WorldWideScience

Sample records for source structure studies

  1. A Study on Conjugate Heat Transfer Analysis of Reactor Vessel including Irradiated Structural Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Kunwoo; Cho, Hyuksu; Im, Inyoung; Kim, Eunkee [KEPCO EnC, Daejeon (Korea, Republic of)

    2015-10-15

    Though Material reliability programs (MRPs) have a purpose to provide the evaluation or management methodologies for the operating RVI, the similar evaluation methodologies can be applied to the APR1400 fleet in the design stage for the evaluation of neutron irradiation effects. The purposes of this study are: to predict the thermal behavior whether or not irradiated structure heat source; to evaluate effective thermal conductivity (ETC) in relation to isotropic and anisotropic conductivity of porous media for APR1400 Reactor Vessel. The CFD simulations are performed so as to evaluate thermal behavior whether or not irradiated structure heat source and effective thermal conductivity for APR1400 Reactor Vessel. In respective of using irradiated structure heat source, the maximum temperature of fluid and core shroud for isotropic ETC are 325.8 .deg. C, 341.5 .deg. C. The total amount of irradiated structure heat source is about 5.41 MWth and not effect to fluid temperature.

  2. Selective structural source identification

    Science.gov (United States)

    Totaro, Nicolas

    2018-04-01

    In the field of acoustic source reconstruction, the inverse Patch Transfer Function (iPTF) has been recently proposed and has shown satisfactory results whatever the shape of the vibrating surface and whatever the acoustic environment. These two interesting features are due to the virtual acoustic volume concept underlying the iPTF methods. The aim of the present article is to show how this concept of virtual subsystem can be used in structures to reconstruct the applied force distribution. Some virtual boundary conditions can be applied on a part of the structure, called virtual testing structure, to identify the force distribution applied in that zone regardless of the presence of other sources outside the zone under consideration. In the present article, the applicability of the method is only demonstrated on planar structures. However, the final example show how the method can be applied to a complex shape planar structure with point welded stiffeners even in the tested zone. In that case, if the virtual testing structure includes the stiffeners the identified force distribution only exhibits the positions of external applied forces. If the virtual testing structure does not include the stiffeners, the identified force distribution permits to localize the forces due to the coupling between the structure and the stiffeners through the welded points as well as the ones due to the external forces. This is why this approach is considered here as a selective structural source identification method. It is demonstrated that this approach clearly falls in the same framework as the Force Analysis Technique, the Virtual Fields Method or the 2D spatial Fourier transform. Even if this approach has a lot in common with these latters, it has some interesting particularities like its low sensitivity to measurement noise.

  3. Structural studies of the lipid membranes at the Siberia-2 synchrotron radiation source

    International Nuclear Information System (INIS)

    Kiselev, M. A.; Ermakova, E. V.; Ryabova, N. Yu.; Nayda, O. V.; Zabelin, A. V.; Pogorely, D. K.; Korneev, V. N.; Balagurov, A. M.

    2010-01-01

    Lipid membranes are a subject of contemporary interdisciplinary studies at the junction of biology, biophysics, pharmacology, and bionanotechnology. The results of the structural studies of several types of lipid membranes by the lamellar and lateral diffraction of X-ray synchrotron radiation are presented. The experiments were performed at the Mediana and DICSI stations of the Siberia-2 synchrotron radiation source at the Russian Research Center Kurchatov Institute. The data obtained are compared with the results of studying lipid membranes at the small-angle scattering beamlines D22 and D24 at LURE (France) and at the A2 beamline at DESY (Germany). The parameters of the DICSI station are shown to meet the basic requirements for the structural study of lipid systems, which are of fundamental and applied interest.

  4. Structural design study of a proton beam window for a 1-MW spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Teraoku, Takuji; Terada, Atsuhiko; Maekawa, Fujio; Meigo, Shin-ichiro; Kaminaga, Masanori; Ishikura, Syuichi; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    A 1-MW spallation neutron source aiming at materials and life science researches will be constructed under the JAERI-KEK High-intensity Proton Accelerator Project (J-PARC). A proton beam passes through a proton beam window, and be injected into a target of the neutron source. The proton beam window functions as a boundary wall between a high vacuum area in the proton beam line and a helium atmosphere at about atmospheric pressure in a helium vessel which contains the target and moderators. The proton beam window is cooled by light water because high heat-density is generated in the window material by interactions with the proton beam. Then, uniformity of the water flow is requested at the window to suppress a hot-spot that causes excessive thermal stress and cooling water boiling. Also, the window has to be strong enough in its structure for inner stress due to water pressure and thermal stress due to heat generation. In this report, we propose two types of proton beam windows; one flat-type that is easy to manufacture, and the other, curved-type that has high stress resistivity. As a part of design study for the windows, evaluation of strength of structure and thermal hydraulic analysis were conducted. As a result, it was found that sufficient heat removal was assured with uniform water flow at the window, and stress caused by internal water pressure and thermal stress could be maintained below allowable stress values. Accordingly, it was confirmed that the proton beam window designs were feasible. (author)

  5. Joint source based analysis of multiple brain structures in studying major depressive disorder

    Science.gov (United States)

    Ramezani, Mahdi; Rasoulian, Abtin; Hollenstein, Tom; Harkness, Kate; Johnsrude, Ingrid; Abolmaesumi, Purang

    2014-03-01

    We propose a joint Source-Based Analysis (jSBA) framework to identify brain structural variations in patients with Major Depressive Disorder (MDD). In this framework, features representing position, orientation and size (i.e. pose), shape, and local tissue composition are extracted. Subsequently, simultaneous analysis of these features within a joint analysis method is performed to generate the basis sources that show signi cant di erences between subjects with MDD and those in healthy control. Moreover, in a cross-validation leave- one-out experiment, we use a Fisher Linear Discriminant (FLD) classi er to identify individuals within the MDD group. Results show that we can classify the MDD subjects with an accuracy of 76% solely based on the information gathered from the joint analysis of pose, shape, and tissue composition in multiple brain structures.

  6. Structural design study of a proton beam window for a 1-MW spallation neutron source

    CERN Document Server

    Teraoku, T; Ishikura, S; Kaminaga, M; Maekawa, F; Meigo, S I; Terada, A

    2003-01-01

    A 1-MW spallation neutron source aiming at materials and life science researches will be constructed under the JAERI-KEK High-intensity Proton Accelerator Project (J-PARC). A proton beam passes through a proton beam window, and be injected into a target of the neutron source. The proton beam window functions as a boundary wall between a high vacuum area in the proton beam line and a helium atmosphere at about atmospheric pressure in a helium vessel which contains the target and moderators. The proton beam window is cooled by light water because high heat-density is generated in the window material by interactions with the proton beam. Then, uniformity of the water flow is requested at the window to suppress a hot-spot that causes excessive thermal stress and cooling water boiling. Also, the window has to be strong enough in its structure for inner stress due to water pressure and thermal stress due to heat generation. In this report, we propose two types of proton beam windows; one flat-type that is easy to m...

  7. Diamonds on Diamond: structural studies at extreme conditions on the Diamond Light Source.

    Science.gov (United States)

    McMahon, M I

    2015-03-06

    Extreme conditions (EC) research investigates how the structures and physical and chemical properties of materials change when subjected to extremes of pressure and temperature. Pressures in excess of one million times atmospheric pressure can be achieved using a diamond anvil cell, and, in combination with high-energy, micro-focused radiation from a third-generation synchrotron such as Diamond, detailed structural information can be obtained using either powder or single-crystal diffraction techniques. Here, I summarize some of the research drivers behind international EC research, and then briefly describe the techniques by which high-quality diffraction data are obtained. I then highlight the breadth of EC research possible on Diamond by summarizing four examples from work conducted on the I15 and I19 beamlines, including a study which resulted in the first research paper from Diamond. Finally, I look to the future, and speculate as to the type of EC research might be conducted at Diamond over the next 10 years. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  8. Multiple-source multiple-harmonic active vibration control of variable section cylindrical structures: A numerical study

    Science.gov (United States)

    Liu, Jinxin; Chen, Xuefeng; Gao, Jiawei; Zhang, Xingwu

    2016-12-01

    Air vehicles, space vehicles and underwater vehicles, the cabins of which can be viewed as variable section cylindrical structures, have multiple rotational vibration sources (e.g., engines, propellers, compressors and motors), making the spectrum of noise multiple-harmonic. The suppression of such noise has been a focus of interests in the field of active vibration control (AVC). In this paper, a multiple-source multiple-harmonic (MSMH) active vibration suppression algorithm with feed-forward structure is proposed based on reference amplitude rectification and conjugate gradient method (CGM). An AVC simulation scheme called finite element model in-loop simulation (FEMILS) is also proposed for rapid algorithm verification. Numerical studies of AVC are conducted on a variable section cylindrical structure based on the proposed MSMH algorithm and FEMILS scheme. It can be seen from the numerical studies that: (1) the proposed MSMH algorithm can individually suppress each component of the multiple-harmonic noise with an unified and improved convergence rate; (2) the FEMILS scheme is convenient and straightforward for multiple-source simulations with an acceptable loop time. Moreover, the simulations have similar procedure to real-life control and can be easily extended to physical model platform.

  9. Structure of the sedimentary cover: The S22 cruise 30 L airgun source seismic reflection studies

    Digital Repository Service at National Institute of Oceanography (India)

    Neprochnov, Y.P.; Murthy, K.S.R.; Levchenko, O.V; Milanovsky, V; Basnak, V.V; Buravtsev, A.A.; Rao, T.C.S.; Lakshminarayana, S.

    stream_size 9 stream_content_type text/plain stream_name Mem_Geol_Soc_India_1998_39_112.pdf.txt stream_source_info Mem_Geol_Soc_India_1998_39_112.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  10. Overview of studies on the effect of recycled aggregates sourced from tested cylinders on concrete material and structural properties

    Directory of Open Access Journals (Sweden)

    Bilal Hamad

    2017-01-01

    Full Text Available The paper presents an overview of a two-phase research program that was designed at the American University of Beirut (AUB to investigate the effect of replacing different percentages of natural coarse aggregates (NCA with recycled coarse aggregates (RCA on the properties of the produced concrete. The source of RCA was tested cylinders in batching plants which would help recycling and reusing portion of the waste products of the concrete industry. In the first phase, the fresh and hardened mechanical properties of the produced concrete mix were investigated. The variables were the concrete strength (28 or 60 MPa and the percentage replacement of NCA with RCA from crushed tested cylinders [0 (control, 20, 40, 60, 80, or 100%. Normal strength tested cylinders were used as source of the recycled aggregates for the normal strength concrete (NSC mix and high strength tested cylinders were used for the high strength concrete (HSC mix. Tests included plastic state slump and hardened state mechanical properties including cylinder compressive strength, cylinder splitting tensile strength, modulus of elasticity, and standard beams flexural strength. The results indicated no significant effect on the slump and around 10% average reduction in the hardened mechanical properties for both investigated levels of concrete compressive strength. In the second phase, the structural behavior of normal strength concrete (NSC reinforced concrete beams prepared by replacing different percentages of NCA with RCA from tested concrete cylinders was studied. For each of three modes of failure (flexural, shear, or bond splitting, three beams with different percentages replacement [0 (control, 40, or 100 percent] were tested. One replicate was prepared for each beam to validate the test results. Results indicated no significant difference in the ultimate load reached or load-deflection behavior that could be related to the percentage replacement of NCA with RCA.

  11. Learning the Semantics of Structured Data Sources

    Science.gov (United States)

    Taheriyan, Mohsen

    2015-01-01

    Information sources such as relational databases, spreadsheets, XML, JSON, and Web APIs contain a tremendous amount of structured data, however, they rarely provide a semantic model to describe their contents. Semantic models of data sources capture the intended meaning of data sources by mapping them to the concepts and relationships defined by a…

  12. Resonant ionization by laser beams: application to ions sources and to study the nuclear structure of radioactive tellurium isotopes

    International Nuclear Information System (INIS)

    Sifi, R.

    2007-07-01

    The radioactive ion beams that are produced through current isotope separators are well separated according to the A mass but not according to the Z parameter. The resonant ionization through laser beams applied to ion sources allows the production of radioactive ion beam in a very selective and efficient way by eliminating the isobaric contamination. The first chapter is dedicated to the resonant ionization by laser beams, we describe the principle, the experimental setting, the lasers used, the ionization schemes and the domain of application. The second chapter deals with the application of resonant ionization to laser ion sources for the production of radioactive ion beams. We present experimental tests performed for getting copper ion beams. Resonant ionization through laser is also used in the spectroscopy experiments performed at the Isolde (isotope separation on-line device) installation in CERN where more than 20 elements are ionized very efficiently. The technique is based on a frequency scanning around the excitation transition of the atoms in order to probe the hyperfine structure. Laser spectroscopy allows the determination of the hyperfine structure as well as the isotopic shift of atoms. In the third chapter the method is applied to the spectroscopy of tellurium atoms. First, we define the 2 parameters on which the extraction is based: charge radius and nuclear moments, then we present several theoretical models that we have used to assess our experimental results. (A.C.)

  13. Particle reacceleration and apparent radio source structure

    International Nuclear Information System (INIS)

    Eilek, J.A.

    1982-01-01

    The radio galaxy model which uses magnetohydrodynamic turbulence generated by surface instabilities to reaccelerate the radiating electrons has striking consequences for apparent source structure. Strong wave damping in the plasma results in a narrow turbulent edge. Particles accelerated in this edge must diffuse across field lines into the radio source; this predicts strong limb brightening in some cases. The structure of this edge and diffusion into the source are described. The relevance of this model to jets, radio tails, and standard double sources is discussed

  14. Bio-functions and molecular carbohydrate structure association study in forage with different source origins revealed using non-destructive vibrational molecular spectroscopy techniques.

    Science.gov (United States)

    Ji, Cuiying; Zhang, Xuewei; Yan, Xiaogang; Mostafizar Rahman, M; Prates, Luciana L; Yu, Peiqiang

    2017-08-05

    The objectives of this study were to: 1) investigate forage carbohydrate molecular structure profiles; 2) bio-functions in terms of CHO rumen degradation characteristics and hourly effective degradation ratio of N to OM (HED N/OM ), and 3) quantify interactive association between molecular structures, bio-functions and nutrient availability. The vibrational molecular spectroscopy was applied to investigate the structure feature on a molecular basis. Two sourced-origin alfalfa forages were used as modeled forages. The results showed that the carbohydrate molecular structure profiles were highly linked to the bio-functions in terms of rumen degradation characteristics and hourly effective degradation ratio. The molecular spectroscopic technique can be used to detect forage carbohydrate structure features on a molecular basis and can be used to study interactive association between forage molecular structure and bio-functions. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Thermal neutron source study

    International Nuclear Information System (INIS)

    Holden, T.M.

    1983-05-01

    The value of intense neutron beams for condensed matter research is discussed with emphasis on the complementary nature of steady state and pulsed neutron sources. A large body of information on neutron sources, both existing and planned, is then summarized under four major headings: fission reactors, electron accelerators with heavy metal targets, pulsed spallation sources and 'steady state' spallation sources. Although the cost of a spallation source is expected to exceed that of a fission reactor of the same flux by a factor of two, there are significant advantages for a spallation device such as the proposed Electronuclear Materials Test Facility (EMTF)

  16. Fine structure of 25 extragalactic radio sources

    International Nuclear Information System (INIS)

    Wittels, J.J.; Knight, C.A.; Shapiro, I.I.; Hinteregger, H.F.; Rogers, A.E.E.; Whitney, A.R.; Clark, T.A.; Hutton, L.K.; Marandino, G.E.; Neill, A.E.; Ronnang, B.G.; Rydbeck, O.E.H.; Klemperer, W.K.; Warnock, W.W.

    1975-01-01

    Between 1972 April and 1973 May, 25 extragalactic radio sources were observed interferometrically at 7.8 GHz(lambdaapprox. =3.8 cm) with five pairings of antennas. These sources exhibit a broad variety of fine structures from very simple to complex. Although the structure and the total power of some of these sources have remained unchanged within the sensitivity of our measurements during the year of observations, both the total flux and the correlated flux of others have undergone large changes in a few weeks

  17. Development of cold source moderator structure

    International Nuclear Information System (INIS)

    Aso, Tomokaze; Ishikura, Syuichi; Terada, Atsuhiko; Teshigawara, Makoto; Watanabe, Noboru; HIno, Ryutaro

    1999-01-01

    The cold and thermal neutrons generated at the target (which works as a spallation neutron source under a 5MW proton beam condition) is filtered with cold source moderators using supercritical hydrogen. Preliminary structural analysis was carried out to clarify technical problems on the concept of the thin-walled structure for the cold source moderator. Structural analytical results showed that the maximum stress of 1 12MPa occurred on the moderator surface, which exceeded the allowable design stresses of ordinary aluminum alloys. Flow patterns measured by water flow experiments agreed well with hydraulic analytical results, which showed that an impinging jet flow from an inner pipe of the moderator caused a recirculation flow on a large scale. Based on analytical and experimental results, new moderator structures with minute frames, blowing flow holes etc. were proposed to keep its strength and to suppress the recirculation flow. (author)

  18. The impacts of source structure on geodetic parameters demonstrated by the radio source 3C371

    Science.gov (United States)

    Xu, Ming H.; Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Karbon, Maria; Schuh, Harald; Wang, Guang L.

    2017-07-01

    Closure quantities measured by very-long-baseline interferometry (VLBI) observations are independent of instrumental and propagation instabilities and antenna gain factors, but are sensitive to source structure. A new method is proposed to calculate a structure index based on the median values of closure quantities rather than the brightness distribution of a source. The results are comparable to structure indices based on imaging observations at other epochs and demonstrate the flexibility of deriving structure indices from exactly the same observations as used for geodetic analysis and without imaging analysis. A three-component model for the structure of source 3C371 is developed by model-fitting closure phases. It provides a real case of tracing how the structure effect identified by closure phases in the same observations as the delay observables affects the geodetic analysis, and investigating which geodetic parameters are corrupted to what extent by the structure effect. Using the resulting structure correction based on the three-component model of source 3C371, two solutions, with and without correcting the structure effect, are made. With corrections, the overall rms of this source is reduced by 1 ps, and the impacts of the structure effect introduced by this single source are up to 1.4 mm on station positions and up to 4.4 microarcseconds on Earth orientation parameters. This study is considered as a starting point for handling the source structure effect on geodetic VLBI from geodetic sessions themselves.

  19. Tracking the source of mineralisation in the Tampere Basin (southern Finland), insights from structure, sedimentology and geophysics studies

    DEFF Research Database (Denmark)

    Moreau, Julien; Torvela, Taija; Kalliomäki, Henrik

    2013-01-01

    The ancient basins are of a wide interest to geoscientists as they archive the early development of plate tectonics, life, and ore-bearing systems. Several basins, especially those involving volcanic-derived materials, contain ore and mineral deposits. The formation of these ores is often related...... marginal basin, and the mechanics of and strain distribution during its subsequent closure. In order to investigate the deposition, the tectonic deformation and the fluid migration, geological mapping of a key area of the basin has been performed. In addition, georadar reflection profiles have been...... covered. This study highlighted several sulphide-rich horizon within the basal succession of the basin infill. The sulphides are either in relation with tectonic structures or with genuinely clay-rich deposits. The studied succession shows a progressive deepening of the basin through time with facies...

  20. Cold source economic study

    International Nuclear Information System (INIS)

    Fuster, Serge.

    1975-01-01

    This computer code is intended for the statement of the general economic balance resulting from using a given cold source. The balance includes the investments needed for constructing the various materials, and also production balances resulting from their utilization. The case of either using an open circuit condenser on sea or river, or using air cooling systems with closed circuits or as auxiliaries can be dealt with. The program can be used to optimize the characteristics of the various parts of the cold source. The performance of the various materials can be evaluated for a given situation from using very full, precise economic balances, these materials can also be classified according to their possible uses, the outer constraints being taken into account (limits for heat disposal into rivers or seas, water temperature, air temperature). Technical choices whose economic consequences are important have been such clarified [fr

  1. Duopigatron ion source studies

    International Nuclear Information System (INIS)

    Bacon, F.M.; Bickes, R.W. Jr.; O'Hagan, J.B.

    1978-07-01

    Ion source performance characteristics consisting of total ion current, ion energy distribution, mass distribution, and ion current density distribution were measured for several models of a duopigatron. Variations on the duopigatron design involved plasma expansion cup material and dimensions, secondary cathode material, and interelectrode spacings. Of the designs tested, the one with a copper and molybdenum secondary cathode and a mild steel plasma expansion cup proved to give the best results. The ion current density distribution was peaked at the center of the plasma expansion cup and fell off to 80 percent of the peak value at the cup wall for a cup 15.2 mm deep. A total ion current of 180 mA consisting of 60 to 70 percent atomic ions was produced with an arc current of 20 A and source pressure of 9.3 Pa. More shallow cups produced a larger beam current and a more sharply peaked ion current density distribution. Typical ion energy distributions were bell-shaped curves with a peak 10 to 20 V below anode potential and with ion energies extending 30 to 40 V on either side of the peak

  2. Robust photometric stereo using structural light sources

    Science.gov (United States)

    Han, Tian-Qi; Cheng, Yue; Shen, Hui-Liang; Du, Xin

    2014-05-01

    We propose a robust photometric stereo method by using structural arrangement of light sources. In the arrangement, light sources are positioned on a planar grid and form a set of collinear combinations. The shadow pixels are detected by adaptive thresholding. The specular highlight and diffuse pixels are distinguished according to their intensity deviations of the collinear combinations, thanks to the special arrangement of light sources. The highlight detection problem is cast as a pattern classification problem and is solved using support vector machine classifiers. Considering the possible misclassification of highlight pixels, the ℓ1 regularization is further employed in normal map estimation. Experimental results on both synthetic and real-world scenes verify that the proposed method can robustly recover the surface normal maps in the case of heavy specular reflection and outperforms the state-of-the-art techniques.

  3. The contribution of Diamond Light Source to the study of strongly correlated electron systems and complex magnetic structures.

    Science.gov (United States)

    Radaelli, P G; Dhesi, S S

    2015-03-06

    We review some of the significant contributions to the field of strongly correlated materials and complex magnets, arising from experiments performed at the Diamond Light Source (Harwell Science and Innovation Campus, Didcot, UK) during the first few years of operation (2007-2014). We provide a comprehensive overview of Diamond research on topological insulators, multiferroics, complex oxides and magnetic nanostructures. Several experiments on ultrafast dynamics, magnetic imaging, photoemission electron microscopy, soft X-ray holography and resonant magnetic hard and soft X-ray scattering are described. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  4. Impact source localisation in aerospace composite structures

    Science.gov (United States)

    De Simone, Mario Emanuele; Ciampa, Francesco; Boccardi, Salvatore; Meo, Michele

    2017-12-01

    The most commonly encountered type of damage in aircraft composite structures is caused by low-velocity impacts due to foreign objects such as hail stones, tool drops and bird strikes. Often these events can cause severe internal material damage that is difficult to detect and may lead to a significant reduction of the structure’s strength and fatigue life. For this reason there is an urgent need to develop structural health monitoring systems able to localise low-velocity impacts in both metallic and composite components as they occur. This article proposes a novel monitoring system for impact localisation in aluminium and composite structures, which is able to determine the impact location in real-time without a-priori knowledge of the mechanical properties of the material. This method relies on an optimal configuration of receiving sensors, which allows linearization of well-known nonlinear systems of equations for the estimation of the impact location. The proposed algorithm is based on the time of arrival identification of the elastic waves generated by the impact source using the Akaike Information Criterion. The proposed approach was demonstrated successfully on both isotropic and orthotropic materials by using a network of closely spaced surface-bonded piezoelectric transducers. The results obtained show the validity of the proposed algorithm, since the impact sources were detected with a high level of accuracy. The proposed impact detection system overcomes current limitations of other methods and can be retrofitted easily on existing aerospace structures allowing timely detection of an impact event.

  5. Lattice Study for the Taiwan Photon Source

    CERN Document Server

    Kuo, Chin-Cheng; Chen Chien Te; Luo, Gwo-Huei; Tsai, Hung-Jen; Wang, Min-Huey

    2005-01-01

    The feasibility study for the new 3.0~3.3 GeV Taiwan synchrotron light source, dubbed Taiwan Photon Source, was initiated in July, 2004. The goal is to construct a high performance light source with extremely bright X-ray in complementary to the existing 1.5 GeV light source in Taiwan. The ring circumference is 518.4 m and a 24-cell DBA lattice structure is chosen. The natural emittance with distributed dispersion is less than 2 nm-rad. A large booster ring of 499.2 m sharing the storage ring tunnel will be adopted.

  6. X-ray structural study of Ge(001):Te 1x1 performed at the advanced photon source. Current status of the surface-interface structure beamline at SPring-8

    CERN Document Server

    Sakata, O

    2002-01-01

    This article is composed of two parts. In the first half, we describe a study that we performed at 5ID-C of the Dupont- Northwestern University-Dow (DND) CAT in the Advanced Photon Source, the Argonne National Laboratory for 1998 to 2000. A surface structure of Ge(001):Te 1x1 was determined by least-squares fits of x-ray scattered intensities with calculations based on some surface atomic structural models. The fitted structural model has a characteristic that a direction of a Ge-Ge dimer bond on the first Ge atomic layer is perpendicular to a Te missing row. It was distinct from those based on first-principles total energy calculations. In the second half, we introduce up-to-the-minute status of BL13XU for surface-interface structural studies at SPring-8. Scientific research goals we desire are mentioned as well. (author)

  7. The Source of Tok Pisin Structures.

    Science.gov (United States)

    Goulden, Rick J.

    1989-01-01

    The source of the similarities and differences produced by pidginization is a central question studied in Pidgin-Creole linguistics. Several explanatory approaches are discussed that have guided research in this area, including simplification, substratum, independent innovation, and universals. (27 references) (Author/OD)

  8. Study on energy demand function of korea considering replacement among energy sources and the structural changes of demand behavior

    Energy Technology Data Exchange (ETDEWEB)

    Moon, C.K. [Korea Energy Economics Institute, Euiwang (Korea, Republic of)

    1997-08-01

    If the necessity of careful study on energy function is mentioned, it should be stressed that energy investment not only needs a long gestation period but also, acts as the bottleneck in the production capacity of an economy when investment is not enough. Thereby, the adverse effect of an energy supply shortage is very big. Especially, the replacement/supplemental relationship between energy and capital which corresponds to the movement on the iso-quanta curve is believed to have a direct relation with the answer as to whether long-term economic development would be possible under an energy crisis and its influence on technology selection. Furthermore, the advantages of technological advances which correspond to the movement on the iso-quanta curve has a direct relation with the question whether long-term economic development would be possible under an energy crisis depending on whether its direction is toward energy-saving or energy-consuming. This study tackles the main issues and outlines of the quantitative approach method based on the accounting approach method for modeling energy demand, quantitative economics approach method, and production model. In order to model energy demand of the Korean manufacturing industry, related data was established and a positive analytical model is completed and presented based on these. 122 refs., 10 tabs.

  9. Structural materials for fusion and spallation sources

    International Nuclear Information System (INIS)

    Cottrell, G.A.; Baker, L.J.

    2003-01-01

    Experimental investigation of neutron-induced irradiation damage in structural materials is fundamental to the development of magnetic confinement fusion. Proposals for the testing of candidate materials are described, indicating that a period of at least 10 years will elapse before a suitable high neutron fluence fusion test facility becomes available. In this circumstance, the possibility that neutron spallation sources could be exploited to shorten the time-scale of fusion materials development is attractive. Although fusion displacement and transmutation reaction rates can be replicated in spallation sources, there are significant differences arising from the harder neutron spectra and the presence of energetic protons. These differences, including higher energy PKA, electron heating effects, transmutation rates and pulsing are described and their consequences discussed, together with the concomitant development of theoretical models, needed to understand the effects. It is concluded that spallation source experiments could make a significant contribution to the database required for the validation of theoretical models, and hence reduce the time scale of fusion materials development

  10. Dynamical structure of hadron emission sources

    CERN Document Server

    Zhao Xi; Zhao Shu Song

    2000-01-01

    NA22 experimental data of the triplet seagull effects show that the Doppler effects of hadron emission sources exist exactly in hadron- hadron collisions. Every source possesses the same average energy (CMS) approximately. The collective seagull effects can be also explained by the (aQ)/sup nu /K/sub nu / (aQ) distributions (generalized functions). The dynamical structure of a hadron emission source is described by the (aQ)/sup nu /K/sub nu / (aQ) distributions. The anomalous dimensions of the pionic quantum fields are gamma /sub B/(g/sub R/)=-0.045+or-0.012, which control the singularities of the production amplitude in quantum field theory. The mathematical parameter epsilon =4-D (the dimension D of space time) in the Feynman integrals can be replaced by the anomalous gamma /sub B/(g/sub R/) of the quantum fields for the regularization. (-2 gamma /sub B/(g/sub R/) to or from epsilon /2=1/ln( Lambda /sup 2//m /sup 2/) Lambda to infinity ). (26 refs).

  11. Dynamical structure of hadron emission sources

    International Nuclear Information System (INIS)

    Zhao Xi; Huang Bangrong; Zhao Shusong

    2000-01-01

    NA22 experimental data of the triplet seagull effects show that the Doppler effects of the hadron emission sources exist exactly in the hadron-hadron collisions. Every source possesses the same average energy (CMS) approximately. The collective seagull effects can be also explained by the (aQ) ν K ν (aQ) distributions (Generalized functions). The dynamical structure of a hadron emission source is described by the (aQ) ν K ν (aQ) distributions. The anomalous dimensions of the pionic quantum fields are γ B (g R ) = - 0.045 +- 0.012, which control the singularities of the production amplitude in quantum field theory. The mathematical parameter ε = 4-D (the dimension D of space time) in the Feynman integrals can be replaced by the anomalous γ B (g R ) of the quantum fields for the regularization. (-2γ B (g R )↔ε/2 1/ln(Λ 2 /m 2 )Λ→∞)

  12. Integrated geophysical investigations for the delineation of source and subsurface structure associated with hydro-uranium anomaly: A case study from South Purulia Shear Zone (SPSZ), India

    Science.gov (United States)

    Sharma, S. P.; Biswas, A.

    2012-12-01

    South Purulia Shear Zone (SPSZ) is an important region for prospecting of uranium mineralization. Geological studies and hydro-uranium anomaly suggest the presence of Uranium deposit around Raghunathpur village which lies about 8 km north of SPSZ. However, detailed geophysical investigations have not been carried out in this region for investigation of uranium mineralization. Since surface signature of uranium mineralization is not depicted near the location, a deeper subsurface source is expected for hydro uranium anomaly. To delineate the subsurface structure and to investigate the origin of hydro-uranium anomaly present in the area, Vertical Electrical Sounding (VES) using Schlumberger array and Gradient Resistivity Profiling (GRP) were performed at different locations along a profile perpendicular to the South Purulia Shear Zone. Apparent resistivity computed from the measured sounding data at various locations shows a continuously increasing trend. As a result, conventional apparent resistivity data is not able to detect the possible source of hydro uranium anomaly. An innovative approach is applied which depicts the apparent conductivity in the subsurface revealed a possible connection from SPSZ to Raghunathpur. On the other hand resistivity profiling data suggests a low resistive zone which is also characterized by low Self-Potential (SP) anomaly zone. Since SPSZ is characterized by the source of uranium mineralization; hydro-uranium anomaly at Raghunathpur is connected with the SPSZ. The conducting zone has been delineated from SPSZ to Raghunathpur at deeper depths which could be uranium bearing. Since the location is also characterized by a low gravity and high magnetic anomaly zone, this conducting zone is likely to be mineralized zone. Keywords: Apparent resistivity; apparent conductivity; Self Potential; Uranium mineralization; shear zone; hydro-uranium anomaly.

  13. Source and LINAC3 studies

    CERN Document Server

    Bellodi, G

    2017-01-01

    In the framework of the LHC Ion Injector Upgrade pro-gramme (LIU), several activities have been carried out in2016 to improve the ion source and Linac3 performance,with the goal to increase the beam current routinely deliv-ered to LEIR. The extraction region of the GTS-LHC ionsource was upgraded with enlarged vacuum chamber aper-tures and the addition of an einzel lens, yielding highertransmission through the rest of the machine. Also, a seriesof experiments have been performed to study the effects ofdouble frequency mixing on the afterglow performance ofthe source after installation of a Travelling Wave Tube Am-plifier (TWTA) as secondary microwave source at variablefrequency. Measurements have been carried out at a dedi-cated oven test stand for better understanding of the ionsource performance. Finally, several MD sessions werededicated to the study and characterization of the strippingfoils, after evidence of degradation in time was discoveredin the 2015 run.

