Preparation of {sup 114m}In low energy conversion electron sources

Energy Technology Data Exchange (ETDEWEB)

Wrede, C., E-mail: wrede@uw.ed [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Filippone, B.W. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Garcia, A.; Harper, G.C. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Lassell, S. [Department of Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Liu, J. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Mendenhall, M.P. [Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Palmer, A.S.C. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Pattie, R.W. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Will, D.I. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Young, A.R. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States)

2011-05-15

Highlights: {yields} Controlled ion implantation of In-113 into thin Al substrate. {yields} Production of In-114m (half life = 50 days) by neutron irradiation. {yields} Use of In-114m as a source of electron lines and continuum for calibrations. {yields} Source reactivation by short neutron irradiation. -- Abstract: The preparation of {sup 114m}In sources of conversion electrons in the energy range 162-190 keV and {beta} continuum with a 1989 keV endpoint via ion implantation of {sup 113}In into Al substrates and subsequent irradiation by thermal and epi-thermal neutrons in a nuclear reactor is described.

Power source system for nuclear fusion

International Nuclear Information System (INIS)

Nakagawa, Satoshi.

1975-01-01

Object: When using an external system power source and an exclusive power source in a power source circuit for supplying power to the coils of a nuclear fusion apparatus, to minimize the capacity of the exclusive power source and provide an economical power source circuit construction. Structure: In the initial stage of the power supply, rectifying means provided in individual blocks are connected in parallel on the AC side, and power is supplied to the coils of the nuclear fusion apparatus from an external system power source with the exclusive power source held in the disconnected state. Further, at an instant when the limit of permissible input is reached, the afore-mentioned parallel circuit consisting of rectifying means is disconnected, while at the same time the exclusive power source is connected to the input side of the rectifying means provided in a block corresponding to the exclusive power source side, thereby supplying power to the coils of the nuclear fusion apparatus from both the external system power source and exclusive power source. (Kamimura, M.)

Advanced scientific computational methods and their applications of nuclear technologies. (1) Overview of scientific computational methods, introduction of continuum simulation methods and their applications (1)

International Nuclear Information System (INIS)

Oka, Yoshiaki; Okuda, Hiroshi

2006-01-01

Scientific computational methods have advanced remarkably with the progress of nuclear development. They have played the role of weft connecting each realm of nuclear engineering and then an introductory course of advanced scientific computational methods and their applications to nuclear technologies were prepared in serial form. This is the first issue showing their overview and introduction of continuum simulation methods. Finite element method as their applications is also reviewed. (T. Tanaka)

Development of nuclear battery using isotope sources

International Nuclear Information System (INIS)

Chang, Won Jun

2004-02-01

Until now, the development of the useful micro electromechanical systems has the problems because previous batteries (solar, chemical, etc) did not satisfy the requirements related to power supply. At this point of time, nuclear battery using isotope sources is rising the solution of this problem. Nuclear battery can provide superior out-put power and lifetime. So a new type of micro power source (nuclear battery) for micro electromechanical systems has been designed and analyzed. In this work, I designed the three parts, isotope source, conversion device, and shielding. I chose suitable sources, and designed semiconductor using the chosen isotope sources. Power is generated by radiation exciting electrons in the semiconductor depletion region. The efficiency of the nuclear battery depends upon the pn-junction. In this study the several conceptual nuclear batteries using radioactive materials are described with pn-junction. And for the safety, I designed the shielding to protect the environment by reducing the kinetic energy of beta particles

On the Nature of Off-limb Flare Continuum Sources Detected by SDO /HMI

Energy Technology Data Exchange (ETDEWEB)

Heinzel, P.; Kašparová, J. [Astronomical Institute, Czech Academy of Sciences, 25165 Ondřejov (Czech Republic); Kleint, L.; Krucker, S., E-mail: pheinzel@asu.cas.cz [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland)

2017-09-20

The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory has provided unique observations of off-limb flare emission. White-light continuum enhancements were detected in the “continuum” channel of the Fe 6173 Å line during the impulsive phase of the observed flares. In this paper we aim to determine which radiation mechanism is responsible for such enhancement being seen above the limb, at chromospheric heights around or below 1000 km. Using a simple analytical approach, we compare two candidate mechanisms, the hydrogen recombination continuum (Paschen) and the Thomson continuum due to scattering of disk radiation on flare electrons. Both mechanisms depend on the electron density, which is typically enhanced during the impulsive phase of a flare as the result of collisional ionization (both thermal and also non-thermal due to electron beams). We conclude that for electron densities higher than 10{sup 12} cm{sup −3}, the Paschen recombination continuum significantly dominates the Thomson scattering continuum and there is some contribution from the hydrogen free–free emission. This is further supported by detailed radiation-hydrodynamical (RHD) simulations of the flare chromosphere heated by the electron beams. We use the RHD code FLARIX to compute the temporal evolution of the flare-heating in a semi-circular loop. The synthesized continuum structure above the limb resembles the off-limb flare structures detected by HMI, namely their height above the limb, as well as the radiation intensity. These results are consistent with recent findings related to hydrogen Balmer continuum enhancements, which were clearly detected in disk flares by the IRIS near-ultraviolet spectrometer.

Plasma instability control toward high fluence, high energy x-ray continuum source

Science.gov (United States)

Poole, Patrick; Kirkwood, Robert; Wilks, Scott; Blue, Brent

2017-10-01

X-ray source development at Omega and NIF seeks to produce powerful radiation with high conversion efficiency for material effects studies in extreme fluence environments. While current K-shell emission sources can achieve tens of kJ on NIF up to 22 keV, the conversion efficiency drops rapidly for higher Z K-alpha energies. Pulsed power devices are efficient generators of MeV bremsstrahlung x-rays but are unable to produce lower energy photons in isolation, and so a capability gap exists for high fluence x-rays in the 30 - 100 keV range. A continuum source under development utilizes instabilities like Stimulated Raman Scattering (SRS) to generate plasma waves that accelerate electrons into high-Z converter walls. Optimizing instabilities using existing knowledge on their elimination will allow sufficiently hot and high yield electron distributions to create a superior bremsstrahlung x-ray source. An Omega experiment has been performed to investigate the optimization of SRS and high energy x-rays using Au hohlraums with parylene inner lining and foam fills, producing 10× greater x-ray yield at 50 keV than conventional direct drive experiments on the facility. Experiment and simulation details on this campaign will be presented. This work was performed under the auspices of the US DoE by LLNL under Contract No. DE-AC52-07NA27344.

Solar radio continuum storms and a breathing magnetic field model. Final report

International Nuclear Information System (INIS)

1975-01-01

Radio noise continuum emissions observed in metric and decametric wave frequencies are, in general, associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. These continuum emission sources, often called type I storm sources, are often associated with type III burst storm activity from metric to hectometric wave frequencies. This storm activity is, therefore, closely connected with the development of these continuum emission sources. It is shown that the S-component emission in microwave frequencies generally precedes, by several days, the emission of these noise continuum storms of lower frequencies. In order for these storms to develop, the growth of sunspot groups into complex types is very important in addition to the increase of the average magnetic field intensity and area of these groups. After giving a review on the theory of these noise continuum storm emissions, a model is briefly considered to explain the relation of the emissions to the storms

Points-Based Safe Path Planning of Continuum Robots

Directory of Open Access Journals (Sweden)

Khuram Shahzad

2015-07-01

Full Text Available Continuum robots exhibit great potential in a number of challenging applications where traditional rigid link robots pose certain limitations, e.g., working in unstructured environments. In order to enable the usage of continuum robots in safety-critical applications, such as surgery and nuclear decontamination, it is extremely important to ensure a safe path for the robot's movement. Existing algorithms for continuum robot path planning have certain limitations that need to be addressed. These include the fact that none of the algorithms provide safety assurance parameters and control for path planning. They are computationally expensive, applicable to a specific type of continuum robots, and mostly they do not incorporate design and kinematics constraints. In this paper, we propose a points-based path planning (PoPP algorithm for continuum robots that computes the path by imposing safety constraints and improves upon the limitations of existing approaches. In the algorithm, we exploit the constant curvature-bending property of continuum robots in their path planning process. The algorithm is computationally efficient and provides a good tradeoff between accuracy and efficiency that can be implemented to enable the safety-critical application of continuum robots. This algorithm also provides information regarding path volume and flexibility in movement. Simulation results confirm that the algorithm possesses promising potential for all types of continuum robots (following the constant curvature-bending property. We believe that this effectively balances the desired safety and efficiency requirements.

Expansion of continuum functions on resonance wave functions and amplitudes

International Nuclear Information System (INIS)

Bang, J.; Gareev, F.A.; Gizzatkulov, M.H.; Goncharov, S.A.

1978-01-01

To overcome difficulties encountered with wave functions of continuum spectrum (for example, in a shell model with continuum) the pole expansion (by the Mittag-Leffler theorem) of wave functions, scattering amplitudes and the Green functions with positive energies are considered. It is shown that resonance functions (the Gamov functions) form a complete set over which the continuum functions could be expanded. The general view of these expansions for final potentials and for the Coulomb repulsion potential are obtained and discussed. It is shown that the application of the method to nuclear structure calculations leads to simple algebraic equations

BCS equations in the continuum

International Nuclear Information System (INIS)

Sandulescu, N.; Liotta, R. J.; Wyss, R.

1998-01-01

The properties of nuclei close to the drip line are significantly influenced by the continuum part of the single-particle spectrum. The main role is played by the resonant states which are largely confined in the region of nuclear potential and therefore stronger coupled with the bound states in an excitation process. Resonant states are also important in the nuclei beyond the drip line. In this case the decay properties of the nucleus can be directly related to the widths of the narrow resonances occupied by the unbound nucleons. The aim of this work is to propose an alternative for evaluating the effect of the resonant part of single-particle spectrum on the pairing correlations calculated within the BCS approximation. We estimated the role of resonances in the case of the isotope 170 Sn. The Resonant-BCS (RBCS) equations are solved for the case of a seniority force. The BCS approximation based on a seniority force cannot be applied in the case of a nucleus immersed in a box if all discrete states simulating the continuum are considered. In such a case the pairing correlations will increase with the number of states in the box. In our case one can still apply a seniority force with RBCS because the effect of the continuum appears here through a finite number of physical resonances, well defined by the given mean field. Because these resonances have a spatial distribution concentrated within the region of the nuclear potential, one expects that the localization probability of nucleons, far out from the nuclear surface, to be small. The gap obtained taking correctly the contribution of resonances, according to RBCS equations, is about 1.3 MeV, while pairing gap calculated only with the bound single-particle spectrum has the value Δ = 1.10 MeV. If we introduce also the resonant states, neglecting completely their widths, the gap will increase to the value Δ = 1.880 MeV. Therefore, one cannot estimate properly the pairing correlations by supplementing the spectrum

High-resolution continuum-source atomic absorption spectrometry: what can we expect?

Directory of Open Access Journals (Sweden)

Welz Bernhard

2003-01-01

Full Text Available A new instrumental concept has been developed for atomic absorption spectrometry (AAS, using a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator and a CCD array detector, providing a resolution of ~2 pm per pixel. Among the major advantages of the system are: i an improved signal-to-noise ratio because of the high intensity of the radiation source, resulting in improved photometric precision and detection limits; ii for the same reason, there are no more 'weak' lines, i.e. secondary lines can be used without compromises; iii new elements might be determined, for which no radiation source has been available; iv the entire spectral environment around the analytical line becomes 'visible', giving a lot more information than current AAS instruments; v the CCD array detector allows a truly simultaneous background correction close to the analytical line; vi the software is capable of storing reference spectra, e.g. of a molecular absorption with rotational fine structure, and of subtracting such spectra from the spectra recorded for a sample, using a least squares algorithm; vii although not yet realized, the system makes possible a truly simultaneous multi-element AAS measurement when an appropriate two-dimensional detector is used, as is already common practice in optical emission spectrometry; vii preliminary experiments have indicated that the instrumental concept could result in a more rugged analytical performance in the determination of trace elements in complex matrices.

Relativistic continuum random phase approximation in spherical nuclei

International Nuclear Information System (INIS)

Daoutidis, Ioannis

2009-01-01

Covariant density functional theory is used to analyze the nuclear response in the external multipole fields. The investigations are based on modern functionals with zero range and density dependent coupling constants. After a self-consistent solution of the Relativistic Mean Field (RMF) equations for the nuclear ground states multipole giant resonances are studied within the Relativistic Random Phase Approximation (RRPA), the small amplitude limit of the time-dependent RMF. The coupling to the continuum is treated precisely by calculating the single particle Greens-function of the corresponding Dirac equation. In conventional methods based on a discretization of the continuum this was not possible. The residual interaction is derived from the same RMF Lagrangian. This guarantees current conservation and a precise decoupling of the Goldstone modes. For nuclei with open shells pairing correlations are taken into account in the framework of BCS theory and relativistic quasiparticle RPA. Continuum RPA (CRPA) presents a robust method connected with an astonishing reduction of the numerical effort as compared to conventional methods. Modes of various multipolarities and isospin are investigated, in particular also the newly discovered Pygmy modes in the vicinity of the neutron evaporation threshold. The results are compared with conventional discrete RPA calculations as well as with experimental data. We find that the full treatment of the continuum is essential for light nuclei and the study of resonances in the neighborhood of the threshold. (orig.)

Relativistic continuum random phase approximation in spherical nuclei

Energy Technology Data Exchange (ETDEWEB)

Daoutidis, Ioannis

2009-10-01

Covariant density functional theory is used to analyze the nuclear response in the external multipole fields. The investigations are based on modern functionals with zero range and density dependent coupling constants. After a self-consistent solution of the Relativistic Mean Field (RMF) equations for the nuclear ground states multipole giant resonances are studied within the Relativistic Random Phase Approximation (RRPA), the small amplitude limit of the time-dependent RMF. The coupling to the continuum is treated precisely by calculating the single particle Greens-function of the corresponding Dirac equation. In conventional methods based on a discretization of the continuum this was not possible. The residual interaction is derived from the same RMF Lagrangian. This guarantees current conservation and a precise decoupling of the Goldstone modes. For nuclei with open shells pairing correlations are taken into account in the framework of BCS theory and relativistic quasiparticle RPA. Continuum RPA (CRPA) presents a robust method connected with an astonishing reduction of the numerical effort as compared to conventional methods. Modes of various multipolarities and isospin are investigated, in particular also the newly discovered Pygmy modes in the vicinity of the neutron evaporation threshold. The results are compared with conventional discrete RPA calculations as well as with experimental data. We find that the full treatment of the continuum is essential for light nuclei and the study of resonances in the neighborhood of the threshold. (orig.)

Analytical characteristics of a continuum-source tungsten coil atomic absorption spectrometer.

Science.gov (United States)

Rust, Jennifer A; Nóbrega, Joaquim A; Calloway, Clifton P; Jones, Bradley T

2005-08-01

A continuum-source tungsten coil electrothermal atomic absorption spectrometer has been assembled, evaluated, and employed in four different applications. The instrument consists of a xenon arc lamp light source, a tungsten coil atomizer, a Czerny-Turner high resolution monochromator, and a linear photodiode array detector. This instrument provides simultaneous multi-element analyses across a 4 nm spectral window with a resolution of 0.024 nm. Such a device might be useful in many different types of analyses. To demonstrate this broad appeal, four very different applications have been evaluated. First of all, the temperature of the gas phase was measured during the atomization cycle of the tungsten coil, using tin as a thermometric element. Secondly, a summation approach for two absorption lines for aluminum falling within the same spectral window (305.5-309.5 nm) was evaluated. This approach improves the sensitivity without requiring any additional preconcentration steps. The third application describes a background subtraction technique, as it is applied to the analysis of an oil emulsion sample. Finally, interference effects caused by Na on the atomization of Pb were studied. The simultaneous measurements of Pb and Na suggests that negative interference arises at least partially from competition between Pb and Na atoms for H2 in the gas phase.

Nuclear reliability assurance data source guide

International Nuclear Information System (INIS)

1976-11-01

Seven sources of reliability and maintainability data are reviewed for their potential for providing nuclear equipment data. Consideration is given to similarity to nuclear application, variety of equipment types reported, availability of data, and obsolescence of data. In addition, discussions of advantages and disadvantages of each data source are presented, and samples of either the data or the character of the data are included as appendixes

Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources

DEFF Research Database (Denmark)

Aatrokoski, J.; Lähteenmäki, A.; Lavonen, N.

2011-01-01

Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz......, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase...... of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data...

The regulations concerning refining business of nuclear source material and nuclear fuel materials

International Nuclear Information System (INIS)

1979-01-01

The regulations are provided for under the law for the regulations of nuclear source materials, nuclear fuel materials and reactors and provisions concerning refining business in the enforcement order for the law. The basic concepts and terms are defined, such as: exposure dose, accumulative dose; controlled area; inspected surrounding area and employee. Refining facilities listed in the application for designation shall be classified into clushing and leaching, thickning, refining facilities, storage facilities of nuclear source materials and nuclear fuel materials, disposal facilities of contaminated substances and building for refining, etc. Business program attached to the application shall include expected time of beginning of refining, estimated production amount of nuclear source materials or nuclear fuel materials for the first three years and funds necessary for construction, etc. Records shall be made and kept for particular periods on delivery and storage of nuclear source materials and nuclear fuel materials, control of radiation, maintenance and accidents of refining facilities. Safety securing, application of internationally regulated substances and measures in dangerous situations are stipulated respectively. Exposure dose of employees and other specified matters shall be reported by the refiner yearly to the Director General of Science and Technology Agency and the Minister of International Trade and Industry. (Okada, K.)

Properties of warm nuclei in the quasi-continuum

Directory of Open Access Journals (Sweden)

Voinov A.

2010-03-01

Full Text Available Nuclear thermodynamic quantities are extracted from nuclear level densities measured with the CACTUS detector array at the Oslo Cyclotron Laboratory. The experiments are performed with light-particle inelastic or transfer reactions. A simple combinatorial model is used to describe the underlying mechanisms responsible for the exponential increasing level density as function of excitation energy. The calculated number of broken Cooper pairs and the parity distribution in continuum are discussed.

Continuum Damage Mechanics A Continuum Mechanics Approach to the Analysis of Damage and Fracture

CERN Document Server

Murakami, Sumio

2012-01-01

Recent developments in engineering and technology have brought about serious and enlarged demands for reliability, safety and economy in wide range of fields such as aeronautics, nuclear engineering, civil and structural engineering, automotive and production industry.  This, in turn, has caused more interest in continuum damage mechanics and its engineering applications.   This book aims to give a concise overview of the current state of damage mechanics, and then to show the fascinating possibility of this promising branch of mechanics, and to provide researchers, engineers and graduate students with an intelligible and self-contained textbook.   The book consists of two parts and an appendix.  Part I  is concerned with the foundation of continuum damage mechanics.  Basic concepts of material damage and the mechanical representation of damage state of various kinds are described in Chapters 1 and 2.  In Chapters 3-5, irreversible thermodynamics, thermodynamic constitutive theory and its application ...

Advanced scientific computational methods and their applications to nuclear technologies. (4) Overview of scientific computational methods, introduction of continuum simulation methods and their applications (4)

International Nuclear Information System (INIS)

Sekimura, Naoto; Okita, Taira

2006-01-01

Scientific computational methods have advanced remarkably with the progress of nuclear development. They have played the role of weft connecting each realm of nuclear engineering and then an introductory course of advanced scientific computational methods and their applications to nuclear technologies were prepared in serial form. This is the fourth issue showing the overview of scientific computational methods with the introduction of continuum simulation methods and their applications. Simulation methods on physical radiation effects on materials are reviewed based on the process such as binary collision approximation, molecular dynamics, kinematic Monte Carlo method, reaction rate method and dislocation dynamics. (T. Tanaka)

Continuum Mechanics

CERN Document Server

Romano, Antonio

2010-01-01

This book offers a broad overview of the potential of continuum mechanics to describe a wide range of macroscopic phenomena in real-world problems. Building on the fundamentals presented in the authors' previous book, Continuum Mechanics using Mathematica(R), this new work explores interesting models of continuum mechanics, with an emphasis on exploring the flexibility of their applications in a wide variety of fields.Specific topics, which have been chosen to show the power of continuum mechanics to characterize the experimental behavior of real phenomena, include: * various aspects of nonlin

Nuclear energy such as an alternative energy source

International Nuclear Information System (INIS)

Domingos, D.B.; Stecher, L.C.; Menzel, F.; Coelho, T.S.; Giariola, R.S

2013-01-01

Nuclear power is still an unknown subject to many and ends up being left out when it comes to alternative energy sources and environmental preservation. Unfamiliarity and the disclosures information that are not always correct end up not to show the public the true risks and benefits of this source. The strength of public opinion is the main barrier to the advancement of this technology. So, this paper aims to demystify the villain aspect of nuclear energy that could become a major source for power generation. For this, will be made a historical retrospective of the theories that enabled the field of nuclear fission, the authors and key points, such as will be described how nuclear fission reaction is produced, controlled and sustained and how energy is produced, will be also made an argument on key facts that lead public opinion to stand up against nuclear power, as the generation of radioactive waste and nuclear weapons. Are presented possible solutions beyond the learning and improvements resulting from the occurred accidents. After these analyzes was observed that, besides being a potentially clean source for power generation, it can be safe in order that the waste generated are already safely managed and intelligence groups also monitor terrorist groups, seeking to ensure global security in relation to nuclear weapons and, at the issue of accidents, each event has brought learning and became the nuclear industry today, one of the safest. (author)

Nuclear energy such as an alternative energy source

Energy Technology Data Exchange (ETDEWEB)

Domingos, D.B.; Stecher, L.C.; Menzel, F.; Coelho, T.S.; Giariola, R.S, E-mail: douglasborgesdomingos@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Nuclear power is still an unknown subject to many and ends up being left out when it comes to alternative energy sources and environmental preservation. Unfamiliarity and the disclosures information that are not always correct end up not to show the public the true risks and benefits of this source. The strength of public opinion is the main barrier to the advancement of this technology. So, this paper aims to demystify the villain aspect of nuclear energy that could become a major source for power generation. For this, will be made a historical retrospective of the theories that enabled the field of nuclear fission, the authors and key points, such as will be described how nuclear fission reaction is produced, controlled and sustained and how energy is produced, will be also made an argument on key facts that lead public opinion to stand up against nuclear power, as the generation of radioactive waste and nuclear weapons. Are presented possible solutions beyond the learning and improvements resulting from the occurred accidents. After these analyzes was observed that, besides being a potentially clean source for power generation, it can be safe in order that the waste generated are already safely managed and intelligence groups also monitor terrorist groups, seeking to ensure global security in relation to nuclear weapons and, at the issue of accidents, each event has brought learning and became the nuclear industry today, one of the safest. (author)

Nuclear power: tomorrow's energy source

International Nuclear Information System (INIS)

2002-01-01

In France, 76% of electricity is produced by nuclear power. The industry's pricing levels are among the most competitive in Europe. Thanks to its 58 nuclear reactors France enjoys almost 50% energy autonomy thus ensuring a highly stable supply. Equally, as a non-producer of greenhouse gases, the nuclear sector can rightfully claim to have an environmentally friendly impact. Against a background to increasing global demand with predictions that fossil fuels will run out and global warming a central issue, it is important to use production methods which face up to problems of this nature. There is no question that nuclear energy has a vital role to play alongside other energy sources. (authors)

Realistic Gamow shell model for resonance and continuum in atomic nuclei

Science.gov (United States)

Xu, F. R.; Sun, Z. H.; Wu, Q.; Hu, B. S.; Dai, S. J.

2018-02-01

The Gamow shell model can describe resonance and continuum for atomic nuclei. The model is established in the complex-moment (complex-k) plane of the Berggren coordinates in which bound, resonant and continuum states are treated on equal footing self-consistently. In the present work, the realistic nuclear force, CD Bonn, has been used. We have developed the full \\hat{Q}-box folded-diagram method to derive the realistic effective interaction in the model space which is nondegenerate and contains resonance and continuum channels. The CD-Bonn potential is renormalized using the V low-k method. With choosing 16O as the inert core, we have applied the Gamow shell model to oxygen isotopes.

Hyperbolic conservation laws in continuum physics

CERN Document Server

Dafermos, Constantine M

2016-01-01

This is a masterly exposition and an encyclopedic presentation of the theory of hyperbolic conservation laws. It illustrates the essential role of continuum thermodynamics in providing motivation and direction for the development of the mathematical theory while also serving as the principal source of applications. The reader is expected to have a certain mathematical sophistication and to be familiar with (at least) the rudiments of analysis and the qualitative theory of partial differential equations, whereas prior exposure to continuum physics is not required. The target group of readers would consist of (a) experts in the mathematical theory of hyperbolic systems of conservation laws who wish to learn about the connection with classical physics; (b) specialists in continuum mechanics who may need analytical tools; (c) experts in numerical analysis who wish to learn the underlying mathematical theory; and (d) analysts and graduate students who seek introduction to the theory of hyperbolic systems of conser...

Nuclear power: an eco friendly energy source for sustainable development

International Nuclear Information System (INIS)

Obaidurrahman, K.; Singh, Om Pal

2009-01-01

When viewed from a large set of criteria such as abundance of energy resources, environmental impacts, low fuel inventory, quantum of waste generated and green house gas emissions, nuclear power can be considered as a large scale sustainable energy source. Among all energy sources, nuclear energy has perhaps the lowest impact on the environment, especially in relation to kilowatt-hr produced, because nuclear plants do not emit harmful gases and produce small quantity of waste. In other words, nuclear energy is the most environmental friendly electricity source. There are no significant adverse effects to water, land, habitat, species and air resources. The present paper discusses the sustainability and feasibility of nuclear power as an eco friendly energy source in the changing and challenging competitive power market. (author)

The integrated radio continuum spectrum of M33 - Evidence for free-free absorption by cool ionized gas

Science.gov (United States)

Israel, F. P.; Mahoney, M. J.; Howarth, N.

1992-01-01

We present measurements of the integrated radio continuum flux density of M33 at frequencies between 22 and 610 MHz and discuss the radio continuum spectrum of M33 between 22 MHz and 10 GHz. This spectrum has a turnover between 500 and 900 MHz, depending on the steepness of the high frequency radio spectrum of M33. Below 500 MHz the spectrum is relatively flat. We discuss possible mechanisms to explain this spectral shape and consider efficient free-free absorption of nonthermal emission by a cool (not greater than 1000 K) ionized gas to be a very likely possibility. The surface filling factor of both the nonthermal and the thermal material appears to be small (of order 0.001), which could be explained by magnetic field/density fluctuations in the M 33 interstellar medium. We briefly speculate on the possible presence of a nuclear radio source with a steep spectrum.

Effect of γ-softness on continuum gamma-ray spectra

International Nuclear Information System (INIS)

Hamamoto, I.; Onishi, N.

1985-01-01

In the case that a nuclear system has a large fluctuation in the direction of triaxiality, we examine the possible feature expected to appear in the continuum gamma-ray spectra, especially a possibility of the filling in the central valley of the two-dimensional gamma-energy coincidence spectra. (orig.)

Mid infra-red hyper-spectral imaging with bright super continuum source and fast acousto-optic tuneable filter for cytological applications

International Nuclear Information System (INIS)

Farries, Mark; Ward, Jon; Valle, Stefano; Stephens, Gary; Moselund, Peter; Van der Zanden, Koen; Napier, Bruce

2015-01-01

Mid-IR imaging spectroscopy has the potential to offer an effective tool for early cancer diagnosis. Current development of bright super-continuum sources, narrow band acousto-optic tunable filters and fast cameras have made feasible a system that can be used for fast diagnosis of cancer in vivo at point of care. The performance of a proto system that has been developed under the Minerva project is described. (paper)

Continuum damage mechanics method for fatigue growth of surface cracks

International Nuclear Information System (INIS)

Feng Xiqiao; He Shuyan

1997-01-01

With the background of leak-before-break (LBB) analysis of pressurized vessels and pipes in nuclear plants, the fatigue growth problem of either circumferential or longitudinal semi-elliptical surface cracks subjected to cyclic loading is studied by using a continuum damage mechanics method. The fatigue damage is described by a scalar damage variable. From the damage evolution equation at the crack tip, a crack growth equation similar to famous Paris' formula is derived, which shows the physical meaning of Paris' formula. Thereby, a continuum damage mechanics approach is developed to analyze the configuration evolution of surface cracks during fatigue growth

Study of the nuclear continuum of 28Si after excitation by inelastic 6Li scattering

International Nuclear Information System (INIS)

Seegert, G.

1985-01-01

For the study of the direct reaction mechanisms which contribute in the inelastic 6 Li scattering to the nuclear continuum of 28 Si at the Karlsruhe Isochronous Cyclotron particle-particle coincidence experiments were performed at an incident 6 Li energy of 156 MeV. Thereby the inelastically scattered 6 Li ions were measured in Si semiconductor telescopes under an angle of THETA=11 0 respectively 10 0 , while the coincident charged particles, mainly α particles with an energy of 70 MeV and protons with an energy up to 50 MeV could be detected in an angular range of -85 0 0 and three angles beyond the reaction plane. For a limited angular range simultaneously the α and 3 He fragments produced by the breakup of the 6 Li particle were taken up in coincidence with all light charged particles. (orig./HSI) [de

Illicit trafficking of nuclear material and other radioactive sources

International Nuclear Information System (INIS)

Yilmazer, A.; Yuecel, A.; Yavuz, U.

2001-01-01

As it is known, for the fact that the illicit trafficking and trading of nuclear materials are being increased over the past few years because of the huge demand of third world states. Nuclear materials like uranium, plutonium, and thorium are used in nuclear explosives that have very attractive features for crime groups, terrorist groups and, the states that are willing to have this power. Crime groups that make illegal trade of nuclear material are also trying to market strategic radioactive sources like red mercury and Osmium. This kind of illegal trade threats public safety, human health, environment also it brings significant threat on world peace and world public health. For these reasons, both states and international organizations should take a role in dealing with illicit trafficking. An important precondition for preventing this kind of incidents is the existence of a strengthened national system for control of all nuclear materials and other radioactive sources. Further, Governments are responsible for law enforcement within their borders for prevention of illegal trading and trafficking of nuclear materials and radiation sources

Investigation of chemical modifiers for phosphorus in a graphite furnace using high-resolution continuum source atomic absorption spectrometry

International Nuclear Information System (INIS)

Lepri, Fabio G.; Dessuy, Morgana B.; Vale, Maria Goreti R.; Borges, Daniel L.G.; Welz, Bernhard; Heitmann, Uwe

2006-01-01

Phosphorus is not one of the elements that are typically determined by atomic absorption spectrometry, but this technique nevertheless offers several advantages that make it attractive, such as the relatively great freedom from interferences. As the main resonance lines for phosphorus are in the vacuum-ultraviolet, inaccessible by conventional atomic absorption spectrometry equipment, L'vov and Khartsyzov proposed to use the non-resonance doublet at 213.5 / 213.6 nm. Later it turned out that with conventional equipment it is necessary to use a chemical modifier in order to get reasonable sensitivity, and lanthanum was the first one suggested for that purpose. In the following years more than 30 modifiers have been proposed for the determination of this element, and there is no consensus about the best one. In this work high-resolution continuum source atomic absorption spectrometry has been used to investigate the determination of phosphorus without a modifier and with the addition of selected modifiers of very different nature, including the originally recommended lanthanum modifier, several palladium-based modifiers and sodium fluoride. As high-resolution continuum source atomic absorption spectrometry is revealing the spectral environment of the analytical line at high resolution, it became obvious that without the addition of a modifier essentially no atomic phosphorus is formed, even at 2700 deg. C . The absorption measured with line source atomic absorption spectrometry in this case is due to the PO molecule, the spectrum of which is overlapping with the atomic line. Palladium, with or without the addition of calcium or ascorbic acid, was found to be the only modifier to produce almost exclusively atomic phosphorus. Lanthanum and particularly sodium fluoride produced a mixture of P and PO, depending on the atomization temperature. This fact can explain at least some of the discrepancies found in the literature and some of the phenomena observed in the

Management of disused sealed sources from nuclear gauges

International Nuclear Information System (INIS)

Reis, Luiz Carlos Alves; Silva, Fabio

2001-01-01

In Brazil there are about 600 Radioactive Facilities that operate 3300 nuclear gauges. The management goal for these sources is minimize the waste that must be stored and disposed, through reutilization or a more efficient method of disposal conditioning. A database is being implemented in order to facilitate the organization and retrieval of information about sources stored at CDTN. Examples of the information being included are: radionuclide, activity and date (e.g. 60 Co, 1 GBq, January 14th 1988); physical and chemical form of radionuclide; producer of the source; source type including dimensions and shape; source serial number; results of tests which have been done, for example leak tests; details of the equipment, i.e. dimensions, material, etc.; measured dose rates (at the surface and at I-m distance from it); whether the source was originally conditioned as special form radioactive material; working life of the equipment, etc. It is intended to reutilize only sealed sources containing certified special form radioactive material. Sources received at CDTN with this certification will be wipe tested in a hot-cell. A special Geiger Muller detector for measuring very low level radiation will be used to detect leakage at detection levels, even lower than the established leakage limit in the CNEN-NE-5.01 Standard. If the source does not exhibit leakage and the shutter operation and shielding of the nuclear gauge is in good condition, it will made available for reuse at a cost savings to the user over the purchase of a new source. Nuclear gauges whose sources do not meet these requirements will be dismantled and the sources efficiently conditioned. The CDTN guidelines for establishing a methodology for conditioning disused sources are: Dismantling the nuclear gauges in the hot-cell; Collecting the sources in an double-lead shielded cylindrical cavity below the hot-cell, until the limit of activity or level is reached; Transferring the internal shielding with the

Continuum random-phase approximation study of the incoherent μ--e- conversion rate and its spurious 1- admixture

International Nuclear Information System (INIS)

Papakonstantinou, P.; Wambach, J.; Kosmas, T.S.; Faessler, A.

2006-01-01

The incoherent transition strength of the exotic μ - -e - conversion in the 208 Pb nucleus is investigated by utilizing the continuum random-phase-approximation method, appropriate for the evaluation of the rate that goes to the continuum of the nuclear spectrum. We find that the contribution of resonances lying high in the continuum is not negligible. Special attention is paid to the detailed study of the pronounced 1 - contribution that according to previous calculations, dominates the overall incoherent rate in about all the nuclear targets. The spurious center-of-mass admixture to the partial rate originating from the 1 - excitations is explored, and its elimination is performed by correcting properly the dipole operators. The results found this way show that the greatest portion of the total 1 - contribution to the incoherent rate is spurious

Nuclear power - an inland energy source, in a way. Nuclear electricity generation permits a balanced energy mix

International Nuclear Information System (INIS)

Kalthoff, B.

1997-01-01

The primary energy demand of Germany currently is met to more than 50 per cent by imports of crude oil, natural gas and coal, with crude oil imports representing by far the largest quota, due to minor inland resources. Nuclear power is the energy source that reduces the country's dependence on imports, so that, also thanks to the nuclear energy source, oil consumption in Germany could be cut back to half in the years from 1970 until 1995. Although nuclear fuels have to be imported, too, uranium resources are plenty, and fuel supplies in the nuclear fuel cycle are guaranteed, so that this energy source can be considered as a quasi inland energy source. (orig.) [de

WWER type reactors used as multipurpose nuclear power sources

International Nuclear Information System (INIS)

Fiala, J.; Mulak, J.

1976-01-01

Safety aspects are assessed of the siting of nuclear power installations in the vicinity of large housing estates and in areas with a high population density, mainly the aspect of the liquidation of the consequences of the maximum credible accident, i.e., the transversal rupture of the primary coolant circuit. The application of WWER type reactors as multipurpose nuclear power sources in Czechoslovakia is justified. It is shown that such a multipurpose nuclear power source differs from a purely condensation nuclear power plant mainly in the design of the secondary stage. The possibilities of such projects are indicated with a view to power and heat operation. (F.M.)

THE SPATIAL EXTENT OF (U)LIRGs IN THE MID-INFRARED. I. THE CONTINUUM EMISSION

International Nuclear Information System (INIS)

DIaz-Santos, T.; Charmandaris, V.; Armus, L.; Petric, A. O.; Howell, J. H.; Murphy, E. J.; Inami, H.; Haan, S.; Marshall, J. A.; Stierwalt, S.; Surace, J. A.; Mazzarella, J. M.; Veilleux, S.; Bothun, G.; Appleton, P. N.; Evans, A. S.; Sanders, D. B.

2010-01-01

We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey sample based on 5-15 μm low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for the galaxies in the sample, FEE λ , defined as the fraction of the emission which originates outside of the unresolved component of a source at a given distance. We find that the FEE λ varies from one galaxy to another, but we can identify three general types of FEE λ : one where FEE λ is constant, one where features due to emission lines and polycyclic aromatic hydrocarbons appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7 μm. More than 30% of the galaxies have a median FEE λ larger than 0.5, implying that at least half of their MIR emission is extended. Luminous Infrared Galaxies (LIRGs) display a wide range of FEE in their warm dust continuum (0 ∼ 13.2 μ m ∼ 13.2 μ m that we find in many LIRGs suggest that the extended component of their MIR continuum emission originates in scales up to 10 kpc and may contribute as much as the nuclear region to their total MIR luminosity. The mean size of the LIRG cores at 13.2 μm is 2.6 kpc. However, once the IR luminosity of the systems reaches the threshold of L IR ∼ 10 11.8 L sun , slightly below the regime of Ultra-luminous Infrared Galaxies (ULIRGs), all sources become clearly more compact, with FEE 13.2 μ m ∼ IR ∼> 10 11.25 L sun strongly increases in those classified as mergers in their final stage of interaction. The FEE 13.2 μ m is also related to the contribution of an active galactic nucleus (AGN) to the MIR emission. Galaxies which are more AGN dominated are less extended, independently of their L IR . We finally find that the extent of the MIR continuum emission is correlated with the far-IR IRAS log(f 60 μ m /f 100 μ m

Investigation of phosphorus atomization using high-resolution continuum source electrothermal atomic absorption spectrometry

International Nuclear Information System (INIS)

Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Welz, Bernhard; Heitmann, Uwe

2007-01-01

The atomization of phosphorus in electrothermal atomic absorption spectrometry has been investigated using a high-resolution continuum source atomic absorption spectrometer and atomization from a graphite platform as well as from a tantalum boat inserted in a graphite tube. A two-step atomization mechanism is proposed for phosphorus, where the first step is a thermal dissociation, resulting in a fast atomization signal early in the atomization stage, and the second step is a slow release of phosphorus atoms from the graphite tube surface following the adsorption of molecular phosphorus at active sites of the graphite surface. Depending on experimental conditions only one of the mechanisms or both might be active. In the absence of a modifier and with atomization from a graphite or tantalum platform the second mechanism appears to be dominant, whereas in the presence of sodium fluoride as a modifier both mechanisms are observed. Intercalation of phosphorus into the graphite platform in the condensed phase has also been observed; this phosphorus, however, appears to be permanently trapped in the structure of the graphite and does not contribute to the absorption signal

Measures Against-Illicit Trafficking of Nuclear Materials and Other Radioactive Sources

International Nuclear Information System (INIS)

Barakat, M.B.; Nassef, M.H.; El Mongy, S.A.

2008-01-01

Since the early nineties, illicit trafficking (IT) of nuclear materials and radioactive sources appeared as a new trend which raised the concern of the international community due to the grave consequences that would merge if these materials or radioactive sources fell into the hands of terrorist groups. However, by the end of the last century illicit trafficking of nuclear materials and radioactive sources lost its considerable salience, in spite of seizure of considerable amounts of 2 '3'5U (76% enrichment) in Bulgaria (May 1999) and also 235 U (30% enrichment) in Georgia (April 2000). Nevertheless, IT should be always considered as a continued and viable threat to the international community. Awareness of the problem should be developed and maintained among concerned circles as the first step towards combating illicit trafficking of nuclear materials and radioactive sources. Illicit trafficking of nuclear and radioactive materials needs serious consideration and proper attention by the governmental law enforcement authorities. Measures to combat with IT of nuclear material or radioactive sources should be effective in recovery, of stolen, removed or lost nuclear materials or radioactive sources due to the failure of the physical protection system or the State System Accounting and Control (SSAC) system which are normally applied for protecting these materials against illegal actions. Measures such as use of modern and efficient radiation monitoring equipment at the borders inspection points, is an important step in preventing the illicit trafficking of nuclear and radioactive materials across the borders. Also providing radiological training to specific personnel and workers in this field will minimize the consequences of a radiological attack in case of its occurrence. There is a real need to start to enter into cooperative agreements to strengthen borders security under the umbrella of IAEA to faster as an international cooperation in the illicit trafficking

Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, Richard B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF has been used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy an is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We use CASINO, a version of DICEBOX that is modified for this purpose. This can be used to simulate the neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modelling of unknown assemblies.

Nuclear heat source design for an advanced HTGR process heat plant

International Nuclear Information System (INIS)

McDonald, C.F.; O'Hanlon, T.W.

1983-01-01

A high-temperature gas-cooled reactor (HTGR) coupled with a chemical process facility could produce synthetic fuels (i.e., oil, gasoline, aviation fuel, methanol, hydrogen, etc.) in the long term using low-grade carbon sources (e.g., coal, oil shale, etc.). The ultimate high-temperature capability of an advanced HTGR variant is being studied for nuclear process heat. This paper discusses a process heat plant with a 2240-MW(t) nuclear heat source, a reactor outlet temperature of 950 0 C, and a direct reforming process. The nuclear heat source outputs principally hydrogen-rich synthesis gas that can be used as a feedstock for synthetic fuel production. This paper emphasizes the design of the nuclear heat source and discusses the major components and a deployment strategy to realize an advanced HTGR process heat plant concept

A nuclear source term analysis for spacecraft power systems

International Nuclear Information System (INIS)

McCulloch, W.H.

1998-01-01

All US space missions involving on board nuclear material must be approved by the Office of the President. To be approved the mission and the hardware systems must undergo evaluations of the associated nuclear health and safety risk. One part of these evaluations is the characterization of the source terms, i.e., the estimate of the amount, physical form, and location of nuclear material, which might be released into the environment in the event of credible accidents. This paper presents a brief overview of the source term analysis by the Interagency Nuclear Safety Review Panel for the NASA Cassini Space Mission launched in October 1997. Included is a description of the Energy Interaction Model, an innovative approach to the analysis of potential releases from high velocity impacts resulting from launch aborts and reentries

A new approach for the determination of sulphur in food samples by high-resolution continuum source flame atomic absorption spectrometer.

Science.gov (United States)

Ozbek, N; Baysal, A

2015-02-01

The new approach for the determination of sulphur in foods was developed, and the sulphur concentrations of various fresh and dried food samples determined using a high-resolution continuum source flame atomic absorption spectrometer with an air/acetylene flame. The proposed method was optimised and the validated using standard reference materials, and certified values were found to be within the 95% confidence interval. The sulphur content of foods ranged from less than the LOD to 1.5mgg(-1). The method is accurate, fast, simple and sensitive. Copyright © 2014 Elsevier Ltd. All rights reserved.

Research on neutron source multiplication method in nuclear critical safety

International Nuclear Information System (INIS)

Zhu Qingfu; Shi Yongqian; Hu Dingsheng

2005-01-01

The paper concerns in the neutron source multiplication method research in nuclear critical safety. Based on the neutron diffusion equation with external neutron source the effective sub-critical multiplication factor k s is deduced, and k s is different to the effective neutron multiplication factor k eff in the case of sub-critical system with external neutron source. The verification experiment on the sub-critical system indicates that the parameter measured with neutron source multiplication method is k s , and k s is related to the external neutron source position in sub-critical system and external neutron source spectrum. The relation between k s and k eff and the effect of them on nuclear critical safety is discussed. (author)

Microscopic theory of light exotic nuclei. Shell Models Embedded in the Continuum

International Nuclear Information System (INIS)

Bennaceur, K.

1999-01-01

The recent advances in experimental nuclear physics make it possible to study nuclear systems far from the beta stability line. The discovery of new phenomena, like halos or neutron skins, requires the development of new theoretical models which enable to study these systems. The first part of this work is devoted to the development and the applications of the Shell Model Embedded in the Continuum (SMEC). This new formalism allows to take into account the correlations between the bound and scattering states of loosely bound nuclei. SMEC is applied here to the study of the spectroscopy of the Mirror nuclei 8 B- 8 Li and 17 F- 17 O. It can also be used to calculate the cross sections of the elastic scattering, the Coulomb breakup processes and the radiative n,p capture processes. The results concerning the reactions of astrophysical interest: 18 O(p, γ) 17 F and 7 Be(p, γ) 8 B, are discussed in details. This last reaction is very important because the disintegration of 8 B is the main source of High energy neutrinos in the sun. The second part of this work is related to the analysis of pairing interaction for weakly bound nuclei. We have developed a new approach, based on the Hartree-Fock-Bogolyubov (HFB) theory, that allows to study the pairing correlations between bound and scattering states, both resonant and not resonant ones. The 'particle-hole' potential is replaced by a model potential for which the solutions are analytically known. This method allows to analyse the effect of pairing on bound and resonant states, independently of their energy position. We have clearly demonstrated that the non-resonant continuum plays a crucial role in the loosely bound nuclei and that solving the HFB equations in the coordinate space is the only method that permits to treat this problem correctly. (author)

Line and continuum spectroscopy as diagnostic tools for gamma ray bursts

International Nuclear Information System (INIS)

Liang, E.P.

1990-12-01

We review the theoretical framework of both line and continuum spectra formation in gamma ray bursts. These include the cyclotron features at 10's of keV, redshifted annihilation features at ∼400 keV, as well as other potentially detectable nuclear transition lines, atomic x-ray lines, proton cyclotron lines and plasma oscillation lines. By combining the parameters derived from line and continuum modeling we can try to reconstruct the location, geometry and physical conditions of the burst emission region, thereby constraining and discriminating the astrophysical models. Hence spectroscopy with current and future generations of detectors should provide powerful diagnostic tools for gamma ray bursters. 48 refs., 10 figs., 4 tabs

Risk Prevention for Nuclear Materials and Radioactive Sources

International Nuclear Information System (INIS)

Badawy, I.

2008-01-01

The present paper investigates the parameters which may have effects on the safety of nuclear materials and other radioactive sources used in peaceful applications of atomic energy. The emergency response planning in such situations are also indicated. In synergy with nuclear safety measures, an approach is developed in this study for risk prevention. It takes into consideration the collective implementation of measures of nuclear material accounting and control, physical protection and monitoring of such strategic and dangerous materials in an integrated and coordinated real-time mode at a nuclear or radiation facility and in any time

Solid-phase extraction and separation procedure for trace aluminum in water samples and its determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

Science.gov (United States)

Ciftci, Harun; Er, Cigdem

2013-03-01

In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L(-1) HNO(3) and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L(-1) and 3.91 μg L(-1), respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples.

Licensing authority's control of radiation sources and nuclear materials in Brazil

International Nuclear Information System (INIS)

Binns, D.A.C.

2002-01-01

Full text: The Brazilian Nuclear Energy Commission is the national licensing authority and among its responsibilities is the control of nuclear materials and radiation sources. This control is carried out in three different ways: 1) Control of the import and export of nuclear materials and radiation sources. To be able to import or export any nuclear material or radiation source, the user has to have an explicit permission of the licensing authority. This is controlled by electronic means in which the user has to fill a special form found on the licensing authority's home page, where he has to fill in his name, license number, license number of his radiation protection officer and data of the material to be imported or exported. These data are checked with a data base that contains all the information of the licensed users and qualified personnel before authorization is emitted. The airport authorities have already installed x-ray machines to check all baggages entering or leaving the country. 2) Transport and transfer permit for radiation sources. In order to transport and/or transfer radiations sources and nuclear materials within the country, the user(s) have to submit an application to the licensing authority. The user(s) fill out an application form where he fills in his company's name, licensing I.D., radiation protection officer's name and I.D and identification of the sources involved. These information are checked with the licensing operations data before the operations is permitted. 3) Inspections and radiation monitoring systems. Routine and regulatory inspections are continuously carried out where the user's radiation sources and nuclear materials inventory are checked. Also the physical security and protection of these materials are verified. The installation of monitoring systems is an item that is being discussed with the airport authorities so as to increase the possibilities of detecting any illegal transport of these materials. (author)

Certified training for nuclear and radioactive source security management

International Nuclear Information System (INIS)

Johnson, Daniel

2017-01-01

Radioactive sources are used by hospitals, research facilities and industry for such purposes as diagnosing and treating illnesses, sterilising equipment and inspecting welds. Unfortunately, many States, regulatory authorities and licensees may not appreciate how people with malevolent intentions could use radioactive sources, and statistics confirm that a number of security incidents happen around the globe. The adversary could be common thieves, activists, insiders, terrorists and organised crime groups. Mitigating this risk requires well trained and competent staff who have developed the knowledge, attributes and skills necessary to successfully discharge their security responsibilities. The International Atomic Energy Agency and the World Institute for Nuclear Security are leading international training efforts. The target audience is a multi-disciplinary group of professionals with management responsibilities for security at facilities with radioactive sources. These efforts to promote training and competence amongst practitioners have been recognised at the 2014 and 2016 Nuclear Security and Nuclear Industry Summits. (author)

Passing waves from atomistic to continuum

Science.gov (United States)

Chen, Xiang; Diaz, Adrian; Xiong, Liming; McDowell, David L.; Chen, Youping

2018-02-01

Progress in the development of coupled atomistic-continuum methods for simulations of critical dynamic material behavior has been hampered by a spurious wave reflection problem at the atomistic-continuum interface. This problem is mainly caused by the difference in material descriptions between the atomistic and continuum models, which results in a mismatch in phonon dispersion relations. In this work, we introduce a new method based on atomistic dynamics of lattice coupled with a concurrent atomistic-continuum method to enable a full phonon representation in the continuum description. This permits the passage of short-wavelength, high-frequency phonon waves from the atomistic to continuum regions. The benchmark examples presented in this work demonstrate that the new scheme enables the passage of all allowable phonons through the atomistic-continuum interface; it also preserves the wave coherency and energy conservation after phonons transport across multiple atomistic-continuum interfaces. This work is the first step towards developing a concurrent atomistic-continuum simulation tool for non-equilibrium phonon-mediated thermal transport in materials with microstructural complexity.

Study on upgrade on nuclear control related open source information website

International Nuclear Information System (INIS)

Kim, H. T.; Park, S. S.; Park, W. S.; Choi, Y. M.

