using layered double hydroxide as the template. Detailed characterization with electron microscopy and X-ray photoelectron spectroscopy demonstrates that the nanosheets are negatively charged and [001] oriented with thicknesses varying from single to a few atomic layers. X-ray absorption spectroscopy reveals unusually low gold–gold coordination numbers. These gold nanosheets exhibit high catalytic activity and stability in the solvent-free selective oxidation of carbon–hydrogen bonds with molecular oxygen.

Two-dimensional gold nanostructures with high activity for selective oxidation of carbon-hydrogen bonds

Science.gov (United States)

Wang, Liang; Zhu, Yihan; Wang, Jian-Qiang; Liu, Fudong; Huang, Jianfeng; Meng, Xiangju; Basset, Jean-Marie; Han, Yu; Xiao, Feng-Shou

2015-04-01

Efficient synthesis of stable two-dimensional (2D) noble metal catalysts is a challenging topic. Here we report the facile synthesis of 2D gold nanosheets via a wet chemistry method, by using layered double hydroxide as the template. Detailed characterization with electron microscopy and X-ray photoelectron spectroscopy demonstrates that the nanosheets are negatively charged and [001] oriented with thicknesses varying from single to a few atomic layers. X-ray absorption spectroscopy reveals unusually low gold-gold coordination numbers. These gold nanosheets exhibit high catalytic activity and stability in the solvent-free selective oxidation of carbon-hydrogen bonds with molecular oxygen.

Topical antifungal agents: an update.

Science.gov (United States)

Diehl, K B

1996-10-01

So many topical antifungal agents have been introduced that it has become very difficult to select the proper agent for a given infection. Nonspecific agents have been available for many years, and they are still effective in many situations. These agents include Whitfield's ointment, Castellani paint, gentian violet, potassium permanganate, undecylenic acid and selenium sulfide. Specific antifungal agents include, among others, the polyenes (nystatin, amphotericin B), the imidazoles (metronidazole, clotrimazole) and the allylamines (terbinafine, naftifine). Although the choice of an antifungal agent should be based on an accurate diagnosis, many clinicians believe that topical miconazole is a relatively effective agent for the treatment of most mycotic infections. Terbinafine and other newer drugs have primary fungicidal effects. Compared with older antifungal agents, these newer drugs can be used in lower concentrations and shorter therapeutic courses. Studies are needed to evaluate the clinical efficacies and cost advantages of both newer and traditional agents.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2005-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered include related applied areas, such as atmospheric science, astrophysics, surface physics and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments. · Reviews timely fields of atomic physics · Articles written by world leaders in those fields · In depth review of the subject with relevant literature · Suitable for researchers in other fields · Only book series of this kind.

Probabilistic analysis and related topics

CERN Document Server

Bharucha-Reid, A T

1983-01-01

Probabilistic Analysis and Related Topics, Volume 3 focuses on the continuity, integrability, and differentiability of random functions, including operator theory, measure theory, and functional and numerical analysis. The selection first offers information on the qualitative theory of stochastic systems and Langevin equations with multiplicative noise. Discussions focus on phase-space evolution via direct integration, phase-space evolution, linear and nonlinear systems, linearization, and generalizations. The text then ponders on the stability theory of stochastic difference systems and Marko

Probabilistic analysis and related topics

CERN Document Server

Bharucha-Reid, A T

1979-01-01

Probabilistic Analysis and Related Topics, Volume 2 focuses on the integrability, continuity, and differentiability of random functions, as well as functional analysis, measure theory, operator theory, and numerical analysis.The selection first offers information on the optimal control of stochastic systems and Gleason measures. Discussions focus on convergence of Gleason measures, random Gleason measures, orthogonally scattered Gleason measures, existence of optimal controls without feedback, random necessary conditions, and Gleason measures in tensor products. The text then elaborates on an

International bulletin on atomic and molecular data for fusion. No. 42-45

International Nuclear Information System (INIS)

Botero, J.

1991-01-01

The bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In Part I the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; polarizabilities, electric moments; interatomic potentials); (ii) atomic and molecular collisions (photon collisions; electro collisions; heavy-particle collisions; homonuclear sequences), and (iii) surface interactions (sputtering; trapping, detrapping; adsorption, desorption; surface damage; blistering, flaking; chemical reactions). Part II contains the bibliographic data for the above listed topics and for plasma composition and impurities; plasma heating, cooling and fuelling; fusion research of general interest; high energy laser- and beam-matter interaction; interaction of atomic particles with fields. A list of evaluated data bases on atomic and molecular collisions and on particle-surface interactions is also given

A rational approach to heavy-atom derivative screening

International Nuclear Information System (INIS)

Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D.

2010-01-01

In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing

A rational approach to heavy-atom derivative screening

Energy Technology Data Exchange (ETDEWEB)

Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D., E-mail: psun@nih.gov [Structural Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, Maryland 20852 (United States)

2010-04-01

In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

Ionization of small molecules by state-selected neon (3P0, 3P2) metastable atoms in the 0.06

NARCIS (Netherlands)

Berg, van den F.T.M.; Schonenberg, J.H.M.; Beijerinck, H.C.W.

1987-01-01

The velocity dependence and absolute values of the total ionisation cross section for the molecules H2, N2, O2, NO, CO, N2O, CO2, and CH4 by metastable Ne* (3P0) and Ne* (3P2) atoms at collision energies ranging from 0.06 to 6.0 eV have been measured in a crossed beam experiment. State selection of

Topical tags vs non-topical tags : Towards a bipartite classification?

NARCIS (Netherlands)

Basile, Valerio; Peroni, Silvio; Tamburini, Fabio; Vitali, Fabio

2015-01-01

In this paper we investigate whether it is possible to create a computational approach that allows us to distinguish topical tags (i.e. talking about the topic of a resource) and non-topical tags (i.e. describing aspects of a resource that are not related to its topic) in folksonomies, in a way that

Knowledge Extraction from Atomically Resolved Images.

Science.gov (United States)

Vlcek, Lukas; Maksov, Artem; Pan, Minghu; Vasudevan, Rama K; Kalinin, Sergei V

2017-10-24

Tremendous strides in experimental capabilities of scanning transmission electron microscopy and scanning tunneling microscopy (STM) over the past 30 years made atomically resolved imaging routine. However, consistent integration and use of atomically resolved data with generative models is unavailable, so information on local thermodynamics and other microscopic driving forces encoded in the observed atomic configurations remains hidden. Here, we present a framework based on statistical distance minimization to consistently utilize the information available from atomic configurations obtained from an atomically resolved image and extract meaningful physical interaction parameters. We illustrate the applicability of the framework on an STM image of a FeSe x Te 1-x superconductor, with the segregation of the chalcogen atoms investigated using a nonideal interacting solid solution model. This universal method makes full use of the microscopic degrees of freedom sampled in an atomically resolved image and can be extended via Bayesian inference toward unbiased model selection with uncertainty quantification.

Topical Conference on High Temperature Plasma Diagnostics, 7th, Napa, CA, Mar. 13-17, 1988, Proceedings

International Nuclear Information System (INIS)

Luhmann, N.C. Jr.; Peebles, W.A.

1988-01-01

Various papers concerning scientific instruments are presented. The general topics addressed include: laser scattering and optical diagnostics, collective scattering and interferometry, millimeter wave and current profile measurements, particle-based diagnostics, data acquisition and analysis, X-ray diagnostics, and particle- and photon-based diagnostics. Individual subjects discussed include: atomic hydrogen density measurements in an ion source plasma using VUV absorption spectrometer, resonant diagnostics of laser-produced Ba plasmas, radiative and diffusional effects to the population densities of the excited-state atoms in hydrogen plasma, and Watt-level millimeter-wave monolithic diode-grid frequency multipliers

The role of topical antibiotics used as prophylaxis in surgical site infection prevention.

LENUS (Irish Health Repository)

McHugh, S M

2011-04-01

Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining \\'topical\\' or \\'local\\' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

The role of topical antibiotics used as prophylaxis in surgical site infection prevention.

LENUS (Irish Health Repository)

McHugh, S M

2012-02-01

Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining \\'topical\\' or \\'local\\' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

Oral Versus Topical Diclofenac Sodium in the Treatment of Osteoarthritis.

Science.gov (United States)

Tieppo Francio, Vinicius; Davani, Saeid; Towery, Chris; Brown, Tony L

2017-06-01

Osteoarthritis (OA) is one of the most common causes of joint pain in the United States and non-steroidal anti-inflammatories (NSAIDs), such as Diclofenac sodium, which is currently available in two main routes of administration; oral and topical distribution have been established as one of the standard treatments for OA. Generally, oral NSAIDs are well tolerated; however our narrative review suggests that the topical solution had a better tolerability property than oral Diclofenac sodium, especially due to side effects of gastrointestinal bleeding with the utilization of the oral format. In addition, the topical route may be considered a reasonable selection by clinicians for management of musculoskeletal pain in those patients with a history of potential risk and adverse side effects. Most studies reviewed comparing oral versus topical solution of Diclofenac sodium revealed comparable efficacy, with minimal side effects utilizing the topical route. The key point of this narrative review is to help clinicians that currently must decide between very inexpensive diclofenac oral presentations and expensive topical presentations especially in the elderly population and the pros and cons of such decision-making process.

Selected Topics on Business Informatics Research: Editorial Introduction to Issue 6 of CSIMQ

Directory of Open Access Journals (Sweden)

Fabrizio Maria Maggi

2016-04-01

Full Text Available Business informatics research bridges management and engineering domains and facilitates communication between scientific and practical applications. The sixth issue of the journal of Complex Systems Informatics and Modeling Quarterly contains four publications that present the extended papers from the workshops of the 14th International Conference on Perspectives in Business Informatics Research (BIR 2015 that was organized in Tartu, Estonia, 26-28 August, 2015. The BIR 2015 workshops captured important and novel topics on information logistics and knowledge supply, security and compliance in business processes, and use of ontologies in information systems. Within this context the fifth publication included in this issue complements the topic of the business informatics research with the investigation of a model-driven approach on the gesture-based interaction in information systems.

Experimental physics. Vol. 5. Quanta, atoms, nuclei, particles; Experimentalphysik. Bd. 5. Quanten, Atome, Kerne, Teilchen

Energy Technology Data Exchange (ETDEWEB)

Pfeiler, Wolfgang [Wien Univ. (Austria). Fakultaet fuer Physik

2017-07-01

The following topics are dealt with: Photo- and Compton effect, photon, particle as wave, de Broglie wavelength, self-interference, dispersion relation, wavepacket, probability interpretation, uncertainty relations, occupation inversion, laser condition, tunnel effect, harmonic oscillator, hydrogen atom, quantum numbers, energy levels, electron spin, fine structure, Zeeman effect, periodic system, nuclear properties, binding energy, nuclear magnetism, nuclear models, radioactive decay, nuclear reactions, nuclear fission, nuclear energy, nuclear fusion, dosimetry, elementary particles, conservation laws, quark model, standard model, cosmology (Hubble law, cosmic background radiation, darkmatter, critical mass density, cosmological standard model), Moessbauer effect.

Integrated plant safety assessment: systematic evaluation program. Haddam Neck Plant, Connecticut Yankee Atomic Power Company. Docket No. 50-213

International Nuclear Information System (INIS)

1983-03-01

The Systematic Evaluation Program was initiated in February 1977 by the US Nuclear Regulatory Commission to review the designs of older operating nuclear reactor plants to confirm and document their safety. The review provides: (1) an assessment of how these plants compare with current licensing safety requirements relating to selected issues, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety. This report documents the review of Haddam Neck Plant, operated by Connecticut Yankee Atomic Power Company. The Haddam Neck Plant is one of 10 plants reviewed under Phase II of this program. This report indicates how 137 topics selected for review under Phase I of the program were addressed. Equipment and procedural changes have been identified as a result of the review

Formulating analytic expressions for atomic collision cross sections

International Nuclear Information System (INIS)

Tabata, Tatsuo; Kubo, Hirotaka; Sataka, Masao

2003-08-01

Methods to formulate analytic expression for atomic collision cross sections as a function of projectile energy are described on the basis of the experiences of the data compilation work for more than 20 years. Topics considered are the choice of appropriate functional forms for the expressions and optimization of adjustable parameters. To make extrapolation possible, functions to be used should have the form with reasonable asymptotic behavior. In this respect, modified Green-McNeal formulas have been found useful for various atomic collision cross sections. For ionization processes, a modified Lotz formula has often given a good fit. The ALESQ code for least-squares fits has been convenient to optimize adjustable parameters in analytic expressions. (author)

A Review of Carbon Dioxide Selective Membranes: A Topical Report

Energy Technology Data Exchange (ETDEWEB)

Dushyant Shekhawat; David R. Luebke; Henry W. Pennline

2003-12-01

Carbon dioxide selective membranes provide a viable energy-saving alternative for CO2 separation, since membranes do not require any phase transformation. This review examines various CO2 selective membranes for the separation of CO2 and N2, CO2 and CH4, and CO2 and H2 from flue or fuel gas. This review attempts to summarize recent significant advances reported in the literature about various CO2 selective membranes, their stability, the effect of different parameters on the performance of the membrane, the structure and permeation properties relationships, and the transport mechanism applied in different CO2 selective membranes.

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.

US-Japan Workshop on atomic-collision data for fusion

International Nuclear Information System (INIS)

Crandall, D.H.; Hafford, P.M.; Itikawa, Y.

1981-04-01

This report, containing abstracts of each of the presentations and discussions, includes: brief talks on the applications of atomic data in tokamaks and in inertial confinement; reviews of the specific atomic collisions projects for fusion in Japan and the United States; discussions of how the data centers operate and manner of exchanging data; brief reviews of the status of electron-ion scattering and ion-atom scattering; discussions of criteria to be used in evaluating and selecting both experimental and theoretical data in these two areas; comparisons of data selected for each of six specific collision reactions which were evaluated by both groups prior to the workshop; brief reviews of activities in the related areas of atomic structure and plasma wall interactions; and a decision to pursue a joint or collaborative compilation of recommended cross sections for oxygen ions for electron impact excitation and electron capture from atomic hydrogen

Topic Variability and Criteria in Interpretational History Teaching

Science.gov (United States)

Wansink, Bjorn; Akkerman, Sanne; Wubbels, Theo

2017-01-01

This paper studies the teacher perceived applicability of historical topics for interpretational history teaching and the criteria teachers use to evaluate this applicability. For this study, 15 expert history teachers in the Netherlands striving for interpretational history teaching were purposefully selected. Teachers were asked to mention…

Method of producing excited states of atomic nuclei

International Nuclear Information System (INIS)

Morita, M.; Morita, R.