  14. Advanced Neutron Source enrichment study

    International Nuclear Information System (INIS)

    Bari, R.A.; Ludewig, H.; Weeks, J.R.

    1996-01-01

    A study has been performed of the impact on performance of using low-enriched uranium (20% 235 U) or medium-enriched uranium (35% 235 U) as an alternative fuel for the Advanced Neutron Source, which was initially designed to use uranium enriched to 93% 235 U. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fuel at increasing material density was specifically addressed by a panel of international experts on research reactor fuels. The most viable alternative designs for the reactor at lower enrichments were identified and discussed. Several sensitivity analyses were performed to gain an understanding of the performance of the reactor at parametric values of power, fuel density, core volume, and enrichment that were interpolations between the boundary values imposed on the study or extrapolations from known technology

  15. Analysis of the Structure Ratios of the Funding Sources

    Directory of Open Access Journals (Sweden)

    Maria Daniela Bondoc

    2014-06-01

    Full Text Available The funding sources of the assets and liabilities in the balance sheet include equity capitals and the debts of the entity. The analysis of the structure rates of the funding sources allows for making assessments related to the funding policy, highlighting the financial autonomy and how resources are provided. Using the literature specializing in economic and financial analysis, this paper aims at presenting these rates that focus, on the one hand, to reflect the degree of financial dependence (the rate of financial stability, the rate of global financial autonomy, the rate of on-term financial autonomy and on the other hand the debt structure (the rate of short-term debts, the global indebtedness rate, the on-term indebtedness rate. Based on the financial statements of an entity in the Argeş County, I analysed these indicators, and I drew conclusions and made assessments related to the autonomy, indebtedness and financial stability of the studied entity.

  16. International seminar on structural investigations on pulsed neutron sources. Proceedings

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.; Taran, Yu.V.

    1993-01-01

    The proceedings of the International seminar on structural investigations using pulsed neutron sources are presented. The seminar is dedicated to the memory of Dr. Yu.M. Ostanevich, a world acknowledged physicist. The problems of structural analysis using pulsed neutron source at the IBR-2 reactor are discussed

  17. Data sources on landscape structure in a highly industrialized area

    Directory of Open Access Journals (Sweden)

    Mazurek Kinga

    2015-03-01

    Full Text Available Landscape may be described as a part of space characterized by a certain physiognomy, which is a dynamic system subject to evolution. An important factor influencing the type and condition of the landscape is human activity which shapes or rebuilds its structure. Interesting results may be obtained on comparison of archival cartographic materials with contemporary studies and zoning plans. The Upper Silesian Coal Basin is a region with a clearly transformed landscape. The determinant of the geographical environment transformation here is the anthropogenic factor. The study area includes the upper part of the Kłodnica catchment (229.6 sq km. The study is a review, and its aim is to systematize data sources used in the research on the transformation of landscape structure of a heavily industrialized area. In the first half of the nineteenth century created the "Urmesstischblätter" in the scale of 1:25 000. Afterwards preparations began to take new topographic images of the country (the "Messtischblätter". In the 1990s initiated the development of a new topographic map (in the scale of 1:10 000. Recent data source is for example the project CORINE Land Cover 2006. There are many of various sources of data on land cover. An important aspect is the proper selection of documents and maps, and their proper interpretation.

  18. The importance of source positions during radio fine structure observations

    International Nuclear Information System (INIS)

    Chernov, Guennadi P.; Yan Yi-Hua; Fu Qi-Jun

    2014-01-01

    The measurement of positions and sizes of radio sources in the observations of the fine structure of solar radio bursts is a determining factor for the selection of the radio emission mechanism. The identical parameters describing the radio sources for zebra structures (ZSs) and fiber bursts confirm there is a common mechanism for both structures. It is very important to measure the size of the source in the corona to determine if it is distributed along the height or if it is point-like. In both models of ZSs (the double plasma resonance (DPR) and the whistler model) the source must be distributed along the height, but by contrast to the stationary source in the DPR model, in the whistler model the source should be moving. Moreover, the direction of the space drift of the radio source must correlate with the frequency drift of stripes in the dynamic spectrum. Some models of ZSs require a local source, for example, the models based on the Bernstein modes, or on explosive instability. The selection of the radio emission mechanism for fast broadband pulsations with millisecond duration also depends on the parameters of their radio sources. (mini-volume: solar radiophysics — recent results on observations and theories)

  19. Radiation studies in the antiproton source

    International Nuclear Information System (INIS)

    Church, M.

    1990-01-01

    Experiment E760 has a lead glass (Pb-G) calorimeter situated in the antiproton source tunnel in the accumulator ring at location A50. This location is exposed to radiation from several sources during antiproton stacking operations. A series of radiation studies has been performed over the last two years to determine the sources of this radiation and as a result, some shielding has been installed in the antiproton source in order to protect the lead glass from radiation damage

  20. ACToR Chemical Structure processing using Open Source ...

    Science.gov (United States)

    ACToR (Aggregated Computational Toxicology Resource) is a centralized database repository developed by the National Center for Computational Toxicology (NCCT) at the U.S. Environmental Protection Agency (EPA). Free and open source tools were used to compile toxicity data from over 1,950 public sources. ACToR contains chemical structure information and toxicological data for over 558,000 unique chemicals. The database primarily includes data from NCCT research programs, in vivo toxicity data from ToxRef, human exposure data from ExpoCast, high-throughput screening data from ToxCast and high quality chemical structure information from the EPA DSSTox program. The DSSTox database is a chemical structure inventory for the NCCT programs and currently has about 16,000 unique structures. Included are also data from PubChem, ChemSpider, USDA, FDA, NIH and several other public data sources. ACToR has been a resource to various international and national research groups. Most of our recent efforts on ACToR are focused on improving the structural identifiers and Physico-Chemical properties of the chemicals in the database. Organizing this huge collection of data and improving the chemical structure quality of the database has posed some major challenges. Workflows have been developed to process structures, calculate chemical properties and identify relationships between CAS numbers. The Structure processing workflow integrates web services (PubChem and NIH NCI Cactus) to d

  1. Study on structural integrity in box structures

    International Nuclear Information System (INIS)

    Asano, Masayuki; Ueta, Masahiro; Kanaoka, Tadashi; Ikeuchi, Toshiaki; Kodama, Tetsuhiro.

    1991-01-01

    This study was carried out to give an experimental foundation to the structural integrity of a box structure. Crack growth tests were performed on the reduced scale models, simulating typical portions of the box structure, in air at room temperature. The results show that the amount of crack growth is too small to injure the structural integrity of the models for the postulated loading cycle, and make clear the effective structure against crack growth. (author)

  2. Study of the 137Cs Stabilizer Source

    Directory of Open Access Journals (Sweden)

    GAO Yan;WANG Yan-ling;XU Zhi-jian;XU Liang;REN Chun-xia;TAN Xiao-ming;CUI Hong-qi

    2014-02-01

    Full Text Available The attenuation laws of the Cesium -137 γ-ray penetrating the ceramic core、stainless steel and tungsten steel were studied. The radioactivity of the 137Cs stabilizer source was determined through the surface dose rate of 137Cs stabilizer sources. In addition, the adsorption properties of the ceramic core were studied to improve the stability of the output rate, and established a production line. The application results showed that the output rate of ray source was accurate and was of a good consistency. At present, the source had been used in logging lithology, and achieved the realization of domestic product.

  3. Semiempirical studies of atomic structure

    International Nuclear Information System (INIS)

    Curtis, L.J.

    1992-01-01

    The energy level structure, transition probabilities, and general spectroscopic properties of highly ionized many-electron systems are studied through the combined use of sensitive semiempirical data systematizations, selected precision experimental measurements, and specialized theoretical computations. Measurements are made primarily through the use of fast ion beam excitation methods, which are combined with available data from laser-and tokamak-produced plasmas, astrophysical sources, and conventional light sources. The experimental studies are strengthened through large-scale ab initio calculations. Typical examples are the following: lifetime measurements in the neon isoelectronic sequence; multiplexed decay curve measurements of Li-like Si XII; and isoelectronic specification of intershell resonance and intercombination decay rates using measured transition probabilities and spectroscopically determined singlet-mixing amplitudes

  4. MODEL OF A PERSONWALKING AS A STRUCTURE BORNE SOUND SOURCE

    DEFF Research Database (Denmark)

    Lievens, Matthias; Brunskog, Jonas

    2007-01-01

    has to be considered and the contact history must be integrated in the model. This is complicated by the fact that nonlinearities occur at different stages in the system either on the source or receiver side. ot only lightweight structures but also soft floor coverings would benefit from an accurate...

  5. Magnetic field structures in active compact radio sources

    International Nuclear Information System (INIS)

    Jones, T.W.; Rudnick, L.; Fiedler, R.L.; Aller, H.D.; Aller, M.F.; Hodge, P.E.

    1985-01-01

    The analysis of simultaneous multifrequency linear polarimetry data between 1.4 GHz and 90 GHz for about 20 active, compact radio sources at six epochs from 1977 December 10 1980 July is presented. In addition, monthly 8 Ghz polarization data on the same sources were examined. The general polarization characteristics of these sources can be well described in terms of magnetic fields which are largely turbulent and slightly anisotropic. The magnetic field symmetry axes are generally aligned with the source structural axes on the milli-arcsecond scale (OJ 287 is a notable exception.) Monte Carlo calculations indicate that observed polarization variations and in particular rotator polarization events can be produced in this model as a consequence of random walks generated through evolution of the turbulent magnetic field. 43 references

  6. Statistical studies of powerful extragalactic radio sources

    Energy Technology Data Exchange (ETDEWEB)

    Macklin, J T

    1981-01-01

    This dissertation is mainly about the use of efficient statistical tests to study the properties of powerful extragalactic radio sources. Most of the analysis is based on subsets of a sample of 166 bright (3CR) sources selected at 178 MHz. The first chapter is introductory and it is followed by three on the misalignment and symmetry of double radio sources. The properties of nuclear components in extragalactic sources are discussed in the next chapter, using statistical tests which make efficient use of upper limits, often the only available information on the flux density from the nuclear component. Multifrequency observations of four 3CR sources are presented in the next chapter. The penultimate chapter is about the analysis of correlations involving more than two variables. The Spearman partial rank correlation coefficient is shown to be the most powerful test available which is based on non-parametric statistics. It is therefore used to study the dependences of the properties of sources on their size at constant redshift, and the results are interpreted in terms of source evolution. Correlations of source properties with luminosity and redshift are then examined.

  7. Trade, Industry Structure and Different Sources of Firm-heterogeneity

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Jørgensen, Jan Guldager

    Recently the workhorse model of intra-industry trade has been augmented with heterogeneous cost structures at the firm level. In principle there exist various sources of heterogeneity, yet the literature appears -- for convenience or other reasons -- to settle on marginal cost heterogeneity...... as the preferred modelling device. The present paper develops a unified model framework allowing a systematic comparison of marginal and fixed cost heterogeneity. We find that both types of heterogeneity are in fact able to capture the central stylized facts of international trade. For example can either source...

  8. Rotationally symmetric structure in two extragalactic radio sources

    International Nuclear Information System (INIS)

    Lonsdale, C.J.; Morison, I.

    1980-01-01

    The new multi-telescope radio-linked interferometer (MTRLI) at Jodrell Bank was used during January and February 1980 at a frequency of 408 MHz to map the extragalactic radio sources 3C196 and 3C305 with a resolution of approximately 1 arc s. It is shown here that both the markedly symmetric structures observed and the spectral index distributions inferred from comparisons with previously published 5 GHz maps provide evidence for the source axes having rotated during the lifetime of the emitting regions. (U.K.)

  9. THE SOURCE STRUCTURE OF 0642+449 DETECTED FROM THE CONT14 OBSERVATIONS

    International Nuclear Information System (INIS)

    Xu, Ming H.; Wang, Guang L.; Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Schuh, Harald

    2016-01-01

    The CONT14 campaign with state-of-the-art very long baseline interferometry (VLBI) data has observed the source 0642+449 with about 1000 observables each day during a continuous observing period of 15 days, providing tens of thousands of closure delays—the sum of the delays around a closed loop of baselines. The closure delay is independent of the instrumental and propagation delays and provides valuable additional information about the source structure. We demonstrate the use of this new “observable” for the determination of the structure in the radio source 0642+449. This source, as one of the defining sources in the second realization of the International Celestial Reference Frame, is found to have two point-like components with a relative position offset of −426 microarcseconds ( μ as) in R.A. and −66 μ as in decl. The two components are almost equally bright, with a flux-density ratio of 0.92. The standard deviation of closure delays for source 0642+449 was reduced from 139 to 90 ps by using this two-component model. Closure delays larger than 1 ns are found to be related to the source structure, demonstrating that structure effects for a source with this simple structure could be up to tens of nanoseconds. The method described in this paper does not rely on a priori source structure information, such as knowledge of source structure determined from direct (Fourier) imaging of the same observations or observations at other epochs. We anticipate our study to be a starting point for more effective determination of the structure effect in VLBI observations.

  10. THE SOURCE STRUCTURE OF 0642+449 DETECTED FROM THE CONT14 OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ming H.; Wang, Guang L. [Shanghai Astronomical Observatory, Chinese Academy of Sciences, No. 80 Nandan Raod, 200030, Shanghai (China); Heinkelmann, Robert; Anderson, James M.; Mora-Diaz, Julian; Schuh, Harald, E-mail: mhxu@shao.ac.cn [DeutschesGeoForschungsZentrum (GFZ), Potsdam, Telegrafenberg, D-14473 Potsdam (Germany)

    2016-11-01

    The CONT14 campaign with state-of-the-art very long baseline interferometry (VLBI) data has observed the source 0642+449 with about 1000 observables each day during a continuous observing period of 15 days, providing tens of thousands of closure delays—the sum of the delays around a closed loop of baselines. The closure delay is independent of the instrumental and propagation delays and provides valuable additional information about the source structure. We demonstrate the use of this new “observable” for the determination of the structure in the radio source 0642+449. This source, as one of the defining sources in the second realization of the International Celestial Reference Frame, is found to have two point-like components with a relative position offset of −426 microarcseconds ( μ as) in R.A. and −66 μ as in decl. The two components are almost equally bright, with a flux-density ratio of 0.92. The standard deviation of closure delays for source 0642+449 was reduced from 139 to 90 ps by using this two-component model. Closure delays larger than 1 ns are found to be related to the source structure, demonstrating that structure effects for a source with this simple structure could be up to tens of nanoseconds. The method described in this paper does not rely on a priori source structure information, such as knowledge of source structure determined from direct (Fourier) imaging of the same observations or observations at other epochs. We anticipate our study to be a starting point for more effective determination of the structure effect in VLBI observations.

  11. Neutron diffractometers for structural biology at spallation neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Schoenborn, B.P.; Pitcher, E. [Los Alamos National Laboratory, NM (United States)

    1994-12-31

    Spallation neutron sources are ideal for diffraction studies of proteins and oriented molecular complexes. With spoliation neutrons and their time dependent wavelength structure, it is easy to electronically select data with an optimal wavelength bandwidth and cover the whole Laue spectrum as time (wavelength) resolved snapshots. This optimized data quality with best peak-to-background ratios and provides adequate spatial and energy resolution to eliminate peak overlaps. The application of this concept will use choppers to select the desired Laue wavelength spectrum and employ focusing optics and large cylindrical {sup 3}He detectors to optimize data collection rates. Such a diffractometer will cover a Laue wavelength range from 1 to 5{Angstrom} with a flight path length of 10m and an energy resolution of 0.25{Angstrom}. Moderator concepts for maximal flux distribution within this energy range will be discussed using calculated flux profiles. Since the energy resolution required for such timed data collection in this super Laue techniques is not very high, the use of a linac only (LAMPF) spoliation target is an exciting possibility with an order of magnitude increase in flux.

  12. Neutron diffractometers for structural biology at spallation neutron sources

    International Nuclear Information System (INIS)

    Schoenborn, B.P.; Pitcher, E.

    1994-01-01

    Spallation neutron sources are ideal for diffraction studies of proteins and oriented molecular complexes. With spoliation neutrons and their time dependent wavelength structure, it is easy to electronically select data with an optimal wavelength bandwidth and cover the whole Laue spectrum as time (wavelength) resolved snapshots. This optimized data quality with best peak-to-background ratios and provides adequate spatial and energy resolution to eliminate peak overlaps. The application of this concept will use choppers to select the desired Laue wavelength spectrum and employ focusing optics and large cylindrical 3 He detectors to optimize data collection rates. Such a diffractometer will cover a Laue wavelength range from 1 to 5 Angstrom with a flight path length of 10m and an energy resolution of 0.25 Angstrom. Moderator concepts for maximal flux distribution within this energy range will be discussed using calculated flux profiles. Since the energy resolution required for such timed data collection in this super Laue techniques is not very high, the use of a linac only (LAMPF) spoliation target is an exciting possibility with an order of magnitude increase in flux

  13. Modified multipole structure for electron cyclotron resonance ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Suominen, P.

    2006-07-01

    Highly-charged heavy-ion beams are usually produced with Electron Cyclotron Resonance Ion Sources (ECRIS) where the microwave heated plasma is confined in a strong magnetic field. The magnetic field is divided into an axial part (produced by solenoid magnets) and to a radial part (produced by multipole magnet). Experiments have shown that the radial magnetic field component plays a crucial role in the production of highly-charged ions. However, in several modern ECRIS the radial magnetic field strength is below the optimum value, mainly due to the limits in permanent magnet technology. Unfortunately, methods to increase the radial magnetic field strength while still using permanent magnets are often limited. In this thesis work new techniques to improve the radial magnetic field have been studied by simulations and experiments. Due to the computer simulations performed a remarkable radial magnetic field improvement was reached with a relatively simple and cost-effective idea called the Modified MultiPole Structure (MMPS). The MMPS differs strongly from former studies as here the magnetic field is increased only locally without affecting the plasma size. It was not known how this would affect the properties of the plasma and production of highly-charged heavy ions. Consequently, the idea had to be studied experimentally and a new MMPS plasma chamber prototype was designed and constructed for the JYFL 6.4 GHz ECRIS. The new construction is versatile and made it possible to perform several new types of measurements. These showed that the MMPS works well and is especially applicable to increase very high charge-state ion production. Typically the ion current increases by a factor of 2 - 3 in the case of highly charged ions such as Ar16+. (orig.)

  14. Modified multipole structure for electron cyclotron resonance ion sources

    International Nuclear Information System (INIS)

    Suominen, P.

    2006-01-01

    Highly-charged heavy-ion beams are usually produced with Electron Cyclotron Resonance Ion Sources (ECRIS) where the microwave heated plasma is confined in a strong magnetic field. The magnetic field is divided into an axial part (produced by solenoid magnets) and to a radial part (produced by multipole magnet). Experiments have shown that the radial magnetic field component plays a crucial role in the production of highly-charged ions. However, in several modern ECRIS the radial magnetic field strength is below the optimum value, mainly due to the limits in permanent magnet technology. Unfortunately, methods to increase the radial magnetic field strength while still using permanent magnets are often limited. In this thesis work new techniques to improve the radial magnetic field have been studied by simulations and experiments. Due to the computer simulations performed a remarkable radial magnetic field improvement was reached with a relatively simple and cost-effective idea called the Modified MultiPole Structure (MMPS). The MMPS differs strongly from former studies as here the magnetic field is increased only locally without affecting the plasma size. It was not known how this would affect the properties of the plasma and production of highly-charged heavy ions. Consequently, the idea had to be studied experimentally and a new MMPS plasma chamber prototype was designed and constructed for the JYFL 6.4 GHz ECRIS. The new construction is versatile and made it possible to perform several new types of measurements. These showed that the MMPS works well and is especially applicable to increase very high charge-state ion production. Typically the ion current increases by a factor of 2 - 3 in the case of highly charged ions such as Ar 16+ . (orig.)

  15. A numerical study of atmospheric perturbations induced by heat from a wildland fire: sensitivity to vertical canopy structure and heat source strength

    Science.gov (United States)

    Michael T. Kiefer; Shiyuan Zhong; Warren E. Heilman; Joseph J. Charney; Xindi. Bian

    2018-01-01

    An improved understanding of atmospheric perturbations within and above a forest during a wildland fire has relevance to many aspects of wildland fires including fire spread, smoke transport and dispersion, and tree mortality. In this study, the ARPS-CANOPY model, a version of the Advanced Regional Prediction System (ARPS) model with a canopy parameterization, is...

  16. Sourcing of internal auditing : An empirical study

    NARCIS (Netherlands)

    Speklé, R.F.; Elten, van H.J.; Kruis, A.

    2007-01-01

    This paper studies the factors associated with organizations’ internal audit sourcing decisions, building from a previous study by Widener and Selto (henceforth W&S) [Widener, S.K., Selto, F.H., 1999. Management control systems and boundaries of the firm: why do firms outsource internal audit

  17. The Source Inversion Validation (SIV) Initiative: A Collaborative Study on Uncertainty Quantification in Earthquake Source Inversions

    Science.gov (United States)

    Mai, P. M.; Schorlemmer, D.; Page, M.

    2012-04-01

    Earthquake source inversions image the spatio-temporal rupture evolution on one or more fault planes using seismic and/or geodetic data. Such studies are critically important for earthquake seismology in general, and for advancing seismic hazard analysis in particular, as they reveal earthquake source complexity and help (i) to investigate earthquake mechanics; (ii) to develop spontaneous dynamic rupture models; (iii) to build models for generating rupture realizations for ground-motion simulations. In applications (i - iii), the underlying finite-fault source models are regarded as "data" (input information), but their uncertainties are essentially unknown. After all, source models are obtained from solving an inherently ill-posed inverse problem to which many a priori assumptions and uncertain observations are applied. The Source Inversion Validation (SIV) project is a collaborative effort to better understand the variability between rupture models for a single earthquake (as manifested in the finite-source rupture model database) and to develop robust uncertainty quantification for earthquake source inversions. The SIV project highlights the need to develop a long-standing and rigorous testing platform to examine the current state-of-the-art in earthquake source inversion, and to develop and test novel source inversion approaches. We will review the current status of the SIV project, and report the findings and conclusions of the recent workshops. We will briefly discuss several source-inversion methods, how they treat uncertainties in data, and assess the posterior model uncertainty. Case studies include initial forward-modeling tests on Green's function calculations, and inversion results for synthetic data from spontaneous dynamic crack-like strike-slip earthquake on steeply dipping fault, embedded in a layered crustal velocity-density structure.

  18. Studies and modeling of cold neutron sources

    International Nuclear Information System (INIS)

    Campioni, G.

    2004-11-01

    With the purpose of updating knowledge in the fields of cold neutron sources, the work of this thesis has been run according to the 3 following axes. First, the gathering of specific information forming the materials of this work. This set of knowledge covers the following fields: cold neutron, cross-sections for the different cold moderators, flux slowing down, different measurements of the cold flux and finally, issues in the thermal analysis of the problem. Secondly, the study and development of suitable computation tools. After an analysis of the problem, several tools have been planed, implemented and tested in the 3-dimensional radiation transport code Tripoli-4. In particular, a module of uncoupling, integrated in the official version of Tripoli-4, can perform Monte-Carlo parametric studies with a spare factor of Cpu time fetching 50 times. A module of coupling, simulating neutron guides, has also been developed and implemented in the Monte-Carlo code McStas. Thirdly, achieving a complete study for the validation of the installed calculation chain. These studies focus on 3 cold sources currently functioning: SP1 from Orphee reactor and 2 other sources (SFH and SFV) from the HFR at the Laue Langevin Institute. These studies give examples of problems and methods for the design of future cold sources

  19. Underground structure characterization using motor vehicles as passive seismic sources

    Science.gov (United States)

    Kuzma, H. A.; Liu, Y.; Zhao, Y.; Rector, J.; Vaidya, S.

    2009-12-01

    The ability to detect and characterize underground voids will be critical to the success of On-Site Inspections (OSI) as mandated by the nuclear Comprehensive Test Ban Treaty (CTBT). OSIs may be conducted in order to successfully locate the Ground Zero of underground tests as well as infrastructure related to testing. Recently, our team has shown the potential of a new technique to detect underground objects using the amplitude of seismic surface waves generated by motor vehicles. In an experiment conducted in June, 2009 we were able to detect an abandoned railroad tunnel by recognizing a clear pattern in the surface waves scattered by the tunnel, using a signal generated by driving a car on a dirt road across the tunnel. Synthetic experiments conducted using physically realistic wave-equation models further suggest that the technique can be readily applied to detecting underground features: it may be possible to image structures of importance to OSI simply by laying out an array of geophones (or using an array already in place for passive listening for event aftershocks) and driving vehicles around the site. We present evidence from a set of field experiments and from synthetic modeling and inversion studies to illustrate adaptations of the technique for OSI. Signature of an abandoned underground railroad tunnel at Donner Summit, CA. To produce this image, a line of geophones was placed along a dirt road perpendicular to the tunnel (black box) and a single car was driven along the road. A normalized mean power-spectrum is displayed on a log scale as a function of meters from the center of the tunnel. The top of the tunnel was 18m below ground surface. The tunnel anomaly is made up of a shadow (light) directly above the tunnel and amplitude build-up (dark) on either side of the tunnel. The size of the anomaly (6 orders of magnitude) suggests that the method can be extended to find deep structures at greater distances from the source and receivers.

  20. GLOBAL SOURCING: A THEORETICAL STUDY ON TURKEY

    Directory of Open Access Journals (Sweden)

    Aytac GOKMEN

    2010-07-01

    Full Text Available Global sourcing is to source from the global market for goods and services across national boundaries in order to take advantage of the global efficiencies in the delivery of a product or service. Such efficiencies are consists of low cost skilled labor, low cost raw materials and other economic factors like tax breaks and deductions as well as low trade tariffs. When we assess the case regarding to Turkey, global sourcing is an effective device for some firms. The domestic firms in Turkey at various industries are inclined to global source finished or intermediate goods from the world markets, finish the production process in Turkey and export. Eventually, on the one hand the export volume of Turkey increases, but on the other hand the import of a considerable volume of finished or intermediate goods bring about a negative trade balance and loss of jobs in Turkey. Therefore, the objective of this study is to assess the concept of global sourcing transactions on Turkey resting on comprehensive publications.

  1. Uncertainty in Earthquake Source Imaging Due to Variations in Source Time Function and Earth Structure

    KAUST Repository

    Razafindrakoto, H. N. T.

    2014-03-25

    One way to improve the accuracy and reliability of kinematic earthquake source imaging is to investigate the origin of uncertainty and to minimize their effects. The difficulties in kinematic source inversion arise from the nonlinearity of the problem, nonunique choices in the parameterization, and observational errors. We analyze particularly the uncertainty related to the choice of the source time function (STF) and the variability in Earth structure. We consider a synthetic data set generated from a spontaneous dynamic rupture calculation. Using Bayesian inference, we map the solution space of peak slip rate, rupture time, and rise time to characterize the kinematic rupture in terms of posterior density functions. Our test to investigate the effect of the choice of STF reveals that all three tested STFs (isosceles triangle, regularized Yoffe with acceleration time of 0.1 and 0.3 s) retrieve the patch of high slip and slip rate around the hypocenter. However, the use of an isosceles triangle as STF artificially accelerates the rupture to propagate faster than the target solution. It additionally generates an artificial linear correlation between rupture onset time and rise time. These appear to compensate for the dynamic source effects that are not included in the symmetric triangular STF. The exact rise time for the tested STFs is difficult to resolve due to the small amount of radiated seismic moment in the tail of STF. To highlight the effect of Earth structure variability, we perform inversions including the uncertainty in the wavespeed only, and variability in both wavespeed and layer depth. We find that little difference is noticeable between the resulting rupture model uncertainties from these two parameterizations. Both significantly broaden the posterior densities and cause faster rupture propagation particularly near the hypocenter due to the major velocity change at the depth where the fault is located.

  2. Uncertainty in Earthquake Source Imaging Due to Variations in Source Time Function and Earth Structure

    KAUST Repository

    Razafindrakoto, H. N. T.; Mai, Paul Martin

    2014-01-01

    One way to improve the accuracy and reliability of kinematic earthquake source imaging is to investigate the origin of uncertainty and to minimize their effects. The difficulties in kinematic source inversion arise from the nonlinearity of the problem, nonunique choices in the parameterization, and observational errors. We analyze particularly the uncertainty related to the choice of the source time function (STF) and the variability in Earth structure. We consider a synthetic data set generated from a spontaneous dynamic rupture calculation. Using Bayesian inference, we map the solution space of peak slip rate, rupture time, and rise time to characterize the kinematic rupture in terms of posterior density functions. Our test to investigate the effect of the choice of STF reveals that all three tested STFs (isosceles triangle, regularized Yoffe with acceleration time of 0.1 and 0.3 s) retrieve the patch of high slip and slip rate around the hypocenter. However, the use of an isosceles triangle as STF artificially accelerates the rupture to propagate faster than the target solution. It additionally generates an artificial linear correlation between rupture onset time and rise time. These appear to compensate for the dynamic source effects that are not included in the symmetric triangular STF. The exact rise time for the tested STFs is difficult to resolve due to the small amount of radiated seismic moment in the tail of STF. To highlight the effect of Earth structure variability, we perform inversions including the uncertainty in the wavespeed only, and variability in both wavespeed and layer depth. We find that little difference is noticeable between the resulting rupture model uncertainties from these two parameterizations. Both significantly broaden the posterior densities and cause faster rupture propagation particularly near the hypocenter due to the major velocity change at the depth where the fault is located.

  3. Solar Coronal Structure Study

    Science.gov (United States)

    Nitta, Nariaki; Bruner, Marilyn E.; Saba, Julia; Strong, Keith; Harvey, Karen

    2000-01-01

    The subject of this investigation is to study the physics of the solar corona through the analysis of the EUV and UV data produced by two flights (12 May 1992 and 25 April 1994) of the Lockheed Solar Plasma Diagnostics Experiment (SPDE) sounding rocket payload, in combination with Yohkoh and ground-based data. Each rocket flight produced both spectral and imaging data. These joint datasets are useful for understanding the physical state of various features in the solar atmosphere at different heights ranging from the photosphere to the corona at the time of the, rocket flights, which took place during the declining phase of a solar cycle, 2-4 years before the minimum. The investigation is narrowly focused on comparing the physics of small- and medium-scale strong-field structures with that of large-scale, weak fields. As we close th is investigation, we have to recall that our present position in the understanding of basic solar physics problems (such as coronal heating) is much different from that in 1995 (when we proposed this investigation), due largely to the great success of SOHO and TRACE. In other words, several topics and techniques we proposed can now be better realized with data from these missions. For this reason, at some point of our work, we started concentrating on the 1992 data, which are more unique and have more supporting data. As a result, we discontinued the investigation on small-scale structures, i.e., bright points, since high-resolution TRACE images have addressed more important physics than SPDE EUV images could do. In the final year, we still spent long time calibrating the 1992 data. The work was complicated because of the old-fashioned film, which had problems not encountered with more modern CCD detectors. After our considerable effort on calibration, we were able to focus on several scientific topics, relying heavily on the SPDE UV images. They include the relation between filaments and filament channels, the identification of hot

  4. Resonant ionization by laser beams: application to ions sources and to study the nuclear structure of radioactive tellurium isotopes; Ionisation resonante par faisceaux laser: application aux sources d'ions et a l'etude de la structure des noyaux radioactifs de tellure

    Energy Technology Data Exchange (ETDEWEB)

    Sifi, R

    2007-07-15

    The radioactive ion beams that are produced through current isotope separators are well separated according to the A mass but not according to the Z parameter. The resonant ionization through laser beams applied to ion sources allows the production of radioactive ion beam in a very selective and efficient way by eliminating the isobaric contamination. The first chapter is dedicated to the resonant ionization by laser beams, we describe the principle, the experimental setting, the lasers used, the ionization schemes and the domain of application. The second chapter deals with the application of resonant ionization to laser ion sources for the production of radioactive ion beams. We present experimental tests performed for getting copper ion beams. Resonant ionization through laser is also used in the spectroscopy experiments performed at the Isolde (isotope separation on-line device) installation in CERN where more than 20 elements are ionized very efficiently. The technique is based on a frequency scanning around the excitation transition of the atoms in order to probe the hyperfine structure. Laser spectroscopy allows the determination of the hyperfine structure as well as the isotopic shift of atoms. In the third chapter the method is applied to the spectroscopy of tellurium atoms. First, we define the 2 parameters on which the extraction is based: charge radius and nuclear moments, then we present several theoretical models that we have used to assess our experimental results. (A.C.)