2002-01-01

The open source information relevant to the nuclear control is regularly collected, analyzed, and published to the three web sites by the Technology Center for Nuclear Control (TCNC) of the Korea Atomic Energy Research Institute (KAERI). These web sites are world-wide, KAERI-wide, and TCNC-wide, respectively. We are to upgrade the KAERI-wide website to the access-controlled world-wide web site with some additional functionality. In this research, the current status of the three nuclear control related open source information websites managed by the TCNC was introduced and methods for upgrading the KAERI-wide open source information website and associated information security technology were reviewed

Possible wave modes of wideband nonthermal continuum radiation in its source region

Czech Academy of Sciences Publication Activity Database

Grimald, S.; Santolík, Ondřej

2010-01-01

Roč. 115, - (2010), A06209/1-A06209/8 ISSN 0148-0227 R&D Projects: GA ČR GA205/09/1253; GA MŠk ME09107 Grant - others:ESA(XE) PECS98025 Institutional research plan: CEZ:AV0Z30420517 Keywords : nonthermal continuum * NTC * wave modes Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.303, year: 2010

Nuclear and x-ray spectroscopy with radioactive sources

International Nuclear Information System (INIS)

Fink, R.W.

1977-01-01

Research in nuclear chemistry for 1977 is reviewed. The greatest part of the effort was directed to nuclear spectroscopy (systematics, models, experimental studies), but some work was also done involving fast neutrons and x rays from radioactive sources. Isotopes of Tl, Hg, Au, and Eu were studied in particular. Personnel and publications lists are also included. 5 figures, 1 table

Etude d'un continuum de lumière en régime femtoseconde. Applications au domaine biologique : microscopies et spectroscopie en temps résolu.

OpenAIRE

Courvoisier , Céline

2006-01-01

For few years, a new type of source, called "continuum of light", has been developed. It presents many advantages like a wideband spectrum, a huge brilliancy, a pulsed nature. The aim of this work is to perform a complete characterization of a continuum generated by the injection of femtosecond pulses into a microstructured fiber, and to consider the use of this continuum as optical source for biomedical applications.With acousto-optic filters, the continuum has been successfully employed as ...

Relation between source term and emergency planning for nuclear power plants

International Nuclear Information System (INIS)

Shi Zhongqi; Yang Ling

1992-01-01

Some background information of the severe accidents and source terms related to the nuclear power plant emergency planning are presented. The new source term information in NUREG-0956 and NUREG-1150, and possible changes in emergency planning requirements in U.S.A. are briefly provided. It is suggested that a principle is used in selecting source terms for establishing the emergency planning policy and a method is used in determining the Emergency Planning Zone (EPZ) size in China. Based on the research results of (1) EPZ size of PWR nuclear power plants being built in China, and (2) impact of reactor size and selected source terms on the EPZ size, it is concluded that the suggested principle and the method are suitable and feasible for PWR nuclear power plants in China

Validation of an analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals in soil.

Science.gov (United States)

Frentiu, Tiberiu; Ponta, Michaela; Hategan, Raluca

2013-03-01

The aim of this paper was the validation of a new analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals (Ag, Cd, Co, Cr, Cu, Ni, Pb and Zn) in soil after microwave assisted digestion in aqua regia. Determinations were performed on the ContrAA 300 (Analytik Jena) air-acetylene flame spectrometer equipped with xenon short-arc lamp as a continuum radiation source for all elements, double monochromator consisting of a prism pre-monocromator and an echelle grating monochromator, and charge coupled device as detector. For validation a method-performance study was conducted involving the establishment of the analytical performance of the new method (limits of detection and quantification, precision and accuracy). Moreover, the Bland and Altman statistical method was used in analyzing the agreement between the proposed assay and inductively coupled plasma optical emission spectrometry as standardized method for the multielemental determination in soil. The limits of detection in soil sample (3σ criterion) in the high-resolution continuum source flame atomic absorption spectrometry method were (mg/kg): 0.18 (Ag), 0.14 (Cd), 0.36 (Co), 0.25 (Cr), 0.09 (Cu), 1.0 (Ni), 1.4 (Pb) and 0.18 (Zn), close to those in inductively coupled plasma optical emission spectrometry: 0.12 (Ag), 0.05 (Cd), 0.15 (Co), 1.4 (Cr), 0.15 (Cu), 2.5 (Ni), 2.5 (Pb) and 0.04 (Zn). Accuracy was checked by analyzing 4 certified reference materials and a good agreement for 95% confidence interval was found in both methods, with recoveries in the range of 94-106% in atomic absorption and 97-103% in optical emission. Repeatability found by analyzing real soil samples was in the range 1.6-5.2% in atomic absorption, similar with that of 1.9-6.1% in optical emission spectrometry. The Bland and Altman method showed no statistical significant difference between the two spectrometric

Continuum mechanics of anisotropic materials

CERN Document Server

Cowin, Stephen C

2013-01-01

Continuum Mechanics of Anisotropic Materials(CMAM) presents an entirely new and unique development of material anisotropy in the context of an appropriate selection and organization of continuum mechanics topics. These features will distinguish this continuum mechanics book from other books on this subject. Textbooks on continuum mechanics are widely employed in engineering education, however, none of them deal specifically with anisotropy in materials. For the audience of Biomedical, Chemical and Civil Engineering students, these materials will be dealt with more frequently and greater accuracy in their analysis will be desired. Continuum Mechanics of Anisotropic Materials' author has been a leader in the field of developing new approaches for the understanding of anisotropic materials.

OBSERVATIONAL STUDY OF THE CONTINUUM AND WATER MASER EMISSION IN THE IRAS 19217+1651 REGION

Energy Technology Data Exchange (ETDEWEB)

Rodriguez-Esnard, T.; Trinidad, M. A. [Departamento de Astronomia, Universidad de Guanajuato, Apdo Postal 144, Guanajuato, GTO, Mexico CP 36000 (Mexico); Migenes, V., E-mail: tatiana@iga.cu, E-mail: trinidad@astro.ugto.mx, E-mail: vmigenes@byu.edu [Department of Physics and Astronomy, Brigham Young University, ESC-N145, Provo, UT 84602 (United States)

2012-12-20

We report interferometric observations of the high-mass star-forming region IRAS 19217+1651. We observed the radio continuum (1.3 cm and 3.6 cm) and water maser emission using the Very Large Array (VLA-EVLA) in transition mode (configuration A). Two radio continuum sources were detected at both wavelengths, I19217-A and I19217-B. In addition, 17 maser spots were observed distributed mainly in two groups, M1 and M2, and one isolated maser. This latter could be indicating the relative position of another continuum source which we did not detect. The results indicate that I19217-A appears to be consistent with an ultracompact H II region associated with a zero-age main-sequence B0-type star. Furthermore, the 1.3 cm continuum emission of this source suggests a cometary morphology. In addition, I19217-B appears to be an H II region consisting of at least two stars, which may be contributing to its complex structure. It was also found that the H{sub 2}O masers of the group M1 are apparently associated with the continuum source I19217-A. These are tracing motions which are not gravitationally bound according to their spatial distribution and kinematics. They also seem to be describing outflows in the direction of the elongated cometary region. On the other hand, the second maser group, M2, could be tracing the base of a jet. Finally, infrared data from Spitzer, Midcourse Space Experiment, and IRIS show that IRAS 19217+1651 is embedded inside a large open bubble, like a broken ring, which possibly has affected the morphology of the cometary H II region observed at 1.3 cm.

Lyman-continuum leakage as dominant source of diffuse ionized gas in the Antennae galaxy

Science.gov (United States)

Weilbacher, Peter M.; Monreal-Ibero, Ana; Verhamme, Anne; Sandin, Christer; Steinmetz, Matthias; Kollatschny, Wolfram; Krajnović, Davor; Kamann, Sebastian; Roth, Martin M.; Erroz-Ferrer, Santiago; Marino, Raffaella Anna; Maseda, Michael V.; Wendt, Martin; Bacon, Roland; Dreizler, Stefan; Richard, Johan; Wisotzki, Lutz

2018-04-01

The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation: the central galaxy interaction and a region near the tip of the southern tidal tail. In these fields, we detect HII regions and diffuse ionized gas to unprecedented depth. About 15% of the ionized gas was undetected by previous observing campaigns. This newly detected faint ionized gas is visible everywhere around the central merger, and shows filamentary structure. We estimate diffuse gas fractions of about 60% in the central field and 10% in the southern region. We are able to show that the southern region contains a significantly different population of HII regions, showing fainter luminosities. By comparing HII region luminosities with the HST catalog of young star clusters in the central field, we estimate that there is enough Lyman-continuum leakage in the merger to explain the amount of diffuse ionized gas that we detect. We compare the Lyman-continuum escape fraction of each HII region against emission line ratios that are sensitive to the ionization parameter. While we find no systematic trend between these properties, the most extreme line ratios seem to be strong indicators of density bounded ionization. Extrapolating the Lyman-continuum escape fractions to the southern region, we conclude that simply from the comparison of the young stellar populations to the ionized gas there is no need to invoke other ionization mechanisms than Lyman-continuum leaking HII regions for the diffuse ionized gas in the Antennae. FITS images and Table of HII regions are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A95 and at http://muse-vlt.eu/science/antennae/

Renewable energy sources and nuclear installations

International Nuclear Information System (INIS)

Hirschberg, S.; Bauer, Ch.; Burgherr, P.; Stucki, S.; Vogel, F.; Biollaz, S.; Schulz, T.; Durisch, W.; Hardegger, P.; Foskolos, K.; Meier, A.; Schenler, W.

2005-02-01

This comprehensive work report for the Swiss Federal Office of Energy (SFOE) made by the Paul Scherrer Institute PSI takes a look at work done in connection with the updating of the office's Energy Perspectives. In particular, the topic of electricity is reviewed in the light of pending important decisions in the area of nuclear energy and the newer renewable sources of energy. The report makes an attempt to estimate the effect on Swiss power production that the new renewables and new nuclear installations could have in the next 30-40 years and to what costs this could be done and which obstacles would have to overcome. The renewable energy sources include small hydro, wind, photovoltaics, solar thermal power plants, biogas, geothermal energy, wave-power and solar chemistry. The methods used include literature study and contacts with internal PSI experts on the various areas involved. The most important system characteristics were noted and learning curves for the various technologies were taken into account. Ecological and social factors were also considered

Scientific opportunities in nuclear resonance spectroscopy from source-driven revolution

Energy Technology Data Exchange (ETDEWEB)

Shenoy, G. K., E-mail: gks@aps.anl.gov [Argonne National Laboratory (United States); Roehlsberger, R. [Deutsches Elektronen Synchrotron, DESY (Germany)

2008-02-15

From the beginning of its discovery the Moessbauer effect has continued to be one of the most powerful tools with broad applications in diverse areas of science and technology. With the advent of synchrotron radiation sources such as the Advanced Photon Source (APS), the European Synchrotron Radiation Facility (ESRF) and the Super Photon Ring-8 (SPring-8), the tool has enlarged its scope and delivered new capabilities. The popular techniques most generally used in the field of materials physics, chemical physics, geoscience, and biology are hyperfine spectroscopy via elastic nuclear forward scattering (NFS), vibrational spectroscopy via nuclear inelastic scattering (NRIXS), and, to a lesser extent, diffusional dynamics from quasielastic nuclear forward scattering (QNFS). As we look ahead, new storage rings with enhanced brilliance such as PETRA-III under construction at DESY, Hamburg, and PEP-III in its early design stage at SLAC, Stanford, will provide new and unique science opportunities. In the next two decades, x-ray free-electron lasers (XFELs), based both on self-amplified spontaneous emission (SASE-XFELs) and a seed (SXFELs), with unique time structure, coherence and a five to six orders higher average brilliance will truly revolutionize nuclear resonance applications in a major way. This overview is intended to briefly address the unique radiation characteristics of new sources on the horizon and to provide a glimpse of scientific prospects and dreams in the nuclear resonance field from the new radiation sources. We anticipate an expanded nuclear resonance research activity with applications such as spin and phonon mapping of a single nanostructure and their assemblies, interfaces, and surfaces; spin dynamics; nonequilibrium dynamics; photochemical reactions; excited-state spectroscopy; and nonlinear phenomena.

Continuum robots and underactuated grasping

Directory of Open Access Journals (Sweden)

N. Giri

2011-02-01

Full Text Available We discuss the capabilities of continuum (continuous backbone robot structures in the performance of under-actuated grasping. Continuum robots offer the potential of robust grasps over a wide variety of object classes, due to their ability to adapt their shape to interact with the environment via non-local continuum contact conditions. Furthermore, this capability can be achieved with simple, low degree of freedom hardware. However, there are practical issues which currently limit the application of continuum robots to grasping. We discuss these issues and illustrate via an experimental continuum grasping case study.

This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources

Science.gov (United States)

Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.;

Nuclear Physics Meets the Sources of the Ultra-High Energy Cosmic Rays.

Science.gov (United States)

Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

2017-07-07

The determination of the injection composition of cosmic ray nuclei within astrophysical sources requires sufficiently accurate descriptions of the source physics and the propagation - apart from controlling astrophysical uncertainties. We therefore study the implications of nuclear data and models for cosmic ray astrophysics, which involves the photo-disintegration of nuclei up to iron in astrophysical environments. We demonstrate that the impact of nuclear model uncertainties is potentially larger in environments with non-thermal radiation fields than in the cosmic microwave background. We also study the impact of nuclear models on the nuclear cascade in a gamma-ray burst radiation field, simulated at a level of complexity comparable to the most precise cosmic ray propagation code. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions in cosmic ray sources and propagation.

Compact, self-regulating nuclear power source

International Nuclear Information System (INIS)

Peterson, Otis G.; Kimpland, Robert H.

2008-01-01

An inherently safe nuclear power source has been designed, that is self-stabilizing and requires no moving mechanical components. Unlike conventional designs, the proposed reactor is self-regulating through the inherent properties of uranium hydride, which serves as a combination fuel and moderator. The temperature driven mobility of the hydrogen contained in the hydride will control the nuclear activity. If the core temperature increases over the set point, the hydrogen is driven out of the core, the moderation drops and the power production decreases. If the temperature drops, the hydrogen returns and the process is reversed. Thus the design is inherently fail-safe and requires only minimal human oversight. The compact nature and inherent safety opens the possibility for low-cost mass production and operation of the reactors. This design has the capability to dramatically alter the manner in which nuclear energy is harnessed for commercial use. (author)

Certified Training for Nuclear and Radioactive Source Security Management.

Science.gov (United States)

Johnson, Daniel

2017-04-01

Radioactive sources are used by hospitals, research facilities and industry for such purposes as diagnosing and treating illnesses, sterilising equipment and inspecting welds. Unfortunately, many States, regulatory authorities and licensees may not appreciate how people with malevolent intentions could use radioactive sources, and statistics confirm that a number of security incidents happen around the globe. The adversary could be common thieves, activists, insiders, terrorists and organised crime groups. Mitigating this risk requires well trained and competent staff who have developed the knowledge, attributes and skills necessary to successfully discharge their security responsibilities. The International Atomic Energy Agency and the World Institute for Nuclear Security are leading international training efforts. The target audience is a multi-disciplinary group of professionals with management responsibilities for security at facilities with radioactive sources. These efforts to promote training and competence amongst practitioners have been recognised at the 2014 and 2016 Nuclear Security and Nuclear Industry Summits. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of integrity of radiation sources of nuclear gauges

International Nuclear Information System (INIS)

Torohate, Wiclif Francisco

2016-01-01

Nuclear equipment meters are mainly used in the industry in quality control and process control. The principle of operation consists in a shielded radioactive source together with a radiation detector such that the radiation interacts with the material to be analyzed before reaching the detector, providing real time data. Can be as their fixed and mobile mobility, the unique properties of ionizing radiation are used in three basic modes, transmission, backscatter or dispersion or induced (reactive). With the advancement and technological modernization in the world, the demand for nuclear gauges becomes increasingly larger. Currently in Brazil there are about 465 process control plants and 21 portable systems and Mozambique about 45 facilities using nuclear gauges. This font registration is done through a process called source inventory that allows also to know the category of the source, the danger or risk to human health that the source offers. The handling of this equipment requires personnel, certified, skilled and well trained in radiation protection area in accordance with the requirements of the various CNEN Rules. Due to the presence of radioactive source and because these devices are used by workers risk because there external radiation. In this context, we made the smear test in two fixed meters from the IRD industry laboratory, which determines the integrity of the source package, mandatory item in periodic integrity testing of the radiation source of this type of device. A set of procedures is made for its implementation as an evaluation of the radiological risk by radiological survey. It was intended to contribute to the learning handling and safe use of these meters. (author)

Variational principles of continuum mechanics. Vol. 1. Fundamentals

Energy Technology Data Exchange (ETDEWEB)

Berdichevsky, Victor L. [Wayne State Univ., Detroit, MI (United States). Dept. of Mechanical Engineering

2009-07-01

The book reviews the two features of the variational approach: its use as a universal tool to describe physical phenomena and as a source for qualitative and quantitative methods of studying particular problems. Berdichevsky's work differs from other books on the subject in focusing mostly on the physical origin of variational principles as well as establishing their interrelations. For example, the Gibbs principles appear as a consequence of the Einstein formula for thermodynamic fluctuations rather than as the first principles of the theory of thermodynamic equilibrium. Mathematical issues are considered as long as they shed light on the physical outcomes and/or provide a useful technique for the direct study of variational problems. In addition, a thorough account of variational principles discovered in various branches of continuum mechanics is given. In this book, the first volume, the author covers the variational principles for systems with a finite number of degrees of freedom; the variational principles of thermodynamics; the basics of continuum mechanics; the variational principles for classical models of continuum mechanics, such as elastic and plastic bodies, and ideal and viscous fluids; and direct methods of calculus of variations. (orig.)

Renewable and nuclear sources of energy reduce the share of fossil fuels

International Nuclear Information System (INIS)

Koprda, V.

2009-01-01

In this paper author presents a statistical data use of nuclear energy, renewable sources and fossil fuels in the share of energy production in the Slovak Republic. It is stated that use of nuclear energy and renewable sources reduce the share of fossil fuels.

Renewable and nuclear sources of energy decreases of share of fossil fuels

International Nuclear Information System (INIS)

Koprda, V.

2009-01-01

In this paper author presents a statistical data use of nuclear energy, renewable sources and fossil fuels in the share of energy production in the Slovak Republic. It is stated that use of nuclear energy and renewable sources decreases of share of fossil fuels.

Toward Understanding the Fanaroff-Riley Dichotomy in Radio Source Morphology and Power

Science.gov (United States)

Baum, Stefi A.; Zirbel, Esther L.; O'Dea, Christopher P.

1995-09-01

In Paper I we presented the results of a study of the interrelationships between host galaxy magnitude, optical line luminosity, and radio luminosity in a large sample of Fanaroff-Riley classes 1 and 2 (FR 1 and FR 2) radio galaxies. We report several important differences between the FR 1 and FR 2 radio galaxies. At the same host galaxy magnitude or radio luminosity, the FR 2's produce substantially more optical line emission (by roughly an order of magnitude or more) than do FR 1's. Similarly, FR 2 sources produce orders of magnitude more line luminosity than do radio-quiet galaxies of the same optical magnitude, while FR 1 sources and radio-quiet galaxies of the same optical magnitude produce similar line luminosities. Combining these results with previous results from the literature, we conclude that while the emission-line gas in the FR 2's is indeed photoionized by a nuclear UV continuum source from the AGN, the emission-line gas in the FR 1's may be energized predominantly by processes associated with the host galaxy itself. The apparent lack of a strong UV continuum source from the central engine in FR 1 sources can be understood in two different ways. In the first scenario, FR l's are much more efficient at covering jet bulk kinetic energy into radio luminosity than FR 2's, such that an FR 1 has a much lower bolometric AGN luminosity (hence nuclear UV continuum source) than does an FR 2 of the same radio luminosity. We discuss the pros and cons of this model and conclude that the efficiency differences needed between FR 2 and FR 1 radio galaxies are quite large and may lead to difficulties with the interpretation since it would suggest that FR 2 radio source deposit very large amounts of kinetic energy into the ISM Intracluster Medium. However, this interpretation remains viable. Alternatively, it may be that the AGNs in FR 1 sources simply produce far less radiant UV energy than do those in FR 2 sources. That is, FR 1 sources may funnel a higher fraction

Continuum mechanics

CERN Document Server

Spencer, A J M

2004-01-01

The mechanics of fluids and the mechanics of solids represent the two major areas of physics and applied mathematics that meet in continuum mechanics, a field that forms the foundation of civil and mechanical engineering. This unified approach to the teaching of fluid and solid mechanics focuses on the general mechanical principles that apply to all materials. Students who have familiarized themselves with the basic principles can go on to specialize in any of the different branches of continuum mechanics. This text opens with introductory chapters on matrix algebra, vectors and Cartesian ten

Proposed principles on the use of nuclear power sources in space

International Nuclear Information System (INIS)

Bennett, G.L.

1988-01-01

Since the 1978 reentry of the Soviet satellite Cosmos 954, the United Nations has been discussing the use of nuclear power sources in outer space. Most of these deliberations have taken place in the U.N. Committee on the Peaceful Uses of Outer Space, its two subcommittees (Scientific and Technical Subcommittee and Legal Subcommittee) and their associated working groups. This paper focuses on the technical agreements reached by the Working Group on the Use of Nuclear Power Sources in Outer Space (WGNPS), the legal principles agreed to by the Legal Subcommittee, and relevant treaties on the use of outer space and the use of nuclear power. To date the conclusion reached by the WGNPS in its 1981 report represents a succinct statement of U.N. consensus and of the U.S. position: The Working Group reaffirmed its previous conclusion that nuclear power sources can be used safely in outer space, provided that all necessary safety precautions are met

Radial pattern of nuclear decay processes

International Nuclear Information System (INIS)

Iskra, W.; Mueller, M.; Rotter, I.; Technische Univ. Dresden

1994-05-01

At high level density of nuclear states, a separation of different time scales is observed (trapping effect). We calculate the radial profile of partial widths in the framework of the continuum shell model for some 1 - resonances with 2p-2h nuclear structure in 16 O as a function of the coupling strength to the continuum. A correlation between the lifetime of a nuclear state and the radial profile of the corresponding decay process is observed. We conclude from our numerical results that the trapping effect creates structures in space and time characterized by a small radial extension and a short lifetime. (orig.)

Continuum limbed robots for locomotion

Science.gov (United States)

Mutlu, Alper

This thesis focuses on continuum robots based on pneumatic muscle technology. We introduce a novel approach to use these muscles as limbs of lightweight legged robots. The flexibility of the continuum legs of these robots offers the potential to perform some duties that are not possible with classical rigid-link robots. Potential applications are as space robots in low gravity, and as cave explorer robots. The thesis covers the fabrication process of continuum pneumatic muscles and limbs. It also provides some new experimental data on this technology. Afterwards, the designs of two different novel continuum robots - one tripod, one quadruped - are introduced. Experimental data from tests using the robots is provided. The experimental results are the first published example of locomotion with tripod and quadruped continuum legged robots. Finally, discussion of the results and how far this technology can go forward is presented.

Comparison between Different Power Sources for Emergency Power Supply at Nuclear Power Plants

International Nuclear Information System (INIS)

Lenasson, Magnus

2015-01-01

Currently the Swedish nuclear power plants are using diesel generator sets and to some extent gas turbines as their emergency AC power sources and batteries as their emergency DC power sources. In the laws governing Swedish nuclear activity, no specific power sources are prescribed. On the other hand, diversification of safety functions should be considered, as well as simplicity and reliability in the safety systems. So far the choices of emergency power sources have been similar between different power plants, and therefore this project investigated a number of alternative power sources and if they are suitable for use as emergency power on nuclear power plants. The goals of the project were to: - Define the parameters that are essential for rending a power source suitable for use at a nuclear power plant. - Present the characteristics of a number of power sources regarding the defined parameters. - Compile the suitability of the different power sources. - Make implementation suggestions for the less conventional of the investigated power sources. (unconventional in the investigated application) 10 different power sources in total have been investigated and to various degrees deemed suitable Out of the 10 power sources, diesel generators, batteries and to some extent gas turbines are seen as conventional technology at the nuclear power plants. In relation to them the other power sources have been assessed regarding diversification gains, foremost with regards to external events. The power sources with the largest diversification gains are: Internal steam turbine, Hydro power, Thermoelectric generators. The work should first and foremost put focus on the fact that under the right circumstances there are power sources that can complement conventional power sources and yield substantial diversification gains. This paper is a shortened version of the report 'Comparison between different power sources for emergency power supply at nuclear power plants'. The

Determination of sulfur in bovine serum albumin and L-cysteine using high-resolution continuum source molecular absorption spectrometry of the CS molecule

Science.gov (United States)

Andrade-Carpente, Eva; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

2016-08-01

In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A microwave lab station (Ethos Plus MW) was used for the digestion of both compounds. During the digestion step, sulfur was converted to sulfate previous to the determination. Good repeatability (4-10%) and analytical recovery (91-106%) was obtained.

Determination of total sulfur in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry.

Science.gov (United States)

Virgilio, Alex; Raposo, Jorge L; Cardoso, Arnaldo A; Nóbrega, Joaquim A; Gomes Neto, José A

2011-03-23

The usefulness of molecular absorption was investigated for the determination of total sulfur (S) in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry. The lines for CS at 257.595, 257.958, and 258.056 nm and for SH at 323.658, 324.064, and 327.990 nm were evaluated. Figures of merit, such as linear dynamic range, sensitivity, linear correlation, characteristic concentration, limit of detection, and precision, were established. For selected CS lines, wavelength-integrated absorbance equivalent to 3 pixels, analytical curves in the 100-2500 mg L(-1) (257.595 nm), 250-2000 mg L(-1) (257.958 nm), and 250-5000 mg L(-1) (258.056 nm) ranges with a linear correlation coefficient better than 0.9980 were obtained. Results were in agreement at a 95% confidence level (paired t test) with those obtained by gravimetry. Recoveries of S in fungicide and fertilizer samples were within the 84-109% range, and the relative standard deviation (n=12) was typically <5%.

Governing equations for a seriated continuum: an unequal velocity model for two-phase flow

International Nuclear Information System (INIS)

Solbrig, C.W.; Hughes, E.D.

1975-05-01

The description of the flow of two-phase fluids is important in many engineering devices. Unexpected transient conditions which occur in these devices cannot, in general, be treated with single-component momentum equations. Instead, the use of momentum equations for each phase is necessary in order to describe the varied transient situations which can occur. These transient conditions can include phases moving in the opposite directions, such as steam moving upward and liquid moving downward, as well as phases moving in the same direction. The derivation of continuity and momentum equations for each phase and an overall energy equation for the mixture are presented. Terms describing interphase forces are described. A seriated (series of) continuum is distinguished from an interpenetrating medium by the representation of interphase friction with velocity differences in the former and velocity gradients in the latter. The seriated continuum also considers imbedded stationary solid surfaces such as occur in nuclear reactor cores. These stationary surfaces are taken into account with source terms. Sufficient constitutive equations are presented to form a complete set of equations. Methods are presented to show that all these coefficients are determinable from microscopic models and well known experimental results. Comparison of the present deviation with previous work is also given. The equations derived here may also be employed in certain multiphase, multicomponent flow applications. (U.S.)

New nuclear heat sources for district heating

International Nuclear Information System (INIS)

Lerouge, B.

1975-01-01

The means by which urban oil heating may be taken over by new energy sources, especially nuclear, are discussed. Several possibilities exist: pressurized water reactors for high powers, and low-temperature swimming-pool-type process-heat reactors for lower powers. Both these cases are discussed [fr

A Dual-Continuum Model for Brine Migration in Salt Associated with Heat-Generating Nuclear Waste: Fully Coupled Thermal-Hydro-Mechanical Analysis

Science.gov (United States)

Hu, M.; Rutqvist, J.

2017-12-01

The disposal of heat-generating nuclear waste in salt host rock establishes a thermal gradient around the waste package that may cause brine inclusions in the salt grains to migrate toward the waste package. In this study, a dual-continuum model is developed to analyze such a phenomenon. This model is based on the Finite Volume Method (FVM), and it is fully thermal-hydro-mechanical (THM) coupled. For fluid flow, the dual-continuum model considers flow in the interconnected pore space and also in the salt grains. The mass balance of salt and water in these two continua is separately established, and their coupling is represented by flux associated with brine migration. Together with energy balance, such a system produces a coupled TH model with strongly nonlinear features. For mechanical analysis, a new formulation is developed based on the Voronoi tessellated mesh. By relating each cell to several connected triangles, first-order approximation is constructed. The coupling between thermal and mechanical fields is only considered in terms of thermal expansion. And the coupling between the hydraulic and mechanical fields in terms of pore-volume effects is consistent with Biot's theory. Therefore, a fully coupled THM model is developed. Several demonstration examples are provided to verify the model. Last the new model is applied to analyze coupled THM behavior and the results are compared with experimental data.

Continuum model for water movement in an unsaturated fractured rock mass

International Nuclear Information System (INIS)

Peters, R.R.; Klavetter, E.A.

1988-01-01

The movement of fluids in a fractured, porous medium has been the subject of considerable study. This paper presents a continuum model that may be used to evaluate the isothermal movement of water in an unsaturated, fractured, porous medium under slowly changing conditions. This continuum model was developed for use in evaluating the unsaturated zone at the Yucca Mountain site as a potential repository for high-level nuclear waste. Thus its development has been influenced by the conditions thought to be present at Yucca Mountain. A macroscopic approach and a microscopic approach are used to develop a continuum model to evaluate water movement in a fractured rock mass. Both approaches assume that the pressure head in the fractures and the matrix are identical in a plane perpendicular to flow. Both approaches lead to a single-flow equation for a fractured rock mass. The two approaches are used to calculate unsaturated hydrologic properties, i.e., relative permeability and saturation as a function of pressure head, for several types of tuff underlying Yucca Mountain, using the best available hydrologic data for the matrix and the fractures. Rock mass properties calculated by both approaches are similar

The Virtuality Continuum Revisited

NARCIS (Netherlands)

Nijholt, Antinus; Traum, D.; Zhai, Sh.; Kellogg, W.

2005-01-01

We survey the themes and the aims of a workshop devoted to the state-of-the-art virtuality continuum. In this continuum, ranging from fully virtual to real physical environments, allowing for mixed, augmented and desktop virtual reality, several perspectives can be taken. Originally, the emphasis

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B. W.; Summers, N.; Escher, J.; Firestone, R. B.; Basunia, S.; Hurst, A.; Krticka, M.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H. D.

2011-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

International Nuclear Information System (INIS)

Sleaford, B.W.; Firestone, R.B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M.; Basunia, S.; Molnar, G.; Belgya, T.; Revay, Z.; Choi, H.D.

2010-01-01

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Importance of self-consistency in relativistic continuum random-phase approximation calculations

International Nuclear Information System (INIS)

Yang Ding; Cao Ligang; Tian Yuan; Ma Zhongyu

2010-01-01

A fully consistent relativistic continuum random phase approximation (RCRPA) is constructed, where the contribution of the continuum spectrum to nuclear excitations is treated exactly by the single-particle Green's function technique. The full consistency of the calculations is achieved that the same effective Lagrangian is adopted for the ground state and the excited states. The negative energy states in the Dirac sea are also included in the single-particle Green's function in the no-sea approximation. The currents from the vector meson and photon exchanges and the Coulomb interaction in RCRPA are treated exactly. The spin-orbit interaction is included naturally in the relativistic frame. Numerical results of the RCRPA are checked with the constrained relativistic mean-field theory. We study the effects of the inconsistency, particularly the currents and Coulomb interaction in various collective multipole excitations.

Comet Halley: An optical continuum study

International Nuclear Information System (INIS)

Hoban, S.M.

1989-01-01

From an analysis of narrowband CCD images of Comet Halley from 1986 January, March, and April, certain dust structures which are redder than the remainder of the dust coma have become apparent. Mie calculations suggest that this reddening is due to an enhancement of particles with sizes comparable to the observing wavelengths. Although the mass range derived from the calculations presented here is somewhat uncertain as a result of the limitations of Mie theory, these values are in the expected range derived from the calculations presented here is somewhat uncertain as a result of particle sizes which would be both sensitive to radiation pressure and significantly reddened with respect to the solar spectrum at the observing wavelengths. Thus, the red envelopes are plausibly the result of size sorting by solar radiation pressure. The red jets observed on 1986 January 10, March 1 and March 9 can then be explained by the enhanced dust flux at the jet sources, and the subsequent trapping of a relative excess of intermediate mass (i.e. red) particles into the jets which are visible in the continuum images. Analysis of narrowband photometry of the optical continuum of Comet Halley reveals no correlation between the color of the dust and heliocentric distance, phase angle, strength of the continuum or gas-to-dust ratio. The photometric data are thus consistent with a post-ejection sorting mechanism. Chemical inhomogeneities of the nucleus are therefore not necessary to explain the observed structure in the color of the dust in Comet Halley

Scoping calculations of power sources for nuclear electric propulsion

International Nuclear Information System (INIS)

Difilippo, F.C.

1994-05-01

This technical memorandum describes models and calculational procedures to fully characterize the nuclear island of power sources for nuclear electric propulsion. Two computer codes were written: one for the gas-cooled NERVA derivative reactor and the other for liquid metal-cooled fuel pin reactors. These codes are going to be interfaced by NASA with the balance of plant in order to making scoping calculations for mission analysis

Nuclear Material Detection by One-Short-Pulse-Laser-Driven Neutron Source

International Nuclear Information System (INIS)

Favalli, Andrea; Aymond, F.; Bridgewater, Jon S.; Croft, Stephen; Deppert, O.; Devlin, Matthew James; Falk, Katerina; Fernandez, Juan Carlos; Gautier, Donald Cort; Gonzales, Manuel A.; Goodsell, Alison Victoria; Guler, Nevzat; Hamilton, Christopher Eric; Hegelich, Bjorn Manuel; Henzlova, Daniela; Ianakiev, Kiril Dimitrov; Iliev, Metodi; Johnson, Randall Philip; Jung, Daniel; Kleinschmidt, Annika; Koehler, Katrina Elizabeth; Pomerantz, Ishay; Roth, Markus; Santi, Peter Angelo; Shimada, Tsutomu; Swinhoe, Martyn Thomas; Taddeucci, Terry Nicholas; Wurden, Glen Anthony; Palaniyappan, Sasikumar; McCary, E.

2015-01-01

Covered in the PowerPoint presentation are the following areas: Motivation and requirements for active interrogation of nuclear material; laser-driven neutron source; neutron diagnostics; active interrogation of nuclear material; and, conclusions, remarks, and future works.

[Determination of sulfur in plant using a high-resolution continuum source atomic absorption spectrometer].

Science.gov (United States)

Wang, Yu; Li, Jia-xi

2009-05-01

A method for the analysis of sulfur (S) in plant by molecular absorption of carbon monosulfide (CS) using a high-resolution continuum source atomic absorption spectrometer (CS AAS) with a fuel-rich air/acetylene flame has been devised. The strong CS absorption band was found around 258 nm. The half-widths of some absorption bands were of the order of picometers, the same as the common atomic absorption lines. The experimental procedure in this study provided optimized instrumental conditions (the ratio of acetylene to air, the burner height) and parameters, and researched the spectral interferences and chemical interferences. The influence of the organic solvents on the CS absorption signals and the different digestion procedures for the determination of sulfur were also investigated. The limit of detection achieved for sulfur was 14 mg x L(-1), using the CS wavelength of 257. 961 nm and a measurement time of 3 s. The accuracy and precision were verified by analysis of two plant standard reference materials. The major applications of this method have been used for the determination of sulfur in plant materials, such as leaves. Compared to the others, this method for the analysis of sulfur is rapid, easy and simple for sulfur determination in plant.

Various technical and legal aspects of nuclear power sources in outer space

International Nuclear Information System (INIS)

Boeck, H.; Summerer, L.

2001-12-01

Since the very first days of space exploration, nuclear power was considered as an alternative to solar cells for the generation of energy in space. Especially for larger exploration missions beyond Mars, nuclear power sources (NPS) are almost unavoidable. NPS are developed, produced and flown on a continuous basis since almost 40 years by the USA and the Soviet Union, now Russia. While the technological capabilities certainly exist within Europe, Europe has not developed space nuclear power sources. This work is structured in four parts, enlightening this subject from different viewpoints on the European level. In a first chapter, European centres researching in the broader field of this technology are listed. A second chapter deals with the properties and hazards connected with plutonium, the element used in Radioisotope Thermal Generators (RTG). Recent technological developments in the field of RTG are reviewed in chapter 4, while chapter 3 deals with the international legal implications of the use of nuclear power sources in outer space. Refs. 30 (author)

Notes on continuum mechanics

CERN Document Server

Chaves, Eduardo W V

2013-01-01

This publication is aimed at students, teachers, and researchers of Continuum Mechanics and focused extensively on stating and developing Initial Boundary Value equations used to solve physical problems. With respect to notation, the tensorial, indicial and Voigt notations have been used indiscriminately.   The book is divided into twelve chapters with the following topics: Tensors, Continuum Kinematics, Stress, The Objectivity of Tensors, The Fundamental Equations of Continuum Mechanics, An Introduction to Constitutive Equations, Linear Elasticity, Hyperelasticity, Plasticity (small and large deformations), Thermoelasticity (small and large deformations), Damage Mechanics (small and large deformations), and An Introduction to Fluids. Moreover, the text is supplemented with over 280 figures, over 100 solved problems, and 130 references.

Radio continuum interferometry of dark clouds: A search for newly formed HII regions

International Nuclear Information System (INIS)

Gilmore, W.S.

1978-01-01

A search for compact HII regions embedded in dark clouds has been carried out in an effort to study local massive star formation. Approximately 20% of the total area of opaque dark cloud material in the sky with Av greater than or equal to 6 mag was surveyed with the NRAO three-element interferometer at 2695 MHz, and at least 5% more was surveyed with the NRAO 300-foot telescope at 4750 MHz. The regions surveyed include the dark cloud complexes in Perseus, Taurus, Orion, and Ophiuchus, as well as several smaller cloud complexes and individual clouds. No hidden compact HII regions embedded inside dark clouds were detected with certainty in the radio continuum. However, eleven HII regions with associated visible emission and eighteen other possible HII regions were detected. Five infrared sources thought to have the luminosities of early B stars were not detected in the radio continuum. These five sources showed high correlation with the presence of CO self-absorption, CO emission over a wide range of velocities, and type I OH masers, but an absence of coincident visible nebulosity and detectable radio continuum emission. Therefore, it is suggested that they represent an earlier evolutionary stage than those HII region detected in the radio continuum. This first evolutionary state marks the presence of ''pre-emergent'' (with respect to the molecular cloud) cocoon stars. HII regions in the second evolutionary state are marked by the presence of detectable radio continuum emission, i.e., they are stronger than 10 mJy at 2695 MHz. They have associated visible nebulosity, are relatively large, and appear to be located at the edges of molecular clouds. These are designated as ''emergent edge'' HII regions. The fact that many young HII regions are edge HII regions implies that massive stars are born near the edges of clouds, a phenomenon previously suggested by several other investigators

Changing public stigma with continuum beliefs.

Science.gov (United States)

Corrigan, Patrick W; Schmidt, Annie; Bink, Andrea B; Nieweglowski, Katherine; Al-Khouja, Maya A; Qin, Sang; Discont, Steve

2017-10-01

Given the egregious effect of public stigma on the lives of people with mental illness, researchers have sought to unpack and identify effective components of anti-stigma programs. We expect to show that continuum messages have more positive effect on stigma and affirming attitudes (beliefs that people with mental illness recover and should be personally empowered) than categorical perspectives. The effect of continuum beliefs will interact with contact strategies. A total of 598 research participants were randomly assigned to online presentations representing one of the six conditions: three messages (continuum, categorical, or neutral control) by two processes (education or contact). Participants completed measures of continuum beliefs (as a manipulation check), stigma and affirming attitudes after viewing the condition. Continuum messages had significantly better effect on views that people with mental illness are "different," a finding that interacted with contact. Continuum messages also had better effects on recovery beliefs, once again an effect that interacted significantly with contact. Implications of these findings for improving anti-stigma programs are discussed.

Weighing the Risks of Nuclear Energy and Climate Change: Trust in Different Information Sources, Perceived Risks, and Willingness to Pay for Alternatives to Nuclear Power.

Science.gov (United States)

Vainio, Annukka; Paloniemi, Riikka; Varho, Vilja

2017-03-01

We examined how individuals perceive nuclear energy in the context of climate change mitigation and how their perceptions are associated with trust in different risk information sources. We analyzed the interrelationships between trust, perceived risk of nuclear power, climate change concern, perception of nuclear energy as an acceptable way to mitigate climate change, and willingness to pay (WTP) for alternatives to nuclear power. A nationwide survey (N = 967) collected in Finland was analyzed with structural equation modeling. The associations between trust and perceived risk of nuclear power, climate change concern, and perception of nuclear power as a way to mitigate climate change varied by the type of information source. Political party support and other background variables were associated with trust in different information sources. The effect of trust in information sources on WTP was mediated by perceived risks and benefits. The results will increase our understanding of how individuals perceive nuclear energy as a way to cut CO 2 emissions and the role of trust in different information sources in shaping nuclear risk perceptions and energy choices. © 2016 Society for Risk Analysis.

Flat super-continuum generation based on normal dispersion nonlinear photonic crystal fibre

DEFF Research Database (Denmark)

Chow, K.K.; Takushima, Y.; Lin, C.

2006-01-01

Flat super-continuum generation spanning over the whole telecommunication band using a passively modelocked fibre laser source at 1550 nm together with a dispersion-flattened nonlinear photoinc crystal fibre is demonstrated. Since the pulses propagate in the normal dispersion regime of the fibre...

Extension versus Bending for Continuum Robots

Directory of Open Access Journals (Sweden)

George Grimes

2008-11-01

Full Text Available In this paper, we analyze the capabilities of a novel class of continuous-backbone ("continuum" robots. These robots are inspired by biological "trunks, and tentacles". However, the capabilities of established continuum robot designs, which feature controlled bending but not extension, fall short of those of their biological counterparts. In this paper, we argue that the addition of controlled extension provides dual and complementary functionality, and correspondingly enhanced performance, in continuum robots. We present an interval-based analysis to show how the inclusion of controllable extension significantly enhances the workspace and capabilities of continuum robots.

Nuclear power, useful energy source

International Nuclear Information System (INIS)

Sorin, F.

2003-01-01

This article is a reprint of an article published in a newspaper named 'Liberation Champagne' from October 7, 2003. It makes a brief analysis of the future world energy needs, of the need to fight against the global warming and to find a substitution to fossil fuels on the way to depletion. The mankind has to face a contradictory problem: increasing the energy production and saving the fossil fuels. The only solution is to accelerate the development of nuclear energy and of renewable energy sources. This is also the only way to fulfill the Kyoto protocol commitments. Short paper. (J.S.)

Solar energy versus nuclear energy as energy sources at the transition period

International Nuclear Information System (INIS)

Sastroamidjojo, MSA.

Technical aspects and social aspects of nuclear power plants and solar energy system as energy sources, were comparatively evaluated. The evaluation proves that solar energy is better than nuclear energy. (SMN)

Management of disused sealed sources from the nuclear industry in China

International Nuclear Information System (INIS)

Fan Xuanlin

2002-01-01

Since the founding of the nuclear industry in China, more than 8000 disused sealed sources accumulated of which more than 1800 are Radium sources. Most of these sources were produced during the period 1960-1980. The disused radioactive sources are temporarily stored in a user's interim store. A project to manage these disused sealed sources is under way which includes inventory investigation, inspection, collection, transportation and long-term storage. (author)

Probabilist methods applied to electric source problems in nuclear safety

International Nuclear Information System (INIS)

Carnino, A.; Llory, M.

1979-01-01

Nuclear Safety has frequently been asked to quantify safety margins and evaluate the hazard. In order to do so, the probabilist methods have proved to be the most promising. Without completely replacing determinist safety, they are now commonly used at the reliability or availability stages of systems as well as for determining the likely accidental sequences. In this paper an application linked to the problem of electric sources is described, whilst at the same time indicating the methods used. This is the calculation of the probable loss of all the electric sources of a pressurized water nuclear power station, the evaluation of the reliability of diesels by event trees of failures and the determination of accidental sequences which could be brought about by the 'total electric source loss' initiator and affect the installation or the environment [fr

Ukrainian efforts in preventing illicit trafficking in nuclear materials and other radioactive sources

International Nuclear Information System (INIS)

Kondratov, S.I.

1998-01-01

The Ukrainian efforts in preventing illicit trafficking in nuclear materials and other radioactive sources are described. Attention is paid for Ukrainian Government's Decree intended, in particular, to facilitate in establishing well-coordinated activities of the Ukrainian law enforcement bodies and other agencies involved, assigning the status of the main expert organization on illicit trafficking in nuclear materials to the Scientific Center 'Institute for Nuclear Research', in developing the three-years Program on prevention illicit trafficking in nuclear materials and other radioactive sources on the Ukrainian territory as well as measures at the State and customs borders. The main directions provided by the draft Program mentioned are presented as well. (author)

The ENSDF based radionuclide source for MCNP

International Nuclear Information System (INIS)

Berlizov, A.N.; Tryshyn, V.V.

2003-01-01

A utility for generating source code of the Source subroutine of MCNP (a general Monte Carlo NxParticle transport code) on the basis of ENSDF (Evaluated Nuclear Structure Data File) is described. The generated code performs statistical simulation of processes, accompanying radioactive decay of a chosen radionuclide through a specified decay branch, providing characteristics of emitted correlated particles on its output. At modeling the following processes are taken into account: emission of continuum energy electrons at beta - -decay to different exited levels of a daughter nucleus; annihilation photon emission accompanying beta + -decay; gamma-ray emission; emission of discrete energy electrons resulted from internal conversion process on atomic K- and L I,II,III -shells; K and LX-ray emission at single and double fluorescence, accompanying electron capture and internal conversion processes. Number of emitted particles, their types, energies and emission times are sampled according to characteristics of a decay scheme of a particular radionuclide as well as characteristics of atomic shells of mother and daughter nuclei. Angular correlations, calculated for a particular combination of nuclear level spins, mixing ratios and gamma-ray multipolarities, are taken into account at sampling of directional cosines of emitted gamma-rays. The paper contains examples of spectrometry system response simulation at measurements with real radionuclide sources. (authors)

1300 micron continuum observations of the Sagittarius B2 molecular cloud core

International Nuclear Information System (INIS)

Goldsmith, P.F.; Snell, R.L.; Lis, D.C.

1987-01-01

Observations with 23-arcsec angular resolution are obtained of the continuum emission at 1300 microns wavelength from the central region of the Sgr B2 molecular cloud, which contains the north and middle high-mass star-forming regions and associated radio continuum and maser sources. The spatial resolution of the present data shows that the 1300-micron continuum emission peak is located at Sgr B2(N), in contrast to the midinfrared emission, which is centered on Sgr B2(M). Comparison with 53 micron data having comparable angular resolution suggests that there is optically thick foreground dust which prevents detection of Sgr B2(N) at wavelengths not greater than 100 microns. Within the about 1.5 x 3.5 pc region mapped, the total mass is 500,000 solar masses and the mean H2 density is 300,000/cu cm, somewhat larger than found in previous investigations. 27 references

Scissors strength in the quasi-continuum of actinides

Directory of Open Access Journals (Sweden)

Guttormsen M.

2014-03-01

Full Text Available The M1-scissors resonance has been measured for the first time in the quasi-continuum of actinides. The strength and position of the resonances in 231,232,233Th were determined by particle-γ coincidences using deuteron induced reactions on a 232Th target. The residual nuclei show a strong integrated strength of BM1 = 9 − 11 µn2 in the Eγ = 1.0 − 3.5 MeV region. The presence of the scissors resonance modifies significantly the (n,γ cross section, which has impact on fuel-cycle simulations of fast nuclear reactors and nucleosynthesis in explosive stellar environments.

Source term estimation during incident response to severe nuclear power plant accidents

International Nuclear Information System (INIS)

McKenna, T.J.; Glitter, J.G.

1988-10-01

This document presents a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. 39 refs., 48 figs., 19 tabs

Nuclear heat source component design considerations for HTGR process heat reactor plant concept

International Nuclear Information System (INIS)

McDonald, C.F.; Kapich, D.; King, J.H.; Venkatesh, M.C.

1982-01-01

Using alternate energy sources abundant in the U.S.A. to help curb foreign oil imports is vitally important from both national security and economic standpoints. Perhaps the most forwardlooking opportunity to realize national energy goals involves the integrated use of two energy sources that have an established technology base in the U.S.A., namely nuclear energy and coal. The coupling of a high-temperature gas-cooled reactor (HTGR) and a chemical process facility has the potential for long-term synthetic fuel production (i.e., oil, gasoline, aviation fuel, hydrogen, etc.) using coal as the carbon source. Studies are in progress to exploit the high-temperature capability of an advanced HTGR variant for nuclear process heat. The process heat plant discussed in this paper has a 1170-MW(t) reactor as the heat source and the concept is based on indirect reforming, i.e., the high-temperature nuclear thermal energy is transported (via an intermediate heat exchanger (IHX)) to the externally located process plant by a secondary helium transport loop. Emphasis is placed on design considerations for the major nuclear heat source (NHS) components, and discussions are presented for the reactor core, prestressed concrete reactor vessel (PCRV), rotating machinery, and heat exchangers

Regularity of the wear control of radioactive sources from the nuclear measurers

International Nuclear Information System (INIS)

Ferreira L, M.

2006-01-01

The control of radioactive sources in Brazil is regulated by the CNEN (National Comissao of Nuclear Energy). The Laboratory of Descontaminacao of the IPEN (Institute of Energy Y Nuclear Investigations) it offers to the companies that work with nuclear measurers, essays for control of the source wear according to the ISO 9978/1992 through the smear tests Y of leakage. The analyses are taken in alpha Y beta detectors of low bottom radiation with annual detection limits around 1 Bq. Certificates of the accepted analyses by the CNEN for sources that already passed its time of validity assured by the makers, but its continue operational are emitted. The smear test is repeated the whole year, while the leakage test repeats to every two years. A balance of the last two years of the activities of the laboratory shows the regularity of the clients Y the growth of companies specialized in radioprotection with official of radioprotection, credited by the regulatory authority that its act as intermediaries in the process, contacting the clients, gathering the samples next to the proprietors of sources Y hiring our services. Overalls, proves that the inspection activities by part of the regulatory authority are fulfil. In 2004, 192 sources were analyzed by the smear method Y 86 sources by leakage. In 2005, 232 sources were analyzed by the smear method Y 60 sources by leakage. All the leakage tests was made in sources of Americium of oneself Y only client that brings the sources so that they dismantle them to him in the Sources production laboratory of the IPEN. By the quantity Y age of the sources that were analyzed in those two years, it is proven that the number of sources without use conditions (total activity measured by the two added methods smaller than 180Bq) it doesn't arrive to 2%. (Author)

Determination of internationally controlled materials according to provisions of the law for the regulations of nuclear source materials, nuclear fuel materials and reactors

International Nuclear Information System (INIS)

1984-01-01

The internationally controlled materials determined according to the law for nuclear source materials, etc. are the following: nuclear source materials, nuclear fuel materials, moderating materials, facilities including reactors, etc. sold, transferred, etc. to Japan according to the agreements for peaceful uses of atomic energy between Japan, and the United States, the United Kingdom, Canada, Australia and France by the respective governments and those organs under them; nuclear fuel materials resulting from usage of the above sold and transferred materials, facilities; nuclear fuel materials sold to Japan according to agreements set by the International Atomic Energy Agency; nuclear fuel materials involved with the safeguards in nuclear weapons non-proliferation treaty with IAEA. (Mori, K.)