1976-01-01

A method is claimed of producing excited states of atomic nuclei which comprises bombarding atoms with x rays or electrons, characterized in that (1) in the atoms selected to be produced in the excited state of their nuclei, (a) the difference between the nuclear excitation energy and the difference between the binding energies of adequately selected two electron orbits is small enough to introduce the nuclear excitation by electron transition, and (b) the system of the nucleus and the electrons in the case of ionizing an orbital electron in said atoms should satisfy the spin and parity conservation laws; and (2) the energy of the bombarding x rays or electrons should be larger than the binding energy of one of the said two electron orbits which is located at shorter distance from the atomic nucleus. According to the present invention, atomic nuclei can be excited in a relatively simple manner without requiring the use of large scale apparatus, equipment and production facilities, e.g., factories. It is also possible to produce radioactive substances or separate a particular isotope with an extremely high purity from a mixture of isotopes by utilizing nuclear excitation

Selective dissemination of information of library in scientific research institution

International Nuclear Information System (INIS)

Liu Wenping

2010-01-01

Selective Dissemination of Information (SDI) Service, which is an important component of intelligence, is the intelligence researcher to select key subjects and major issues and key technology or innovation goals under the actual needs of scientific research personnel issues, using network communication technology and database technology and information retrieval technologies, sustained and in a timely manner to track all kinds of literature for the front-line services, until the completion of research topics or key problem-solving. Library of China Institute of Atomic Energy is struggling to meet the diverse needs of customers, targeted to provide a lot of useful information for scientific researchers to use less time as possible to obtain as much intelligence information, and to research workers and leading to the successful completion of research tasks, and various decisions. The implementation of SDI services to identify clients and scope, to format SDI service team, to determine the SDI service principles and service mode. SDI services Selective demand intelligence researchers have been asked to improve their quality, to improve their interpersonal communication skills. (author)

The physics of atoms and quanta introduction to experiments and theory

CERN Document Server

Haken, Hermann; Brewer, William D

2005-01-01

The Physics of Atoms and Quanta is a thorough introduction to experiments and theory in this field. Every classical and modern aspect is included and discussed in detail. The new edition is completely revised, new sections on atoms in strong electric fields and high magnetic fields complete the comprehensive coverage of all topics related to atoms and quanta. All new developments, such as new experiments on quantum entanglement, the quantum computer, quantum information, the Einstein-Podolsky-Rosen paradoxon, Bell's inequality, Schrödinger's cat, decoherence, Bose-Einstein-Condensation and the atom laser are discussed. Over 170 problems and their solutions help deepen the insight in this subject area and make this book a real study text. The second and more advanced book by the same authors entitled "Molecular Physics and Elements of Quantum Chemistry" is the completion of this unique textbook.

Proceedings of the NASA workshop on atomic oxygen effects

International Nuclear Information System (INIS)

Brinza, D.E.

1987-06-01

A workshop was held to address the scientific issues concerning the effects of atomic oxygen on materials in the low Earth orbital (LEO) environment. The program included 18 invited speakers plus contributed posters covering topics such as LEO spaceflight experiments, interaction mechanisms, and atomic oxygen source development. Discussion sessions were also held to organize a test program to evaluate atomic oxygen exposure facilities. The key issues raised in the workshop were: (1) the need to develop a reliable predictive model of the effects of long-term exposure of materials to the LEO environment; (2) the ability of ground-based exposure facilities to provide useful data for development of durable materials; and (3) accurate determination of the composition of the LEO environment. These proceedings include the invited papers, the abstracts for the contributed posters, and an account of the test program discussion sessions

Parity and time-reversal violation in nuclei and atoms

International Nuclear Information System (INIS)

Adelberger, E.G.

1986-01-01

Two topics are briefly reviewed: the parity (P)-violating NN interaction and the time-reversal (T) and P-violating electric moments (EDM's) of atoms. The ΔI = 1 P-violating NN amplitude dominated by weak π +- exchange is found to be appreciably smaller than bag-model predictions. This may be a dynamical symmetry of flavor-conserving hadronic weak processes reminiscent of the ΔI = 1/2 rule in flavor-changing decays. General principles of experimental searches for atomic EDM's are discussed. Atomic EDM's are sensitive to electronic or nuclear EDM's and to a P-and-T-violating electron-quark interaction. Even though the experimental precision is still ∼10 4 times worse than counting statistics, the recent results have reached a sensitivity to nuclear EDM's which rivals that of the neutron EDM data. Further significant improvements can be expected

Homeschooling in the United States: A review of select research topics

Directory of Open Access Journals (Sweden)

Milton Gaither

Full Text Available Abstract The U.S. homeschooling movement has grown steadily since the early 1980s. In that time, a growing body of academic literature has been published that assesses various aspects of the phenomenon. This article first explains some of the methodological issues surrounding this literature as it has developed. It then summarizes the findings of the literature with respect to the following topics: the history of homeschooling, demographics (including parental motivation, academic achievement, and transition to college/adulthood.

Selective Production of Renewable para-Xylene by Tungsten Carbide Catalyzed Atom-Economic Cascade Reactions.

Science.gov (United States)

Dai, Tao; Li, Changzhi; Li, Lin; Zhao, Zongbao Kent; Zhang, Bo; Cong, Yu; Wang, Aiqin

2018-02-12

Tungsten carbide was employed as the catalyst in an atom-economic and renewable synthesis of para-xylene with excellent selectivity and yield from 4-methyl-3-cyclohexene-1-carbonylaldehyde (4-MCHCA). This intermediate is the product of the Diels-Alder reaction between the two readily available bio-based building blocks acrolein and isoprene. Our results suggest that 4-MCHCA undergoes a novel dehydroaromatization-hydrodeoxygenation cascade process by intramolecular hydrogen transfer that does not involve an external hydrogen source, and that the hydrodeoxygenation occurs through the direct dissociation of the C=O bond on the W 2 C surface. Notably, this process is readily applicable to the synthesis of various (multi)methylated arenes from bio-based building blocks, thus potentially providing a petroleum-independent solution to valuable aromatic compounds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Atom-by-atom assembly

International Nuclear Information System (INIS)

Hla, Saw Wai

2014-01-01

Atomic manipulation using a scanning tunneling microscope (STM) tip enables the construction of quantum structures on an atom-by-atom basis, as well as the investigation of the electronic and dynamical properties of individual atoms on a one-atom-at-a-time basis. An STM is not only an instrument that is used to ‘see’ individual atoms by means of imaging, but is also a tool that is used to ‘touch’ and ‘take’ the atoms, or to ‘hear’ their movements. Therefore, the STM can be considered as the ‘eyes’, ‘hands’ and ‘ears’ of the scientists, connecting our macroscopic world to the exciting atomic world. In this article, various STM atom manipulation schemes and their example applications are described. The future directions of atomic level assembly on surfaces using scanning probe tips are also discussed. (review article)

Atomic Energy Commission reports. Volume 6. Opinions and decisions of the Atomic Energy Commission with selected orders, January 1, 1973 to December 31, 1973

International Nuclear Information System (INIS)

1974-01-01

Issuances of the Atomic Energy Commission, the Atomic Safety and Licensing Appeal Boards, the Atomic Safety and Licensing Boards, and the Board of Contract Appeals including the Contract Adjustment Board are presented. (U.S.)

New trends in atomic and molecular physics. Advanced technological applications

International Nuclear Information System (INIS)

Mohan, Man

2013-01-01

Represents an up-to-date scientific status report on new trends in atomic and molecular physics. Multi-disciplinary approach. Also of interest to researchers in astrophysics and fusion plasma physics. Contains material important for nano- and laser technology. The field of Atomic and Molecular Physics (AMP) has reached significant advances in high-precision experimental measurement techniques. The area covers a wide spectrum ranging from conventional to new emerging multi-disciplinary areas like physics of highly charged ions (HCI), molecular physics, optical science, ultrafast laser technology etc. This book includes the important topics of atomic structure, physics of atomic collision, photoexcitation, photoionization processes, Laser cooling and trapping, Bose Einstein condensation and advanced technology applications of AMP in the fields of astronomy, astrophysics, fusion, biology and nanotechnology. This book is useful for researchers, professors, graduate, post graduate and PhD students dealing with atomic and molecular physics. The book has a wide scope with applications in neighbouring fields like plasma physics, astrophysics, cold collisions, nanotechnology and future fusion energy sources like ITER (international Thermonuclear Experimental Reactor) Tokomak plasma machine which need accurate AMP data.

Atomic and molecular physics - Ions in solids - Laser systems. Courses, corrected exercises and problems Level M1/M2

International Nuclear Information System (INIS)

Cremer, Georgette-Laura; Moncorge, Richard; Chesnel, Jean-Yves; Adoui, Lamri; Lelievre, Gerard

2010-01-01

This document proposes the table of contents and a brief presentation of a course book for students in atomic and molecular physics. After some generalities on energy quantification and on photon momentum / Compton Effect, the different chapters address topics like hydrogen and helium atoms, alkalis, alkaline-earth, atoms with several valence electrons, the atom-radiation interaction, molecule and ion spectroscopy in solids, and the most significant laser systems using an active media based on atoms, ions or molecules in a diluted environment. Each chapter contains exercises and problems

Atomic density effects on temperature characteristics and thermal transport at grain boundaries through a proper bin size selection

Energy Technology Data Exchange (ETDEWEB)

Vo, Truong Quoc; Kim, BoHung, E-mail: muratbarisik@iyte.edu.tr, E-mail: bohungk@ulsan.ac.kr [School of Mechanical Engineering, University of Ulsan, Daehak-ro 93, Namgu, Ulsan 680-749 (Korea, Republic of); Barisik, Murat, E-mail: muratbarisik@iyte.edu.tr, E-mail: bohungk@ulsan.ac.kr [Department of Mechanical Engineering, Izmir Institute of Technology, Urla, Izmir 35430 (Turkey)

2016-05-21

This study focuses on the proper characterization of temperature profiles across grain boundaries (GBs) in order to calculate the correct interfacial thermal resistance (ITR) and reveal the influence of GB geometries onto thermal transport. The solid-solid interfaces resulting from the orientation difference between the (001), (011), and (111) copper surfaces were investigated. Temperature discontinuities were observed at the boundary of grains due to the phonon mismatch, phonon backscattering, and atomic forces between dissimilar structures at the GBs. We observed that the temperature decreases gradually in the GB area rather than a sharp drop at the interface. As a result, three distinct temperature gradients developed at the GB which were different than the one observed in the bulk solid. This behavior extends a couple molecular diameters into both sides of the interface where we defined a thickness at GB based on the measured temperature profiles for characterization. Results showed dependence on the selection of the bin size used to average the temperature data from the molecular dynamics system. The bin size on the order of the crystal layer spacing was found to present an accurate temperature profile through the GB. We further calculated the GB thickness of various cases by using potential energy (PE) distributions which showed agreement with direct measurements from the temperature profile and validated the proper binning. The variation of grain crystal orientation developed different molecular densities which were characterized by the average atomic surface density (ASD) definition. Our results revealed that the ASD is the primary factor affecting the structural disorders and heat transfer at the solid-solid interfaces. Using a system in which the planes are highly close-packed can enhance the probability of interactions and the degree of overlap between vibrational density of states (VDOS) of atoms forming at interfaces, leading to a reduced ITR. Thus, an

Submicron Positioning of Single Atoms in a Microcavity

International Nuclear Information System (INIS)

Nussmann, Stefan; Hijlkema, Markus; Weber, Bernhard; Rohde, Felix; Rempe, Gerhard; Kuhn, Axel

2005-01-01

The coupling of individual atoms to a high-finesse optical cavity is precisely controlled and adjusted using a standing-wave dipole-force trap, a challenge for strong atom-cavity coupling. Ultracold Rubidium atoms are first loaded into potential minima of the dipole trap in the center of the cavity. Then we use the trap as a conveyor belt that we set into motion perpendicular to the cavity axis. This allows us to repetitively move atoms out of and back into the cavity mode with a repositioning precision of 135 nm. This makes it possible to either selectively address one atom of a string of atoms by the cavity, or to simultaneously couple two precisely separated atoms to a higher mode of the cavity

Minutes of the fourth meeting of the joint IFRC/INDC subcommittee on atomic and molecular data for fusion. Vienna, 30 September 1978

International Nuclear Information System (INIS)

Lorenz, A.; Seamon, R.E.

1978-10-01

This paper reports on the Fourth Meeting of the Joint IFRC/INDC Subcommittee on Atomic and Molecular Data for Fusion held in Vienna, 30 September 1978. Main topics are: a) The progress of the Atomic and Molecular Data Unit of IAEA. (Bulletin on A+M data, Atomic data Collision Index). b) The proposals for the future IAEA program on atomic and molecular data for fusion

Worldwide Utilization of Topical Remedies in Treatment of Psoriasis

DEFF Research Database (Denmark)

Svendsen, Mathias Tiedemann; Jeyabalan, Janithika; Andersen, Klaus Ejner

2017-01-01

OBJECTIVE: To review published literature describing the global use of topical antipsoriatics. MATERIAL AND METHODS: Search for English-language articles in Embase, Pubmed, PsycINFO, and Cochrane Library. RESULTS: Fifty-four selected publications were found, describing psoriasis patients' use of ...

Topic modeling for cluster analysis of large biological and medical datasets.

Science.gov (United States)

Zhao, Weizhong; Zou, Wen; Chen, James J

2014-01-01

The big data moniker is nowhere better deserved than to describe the ever-increasing prodigiousness and complexity of biological and medical datasets. New methods are needed to generate and test hypotheses, foster biological interpretation, and build validated predictors. Although multivariate techniques such as cluster analysis may allow researchers to identify groups, or clusters, of related variables, the accuracies and effectiveness of traditional clustering methods diminish for large and hyper dimensional datasets. Topic modeling is an active research field in machine learning and has been mainly used as an analytical tool to structure large textual corpora for data mining. Its ability to reduce high dimensionality to a small number of latent variables makes it suitable as a means for clustering or overcoming clustering difficulties in large biological and medical datasets. In this study, three topic model-derived clustering methods, highest probable topic assignment, feature selection and feature extraction, are proposed and tested on the cluster analysis of three large datasets: Salmonella pulsed-field gel electrophoresis (PFGE) dataset, lung cancer dataset, and breast cancer dataset, which represent various types of large biological or medical datasets. All three various methods are shown to improve the efficacy/effectiveness of clustering results on the three datasets in comparison to traditional methods. A preferable cluster analysis method emerged for each of the three datasets on the basis of replicating known biological truths. Topic modeling could be advantageously applied to the large datasets of biological or medical research. The three proposed topic model-derived clustering methods, highest probable topic assignment, feature selection and feature extraction, yield clustering improvements for the three different data types. Clusters more efficaciously represent truthful groupings and subgroupings in the data than traditional methods, suggesting

Contemporary models of the atomic nucleus

CERN Document Server

Nemirovskii, P E

2013-01-01

Contemporary Models of the Atomic Nucleus discusses nuclear structure and properties, expounding contemporary theoretical concepts of the low-energy nuclear processes underlying in nuclear models. This book focuses on subjects such as the optical nuclear model, unified or collective model, and deuteron stripping reaction. Other topics discussed include the basic nuclear properties; shell model; theoretical analysis of the shell model; and radiative transitions and alpha-decay. The deuteron theory and the liquid drop nuclear model with its application to fission theory are also mentioned, but o

Kinetics of elementary atom and radical reactions

International Nuclear Information System (INIS)

Gordon, R.J.