  5. Connectivity and propagule sources composition drive ditch plant metacommunity structure

    Science.gov (United States)

    Favre-Bac, Lisa; Ernoult, Aude; Mony, Cendrine; Rantier, Yann; Nabucet, Jean; Burel, Françoise

    2014-11-01

    The fragmentation of agricultural landscapes has a major impact on biodiversity. In addition to habitat loss, dispersal limitation increasingly appears as a significant driver of biodiversity decline. Landscape linear elements, like ditches, may reduce the negative impacts of fragmentation by enhancing connectivity for many organisms, in addition to providing refuge habitats. To characterize these effects, we investigated the respective roles of propagule source composition and connectivity at the landscape scale on hydrochorous and non-hydrochorous ditch bank plant metacommunities. Twenty-seven square sites (0.5 km2 each) were selected in an agricultural lowland of northern France. At each site, plant communities were sampled on nine ditch banks (totaling 243 ditches). Variables characterizing propagule sources composition and connectivity were calculated for landscape mosaic and ditch network models. The landscape mosaic influenced only non-hydrochorous species, while the ditch network impacted both hydrochorous and non-hydrochorous species. Non-hydrochorous metacommunities were dependent on a large set of land-use elements, either within the landscape mosaic or adjacent to the ditch network, whereas hydrochorous plant metacommunities were only impacted by the presence of ditches adjacent to crops and roads. Ditch network connectivity also influenced both hydrochorous and non-hydrochorous ditch bank plant metacommunity structure, suggesting that beyond favoring hydrochory, ditches may also enhance plant dispersal by acting on other dispersal vectors. Increasing propagule sources heterogeneity and connectivity appeared to decrease within-metacommunity similarity within landscapes. Altogether, our results suggest that the ditch network's composition and configuration impacts plant metacommunity structure by affecting propagule dispersal possibilities, with contrasted consequences depending on species' dispersal vectors.

  6. Nuclear structure studies

    International Nuclear Information System (INIS)

    Walters, W.B.

    1992-01-01

    New results are reported for the decay and nuclear orientation of 114,116 I and 114 Sb as well as data for the structure of daughter nuclides 114,116 Te. New results for IBM-2 calculations for the structure of 126 Xe are also reported. A new approach to the problem of the underproduction of A = 120 nuclides in the astrophysical r-process is reported

  7. Data structure for estimating emissions from non-road sources

    Energy Technology Data Exchange (ETDEWEB)

    Sorenson, S C; Kalivoda, M; Vacarro, R; Trozzi, C; Samaras, Z; Lewis, C A

    1997-03-01

    The work described in the following is a portion of the MEET project (Methodologies for Estimation Air Pollutant Emissions from Transport). The overall goal of the MEET project is to consolidate and present methodologies which can be used to estimate air pollutant emissions from various types of traffic sources. One of the goals of MEET is to provide methodologies to be used in the COMMUTE project also funded by DG VII. COMMUTE is developing computer software which can be used to provide emissions inventories on the European scale. Although COMMUTE is viewed as a prime user of the information generated in MEET, the MEET results are intended to be used in a broader area, and on both smaller and larger spatial scales. The methodologies and data presented will be useful for planners on a more local scale than a national or continental basis. While most attention in previous years has been concentrated on emissions from road transport, it has become increasingly apparent in later years that the so-called off road transportation contributes significantly to the emission of air pollutants. The three most common off-road traffic modes are Air Traffic, Rail Traffic, and Ship or Marine traffic. In the following, the basic structure of the methods for estimating the emissions from these sectors will be given and of the input and output data associated with these calculations. The structures will of necessity be different for the different types of traffic. The data structures in the following reflect these variations and uncertainties. In some instances alternative approaches to emissions estimation will be suggested. The user must evaluate the amount and reliability of available data for the application at hand, and select the method which would be expected to give the highest accuracy. In any event, a large amount of uncertainty is inherent in the estimation of emissions from the non-road traffic sources, particularly those involving rail and maritime transport. (EG)

  8. Cell Structure Study.

    Science.gov (United States)

    Ekstrom, James V.

    2000-01-01

    Presents an activity in which students use microscopes and digital images to examine Elodea, a fresh water plant, before and after the process of plasmolysis, identify plant cellular structures before and after plasmolysis, and calculate the size of the plant's vacuole. (ASK)

  9. BNL feasibility studies of spallation neutron sources

    International Nuclear Information System (INIS)

    Lee, Y.Y.; Ruggiero, A.G.; Van Steenbergen, A.; Weng, W.T.

    1995-01-01

    This paper is the summary of conceptual design studies of a 5 MW Pulsed Spallation Neutron Source (PSNS) conducted by an interdepartmental study group at Brookhaven National Laboratory. The study was made of two periods. First, a scenario based on the use of a 600 MeV Linac followed by two fast-cycling 3.6 GeV Synchrotrons was investigated. Then, in a subsequent period, the attention of the study was directed toward an Accumulator scenario with two options: (1) a 1.25 GeV normal conducting Linac followed by two Accumulator Rings, and (2) a 2.4 GeV superconducting Linac followed by a single Accumulator Ring. The study did not make any reference to a specific site

  10. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  11. Population studies of the unidentified EGRET sources

    Energy Technology Data Exchange (ETDEWEB)

    Siegal-Gaskins, J M [University of Chicago, Chicago, IL 60637 (United States); Pavlidou, V [University of Chicago, Chicago, IL 60637 (United States); Olinto, A V [University of Chicago, Chicago, IL 60637 (United States); Brown, C [University of Chicago, Chicago, IL 60637 (United States); Fields, B D [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2007-03-15

    The third EGRET catalog contains a large number of unidentified sources. Current data allows the intriguing possibility that some of these objects may represent a new class of yet undiscovered gamma-ray sources. By assuming that galaxies similar to the Milky Way host comparable populations of objects, we constrain the allowed Galactic abundance and distribution of various classes of gamma-ray sources using the EGRET data set. Furthermore, regardless of the nature of the unidentified sources, faint unresolved objects of the same class contribute to the observed diffuse gamma-ray background. We investigate the potential contribution of these unresolved sources to the extragalactic gamma-ray background.

  12. Population studies of the unidentified EGRET sources

    International Nuclear Information System (INIS)

    Siegal-Gaskins, J M; Pavlidou, V; Olinto, A V; Brown, C; Fields, B D

    2007-01-01

    The third EGRET catalog contains a large number of unidentified sources. Current data allows the intriguing possibility that some of these objects may represent a new class of yet undiscovered gamma-ray sources. By assuming that galaxies similar to the Milky Way host comparable populations of objects, we constrain the allowed Galactic abundance and distribution of various classes of gamma-ray sources using the EGRET data set. Furthermore, regardless of the nature of the unidentified sources, faint unresolved objects of the same class contribute to the observed diffuse gamma-ray background. We investigate the potential contribution of these unresolved sources to the extragalactic gamma-ray background

  13. A simple iterative independent component analysis algorithm for vibration source signal identification of complex structures

    Directory of Open Access Journals (Sweden)

    Dong-Sup Lee

    2015-01-01

    Full Text Available Independent Component Analysis (ICA, one of the blind source separation methods, can be applied for extracting unknown source signals only from received signals. This is accomplished by finding statistical independence of signal mixtures and has been successfully applied to myriad fields such as medical science, image processing, and numerous others. Nevertheless, there are inherent problems that have been reported when using this technique: insta- bility and invalid ordering of separated signals, particularly when using a conventional ICA technique in vibratory source signal identification of complex structures. In this study, a simple iterative algorithm of the conventional ICA has been proposed to mitigate these problems. The proposed method to extract more stable source signals having valid order includes an iterative and reordering process of extracted mixing matrix to reconstruct finally converged source signals, referring to the magnitudes of correlation coefficients between the intermediately separated signals and the signals measured on or nearby sources. In order to review the problems of the conventional ICA technique and to vali- date the proposed method, numerical analyses have been carried out for a virtual response model and a 30 m class submarine model. Moreover, in order to investigate applicability of the proposed method to real problem of complex structure, an experiment has been carried out for a scaled submarine mockup. The results show that the proposed method could resolve the inherent problems of a conventional ICA technique.

  14. Pollen source effects on growth of kernel structures and embryo chemical compounds in maize.

    Science.gov (United States)

    Tanaka, W; Mantese, A I; Maddonni, G A

    2009-08-01

    Previous studies have reported effects of pollen source on the oil concentration of maize (Zea mays) kernels through modifications to both the embryo/kernel ratio and embryo oil concentration. The present study expands upon previous analyses by addressing pollen source effects on the growth of kernel structures (i.e. pericarp, endosperm and embryo), allocation of embryo chemical constituents (i.e. oil, protein, starch and soluble sugars), and the anatomy and histology of the embryos. Maize kernels with different oil concentration were obtained from pollinations with two parental genotypes of contrasting oil concentration. The dynamics of the growth of kernel structures and allocation of embryo chemical constituents were analysed during the post-flowering period. Mature kernels were dissected to study the anatomy (embryonic axis and scutellum) and histology [cell number and cell size of the scutellums, presence of sub-cellular structures in scutellum tissue (starch granules, oil and protein bodies)] of the embryos. Plants of all crosses exhibited a similar kernel number and kernel weight. Pollen source modified neither the growth period of kernel structures, nor pericarp growth rate. By contrast, pollen source determined a trade-off between embryo and endosperm growth rates, which impacted on the embryo/kernel ratio of mature kernels. Modifications to the embryo size were mediated by scutellum cell number. Pollen source also affected (P embryo chemical compounds. Negative correlations among embryo oil concentration and those of starch (r = 0.98, P embryos with low oil concentration had an increased (P embryo/kernel ratio and allocation of embryo chemicals seems to be related to the early established sink strength (i.e. sink size and sink activity) of the embryos.

  15. Study of a viscoplastic structure

    International Nuclear Information System (INIS)

    Bahbouhi, A.F.; Cousin, M.; Jullien, J.F.

    1987-01-01

    This study concerns the thermoplastic behavior of metallic structures under cyclic thermal loading. This work aims to bring about a contribution to the experimental plan as well as to the numerical modelisation aspect of the viscoplastic behavior of the structures. This experimental device allows the variation of the thermal loading story especially the duration of the cycle and the fixed temperature time. The numerical analysis of the viscoplastic behavior of the structures was carried out by treating the plastic strains independently of the creep strains. The comparison of the experimental and numerical results brings about important elements concerning the numerical analysis of the viscoplastic behavior of such structures. (orig.)

  16. GIS: a comprehensive source for protein structure similarities.

    Science.gov (United States)

    Guerler, Aysam; Knapp, Ernst-Walter

    2010-07-01

    A web service for analysis of protein structures that are sequentially or non-sequentially similar was generated. Recently, the non-sequential structure alignment algorithm GANGSTA+ was introduced. GANGSTA+ can detect non-sequential structural analogs for proteins stated to possess novel folds. Since GANGSTA+ ignores the polypeptide chain connectivity of secondary structure elements (i.e. alpha-helices and beta-strands), it is able to detect structural similarities also between proteins whose sequences were reshuffled during evolution. GANGSTA+ was applied in an all-against-all comparison on the ASTRAL40 database (SCOP version 1.75), which consists of >10,000 protein domains yielding about 55 x 10(6) possible protein structure alignments. Here, we provide the resulting protein structure alignments as a public web-based service, named GANGSTA+ Internet Services (GIS). We also allow to browse the ASTRAL40 database of protein structures with GANGSTA+ relative to an externally given protein structure using different constraints to select specific results. GIS allows us to analyze protein structure families according to the SCOP classification scheme. Additionally, users can upload their own protein structures for pairwise protein structure comparison, alignment against all protein structures of the ASTRAL40 database (SCOP version 1.75) or symmetry analysis. GIS is publicly available at http://agknapp.chemie.fu-berlin.de/gplus.

  17. Scintillating confusion: Evaluation of a technique for measuring compact structure in weak radio sources

    International Nuclear Information System (INIS)

    Spangler, S.R.; Cordes, J.M.; Meyers, K.A.

    1979-01-01

    An attractive scheme for investigating compact structure in weak radio sources is to study the scintillation properties of confusion in a large single-dish radio telescope. We have investigated the utility of this technique by observing the scintillations of 860-MHz confusion of the NRAO 300' (91 m) telescope. Analysis of these data indicated a reduction in the mean scintillation index with decreasing flux density which implied that weaker sources possessed less compact structure. More direct observations indicated that the weak sources of interest were not significantly deficient in compact structure, so the first result is probably due to properties of the IPS process in the strong scintillation regime. Our results may be due to overresolution (by the IPS process in the strong scintillation regime) of the ''hot spots'' responsible for scintillation in most strong sources at frequencies below 1000 MHz, or may indicate abnormally strong turbulence in the solar wind during August, 1977. Future applications of this method would be best conducted at lower frequencies with larger reflectors or short-spacing interferometers

  18. Neutral beam source commercialization study. Final report

    International Nuclear Information System (INIS)

    King, H.J.

    1980-06-01

    The basic tasks of this Phase II project were to: generate a set of design drawings suitable for quantity production of sources of this design; fabricate a functional neutral beam source incorporating as many of the proposed design changes as proved feasible; and document the procedures and findings developed during the contract. These tasks have been accomplished and represent a demonstrated milestone in the industrialization of this complete device

  19. Studies of the infrared source CRL 2688

    International Nuclear Information System (INIS)

    Ney, E.P.; Merrill, K.M.; Becklin, E.E.; Neugebauer, G.; Wynn-Williams, C.G.

    1975-01-01

    Infrared, optical, and radio observations are descirbed of a newly discovered galactic infrared source. Most of the radiation comes from 1/sup double-prime/./sub /5 diameter infrared source at a temperature of about 150 K, but some visible emission in the form of a symmetrical highly polarized reflection nebulosity is also seen. The object could represent either a very early or a very late stage in stellar evolution

  20. Earthquake source studies and seismic imaging in Alaska

    Science.gov (United States)

    Tape, C.; Silwal, V.

    2015-12-01

    Alaska is one of the world's most seismically and tectonically active regions. Its enhanced seismicity, including slab seismicity down to 180 km, provides opportunities (1) to characterize pervasive crustal faulting and slab deformation through the estimation of moment tensors and (2) to image subsurface structures to help understand the tectonic evolution of Alaska. Most previous studies of earthquakes and seismic imaging in Alaska have emphasized earthquake locations and body-wave travel-time tomography. In the past decade, catalogs of seismic moment tensors have been established, while seismic surface waves, active-source data, and potential field data have been used to improve models of seismic structure. We have developed moment tensor catalogs in the regions of two of the largest sedimentary basins in Alaska: Cook Inlet forearc basin, west of Anchorage, and Nenana basin, west of Fairbanks. Our moment tensor solutions near Nenana basin suggest a transtensional tectonic setting, with the basin developing in a stepover of a left-lateral strike-slip fault system. We explore the effects of seismic wave propagation from point-source and finite-source earthquake models by performing three-dimensional wavefield simulations using seismic velocity models that include major sedimentary basins. We will use our catalog of moment tensors within an adjoint-based, iterative inversion to improve the three-dimensional tomographic model of Alaska.

  1. Preliminary study of mercury target structure

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kumasaka, Katsuyuki; Uchida, Shoji; Nakagawa, Toshi; Mori, Seiji; Nishikawa, Akira

    1997-11-01

    Development of a proton accelerator based neutron source (1.5 GeV, 5.3 mA (for neutron source 3.3 mA), thermal power 8 MW) is currently conducted by the Special Task Force for Neutron Science Initiative, JAERI. Preliminary design studies and related R and D of a solid metal target for the first stage (1.5 GeV, 1 mA) and a liquid metal target for both the first and second stages (1.5 GeV, 3.3 mA) are conducted by the Target Group to develop both solid and liquid metal target systems. A few kinds of target structures have been investigated in FY 1996 and the preliminary results for the target structures are described in this paper. Investigation results of alternative materials for the target container are also described in this paper. (author)

  2. Physics-Based Hazard Assessment for Critical Structures Near Large Earthquake Sources

    Science.gov (United States)

    Hutchings, L.; Mert, A.; Fahjan, Y.; Novikova, T.; Golara, A.; Miah, M.; Fergany, E.; Foxall, W.

    2017-09-01

    We argue that for critical structures near large earthquake sources: (1) the ergodic assumption, recent history, and simplified descriptions of the hazard are not appropriate to rely on for earthquake ground motion prediction and can lead to a mis-estimation of the hazard and risk to structures; (2) a physics-based approach can address these issues; (3) a physics-based source model must be provided to generate realistic phasing effects from finite rupture and model near-source ground motion correctly; (4) wave propagations and site response should be site specific; (5) a much wider search of possible sources of ground motion can be achieved computationally with a physics-based approach; (6) unless one utilizes a physics-based approach, the hazard and risk to structures has unknown uncertainties; (7) uncertainties can be reduced with a physics-based approach, but not with an ergodic approach; (8) computational power and computer codes have advanced to the point that risk to structures can be calculated directly from source and site-specific ground motions. Spanning the variability of potential ground motion in a predictive situation is especially difficult for near-source areas, but that is the distance at which the hazard is the greatest. The basis of a "physical-based" approach is ground-motion syntheses derived from physics and an understanding of the earthquake process. This is an overview paper and results from previous studies are used to make the case for these conclusions. Our premise is that 50 years of strong motion records is insufficient to capture all possible ranges of site and propagation path conditions, rupture processes, and spatial geometric relationships between source and site. Predicting future earthquake scenarios is necessary; models that have little or no physical basis but have been tested and adjusted to fit available observations can only "predict" what happened in the past, which should be considered description as opposed to prediction

  3. Exploring Coordination Structures in Open Source Software Development

    NARCIS (Netherlands)

    van Hillegersberg, Jos; Harmsen, Frank; Hegeman, J.H.; Amrit, Chintan Amrit; Geisberger, Eva; Keil, Patrick; Kuhrmann, Marco

    2007-01-01

    Coordination is difficult to achieve in a large globally distributed project setting. The problem is multiplied in open source software development projects, where most of the traditional means of coordination such as plans, system-level designs, schedules and defined process are not used. In order

  4. Sheath structure in negative ion sources for fusion (invited)

    International Nuclear Information System (INIS)

    McAdams, R.; King, D. B.; Surrey, E.; Holmes, A. J. T.

    2012-01-01

    In fusion negative ion sources, the negative ions are formed on the caesiated plasma grid predominantly by hydrogen atoms from the plasma. The space charge of the negative ions leaving the wall is not fully compensated by incoming positive ions and at high enough emission a virtual cathode is formed. This virtual cathode limits the flux of negative ions transported across the sheath to the plasma. A 1D collisionless model of the sheath is presented taking into account the virtual cathode. The model will be applied to examples of the ion source operation. Extension of the model to the bulk plasma shows good agreement with experimental data. A possible role for fast ions is discussed.

  5. Rotating coherent flow structures as a source for narrowband tip clearance noise from axial fans

    Science.gov (United States)

    Zhu, Tao; Lallier-Daniels, Dominic; Sanjosé, Marlène; Moreau, Stéphane; Carolus, Thomas

    2018-03-01

    Noise from axial fans typically increases significantly as the tip clearance is increased. In addition to the broadband tip clearance noise at the design flow rate, narrowband humps also associated with the tip flow are observed in the far-field acoustic spectra at lower flow rate. In this study, both experimental and numerical methods are used to shed more light on the noise generation mechanism of this narrowband tip clearance noise and provide a unified description of this source. Unsteady aeroacoustic predictions with the Lattice-Boltzmann Method (LBM) are successfully compared with experiment. Such a validation allows using LBM data to conduct a detailed modal analysis of the pressure field for detecting rotating coherent flow structures which might be considered as noise sources. As previously found in ring fans the narrowband humps in the far-field noise spectra are found to be related to the tip clearance noise that is generated by an interaction of coherent flow structures present in the tip region with the leading edge of the impeller blades. The visualization of the coherent structures shows that they are indeed part of the unsteady tip clearance vortex structures. They are hidden in a complex, spatially and temporally inhomogeneous flow field, but can be recovered by means of appropriate filtering techniques. Their pressure trace corresponds to the so-called rotational instability identified in previous turbomachinery studies, which brings a unified picture of this tip-noise phenomenon for the first time.

  6. Sourcing of internal auditing : An empirical study

    NARCIS (Netherlands)

    Speklé, R.F.; Elten, van H.J.; Kruis, A.

    2005-01-01

    In recent years, the scope of internal auditing has broadened considerably, increasing the importance of internal auditing as part of the organization’s management control structure. This expanding role has changed the demands being put on internal auditors. Their new role requires different skills

  7. Sourcing of Internal Auditing: An Empirical Study

    NARCIS (Netherlands)

    R.F. Speklé (Roland); H.J. van Elten (Hilco); A.M. Kruis

    2005-01-01

    textabstractIn recent years, the scope of internal auditing has broadened considerably, increasing the importance of internal auditing as part of the organization’s management control structure. This expanding role has changed the demands being put on internal auditors. Their new role requires

  8. SELECTION OF HEAT SUPPLY SOURCE FOR MOBILE BUILDING STRUCTURE

    OpenAIRE

    T. I. Dolgikh; S. V. Morozov; Yu. P. Orlov; A. B. Reis; A. Yu Yakovlev

    2014-01-01

    The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat suppl...

  9. Reactivity studies on the advanced neutron source

    International Nuclear Information System (INIS)

    Ryskamp, J.M.; Redmond, E.L. II; Fletcher, C.D.

    1990-01-01

    An Advanced Neutron Source (ANS) with a peak thermal neutron flux of about 8.5 x 10 19 m -2 s -1 is being designed for condensed matter physics, materials science, isotope production, and fundamental physics research. The ANS is a new reactor-based research facility being planned by Oak Ridge National Laboratory (ORNL) to meet the need for an intense steady-state source of neutrons. The design effort is currently in the conceptual phase. A reference reactor design has been selected in order to examine the safety, performance, and costs associated with this one design. The ANS Project has an established, documented safety philosophy, and safety-related design criteria are currently being established. The purpose of this paper is to present analyses of safety aspects of the reference reactor design that are related to core reactivity events. These analyses include control rod worth, shutdown rod worth, heavy water voiding, neutron beam tube flooding, light water ingress, and single fuel element criticality. Understanding these safety aspects will allow us to make design modifications that improve the reactor safety and achieve the safety related design criteria. 8 refs., 3 tabs

  10. Structural Narratology and Interdisciplinary Studies

    Directory of Open Access Journals (Sweden)

    A. Mohammadi Kalesar

    2016-02-01

    Full Text Available The aim of this paper is to investigate the relationship between structural narratology and interdisciplinary studies. We will try to answer two main questions: What factors have been effective in narratology’s orientation toward interdisciplinary studies? Is this tendency the result of a possibility in narration or a methodological necessity? The movement of narratology to interdisciplinary is observable not only in new narratological tendencies but also in changes in structural theories. Therefore, this article will trace the roots of this tendency in the revises and critiques of these theories until 1970s. By tracing these changes it can be realized that the theories of structural narrotology have broken with idea of independence and self-sufficiency of literature and embraced other disciplines. The main factors in these changes are: attention to cultural elements and reading process in the perception of narrative structure. These considerations have been accompanied by some results; first, the main targets of narratology changed from investigating textual properties to reading and understanding the narration process; second, some disciplines and fields related to culture and mind studies found their way into narratology.

  11. A study on soil structure

    NARCIS (Netherlands)

    Schuylenborgh, van J.

    1947-01-01

    As soils differ in capacity to form a structure, it is necessary to distinguish between intrinsic structure and actual structure. Intrinsic structure is the capacity of a soil to form a certain structure. Actual structure is the structure of the soil at a certain moment.

    Using experiments and

  12. Studies on the method of producing radiographic 170Tm source

    International Nuclear Information System (INIS)

    Maeda, Sho

    1976-08-01

    A method of producing radiographic 170 Tm source has been studied, including target preparation, neutron irradiation, handling of the irradiated target in the hot cell and source capsules. On the basis of the results, practical 170 Tm radiographic sources (29 -- 49Ci, with pellets 3mm in diameter and 3mm long) were produced in trial by neutron irradiation with the JMTR. (auth.)

  13. [Research progress on food sources and food web structure of wetlands based on stable isotopes].

    Science.gov (United States)

    Chen, Zhan Yan; Wu, Hai Tao; Wang, Yun Biao; Lyu, Xian Guo

    2017-07-18

    The trophic dynamics of wetland organisms is the basis of assessing wetland structure and function. Stable isotopes of carbon and nitrogen have been widely applied to identify trophic relationships in food source, food composition and food web transport in wetland ecosystem studies. This paper provided an overall review about the current methodology of isotope mixing model and trophic level in wetland ecosystems, and discussed the standards of trophic fractionation and baseline. Moreover, we characterized the typical food sources and isotopic compositions of wetland ecosystems, summarized the food sources in different trophic levels of herbivores, omnivores and carnivores based on stable isotopic analyses. We also discussed the limitations of stable isotopes in tra-cing food sources and in constructing food webs. Based on the current results, development trends and upcoming requirements, future studies should focus on sample treatment, conservation and trophic enrichment measurement in the wetland food web, as well as on combing a variety of methodologies including traditional stomach stuffing, molecular markers, and multiple isotopes.

  14. SELECTION OF HEAT SUPPLY SOURCE FOR MOBILE BUILDING STRUCTURE

    Directory of Open Access Journals (Sweden)

    T. I. Dolgikh

    2014-01-01

    Full Text Available The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat supply of the mobile object (field hospital.

  15. Getting Grip on Security Requirements Elicitation by Structuring and Reusing Security Requirements Sources

    Directory of Open Access Journals (Sweden)

    Christian Schmitt

    2015-07-01

    Full Text Available This paper presents a model for structuring and reusing security requirements sources. The model serves as blueprint for the development of an organization-specific repository, which provides relevant security requirements sources, such as security information and knowledge sources and relevant compliance obligations, in a structured and reusable form. The resulting repository is intended to be used by development teams during the elicitation and analysis of security requirements with the goal to understand the security problem space, incorporate all relevant requirements sources, and to avoid unnecessary effort for identifying, understanding, and correlating applicable security requirements sources on a project-wise basis. We start with an overview and categorization of important security requirements sources, followed by the description of the generic model. To demonstrate the applicability and benefits of the model, the instantiation approach and details of the resulting repository of security requirements sources are presented.

  16. Noise pollution from wind turbine gears loudness of structural noise sources related to gears

    International Nuclear Information System (INIS)

    Crone, A.

    1995-04-01

    The purpose of the project has been to develop a method for determination of the structure-borne noise source strength of the gearbox in a typical modern Danish wind turbine construction, with special reference to the tonal noise emission form the turbines. Through study and evaluation of eight potential methods, a simple method has ben formulated. The method is based on measurements of the free vibration velocity level on the gearbox in a load test bed. The relation between this source strength measure and the gearbox related noise from wind turbines has been documented by measurements made during the project together with earlier measurements. The method is intended as a tool for the wind turbine manufacturer, for control of the gearbox related noise from the wind turbines, due to structure-borne noise from the gearbox. It may be used for preparation of specifications to the gearbox manufacturer on test procedure and acceptable source strength levels. Also, it may be used for evaluation of the transmission and radiation of gearbox related noise, for example in order to uncover weaknesses in a prototype turbine. Suggestions for adaptation and evolution of the method has been given, thereby improving the strength of the method for the individual wind turbine manufacturer. (au) 19 refs

  17. Photoemission studies using laboratory and synchrotron sources

    International Nuclear Information System (INIS)

    Phase, D.M.

    2012-01-01

    Synchrotron radiation sources, providing intense, polarized and stable beams of ultra violet soft and hard X-ray photons, are having great impact on physics, chemistry, biology materials science and other areas research. In particular synchrotron radiation has revolutionized photoelectron spectroscopy by enhancing its capabilities for investigating the electronic properties of solids. The first Indian synchrotron storage ring, Indus- 1 is in operation at RRCAT, Indore. The UGC-DAE CSR with the help of university scientist had designed and developed an angle integrated photoelectron spectroscopy (PES) beamline on this 450 MeV storage ring. A storage ring of this kind is most suitable for investigation in the energy range from few electron volts to around five hundred electron volts. In this lecture we will describe the details of PES beamline and its experimental station. Till date the different university users carried out photoemission measurements on variety of samples. Some of the spectra recorded by users will be presented in order to show the capability of this beamline. In the later part we will report a review of our recent research work carried out on dilute magnetic thin films using this beamline. (author)

  18. Formation and quantification of calcium titanate with the perovskite structure from alternative sources of titanium

    International Nuclear Information System (INIS)

    Gralik, G.; Raupp-Pereira, F.; Hotza, D.; Labrincha, J.A.; Zanelli, C.; Dondi, M.

    2014-01-01

    This study aimed to evaluate and quantify the formation of calcium titanate (CaTiO3) with perovskite structure from alternative sources of titanium (rutile, ilmenite). Commercial raw materials of the high purity were also characterized as reference. With base in the characterization by X-ray fluorescence of the mineral springs different compositions were formulated and subsequently sintered for 2 h in resistive furnace at temperatures in the range 1000 to 1400°C. After thermal processing the samples were analyzed by X-ray diffraction and the quantification of phases formed by the Rietveld method obtained. The results show that the formation and the amount of calcium titanate minerals from alternative sources depend on factors related to stages of sintering and impurities. The microstructures of the compositions were analyzed by SEM/EDS and bulk density also measured. (author)

  19. Structure of production costs of different energy sources (fossile fuels and nuclear energy) (group 11)

    International Nuclear Information System (INIS)

    Girard, Ph.

    2002-01-01

    This article is the work of a group of students from the ''Ecole Nationale d'Administration'', they had to study the structure of the costs of the different energy sources. This analysis shows some common features between the energy sources. The cost is very dependent on the partial costs of technological constraints due to exploration, production, transport and distribution. For primary energies the market appears to be not very competitive, the price depends strongly on the market power of the operator and benefits are generally important. In France, taxes play a role to assure competitiveness of gas and coal against oil. Uranium fuel presents the lowest production and transformation costs at the same energy content. Transport costs are important for natural gas which implies a strong mutual dependence between gas producers and consumers. The irreplaceable use of oil in transport assures regular high revenues for oil companies. (A.C.)

  20. Fan-structure wave as a source of earthquake instability

    Science.gov (United States)

    Tarasov, Boris

    2015-04-01

    Today frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength at confined compression corresponding to the seismogenic layer. This determines the lithospheric strength and the primary earthquake mechanism associated with frictional stick-slip instability on pre-existing faults. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism the rock failure, associated with consecutive creation of small slabs (known as 'domino-blocks') from the intact rock in the rupture tip, is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new domino-blocks), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the lower limit of the lithospheric strength and favours the generation of new faults in pristine rocks in preference to frictional stick-slip instability along pre-existing faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created

  1. Cultural regulation of emotion: Individual, relational, and structural sources

    Directory of Open Access Journals (Sweden)

    Jozefien eDe Leersnyder

    2013-02-01

    Full Text Available The most prevalent and intense emotional experiences differ across cultures. These differences in emotional experience can be understood as the outcomes of emotion regulation, because emotions that fit the valued relationships within a culture tend to be most common and intense. We review evidence suggesting that emotion regulation underlying cultural differences in emotional experience often takes place at the point of emotion elicitation through the promotion of situations and appraisals that are consistent with culturally valued relationships. These regulatory processes depend on individual tendencies, but are also co-regulated within relationships—close others shape people’s environment and help them appraise events in culturally valued ways—and are afforded by structural conditions—people’s daily lives limit the opportunities for emotion, and afford certain appraisals. The combined evidence suggests that cultural differences in emotion regulation go well beyond the effortful regulation based on display rules.

  2. Cultural regulation of emotion: individual, relational, and structural sources.

    Science.gov (United States)

    De Leersnyder, Jozefien; Boiger, Michael; Mesquita, Batja

    2013-01-01

    The most prevalent and intense emotional experiences differ across cultures. These differences in emotional experience can be understood as the outcomes of emotion regulation, because emotions that fit the valued relationships within a culture tend to be most common and intense. We review evidence suggesting that emotion regulation underlying cultural differences in emotional experience often takes place at the point of emotion elicitation through the promotion of situations and appraisals that are consistent with culturally valued relationships. These regulatory processes depend on individual tendencies, but are also co-regulated within relationships-close others shape people's environment and help them appraise events in culturally valued ways-and are afforded by structural conditions-people's daily lives "limit" the opportunities for emotion, and afford certain appraisals. The combined evidence suggests that cultural differences in emotion regulation go well beyond the effortful regulation based on display rules.