The law for the regulations of nuclear source materials, nuclear fuel materials and reactors

International Nuclear Information System (INIS)

1979-01-01

The law aims to perform regulations on enterprises of refining, processing and reprocessing of nuclear source and fuel materials and on establishment and operation of reactors to realize the peaceful and deliberate utilization of atomic energy according to the principle of the atomic energy basic law. Regulations of use of internationally regulated substances are also envisaged to observe international agreements. Basic concepts and terms are defined, such as: atomic energy; nuclear fuel material; nuclear source material; reactor; refining; processing; reprocessing and internationally regulated substance. Any person besides the Power Reactor and Nuclear Fuel Material Developing Corporation who undertakes refining shall be designated by the Prime Minister and the Minister of International Trade and Industry. An application shall be filed to the ministers concerned, listing name and address of the person, name and location of the refining works, equipment and method of refining, etc. The permission of the Prime Minister is necessary for any person who engages in processing. An application shall be filed to the Prime Minister, listing name and address of the person, name and location of the processing works and equipment and method of processing, etc. Permission of the Prime Minister, the Minister of International Trade and Industry or the Minister of Transport is necessary for any person who sets up reactors. An application shall be filed to the minister concerned, listing name and address of the person, purpose of operation, style, thermal output of reactor and number of units, etc. (Okada, K.)

Continuum emission in the 1980 July 1 solar flare

International Nuclear Information System (INIS)

Zirin, H.; Neidig, D.F.

1981-01-01

Comparison of continuum measurements of the 1980 July 1 flare at Big Bear Solar Observatory and Sacramento Peak Observatory show strong blue emission kernels with the ratio of Balmer continuum (Bac):lambda3862 continuum:continuum above 4275 A to be about 10:5:1. The blue continuum at 3862 A is too strong to be explained by unresolved lines. The Bac intensity was 2.5 times the photosphere and the strongest lambda3862 continuum was 2 times the photosphere. The brightest continuum kernel occurred late in the flare, after the hard X-ray peak and related in time to an isolated peak in the 2.2 MeV line, suggesting that the continuum was excited by protons above 20 MeV

Establishing control over nuclear materials and radiation sources in Georgia

International Nuclear Information System (INIS)

Basilia, G.

2010-01-01

Regulatory control over radiation sources in Georgia was lost after disintegration of the Soviet Union. A number of radiation accidents and illegal events occurred in Georgia. From 1999 Nuclear and Radiation Safety Service of the Ministry of Environmental Protection and Natural Resources is responsible for regulatory control over radiation sources in Georgia. US NRC Regulatory Assistance Program in Georgia Assist the Service in establishing long term regulatory control over sources. Main focuses of US NRC program are country-wide inventory, create National Registry of sources, safe storage of disused sources, upgrade legislation and regulation, implementation licensing and inspection activities

The continuum of behavior guidance.

Science.gov (United States)

Nelson, Travis

2013-01-01

Behavior guidance is a continuum of techniques, basic and advanced, fundamental to the provision of quality dental care for pediatric patients. This practice must be individualized, pairing the correct method of behavior guidance with each child. To select the appropriate technique, the clinician must have a thorough understanding of each aspect of the continuum and anticipate parental expectations, child temperament, and the technical procedures necessary to complete care. By effectively using techniques within the continuum of behavior guidance, a healing relationship with the family is maintained while addressing dental disease and empowering the child to receive dental treatment throughout their lifetime. Copyright © 2013 Elsevier Inc. All rights reserved.

Lattice QCD for nuclear physics

CERN Document Server

Meyer, Harvey

2015-01-01

With ever increasing computational resources and improvements in algorithms, new opportunities are emerging for lattice gauge theory to address key questions in strongly interacting systems, such as nuclear matter. Calculations today use dynamical gauge-field ensembles with degenerate light up/down quarks and the strange quark and it is possible now to consider including charm-quark degrees of freedom in the QCD vacuum. Pion masses and other sources of systematic error, such as finite-volume and discretization effects, are beginning to be quantified systematically. Altogether, an era of precision calculation has begun, and many new observables will be calculated at the new computational facilities.  The aim of this set of lectures is to provide graduate students with a grounding in the application of lattice gauge theory methods to strongly interacting systems, and in particular to nuclear physics.  A wide variety of topics are covered, including continuum field theory, lattice discretizations, hadron spect...

A description of a wide beam saddle field ion source used for nuclear target applications

International Nuclear Information System (INIS)

Greene, J.P.; Schiel, S.L.; Thomas, G.E.

1997-01-01

A description is given of a new, wide beam saddle field sputter source used for the preparation of targets applied in nuclear physics experiments. The ion source characteristics are presented and compared with published results obtained with other sources. Deposition rates acquired utilizing this source are given for a variety of target materials encountered in nuclear target production. New applications involving target thinning and ion milling are discussed

Compact continuum radio sources in the Orion Nebula

International Nuclear Information System (INIS)

Garay, G.; Moran, J.M.; Reid, M.J.; European Southern Observatory, Garching, West Germany)

1987-01-01

The Orion Nebula was observed with the VLA in order to search for radio emission from compact H II regions indicative of embedded OB stars or from winds associated with pre-main sequence, low-mass stars. Fourteen of the 21 detected radio sources are within 30 arcsec of Omega 1 Orionis C; 13 of these objects are probably neutral condensations surrounded by ionized envelopes that are excited by the star. If the temperature of the ionized envelopes is 10,000 K and their electron densities decrease as the square of the distance from the core center, then a typical neutral condensation has a radius of 10 to the 15th cm and a peak electron density of 400,000/cu cm. Seven sources are in or near the Orion molecular cloud. Four of the sources have optical counterparts. Two are highly variable radio sources associated with X-ray sources, and two have radio spectra indicative of thermal emission. Two of the three optically invisible sources have radio emission likely to arise in a dense ionized envelope surrounding and excited by an early B-type star. 46 references

The encapsulated nuclear heat source reactor for proliferation-resistant nuclear energy

International Nuclear Information System (INIS)

Brown, N.W.; Hossain, Q.; Carelli, M.D.; Conway, L.; Dzodzo, M.; Greenspan, E.; Saphier, D.

2001-01-01

The encapsulated nuclear heat source (ENHS) is a modular reactor that was selected by the 1999 DOE NERI program as a candidate ''Generation-IV'' reactor concept. It is a fast neutron spectrum reactor cooled by Pb-Bi using natural circulation. It is designed for passive load following, for high level of passive safety, and for 15 years without refueling. One of the unique features of the ENHS is that the fission-generated heat is transferred from the primary coolant to the secondary coolant across the reactor vessel wall by conduction-providing for an essentially sealed module that is easy to install and replace. Because the fuel is encapsulated within a heavy steel container throughout its life it provides a unique improvement to the proliferation resistance of the nuclear fuel cycle. This paper presents the innovative technology of the ENHS. (author)

Performance-based shape optimization of continuum structures

International Nuclear Information System (INIS)

Liang Qingquan

2010-01-01

This paper presents a performance-based optimization (PBO) method for optimal shape design of continuum structures with stiffness constraints. Performance-based design concepts are incorporated in the shape optimization theory to achieve optimal designs. In the PBO method, the traditional shape optimization problem of minimizing the weight of a continuum structure with displacement or mean compliance constraints is transformed to the problem of maximizing the performance of the structure. The optimal shape of a continuum structure is obtained by gradually eliminating inefficient finite elements from the structure until its performance is maximized. Performance indices are employed to monitor the performance of optimized shapes in an optimization process. Performance-based optimality criteria are incorporated in the PBO method to identify the optimum from the optimization process. The PBO method is used to produce optimal shapes of plane stress continuum structures and plates in bending. Benchmark numerical results are provided to demonstrate the effectiveness of the PBO method for generating the maximum stiffness shape design of continuum structures. It is shown that the PBO method developed overcomes the limitations of traditional shape optimization methods in optimal design of continuum structures. Performance-based optimality criteria presented can be incorporated in any shape and topology optimization methods to obtain optimal designs of continuum structures.

Citizens’ preferences on nuclear and renewable energy sources: Evidence from Turkey

International Nuclear Information System (INIS)

Ertör-Akyazı, Pınar; Adaman, Fikret; Özkaynak, Begüm; Zenginobuz, Ünal

2012-01-01

Based on data from a face-to-face survey of 2422 residents from urban Turkey, this paper presents an analysis of citizens’ preferences in Turkey on nuclear and renewable energy sources. Findings indicate that opposition to nuclear power was strong, and only a small number of respondents endorsed it by listing it in their top two choices. Conversely, almost two-thirds of the sample endorsed investment in renewable energy sources (such as wind and solar), and only a small minority was opposed to it. Econometric analyses revealed that knowledge of the climate change problem was a common factor that explained endorsement of both nuclear and renewables. Yet, high levels of concern for the environment and a negative perception regarding its future differentiated the endorsers of renewables from those of nuclear energy. Endorsers of nuclear energy were found to be males who were knowledgeable about climate change and engaged in environmental issues, but less concerned about the environment, and optimistic about its future. Nuclear opponents, on the other hand, were found to be concerned about the environment, pessimistic about its future, and not fully relying on technology. - Highlights: ► We explore determinants of citizens’ preferences for renewable and nuclear energy. ► The analysis is based on a survey conducted in urban Turkey with 2422 respondents. ► Knowledge of climate change is a common factor of renewable and nuclear endorsement. ► Divergences relate to environmental concern and optimism, and reliance on technology. ► Energy conflicts emerge as complex and related to environmental values and attitudes.

Area Regge calculus and continuum limit

International Nuclear Information System (INIS)

Khatsymovsky, V.M.

2002-01-01

Encountered in the literature generalisations of general relativity to independent area variables are considered, the discrete (generalised Regge calculus) and continuum ones. The generalised Regge calculus can be either with purely area variables or, as we suggest, with area tensor-connection variables. Just for the latter, in particular, we prove that in analogy with corresponding statement in ordinary Regge calculus (by Feinberg, Friedberg, Lee and Ren), passing to the (appropriately defined) continuum limit yields the generalised continuum area tensor-connection general relativity

Source term estimation during incident response to severe nuclear power plant accidents. Draft

Energy Technology Data Exchange (ETDEWEB)

McKenna, T J; Giitter, J

1987-07-01

The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. The goal is to present a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. (author)

Source term estimation during incident response to severe nuclear power plant accidents. Draft

International Nuclear Information System (INIS)

McKenna, T.J.; Giitter, J.

1987-01-01

The various methods of estimating radionuclide release to the environment (source terms) as a result of an accident at a nuclear power reactor are discussed. The major factors affecting potential radionuclide releases off site (source terms) as a result of nuclear power plant accidents are described. The quantification of these factors based on plant instrumentation also is discussed. A range of accident conditions from those within the design basis to the most severe accidents possible are included in the text. A method of gross estimation of accident source terms and their consequences off site is presented. The goal is to present a method of source term estimation that reflects the current understanding of source term behavior and that can be used during an event. (author)

Energy sources and nuclear energy. Comparative analysis and ethical reflections

International Nuclear Information System (INIS)

Hoenraet, C.

1999-01-01

Under the authority of the episcopacy of Brugge in Belgium an independent working group Ethics and Nuclear Energy was set up. The purpose of the working group was to collect all the necessary information on existing energy sources and to carry out a comparative analysis of their impact on mankind and the environment. Also attention was paid to economical and social aspects. The results of the study are subjected to an ethical reflection. The book is aimed at politicians, teachers, journalists and every interested layman who wants to gain insight into the consequences of the use of nuclear energy and other energy sources. Based on the information in this book one should be able to objectively define one's position in future debates on this subject

Detection of Nuclear Sources by UAV Teleoperation Using a Visuo-Haptic Augmented Reality Interface.

Science.gov (United States)

Aleotti, Jacopo; Micconi, Giorgio; Caselli, Stefano; Benassi, Giacomo; Zambelli, Nicola; Bettelli, Manuele; Zappettini, Andrea

2017-09-29

A visuo-haptic augmented reality (VHAR) interface is presented enabling an operator to teleoperate an unmanned aerial vehicle (UAV) equipped with a custom CdZnTe-based spectroscopic gamma-ray detector in outdoor environments. The task is to localize nuclear radiation sources, whose location is unknown to the user, without the close exposure of the operator. The developed detector also enables identification of the localized nuclear sources. The aim of the VHAR interface is to increase the situation awareness of the operator. The user teleoperates the UAV using a 3DOF haptic device that provides an attractive force feedback around the location of the most intense detected radiation source. Moreover, a fixed camera on the ground observes the environment where the UAV is flying. A 3D augmented reality scene is displayed on a computer screen accessible to the operator. Multiple types of graphical overlays are shown, including sensor data acquired by the nuclear radiation detector, a virtual cursor that tracks the UAV and geographical information, such as buildings. Experiments performed in a real environment are reported using an intense nuclear source.

PLOTLIB: a computerized nuclear waste source-term library storage and retrieval system

International Nuclear Information System (INIS)

Marshall, J.R.; Nowicki, J.A.

1978-01-01

The PLOTLIB code was written to provide computer access to the Nuclear Waste Source-Term Library for those users with little previous computer programming experience. The principles of user orientation, quick accessibility, and versatility were extensively employed in the development of the PLOTLIB code to accomplish this goal. The Nuclear Waste Source-Term Library consists of 16 ORIGEN computer runs incorporating a wide variety of differing light water reactor (LWR) fuel cycles and waste streams. The typical isotopic source-term data consist of information on watts, curies, grams, etc., all of which are compiled as a function of time after reactor discharge and unitized on a per metric ton heavy metal basis. The information retrieval code, PLOTLIB, is used to process source-term information requests into computer plots and/or user-specified output tables. This report will serve both as documentation of the current data library and as an operations manual for the PLOTLIB computer code. The accompanying input description, program listing, and sample problems make this code package an easily understood tool for the various nuclear waste studies under way at the Office of Waste Isolation

Continuum mechanics of single-substance bodies

CERN Document Server

Eringen, A Cemal

1975-01-01

Continuum Physics, Volume II: Continuum Mechanics of Single-Substance Bodies discusses the continuum mechanics of bodies constituted by a single substance, providing a thorough and precise presentation of exact theories that have evolved during the past years. This book consists of three parts-basic principles, constitutive equations for simple materials, and methods of solution. Part I of this publication is devoted to a discussion of basic principles irrespective of material geometry and constitution that are valid for all kinds of substances, including composites. The geometrical notions, k

Seismic signal simulation and study of underground nuclear sources by moment inversion

International Nuclear Information System (INIS)

Crusem, R.

1986-09-01

Some problems of underground nuclear explosions are examined from the seismological point of view. In the first part a model is developed for mean seismic propagation through the lagoon of Mururoa atoll and for calculation of synthetic seismograms (in intermediate fields: 5 to 20 km) by summation of discrete wave numbers. In the second part this ground model is used with a linear inversion method of seismic moments for estimation of elastic source terms equivalent to the nuclear source. Only the isotrope part is investigated solution stability is increased by using spectral smoothing and a minimal phase hypothesis. Some examples of applications are presented: total energy estimation of a nuclear explosion, simulation of mechanical effects induced by an underground explosion [fr

Evaluation of integrity of radiation sources of nuclear gauges; Avaliacao da integridade de fontes radioativas de medidores nucleares

Energy Technology Data Exchange (ETDEWEB)

Torohate, Wiclif Francisco

2016-11-01

Nuclear equipment meters are mainly used in the industry in quality control and process control. The principle of operation consists in a shielded radioactive source together with a radiation detector such that the radiation interacts with the material to be analyzed before reaching the detector, providing real time data. Can be as their fixed and mobile mobility, the unique properties of ionizing radiation are used in three basic modes, transmission, backscatter or dispersion or induced (reactive). With the advancement and technological modernization in the world, the demand for nuclear gauges becomes increasingly larger. Currently in Brazil there are about 465 process control plants and 21 portable systems and Mozambique about 45 facilities using nuclear gauges. This font registration is done through a process called source inventory that allows also to know the category of the source, the danger or risk to human health that the source offers. The handling of this equipment requires personnel, certified, skilled and well trained in radiation protection area in accordance with the requirements of the various CNEN Rules. Due to the presence of radioactive source and because these devices are used by workers risk because there external radiation. In this context, we made the smear test in two fixed meters from the IRD industry laboratory, which determines the integrity of the source package, mandatory item in periodic integrity testing of the radiation source of this type of device. A set of procedures is made for its implementation as an evaluation of the radiological risk by radiological survey. It was intended to contribute to the learning handling and safe use of these meters. (author)

Nuclear heat source component design considerations for HTGR process heat reactor plant concept

International Nuclear Information System (INIS)

McDonald, C.F.; Kapich, D.; King, J.H.; Venkatesh, M.C.

1982-05-01

The coupling of a high-temperature gas-cooled reactor (HTGR) and a chemical process facility has the potential for long-term synthetic fuel production (i.e., oil, gasoline, aviation fuel, hydrogen, etc) using coal as the carbon source. Studies are in progress to exploit the high-temperature capability of an advanced HTGR variant for nuclear process heat. The process heat plant discussed in this paper has a 1170-MW(t) reactor as the heat source and the concept is based on indirect reforming, i.e., the high-temperature nuclear thermal energy is transported [via an intermediate heat exchanger (IHX)] to the externally located process plant by a secondary helium transport loop. Emphasis is placed on design considerations for the major nuclear heat source (NHS) components, and discussions are presented for the reactor core, prestressed concrete reactor vessel (PCRV), rotating machinery, and heat exchangers

Exotic nuclear beta transitions astrophysical examples

CERN Document Server

Takahashi, K

1981-01-01

A theoretical study of nuclear beta -transitions under various astrophysical circumstances is reviewed by illustrative examples: 1) continuum-state electron captures in a matter in the nuclear statistical equiplibrium, and ii) bound-state beta -decays in stars in connection with a cosmochronometer and with the s-process branchings. (45 refs).

Continuum of eLearning: 2012 Project Summary Report

Science.gov (United States)

2012-10-01

multimedia, and Continuum of eLearning | Purpose and Vision 19 << UNCLASSIFIED>> (limited) situated learning. Future versions of the CoL self-paced...Continuum of eLearning : 2012 Project Summary Report Continuum of eLearning The Next Evolution of Joint Training on JKO October 2012 Joint...Technical Report November 2011 – August 2012 Continuum of eLearning : 2012 Project Summary Report N00140-06-D-0060 David T. Fautua, Sae Schatz, Andrea

Continuum spectra in light-ion reactions

Energy Technology Data Exchange (ETDEWEB)

Tamura, T.; Udagawa, T. [Texas Univ., Austin (USA). Dept. of Physics; Ikegami, H.; Muraoka, M [eds.

1980-01-01

Recent developments in the use of multi-step direct reaction method, to fit continuum cross sections of light-ion reactions, are reviewed. There has been a long-standing difficulty in reproducing sufficiently large (p, p') continuum cross section, but it has now been all but removed. It will be discussed in some detail, how this was achieved. Analyses of very recent data on analyzing powers in the continuum of (p, p') and (p, ..cap alpha..) reactions will also be discussed. Finally, analysis of the breakup of h into d and p will be presented.

HTGR nuclear heat source component design and experience

International Nuclear Information System (INIS)

Peinado, C.O.; Wunderlich, R.G.; Simon, W.A.

1982-05-01

The high-temperature gas-cooled reactor (HTGR) nuclear heat source components have been under design and development since the mid-1950's. Two power plants have been designed, constructed, and operated: the Peach Bottom Atomic Power Station and the Fort St. Vrain Nuclear Generating Station. Recently, development has focused on the primary system components for a 2240-MW(t) steam cycle HTGR capable of generating about 900 MW(e) electric power or alternately producing high-grade steam and cogenerating electric power. These components include the steam generators, core auxiliary heat exchangers, primary and auxiliary circulators, reactor internals, and thermal barrier system. A discussion of the design and operating experience of these components is included

New numerical methods for quantum field theories on the continuum

Energy Technology Data Exchange (ETDEWEB)

Emirdag, P.; Easter, R.; Guralnik, G.S.; Hahn, S.C

2000-03-01

The Source Galerkin Method is a new numerical technique that is being developed to solve Quantum Field Theories on the continuum. It is not based on Monte Carlo techniques and has a measure to evaluate relative errors. It promises to increase the accuracy and speed of calculations, and takes full advantage of symmetries of the theory. The application of this method to the non-linear {sigma} model is outlined.

Nuclear energetics as environmentally affable source - present and and future

International Nuclear Information System (INIS)

Suchomel, J.

2002-01-01

In this paper the situation in nuclear energetics in the world in 2000 year is presented. Climatic changes initiated by burning of the fossil fuels an influence of nuclear energetics are discussed. Author informs that European Union and U.S.A. supports developing of nuclear energetics. Nuclear phobia from radiation risk of some inhabitants is compared with risks of other man activities. Possibilities of the electricity production by alternative sources are compared. Liability of the Slovak Republic for decommissioning of two reactor of the V-1 Jaslovske Bohunice NPP in 2006 and 2008, which is compared with the Program of safety improvement of these reactors are discussed. Author and Slovak Nuclear Society accept gladly the suggestion of government of the Slovak Republic that they reassess this liability. The best alternative for decommissioned Jaslovske Bohunice NPP will be the completion of the 3 rd and 4 th blocks of the Mochovce NPP

Giant resonances in the deformed continuum

International Nuclear Information System (INIS)

Nakatsukasa, T.; Yabana, K.

2004-01-01

Giant resonances in the continuum for deformed nuclei are studied with the time-dependent Hartree-Fock (TDHF) theory in real time and real space. The continuum effect is effectively taken into account by introducing a complex Absorbing Boundary Condition (ABC). (orig.)

Nature of the ionizing source of the nuclear gas in NGC 1052

International Nuclear Information System (INIS)

Keel, W.C.; Miller, J.S.

1983-01-01

We examine the ionization and physical state of the emission-line region in the nucleus of elliptical galaxy NGC 1052. The [O III] lambda4363/lambda5007 ratio, frequently used as a diagnostic for ionization mechanisms, is very poorly determined because of difficulties in matching the underlying stellar continuum spectrum, which is unusual in having very strong lines for the galaxy luminosity. Within these limitations, we find the [O III] temperature to be only marginally compatible with shock models, and the overall emission spectrum to be better fitted by photoionization models with a very dilute flat-spectrum central source. In any event, the case for NGC 1052 as a shock-heated nucleus is not strong

Fundamentals of continuum mechanics

CERN Document Server

Rudnicki, John W

2014-01-01

A concise introductory course text on continuum mechanics Fundamentals of Continuum Mechanics focuses on the fundamentals of the subject and provides the background for formulation of numerical methods for large deformations and a wide range of material behaviours. It aims to provide the foundations for further study, not just of these subjects, but also the formulations for much more complex material behaviour and their implementation computationally.  This book is divided into 5 parts, covering mathematical preliminaries, stress, motion and deformation, balance of mass, momentum and energ

Introduction to continuum mechanics

CERN Document Server

Lai, W Michael; Rubin, David

1996-01-01

Introduction to Continuum Mechanics is a recently updated and revised text which is perfect for either introductory courses in an undergraduate engineering curriculum or for a beginning graduate course.Continuum Mechanics studies the response of materials to different loading conditions. The concept of tensors is introduced through the idea of linear transformation in a self-contained chapter, and the interrelation of direct notation, indicial notation, and matrix operations is clearly presented. A wide range of idealized materials are considered through simple static and dynamic problems, a

Angle-correlated cross sections in the framework of the continuum shell model

International Nuclear Information System (INIS)

Moerschel, K.P.

1984-01-01

In the present thesis in the framework of the continuum shell modell a concept for the treatment of angle-correlated cross sections was developed by which coincidence experiments on electron scattering on nuclei are described. For this the existing Darmstadt continuum-shell-model code had to be extended to the calculation of the correlation coefficients in which nuclear dynamics enter and which determine completely the angle-correlated cross sections. Under inclusion of the kinematics a method for the integration over the scattered electron was presented and used for the comparison with corresponding experiments. As application correlation coefficients for the proton channel in 12 C with 1 - and 2 + excitations were studied. By means of these coefficients finally cross sections for the reaction 12 C (e,p) 11 B could be calculated and compared with the experiment whereby the developed methods were proved as suitable to predict correctly both the slope and the quantity of the experimental cross sections. (orig.) [de

The shadow continuum : testing the records continuum model through the Djogdja Documenten and the migrated archives

NARCIS (Netherlands)

Karabinos, Michael Joseph

2015-01-01

This dissertation tests the universal suitability of the records continuum model by using two cases from the decolonization of Southeast Asia. The continuum model is a new model of records visualization invented in the 1990s that sees records as free to move throughout four ‘dimensions’ rather than

New nuclear data evaluations for Ca and Sc isotopes

International Nuclear Information System (INIS)

Koning, Arjan; Duijvestijn, Marieke

2007-01-01

New ENDF-6 formatted nuclear data libraries are presented for 40,42,43,44,46,48 Ca and 45 Sc, for incident neutrons and protons. Apart from the resonance range, which we have adopted from the best available source in existing libraries, the nuclear data evaluations are completely revised in the 0-20MeV energy range, and, moreover, extend up to 200 MeV. This collection of isotopic evaluations is created by using the nuclear model code TALYS with a consistent set of input parameters for all isotopes. The most important nuclear reaction models needed for our data files are described. We have intended to make these evaluations complete in their description of reaction channels and use a consistent method to store the data in ENDF-6 format, which include cross sections, angular distributions, double-differential spectra, discrete and continuum photon production cross sections, and residual production (activation) cross sections including isomers. It is shown that the data present in our libraries give an improved agreement with the existing basic experimental data. (author)

Elementary Continuum Mechanics for Everyone - and Some More

DEFF Research Database (Denmark)

Byskov, Esben

Quite trivially, Continuum mechanics per se deals with the description of deformations of three-dimensional continua i.e. models whose properties are independent of scale in that the continuum does not possess a structure. Thus, continuum mechanics does not try to model the atomic structure...

Elementary Continuum Mechanics for Everyone - And Some More

DEFF Research Database (Denmark)

Byskov, Esben

Quite trivially, Continuum mechanics per se deals with the description of deformations of three-dimensional continua i.e. models whose properties are independent of scale in that the continuum does not possess a structure. Thus, continuum mechanics does not try to model the atomic structure...

On the Nature of Orion Source I

Science.gov (United States)

Báez-Rubio, A.; Jiménez-Serra, I.; Martín-Pintado, J.; Zhang, Q.; Curiel, S.

2018-01-01

The Kleinmann–Low nebula in Orion, the closest region of massive star formation, harbors Source I, whose nature is under debate. Knowledge of this source may have profound implications for our understanding of the energetics of the hot core in Orion KL since it might be the main heating source in the region. The spectral energy distribution of this source in the radio is characterized by a positive spectral index close to 2, which is consistent with (i) thermal bremsstrahlung emission of ionized hydrogen gas produced by a central massive protostar, or (ii) photospheric bremsstrahlung emission produced by electrons when deflected by the interaction with neutral and molecular hydrogen like Mira-like variable stars. If ionized hydrogen gas were responsible for the observed continuum emission, its modeling would predict detectable emission from hydrogen radio recombination lines (RRLs). However, our SMA observations were obtained with a high enough sensitivity to rule out that the radio continuum emission arises from a dense hypercompact H II region because the H26α line would have been detected, in contrast with our observations. To explain the observational constraints, we investigate further the nature of the radio continuum emission from source I. We have compared available radio continuum data with the predictions from our upgraded non-LTE 3D radiative transfer model, MOdel for REcombination LInes, to show that radio continuum fluxes and sizes can only be reproduced by assuming both dust and bremsstrahlung emission from neutral gas. The dust emission contribution is significant at ν ≥ 43 GHz. In addition, our RRL peak intensity predictions for the ionized metals case are consistent with the nondetection of Na and K RRLs at millimeter and submillimeter wavelengths.

Continuum capture in the three-body problem

International Nuclear Information System (INIS)

Sellin, I.A.

1980-01-01

The three-body problem, especially the problem of electron capture to the continuum in heavy particle collisions is reviewed. Major topics covered include: second born-induced asymmetry in electron capture to the continuum; historical context, links to other tests of atomic scattering theory; experiments characterizing the velocity distribution of ECC electrons; other atomic physics tests of high velocity Born expansions; atom capture; capture by positrons; and pion capture to the continuum

Detection of Nuclear Sources by UAV Teleoperation Using a Visuo-Haptic Augmented Reality Interface

Directory of Open Access Journals (Sweden)

Jacopo Aleotti

2017-09-01

Full Text Available A visuo-haptic augmented reality (VHAR interface is presented enabling an operator to teleoperate an unmanned aerial vehicle (UAV equipped with a custom CdZnTe-based spectroscopic gamma-ray detector in outdoor environments. The task is to localize nuclear radiation sources, whose location is unknown to the user, without the close exposure of the operator. The developed detector also enables identification of the localized nuclear sources. The aim of the VHAR interface is to increase the situation awareness of the operator. The user teleoperates the UAV using a 3DOF haptic device that provides an attractive force feedback around the location of the most intense detected radiation source. Moreover, a fixed camera on the ground observes the environment where the UAV is flying. A 3D augmented reality scene is displayed on a computer screen accessible to the operator. Multiple types of graphical overlays are shown, including sensor data acquired by the nuclear radiation detector, a virtual cursor that tracks the UAV and geographical information, such as buildings. Experiments performed in a real environment are reported using an intense nuclear source.

Survey of sources of manpower supply for the nuclear power industry

International Nuclear Information System (INIS)

1981-01-01

The following is a report of a survey designed to determine sources of manpower supply available to the Nuclear Power Industry. The survey is part of a larger research effort which is also designed to investigate occupational employment and training in the Nuclear Power Industry and competing sources of demand for technically qualified manpower. The results of those other studies have been published separately and are available upon request. This report includes a brief discussion of the background of the study, the research methods employed, the results obtained, and some implications of those findings. The appendices contain copies of the questionnaires used in the survey as well as some additional related data

A dual neutron/gamma source for the Fissmat Inspection for Nuclear Detection (FIND) system.

Energy Technology Data Exchange (ETDEWEB)

Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); King, Michael; Rossi, Paolo (Sandia National Laboratories, Albuquerque, NM); McDaniel, Floyd Del (Sandia National Laboratories, Albuquerque, NM); Morse, Daniel Henry; Antolak, Arlyn J.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM); Raber, Thomas N.

2008-12-01

Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and gamma-rays can penetrate neutron shielding. Both source particles then induce unique detectable signals from fission. In this LDRD, we explored a new type of interrogation source that uses low-energy proton- or deuteron-induced nuclear reactions to generate high fluxes of mono-energetic gammas or neutrons. Accelerator-based experiments, computational studies, and prototype source tests were performed to obtain a better understanding of (1) the flux requirements, (2) fission-induced signals, background, and interferences, and (3) operational performance of the source. The results of this research led to the development and testing of an axial-type gamma tube source and the design/construction of a high power coaxial-type gamma generator based on the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction.

Development of the methodology for application of revised source term to operating nuclear power plants in Korea

International Nuclear Information System (INIS)

Kang, M.S.; Kang, P.; Kang, C.S.; Moon, J.H.

2004-01-01

Considering the current trend in applying the revised source term proposed by NUREG-1465 to the nuclear power plants in the U.S., it is expected that the revised source term will be applied to the Korean operating nuclear power plants in the near future, even though the exact time can not be estimated. To meet the future technical demands, it is necessary to prepare the technical system including the related regulatory requirements in advance. In this research, therefore, it is intended to develop the methodology to apply the revised source term to operating nuclear power plants in Korea. Several principles were established to develop the application methodologies. First, it is not necessary to modify the existing regulations about source term (i.e., any back-fitting to operating nuclear plants is not necessary). Second, if the pertinent margin of safety is guaranteed, the revised source term suggested by NUREG-1465 may be useful to full application. Finally, a part of revised source term could be selected to application based on the technical feasibility. As the results of this research, several methodologies to apply the revised source term to the Korean operating nuclear power plants have been developed, which include: 1) the selective (or limited) application to use only some of all the characteristics of the revised source term, such as release timing of fission products and chemical form of radio-iodine and 2) the full application to use all the characteristics of the revised source term. The developed methodologies are actually applied to Ulchin 9 and 4 units and their application feasibilities are reviewed. The results of this research are used as either a manual in establishing the plan and the procedure for applying the revised source term to the domestic nuclear plant from the utility's viewpoint; or a technical basis of revising the related regulations from the regulatory body's viewpoint. The application of revised source term to operating nuclear

NEAR- AND FAR-FIELD RESPONSE TO COMPACT ACOUSTIC SOURCES IN STRATIFIED CONVECTION ZONES

International Nuclear Information System (INIS)

Cally, Paul S.

2013-01-01

The role of the acoustic continuum associated with compact sources in the Sun's interior wave field is explored for a simple polytropic model. The continuum produces a near-field acoustic structure—the so-called acoustic jacket—that cannot be represented by a superposition of discrete normal modes. Particular attention is paid to monochromatic point sources of various frequency and depth, and to the surface velocity power that results, both in the discrete f- and p-mode spectrum and in the continuum. It is shown that a major effect of the continuum is to heal the surface wave field produced by compact sources, and therefore to hide them from view. It is found that the continuous spectrum is not a significant contributor to observable inter-ridge seismic power.

Computational Continuum Mechanics

CERN Document Server

Shabana, Ahmed A

2011-01-01

This text presents the theory of continuum mechanics using computational methods. Ideal for students and researchers, the second edition features a new chapter on computational geometry and finite element analysis.

Detection of silver nanoparticles in parsley by solid sampling high-resolution-continuum source atomic absorption spectrometry.

Science.gov (United States)

Feichtmeier, Nadine S; Leopold, Kerstin

2014-06-01

In this work, we present a fast and simple approach for detection of silver nanoparticles (AgNPs) in biological material (parsley) by solid sampling high-resolution-continuum source atomic absorption spectrometry (HR-CS AAS). A novel evaluation strategy was developed in order to distinguish AgNPs from ionic silver and for sizing of AgNPs. For this purpose, atomisation delay was introduced as significant indication of AgNPs, whereas atomisation rates allow distinction of 20-, 60-, and 80-nm AgNPs. Atomisation delays were found to be higher for samples containing silver ions than for samples containing silver nanoparticles. A maximum difference in atomisation delay normalised by the sample weight of 6.27 ± 0.96 s mg(-1) was obtained after optimisation of the furnace program of the AAS. For this purpose, a multivariate experimental design was used varying atomisation temperature, atomisation heating rate and pyrolysis temperature. Atomisation rates were calculated as the slope of the first inflection point of the absorbance signals and correlated with the size of the AgNPs in the biological sample. Hence, solid sampling HR-CS AAS was proved to be a promising tool for identifying and distinguishing silver nanoparticles from ionic silver directly in solid biological samples.

Lower thermospheric nitric oxide concentrations derived from WINDII observations of the green nightglow continuum at 553.1 nm

Directory of Open Access Journals (Sweden)

C. H. A. von Savigny

1999-11-01

Full Text Available Vertical profiles of nitric oxide in the altitude range 90 to 105 km are derived from 553 nm nightglow continuum measurements made with the Wind Imaging Interferometer (WINDII on the Upper Atmosphere Research Satellite (UARS. The profiles are derived under the assumption that the continuum emission is due entirely to the NO+O air afterglow reaction. Vertical profiles of the atomic oxygen density, which are required to determine the nitric oxide concentrations, are derived from coordinated WINDII measurements of the atomic oxygen OI 557.7 nm nightglow emission. Data coverage for local solar times ranging from 20 h to 04 h, and latitudes ranging from 42°S to 42°N, is achieved by zonally averaging and binning data obtained on 18 nights during a two-month period extending from mid-November 1992 until mid-January 1993. The derived nitric oxide concentrations are significantly smaller than those obtained from rocket measurements of the airglow continuum but they do compare well with model expectations and nitric oxide densities measured using the resonance fluorescence technique on the Solar Mesosphere Explorer satellite. The near-global coverage of the WINDII observations and the similarities to the nitric oxide global morphology established from other satellite measurements strongly suggests that the NO+O reaction is the major source of the continuum near 553 nm and that there is no compelling reason to invoke additional sources of continuum emission in this immediate spectral region.Key words. Atmospheric composition and structure (airglow and aurora; thermosphere – composition and chemistry; instruments and techniques

Subcriticality calculation in nuclear reactors with external neutron sources

Energy Technology Data Exchange (ETDEWEB)

Silva, Adilson Costa da; Martinez, Aquilino Senra; Silva, Fernando Carvalho da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mails: asilva@con.ufrj.br; aquilino@lmp.ufrj.br; fernando@con.ufrj.br

2007-07-01

The main objective of this paper consists on the development of a methodology to monitor subcriticality. We used the inverse point kinetic equation with 6 precursor groups and external neutron sources for the calculation of reactivity. The input data for the inverse point kinetic equation was adjusted, in order to use the neutron counting rates obtained from the subcritical multiplication (1/M) in a nuclear reactor. In this paper, we assumed that the external neutron sources strength is constant and we define it in terms of a known initial condition. The results obtained from inverse point kinetic equation with external neutron sources were compared with the results obtained with a benchmark calculation, and showed good accuracy (author)

Subcriticality calculation in nuclear reactors with external neutron sources

International Nuclear Information System (INIS)

Silva, Adilson Costa da; Martinez, Aquilino Senra; Silva, Fernando Carvalho da

2007-01-01

The main objective of this paper consists on the development of a methodology to monitor subcriticality. We used the inverse point kinetic equation with 6 precursor groups and external neutron sources for the calculation of reactivity. The input data for the inverse point kinetic equation was adjusted, in order to use the neutron counting rates obtained from the subcritical multiplication (1/M) in a nuclear reactor. In this paper, we assumed that the external neutron sources strength is constant and we define it in terms of a known initial condition. The results obtained from inverse point kinetic equation with external neutron sources were compared with the results obtained with a benchmark calculation, and showed good accuracy (author)

Variational principles of continuum mechanics I fundamentals

CERN Document Server

Berdichevskii, V L

2009-01-01

This is a concise and understandable book about variational principles of continuum mechanics. The book is accessible to applied mathematicians, physicists and engineers who have an interest in continuum mechanics.

HERSCHEL/PACS SURVEY OF PROTOPLANETARY DISKS IN TAURUS/AURIGA—OBSERVATIONS OF [O I] AND [C II], AND FAR-INFRARED CONTINUUM

International Nuclear Information System (INIS)

Howard, Christian D.; Sandell, Göran; Vacca, William D.; Duchêne, Gaspard; Mathews, Geoffrey; Augereau, Jean-Charles; Ménard, Francois; Pinte, Christophe; Podio, Linda; Thi, Wing-Fai; Barrado, David; Riviere-Marichalar, Pablo; Dent, William R. F.; Eiroa, Carlos; Meeus, Gwendolyn; Grady, Carol; Roberge, Aki; Kamp, Inga; Vicente, Silvia; Williams, Jonathan P.

2013-01-01

The Herschel Space Observatory was used to observe ∼120 pre-main-sequence stars in Taurus as part of the GASPS Open Time Key project. Photodetector Array Camera and Spectrometer was used to measure the continuum as well as several gas tracers such as [O I] 63 μm, [O I] 145 μm, [C II] 158 μm, OH, H 2 O, and CO. The strongest line seen is [O I] at 63 μm. We find a clear correlation between the strength of the [O I] 63 μm line and the 63 μm continuum for disk sources. In outflow sources, the line emission can be up to 20 times stronger than in disk sources, suggesting that the line emission is dominated by the outflow. The tight correlation seen for disk sources suggests that the emission arises from the inner disk (<50 AU) and lower surface layers of the disk where the gas and dust are coupled. The [O I] 63 μm is fainter in transitional stars than in normal Class II disks. Simple spectral energy distribution models indicate that the dust responsible for the continuum emission is colder in these disks, leading to weaker line emission. [C II] 158 μm emission is only detected in strong outflow sources. The observed line ratios of [O I] 63 μm to [O I] 145 μm are in the regime where we are insensitive to the gas-to-dust ratio, neither can we discriminate between shock or photodissociation region emission. We detect no Class III object in [O I] 63 μm and only three in continuum, at least one of which is a candidate debris disk

Simulation of neutron multiplicity measurements using Geant4. Open source software for nuclear arms control

Energy Technology Data Exchange (ETDEWEB)

Kuett, Moritz

2016-07-07

Nuclear arms control, including nuclear safeguards and verification technologies for nuclear disarmament typically use software as part of many different technological applications. This thesis proposes to use three open source criteria for such software, allowing users and developers to have free access to a program, have access to the full source code and be able to publish modifications for the program. This proposition is presented and analyzed in detail, together with the description of the development of ''Open Neutron Multiplicity Simulation'', an open source software tool to simulate neutron multiplicity measurements. The description includes physical background of the method, details of the developed program and a comprehensive set of validation calculations.

Photometric redshifts for the next generation of deep radio continuum surveys - I. Template fitting

Science.gov (United States)

Duncan, Kenneth J.; Brown, Michael J. I.; Williams, Wendy L.; Best, Philip N.; Buat, Veronique; Burgarella, Denis; Jarvis, Matt J.; Małek, Katarzyna; Oliver, S. J.; Röttgering, Huub J. A.; Smith, Daniel J. B.

2018-01-01

We present a study of photometric redshift performance for galaxies and active galactic nuclei detected in deep radio continuum surveys. Using two multiwavelength data sets, over the NOAO Deep Wide Field Survey Boötes and COSMOS fields, we assess photometric redshift (photo-z) performance for a sample of ∼4500 radio continuum sources with spectroscopic redshifts relative to those of ∼63 000 non-radio-detected sources in the same fields. We investigate the performance of three photometric redshift template sets as a function of redshift, radio luminosity and infrared/X-ray properties. We find that no single template library is able to provide the best performance across all subsets of the radio-detected population, with variation in the optimum template set both between subsets and between fields. Through a hierarchical Bayesian combination of the photo-z estimates from all three template sets, we are able to produce a consensus photo-z estimate that equals or improves upon the performance of any individual template set.

Variational principles of continuum mechanics II applications

CERN Document Server

Berdichevsky, Victor L

2009-01-01

This concise and understandable book about variational principles of continuum mechanics presents the classical models. The book is accessible to applied mathematicians, physicists and engineers who have an interest in continuum mechanics.

Precision linac and laser technologies for nuclear photonics gamma-ray sources

Energy Technology Data Exchange (ETDEWEB)

Albert, F.; Hartemann, F. V.; Anderson, S. G.; Cross, R. R.; Gibson, D. J.; Hall, J.; Marsh, R. A.; Messerly, M.; Wu, S. S.; Siders, C. W.; Barty, C. P. J. [Lawrence Livermore National Laboratory, NIF and Photon Science, 7000 East Avenue, Livermore, California 94550 (United States)

2012-05-15

Tunable, high precision gamma-ray sources are under development to enable nuclear photonics, an emerging field of research. This paper focuses on the technological and theoretical challenges related to precision Compton scattering gamma-ray sources. In this scheme, incident laser photons are scattered and Doppler upshifted by a high brightness electron beam to generate tunable and highly collimated gamma-ray pulses. The electron and laser beam parameters can be optimized to achieve the spectral brightness and narrow bandwidth required by nuclear photonics applications. A description of the design of the next generation precision gamma-ray source currently under construction at Lawrence Livermore National Laboratory is presented, along with the underlying motivations. Within this context, high-gradient X-band technology, used in conjunction with fiber-based photocathode drive laser and diode pumped solid-state interaction laser technologies, will be shown to offer optimal performance for high gamma-ray spectral flux, narrow bandwidth applications.

Control for nuclear thermionic power source

International Nuclear Information System (INIS)

Fletcher, J.C.; Sawyer, C.D.

1978-01-01

A control for a power source is described which includes nuclear fuel interspersed with thermionic converters, including a power regulator that maintains a substantially constant output voltage to a variable load, and a control circuit that drives a neutron flux regulator in accordance with the current supplied to the power regulator and the neutron flux density in the region of the converters. The control circuit generates a control signal which is the difference between the neutron flux density and a linear fucntion of the current, and which drives the neutron regulator in a direction to decrease or increase the neutron flux according to the polarity of the control signal

Nuclear energy versus other energy sources

International Nuclear Information System (INIS)

King, F.K.

1994-01-01

This paper deals with nuclear and other sources of energy as they relate to the production of electricity. It first examines the current role of electricity in the world and its means of production and how future economic growth, associated with growing populations striving for better living conditions, will lead to increased demands for new electricity generation. The second part of the paper deals with the health and environmental impacts of the major options for generating electricity likely to be used to meet this need, and how a comparative assessment of these impacts is important to understand the full implications of electricity generation planning decisions. 6 refs, 12 figs

Drift Scale Modeling: Study of Unsaturated Flow into a Drift Using a Stochastic Continuum Model

International Nuclear Information System (INIS)

Birkholzer, J.T.; Tsang, C.F.; Tsang, Y.W.; Wang, J.S

1996-01-01

Unsaturated flow in heterogeneous fractured porous rock was simulated using a stochastic continuum model (SCM). In this model, both the more conductive fractures and the less permeable matrix are generated within the framework of a single continuum stochastic approach, based on non-parametric indicator statistics. High-permeable fracture zones are distinguished from low-permeable matrix zones in that they have assigned a long range correlation structure in prescribed directions. The SCM was applied to study small-scale flow in the vicinity of an access tunnel, which is currently being drilled in the unsaturated fractured tuff formations at Yucca Mountain, Nevada. Extensive underground testing is underway in this tunnel to investigate the suitability of Yucca Mountain as an underground nuclear waste repository. Different flow scenarios were studied in the present paper, considering the flow conditions before and after the tunnel emplacement, and assuming steady-state net infiltration as well as episodic pulse infiltration. Although the capability of the stochastic continuum model has not yet been fully explored, it has been demonstrated that the SCM is a good alternative model feasible of describing heterogeneous flow processes in unsaturated fractured tuff at Yucca Mountain

NEAR- AND FAR-FIELD RESPONSE TO COMPACT ACOUSTIC SOURCES IN STRATIFIED CONVECTION ZONES

Energy Technology Data Exchange (ETDEWEB)

Cally, Paul S., E-mail: paul.cally@monash.edu [Monash Centre for Astrophysics and School of Mathematical Sciences, Monash University, Clayton, Victoria 3800 (Australia)

2013-05-01

The role of the acoustic continuum associated with compact sources in the Sun's interior wave field is explored for a simple polytropic model. The continuum produces a near-field acoustic structure-the so-called acoustic jacket-that cannot be represented by a superposition of discrete normal modes. Particular attention is paid to monochromatic point sources of various frequency and depth, and to the surface velocity power that results, both in the discrete f- and p-mode spectrum and in the continuum. It is shown that a major effect of the continuum is to heal the surface wave field produced by compact sources, and therefore to hide them from view. It is found that the continuous spectrum is not a significant contributor to observable inter-ridge seismic power.

Patients' experiences with continuum of care across hospitals. A multilevel analysis of Consumer Quality Index Continuum of Care

NARCIS (Netherlands)

Kollen, Boudewijn J.; Groenier, Klaas H.; Berendsen, Annette J.

Objective: Communication between professionals is essential because it contributes to an optimal continuum of care. Whether patients experience adequate continuum of care is uncertain. To address this, a questionnaire was developed to elucidate this care process from a patients' perspective. In this

Continuum-Coupling in Electron-Atom scattering

International Nuclear Information System (INIS)

Ballance, C.P.; Griffin, D.C.; Badnell, N.R.; Loch, S.D.; Pindzola, M.S.

2004-01-01

High quality fundamental atomic data provide the foundation of accurate collisional-radiative models of laboratory and astrophysical plasmas. In the SciDAC (Scientific Discovery through Advanced Computing) project entitled 'Terascale Computational Atomic Physics for the Edge Region in Controlled Fusion Plasmas', we employ an integrated approach from the calculation of basic atomic data to the modeling necessary for the interpretation of controlled nuclear fusion experiments. For example, helium electron-impact excitation results support helium puff experiments on the MAST (Mega Ampere Spherical Tokamak) at Culham to diagnose the radial variation in plasma density and temperature. Similarly, electron-impact excitation/ionization work for isonuclear beryllium will prove vital if beryllium is adopted as a surface material for the plasma-facing walls for ITER. Here we will discuss some examples of electron-impact excitation and ionization, where the effects of coupling to and between the target continuum states are large, and advanced close-coupling methods are required in order to generate data of sufficient accuracy

Development of the detection technology of the source area derived from nuclear activities

International Nuclear Information System (INIS)

Suh, Kyungsuk; Kim, Ingyu; Keum, Dongkwon; Lim, Kwangmuk; Lee, Jinyong

2012-07-01

- It is necessary to establish of the overall preparedness for analysis of the nuclear activities near the neighboring countries by increasing of the construction of the nuclear power plants and reprocessing facilities in China, North Korean Japan and Russia. - In Korea, the analysis and measurements for nuclear activities have been conducted, however the detection technology to find out the source area has not been developed. It is important to estimate the source origin of the radioisotope from the neighboring countries including Korea in the aspects of the surveillance and safety for the covert nuclear activities in Northeast Asia region - In this study, the data DB, treatment of the weather data and the development of connection module were conducted to track the origin of the radioisotope in the first year of the research. It had constructed the DB like the reactor types, places in China, Taiwan, Japan and Korea and the release amounts of the noble gas released into the air

Development of the detection technology of the source area derived from nuclear activities

Energy Technology Data Exchange (ETDEWEB)

Suh, Kyungsuk; Kim, Ingyu; Keum, Dongkwon; Lim, Kwangmuk; Lee, Jinyong

2012-07-15

- It is necessary to establish of the overall preparedness for analysis of the nuclear activities near the neighboring countries by increasing of the construction of the nuclear power plants and reprocessing facilities in China, North Korean Japan and Russia. - In Korea, the analysis and measurements for nuclear activities have been conducted, however the detection technology to find out the source area has not been developed. It is important to estimate the source origin of the radioisotope from the neighboring countries including Korea in the aspects of the surveillance and safety for the covert nuclear activities in Northeast Asia region - In this study, the data DB, treatment of the weather data and the development of connection module were conducted to track the origin of the radioisotope in the first year of the research. It had constructed the DB like the reactor types, places in China, Taiwan, Japan and Korea and the release amounts of the noble gas released into the air.