1990-06-01

During the past three years we have been working on four problems in the general area of gas phase kinetics and energy transfer of small molecules. These are: (1) measurements of the fine structure populations of ground state oxygen atoms produced in photodissociation reactions; (2) quenching of the Rydberg B ( 1 Σ + ) state of CO; (3) vibrational relaxation of highly excited molecules; and (4) kinetics of hydrogen molecules. The first two topics, which involve transitions between different electronic states of the parent molecule, are a departure from our previous research interests. In the accompanying renewal proposal we discuss plans to pursue these new topics vigorously during the coming year. The third topic is a continuation of our long interest in the energy dependence of the rates laws governing vibrational-to-translational energy transfer of molecules having large initial amounts of vibrational excitation. The final topic is a continuation of our studies of the reaction of O( 3 P) + H 2 . In this work we measured the rate constant for the reaction O( 3 P) with deuterium and also analyzed spectroscopically different sources of vibrationally excited hydrogen for possible future work. We discuss each of these four studies in the following sections

Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

Science.gov (United States)

Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

1987-01-01

Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

Magnetic trapping of cold bromine atoms.

Science.gov (United States)

Rennick, C J; Lam, J; Doherty, W G; Softley, T P

2014-01-17

Magnetic trapping of bromine atoms at temperatures in the millikelvin regime is demonstrated for the first time. The atoms are produced by photodissociation of Br2 molecules in a molecular beam. The lab-frame velocity of Br atoms is controlled by the wavelength and polarization of the photodissociation laser. Careful selection of the wavelength results in one of the pair of atoms having sufficient velocity to exactly cancel that of the parent molecule, and it remains stationary in the lab frame. A trap is formed at the null point between two opposing neodymium permanent magnets. Dissociation of molecules at the field minimum results in the slowest fraction of photofragments remaining trapped. After the ballistic escape of the fastest atoms, the trapped slow atoms are lost only by elastic collisions with the chamber background gas. The measured loss rate is consistent with estimates of the total cross section for only those collisions transferring sufficient kinetic energy to overcome the trapping potential.

Topics in statistical mechanics

International Nuclear Information System (INIS)

Elser, V.

1984-05-01

This thesis deals with four independent topics in statistical mechanics: (1) the dimer problem is solved exactly for a hexagonal lattice with general boundary using a known generating function from the theory of partitions. It is shown that the leading term in the entropy depends on the shape of the boundary; (2) continuum models of percolation and self-avoiding walks are introduced with the property that their series expansions are sums over linear graphs with intrinsic combinatorial weights and explicit dimension dependence; (3) a constrained SOS model is used to describe the edge of a simple cubic crystal. Low and high temperature results are derived as well as the detailed behavior near the crystal facet; (4) the microscopic model of the lambda-transition involving atomic permutation cycles is reexamined. In particular, a new derivation of the two-component field theory model of the critical behavior is presented. Results for a lattice model originally proposed by Kikuchi are extended with a high temperature series expansion and Monte Carlo simulation. 30 references

Changing the Topic. Topic Position in Ancient Greek Word Order

NARCIS (Netherlands)

Allan, R.J.

2014-01-01

Ancient Greek, topics can be expressed as intra-clausal constituents but they can also precede or follow the main clause as extra-clausal constituents. Together, these various topic expressions constitute a coherent system of complementary pragmatic functions. For a comprehensive account of topic

Special topics in the theory of piezoelectricity

CERN Document Server

Yang, Jiashi

2009-01-01

Piezoelectricity has been a steadily growing field, with recent advances made by researchers from applied physics, acoustics, materials science, and engineering. This collective work presents a comprehensive treatment of selected advanced topics in the subject. The book is written for an intermediate graduate level and is intended for researchers, mechanical engineers, and applied mathematicians interested in the advances and new applications in piezoelectricity.

Conference on atomic processes in high temperature plasmas: a topical conference of the American Physical Society Division of Plasma Physics

International Nuclear Information System (INIS)

1977-01-01

Abstracts are included for approximately 100 of the papers presented at the meeting. The following sessions were held at the conference: (1) electron ionization and excitation rates, (2) radiation from low density plasmas, (3) electron-ion cross sections and rates, (4) oscillator strengths and atomic structure, (5) spectroscopy and atomic structure, (6) astrophysical plasmas, (7) particle transport, (8) ion-atom cross sections and rates, (9) wall effects in laboratory plasmas, (10) spectroscopy and photoionization, and (11) radiation from high density plasmas

Developing topic-specific search filters for PubMed with click-through data.

Science.gov (United States)

Li, J; Lu, Z

2013-01-01

Search filters have been developed and demonstrated for better information access to the immense and ever-growing body of publications in the biomedical domain. However, to date the number of filters remains quite limited because the current filter development methods require significant human efforts in manual document review and filter term selection. In this regard, we aim to investigate automatic methods for generating search filters. We present an automated method to develop topic-specific filters on the basis of users' search logs in PubMed. Specifically, for a given topic, we first detect its relevant user queries and then include their corresponding clicked articles to serve as the topic-relevant document set accordingly. Next, we statistically identify informative terms that best represent the topic-relevant document set using a background set composed of topic irrelevant articles. Lastly, the selected representative terms are combined with Boolean operators and evaluated on benchmark datasets to derive the final filter with the best performance. We applied our method to develop filters for four clinical topics: nephrology, diabetes, pregnancy, and depression. For the nephrology filter, our method obtained performance comparable to the state of the art (sensitivity of 91.3%, specificity of 98.7%, precision of 94.6%, and accuracy of 97.2%). Similarly, high-performing results (over 90% in all measures) were obtained for the other three search filters. Based on PubMed click-through data, we successfully developed a high-performance method for generating topic-specific search filters that is significantly more efficient than existing manual methods. All data sets (topic-relevant and irrelevant document sets) used in this study and a demonstration system are publicly available at http://www.ncbi.nlm.nih.gov/CBBresearch/Lu/downloads/CQ_filter/

Summary of SMIRT20 Preconference Topical Workshop - Identifying Structural Issues in Advanced Reactors

International Nuclear Information System (INIS)

Richins, William; Novascone, Stephen; O'Brien, Cheryl

2009-01-01

The Idaho National Laboratory (INL, USA) and IASMiRT sponsored an international forum Nov 5-6, 2008 in Porvoo, Finland for nuclear industry, academic, and regulatory representatives to identify structural issues in current and future advanced reactor design, especially for extreme conditions and external threats. The purpose of this Topical Workshop was to articulate research, engineering, and regulatory Code development needs. The topics addressed by the Workshop were selected to address critical industry needs specific to advanced reactor structures that have long lead times and can be the subject of future SMiRT technical sessions. The topics were; (1) structural/materials needs for extreme conditions and external threats in contemporary (Gen. III) and future (Gen. IV and NGNP) advanced reactors and (2) calibrating simulation software and methods that address topic 1. The workshop discussions and research needs identified are presented. The Workshop successfully produced interactive discussion on the two topics resulting in a list of research and technology needs. It is recommended that IASMiRT communicate the results of the discussion to industry and researchers to encourage new ideas and projects. In addition, opportunities exist to retrieve research reports and information that currently exists, and encourage more international cooperation and collaboration. It is recommended that IASMiRT continue with an off-year workshop series on select topics.

Topics in theoretical and applied statistics

CERN Document Server

Giommi, Andrea

2016-01-01

This book highlights the latest research findings from the 46th International Meeting of the Italian Statistical Society (SIS) in Rome, during which both methodological and applied statistical research was discussed. This selection of fully peer-reviewed papers, originally presented at the meeting, addresses a broad range of topics, including the theory of statistical inference; data mining and multivariate statistical analysis; survey methodologies; analysis of social, demographic and health data; and economic statistics and econometrics.

NATO Advanced Study Institute on Atoms in Strong Fields

CERN Document Server

Clark, Charles; Nayfeh, Munir

1990-01-01

This book collects the lectures given at the NATO Advanced Study Institute on "Atoms in Strong Fields", which took place on the island of Kos, Greece, during the two weeks of October 9-21,1988. The designation "strong field" applies here to an external electromagnetic field that is sufficiently strong to cause highly nonlinear alterations in atomic or molecular struc­ ture and dynamics. The specific topics treated in this volume fall into two general cater­ gories, which are those for which strong field effects can be studied in detail in terrestrial laboratories: the dynamics of excited states in static or quasi-static electric and magnetic fields; and the interaction of atoms and molecules with intense laser radiation. In both areas there exist promising opportunities for research of a fundamental nature. An electric field of even a few volts per centimeter can be very strong on the atom­ ic scale, if it acts upon a weakly bound state. The study of Rydberg states with high reso­ lution laser spectroscop...

Electron-atom collisions in a laser field

International Nuclear Information System (INIS)

Ehlotzky, F.

1998-01-01

The present work is a report on recent progress made in our understanding of electron-atom collisions in a laser field. To some extent it is a continuation of a previous review covering a somewhat larger subject (Can. J. Phys. 63 (1985)). We shall discuss the present status of investigations in this field from the theoretical as well as experimental point of view but most of the report will be devoted to an analysis of the various approximation schemes used at present in this field to describe the different aspects of laser-assisted electron-atom interactions. As the table of contents shows, most of the work done so far is treating the atom as a spectator, described by a potential and only very little has been achieved over the years to include the atomic structure into consideration since the inclusion of these structure effects poses considerable computational problems. Since, for example, multiphoton ionization and its inverse process laser-assisted recombination may be considered as one half of a scattering process, it is quite natural that some of the theoretical techniques described here are also of interest for the treatment of other multiphoton processes not considered here since there are several other recent reviews available on these topics. (orig.)

What's on Your Mind? Conversation Topics Chosen by People With Degenerative Cognitive-Linguistic Disorders for Communication Boards.

Science.gov (United States)

Fried-Oken, Melanie; Daniels, Darlene; Ettinger, Olivia; Mooney, Aimee; Noethe, Glory; Rowland, Charity

2015-05-01

Conversational topics chosen by a group of adults with degenerative cognitive-linguistic disorders for personalized communication board development were examined. The patient-generated themes commonly selected are presented to guide treatment planning and communication board development. Communication boards were created for 109 adults as part of a larger research project. One autobiographical topic that each participant would enjoy discussing multiple times was represented on each communication board with 16 pictures and word labels. For this review, topics were collapsed into general themes through a consensus process and examined by gender and age. Sixty unique conversational topics were identified from 109 participants and collapsed into 9 general themes: Hobbies, Family, Travel, Work, Home/Places I've Lived, Sports/Fitness, Religion, Animals, and World War II. Age and gender produced variations in themes chosen, though no significance in rank orders was found across groups. Topics selected by adults with degenerative cognitive-linguistic disorders for communication boards resemble common conversational adult themes and do not center around basic needs or medical issues. Differences in gender and age for topic selection tend to be based on traditional roles. These general themes should be used when creating personalized communication boards for those who benefit from conversational aids.

Highly versatile atomic micro traps generated by multifrequency magnetic field modulation

International Nuclear Information System (INIS)

Courteille, Ph W; Deh, B; Fortagh, J; Guenther, A; Kraft, S; Marzok, C; Slama, S; Zimmermann, C

2006-01-01

We propose the realization of custom-designed adiabatic potentials for cold atoms based on multimode radio frequency radiation in combination with static inhomogeneous magnetic fields. For example, the use of radio frequency combs gives rise to periodic potentials acting as gratings for cold atoms. In strong magnetic field gradients, the lattice constant can be well below 1 μm. By changing the frequencies of the comb in time the gratings can easily be propagated in space, which may prove useful for Bragg scattering atomic matter waves. Furthermore, almost arbitrarily shaped potentials are possible such as disordered potentials on a scale of several 100 nm or lattices with a spatially varying lattice constant. The potentials can be made state selective and, in the case of atomic mixtures, also species selective. This opens new perspectives for generating tailored quantum systems based on ultracold single atoms or degenerate atomic and molecular quantum gases

Bottlenecks in the development of topical analgesics: molecule, formulation, dose-finding, and phase III design

Directory of Open Access Journals (Sweden)

Keppel Hesselink JM

2017-03-01

Full Text Available Jan M Keppel Hesselink,1 David J Kopsky,2 Stephen M Stahl3 1Institute Neuropathic Pain, Bosch en Duin, the Netherlands; 2Institute Neuropathic Pain, Amsterdam, the Netherlands; 3University of California San Diego, La Jolla, CA, USA Abstract: Topical analgesics can be defined as topical formulations containing analgesics or co-analgesics. Since 2000, interest in such formulations has been on the rise. There are, however, four critical issues in the research and development phases of topical analgesics: 1 The selection of the active pharmaceutical ingredient. Analgesics and co-analgesics differ greatly in their mechanism of action, and it is required to find the most optimal fit between such mechanisms of action and the pathogenesis of the targeted (neuropathic pain. 2 Issues concerning the optimized formulation. For relevant clinical efficacy, specific characteristics for the selected vehicle (eg, cream base or gel base are required, depending on the physicochemical characteristics of the active pharmaceutical ingredient(s to be delivered. 3 Well-designed phase II dose-finding studies are required, and, unfortunately, such trials are missing. In fact, we will demonstrate that underdosing is one of the major hurdles to detect meaningful and statistically relevant clinical effects of topical analgesics. 4 Selection of clinical end points and innovatively designed phase III trials. End point selection can make or break a trial. For instance, to include numbness together with tingling as a composite end point for neuropathic pain seems stretching the therapeutic impact of an analgesic too far. Given the fast onset of action of topical analgesics (usually within 30 minutes, enrichment designs might enhance the chances for success, as the placebo response might decrease. Topical analgesics may become promising inroads for the treatment of neuropathic pain, once sufficient attention is given to these four key aspects. Keywords: topical, analgesics

Integrated Plant Safety Assessment: Systematic Evaluation Program. Yankee Nuclear Power Station, Yankee Atomic Electric Company, Docket No. 50-29. Final report

International Nuclear Information System (INIS)

1983-06-01

The Systematic Evaluation program was initiated in February 1977 by the US Nuclear Regulatory Commission to review the designs of older operating nuclear reactor plants to confirm and document their safety. The review provides: (1) an assessment of how these plants compare with current licensing safety requirements relating to selected issues, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety. This report documents the review of Yankee Nuclear Power Station, operated by Yankee Atomic Electric Company. The Yankee plant is one of 10 plants reviewed under Phase II of this program. This report indicates how 137 topics selected for review under Phase I of the program were addressed. Equipment and procedural changes have been identified as a result of the review

Integrated Plant Safety Assessment, Systematic Evaluation Program. Yankee Nuclear Power Station, Yankee Atomic Electric Company, Docket No. 50-29. Draft report

International Nuclear Information System (INIS)

1983-02-01

The Systematic Evaluation Program was initiated in February 1977 by the US Nuclear Regulatory Commission to review the designs of older operating nuclear reactor plants to confirm and document their safety. The review provides (1) an assessment of how these plants compare with current licensing safety requirements relating to selected issues, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety. This report documents the review of Yankee Nuclear Power Station, operated by Yankee Atomic Electric Company. The Yankee plant is one of 10 plants reviewed under Phase II of this program. This report indicates how 137 topics selected for review under Phase I of the program were addressed. Equipment and procedural changes have been identified as a result of the review

Integrated Plant Safety Assessment: Systematic Evaluation Program. Haddam Neck Plant, Connecticut Yankee Atomic Power Company, Docket No. 50-213. Final report

International Nuclear Information System (INIS)

1983-01-01

The Systematic Evaluation Progam was initiated in February 1977 by the US Nuclear Regulatory Commission review the designs of older operating nuclear reactor plants to confirm and document their safety. The review provides: (1) an assessment of how these plants compare with curent licensing safety requirements relating to selected issues, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety. This report documents the review of Haddam Neck Plant, operated by Connecticut Yankee Atomic Power Company. The Haddam Neck Plant is one of 10 plants reviewed under Phase II of this program. This report indicates how 137 topics selected for review under Phase I of the program were addressed. Equipment and procedural changes have been identified as a result of the review

Topic models for conference session assignment: organising PRASA 2014(5)

CSIR Research Space (South Africa)

Burke, Michael G

2015-11-01

Full Text Available Conference scheduling and organising is a particularly laborious task and can be exteremely time consuming. While many online conference platforms allow manual topic selection, these can be expensive and typically still require that individual...