  3. PUREX source Aggregate Area management study report

    International Nuclear Information System (INIS)

    1993-03-01

    This report presents the results of an aggregate area management study (AAMS) for the PUREX Plant Aggregate Area in the 200 Areas of the US Department of Energy (DOE)Hanford Site in Washington State. This scoping level study provides the basis for initiating Remedial Investigation/Feasibility Study (RI/FS) activities under the comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS) under RCRA. This report also integrates select RCRA treatment, storage, or disposal (TSD) closure activities with CERCLA and RCRA past-practice investigations

  4. 42 CFR 456.244 - Data sources for studies.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Data sources for studies. 456.244 Section 456.244 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...: Medical Care Evaluation Studies § 456.244 Data sources for studies. Data that the committee uses to...

  5. 42 CFR 456.144 - Data sources for studies.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Data sources for studies. 456.144 Section 456.144 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Care Evaluation Studies § 456.144 Data sources for studies. Data that the committee uses to perform...

  6. Ballistic studies on layered structures

    International Nuclear Information System (INIS)

    Jena, P.K.; Ramanjeneyulu, K.; Siva Kumar, K.; Balakrishna Bhat, T.

    2009-01-01

    This paper presents the ballistic behavior and penetration mechanism of metal-metal and metal-fabric layered structures against 7.62 armour piercing projectiles at a velocity of 840 ± 15 m/s at 30 o angle of impact and compares the ballistic results with that of homogeneous metallic steel armour. This study also describes the effect of keeping a gap between the target layers. Experimental results showed that among the investigated materials, the best ballistic performance was attained with metal-fabric layered structures. The improvements in ballistic performance were analyzed in terms of mode of failure and fracture mechanisms of the samples by using optical and electron microscope, X-ray radiography and hardness measurement equipments.

  7. Effect of Fuel Structure Materials on Radiation Source Term in Reactor Core Meltdown

    International Nuclear Information System (INIS)

    Jeong, Hae Sun; Ha, Kwang Soon

    2014-01-01

    The fission product (Radiation Source) releases from the reactor core into the containment is obligatorily evaluated to guarantee the safety of Nuclear Power Plant (NPP) under the hypothetical accident involving a core meltdown. The initial core inventory is used as a starting point of all radiological consequences and effects on the subsequent results of accident assessment. Hence, a proper evaluation for the inventory can be regarded as one of the most important part over the entire procedure of accident analysis. The inventory of fission products is typically evaluated on the basis of the uranium material (e.g., UO2 and USi2) loaded in nuclear fuel assembly, except for the structure materials such as the end fittings, grids, and some kinds of springs. However, the structure materials are continually activated by the neutrons generated from the nuclear fission, and some nuclides of them (e.g., 14 C and 60 Co) can significantly influence on accident assessment. During the severe core accident, the structure components can be also melted with the melting points of temperature relatively lower than uranium material. A series of the calculation were performed by using ORIGEN-S module in SCALE 6.1 package code system. The total activity in each part of structure materials was specifically analyzed from these calculations. The fission product inventory is generally evaluated based on the uranium materials of fuel only, even though the structure components of the assembly are continually activated by the neutrons generated from the nuclear fission. In this study, the activation calculation of the fuel structure materials was performed for the initial source term assessment in the accident of reactor core meltdown. As a result, the lower end fitting and the upper plenum greatly contribute to the total activity except for the cladding material. The nuclides of 56 Mn, '5 1 Cr, 55 Fe, 58 Co, 54 Mn, and 60 Co are analyzed to mainly effect on the activity. This result

  8. Uncertainty sources in radiopharmaceuticals clinical studies

    International Nuclear Information System (INIS)

    Degenhardt, Aemilie Louize; Oliveira, Silvia Maria Velasques de

    2014-01-01

    The radiopharmaceuticals should be approved for consumption by evaluating their quality, safety and efficacy. Clinical studies are designed to verify the pharmacodynamics, pharmacological and clinical effects in humans and are required for assuring safety and efficacy. The Bayesian analysis has been used for clinical studies effectiveness evaluation. This work aims to identify uncertainties associated with the process of production of the radionuclide and radiopharmaceutical labelling as well as the radiopharmaceutical administration and scintigraphy images acquisition and processing. For the development of clinical studies in the country, the metrological chain shall assure the traceability of the surveys performed in all phases. (author)

  9. Active pipe-embedded structures in buildings for utilizing low-grade energy sources: A review

    International Nuclear Information System (INIS)

    Xu, Xinhua; Wang, Jinbo; Wang, Shengwei; Xiao, Fu

    2010-01-01

    Low-grade energy sources such as geothermal energy, favorable ambient air and industrial waste heat etc. exist widely. Sufficient utilization of these low-grade energy sources may reduce our daily dependence on high-grade energy sources such as electricity resulting in reduced emission of green house gas for environmental conservation. Active pipe-embedded structure as floor/ceiling usually with water as the medium to carry heat or coolth may utilize these low-grade energy sources for providing space air-conditioning. Compact arrangement of pipes in the structure may significantly enlarge heat transfer surface between the slab mass and water in the pipe allowing substantial heat flows even for relatively small temperature differences. Application of the heat or coolth storage capacity of this structure for preheating or pre-cooling is also one among the advantages of this structure for shifting load and exploiting the nighttime cheap electricity tariff in some regions. This paper presents the technology of the active pipe-embedded structure for utilizing widely existing low-grade energy sources following by a comprehensive review on the heat transfer calculation models of this structure and its practical applications in real building systems for space air-conditioning. This review shows that more works on the active structure, especially simple and transient models for dynamic and accurate performance prediction and easy integration with existing building energy simulation packages, are worthwhile for further promoting the practical application wherever the low-grade energy sources are favorable. (author)

  10. Semiworks source aggregate area management study report

    International Nuclear Information System (INIS)

    1993-05-01

    This report presents the results of an aggregate area management study (AAMS) for the Semi-Works Aggregate Area in the 200 Areas of the US Department of Energy (DOE) . Hanford Site in Washington State. This scoping level study provides the basis for initiating Remedial Investigation/Feasibility Study (RI/FS) activities under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) or Resource Conservation and Recovery Act (RCRA) Facility Investigations WD and Corrective Measures Studies (CMS) under RCRA. This report also integrates select RCRA treatment storage, or disposal (TSD) closure activities with CERCLA and RCRA past-practice investigations. This approach is described and justified in The Hanford Federal Facility Agreement and Consent Order Change Package. This strategy provides new concepts for: accelerating decision-malting by maximizing the use of existing data consistent with data quality objectives (DQOs); and undertaking expedited response actions (ERAS) and/or interim remedial measures (IRMs), as appropriate, to either remove threats to human health and welfare and the environment, or to reduce risk by reducing toxicity, mobility, or volume of contaminants

  11. A Study of Porphyrins in Petroleum Source Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Huseby, Berit

    1997-12-31

    This thesis discusses several aspects of porphyrin geochemistry. Degradation experiments have been performed on the Messel oil shale (Eocene, Germany) to obtain information on porphyrins bound or incorporated into macromolecular structures. Thermal heating of the preextracted kerogen by hydrous pyrolysis was used to study the release of porphyrins and their temperature dependent changes during simulated diagenesis and catagenesis. Selective chemical degradation experiments were performed on the preextracted sediment to get more detailed information about porphyrins that are specifically bound to the macromolecular structures via ester bonds. From the heating experiments, in a separate study, the porphyrin nitrogen content in the generated bitumens was compared to the bulk of organic nitrogen compounds in the fraction. The bulk nitrogen contents in the generated bitumens, the water phase and the residual organic matter was recorded to establish the distribution of nitrogen between the kerogen and product phases. Porphyrins as biomarkers were examined in naturally matured Kimmeridge clay source rocks (Upper Jurassic, Norway), and the use of porphyrins as general indicators of maturity was evaluated. Underlying maturity trends in the biomarker data was investigated by Partial Least Squares analysis. Porphyrin as indicators of depositional conditions was also addressed, where the correlations between the (amounts) abundance of nickel and vanadyl porphyrins were mapped together with other descriptors that are assumed to be indicative of redox depositional conditions. 252 refs., 28 figs., 4 tabs.

  12. A Study of Porphyrins in Petroleum Source Rocks

    Energy Technology Data Exchange (ETDEWEB)

    Huseby, Berit

    1996-12-31

    This thesis discusses several aspects of porphyrin geochemistry. Degradation experiments have been performed on the Messel oil shale (Eocene, Germany) to obtain information on porphyrins bound or incorporated into macromolecular structures. Thermal heating of the preextracted kerogen by hydrous pyrolysis was used to study the release of porphyrins and their temperature dependent changes during simulated diagenesis and catagenesis. Selective chemical degradation experiments were performed on the preextracted sediment to get more detailed information about porphyrins that are specifically bound to the macromolecular structures via ester bonds. From the heating experiments, in a separate study, the porphyrin nitrogen content in the generated bitumens was compared to the bulk of organic nitrogen compounds in the fraction. The bulk nitrogen contents in the generated bitumens, the water phase and the residual organic matter was recorded to establish the distribution of nitrogen between the kerogen and product phases. Porphyrins as biomarkers were examined in naturally matured Kimmeridge clay source rocks (Upper Jurassic, Norway), and the use of porphyrins as general indicators of maturity was evaluated. Underlying maturity trends in the biomarker data was investigated by Partial Least Squares analysis. Porphyrin as indicators of depositional conditions was also addressed, where the correlations between the (amounts) abundance of nickel and vanadyl porphyrins were mapped together with other descriptors that are assumed to be indicative of redox depositional conditions. 252 refs., 28 figs., 4 tabs.

  13. Jackson Bar Training Structure Study

    Science.gov (United States)

    2015-05-01

    comparison of the one-dimensional bridge hydraulic routines from: HEC - RAS , HEC -2, and WSPRO. Davis, CA: U.S. Army Corps of Engineers, Hydrologic Engineering...ER D C/ CH L TR -1 5- 4 Jackson Bar Training Structure Study Co as ta l a nd H yd ra ul ic s La bo ra to ry Jeremy A. Sharp and...Leroy Gage), a previously constructed HEC -2 model, and a previously constructed WES physical model from 1987. Three alternatives were modeled in an

  14. Structural studies of bee melittin

    Energy Technology Data Exchange (ETDEWEB)

    Eisenberg, D.; Terwilliger, T.C.; Tsui, F.

    1980-10-01

    The question of how proteins refold in passing from an aqueous phase to an amphipathic environment such as a membrane is beig addressed by a structural study of bee melittin. Melittin is the toxic, main protein of bee venom, and has been shown by others to integrate into natural and synthetic membranes and to lyse a variety of cells. This function is presumably related to its unusual sequence. Except for charges at the N-terminus and at lysine 7, the first 20 residues are largely apolar. In contrast, the last six residues contain four charges and two polar residues.

  15. Open-Source Data and the Study of Homicide.

    Science.gov (United States)

    Parkin, William S; Gruenewald, Jeff

    2015-07-20

    To date, no discussion has taken place in the social sciences as to the appropriateness of using open-source data to augment, or replace, official data sources in homicide research. The purpose of this article is to examine whether open-source data have the potential to be used as a valid and reliable data source in testing theory and studying homicide. Official and open-source homicide data were collected as a case study in a single jurisdiction over a 1-year period. The data sets were compared to determine whether open-sources could recreate the population of homicides and variable responses collected in official data. Open-source data were able to replicate the population of homicides identified in the official data. Also, for every variable measured, the open-sources captured as much, or more, of the information presented in the official data. Also, variables not available in official data, but potentially useful for testing theory, were identified in open-sources. The results of the case study show that open-source data are potentially as effective as official data in identifying individual- and situational-level characteristics, provide access to variables not found in official homicide data, and offer geographic data that can be used to link macro-level characteristics to homicide events. © The Author(s) 2015.

  16. Validation and calibration of structural models that combine information from multiple sources.

    Science.gov (United States)

    Dahabreh, Issa J; Wong, John B; Trikalinos, Thomas A

    2017-02-01

    Mathematical models that attempt to capture structural relationships between their components and combine information from multiple sources are increasingly used in medicine. Areas covered: We provide an overview of methods for model validation and calibration and survey studies comparing alternative approaches. Expert commentary: Model validation entails a confrontation of models with data, background knowledge, and other models, and can inform judgments about model credibility. Calibration involves selecting parameter values to improve the agreement of model outputs with data. When the goal of modeling is quantitative inference on the effects of interventions or forecasting, calibration can be viewed as estimation. This view clarifies issues related to parameter identifiability and facilitates formal model validation and the examination of consistency among different sources of information. In contrast, when the goal of modeling is the generation of qualitative insights about the modeled phenomenon, calibration is a rather informal process for selecting inputs that result in model behavior that roughly reproduces select aspects of the modeled phenomenon and cannot be equated to an estimation procedure. Current empirical research on validation and calibration methods consists primarily of methodological appraisals or case-studies of alternative techniques and cannot address the numerous complex and multifaceted methodological decisions that modelers must make. Further research is needed on different approaches for developing and validating complex models that combine evidence from multiple sources.

  17. Large scale nuclear structure studies

    International Nuclear Information System (INIS)

    Faessler, A.

    1985-01-01

    Results of large scale nuclear structure studies are reported. The starting point is the Hartree-Fock-Bogoliubov solution with angular momentum and proton and neutron number projection after variation. This model for number and spin projected two-quasiparticle excitations with realistic forces yields in sd-shell nuclei similar good results as the 'exact' shell-model calculations. Here the authors present results for a pf-shell nucleus 46 Ti and results for the A=130 mass region where they studied 58 different nuclei with the same single-particle energies and the same effective force derived from a meson exchange potential. They carried out a Hartree-Fock-Bogoliubov variation after mean field projection in realistic model spaces. In this way, they determine for each yrast state the optimal mean Hartree-Fock-Bogoliubov field. They apply this method to 130 Ce and 128 Ba using the same effective nucleon-nucleon interaction. (Auth.)

  18. Preliminary study of airborne electromagnetic survey using grounded source; Chihyo source gata kuchu denji tansa no kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, T [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Shimoizumi, M [Kitakyushu Polytechnic College, Kitakyushu (Japan); Kusunoki, K [Central Research Institute of Electric Power Industry, Tokyo (Japan); Morikawa, T [Dowa Engineering Co. Ltd., Okayama (Japan); Jomori, N [Chiba Electronics Research Institute, Chiba (Japan)

    1996-05-01

    For the development of an airborne electromagnetic prospecting method capable of deeper exploration, a basic study was made about a system wherein a transmitter (source) is positioned on the ground and the receiving is done in the sky. Even in case of this airborne electromagnetic method, the TDEM method is supposedly advantageous over others as in case of groundborne exploration. In the study, the transient response of an airborne vertical magnetic field to a horizontal layered structure was calculated. The current source was 2000m long with a capacity of 30A. The one-layer structure was a 10 Ohm m semi-infinite ground, and the two-layer structure had a 100 Ohm m structure just under the one-layer structure. The result of the calculation suggests that, in the absence of a layer of extremely low resistivity, observation of an approximately 1 second long transient response aboard a helicopter flying at approximately 50km/h will enable an approximately 1000m deep exploration. Problems to affect airborne observation, such as swinging, natural magnetic field fluctuation, and artificially produced noises were investigated by use of a magnetometer suspended from a helicopter in flight. 2 refs., 6 figs.

  19. St. Sofia in Ohrid, space, structure, forms: Sources

    Directory of Open Access Journals (Sweden)

    Korać Vojislav

    2008-01-01

    Full Text Available This work comments in particular on studies dealing with the church of St. Sofia in Ohrid. Among them are the monographs of two authors, Barbara Maria Schellewald (Die Arhitektur der Sophien Kirchen in Ohrid, Bon 1986 and Boris Čipan (Sveta Sofija, katedralen hram na ohridskata arhiepiskopija, Skopje 1995. Special attention is devoted to the typological interpretation of St. Sofia, to its initial design as a triple-nave basilica with a dome at the centre. Insightful descriptions are given about the older monuments in the Byzantine capital, Constantinople. Special attention is paid to the external architectonic workmanship. The western façade of St. Sofia demonstrates the features of Late Byzantine architecture, while the eastern façade directly reveals the triple-nave spatial design. That is why this article on St. Sofia contains sketches of the western and the eastern façades, illustrating the features of its architectonic specificities. On the whole, the author presents St. Sofia in Ohrid as a unique work of architecture of the Byzantine region. .

  20. Structural studies of cyanobacterial PSII

    International Nuclear Information System (INIS)

    Da Fonseca, Paula Cristina Alves

    2001-01-01

    Photosystem II (PSII) is the photosynthetic transmembrane protein-pigment complex which utilises light energy to drive the splitting of water and release of oxygen, a unique reaction in biological systems. The determination of the structure of PSII at high resolution is required in order to understand its mechanisms of reaction. For this reason, methods have been developed to purify highly active PSII complexes from the thermophilic cyanobacterium Synechococcus elongate These complexes have been studied by high resolution electron microscopy, using both single particle analysis and electron crystallography. A 30A three-dimensional map of the cyanobacterial PSII complex was obtained by single particle analysis. The comparison of this map with structural data from the spinach PSII core dimer revealed that both complexes share similar overall size and shape. These data also allowed a discussion on the organisation and positioning of the extrinsic lumenal proteins within the cyanobacterial PSII complex. A Synechococcus elongatus PSII projection map, at a resolution of 20A, was determined by image processing of two-dimensional crystals formed by the in vitro reconstitution method. This was the first projection map obtained by electron crystallography of a cyanobacterial highly active PSII complex, with all the extrinsic subunits retained. The analysis of this map and its comparison with a 10A three-dimensional map recently obtained from the spinach PSII core dimer revealed a similar organisation of the main transmembrane subunits. Moreover, at the level of resolution of the present data it is possible to identify differences which can be related to the content and organisation of the small subunits forming the PSII complex from both organisms. Cytochrome b559, an important but incompletely understood PSII subunit, was purified and subjected to crystallisation trials in order to aid the interpretation of intermediate resolution PSII structural data. Small crystals were

  1. A 12 GHz RF Power Source for the CLIC Study

    Energy Technology Data Exchange (ETDEWEB)

    Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  2. A 12 GHZ RF Power source for the CLIC study

    CERN Document Server

    Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

    2010-01-01

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  3. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  4. OpenMx: An Open Source Extended Structural Equation Modeling Framework

    Science.gov (United States)

    Boker, Steven; Neale, Michael; Maes, Hermine; Wilde, Michael; Spiegel, Michael; Brick, Timothy; Spies, Jeffrey; Estabrook, Ryne; Kenny, Sarah; Bates, Timothy; Mehta, Paras; Fox, John

    2011-01-01

    OpenMx is free, full-featured, open source, structural equation modeling (SEM) software. OpenMx runs within the "R" statistical programming environment on Windows, Mac OS-X, and Linux computers. The rationale for developing OpenMx is discussed along with the philosophy behind the user interface. The OpenMx data structures are…

  5. Exploring the impact of socio-technical core-periphery structures in open source software development

    NARCIS (Netherlands)

    Amrit, Chintan Amrit; van Hillegersberg, Jos

    2010-01-01

    In this paper we apply the social network concept of core-periphery structure to the socio-technical structure of a software development team. We propose a socio-technical pattern that can be used to locate emerging coordination problems in Open Source projects. With the help of our tool and method

  6. Dual resonant structure for energy harvesting from random vibration sources at low frequency

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-01-01

    Full Text Available We introduce a design with dual resonant structure which can harvest energy from random vibration sources at low frequency range. The dual resonant structure consists of two spring-mass subsystems with different frequency responses, which exhibit strong coupling and broad bandwidth when the two masses collide with each other. Experiments with piezoelectric elements show that the energy harvesting device with dual resonant structure can generate higher power output than the sum of the two separate devices from random vibration sources.

  7. Source Term Characterization for Structural Components in 17 x 17 KOFA Spent Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dong Keun; Kook, Dong Hak; Choi, Heui Joo; Choi, Jong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-12-15

    Source terms of metal waste comprising a spent fuel assembly are relatively important when the spent fuel is pyroprocessed, because cesium, strontium, and transuranics are not a concern any more in the aspect of source term of permanent disposal. In this study, characteristics of radiation source terms for each structural component in spent fuel assembly was analyzed by using ORIGEN-S with a assumption that 10 metric tons of uranium is pyroprocessed. At first, mass and volume for each structural component of the fuel assembly were calculated in detail. Activation cross section library was generated by using KENO-VI/ORIGEN-S module for top-end piece and bottom-end piece, because those are located at outer core with different neutron spectrum compared to that of inner core. As a result, values of radioactivity, decay heat, and hazard index were reveled to be 1.40 x 10{sup 15} Bequerels, 236 Watts, 4.34 x 10{sup 9} m{sup 3}-water, respectively, at 10 years after discharge. Those values correspond to 0.7 %, 1.1 %, 0.1 %, respectively, compared to that of spent fuel. Inconel 718 grid plate was shown to be the most important component in the all aspects of radioactivity, decay heat, and hazard index although the mass occupies only 1 % of the total. It was also shown that if the Inconel 718 grid plate is managed separately, the radioactivity and hazard index of metal waste could be decreased to 20 {approx} 45 % and 30 {approx} 45 %, respectively. As a whole, decay heat of metal waste was shown to be negligible in the aspect of disposal system design, while the radioactivity and hazard index are important.

  8. Source Term Characteristics Analysis for Structural Components in PWR spent fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kook, Dong Hak; Choi, Heui Joo; Cho, Dong Keun [KAERI, Daejeon (Korea, Republic of)

    2010-12-15

    Source terms of metal waste comprising a spent fuel assembly are relatively important when the spent fuel is pyroprocessed, because cesium, strontium, and transuranics are not a concern any more in the aspect of source term of permanent disposal. In this study, characteristics of radiation source terms for each structural component in spent fuel assembly was analyzed by using ORIGEN-S with a assumption that 10 metric tons of uranium is pyroprocessed. At first, mass and volume for each structural component of the fuel assembly were calculated in detail. Activation cross section library was generated by using KENO-VI/ORIGEN-S module for top-end piece and bottom-end piece, because those are located at outer core under different neutron spectrum compared to that of inner core. As a result, values of radioactivity, decay heat, and hazard index were reveled to be 1.32x1015 Bequerels, 238 Watts, 4.32x109 m3 water, respectively, at 10 years after discharge. Those values correspond to 0.6 %, 1.1 %, 0.1 %, respectively, compared to that of spent fuel. Inconel 718 grid plate was shown to be the most important component in the all aspects of radioactivity, decay heat, and hazard index although the mass occupies only 1 % of the total. It was also shown that if the Inconel 718 grid plate is managed separately, the radioactivity and hazard index of metal waste could be decreased to 25{approx}50 % and 35{approx}40 %, respectively. As a whole, decay heat of metal waste was shown to be negligible in the aspect of disposal system design, while the radioactivity and hazard index are important

  9. The Structures and Possible Sources of Preservice Elementary Teachers' Mental Models About Moon Phases

    Directory of Open Access Journals (Sweden)

    Jun-Young Oh

    2005-09-01

    Full Text Available This study was to understand the components that influence preservice elementary teachers' mental models about `astronomical phenomena' such as the Seasons of the year, and the Lunar Phases of the month. We selected university of education students among whom 23 were in the second year. The data collected from the paper-pencil test and individual interview with students. The results of this study show that the students had apparent synthetic Mental models, and that the 'distance theory, and occultation theory' had most important effects on their Mental Models. It can be said that preservice elementary teachers' initial mental models of the `astronomical phenomenon' have their origin in their belief sets (specific theory related to `astronomical phenomenon', on the basis of which they can interpret their observations and cultural information with the constraints of a naive framework of physics. The structures and possible sources of their mental models for overcoming these synthetic mental models were also discussed.

  10. Emotion impairs extrinsic source memory--An ERP study.

    Science.gov (United States)

    Mao, Xinrui; You, Yuqi; Li, Wen; Guo, Chunyan

    2015-09-01

    Substantial advancements in understanding emotional modulation of item memory notwithstanding, controversies remain as to how emotion influences source memory. Using an emotional extrinsic source memory paradigm combined with remember/know judgments and two key event-related potentials (ERPs)-the FN400 (a frontal potential at 300-500 ms related to familiarity) and the LPC (a later parietal potential at 500-700 ms related to recollection), our research investigated the impact of emotion on extrinsic source memory and the underlying processes. We varied a semantic prompt (either "people" or "scene") preceding a study item to manipulate the extrinsic source. Behavioral data indicated a significant effect of emotion on "remember" responses to extrinsic source details, suggesting impaired recollection-based source memory in emotional (both positive and negative) relative to neutral conditions. In parallel, differential FN400 and LPC amplitudes (correctly remembered - incorrectly remembered sources) revealed emotion-related interference, suggesting impaired familiarity and recollection memory of extrinsic sources associated with positive or negative items. These findings thus lend support to the notion of emotion-induced memory trade off: while enhancing memory of central items and intrinsic/integral source details, emotion nevertheless disrupts memory of peripheral contextual details, potentially impairing both familiarity and recollection. Importantly, that positive and negative items result in comparable memory impairment suggests that arousal (vs. affective valence) plays a critical role in modulating dynamic interactions among automatic and elaborate processes involved in memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Radiotracer and Sealed Source Applications in Sediment Transport Studies

    International Nuclear Information System (INIS)

    2014-01-01

    The investigation of sediment transport in seas and rivers is crucial for civil engineering and littoral protection and management. Coastlines and seabeds are dynamic regions, with sediments undergoing periods of erosion, transport, sedimentation and consolidation. The main causes for erosion in beaches include storms and human actions such as the construction of seawalls, jetties and the dredging of stream mouths. Each of these human actions disrupts the natural flow of sand. Current policies and practices are accelerating the beach erosion process. However, there are viable options available to mitigate this damage and to provide for sustainable coastlines. Radioactive methods can help in investigating sediment dynamics, providing important parameters for better designing, maintaining and optimizing civil engineering structures. Radioisotopes as tracers and sealed sources have been useful and often irreplaceable tools for sediment transport studies. The training course material is based on lecture notes and practical works delivered by many experts in IAEA supported activities. Lectures and case studies were reviewed by a number of specialists in this field

  12. Engagement as a source of positive consumer behaviour: a study ...

    African Journals Online (AJOL)

    Engagement as a source of positive consumer behaviour: a study amongst South African football fans. ... Remember me ... Further, the potential of fan engagement as a predictor of positive consumer behaviours (match attendance and ...

  13. Study of quark structure functions

    International Nuclear Information System (INIS)

    Dao, F.T.; Flaminio, E.; Lai, K.; Metcalf, M.; Wang, L.

    1977-01-01

    The quark structure functions of the proton are determined through a combined analysis of the reactions pN → ll-barX and eN → eX. The valence-quark structure function of the pion is also given by analyzing the πN → μμ-barX data measured by the Branson et al

  14. Relative effectiveness of structures as protection from gamma radiation from cloud and fallout sources as a function of source energy

    International Nuclear Information System (INIS)

    Fingerlos, J.P.

    1984-01-01

    In the event of a release of radioactive material, it is necessary to know the doses the public could receive in order to make decisions that minimize the public's risk. In order to determine what doses the public might receive if they try to evacuate or seek shelter, it is necessary to know how much protection structures such as homes and vehicles provide. This information is well known only for a few gamma ray spectra, such as that from weapon fallout. The research reported here transfers the knowledge gained from the previous weapon-fallout shielding work to realistic protection factors for possible accidental releases whatever the released spectrum might be. Point kernel models were developed for both the fallout and cloud sources. That development included a method of accurately combining buildup factors in multi-region problems over wide ranges of energy and photon mean free path. A generalized method for calculating the effect of ground roughness on the attentuation factor for fallout sources was also developed. The results were reported for the 1-hr weapon fallout, and TMI-2 cloud and fallout spectra, as well as for discrete energies from 15 KeV to 15 MeV. The structures given as examples include small wood frame and large brick houses

  15. Characterization of Crystallographic Structures Using Bragg-Edge Neutron Imaging at the Spallation Neutron Source

    Directory of Open Access Journals (Sweden)

    Gian Song

    2017-12-01

    Full Text Available Over the past decade, wavelength-dependent neutron radiography, also known as Bragg-edge imaging, has been employed as a non-destructive bulk characterization method due to its sensitivity to coherent elastic neutron scattering that is associated with crystalline structures. Several analysis approaches have been developed to quantitatively determine crystalline orientation, lattice strain, and phase distribution. In this study, we report a systematic investigation of the crystal structures of metallic materials (such as selected textureless powder samples and additively manufactured (AM Inconel 718 samples, using Bragg-edge imaging at the Oak Ridge National Laboratory (ORNL Spallation Neutron Source (SNS. Firstly, we have implemented a phenomenological Gaussian-based fitting in a Python-based computer called iBeatles. Secondly, we have developed a model-based approach to analyze Bragg-edge transmission spectra, which allows quantitative determination of the crystallographic attributes. Moreover, neutron diffraction measurements were carried out to validate the Bragg-edge analytical methods. These results demonstrate that the microstructural complexity (in this case, texture plays a key role in determining the crystallographic parameters (lattice constant or interplanar spacing, which implies that the Bragg-edge image analysis methods must be carefully selected based on the material structures.

  16. Thermal-hydraulic studies of the Advanced Neutron Source cold source

    International Nuclear Information System (INIS)

    Williams, P.T.; Lucas, A.T.

    1995-08-01

    The Advanced Neutron Source (ANS), in its conceptual design phase at Oak Ridge National Laboratory, was to be a user-oriented neutron research facility producing the most intense steady-state flux of thermal and cold neutrons in the world. Among its many scientific applications, the production of cold neutrons was a significant research mission for the ANS. The cold neutrons come from two independent cold sources positioned near the reactor core. Contained by an aluminum alloy vessel, each cold source is a 410-mm-diam sphere of liquid deuterium that functions both as a neutron moderator and a cryogenic coolant. With nuclear heating of the containment vessel and internal baffling, steady-state operation requires close control of the liquid deuterium flow near the vessel's inner surface. Preliminary thermal-hydraulic analyses supporting the cold source design were performed with heat conduction simulations of the vessel walls and multidimensional computational fluid dynamics simulations of the liquid deuterium flow and heat transfer. This report presents the starting phase of a challenging program and describes the cold source conceptual design, the thermal-hydraulic feasibility studies of the containment vessel, and the future computational and experimental studies that were planned to verify the final design

  17. Studies and modeling of cold neutron sources; Etude et modelisation des sources froides de neutron

    Energy Technology Data Exchange (ETDEWEB)

    Campioni, G

    2004-11-15

    With the purpose of updating knowledge in the fields of cold neutron sources, the work of this thesis has been run according to the 3 following axes. First, the gathering of specific information forming the materials of this work. This set of knowledge covers the following fields: cold neutron, cross-sections for the different cold moderators, flux slowing down, different measurements of the cold flux and finally, issues in the thermal analysis of the problem. Secondly, the study and development of suitable computation tools. After an analysis of the problem, several tools have been planed, implemented and tested in the 3-dimensional radiation transport code Tripoli-4. In particular, a module of uncoupling, integrated in the official version of Tripoli-4, can perform Monte-Carlo parametric studies with a spare factor of Cpu time fetching 50 times. A module of coupling, simulating neutron guides, has also been developed and implemented in the Monte-Carlo code McStas. Thirdly, achieving a complete study for the validation of the installed calculation chain. These studies focus on 3 cold sources currently functioning: SP1 from Orphee reactor and 2 other sources (SFH and SFV) from the HFR at the Laue Langevin Institute. These studies give examples of problems and methods for the design of future cold sources.

  18. Separation of simultaneous sources using a structural-oriented median filter in the flattened dimension

    Science.gov (United States)

    Gan, Shuwei; Wang, Shoudong; Chen, Yangkang; Chen, Xiaohong; Xiang, Kui

    2016-01-01

    Simultaneous-source shooting can help tremendously shorten the acquisition period and improve the quality of seismic data for better subsalt seismic imaging, but at the expense of introducing strong interference (blending noise) to the acquired seismic data. We propose to use a structural-oriented median filter to attenuate the blending noise along the structural direction of seismic profiles. The principle of the proposed approach is to first flatten the seismic record in local spatial windows and then to apply a traditional median filter (MF) to the third flattened dimension. The key component of the proposed approach is the estimation of the local slope, which can be calculated by first scanning the NMO velocity and then transferring the velocity to the local slope. Both synthetic and field data examples show that the proposed approach can successfully separate the simultaneous-source data into individual sources. We provide an open-source toy example to better demonstratethe proposed methodology.

  19. Comparison of seismic sources for imaging geologic structures on the Oak Ridge Reservation, Tennessee

    International Nuclear Information System (INIS)

    Doll, W.E.