Relative source comparison of the NPE to underground nuclear explosions at local distances

Energy Technology Data Exchange (ETDEWEB)

Smith, A.T. [Lawrence Livermore National Lab., CA (United States)

1994-12-31

The Non-Proliferation Experiment (NPE) provides an opportunity to compare broadband characteristics of chemical to nuclear explosions at a group of local stations (4 to 40 km distant). The locations for these stations were established on bedrock to record a small partially decoupled nuclear explosion and two nearby nuclear experiments, all shots within {open_quotes}N{close_quotes} Tunnel on Rainier Mesa, Area 12. These sites were also occupied to record aftershocks from the Little Skull Mountain earthquake and chemical explosions from the USGS Sierra Experiment. To minimize calibration errors during this period, redundant instrumentation were used for each event. THe analysis emphasizes the source characteristics of the different explosions. The 300-lb chemical calibration explosion allows removal of path effects from each explosion. The NPE and nearby experiments produce very similar waveforms. The decoupled nuclear explosion and the 300-lb chemical calibration explosion show higher frequency content consistent with a higher corner frequency for the sources.

Discovery of a Kiloparsec Extended Hard X-Ray Continuum and Fe-Kα from the Compton Thick AGN ESO 428-G014

Science.gov (United States)

Fabbiano, G.; Elvis, M.; Paggi, A.; Karovska, M.; Maksym, W. P.; Raymond, J.; Risaliti, G.; Wang, Junfeng

2017-06-01

We report the discovery of kiloparsec-scale diffuse emission in both the hard continuum (3-6 keV) and in the Fe-Kα line in the Compton thick (CT) Seyfert galaxy ESO 428-G014. This extended hard component contains at least ˜24% of the observed 3-8 keV emission, and follows the direction of the extended optical line emission (ionization cone) and radio jet. The extended hard component has ˜0.5% of the intrinsic 2-10 keV luminosity within the bi-cones. A uniform scattering medium of density 1 {{cm}}-3 would produce this luminosity in a 1 kpc path length in the bi-cones. Alternatively, higher column density molecular clouds in the disk of ESO 428-G014 may be responsible for these components. The continuum may also be enhanced by the acceleration of charged particles in the radio jet. The steeper spectrum (Γ ˜ 1.7 ± 0.4) of the hard continuum outside of the central 1.″5 radius nuclear region suggests a contribution of scattered/fluorescent intrinsic Seyfert emission. Ultrafast nuclear outflows cannot explain the extended Fe-Kα emission. This discovery suggests that we may need to revise the picture at the base of our interpretation of CT AGN spectra.

LOOKING INTO THE HEARTS OF BOK GLOBULES: MILLIMETER AND SUBMILLIMETER CONTINUUM IMAGES OF ISOLATED STAR-FORMING CORES

International Nuclear Information System (INIS)

Launhardt, R.; Henning, Th.; Khanzadyan, T.; Schmalzl, M.; Wolf, S.; Nutter, D.; Ward-Thompson, D.; Bourke, T. L.; Zylka, R.

2010-01-01

We present the results of a comprehensive infrared, submillimeter, and millimeter continuum emission study of isolated low-mass star-forming cores in 32 Bok globules, with the aim to investigate the process of star formation in these regions. The submillimeter and millimeter dust continuum emission maps together with the spectral energy distributions are used to model and derive the physical properties of the star-forming cores, such as luminosities, sizes, masses, densities, etc. Comparisons with ground-based near-infrared and space-based mid- and far-infrared images from Spitzer are used to reveal the stellar content of the Bok globules, association of embedded young stellar objects (YSOs) with the submillimeter dust cores, and the evolutionary stages of the individual sources. Submillimeter dust continuum emission was detected in 26 out of the 32 globule cores observed. For 18 globules with detected (sub)millimeter cores, we derive evolutionary stages and physical parameters of the embedded sources. We identify nine starless cores, most of which are presumably prestellar, nine Class 0 protostars, and twelve Class I YSOs. Specific source properties like bolometric temperature, core size, and central densities are discussed as a function of evolutionary stage. We find that at least two thirds (16 out of 24) of the star-forming globules studied here show evidence of forming multiple stars on scales between 1000 and 50,000 AU. However, we also find that most of these small prototstar and star groups are comprised of sources with different evolutionary stages, suggesting a picture of slow and sequential star formation in isolated globules.

Some problems of neutron source multiplication method for site measurement technology in nuclear critical safety

International Nuclear Information System (INIS)

Shi Yongqian; Zhu Qingfu; Hu Dingsheng; He Tao; Yao Shigui; Lin Shenghuo

2004-01-01

The paper gives experiment theory and experiment method of neutron source multiplication method for site measurement technology in the nuclear critical safety. The measured parameter by source multiplication method actually is a sub-critical with source neutron effective multiplication factor k s , but not the neutron effective multiplication factor k eff . The experiment research has been done on the uranium solution nuclear critical safety experiment assembly. The k s of different sub-criticality is measured by neutron source multiplication experiment method, and k eff of different sub-criticality, the reactivity coefficient of unit solution level, is first measured by period method, and then multiplied by difference of critical solution level and sub-critical solution level and obtained the reactivity of sub-critical solution level. The k eff finally can be extracted from reactivity formula. The effect on the nuclear critical safety and different between k eff and k s are discussed

Safety Framework for Nuclear Power Source Applications in Outer Space

International Nuclear Information System (INIS)

2009-01-01

Nuclear power sources (NPS) for use in outer space have been developed and used in space applications where unique mission requirements and constraints on electrical power and thermal management precluded the use of non-nuclear power sources. Such missions have included interplanetary missions to the outer limits of the Solar System, for which solar panels were not suitable as a source of electrical power because of the long duration of these missions at great distances from the Sun. According to current knowledge and capabilities, space NPS are the only viable energy option to power some space missions and significantly enhance others. Several ongoing and foreseeable missions would not be possible without the use of space NPS. Past, present and foreseeable space NPS applications include radioisotope power systems (for example, radioisotope thermoelectric generators and radioisotope heater units) and nuclear reactor systems for power and propulsion. The presence of radioactive materials or nuclear fuels in space NPS and their consequent potential for harm to people and the environment in Earth's biosphere due to an accident require that safety should always be an inherent part of the design and application of space NPS. NPS applications in outer space have unique safety considerations compared with terrestrial applications. Unlike many terrestrial nuclear applications, space applications tend to be used infrequently and their requirements can vary significantly depending upon the specific mission. Mission launch and outer space operational requirements impose size, mass and other space environment limitations not present for many terrestrial nuclear facilities. For some applications, space NPS must operate autonomously at great distances from Earth in harsh environments. Potential accident conditions resulting from launch failures and inadvertent re-entry could expose NPS to extreme physical conditions. These and other unique safety considerations for the use of

Measures against illicit trafficking of nuclear material and radioactive sources in the Republic of Belarus

International Nuclear Information System (INIS)

Piotoukh, O.

2001-01-01

Full text: The Republic of Belarus strives to take an active part in international cooperation in the field of prevention and interception of illicit uses of nuclear material and radioactive sources through: multilateral international agreements and bilateral interagency treatments; information exchange within the IAEA Illicit Trafficking Database; participation in different international seminars, workshops, conferences including those under the IAEA auspices etc. Belarus is constantly improving regulatory, legal and technical aspects of activities aimed at: accounting, control and ensuring of physical protection of nuclear material and security of radioactive sources; exercising efficient control over their export and import; detecting cases of their illicit uses and illegal cross-border movements and informing of such cases through the IAEA Illicit Trafficking Database; developing and providing training opportunities for personnel. Through Resolution 'On Measures for Physical Protection of Nuclear Materials' issued by the Council of Ministers in 1993, Committee for Supervision of Industrial and Nuclear Safety (PROMATOMNADZOR) was appointed as the authority responsible for ensuring physical protection of nuclear materials and facilities. Through Resolution 'On Measures for Fulfillment of Provisions of the Non-Proliferation Treaty' issued by the Council of Ministers in 1993, Promatomnadzor was designated as the national competent authority responsible for the establishment and maintenance of the State System of Accounting and Control of nuclear material. The system accounts all the nuclear material meeting the criteria defined in the Safeguards Agreement with the IAEA. The system includes two levels: i.e. on-site accounting and control and state accounting and control exercised by Promatomnadzor. Apart from reporting to the Agency, the system also provides for national tasks being accomplished: control over uses of nuclear material, its physical protection, access

Detection of Nuclear Sources by UAV Teleoperation Using a Visuo-Haptic Augmented Reality Interface

OpenAIRE

Jacopo Aleotti; Giorgio Micconi; Stefano Caselli; Giacomo Benassi; Nicola Zambelli; Manuele Bettelli; Andrea Zappettini

2017-01-01

A visuo-haptic augmented reality (VHAR) interface is presented enabling an operator to teleoperate an unmanned aerial vehicle (UAV) equipped with a custom CdZnTe-based spectroscopic gamma-ray detector in outdoor environments. The task is to localize nuclear radiation sources, whose location is unknown to the user, without the close exposure of the operator. The developed detector also enables identification of the localized nuclear sources. The aim of the VHAR interface is to increase the sit...

Order for execution of the law concerning regulations of nuclear source materials, nuclear fuel materials and reactors

International Nuclear Information System (INIS)

1978-01-01

Under the above mentioned law this order prescribes the procedures of controls given to the persons who wish to conduct refining and fabricating businesses, to construct and operate reactors, and to use nuclear source materials, nuclear fuel materials and internationally controlled materials. The common controlling principle prescribed is that the permission or authorization necessary for above listed businesses should be applied for at each factory or each place of business. Based on the principle, the order prescribes: the procedures to apply for the authorization of the refining business, the permission of the change thereof, and the permission of the fabricating business and the change, thereof (the 1st chapter); the procedures to apply for the permission of the construction of reactors and of the change of the construction, as well as the procedure to do periodic inspections of reactor facilities (the 2nd chapter); the procedures to apply for the permission to use nuclear fuel materials and to change the use thereof, the submission of the report to use nuclear source materials, as well as the procedure to apply for the permission to use internationally controlled materials. In the 4th chapter the order lists up the items on which the competent Ministers may require reports from the person who carries on the relevant business. (Matsushima, A.)

Open-Source Integrated Design-Analysis Environment For Nuclear Energy Advanced Modeling & Simulation Final Scientific/Technical Report

Energy Technology Data Exchange (ETDEWEB)

O' Leary, Patrick [Kitware, Inc., Clifton Park, NY (United States)

2017-01-30

The framework created through the Open-Source Integrated Design-Analysis Environment (IDAE) for Nuclear Energy Advanced Modeling & Simulation grant has simplify and democratize advanced modeling and simulation in the nuclear energy industry that works on a range of nuclear engineering applications. It leverages millions of investment dollars from the Department of Energy's Office of Nuclear Energy for modeling and simulation of light water reactors and the Office of Nuclear Energy's research and development. The IDEA framework enhanced Kitware’s Computational Model Builder (CMB) while leveraging existing open-source toolkits and creating a graphical end-to-end umbrella guiding end-users and developers through the nuclear energy advanced modeling and simulation lifecycle. In addition, the work deliver strategic advancements in meshing and visualization for ensembles.

The sources of the specificity of nuclear law and environmental law

International Nuclear Information System (INIS)

Rainaud, J.M.; Cristini, R.

1983-01-01

This paper analyses the sources of the specificity of nuclear law and its relationship with environmental law as well as with ordinary law. The characteristics of nuclear law are summarized thus: recent discovery of the atom's uses and mandatory protection against its effects; internationalization of its use, leading to a limitation of national authorities competence. Several international treaties are cited (Antarctic Treaty, NPT, London Dumping Convention etc.) showing the link between radiation protection and the environment. (NEA) [fr

Positron annihilation radiation from the Galactic center - Cheshire cat' Compton scattering and the origin of excess continuum

International Nuclear Information System (INIS)

Bildsten, L.; Zurek, W.H.

1988-01-01

Two observations of the gamma-ray spectrum from the direction of the Galactic center were made by HEAO 3 in the fall of 1979 and the spring of 1980. The 2-gamma 511 keV annihilation line flux decreased by a factor of about three during the 6 months between these observations, while the excess gamma-ray continuum below the annihilation line, often interpreted as 3-gamma decay of orthopositronium, barely changed. This discrepancy in temporal behavior makes the identification of the bulk of excess continuum as 3-gamma decay of positronium difficult. It is shown that Compton scattering of the line and high-energy radiation provides a natural explanation for the surprisingly small changes seen in the excess continuum. Scattered photons are delayed by a time corresponding to the size of the scattering region. For the annihilation source in the Galactic center, this distance is probably a fraction of a parsec. Thus, even after the high-energy continuum and annihilation line are gone, low-energy Compton-scattered photons can still be detected with an almost unchanged flux. 23 references

Design and application for a high-temperature nuclear heat source

International Nuclear Information System (INIS)

Quade, R.N.

1980-01-01

Recent actions by OPEC have sharply increased interest in the United States in synfuels, with coal being the logical choice for the carbon source. Two coal liquefaction processes, direct and indirect, have been examined. Each can produce about 50% more output when coupled to an HTGR for process heat. The nuclear reactor designed for process heat has a power output of 842MW(t), a core outlet temperature of 950 0 C (1742 0 F), and an intermediate helium loop to separate the heat source from the process heat exchangers. Steam-methane reforming is the reference process. As part of the development of a nuclear process heat system, a computer code, Process Heat Reactor Evaluation and Design, is being developed. This code models both the reactor plant and a steam reforming plant. When complete, the program will have the capability to calculate an overall mass and heat balance, size the plant components, and estimate the plant cost for a wide variety of independent variables. (author)

Nuclear source of district heating in the north-east region of Russia

International Nuclear Information System (INIS)

Dolgov, V.V.

1998-01-01

The operation of the Bilibin Nuclear Co-generation Plant (BNCP) as a local district heating source is reviewed in this paper. Specific features of the BNCP power unit are given with special emphases on the components of the technological scheme, which are involved in the heat production and supply to the consumers. The scheme of steam extraction from the turbine, the flow diagram of steam in the turbine, as well as the three circuit heat removal system are described. The numerical characteristics of the nuclear heat supply system in various operating modes are presented. The real information characterizing current radiological conditions in the vicinity of the heat generation and distribution equipment is also presented in the paper. The BNCP technical and economical characteristics are compared with those of conventional energy sources. Both advantages and some problems revealed during the twenty-year experience of the BNCP nuclear heat utilization are generally assessed. Safety and reliability characteristics of the reactor and the heat supply system are also described. (author)

Lattice gravity near the continuum limit

International Nuclear Information System (INIS)

Feinberg, G.; Friedberg, R.; Lee, T.D.; Ren, H.C.

1984-01-01

We prove that the lattice gravity always approaches the usual continuum limit when the link length l -> 0, provided that certain general boundary conditions are satisfied. This result holds for any lattice, regular or irregular. Furthermore, for a given lattice, the deviation from its continuum limit can be expressed as a power series in l 2 . General formulas for such a perturbative calculation are given, together with a number of illustrative examples, including the graviton propagator. The lattice gravity satisfies all the invariance properties of Einstein's theory of general relativity. In addition, it is symmetric under a new class of transformations that are absent in the usual continuum theory. The possibility that the lattice theory (with a nonzero l) may be more fundamental is discussed. (orig.)

Continuum Level Density in Complex Scaling Method

International Nuclear Information System (INIS)

Suzuki, R.; Myo, T.; Kato, K.

2005-01-01

A new calculational method of continuum level density (CLD) at unbound energies is studied in the complex scaling method (CSM). It is shown that the CLD can be calculated by employing the discretization of continuum states in the CSM without any smoothing technique

RENEWAL OF BASIC LAWS AND PRINCIPLES FOR POLAR CONTINUUM THEORIES (Ⅱ)-MICROMORPHIC CONTINUUM THEORY AND COUPLE STRESS THEORY

Institute of Scientific and Technical Information of China (English)

戴天民

2003-01-01

The purpose is to reestablish the balance laws of momentum, angular momentumand energy and to derive the corresponding local and nonlocal balance equations formicromorphic continuum mechanics and couple stress theory. The desired results formicromorphic continuum mechanics and couple stress theory are naturally obtained via directtransitions and reductions from the coupled conservation law of energy for micropolarcontinuum theory, respectively. The basic balance laws and equation s for micromorphiccontinuum mechanics and couple stress theory are constituted by combining these resultsderived here and the traditional conservation laws and equations of mass and microinertiaand the entropy inequality. The incomplete degrees of the former related continuum theoriesare clarified. Finally, some special cases are conveniently derived.

The International Safety Framework for nuclear power source applications in outer space-Useful and substantial guidance

Science.gov (United States)

Summerer, L.; Wilcox, R. E.; Bechtel, R.; Harbison, S.

2015-06-01

In 2009, the International Safety Framework for Nuclear Power Source Applications in Outer Space was adopted, following a multi-year process that involved all major space faring nations under the auspices of a partnership between the UN Committee on the Peaceful Uses of Outer Space and the International Atomic Energy Agency. The Safety Framework reflects an international consensus on best practices to achieve safety. Following the 1992 UN Principles Relevant to the Use of Nuclear Power Sources in Outer Space, it is the second attempt by the international community to draft guidance promoting the safety of applications of nuclear power sources in space missions. NPS applications in space have unique safety considerations compared with terrestrial applications. Mission launch and outer space operational requirements impose size, mass and other space environment limitations not present for many terrestrial nuclear facilities. Potential accident conditions could expose nuclear power sources to extreme physical conditions. The Safety Framework is structured to provide guidance for both the programmatic and technical aspects of safety. In addition to sections containing specific guidance for governments and for management, it contains technical guidance pertinent to the design, development and all mission phases of space NPS applications. All sections of the Safety Framework contain elements directly relevant to engineers and space mission designers for missions involving space nuclear power sources. The challenge for organisations and engineers involved in the design and development processes of space nuclear power sources and applications is to implement the guidance provided in the Safety Framework by integrating it into the existing standard space mission infrastructure of design, development and operational requirements, practices and processes. This adds complexity to the standard space mission and launch approval processes. The Safety Framework is deliberately

Design and analysis of nuclear battery driven by the external neutron source

International Nuclear Information System (INIS)

Wang, Sanbing; He, Chaohui

2014-01-01

Highlights: • A new type of space nuclear power called NBDEx is investigated. • NBDEx with 252 Cf has better performance than RTG with similar structure. • Its thermal power gets great improvement with increment of fuel enrichment. • The service life of NBDEx is about 2.96 year. • The launch abortion accident analysis fully demonstrates the advantage of NBDEx. - Abstract: Based on the theory of ADS (Accelerator Driven Subcritical reactor), a new type of nuclear battery was investigated, which was composed of a subcritical fission module and an isotope neutron source, called NBDEx (Nuclear Battery Driven by External neutron source). According to the structure of GPHS-RTG (General Purpose Heat Source Radioisotope Thermoelectric Generator), the fuel cell model and fuel assembly model of NBDEx were set up, and then their performances were analyzed with MCNP code. From these results, it was found that the power and power density of NBDEx were almost six times higher than the RTG’s. For fully demonstrating the advantage of NBDEx, the analysis of its impact factors was performed with MCNP code, and its lifetime was also calculated using the Origen code. These results verified that NBDEx was more suitable for the space missions than RTG

Determination of sulfur in coal and ash slurry by high-resolution continuum source electrothermal molecular absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Nakadi, Flávio V.; Rosa, Lilian R.; Veiga, Márcia A.M.S. da, E-mail: mamsveiga@ffclrp.usp.br

2013-10-01

We propose a procedure for the determination of sulfur in coal slurries by high resolution continuum source electrothermal molecular absorption spectrometry. The slurry, whose concentration is 1 mg mL{sup −1}, was prepared by mixing 50 mg of the sample with 5% v/v nitric acid and 0.04% m/v Triton X-100 and was homogenized manually. It sustained good stability. The determination was performed via CS molecular absorption at 257.592 nm, and the optimized vaporization temperature was 2500 °C. The accuracy of the method was ensured by analysis of certified reference materials SRM 1632b (trace elements in coal) and SRM 1633b (coal fly ash) from the National Institute of Standards and Technology, using external calibration with aqueous standards prepared in the same medium and used as slurry. We achieved good agreement with the certified reference materials within 95% confidence interval, LOD of 0.01% w/w, and RSD of 6%, which confirms the potential of the proposed method. - Highlights: • HR-CS ET MAS as a technique to determine sulfur in coal and ash • Utilization of (coal and coal fly ash) slurry as a sample preparation • Simple and fast method, which uses external calibration with aqueous standards without chemical modifier.

Characterization of noise sources in nuclear power reactors

International Nuclear Information System (INIS)

Andhill, Gustav

2004-03-01

Algorithms for unfolding noise sources in nuclear power reactors are investigated. No preliminary knowledge of the functional form of the space dependence is assumed in contrast to the usual methods. The advantage of this is that the algorithms can be applied to various noise sources and the results can be interpreted without expert knowledge. The results can therefore be directly displayed to the plant operators. The precision will however be lower than that of the traditional methods because of the arbitrariness in the type of the noise source. Two different reactor models are studied. First a simple one-dimensional and homogeneous core is considered. Three methods for finding the noise source from the measured flux noise are investigated here. The first one is based on the inversion of an appropriate pre-calculated noise source-to-measured induced neutron noise transfer function. The second one relies on the use of the measured neutron noise as the solution of the equations giving the neutron noise induced by a given noise source. The advantage of this second method is that the noise source can be determined directly, i.e., without any Inversion of a transfer function. The second method is thus called the direct method. The last method is based on a reconstruction of the noise source by spatial Fourier expansion. The two latter techniques are found usable for different locations of the actual noise source in the 1D core. They are therefore tried on more sophisticated two-dimensional models of cores. The direct method is able both to determine the nature of the noise source and its location in 2D

Characterization of noise sources in nuclear power reactors

Energy Technology Data Exchange (ETDEWEB)

Andhill, Gustav

2004-03-01

Algorithms for unfolding noise sources in nuclear power reactors are investigated. No preliminary knowledge of the functional form of the space dependence is assumed in contrast to the usual methods. The advantage of this is that the algorithms can be applied to various noise sources and the results can be interpreted without expert knowledge. The results can therefore be directly displayed to the plant operators. The precision will however be lower than that of the traditional methods because of the arbitrariness in the type of the noise source. Two different reactor models are studied. First a simple one-dimensional and homogeneous core is considered. Three methods for finding the noise source from the measured flux noise are investigated here. The first one is based on the inversion of an appropriate pre-calculated noise source-to-measured induced neutron noise transfer function. The second one relies on the use of the measured neutron noise as the solution of the equations giving the neutron noise induced by a given noise source. The advantage of this second method is that the noise source can be determined directly, i.e., without any Inversion of a transfer function. The second method is thus called the direct method. The last method is based on a reconstruction of the noise source by spatial Fourier expansion. The two latter techniques are found usable for different locations of the actual noise source in the 1D core. They are therefore tried on more sophisticated two-dimensional models of cores. The direct method is able both to determine the nature of the noise source and its location in 2D.

Energy absorption due to spatial resonance of Alfven waves at continuum tip

Science.gov (United States)

Chen, Eugene; Berk, Herb; Breizman, Boris; Zheng, Linjin

2011-10-01

We investigate the response of tokamak plasma to an external driving source. An impedance-like function depending on the driving frequency that is growing at a small rate, is calculated and interpreted with different source profiles. Special attention is devoted to the case where driving frequency approaches that of the TAE continuum tip. The calculation can be applied to the estimation of TAE damping rate by analytically continuing the inverse of the impedance function to the lower half plane. The root of the analytic continuation corresponds to the existence of a quasi-mode, from which the damping rate can be found.

Spectrometer system using a modular echelle spectrograph and a laser-driven continuum source for simultaneous multi-element determination by graphite furnace absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Geisler, Sebastian; Okruss, Michael; Becker-Ross, Helmut; Huang, Mao Dong, E-mail: huang@isas.de; Esser, Norbert; Florek, Stefan

2015-05-01

A multi-element absorption spectrometer system has been developed based on a laser-driven xenon continuum source and a modular simultaneous echelle spectrograph (MOSES), which is characterized by a minimized number of optical components resulting in high optical throughput, high transmittance and high image quality. The main feature of the new optical design is the multifunction usage of a Littrow prism, which is attached on a rotation stage. It operates as an order-sorter for the echelle grating in a double-pass mode, as a fine positioning device moving the echelle spectrum on the detector, and as a forwarder to address different optical components, e.g., echelle gratings, in the setup. Using different prisms, which are mounted back to back on the rotation stage, a multitude of different spectroscopic modes like broad-range panorama observations, specific UV–VIS and NIR studies or high resolution zoom investigations of variable spectral channels can be realized. In the UV panorama mode applied in this work, MOSES has simultaneously detectable wavelength coverage from 193 nm to 390 nm with a spectral resolution λ/Δλ of 55,000 (3-pixel criterion). In the zoom mode the latter can be further increased by a factor of about two for a selectable section of the full wavelength range. The applicability and the analytical performance of the system were tested by simultaneous element determination in a graphite furnace, using eight different elements. Compared to an instrument operating in the optimized single line mode, the achieved analytical sensitivity using the panorama mode was typically a factor of two lower. Using the zoom mode for selected elements, comparable sensitivities were obtained. The results confirm the influence of the different spectral resolutions. - Highlights: • Echelle spectrometer with a full frame CCD array detector • High and variable spectral resolution from λ/Δλ of 55,000 to 95,000 • Laser-driven continuum light source �

Physics of the continuum of borromean nuclei

Energy Technology Data Exchange (ETDEWEB)

Vaagen, J S; Rogde, T [Dept. of Physics, Univ. of Bergen (Norway); Danilin, B V [RRC The Kurchatov Inst., Kurchatov, Moscow (Russian Federation); Ershov, S N [JINR, Dubna, Moscow (Russian Federation); Thompson, I J [Dept. of Physics, Univ. of Surrey, Guildford (United Kingdom); Zhukov, M V [Chalmers Univ. of Technology and Goeteborg Univ., Goeteborg (Sweden); RNBT Collaboration

1998-06-01

The continuum states of two-neutron halo nuclei are calculated in the method of hyperspherical harmonics. Using DWIA theory appropriate for dilute halo matter we have probed the structure of the low-lying {sup 6}He continuum via calculations of charge-exchange and inelastic scattering. (orig.)

Gamma-ray continuum spectra from heavy ion reactions

International Nuclear Information System (INIS)

Beene, J.R.; Halbert, M.L.; Hensley, D.C.; Sarantites, D.G.; Westerberg, L.W.; Geoffroy, K.; Woodward, R.

1979-01-01

A detailed quantitative analysis of the yrast continuum was attempted by subtracting the underlying statistical continnuum in a way that makes allowance for ignorance of its detailed shape. This procedure makes it possible to obtain the moment of inertia as a function of spin over a wide range of spins. The results of this continuum spectra shape analysis can be used to calculate the first and second moments of the continuum multiplicity distribution. Continuum spectra were taken during the bombardment of 150 Nd by 115- and 130-MeV beams of 20 Ne, also the first and second moments of the γ-ray multiplicity distribution as a function of the gamma energy. The moment of inertia versus spin and the deduced Yrast continuua are shown. 10 references

Sources and transformations of anthropogenic nitrogen along an urban river–estuarine continuum

Directory of Open Access Journals (Sweden)

M. J. Pennino

2016-11-01

Full Text Available Urbanization has altered the fate and transport of anthropogenic nitrogen (N in rivers and estuaries globally. This study evaluates the capacity of an urbanizing river–estuarine continuum to transform N inputs from the world's largest advanced (e.g., phosphorus and biological N removal wastewater treatment facility. Effluent samples and surface water were collected monthly along the Potomac River estuary from Washington D.C. to the Chesapeake Bay over a distance of 150 km. In conjunction with box model mass balances, nitrate stable isotopes and mixing models were used to trace the fate of urban wastewater nitrate. Nitrate concentrations and δ15N-NO3− values were higher down-estuary from the Blue Plains wastewater outfall in Washington D.C. (2.25 ± 0.62 mg L−1 and 25.7 ± 2.9 ‰, respectively compared to upper-estuary concentrations (1.0 ± 0.2 mg L−1 and 9.3 ± 1.4 ‰, respectively. Nitrate concentration then decreased rapidly within 30 km down-estuary (to 0.8 ± 0.2 mg L−1, corresponding to an increase in organic nitrogen and dissolved organic carbon, suggesting biotic uptake and organic transformation. TN loads declined down-estuary (from an annual average of 48 000 ± 5000 kg day−1 at the sewage treatment plant outfall to 23 000 ± 13 000 kg day−1 at the estuary mouth, with the greatest percentage decrease during summer and fall. Annually, there was a 70 ± 31 % loss in wastewater NO3− along the estuary, and 28 ± 6 % of urban wastewater TN inputs were exported to the Chesapeake Bay, with the greatest contribution of wastewater TN loads during the spring. Our results suggest that biological transformations along the urban river–estuary continuum can significantly transform wastewater N inputs from major cities globally, and more work is necessary to evaluate the potential of organic nitrogen and carbon to contribute to eutrophication and hypoxia.

Determination of internationally controlled materials according to provisions of the law for the regulations of nuclear source materials, nuclear fuel materials and reactors

International Nuclear Information System (INIS)

1977-01-01

According to the provisions of The Law, those stipulated as internationally controlled materials are nuclear source materials, nuclear fuel materials, moderating materials, reactors and facilities, transferred from such as the U.S.A., the U.K. and Canada on the agreements of peaceful uses of atomic energy, and nuclear fuel materials accruing therefrom. (Mori, K.)

Loop quantization as a continuum limit

International Nuclear Information System (INIS)

Manrique, Elisa; Oeckl, Robert; Weber, Axel; Zapata, Jose A

2006-01-01

We present an implementation of Wilson's renormalization group and a continuum limit tailored for loop quantization. The dynamics of loop-quantized theories is constructed as a continuum limit of the dynamics of effective theories. After presenting the general formalism we show as a first explicit example the 2D Ising field theory, an interacting relativistic quantum field theory with local degrees of freedom quantized by loop quantization techniques

Continuum emission from classical nova winds

International Nuclear Information System (INIS)

Harkness, R.P.

1983-01-01

The emergent continuum of a slow classical nova during outburst is considered in the quasi-steady optically thick, transonic wind model. Models are presented for various steady mass loss rates and are related to the evolution of slow novae during decline and early post-maximum. The continuum emission is found to depart radically from a blackbody spectrum and to exhibit features common to highly extended stellar atmospheres. (author)

Advancing Explosion Source Theory through Experimentation: Results from Seismic Experiments Since the Moratorium on Nuclear Testing

Science.gov (United States)

Bonner, J. L.; Stump, B. W.

2011-12-01

On 23 September 1992, the United States conducted the nuclear explosion DIVIDER at the Nevada Test Site (NTS). It would become the last US nuclear test when a moratorium ended testing the following month. Many of the theoretical explosion seismic models used today were developed from observations of hundreds of nuclear tests at NTS and around the world. Since the moratorium, researchers have turned to chemical explosions as a possible surrogate for continued nuclear explosion research. This talk reviews experiments since the moratorium that have used chemical explosions to advance explosion source models. The 1993 Non-Proliferation Experiment examined single-point, fully contained chemical-nuclear equivalence by detonating over a kiloton of chemical explosive at NTS in close proximity to previous nuclear explosion tests. When compared with data from these nearby nuclear explosions, the regional and near-source seismic data were found to be essentially identical after accounting for different yield scaling factors for chemical and nuclear explosions. The relationship between contained chemical explosions and large production mining shots was studied at the Black Thunder coal mine in Wyoming in 1995. The research led to an improved source model for delay-fired mining explosions and a better understanding of mining explosion detection by the International Monitoring System (IMS). The effect of depth was examined in a 1997 Kazakhstan Depth of Burial experiment. Researchers used local and regional seismic observations to conclude that the dominant mechanism for enhanced regional shear waves was local Rg scattering. Travel-time calibration for the IMS was the focus of the 1999 Dead Sea Experiment where a 10-ton shot was recorded as far away as 5000 km. The Arizona Source Phenomenology Experiments provided a comparison of fully- and partially-contained chemical shots with mining explosions, thus quantifying the reduction in seismic amplitudes associated with partial

Tracking of Radioactive Sources in Malaysian Nuclear Agency

International Nuclear Information System (INIS)

Mohd Fazlie Abdul Rashid; Noor Fadilla Ismail; Khairuddin Mohamad Kontol; Hairul Nizam Idris; Azimawati Ahmad; Suzilawati Muhd Sarowi; Raymond, Y.T.L.

2014-01-01

Radioactive materials are used in Malaysian Nuclear Agency for various purposes such as research and development, calibration, tracer and irradiation. Inventory of radioactive materials is crucial for ensuring the security and control of all radioactive materials owned and used so as not to be lost or fall into the hands of people who do not have permission to possess or use it. Experience in many countries around the world proves that the improper inventory of radioactive material would lead to loss of control of radioactive materials and will eventually cause an accident of radiation exposure. Radioactive material database has been developed for the need to ensure traceability of radioactive materials in Malaysian Nuclear Agency. Records of radioactive materials are regularly updated based on the classification of the type of radionuclide, the total distribution in each building and the initial activity of radioactive sources. (author)

The problem of space nuclear power sources collisions with artificial space objects in near-earth orbits

International Nuclear Information System (INIS)

Gafarov, A.A.

1993-01-01

Practically all space objects with onboard nuclear power sources stay in earth satellite orbits with an orbital lifetime long enough to reduce their radioactivity to levels presenting no danger for the Earth population. One of the reasons for orbit lifetime reduction can be collisions with other space objects in near-earth orbits. The possible consequence of collisions can be partial, or even complete, destruction of the spacecraft with an onboard nuclear power source; as well as delivery of additional impulse both to the spacecraft and its fragments. It is shown that collisions in orbit do not cause increase of radiation hazard for the Earth population if there is aerodynamic breakup of nuclear power sources into fragments of safe sizes during atmospheric reentry

Continuum solutions of the Klein-Gordon equation

International Nuclear Information System (INIS)

Jansen, G.; Pusch, M.; Soff, G.

1987-10-01

We construct explicit solutions of the Klein-Gordon equation for continuum states. The role of the energy in the single-particle Klein-Gordon theory is elucidated. Special emphasis is laid on the determination of resonance states in the continuum for overcritical potentials. As examples for long-range interaction we depict solutions for the Coulomb potential of a point-like nucleus as an extended nucleus. The square-well potential and the exponential potential are treated to exemplify pecularities of short-range interactions. We also derive continuum solutions for a scalar interaction of square-well type. Finally we discuss the behaviour of a spin-0 particle in an external homogeneous magnetic field. (orig.)

Continuum shell-model with complicated configurations

International Nuclear Information System (INIS)

Barz, H.W.; Hoehn, J.

1977-05-01

The traditional shell model has been combined with the coupled channels method in order to describe resonance reactions. For that purpose the configuration space is divided into two subspaces (Feshbach projection method). Complicated shell-model configurations can be included into the subspace of discrete states which contains the single particle resonance states too. In the subspace of scattering states the equation of motion is solved by using the coupled channels method. Thereby the orthogonality between scattering states and discrete states is ensured. Resonance states are defined with outgoing waves in all channels. By means of simple model calculations the special role of the continuum is investigated. In this connection the energy dependence of the resonance parameters, the isospin mixture via the continuum, threshold effect, as well as the influence of the number of channels taken into account on the widths, positions and dipole strengths of the resonance are discussed. The model is mainly applied to the description of giant resonances excited by the scattering of nucleons and photo-nucleus processes (source term method) found in reactions on light nuclei. The giant resonance observed in the 15 N(p,n) reaction is explained by the inclusion of 2p-2h states. The same is true for the giant resonance in 13 C(J = 1/2, 3/2) as well as for the giant resonance built on the first 3 - state in 16 O. By means of a correlation analysis for the reduced widths amplitudes an access to the doorway conception is found. (author)

Determination of Chlorine in Milk via Molecular Absorption of SrCl Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry.

Science.gov (United States)

Ozbek, Nil; Akman, Suleyman

2016-07-20

Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1).

Continuum of active nuclei of galaxies

International Nuclear Information System (INIS)

Boisson, C.; Durret, F.

1987-01-01

Most of the luminosity of active galactic nuclei (NAG) is radiated in the form of a continuum extending from radio to X-ray energies. It is important to understand the origin of this continuum in order to explain the relative importance of thermal and non-thermal processes in the different classes of NAG. We present here the observational aspect. A detailed study of the mechanisms will be presented by J.L. Masnou [fr

10 CFR 40.11 - Persons using source material under certain Department of Energy and Nuclear Regulatory...

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Persons using source material under certain Department of Energy and Nuclear Regulatory Commission contracts. 40.11 Section 40.11 Energy NUCLEAR REGULATORY... certain Department of Energy and Nuclear Regulatory Commission contracts. Except to the extent that...

A source term estimation method for a nuclear accident using atmospheric dispersion models

DEFF Research Database (Denmark)

Kim, Minsik; Ohba, Ryohji; Oura, Masamichi

2015-01-01

The objective of this study is to develop an operational source term estimation (STE) method applicable for a nuclear accident like the incident that occurred at the Fukushima Dai-ichi nuclear power station in 2011. The new STE method presented here is based on data from atmospheric dispersion...... models and short-range observational data around the nuclear power plants.The accuracy of this method is validated with data from a wind tunnel study that involved a tracer gas release from a scaled model experiment at Tokai Daini nuclear power station in Japan. We then use the methodology developed...... and validated through the effort described in this manuscript to estimate the release rate of radioactive material from the Fukushima Dai-ichi nuclear power station....

The 21st century nuclear park: A source of energy, water, food, and jobs

International Nuclear Information System (INIS)

Madia, W.J.

2004-01-01

The concept of a nuclear-powered agro-industrial complex, or 'nuplex', first advanced 40 years ago, provides an increasingly attractive means of addressing critical challenges in developing nations. The nuplex concept, updated for the 21st century, can serve as the basis for a nuclear park that provides a safe, environmentally friendly, and reliable source of energy at a cost comparable to other means of generation. This 21st century nuclear park can meet burgeoning demands for new sources of power and water, support the development of highly efficient agriculture to supply food to a growing world population, and offer employment at levels ranging from unskilled to highly skilled, thus creating opportunities for economic development and improving the quality of life in regions where it is deployed. (author)

PREFACE: Continuum Models and Discrete Systems Symposia (CMDS-12)

Science.gov (United States)

Chakrabarti, Bikas K.

2011-09-01

The 12th International Symposium on Continuum Models and Discrete Systems (CMDS-12) (http://www.saha.ac.in/cmp/cmds.12/) took place at the Saha Institute of Nuclear Physics in Kolkata from 21-25 February 2011. Previous CMDS symposia were held in Kielce (Poland, 1975), Mont Gabriel (Canada, 1977), Freudenstadt (Federal Republic of Germany, 1979), Stockholm (Sweden, 1981), Nottingham (United Kingdom, 1985), Dijon (France, 1989), Paderborn (Germany, 1992), Varna (Bulgaria, 1995), Istanbul (Turkey, 1998), Shoresh (Israel, 2003) and Paris (France, 2007). The broad interdisciplinary character, limited number of participants (not exceeding 100) and informal and friendly atmosphere of these meetings has made them a well-acknowledged place to make highly fruitful contacts and exchange ideas, methods and results. The purpose of CMDS is to bring together scientists with different backgrounds who work on continuum theories of discrete mechanical and thermodynamical systems in the fields of mathematics, theoretical and applied mechanics, physics, material science, and engineering. The spirit of the CMDS meetings is to stimulate extensive and active interdisciplinary research. The International Scientific Committee members of this conference were: David J Bergman (Chairman CMDS 10), Tel Aviv University, Israel; Bikas K Chakrabarti (Chairman CMDS 12), Saha Institute of Nuclear Physics, India; Alex Hansen, Norwegian University of Science and Technology, Norway; Hans Jürgen Herrmann, Institute for Building Materials, ETH, Switzerland; Esin Inan (Chairman CMDS 9), Istanbul Technical University, Turkey; Dominique Jeulin (Chairman CMDS 11), Ecole des Mines de Paris, France; Frank Juelicher, Max-Planck-Institute for the Physics of Complex Systems, Germany; Hikaru Kawamura, University of Osaka, Japan; Graeme Milton, University of Utah, USA; Natalia Movchan, University of Liverpool, UK; and Ping Sheng, The Hong Kong University of Science and Technology, Hong Kong. At CMDS-12 the topics

Determination of sulfur in human hair using high resolution continuum source graphite furnace molecular absorption spectrometry and its correlation with total protein and albumin

Science.gov (United States)

Ozbek, Nil; Baysal, Asli

2017-04-01

Human hair is a valuable contributor for biological monitoring. It is an information storage point to assess the effects of environmental, nutritional or occupational sources on the body. Human proteins, amino acids or other compounds are among the key components to find the sources of different effects or disorders in the human body. Sulfur is a significant one of these compounds, and it has great affinity to some metals and compounds. This property of the sulfur affects the human health positively or negatively. In this manuscript, sulfur was determined in hair samples of autistic and age-match control group children via molecular absorption of CS using a high-resolution continuum source graphite furnace atomic absorption spectrometer. For this purpose, hair samples were appropriately washed and dried at 75 °C. Then samples were dissolved in microwave digestion using HNO3 for sulfur determination. Extraction was performed with HCl hydrolysation by incubation for 24 h at 110 °C for total protein and albumin determination. The validity of the method for the sulfur determination was tested using hair standard reference materials. The results were in the uncertainty limits of the certified values at 95% confidence level. Finally correlation of sulfur levels of autistic children's hair with their total protein and albumin levels were done.

Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

Science.gov (United States)

Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

2014-11-01

In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93-105% with the repeatability in the range of 4.1-5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

Lower-energy neutron sources for increasing the sensitivity of nuclear gages for measuring the water content of bulk materials

International Nuclear Information System (INIS)

Bailey, S.M.

1977-01-01

The sensitivity of a gage using a nuclear source for measuring the water content of bulk materials, such as plastic concrete, is increased by use of a lithium or fluorine neutron nuclear source. 3 figures

Continuum simulations of water flow past fullerene molecules

DEFF Research Database (Denmark)

Popadic, A.; Praprotnik, M.; Koumoutsakos, P.

2015-01-01

We present continuum simulations of water flow past fullerene molecules. The governing Navier-Stokes equations are complemented with the Navier slip boundary condition with a slip length that is extracted from related molecular dynamics simulations. We find that several quantities of interest...... as computed by the present model are in good agreement with results from atomistic and atomistic-continuum simulations at a fraction of the cost. We simulate the flow past a single fullerene and an array of fullerenes and demonstrate that such nanoscale flows can be computed efficiently by continuum flow...

Continuum mechanics for engineers

CERN Document Server

Mase, G Thomas; Mase, George E

2009-01-01

Continuum TheoryContinuum MechanicsStarting OverNotationEssential MathematicsScalars, Vectors and Cartesian TensorsTensor Algebra in Symbolic Notation - Summation ConventionIndicial NotationMatrices and DeterminantsTransformations of Cartesian TensorsPrincipal Values and Principal DirectionsTensor Fields, Tensor CalculusIntegral Theorems of Gauss and StokesStress PrinciplesBody and Surface Forces, Mass DensityCauchy Stress PrincipleThe Stress TensorForce and Moment Equilibrium; Stress Tensor SymmetryStress Transformation LawsPrincipal Stresses; Principal Stress DirectionsMaximum and Minimum Stress ValuesMohr's Circles For Stress Plane StressDeviator and Spherical Stress StatesOctahedral Shear StressKinematics of Deformation and MotionParticles, Configurations, Deformations and MotionMaterial and Spatial CoordinatesLangrangian and Eulerian DescriptionsThe Displacement FieldThe Material DerivativeDeformation Gradients, Finite Strain TensorsInfinitesimal Deformation TheoryCompatibility EquationsStretch RatiosRot...

The water vapour continuum in near-infrared windows - Current understanding and prospects for its inclusion in spectroscopic databases

Science.gov (United States)

Shine, Keith P.; Campargue, Alain; Mondelain, Didier; McPheat, Robert A.; Ptashnik, Igor V.; Weidmann, Damien

2016-09-01

report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.

Determination of boron isotope ratios by high-resolution continuum source molecular absorption spectrometry using graphite furnace vaporizers

Science.gov (United States)

Abad, Carlos; Florek, Stefan; Becker-Ross, Helmut; Huang, Mao-Dong; Heinrich, Hans-Joachim; Recknagel, Sebastian; Vogl, Jochen; Jakubowski, Norbert; Panne, Ulrich

2017-10-01

Boron isotope amount ratios n(10B)/n(11B) have been determined by monitoring the absorption spectrum of boron monohydride (BH) in a graphite furnace using high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Bands (0 → 0) and (1 → 1) for the electronic transition X1Σ+ → A1Π were evaluated around wavelengths 433.1 nm and 437.1 nm respectively. Clean and free of memory effect molecular spectra of BH were recorded. In order to eliminate the memory effect of boron, a combination of 2% (v/v) hydrogen gas in argon and 1% trifluoromethane in argon, an acid solution of calcium chloride and mannitol as chemical modifiers was used. Partial least square regression (PLS) for analysis of samples and reference materials were applied. For this, a spectral library with different isotopes ratios for PLS regression was built. Results obtained around the 433.1 nm and 437.1 nm spectral regions are metrologically compatible with those reported by mass spectrometric methods. Moreover, for the evaluated region of 437 nm, an accuracy of 0.15‰ is obtained as the average deviation from the isotope reference materials. Expanded uncertainties with a coverage factor of k = 2 range between 0.15 and 0.44‰. This accuracy and precision are compatible with those obtained by mass spectrometry for boron isotope ratio measurements.

Map of fluid flow in fractal porous medium into fractal continuum flow.

Science.gov (United States)

Balankin, Alexander S; Elizarraraz, Benjamin Espinoza

2012-05-01

This paper is devoted to fractal continuum hydrodynamics and its application to model fluid flows in fractally permeable reservoirs. Hydrodynamics of fractal continuum flow is developed on the basis of a self-consistent model of fractal continuum employing vector local fractional differential operators allied with the Hausdorff derivative. The generalized forms of Green-Gauss and Kelvin-Stokes theorems for fractional calculus are proved. The Hausdorff material derivative is defined and the form of Reynolds transport theorem for fractal continuum flow is obtained. The fundamental conservation laws for a fractal continuum flow are established. The Stokes law and the analog of Darcy's law for fractal continuum flow are suggested. The pressure-transient equation accounting the fractal metric of fractal continuum flow is derived. The generalization of the pressure-transient equation accounting the fractal topology of fractal continuum flow is proposed. The mapping of fluid flow in a fractally permeable medium into a fractal continuum flow is discussed. It is stated that the spectral dimension of the fractal continuum flow d(s) is equal to its mass fractal dimension D, even when the spectral dimension of the fractally porous or fissured medium is less than D. A comparison of the fractal continuum flow approach with other models of fluid flow in fractally permeable media and the experimental field data for reservoir tests are provided.

Frequency chirpings in Alfven continuum

Science.gov (United States)

Wang, Ge; Berk, Herb; Breizman, Boris; Zheng, Linjin

2017-10-01

We have used a self-consistent mapping technique to describe both the nonlinear wave-energetic particle resonant interaction and its spatial mode structure that depends upon the resonant energetic particle pressure. At the threshold for the onset of the energetic particle mode (EPM), strong chirping emerges in the lower continuum close to the TAE gap and then, driven by strong continuum damping, chirps rapidly to lower frequencies in the Alfven continuum. An adiabatic theory was developed that accurately replicated the results from the simulation where the nonlinearity was only due to the EPM resonant particles. The results show that the EPM-trapped particles have their action conserved during the time of rapid chirping. This adiabaticity enabled wave trapped particles to be confined within their separatrix, and produce even larger resonant structures, that can produce a large amplitude mode far from linearly predicted frequencies. In the present work we describe the effect of additional MHD nonlinearity to this calculation. We studied how the zonal flow component and its nonlinear feedback to the fundamental frequency and found that the MHD nonlinearity doesn't significantly alter the frequency chirping response that is predicted by the calculation that neglects the MHD nonlinearity.

Defining and testing a granular continuum element

Energy Technology Data Exchange (ETDEWEB)

Rycroft, Chris H.; Kamrin, Ken; Bazant, Martin Z.

2007-12-03

Continuum mechanics relies on the fundamental notion of amesoscopic volume "element" in which properties averaged over discreteparticles obey deterministic relationships. Recent work on granularmaterials suggests a continuum law may be inapplicable, revealinginhomogeneities at the particle level, such as force chains and slow cagebreaking. Here, we analyze large-scale Discrete-Element Method (DEM)simulations of different granular flows and show that a "granularelement" can indeed be defined at the scale of dynamical correlations,roughly three to five particle diameters. Its rheology is rather subtle,combining liquid-like dependence on deformation rate and solid-likedependence on strain. Our results confirm some aspects of classicalplasticity theory (e.g., coaxiality of stress and deformation rate),while contradicting others (i.e., incipient yield), and can guide thedevelopment of more realistic continuum models.

Nuclear and x-ray spectroscopy with radioactive sources. Fifteenth annual progress report

International Nuclear Information System (INIS)

Rink, R.W.; Wood, J.L.

1979-01-01

Research during the year is summarized briefly for the following areas: nuclear spectroscopy (including nuclear systematics and models and experimental studies of heavy-nucleus decays), x rays from radioactive sources (including L-subshell x-ray fluorescence and Coster-Kronig yields and the measurement of tailing corrections in low-energy coincidence intensity determinations), and miscellaneous topics concerning computer codes and equipment. One may assume publication of completed work in the usual channels. Lists of personnel, publications, etc., are included. 7 figures

Scoping Study of Machine Learning Techniques for Visualization and Analysis of Multi-source Data in Nuclear Safeguards

Energy Technology Data Exchange (ETDEWEB)

Cui, Yonggang

2018-05-07

In implementation of nuclear safeguards, many different techniques are being used to monitor operation of nuclear facilities and safeguard nuclear materials, ranging from radiation detectors, flow monitors, video surveillance, satellite imagers, digital seals to open source search and reports of onsite inspections/verifications. Each technique measures one or more unique properties related to nuclear materials or operation processes. Because these data sets have no or loose correlations, it could be beneficial to analyze the data sets together to improve the effectiveness and efficiency of safeguards processes. Advanced visualization techniques and machine-learning based multi-modality analysis could be effective tools in such integrated analysis. In this project, we will conduct a survey of existing visualization and analysis techniques for multi-source data and assess their potential values in nuclear safeguards.