Inquiry of selected topics on heat exchanger design

International Nuclear Information System (INIS)

Mueller, A.C.

1977-01-01

Three specific topics of heat exchanger design are discussed. First is an examination of the effect of maldistribution on the performance of an exchanger. Three different patterns of maldistribution are investigated and for each type when the overall coefficient is independent of the maldistribution (constant) and when the maldistributed fluid is the controlling resistance and, hence, is a function of the maldistribution. It is the purpose of this investigation to determine how serious the maldistribution problem can be and hopefully, develop guidelines for the designer. Second, the simple laminar flow in tube heat transfer problem was examined with the further complications of appreciable external resistance and for countercurrent flow with appreciable temperature changes in the secondary fluid. This is a complex problem theoretically and it is shown how this would be simplified by means of several simple plots. Based on an old analog solution, the possible error if one used the conventional methods of applying overall coefficients in the design of laminar flow exchangers is discussed. Third, laminar flow heat transfer in tube banks was reviewed. The fundamental problem here is how does one handle the effect of the number of tube rows in baffled exchangers. Another form of correlation is suggested but basically it was found that insufficient experimental data were available to determine the best form of correlation. Further experimental data are needed

Atomic level characterization in corrosion studies

Science.gov (United States)

Marcus, Philippe; Maurice, Vincent

2017-06-01

Atomic level characterization brings fundamental insight into the mechanisms of self-protection against corrosion of metals and alloys by oxide passive films and into how localized corrosion is initiated on passivated metal surfaces. This is illustrated in this overview with selected data obtained at the subnanometre, i.e. atomic or molecular, scale and also at the nanometre scale on single-crystal copper, nickel, chromium and stainless steel surfaces passivated in well-controlled conditions and analysed in situ and/or ex situ by scanning tunnelling microscopy/spectroscopy and atomic force microscopy. A selected example of corrosion modelling by ab initio density functional theory is also presented. The discussed aspects include the surface reconstruction induced by hydroxide adsorption and formation of two-dimensional (hydr)oxide precursors, the atomic structure, orientation and surface hydroxylation of three-dimensional ultrathin oxide passive films, the effect of grain boundaries in polycrystalline passive films acting as preferential sites of passivity breakdown, the differences in local electronic properties measured at grain boundaries of passive films and the role of step edges at the exposed surface of oxide grains on the dissolution of the passive film. This article is part of the themed issue 'The challenges of hydrogen and metals'.

Quantum electronics for atomic physics and telecommunication

CERN Document Server

Nagourney, Warren G

2014-01-01

Nagourney provides a course in quantum electronics for researchers in atomic physics and other related areas (including telecommunications). The book covers the usual topics, such as Gaussian beams, optical cavities, lasers, non-linear optics, modulation techniques and fibre optics, but also includes a number of areas not usually found in a textbook on quantum electronics, such as the enhancement of non-linear processes in a build-up cavity or periodically poled waveguide, impedance matching into a cavity and astigmatism in ring cavities.

Atomic spectroscopy sympsoium, Gaithersburg, Maryland, September 23--26, 1975. [Program, abstracts, and author index

Energy Technology Data Exchange (ETDEWEB)

1975-01-01

Abstracts of one hundred papers given at the conference are presented along with the conference program and an author index. Session topics include: highly ionized atoms; laser spectroscopy and hyperfine structure; complex spectra; laser spectroscopy, radiation theory; theory of highly ionized atoms and analysis of plasmas; plasma spectroscopy, line strengths; spectral analysis, instrumentation, reference wavelengths; beam foil spectroscopy, line strengths, energy levels; absorption spectroscopy, autoionization, and related theory; and spectral analysis, instrumentation, and VUV physics. (GHT)

Development, Validation and Summative Evaluation of Card Pairing Games for Selected Math 8 Topics

Directory of Open Access Journals (Sweden)

Ronald O. Ocampo

2015-12-01

Full Text Available Traditional classroom situation where students are taught predominantly of lecture-discussion method put the classroom in a mathophobic atmosphere. Oftentimes, students exposed to this classroom atmosphere lead to math anxiety and eventually hate the subject and the teacher. Addressing this, varied interactive strategies to create an atmosphere of discourse has been developed and promoted. The use of instructional games has been viewed as one strategy that promotes active learning inside the classroom. Instructional games support constructivist learning and social learning. This study is aimed at developing, validating and evaluating card pairing games for specific topics in Math 8. The Research and Development model ( R& D was used. The card pairing games was validated by subject experts and experts in developing games. In evaluating the card pairing games, the Quasi-Experimental Pretest-Posttest design was used. There are six card pairing games developed for specific topics in Math 8; the card pairing game is highly valid based on the result of the validation; Students exposed to card pairing game become more intact (homogeneous; Students exposed to card games enhance academic performance. It is recommended to test the effectiveness of card pairing games to other group of students; Encourage math teachers to use the developed math card pairing games for classroom instruction; Develop other card pairing game for specific topics in math.

Not strange but not true: self-reported interest in a topic increases false memory.

Science.gov (United States)

O'Connell, Anthony; Greene, Ciara M

2017-09-01

People are more likely to recall both true and false information that is consistent with their pre-existing stereotypes, schemata and desires. In addition, experts in a particular field are more likely to experience false memory in relation to their area of expertise. Here, we investigate whether level of interest, as distinct from level of knowledge, and in the absence of self-professed expertise, is associated with increased false memory. 489 participants were asked to rank 7 topics from most to least interesting. They were then asked if they remembered the events described in four news items related to the topic they selected as the most interesting and four items related to the topic selected as least interesting. In each case, three of the events depicted had really happened and one was fictional. A high level of interest in a topic increased true memories for the topic and doubled the frequency of false memories, even after controlling for level of knowledge. We interpret the results in the context of the source-monitoring framework and suggest that false memories arise as a result of interference from existing information stored in domain-related schemata.

Topic Modeling of NASA Space System Problem Reports: Research in Practice

Science.gov (United States)

Layman, Lucas; Nikora, Allen P.; Meek, Joshua; Menzies, Tim

2016-01-01

Problem reports at NASA are similar to bug reports: they capture defects found during test, post-launch operational anomalies, and document the investigation and corrective action of the issue. These artifacts are a rich source of lessons learned for NASA, but are expensive to analyze since problem reports are comprised primarily of natural language text. We apply topic modeling to a corpus of NASA problem reports to extract trends in testing and operational failures. We collected 16,669 problem reports from six NASA space flight missions and applied Latent Dirichlet Allocation topic modeling to the document corpus. We analyze the most popular topics within and across missions, and how popular topics changed over the lifetime of a mission. We find that hardware material and flight software issues are common during the integration and testing phase, while ground station software and equipment issues are more common during the operations phase. We identify a number of challenges in topic modeling for trend analysis: 1) that the process of selecting the topic modeling parameters lacks definitive guidance, 2) defining semantically-meaningful topic labels requires nontrivial effort and domain expertise, 3) topic models derived from the combined corpus of the six missions were biased toward the larger missions, and 4) topics must be semantically distinct as well as cohesive to be useful. Nonetheless,topic modeling can identify problem themes within missions and across mission lifetimes, providing useful feedback to engineers and project managers.

Deposition of size-selected atomic clusters on surfaces

International Nuclear Information System (INIS)

Carroll, S.J.

1999-06-01

This dissertation presents technical developments and experimental and computational investigations concerned with the deposition of atomic clusters onto surfaces. It consists of a collection of papers, in which the main body of results are contained, and four chapters presenting a subject review, computational and experimental techniques and a summary of the results presented in full within the papers. Technical work includes the optimization of an existing gas condensation cluster source based on evaporation, and the design, construction and optimization of a new gas condensation cluster source based on RF magnetron sputtering (detailed in Paper 1). The result of cluster deposition onto surfaces is found to depend on the cluster deposition energy; three impact energy regimes are explored in this work. (1) Low energy: n clusters create a defect in the surface, which pins the cluster in place, inhibiting cluster diffusion at room temperature (Paper V). (3) High energy: > 50 eV/atom. The clusters implant into the surface. For Ag 20 -Ag 200 clusters, the implantation depth is found to scale linearly with the impact energy and inversely with the cross-sectional area of the cluster, with an offset due to energy lost to the elastic compression of the surface (Paper VI). For smaller (Ag 3 ) clusters the orientation of the cluster with respect to the surface and the precise impact site play an important role; the impact energy has to be 'focused' in order for cluster implantation to occur (Paper VII). The application of deposited clusters for the creation of Si nanostructures by plasma etching is explored in Paper VIII. (author)

Single photon emission computed tomography and oth selected computer topics

International Nuclear Information System (INIS)

Frey, G.D.

1981-01-01

This book, the proceedings of a meeting in January 1980, contains 21 papers. Thirteen are devoted to aspects of emission tomography, four to nuclear cardiology, and five to other topics. The initial set of papers consists of reviews of the single photon emission tomography process. These include transverse axial tomography using scintillation cameras and other devices, longitudinal section tomography, and pin-hole and slant-hole systems. These reviews are generally well done, but as might be expected, lack any coherence from paper to paper. The papers on nuclear cardiology include several of Fourier analysis in nuclear cardiology and one on shunt quantification. Other clinical papers are on quantifying Tc-99m glucoheptonate uptake in the brain and on iron-59 retention studies. A general criticism of the book is the poor quality of photographic reproductions

Coherence effects in atomic impact processes

International Nuclear Information System (INIS)

Blum, K.

1980-01-01

The author considers excitation of target atoms by projectile particles and the coincident detection of the scattered projectiles and the photons emitted in the subsequent decay by the target atoms. The observation is restricted to radiation emitted by those atoms only which 'scattered' the projectiles with a given energy in a given direction defined by the particle detector. Thus, a certain subensemble of atoms is selected in the experiment. The author reviews the theoretical scheme used for the description of the excited subensemble with the emphasis on the coherence properties. The author reviews developments of the Fano-Macek theory concerning the description of coherently excited states with different angular momenta and parities. A comprehensive expression for the angular distribution of the emitted radiation, including all possible interference terms is given. (Auth.)

Electron microscopy at atomic resolution

Energy Technology Data Exchange (ETDEWEB)

Gronsky, R.

1983-11-01

The direct imaging of atomic structure in solids has become increasingly easier to accomplish with modern transmission electron microscopes, many of which have an information retrieval limit near 0.2 nm point resolution. Achieving better resolution, particularly with any useful range of specimen tilting, requires a major design effort. This presentation describes the new Atomic Resolution Microscope (ARM), recently put into operation at the Lawrence Berkeley Laboratory. Capable of 0.18 nm or better interpretable resolution over a voltage range of 400 kV to 1000 kV with +- 40/sup 0/ biaxial specimen tilting, the ARM features a number of new electron-optical and microprocessor-control designs. These are highlighted, and its atomic resolution performance demonstrated for a selection of inorganic crystals.

Electron microscopy at atomic resolution

International Nuclear Information System (INIS)

Gronsky, R.

1983-11-01

The direct imaging of atomic structure in solids has become increasingly easier to accomplish with modern transmission electron microscopes, many of which have an information retrieval limit near 0.2 nm point resolution. Achieving better resolution, particularly with any useful range of specimen tilting, requires a major design effort. This presentation describes the new Atomic Resolution Microscope (ARM), recently put into operation at the Lawrence Berkeley Laboratory. Capable of 0.18 nm or better interpretable resolution over a voltage range of 400 kV to 1000 kV with +- 40 0 biaxial specimen tilting, the ARM features a number of new electron-optical and microprocessor-control designs. These are highlighted, and its atomic resolution performance demonstrated for a selection of inorganic crystals

Application of resonance ionisation spectroscopy in atomic physics

International Nuclear Information System (INIS)

Kluge, H.J.

1997-01-01

Resonance ionization spectroscopy (RIS) and resonance ionization mass spectroscopy (RIMS) techniques have proved to be a powerful tool in atomic spectroscopy and trace analysis. Detailed atomic spectroscopy can be performed on samples containing less than 10 12 atoms. This sensitivity is especially important for investigating atomic properties of transuranium elements. RIMS is especially suitable for ultra trace determination of long lived radioactive isotopes. The extremely low detection limits allow analysis of samples in the sub-femtogram regime. High elemental and isotopic selectivity can be obtained. To produce isobarically pure ion beams, a RIS based laser ion source can be used

Atomic and molecular data for optical stellar spectroscopy

International Nuclear Information System (INIS)

Heiter, U; Lind, K; Barklem, P S; Asplund, M; Bergemann, M; Magrini, L; Masseron, T; Mikolaitis, Š; Pickering, J C; Ruffoni, M P

2015-01-01

High-precision spectroscopy of large stellar samples plays a crucial role for several topical issues in astrophysics. Examples include studying the chemical structure and evolution of the Milky Way Galaxy, tracing the origin of chemical elements, and characterizing planetary host stars. Data are accumulating from instruments that obtain high-quality spectra of stars in the ultraviolet, optical and infrared wavelength regions on a routine basis. These instruments are located at ground-based 2–10 m class telescopes around the world, in addition to the spectrographs with unique capabilities available at the Hubble Space Telescope. The interpretation of these spectra requires high-quality transition data for numerous species, in particular neutral and singly ionized atoms, and di- or triatomic molecules. We rely heavily on the continuous efforts of laboratory astrophysics groups that produce and improve the relevant experimental and theoretical atomic and molecular data. The compilation of the best available data is facilitated by databases and electronic infrastructures such as the NIST Atomic Spectra Database, the VALD database, or the Virtual Atomic and Molecular Data Centre. We illustrate the current status of atomic data for optical stellar spectra with the example of the Gaia-ESO Public Spectroscopic Survey. Data sources for 35 chemical elements were reviewed in an effort to construct a line list for a homogeneous abundance analysis of up to 10 5 stars. (paper)

Atomic and molecular data for optical stellar spectroscopy

Science.gov (United States)

Heiter, U.; Lind, K.; Asplund, M.; Barklem, P. S.; Bergemann, M.; Magrini, L.; Masseron, T.; Mikolaitis, Š.; Pickering, J. C.; Ruffoni, M. P.

2015-05-01

High-precision spectroscopy of large stellar samples plays a crucial role for several topical issues in astrophysics. Examples include studying the chemical structure and evolution of the Milky Way Galaxy, tracing the origin of chemical elements, and characterizing planetary host stars. Data are accumulating from instruments that obtain high-quality spectra of stars in the ultraviolet, optical and infrared wavelength regions on a routine basis. These instruments are located at ground-based 2-10 m class telescopes around the world, in addition to the spectrographs with unique capabilities available at the Hubble Space Telescope. The interpretation of these spectra requires high-quality transition data for numerous species, in particular neutral and singly ionized atoms, and di- or triatomic molecules. We rely heavily on the continuous efforts of laboratory astrophysics groups that produce and improve the relevant experimental and theoretical atomic and molecular data. The compilation of the best available data is facilitated by databases and electronic infrastructures such as the NIST Atomic Spectra Database, the VALD database, or the Virtual Atomic and Molecular Data Centre. We illustrate the current status of atomic data for optical stellar spectra with the example of the Gaia-ESO Public Spectroscopic Survey. Data sources for 35 chemical elements were reviewed in an effort to construct a line list for a homogeneous abundance analysis of up to 105 stars.