    1997-02-01

    In this study, five non-invasive swept sources, three non-invasive impulsive sources and one invasive impulsive source were compared. Previous shallow seismic source tests (Miller and others, 1986, 1992, 1994) have established that site characteristics should be considered in determining the optimal source. These studies evaluated a number of invasive sources along with a few non-invasive impulsive sources. Several sources (particularly the high frequency vibrators) that were included in the ORR test were not available or not practical during previous tests, cited above. This study differs from previous source comparisons in that it (1) includes many swept sources, (2) is designed for a greater target depth, (3) was conducted in a very different geologic environment, and (4) generated a larger and more diverse data set (including high fold CMP sections and walkaway vertical seismic profiles) for each source. The test site is centered around test injection well HF-2, between the southern end of Waste Area Grouping 5 (WAG 5) and the High Flux Isotope Reactor (HFIR)

  20. Experimental study of adsorption chiller driven by variable heat source

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L. [College of Electromechanical Engineering, Qingdao University, Qingdao 266071 (China); Wu, J.Y. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-05-15

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed. (author)

  1. Experimental study of adsorption chiller driven by variable heat source

    International Nuclear Information System (INIS)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L.; Wu, J.Y.

    2008-01-01

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed

  2. Remote defect imaging for plate-like structures based on the scanning laser source technique

    Science.gov (United States)

    Hayashi, Takahiro; Maeda, Atsuya; Nakao, Shogo

    2018-04-01

    In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe.

  3. Laser plasmas as x-ray sources for lithographic imaging of submicron structures

    International Nuclear Information System (INIS)

    Bijkerk, F.; van Dorssen, G.E.; van der Wiel, M.J.

    1988-01-01

    Laser radiation can be used efficiently to generate x-rays for lithographic imaging of submicron patterns, e.g., for VLSI device fabrication. Due to their short wavelength and high average power, excimer lasers show much potential for this application. Results are presented of scaling studies for high repetition rate excimer laser application, using the frequency doubled output of a low repetition rate Nd:YAG/Glass laser. Spectral and spatial characteristics of x-ray emission of the laser plasma are shown. The power density in the laser focus was 3 x 10 12 W/cm 2 . With this source Si x-ray masks with submicron Au absorber profiles are imaged into high sensitivity x-ray photoresist. For the exposures 80 laser shots sufficed to yield high quality submicron structures. Extrapolation of the results to a high power excimer laser reduces the exposure time of the photoresists to several seconds, enabling a wafer throughput at an industrial level

  4. A study on CCDTL structure

    International Nuclear Information System (INIS)

    Zhang Mutian; Xu Taoguang; Xu Wenwu; Zhou Linong

    2002-01-01

    The CCDTL (Coupled Cavity Drift Tube Linac) structure presented by Los Alamos Lab is a new structure for proton's velocity from 0.1 c to 0.5 c. The CCDTL aluminium and copper model are manufactured. The final OFHC (Oxygen Free High Conductivity) model consists of four accelerating cavities and three coupling cavities. There is only one drift tube in the accelerating cavity, so one accelerating cavity has two accelerating gaps. The model was made and tuned. The basic characteristics of the structure such as cavity frequency, dispersion curve, coupling, field profile are measured

  5. Sucrose Fermentation by Brazilian Ethanol Production Yeasts in Media Containing Structurally Complex Nitrogen Sources

    OpenAIRE

    Miranda Junior, Messias [UNESP; Batistote, Margareth [UNESP; Cilli, Eduardo Maffud [UNESP; Ernandes, Jose Roberto [UNESP

    2009-01-01

    Four Saccharomyces cerevisiae Brazilian industrial ethanol production strains were grown, under shaken and static conditions, in media containing 22% (w/v) sucrose supplemented with nitrogen sources varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids) and peptides (peptone). Sucrose fermentations by Brazilian industrial ethanol production yeasts strains were strongly affected by both the structural complexity of the nitrogen source and the availability o...

  6. Structures of interplanetary magnetic flux ropes and comparison with their solar sources

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qiang [Department of Space Science/CSPAR, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Qiu, Jiong [Department of Physics, Montana State University, Bozeman, MT 59717-3840 (United States); Dasgupta, B.; Khare, A.; Webb, G. M., E-mail: qh0001@uah.edu, E-mail: qiu@physics.montana.edu [Center for Space Plasma and Aeronomic Research (CSPAR), University of Alabama in Huntsville, Huntsville, AL 35805 (United States)

    2014-09-20

    Whether a magnetic flux rope is pre-existing or formed in situ in the Sun's atmosphere, there is little doubt that magnetic reconnection is essential to release the flux rope during its ejection. During this process, the question remains: how does magnetic reconnection change the flux-rope structure? In this work, we continue with the original study of Qiu et al. by using a larger sample of flare-coronal mass ejection (CME)-interplanetary CME (ICME) events to compare properties of ICME/magnetic cloud (MC) flux ropes measured at 1 AU and properties of associated solar progenitors including flares, filaments, and CMEs. In particular, the magnetic field-line twist distribution within interplanetary magnetic flux ropes is systematically derived and examined. Our analysis shows that, similar to what was found before, for most of these events, the amount of twisted flux per AU in MCs is comparable with the total reconnection flux on the Sun, and the sign of the MC helicity is consistent with the sign of the helicity of the solar source region judged from the geometry of post-flare loops. Remarkably, we find that about half of the 18 magnetic flux ropes, most of them associated with erupting filaments, have a nearly uniform and relatively low twist distribution from the axis to the edge, and the majority of the other flux ropes exhibit very high twist near the axis, up to ≳ 5 turns per AU, which decreases toward the edge. The flux ropes are therefore not linearly force-free. We also conduct detailed case studies showing the contrast of two events with distinct twist distribution in MCs as well as different flare and dimming characteristics in solar source regions, and discuss how reconnection geometry reflected in flare morphology may be related to the structure of the flux rope formed on the Sun.

  7. SMARTer for magnetic structure studies

    Indian Academy of Sciences (India)

    Small angle neutron scattering; magnetic structure; Cu(NiFe); CuCo; ... micromagnetism, magnetic clusters embedded in a solid nonmagnetic matrix, mag- .... project. E G R Putra acknowledges the support from IAEA through the ISNS2008.

  8. A Separation Algorithm for Sources with Temporal Structure Only Using Second-order Statistics

    Directory of Open Access Journals (Sweden)

    J.G. Wang

    2013-09-01

    Full Text Available Unlike conventional blind source separation (BSS deals with independent identically distributed (i.i.d. sources, this paper addresses the separation from mixtures of sources with temporal structure, such as linear autocorrelations. Many sequential extraction algorithms have been reported, resulting in inevitable cumulated errors introduced by the deflation scheme. We propose a robust separation algorithm to recover original sources simultaneously, through a joint diagonalizer of several average delayed covariance matrices at positions of the optimal time delay and its integers. The proposed algorithm is computationally simple and efficient, since it is based on the second-order statistics only. Extensive simulation results confirm the validity and high performance of the algorithm. Compared with related extraction algorithms, its separation signal-to-noise rate for a desired source can reach 20dB higher, and it seems rather insensitive to the estimation error of the time delay.

  9. Sources of motivation, interpersonal conflict management styles, and leadership effectiveness: a structural model.

    Science.gov (United States)

    Barbuto, John E; Xu, Ye

    2006-02-01

    126 leaders and 624 employees were sampled to test the relationship between sources of motivation and conflict management styles of leaders and how these variables influence effectiveness of leadership. Five sources of motivation measured by the Motivation Sources Inventory were tested-intrinsic process, instrumental, self-concept external, self-concept internal, and goal internalization. These sources of work motivation were associated with Rahim's modes of interpersonal conflict management-dominating, avoiding, obliging, complying, and integrating-and to perceived leadership effectiveness. A structural equation model tested leaders' conflict management styles and leadership effectiveness based upon different sources of work motivation. The model explained variance for obliging (65%), dominating (79%), avoiding (76%), and compromising (68%), but explained little variance for integrating (7%). The model explained only 28% of the variance in leader effectiveness.

  10. Source study of local coalfield events using the modal synthesis of shear and surface waves

    Energy Technology Data Exchange (ETDEWEB)

    MacBeth, C.D.; Redmayne, D.W.

    1989-10-01

    Results from the BGS LOWNET array from the Midlothian coalfield in Scotland have been studied. Vertical component seismograms have been analysed using a waveform matching technique based on the modal summation method for constructing synthetic seismograms. Results of the analysis are applied to S and surface wave portions of the seismogram. Effects of different earth structures, source depths, source orientation, and type of event, rockburst or triggered earthquake 2-3 km from the mine workings, can be evaluated.

  11. Comparative studies of energy sources in gynecologic laparoscopy.

    Science.gov (United States)

    Law, Kenneth S K; Lyons, Stephen D

    2013-01-01

    Energy sources incorporating "vessel sealing" capabilities are being increasingly used in gynecologic laparoscopic surgery although conventional monopolar and bipolar electrosurgery remain popular. The preference for one device over another is based on a combination of factors, including the surgeon's subjective experience, availability, and cost. Although comparative clinical studies and meta-analyses of laparoscopic energy sources have reported small but statistically significant differences in volumes of blood loss, the clinical significance of such small volumes is questionable. The overall usefulness of the various energy sources available will depend on a number of factors including vessel burst pressure and seal time, lateral thermal spread, and smoke production. Animal studies and laboratory-based trials are useful in providing a controlled environment to investigate such parameters. At present, there is insufficient evidence to support the use of one energy source over another. Copyright © 2013 AAGL. All rights reserved.

  12. Earthquake Source Spectral Study beyond the Omega-Square Model

    Science.gov (United States)

    Uchide, T.; Imanishi, K.

    2017-12-01

    Earthquake source spectra have been used for characterizing earthquake source processes quantitatively and, at the same time, simply, so that we can analyze the source spectra for many earthquakes, especially for small earthquakes, at once and compare them each other. A standard model for the source spectra is the omega-square model, which has the flat spectrum and the falloff inversely proportional to the square of frequencies at low and high frequencies, respectively, which are bordered by a corner frequency. The corner frequency has often been converted to the stress drop under the assumption of circular crack models. However, recent studies claimed the existence of another corner frequency [Denolle and Shearer, 2016; Uchide and Imanishi, 2016] thanks to the recent development of seismic networks. We have found that many earthquakes in areas other than the area studied by Uchide and Imanishi [2016] also have source spectra deviating from the omega-square model. Another part of the earthquake spectra we now focus on is the falloff rate at high frequencies, which will affect the seismic energy estimation [e.g., Hirano and Yagi, 2017]. In June, 2016, we deployed seven velocity seismometers in the northern Ibaraki prefecture, where the shallow crustal seismicity mainly with normal-faulting events was activated by the 2011 Tohoku-oki earthquake. We have recorded seismograms at 1000 samples per second and at a short distance from the source, so that we can investigate the high-frequency components of the earthquake source spectra. Although we are still in the stage of discovery and confirmation of the deviation from the standard omega-square model, the update of the earthquake source spectrum model will help us systematically extract more information on the earthquake source process.

  13. PM10 source apportionment study in Pleasant Valley, Nevada

    International Nuclear Information System (INIS)

    Egami, R.T.; Chow, J.C.; Watson, J.G.; DeLong, T.

    1990-01-01

    A source apportionment study was conducted between March 18 and April 4, 1988, at Pleasant Valley, Nevada, to evaluate air pollutant concentrations to which community residents were exposed and the source contributions to those pollutants. Daily PM 10 samples were taken for chemical speciation of 40 trace elements, ions, and organic and elemental carbon. This paper reports that the objectives of this case study are: to determine the emissions source composition of the potential upwind source, a geothermal plant; to measure the ambient particulate concentration and its chemical characteristics in Pleasant Valley; and to estimate the contributions of different emissions sources to PM 10 . The study found that: particulate emissions from the geothermal cooling-tower plume consisted primarily of sulfate, ammonia, chloride, and trace elements; no significant quantities of toxic inorganic species were found in the ambient air; ambient PM 10 concentrations in Pleasant Valley were within Federal standards; and source contribution to PM 10 were approximately 60% geological material; 20% motor vehicle exhaust; and 10% cooling-tower plume

  14. Magnetic structures: neutron diffraction studies

    International Nuclear Information System (INIS)

    Bouree-Vigneron, F.

    1990-01-01

    Neutron diffraction is often an unequivocal method for determining magnetic structures. Here we present some typical examples, stressing the sequence through experiments, data analysis, interpretation and modelisation. Two series of compounds are chosen: Tb Ni 2 Ge 2 and RBe 13 (R = Gd, Tb, Dy, Ho, Er). Depending on the nature of the elements, the magnetic structures produced can be commensurate, incommensurate or even show a transition between two such phases as a function of temperature. A model, taking magnetic exchange and anisotropy into account, will be presented in the case of commensurate-incommensurate magnetic transitions in RBe 13

  15. A pulsed source neutron reflectometer for surface studies

    International Nuclear Information System (INIS)

    Penfold, J.; Williams, W.G.

    1985-05-01

    A design for a neutron reflectometer for surface studies to be constructed at the SNS is presented. Examples of its use to study problems in surface chemistry, surface magnetism and low dimensional structures are highlighted. (author)

  16. Simulation study on ion extraction from ECR ion sources

    International Nuclear Information System (INIS)

    Fu, S.; Kitagawa, A.; Yamada, S.

    1993-07-01

    In order to study beam optics of NIRS-ECR ion source used in HIMAC, EGUN code has been modified to make it capable of modeling ion extraction from a plasma. Two versions of the modified code are worked out with two different methods in which 1-D and 2-D sheath theories are used respectively. Convergence problem of the strong nonlinear self-consistent equations is investigated. Simulations on NIRS-ECR ion source and HYPER-ECR ion source (in INS, Univ. of Tokyo) are presented in this paper, exhibiting an agreement with the experimental results. Some preliminary suggestions on the upgrading the extraction systems of these sources are also proposed. (author)

  17. Simulation study on ion extraction from ECR ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S.; Kitagawa, A.; Yamada, S.

    1993-07-01

    In order to study beam optics of NIRS-ECR ion source used in HIMAC, EGUN code has been modified to make it capable of modeling ion extraction from a plasma. Two versions of the modified code are worked out with two different methods in which 1-D and 2-D sheath theories are used respectively. Convergence problem of the strong nonlinear self-consistent equations is investigated. Simulations on NIRS-ECR ion source and HYPER-ECR ion source (in INS, Univ. of Tokyo) are presented in this paper, exhibiting an agreement with the experimental results. Some preliminary suggestions on the upgrading the extraction systems of these sources are also proposed. (author).

  18. Study of extragalactic sources with H.E.S.S

    International Nuclear Information System (INIS)

    Giebels, Berrie

    2007-01-01

    The field of Very High Energy (VHE) γ-ray emitting extragalactic sources has considerably evolved since the new generation of atmospheric Cerenkov telescopes (ACT) of improved sensitivity, such as H.E.S.S. array and the MAGIC ACT, have started operating. This has led to a wealth of new clues about emission mechanisms at high energy through the discovery of new sources, more accurate spectra and temporal studies of sources known previously, and simultaneous multi-wavelength (MWL) campaigns since broad band variability is a key phenomenon to the underlying physical mechanisms at play. The fact that some of these new sources are located at redshifts close to z ∼ 0.2 makes them powerful probes of the Extragalactic Background Light (EBL) through the attenuation of γ-rays above 100 GeV

  19. Critical Study of Corrosion Damaged Concrete Structures

    OpenAIRE

    Sallehuddin Shah Ayop; John Cairns

    2013-01-01

    Corrosion of steel reinforcement in concrete is one of the major problems with respect to the durability of reinforced concrete structures. The degradation of the structure strength due to reinforcement corrosion decreases its design life. This paper presents the literature study on the influence of the corrosion on concrete structure starting from the mechanism of the corrosion until the deterioration stage and the structural effects of corrosion on concrete structures.

  20. A primer on polymer nomenclature: Structure-based, sourced-based and trade names

    Science.gov (United States)

    Polymer nomenclature is important because it is part of the language of polymer science and is needed for polymer identification, reference, and documentation. A primer on polymer nomenclature is provided herein for people new to the field or for instructional use. Both structure-based and source-...

  1. 40 CFR 60.2035 - How are these new source performance standards structured?

    Science.gov (United States)

    2010-07-01

    ... standards structured? 60.2035 Section 60.2035 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... source performance standards contain the eleven major components listed in paragraphs (a) through (k) of this section. (a) Preconstruction siting analysis. (b) Waste management plan. (c) Operator training and...

  2. A plausible energy source and structure for quasi-stellar objects

    Science.gov (United States)

    Daltabuit, E.; Cox, D.

    1972-01-01

    If a collision of two large, massive, fast gas clouds occurs, their kinetic energy is converted to radiation in a pair of shock fronts at their interface. The resulting structure is described, and the relevance of this as a radiation source for quasi-stellar objects is considered.

  3. Structure shielding from cloud and fallout gamma ray sources for assessing the consequences of reactor accidents

    International Nuclear Information System (INIS)

    Burson, Z.G.; Profio, A.E.

    1975-12-01

    Radiation shielding provided by transportation vehicles and structures typical of where people live and work were estimated for cloud and fallout gamma-ray sources resulting from a hypothetical reactor accident. Dose reduction factors are recommended for a variety of situations for realistically assessing the consequences of reactor accidents

  4. Source Identification in Structural Acoustics with an Inverse Frequency Response Function Technique

    NARCIS (Netherlands)

    Visser, Rene

    2002-01-01

    Inverse source identification based on acoustic measurements is essential for the investigation and understanding of sound fields generated by structural vibrations of various devices and machinery. Acoustic pressure measurements performed on a grid in the nearfield of a surface can be used to

  5. Study of zirconia microporous structure

    International Nuclear Information System (INIS)

    Gavrilov, V.Yu.

    2000-01-01

    Microporous structure of zirconium dioxide obtained by precipitation at variation of precipitating pH and time of gel aging was investigated with use of data on physical adsorption of nitrogen, oxygen and molecular hydrogen. Proportional increase of the supermicropore surface value measured on adsorption of O 2 over the value measured on adsorption of N 2 depending on the value of properly supermicropore detected earlier was shown to be held for zirconium dioxide. Formation of ZrO 2 microporous structure is precipitation pH dependent. Increase of pH on the 4 - 7 interval leads to decrease of volume of micropores during synchronous increase of supermicropore surface value, and mesopore at pH > 5. Gel aging is followed by additional reconstruction involving increase of sizes of micropores at minor increase of their common volume. Limit volume of sorption space of xerogel and common porosity grow take place too [ru

  6. Structure studies of macromolecular systems

    Czech Academy of Sciences Publication Activity Database

    Hašek, Jindřich; Dohnálek, Jan; Skálová, Tereza; Dušková, Jarmila; Kolenko, Petr

    2006-01-01

    Roč. 13, č. 3 (2006), s. 136 ISSN 1211-5894. [Czech and Slovak Crystallographic Colloquium. 22.06.2006-24.06.2006, Grenoble] R&D Projects: GA AV ČR IAA4050811; GA MŠk 1K05008 Keywords : structure * X-ray diffraction * synchrotron Subject RIV: CD - Macromolecular Chemistry http://www. xray .cz/ms/default.htm

  7. Sealed source and device removal and consolidation feasibility study

    International Nuclear Information System (INIS)

    Ward, J.E.; Carter, J.G.; Meyers, R.L.

    1993-02-01

    The purpose of this study is to assess the feasibility of removing Greater-Than-Class C (GTCC) sealed sources from their containment device and consolidating them for transport to a storage or disposal facility. A sealed source is a sealed capsule containing a radioactive material that is placed in a device providing radioactive containment. It is used in the medical, industrial, research, and food-processing communities for calibrating, measuring, gauging, controlling processes, and testing. This feasibility study addresses the key operational, safety, regulatory, and financial requirements of the removal/consolidation process. This report discusses the process to receive, handle, repackage, and ship these sources to an interim or dedicated storage facility until a final disposal repository can be built and become operational (∼ c. 2010). The study identifies operational and facility requirements to perform this work. Hanford, other DOE facilities, and private hot-cell facilities were evaluated to determine which facilities could perform this work. The personnel needed, design and engineering, facility preparation, process waste disposal requirements, and regulatory compliance were evaluated to determine the cost to perform this work. Cost requirements for items that will have to meet future changing regulatory requirements for transportation, transportation container design and engineering, and disposal were not included in this study. The cost associated with in-process consolidation of the sealed sources reported in this study may have not been modified for inflation and were based on 1992 dollars. This study shows that sealed source consolidation is possible with minimal personnel exposure, and would reduce the risk of radioactive releases to the environment. An initial pilot-scale operation could evaluate the possible methods to reduce the cost and consolidate sources

  8. Langmuir probe studies on a RF ion source for NBI

    International Nuclear Information System (INIS)

    McNeely, P.; Heineman, B.; Kraus, W.; Riedl, R.; Speth, E.; Vollmer, O.

    2001-01-01

    IPP Garching has been developing a RF ion source for H - production. In order to improve the data quality a new scanning probe system with passive RF compensation has been installed on the Type VI ion source on the BATMAN test stand. Using this probe, measurements have been carried out to study changes to the plasma parameters (electron density, electron temperature, and plasma potential) due to variation in the source operating conditions. The data were collected at a source pressure of 0.5 Pa and with 60±5 kW applied RF power. Presented are some of the results of these measurements, focusing on the effect of: argon seeding, addition of Cs to the source, and the newly added Faraday screen. The electron density behaves in a fashion that agrees with the theory of ambipolar diffusion. Typically there is little change to the average electron energy observed regardless of which effect is considered. The plasma potential shows the most significant changes with external source conditions, both in value for all cases and shape when the Faraday screen was added

  9. Review of SFR In-Vessel Radiological Source Term Studies

    International Nuclear Information System (INIS)

    Suk, Soo Dong; Lee, Yong Bum

    2008-10-01

    An effort has been made in this study to search for and review the literatures in public domain on the studies of the phenomena related to the release of radionuclides and aerosols to the reactor containment of the sodium fast reactor (SFR) plants (i.e., in-vessel source term), made in Japan and Europe including France, Germany and UK over the last few decades. Review work is focused on the experimental programs to investigate the phenomena related to determining the source terms, with a brief review on supporting analytical models and computer programs. In this report, the research programs conducted to investigate the CDA (core disruptive accident) bubble behavior in the sodium pool for determining 'primary' or 'instantaneous' source term are first introduced. The studies performed to determine 'delayed source term' are then described, including the various stages of phenomena and processes: fission product (FP) release from fuel , evaporation release from the surface of the pool, iodine mass transfer from fission gas bubble, FP deposition , and aerosol release from core-concrete interaction. The research programs to investigate the release and transport of FPs and aerosols in the reactor containment (i.e., in-containment source term) are not described in this report

  10. Study of two different radioactive sources for prostate brachytherapy treatment

    International Nuclear Information System (INIS)

    Pereira Neves, Lucio; Perini, Ana Paula; Souza Santos, William de; Caldas, Linda V.E.; Belinato, Walmir

    2015-01-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a 192 Ir and a 125 I radioactive sources. The 192 Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The 125 I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of 125 I and one of 192 Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the 192 Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the 125 I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  11. Study of two different radioactive sources for prostate brachytherapy treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Neves, Lucio; Perini, Ana Paula [Instituto de Fisica, Universidade Federal de Uberlandia, Caixa Postal 593, 38400-902, Uberlandia, MG (Brazil); Souza Santos, William de; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares, Comissao Nacional de Energia Nuclear, IPENCNEN/SP, Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, 05508-000 Sao Paulo, SP (Brazil); Belinato, Walmir [Departamento de Ensino, Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia, Campus Vitoria da Conquista, Zabele, Av. Amazonas 3150, 45030-220 Vitoria da Conquista, BA (Brazil)

    2015-07-01

    In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

  12. Study of an hybrid positron source using channeling for CLIC

    CERN Document Server

    Dadoun, O; Chehab, R; Poirier, F; Rinolfi, L; Strakhovenko, V; Variola, A; Vivoli, A

    2009-01-01

    The CLIC study considers the hybrid source using channeling as the baseline for positron production. The hybrid source uses a few GeV electron beam impinging on a crystal tungsten radiator. With the tungsten crystal oriented on its axis it results an intense, relatively low energy photon beam due mainly to channeling radiation. Those photons are then impinging on an amorphous tungsten target producing positrons by e+e− pair creation. In this note the optimization of the positron yield and the peak energy deposition density in the amorphous target are studied according to the distance between the crystal and the amorphous targets, the primary electron energy and the amorphous target thickness.

  13. Do knowledge, knowledge sources and reasoning skills affect the accuracy of nursing diagnoses? a randomised study

    NARCIS (Netherlands)

    Paans, W.; Sermeus, W.; Nieweg, R.M.; Krijnen, W.P.; van der Schans, C.P.

    2012-01-01

    ABSTRACT: BACKGROUND: This paper reports a study about the effect of knowledge sources, such as handbooks, an assessment format and a predefined record structure for diagnostic documentation, as well as the influence of knowledge, disposition toward critical thinking and reasoning skills, on the

  14. Do knowledge, knowledge sources and reasoning skills affect the accuracy of nursing diagnoses? : a randomised study

    NARCIS (Netherlands)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos; Krijnen, Wim P.; van der Schans, Cees P.

    2012-01-01

    BACKGROUND: This paper reports a study about the effect of knowledge sources, such as handbooks, an assessment format and a predefined record structure for diagnostic documentation, as well as the influence of knowledge, disposition toward critical thinking and reasoning skills, on the accuracy of

  15. A californium-252 source for radiobiological studies at Hiroshima University

    International Nuclear Information System (INIS)

    Kato, Kazuo; Takeoka, Seiji; Kuroda, Tokue; Tsujimura, Tomotaka; Kawami, Masaharu; Hoshi, Masaharu; Sawada, Shozo

    1987-01-01

    A 1.93 Ci (3.6 mg) californium-252 source was installed in the radiation facility of the Research Institute for Nuclear Medicine and Biology, Hiroshima University. This source produces fission neutrons (8.7 x 10 9 n/s at the time of its installation), which are similar to neutron spectrum of the atomic bombs. It is useful for studying biological effects of fission neutrons and neutron dosimetry. An apparatus was dosigned to accomodate this source and to apply it to such studies. It has resulted in profitable fission neutron exposures, while suppressing scattered neutrons and secondary gamma rays. This apparatus incorporates many safety systems, including one which interlocks with all of doors and an elevator serving the exposure room, so as to prevent accidents involving users. (author)

  16. Extracting and connecting chemical structures from text sources using chemicalize.org.

    Science.gov (United States)

    Southan, Christopher; Stracz, Andras

    2013-04-23

    Exploring bioactive chemistry requires navigating between structures and data from a variety of text-based sources. While PubChem currently includes approximately 16 million document-extracted structures (15 million from patents) the extent of public inter-document and document-to-database links is still well below any estimated total, especially for journal articles. A major expansion in access to text-entombed chemistry is enabled by chemicalize.org. This on-line resource can process IUPAC names, SMILES, InChI strings, CAS numbers and drug names from pasted text, PDFs or URLs to generate structures, calculate properties and launch searches. Here, we explore its utility for answering questions related to chemical structures in documents and where these overlap with database records. These aspects are illustrated using a common theme of Dipeptidyl Peptidase 4 (DPPIV) inhibitors. Full-text open URL sources facilitated the download of over 1400 structures from a DPPIV patent and the alignment of specific examples with IC50 data. Uploading the SMILES to PubChem revealed extensive linking to patents and papers, including prior submissions from chemicalize.org as submitting source. A DPPIV medicinal chemistry paper was completely extracted and structures were aligned to the activity results table, as well as linked to other documents via PubChem. In both cases, key structures with data were partitioned from common chemistry by dividing them into individual new PDFs for conversion. Over 500 structures were also extracted from a batch of PubMed abstracts related to DPPIV inhibition. The drug structures could be stepped through each text occurrence and included some converted MeSH-only IUPAC names not linked in PubChem. Performing set intersections proved effective for detecting compounds-in-common between documents and merged extractions. This work demonstrates the utility of chemicalize.org for the exploration of chemical structure connectivity between documents and

  17. Structural studies on lipoprotein lipase

    International Nuclear Information System (INIS)

    Socorro, L.

    1985-01-01

    The structure of lipoprotein lipase is not known. The lack of information on its primary sequence has been due to the inability of preparing it in homogeneous and stable form. This research has focused on the structural characterization of lipoprotein lipase. The first approach taken was to develop a purification method using bovine milk and affinity chromatography on heparin-Sepharose. The protein obtained was a heterogeneous peak with the activity shifted towards the trailing edge fractions. These fractions only presented a 55 Kdalton band on polyacrylamide gel electrophoresis. Monoclonal antibodies against this band detected an endogenous, phenyl methane sulfonyl fluoride-sensitive protease responsible for the presence of lower molecular weight fragments. The second approach was to label the lipoprotein lipase with a radioactive, active site, directed probe. After incubation and affinity chromatography a complex [ 3 H]inhibitor enzyme was isolated with a stoichiometry of 1.00 +/- 0.2. The complex was digested with CNBr and the insoluble peptides at low ionic strength (>90% [ 3 H]dpm) were used for further purification. Differential extraction of the [ 3 H]-peptide, digestion with S. aureus V8 protease, and high performance liquid chromatography yielded a hexapeptide with a composition consistent with the consensus sequence of the active site peptides of many serine-esterase. This and the kinetic data imply this being the mechanism of action for lipoprotein lipase

  18. Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

    Science.gov (United States)

    Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

    2018-03-01

    As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

  19. Study of non-metallic inclusion sources in steel

    International Nuclear Information System (INIS)

    Khons, Ya.; Mrazek, L.

    1976-01-01

    A study of potential inclusion sources was carried out at the Tvinec steel plant using an unified labelling procedure for different sources. A lanthanum oxide labelling method has been used for refractories with the subsequent La determination in steel by the neutron activation analysis. Samarium and cerium oxides and the 141 Ce radionuclide have been used in conjunction with the testing. The following sources of exogenous inclusions have been studied: 1)Refractory material comprising fireclay and corundum for steel-teeming trough in open-heart furnaces; 2) Fireclay bottom-pouring refractories; 3) Steel-teeming laddle lining; 4) Heat-insulating and exothermic compounds for steel ingots; 5) Vacuum treatment plant lining; 6) Open-hearth and electric arc furnace slag. The major oxide inclusion source in steel was found to be represented by the furnace slag, since it forms about 40 p.c. of all oxide inclusions. The contributions of the remaining sources did not exceede 5 p.c. each

  20. Study of liquid hydrogen and liquid deuterium cold neutron sources

    International Nuclear Information System (INIS)

    Harig, H.D.

    1969-01-01

    In view of the plant of the cold neutron source for a high flux reactor (maximal thermal flux of about 10 15 n/cm 2 s) an experimental study of several cold sources of liquid hydrogen and liquid deuterium has been made in a low power reactor (100 kW, about 10 12 n/cm 2 s). We have investigated: -cold neutron sources of liquid hydrogen shaped as annular layers of different thickness. Normal liquid hydrogen was used as well as hydrogen with a high para-percentage. -Cold neutron sources of liquid deuterium in cylinders of 18 and 38 cm diameter. In this case the sources could be placed into different positions to the reactor core within the heavy water reflector. This report gives a general description of the experimental device and deals more detailed with the design of the cryogenic systems. Then, the measured results are communicated, interpreted and finally compared with those of a theoretical study about the same cold moderators which have been the matter of the experimental investigation. (authors) [fr

  1. LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

    Science.gov (United States)

    Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

    2009-06-01

    Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

  2. A Comparative Study Of Source Location And Depth Estimates From ...

    African Journals Online (AJOL)

    ... the analytic signal amplitude (ASA) and the local wave number (LWN) of the total intensity magnetic field. In this study, a synthetic magnetic field due to four buried dipoles was analysed to show that estimates of source location and depth can be improved significantly by reducing the data to the pole prior to the application ...

  3. A study investigating sound sources and noise levels in neonatal ...

    African Journals Online (AJOL)

    Background. Exposure to noise in the neonatal intensive care unit (NICU) has the potential to affect neonatal auditory development, sleep patterns and physiological stability, thus impacting on developmental progress. Objectives. This study aimed to identify noise sources in three NICUs in Johannesburg, South Africa, and ...