THE BOLOCAM GALACTIC PLANE SURVEY. X. A COMPLETE SPECTROSCOPIC CATALOG OF DENSE MOLECULAR GAS OBSERVED TOWARD 1.1 mm DUST CONTINUUM SOURCES WITH 7.°5 ≤ l ≤ 194°

International Nuclear Information System (INIS)

Shirley, Yancy L.; Svoboda, Brian; Ellsworth-Bowers, Timothy P.; Schlingman, Wayne M.; Ginsburg, Adam; Battersby, Cara; Stringfellow, Guy; Glenn, Jason; Bally, John; Rosolowsky, Erik; Gerner, Thomas; Mairs, Steven; Dunham, Miranda K.

2013-01-01

The Bolocam Galactic Plane Survey (BGPS) is a 1.1 mm continuum survey of dense clumps of dust throughout the Galaxy covering 170 deg 2 . We present spectroscopic observations using the Heinrich Hertz Submillimeter Telescope of the dense gas tracers, HCO + and N 2 H + 3-2, for all 6194 sources in the BGPS v1.0.1 catalog between 7.°5 ≤ l ≤ 194°. This is the largest targeted spectroscopic survey of dense molecular gas in the Milky Way to date. We find unique velocities for 3126 (50.5%) of the BGPS v1.0.1 sources observed. Strong N 2 H + 3-2 emission (T mb > 0.5 K) without HCO + 3-2 emission does not occur in this catalog. We characterize the properties of the dense molecular gas emission toward the entire sample. HCO + is very sub-thermally populated and the 3-2 transitions are optically thick toward most BGPS clumps. The median observed line width is 3.3 km s –1 consistent with supersonic turbulence within BGPS clumps. We find strong correlations between dense molecular gas integrated intensities and 1.1 mm peak flux and the gas kinetic temperature derived from previously published NH 3 observations. These intensity correlations are driven by the sensitivity of the 3-2 transitions to excitation conditions rather than by variations in molecular column density or abundance. We identify a subset of 113 sources with stronger N 2 H + than HCO + integrated intensity, but we find no correlations between the N 2 H + /HCO + ratio and 1.1 mm continuum flux density, gas kinetic temperature, or line width. Self-absorbed profiles are rare (1.3%)

SEACAS Theory Manuals: Part II. Nonlinear Continuum Mechanics

Energy Technology Data Exchange (ETDEWEB)

Attaway, S.W.; Laursen, T.A.; Zadoks, R.I.

1998-09-01

This report summarizes the key continuum mechanics concepts required for the systematic prescription and numerical solution of finite deformation solid mechanics problems. Topics surveyed include measures of deformation appropriate for media undergoing large deformations, stress measures appropriate for such problems, balance laws and their role in nonlinear continuum mechanics, the role of frame indifference in description of large deformation response, and the extension of these theories to encompass two dimensional idealizations, structural idealizations, and rigid body behavior. There are three companion reports that describe the problem formulation, constitutive modeling, and finite element technology for nonlinear continuum mechanics systems.

Safety and Security of Radioactive Sources: Initiatives of the Forum of Nuclear Regulatory Bodies in Africa (FNRBA)

International Nuclear Information System (INIS)

Severa, R.

2010-01-01

Safety and Security of Radioactive Sources: Initiatives of the Forum of Nuclear Regulatory Bodies in Africa(FNRBA) is a regional organization comprising of nuclear regulatory bodies it’s goals are to promote the establishment of regulatory infrastructure in all countries of the Region to adopt joint action plan for implementation of self-assessment and work with Member States to upgrade their regulatory infrastructures, develop and promote a framework for capacity building in areas of radiation and nuclear safety and security, to create an opportunity for mutual support and coordination of regional initiatives by leveraging the development and utilization of regional and international resources and expertise and to serve as reference body on matters relating to nuclear and radiation safety and security in the Region. Radioactive active sources continue to play an increasingly important role in socio-economic activities on the African continent. There is also an ever increasing need to ensure that radioactive sources are utilized in a safe and secure manner

Influence of gyroradius and dissipation on the Alfven-wave continuum

International Nuclear Information System (INIS)

Connor, J.W.; Tang, W.M.; Taylor, J.B.

1982-01-01

It is well known that in ideal magnetohydrodynamics there is a continuous spectrum of real frequencies associated with a singularity of the shear Alfven waves on the surface k/sub parallel to/v/sub A/ = omega. It is also known that the introduction of first-order gyroradius effects eliminates the continuum. In the present work we examine the influence of the full gyroradius response and of dissipation on the continuum. In the absence of dissipation we first confirm that if only first-order gyroradius effects are incorporated, the continuum disappears. However, when the full gyroradius response is included, this discrete spectrum vanishes, and a new continuum (associated with singularities at k/sub parallel to/v/sub A/ = 0) appears. The introduction of collisional dissipation removes the original MHD continuum leaving discrete modes whose frequency tends to zero with the collision rate as ν/sup 1/3/. collisions also remove the new continuum of the full gyroradius model leaving discrete modes whose frequency tends to zero as (log ν) -1 . Collisionless Landau damping has a similar effect

A Behavioral Continuum: A Look at Personality Disorders.

Science.gov (United States)

Harris, George; Kirk, Nancy A.

1985-01-01

Suggests that narcissistic, borderline, and antisocial personality disorders are not discrete diagnostic categories, but that they lie along a continuum and have in common the dimensions of degree of self-centeredness and degree of differentiation. Presents evidence supporting existence of continuum of behavior rather than discrete diagnostic…

Nuclear energy: today and tomorrow in the RSA

International Nuclear Information System (INIS)

Schumann, W.A.

1985-01-01

The energy content of relevant materials and world energy resources are briefly discussed. A short review is given of the typical fission fuel cycle. The article also covers the fundamental aspects of uranium enrichment and the disposal of radio-active material as part of the conventional nuclear fuel cycle. The present nuclear energy situation and possible alternatives for the future of power supply in South Africa is discussed. The alternative energy production systems are based on the spectrum of choices presented by the nuclear energy continuum of nuclear fission, fusion and spallation particle accelerator systems

Nuclear vorticity and the low-energy nuclear response. Towards the neutron drip line

International Nuclear Information System (INIS)

Papakonstantinou, P.; Athens Univ.; Wambach, J.; Ponomarev, V.Y.; Mavrommatis, E.

2004-01-01

The transition density and current provide valuable insight into the nature of nuclear vibrations. Nuclear vorticity is a quantity related to the transverse transition current. In this work, we study the evolution of the strength distribution, related to density fluctuations, and the vorticity strength distribution, as the neutron drip line is approached. Our results on the isoscalar, natural-parity multipole response of Ni isotopes, obtained by using a self-consistent Skyrme-Hartree-Fock+continuum RPA model, indicate that, close to the drip line, the low-energy response is dominated by L > 1 vortical transitions. (orig.)

Main Activities to Improve the Control of Radioactive Sources and Maintain an Effective Regulatory Nuclear Systems in Brazil

International Nuclear Information System (INIS)

Marechal, M.H.

2016-01-01

Since 2006, the Directorate of Nuclear Safety and Security, DRS, of National Nuclear Energy Commission, CNEN, has gone through many improvements. In 2006 CNEN signed the commitment to the recommendations of the Code of Conduct on The Safety and Security of Radioactive Sources and the Guidance on The Import and Export of Radioactive Sources. The DRS is responsible for the licensing and control of nuclear facilities, fuel cycle, waste management and the control of radioactive sources and authorizations of medical and industrial installations. In 2009 the department responsible for the control of radioactive sources and authorizations of medical and industrial installations implemented an “Electronic Management System” in which this System integrates the transport department and waste management department. The Electronic Management System is linked to the register of radioactive sources and facilities and there is an access on line to the Customs, making the control of import and export of radioactive sources robust, efficient and fast. During the period from 2006 until 2015 the most relevant regulations related to the control of radioactive sources and authorizations of medical and industrial installations were reviewed and some were elaborated and issued. These documents were in line with the Categorization of Radioactive Sources and the International Basic Safety Standards, issued in the IAEA Safety Standard Series as General Safety Requirements Part 3 (GSR Part 3). The paper describes all the steps that were adopted in order to implement these systems and the improvements on our Nuclear Regulatory Systems. (author)

Preliminary Study of the Efficacy of Using Nuclear Resonance Fluorescence with Quasi-Monoenergetic Gamma-Ray Sources for Nuclear Safeguards Assay

Energy Technology Data Exchange (ETDEWEB)

Johnson, M S; McNabb, D P; Hall, J M; Gonzalez, J J

2011-02-17

We have studied the efficacy of using nuclear resonance fluorescence (NRF)-based techniques to assay spent nuclear fuel for Pu content using quasi-monoenergetic sources. We have developed two techniques to precisely determine the Pu content in a fuel rod/pin. One of our approaches is virtually free of systematic uncertainties. Using analytical models, we have determined the amount of time required to measure the Pu content in spent nuclear fuel rods and spent fuel assemblies to within 1% precision. We note that Pu content can be determined in a fuel assembly about as fast as in a single fuel pin. The performance of NRF-based assay techniques with improved photon sources, which are currently under development, will also estimated. For follow-on research we propose to: (1) Construct research prototype detection systems for both of the NRF-based assay systems proposed in this paper and measure their calibration curves; (2) Determine the systematic errors associated with both assay methods, explore ways to reduce the errors and fold the results into future performance calculations; (3) Develop an algorithm to assay a fuel assembly; (4) Perform validation measurements using a single pin and scaled assemblies; (5) Research and develop current-mode detection and/or threshold detection techniques to improve assay times; (6) Characterize the flux of newly constructed sources and fold the results into the calculations presented here to determine the feasibility of a variety of proposed sources; and (7) Collaborate with others in the safeguards community to build a prototype system and perform an NRF-based assay demonstration on spent fuel.

Determination of silicon in biomass and products of pyrolysis process via high-resolution continuum source atomic absorption spectrometry.

Science.gov (United States)

Nakadi, Flávio V; Prodanov, Caroline; Boschetti, Wiliam; Vale, Maria Goreti R; Welz, Bernhard; de Andrade, Jailson B

2018-03-01

Thermochemical processes can convert the biomass into fuels, such as bio-oil. The biomass submitted to pyrolysis process, such as fibers, are generally rich in silicon, an element that can lead to damages in an engine when there is high concentration in a fuel. High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) is an interesting alternative for Si determination in the products and byproducts of the pyrolysis process because, besides the flame (F) and graphite furnace (GF) atomizers, it has enhanced the application of direct analysis of solid samples (SS) within GF. This study aimed the development of methods to determine Si in biomass samples, their products and byproducts using HR-CS AAS. A high-resolution continuum source atomic absorption spectrometer contrAA 700 equipped with F and GF atomizers was used throughout the study. HR-CS F AAS (λ = 251.611nm, 1 detection pixel, N 2 O/C 2 H 2 flame) was used to evaluate Si content in biomass and ash, after a microwave-assisted acid digestion with HNO 3 and HF. HR-CS GF AAS (T pyr = 1400°C, T atom = 2650°C) has evaluated Si in pyrolysis water and bio-oil at 251.611nm, and in peach pit biomass and ash at 221.174nm using SS, both wavelengths with 1 detection pixel. Rhodium (300μg) was applied as permanent modifier and 10μgPd + 6μg Mg were pipetted onto the standards/samples at each analysis. Three different biomass samples were studied: palm tree fiber, coconut fiber and peach pit, and three certified reference materials (CRM) were used to verify the accuracy of the methods. The figures of merit were LOD 0.09-20mgkg -1 , and LOQ 0.3-20mgkg -1 , considering all the methods. There were no significant differences between the CRM certified values and the determined ones, using a Student t-test with a confidence interval of 95% (n = 5). Si concentration ranged from 0.11-0.92% mm -1 , 1.1-1.7mgkg -1 , 3.3-13mgkg -1 , and 0.41-1.4%mm -1 , in biomass, bio-oil, pyrolysis water and ash, respectively

Teaching Continuum Mechanics in a Mechanical Engineering Program

Science.gov (United States)

Liu, Yucheng

2011-01-01

This paper introduces a graduate course, continuum mechanics, which is designed for and taught to graduate students in a Mechanical Engineering (ME) program. The significance of continuum mechanics in engineering education is demonstrated and the course structure is described. Methods used in teaching this course such as topics, class…

Performance test of multicomponent quantum mechanical calculation with polarizable continuum model for proton chemical shift.

Science.gov (United States)

Kanematsu, Yusuke; Tachikawa, Masanori

2015-05-21

Multicomponent quantum mechanical (MC_QM) calculations with polarizable continuum model (PCM) have been tested against liquid (1)H NMR chemical shifts for a test set of 80 molecules. Improvement from conventional quantum mechanical calculations was achieved for MC_QM calculations. The advantage of the multicomponent scheme could be attributed to the geometrical change from the equilibrium geometry by the incorporation of the hydrogen nuclear quantum effect, while that of PCM can be attributed to the change of the electronic structure according to the polarization by solvent effects.

Problems and management of radioactive sources and measures against illicit trafficking of nuclear materials in Bulgaria

International Nuclear Information System (INIS)

Strezov, A.

1998-01-01

Illicit trafficking of nuclear materials continues to pose a danger to public health and safety and to nuclear non proliferation efforts. The majority of cases so far have involved only small amounts of fissile materials or mainly radioactive sources in Bulgaria. A proper scheme for analysis of seized nuclear materials will be developed based on existing equipment for NDA analysis of nuclear materials supplemented by new system through PHARE project assistance by EU experts. (author)

A New ECR Ion Source for Nuclear Astrophysics Studies

Science.gov (United States)

Cesaratto, John M.

2008-10-01

The Laboratory for Experimental Nuclear Astrophysics (LENA) is a low energy facility designed to study nuclear reactions of astrophysical interest at energies which are important for nucleosysthesis. In general, these reactions have extremely small cross sections, requiring intense beams and efficient detection systems. Recently, a new, high intensity electron-cyclotron-resonance (ECR) ion source has been constructed (based on a design by Wills et al.[1]), which represents a substantial improvement in the capabilities of LENA. Beam is extracted from an ECR plasma excited at 2.45 GHz and confined by an array of permanent magnets. It has produced H^+ beams in excess of 1 mA on target over the energy range 100 - 200 keV, which greatly increases our ability to measure small cross sections. Initial measurements will focus on the ^23Na(p,γ)^24Mg reaction, which is of interest in a variety of astrophysical scenarios. The present uncertainty in the rate of this reaction is the result of an unobserved resonance expected at Elab =144 keV, which should be detectable using beams from the new ECR source. In collaboration with Arthur E. Champagne and Thomas B. Clegg, University of North Carolina, Chapel Hill and TUNL. [3pt] [1] J. S. C. Wills et al., Rev. Sci. Instrum. 69, 65 (1999).

Deuteron nuclear data for the design of accelerator-based neutron sources: Measurement, model analysis, evaluation, and application

Science.gov (United States)

Watanabe, Yukinobu; Kin, Tadahiro; Araki, Shouhei; Nakayama, Shinsuke; Iwamoto, Osamu

2017-09-01

A comprehensive research program on deuteron nuclear data motivated by development of accelerator-based neutron sources is being executed. It is composed of measurements of neutron and gamma-ray yields and production cross sections, modelling of deuteron-induced reactions and code development, nuclear data evaluation and benchmark test, and its application to medical radioisotopes production. The goal of this program is to develop a state-of-the-art deuteron nuclear data library up to 200 MeV which will be useful for the design of future (d,xn) neutron sources. The current status and future plan are reviewed.

Multi-purpose nuclear heat source for advanced gas-cooled reactor plants

International Nuclear Information System (INIS)

McDonald, C.F.

1993-01-01

Nuclear power has the potential to be the ultimate green technology in that it could eliminate the need for burning fossil fuels with their polluting combustion products and greenhouse gases. This view is shared by many technologists, but it may be a generation before the public becomes convinced, and that will involve overcoming many safety, institutional, financial, and technical impediments. This paper addresses only the latter topic; a major theme being that for nuclear power to truly be a green technology and significantly benefit society, it must meet the needs of the full energy spectrum. Specifically, it must satisfy energy needs beyond just the electricity generating sector by today's nuclear plants. By virtue of its high temperature capability, the Modular High Temperature Gas-Cooled Reactor (MHTGR) is the only type of reactor that has the potential to meet the wide range of energy needs that will emerge in the future. This paper discusses the nuclear heat source that gives the MHTGR multi-purpose capability, which is recognized today, but will not be implemented until early in the next century

The Co-creation Continuum

DEFF Research Database (Denmark)

Ind, Nicholas; Iglesias, Oriol; Markovic, Stefan

2017-01-01

-creation - from tactical market research tool to strategic collaborative innovation method, and shows that brands can be positioned along a continuum between these two polarities. This article also presents the implications for those that want to seize the potential of co-creation....

Effects of continuum breakdown on hypersonic aerothermodynamics for reacting flow

Science.gov (United States)

Holman, Timothy D.; Boyd, Iain D.

2011-02-01

This study investigates the effects of continuum breakdown on the surface aerothermodynamic properties (pressure, stress, and heat transfer rate) of a sphere in a Mach 25 flow of reacting air in regimes varying from continuum to a rarefied gas. Results are generated using both continuum [computational fluid dynamics (CFD)] and particle [direct simulation Monte Carlo (DSMC)] approaches. The DSMC method utilizes a chemistry model that calculates the backward rates from an equilibrium constant. A preferential dissociation model is modified in the CFD method to better compare with the vibrationally favored dissociation model that is utilized in the DSMC method. Tests of these models are performed to confirm their validity and to compare the chemistry models in both numerical methods. This study examines the effect of reacting air flow on continuum breakdown and the surface properties of the sphere. As the global Knudsen number increases, the amount of continuum breakdown in the flow and on the surface increases. This increase in continuum breakdown significantly affects the surface properties, causing an increase in the differences between CFD and DSMC. Explanations are provided for the trends observed.

Source book for planning nuclear dual-purpose electric/distillation desalination plants

International Nuclear Information System (INIS)

Reed, S.A.

1981-02-01

A source book on nuclear dual-purpose electric/distillation desalination plants was prepared to assist government and other planners in preparing broad evaluations of proposed applications of dual-purpose plants. The document is divided into five major sections. Section 1 presents general discussions relating to the benefits of dual-purpose plants, and spectrum for water-to-power ratios. Section 2 presents information on commercial nuclear plants manufactured by US manufacturers. Section 3 gives information on distillation desalting processes and equipment. Section 4 presents a discussion on feedwater pretreatment and scale control. Section 5 deals with methods for coupling the distillation and electrical generating plants to operate in the dual mode

Source book for planning nuclear dual-purpose electric/distillation desalination plants

Energy Technology Data Exchange (ETDEWEB)

Reed, S.A.

1981-02-01

A source book on nuclear dual-purpose electric/distillation desalination plants was prepared to assist government and other planners in preparing broad evaluations of proposed applications of dual-purpose plants. The document is divided into five major sections. Section 1 presents general discussions relating to the benefits of dual-purpose plants, and spectrum for water-to-power ratios. Section 2 presents information on commercial nuclear plants manufactured by US manufacturers. Section 3 gives information on distillation desalting processes and equipment. Section 4 presents a discussion on feedwater pretreatment and scale control. Section 5 deals with methods for coupling the distillation and electrical generating plants to operate in the dual mode.

Proposal for implementation of alternative source term in the nuclear power plant of Laguna Verde

International Nuclear Information System (INIS)

Bazan L, A.; Lopez L, M.; Vargas A, A.; Cardenas J, J. B.

2009-10-01

In 2010 the nuclear power plant of Laguna Verde will implement the extended power upbeat in both units of the plant. Agree with methodology of NEDC-33004P-A, (constant pressure power up rate), and the source term of core, for accidents evaluations, were increased in proportion to the ratio of power level. This means that for the case of a design basis accident of loss of coolant an increase of power of 15% originated an increase of 15% in dose to main control room. Using the method of NEDC-33004P-A to extended power upbeat conditions was determined that the dose value to main control room is very near to regulatory limit established by SRP 6.4. By the above and in order to recover the margin, the nuclear power plant of Laguna Verde will calculate an alternative source term following the criteria established in RG 1.183 (alternative radiological source term for evaluating DBA at nuclear power reactor). This approach also have a more realistic dose value using the criterion of 10-CFR-50.67, in addition is predicted to get the benefit of additional operational flexibilities. This paper present the proposal of implementing the alternative source term in Laguna Verde. (Author)

Capabilities of a DT tokamak fusion neutron source for driving a spent nuclear fuel transmutation reactor

International Nuclear Information System (INIS)

Stacey, W.M.

2001-01-01

The capabilities of a DT fusion neutron source for driving a spent nuclear fuel transmutation reactor are characterized by identifying limits on transmutation rates that would be imposed by tokamak physics and engineering limitations on fusion neutron source performance. The need for spent nuclear fuel transmutation and the need for a neutron source to drive subcritical fission transmutation reactors are reviewed. The likely parameter ranges for tokamak neutron sources that could produce an interesting transmutation rate of 100s to 1000s of kg/FPY (where FPY stands for full power year) are identified (P fus ∼ 10-100 MW, β N ∼ 2-3, Q p ∼ 2-5, R ∼ 3-5 m, I ∼ 6-10 MA). The electrical and thermal power characteristics of transmutation reactors driven by fusion and accelerator spallation neutron sources are compared. The status of fusion development vis-a-vis a neutron source is reviewed. (author)

Meeting Czechoslovak demands for heat in long-term prospective, especially with regard to nuclear sources

International Nuclear Information System (INIS)

Klail, M.

1988-01-01

The development was studied of heat demand in the CSSR till the year 2030. The ratio of centralized and decentralized heat supply is currently 60 to 40; in the future a slight increase is expected in the decentralized type of heat supply, mainly as a result of more intensive use of natural gas. In 2030, 710 PU of centralized heat should be produced. A decisive element in meeting the demand will be a growing proportion of combined production of electric power and heat by nuclear power plants. The installed capacity of the nuclear power plants in 2030 should range between 23 and 41 thousand MW, the production of electric power in these plants should be 193 to 238 TWh/y. 109 territorial areas potentially suitable for use of heat from nuclear sources were selected. They were included in 19 regions of which 9 should in the year 2010 be linked to heat supply from nuclear power plants that will be in operation. It is expected that in the year 2030, nuclear sources will supply 250 PU of centralized heat. (Z.M.). 2 tabs., 14 refs

Bursts and shocks in a continuum shell model

DEFF Research Database (Denmark)

Andersen, Ken Haste; Bohr, Tomas; Jensen, M.H.

1998-01-01

We study a burst event, i.e., the evolution of an initial condition having support only in a finite interval of k-space, in the continuum shell model due to Parisi. We show that the continuum equation without forcing or dissipation can be explicitly written in characteristic form and that the right...

Determination of gold and cobalt dopants in advanced materials based on tin oxide by slurry sampling high-resolution continuum source graphite furnace atomic absorption spectrometry

Science.gov (United States)

Filatova, Daria G.; Eskina, Vasilina V.; Baranovskaya, Vasilisa B.; Vladimirova, Svetlana A.; Gaskov, Alexander M.; Rumyantseva, Marina N.; Karpov, Yuri A.

2018-02-01

A novel approach is developed for the determination of Co and Au dopants in advanced materials based on tin oxide using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) with direct slurry sampling. Sodium carboxylmethylcellulose (Na-CMC) is an effective stabilizer for diluted suspensions. Use Na-CMC allows to transfer the analytes into graphite furnace completely and reproducibly. The relative standard deviation obtained by HR CS GFAAS was not higher than 4%. Accuracy was proven by means inductively coupled plasma mass spectrometry (ICP-MS) in solutions after decomposition as a comparative technique. To determine Au and Co in the volume of SnO2, the acid decomposition conditions (HCl, HF) of the samples were suggested by means of an autoclave in a microwave oven.

Advanced Laser-Compton Gamma-Ray Sources for Nuclear Materials Detection, Assay and Imaging

Science.gov (United States)

Barty, C. P. J.

2015-10-01

Highly-collimated, polarized, mono-energetic beams of tunable gamma-rays may be created via the optimized Compton scattering of pulsed lasers off of ultra-bright, relativistic electron beams. Above 2 MeV, the peak brilliance of such sources can exceed that of the world's largest synchrotrons by more than 15 orders of magnitude and can enable for the first time the efficient pursuit of nuclear science and applications with photon beams, i.e. Nuclear Photonics. Potential applications are numerous and include isotope-specific nuclear materials management, element-specific medical radiography and radiology, non-destructive, isotope-specific, material assay and imaging, precision spectroscopy of nuclear resonances and photon-induced fission. This review covers activities at the Lawrence Livermore National Laboratory related to the design and optimization of mono-energetic, laser-Compton gamma-ray systems and introduces isotope-specific nuclear materials detection and assay applications enabled by them.

Continuum variational and diffusion quantum Monte Carlo calculations

International Nuclear Information System (INIS)

Needs, R J; Towler, M D; Drummond, N D; Lopez RIos, P

2010-01-01

This topical review describes the methodology of continuum variational and diffusion quantum Monte Carlo calculations. These stochastic methods are based on many-body wavefunctions and are capable of achieving very high accuracy. The algorithms are intrinsically parallel and well suited to implementation on petascale computers, and the computational cost scales as a polynomial in the number of particles. A guide to the systems and topics which have been investigated using these methods is given. The bulk of the article is devoted to an overview of the basic quantum Monte Carlo methods, the forms and optimization of wavefunctions, performing calculations under periodic boundary conditions, using pseudopotentials, excited-state calculations, sources of calculational inaccuracy, and calculating energy differences and forces. (topical review)

Nuclear thermal source transfer unit, post-blast soil sample drying system

Energy Technology Data Exchange (ETDEWEB)

Wiser, Ralph S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Valencia, Matthew J [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-01-03

Los Alamos National Laboratory states that its mission is “To solve national security challenges through scientific excellence.” The Science Undergraduate Laboratory Internship (SULI) programs exists to engage undergraduate students in STEM work by providing opportunity to work at DOE facilities. As an undergraduate mechanical engineering intern under the SULI program at Los Alamos during the fall semester of 2016, I had the opportunity to contribute to the mission of the Laboratory while developing skills in a STEM discipline. I worked with Technology Applications, an engineering group that supports non-proliferation, counter terrorism, and emergency response missions. This group specializes in tool design, weapons engineering, rapid prototyping, and mission training. I assisted with two major projects during my appointment Los Alamos. The first was a thermal source transportation unit, intended to safely contain a nuclear thermal source during transit. The second was a soil drying unit for use in nuclear postblast field sample collection. These projects have given me invaluable experience working alongside a team of professional engineers. Skills developed include modeling, simulation, group design, product and system design, and product testing.

Nuclear thermal source transfer unit, post-blast soil sample drying system

International Nuclear Information System (INIS)

Wiser, Ralph S.; Valencia, Matthew J

2017-01-01

Los Alamos National Laboratory states that its mission is ''To solve national security challenges through scientific excellence.'' The Science Undergraduate Laboratory Internship (SULI) programs exists to engage undergraduate students in STEM work by providing opportunity to work at DOE facilities. As an undergraduate mechanical engineering intern under the SULI program at Los Alamos during the fall semester of 2016, I had the opportunity to contribute to the mission of the Laboratory while developing skills in a STEM discipline. I worked with Technology Applications, an engineering group that supports non-proliferation, counter terrorism, and emergency response missions. This group specializes in tool design, weapons engineering, rapid prototyping, and mission training. I assisted with two major projects during my appointment Los Alamos. The first was a thermal source transportation unit, intended to safely contain a nuclear thermal source during transit. The second was a soil drying unit for use in nuclear postblast field sample collection. These projects have given me invaluable experience working alongside a team of professional engineers. Skills developed include modeling, simulation, group design, product and system design, and product testing.

Renewable energy sources and nuclear installations; Erneuerbare Energien und neue Nuklearanlagen

Energy Technology Data Exchange (ETDEWEB)

Hirschberg, S.; Bauer, Ch.; Burgherr, P.; Stucki, S.; Vogel, F.; Biollaz, S.; Schulz, T.; Durisch, W.; Hardegger, P.; Foskolos, K.; Meier, A.; Schenler, W.

2005-02-15

This comprehensive work report for the Swiss Federal Office of Energy (SFOE) made by the Paul Scherrer Institute PSI takes a look at work done in connection with the updating of the office's Energy Perspectives. In particular, the topic of electricity is reviewed in the light of pending important decisions in the area of nuclear energy and the newer renewable sources of energy. The report makes an attempt to estimate the effect on Swiss power production that the new renewables and new nuclear installations could have in the next 30-40 years and to what costs this could be done and which obstacles would have to overcome. The renewable energy sources include small hydro, wind, photovoltaics, solar thermal power plants, biogas, geothermal energy, wave-power and solar chemistry. The methods used include literature study and contacts with internal PSI experts on the various areas involved. The most important system characteristics were noted and learning curves for the various technologies were taken into account. Ecological and social factors were also considered

Lyman continuum observations of solar flares

Science.gov (United States)

Machado, M. E.; Noyes, R. W.

1978-01-01

A study is made of Lyman continuum observations of solar flares, using data obtained by the EUV spectroheliometer on the Apollo Telescope Mount. It is found that there are two main types of flare regions: an overall 'mean' flare coincident with the H-alpha flare region, and transient Lyman continuum kernels which can be identified with the H-alpha and X-ray kernels observed by other authors. It is found that the ground level hydrogen population in flares is closer to LTE than in the quiet sun and active regions, and that the level of Lyman continuum formation is lowered in the atmosphere from a mass column density .000005 g/sq cm in the quiet sun to .0003 g/sq cm in the mean flare, and to .001 g/sq cm in kernels. From these results the amount of chromospheric material 'evaporated' into the high temperature region is derived, which is found to be approximately 10 to the 15th g, in agreement with observations of X-ray emission measures.

The Bologna complete sample of nearby radio sources. II. Phase referenced observations of faint nuclear sources

Science.gov (United States)

Liuzzo, E.; Giovannini, G.; Giroletti, M.; Taylor, G. B.

2009-10-01

Aims: To study statistical properties of different classes of sources, it is necessary to observe a sample that is free of selection effects. To do this, we initiated a project to observe a complete sample of radio galaxies selected from the B2 Catalogue of Radio Sources and the Third Cambridge Revised Catalogue (3CR), with no selection constraint on the nuclear properties. We named this sample “the Bologna Complete Sample” (BCS). Methods: We present new VLBI observations at 5 and 1.6 GHz for 33 sources drawn from a sample not biased toward orientation. By combining these data with those in the literature, information on the parsec-scale morphology is available for a total of 76 of 94 radio sources with a range in radio power and kiloparsec-scale morphologies. Results: The fraction of two-sided sources at milliarcsecond resolution is high (30%), compared to the fraction found in VLBI surveys selected at centimeter wavelengths, as expected from the predictions of unified models. The parsec-scale jets are generally found to be straight and to line up with the kiloparsec-scale jets. A few peculiar sources are discussed in detail. Tables 1-4 are only available in electronic form at http://www.aanda.org

A Coupling Tool for Parallel Molecular Dynamics-Continuum Simulations

KAUST Repository

Neumann, Philipp; Tchipev, Nikola

2012-01-01

We present a tool for coupling Molecular Dynamics and continuum solvers. It is written in C++ and is meant to support the developers of hybrid molecular - continuum simulations in terms of both realisation of the respective coupling algorithm

Geometric continuum regularization of quantum field theory

International Nuclear Information System (INIS)

Halpern, M.B.

1989-01-01

An overview of the continuum regularization program is given. The program is traced from its roots in stochastic quantization, with emphasis on the examples of regularized gauge theory, the regularized general nonlinear sigma model and regularized quantum gravity. In its coordinate-invariant form, the regularization is seen as entirely geometric: only the supermetric on field deformations is regularized, and the prescription provides universal nonperturbative invariant continuum regularization across all quantum field theory. 54 refs

Hybrid district heating system with heat supply from nuclear source

International Nuclear Information System (INIS)

Havelka, Z.; Petrovsky, I.

1987-01-01

Several designs are described of heat supply from large remote power sources (e.g., WWER-1000 nuclear power plants with a 1000 MW turbine) to localities where mainly steam distribution networks have been built but only some or none networks for hot water distribution. The benefits of the designs stem from the fact that they do not require the conversion of the local steam distribution system to a hot water system. They are based on heat supply from the nuclear power plant to the consumer area in hot water of a temperature of 150 degC to 200 degC. Part of the hot water heat will be used for the production of low-pressure steam which will be compressed using heat pumps (steam compressors) to achieve the desired steam distribution network specifications. Water of lower temperature can be used in the hot water network. The hot water feeder forms an automatic pressure safety barrier in heat supply of heating or technological steam from a nuclear installation. (Z.M.). 5 figs., 9 refs

The nuclear energy: an essential source of the energy package

International Nuclear Information System (INIS)

Ngo, Ch.

2007-01-01

In the framework of the energy consumption facing the environmental quality, the author presents the energy sources, used and possible. He shows the necessity to reduce the dependency towards the fossil fuels. He discusses the possibility of the CO 2 storage, the electric power use to decrease the CO 2 emissions. He then analyses the cogeneration alternative, the hybrid vehicles and the advantages of the nuclear energy. (A.L.B.)

Assessing continuum postulates in simulations of granular flow

Energy Technology Data Exchange (ETDEWEB)

Rycroft, Chris; Kamrin, Ken; Bazant, Martin

2008-08-26

Continuum mechanics relies on the fundamental notion of a mesoscopic volume"element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional Discrete-Element Method (DEM) simulations of different granular flows and show that an approximate"granular element" defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships betweenaverage variables.

One millimeter continuum observations of high redshift quasars

International Nuclear Information System (INIS)

Ennis, D.J.; Soifer, B.T.

1981-01-01

Upper limits to the one-millimeter continuum flux densities of the high redshift quasars B2 1225 + 31, Ton 490, and PHL 957 are presented. The upper limit to the power observed from these quasars at 1 mm is, on the average, one half of the observed power in the continuum at L-alpha. These observations are used to constrain the temperature of a hypothetical dust shell which reddens the quasar line and continuum emission by an extinction optical depth sufficient to account for the anomalously low L-alpha/H-alpha emission line ratio observed in each of these quasars. For the quasars studied, dust shell temperatures between 25 K and 50 to 95 K are prohibited by the present data. A dust shell at a temperature within this span reradiating all the power absorbed from the quasar ultraviolet continuum would produce a one-millimeter flux density greater than the measured upper limit. The average radius of the model dust shell cannot be between 70 kpc and 1 Mpc

Information Sources as Explanatory Variables for the Belgian Health-Related Risk Perception of the Fukushima Nuclear Accident.

Science.gov (United States)

Vyncke, Bart; Perko, Tanja; Van Gorp, Baldwin

2017-03-01

The media play an important role in risk communication, providing information about accidents, both nearby and far away. Each media source has its own presentation style, which could influence how the audience perceives the presented risk. This study investigates the explanatory power of 12 information sources (traditional media, new media, social media, and interpersonal communication) for the perceived risk posed by radiation released from the damaged Fukushima nuclear power plant on respondents' own health and that of the population in general. The analysis controlled for attitude toward nuclear energy, gender, education, satisfaction with the media coverage, and duration of attention paid to the coverage. The study uses a large empirical data set from a public opinion survey, which is representative for the Belgian population with respect to six sociodemographic variables. Results show that three information sources are significant regressors of perceived health-related risk of the nuclear accident: television, interpersonal communication, and the category of miscellaneous online sources. More favorable attitudes toward nuclear power, longer attention to the coverage, and higher satisfaction with the provided information lead to lower risk perception. Taken together, the results suggest that the media can indeed have a modest influence on how the audience perceives a risk. © 2016 Society for Risk Analysis.

Nuclear Knowledge and Competence: Fundamental Prerequisites for the Safe Utilization of Radiation Sources in a Small Non-Nuclear Country — Experience of Montenegro

International Nuclear Information System (INIS)

Jovanovic, S.; Dlabac, A.

2016-01-01

Provision of adequate knowledge, competence and expertise represents a major concern when addressing nuclear and radiation safety issues in small countries — if inadequate, safety will eventually be jeopardized. Montenegro is such a small, developing and “nonnuclear” country—the use of radiation sources being modest and limited to a few ordinary applications (primarily in health care). Even though, there is (or will be in the foreseeable future) a significant need in nuclear knowledge, competence and expertise — directly or indirectly related to nuclear/radiation safety and security issues. It goes about the following, the list being not exhaustive: (i) medical applications (diagnostics, radiotherapy, palliation, sterilization of equipment, consumables, blood products, etc.), (ii) radiation protection, including various dosimetry services and QC/QA of radiation sources; (iii) environmental protection (radioecology, analytical and monitoring services, etc.), (iv) low and medium activity radioactive waste management (including a newly licenced storage), (v) industrial, geological, hydrological, agricultural, biochemical and archaeological applications (non-destructive testing, various gauges, radioisotope labeling, harmful insects sterilization, etc.), (vi) scientific and educational uses, (vii) cultural heritage preservation and investigation, (viii) legislative and regulatory aspects, including complying to international safety/security norms and joining international conventions in the field, (ix) preparedness and response to radiological and nuclear emergency situations, (x) combating illicit trafficking of nuclear and other radioactive materials, (xi) nuclear forensics, (xii) security systems based on X-ray and other nuclear methods, (xiii) introduction of some future topics (e.g., nuclear power for electricity generation and sea water desalination), (xiv) public information and communication with media, etc.

An ALMA continuum survey of circumstellar disks in the upper Scorpius OB association

Energy Technology Data Exchange (ETDEWEB)

Carpenter, John M.; Ricci, Luca; Isella, Andrea [Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)

2014-05-20

We present ALMA 880 μm continuum observations of 20 K- and M-type stars in the Upper Scorpius OB association (Upper Sco) that are surrounded by protoplanetary disks. These data are used to measure the dust content in disks around low-mass stars (0.1-1.6 M {sub ☉}) at a stellar age of 5-11 Myr. Thirteen sources were detected in the 880 μm dust continuum at ≥3σ with inferred dust masses between 0.3 and 52 M {sub ⊕}. The dust masses tend to be higher around the more massive stars, but the significance is marginal in that the probability of no correlation is p ≈ 0.03. The evolution in the dust content in disks was assessed by comparing the Upper Sco observations with published continuum measurements of disks around ∼1-2 Myr stars in the Class II stage in the Taurus molecular cloud. While the dust masses in the Upper Sco disks are on average lower than in Taurus, any difference in the dust mass distributions is significant at less than 3σ. For stellar masses between 0.49 M {sub ☉} and 1.6 M {sub ☉}, the mean dust mass in disks is lower in Upper Sco relative to Taurus by Δlog M {sub dust} = 0.44 ± 0.26.

Classical description of the electron capture to the continuum cusp formation in ion-atom collisions

International Nuclear Information System (INIS)

Illescas, Clara; Pons, B.; Riera, A.

2002-01-01

Classical calculations are used to describe the dynamics of the electron capture to the continuum (ECC) cusp formation in H + +He collisions. We illustrate the frontier character of the ECC electrons between capture and ionization, and confirm that it is a temporary capture, through projectile focusing, that is responsible for the ECC cusp. Furthermore, the cusp is not a divergence smoothed by the experiment, and is slightly shifted from the impact-velocity value because of the residual pull from the target after ionization. This shift is larger the smaller the nuclear velocity

THE BOLOCAM GALACTIC PLANE SURVEY. X. A COMPLETE SPECTROSCOPIC CATALOG OF DENSE MOLECULAR GAS OBSERVED TOWARD 1.1 mm DUST CONTINUUM SOURCES WITH 7.°5 ≤ l ≤ 194°

Energy Technology Data Exchange (ETDEWEB)

Shirley, Yancy L.; Svoboda, Brian [Steward Observatory, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Ellsworth-Bowers, Timothy P.; Schlingman, Wayne M.; Ginsburg, Adam; Battersby, Cara; Stringfellow, Guy; Glenn, Jason; Bally, John [CASA, University of Colorado, CB 389, Boulder, CO 80309 (United States); Rosolowsky, Erik [Department of Physics, University of Alberta, 4-181 CCIS Edmonton AB T6G 2E1 (Canada); Gerner, Thomas [Max-Planck-Institut für Astronomie (MPIA), Knigstuhl 17, D-69117 Heidelberg (Germany); Mairs, Steven [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, STN CSC, Victoria, BC V8W 3P6 (Canada); Dunham, Miranda K. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States)

2013-11-01

The Bolocam Galactic Plane Survey (BGPS) is a 1.1 mm continuum survey of dense clumps of dust throughout the Galaxy covering 170 deg{sup 2}. We present spectroscopic observations using the Heinrich Hertz Submillimeter Telescope of the dense gas tracers, HCO{sup +} and N{sub 2}H{sup +} 3-2, for all 6194 sources in the BGPS v1.0.1 catalog between 7.°5 ≤ l ≤ 194°. This is the largest targeted spectroscopic survey of dense molecular gas in the Milky Way to date. We find unique velocities for 3126 (50.5%) of the BGPS v1.0.1 sources observed. Strong N{sub 2}H{sup +} 3-2 emission (T {sub mb} > 0.5 K) without HCO{sup +} 3-2 emission does not occur in this catalog. We characterize the properties of the dense molecular gas emission toward the entire sample. HCO{sup +} is very sub-thermally populated and the 3-2 transitions are optically thick toward most BGPS clumps. The median observed line width is 3.3 km s{sup –1} consistent with supersonic turbulence within BGPS clumps. We find strong correlations between dense molecular gas integrated intensities and 1.1 mm peak flux and the gas kinetic temperature derived from previously published NH{sub 3} observations. These intensity correlations are driven by the sensitivity of the 3-2 transitions to excitation conditions rather than by variations in molecular column density or abundance. We identify a subset of 113 sources with stronger N{sub 2}H{sup +} than HCO{sup +} integrated intensity, but we find no correlations between the N{sub 2}H{sup +}/HCO{sup +} ratio and 1.1 mm continuum flux density, gas kinetic temperature, or line width. Self-absorbed profiles are rare (1.3%)

A nuclear source: a resource kit for teachers

International Nuclear Information System (INIS)

Hawkins, Gay.

1992-01-01

The aim of this Resource Kit is to provide information, diagrams, overheads and classroom activities, set in an Australian context, to broaden and enrich the teaching of nuclear science from both technical and social science aspects. It has been written to address the the Australian secondary school syllabuses and reflects this in both its format and contents. Emphasis has been given to the applications of nuclear physics to our lives today, from new medical diagnostic techniques to efficient methods of monitoring our own environment. This Resource Kit is a valuable source of information not readily available to teachers from textbooks. It provides a unique opportunity to present the picture in Australia, making us all more aware of Australia's front line in Australia, making us all more aware of Australia's front line role in nuclear research. The kit is meant to be used in conjunction with current textbooks, to complement and enrich them. The kit begins with a review of the many applications of nuclear science in order to provide a broad concrete base to motivate students to discover more of the specific details of the basic discoveries contained in the later sections. Topics such as the Structure of the Atom, which are well documented in textbooks, have been approached in a more creative and less rigorous manner to give teachers a fresh approach to the topic. The kit is divided into 10 separate sections and presented in loose-leaf form to facilitate its use in the classroom. Diagrams are inserted into the text to clarify and enrich descriptions, as well as being provided at the back of each section as black line masters for photocopying and overhead projections. ills., tabs

Emergency preparedness source term development for the Office of Nuclear Material Safety and Safeguards-Licensed Facilities

International Nuclear Information System (INIS)

Sutter, S.L.; Mishima, J.; Ballinger, M.Y.; Lindsey, C.G.

1984-08-01

In order to establish requirements for emergency preparedness plans at facilities licensed by the Office of Nuclear Materials Safety and Safeguards, the Nuclear Regulatory Commission (NRC) needs to develop source terms (the amount of material made airborne) in accidents. These source terms are used to estimate the potential public doses from the events, which, in turn, will be used to judge whether emergency preparedness plans are needed for a particular type of facility. Pacific Northwest Laboratory is providing the NRC with source terms by developing several accident scenarios for eleven types of fuel cycle and by-product operations. Several scenarios are developed for each operation, leading to the identification of the maximum release considered for emergency preparedness planning (MREPP) scenario. The MREPP scenarios postulated were of three types: fire, tornado, and criticality. Fire was significant at oxide fuel fabrication, UF 6 production, radiopharmaceutical manufacturing, radiopharmacy, sealed source manufacturing, waste warehousing, and university research and development facilities. Tornadoes were MREPP events for uranium mills and plutonium contaminated facilities, and criticalities were significant at nonoxide fuel fabrication and nuclear research and development facilities. Techniques for adjusting the MREPP release to different facilities are also described

Localization of Vibrating Noise Sources in Nuclear Reactor Cores

International Nuclear Information System (INIS)

Hultqvist, Pontus

2004-09-01

In this thesis the possibility of locating vibrating noise sources in a nuclear reactor core from the neutron noise has been investigated using different localization methods. The influence of the vibrating noise source has been considered to be a small perturbation of the neutron flux inside the reactor. Linear perturbation theory has been used to construct the theoretical framework upon which the localization methods are based. Two different cases have been considered: one where a one-dimensional one-group model has been used and another where a two-dimensional two-energy group noise simulator has been used. In the first case only one localization method is able to determine the position with good accuracy. This localization method is based on finding roots of an equation and is sensitive to other perturbations of the neutron flux. It will therefore work better with the assistance of approximative methods that reconstruct the noise source to determine if the results are reliable or not. In the two-dimensional case the results are more promising. There are several different localization techniques that reproduce both the vibrating noise source position and the direction of vibration with enough precision. The approximate methods that reconstruct the noise source are substantially better and are able to support the root finding method in a more constructive way. By combining the methods, the results will be more reliable

Nuclear physics meets the sources of the ultra-high energy cosmic rays

International Nuclear Information System (INIS)

Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

2016-07-01

We study the implications of nuclear data and models for cosmic-ray astrophysics, which involves the photodisintegration of nuclei up to iron in astrophysical environments. We demonstrate that data on photo-absorption cross sections are sparse in that mass range by screening nuclear databases, such as EXFOR; these cross sections are needed to compute the photodisintegration rates. We also test the prediction power of models, such as TALYS, and find uncertainties of the order of a factor two. If however the radiation fields are strong enough such that the nuclear cascade in the astrophysical source can develop, we find that differences among different models average out -- unless there is a systematic offset in the interaction model. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions, supported by simulating the entire disintegration chain in a gamma-ray burst. We also point out that a first consistency check may be the measurement of the absorption cross section for different isobars.

Nuclear physics meets the sources of the ultra-high energy cosmic rays

Energy Technology Data Exchange (ETDEWEB)

Boncioli, Denise; Fedynitch, Anatoli; Winter, Walter

2016-07-15

We study the implications of nuclear data and models for cosmic-ray astrophysics, which involves the photodisintegration of nuclei up to iron in astrophysical environments. We demonstrate that data on photo-absorption cross sections are sparse in that mass range by screening nuclear databases, such as EXFOR; these cross sections are needed to compute the photodisintegration rates. We also test the prediction power of models, such as TALYS, and find uncertainties of the order of a factor two. If however the radiation fields are strong enough such that the nuclear cascade in the astrophysical source can develop, we find that differences among different models average out -- unless there is a systematic offset in the interaction model. We conclude with an isotope chart describing which information is in principle necessary to describe nuclear interactions, supported by simulating the entire disintegration chain in a gamma-ray burst. We also point out that a first consistency check may be the measurement of the absorption cross section for different isobars.

Determination of trace concentrations of chlorine in aqueous solutions by high-resolution continuum source graphite furnace molecular absorption spectrometry

Science.gov (United States)

Machyňák, Ľubomír; Čacho, František; Němeček, Martin; Beinrohr, Ernest

2016-11-01

Trace concentrations of total chlorine were determined by means of molecular absorption of indium mono-chloride (InCl) at 267.217 nm using high-resolution continuum source graphite furnace molecular absorption spectrometry. The effects of chemical modifiers and the amount of In on the sensitivity and accuracy were investigated. The optimum pyrolysis and vaporization temperatures were 600 °C and 1400 °C, respectively. The limit of detection and characteristic mass were found to be 0.10 ng and 0.21 ng, respectively. Potential non-spectral and spectral interferences were tested for various metals and non-metals at concentrations up to 50 mg L- 1 and for phosphoric, sulphuric and nitric acids. No spectral interferences were observed. Significant non-spectral interferences were observed with F, Br, and I at concentrations higher than 1 mg L- 1, 5 mg L- 1 and 25 mg L- 1, respectively, which is probably caused by formation of competitive indium halogen molecules. Higher concentrations of mineral acids depressed the signal owing to the formation of volatile HCl. The calibration curve was linear in the range between 0.3 and 10 ng with a correlation coefficient of R = 0.993. The elaborated method was used for the chlorine determination in various waters and a drug sample.

Methods of thermal power extraction from nuclear sources for meeting the consumer system demands

International Nuclear Information System (INIS)

Sellej, J.

1985-01-01

The technical design is discussed of heat extraction from nuclear power plants and heating plants. Variant technical designs are discussed of hot water and steam supply, including the basic aspects of nuclear safety. Hot water supplies are technically provided by heat exchanger units connected to turbines, or by heating turbines. The advantages and disadvantages of the two designs are discussed. The possibility of heat extraction by steam from the nuclear power plant is provided by steam exchangers, i.e., steam exchanger cascades, the so-called inserted steam circuit. Supplies of steam from nuclear sources, as against supplies of hot water have not yet been technically resolved with regard to safety, design and economic benefit. Nuclear heating plants have also been designed for hot water supply, but not yet for steam supply. (Pu)

On deformation of complex continuum immersed in a plane space

Science.gov (United States)

Kovalev, V. A.; Murashkin, E. V.; Radayev, Y. N.

2018-05-01

The present paper is devoted to mathematical modelling of complex continua deformations considered as immersed in an external plane space. The complex continuum is defined as a differential manifold supplied with metrics induced by the external space. A systematic derivation of strain tensors by notion of isometric immersion of the complex continuum into a plane space of a higher dimension is proposed. Problem of establishing complete systems of irreducible objective strain and extrastrain tensors for complex continuum immersed in an external plane space is resolved. The solution to the problem is obtained by methods of the field theory and the theory of rational algebraic invariants. Strain tensors of the complex continuum are derived as irreducible algebraic invariants of contravariant vectors of the external space emerging as functional arguments in the complex continuum action density. Present analysis is restricted to rational algebraic invariants. Completeness of the considered systems of rational algebraic invariants is established for micropolar elastic continua. Rational syzygies for non-quadratic invariants are discussed. Objective strain tensors (indifferent to frame rotations in the external plane space) for micropolar continuum are alternatively obtained by properly combining multipliers of polar decompositions of deformation and extra-deformation gradients. The latter is realized only for continua immersed in a plane space of the equal mathematical dimension.