Visualising reacting single atoms under controlled conditions: Advances in atomic resolution in situ Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM)

Science.gov (United States)

Boyes, Edward D.; Gai, Pratibha L.

2014-02-01

Advances in atomic resolution Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM) for probing gas-solid catalyst reactions in situ at the atomic level under controlled reaction conditions of gas environment and temperature are described. The recent development of the ESTEM extends the capability of the ETEM by providing the direct visualisation of single atoms and the atomic structure of selected solid state heterogeneous catalysts in their working states in real-time. Atomic resolution E(S)TEM provides a deeper understanding of the dynamic atomic processes at the surface of solids and their mechanisms of operation. The benefits of atomic resolution-E(S)TEM to science and technology include new knowledge leading to improved technological processes with substantial economic benefits, improved healthcare, reductions in energy needs and the management of environmental waste generation. xml:lang="fr"

Coherent atomic spectroscopy

International Nuclear Information System (INIS)

Garton, W.R.S.

1988-01-01

The Argonne Spectroscopy Laboratory, initiated and advanced over several decades by F.S. Tomkins and M. Fred, has been a major international facility. A range of collaborative work in atomic spectroscopy is selected to illustrate advances in experimental physics which have been made possible by combination of the talents of Tomkins and Fred with the unique facilities of the Argonne Laboratory. (orig.)

Preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization for the selective recognition of tetracycline from aqueous medium

International Nuclear Information System (INIS)

Dai, Jiangdong; Pan, Jianming; Xu, Longcheng; Li, Xiuxiu; Zhou, Zhiping; Zhang, Rongxian; Yan, Yongsheng

2012-01-01

Highlights: ► Atom transfer radical emulsion polymerization is a “living” and green technique. ► Nanoparticles can overcome mass transfer limitations and improve accessibility. ► Molecular imprinted nanoparticles with magnetic property for fast separation. ► The performance of imprinted nanoparticles was investigated in detail. ► Nanoparticles were used to selective recognize Tetracycline from water medium. - Abstract: In the work, we reported an effective method for the preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization (ATREP), and then as-prepared magnetic molecularly imprinted nanoparticles (MMINs) were evaluated as adsorbents for selective recognition of tetracycline (TC) molecules from aqueous medium. The resulting nanoparticles were characterized by FT-IR, TGA, VSM, SEM and TEM. The results demonstrated MMINs with a narrow diameter distribution were cross-linked with modified Fe 3 O 4 particles, composed of imprinted layer and exhibited good magnetic sensitivity, magnetic and thermal stability. Batch rebinding studies were carried out to determine the specific adsorption equilibrium, kinetics, and selective recognition. The estimated adsorption capacity of MMINs towards TC by the Langmuir isotherm model was 12.10 mg g −1 at 298 K, which was 6.33 times higher than that of magnetic non-molecularly imprinted nanoparticles (MNINs). The kinetic property of MMINs was well-described by the pseudo-second-order rate equation. The results of selective recognition experiments demonstrated outstanding affinity and selectivity towards TC over competitive antibiotics. The reusability of MMINs showed no obviously deterioration at least five repeated cycles in performance. In addition, the MMINs prepared were successfully applied to the extraction of TC from the spiked pork sample.

Direct Frequency Comb Spectroscopy of Alkali Atoms

Science.gov (United States)

Pradhananga, Trinity; Palm, Christopher; Nguyen, Khoa; Guttikonda, Srikanth; Kimball, Derek Jackson

2011-11-01

We are using direct frequency comb spectroscopy to study transition frequencies and excited state hyperfine structure in potassium and rubidium using 2-photon transitions excited directly with the frequency-doubled output of a erbium fiber optical frequency comb. The frequency comb output is directed in two counterpropagating directions through a vapor cell containing the atomic vapor of interest. A pair of optical filters is used to select teeth of the comb in order to identify the transition wavelengths. A photomultiplier tube (PMT) measures fluorescence from a decay channel wavelength selected with another optical filter. Using different combinations of filters enables a wide range of transitions to be investigated. By scanning the repetition rate, a Doppler-free spectrum can be obtained enabling kHz-resolution spectral measurements. The thermal motion of the atoms in the vapor cell actually eliminates the need to fine-tune the offset frequency and repetition rate, alleviating a somewhat challenging requirement for spectroscopy of cold atoms. Our investigations are laying the groundwork for a long-term research program to use direct frequency comb spectroscopy to understand the complex spectra of rare-earth atoms.

Proceedings of the 10th international topical meeting on nuclear thermal hydraulics, operation and safety (NUTHOS-10)

International Nuclear Information System (INIS)

2014-01-01

The 10th International Topical Meeting on Nuclear Thermal Hydraulics, Operations and Safety (NUTHOS-10) in Okinawa, Japan is sponsored by Atomic Energy Society of Japan, in cooperation with the International Atomic Energy Agency, and co-sponsored by American Nuclear Society Thermal Hydraulics Division among others. Enhanced safety and reducing cost are going together, which can be achieved through continued research and development efforts. NUTHOS keeps you abreast of the most updated information in the advancement of science and technology in nuclear thermal hydraulics, operations and safety, and provides you insights into the future. (J.P.N.)

The quantum beat principles and applications of atomic clocks

CERN Document Server

Major, F

2007-01-01

This work attempts to convey a broad understanding of the physical principles underlying the workings of these quantum-based atomic clocks, with introductory chapters placing them in context with the early development of mechanical clocks and the introduction of electronic time-keeping as embodied in the quartz-controlled clocks. While the book makes no pretense at being a history of atomic clocks, it nevertheless takes a historical perspective in its treatment of the subject. Intended for nonspecialists with some knowledge of physics or engineering, The Quantum Beat covers a wide range of salient topics relevant to atomic clocks, treated in a broad intuitive manner with a minimum of mathematical formalism. Detailed descriptions are given of the design principles of the rubidium, cesium, hydrogen maser, and mercury ion standards; the revolutionary changes that the advent of the laser has made possible, such as laser cooling, optical pumping, the formation of "optical molasses," and the cesium "fountain" stand...

Atomic spectroscopy with diode lasers

International Nuclear Information System (INIS)

Tino, G.M.

1994-01-01

Some applications of semiconductor diode lasers in atomic spectroscopy are discussed by describing different experiments performed with lasers emitting in the visible and in the near-infrared region. I illustrate the results obtained in the investigation of near-infrared transitions of atomic oxygen and of the visible intercombination line of strontium. I also describe how two offset-frequency-locked diode lasers can be used to excite velocity selective Raman transitions in Cs. I discuss the spectral resolution, the accuracy of frequency measurements, and the detection sensitivity achievable with diode lasers. (orig.)

Geometric stability and electronic structure of infinite and finite phosphorus atomic chains

International Nuclear Information System (INIS)

Qiao Jingsi; Zhou Linwei; Ji Wei

2017-01-01

One-dimensional mono- or few-atomic chains were successfully fabricated in a variety of two-dimensional materials, like graphene, BN, and transition metal dichalcogenides, which exhibit striking transport and mechanical properties. However, atomic chains of black phosphorus (BP), an emerging electronic and optoelectronic material, is yet to be investigated. Here, we comprehensively considered the geometry stability of six categories of infinite BP atomic chains, transitions among them, and their electronic structures. These categories include mono- and dual-atomic linear, armchair, and zigzag chains. Each zigzag chain was found to be the most stable in each category with the same chain width. The mono-atomic zigzag chain was predicted as a Dirac semi-metal. In addition, we proposed prototype structures of suspended and supported finite atomic chains. It was found that the zigzag chain is, again, the most stable form and could be transferred from mono-atomic armchair chains. An orientation dependence was revealed for supported armchair chains that they prefer an angle of roughly 35 ° –37 ° perpendicular to the BP edge, corresponding to the [110] direction of the substrate BP sheet. These results may promote successive research on mono- or few-atomic chains of BP and other two-dimensional materials for unveiling their unexplored physical properties. (special topic)

Element selective detection of molecular species applying chromatographic techniques and diode laser atomic absorption spectrometry.

Science.gov (United States)

Kunze, K; Zybin, A; Koch, J; Franzke, J; Miclea, M; Niemax, K

2004-12-01

Tunable diode laser atomic absorption spectroscopy (DLAAS) combined with separation techniques and atomization in plasmas and flames is presented as a powerful method for analysis of molecular species. The analytical figures of merit of the technique are demonstrated by the measurement of Cr(VI) and Mn compounds, as well as molecular species including halogen atoms, hydrogen, carbon and sulfur.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2001-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2000-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

2002-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered include related applied areas, such as atmospheric science, astrophysics, surface physics and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material and detailed descriptions of important recent developments.

Key Concept Identification: A Comprehensive Analysis of Frequency and Topical Graph-Based Approaches

Directory of Open Access Journals (Sweden)

Muhammad Aman

2018-05-01

Full Text Available Automatic key concept extraction from text is the main challenging task in information extraction, information retrieval and digital libraries, ontology learning, and text analysis. The statistical frequency and topical graph-based ranking are the two kinds of potentially powerful and leading unsupervised approaches in this area, devised to address the problem. To utilize the potential of these approaches and improve key concept identification, a comprehensive performance analysis of these approaches on datasets from different domains is needed. The objective of the study presented in this paper is to perform a comprehensive empirical analysis of selected frequency and topical graph-based algorithms for key concept extraction on three different datasets, to identify the major sources of error in these approaches. For experimental analysis, we have selected TF-IDF, KP-Miner and TopicRank. Three major sources of error, i.e., frequency errors, syntactical errors and semantical errors, and the factors that contribute to these errors are identified. Analysis of the results reveals that performance of the selected approaches is significantly degraded by these errors. These findings can help us develop an intelligent solution for key concept extraction in the future.

Current State of Nanomedicines in the Treatment of Topical Infectious Disorders.

Science.gov (United States)

Thakur, Kanika; Sharma, Gajanand; Singh, Bhupinder; Chhibber, Sanjay; Katare, Om Prakash

2018-05-28

Topical infections, involving a number of diseases such as impetigo, eczema, pustular acne, psoriasis and infected seborrheic dermatitis are one among the many challenges to health which stand out for their profound impact on human species. The treatment of topical infections has always been a difficult proposition because of the lack of efficacy of existing anti-infectives, longer period of treatment and yet incomplete recovery. The increasing emergence of antibiotic resistant bacterial strains like Staphylococcus aureus, Methicillin-Resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa undermine the need of development of new delivery systems to enhance the therapeutic efficacy of existing topical anti-infectives. The application of nanotechnology to medicine, or nanomedicine, is rapidly becoming a major driving force behind ongoing changes in the anti-infective field because of its interaction at the sub-atomic level with the skin tissue. The latter, in the current scenario, points towards vesicular carriers like liposomes, lipidic nanoparticles and silver nanoparticles etc. as the most promising drug delivery solutions for topical infection disorders. These have exhibited immense significance owing to their uniqueness to facilitate the interactions at interfaces with the barrier membranes. The present review summarizes the emerging efforts in combating topical infections particularly using nanomedicine based delivery systems as new tools to tackle the current challenges in treating infectious diseases. Besides, compiling various research reports, this article also includes formulation considerations, mechanisms of penetration and patents reported. Despite the new emerging technologies and delivery systems, efforts are still needed in the right direction to combat this global challenge. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Les Houches Summer School of Theoretical Physics : Session 72, Coherent Atomic Matter Waves

CERN Document Server

Westbrook, C; David, F; Coherent Atomic Matter Waves

2001-01-01

Progress in atomic physics has been so vigorous during the past decade that one is hard pressed to follow all the new developments. In the early 1990s the first atom interferometers opened a new field in which we have been able to use the wave nature of atoms to probe fundamental quantum me chanics questions as well as to make precision measurements. Coming fast on the heels of this development was the demonstration of Bose Einstein condensation in dilute atomic vapors which intensified research interest in studying the wave nature of matter, especially in a domain in which "macro scopic" quantum effects (vortices, stimulated scattering of atomic beams) are visible. At the same time there has been much progress in our understanding of the behavior of waves (notably electromagnetic) in complex media, both periodic and disordered. An obvious topic of speculation and probably of future research is whether any new insight or applications will develop if one examines the behavior of de Broglie waves in ana...

Beams made of twisted atoms: A theoretical analysis

Energy Technology Data Exchange (ETDEWEB)

Hayrapetyan, Armen [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, 69120 Heidelberg (Germany); Matula, Oliver [Physikalisches Institut, Ruprecht-Karls-Universitaet Heidelberg, 69120 Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Surzhykov, Andrey [Helmholtz-Institut Jena, 07743 Jena (Germany); Fritzsche, Stephan [Helmholtz-Institut Jena, 07743 Jena (Germany); Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universitaet Jena, 07743 Jena (Germany)

2014-07-01

We have analyzed Bessel beams of two-level atoms that are driven by a linearly polarized laser light. Based on the Schroedinger equation for two-level systems, we first determine the states of two-level atoms in a plane-wave field by taking into account propagation directions both of the atom and the field. For such laser-driven two-level atoms, we construct Bessel beams by going beyond the typical paraxial approximation. In particular, we show that the probability density of these atomic beams exhibits a non-trivial, Bessel-squared-type behavior. The profile of such twisted atoms is affected by atom and laser parameters, such as the nuclear charge, atom velocity, laser frequency, and propagation geometry of the atom and laser beams. Moreover, we spatially and temporally characterize the beam of hydrogen and selected (neutral) alkali-metal atoms that carry non-zero orbital angular momentum (OAM). The proposed spatiotemporal Bessel states (i) are able to describe twisted states of any two-level system which is driven by the radiation field and (ii) have potential applications in atomic and nuclear processes as well as in quantum communication.

Resonance absorption spectroscopy for laser-ablated lanthanide atom. (1) Optimized experimental conditions for isotope-selective absorption of gadolinium (Contract research)

International Nuclear Information System (INIS)

Miyabe, Masabumi; Oba, Masaki; Iimura, Hideki; Akaoka, Katsuaki; Maruyama, Yoichiro; Wakaida, Ikuo; Watanabe, Kazuo

2008-06-01

For remote isotope analysis of low-decontaminated TRU fuel, we are developing an analytical technique on the basis of the resonance absorption spectroscopy for the laser-ablation plume. To improve isotopic selectivity and detection sensitivity of this technique, we measured absorption spectra of Gd atom with various plume production conditions (ablation laser intensity, ambient gas and its pressure) and observation conditions (transition, probe height from sample, observation timing). As a result, high resolution spectrum was obtained from the observation of slow component of the plume produced under low-pressure rare-gas ambient. The observed narrowest linewidth of about 0.85GHz was found to be close to the Doppler width estimated for Gd atom of room temperature. Furthermore, relaxation rate of higher meta-stable state was found to be higher than that of ground state, suggesting that use of the transition arising from ground state or lower meta-stable state is preferable for highly sensitive isotope analysis. (author)

Diphenylcyclopropenone in patients with alopecia areata. A critically appraised topic

NARCIS (Netherlands)

Kuin, R. A.; Spuls, P. I.; Limpens, J.; van Zuuren, E. J.