  4. Free and Open Source Chemistry Software in Research of Quantitative Structure-Toxicity Relationship of Pesticides

    Directory of Open Access Journals (Sweden)

    Rastija Vesna

    2017-01-01

    Full Text Available Pesticides are toxic chemicals aimed for the destroying pest on crops. Numerous data evidence about toxicity of pesticides on aquatic organisms. Since pesticides with similar properties tend to have similar biological activities, toxicity may be predicted from structure. Their structure feature and properties are encoded my means of molecular descriptors. Molecular descriptors can capture quite simple two-dimensional (2D chemical structures to highly complex three-dimensional (3D chemical structures. Quantitative structure-toxicity relationship (QSTR method uses linear regression analyses for correlation toxicity of chemical with their structural feature using molecular descriptors. Molecular descriptors were calculated using open source software PaDEL and in-house built PyMOL plugin (PyDescriptor. PyDescriptor is a new script implemented with the commonly used visualization software PyMOL for calculation of a large and diverse set of easily interpretable molecular descriptors encoding pharmacophoric patterns and atomic fragments. PyDescriptor has several advantages like free and open source, can work on all major platforms (Windows, Linux, MacOS. QSTR method allows prediction of toxicity of pesticides without experimental assay. In the present work, QSTR analysis for toxicity of a dataset of mixtures of 5 classes of pesticides comprising has been performed.

  5. An efficient closed-form solution for acoustic emission source location in three-dimensional structures

    Directory of Open Access Journals (Sweden)

    Xibing Li

    2014-02-01

    Full Text Available This paper presents an efficient closed-form solution (ECS for acoustic emission(AE source location in three-dimensional structures using time difference of arrival (TDOA measurements from N receivers, N ≥ 6. The nonlinear location equations of TDOA are simplified to linear equations. The unique analytical solution of AE sources for unknown velocity system is obtained by solving the linear equations. The proposed ECS method successfully solved the problems of location errors resulting from measured deviations of velocity as well as the existence and multiplicity of solutions induced by calculations of square roots in existed close-form methods.

  6. Study of localized photon source in space of measures

    International Nuclear Information System (INIS)

    Lisi, M.

    2010-01-01

    In this paper we study a three-dimensional photon transport problem in an interstellar cloud, with a localized photon source inside. The problem is solved indirectly, by defining the adjoint of an operator acting on an appropriate space of continuous functions. By means of sun-adjoint semi groups theory of operators in a Banach space of regular Borel measures, we prove existence and uniqueness of the solution of the problem. A possible approach to identify the localization of the photon source is finally proposed.

  7. Development of a high-resolution soft x-ray (30--1500 eV) beamline at the Advanced Light Source and its use for the study of angle-resolved photoemission extended fine structure

    International Nuclear Information System (INIS)

    Huff, W.R.A.

    1996-02-01

    ALS Bending magnet beamline 9.3.2 is for high resolution spectroscopy, with circularly polarized light. Fixed included-angle SGM uses three gratings for 30--1500 eV photons; circular polarization is produced by an aperture for selecting the beam above or below the horizontal plane. Photocurrent from upper and lower jaws of entrance slit sets a piezoelectric drive feedback loop on the vertically deflecting mirror for stable beam. End station has a movable platform. With photomeission data from Stanford, structure of c(2x2)P/Fe(100) was determined using angle-resolved photoemission extended fine structure (ARPEFS). Multiple-scattering spherical-wave (MSSW) calculations indicate that P atoms adsorb in fourfold hollow sites 1.02A above the first Fe layer. Self-consistent-field Xα scattered wave calculation confirm that the Fe 1 -Fe 2 space is contracted for S/Fe but not for P/Fe; comparison is made to atomic N and O on Fe(100). Final-state effects on ARPEFS curves used literature data from the S 1s and 2p core levels of c(2x2)S/Ni(001); a generalized Ramsauer-Townsend splitting is present in the 1s but not 2p data. An approximate method for analyzing ARPEFS data from a non-s initial state using only the higher-ell partial wave was tested successfully. ARPEFS data from clean surfaces were collected normal to Ni(111) (3p core levels) and 5 degree off-normal from Cu(111)(3s, 3p). Fourier transforms (FT) resemble adsorbate systems, showing backscattering signals from atoms up to 4 layers below emitters. 3p FTs show scattering from 6 nearest neighbors in the same crystal layer as the emitters. MSSW calulation indicate that Cu 3p photoemission is mostly d-wave. FTs also indicate double-scattering and single-scattering from laterally distant atoms; calculations indicate that the signal is dominated by photoemission from the first 2 crystal layers

  8. Open-Source RTOS Space Qualification: An RTEMS Case Study

    Science.gov (United States)

    Zemerick, Scott

    2017-01-01

    NASA space-qualification of reusable off-the-shelf real-time operating systems (RTOSs) remains elusive due to several factors notably (1) The diverse nature of RTOSs utilized across NASA, (2) No single NASA space-qualification criteria, lack of verification and validation (V&V) analysis, or test beds, and (3) different RTOS heritages, specifically open-source RTOSs and closed vendor-provided RTOSs. As a leader in simulation test beds, the NASA IV&V Program is poised to help jump-start and lead the space-qualification effort of the open source Real-Time Executive for Multiprocessor Systems (RTEMS) RTOS. RTEMS, as a case-study, can be utilized as an example of how to qualify all RTOSs, particularly the reusable non-commercial (open-source) ones that are gaining usage and popularity across NASA. Qualification will improve the overall safety and mission assurance of RTOSs for NASA-agency wide usage. NASA's involvement in space-qualification of an open-source RTOS such as RTEMS will drive the RTOS industry toward a more qualified and mature open-source RTOS product.

  9. A Study on Water Pollution Source Localization in Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jun Yang

    2016-01-01

    Full Text Available The water pollution source localization is of great significance to water environment protection. In this paper, a study on water pollution source localization is presented. Firstly, the source detection is discussed. Then, the coarse localization methods and the localization methods based on diffusion models are introduced and analyzed, respectively. In addition, the localization method based on the contour is proposed. The detection and localization methods are compared in experiments finally. The results show that the detection method using hypotheses testing is more stable. The performance of the coarse localization algorithm depends on the nodes density. The localization based on the diffusion model can yield precise localization results; however, the results are not stable. The localization method based on the contour is better than the other two localization methods when the concentration contours are axisymmetric. Thus, in the water pollution source localization, the detection using hypotheses testing is more preferable in the source detection step. If concentration contours are axisymmetric, the localization method based on the contour is the first option. And, in case the nodes are dense and there is no explicit diffusion model, the coarse localization algorithm can be used, or else the localization based on diffusion models is a good choice.

  10. Systematic study of source mask optimization and verification flows

    Science.gov (United States)

    Ben, Yu; Latypov, Azat; Chua, Gek Soon; Zou, Yi

    2012-06-01

    Source mask optimization (SMO) emerged as powerful resolution enhancement technique (RET) for advanced technology nodes. However, there is a plethora of flow and verification metrics in the field, confounding the end user of the technique. Systemic study of different flows and the possible unification thereof is missing. This contribution is intended to reveal the pros and cons of different SMO approaches and verification metrics, understand the commonality and difference, and provide a generic guideline for RET selection via SMO. The paper discusses 3 different type of variations commonly arise in SMO, namely pattern preparation & selection, availability of relevant OPC recipe for freeform source and finally the metrics used in source verification. Several pattern selection algorithms are compared and advantages of systematic pattern selection algorithms are discussed. In the absence of a full resist model for SMO, alternative SMO flow without full resist model is reviewed. Preferred verification flow with quality metrics of DOF and MEEF is examined.

  11. A Study on Improvement of Algorithm for Source Term Evaluation

    International Nuclear Information System (INIS)

    Park, Jeong Ho; Park, Do Hyung; Lee, Jae Hee

    2010-03-01

    The program developed by KAERI for source term assessment of radwastes from the advanced nuclear fuel cycle consists of spent fuel database analysis module, spent fuel arising projection module, and automatic characterization module for radwastes from pyroprocess. To improve the algorithm adopted the developed program, following items were carried out: - development of an algorithm to decrease analysis time for spent fuel database - development of setup routine for a analysis procedure - improvement of interface for spent fuel arising projection module - optimization of data management algorithm needed for massive calculation to estimate source terms of radwastes from advanced fuel cycle The program developed through this study has a capability to perform source term estimation although several spent fuel assemblies with different fuel design, initial enrichment, irradiation history, discharge burnup, and cooling time are processed at the same time in the pyroprocess. It is expected that this program will be very useful for the design of unit process of pyroprocess and disposal system

  12. Study of the Release Process of Open Source Software: Case Study

    OpenAIRE

    Eide, Tor Erik

    2007-01-01

    This report presents the results of a case study focusing on the release process of open source projects initiated with commercial motives. The purpose of the study is to gain an increased understanding of the release process, how a community can be attracted to the project, and how the interaction with the community evolves in commercial open source initiatives. Data has been gathered from four distinct sources to form the basis of this thesis. A thorough review of the open source literatu...

  13. Study of local structure by DAFS

    International Nuclear Information System (INIS)

    Mizuki, Jun-ichiro

    1997-01-01

    We will describe a rather new X-ray structural technique, Diffraction Anomalous Fine Structure (DAFS), in which the Bragg diffraction intensities of a fixed momentum transfer is measured as a function of the incident X-ray energy. This technique can provide the same short-range structural information as XAFS. Because DAFS combines the capabilities of diffraction and XAFS into a single technique, it has two enhanced sensitivities compared to the separate technique. These are 'spatial selectivity' and 'site selectivity'. In this chapter semiconductor interface structure study as an example for spatial selectivity and structural study of high Tc superconductor as an example for site selectivity will be shown. (author)

  14. Structural and Shielding Safety of a Transport Package for Radioisotope Sealed Source Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kiseog; Cho, Ilje; Kim, Donghak [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    As some kinds of radioisotope (RI) sealed source are produced by HANARO research reactor, a demand of RI transport package is increasing gradually. Foreign countries, which produce the various RIs, have the intrinsic model of the RI transport package. It is necessary to develop a RI and its transport package simultaneously. It is difficult to design a shielding part for this transport package because the passage for this source assembly should be provided from the center of shielding part to the outside of the package. In order to endure the accident conditions such as a 9 m drop and puncture, this transport package consists of the guide tubes, a gamma shield and a shock absorber. This paper describe that a shielding and structural safety of RI sealed source transport package are evaluated under the accident conditions.

  15. Structural and Shielding Safety of a Transport Package for Radioisotope Sealed Source Assembly

    International Nuclear Information System (INIS)

    Seo, Kiseog; Cho, Ilje; Kim, Donghak

    2006-01-01

    As some kinds of radioisotope (RI) sealed source are produced by HANARO research reactor, a demand of RI transport package is increasing gradually. Foreign countries, which produce the various RIs, have the intrinsic model of the RI transport package. It is necessary to develop a RI and its transport package simultaneously. It is difficult to design a shielding part for this transport package because the passage for this source assembly should be provided from the center of shielding part to the outside of the package. In order to endure the accident conditions such as a 9 m drop and puncture, this transport package consists of the guide tubes, a gamma shield and a shock absorber. This paper describe that a shielding and structural safety of RI sealed source transport package are evaluated under the accident conditions

  16. Metre-wavelength fine structure in 30 extragalactic radio sources with sizes of a few arcsec

    International Nuclear Information System (INIS)

    Banhatti, D.G.; Ananthakrishnan, S.; Pramesh Rao, A.

    1983-01-01

    Interplanetary scintillation (IPS) observations at 327 MHz of an unbiased sample of 30 extragalactic radio sources having overall sizes between 1 and 4 arcsec, and flux densities greater than 1 Jy at 327 MHz are reported. From VLBI observations, these sources have been reported to contain compact components of sizes < approx.= to 0.02 arcsec contributing on an average about 25 per cent of the total emission at 5 HGz. The IPS observations show that about 45 per cent of the total emission at 327 MHz arises from structures of sizes between 0.05 and 0.5 arcsec (corresponding typically to 0.5 to 5 kpc). A comparison of the VLBI and IPS results indicates that the VLBI and IPS components probably refer to the same physical features in these sources. (author)

  17. A probabilistic framework for acoustic emission source localization in plate-like structures

    International Nuclear Information System (INIS)

    Dehghan Niri, E; Salamone, S

    2012-01-01

    This paper proposes a probabilistic approach for acoustic emission (AE) source localization in isotropic plate-like structures based on an extended Kalman filter (EKF). The proposed approach consists of two main stages. During the first stage, time-of-flight (TOF) measurements of Lamb waves are carried out by a continuous wavelet transform (CWT), accounting for systematic errors due to the Heisenberg uncertainty; the second stage uses an EKF to iteratively estimate the AE source location and the wave velocity. The advantages of the proposed algorithm over the traditional methods include the capability of: (1) taking into account uncertainties in TOF measurements and wave velocity and (2) efficiently fusing multi-sensor data to perform AE source localization. The performance of the proposed approach is validated through pencil-lead breaks performed on an aluminum plate at systematic grid locations. The plate was instrumented with an array of four piezoelectric transducers in two different configurations. (paper)

  18. Monte Carlo Simulations Validation Study: Vascular Brachytherapy Beta Sources

    International Nuclear Information System (INIS)

    Orion, I.; Koren, K.

    2004-01-01

    During the last decade many versions of angioplasty irradiation treatments have been proposed. The purpose of this unique brachytherapy is to administer a sufficient radiation dose into the vein walls in order to prevent restonosis, a clinical sequel to balloon angioplasty. The most suitable sources for this vascular brachytherapy are the β - emitters such as Re-188, P-32, and Sr-90/Y-90, with a maximum energy range of up to 2.1 MeV [1,2,3]. The radioactive catheters configurations offered for these treatments can be a simple wire [4], a fluid filled balloon or a coated stent. Each source is differently positioned inside the blood vessel, and the emitted electrons ranges therefore vary. Many types of sources and configurations were studied either experimentally or with the use of the Monte Carlo calculation technique, while most of the Monte Carlo simulations were carried out using EGS4 [5] or MCNP [6]. In this study we compared the beta-source absorbed-dose versus radial-distance of two treatment configurations using MCNP and EGS4 simulations. This comparison was aimed to discover the differences between the MCNP and the EGS4 simulation code systems in intermediate energies electron transport

  19. Acoustic emission non-destructive testing of structures using source location techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, Alan G.

    2013-09-01

    The technology of acoustic emission (AE) testing has been advanced and used at Sandia for the past 40 years. AE has been used on structures including pressure vessels, fire bottles, wind turbines, gas wells, nuclear weapons, and solar collectors. This monograph begins with background topics in acoustics and instrumentation and then focuses on current acoustic emission technology. It covers the overall design and system setups for a test, with a wind turbine blade as the object. Test analysis is discussed with an emphasis on source location. Three test examples are presented, two on experimental wind turbine blades and one on aircraft fire extinguisher bottles. Finally, the code for a FORTRAN source location program is given as an example of a working analysis program. Throughout the document, the stress is on actual testing of real structures, not on laboratory experiments.

  20. Open source drug discovery in practice: a case study.

    Science.gov (United States)

    Årdal, Christine; Røttingen, John-Arne

    2012-01-01

    Open source drug discovery offers potential for developing new and inexpensive drugs to combat diseases that disproportionally affect the poor. The concept borrows two principle aspects from open source computing (i.e., collaboration and open access) and applies them to pharmaceutical innovation. By opening a project to external contributors, its research capacity may increase significantly. To date there are only a handful of open source R&D projects focusing on neglected diseases. We wanted to learn from these first movers, their successes and failures, in order to generate a better understanding of how a much-discussed theoretical concept works in practice and may be implemented. A descriptive case study was performed, evaluating two specific R&D projects focused on neglected diseases. CSIR Team India Consortium's Open Source Drug Discovery project (CSIR OSDD) and The Synaptic Leap's Schistosomiasis project (TSLS). Data were gathered from four sources: interviews of participating members (n = 14), a survey of potential members (n = 61), an analysis of the websites and a literature review. Both cases have made significant achievements; however, they have done so in very different ways. CSIR OSDD encourages international collaboration, but its process facilitates contributions from mostly Indian researchers and students. Its processes are formal with each task being reviewed by a mentor (almost always offline) before a result is made public. TSLS, on the other hand, has attracted contributors internationally, albeit significantly fewer than CSIR OSDD. Both have obtained funding used to pay for access to facilities, physical resources and, at times, labor costs. TSLS releases its results into the public domain, whereas CSIR OSDD asserts ownership over its results. Technically TSLS is an open source project, whereas CSIR OSDD is a crowdsourced project. However, both have enabled high quality research at low cost. The critical success factors appear to be clearly

  1. Open Source Drug Discovery in Practice: A Case Study

    Science.gov (United States)

    Årdal, Christine; Røttingen, John-Arne

    2012-01-01

    Background Open source drug discovery offers potential for developing new and inexpensive drugs to combat diseases that disproportionally affect the poor. The concept borrows two principle aspects from open source computing (i.e., collaboration and open access) and applies them to pharmaceutical innovation. By opening a project to external contributors, its research capacity may increase significantly. To date there are only a handful of open source R&D projects focusing on neglected diseases. We wanted to learn from these first movers, their successes and failures, in order to generate a better understanding of how a much-discussed theoretical concept works in practice and may be implemented. Methodology/Principal Findings A descriptive case study was performed, evaluating two specific R&D projects focused on neglected diseases. CSIR Team India Consortium's Open Source Drug Discovery project (CSIR OSDD) and The Synaptic Leap's Schistosomiasis project (TSLS). Data were gathered from four sources: interviews of participating members (n = 14), a survey of potential members (n = 61), an analysis of the websites and a literature review. Both cases have made significant achievements; however, they have done so in very different ways. CSIR OSDD encourages international collaboration, but its process facilitates contributions from mostly Indian researchers and students. Its processes are formal with each task being reviewed by a mentor (almost always offline) before a result is made public. TSLS, on the other hand, has attracted contributors internationally, albeit significantly fewer than CSIR OSDD. Both have obtained funding used to pay for access to facilities, physical resources and, at times, labor costs. TSLS releases its results into the public domain, whereas CSIR OSDD asserts ownership over its results. Conclusions/Significance Technically TSLS is an open source project, whereas CSIR OSDD is a crowdsourced project. However, both have enabled high quality

  2. Experimental study on source efficiencies for estimating surface contamination level

    International Nuclear Information System (INIS)

    Ichiji, Takeshi; Ogino, Haruyuki

    2008-01-01

    Source efficiency was measured experimentally for various materials, such as metals, nonmetals, flooring materials, sheet materials and other materials, contaminated by alpha and beta emitter radioactive nuclides. Five nuclides, 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr- 90 Y, were used as the beta emitters, and one nuclide 241 Am was used as the alpha emitter. The test samples were prepared by placing drops of the radioactive standardized solutions uniformly on the various materials using an automatic quantitative dispenser system from Musashi Engineering, Inc. After placing drops of the radioactive standardized solutions, the test materials were allowed to dry for more than 12 hours in a draft chamber with a hood. The radioactivity of each test material was about 30 Bq. Beta rays or alpha rays from the test materials were measured with a 2-pi gas flow proportional counter from Aloka Co., Ltd. The source efficiencies of the metals, nonmetals and sheet materials were higher than 0.5 in the case of contamination by the 137 Cs, 204 Tl and 90 Sr- 90 Y radioactive standardized solutions, higher than 0.4 in the case of contamination by the 60 Co radioactive standardized solution, and higher than 0.25 in the case of contamination by the alpha emitter the 241 Am radioactive standardized solution. These values were higher than those given in Japanese Industrial Standards (JIS) documents. In contrast, the source efficiencies of some permeable materials were lower than those given in JIS documents, because source efficiency varies depending on whether the materials or radioactive sources are wet or dry. This study provides basic data on source efficiency, which is useful for estimating the surface contamination level of materials. (author)

  3. Structural Source of the Trap of ICT Advancement - Lessons from World ICT Top Leaders

    OpenAIRE

    Watanabe, Chihiro; Naveed, Kashif; Zhao, Weilin

    2014-01-01

    In light of the significant consequence of the trap of dramatic advancement of information and communication technology (ICT) in the global economy, both nations and firms that have been compelling their productivity decline. This resulted in great stagnation of ICT advanced economies and therefore its structural sources were analyzed. Based on an empirical analysis tracing, the trend in marginal productivity of ICT and its subsequent prices among the top ICT leaders in the ...

  4. The vibrational source strength descriptor using power input from equivalent forces: a simulation study

    DEFF Research Database (Denmark)

    Laugesen, Søren; Ohlrich, Mogens

    1994-01-01

    Simple, yet reliable methods for the approximate determination of the vibratory power supplied by the internal excitation forces of a given vibrational source are of great interest. One such method that relies on the application of a number of “equivalent forces” and measurements of the mean...... squared velocity on either the source or the receiving structure is studied in this paper by means of computer simulations. The study considers a simple system of two flexural beams coupled via a pair of springs. The investigation shows that a relatively small number of equivalent forces suffice...

  5. High resolution structuring of emitter tips for the gaseous field ionization source

    International Nuclear Information System (INIS)

    Kubby, J.A.; Siegel, B.M.

    1986-01-01

    Extraction of a stable, high brightness ion beam from an apertured field ion emitter surface requires microfabrication procedures to sculpture the surface topography on both microscopic (100 --1000 nm) and near atomic (10 --100 nm) length scales. Structuring on a near atomic scale is required to confine and stabilize the ion beam by local enhancement of the surface electrostatic field and to orient that emission on the optical axis. Control of the emitter contour on a microscopic scale is required for manipulating the supply of neutral molecules to the ionization site and also affects beam stability. We have developed a method using ion milling for configuring surface contour on microscopic and near atomic length scales which utilizes the morphological changes occurring at ion bombarded surfaces as a result of erosion by sputtering. A SEM study of the microscopic emitter topographical development is compared to computer simulations of the kinematical wave equation which depicts the erosion process. In this way, prediction of configuration on a length scale large compared to the ion penetration depth has been established. TEM observations show the surface development on the length scale of ion penetration depth. Preliminary results using this microfabricated emitter in a gaseous field ion source to produce a hydrogen ion beam with high angular beam confinement are given. Requirements for surface topography that are essential to obtain stable high brightness ion beams are discussed

  6. Theoretical studies in nuclear structure

    International Nuclear Information System (INIS)

    Marshalek, E.R.

    1991-11-01

    In this period, the work has centered on two topics. The first is the study of a novel type of collective rotation in which an atomic nucleus with an inversion-symmetric shape rotates uniformly about an axis that is not a principal axis of the quadrupole tensor of the density distribution. This mode is referred to as tilted rotation. By using the cranking model together with higher-order corrections, it was shown that tilted rotation is indeed possible, not only within a microscopic framework, but also within the framework of collective models such as the IBM. The maximum tilt angle of π/4 is realized for a certain class of states in the U(5) limit. The second topic, which actually was suggested during the course of the first investigation, is concerned with a new way of representing collective harmonic-oscillator algebras using boson-mapping techniques. In this approach, the many-phonon eigenvectors of a 2λ+1-dimensional oscillator having good angular momentum are represented by simple products of boson operators acting on a vacuum. This representation may simplify the calculation of reduced matrix elements of arbitrary operators in collective models, but more work needs to be done

  7. Studies of electron cyclotron resonance ion source plasma physics

    International Nuclear Information System (INIS)

    Tarvainen, O.

    2005-01-01

    This thesis consists of an introduction to the plasma physics of electron cyclotron resonance ion sources (ECRIS) and a review of the results obtained by the author and co-workers including discussion of related work by others. The thesis begins with a theoretical discussion dealing with plasma physics relevant for the production of highly charged ions in ECR ion source plasmas. This is followed by an overview of different techniques, such as gas mixing and double frequency heating, that can be used to improve the performance of this type of ion source. The experimental part of the work consists of studies related to ECRIS plasma physics. The effect of the gas mixing technique on the production efficiency of different ion beams was studied with both gaseous and solid materials. It was observed that gas mixing improves the confinement of the heavier element while the confinement of the lighter element is reduced. When the effect of gas mixing on MIVOC-plasmas was studied with several mixing gases it was observed that applying this technique can reduce the inevitable carbon contamination by a significant factor. In order to understand the different plasma processes taking place in ECRIS plasmas, a series of plasma potential and emittance measurements was carried out. An instrument, which can be used to measure the plasma potential in a single measurement without disturbing the plasma, was developed for this work. Studying the plasma potential of ECR ion sources is important not only because it helps to understand different plasma processes, but also because the information can be used as an input parameter for beam transport simulations and ion source extraction design. The experiments performed have revealed clear dependencies of the plasma potential on certain source parameters such as the amount of carbon contamination accumulated on the walls of the plasma chamber during a MIVOC-run. It was also observed that gas mixing affects not only the production efficiency

  8. Electromagnetic studies of nuclear structure and reactions

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, F.W.; Dawson, J.F.; Heisenberg, J.H.; Calarco, J.R.

    1990-06-01

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation.

  9. Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    Hersman, F.W.; Dawson, J.F.; Heisenberg, J.H.; Calarco, J.R.

    1990-06-01

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation

  10. Sources for comparative studies of placentation I. Embryological collections

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2008-01-01

    A rich source of material for comparative studies of the placenta is the collections made by pioneers in the field such as H.W. Mossman, A.A.W. Hubrecht and J.P. Hill. This overview gives a brief description of collections known to be available and information on how each can be accessed. Include...... are some of the major series of human and animal embryos, such as the Boyd and Carnegie collections, as these also house placental material....

  11. French studies for improvement of the data for radioactive sources

    International Nuclear Information System (INIS)

    Duchemin, B.; Nimal, B.; Nimal, J.C.; Blachot, J.; Chouha, M.

    1988-01-01

    The 1987 version of the CEA radioactivity data bank is just distributed. This data bank is used to compute concentrations, activities, β and γ spectra, which give sources for shielding purposes. To improve this data bank at short cooling time (t < 200 sec) a methodology based on the statistical model is used to take account of the upper unknown levels. To give an example of the results we get, a brief summary of the studies we made for the TCHERNOBYL case is given

  12. High flux isotope reactor cold source preconceptual design study report

    International Nuclear Information System (INIS)

    Selby, D.L.; Bucholz, J.A.; Burnette, S.E.

    1995-12-01

    In February 1995, the deputy director of Oak Ridge National Laboratory (ORNL) formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced Neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. The anticipated cold source will consist of a cryogenic LH 2 moderator plug, a cryogenic pump system, a refrigerator that uses helium gas as a refrigerant, a heat exchanger to interface the refrigerant with the hydrogen loop, liquid hydrogen transfer lines, a gas handling system that includes vacuum lines, and an instrumentation and control system to provide constant system status monitoring and to maintain system stability. The scope of this project includes the development, design, safety analysis, procurement/fabrication, testing, and installation of all of the components necessary to produce a working cold source within an existing HFIR beam tube. This project will also include those activities necessary to transport the cold neutron beam to the front face of the present HFIR beam room. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and research and development (R and D), (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the preconceptual phase and establishes the concept feasibility. The information presented includes the project scope, the preliminary design requirements, the preliminary cost and schedule, the preliminary performance data, and an outline of the various plans for completing the project

  13. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

  14. A simple method for estimating potential source term bypass fractions from confinement structures

    International Nuclear Information System (INIS)

    Kalinich, D.A.; Paddleford, D.F.

    1997-01-01

    Confinement structures house many of the operating processes at the Savannah River Site (SRS). Under normal operating conditions, a confinement structure in conjunction with its associated ventilation systems prevents the release of radiological material to the environment. However, under potential accident conditions, the performance of the ventilation systems and integrity of the structure may be challenged. In order to calculate the radiological consequences associated with a potential accident (e.g. fires, explosion, spills, etc.), it is necessary to determine the fraction of the source term initially generated by the accident that escapes from the confinement structure to the environment. While it would be desirable to estimate the potential bypass fraction using sophisticated control-volume/flow path computer codes (e.g. CONTAIN, MELCOR, etc.) in order to take as much credit as possible for the mitigative effects of the confinement structure, there are many instances where using such codes is not tractable due to limits on the level-of-effort allotted to perform the analysis. Moreover, the current review environment, with its emphasis on deterministic/bounding-versus probabilistic/best-estimate-analysis discourages using analytical techniques that require the consideration of a large number of parameters. Discussed herein is a simplified control-volume/flow path approach for calculating source term bypass fraction that is amenable to solution in a spreadsheet or with a commercial mathematical solver (e.g. MathCad or Mathematica). It considers the effects of wind and fire pressure gradients on the structure, ventilation system operation, and Halon discharges. Simple models are used to characterize the engineered and non-engineered flow paths. By making judicious choices for the limited set of problem parameters, the results from this approach can be defended as bounding and conservative

  15. Study of structural reliability of existing concrete structures

    Science.gov (United States)

    Druķis, P.; Gaile, L.; Valtere, K.; Pakrastiņš, L.; Goremikins, V.

    2017-10-01

    Structural reliability of buildings has become an important issue after the collapse of a shopping center in Riga 21.11.2013, caused the death of 54 people. The reliability of a building is the practice of designing, constructing, operating, maintaining and removing buildings in ways that ensure maintained health, ward suffered injuries or death due to use of the building. Evaluation and improvement of existing buildings is becoming more and more important. For a large part of existing buildings, the design life has been reached or will be reached in the near future. The structures of these buildings need to be reassessed in order to find out whether the safety requirements are met. The safety requirements provided by the Eurocodes are a starting point for the assessment of safety. However, it would be uneconomical to require all existing buildings and structures to comply fully with these new codes and corresponding safety levels, therefore the assessment of existing buildings differs with each design situation. This case study describes the simple and practical procedure of determination of minimal reliability index β of existing concrete structures designed by different codes than Eurocodes and allows to reassess the actual reliability level of different structural elements of existing buildings under design load.

  16. Rietveld refinement of magnetic structures from pulsed-neutron-source powder-diffraction data

    International Nuclear Information System (INIS)

    Robinson, R.A.; Lawson, A.C.; Larson, A.C.; Von Dreele, R.B.; Goldstone, J.A.

    1994-01-01

    The General Structure Analysis System, GSAS, has recently been modified to include magnetic neutron- scattering cross-sections. Low-temperature diffraction data have been taken on the hexagonal noncollinear antiferromagnet UPdSn on both the HIPD and the NPD powder diffractometers ail LANSCE. The low-resolution data reveal that the magnetic structure has orthorhombic symmetry (magnetic space group P c m'c2 1 ) between 25K and 40K, and monoclinic symmetry (magnetic space group PC 1121 ) below 25K. The high-resolution data reveal that there are structural distortions with corresponding symmetry changes in each of these phases, to give chemical space groups Cmc2 1 and P2 1 , respectively, while the paramagnetic phase above 40K has space group P6 3 mc. Using GSAS, we have refined data sets from both diffractometers simultaneously, including both magnetic and structural cross-sections. Magnetoelastic coefficients for the distortions have been extracted and we have determined the sign of the coupling between the structural monoclinicity and the magnetic monoclinicity. The magnetic results from Rietveld refinement are in good agreement with model fitting to the integrated intensities of seven independent magnetic reflections and these, in turn, agree with measurements made on the same sample using the constant-wavelength reactor technique. Our results therefore validate, to some level, both the technique of using spallation sources for complicated magnetic structures and the specifics of the GSAS Rietveld code

  17. Polarization Study for NLC Positron Source Using EGS4

    Energy Technology Data Exchange (ETDEWEB)

    Liu, James C

    2000-09-20

    SLAC is exploring a polarized positron source to study new physics for the NLC project. The positron source envisioned in this paper consists of a polarized electron source, a 50-MeV electron accelerator, a thin target less-than-or-equal-to 0.2 radiation length for positron production, and a capture system for high-energy, small angular divergence positrons. The EGS4 code was used to study the yield, energy spectra, emission-angle distribution, and the mean polarization of the positrons emanating from W-Re and Ti targets hit by longitudinally polarized electron and photon beams. To account for polarization within the EGS4 code a method devised by Flottmann was used, which takes into account polarization transfer for pair production, bremsstrahlung, and Compton interactions. A mean polarization of 0.85 for positrons with energies greater than 25 MeV was obtained. Most of the high-energy positrons were emitted within a forward angle of 20 degrees. The yield of positrons above 25 MeV per incident photon was 0.034, which was about 70 times higher than that obtained with an electron beam.

  18. Study of spear as a dedicated source of synchrotron radiation

    International Nuclear Information System (INIS)

    Cerino, J.; Golde, A.; Hastings, J.; Lindau, I.; Salsburg, B.; Winick, H.; Lee, M.; Morton, P.; Garren, A.