Continuum gamma-ray spectroscopy

International Nuclear Information System (INIS)

Diamond, R.M.

1981-06-01

When angular momentum is added to a nucleus, it is, of course, carried by the individual nucleons, but two limiting types of behavior may be distinguished: (1) a small number of high-j particles align with the rotation axis and (2) the nucleus is deformed and rotates as a whole. At high spin all nuclei seem to show a compromise utilizing both motions. The excited nuclei left as products of (HI,xn) reactions have so many pathways down that none of the γ-ray transitions have enough intensity to be seen individually until the population gathers near the yrast line. This occurs usually between spin 20 to 40 h-bar. All our information on the higher states comes from their continuum spectra. With the new techniques that are developing, including the use of multiplicity filters, total-energy spectrometers, energy correlation studies, crystal balls, and observation of giant dipole resonances in the continuum spectra, there is hope to learn much about the nature of the high-spin states

Nonlocal continuum field theories

CERN Document Server

2002-01-01

Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

Preliminary Results of Nuclear Fluorescence Imaging of Alpha and Beta Emitting Sources

International Nuclear Information System (INIS)

Feener, Jessica S.; Charlton, William S.

2013-06-01

The preliminary results from a series of nuclear fluorescence imaging experiments using a variety of radioactive sources and shielding are given. These experiments were done as part of a proof of concept to determine if nuclear fluorescence imaging could be used as a safeguards measurements tool or for nuclear warhead verification for nuclear arms control treaties such as the New Strategic Arms Reduction Treaty and the Fissile Material Cut-Off Treaty. An off-the-shelf Princeton Instruments charged coupled device camera system was used to image the emission of fluorescence photons from the de-excitation of nitrogen molecules in air that have been excited by ionizing radiation. The fluorescence emissions are primarily in the near ultraviolet range; between the wavelengths of 300 and 400 nm. Fluorescent imaging techniques are currently being investigated in a number of applications. A French research team has successfully demonstrated this concept for remote imaging of alpha contamination. It has also been shown that the phenomenon can be seen through translucent materials and that alpha radiation can be seen in the presence of large gamma backgrounds. Additionally, fluorescence telescopes and satellites utilize the de-excitation of nitrogen molecules to observe cosmic ray showers in the atmosphere. In cosmic ray shower detection, electrons are the main contributor to the excitation of the of nitrogen molecules in air. The experiments presented in this paper were designed to determine if the imaging system could observe beta emitting sources, differentiate between beta emitters and alpha emitting materials such as uranium oxide and uranium metal, and to further investigate the phenomenon through translucent and non-translucent materials. The initial results show that differentiation can be made between beta and alpha emitting sources and that the device can observe the phenomenon through very thin non-transparent material. Additionally, information is given on the

Near-infrared water vapour self-continuum at close to room temperature

International Nuclear Information System (INIS)

Ptashnik, I.V.; Petrova, T.M.; Ponomarev, Yu.N.; Shine, K.P.; Solodov, A.A.; Solodov, A.M.

2013-01-01

The gaseous absorption of solar radiation within near-infrared atmospheric windows in the Earth's atmosphere is dominated by the water vapour continuum. Recent measurements by Baranov et al. (2011) [17] in 2500 cm −1 (4 μm) window and by Ptashnik et al. (2011) [18] in a few near-infrared windows revealed that the self-continuum absorption is typically an order of magnitude stronger than given by the MT C KD continuum model prior to version 2.5. Most of these measurements, however, were made at elevated temperatures, which makes their application to atmospheric conditions difficult. Here we report new laboratory measurements of the self-continuum absorption at 289 and 318 K in the near-infrared spectral region 1300–8000 cm −1 , using a multipass 30 m base cell with total optical path 612 m. Our results confirm the main conclusions of the previous measurements both within bands and in windows. Of particular note is that we present what we believe to be the first near-room temperature measurement using Fourier Transform Spectrometry of the self-continuum in the 6200 cm −1 (1.6 μm) window, which provides tentative evidence that, at such temperatures, the water vapour continuum absorption may be as strong as it is in 2.1 μm and 4 μm windows and up to 2 orders of magnitude stronger than the MT C KD-2.5 continuum. We note that alternative methods of measuring the continuum in this window have yielded widely differing assessment of its strength, which emphasises the need for further measurements. -- Highlights: ► New lab measurements of the near-infrared water vapour self-continuum absorption. ► First room-temperature data on the self-continuum in the 1.6 μm window. ► In the 1.6 μm window the new data exceed MT C KD-2.5 model by 2 orders of magnitude

Influence of the crustal and subcrustal Vrancea seismic sources on Cernavoda nuclear power plant site

International Nuclear Information System (INIS)

Marmureanu, Gheorghe; Popescu, Emilia; Mircea Radulian

2002-01-01

The basis of the seismic hazard assessment in different geographical regions with dense-populated areas and strategic objectives (dams, nuclear power plants, etc.) is the study of seismicity of the seismogenic sources which affect these sites. The purpose of this paper is to provide a complete set of information relative to the Vrancea seismic source (in the crust and the intermediate depth domains) that is fundamental for the seismic hazard evaluation at Cernavoda nuclear power plant site. The analysis that we propose has to deal with the following items: (1) geometrical definition of the seismic sources; (2) setting the earthquake catalog associated to each seismic source; (3) estimation of the maximum possible magnitude; (4) estimation of the frequency - magnitude relationship; (5) computation of the distribution function for focal distance; (6) correlation between focal depth and magnitude; (7) attenuation law. We discuss also the implications of the model parameters on the seismic hazard level. (authors)

Consideration of ultra-high temperature nuclear heat sources for MHD conversion systems

International Nuclear Information System (INIS)

Holman, R.R.; Tobin, J.M.; Young, W.E.

1975-01-01

The nuclear technology reactors developed and tested in the Nuclear Engine Rocket Vehicle Application (NERVA) program operated with fuel exit gas temperatures in excess of 2600 K. This experience provided a significant ultra-high temperature technology base and design insight for commercial power applications. Design approaches to accommodate fission product retention and other key prevailing requirements are examined in view of the basic overriding functional requirements, and some interesting reconsiderations are suggested. Predicted overall system performance potentials for a 2000 K MHD conversion system and reactor parameter requirements are compared and related to existing technology status. Needed verification and development efforts are suggested. A reconsideration of basic design approaches is suggested that could open the door for immediate development of ultrahigh temperature nuclear heat sources for advanced energy systems

Reference sources for radionuclide calibrations in nuclear programmes

International Nuclear Information System (INIS)

Almeida, M.C.M. de; Delgado, J.U.; Poledna, R.; Silva, R.L. da; Oliveira, E.M. de; Di Prinzio, M.A.R.

2009-01-01

The radionuclide metrology laboratories aim to provide radioactive standards for detector calibrations in nuclear safety areas. To produce the reference sources to be furnished to users the following standards of 57 Co, 60 Co, 133 Ba, 241 Am, 152 Eu and 166 Ho are commonly used. In this work was made a verifying of the uncertainties obtained for the two methods: comparative (sample-standards) and efficiency curve. The total uncertainties obtained by sample-standard method varied from 0.4 to 1.2% (k = 1). The results using efficiency curve method to the same radioisotopes and same conditions are between 0.9 to 2.2% (k = 1). (author)

Backreaction and continuum limit in a closed universe filled with black holes

International Nuclear Information System (INIS)

Korzyński, Mikołaj

2014-01-01

We discuss the continuum limit of the initial data for a vacuum, closed cosmological model with black holes as the only sources of the gravitational field. The model we consider is an exact solution of the constraint equations and represents a vacuum universe with a number of black holes placed on a spatial slice of S 3 topology considered at the moment of its largest expansion when the black holes are momentary at rest. We explain how and under what conditions the Friedmann–Lemaître–Robertson–Walker (FLRW) metric arises as the continuum limit when the number of black holes contained in the model goes to infinity. We also discuss the relation between the effective cosmological parameters of the model, inferred from the large scale geometry of the spacetime, and the masses of individual black holes. In particular, we prove an estimate for the difference between the total effective mass of the system and the sum of the masses of all black holes, thus quantifying the effects of the inhomogeneities in the matter distribution or the cosmological backreaction. (paper)

Continuum regularized Yang-Mills theory

International Nuclear Information System (INIS)

Sadun, L.A.

1987-01-01

Using the machinery of stochastic quantization, Z. Bern, M. B. Halpern, C. Taubes and I recently proposed a continuum regularization technique for quantum field theory. This regularization may be implemented by applying a regulator to either the (d + 1)-dimensional Parisi-Wu Langevin equation or, equivalently, to the d-dimensional second order Schwinger-Dyson (SD) equations. This technique is non-perturbative, respects all gauge and Lorentz symmetries, and is consistent with a ghost-free gauge fixing (Zwanziger's). This thesis is a detailed study of this regulator, and of regularized Yang-Mills theory, using both perturbative and non-perturbative techniques. The perturbative analysis comes first. The mechanism of stochastic quantization is reviewed, and a perturbative expansion based on second-order SD equations is developed. A diagrammatic method (SD diagrams) for evaluating terms of this expansion is developed. We apply the continuum regulator to a scalar field theory. Using SD diagrams, we show that all Green functions can be rendered finite to all orders in perturbation theory. Even non-renormalizable theories can be regularized. The continuum regulator is then applied to Yang-Mills theory, in conjunction with Zwanziger's gauge fixing. A perturbative expansion of the regulator is incorporated into the diagrammatic method. It is hoped that the techniques discussed in this thesis will contribute to the construction of a renormalized Yang-Mills theory is 3 and 4 dimensions

Comparison of the performance, advantages and disadvantages of nuclear power generation compared to other clean sources of electricity

Energy Technology Data Exchange (ETDEWEB)

Mata, Jônatas F.C. da; Neto, Rieder O., E-mail: jonatasfmata@yahoo.com.br, E-mail: rieder.neto@gmail.com [Universidade do Estado de Minas Gerais (UEMG), João Monlevade, MG (Brazil); Mesquita, Amir Z., E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Nowadays, there is an increase in the demand for electricity in emerging countries, such as India, China and Brazil. There are several alternatives to increase energy generation, and each country has followed certain strategies to achieve this goal. For a long time, developed countries, such as the United States, the United Kingdom and Germany, had focused their efforts on the use of thermoelectric generators through the combustion of non-renewable sources such as coal, natural gas and oil. These examples were followed, also, by the emerging countries. However, pollution levels, generated by these sources, have required the breakdown of this paradigm, and the consequent reversal of large investments in clean energy sources, such as hydraulics, solar and wind. Nucleo-electric energy is also considered a clean energy source, since it does not generate polluting gases during the processing of concentrated uranium in nuclear reactors. In addition, all radioactive waste occupying relatively small volumes and being stored in controlled deposits, in aspects of health, environment and safety. The objective of this article is to compare the performance, in economic, environmental and safety aspects, of nuclear power in relation to renewable energy sources. The results show that nuclear energy has become increasingly competitive in all these fields, justifying the growth of investments in new nuclear technologies. Therefore, the coexistence between the use of clean sources of electricity and the thermonuclear matrix will bring, for humanity, truly sustainable systems of energy generation. (author)

Comparison of the performance, advantages and disadvantages of nuclear power generation compared to other clean sources of electricity

International Nuclear Information System (INIS)

Mata, Jônatas F.C. da; Neto, Rieder O.; Mesquita, Amir Z.

2017-01-01

Nowadays, there is an increase in the demand for electricity in emerging countries, such as India, China and Brazil. There are several alternatives to increase energy generation, and each country has followed certain strategies to achieve this goal. For a long time, developed countries, such as the United States, the United Kingdom and Germany, had focused their efforts on the use of thermoelectric generators through the combustion of non-renewable sources such as coal, natural gas and oil. These examples were followed, also, by the emerging countries. However, pollution levels, generated by these sources, have required the breakdown of this paradigm, and the consequent reversal of large investments in clean energy sources, such as hydraulics, solar and wind. Nucleo-electric energy is also considered a clean energy source, since it does not generate polluting gases during the processing of concentrated uranium in nuclear reactors. In addition, all radioactive waste occupying relatively small volumes and being stored in controlled deposits, in aspects of health, environment and safety. The objective of this article is to compare the performance, in economic, environmental and safety aspects, of nuclear power in relation to renewable energy sources. The results show that nuclear energy has become increasingly competitive in all these fields, justifying the growth of investments in new nuclear technologies. Therefore, the coexistence between the use of clean sources of electricity and the thermonuclear matrix will bring, for humanity, truly sustainable systems of energy generation. (author)

Continuum of Care (COC) Areas

Data.gov (United States)

Department of Housing and Urban Development — The purpose of the Continuum of Care (CoC) Homeless Assistance Programs is to reduce the incidence of homelessness in CoC communities by assisting homeless...

Nuclear Insurance Subsidies Cost from Post-Fukushima Accounting Based on Media Sources

Directory of Open Access Journals (Sweden)

John J. Laureto

2016-12-01

Full Text Available Quantification of nuclear liability insurance is difficult without arbitrary liability caps; however, post-mortem calculations can be used to calculate insurance costs. This study analyzes the Fukushima (Daiichi nuclear power plant disaster to quantify the cost per unit electricity ($/kWh of nuclear energy from the lifetime of the plant after accounting for the true cost of the liability needed to cover the damages from the nuclear disaster determined from news reports. These costs are then compared to the cost of electricity currently paid by Japanese consumers, and then are aggregated to determine the indirect subsidy for nuclear power providers in both Japan and the USA. The results show that the reported costs of the Fukushima nuclear disaster are $20–525 billion, which results in a real insurance cost from the lifetime of electricity produced at the plants between $0.22–5.78/kWh. These values are far higher than the current insurance costs by Japanese law of $0.01/kWh and even the total costs consumers pay for electricity. Although the spread in the input costs is large and the reported metrics are incomplete, the nuclear insurance subsidy is clearly substantial in Japan and in the USA. Ideally, energy sources should be economically sustainable without the need for a government insurance subsidy. For the electricity market to function effectively and efficiently in all other countries using nuclear power, the insurance costs should be reported accurately and included in nuclear electricity costs without arbitrary government liability caps.

A brief review of advances in complex networks of nuclear science and technology field

International Nuclear Information System (INIS)

Fang Jinqing

2010-01-01

A brief review of advances in complex networks of nuclear science and technology field at home and is given and summarized. These complex networks include: nuclear energy weapon network, network centric warfare, beam transport networks, continuum percolation evolving network associated with nuclear reactions, global nuclear power station network, (nuclear) chemistry reaction networks, radiological monitoring and anti-nuclear terror networks, and so on. Some challenge issues and development prospects of network science are pointed out finally. (authors)

The design of nuclear magnetic resonance programmable pulsed source based SOPC

International Nuclear Information System (INIS)

Zhang Qingshun; Zhang Yakun; Wang Wenli

2012-01-01

The design of pulse source in the equipment of pulsed Nuclear Magnetic Resonance is studied based on SOPC. The strong processing power of Nios Ⅱ embedded processor and the design flexibility of FPGA are fully used. The SOPC system is built. The overall design plan for the pulse source is described. The design of programmable multi-pulse generation logic user-defined components in the FPGA is introduced mainly. Part of the implementation program and the task logic simulation waveforms are presented. The pulse source has better application value because a clear, stable and good quality multi-pulse output waveform can be shown on the oscilloscope finally. The system software and hardware are easy to be modified and upgraded, meeting different application of pulsed NMR pulse sequence in variety of requirements. (authors)

Technical Guidance from the International Safety Framework for Nuclear Power Source Applications in Outer Space for Design and Development Phases

Science.gov (United States)

Summerer, Leopold

2014-08-01

In 2009, the International Safety Framework for Nuclear Power Source Applications in Outer Space [1] has been adopted, following a multi-year process that involved all major space faring nations in the frame of the International Atomic Energy Agency and the UN Committee on the Peaceful Uses of Outer Space. The safety framework reflects an international consensus on best practices. After the older 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space, it is the second document at UN level dedicated entirely to space nuclear power sources.This paper analyses aspects of the safety framework relevant for the design and development phases of space nuclear power sources. While early publications have started analysing the legal aspects of the safety framework, its technical guidance has not yet been subject to scholarly articles. The present paper therefore focuses on the technical guidance provided in the safety framework, in an attempt to assist engineers and practitioners to benefit from these.

Continuum methods of physical modeling continuum mechanics, dimensional analysis, turbulence

CERN Document Server

Hutter, Kolumban

2004-01-01

The book unifies classical continuum mechanics and turbulence modeling, i.e. the same fundamental concepts are used to derive model equations for material behaviour and turbulence closure and complements these with methods of dimensional analysis. The intention is to equip the reader with the ability to understand the complex nonlinear modeling in material behaviour and turbulence closure as well as to derive or invent his own models. Examples are mostly taken from environmental physics and geophysics.

Continuum Thinking and the Contexts of Personal Information Management

Science.gov (United States)

Huvila, Isto; Eriksen, Jon; Häusner, Eva-Maria; Jansson, Ina-Maria

2014-01-01

Introduction: Recent personal information management literature has underlined the significance of the contextuality of personal information and its use. The present article discusses the applicability of the records continuum model and its generalisation, continuum thinking, as a theoretical framework for explicating the overlap and evolution of…

The use of neutron sources in nuclear reactors start-up after long shutdown periods

International Nuclear Information System (INIS)

Ponzoni Filho, P.; Borges, J.B.

1990-01-01

The reasons for the use of neutron sources in nuclear reactors, the different kinds of sources used and the alternatives to obtain the required minimum neutron counts in the external source range detectors after long maintenance and refueling periods are presented and discussed. The paper presents a formulation based in physics principles and experimental data, to calculate the power and time of reactor operation required to increase the effective fluence of secondary neutron sources. The option of using actinides produced during operation of the reactor as an additional source of neutrons is also discussed in depth to allow similar calculations in other kinds of reactors. The re-utilization of primary sources is considered as a last option. (author)

Lattice Boltzmann method for multi-component, non-continuum mass diffusion

International Nuclear Information System (INIS)

Joshi, Abhijit S; Peracchio, Aldo A; Grew, Kyle N; Chiu, Wilson K S

2007-01-01

Recently, there has been a great deal of interest in extending the lattice Boltzmann method (LBM) to model transport phenomena in the non-continuum regime. Most of these studies have focused on single-component flows through simple geometries. This work examines an ad hoc extension of a recently developed LBM model for multi-component mass diffusion (Joshi et al 2007 J. Phys. D: Appl. Phys. 40 2961) to model mass diffusion in the non-continuum regime. In order to validate the method, LBM results for ternary diffusion in a two-dimensional channel are compared with predictions of the dusty gas model (DGM) over a range of Knudsen numbers. A calibration factor based on the DGM is used in the LBM to correlate Knudsen diffusivity to pore size. Results indicate that the LBM can be a useful tool for predicting non-continuum mass diffusion (Kn > 0.001), but additional research is needed to extend the range of applicability of the algorithm for a larger parameter space. Guidelines are given on using the methodology described in this work to model non-continuum mass transport in more complex geometries where the DGM is not easily applicable. In addition, the non-continuum LBM methodology can be extended to three-dimensions. An envisioned application of this technique is to model non-continuum mass transport in porous solid oxide fuel cell electrodes

General-purpose heat source project and space nuclear safety and fuels program. Progress report

International Nuclear Information System (INIS)

Maraman, W.J.

1979-12-01

This formal monthly report covers the studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed hear are of a continuing nature. Results and conclusions described may change as the work continues

RELATIVISTIC PLASMA AS THE DOMINANT SOURCE OF THE OPTICAL CONTINUUM EMISSION IN THE BROAD-LINE RADIO GALAXY 3C 120

International Nuclear Information System (INIS)

Leon-Tavares, J.; Lobanov, A. P.; Arshakian, T. G.; Chavushyan, V. H.; Doroshenko, V. T.; Sergeev, S. G.; Efimov, Y. S.; Nazarov, S. V.

2010-01-01

We report a relation between radio emission in the inner jet of the Seyfert galaxy 3C 120 and optical continuum emission in this galaxy. Combining the optical variability data with multi-epoch high-resolution very long baseline interferometry observations reveals that an optical flare rises when a superluminal component emerges into the jet, and its maxima is related to the passage of such component through the location of a stationary feature at a distance of ∼1.3 pc from the jet origin. This indicates that a significant fraction of the optical continuum produced in 3C 120 is non-thermal, and it can ionize material in a sub-relativistic wind or outflow. We discuss implications of this finding for the ionization and structure of the broad emission line region, as well as for the use of broad emission lines for determining black hole masses in radio-loud active galactic nucleus.

Determination of phospholipids in soybean lecithin samples via the phosphorus monoxide molecule by high-resolution continuum source graphite furnace molecular absorption spectrometry.

Science.gov (United States)

Pires, Laís N; Brandão, Geovani C; Teixeira, Leonardo S G

2017-06-15

This paper presents a method for determining phospholipids in soybean lecithin samples by phosphorus determination using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) via molecular absorption of phosphorus monoxide. Samples were diluted in methyl isobutyl ketone. The best conditions were found to be 213.561nm with a pyrolysis temperature of 1300°C, a volatilization temperature of 2300°C and Mg as a chemical modifier. To increase the analytical sensitivity, measurement of the absorbance signal was obtained by summing molecular transition lines for PO surrounding 213nm: 213.561, 213.526, 213.617 and 213.637nm. The limit of detection was 2.35mgg -1 and the precision, evaluated as relative standard deviation (RSD), was 2.47% (n=10) for a sample containing 2.2% (w/v) phosphorus. The developed method was applied for the analysis of commercial samples of soybean lecithin. The determined concentrations of phospholipids in the samples varied between 38.1 and 45% (w/v). Copyright © 2017 Elsevier Ltd. All rights reserved.

Memory binding in clinical and non-clinical psychotic experiences: how does the continuum model fare?

Science.gov (United States)

Chhabra, S; Badcock, J C; Maybery, M T

2013-07-01

Both clinical and non-clinical auditory hallucinations (AH) have been associated with source memory deficits, supporting a continuum of underlying cognitive mechanisms, though few studies have employed the same task in patient and nonpatient samples. Recent commentators have called for more debate on the continuum model of psychosis. Consequently, the current study investigated the continuity model of AH with reference to memory binding. We used an identical voice and word recognition memory task to assess binding in two separate studies of: (1) healthy hallucination-prone individuals and controls (30 high and 30 low scorers on the Launay-Slade Hallucination Scale-Revised) and (2) schizophrenia patient samples (32 with AH, 32 without AH) and 32 healthy controls. There was no evidence of impaired binding in high hallucination-prone, compared to low hallucination-prone individuals. In contrast, individuals with schizophrenia (both with and without AH) had difficulties binding (remembering "who said what"), alongside difficulties remembering individual words and voices. Binding ability and memory for voices were also negatively linked to the loudness of hallucinated voices reported by patients with AH. These findings suggest that different mechanisms may exist in clinical and non-clinical hallucinators, adding to the growing debate on the continuum model of psychotic symptoms.

Continuum mechanics using Mathematica fundamentals, methods, and applications

CERN Document Server

Romano, Antonio

2014-01-01

This textbook's methodological approach familiarizes readers with the mathematical tools required to correctly define and solve problems in continuum mechanics. Covering essential principles and fundamental applications, this second edition of Continuum Mechanics using Mathematica® provides a solid basis for a deeper study of more challenging and specialized problems related to nonlinear elasticity, polar continua, mixtures, piezoelectricity, ferroelectricity, magneto-fluid mechanics, and state changes (see A. Romano, A. Marasco, Continuum Mechanics: Advanced Topics and Research Trends, Springer (Birkhäuser), 2010, ISBN 978-0-8176-4869-5). Key topics and features: * Concise presentation strikes a balance between fundamentals and applications * Requisite mathematical background carefully collected in two introductory chapters and one appendix * Recent developments highlighted through coverage of more significant applications to areas such as wave propagation, fluid mechanics, porous media, linear elasticity....

ICMS Workshop on Differential Geometry and Continuum Mechanics

CERN Document Server

Grinfeld, Michael; Knops, R

2015-01-01

This book examines the exciting interface between differential geometry and continuum mechanics, now recognised as being of increasing technological significance. Topics discussed include isometric embeddings in differential geometry and the relation with microstructure in nonlinear elasticity, the use of manifolds in the description of microstructure in continuum mechanics, experimental measurement of microstructure, defects, dislocations, surface energies, and nematic liquid crystals. Compensated compactness in partial differential equations is also treated. The volume is intended for specialists and non-specialists in pure and applied geometry, continuum mechanics, theoretical physics, materials and engineering sciences, and partial differential equations. It will also be of interest to postdoctoral scientists and advanced postgraduate research students. These proceedings include revised written versions of the majority of papers presented by leading experts at the ICMS Edinburgh Workshop on Differential G...

The German system to prevent, detect and respond to illicit uses of nuclear materials and radioactive sources

International Nuclear Information System (INIS)

Fechner, J.B.

2001-01-01

The German system to prevent, detect and respond to illicit uses of nuclear materials and radioactive sources consists of a variety of different elements: International and national laws and regulations covering safeguards, physical protection, and import/export control; Licensing and regulatory supervision of all activities related to nuclear materials and radioactive sources, including import and export; Responsibility of the licensee to ensure compliance with licensing conditions; sanctions; Law enforcement by police, security and customs authorities; prosecution and penalties; Detection of illicitly trafficked radioactive materials through intelligence and technical means; analysis capabilities; Response arrangements for normal and for severe cases of illicit use of nuclear materials; Participation in international programmes and POC-systems. Safeguards measures have been implemented in Germany in accordance with the Non- Proliferation Treaty and with safeguards agreements based on INFCIRC/153. As Germany is a member of the European Union, the Euratom Treaty and the Euratom-Ordinance Nr. 3227/76 together with the Verification Agreement between the IAEA, the European Commission and the European Member States have led to safeguards measures jointly implemented by the IAEA and by Euratom. The relevant international law for the physical protection of nuclear material in force in Germany is the Convention on the Physical Protection of Nuclear Material. The recommendations on physical protection objectives and fundamentals and on physical protection measures specified in INFCIRC/225/Rev. 4 have been taken into account in various national regulations pertaining to the national design basis threat, the physical protection of LWR nuclear power plants, of interim spent fuel storage facilities, of facilities containing category III material, of nuclear material and radioactive waste transports by road or railway vehicles, aircraft or sea vessels; additional guidelines

Source modelling in seismic risk analysis for nuclear power plants

International Nuclear Information System (INIS)

Yucemen, M.S.

1978-12-01

The proposed probabilistic procedure provides a consistent method for the modelling, analysis and updating of uncertainties that are involved in the seismic risk analysis for nuclear power plants. The potential earthquake activity zones are idealized as point, line or area sources. For these seismic source types, expressions to evaluate their contribution to seismic risk are derived, considering all the possible site-source configurations. The seismic risk at a site is found to depend not only on the inherent randomness of the earthquake occurrences with respect to magnitude, time and space, but also on the uncertainties associated with the predicted values of the seismic and geometric parameters, as well as the uncertainty in the attenuation model. The uncertainty due to the attenuation equation is incorporated into the analysis through the use of random correction factors. The influence of the uncertainty resulting from the insufficient information on the seismic parameters and source geometry is introduced into the analysis by computing a mean risk curve averaged over the various alternative assumptions on the parameters and source geometry. Seismic risk analysis is carried for the city of Denizli, which is located in the seismically most active zone of Turkey. The second analysis is for Akkuyu

The Radiation Source ELBE and its Research Program in Nuclear Physics

International Nuclear Information System (INIS)

Lehnert, U.; Michel, P.; Schwengner, R.

2005-01-01

The new radiation source 'Strahlungsquelle ELBE' at the Forschungszentrum Rossendorf (FZR) near Dresden, Germany, is a user facility that utilizes a superconducting linear accelerator to produce various secondary beams for experiments in nuclear science, solid state physics, materials research, environmental chemistry and in the life sciences. The high brilliance electron beam of up to 40 MeV and 1 mA (cw) is mainly used to drive free electron lasers producing infrared light in the 5-150 μm wavelength region. Additionally, polarized MeV-Bremsstrahlung and X-rays from electron channeling are available, facilities for neutron and positron production are under construction. The talk outlines the ongoing research activities at ELBE with special attention to the nuclear resonance fluorescence experiments

Relative economic incentives for hydrogen from nuclear, renewable, and fossil energy sources

International Nuclear Information System (INIS)

Gorensek, Maximilian B.; Forsberg, Charles W.

2009-01-01

The specific hydrogen market determines the value of hydrogen from different sources. Each hydrogen production technology has its own distinct characteristics. For example, steam reforming of natural gas produces only hydrogen. In contrast, nuclear and solar hydrogen production facilities produce hydrogen together with oxygen as a by-product or co-product. For a user who needs both oxygen and hydrogen, the value of hydrogen from nuclear and solar plants is higher than that from a fossil plant because ''free'' oxygen is produced as a by-product. Six factors that impact the relative economics of fossil, nuclear, and solar hydrogen production to the customer are identified: oxygen by-product, avoidance of carbon dioxide emissions, hydrogen transport costs, storage costs, availability of low-cost heat, and institutional factors. These factors imply that different hydrogen production technologies will be competitive in different markets and that the first markets for nuclear and solar hydrogen will be those markets in which they have a unique competitive advantage. These secondary economic factors are described and quantified in terms of dollars per kilogram of hydrogen. (author)

Reference sources for radionuclide calibrations in nuclear programmes

Energy Technology Data Exchange (ETDEWEB)

Almeida, M.C.M. de; Delgado, J.U.; Poledna, R.; Silva, R.L. da; Oliveira, E.M. de; Di Prinzio, M.A.R., E-mail: marcandida@yahoo.com.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

2009-07-01

The radionuclide metrology laboratories aim to provide radioactive standards for detector calibrations in nuclear safety areas. To produce the reference sources to be furnished to users the following standards of {sup 57}Co, {sup 60}Co, {sup 133}Ba, {sup 241}Am, {sup 152}Eu and {sup 166}Ho are commonly used. In this work was made a verifying of the uncertainties obtained for the two methods: comparative (sample-standards) and efficiency curve. The total uncertainties obtained by sample-standard method varied from 0.4 to 1.2% (k = 1). The results using efficiency curve method to the same radioisotopes and same conditions are between 0.9 to 2.2% (k = 1). (author)

Flare continuum

International Nuclear Information System (INIS)

Robinson, R.D.

1985-01-01

This paper reviews the metre-wave continuum radiation which is related to similar solar emissions observed in the decimetre and centimetre spectral regions. This type of emission, known as Flare Contiuum, is related to the radio bursts of types II and IV. After summarising the history of the phenomenon and reviewing the observational work, the author discusses the various possible radiation mechanisms and their relation to the solar corona, the interplanetary medium and related regions. The theoretical topics covered include the role of high-energy particles, the trapping of such particles, gyro-synchrotron radiation, polarization and plasma interactions. (U.K.)

Dynamic Modelling for Planar Extensible Continuum Robot Manipulators

Science.gov (United States)

2006-01-01

to the OCTARM continuum ma- nipulator. The OCTARM manipulator is a biologically inspired soft robot manipulator resembling an elephant trunk or an... octopus arm [18]. The OCTARM, shown in Figure 1, is a three-section robot with nine degrees of freedom. Aside from two axis bending with constant...increasing interest in designing �biologically inspired � continuum robots . Some of these designs are mimicking trunks [8], [25], tentacles [17], [21], [24

Research in theoretical nuclear physics

International Nuclear Information System (INIS)

Udagawa, T.

1993-11-01

This report describes the accomplishments in basic research in nuclear physics carried out by the theoretical nuclear physics group in the Department of Physics at the University of Texas at Austin, during the period of November 1, 1992 to October 31, 1993. The work done covers three separate areas, low-energy nuclear reactions, intermediate energy physics, and nuclear structure studies. Although the subjects are thus spread among different areas, they are based on two techniques developed in previous years. These techniques are a powerful method for continuum-random-phase-approximation (CRPA) calculations of nuclear response and the breakup-fusion (BF) approach to incomplete fusion reactions, which calculation on a single footing of various incomplete fusion reaction cross sections within the framework of direct reaction theories. The approach was developed as a part of a more general program for establishing an approach to describing all different types of nuclear reactions, i.e., complete fusion, incomplete fusion and direct reactions, in a systematic way based on single theoretical framework

Theoretical Calculation and Validation of the Water Vapor Continuum Absorption

Science.gov (United States)

Ma, Qiancheng; Tipping, Richard H.

1998-01-01

The primary objective of this investigation is the development of an improved parameterization of the water vapor continuum absorption through the refinement and validation of our existing theoretical formalism. The chief advantage of our approach is the self-consistent, first principles, basis of the formalism which allows us to predict the frequency, temperature and pressure dependence of the continuum absorption as well as provide insights into the physical mechanisms responsible for the continuum absorption. Moreover, our approach is such that the calculated continuum absorption can be easily incorporated into satellite retrieval algorithms and climate models. Accurate determination of the water vapor continuum is essential for the next generation of retrieval algorithms which propose to use the combined constraints of multi-spectral measurements such as those under development for EOS data analysis (e.g., retrieval algorithms based on MODIS and AIRS measurements); current Pathfinder activities which seek to use the combined constraints of infrared and microwave (e.g., HIRS and MSU) measurements to improve temperature and water profile retrievals, and field campaigns which seek to reconcile spectrally-resolved and broad-band measurements such as those obtained as part of FIRE. Current widely used continuum treatments have been shown to produce spectrally dependent errors, with the magnitude of the error dependent on temperature and abundance which produces errors with a seasonal and latitude dependence. Translated into flux, current water vapor continuum parameterizations produce flux errors of order 10 W/ml, which compared to the 4 W/m' magnitude of the greenhouse gas forcing and the 1-2 W/m' estimated aerosol forcing is certainly climatologically significant and unacceptably large. While it is possible to tune the empirical formalisms, the paucity of laboratory measurements, especially at temperatures of interest for atmospheric applications, preclude tuning

Generalized Continuum: from Voigt to the Modeling of Quasi-Brittle Materials

Directory of Open Access Journals (Sweden)

Jamile Salim Fuina

2010-12-01

Full Text Available This article discusses the use of the generalized continuum theories to incorporate the effects of the microstructure in the nonlinear finite element analysis of quasi-brittle materials and, thus, to solve mesh dependency problems. A description of the problem called numerically induced strain localization, often found in Finite Element Method material non-linear analysis, is presented. A brief historic about the Generalized Continuum Mechanics based models is presented, since the initial work of Voigt (1887 until the more recent studies. By analyzing these models, it is observed that the Cosserat and microstretch approaches are particular cases of a general formulation that describes the micromorphic continuum. After reporting attempts to incorporate the material microstructure in Classical Continuum Mechanics based models, the article shows the recent tendency of doing it according to assumptions of the Generalized Continuum Mechanics. Finally, it presents numerical results which enable to characterize this tendency as a promising way to solve the problem.

Simulated nuclear optical signatures using explosive light sources (ELS)

International Nuclear Information System (INIS)

Glaser, R.F.

1979-05-01

Four Explosive Light Source (aluminium powder and oxygen) tests were conducted on the test range at Sandia Laboratories in Albuquerque (SLA) from 28 February through 7 March 1978. Although several types of measuring devices were used, the report documents only the optical time histories measured by the bhangmeters and the NBDS, and explains the conclusions reached. In general, the four shots made it possible to gather clear-air optical transmission data, determine the suitability of ELS to simulate the optical effects of a nuclear burst, and provide experience for the larger scale ELS tests to be conducted at Fort Ord, CA in April

Simulated nuclear optical signatures using explosive light sources (ELS)

Energy Technology Data Exchange (ETDEWEB)

Glaser, R.F.

1979-05-01

Four Explosive Light Source (aluminium powder and oxygen) tests were conducted on the test range at Sandia Laboratories in Albuquerque (SLA) from 28 February through 7 March 1978. Although several types of measuring devices were used, the report documents only the optical time histories measured by the bhangmeters and the NBDS, and explains the conclusions reached. In general, the four shots made it possible to gather clear-air optical transmission data, determine the suitability of ELS to simulate the optical effects of a nuclear burst, and provide experience for the larger scale ELS tests to be conducted at Fort Ord, CA in April.

Impacts of non-nuclear energy sources on the environment

International Nuclear Information System (INIS)

Tavkaya, E.

2006-01-01

Fossil fuels (i.e., petroleum, natural gas and coal) , which meet most of the world's energy demand today, are being depleted fast. Also, their combustion products are causing the global problems, such as the greenhouse effect, ozone layer depletion, acid rains and pollution, which are posing great danger for our environment and eventually for the life in our planet. If humankind is going to have a future on this planet, at least a high-technology future, with a significant population of several billions of humans continuing to inhabit the Earth, it is absolutely inevitable that we will have to find another energy source. Table 1: The environmental effects for some energy systems; SOURCES: Fossil fuels (petroleum, natural gas and coal) ENVIRONMENTAL EFFECTS : - Ozone layer depletion - Changes of atmospheric conditions - Decrease of air quality (Coal , petroleum) - Acid rains and destroy of forests (coal, petroleum ) - Pollution from toxic wastes (coal ash, slag and smoke hole gases) - Pollution of surface water - Seaside and sea pollutions (petroleum) - Terrain devolution - Large amount of fuel and transportation requirements - Sources depletion SOURCES: Hydroelectric ENVIRONMENTAL EFFECTS - Large area requirements - Population situation changes - Erosion and usage changes - Ecosystem changes and health effects - Disappearing of biological variety - Downfall of dams - Leave out of production SOURCES: Renewable (sun, wind, geothermal, biomass) ENVIRONMENTAL EFFECTS : - Decrease of air quality (geothermal, biomass) - Large area usage - Ecologic system changes - Fabrication effects (CO 2 effect due to production of photovoltaic cells that work with sun) - Noise (wind) SOURCES: Nuclear (All energy chain) ENVIRONMENTAL EFFECTS : - Radioactive oscillation because of serious reactor accident - Radiation of waste storage. In this study, the environmental effects for some energy systems are investigated with all details

Continuum of Counseling Goals: A Framework for Differentiating Counseling Strategies.

Science.gov (United States)

Bruce, Paul

1984-01-01

Presents counseling goals in a developmental continuum similar in concept to Maslow's hierarchy of needs. Discusses ego development goals, socialization goals, developmental goals, self-esteem goals, and self-realization goals and describes characteristics and implications of the continuum. (JAC)

The geometry of continuum regularization

International Nuclear Information System (INIS)

Halpern, M.B.

1987-03-01

This lecture is primarily an introduction to coordinate-invariant regularization, a recent advance in the continuum regularization program. In this context, the program is seen as fundamentally geometric, with all regularization contained in regularized DeWitt superstructures on field deformations

HIV continuum of care in Europe and Central Asia.

Science.gov (United States)

Drew, R S; Rice, B; Rüütel, K; Delpech, V; Attawell, K A; Hales, D K; Velasco, C; Amato-Gauci, A J; Pharris, A; Tavoschi, L; Noori, T

2017-08-01

The European Centre for Disease Prevention and Control (ECDC) supports countries to monitor progress in their response to the HIV epidemic. In line with these monitoring responsibilities, we assess how, and to what extent, the continuum of care is being measured across countries. The ECDC sent out questionnaires to 55 countries in Europe and Central Asia in 2014. Nominated country representatives were questioned on how they defined and measured six elements of the continuum. We present our results using three previously described frameworks [breakpoints; Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets; diagnosis and treatment quadrant]. Forty countries provided data for at least one element of the continuum. Countries reported most frequently on the number of people diagnosed with HIV infection (37; 93%), and on the number in receipt of antiretroviral therapy (ART) (35; 88%). There was little consensus across countries in their approach to defining linkage to, and retention in, care. The most common breakpoint (>19% reduction between two adjacent elements) related to the estimated number of people living with HIV who were diagnosed (18 of 23; 78%). We present continuum data from multiple countries that provide both a snapshot of care provision and a baseline against which changes over time in care provision across Europe and Central Asia may be measured. To better inform HIV testing and treatment programmes, standard data collection approaches and definitions across the HIV continuum of care are needed. If countries wish to ensure an unbroken HIV continuum of care, people living with HIV need to be diagnosed promptly, and ART needs to be offered to all those diagnosed. © 2017 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association.

Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

Science.gov (United States)

Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

2014-09-01

In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nuclear power: tomorrow's energy source; Le nucleaire: une energie pour l'avenir

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

In France, 76% of electricity is produced by nuclear power. The industry's pricing levels are among the most competitive in Europe. Thanks to its 58 nuclear reactors France enjoys almost 50% energy autonomy thus ensuring a highly stable supply. Equally, as a non-producer of greenhouse gases, the nuclear sector can rightfully claim to have an environmentally friendly impact. Against a background to increasing global demand with predictions that fossil fuels will run out and global warming a central issue, it is important to use production methods which face up to problems of this nature. There is no question that nuclear energy has a vital role to play alongside other energy sources. (authors)

Nuclear chemistry research and spectroscopy with radioactive sources. Nineteenth annual progress report

International Nuclear Information System (INIS)

Fink, R.W.

1983-01-01

Our effort is centered on radioactive decay studies of far-from-stable nuclides produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). Progress is reported on the following studies: lifetime of the g/sub 7/2/ level in 109 Ag; halflife of the h/sub 9/2/ level in 187 Au; decay of 8.4 min 187 Au → 187 Pt; orbital EC probabilities and decay energy of 207 Bi; decay of 9 min /sup 201m/Po and 16 min /sup 201g/Po; decay of 2.5 min 125 Ba; decay of 7.4 min 203 At; exploration of neutron-deficient Sm, Pm, and Nd nuclides; preparation of thoron active deposit conversion electron sources; inception of nuclear laser spectroscopy at UNISOR; and nuclear structure calculations with nuclear models. Publications are listed

Information source exploitation/exploration and NPD decision-making

DEFF Research Database (Denmark)

Jespersen, Kristina Risom

different Scandinavian companies. Data was analyzed using hierarchical regression models across decision criteria dimensions and NPD stages as well as analyzing the combination of selected information sources. Rather than forwarding one optimal search behavior for the entire NPD process, we find optimal...... information search behavior at either end of the exploitation/exploration continuum. Additionally, we find that overexploitation and overexploration is caused by managerial bias. This creates managerial misbehavior at gate decision-points of the NPD process.......The purpose of this study is to examine how the exploration/exploitation continuum is applied by decision-makers in new product gate decision-making. Specifically, we analyze at gate decision-points how the evaluation of a new product project is affected by the information source exploitation...

Change Detection for Remote Monitoring of Underground Nuclear Testing: Comparison with Seismic and Associated Explosion Source Phenomenological Data

DEFF Research Database (Denmark)

Canty, M.; Jahnke, G.; Nielsen, Allan Aasbjerg

2005-01-01

The analysis of open-source satellite imagery is in process of establishing itself as an important tool for monitoring nuclear activities throughout the world which are relevant to disarmament treaties, like e. g. the Comprehensive Nuclear-Test-Ban Treaty (CTBT). However, the detection of anthrop......The analysis of open-source satellite imagery is in process of establishing itself as an important tool for monitoring nuclear activities throughout the world which are relevant to disarmament treaties, like e. g. the Comprehensive Nuclear-Test-Ban Treaty (CTBT). However, the detection...... of conventional multispectral satellite platforms with moderate ground resolution (Landsat TM, ASTER) to detect changes over wide areas.We chose the Nevada Test Site (NTS), USA, for a case study because of the large amount of available ground truth information. The analysis is based on the multivariate alteration...

Discrimination between discrete and continuum scattering from the sub-seafloor.

Science.gov (United States)

Holland, Charles W; Steininger, Gavin; Dosso, Stan E

2015-08-01

There is growing evidence that seabed scattering is often dominated by heterogeneities within the sediment volume as opposed to seafloor roughness. From a theoretical viewpoint, sediment volume heterogeneities can be described either by a fluctuation continuum or by discrete particles. In at-sea experiments, heterogeneity characteristics generally are not known a priori. Thus, an uninformed model selection is generally made, i.e., the researcher must arbitrarily select either a discrete or continuum model. It is shown here that it is possible to (acoustically) discriminate between continuum and discrete heterogeneities in some instances. For example, when the spectral exponent γ3>4, the volume scattering cannot be described by discrete particles. Conversely, when γ3≤2, the heterogeneities likely arise from discrete particles. Furthermore, in the range 2discrete vs continuum heterogeneities via acoustic remote sensing may lead to improved observations and concomitant increased understanding of the marine benthic environment.

Modified ensemble Kalman filter for nuclear accident atmospheric dispersion: prediction improved and source estimated.

Science.gov (United States)

Zhang, X L; Su, G F; Yuan, H Y; Chen, J G; Huang, Q Y

2014-09-15

Atmospheric dispersion models play an important role in nuclear power plant accident management. A reliable estimation of radioactive material distribution in short range (about 50 km) is in urgent need for population sheltering and evacuation planning. However, the meteorological data and the source term which greatly influence the accuracy of the atmospheric dispersion models are usually poorly known at the early phase of the emergency. In this study, a modified ensemble Kalman filter data assimilation method in conjunction with a Lagrangian puff-model is proposed to simultaneously improve the model prediction and reconstruct the source terms for short range atmospheric dispersion using the off-site environmental monitoring data. Four main uncertainty parameters are considered: source release rate, plume rise height, wind speed and wind direction. Twin experiments show that the method effectively improves the predicted concentration distribution, and the temporal profiles of source release rate and plume rise height are also successfully reconstructed. Moreover, the time lag in the response of ensemble Kalman filter is shortened. The method proposed here can be a useful tool not only in the nuclear power plant accident emergency management but also in other similar situation where hazardous material is released into the atmosphere. Copyright © 2014 Elsevier B.V. All rights reserved.

Locating sensors for detecting source-to-target patterns of special nuclear material smuggling: a spatial information theoretic approach.

Science.gov (United States)

Przybyla, Jay; Taylor, Jeffrey; Zhou, Xuesong

2010-01-01

In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM) smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

Locating Sensors for Detecting Source-to-Target Patterns of Special Nuclear Material Smuggling: A Spatial Information Theoretic Approach

Directory of Open Access Journals (Sweden)

Xuesong Zhou

2010-08-01

Full Text Available In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

Integrated societal risk assessment framework for nuclear power and renewable energy sources

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2015-01-01

Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh) of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources

Integrated societal risk assessment framework for nuclear power and renewable energy sources

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Hun; Kang, Hyun Gook [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of)

2015-06-15

Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh) of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources.

Continuum gauge fields from lattice gauge fields

International Nuclear Information System (INIS)

Goeckeler, M.; Kronfeld, A.S.; Schierholz, G.; Wiese, U.J.

1993-01-01

On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant and complies with geometrical constructions of the topological charge on the lattice, is given in this paper. The procedure is explicitly carried out in the U(1) theory in two dimensions, where it leads to simple results. (orig.)

Nuclear fuel: sustainable source of energy or burden on society?

International Nuclear Information System (INIS)

Williams, T.; Klaiber, G.

2007-01-01

In the past, the question concerning the sustainability of a resource primarily addressed its finite nature. Accordingly, electricity production using renewable energies was clearly sustainable. Contrasting this are systems based on oil, gas, coal or uranium. However, from the perspective of 'neo-sustainability' being analyzed today, this assessment appears less clear-cut, especially in light of the definition of sustainability as provided by the Brundtland report. Nowadays, the depletion time of fuel resources is thus not the only significant aspect, but factors such as efficiency, ecofriendliness and social responsibility also figure in. The nuclear fuel supply is analyzed from a sustainability perspective. After a short description of the supply chain, each of the most important aspects of sustainability are related to the individual stages of the supply chain and evaluated. This method aims at answering the question concerning to what extent nuclear fuel is a sustainable source of energy. Although the recycling of fissile materials from reprocessing and the deployment of advanced reactors are key factors as regards the issue of sustainability, these topics are deliberately only touched on. The main focus lies on the sustainability of the nuclear fuel cycle as it is currently utilized in light water reactors, without discussing the subject of reprocessing. (orig.)

Continuum limit of Bk from 2+1 flavor domain wall QCD

International Nuclear Information System (INIS)

2011-01-01

We determine the neutral kaon mixing matrix element B K in the continuum limit with 2+1 flavors of domain wall fermions, using the Iwasaki gauge action at two different lattice spacings. These lattice fermions have near exact chiral symmetry and therefore avoid artificial lattice operator mixing. We introduce a significant improvement to the conventional nonperturbative renormalization (NPR) method in which the bare matrix elements are renormalized nonperturbatively in the regularization invariant momentum scheme (RI-MOM) and are then converted into the MS - scheme using continuum perturbation theory. In addition to RI-MOM, we introduce and implement four nonexceptional intermediate momentum schemes that suppress infrared nonperturbative uncertainties in the renormalization procedure. We compute the conversion factors relating the matrix elements in this family of regularization invariant symmetric momentum schemes (RI-SMOM) and MS - at one-loop order. Comparison of the results obtained using these different intermediate schemes allows for a more reliable estimate of the unknown higher-order contributions and hence for a correspondingly more robust estimate of the systematic error. We also apply a recently proposed approach in which twisted boundary conditions are used to control the Symanzik expansion for off-shell vertex functions leading to a better control of the renormalization in the continuum limit. We control chiral extrapolation errors by considering both the next-to-leading order SU(2) chiral effective theory, and an analytic mass expansion. We obtain B K MS- (3 GeV) = 0.529(5) stat (15) χ (2) FV (11) NPR . This corresponds to B - K RGI- = 0.749(7) stat (21) χ (3) FV (15) NPR . Adding all sources of error in quadrature, we obtain B - K RGI- = 0.749(27) combined , with an overall combined error of 3.6%.

Determination of activation level energy of nuclear isomers by calibration of microspectra of radioactive sources

International Nuclear Information System (INIS)

Veres, A.; Pavlicsek, I.

1980-01-01

Nuclear isomers with unknown activation level were irradiated by calibrated radioactive sources. The integral cross sections were calculated for different energies of the sources. The activation energy was given by values coinciding with each other within the limits of error. The method made the determination of the unknown level of 1180+-10 keV of 195 Pt nucleus possible. (author)

Photometric redshifts for the next generation of deep radio continuum surveys - II. Gaussian processes and hybrid estimates

Science.gov (United States)

Duncan, Kenneth J.; Jarvis, Matt J.; Brown, Michael J. I.; Röttgering, Huub J. A.