2015-01-01

To assess the efficacy and safety of topical diphenylcyclopropenone (DPCP) in patients with alopecia areata. Study selection, data extraction, risk of bias assessment and analyses were carried out independently by two authors. The quality of evidence was rated with Grading of Recommendations

Atom-surface potentials and atom interferometry

International Nuclear Information System (INIS)

Babb, J.F.

1998-01-01

Long-range atom-surface potentials characterize the physics of many actual systems and are now measurable spectroscopically in deflection of atomic beams in cavities or in reflection of atoms in atomic fountains. For a ground state, spherically symmetric atom the potential varies as -1/R 3 near the wall, where R is the atom-surface distance. For asymptotically large distances the potential is weaker and goes as -1/R 4 due to retardation arising from the finite speed of light. This diminished interaction can also be interpreted as a Casimir effect. The possibility of measuring atom-surface potentials using atomic interferometry is explored. The particular cases studied are the interactions of a ground-state alkali-metal atom and a dielectric or a conducting wall. Accurate descriptions of atom-surface potentials in theories of evanescent-wave atomic mirrors and evanescent wave-guided atoms are also discussed. (author)

Cardiovascular disease among atomic bomb survivors.

Science.gov (United States)

Ozasa, Kotaro; Takahashi, Ikuno; Grant, Eric J; Kodama, Kazunori

2017-10-01

The profile of cardiovascular disease in Japan has been different from that in Western countries. Hypertension was the major cause not only for hemorrhagic stroke but also for ischemic stroke and heart disease in the past, and the influence of hypertension has decreased with calendar years because of reduced salt intake and westernization of lifestyle, and also improved medical care. The health status of atomic bomb survivors has reflected this profile as well as radiation effects. It is also likely that this cohort has been affected by the difficult conditions experienced in the aftermath of the war and atomic bombings. In this article, we tried to make a consistent interpretation of epidemiological findings of atomic bomb radiation effects on cardiovascular disease. Among the atomic bomb survivors, radiation exposure was associated with some cardiovascular diseases that are often associated with hypertension, and dose response appeared to be primarily non-linear among those who were exposed at younger ages. These effects are thought to reflect the nature of whole body irradiation. But, some findings remain inconsistent, possibly because of possible misclassification in death certificate diagnoses in the Life Span Study as well as selected information from the Adult Health Study which was limited to participants, focused on specific outcomes, and gathered in selected periods of follow-up. Therefore, a comprehensive and balanced interpretation of the results from both groups is necessary.

Bremsstrahlung in atom-atom collisions

International Nuclear Information System (INIS)

Amus'ya, M.Y.; Kuchiev, M.Y.; Solov'ev, A.V.

1985-01-01

It is shown that in the collision of a fast atom with a target atom when the frequencies are on the order of the potentials or higher, there arises bremsstrahlung comparable in intensity with the bremsstrahlung emitted by an electron with the same velocity in the field of the target atom. The mechanism by which bremsstrahlung is produced in atom-atom collisions is elucidated. Results of specific calculations of the bremsstrahlung spectra are given for α particles and helium atoms colliding with xenon

Evaluating topic models with stability

CSIR Research Space (South Africa)

De Waal, A

2008-11-01

Full Text Available Topic models are unsupervised techniques that extract likely topics from text corpora, by creating probabilistic word-topic and topic-document associations. Evaluation of topic models is a challenge because (a) topic models are often employed...

Topical report review status

International Nuclear Information System (INIS)

1997-08-01

This report provides industry with procedures for submitting topical reports, guidance on how the U.S. Nuclear Regulatory Commission (NRC) processes and responds to topical report submittals, and an accounting, with review schedules, of all topical reports currently accepted for review schedules, of all topical reports currently accepted for review by the NRC. This report will be published annually. Each sponsoring organization with one or more topical reports accepted for review copies

The study of human organs by phosphorus-31 topical magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Oberhaensli, R.D.; Galloway, G.J.; Hilton-Jones, David; Bore, P.J.; Styles, Peter; Rajagopalan, Bheeshma; Taylor, D.J.; Radda, G.K.

1987-01-01

The potential clinical use of topical magnetic resonance spectroscopy (volume selection by static magnetic field gradients) was tested in 50 studies in volunteers. Topical magnetic resonance spectroscopy (MRS) was shown to be a straightforward method for localising 31 P spectra of brain and liver. However, the spherical shape and fixed position of the selected volume posed serious limitations to the study of heart and transplanted kidney by topical MRS. Phosphorus-31 spectra of approx. 30 cm -3 of brain or liver could be obtained in 8 min. Ratios of metabolite concentrations could be determined with a coefficient of variation ranging from 10% to 30%. The ratios of phosphocreatine/ATP and inorganic phosphate/ATP in brain were 1.8 and 0.3, respectively. The ratio of inorganic phosphate/ATP in liver was 0.9. Intracellular pH was 7.03 in brain and 7.24 in liver. The T 1 relaxation times of phosphocreatine, inorganic phosphate and γ-ATP in brain were 4.8 s, 2.5 s and 1.0 s, respectively. (author)

Preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization for the selective recognition of tetracycline from aqueous medium

Energy Technology Data Exchange (ETDEWEB)

Dai, Jiangdong; Pan, Jianming; Xu, Longcheng; Li, Xiuxiu [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhou, Zhiping [School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Zhang, Rongxian [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Yan, Yongsheng, E-mail: djdxxx123@163.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100191 (China)

2012-02-29

Highlights: Black-Right-Pointing-Pointer Atom transfer radical emulsion polymerization is a 'living' and green technique. Black-Right-Pointing-Pointer Nanoparticles can overcome mass transfer limitations and improve accessibility. Black-Right-Pointing-Pointer Molecular imprinted nanoparticles with magnetic property for fast separation. Black-Right-Pointing-Pointer The performance of imprinted nanoparticles was investigated in detail. Black-Right-Pointing-Pointer Nanoparticles were used to selective recognize Tetracycline from water medium. - Abstract: In the work, we reported an effective method for the preparation of molecularly imprinted nanoparticles with superparamagnetic susceptibility through atom transfer radical emulsion polymerization (ATREP), and then as-prepared magnetic molecularly imprinted nanoparticles (MMINs) were evaluated as adsorbents for selective recognition of tetracycline (TC) molecules from aqueous medium. The resulting nanoparticles were characterized by FT-IR, TGA, VSM, SEM and TEM. The results demonstrated MMINs with a narrow diameter distribution were cross-linked with modified Fe{sub 3}O{sub 4} particles, composed of imprinted layer and exhibited good magnetic sensitivity, magnetic and thermal stability. Batch rebinding studies were carried out to determine the specific adsorption equilibrium, kinetics, and selective recognition. The estimated adsorption capacity of MMINs towards TC by the Langmuir isotherm model was 12.10 mg g{sup -1} at 298 K, which was 6.33 times higher than that of magnetic non-molecularly imprinted nanoparticles (MNINs). The kinetic property of MMINs was well-described by the pseudo-second-order rate equation. The results of selective recognition experiments demonstrated outstanding affinity and selectivity towards TC over competitive antibiotics. The reusability of MMINs showed no obviously deterioration at least five repeated cycles in performance. In addition, the MMINs prepared were successfully

The International Atomic Energy Agency - Organization, Work and Services in Selected Fields

International Nuclear Information System (INIS)

Köteles, G.J.

1979-01-01

In an address to the 8th General Assembly of the United Nations (1953) the President of the United States suggested that Governments should begin to make joint contributions from their stockpiles of fissile materials to an international atomic energy agency which would be set up under the aegis of the United Nations. The fissile material so collected would be used to serve the peaceful pursuits of mankind. Experts would be mobilized to apply atomic energy to the needs of agriculture, medicine and other peaceful purposes and a special effort would be made to provide abundant electrical energy in the power-starved areas of the world. This suggestion was taken up. A Statute which defines the structure and purpose of the International Atomic Energy Agency (IAEA) was prepared by a group of nations and approved by a conference at the United Nations Headquarters in 1956. The Statute entered into force on 29 July 1957. The Agency's objectives, as defined in its Statute, are that it ''shall seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world. It shall ensure, as far as it is able, that assistance provided by it or at its request or under its supervision or control is not used in such a way as to further any military purpose''. To attain these objectives, the IAEA is authorized ''to encourage and assist research on, and development and practical application of, atomic energy for peaceful uses throughout the world; and, if requested to do so, to act as an intermediary for the purposes of securing the performance of services or the supplying of materials, equipment, or facilities by one member of the Agency for another''; to ''... assemble and make available in an accessible form the [scientific] information made available to it...'' and furthermore ''to make provision, ... for materials, services, equipment, and facilities to meet the

Italian Mass Media and the Atom in the 1960s: The Memory of Hiroshima and Nagasaki and the Peaceful Atom (1963-1967)

International Nuclear Information System (INIS)

Ciglioni, Laura

2017-01-01

The chapter investigates the representations of both fears and hopes related to atomic issues in Italian mass media from 1963 to 1967, through the analysis of a selection of highly circulated mass-market magazines (representing a broad spectrum of political cultures) and of television programs broadcast by the two Italian public networks of the time. The fears of the “atomic age” are analyzed through the memory of Hiroshima and Nagasaki, which represents one of the privileged venues for both molding representations of the atomic bomb and negotiating fears. “Atomic hopes” are investigated, instead, examining the emergent fascination for the peaceful uses of atomic energy, analyzed as the catalyst for a positive perception of the atom at a time when national energy policies were at a crucial turning point.

Follicular and percutaneous penetration pathways of topically applied minoxidil foam.

Science.gov (United States)

Blume-Peytavi, Ulrike; Massoudy, Lida; Patzelt, Alexa; Lademann, Jürgen; Dietz, Ekkehart; Rasulev, Utkur; Garcia Bartels, Natalie

2010-11-01

In the past, it was assumed that the intercellular route was the only relevant penetration pathway for topically applied substances. Recent results on follicular penetration emphasize that the hair follicles represent a highly relevant and efficient penetration pathway and reservoir for topically applied substances. This study investigates a selective closure technique of hair follicle orifices in vivo assessing interfollicular and follicular absorption rates of topical minoxidil foam in humans. In delimited skin area, single hair orifices or interfollicular skin were blocked with a microdrop of special varnish-wax-mixture in vivo. Minoxidil foam (5%) was topically applied, and transcutaneous absorption was measured by a new surface ionization mass spectrometry technique in serum. Different settings (open, closed or none of both) enabled to clearly distinguish between interfollicular and follicular penetration of the topically applied minoxidil foam. Five minutes after topical application, minoxidil was detected in blood samples when follicles remained open, whereas with closed follicles 30 min were needed. Highest levels were found first when both pathways were open, followed by open follicles and subsequently by closed follicles. These results demonstrate the high importance of the follicular penetration pathway. Hair follicles are surrounded by a dense network of blood capillaries and dendritic cells and have stem cells in their immediate vicinity, making them ideal targets for drug delivery. Copyright © 2010 Elsevier B.V. All rights reserved.

Advances in atomic, molecular, and optical physics

CERN Document Server

Walther, Herbert; Walther, Herbert

1998-01-01

This series, established in 1965, is concerned with recent developments in the general area of atomic, molecular, and optical physics. The field is in a state of rapid growth, as new experimental and theoretical techniques are used on many old and new problems. Topics covered also include related applied areas, such as atmospheric science, astrophysics, surface physics, and laser physics. Articles are written by distinguished experts who are active in their research fields. The articles contain both relevant review material as well as detailed descriptions of important recent developments.

Pump-probe experiments in atoms involving laser and synchrotron radiation: an overview

International Nuclear Information System (INIS)

Wuilleumier, F J; Meyer, M

2006-01-01

The combined use of laser and synchrotron radiations for atomic photoionization studies started in the early 1980s. The strong potential of these pump-probe experiments to gain information on excited atomic states is illustrated through some exemplary studies. The first series of experiments carried out with the early synchrotron sources, from 1960 to about 1995, are reviewed, including photoionization of unpolarized and polarized excited atoms, and time-resolved laser-synchrotron studies. With the most advanced generation of synchrotron sources, a whole new class of pump-probe experiments benefiting from the high brightness of the new synchrotron beams has been developed since 1996. A detailed review of these studies as well as possible future applications of pump-probe experiments using third generation synchrotron sources and free electron lasers is presented. (topical review)

Etodolac Containing Topical Niosomal Gel: Formulation Development and Evaluation

Directory of Open Access Journals (Sweden)

Gyati Shilakari Asthana

2016-01-01

Full Text Available The present study aimed to investigate the delivery potential of Etodolac (ETD containing topical niosomal gel. Niosomal formulations were prepared by thin film hydration method at various ratios of cholesterol and Span 60 and were evaluated with respect to particle size, shape, entrapment efficiency, and in vitro characteristics. Dicetyl phosphate (DCP was also added in the niosomal formulation. Mean particle size of niosomal formulation was found to be in the range of 2 μm to 4 μm. Niosomal formulation N2 (1 : 1 ratio of cholesterol and surfactant displayed good entrapment efficiency (96.72%. TEM analyses showed that niosomal formulation was spherical in shape. Niosomal formulation (N2 displayed high percentage of drug release after 24 h (94.91 at (1 : 1 ratio of cholesterol : surfactant. Further selected niosomal formulation was used to formulate topical gel and was characterized with respect to its various parameters such as pH, viscosity, spreadability, ex vivo study, and in vivo potential permeation. Ex vivo study showed that niosomal gel possessed better skin permeation study than the plain topical gel. Further in vivo study revealed good inhibition of inflammation in case of topical niosomal gel than plain gel and niosomal formulation. The present study suggested that topical niosomal gel formulations provide sustained and prolonged delivery of drug.

Syntacticized topics in Kurmuk

DEFF Research Database (Denmark)

Andersen, Torben

2015-01-01

This article argues that Kurmuk, a little-described Western Nilotic language, is characterized by a syntacticized topic whose grammatical relation is variable. In this language, declarative clauses have as topic an obligatory preverbal NP which is either a subject, an object or an adjunct....... The grammatical relation of the topic is expressed by a voice-like inflection of the verb, here called orientation. While subject-orientation is morphologically unmarked, object-oriented and adjunct-oriented verbs are marked by a subject suffix or by a suffix indicating that the topic is not subject, and adjunct......-orientation differs from object-orientation by a marked tone pattern. Topic choice largely reflects information structure by indicating topic continuity. The topic also plays a crucial role in relative clauses and in clauses with contrastive constituent focus, in that objects and adjuncts can only be relativized...

Atomic structure calculations using the relativistic random phase approximation

International Nuclear Information System (INIS)

Cheng, K.T.; Johnson, W.R.