    1977-11-01

    A study was made of the potential of SPEAR as a dedicated source of synchrotron radiation, based on the expectation that SPEAR will become increasingly available for this purpose as PEP, the 18-GeV colliding-beam storage ring now under construction by LBL and SLAC, becomes operational. A synchrotron radiation research program has been underway since May, 1974. Two beam ports capable of serving 9 simultaneous users are now operational. In single-beam multi-bunch operation high currents are possible (225 mA has been achieved and > approximately 300 mA is expected) and the electron beam emittance can be made smaller, resulting in higher source point brightness. Descriptions are given of SPEAR capabilities and of plans to expand the research capability by adding beam runs and by inserting wiggler magnets in SPEAR straight sections

  19. Beam Collimation Studies for the ILC Positron Source

    Energy Technology Data Exchange (ETDEWEB)

    Drozhdin, A.; /Fermilab; Nosochkov, Y.; Zhou, F.; /SLAC

    2008-06-26

    Results of the collimation studies for the ILC positron source beam line are presented. The calculations of primary positron beam loss are done using the ELEGANT code. The secondary positron and electron beam loss, the synchrotron radiation along the beam line and the bremsstrahlung radiation in the collimators are simulated using the STRUCT code. The first part of the collimation system, located right after the positron source target (0.125 GeV), is used for protection of the RF Linac sections from heating and radiation. The second part of the system is used for final collimation before the beam injection into the Damping Ring at 5 GeV. The calculated power loss in the collimation region is within 100 W/m, with the loss in the collimators of 0.2-5 kW. The beam transfer efficiency from the target to the Damping Ring is 13.5%.

  20. Source apportionment of population representative samples of PM(2.5) in three European cities using structural equation modelling.

    Science.gov (United States)

    Ilacqua, Vito; Hänninen, Otto; Saarela, Kristina; Katsouyanni, Klea; Künzli, Nino; Jantunen, Matti

    2007-10-01

    Apportionment of urban particulate matter (PM) to sources is central for air quality management and efficient reduction of the substantial public health risks associated with fine particles (PM(2.5)). Traffic is an important source combustion particles, but also a significant source of resuspended particles that chemically resemble Earth's crust and that are not affected by development of cleaner motor technologies. A substantial fraction of urban ambient PM originates from long-range transport outside the immediate urban environment including secondary particles formed from gaseous emissions of mainly sulphur, nitrogen oxides and ammonia. Most source apportionment studies are based on small number of fixed monitoring sites and capture well population exposures to regional and long-range transported particles. However, concentrations from local sources are very unevenly distributed and the results from such studies are therefore poorly representative of the actual exposures. The current study uses PM(2.5) data observed at population based random sampled residential locations in Athens, Basle and Helsinki with 17 elemental constituents, selected VOCs (xylenes, trimethylbenzenes, nonane and benzene) and light absorbance (black smoke). The major sources identified across the three cities included crustal, salt, long-range transported inorganic and traffic sources. Traffic was associated separately with source categories with crustal (especially Athens and Helsinki) and long-range transported chemical composition (all cities). Remarkably high fractions of the variability of elemental (R(2)>0.6 except for Ca in Basle 0.38) and chemical concentrations (R(2)>0.5 except benzene in Basle 0.22 and nonane in Athens 0.39) are explained by the source factors of an SEM model. The RAINS model that is currently used as the main tool in developing European air quality management policies seems to capture the local urban fraction (the city delta term) quite well, but underestimates

  1. A method to analyze “source–sink” structure of non-point source pollution based on remote sensing technology

    International Nuclear Information System (INIS)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-01-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the “source–sink” theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of “source” of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km 2 in 2008, and the “sink” was 172.06 km 2 . The “source” of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the “sink” was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of “source” gets weaker along with the distance from the seas boundary increase, while “sink” gets stronger. -- Highlights: •We built an index to study the “source–sink” structure of NSP in a space scale. •The Index was applied in Jiulongjiang estuary and got a well result. •The study is beneficial to discern the high load area of non-point source pollution. -- “Source–Sink” Structure of non-point source nitrogen and phosphorus pollution in Jiulongjiang estuary in China was worked out by the Grid Landscape Contrast Index

  2. The advanced neutron source facility: Safety philosophy and studies

    International Nuclear Information System (INIS)

    Greene, S.R.; Harrington, R.M.

    1988-01-01

    The Advanced Neutron Source (ANS) is currently the only new civilian nuclear reactor facility proposed for construction in the United States. Even though the thermal power of this research-oriented reactor is a relatively low 300 MW, the design will undoubtedly receive intense scrutiny before construction is allowed to proceed. Safety studies are already under way to ensure that the maximum degree of safety in incorporated into the design and that the design is acceptable to the Department of Energy (DOE) and can meet the Nuclear Regulatory Commission regulations. This document discusses these safety studies

  3. Conceptual Design of Dielectric Accelerating Structures for Intense Neutron and Monochromatic X-ray Sources

    Science.gov (United States)

    Blanovsky, Anatoly

    2004-12-01

    Bright compact photon sources, which utilize electron beam interaction with periodic structures, may benefit a broad range of medical, industrial and scientific applications. A class of dielectric-loaded periodic structures for hard and soft X-ray production has been proposed that would provide a high accelerating gradient when excited by an external RF and/or primary electron beam. Target-distributed accelerators (TDA), in which an additional electric field compensates for lost beam energy in internal targets, have been shown to provide the necessary means to drive a high flux subcritical reactor (HFSR) for nuclear waste transmutation. The TDA may also be suitable for positron and nuclear isomer production, X-ray lithography and monochromatic computer tomography. One of the early assumptions of the theory of dielectric wake-field acceleration was that, in electrodynamics, the vector potential was proportional to the scalar potential. The analysis takes into consideration a wide range of TDA design aspects including the wave model of observed phenomena, a layered compound separated by a Van der Waals gap and a compact energy source based on fission electric cells (FEC) with a multistage collector. The FEC is a high-voltage power source that directly converts the kinetic energy of the fission fragments into electrical potential of about 2MV.

  4. NMR studies of the structure of glasses

    International Nuclear Information System (INIS)

    Bray, P.J.; Gravina, S.J.; Stallworth, P.E.; Szu, S.P.; Jianhui Zhong

    1988-01-01

    Earlier continuous wave (CW) NMR studies of chemical bonding and structure in glasses are summarized. Examples are given of this use of the quadrupolar interaction and chemical shift to obtain structural information. New NMR data and analyses are presented for alkali borate and gallate glasses. Extensions to other elements (e.g. molybdenum, lanthanum) are suggested. 44 refs. (author)

  5. Determining the depth of certain gravity sources without a priori specification of their structural index

    Science.gov (United States)

    Zhou, Shuai; Huang, Danian

    2015-11-01

    We have developed a new method for the interpretation of gravity tensor data based on the generalized Tilt-depth method. Cooper (2011, 2012) extended the magnetic Tilt-depth method to gravity data. We take the gradient-ratio method of Cooper (2011, 2012) and modify it so that the source type does not need to be specified a priori. We develop the new method by generalizing the Tilt-depth method for depth estimation for different types of source bodies. The new technique uses only the three vertical tensor components of the full gravity tensor data observed or calculated at different height plane to estimate the depth of the buried bodies without a priori specification of their structural index. For severely noise-corrupted data, our method utilizes different upward continuation height data, which can effectively reduce the influence of noise. Theoretical simulations of the gravity source model with and without noise illustrate the ability of the method to provide source depth information. Additionally, the simulations demonstrate that the new method is simple, computationally fast and accurate. Finally, we apply the method using the gravity data acquired over the Humble Salt Dome in the USA as an example. The results show a good correspondence to the previous drilling and seismic interpretation results.

  6. A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

    Science.gov (United States)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-11-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. A radio and optical study of Molonglo radio sources

    Science.gov (United States)

    Ishwara-Chandra, C. H.; Saikia, D. J.; McCarthy, P. J.; van Breugel, W. J. M.

    2001-05-01

    We present multi-wavelength radio observations with the Very Large Array, and narrow- and broad-band optical observations with the 2.5-m telescope at the Las Campanas Observatory, of a well-defined sample of high-luminosity Fanaroff-Riley class II radio galaxies and quasars, selected from the Molonglo Reference Catalogue 1-Jy sample. These observations were carried out as part of a programme to investigate the effects of orientation and environment on some of the observed properties of these sources. We examine the dependence of the Liu-Pooley relationship, which shows that radio lobes with flatter radio spectra are less depolarized, on size, identification and redshift, and show that it is significantly stronger for smaller sources, with the strength of the relationship being similar for both radio galaxies and quasars. In addition to Doppler effects, there appear to be intrinsic differences between the lobes on opposite sides. We discuss the asymmetry in brightness and location of the hotspots, and present estimates of the ages and velocities from matched-resolution observations in the L and C bands. Narrow- and broad-band optical images of some of these sources were made to study their environments and correlate with the symmetry parameters. An extended emission-line region is seen in a quasar, and in four of the objects possible companion galaxies are seen close to the radio axis.

  8. Electrostatic energy harvesting device with dual resonant structure for wideband random vibration sources at low frequency.

    Science.gov (United States)

    Zhang, Yulong; Wang, Tianyang; Zhang, Ai; Peng, Zhuoteng; Luo, Dan; Chen, Rui; Wang, Fei

    2016-12-01

    In this paper, we present design and test of a broadband electrostatic energy harvester with a dual resonant structure, which consists of two cantilever-mass subsystems each with a mass attached at the free edge of a cantilever. Comparing to traditional devices with single resonant frequency, the proposed device with dual resonant structure can resonate at two frequencies. Furthermore, when one of the cantilever-masses is oscillating at resonance, the vibration amplitude is large enough to make it collide with the other mass, which provides strong mechanical coupling between the two subsystems. Therefore, this device can harvest a decent power output from vibration sources at a broad frequency range. During the measurement, continuous power output up to 6.2-9.8 μW can be achieved under external vibration amplitude of 9.3 m/s 2 at a frequency range from 36.3 Hz to 48.3 Hz, which means the bandwidth of the device is about 30% of the central frequency. The broad bandwidth of the device provides a promising application for energy harvesting from the scenarios with random vibration sources. The experimental results indicate that with the dual resonant structure, the vibration-to-electricity energy conversion efficiency can be improved by 97% when an external random vibration with a low frequency filter is applied.

  9. XTALOPT version r11: An open-source evolutionary algorithm for crystal structure prediction

    Science.gov (United States)

    Avery, Patrick; Falls, Zackary; Zurek, Eva

    2018-01-01

    Version 11 of XTALOPT, an evolutionary algorithm for crystal structure prediction, has now been made available for download from the CPC library or the XTALOPT website, http://xtalopt.github.io. Whereas the previous versions of XTALOPT were published under the Gnu Public License (GPL), the current version is made available under the 3-Clause BSD License, which is an open source license that is recognized by the Open Source Initiative. Importantly, the new version can be executed via a command line interface (i.e., it does not require the use of a Graphical User Interface). Moreover, the new version is written as a stand-alone program, rather than an extension to AVOGADRO.

  10. Linac Coherent Light Source (LCLS) Design Study Report

    Energy Technology Data Exchange (ETDEWEB)

    Cornacchia, Massimo

    1998-12-04

    The Stanford Linear Accelerator Center, in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the wavelength range 1.5-15 {angstrom}. This FEL, called the ''Linac Coherent Light Source'' (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. Starting in FY 1998, the first two-thirds of the SLAC linac will be used for injection into the B factory. This leaves the last one-third free for acceleration to 15 GeV. The LCLS takes advantage of this opportunity, opening the way for the next generation of synchrotron light sources with largely proven technology and cost effective methods. This proposal is consistent with the recommendations of the Report of the Basic Energy Sciences Advisory Committee (Synchrotron Radiation Light Source Working Group, October 18-19, 1997). The report recognizes that ''fourth-generation x-ray sources...will in all likelihood be based on the free electron laser concepts. If successful, this technology could yield improvements in brightness by many orders of magnitude.'' This Design Study, the authors believe, confirms the feasibility of constructing an x-ray FEL based on the SLAC linac. Although this design is based on a consistent and feasible set of parameters, some components require more research and development to guarantee the performance. Given appropriate funding, this R and D phase can be completed in 2 years.

  11. imide, crystal structure, thermal and dielectric studies

    Indian Academy of Sciences (India)

    methyl imidazolium methylidene bis(trifluoromethanesulfonyl)imide, crystal structure, thermal and dielectric studies. BOUMEDIENE HADDAD1,2,3,∗, TAQIYEDDINE MOUMENE2, DIDIER VILLEMIN1,. JEAN-FRANÇOIS LOHIER1 and EL-HABIB ...

  12. THE MULTIPHASE STRUCTURE AND POWER SOURCES OF GALACTIC WINDS IN MAJOR MERGERS

    International Nuclear Information System (INIS)

    Rupke, David S. N.; Veilleux, Sylvain

    2013-01-01

    Massive, galaxy-scale outflows are known to be ubiquitous in major mergers of disk galaxies in the local universe. In this paper, we explore the multiphase structure and power sources of galactic winds in six ultraluminous infrared galaxies (ULIRGs) at z –1 , and the highest velocities (2000-3000 km s –1 ) are seen only in ionized gas. The outflow energy and momentum in the QSOs are difficult to produce from a starburst alone, but are consistent with the QSO contributing significantly to the driving of the flow. Finally, when all gas phases are accounted for, the outflows are massive enough to provide negative feedback to star formation.

  13. Linac design study for an intense neutron-source driver

    International Nuclear Information System (INIS)

    Lynch, M.T.; Browman, A.; DeHaven, R.; Jameson, R.; Jason, A.; Neuschaefer, G.; Tallerico, P.; Regan, A.

    1993-01-01

    The 1-MW spallation-neutron source under design study at Los Alamos is driven by a linac-compressor-ring scheme that utilizes a large portion of the existing Los Alamos Meson Physics Facility (LAMPF) linac, as well as the facility infrastructure. The project is referred to as the National Center for Neutron Research (NCNR). A second phase of the proposal will upgrade the driver power to 5 MW. A description of the 1-MW scheme is given in this paper. In addition, the upgrade path to the substantial increase of beam power required for the 5 MW scenario is discussed

  14. Study of phenol extraction from coke-chemical sources

    Energy Technology Data Exchange (ETDEWEB)

    Catana, E.; Mateescu, I.; Giurcaneanu, V.; Bota, T.

    1990-09-01

    The paper presents an experimental study of the phase equilibrium in the coke-chemical tarphenols-solvent system (NaOH) solution and (phenolate solution) implied in the extraction of the phenols from coke-chemical sources. The possibility of using the phenolate solution as an extraction agent, thus making possible the improvement of the specific consumption and also simplifying the problem of the corrosion and of the waste water at the same time is presented. The influence of the solvent tar mass ratio on the selectivity of the process is discussed, this criterion being considered for establishing the conditions of the extraction. 2 figs., 7 tabs., 13 refs.

  15. Structure and sources of solar wind in the growing phase of 24th solar cycle

    Science.gov (United States)

    Slemzin, Vladimir; Goryaev, Farid; Shugay, Julia; Rodkin, Denis; Veselovsky, Igor

    2015-04-01

    We present analysis of the solar wind (SW) structure and its association with coronal sources during the minimum and rising phase of 24th solar cycle (2009-2011). The coronal sources prominent in this period - coronal holes, small areas of open magnetic fields near active regions and transient sources associated with small-scale solar activity have been investigated using EUV solar images and soft X-ray fluxes obtained by the CORONAS-Photon/TESIS/Sphinx, PROBA2/SWAP, Hinode/EIS and AIA/SDO instruments as well as the magnetograms obtained by HMI/SDO. It was found that at solar minimum (2009) velocity and magnetic field strength of high speed wind (HSW) and transient SW from small-scale flares did not differ significantly from those of the background slow speed wind (SSW). The major difference between parameters of different SW components was seen in the ion composition represented by the C6/C5, O7/O6, Fe/O ratios and the mean charge of Fe ions. With growing solar activity, the speed of HSW increased due to transformation of its sources - small-size low-latitude coronal holes into equatorial extensions of large polar holes. At that period, the ion composition of transient SW changed from low-temperature to high-temperature values, which was caused by variation of the source conditions and change of the recombination/ionization rates during passage of the plasma flow through the low corona. However, we conclude that criteria of separation of the SW components based on the ion ratios established earlier by Zhao&Fisk (2009) for higher solar activity are not applicable to the extremely weak beginning of 24th cycle. The research leading to these results has received funding from the European Commission's Seventh Framework Programme (FP7/2007-2013) under the grant agreement eHeroes (project n° 284461, www.eheroes.eu).

  16. High power laser source for space applications. Phase 1 study: Executive summary

    Science.gov (United States)

    1986-07-01

    A study to design a high power laser diode, to manufacture samples, to test them, and to identify the problems raised by the manufacture of such power sources in order to evaluate the effort required to overcome the difficulties in view of a component qualification was initiated. Theoretical modeling, manufacturing and test of samples, and environmental evaluation were completed. To obtain 200 mW monomode, a reversed CSP structure manufactured by chemical vapor deposition is recommended.

  17. The training of Olympic wrestling coaches: study of the sources of knowledge and essential training contents

    Directory of Open Access Journals (Sweden)

    Paulo Martins

    2017-08-01

    Full Text Available The aim of this study was to analyze the representation of wrestling coaches regarding the sources of knowledge and the training contents to be adopted during the training process of young wrestlers’ coaches. The study was based on Grossman’s (1990 model of professional knowledge for teaching and followed a qualitative, multiple case study methodology. Following a semi-structured script, six Olympic wrestling experts were interviewed in-depth, trying to identify the sources of knowledge that the coaches used for their training and what didactic-methodological contents they considered essential to play their role as coach. The analysis revealed that the coaches’ sources of professional knowledge were diverse, including academic training and professional experience as the main sources of access to professional knowledge. The coaches also pointed out that their first sources of knowledge were their experiences as competitive athletes. Finally, this study concludes that expert coaches must acquire a profound knowledge of the competition environment, seeking to optimize their influence on athletes, which should extend not only to the sport practice of the youngster – as an athlete – but also at the level of the athlete as a person.

  18. Structural Studies of Biological Solids Using NMR

    Science.gov (United States)

    Ramamoorthy, Ayyalusamy

    2011-03-01

    High-resolution structure and dynamics of biological molecules are important in understanding their function. While studies have been successful in solving the structures of water-soluble biomolecules, it has been proven difficult to determine the structures of membrane proteins and fibril systems. Recent studies have shown that solid-state NMR is a promising technique and could be highly valuable in studying such non-crystalline and non-soluble biosystems. I will present strategies to study the structures of such challenging systems and also about the applications of solid-state NMR to study the modes of membrane-peptide interactions for a better assessment of the prospects of antimicrobial peptides as substitutes to antibiotics in the control of human disease. Our studies on the mechanism of membrane disruption by LL-37 (a human antimicrobial peptide), analogs of the naturally occurring antimicrobial peptide magainin2 extracted from the skin of the African frog Xenopus Laevis, and pardaxin will be presented. Solid-state NMR experiments were used to determine the secondary structure, dynamics and topology of these peptides in lipid bilayers. Similarities and difference in the cell-lysing mechanism, and their dependence on the membrane composition, of these peptides will be discussed. Atomic-level resolution NMR structures of amyloidogenic proteins revealing the misfolding pathway and early intermediates that play key roles in amyloid toxicity will also be presented.

  19. Ground-source heat pump case studies and utility programs

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Boyd, T.L.; Rogers, R.L.

    1995-04-01

    Ground-source heat pump systems are one of the promising new energy technologies that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to consumers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school and commercial building applications. In order to verify the performance, information was collected for 253 case studies from mainly utilities throughout the United States. The case studies were compiled into a database. The database was organized into general information, system information, ground system information, system performance, and additional information. Information was developed on the status of demand-side management of ground-source heat pump programs for about 60 electric utility and rural electric cooperatives on marketing, incentive programs, barriers to market penetration, number units installed in service area, and benefits.

  20. Structural heterogeneities in the source area of the Mw 7.9 2008 Wenchuan Earthquake, China

    Science.gov (United States)

    Wang, Z.; Fukao, Y.; Pei, S.

    2008-12-01

    The Mw 7.9 Wenchuan Earthquake occurred on May 12, 2008 (06:28:01 UTC) in the Longmen-Shan fault zone at the eastern margin of Tibet and adjacent to the Sichuan foreland basin, where as much as 9 m of coseismic slip was observed. This is the most significant earthquake to have struck China since the 1976 Tangshan Earthquake (Mw 7.6). Chinese authorities estimated more than 69,000 people were killed and 374,176 injured. About 1,485,000 people were forced into temporary shelters (http://www.gov.cn). The coseismic faulting zone coincides roughly with this aftershock distribution. The extent of the great damage may have resulted from the variation of crustal structures along the tectonic thrust faulting and strike slipping zone, causing significant coseismic displacement and acceleration on a regional scale. For a better understanding of what may have triggered this earthquake and how the rupture proceeded after the initiation, we conducted an investigation of the seismic structure in the Wenchuan earthquake source area. A large number of arrival time data of P and Pn, S and Sn phases from local earthquakes were collected and inverted jointly for the three-dimensional P- and S-wave velocity (Vp and Vs) models. The Poisson's ratio model was then calculated from these velocity models. The overall patterns of Vp and Vs anomalies are similar to each other at any of these three depths. The Sichuan Basin is a distinct entity in tomographic images, anomalously slow at 13 km depth and anomalously fast at 20 km depth, in sharp contrast to the anomalies on the mountain side across the Longmen-Shan fault zone. The area of the fault zone is characterized in general by high Vp and Vs anomalies at a depth of 13 km, although a low Vp and Vs anomaly patch is present in the middle of a total fault length of 300 km. At depths around 20 km, low Vp and Vs anomalies dominate on the mountain side including its eastern margin, where the shallower (˜13 km) and deeper (˜30 km) depths are

  1. SLStudio: Open-source framework for real-time structured light

    DEFF Research Database (Denmark)

    Wilm, Jakob; Olesen, Oline Vinter; Larsen, Rasmus

    2014-01-01

    that this software makes real-time 3D scene capture more widely accessible and serves as a foundation for new structured light scanners operating in real-time, e.g. 20 depth images per second and more. The use cases for such scanners are plentyfull, however due to the computational constraints, all public......An open-source framework for real-time structured light is presented. It is called “SLStudio”, and enables real-time capture of metric depth images. The framework is modular, and extensible to support new algorithms for scene encoding/decoding, triangulation, and aquisition hardware. It is the aim...... implementations so far are limited to offline processing. With “SLStudio”, we are making a platform available which enables researchers from many different fields to build application specific real time 3D scanners. The software is hosted at http://compute.dtu.dk/~jakw/slstudio....

  2. Structure of massive star forming clumps from the Red MSX Source Survey

    Science.gov (United States)

    Figura, Charles C.; Urquhart, J. S.; Morgan, L.

    2014-01-01

    We present ammonia (1,1) and (2,2) emission maps of 61 high-mass star forming regions drawn from the Red MSX Source (RMS) Survey and observed with the Green Bank Telescope's K-Band Focal Plane Array. We use these observations to investigate the spatial distribution of the environmental conditions associated with this sample of embedded massive young stellar objects (MYSOs). Ammonia is an excellent high-density tracer of star-forming regions as its hyperfine structure allows relatively simple characterisation of the molecular environment. These maps are used to measure the column density, kinetic gas temperature distributions and velocity structure across these regions. We compare the distribution of these properties to that of the associated dust and mid-infrared emission traced by the ATLASGAL 870 micron emission maps and the Spitzer GLIMPSE IRAC images. We present a summary of these results and highlight some of more interesting finds.

  3. The adoption of total cost of ownership for sourcing decisions - a structural equations analysis

    NARCIS (Netherlands)

    Wouters, Marc; Anderson, James C.; Wynstra, Finn

    2005-01-01

    This study investigates the adoption of total cost of ownership (TCO) analysis to improve sourcing decisions. TCO can be seen as an application of activity based costing (ABC) that quantifies the costs that are involved in acquiring and using purchased goods or services. TCO supports purchasing

  4. Dosimetric characterization of two radium sources for retrospective dosimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Karlsson, M. [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85 (Sweden); Lundell, M. [Department of Medical Physics and Oncology, Karolinska University Hospital and Karolinska Institute, Stockholm SE 171 76 (Sweden); Ballester, F. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Tedgren, Å. Carlsson [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85, Sweden and Swedish Radiation Safety Authority, Stockholm SE 171 16 (Sweden)

    2015-05-15

    Purpose: During the first part of the 20th century, {sup 226}Ra was the most used radionuclide for brachytherapy. Retrospective accurate dosimetry, coupled with patient follow up, is important for advancing knowledge on long-term radiation effects. The purpose of this work was to dosimetrically characterize two {sup 226}Ra sources, commonly used in Sweden during the first half of the 20th century, for retrospective dose–effect studies. Methods: An 8 mg {sup 226}Ra tube and a 10 mg {sup 226}Ra needle, used at Radiumhemmet (Karolinska University Hospital, Stockholm, Sweden), from 1925 to the 1960s, were modeled in two independent Monte Carlo (MC) radiation transport codes: GEANT4 and MCNP5. Absorbed dose and collision kerma around the two sources were obtained, from which the TG-43 parameters were derived for the secular equilibrium state. Furthermore, results from this dosimetric formalism were compared with results from a MC simulation with a superficial mould constituted by five needles inside a glass casing, placed over a water phantom, trying to mimic a typical clinical setup. Calculated absorbed doses using the TG-43 formalism were also compared with previously reported measurements and calculations based on the Sievert integral. Finally, the dose rate at large distances from a {sup 226}Ra point-like-source placed in the center of 1 m radius water sphere was calculated with GEANT4. Results: TG-43 parameters [including g{sub L}(r), F(r, θ), Λ, and s{sub K}] have been uploaded in spreadsheets as additional material, and the fitting parameters of a mathematical curve that provides the dose rate between 10 and 60 cm from the source have been provided. Results from TG-43 formalism are consistent within the treatment volume with those of a MC simulation of a typical clinical scenario. Comparisons with reported measurements made with thermoluminescent dosimeters show differences up to 13% along the transverse axis of the radium needle. It has been estimated that

  5. The Effect of Initial Inoculum Source on the Microbial Community Structure and Dynamics in Laboratory-Scale Sequencing Batch Reactors

    KAUST Repository

    Hernandez, Susana

    2011-07-01

    Understanding the factors that shapes the microbial community assembly in activated sludge wastewater treatment processes provide a conceptual foundation for improving process performance. The aim of this study was to compare two major theories (deterministic theory and neutral theory) regarding the assembly of microorganisms in activated sludge: Six lab-scale activated sludge sequencing batch reactors were inoculated with activated sludge collected from three different sources (domestic, industrial, and sugar industry WWTP). Additionally, two reactors were seeded with equal proportion of sludge from the three WWTPs. Duplicate reactors were used for each sludge source (i.e. domestic, industrial, sugar and mix). Reactors were operated in parallel for 11 weeks under identical conditions. Bacterial diversity and community structure in the eight SBRs were assessed by 16S rRNA gene pyrosequencing. The 16S rRNA gene sequences were analyzed using taxonomic and clustering analysis and by measuring diversity indices (Shannon-weaver and Chao1 indices). Cluster analysis revealed that the microbial community structure was dynamic and that replicate reactors evolved differently. Also the microbial community structure in the SBRs seeded with a different sludge did not converge after 11 weeks of operation under identical conditions. These results suggest that history and distribution of taxa in the source inoculum were stronger regulating factors in shaping bacterial community structure than environmental factors. This supports the neutral theory which states that the assembly of the local microbial community from the metacommunity is random and is regulated by the size and diversity of the metacommunity. Furthermore, sludge performance, measured by COD and ammonia removal, confirmed that broad-scale functions (e.g. COD removal) are not influenced by dynamics in the microbial composition, while specific functions (e.g. nitrification) are more susceptible to these changes.

  6. FR-type radio sources in COSMOS: relation of radio structure to size, accretion modes and large-scale environment

    Science.gov (United States)

    Vardoulaki, Eleni; Faustino Jimenez Andrade, Eric; Delvecchio, Ivan; Karim, Alexander; Smolčić, Vernesa; Magnelli, Benjamin; Bertoldi, Frank; Schinnener, Eva; Sargent, Mark; Finoguenov, Alexis; VLA COSMOS Team

    2018-01-01

    The radio sources associated with active galactic nuclei (AGN) can exhibit a variety of radio structures, from simple to more complex, giving rise to a variety of classification schemes. The question which still remains open, given deeper surveys revealing new populations of radio sources, is whether this plethora of radio structures can be attributed to the physical properties of the host or to the environment. Here we present an analysis on the radio structure of radio-selected AGN from the VLA-COSMOS Large Project at 3 GHz (JVLA-COSMOS; Smolčić et al.) in relation to: 1) their linear projected size, 2) the Eddington ratio, and 3) the environment their hosts lie within. We classify these as FRI (jet-like) and FRII (lobe-like) based on the FR-type classification scheme, and compare them to a sample of jet-less radio AGN in JVLA-COSMOS. We measure their linear projected sizes using a semi-automatic machine learning technique. Their Eddington ratios are calculated from X-ray data available for COSMOS. As environmental probes we take the X-ray groups (hundreds kpc) and the density fields (~Mpc-scale) in COSMOS. We find that FRII radio sources are on average larger than FRIs, which agrees with literature. But contrary to past studies, we find no dichotomy in FR objects in JVLA-COSMOS given their Eddington ratios, as on average they exhibit similar values. Furthermore our results show that the large-scale environment does not explain the observed dichotomy in lobe- and jet-like FR-type objects as both types are found on similar environments, but it does affect the shape of the radio structure introducing bents for objects closer to the centre of an X-ray group.

  7. Do knowledge, knowledge sources and reasoning skills affect the accuracy of nursing diagnoses? a randomised study.

    Science.gov (United States)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos Mb; Krijnen, Wim P; van der Schans, Cees P

    2012-08-01

    This paper reports a study about the effect of knowledge sources, such as handbooks, an assessment format and a predefined record structure for diagnostic documentation, as well as the influence of knowledge, disposition toward critical thinking and reasoning skills, on the accuracy of nursing diagnoses.Knowledge sources can support nurses in deriving diagnoses. A nurse's disposition toward critical thinking and reasoning skills is also thought to influence the accuracy of his or her nursing diagnoses. A randomised factorial design was used in 2008-2009 to determine the effect of knowledge sources. We used the following instruments to assess the influence of ready knowledge, disposition, and reasoning skills on the accuracy of diagnoses: (1) a knowledge inventory, (2) the California Critical Thinking Disposition Inventory, and (3) the Health Science Reasoning Test. Nurses (n = 249) were randomly assigned to one of four factorial groups, and were instructed to derive diagnoses based on an assessment interview with a simulated patient/actor. The use of a predefined record structure resulted in a significantly higher accuracy of nursing diagnoses. A regression analysis reveals that almost half of the variance in the accuracy of diagnoses is explained by the use of a predefined record structure, a nurse's age and the reasoning skills of `deduction' and `analysis'. Improving nurses' dispositions toward critical thinking and reasoning skills, and the use of a predefined record structure, improves accuracy of nursing diagnoses.

  8. Do knowledge, knowledge sources and reasoning skills affect the accuracy of nursing diagnoses? a randomised study

    Directory of Open Access Journals (Sweden)

    Paans Wolter

    2012-08-01

    Full Text Available Abstract Background This paper reports a study about the effect of knowledge sources, such as handbooks, an assessment format and a predefined record structure for diagnostic documentation, as well as the influence of knowledge, disposition toward critical thinking and reasoning skills, on the accuracy of nursing diagnoses. Knowledge sources can support nurses in deriving diagnoses. A nurse’s disposition toward critical thinking and reasoning skills is also thought to influence the accuracy of his or her nursing diagnoses. Method A randomised factorial design was used in 2008–2009 to determine the effect of knowledge sources. We used the following instruments to assess the influence of ready knowledge, disposition, and reasoning skills on the accuracy of diagnoses: (1 a knowledge inventory, (2 the California Critical Thinking Disposition Inventory, and (3 the Health Science Reasoning Test. Nurses (n = 249 were randomly assigned to one of four factorial groups, and were instructed to derive diagnoses based on an assessment interview with a simulated patient/actor. Results The use of a predefined record structure resulted in a significantly higher accuracy of nursing diagnoses. A regression analysis reveals that almost half of the variance in the accuracy of diagnoses is explained by the use of a predefined record structure, a nurse’s age and the reasoning skills of `deduction’ and `analysis’. Conclusions Improving nurses’ dispositions toward critical thinking and reasoning skills, and the use of a predefined record structure, improves accuracy of nursing diagnoses.