2018-04-01

Building on the first paper in this series (Duncan et al. 2018), we present a study investigating the performance of Gaussian process photometric redshift (photo-z) estimates for galaxies and active galactic nuclei detected in deep radio continuum surveys. A Gaussian process redshift code is used to produce photo-z estimates targeting specific subsets of both the AGN population - infrared, X-ray and optically selected AGN - and the general galaxy population. The new estimates for the AGN population are found to perform significantly better at z > 1 than the template-based photo-z estimates presented in our previous study. Our new photo-z estimates are then combined with template estimates through hierarchical Bayesian combination to produce a hybrid consensus estimate that outperforms both of the individual methods across all source types. Photo-z estimates for radio sources that are X-ray sources or optical/IR AGN are significantly improved in comparison to previous template-only estimates - with outlier fractions and robust scatter reduced by up to a factor of ˜4. The ability of our method to combine the strengths of the two input photo-z techniques and the large improvements we observe illustrate its potential for enabling future exploitation of deep radio continuum surveys for both the study of galaxy and black hole co-evolution and for cosmological studies.

Non-classical solutions of a continuum model for rock descriptions

Directory of Open Access Journals (Sweden)

Mikhail A. Guzev

2014-06-01

Full Text Available The strain-gradient and non-Euclidean continuum theories are employed for construction of non-classical solutions of continuum models. The linear approximation of both models' results in identical structures in terms of their kinematic and stress characteristics. The solutions obtained in this study exhibit a critical behaviour with respect to the external loading parameter. The conclusions are obtained based on an investigation of the solution for the scalar curvature in the non-Euclidean continuum theory. The proposed analysis enables us to use different theoretical approaches for description of rock critical behaviour under different loading conditions.

Reducing Actuator Requirements in Continuum Robots Through Optimized Cable Routing.

Science.gov (United States)

Case, Jennifer C; White, Edward L; SunSpiral, Vytas; Kramer-Bottiglio, Rebecca

2018-02-01

Continuum manipulators offer many advantages compared to their rigid-linked counterparts, such as increased degrees of freedom and workspace volume. Inspired by biological systems, such as elephant trunks and octopus tentacles, many continuum manipulators are made of multiple segments that allow large-scale deformations to be distributed throughout the body. Most continuum manipulators currently control each segment individually. For example, a planar cable-driven system is typically controlled by a pair of cables for each segment, which implies two actuators per segment. In this article, we demonstrate how highly coupled crossing cable configurations can reduce both actuator count and actuator torque requirements in a planar continuum manipulator, while maintaining workspace reachability and manipulability. We achieve highly coupled actuation by allowing cables to cross through the manipulator to create new cable configurations. We further derive an analytical model to predict the underactuated manipulator workspace and experimentally verify the model accuracy with a physical system. We use this model to compare crossing cable configurations to the traditional cable configuration using workspace performance metrics. Our work here focuses on a simplified planar robot, both in simulation and in hardware, with the goal of extending this to spiraling-cable configurations on full 3D continuum robots in future work.

Nuclear, disk-focused wind and the bipolar structure of the spiral galaxy NGC 3079

International Nuclear Information System (INIS)

Duric, N.; Seaquist, E.R.

1988-01-01

A high-resolution, radio continuum study of the spiral galaxy NGC 3079 is presented which reveals the presence of a figure eight morphology along the minor axis, centered on the nucleus. The nucleus itself dominates the emission from the galaxy. It has an inverted spectrum and is a possible VLBI source. The morphology is successfully modeled as the interaction between a nuclear wind and interstellar gas in the disk and halo. In this model, the wind plows up interstellar material as it propagates away from the nucleus. The disk focuses the wind along the minor axis, thereby creating the observed features. The restricted volume of space where the wind originates and the high energies associated with the wind point to a compact object such as a black hole or an unusually compact and massive star cluster as the source of the wind. 24 references

Missing links in the root-soil organic matter continuum

Energy Technology Data Exchange (ETDEWEB)

O' Brien, Sarah L. [Argonne National Laboratory (ANL); Iversen, Colleen M [ORNL

2009-01-01

The soil environment remains one of the most complex and poorly understood research frontiers in ecology. Soil organic matter (SOM), which spans a continuum from fresh detritus to highly processed, mineral-associated organic matter, is the foundation of sustainable terrestrial ecosystems. Heterogeneous SOM pools are fueled by inputs from living and dead plants, driven by the activity of micro- and mesofauna, and are shaped by a multitude of abiotic factors. The specialization required to measure unseen processes that occur on a wide range of spatial and temporal scales has led to the partitioning of soil ecology research across several disciplines. In the organized oral session 'Missing links in the root-soil organic matter continuum' at the annual Ecological Society of America meeting in Albuquerque, NM, USA, we joined the call for greater communication and collaboration among ecologists who work at the root-soil interface (e.g. Coleman, 2008). Our goal was to bridge the gap between scientific disciplines and to synthesize disconnected pieces of knowledge from root-centric and soil-centric studies into an integrated understanding of belowground ecosystem processes. We focused this report around three compelling themes that arose from the session: (1) the influence of the rhizosphere on SOM cycling, (2) the role of soil heterotrophs in driving the transformation of root detritus to SOM, and (3) the controlling influence of the soil environment on SOM dynamics. We conclude with a discussion of new approaches for gathering data to bridge gaps in the root-SOM continuum and to inform the next generation of ecosystem models. Although leaf litter has often been considered to be the main source of organic inputs to soil, Ann Russell synthesized a convincing body of work demonstrating that roots, rather than surface residues, control the accumulation of SOM in a variety of ecosystems. Living roots, which are chemically diverse and highly dynamic, also influence a

Computational Method for Atomistic-Continuum Homogenization

National Research Council Canada - National Science Library

Chung, Peter

2002-01-01

The homogenization method is used as a framework for developing a multiscale system of equations involving atoms at zero temperature at the small scale and continuum mechanics at the very large scale...

A constitutive model of soft tissue: From nanoscale collagen to tissue continuum

KAUST Repository

Tang, Huang

2009-04-08

Soft collagenous tissue features many hierarchies of structure, starting from tropocollagen molecules that form fibrils, and proceeding to a bundle of fibrils that form fibers. Here we report the development of an atomistically informed continuum model of collagenous tissue. Results from full atomistic and molecular modeling are linked with a continuum theory of a fiber-reinforced composite, handshaking the fibril scale to the fiber and continuum scale in a hierarchical multi-scale simulation approach. Our model enables us to study the continuum-level response of the tissue as a function of cross-link density, making a link between nanoscale collagen features and material properties at larger tissue scales. The results illustrate a strong dependence of the continuum response as a function of nanoscopic structural features, providing evidence for the notion that the molecular basis for protein materials is important in defining their larger-scale mechanical properties. © 2009 Biomedical Engineering Society.

Temperature Dependences of Mechanisms Responsible for the Water-Vapor Continuum Absorption

Science.gov (United States)

Ma, Qiancheng

2014-01-01

The water-vapor continuum absorption plays an important role in the radiative balance in the Earth's atmosphere. It has been experimentally shown that for ambient atmospheric conditions, the continuum absorption scales quadratically with the H2O number density and has a strong, negative temperature dependence (T dependence). Over the years, there have been three different theoretical mechanisms postulated: far-wings of allowed transition lines, water dimers, and collision-induced absorption. The first mechanism proposed was the accumulation of absorptions from the far-wings of the strong allowed transition lines. Later, absorption by water dimers was proposed, and this mechanism provides a qualitative explanation for the continuum characters mentioned above. Despite the improvements in experimental data, at present there is no consensus on which mechanism is primarily responsible for the continuum absorption.

Surface green function matching for a three-dimensional non-local continuum

International Nuclear Information System (INIS)

Idiodi, J.O.A.

1985-07-01

With a view toward helping to bridge the gap, from the continuum side, between discrete and continuum models of crystalline, elastic solids, explicit results are presented for non-local stress tensors that describe exactly some lattice dynamical models that have been widely used in the literature for cubic lattices. The Surface Green Function Matching (SGFM) method, which has been used successfully for a variety of surface problems, is then extended, within a continuum approach, to a non-local continuum that models a three-dimensional discrete lattice. The practical use of the method is demonstrated by performing a fairly complete analytical study of the vibrational surface modes of the SCC semi-infinite medium. Some results are presented for the [100] direction of the (001) surface of the SCC lattice. (author)

The safe management of sources of radiation: Principles and strategies. INSAG-11. A report by the International Nuclear Safety Advisory Group

International Nuclear Information System (INIS)

1999-01-01

The IAEA activities relating to nuclear safety are based upon a number of premises. First and foremost, each Member State bears full responsibility for the safety of its nuclear facilities. States can be advised, but cannot be relieved of this responsibility. Secondly, much can be gained by exchanging experience; lessons learned can prevent accidents. Finally, the image of nuclear safety is international; a serious accident anywhere affects the public view of nuclear power everywhere. With the intention of strengthening its contribution to ensuring safety of nuclear power plants, the IAEA established the International Safety Advisory Group (INSAG), whose duties include serving as a forum for the exchange of information on nuclear safety issues of international significance and formulating commonly shared safety principles. The present report deals with the general principles governing the safety of all sources of radiation and with application of these principles. It intends to show that, at the conceptual level, the distinction traditionally made between nuclear safety and radiation protection is hardly justifiable. It is intended primarily for those non-specialists who need to take decisions about safe management of sources of radiation and who wish to gain a better understanding of the approach followed in managing the safety of these sources

Micro-sampling method based on high-resolution continuum source graphite furnace atomic absorption spectrometry for calcium determination in blood and mitochondrial suspensions.

Science.gov (United States)

Gómez-Nieto, Beatriz; Gismera, Mª Jesús; Sevilla, Mª Teresa; Satrústegui, Jorgina; Procopio, Jesús R

2017-08-01

A micro-sampling and straightforward method based on high resolution continuum source atomic absorption spectrometry (HR-CS AAS) was developed to determine extracellular and intracellular Ca in samples of interest in clinical and biomedical analysis. Solid sampling platforms were used to introduce the micro-samples into the graphite furnace atomizer. The secondary absorption line for Ca, located at 239.856nm, was selected to carry out the measurements. Experimental parameters such as pyrolysis and atomization temperatures and the amount of sample introduced for the measurements were optimized. Calibration was performed using aqueous standards and the approach to measure at the wings of the absorption lines was employed for the expansion of the linear response range. The limit of detection was of 0.02mgL -1 Ca (0.39ng Ca) and the upper limit of linear range was increased up to 8.0mgL -1 Ca (160ng Ca). The proposed method was used to determine Ca in mitochondrial suspensions and whole blood samples with successful results. Adequate recoveries (within 91-107%) were obtained in the tests performed for validation purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

Theory of nuclear excitation by electron capture for heavy ions

International Nuclear Information System (INIS)

Palffy, Adriana; Scheid, Werner; Harman, Zoltan

2006-01-01

We investigate the resonant process of nuclear excitation by electron capture (NEEC), in which a continuum electron is captured into a bound state of an ion with the simultaneous excitation of the nucleus. In order to derive the cross section a Feshbach projection operator formalism is introduced. Nuclear states and transitions are described by a nuclear collective model and making use of experimental data. Transition rates and total cross sections for NEEC followed by the radiative decay of the excited nucleus are calculated for various heavy-ion collision systems

Treatment of continuum in weakly bound systems in structure and reactions

Energy Technology Data Exchange (ETDEWEB)

Vitturi, Andrea [Dipartimento di Fisica and INFN, Padova (Italy); Perez-Bernal, Francisco [Facultad de Ciencias Experimentales, Departamento de Fisica Aplicada, Universidad de Huelva, Huelva (Spain)

2010-03-01

We investigate different treatments of continuum states in a simple structure case: two particles moving in a one-dimensional mean field and interacting via a density-dependent short range residual interaction. We find that in procedures that involve continuum discretization a rather large basis has to be used in order to get convergence to the exact results, in particular for the radial dependence of the two-particle wave function. This may lead to unpracticable situations in the case of many interacting particles in the continuum.

Elementary Continuum Mechanics for Everyone

DEFF Research Database (Denmark)

Byskov, Esben

numerical method, the finite element method, including means of mending inherent problems •An informal, yet precise exposition that emphasizes not just how a topic is treated, but discusses why a particular choice is made The book opens with a derivation of kinematically nonlinear 3-D continuum mechanics...

Continuum analogues of contragredient Lie algebras

International Nuclear Information System (INIS)

Saveliev, M.V.; Vershik, A.M.

1989-03-01

We present an axiomatic formulation of a new class of infinite-dimensional Lie algebras - the generalizations of Z-graded Lie algebras with, generally speaking, an infinite-dimensional Cartan subalgebra and a contiguous set of roots. We call such algebras ''continuum Lie algebras''. The simple Lie algebras of constant growth are encapsulated in our formulation. We pay particular attention to the case when the local algebra is parametrized by a commutative algebra while the Cartan operator (the generalization of the Cartan matrix) is a linear operator. Special examples of these algebras are the Kac-Moody algebras, algebras of Poisson brackets, algebras of vector fields on a manifold, current algebras, and algebras with differential or integro-differential Cartan operator. The nonlinear dynamical systems associated with the continuum contragredient Lie algebras are also considered. (author). 9 refs

Sources to environmental radioactive contamination from nuclear activities in the former USSR

International Nuclear Information System (INIS)

Polikarpov, G.G.; Aarkrog, A.

1993-01-01

There is three major sites of radioactive environmental contamination in the former USSR: the Cheliabinsk region in the Urals, Chernobyl NPP in Ukraine and Novaya Zemlya in the Arctic Ocean. The first mentioned is the most important with regard to local (potential) contamination, the last one dominates the global contamination. A number of sites and sources are less well known with regard to environmental contamination. This is thus the case for the plutonium production factories at Tomsk and Dodonovo. More information on nuclear reactors in lost or dumped submarines is also needed. From a global point of view reliable assessment of the radioactive run-off from land and deposits of nuclear waste in the Arctic Ocean are in particular pertinent

Optimal kernel shape and bandwidth for atomistic support of continuum stress

International Nuclear Information System (INIS)

Ulz, Manfred H; Moran, Sean J

2013-01-01

The treatment of atomistic scale interactions via molecular dynamics simulations has recently found favour for multiscale modelling within engineering. The estimation of stress at a continuum point on the atomistic scale requires a pre-defined kernel function. This kernel function derives the stress at a continuum point by averaging the contribution from atoms within a region surrounding the continuum point. This averaging volume, and therefore the associated stress at a continuum point, is highly dependent on the bandwidth and shape of the kernel. In this paper we propose an effective and entirely data-driven strategy for simultaneously computing the optimal shape and bandwidth for the kernel. We thoroughly evaluate our proposed approach on copper using three classical elasticity problems. Our evaluation yields three key findings: firstly, our technique can provide a physically meaningful estimation of kernel bandwidth; secondly, we show that a uniform kernel is preferred, thereby justifying the default selection of this kernel shape in future work; and thirdly, we can reliably estimate both of these attributes in a data-driven manner, obtaining values that lead to an accurate estimation of the stress at a continuum point. (paper)

Determination of bromide in aqueous solutions via the TlBr molecule using high-resolution continuum source graphite furnace molecular absorption spectrometry

Science.gov (United States)

Cacho, Frantisek; Machynak, Lubomir; Nemecek, Martin; Beinrohr, Ernest

2018-06-01

The paper describes the determination of bromide by evaluating the molecular absorption of thallium mono-bromide (TlBr) at the rotational line at 342.9815 nm by making use a high-resolution continuum source graphite furnace atomic absorption spectrometer. The effects of variables such as the wavelength, graphite furnace program, amount of Tl and the use of a modifier were investigated and optimized. Various chemical modifiers have been studied, such as Pd, Mg, Ag and a mixture of Pd/Mg. It was found that best results were obtained by using Ag which prevents losses of bromide during pyrolysis step through precipitation of bromide as AgBr. In this way, a maximum pyrolysis temperature of 400 °C could be used. The optimum molecule forming temperature was found to be 900 °C. Bromide concentrations in various water samples (CRM, bottled drinking water and tap water) were determined. The quantification was made by both linear calibration and standard addition techniques. The results were matched well those of the reference method. The calibration curve was linear in the range between 1 and 1000 ng Br with a correlation coefficient R = 0.999. The limit of detection and characteristic mass of the method were 0.3 ng and 4.4 ng of Br.

Use of slurry sampling for the direct determination of zinc in yogurt by high resolution-continuum source flame atomic absorption spectrometry.

Science.gov (United States)

Brandao, Geovani C; de Jesus, Raildo M; da Silva, Erik G P; Ferreira, Sergio L C

2010-06-15

This paper presents an analytical procedure for the direct determination of zinc in yogurt employing sampling slurry and high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The step optimization established the experimental conditions of: 2.0molL(-1) hydrochloric acid, a sonication time of 20min and a sample mass of 1.0g for a slurry volume of 25mL. This method allows the determination of zinc with a limit of quantification of 0.32microgg(-1). The precision expressed as relative standard deviation (RSD) were 0.82 and 2.08% for yogurt samples containing zinc concentrations of 4.85 and 2.49microgg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of non-fat milk powder furnished by the National Institute of Standard and Technology. The proposed method was applied for the determination of zinc in seven yogurt samples. The zinc content was varied from 2.19 to 4.85microgg(-1). These results agreed with those reported in the literature. The samples were also analyzed after acid digestion and zinc determination by FAAS. No statistical difference was observed between the results obtained by both of the procedures performed.

Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

International Nuclear Information System (INIS)

Virgilio, Alex; Nóbrega, Joaquim A.; Rêgo, Jardes F.; Neto, José A. Gomes

2012-01-01

A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 °C and 2400 °C, respectively. Slopes of calibration curves (50–750 pg Cr, R 2 > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3–17.7 μg g −1 Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 ± 2.1 μg g −1 Cr. The limit of detection was 3.3 ng g −1 Cr. - Highlights: ► Direct solid sampling is first time employed for Cr in plant materials. ► Calibration curves with liquids and solids are coincident. ► Microanalysis of plants for Cr is validated by reference materials. ► The proposed HR-CS GF AAS method is environmental friendly.

Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

Energy Technology Data Exchange (ETDEWEB)

Virgilio, Alex; Nobrega, Joaquim A. [Department of Chemistry, Federal University of Sao Carlos, Post Office Box 676, 13560-970, Sao Carlos-SP (Brazil); Rego, Jardes F. [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil); Neto, Jose A. Gomes, E-mail: anchieta@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil)

2012-12-01

A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 Degree-Sign C and 2400 Degree-Sign C, respectively. Slopes of calibration curves (50-750 pg Cr, R{sup 2} > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3-17.7 {mu}g g{sup -1} Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 {+-} 2.1 {mu}g g{sup -1} Cr. The limit of detection was 3.3 ng g{sup -1} Cr. - Highlights: Black-Right-Pointing-Pointer Direct solid sampling is first time employed for Cr in plant materials. Black-Right-Pointing-Pointer Calibration curves with liquids and solids are coincident. Black-Right-Pointing-Pointer Microanalysis of plants for Cr is validated by reference materials. Black-Right-Pointing-Pointer The proposed HR-CS GF AAS method is environmental friendly.

Infrared spectroscopy of a Cygnus A - Implications for the obscured active nucleus

Science.gov (United States)

Ward, Martin J.; Blanco, Philip R.; Wilson, Andrew S.; Nishida, Minoru

1991-01-01

Near-infrared spectroscopic observations of the central regions of the luminous radio galaxy Cygnus A are presented and interpreted in terms of an obscured quasar nucleus. Strong emission is detected in the molecular hydrogen lines 1-0 S(1) and 1-0 S(3), the strengths of which are accounted for through heating by the nuclear hard X-ray source. The large equivalent widths of these molecular hydrogen lines and the near-infrared narrow hydrogen recombination lines suggest that the observed nuclear continuum is strongly attenuated at 2 microns. The observed upper limit to the flux of broad Pa-alpha implies an extinction to the putative broad line region AV(BL) of at least 24 mag, and the observed continuum intensity of the nuclear point source at 2.2 microns gives an extinction of 43 +/-9 mag toward the optical-infrared continuum. These estimates are consistent with the gas column density inferred from the low-energy X-ray cutoff. Strong forbidden Si VI 1.962-micron line emission from Cygnus A is also reported.

A historic look at the fears surrounding new energy sources and the nuclear debate

International Nuclear Information System (INIS)

Timbal-Duclaux, Louis

1982-01-01

The authors sets out to analyze some of the fears and opposition the use of new sources of energy has given rise to in the past. He then traces the historical background of the nuclear question and its various aspects (pacifism, ecology, etc.) [fr

Integrated societal risk assessment framework for nuclear power and renewable energy sources

Directory of Open Access Journals (Sweden)

Sang Hun Lee

2015-06-01

Full Text Available Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources.

Modeling of Continuum Manipulators Using Pythagorean Hodograph Curves.

Science.gov (United States)

Singh, Inderjeet; Amara, Yacine; Melingui, Achille; Mani Pathak, Pushparaj; Merzouki, Rochdi

2018-05-10

Research on continuum manipulators is increasingly developing in the context of bionic robotics because of their many advantages over conventional rigid manipulators. Due to their soft structure, they have inherent flexibility, which makes it a huge challenge to control them with high performances. Before elaborating a control strategy of such robots, it is essential to reconstruct first the behavior of the robot through development of an approximate behavioral model. This can be kinematic or dynamic depending on the conditions of operation of the robot itself. Kinematically, two types of modeling methods exist to describe the robot behavior; quantitative methods describe a model-based method, and qualitative methods describe a learning-based method. In kinematic modeling of continuum manipulator, the assumption of constant curvature is often considered to simplify the model formulation. In this work, a quantitative modeling method is proposed, based on the Pythagorean hodograph (PH) curves. The aim is to obtain a three-dimensional reconstruction of the shape of the continuum manipulator with variable curvature, allowing the calculation of its inverse kinematic model (IKM). It is noticed that the performances of the PH-based kinematic modeling of continuum manipulators are considerable regarding position accuracy, shape reconstruction, and time/cost of the model calculation, than other kinematic modeling methods, for two cases: free load manipulation and variable load manipulation. This modeling method is applied to the compact bionic handling assistant (CBHA) manipulator for validation. The results are compared with other IKMs developed in case of CBHA manipulator.

Evidence against the continuum structure underlying motivation measures derived from self-determination theory.

Science.gov (United States)

Chemolli, Emanuela; Gagné, Marylène

2014-06-01

Self-determination theory (SDT) proposes a multidimensional conceptualization of motivation in which the different regulations are said to fall along a continuum of self-determination. The continuum has been used as a basis for using a relative autonomy index as a means to create motivational scores. Rasch analysis was used to verify the continuum structure of the Multidimensional Work Motivation Scale and of the Academic Motivation Scale. We discuss the concept of continuum against SDT's conceptualization of motivation and argue against the use of the relative autonomy index on the grounds that evidence for a continuum structure underlying the regulations is weak and because the index is statistically problematic. We suggest exploiting the full richness of SDT's multidimensional conceptualization of motivation through the use of alternative scoring methods when investigating motivational dynamics across life domains.

Intense resonance neutron source (IREN) - new pulsed source for nuclear physical and applied investigations

International Nuclear Information System (INIS)

Anan'ev, V.D.; Furman, W.I.; Kobets, V.V.; Meshkov, I.N.; Pyataev, V.G.; Shirkov, G.D.; Shvets, V.A.; Sumbaev, A.P.; Kuatbekov, R.P.; Tret'yakov, I.T.; Frolov, A.R.; Gurov, S.M.; Logachev, P.V.; Pavlov, V.M.; Skarbo, B.A.

2005-01-01

An accelerator-driven subcritical system (200 MeV electron linac + metallic plutonium subcritical core) IREN is constructed at the Joint Institute for Nuclear Research (JINR). The new pulsed neutron source IREN is optimized for maximal yield of resonance neutrons (1-10 5 eV). The S-band electron linac with a pulse duration near 200 ns, repetition rate up to 150 Hz and the mean beam power 10 kW delivers 200-MeV electrons onto a specially designed tungsten target (an electron-neutron converter) situated in the center of a very compact and fast subcritical assembly with K eff 15 per second. A mean fission power of the multiplying target is planned to be near 15 kW. The current status of the project is presented

Nuclear imaging system

International Nuclear Information System (INIS)

Barrett, H.H.; Horrigan, F.A.

1975-01-01

This invention relates to a nuclear imaging system for mapping the source of high energy nuclear particles from a living organ which has selectively absorbed a radioactive compound by spatially coding the energy from the source in a Fresnel pattern on a detector and decoding the detector output to prouce an image of the source. The coding is produced by a Fresnel zone plate interposed between the nuclear energy source and the detector whose position is adjustable with respect to the detector to focus the slices of the nuclear source on the detector. By adjusting the zone plate to a plurality of positions, data from a plurality of cross-sectional slices are produced from which a three-dimensional image of the nuclear source may be obtained. (Patent Office Record)

Lattice continuum and diffusional creep.

Science.gov (United States)

Mesarovic, Sinisa Dj

2016-04-01

Diffusional creep is characterized by growth/disappearance of lattice planes at the crystal boundaries that serve as sources/sinks of vacancies, and by diffusion of vacancies. The lattice continuum theory developed here represents a natural and intuitive framework for the analysis of diffusion in crystals and lattice growth/loss at the boundaries. The formulation includes the definition of the Lagrangian reference configuration for the newly created lattice, the transport theorem and the definition of the creep rate tensor for a polycrystal as a piecewise uniform, discontinuous field. The values associated with each crystalline grain are related to the normal diffusional flux at grain boundaries. The governing equations for Nabarro-Herring creep are derived with coupled diffusion and elasticity with compositional eigenstrain. Both, bulk diffusional dissipation and boundary dissipation accompanying vacancy nucleation and absorption, are considered, but the latter is found to be negligible. For periodic arrangements of grains, diffusion formally decouples from elasticity but at the cost of a complicated boundary condition. The equilibrium of deviatorically stressed polycrystals is impossible without inclusion of interface energies. The secondary creep rate estimates correspond to the standard Nabarro-Herring model, and the volumetric creep is small. The initial (primary) creep rate is estimated to be much larger than the secondary creep rate.

The challenge to keep nuclear fusion alive as a future energy source

International Nuclear Information System (INIS)

D'haeseleer, W.D.

1999-01-01

Few people are preoccupied with the energy issue. Indeed, inflation-corrected energy prices (in euros) are currently lower than before the first oil crisis of 1973; the annual growth rate of primary-energy use in the industrialized world has diminished considerably compared to before 1970, and oil and gas production is characterized by increased exploration activity and a wider geographical spread. Nevertheless, there is a real energy issue. If the greenhouse effect turns out to be real, then mankind should at least slow down the consumption of fossil fuels. Given the fact that world energy consumption (especially by the developing countries) will rise in the future, and that nuclear fission power has become unpopular in the western world, the idea reigning in some circles to cope with this situation by total reliance on energy savings and renewable energy sources comes close to wishful thinking. A realistic analysis makes it clear that there will be a need for large workhorses for electricity generation to keep the overall electricity grid sufficiently robust. From a global and long-term perspective, the logical conclusion is the following: because mankind cannot count on the continued use of fossil fuels (due to the finiteness of the resources combined with the possible climate change effects), our generation has the responsibility to develop alternative energy sources for the distant future. Many parallel lines of research and development therefore need be pursued; because of the uncertainties with other alternative sources, it would be irresponsible to kill some of these development lines. This holds for renewable sources, the nuclear fission breeder, and for nuclear fusion. A major hurdle for the survival of long term energy research and development is the liberalization of the electricity market. Because of the revolutionary changes taking place, utilities concentrate on cost cutting and short-term survival. In addition, they are no longer supposed to take

Safe management of sealed radioactive sources at Karachi nuclear power complex

International Nuclear Information System (INIS)

Tahir, T.B.; Qamar, A.

2000-01-01

This paper describes the conditioning of sealed radioactive sources, carried out at the Karachi Nuclear Power Complex (KNPC) in co-operation with the IAEA. The radioactive sources were radium needles of various size, used by various radiotherapy units in different hospitals throughout the country. For some time the use of radium needles had been abandoned and they were stored in hospitals awaiting proper disposal. Since their storage conditions were not ideal and there was a potential of leakage of radioactive material into the environment, it was decided to condition and store them safely. A significant logistic effort was required to identify these sources, bring them to a central facility and condition them according to current international standards. Various steps were involved in conditioning the sources: place it in a stainless steel capsule, weld the capsule, test it for a leak, place the capsule in a lead shielded package, put and seal the shielded package in a concrete-lined steel drum and finally store it at the waste storage facility. A total amount of about 1500 mg of Radium needles were conditioned. Radiation exposure during the entire operation was within acceptable limits. (author)

Coarse-to-Fine Segmentation with Shape-Tailored Continuum Scale Spaces

KAUST Repository

Khan, Naeemullah

2017-11-09

We formulate an energy for segmentation that is designed to have preference for segmenting the coarse over fine structure of the image, without smoothing across boundaries of regions. The energy is formulated by integrating a continuum of scales from a scale space computed from the heat equation within regions. We show that the energy can be optimized without computing a continuum of scales, but instead from a single scale. This makes the method computationally efficient in comparison to energies using a discrete set of scales. We apply our method to texture and motion segmentation. Experiments on benchmark datasets show that a continuum of scales leads to better segmentation accuracy over discrete scales and other competing methods.

Coarse-to-Fine Segmentation with Shape-Tailored Continuum Scale Spaces

KAUST Repository

Khan, Naeemullah; Hong, Byung-Woo; Yezzi, Anthony; Sundaramoorthi, Ganesh

2017-01-01

We formulate an energy for segmentation that is designed to have preference for segmenting the coarse over fine structure of the image, without smoothing across boundaries of regions. The energy is formulated by integrating a continuum of scales from a scale space computed from the heat equation within regions. We show that the energy can be optimized without computing a continuum of scales, but instead from a single scale. This makes the method computationally efficient in comparison to energies using a discrete set of scales. We apply our method to texture and motion segmentation. Experiments on benchmark datasets show that a continuum of scales leads to better segmentation accuracy over discrete scales and other competing methods.

Calculation of media temperatures for nuclear sources in geologic depositories by a finite-length line source superposition model (FLLSSM)

Energy Technology Data Exchange (ETDEWEB)

Kays, W M; Hossaini-Hashemi, F [Stanford Univ., Palo Alto, CA (USA). Dept. of Mechanical Engineering; Busch, J S [Kaiser Engineers, Oakland, CA (USA)

1982-02-01

A linearized transient thermal conduction model was developed to economically determine media temperatures in geologic repositories for nuclear wastes. Individual canisters containing either high-level waste or spent fuel assemblies are represented as finite-length line sources in a continuous medium. The combined effects of multiple canisters in a representative storage pattern can be established in the medium at selected point of interest by superposition of the temperature rises calculated for each canister. A mathematical solution of the calculation for each separate source is given in this article, permitting a slow hand calculation. The full report, ONWI-94, contains the details of the computer code FLLSSM and its use, yielding the total solution in one computer output.

Thermal hydraulic analysis of the encapsulated nuclear heat source

Energy Technology Data Exchange (ETDEWEB)

Sienicki, J.J.; Wade, D.C. [Argonne National Lab., IL (United States)

2001-07-01

An analysis has been carried out of the steady state thermal hydraulic performance of the Encapsulated Nuclear Heat Source (ENHS) 125 MWt, heavy liquid metal coolant (HLMC) reactor concept at nominal operating power and shutdown decay heat levels. The analysis includes the development and application of correlation-type analytical solutions based upon first principles modeling of the ENHS concept that encompass both pure as well as gas injection augmented natural circulation conditions, and primary-to-intermediate coolant heat transfer. The results indicate that natural circulation of the primary coolant is effective in removing heat from the core and transferring it to the intermediate coolant without the attainment of excessive coolant temperatures. (authors)

Integral equation hierarchy for continuum percolation

International Nuclear Information System (INIS)

Given, J.A.

1988-01-01

In this thesis a projection operator technique is presented that yields hierarchies of integral equations satisfied exactly by the n-point connectedness functions in a continuum version of the site-bond percolation problem. The n-point connectedness functions carry the same structural information for a percolation problem as then-point correlation functions do for a thermal problem. This method extends the Potts model mapping of Fortuin and Kastelyn to the continuum by exploiting an s-state generalization of the Widom-Rowlinson model, a continuum model for phase separation. The projection operator technique is used to produce an integral equation hierarchy for percolation similar to the Born-Green heirarchy. The Kirkwood superposition approximation (SA) is extended to percolation in order to close this hierarchy and yield a nonlinear integral equation for the two-point connectedness function. The fact that this function, in the SA, is the analytic continuation to negative density of the two-point correlation function in a corresponding thermal problem is discussed. The BGY equation for percolation is solved numerically, both by an expansion in powers of the density, and by an iterative technique due to Kirkwood. It is argued both analytically and numerically, that the BYG equation for percolation, unlike its thermal counterpart, shows non-classical critical behavior, with η = 1 and γ = 0.05 ± .1. Finally a sequence of refinements to the superposition approximations based in the theory of fluids by Rice and Lekner is discussed

Stonefly (Plecoptera) Feeding Modes: Variation Along a California River Continuum

Science.gov (United States)

Richard L. Bottorff; Allen W. Knight

1989-01-01

The distribution of Plecoptera along a California river was used to test several predictions of the River Continuum Concept about how functional feeding groups should change along a stream's length. Stoneflies were collected from stream orders 1-6 (123 km) of the Cosumnes River continuum in the central Sierra Nevada. The 69 stonefly species collected were...

The AGN nature of LINER nuclear sources

Science.gov (United States)

Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; del Olmo, Ascensión

2017-11-01

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2-10 keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN towards lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L_X(2-10 keV) > 10^{41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with both

The AGN Nature of LINER Nuclear Sources

Energy Technology Data Exchange (ETDEWEB)

Márquez, Isabel; Masegosa, Josefa [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); González-Martin, Omaira [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Morelia (Mexico); Hernández-Garcia, Lorena [Istituto di Astrofisica e Planetologia Spaziali, Rome (Italy); Pović, Mirjana [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); Ethiopian Space Science and Technology Institute and Entoto Observatory and Research Center, Addis Ababa (Ethiopia); Netzer, Hagai [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy and the Wise Observatory, Tel-Aviv University, Tel Aviv (Israel); Cazzoli, Sara; Olmo, Ascensión del, E-mail: isabel@iaa.es [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain)

2017-11-16

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L{sub X}(2–10 keV) > 10{sup 41} erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison

The AGN Nature of LINER Nuclear Sources

International Nuclear Information System (INIS)

Márquez, Isabel; Masegosa, Josefa; González-Martin, Omaira; Hernández-Garcia, Lorena; Pović, Mirjana; Netzer, Hagai; Cazzoli, Sara; Olmo, Ascensión del

2017-01-01

Low-ionization nuclear emission-line regions (LINERs) are specially interesting objects since not only they represent the most numerous local Active Galactic Nuclei population, but they could be the link between normal and active galaxies as suggested by their low X-ray luminosities. The origin of LINER nuclei being still controversial, our works, through a multiwavelength approach, have contributed, firstly, to confirm that a large number of nuclear LINERs in the local universe are AGN powered. Secondly, from the study of X-ray spectral variability, we found that long term variations are very common, and they are mostly related to hard energies (2–10keV). These variations might be due to changes in the absorber and/or intrinsic variations of the source. Thirdly, Mid-infrared (MIR) imaging also indicates that LINERs are the low luminosity end of AGN toward lower luminosities, and MIR spectroscopy shows that the average spectrum of AGN-dominated LINERs with X-ray luminosities L X (2–10 keV) > 10 41 erg/s is similar to the average mid-IR spectrum of AGN-dominated Seyfert 2s; for fainter LINERS, their spectral shape suggests that the dusty-torus may disappear. Fourth, the extended Hα emission of LINERs at HST resolution indicates that they follow remarkably well the Narrow Line Region morphology and the luminosity-size relation obtained for Seyfert and QSOs; HST Hα morphology may suggest the presence of outflows, which could contribute to the line broadening, with the resulting consequences on the percentage of LINERs where the Broad Line Region is detected. This issue is being revisited by our group with a high spectral resolution set of optical data for nearby type-1 LINERs. Finally, concerning systematic studies on the role of star formation in LINERs, which are scarce, our contribution deals with the study of a sample of the most luminous, highest star formation rate LINERs in the local Universe (at z from 0.04 to 0.11), together with its comparison with

Limitation of fusion power plant installation on future power grids under the effect of renewable and nuclear power sources

Energy Technology Data Exchange (ETDEWEB)

Takeda, Shutaro, E-mail: takeda.shutarou.55r@st.kyoto-u.ac.jp [Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, Kyoto (Japan); Sakurai, Shigeki [Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, Kyoto (Japan); Yamamoto, Yasushi [Faculty of Engineering Science, Kansai University, Suita, Osaka (Japan); Kasada, Ryuta; Konishi, Satoshi [Institute of Advanced Energy, Kyoto University, Uji, Kyoto (Japan)

2016-11-01

Graphical abstract: - Highlights: • Future power grids would be unstable due to renewable and nuclear power sources. • Output interruptions of fusion plant would cause disturbances to future grids. • Simulation results suggested they would create limitations in fusion installation. • A novel diagram was presented to illustrate this suggested limitation. - Abstract: Future power grids would be unstable because of the larger share of renewable and nuclear power sources. This instability might bring some additional difficulties to fusion plant installation. Therefore, the authors carried out a quantitative feasibility study from the aspect of grid stability through simulation. Results showed that the more renewable and nuclear sources are linked to a grid, the greater disturbance the grid experiences upon a sudden output interruption of a fusion power plant, e.g. plasma disruption. The frequency deviations surpassed 0.2 Hz on some grids, suggesting potential limitations of fusion plant installation on future grids. To clearly show the suggested limitations of fusion plant installations, a novel diagram was presented.

Global mass conservation method for dual-continuum gas reservoir simulation

KAUST Repository

Wang, Yi; Sun, Shuyu; Gong, Liang; Yu, Bo

2018-01-01

In this paper, we find that the numerical simulation of gas flow in dual-continuum porous media may generate unphysical or non-robust results using regular finite difference method. The reason is the unphysical mass loss caused by the gas compressibility and the non-diagonal dominance of the discretized equations caused by the non-linear well term. The well term contains the product of density and pressure. For oil flow, density is independent of pressure so that the well term is linear. For gas flow, density is related to pressure by the gas law so that the well term is non-linear. To avoid these two problems, numerical methods are proposed using the mass balance relation and the local linearization of the non-linear source term to ensure the global mass conservation and the diagonal dominance of discretized equations in the computation. The proposed numerical methods are successfully applied to dual-continuum gas reservoir simulation. Mass conservation is satisfied while the computation becomes robust. Numerical results show that the location of the production well relative to the large-permeability region is very sensitive to the production efficiency. It decreases apparently when the production well is moved from the large-permeability region to the small-permeability region, even though the well is very close to the interface of the two regions. The production well is suggested to be placed inside the large-permeability region regardless of the specific position.

Global mass conservation method for dual-continuum gas reservoir simulation

KAUST Repository

Wang, Yi

2018-03-17

In this paper, we find that the numerical simulation of gas flow in dual-continuum porous media may generate unphysical or non-robust results using regular finite difference method. The reason is the unphysical mass loss caused by the gas compressibility and the non-diagonal dominance of the discretized equations caused by the non-linear well term. The well term contains the product of density and pressure. For oil flow, density is independent of pressure so that the well term is linear. For gas flow, density is related to pressure by the gas law so that the well term is non-linear. To avoid these two problems, numerical methods are proposed using the mass balance relation and the local linearization of the non-linear source term to ensure the global mass conservation and the diagonal dominance of discretized equations in the computation. The proposed numerical methods are successfully applied to dual-continuum gas reservoir simulation. Mass conservation is satisfied while the computation becomes robust. Numerical results show that the location of the production well relative to the large-permeability region is very sensitive to the production efficiency. It decreases apparently when the production well is moved from the large-permeability region to the small-permeability region, even though the well is very close to the interface of the two regions. The production well is suggested to be placed inside the large-permeability region regardless of the specific position.

Order for execution of the law concerning regulations of nuclear source materials, nuclear fuel materials and reactors

International Nuclear Information System (INIS)

1979-01-01

The order is enacted under the law for the regulations of nuclear source materials, nuclear fuel materials and reactors. Any person who engages in refining business shall get designation for each works or place of enterprise. The application shall be filed through the director of International Trade and Industry Office in charge of the location of the works or the enterprise with a business program and other specified documents attached. Any person who undertakes processing business shall get permission for each works or place of enterprise. The application shall be submitted with a business program and other documents defined by the Ordinance of the Prime Minister's Office. Any person who sets up reactor shall get permission for each works or place of enterprise. The application shall be presented with a financial project and other documents stipulated by the ordinance. Fast breeding reactor, heavy-water moderated boiling water reactor and light-water moderated pressurized water reactor are designated as reactor in the phase of research and development. Each foreign nuclear ship equipped with reactor which enters into Japanese waters shall get permission of the Minister of Transport. The application shall be presented with the papers explaining safety of reactor facilities and other documents provided by the ordinance of the ministry concerned. (Okada, K.)

High-resolution continuum source electrothermal atomic absorption spectrometry: Linearization of the calibration curves within a broad concentration range

Energy Technology Data Exchange (ETDEWEB)

Katskov, Dmitri, E-mail: katskovda@tut.ac.za [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Hlongwane, Miranda [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Heitmann, Uwe [German Aerospace Center, Rose-Luxemburg Str. 2, 10178 Berlin (Germany); Florek, Stefan [ISAS-Leibniz-Institut fuer Analytische Wissenschaften e.V., Albert-Einstein-Str. 9,12489 Berlin (Germany)

2012-05-15

The calculation algorithm suggested provides linearization of the calibration curves in high-resolution continuum source electrothermal atomic absorption spectrometry. The algorithm is based on the modification of the function wavelength-integrated absorbance vs. concentration of analyte vapor in the absorption volume. According to the suggested approach, the absorption line is represented by a triangle for low and trapezium for high analyte vapor concentration in the absorption volume. The respective semi-empirical formulas include two linearization parameters, which depend on properties of the absorption line and characteristics of the atomizer and spectrometer. The parameters can be approximately evaluated from the theory and determined in practice from the original broad-range calibration curve. The parameters were found and the proposed calculation algorithm verified in the experiments on direct determination of Ag, Cd, Cu, Fe, Mn and Pb in the solutions within a concentration ranges from 0.15 to 625 {mu}g{center_dot}L{sup -1} using tube, platform tube and filter furnace atomizers. The use of various atomizers, lines, elements and atomization temperatures made possible the simulation of various practical analytical conditions. It was found that the algorithm and optimal linearization parameters made it possible to obtain for each line and atomizer linear approximations of the calibration curves within 3-4 orders of magnitude with correlation coefficients close to 0.999. The algorithm makes possible to employ a single line for the direct element determination over a broad concentration range. The sources of errors and the possibility of a priori theoretical evaluation of the linearization parameters are discussed. - Highlights: Black-Right-Pointing-Pointer New calculation algorithm for HR-CS ET AAS measurements was proposed and applied. Black-Right-Pointing-Pointer The suggested formulas include two parameters to be determined experimentally. Black

Commitment to Quality throughout the Continuum.

Science.gov (United States)

Gillet, Pamela

1995-01-01

This editorial by the president of the Council for Exceptional Children indicates the organization's support of a continuum of special education placements for students with special needs and calls for improving transition of students from one placement to another. (JDD)

Chemical Explosion Experiments to Improve Nuclear Test Monitoring - Developing a New Paradigm for Nuclear Test Monitoring with the Source Physics Experiments (SPE)

International Nuclear Information System (INIS)

Snelson, Catherine M.; Abbott, Robert E.; Broome, Scott T.; Mellors, Robert J.; Patton, Howard J.; Sussman, Aviva J.; Townsend, Margaret J.; Walter, William R.

2013-01-01

A series of chemical explosions, called the Source Physics Experiments (SPE), is being conducted under the auspices of the U.S. Department of Energy's National Nuclear Security Administration (NNSA) to develop a new more physics-based paradigm for nuclear test monitoring. Currently, monitoring relies on semi-empirical models to discriminate explosions from earthquakes and to estimate key parameters such as yield. While these models have been highly successful monitoring established test sites, there is concern that future tests could occur in media and at scale depths of burial outside of our empirical experience. This is highlighted by North Korean tests, which exhibit poor performance of a reliable discriminant, mb:Ms (Selby et al., 2012), possibly due to source emplacement and differences in seismic responses for nascent and established test sites. The goal of SPE is to replace these semi-empirical relationships with numerical techniques grounded in a physical basis and thus applicable to any geologic setting or depth

The ASKAP/EMU Source Finding Data Challenge

NARCIS (Netherlands)

Hopkins, A. M.; Whiting, M. T.; Seymour, N.; Chow, K. E.; Norris, R. P.; Bonavera, L.; Breton, R.; Carbone, D.; Ferrari, C.; Franzen, T. M. O.; Garsden, H.; Gonzalez-Nuevo, J.; Hales, C. A.; Hancock, P. J.; Heald, G.; Herranz, D.; Huynh, M.; Jurek, R. J.; Lopez-Caniego, M.; Massardi, M.; Mohan, N.; Molinari, S.; Orru, E.; Paladino, R.; Pestalozzi, M.; Pizzo, R.; Rafferty, D.; Rottgering, H. J. A.; Rudnick, L.; Schisano, E.; Shulevski, A.; Swinbank, J.; Taylor, R.; van der Horst, A. J.

2015-01-01

The Evolutionary Map of the Universe (EMU) is a proposed radio continuum survey of the Southern Hemisphere up to declination +30 deg., with the Australian Square Kilometre Array Pathfinder (ASKAP). EMU will use an automated source identification and measurement approach that is demonstrably optimal,

The near-infrared broad emission line region of active galactic nuclei - II. The 1-μm continuum

Science.gov (United States)

Landt, Hermine; Elvis, Martin; Ward, Martin J.; Bentz, Misty C.; Korista, Kirk T.; Karovska, Margarita

2011-06-01

We use quasi-simultaneous near-infrared (near-IR) and optical spectroscopy from four observing runs to study the continuum around 1 μm in 23 well-known broad emission line active galactic nuclei (AGN). We show that, after correcting the optical spectra for host galaxy light, the AGN continuum around this wavelength can be approximated by the sum of mainly two emission components, a hot dust blackbody and an accretion disc. The accretion disc spectrum appears to dominate the flux at ˜ 1 μm, which allows us to derive a relation for estimating AGN black hole masses based on the near-IR virial product. This result also means that a near-IR reverberation programme can determine the AGN state independent of simultaneous optical spectroscopy. On average we derive hot dust blackbody temperatures of ˜1400 K, a value close to the sublimation temperature of silicate dust grains, and relatively low hot dust covering factors of ˜7 per cent. Our preliminary variability studies indicate that in most sources, the hot dust emission responds to changes in the accretion disc flux with the expected time lag; however, a few sources show a behaviour that can be attributed to dust destruction.

An Image-based Micro-continuum Pore-scale Model for Gas Transport in Organic-rich Shale

Science.gov (United States)

Guo, B.; Tchelepi, H.

2017-12-01

Gas production from unconventional source rocks, such as ultra-tight shales, has increased significantly over the past decade. However, due to the extremely small pores ( 1-100 nm) and the strong material heterogeneity, gas flow in shale is still not well understood and poses challenges for predictive field-scale simulations. In recent years, digital rock analysis has been applied to understand shale gas transport at the pore-scale. An issue with rock images (e.g. FIB-SEM, nano-/micro-CT images) is the so-called "cutoff length", i.e., pores and heterogeneities below the resolution cannot be resolved, which leads to two length scales (resolved features and unresolved sub-resolution features) that are challenging for flow simulations. Here we develop a micro-continuum model, modified from the classic Darcy-Brinkman-Stokes framework, that can naturally couple the resolved pores and the unresolved nano-porous regions. In the resolved pores, gas flow is modeled with Stokes equation. In the unresolved regions where the pore sizes are below the image resolution, we develop an apparent permeability model considering non-Darcy flow at the nanoscale including slip flow, Knudsen diffusion, adsorption/desorption, surface diffusion, and real gas effect. The end result is a micro-continuum pore-scale model that can simulate gas transport in 3D reconstructed shale images. The model has been implemented in the open-source simulation platform OpenFOAM. In this paper, we present case studies to demonstrate the applicability of the model, where we use 3D segmented FIB-SEM and nano-CT shale images that include four material constituents: organic matter, clay, granular mineral, and pore. In addition to the pore structure and the distribution of the material constituents, we populate the model with experimental measurements (e.g. size distribution of the sub-resolution pores from nitrogen adsorption) and parameters from the literature and identify the relative importance of different

Lattice fluid dynamics from perfect discretizations of continuum flows

International Nuclear Information System (INIS)

Katz, E.; Wiese, U.

1998-01-01

We use renormalization group methods to derive equations of motion for large scale variables in fluid dynamics. The large scale variables are averages of the underlying continuum variables over cubic volumes and naturally exist on a lattice. The resulting lattice dynamics represents a perfect discretization of continuum physics, i.e., grid artifacts are completely eliminated. Perfect equations of motion are derived for static, slow flows of incompressible, viscous fluids. For Hagen-Poiseuille flow in a channel with a square cross section the equations reduce to a perfect discretization of the Poisson equation for the velocity field with Dirichlet boundary conditions. The perfect large scale Poisson equation is used in a numerical simulation and is shown to represent the continuum flow exactly. For nonsquare cross sections one can use a numerical iterative procedure to derive flow equations that are approximately perfect. copyright 1998 The American Physical Society

Alfven continuum and high-frequency eigenmodes in optimized stellarators

International Nuclear Information System (INIS)

Kolesnichenko, Ya.I.; Lutsenko, V.V.; Wobig, H.; Yakovenko, Yu.V.; Fesenyuk, O.P.

2001-01-01

An equation of shear Alfven eigenmodes (AE) in optimized stellarators of Wendelstein line (Helias configurations) is derived. The metric tensor coefficients, which are contained in this equation, are calculated analytically. Two numerical codes are developed: the first one, COBRA (COntinuum BRanches of Alfven waves), is intended for the investigation of the structure of Alfven continuum; the second, BOA (Branches Of Alfven modes), solves the eigenvalue problem. The family of possible gaps in Alfven continuum of a Helias configuration is obtained. It is predicted that there exist gaps which arise due to or are strongly affected by the variation of the shape of the plasma cross section along the large azimuth of the torus. In such gaps, discrete eigenmodes, namely, helicity-induced eigenmodes (HAE 21 ) and mirror-induced eigenmodes (MAE) are found. It is shown that plasma inhomogeneity may suppress the AEs with a wide region of localization

Discrete-to-continuum modelling of weakly interacting incommensurate two-dimensional lattices.