1981-01-01

A brief review is given for the relativistic random phase approximation (RRPA) applied to atomic transition problems. Selected examples of RRPA calculations on discrete excitations and photoionization are given to illustrate the need of relativistic many-body theories in dealing with atomic processes where both relativity and correlation are important

Proceedings of the international conference on selected topics in quantum field theory and mathematical physics

Energy Technology Data Exchange (ETDEWEB)

Niederle, J; Bednar, M; Bicak, J

1987-01-01

The conference, the fourth in the series of conferences on this subject, was held at the Bechyne castle (Czechoslovakia) on June 23-27, 1986, and was attended by about 100 theoreticians from 15 countries. The conference was organized by the Institute of Physics of the Czechoslovak Academy of Sciences in Prague together with the Faculties of Mathematics and Physics of the Charles University, Prague, and of the Comenius University, Bratislava, the Faculty of Nuclear Science and Physical Engineering of the Czech Techical University, Prague, with the Institute of Physics of the Electro-Physical Research Centre of the Slovak Academy of Sciences, Bratislava, and the Institute of Nuclear Physics of the Czechoslovak Academy of Sciences in Rez. It was sponsored by the International Union for Pure and Applied Physics, the International Association of Mathematical Physics and the Physical Scientific Section of the Union of Czechoslovak Mathematicians and Physicists. The main subjects discussed at the conference were: supersymmetries, supergravity and superstring theories; quantum field theory and in particular gauge theories, theories on lattices, renormalization; selected topics in non-linear equations, scattering theory and quantization. Details are given in the attached program. The proceedings include invited talks and contributions presented respectively at the morning and afternoon sessions of the conference. The main part of the proceedings will be published in the Czechoslovak Journal of Physics v. 37(1987), nos. 3,4 and 9.

Proceedings of the international conference on selected topics in quantum field theory and mathematical physics

International Nuclear Information System (INIS)

Niederle, J.; Bednar, M.; Bicak, J.

1987-01-01

The conference, the fourth in the series of conferences on this subject, was held at the Bechyne castle (Czechoslovakia) on June 23-27, 1986, and was attended by about 100 theoreticians from 15 countries. The conference was organized by the Institute of Physics of the Czechoslovak Academy of Sciences in Prague together with the Faculties of Mathematics and Physics of the Charles University, Prague, and of the Comenius University, Bratislava, the Faculty of Nuclear Science and Physical Engineering of the Czech Techical University, Prague, with the Institute of Physics of the Electro-Physical Research Centre of the Slovak Academy of Sciences, Bratislava, and the Institute of Nuclear Physics of the Czechoslovak Academy of Sciences in Rez. It was sponsored by the International Union for Pure and Applied Physics, the International Association of Mathematical Physics and the Physical Scientific Section of the Union of Czechoslovak Mathematicians and Physicists. The main subjects discussed at the conference were: supersymmetries, supergravity and superstring theories; quantum field theory and in particular gauge theories, theories on lattices, renormalization; selected topics in non-linear equations, scattering theory and quantization. Details are given in the attached program. The proceedings include invited talks and contributions presented respectively at the morning and afternoon sessions of the conference. The main part of the proceedings will be published in the Czechoslovak Journal of Physics v. 37(1987), nos. 3,4 and 9. (author)

International Bulletin on Atomic and Molecular Data for Fusion. No. 31

International Nuclear Information System (INIS)

Hughes, J.G.

1985-12-01

This bulletin presents a selected bibliography (363 literature pieces) on atomic and molecular data for fusion. It also gives a list of indexed papers on structure and spectra, atomic and molecular collisions, and surface interactions

Noninterferometric phase imaging of a neutral atomic beam

International Nuclear Information System (INIS)

Fox, P.J.; Mackin, T.R.; Turner, L.D.; Colton, I.; Nugent, K.A.; Scholten, R.E.

2002-01-01

We demonstrate quantitative phase imaging of a neutral atomic beam by using a noninterferometric technique. A collimated thermal atomic beam is phase shifted by an off-resonant traveling laser beam with both a Gaussian and a TEM 01 profile and with both red and blue detuning of as much as 50 GHz. Phase variations of more than 1000 rad were recovered from velocity-selective measurements of the propagation of the atomic beam and were found to be in quantitative agreement with theoretical predictions based on independently measured phase object intensity profiles and detunings

Manipulation of single neutral atoms in optical lattices

International Nuclear Information System (INIS)

Zhang Chuanwei; Das Sarma, S.; Rolston, S. L.

2006-01-01

We analyze a scheme to manipulate quantum states of neutral atoms at individual sites of optical lattices using focused laser beams. Spatial distributions of focused laser intensities induce position-dependent energy shifts of hyperfine states, which, combined with microwave radiation, allow selective manipulation of quantum states of individual target atoms. We show that various errors in the manipulation process are suppressed below 10 -4 with properly chosen microwave pulse sequences and laser parameters. A similar idea is also applied to measure quantum states of single atoms in optical lattices

Progress of highly charged atomic physics at IMP

International Nuclear Information System (INIS)

Ma, X; Zhu, X L; Liu, H P; Li, B; Wei, B R; Sha, S; Cao, S P; Chen, L F; Zhang, S F; Feng, W T; Zhang, D C; Qian, D B

2007-01-01

The progress of atomic physics researches at the Institute of Modern Physics (IMP) is reviewed, covering the studies on ion-atom/molecule collisions, ion-cluster interaction, negative ion formation, state-selective electron capture studied by COLTRIMS, as well as the progress of a new experimental area dedicated for atomic researches at moderate energies, and the advances of the cooler storage rings at the Heavy Ion Research Facility in Lanzhou (HIRFL). New opportunities to study collision dynamics from femto-second to atto-second regime are opened based on the present facilities and the on-going projects

Culture-Related Topic Selection in Small Talk Conversations across Germany and Japan

DEFF Research Database (Denmark)

Endrass, Birgit; Nakano, Yukiko; Lipi, Afia Akhter

2011-01-01

Small talk can be used in order to build a positive relationship towards a virtual character. However the choice of topics in a conversation can be dependent on social backgrounds such as culture. In this paper, we explore culture-related differences in small talk for the German and Japanese...... cultures. Based on findings from the literature and verified by a corpus analysis, we integrated prototypical German and Japanese small talk conversations into a multiagent system. In evaluation studies conducted in the two target cultures, we investigated whether participants prefer agent dialogs...

Development of atomic spectroscopy technology

International Nuclear Information System (INIS)

Lee, Jong Min; Cha, Hyung Ki; Song, Kyu Seok; Yang, Ki Ho; Baik, Dae Hyun; Lee, Young Joo; Yi, Jong Hoon; Jeong, Do Young; Jeong, Eui Chang; Yoo, Byung Duk; Cha, Byung Heon; Kim, Seong Ho; Nam, Seong Mo; Kim, Sun Kuk; Lee, Byung Cheol; Choi, Hwa Lim; Ko, Dok Yung; Han, Jae Min; Rho, Si Pyo; Lim, Chang Hwan; Choi, An Seong

1992-12-01

This project is aimed for the 'Development of extraction and separation techniques for stable isotopes by atomic laser spectroscopy technique'. The project is devided by two sub-projects. One is the 'Development of the selective photoionization technology' and the other is 'Development of ultrasensitive spectroscopic analysis technololgy'. This year studies on Hg and Yb, both of which have 7 isotopes, have been performed and, as a result, it was proved that specific isotopes of these elements could be selectively extracted. In addition study on plasma extraction technique, development of atomizers, design of electron gun have been the result of the project in 1992. In second sub-project trace determination of Pb has been performed with laser resonance ionization spectroscopy. As a result 20 picogram of detection limit has been obtained. In addition to these results, design of high sensitive laser induced fluorescence detection system as well as remote sensing DIAL system have been done. (Author)

PREFACE: International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS2014)

Science.gov (United States)

Ancarani, Lorenzo Ugo

2015-04-01

This volume contains a collection of contributions from the invited speakers at the 2014 edition of the International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces held in Metz, France, from 15th to 18th July 2014. This biennial conference alternates with the ICPEAC satellite International Symposium on (e,2e), Double Photoionization and Related Topics, and is concerned with experimental and theoretical studies of radiation interactions with matter. These include many-body and electron-electron correlation effects in excitation, and in single and multiple ionization of atoms, molecules, clusters and surfaces with various projectiles: electrons, photons and ions. More than 80 scientists, from 19 different countries around the world, came together to discuss the most recent progress on these topics. The scientific programme included 28 invited talks and a poster session extending over the three days of the meeting. Amongst the 51 posters, 11 have been selected and were advertised through short talks. Besides, Professor Nora Berrah gave a talk in memory of Professor Uwe Becker who sadly passed away shortly after co-chairing the previous edition of this conference. Financial support from the Institut Jean Barriol, Laboratoire SRSMC, Groupement de Recherche THEMS (CNRS), Ville de Metz, Metz Métropole, Conseil Général de la Moselle and Région Lorraine is gratefully acknowledged. Finally, I would like to thank the members of the local committee and the staff of the Université de Lorraine for making the conference run smoothly, the International Advisory Board for building up the scientific programme, the sessions chairpersons, those who gave their valuable time in carefully refereeing the articles of this volume and last, but not least, all participants for contributing to lively and fruitful discussions throughout the meeting.

Atoms, molecules and optical physics 1. Atoms and spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Hertel, Ingolf V.; Schulz, Claus-Peter

2015-09-01

This is the first volume of textbooks on atomic, molecular and optical physics, aiming at a comprehensive presentation of this highly productive branch of modern physics as an indispensable basis for many areas in physics and chemistry as well as in state of the art bio- and material-sciences. It primarily addresses advanced students (including PhD students), but in a number of selected subject areas the reader is lead up to the frontiers of present research. Thus even the active scientist is addressed. This volume 1 provides the canonical knowledge in atomic physics together with basics of modern spectroscopy. Starting from the fundamentals of quantum physics, the reader is familiarized in well structured chapters step by step with the most important phenomena, models and measuring techniques. The emphasis is always on the experiment and its interpretation, while the necessary theory is introduced from this perspective in a compact and occasionally somewhat heuristic manner, easy to follow even for beginners.

Topical Drugs for Pain Relief

Directory of Open Access Journals (Sweden)

Anjali Srinivasan

2015-03-01

Full Text Available Topical therapy helps patients with oral and perioral pain problems such as ulcers, burning mouth syndrome, temporomandibular disorders, neuromas, neuropathies and neuralgias. Topical drugs used in the field of dentistry are topical anaesthetics, topical analgesics, topical antibiotics and topical corticosteroids. It provides symptomatic/curative effect. Topical drugs are easy to apply, avoids hepatic first pass metabolism and more sites specific. But it can only be used for medications that require low plasma concentrations to achieve a therapeutic effect.

Steering neutral atoms in strong laser fields

International Nuclear Information System (INIS)

Eilzer, S; Eichmann, U

2014-01-01

The seminal strong-field tunnelling theory introduced by L V Keldysh plays a pivotal role. It has shaped our understanding of atomic strong-field processes, where it represents the first step in complex ionisation dynamics and provides reliable tunnelling rates. Tunnelling rates, however, cannot be necessarily equated with ionisation rates. Taking into account the electron dynamics in the Coulomb potential following the tunnelling process, the process of frustrated tunnelling ionisation has been found to lead to excited Rydberg atoms. Here, we excite He atoms in the strong-field tunnelling regime into Rydberg states. A high percentage of these Rydberg atoms survive in high intensity laser fields. We exploit this fact together with their high polarisability to kinematically manipulate the Rydberg atoms with a second elliptically polarised focused strong laser field. By varying the spatial overlap of the two laser foci, we are able to selectively control the deflection of the Rydberg atoms. The results of semi-classical calculations, which are based on the frustrated tunnelling model and on the ponderomotive acceleration, are in accord with our experimental data. (paper)

Atomic physics at the future facility for antiproton and ion research: status report 2014

International Nuclear Information System (INIS)

Gumberidze, A; Stöhlker, Th; Litvinov, Yu A

2015-01-01

In this contribution, a brief overview of the Stored Particle Atomic physics Research Collaboration scientific program at the upcoming Facility for Antiproton and Ion Research (FAIR) is given. The program comprises a very broad range of research topics addressing atomic structure and dynamics in hitherto unexplored regimes, light–matter interactions, lepton pair production phenomena, precision tests of quantum electrodynamics and standard model in the regime of extreme fields and many more. We also present the current strategy for the realization of the envisioned physics program within the modularized start version (MSV) of FAIR. (paper)

Application of Delaunay tessellation for the characterization of solute-rich clusters in atom probe tomography

International Nuclear Information System (INIS)

Lefebvre, W.; Philippe, T.; Vurpillot, F.

2011-01-01

This work presents an original method for cluster selection in Atom Probe Tomography designed to be applied to large datasets. It is based on the calculation of the Delaunay tessellation generated by the distribution of atoms of a selected element. It requires a single input parameter from the user. Furthermore, no prior knowledge of the material is needed. The sensitivity of the proposed Delaunay cluster selection is demonstrated by its application on simulated APT datasets. A strong advantage of the proposed methodology is that it is reinforced by the availability of an analytical model for the distribution of Delaunay cells circumspheres, which is used to control the accuracy of the cluster selection procedure. Another advantage of the Delaunay cluster selection is the direct calculation of a sharp envelope for each identified cluster or precipitate, which leads to the more appropriate morphology of the objects as they are reconstructed in the APT dataset. -- Research Highligthts: →Original method for cluster selection in Atom Probe Tomography. →Delaunay tessellation generated by the distribution of solute atoms. →Direct calculation of a sharp envelope for each identified cluster or precipitate. →Delaunay cluster selection demonstrated by its application on simulated APT datasets.

Dialect topic modeling for improved consumer medical search.

Science.gov (United States)

Crain, Steven P; Yang, Shuang-Hong; Zha, Hongyuan; Jiao, Yu

2010-11-13

Access to health information by consumers is hampered by a fundamental language gap. Current attempts to close the gap leverage consumer oriented health information, which does not, however, have good coverage of slang medical terminology. In this paper, we present a Bayesian model to automatically align documents with different dialects (slang, common and technical) while extracting their semantic topics. The proposed diaTM model enables effective information retrieval, even when the query contains slang words, by explicitly modeling the mixtures of dialects in documents and the joint influence of dialects and topics on word selection. Simulations using consumer questions to retrieve medical information from a corpus of medical documents show that diaTM achieves a 25% improvement in information retrieval relevance by nDCG@5 over an LDA baseline.

Dialect Topic Modeling for Improved Consumer Medical Search

Energy Technology Data Exchange (ETDEWEB)

Crain, Steven P. [Georgia Institute of Technology; Yang, Shuang-Hong [Georgia Institute of Technology; Zha, Hongyuan [Georgia Institute of Technology; Jiao, Yu [ORNL

2010-01-01

Access to health information by consumers is ham- pered by a fundamental language gap. Current attempts to close the gap leverage consumer oriented health information, which does not, however, have good coverage of slang medical terminology. In this paper, we present a Bayesian model to automatically align documents with different dialects (slang, com- mon and technical) while extracting their semantic topics. The proposed diaTM model enables effective information retrieval, even when the query contains slang words, by explicitly modeling the mixtures of dialects in documents and the joint influence of dialects and topics on word selection. Simulations us- ing consumer questions to retrieve medical information from a corpus of medical documents show that diaTM achieves a 25% improvement in information retrieval relevance by nDCG@5 over an LDA baseline.

Pre-Service Physics Teachers' Ideas on Size, Visibility and Structure of the Atom

Science.gov (United States)

Unlu, Pervin

2010-01-01

Understanding the atom gives the opportunity to both understand and conceptually unify the various domains of science, such as physics, chemistry, biology, astronomy and geology. Among these disciplines, physics teachers are expected to be particularly well educated in this topic. It is important that pre-service physics teachers know what sort of…

Laser-assisted atom-atom collisions

International Nuclear Information System (INIS)

Roussel, F.

1984-01-01

The basic layer-assisted atom-atom collision processes are reviewed in order to get a simpler picture of the main physical facts. The processes can be separated into two groups: optical collisions where only one atom is changing state during the collision, the other acting as a spectator atom, and radiative collisions where the states of the two atoms are changing during the collision. All the processes can be interpreted in terms of photoexcitation of the quasimolecule formed during the collisional process. (author)

Selected Research and Development Topics on Aerospace Communications at NASA Glenn Research Center

Science.gov (United States)

Miranda, Felix A.; Romanofsky, Robert R.; Nessel, James A.

2014-01-01

This presentation discusses some of the efforts on communications RD that have been performed or are currently underway at NASA Glenn Research Center. The primary purpose of this presentation is to outline some RD topics to serve as talking points for a Technical Interchange Meeting with the Ohio State University. The meeting is scheduled to take place at The ElectroScience Laboratory of the Ohio State University on February 24, 2014.

Documenting and predicting topic changes in Computers in Biology and Medicine: A bibliometric keyword analysis from 1990 to 2017

Directory of Open Access Journals (Sweden)

Oliver Faust

Full Text Available The Computers in Biology and Medicine (CBM journal promotes the use of computing machinery in the fields of bioscience and medicine. Since the first volume in 1970, the importance of computers in these fields has grown dramatically, this is evident in the diversification of topics and an increase in the publication rate. In this study, we quantify both change and diversification of topics covered in. This is done by analysing the author supplied keywords, since they were electronically captured in 1990. The analysis starts by selecting 40 keywords, related to Medical (M (7, Data (D (10, Feature (F (17 and (AI (6 methods. Automated keyword clustering shows the statistical connection between the selected keywords. We found that the three most popular topics in CBM are: Support Vector Machine (SVM, Electroencephalography (EEG and IMAGE PROCESSING. In a separate analysis step, we bagged the selected keywords into sequential one year time slices and calculated the normalized appearance. The results were visualised with graphs that indicate the CBM topic changes. These graphs show that there was a transition from Artificial Neural Network (ANN to SVM. In 2006 SVM replaced ANN as the most important AI algorithm. Our investigation helps the editorial board to manage and embrace topic change. Furthermore, our analysis is interesting for the general reader, as the results can help them to adjust their research directions. Keywords: Research trends, Topic analysis, Topic detection and tracking, Text mining, Computers in biology and medicine

Understanding ensemble protein folding at atomic detail

International Nuclear Information System (INIS)

Wallin, Stefan; Shakhnovich, Eugene I

2008-01-01

Although far from routine, simulating the folding of specific short protein chains on the computer, at a detailed atomic level, is starting to become a reality. This remarkable progress, which has been made over the last decade or so, allows a fundamental aspect of the protein folding process to be addressed, namely its statistical nature. In order to make quantitative comparisons with experimental kinetic data a complete ensemble view of folding must be achieved, with key observables averaged over the large number of microscopically different folding trajectories available to a protein chain. Here we review recent advances in atomic-level protein folding simulations and the new insight provided by them into the protein folding process. An important element in understanding ensemble folding kinetics are methods for analyzing many separate folding trajectories, and we discuss techniques developed to condense the large amount of information contained in an ensemble of trajectories into a manageable picture of the folding process. (topical review)

Clock Technology Development for the Laser Cooling and Atomic Physics (LCAP) Program

Science.gov (United States)

Klipstein, W. M.; Thompson, R. J.; Seidel, D. J.; Kohel, J.; Maleki, L.

1998-01-01

The Time and Frequency Sciences and Technology Group at Jet Propulsion Laboratory (JPL) has developed a laser cooling capability for flight and has been selected by NASA to support the Laser-Cooling and Atomic Physics (LCAP) program. Current work in the group includes design and development for tee two laser-cooled atomic clock experiments which have been selected for flight on the International Space Station.

Conference proceedings on X84 International Conference on X-ray and Inner-Shell Processes in Atoms, Molecules and Solids

International Nuclear Information System (INIS)

Meisel, A.; Finster, J.

1984-01-01

The proceedings contain 46 lectures and contributions presented at the 1984 conference. Topics of the conference were ion-atom collisions, inner-shell ionization phenomena, X-ray spectroscopy and electron spectroscopy

Probing Single Pt Atoms in Complex Intermetallic Al13Fe4.

Science.gov (United States)

Yamada, Tsunetomo; Kojima, Takayuki; Abe, Eiji; Kameoka, Satoshi; Murakami, Yumi; Gille, Peter; Tsai, An Pang

2018-03-21

The atomic structure of a 0.2 atom % Pt-doped complex metallic alloy, monoclinic Al 13 Fe 4 , was investigated using a single crystal prepared by the Czochralski method. High-angle annular dark-field scanning transmission electron microscopy showed that the Pt atoms were dispersed as single atoms and substituted at Fe sites in Al 13 Fe 4 . Single-crystal X-ray structural analysis revealed that the Pt atoms preferentially substitute at Fe(1). Unlike those that have been reported, Pt single atoms in the surface layers showed lower activity and selectivity than those of Al 2 Pt and bulk Pt for propyne hydrogenation, indicating that the active state of a given single-atom Pt site is strongly dominated by the bonding to surrounding Al atoms.

Forbidden atomic transitions driven by an intensity-modulated laser trap.

Science.gov (United States)

Moore, Kaitlin R; Anderson, Sarah E; Raithel, Georg

2015-01-20

Spectroscopy is an essential tool in understanding and manipulating quantum systems, such as atoms and molecules. The model describing spectroscopy includes the multipole-field interaction, which leads to established spectroscopic selection rules, and an interaction that is quadratic in the field, which is not often employed. However, spectroscopy using the quadratic (ponderomotive) interaction promises two significant advantages over spectroscopy using the multipole-field interaction: flexible transition rules and vastly improved spatial addressability of the quantum system. Here we demonstrate ponderomotive spectroscopy by using optical-lattice-trapped Rydberg atoms, pulsating the lattice light and driving a microwave atomic transition that would otherwise be forbidden by established spectroscopic selection rules. This ability to measure frequencies of previously inaccessible transitions makes possible improved determinations of atomic characteristics and constants underlying physics. The spatial resolution of ponderomotive spectroscopy is orders of magnitude better than the transition frequency would suggest, promising single-site addressability in dense particle arrays for quantum computing applications.

The effects of oral and topical corticosteroid in rabbit corneas.

Science.gov (United States)

Araki-Sasaki, Kaoru; Katsuta, Osamu; Mano, Hidetoshi; Nagano, Takashi; Nakamura, Masatsugu

2016-09-05

orally and topically administered corticosteroids on the ocular surface. The data may provide the useful information in selecting the appropriate route of corticosteroid application for the treatment of ocular surface disease.

The contaminated Western Hero and other madness during the Atomic Age; Der verstrahlte Westernheld und anderer Irrsinn aus dem Atomzeitalter

Energy Technology Data Exchange (ETDEWEB)

Herzog, Rudolph

2012-11-01

The book on mad activities during the Atomic Age includes the following topics: The second most hazardous invention in all time; the red bomb; the story on the tactic nuclear war; the contaminated Western hero or how the bomb came to Alaska; swords into plowshares; the apocalypse machine; flying reactors; how safe is safe?; atomic Australia; nuclear medicine on wrong ways; broken arrows.

Identifying biological concepts from a protein-related corpus with a probabilistic topic model

Directory of Open Access Journals (Sweden)

Lu Xinghua

2006-02-01

Full Text Available Abstract Background Biomedical literature, e.g., MEDLINE, contains a wealth of knowledge regarding functions of proteins. Major recurring biological concepts within such text corpora represent the domains of this body of knowledge. The goal of this research is to identify the major biological topics/concepts from a corpus of protein-related MEDLINE© titles and abstracts by applying a probabilistic topic model. Results The latent Dirichlet allocation (LDA model was applied to the corpus. Based on the Bayesian model selection, 300 major topics were extracted from the corpus. The majority of identified topics/concepts was found to be semantically coherent and most represented biological objects or concepts. The identified topics/concepts were further mapped to the controlled vocabulary of the Gene Ontology (GO terms based on mutual information. Conclusion The major and recurring biological concepts within a collection of MEDLINE documents can be extracted by the LDA model. The identified topics/concepts provide parsimonious and semantically-enriched representation of the texts in a semantic space with reduced dimensionality and can be used to index text.

Women: A Select Bibliography.

Science.gov (United States)

Kusnerz, Peggy A., Comp.; Pollack, Ann M., Comp.

This select bibliography lists books, monographs, journals and newsletters which relate to feminism, women's studies, and other perspectives on women. Selections are organized by topic: general, bibliographies, art and literature, biography/autobiography, economics, education, family and marriage, history, politics and sex roles. Also included is…

Photoionisation detection of single 87Rb-atoms using channel electron multipliers

International Nuclear Information System (INIS)

Henkel, Florian Alexander

2011-01-01

Fast and efficient detection of single atoms is a universal requirement concerning modern experiments in atom physics, quantum optics, and precision spectroscopy. In particular for future quantum information and quantum communication technologies, the efficient readout of qubit states encoded in single atoms or ions is an elementary prerequisite. The rapid development in the field of quantum optics and atom optics in the recent years has enabled to prepare individual atoms as quantum memories or arrays of single atoms as qubit registers. With such systems, the implementation of quantum computation or quantum communication protocols seems feasible. This thesis describes a novel detection scheme which enables fast and efficient state analysis of single neutral atoms. The detection scheme is based on photoionisation and consists of two parts: the hyperfine-state selective photoionisation of single atoms and the registration of the generated photoion-electron pairs via two channel electron multipliers (CEMs). In this work, both parts were investigated in two separate experiments. For the first step, a photoionisation probability of p ion =0.991 within an ionisation time of t ion =386 ns is achieved for a single 87 Rb-atom in an optical dipole trap. For the second part, a compact detection system for the ionisation fragments was developed consisting of two opposing CEM detectors. Measurements show that single neutral atoms can be detected via their ionisation fragments with a detection efficiency of η atom =0.991 within a detection time of t det =415.5 ns. In a future combined setup, this will allow the state-selective readout of optically trapped, single neutral 87 Rb-atoms via photoionisation detection with an estimated detection efficiency η=0.982 and a detection time of t tot = 802 ns. Although initially developed for single 87 Rb-atoms, the concept of photoionisation detection is in principle generally applicable to any atomic or molecular species. As efficient

Topical report review status

International Nuclear Information System (INIS)

1982-08-01

A Topical Report Review Status is scheduled to be published semi-annually. The primary purpose of this document is to provide periodic progress reports of on-going topical report reviews, to identify those topical reports for which the Nuclear Regulatory Commission (NRC) staff review has been completed and, to the extent practicable, to provide NRC management with sufficient information regarding the conduct of the topical report program to permit taking whatever actions deemed necessary or appropriate. This document is also intended to be a source of information to NRC Licensing Project Managers and other NRC personnel regarding the status of topical reports which may be referenced in applications for which they have responsibility. This status report is published primarily for internal NRC use in managing the topical report program, but is also used by NRC to advise the industry of report review status

Topical report review status

International Nuclear Information System (INIS)

1983-01-01

A Topical Report Review Status is scheduled to be published semi-annually. The primary purpose of this document is to provide periodic progress reports of on-going topical report reviews, to identify those topical reports for which the Nuclear Regulatory Commission (NRC) staff review has been completed and, to the extent practicable, to provide NRC management with sufficient information regarding the conduct of the topical report program to permit taking whatever actions deemed necessary or appropriate. This document is also intended to be a source of information to NRC Licensing Project Managers and other NRC personnel regarding the status of topical reports which may be referenced in applications for which they have responsibility. This status report is published primarily for internal NRC use in managing the topical report program, but is also used by NRC to advise the industry of report review status

International Bulletin on Atomic and Molecular Data for Fusion. No. 28

International Nuclear Information System (INIS)

Hughes, J.G.

1985-03-01

The bulletin presents a selected bibliography (462 literature pieces) on atomic and molecular data relevant to fusion research and technology. It also gives a list of indexed papers, separately on structure and spectra, atomic and molecular collisions, and surface effects

Animated movies and cartoons in teaching science topics

OpenAIRE

Jeraj, Tina; Susman, Katarina

2016-01-01

Children meet cartoons in their early childhood in their home environment and afterwards also in their school environment. Cartoons and animated movies in teaching process strongly motivates and evoke good learning processes through watching, discussing and active participation in accompanying classroom activities. In this contribution, the survey about the presence of science topics and science sli-ups (errors, in contrary with reality) in selected cartoons is presented. In the research, ten...

Topics in nuclear and radiochemistry for college curricula and high school science programs

Energy Technology Data Exchange (ETDEWEB)

1990-01-01

The concern with the current status and trends of nuclear chemistry and radiochemistry education in academic institutions was addressed in a recent workshop. The 1988 workshop considered the important contributions that scientist with nuclear and radiochemistry backgrounds have made and are continuing to make to other sciences and to various applied fields. Among the areas discussed were environmental studies, life sciences, materials science, separation technology, hot atom chemistry, cosmochemistry, and the rapidly growing field of nuclear medicine. It is intent of the organizer and participants of this symposium entitled Topics in Nuclear and Radiochemistry for College Curricula and High School Science Program'' to provide lecture material on topics related to nuclear and radiochemistry to educators. It is our hope that teachers, who may or may not be familiar with the field, will find this collections of articles useful and incorporate some of them into their lectures.

Topics in nuclear and radiochemistry for college curricula and high school science programs

International Nuclear Information System (INIS)

1990-01-01

The concern with the current status and trends of nuclear chemistry and radiochemistry education in academic institutions was addressed in a recent workshop. The 1988 workshop considered the important contributions that scientist with nuclear and radiochemistry backgrounds have made and are continuing to make to other sciences and to various applied fields. Among the areas discussed were environmental studies, life sciences, materials science, separation technology, hot atom chemistry, cosmochemistry, and the rapidly growing field of nuclear medicine. It is intent of the organizer and participants of this symposium entitled ''Topics in Nuclear and Radiochemistry for College Curricula and High School Science Program'' to provide lecture material on topics related to nuclear and radiochemistry to educators. It is our hope that teachers, who may or may not be familiar with the field, will find this collections of articles useful and incorporate some of them into their lectures

Beef Cattle: Selection and Evaluation.

Science.gov (United States)

Clemson Univ., SC. Vocational Education Media Center.

Designed for secondary vocational agriculture students, this text provides an overview of selecting and evaluating beef cattle in Future Farmers of America livestock judging events. The first of four major sections addresses topics such as the ideal beef animal, selecting steers, selecting breeding animals, studying the animal systematically, and…

75 FR 26647 - Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution

Science.gov (United States)

2010-05-12

.... FDA-2010-N-0002] Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution... are treated with a topical solution of ivermectin. DATES: This rule is effective May 12, 2010. FOR... ANADA 200-340 for PRIVERMECTIN (ivermectin), a topical solution used on cattle to control infestations...

Ion-selective electrode reviews