Science.gov (United States)

Español, Malena I; Golovaty, Dmitry; Wilber, J Patrick

2018-01-01

In this paper, we derive a continuum variational model for a two-dimensional deformable lattice of atoms interacting with a two-dimensional rigid lattice. The starting point is a discrete atomistic model for the two lattices which are assumed to have slightly different lattice parameters and, possibly, a small relative rotation. This is a prototypical example of a three-dimensional system consisting of a graphene sheet suspended over a substrate. We use a discrete-to-continuum procedure to obtain the continuum model which recovers both qualitatively and quantitatively the behaviour observed in the corresponding discrete model. The continuum model predicts that the deformable lattice develops a network of domain walls characterized by large shearing, stretching and bending deformation that accommodates the misalignment and/or mismatch between the deformable and rigid lattices. Two integer-valued parameters, which can be identified with the components of a Burgers vector, describe the mismatch between the lattices and determine the geometry and the details of the deformation associated with the domain walls.

A continuum model for pressure-flow relationship in human pulmonary circulation.

Science.gov (United States)

Huang, Wei; Zhou, Qinlian; Gao, Jian; Yen, R T

2011-06-01

A continuum model was introduced to analyze the pressure-flow relationship for steady flow in human pulmonary circulation. The continuum approach was based on the principles of continuum mechanics in conjunction with detailed measurement of vascular geometry, vascular elasticity and blood rheology. The pulmonary arteries and veins were considered as elastic tubes and the "fifth-power law" was used to describe the pressure-flow relationship. For pulmonary capillaries, the "sheet-flow" theory was employed and the pressure-flow relationship was represented by the "fourth-power law". In this paper, the pressure-flow relationship for the whole pulmonary circulation and the longitudinal pressure distribution along the streamlines were studied. Our computed data showed general agreement with the experimental data for the normal subjects and the patients with mitral stenosis and chronic bronchitis in the literature. In conclusion, our continuum model can be used to predict the changes of steady flow in human pulmonary circulation.

U Y 105 standard use of non sealed radioactive sources in nuclear medicine: approve for Industry energy and Mining Ministry 28/6/2002 Resolution

International Nuclear Information System (INIS)

2002-01-01

Establish minimal requirements radiological safety for use non sealed radioactive sources in nuclear medicine.The present standard is used in operation or nuclear medicine practices using non sealed radioactive sources with diagnostic and therapeutic purposes in vivo and in vitro

Shape Modeling of a Concentric-tube Continuum Robot

DEFF Research Database (Denmark)

Bai, Shaoping; Xing, Charles Chuhao

2012-01-01

Concentric-tube continuum robots feature with simple and compact structures and have a great potential in medical applications. The paper is concerned with the shape modeling of a type of concentric-tube continuum robot built with a collection of super-elastic NiTiNol tubes. The mechanics...... is modeled on the basis of energy approach for both the in-plane and out-plane cases. The torsional influences on the shape of the concentric-tube robots are considered. An experimental device was build for the model validation. The results of simulation and experiments are included and analyzed....

Fractional Quantum Field Theory: From Lattice to Continuum

Directory of Open Access Journals (Sweden)

Vasily E. Tarasov

2014-01-01

Full Text Available An approach to formulate fractional field theories on unbounded lattice space-time is suggested. A fractional-order analog of the lattice quantum field theories is considered. Lattice analogs of the fractional-order 4-dimensional differential operators are proposed. We prove that continuum limit of the suggested lattice field theory gives a fractional field theory for the continuum 4-dimensional space-time. The fractional field equations, which are derived from equations for lattice space-time with long-range properties of power-law type, contain the Riesz type derivatives on noninteger orders with respect to space-time coordinates.

Towards an improved continuum theory for phase transformations

International Nuclear Information System (INIS)

Tijssens, M.G.A.; James, R.D.

2003-01-01

We develop a continuum theory for martensitic phase transformations in which explicit use is made of atomistic calculations based on density functional theory. Following the work of Rabe and coworkers, branches of the phonon-dispersion relation with imaginary frequencies are selected to construct a localized basis tailored to the symmetry of the crystal lattice. This so-called Wannier basis helps to construct an effective Hamiltonian of a particularly simple form. We extend the methodology by incorporating finite deformations and passing the effective Hamiltonian fully to continuum level. The developments so far are implemented on the shape memory material NiTi

Proposal for implementation of alternative source term in the nuclear power plant of Laguna Verde; Propuesta de implementacion del termino fuente alternativo en la central nuclear Laguna Verde

Energy Technology Data Exchange (ETDEWEB)

Bazan L, A.; Lopez L, M.; Vargas A, A.; Cardenas J, J. B. [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Km. 7.5 Carretera Veracruz-Medellin, Dos Bocas, Veracruz (Mexico)], e-mail: ariadna.bazan@cfe.gob.mx

2009-10-15

In 2010 the nuclear power plant of Laguna Verde will implement the extended power upbeat in both units of the plant. Agree with methodology of NEDC-33004P-A, (constant pressure power up rate), and the source term of core, for accidents evaluations, were increased in proportion to the ratio of power level. This means that for the case of a design basis accident of loss of coolant an increase of power of 15% originated an increase of 15% in dose to main control room. Using the method of NEDC-33004P-A to extended power upbeat conditions was determined that the dose value to main control room is very near to regulatory limit established by SRP 6.4. By the above and in order to recover the margin, the nuclear power plant of Laguna Verde will calculate an alternative source term following the criteria established in RG 1.183 (alternative radiological source term for evaluating DBA at nuclear power reactor). This approach also have a more realistic dose value using the criterion of 10-CFR-50.67, in addition is predicted to get the benefit of additional operational flexibilities. This paper present the proposal of implementing the alternative source term in Laguna Verde. (Author)

IUTAM-Symposium on The Generalized Cosserat Continuum and the Continuum Theory of Dislocations with Applications

CERN Document Server

1968-01-01

5 The symposium was held in Freudenstadt from 28\\h to 31 \\ ofAugust st nd 1967 and in Stuttgart from 1 to 2 of September 1967. The proposal to hold this symposium originated with the German Society of Applied Mathematics and Mechanics (GAMM) late in 1964 and was examined by a committee of IUTAM especially appointed for this purpose. The basis of this examination was a report in which the present situation in the field and the possible aims of the symposium were surveyed. Briefly, the aims of the symposium were stated to be 1. the unification of the various approaches developed in recent years with the aim of penetrating into the microscopic world of matter by means of continuum theories; 2. the bridging of the gap between microscopic (or atomic) research on mechanics on one hand, and the phenomenological (or continuum mechanical) approach on the other hand; 3. the physical interpretation and the relation to actual material behaviour of the quantities and laws introduced into the new theories, together with ap...

Investigation of artifacts caused by deuterium background correction in the determination of phosphorus by electrothermal atomization using high-resolution continuum source atomic absorption spectrometry

International Nuclear Information System (INIS)

Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Borges, Daniel L.G.; Welz, Bernhard; Silva, Marcia M.; Heitmann, Uwe

2008-01-01

The artifacts created in the measurement of phosphorus at the 213.6-nm non-resonance line by electrothermal atomic absorption spectrometry using line source atomic absorption spectrometry (LS AAS) and deuterium lamp background correction (D 2 BC) have been investigated using high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). The absorbance signals and the analytical curves obtained by LS AAS without and with D 2 BC, and with HR-CS AAS without and with automatic correction for continuous background absorption, and also with least-squares background correction for molecular absorption with rotational fine structure were compared. The molecular absorption due to the suboxide PO that exhibits pronounced fine structure could not be corrected by the D 2 BC system, causing significant overcorrection. Among the investigated chemical modifiers, NaF, La, Pd and Pd + Ca, the Pd modifier resulted in the best agreement of the results obtained with LS AAS and HR-CS AAS. However, a 15% to 100% higher sensitivity, expressed as slope of the analytical curve, was obtained for LS AAS compared to HR-CS AAS, depending on the modifier. Although no final proof could be found, the most likely explanation is that this artifact is caused by a yet unidentified phosphorus species that causes a spectrally continuous absorption, which is corrected without problems by HR-CS AAS, but which is not recognized and corrected by the D 2 BC system of LS AAS

Development of probabilistic fatigue curve for asphalt concrete based on viscoelastic continuum damage mechanics

Directory of Open Access Journals (Sweden)

Himanshu Sharma

2016-07-01

Full Text Available Due to its roots in fundamental thermodynamic framework, continuum damage approach is popular for modeling asphalt concrete behavior. Currently used continuum damage models use mixture averaged values for model parameters and assume deterministic damage process. On the other hand, significant scatter is found in fatigue data generated even under extremely controlled laboratory testing conditions. Thus, currently used continuum damage models fail to account the scatter observed in fatigue data. This paper illustrates a novel approach for probabilistic fatigue life prediction based on viscoelastic continuum damage approach. Several specimens were tested for their viscoelastic properties and damage properties under uniaxial mode of loading. The data thus generated were analyzed using viscoelastic continuum damage mechanics principles to predict fatigue life. Weibull (2 parameter, 3 parameter and lognormal distributions were fit to fatigue life predicted using viscoelastic continuum damage approach. It was observed that fatigue damage could be best-described using Weibull distribution when compared to lognormal distribution. Due to its flexibility, 3-parameter Weibull distribution was found to fit better than 2-parameter Weibull distribution. Further, significant differences were found between probabilistic fatigue curves developed in this research and traditional deterministic fatigue curve. The proposed methodology combines advantages of continuum damage mechanics as well as probabilistic approaches. These probabilistic fatigue curves can be conveniently used for reliability based pavement design. Keywords: Probabilistic fatigue curve, Continuum damage mechanics, Weibull distribution, Lognormal distribution

Continuum-mediated dark matter–baryon scattering

CERN Document Server

Katz, Andrey; Sajjad, Aqil

2016-01-01

Many models of dark matter scattering with baryons may be treated either as a simple contact interaction or as the exchange of a light mediator particle. We study an alternative, in which a continuum of light mediator states may be exchanged. This could arise, for instance, from coupling to a sector which is approximately conformal at the relevant momentum transfer scale. In the non-relativistic effective theory of dark matter-baryon scattering, which is useful for parametrizing direct detection signals, the effect of such continuum mediators is to multiply the amplitude by a function of the momentum transfer q, which in the simplest case is just a power law. We develop the basic framework and study two examples: the case where the mediator is a scalar operator coupling to the Higgs portal (which turns out to be highly constrained) and the case of an antisymmetric tensor operator ${\\cal O}_{\\mu \

High resolution far-infrared survey of A section of the galactic plane. I. The nature of the sources

International Nuclear Information System (INIS)

Jaffe, D.T.; Stier, M.T.; Fazio, G.G.

1982-01-01

We have surveyed a 7.5 deg 2 portion of the galactic plane between l/sup II/ = 10 0 and l/sup II/ = 16 0 at 70 μm with a 1' beam. We present far-infrared, radio continuum, and 12 CO and 13 CO line observations of the 42 far-infrared sources in the survey region. The sources range in luminosity from 4 x 10 3 to 3 x 10 6 L/sub sun/. Most are associated with 12 CO peaks. More than half of the sources have associated H 2 O maser emission. Half have associated radio continuum emission at a limit of 100 mJy. Eight sources have radio emission at weaker levels. In a number of cases, the far-infrared source is smaller than its associated radio source. This difference can be explained in the context of the ''blister'' picture of H II regions. One group of sources emits many fewer Lyman continuum photons than expected, given the far-infrared luminosities. We examine a number of possible reasons for this and conclude that the most reasonable explanation is that clusters of early type stars rather than single stars excite the far-infrared sources. We examine the energetics in the molecular clouds surrounding the infrared sources and conclude that the sources could supply the energy to explain the observed temperature structure and velocity field in the molecular gas

Nuclear reaction models - source term estimation for safety design in accelerators

International Nuclear Information System (INIS)

Nandy, Maitreyee

2013-01-01

Accelerator driven subcritical system (ADSS) employs proton induced spallation reaction at a few GeV. Safety design of these systems involves source term estimation in two steps - multiple fragmentation of the target and n+γ emission through a fast process followed by statistical decay of the primary fragments. The prompt radiation field is estimated in the framework of quantum molecular dynamics (QMD) theory, intra-nuclear cascade or Monte Carlo calculations. A few nuclear reaction model codes used for this purpose are QMD, JQMD, Bertini, INCL4, PHITS, followed by statistical decay codes like ABLA, GEM, GEMINI, etc. In the case of electron accelerators photons and photoneutrons dominate the prompt radiation field. High energy photon yield through Bremsstrahlung is estimated in the framework of Born approximation while photoneutron production is calculated using giant dipole resonance and quasi-deuteron formation cross section. In this talk hybrid and exciton PEQ models and QMD formalism will be discussed briefly

Behaviour of 144Gd at very high angular momentum. Study of the continuum

International Nuclear Information System (INIS)

Nourreddine, A.

1984-01-01

The specific physical concepts that dictated the choice of 144 Gd for the present high spin study are presented in the first part of this work. The second part describes the various formalisms and techniques used to extract the multiplicities, multipolarities and moments of inertia from continuous γ ray spectra. The third part relates the results of the quasi-continuum γ ray of 144 Gd formed in the fusion-evaporation reaction 120 Sn( 28 Si, 4nγ) with four bombarding energies. A detailed balance of energy and angular momentum of the compound nucleus desexcitation has been given. Finally the evolution of the nuclear shape as a function of spin has been determined from the experimental data and interpreted by a combined micro and macroscopic theoretical calculations using a Woods-Saxon potential [fr

Theoretical and instrumental aspects of preparation of radioactive sources for precise nuclear spectroscopy

International Nuclear Information System (INIS)

Babenkov, M.I.; Kadyrzhanov, K.K.; Zhdanov, V.S.

2005-01-01

Full text: Precise investigations of spectra from nuclear radiations are quite sensitive to quality of radiation sources used. In an ideal case a source should introduce no noticeable distortion into registered spectrum. In spectroscopy of low-energy gamma-quanta, electrons and alpha particles sample preparation quite frequently turns to be challenging independent scientific investigation. Source preparation is conventionally performed at two stages - extraction of activity from a target and its uniform distribution over a substrate. A general requirement to such radioactive layer is maximal total and specific activity. Unfortunately, there is no universal source preparation method currently available for precise spectroscopy. In a number of cases excellent results are provided by fractional sublimation method based on ability of some elements to evaporate from target material at heating. The method demonstrates a several advantages. The paper introduces a complex of experimental equipment for preparation of high-quality radioactive sources. This complex is arranged in a well-protected heavy box equipped with master-slave manipulators. Biological protection of the box makes it possible to handle activities up to 10 11 Bq. Main part of the complex is a special vacuum post that assures works with active samples in the vacuum up to 10 -7 mm Hg - the operations include fractional sublimation, thermal evaporation, thermal diffusion, evaporation by electron beam, etc. All units of the vacuum post arranged in the box are designed to work with master-slave manipulators. The post is mainly used for preparation of a high-quality beta sources and extraction of microamounts of radionuclides from reactor and cyclotron targets by the method of fractional sublimation. Another important unit of the complex is an equipment for selective chemisorption in vacuum. Complex comprises all required auxiliary equipment The entire complex operated at high rate of reliability. The paper pays

Nuclear Powerplant Safety: Source Terms. Nuclear Energy.

Science.gov (United States)

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

There has been increased public interest in the potential effects of nuclear powerplant accidents since the Soviet reactor accident at Chernobyl. People have begun to look for more information about the amount of radioactivity that might be released into the environment as a result of such an accident. When this issue is discussed by people…

Social and legal aspects of preparing the construction and operation of a nuclear power source

International Nuclear Information System (INIS)

Curin, K.

1989-01-01

The main activities are described involved in creating territorial, technical and economic conditions for the building of nuclear power plants. The basic precondition is the prognostic evaluation of national requirements for power in each planning time stage. From this proceeds the need of a range of power sources with a definition of their types and their incorporation in the power system and of possible power supply to the district heating system. As for nuclear power plants the building should be divided into three stages: from planning investments to the issuance of an investment intent, the stage of construction and that of operation. A detailed description is presented of the activities of all participants in building nuclear power plants in Czechoslovak conditions. Attention is devoted to the aspects of reliability and safety of nuclear power plants and to the effect of the respective activities on reliability and safety. (Z.M.). 1 tab

Nuclear safety. Seguranca nuclear

Energy Technology Data Exchange (ETDEWEB)

Aveline, A [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica

1981-01-01

What is nuclear safety Is there any technical way to reduce risks Is it possible to put them at reasonable levels Are there competitiveness and economic reliability to employ the nuclear energy by means of safety technics Looking for answers to these questions the author describes the sources of potential risks to nuclear reactors and tries to apply the answers to the Brazilian Nuclear Programme. (author).

Open Source Parallel Image Analysis and Machine Learning Pipeline, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Continuum Analytics proposes a Python-based open-source data analysis machine learning pipeline toolkit for satellite data processing, weather and climate data...

Response of current phosphorus mitigation measures across the nutrient transfer continuum in two hydrological contrasting agricultural catchments

Science.gov (United States)

McDonald, Noeleen; Shore, Mairead; Mellander, Per-Erik; Shortle, Ger; Jordan, Phil

2015-04-01

Effective assessment of National Action Programme (NAP) measures introduced under the EU Nitrates Directive (ND), to manage nutrient use and risk of loss to waters from agriculture, is best achieved when examined across the nutrient transfer continuum at catchment scale. The Irish NAP measures are implemented on a whole-territory basis for both nitrogen (N) and phosphorus (P), with P being the key trophic pressure. The aim of this research was to observe the efficacy of P regulation measures and P source management across the transfer continuum and resultant water quality status (i.e. source to impact), in two contrasting agricultural catchments over a four year period. The catchments are ca. 11 km2 and are located in the south-east of Ireland. One is well-drained and arable dominated, while the other is mostly poorly-drained and grassland dominated. In 2009 and 2013 soil surveys for plant-available P were carried out (Importantly, the proportion of farmland with excessive soil P concentrations decreased in both the arable (20% to 11.8%) and grassland catchments (5.9 to 3.6%). However, soil P concentrations also declined critically in both catchments, as proportional areas below the national crop agronomic optimum thresholds (grassland; indicates a reduced or sustained level of P inputs in both catchments. Indications of responses to soil P change in the surface waters of these catchments appeared to be highly influenced by their hydrological differences and the impact that annual and inter-annual climate and hydrological processes have on nutrient delivery. In the arable catchment total reactive P (TRP) concentrations in interpreted pathways declined across the quickflow, interflow and shallow groundwater of the slowflow, while TRP concentrations in the deeper groundwater, mostly contributing to baseflow, remained the same. However, the complexity of the flow pathways in the grassland catchment made it difficult to determine any trends in P concentrations as a

High-resolution continuum source atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple lines. A critical review of current possibilities

International Nuclear Information System (INIS)

Resano, M.; Flórez, M.R.; García-Ruiz, E.

2013-01-01

This work examines the capabilities and limitations of commercially available high-resolution continuum source atomic absorption spectrometry instrumentation for multi-line monitoring, discussing in detail the possible strategies to develop multi-element methodologies that are truly simultaneous, or else sequential, but from the same sample aliquot. Moreover, the simultaneous monitoring of various atomic or molecular lines may bring other important analytical advantages, such as: i) expansion of the linear range by monitoring multiplets; ii) improvements in the limit of detection and in precision by summing the signals from different lines of the same element or molecule; iii) simple correction for matrix-effects by selecting a suitable internal standard; or iv) accurate mathematical correction of spectral overlaps by simultaneous monitoring of free lines of the interfering molecule or element. This work discusses how authors have made use of these strategies to develop analytical methodologies that permit the straightforward analysis of complex samples. - Highlights: • HR CS AAS potential for simultaneous multi-line monitoring is critically examined. • Strategies to develop simultaneous multi-element methods are discussed. • Other benefits of multi-line monitoring (e.g., use of an IS or LSBC) are highlighted. • Selected examples from the literature are discussed in detail

Spatial stochasticity and non-continuum effects in gas flows

Energy Technology Data Exchange (ETDEWEB)

Dadzie, S. Kokou, E-mail: k.dadzie@glyndwr.ac.uk [Mechanical and Aeronautical Engineering, Glyndwr University, Mold Road, Wrexham LL11 2AW (United Kingdom); Reese, Jason M., E-mail: jason.reese@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)

2012-02-06

We investigate the relationship between spatial stochasticity and non-continuum effects in gas flows. A kinetic model for a dilute gas is developed using strictly a stochastic molecular model reasoning, without primarily referring to either the Liouville or the Boltzmann equations for dilute gases. The kinetic equation, a stochastic version of the well-known deterministic Boltzmann equation for dilute gas, is then associated with a set of macroscopic equations for the case of a monatomic gas. Tests based on a heat conduction configuration and sound wave dispersion show that spatial stochasticity can explain some non-continuum effects seen in gases. -- Highlights: ► We investigate effects of molecular spatial stochasticity in non-continuum regime. ► Present a simplify spatial stochastic kinetic equation. ► Present a spatial stochastic macroscopic flow equations. ► Show effects of the new model on sound wave dispersion prediction. ► Show effects of the new approach in density profiles in a heat conduction.

Amplification of non-Markovian decay due to bound state absorption into continuum

International Nuclear Information System (INIS)

Garmon, S.; Simine, L.; Segal, D.; Petrosky, T.

2013-01-01

It is known that quantum systems yield non-exponential (power law) decay on long time scales, associated with continuum threshold effects contributing to the survival probability for a prepared initial state. For an open quantum system consisting of a discrete state coupled to continuum, we study the case in which a discrete bound state of the full Hamiltonian approaches the energy continuum as the system parameters are varied. We find in this case that at least two regions exist yielding qualitatively different power law decay behaviors; we term these the long time 'near zone' and long time 'far zone'. In the near zone the survival probability falls off according to a t -1 power law, and in the far zone i t falls off as t -3 . We show that the timescale T Q separating these two regions is inversely related to the gap between the discrete bound state energy and the continuum threshold. In the case that the bound state is absorbed into the continuum and vanishes, then the time scale T Q diverges and the survival probability follows the t -1 power law even on asymptotic scales. Conversely, one could study the case of an anti-bound state approaching the threshold before being ejected from the continuum to form a bound state. Again the t -1 power law dominates precisely at the point of ejection. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Mirrored continuum and molecular scale simulations of the ignition of gamma phase RDX

Science.gov (United States)

Stewart, D. Scott; Chaudhuri, Santanu; Joshi, Kaushik; Lee, Kibaek

2017-01-01

We describe the ignition of an explosive crystal of gamma-phase RDX due to a thermal hot spot with reactive molecular dynamics (RMD), with first-principles trained, reactive force field based molecular potentials that represents an extremely complex reaction network. The RMD simulation is analyzed by sorting molecular product fragments into high and low molecular weight groups, to represent identifiable components that can be interpreted by a continuum model. A continuum model based on a Gibbs formulation has a single temperature and stress state for the mixture. The continuum simulation that mirrors the atomistic simulation allows us to study the atomistic simulation in the familiar physical chemistry framework and provides an essential, continuum/atomistic link.

Moving contact lines: linking molecular dynamics and continuum-scale modelling.

Science.gov (United States)

Smith, Edward R; Theodorakis, Panagiotis E; Craster, Richard V; Matar, Omar K

2018-05-04

Despite decades of research, the modelling of moving contact lines has remained a formidable challenge in fluid dynamics whose resolution will impact numerous industrial, biological, and daily-life applications. On the one hand, molecular dynamics (MD) simulation has the ability to provide unique insight into the microscopic details that determine the dynamic behavior of the contact line, which is not possible with either continuum-scale simulations or experiments. On the other hand, continuum-based models provide the link to the macroscopic description of the system. In this Feature Article, we explore the complex range of physical factors, including the presence of surfactants, which govern the contact line motion through MD simulations. We also discuss links between continuum- and molecular-scale modelling, and highlight the opportunities for future developments in this area.

An advanced kinetic theory for morphing continuum with inner structures

Science.gov (United States)

Chen, James

2017-12-01

Advanced kinetic theory with the Boltzmann-Curtiss equation provides a promising tool for polyatomic gas flows, especially for fluid flows containing inner structures, such as turbulence, polyatomic gas flows and others. Although a Hamiltonian-based distribution function was proposed for diatomic gas flow, a general distribution function for the generalized Boltzmann-Curtiss equations and polyatomic gas flow is still out of reach. With assistance from Boltzmann's entropy principle, a generalized Boltzmann-Curtiss distribution for polyatomic gas flow is introduced. The corresponding governing equations at equilibrium state are derived and compared with Eringen's morphing (micropolar) continuum theory derived under the framework of rational continuum thermomechanics. Although rational continuum thermomechanics has the advantages of mathematical rigor and simplicity, the presented statistical kinetic theory approach provides a clear physical picture for what the governing equations represent.

Unexpected strong attraction in the presence of continuum bound state

International Nuclear Information System (INIS)

Delfino, A.; Frederico, T.

1992-06-01

The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)

Promising design options for the encapsulated nuclear heat source reactor

International Nuclear Information System (INIS)

Conway, L.; Carelli, M.D.; Dzodzo, M.; Hossain, Q.; Brown, N.W.; Wade, D.C.; Sienick, J.J.; Greenspan, E.; Kastenberg, W.E.; Saphier, D.

2001-01-01

Promising design options for the Encapsulated Nuclear Heat Source (ENHS) liquid-metal cooled fast reactor were identified during the first year of the DOE NERI program sponsored feasibility study. Many opportunities for incorporation of innovations in design and fabrication were identified. Three of the innovations are hereby described: a novel IHX (intermediate heat exchanger) made of a relatively small number of rectangular channels, an ENHS module design featuring 100% natural circulation, and a novel conceptual design of core support and fuelling. As a result of the first year study the ENHS concept appears more practical and more promising than perceived at the outset of this study. (authors)

Promising design options for the encapsulated nuclear heat source reactor

Energy Technology Data Exchange (ETDEWEB)

Conway, L.; Carelli, M.D.; Dzodzo, M. [Westinghouse Science and Technology, Pittsburgh, PA (United States); Hossain, Q.; Brown, N.W. [Lawrence Livermore National Lab., CA (United States); Wade, D.C.; Sienick, J.J. [Argonne National Lab., IL (United States); Greenspan, E.; Kastenberg, W.E.; Saphier, D. [University of California Dept of Nuclear Engineering, Berkeley, CA (United States)

2001-07-01

Promising design options for the Encapsulated Nuclear Heat Source (ENHS) liquid-metal cooled fast reactor were identified during the first year of the DOE NERI program sponsored feasibility study. Many opportunities for incorporation of innovations in design and fabrication were identified. Three of the innovations are hereby described: a novel IHX (intermediate heat exchanger) made of a relatively small number of rectangular channels, an ENHS module design featuring 100% natural circulation, and a novel conceptual design of core support and fuelling. As a result of the first year study the ENHS concept appears more practical and more promising than perceived at the outset of this study. (authors)

Hybrid continuum-coarse-grained modeling of erythrocytes

Science.gov (United States)

Lyu, Jinming; Chen, Paul G.; Boedec, Gwenn; Leonetti, Marc; Jaeger, Marc

2018-06-01

The red blood cell (RBC) membrane is a composite structure, consisting of a phospholipid bilayer and an underlying membrane-associated cytoskeleton. Both continuum and particle-based coarse-grained RBC models make use of a set of vertices connected by edges to represent the RBC membrane, which can be seen as a triangular surface mesh for the former and a spring network for the latter. Here, we present a modeling approach combining an existing continuum vesicle model with a coarse-grained model for the cytoskeleton. Compared to other two-component approaches, our method relies on only one mesh, representing the cytoskeleton, whose velocity in the tangential direction of the membrane may be different from that of the lipid bilayer. The finitely extensible nonlinear elastic (FENE) spring force law in combination with a repulsive force defined as a power function (POW), called FENE-POW, is used to describe the elastic properties of the RBC membrane. The mechanical interaction between the lipid bilayer and the cytoskeleton is explicitly computed and incorporated into the vesicle model. Our model includes the fundamental mechanical properties of the RBC membrane, namely fluidity and bending rigidity of the lipid bilayer, and shear elasticity of the cytoskeleton while maintaining surface-area and volume conservation constraint. We present three simulation examples to demonstrate the effectiveness of this hybrid continuum-coarse-grained model for the study of RBCs in fluid flows.

The quantum and the continuum : Einstein's dichotomous legacies

International Nuclear Information System (INIS)

Majumdar, Parthasarathi

2015-01-01

This talk begins with a summary of some of Einstein's seminal contributions in the quantum domain, like Brownian motion and the Light Quantum Hypothesis, as well as on the spacetime continuum enshrined in the theories of special and general relativity. Following up on Einstein's rationale for postulating the Light Quantum Hypothesis, we attempt to point to a possible dichotomy in his thinking about these two legacies of his, which may have been noticed by him, but was not much discussed by him in the public domain. One may speculate that this may have had something to do with his well-known distaste for the probability interpretation of quantum mechanics as a fundamental interpretation. We argue that Einstein's general relativity theory itself contains the seeds of a dramatic modification of our ideas of the Einsteinian spacetime continuum, thus underlining the dichotomy even more strongly. We then survey one modern attempt to resolve the dichotomy, at least partly, by bringing into the spacetime continuum, aspects of quantum mechanics with its underlying statistical interpretation, an approach which Einstein may not have whole-heartedly endorsed, but which seems to work so far, with good prospects for the future. (author)

Additive manufacturing of patient-specific tubular continuum manipulators

Science.gov (United States)

Amanov, Ernar; Nguyen, Thien-Dang; Burgner-Kahrs, Jessica

2015-03-01

Tubular continuum robots, which are composed of multiple concentric, precurved, elastic tubes, provide more dexterity than traditional surgical instruments at the same diameter. The tubes can be precurved such that the resulting manipulator fulfills surgical task requirements. Up to now the only material used for the component tubes of those manipulators is NiTi, a super-elastic shape-memory alloy of nickel and titan. NiTi is a cost-intensive material and fabrication processes are complex, requiring (proprietary) technology, e.g. for shape setting. In this paper, we evaluate component tubes made of 3 different thermoplastic materials (PLA, PCL and nylon) using fused filament fabrication technology (3D printing). This enables quick and cost-effective production of custom, patient-specific continuum manipulators, produced on site on demand. Stress-strain and deformation characteristics are evaluated experimentally for 16 fabricated tubes of each thermoplastic with diameters and shapes equivalent to those of NiTi tubes. Tubes made of PCL and nylon exhibit properties comparable to those made of NiTi. We further demonstrate a tubular continuum manipulator composed of 3 nylon tubes in a transnasal, transsphenoidal skull base surgery scenario in vitro.

YM2: Continuum expectations, lattice convergence, and lassos

International Nuclear Information System (INIS)

Driver, B.K.

1989-01-01

The two dimensional Yang-Mills theory (YM 2 ) is analyzed in both the continuum and the lattice. In the complete axial gauge the continuum theory may be defined in terms of a Lie algebra valued white noise, and parallel translation may be defined by stochastic differential equations. This machinery is used to compute the expectations of gauge invariant functions of the parallel translation operators along a collection of curves C. The expectation values are expressed as finite dimensional integrals with densities that are products of the heat kernel on the structure group. The time parameters of the heat kernels are determined by the areas enclosed by the collection C, and the arguments are determined by the crossing topologies of the curves in C. The expectations for the Wilson lattice models have a similar structure, and from this it follows that in the limit of small lattice spacing the lattice expectations converge to the continuum expectations. It is also shown that the lasso variables advocated by L. Gross exist and are sufficient to generate all the measurable functions on the YM 2 -measure space. (orig.)

Discrete expansions of continuum wave functions

International Nuclear Information System (INIS)

Bang, J.; Ershov, S.N.; Gareev, F.A.; Kazacha, G.S.

1980-01-01

Different methods of expanding continuum wave functions in terms of discrete basis sets are discussed. The convergence properties of these expansions are investigated, both from a mathematical and a numerical point of view, for the case of potentials of Woods-Saxon and square well type. (orig.)

The safe management of sources of radiation: Principles and strategies. INSAG-11. A report by the International Nuclear Safety Advisory Group (Russian Edition)

International Nuclear Information System (INIS)

2015-01-01

The IAEA activities relating to nuclear safety are based upon a number of premises. First and foremost, each Member State bears full responsibility for the safety of its nuclear facilities. States can be advised, but cannot be relieved of this responsibility. Secondly, much can be gained by exchanging experience; lessons learned can prevent accidents. Finally, the image of nuclear safety is international; a serious accident anywhere affects the public view of nuclear power everywhere. With the intention of strengthening its contribution to ensuring safety of nuclear power plants, the IAEA established the International Safety Advisory Group (INSAG), whose duties include serving as a forum for the exchange of information on nuclear safety issues of international significance and formulating commonly shared safety principles. The present report deals with the general principles governing the safety of all sources of radiation and with application of these principles. It intends to show that, at the conceptual level, the distinction traditionally made between nuclear safety and radiation protection is hardly justifiable. It is intended primarily for those non-specialists who need to take decisions about safe management of sources of radiation and who wish to gain a better understanding of the approach followed in managing the safety of these sources

Dosimetry of beta sources utilized in nuclear medicine and biomedicine

International Nuclear Information System (INIS)

Bergoc, R.M.; Rivera, E.; Cricco, G.; Martin, G.; Cocca, C.; Caro, R.A.

1998-01-01

Full text: The use of high energy pure beta sources (i.e., 32 P= 1.71 MeV/des) is common in medicine (intratumoral therapy or treatment of non-malignant illness as restenosis) and in biochemistry (molecular biology). The external dosimetry of these sources offers some important points that must be considered: 1) beta particles emitted by the source are not monoenergetic; 2) the range (R 0 ) vary with the source energy and the Z of the absorber; 3) below an energy of 1 MeV, the specific ionization in the absorbent medium (air, water, lucite) increases as the beta energy (E β ) decreases; 4) the range of beta particles, R β , is independent from Z of the material, provided Z is low and the material has no hydrogen; in this case, the expression: R β δ 1 = R β δ 2 is valid; 5) the calculation of the external beta dosimetry must consider that since the used sources are not punctual there is self-absorption which should be taken into account. However, in the range of the fractions of activities for the above mentioned practices a theoretical model for punctual sources can be used; in this case, it is valid to use the expression: Dose Rate: = A (S/δ)E β e -S/δ δx /4 π d 2 , where: (S/δ) is the absorbent Mass Stopping Power and represents the loss of energy by unit mass thickness; it depends from E β and it is independent from Z; (δx) is the mass thickness of the absorber. By this way, e -S/δ δx is the attenuation of the beta particles flow. From the application of this formula it can be deduced that, for sources of 1 mCi of 32 P activities, as those employed in biochemistry, a small thickness of lucite is enough shield. When the source has higher activities, as those used in radiotherapy, the operator should take into account the regulations for a strict dosimetric control. These formulae allow a simplified calculation of the 32 P dosimetry of sources used in nuclear medicine and biomedical practices. (author) [es

What is nuclear forensics?

International Nuclear Information System (INIS)

Halevy, Itzhak

2014-01-01

Nuclear forensics is the investigation of nuclear materials to find evidence for example the source, the trafficking, and the enrichment of the material. The material can be recovered from various sources including dust from the vicinity of a nuclear facility, or from the radioactive debris following a nuclear explosion. Results of nuclear forensic testing are used by different organizations to make decisions. The information is typically combined with other sources of information such as law enforcement and intelligence information

Mesoscopic and continuum modelling of angiogenesis

KAUST Repository

Spill, F.; Guerrero, P.; Alarcon, T.; Maini, P. K.; Byrne, H. M.

2014-01-01

Angiogenesis is the formation of new blood vessels from pre-existing ones in response to chemical signals secreted by, for example, a wound or a tumour. In this paper, we propose a mesoscopic lattice-based model of angiogenesis, in which processes that include proliferation and cell movement are considered as stochastic events. By studying the dependence of the model on the lattice spacing and the number of cells involved, we are able to derive the deterministic continuum limit of our equations and compare it to similar existing models of angiogenesis. We further identify conditions under which the use of continuum models is justified, and others for which stochastic or discrete effects dominate. We also compare different stochastic models for the movement of endothelial tip cells which have the same macroscopic, deterministic behaviour, but lead to markedly different behaviour in terms of production of new vessel cells. © 2014 Springer-Verlag Berlin Heidelberg.

Mesoscopic and continuum modelling of angiogenesis

KAUST Repository

Spill, F.

2014-03-11

Angiogenesis is the formation of new blood vessels from pre-existing ones in response to chemical signals secreted by, for example, a wound or a tumour. In this paper, we propose a mesoscopic lattice-based model of angiogenesis, in which processes that include proliferation and cell movement are considered as stochastic events. By studying the dependence of the model on the lattice spacing and the number of cells involved, we are able to derive the deterministic continuum limit of our equations and compare it to similar existing models of angiogenesis. We further identify conditions under which the use of continuum models is justified, and others for which stochastic or discrete effects dominate. We also compare different stochastic models for the movement of endothelial tip cells which have the same macroscopic, deterministic behaviour, but lead to markedly different behaviour in terms of production of new vessel cells. © 2014 Springer-Verlag Berlin Heidelberg.

Continuum deformation of multi-agent systems

CERN Document Server

Rastgoftar, Hossein

2016-01-01

This monograph presents new algorithms for formation control of multi-agent systems (MAS) based on principles of continuum mechanics. Beginning with an overview of traditional methods, the author then introduces an innovative new approach whereby agents of an MAS are considered as particles in a continuum evolving in ℝn whose desired configuration is required to satisfy an admissible deformation function. The necessary theory and its validation on a mobile-agent-based swarm test bed are considered for two primary tasks: homogeneous transformation of the MAS and deployment of a random distribution of agents on a desired configuration. The framework for this model is based on homogeneous transformations for the evolution of an MAS under no inter-agent communication, local inter-agent communication, and intelligent perception by agents. Different communication protocols for MAS evolution, the robustness of tracking of a desired motion by an MAS evolving in ℝn, and the effect of communication delays in an MAS...

Continuum multiple-scattering approach to electron-molecule scattering and molecular photoionization

International Nuclear Information System (INIS)

Dehmer, J.L.; Dill, D.

1979-01-01

The multiple-scattering approach to the electronic continuum of molecules is described. The continuum multiple-scattering model (CMSM) was developed as a survey tool and, as such was required to satisfy two requirements. First, it had to have a very broad scope, which means (i) molecules of arbitrary geometry and complexity containing any atom in the periodic system, (ii) continuum electron energies from 0-1000 eV, and (iii) capability to treat a large range of processes involving both photoionization and electron scattering. Second, the structure of the theory was required to lend itself to transparent, physical interpretation of major spectral features such as shape resonances. A comprehensive theoretical framework for the continuum multiple scattering method is presented, as well as its applications to electron-molecule scattering and molecular photoionization. Highlights of recent applications in these two areas are reviewed. The major impact of the resulting studies over the last few years has been to establish the importance of shape resonances in electron collisions and photoionization of practically all (non-hydride) molecules

Molecular-state close-coupling theory including continuum states. I. Derivation of close-coupled equations

International Nuclear Information System (INIS)

Thorson, W.R.; Bandarage, G.

1988-01-01

We formulate a close-coupling theory of slow ion-atom collisions based on molecular (adiabatic) electronic states, and including the electronic continuum. The continuum is represented by packet states spanning it locally and constructed explicitly from exact continuum states. Particular attention is given to two fundamental questions: (1) Unbound electrons can escape from the local region spanned by the packet states. We derive close-coupled integral equations correctly including the escape effects; the ''propagator'' generated by these integral equations does not conserve probability within the close-coupled basis. Previous molecular-state formulations including the continuum give no account of escape effects. (2) Nonadiabatic couplings of adiabatic continuum states with the same energy are singular, reflecting the fact that an adiabatic description of continuum behavior is not valid outside a local region. We treat these singularities explicitly and show that an accurate representation of nonadiabatic couplings within the local region spanned by a set of packet states is well behaved. Hence an adiabatic basis-set description can be used to describe close coupling to the continuum in a local ''interaction region,'' provided the effects of escape are included. In principle, the formulation developed here can be extended to a large class of model problems involving many-electron systems and including models for Penning ionization and collisional detachment processes

Accidental bound states in the continuum in an open Sinai billiard

Energy Technology Data Exchange (ETDEWEB)

Pilipchuk, A.S. [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation); Siberian Federal University, 660080 Krasnoyarsk (Russian Federation); Sadreev, A.F., E-mail: almas@tnp.krasn.ru [Kirensky Institute of Physics, Federal Research Center KSC SB RAS, 660036 Krasnoyarsk (Russian Federation)

2017-02-19

The fundamental mechanism of the bound states in the continuum is the full destructive interference of two resonances when two eigenlevels of the closed system are crossing. There is, however, a wide class of quantum chaotic systems which display only avoided crossings of eigenlevels. As an example of such a system we consider the Sinai billiard coupled with two semi-infinite waveguides. We show that notwithstanding the absence of degeneracy bound states in the continuum occur due to accidental decoupling of the eigenstates of the billiard from the waveguides. - Highlights: • Bound states in the continuum in open chaotic billiards occur to accidental vanishing of coupling of eigenstate of billiard with waveguides.

Correcting X-ray spectra obtained from the AXAF VETA-I mirror calibration for pileup, continuum, background and deadtime

Science.gov (United States)

Chartas, G.; Flanagan, K.; Hughes, J. P.; Kellogg, E. M.; Nguyen, D.; Zombek, M.; Joy, M.; Kolodziejezak, J.

1993-01-01

The VETA-I mirror was calibrated with the use of a collimated soft X-ray source produced by electron bombardment of various anode materials. The FWHM, effective area and encircled energy were measured with the use of proportional counters that were scanned with a set of circular apertures. The pulsers from the proportional counters were sent through a multichannel analyzer that produced a pulse height spectrum. In order to characterize the properties of the mirror at different discrete photon energies one desires to extract from the pulse height distribution only those photons that originated from the characteristic line emission of the X-ray target source. We have developed a code that fits a modeled spectrum to the observed X-ray data, extracts the counts that originated from the line emission, and estimates the error in these counts. The function that is fitted to the X-ray spectra includes a Prescott function for the resolution of the detector a second Prescott function for a pileup peak and a X-ray continuum function. The continuum component is determined by calculating the absorption of the target Bremsstrahlung through various filters, correcting for the reflectivity of the mirror and convolving with the detector response.

kHz femtosecond laser-plasma hard X-ray and fast ion source

International Nuclear Information System (INIS)

Thoss, A.; Korn, G.; Stiel, H.; Voigt, U.; Elsaesser, T.; Richardson, M.C.; Siders, C.W.; Faubel, M.

2002-01-01

We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and K α emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, K α and K β lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ∼500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

Photofragmentation of water and hydrogen sulphide in the first continuum: A critical survey

International Nuclear Information System (INIS)

Mohamed, K.A.

1987-06-01

Photofragmentation of H 2 O and H 2 S in the first absorption continuum has been investigated experimentally and theoretically by several authors. The fragmentation dynamics of both molecules are reviewed in this article. While the excited 1 B 1 state in H 2 O is responsible for the first continuum, ambiguity exists in the true nature of the upper state of the first continuum in H 2 S. From the evidence available so far, it is proposed that both in water and hydrogen sulphide, a single state of B 1 symmetry, which is of Rydberg type for short internuclear distances and of valence type for large internuclear distances, is the possible upper state which dissociates to produce the absorption continuum. (author). Refs

Visible continuum pulses based on enhanced dispersive wave generation for endogenous fluorescence imaging.

Science.gov (United States)

Cui, Quan; Chen, Zhongyun; Liu, Qian; Zhang, Zhihong; Luo, Qingming; Fu, Ling

2017-09-01

In this study, we demonstrate endogenous fluorescence imaging using visible continuum pulses based on 100-fs Ti:sapphire oscillator and a nonlinear photonic crystal fiber. Broadband (500-700 nm) and high-power (150 mW) continuum pulses are generated through enhanced dispersive wave generation by pumping femtosecond pulses at the anomalous dispersion region near zero-dispersion wavelength of high-nonlinear photonic crystal fibers. We also minimize the continuum pulse width by determining the proper fiber length. The visible-wavelength two-photon microscopy produces NADH and tryptophan images of mice tissues simultaneously. Our 500-700 nm continuum pulses support extending nonlinear microscopy to visible wavelength range that is inaccessible to 100-fs Ti:sapphire oscillators and other applications requiring visible laser pulses.

Size of nuclear sources from measurements of proton-proton correlations at small relative momentum

International Nuclear Information System (INIS)

Rebreyend, D.; Kox, S.; Merchez, F.; Noren, B.; Perrin, C.; Khelfaoui, B.; Gondrand, J.C.; Bondorf, J.P.

1990-01-01

This contribution will present recent measurements performed on light heavy ion reactions at intermediate energies. Nuclear source sizes were determined by measuring the correlation at small relative momentum, between two protons detected in the EMRIC set-up. This technique allows the determination of the extent of the emitting source by constructing a correlation function for the coincident protons and analyzing it in the framework of a final state interaction model. We found the apparent source size to be large compared to the dimension of the studied system and low sensitivity of the extracted radii as a function of the target mass and detection angle. We will show that simulations may be needed to fully estimate the correlation induced by detectors with small angular acceptance

Integrating large-scale cogeneration of hydrogen and electricity from wind and nuclear sources (NUWINDTM)

International Nuclear Information System (INIS)

Miller, A. I.; Duffey, R. B.

2008-01-01

As carbon-free fuels, hydrogen and electricity are headed for major roles in replacing hydrocarbons as the world constrains carbon dioxide (CO 2 ) emissions. This will apply particularly to the transport sector. A general trend toward electric drive on-board vehicles is already evident and hydrogen converted to electricity by a fuel cell is likely to be a major source of on-board electricity. The major car manufacturers continue to invest heavily in this option and significant government initiatives in both the USA and Canada are beginning demonstration deployments of the infrastructure needed for hydrogen refueling. However, early adoption of hydrogen as a transport fuel may well be concentrated on heavy-duty transportation: trains, ships and trucks, where battery storage of electricity is unlikely to be practical. But both hydrogen and electricity are secondary fuels and are only effective if the source of the primary energy is a low CO 2 emitter such as nuclear and wind. A competitive cost is also essential and, to achieve this, one must rely on off-peak electricity prices. This paper examines historical data for electricity prices and the actual output of the main wind farms in Ontario to show how nuclear and wind can be combined to generate hydrogen by water electrolysis at prices that are competitive with fossil-based hydrogen production. The NuWind TM concept depends on operating electrolysis cells over an extended range of current densities to accommodate the inherent variability of wind and of electricity prices as they vary in open markets. The cost of co-producing hydrogen with electricity originating from nuclear plants (80%) and from wind turbines (20%) is very close to that of production from a constantly available electricity source. In contrast, the price of hydrogen produced using electricity from wind alone is estimated to cost about $1500/tonne more than hydrogen from NuWind or nuclear alone because the electrolysis facility must be much larger

Fundamentals of continuum mechanics – classical approaches and new trends

Science.gov (United States)

Altenbach, H.

2018-04-01

Continuum mechanics is a branch of mechanics that deals with the analysis of the mechanical behavior of materials modeled as a continuous manifold. Continuum mechanics models begin mostly by introducing of three-dimensional Euclidean space. The points within this region are defined as material points with prescribed properties. Each material point is characterized by a position vector which is continuous in time. Thus, the body changes in a way which is realistic, globally invertible at all times and orientation-preserving, so that the body cannot intersect itself and as transformations which produce mirror reflections are not possible in nature. For the mathematical formulation of the model it is also assumed to be twice continuously differentiable, so that differential equations describing the motion may be formulated. Finally, the kinematical relations, the balance equations, the constitutive and evolution equations and the boundary and/or initial conditions should be defined. If the physical fields are non-smooth jump conditions must be taken into account. The basic equations of continuum mechanics are presented following a short introduction. Additionally, some examples of solid deformable continua will be discussed within the presentation. Finally, advanced models of continuum mechanics will be introduced. The paper is dedicated to Alexander Manzhirov’s 60th birthday.

An improved particle population balance equation in the continuum-slip regime

Directory of Open Access Journals (Sweden)

Xie Mingliang

2016-01-01

Full Text Available An improved moment model is proposed to solve the population balance equation for Brownian coagulation in the continuum-slip regime, and it reduces to a known one in open literature when the non-linear terms in the slip correction factor are ignored. The present model shows same asymptotic behavior as that in the continuum regime.

77 FR 45421 - Homeless Emergency Assistance and Rapid Transition to Housing: Continuum of Care Program

Science.gov (United States)

2012-07-31

... which service providers are familiar. The following highlights key definitions used in the Continuum of... Continuum of Care in 1995. Local grantees and stakeholders are familiar with the Continuum of Care as the... violence, dating violence, sexual assault, and stalking. In developing the baseline requirements for a...

Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

International Nuclear Information System (INIS)

Wu, Q.; Sun, L.T.; Cui, B.Q.; Lian, G.; Yang, Y.; Ma, H.Y.; Tang, X.D.; Zhang, X.Z.; Zhang, Z.M.; Liu, W.P.

2016-01-01

The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H + , 10 emA He + and 2.0 emA He 2+ beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

Design of an intense ion source and LEBT for Jinping Underground Nuclear Astrophysics experiments

Energy Technology Data Exchange (ETDEWEB)

Wu, Q., E-mail: wuq@impcas.ac.cn [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Sun, L.T., E-mail: sunlt@impcas.ac.cn [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Cui, B.Q.; Lian, G. [China Institute of Atomic Energy, Beijing 102413 (China); Yang, Y.; Ma, H.Y.; Tang, X.D.; Zhang, X.Z.; Zhang, Z.M. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, W.P. [China Institute of Atomic Energy, Beijing 102413 (China)

2016-09-11

The ongoing Jinping Underground Nuclear Astrophysics experiment (JUNA) will take the advantage of the ultralow background in China Jinping Underground Laboratory (CJPL), high current accelerator driven by on an ECR source and highly sensitive detector to study directly a number of important reactions for the first time within their relevant stellar energy range. A 2.45 GHz ECR ion source is one of its key components to provide 10 emA H{sup +}, 10 emA He{sup +} and 2.0 emA He{sup 2+} beams for the study of (p,γ), (p,α), (α,p) and (α,γ) reactions in the first phase of the JUNA project. Ion beam is extracted from the source with energies up to 50 kV/q. The following low energy beam transport (LEBT) system transports and matches the ion beam from the exit of ion source to the acceleration tube (AT). The design status of the ECR ion source and LEBT system for the JUNA project are presented. The potential risks of the ion source are also discussed and analysed.

Searching for hidden radioactive sources in the Barents Rescue 2001 nuclear emergency exercise

International Nuclear Information System (INIS)

Smethurst, Mark A.; Mogaard, John O.; Mauring, Eirik; Koziel, Janusz; Kihle, Ola