  9. GENERATING ACCURATE 3D MODELS OF ARCHITECTURAL HERITAGE STRUCTURES USING LOW-COST CAMERA AND OPEN SOURCE ALGORITHMS

    Directory of Open Access Journals (Sweden)

    M. Zacharek

    2017-05-01

    Full Text Available These studies have been conductedusing non-metric digital camera and dense image matching algorithms, as non-contact methods of creating monuments documentation.In order toprocess the imagery, few open-source software and algorithms of generating adense point cloud from images have been executed. In the research, the OSM Bundler, VisualSFM software, and web application ARC3D were used. Images obtained for each of the investigated objects were processed using those applications, and then dense point clouds and textured 3D models were created. As a result of post-processing, obtained models were filtered and scaled.The research showedthat even using the open-source software it is possible toobtain accurate 3D models of structures (with an accuracy of a few centimeters, but for the purpose of documentation and conservation of cultural and historical heritage, such accuracy can be insufficient.

  10. Feasibility study of a 1-MW pulsed spallation source

    International Nuclear Information System (INIS)

    Cho, Y.; Chae, Y.C.; Crosbie, E.

    1995-01-01

    A feasibility study of a 1-MW pulsed spallation source based on a rapidly cycling proton synchrotron (RCS) has been completed. The facility consists of a 400-MeV HP - linac, a 30-Hz RCS that accelerates the 400-MeV beam to 2 GeV, and two neutron-generating target stations. The design time-averaged current of the accelerator system is 0.5 mA, or 1.04x1014 protons per pulse. The linac system consists of an H - ion source, a 2-MeV RFQ, a 70-MeV DTL and a 330-MeV CCL. Transverse phase space painting to achieve a Kapchinskij-Vladimirskij (K-V) distribution of the injected particles in the RCS is accomplished by charge exchange injection and programming of the closed orbit during injection. The synchrotron lattice uses FODO cells of ∼90 degrees phase advance. Dispersion-free straight sections are obtained by using a missing magnet scheme. Synchrotron magnets are powered by a dual-frequency resonant circuit that excites the magnets at a 20-Hz rate and de-excites them at a 60-Hz rate, resulting in an effective rate of 30 Hz, and reducing the required peak rf voltage by 1/3. A key feature, of the design of this accelerator system is that beam losses are from injection to extraction, reducing activation to levels consistent with hands-on maintenance. Details of the study are presented

  11. Preliminary studies of Brazilian wood using different radioisotopic sources

    International Nuclear Information System (INIS)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e

    2013-01-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  12. High power microwave source with a three dimensional printed metamaterial slow-wave structure

    International Nuclear Information System (INIS)

    French, David M.; Shiffler, Don

    2016-01-01

    For over the last decade, the concept of metamaterials has led to new approaches for considering the interaction of radiation with complex structures. However, practical manifestations of such a device operating at high power densities have proven difficult to achieve due to the resonant nature of metamaterials and the resultant high electric fields, which place severe constraints on manufacturing the slow wave structures. In this paper, we describe the first experimental manifestation of a high power microwave device utilizing a metallic slow wave structure (metamaterial-like) fabricated using additive manufacturing. The feasibility of utilizing additive manufacturing as a technique for building these relatively complicated structures has thus been demonstrated. The MW class microwave source operates in the C-band and shows frequency tunablility with electron beam voltage. The basic electromagnetic characteristics of this device, the construction using additive manufacturing, and the basic performance as a microwave oscillator are considered. Due to the tunable nature of the device, it shows promise not only as an oscillator but also as a microwave amplifier. Therefore, the dispersive characteristics and a discussion of the anticipated gain is included as it relates to an amplifier configuration.

  13. High power microwave source with a three dimensional printed metamaterial slow-wave structure

    Energy Technology Data Exchange (ETDEWEB)

    French, David M.; Shiffler, Don [Air Force Research Laboratory, Directed Energy Directorate, Albuquerque, New Mexico 871117 (United States)

    2016-05-15

    For over the last decade, the concept of metamaterials has led to new approaches for considering the interaction of radiation with complex structures. However, practical manifestations of such a device operating at high power densities have proven difficult to achieve due to the resonant nature of metamaterials and the resultant high electric fields, which place severe constraints on manufacturing the slow wave structures. In this paper, we describe the first experimental manifestation of a high power microwave device utilizing a metallic slow wave structure (metamaterial-like) fabricated using additive manufacturing. The feasibility of utilizing additive manufacturing as a technique for building these relatively complicated structures has thus been demonstrated. The MW class microwave source operates in the C-band and shows frequency tunablility with electron beam voltage. The basic electromagnetic characteristics of this device, the construction using additive manufacturing, and the basic performance as a microwave oscillator are considered. Due to the tunable nature of the device, it shows promise not only as an oscillator but also as a microwave amplifier. Therefore, the dispersive characteristics and a discussion of the anticipated gain is included as it relates to an amplifier configuration.

  14. Structural Health Monitoring of Wind Turbine Blades: Acoustic Source Localization Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Omar Mabrok Bouzid

    2015-01-01

    Full Text Available Structural health monitoring (SHM is important for reducing the maintenance and operation cost of safety-critical components and systems in offshore wind turbines. This paper proposes an in situ wireless SHM system based on an acoustic emission (AE technique. By using this technique a number of challenges are introduced due to high sampling rate requirements, limitations in the communication bandwidth, memory space, and power resources. To overcome these challenges, this paper focused on two elements: (1 the use of an in situ wireless SHM technique in conjunction with the utilization of low sampling rates; (2 localization of acoustic sources which could emulate impact damage or audible cracks caused by different objects, such as tools, bird strikes, or strong hail, all of which represent abrupt AE events and could affect the structural health of a monitored wind turbine blade. The localization process is performed using features extracted from aliased AE signals based on a developed constraint localization model. To validate the performance of these elements, the proposed system was tested by testing the localization of the emulated AE sources acquired in the field.

  15. Fine structure studies of terbium atoms

    International Nuclear Information System (INIS)

    Abhay Kumar; Bandyopadhyay, Krishnanath; Niraj Kumar

    2012-01-01

    Terbium (Z = 65) is a typical rare-earth element. Fine structure of spectural lines of terbium (Tb) are presented using the laser optogalvanic spectroscopic technique. Altogether eighty transitions in the 5686-6367 A range have been observed in the fine structure spectrum of 159 Tb. Wavelengths of all the observed transitions have been determined. Out of 80 transitions of Tb, a total of 59 transitions are being reported for the first time. Classifications of 39 new transitions have been provided using the known energy levels, Doppler-limited optogalvanic spectroscopic technique is employed to study the fine structure (fs) 159 Tb. (author)

  16. Characteristics studies of molecular structures in drugs

    Directory of Open Access Journals (Sweden)

    Wei Gao

    2017-05-01

    Full Text Available In theoretical medicine, topological indices are defined to test the medicine and pharmacy characteristics, such as melting point, boiling point, toxicity and other biological activities. As basic molecular structures, hexagonal jagged-rectangle and distance-regular structure are widely appeared in medicine, pharmacy and biology engineering. In this paper, we study the chemical properties of hexagonal jagged-rectangle from the mathematical point of view. Several vertex distance-based indices are determined. Furthermore, the Wiener related indices of distance-regular structure are also considered.

  17. FEASIBILITY STUDY II OF A MUON BASED NEUTRINO SOURCE.

    Energy Technology Data Exchange (ETDEWEB)

    GALLARDO,J.C.; OZAKI,S.; PALMER,R.B.; ZISMAN,M.

    2001-06-30

    The concept of using a muon storage ring to provide a well characterized beam of muon and electron neutrinos (a Neutrino Factory) has been under study for a number of years now at various laboratories throughout the world. The physics program of a Neutrino Factoryis focused on the relatively unexplored neutrino sector. In conjunction with a detector located a suitable distance from the neutrino source, the facility would make valuable contributions to the study of neutrino masses and lepton mixing. A Neutrino Factory is expected to improve the measurement accuracy of sin{sup 2}(2{theta}{sub 23}) and {Delta}m{sup 2}{sub 32} and provide measurements of sin{sup 2}(2{theta}{sub 13}) and the sign of {Delta}m{sup 2}{sub 32}. It may also be able to measure CP violation in the lepton sector.

  18. Open-Source Software in Computational Research: A Case Study

    Directory of Open Access Journals (Sweden)

    Sreekanth Pannala

    2008-04-01

    Full Text Available A case study of open-source (OS development of the computational research software MFIX, used for multiphase computational fluid dynamics simulations, is presented here. The verification and validation steps required for constructing modern computational software and the advantages of OS development in those steps are discussed. The infrastructure used for enabling the OS development of MFIX is described. The impact of OS development on computational research and education in gas-solids flow, as well as the dissemination of information to other areas such as geophysical and volcanology research, is demonstrated. This study shows that the advantages of OS development were realized in the case of MFIX: verification by many users, which enhances software quality; the use of software as a means for accumulating and exchanging information; the facilitation of peer review of the results of computational research.

  19. Sources of International Courts' Legitimacy: A comparative study

    DEFF Research Database (Denmark)

    Godzimirska, Zuzanna; Creamer, Cosette

    Despite ample scholarship on the legitimacy of international legal institutions, existing studies on international courts (ICs) tend to adopt normative or deductive approaches to specify their legitimacy and assess its effects. Very few adopt empirical or inductive approaches and examine the reas......Despite ample scholarship on the legitimacy of international legal institutions, existing studies on international courts (ICs) tend to adopt normative or deductive approaches to specify their legitimacy and assess its effects. Very few adopt empirical or inductive approaches and examine...... the reasons why an IC is considered more or less legitimate in the eyes of a court’s constituents. This paper addresses this scholarly gap by identifying the sources of ICs’ legitimacy within the expressed views of one category of constituents: a court’s member states. Although we emphasize the importance...

  20. Genetic structure and inferences on potential source areas for Bactrocera dorsalis (Hendel based on mitochondrial and microsatellite markers.

    Directory of Open Access Journals (Sweden)

    Wei Shi

    Full Text Available Bactrocera dorsalis (Diptera: Tephritidae is mainly distributed in tropical and subtropical Asia and in the Pacific region. Despite its economic importance, very few studies have addressed the question of the wide genetic structure and potential source area of this species. This pilot study attempts to infer the native region of this pest and its colonization pathways in Asia. Combining mitochondrial and microsatellite markers, we evaluated the level of genetic diversity, genetic structure, and the gene flow among fly populations collected across Southeast Asia and China. A complex and significant genetic structure corresponding to the geographic pattern was found with both types of molecular markers. However, the genetic structure found was rather weak in both cases, and no pattern of isolation by distance was identified. Multiple long-distance dispersal events and miscellaneous host selection by this species may explain the results. These complex patterns may have been influenced by human-mediated transportation of the pest from one area to another and the complex topography of the study region. For both mitochondrial and microsatellite data, no signs of bottleneck or founder events could be identified. Nonetheless, maximal genetic diversity was observed in Myanmar, Vietnam and Guangdong (China and asymmetric migration patterns were found. These results provide indirect evidence that the tropical regions of Southeast Asia and southern coast of China may be considered as the native range of the species and the population expansion is northward. Yunnan (China is a contact zone that has been colonized from different sources. Regions along the southern coast of Vietnam and China probably served to colonize mainly the southern region of China. Southern coastal regions of China may also have colonized central parts of China and of central Yunnan.

  1. Advances in soil-structure interaction studies

    International Nuclear Information System (INIS)

    Maheshwari, B.K.

    2011-01-01

    It is utmost important that lifeline infrastructures (such as bridges, hospitals, power plants, dams etc.) are safe and functional during earthquakes as damage or collapse of these structures may have far reaching implications. A lifeline's failure may hamper relief and rescue operations required just after an earthquake and secondly its indirect economical losses may be very severe. Therefore, safety of these structures during earthquakes is vital. Further, damage to nuclear facilities during earthquake may lead to disaster. These structures should be designed adequately taking into account all the important issues. Soil-Structure Interaction (SSI) is one of the design issues, which is often overlooked and even in some cases ignored. The effects of dynamic SSI are well understood and practiced in the nuclear power industry (for large foundations of the nuclear containment structures) since sixties. However, in last decade, there are many advances in techniques of SSI and those need to be incorporated in practice. Failures of many structures occurred during the 1989 Loma Prieta and 1994 Northridge, California earthquakes and the 1995 Kobe, Japan earthquake due to SSI or a related issue. Many jetties had failed in Andaman and Nicobar islands due to Sumatra earthquake and ensuing tsunamis. It is because of this recent experience that the importance of SSI on dynamic response of structures during earthquakes has been fully realized. General belief that the SSI effects are always beneficial for the structure is not correct. Some cases have been presented where it is shown that SSI effects are detrimental for the stability of the structure. This paper addresses the effects of dynamic SSI on the response of the structures and explains its importance. Further advances in SSI studies have been discussed

  2. Feasibility study for the spallation neutron source (SNQ). Pt. 1

    International Nuclear Information System (INIS)

    Bauer, G.S.; Sebening, H.; Vetter, J.E.; Willax, H.

    1981-06-01

    A concept for a new neutron source for fundamental research has been developed and is described in this report. The spallation neutron source SNQ is characterized in its first stage by a time average thermal neutron flux of 7 x 10 14 cm -2 s -1 and a peak flux of 1.3 x 10 16 cm -2 s -1 at 100 Hz repetition rate. The scientific case is presented with particular emphasis on solid state and nuclear physics. In these research domains, unique conditions are given for experimental use. The proposed machine consists in its basic stage of a 1.1 GeV, 5 mA time average, 100 mA peak current proton linear accelerator, a rotating lead target, and H 2 O and D 2 O moderators. Additional beam channels are provided for experiments with protons at 350 MeV and at the final energy. Construction of the SNQ is considered feasible within eight years at a cost of 680 million DM. As future options, use of uranium as a target material, increase of the accelerator beam power by a factor of 2, addition of a pulse compressor and a second target station for pulsed neutron and neutrino research are described. As a back-up solution to the rotating target, a liquid metal target was studied. (orig.) [de

  3. FEL polarization control studies on Dalian coherent light source

    International Nuclear Information System (INIS)

    Zhang Tong; Deng Haixiao; Wang Dong; Zhao Zhentang; Zhang Weiqing; Wu Guorong; Dai Dongxu; Yang Xueming

    2013-01-01

    The polarization switch of a free-electron laser (FEL) is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. The elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical permanent undulator section, circular polarized FEL with pulse energy exceeding 100 μJ could be achieved at Dalian coherent light source. (authors)

  4. 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).

  5. Integrated source-risk model for radon: A definition study

    International Nuclear Information System (INIS)

    Laheij, G.M.H.; Aldenkamp, F.J.; Stoop, P.

    1993-10-01

    The purpose of a source-risk model is to support policy making on radon mitigation by comparing effects of various policy options and to enable optimization of counter measures applied to different parts of the source-risk chain. There are several advantages developing and using a source-risk model: risk calculations are standardized; the effects of measures applied to different parts of the source-risk chain can be better compared because interactions are included; and sensitivity analyses can be used to determine the most important parameters within the total source-risk chain. After an inventory of processes and sources to be included in the source-risk chain, the models presently available in the Netherlands are investigated. The models were screened for completeness, validation and operational status. The investigation made clear that, by choosing for each part of the source-risk chain the most convenient model, a source-risk chain model for radon may be realized. However, the calculation of dose out of the radon concentrations and the status of the validation of most models should be improved. Calculations with the proposed source-risk model will give estimations with a large uncertainty at the moment. For further development of the source-risk model an interaction between the source-risk model and experimental research is recommended. Organisational forms of the source-risk model are discussed. A source-risk model in which only simple models are included is also recommended. The other models are operated and administrated by the model owners. The model owners execute their models for a combination of input parameters. The output of the models is stored in a database which will be used for calculations with the source-risk model. 5 figs., 15 tabs., 7 appendices, 14 refs

  6. Sustainability in Open Source Software Commons: Lessons Learned from an Empirical Study of SourceForge Projects

    OpenAIRE

    Charles M. Schweik

    2013-01-01

    In this article, we summarize a five-year US National Science Foundation funded study designed to investigate the factors that lead some open source projects to ongoing collaborative success while many others become abandoned. Our primary interest was to conduct a study that was closely representative of the population of open source software projects in the world, rather than focus on the more-often studied, high-profile successful cases. After building a large database of projects (n=174,33...

  7. Source rock contributions to the Lower Cretaceous heavy oil accumulations in Alberta: a basin modeling study

    Science.gov (United States)

    Berbesi, Luiyin Alejandro; di Primio, Rolando; Anka, Zahie; Horsfield, Brian; Higley, Debra K.

    2012-01-01

    The origin of the immense oil sand deposits in Lower Cretaceous reservoirs of the Western Canada sedimentary basin is still a matter of debate, specifically with respect to the original in-place volumes and contributing source rocks. In this study, the contributions from the main source rocks were addressed using a three-dimensional petroleum system model calibrated to well data. A sensitivity analysis of source rock definition was performed in the case of the two main contributors, which are the Lower Jurassic Gordondale Member of the Fernie Group and the Upper Devonian–Lower Mississippian Exshaw Formation. This sensitivity analysis included variations of assigned total organic carbon and hydrogen index for both source intervals, and in the case of the Exshaw Formation, variations of thickness in areas beneath the Rocky Mountains were also considered. All of the modeled source rocks reached the early or main oil generation stages by 60 Ma, before the onset of the Laramide orogeny. Reconstructed oil accumulations were initially modest because of limited trapping efficiency. This was improved by defining lateral stratigraphic seals within the carrier system. An additional sealing effect by biodegraded oil may have hindered the migration of petroleum in the northern areas, but not to the east of Athabasca. In the latter case, the main trapping controls are dominantly stratigraphic and structural. Our model, based on available data, identifies the Gordondale source rock as the contributor of more than 54% of the oil in the Athabasca and Peace River accumulations, followed by minor amounts from Exshaw (15%) and other Devonian to Lower Jurassic source rocks. The proposed strong contribution of petroleum from the Exshaw Formation source rock to the Athabasca oil sands is only reproduced by assuming 25 m (82 ft) of mature Exshaw in the kitchen areas, with original total organic carbon of 9% or more.

  8. Positron annihilation lifetime spectroscopy source correction determination: A simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Gurmeet S.; Keeble, David J., E-mail: d.j.keeble@dundee.ac.uk

    2016-02-01

    Positron annihilation lifetime spectroscopy (PALS) can provide sensitive detection and identification of vacancy-related point defects in materials. These measurements are normally performed using a positron source supported, and enclosed by, a thin foil. Annihilation events from this source arrangement must be quantified and are normally subtracted from the spectrum before analysis of the material lifetime components proceeds. Here simulated PALS spectra reproducing source correction evaluation experiments have been systematically fitted and analysed using the packages PALSfit and MELT. Simulations were performed assuming a single lifetime material, and for a material with two lifetime components. Source correction terms representing a directly deposited source and various foil supported sources were added. It is shown that in principle these source terms can be extracted from suitably designed experiments, but that fitting a number of independent, nominally identical, spectra is recommended.

  9. Structural Studies of Complex Carbohydrates of Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

    2015-02-17

    Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

  10. ProDaMa: an open source Python library to generate protein structure datasets.

    Science.gov (United States)

    Armano, Giuliano; Manconi, Andrea

    2009-10-02

    The huge difference between the number of known sequences and known tertiary structures has justified the use of automated methods for protein analysis. Although a general methodology to solve these problems has not been yet devised, researchers are engaged in developing more accurate techniques and algorithms whose training plays a relevant role in determining their performance. From this perspective, particular importance is given to the training data used in experiments, and researchers are often engaged in the generation of specialized datasets that meet their requirements. To facilitate the task of generating specialized datasets we devised and implemented ProDaMa, an open source Python library than provides classes for retrieving, organizing, updating, analyzing, and filtering protein data. ProDaMa has been used to generate specialized datasets useful for secondary structure prediction and to develop a collaborative web application aimed at generating and sharing protein structure datasets. The library, the related database, and the documentation are freely available at the URL http://iasc.diee.unica.it/prodama.

  11. ProDaMa: an open source Python library to generate protein structure datasets

    Directory of Open Access Journals (Sweden)

    Manconi Andrea

    2009-10-01

    Full Text Available Abstract Background The huge difference between the number of known sequences and known tertiary structures has justified the use of automated methods for protein analysis. Although a general methodology to solve these problems has not been yet devised, researchers are engaged in developing more accurate techniques and algorithms whose training plays a relevant role in determining their performance. From this perspective, particular importance is given to the training data used in experiments, and researchers are often engaged in the generation of specialized datasets that meet their requirements. Findings To facilitate the task of generating specialized datasets we devised and implemented ProDaMa, an open source Python library than provides classes for retrieving, organizing, updating, analyzing, and filtering protein data. Conclusion ProDaMa has been used to generate specialized datasets useful for secondary structure prediction and to develop a collaborative web application aimed at generating and sharing protein structure datasets. The library, the related database, and the documentation are freely available at the URL http://iasc.diee.unica.it/prodama.

  12. Preliminary studies of Brazilian wood using different radioisotopic sources

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e, E-mail: gcarval@ipen.br, E-mail: ftgasilva@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  13. Comparative Analysis Study of Open Source GIS in Malaysia

    International Nuclear Information System (INIS)

    Rasid, Muhammad Zamir Abdul; Kamis, Naddia; Halim, Mohd Khuizham Abd

    2014-01-01

    Open source origin might appear like a major prospective change which is qualified to deliver in various industries and also competing means in developing countries. The leading purpose of this research study is to basically discover the degree of adopting Open Source Software (OSS) that is connected with Geographic Information System (GIS) application within Malaysia. It was derived based on inadequate awareness with regards to the origin ideas or even on account of techie deficiencies in the open origin instruments. This particular research has been carried out based on two significant stages; the first stage involved a survey questionnaire: to evaluate the awareness and acceptance level based on the comparison feedback regarding OSS and commercial GIS. This particular survey was conducted among three groups of candidates: government servant, university students and lecturers, as well as individual. The approaches of measuring awareness in this research were based on a comprehending signal plus a notion signal for each survey questions. These kinds of signs had been designed throughout the analysis in order to supply a measurable and also a descriptive signal to produce the final result. The second stage involved an interview session with a major organization that carries out available origin internet GIS; the Federal Department of Town and Country Planning Peninsular Malaysia (JPBD). The impact of this preliminary study was to understand the particular viewpoint of different groups of people on the available origin, and also their insufficient awareness with regards to origin ideas as well as likelihood may be significant root of adopting level connected with available origin options

  14. Study on geologic structure of hydrogenic deposits

    International Nuclear Information System (INIS)

    1985-01-01

    The problem of studying geologic structure of hydrogenic uranium deposits developed by underground leaching (UL), is elucidated. Geologic maps of the surface are used to characterize engineering and geologic conditions. Main geologoic papers are maps drawn up according to boring data. For total geologic characteristic of the deposit 3 types of maps are usually drawn up: structural maps of isohypses or isodepths, lithologic-facies maps on the horizon and rhythm, and maps of epigenetic alterations (geochemmcal). Besides maps systems of sections are drawn up. Problems of studying lithologic-facies and geohemical peculiarities of deposits, epigenotic alterations, substance composition of ores and enclosing rocks, documentation and core sampting, are considered in details

  15. Study of fine structure of deformed hafnium

    International Nuclear Information System (INIS)

    Voskresenskaya, L.A.; Petukhova, A.S.; Kovalev, K.S.

    1978-01-01

    Variations in the hafnium fine structure following the cold plastic deformation have been studied. The fine structure condition has been studied through the harmonic analysis of the profile of the X-ray diffraction line, obtained at the DRON-I installation. Received has been the dependence of the crystal lattice microdistortions value on the deformation extent for hafnium. This dependence is compared with the corresponding one for zirconium. It is found out that at all the deformations the microdistortion distribution is uniform. The microdistortion value grows with the increase in the compression. During the mechanical impact higher microdistortions of the crystal lattice occur in the hafnium rather than in zirconium

  16. Decoupling and Sources of Structural Transformation of East Asian Economies: An International Input-Output Decomposition Analysis

    Directory of Open Access Journals (Sweden)

    Jong-Hwan Ko

    2014-03-01

    Full Text Available This study aims to answer two questions using input-output decomposition analysis: 1 Have emerging Asian economies decoupled? 2 What are the sources of structural changes in gross outputs and value-added of emerging Asian economies related to the first question? The main findings of the study are as follows: First, since 1990, there has been a trend of increasing dependence on exports to extra-regions such as G3 and the ROW, indicating no sign of "decoupling", but rather an increasing integration of emerging Asian countries into global trade. Second, there is a contrasting feature in the sources of structural changes between non-China emerging Asia and China. Dependence of non-China emerging Asia on intra-regional trade has increased in line with strengthening economic integration in East Asia, whereas China has disintegrated from the region. Therefore, it can be said that China has contributed to no sign of decoupling of emerging Asia as a whole.

  17. Numerical study of the aerodynamics of sound sources in a bass-reflex port

    Directory of Open Access Journals (Sweden)

    V.M. Garcia-Alcaide

    2017-01-01

    Full Text Available The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.

  18. Corn steep liquor as a nutritional source for biocementation and its impact on concrete structural properties.

    Science.gov (United States)

    Joshi, Sumit; Goyal, Shweta; Reddy, M Sudhakara

    2018-05-28

    Microbial-induced carbonate precipitation (MICP) has a potential to improve the durability properties and remediate cracks in concrete. In the present study, the main emphasis is placed upon replacing the expensive laboratory nutrient broth (NB) with corn steep liquor (CSL), an industrial by-product, as an alternate nutrient medium during biocementation. The influence of organic nutrients (carbon and nitrogen content) of CSL and NB on the chemical and structural properties of concrete structures is studied. It has been observed that cement-setting properties were unaffected by CSL organic content, while NB medium influenced it. Carbon and nitrogen content in concrete structures was significantly lower in CSL-treated specimens than in NB-treated specimens. Decreased permeability and increased compressive strength were reported when NB is replaced with CSL in bacteria-treated specimens. The present study results suggest that CSL can be used as a replacement growth medium for MICP technology at commercial scale.

  19. Study of characteristic X-ray source and its applications

    International Nuclear Information System (INIS)

    Li Fuquan

    1994-11-01

    The law of characteristic X-rays emitted by target element under the radiation of isotope source in a range of low energy is discussed. Both the way of improving the rate of γ-X conversion and the method to eliminate the influence of scatter rays are introduced. The influence of the variation of isotopes source, targets and the relative position of source-target to the output of X-rays is also discussed and then the conditions of improving signal-to-noise radio is presented. The X-ray source based on these results can produce different energy X-rays, and so can be broadly used on nuclear instruments and other fields as a low energy source. The thickness gauge, as one of the applications, has succeeded in thickness measuring of the different materials in large range, and it presents a new application field for characteristic X-ray source. (11 figs., 10 tabs.)

  20. A Business Case Study of Open Source Software

    Science.gov (United States)

    2001-07-01

    include cost or price, availability or multiple distribution sources, and popularity or brand /reputation. While both the commercial and government...availability, quality, security, management, scalability, brand /reputation, and service and support. 1 2 3 4 5 Pr ice Re lia bil ity Pe rfo rm an ce Av ail...source community. Open source, and Linux in particular, is often regarded as the heroic underdog . Linux has been touted as a “Windows killer.”44 Over

  1. Comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, S.

    2009-07-01

    During the past two decades, active power filters have increasingly grown their popularity as a viable method for improving electric power quality. The main reasons for this have been the advent of fast self-commutating solid-state devices, the progression of digital technology and the improved sensor technology. Four-wire active power filters provide an efficient solution for improving the quality of supply in grounded three-phase systems or three-phase systems with neutral conductors, which are commonly used for powering residential, office and public buildings. Four-wire active power filters are applicable in compensating current harmonics, reactive power, neutral current and load phase imbalance.This thesis presents a comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters. The study includes two voltage source topologies and a current source topology with two different dc-link energy storage structures, which are compared on the basis of their filtering properties, filtering performance and efficiency. The obtained results are used for determining the suitability of current source technology for four-wire active power filtering and finding the most viable four-wire shunt active power filter topology. One commonly recognized disadvantage of the current source active power filter has always been the bulky dc-link inductor. To reduce the size of the dc-link inductor, an alternative dc-link structure for current source active power filters was introduced in the late 80's. The hybrid energy storage consists of both inductive and capacitive energy storage elements, two diodes and two controllable semiconductor switching devices. Since the capacitive element is used as a main storage unit, the inductance of the dc-link inductor can be considerably reduced. However, the original dc current control method proposed is not able to utilize the full potential of the hybrid energy storage and the inductance

  2. Evaluation of an Information Source Illustrated by a Case Study

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2011-01-01

    It is argued that to evaluate an information source (e.g., a Wikipedia article), it is necessary to relate the content of that source to an interpretation of the state of knowledge at the research front (which is typically developing dynamically). In the research literature, there is a controversy...... about the effect of screening programs for breast cancer. This controversy is used to compare the value of Wikipedia with Encyclopedia Britannica and two Danish encyclopedias as information sources. It is argued that this method of examining information sources is preferable to other methods which have...

  3. Experimental study of structural response to earthquakes

    International Nuclear Information System (INIS)

    Clough, R.W.; Bertero, V.V.; Bouwkamp, J.G.; Popov, E.P.

    1975-01-01

    The objectives, methods, and some of the principal results obtained from experimental studies of the behavior of structures subjected to earthquakes are described. Although such investigations are being conducted in many laboratories throughout the world, the information presented deals specifically with projects being carried out at the Earthquake Engineering Research Center (EERC) of the University of California, Berkeley. A primary purpose of these investigations is to obtain detailed information on the inelastic response mechanisms in typical structural systems so that the experimentally observed performance can be compared with computer generated analytical predictions. Only by such comparisons can the mathematical models used in dynamic nonlinear analyses be verified and improved. Two experimental procedures for investigating earthquake structural response are discussed: the earthquake simulator facility which subjects the base of the test structure to acceleration histories similar to those recorded in actual earthquakes, and systems of hydraulic rams which impose specified displacement histories on the test components, equivalent to motions developed in structures subjected to actual'quakes. The general concept and performance of the 20ft square EERC earthquake simulator is described, and the testing of a two story concrete frame building is outlined. Correlation of the experimental results with analytical predictions demonstrates that satisfactory agreement can be obtained only if the mathematical model incorporates a stiffness deterioration mechanism which simulates the cracking and other damage suffered by the structure

  4. Structural studies on leukaemia inhibitory factor

    Energy Technology Data Exchange (ETDEWEB)

    Norton, R.S.; Maurer, T.; Smith, D.K. [Biomolecular Research Institute, Parville (Australia); Nicola, N.A. [Institute of Medical Research, Melbourne (Australia)

    1994-12-01

    Leukaemia Inhibitory Factor (LIF) is a pleiotropic cytokine that acts on a wide range of target cells, including mega-karyocytes, osteoblasts, hepatocytes, adipocytes, neurons, embryonic stem cells, and primordial germ cells. Many of its activities are shared with other cytokines, particularly interleukin-6, oncostatin-M, ciliary neurotrophic factor, and granulocyte colony-stimulating factor (G-CSF). Although secreted in vivo as a glycoprotein, nonglycosylated recombinant protein expressed in E. coli is fully active and has been used in our nuclear magnetic resonance (NMR) studies of the three-dimensional structure and structure-function relationships of LIF. With 180 amino acids and a molecular mass of about 20 kDa, OF is too large for direct structure determination by two-dimensional and three-dimensional {sup 1}HNMR. It is necessary to label the protein with the stable isotopes {sup 15}N and {sup 13}C and employ heteronuclear three-dimensional NMR in order to resolve and interpret the spectral information required for three-dimensional structure determination. This work has been undertaken with both human LIF and a mouse-human chimaera that binds to the human LIF receptor with the same affinity as the human protein and yet expresses in E. coli at much higher levels. Sequence-specific resonance assignments and secondary structure elements for these proteins will be presented and progress towards determination of their three-dimensional structures described.

  5. Barrow Black Carbon Source and Impact Study Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Tate

    2014-07-01

    The goal of the Barrow Black Carbon Source and Impact campaign was to characterize the concentration and isotopic composition of carbonaceous atmospheric particulate matter (PM) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility site in Barrow, Alaska. The carbonaceous component was characterized by measuring the organic and black carbon (OC and BC) components of the total PM. To facilitate complete characterization of the PM, filter-based collections were used, including a medium volume PM2.5 sampler and a high volume PM10 sampler. Thirty-eight fine PM fractions (PM2.5) and 49 coarse (PM10) PM fractions were collected at weekly and bi-monthly intervals. The PM2.5 sampler operated with minimal maintenance during the 12 month campaign. The PM10 sampler used for the Barrow Black Carbon Source and Impact (BBCSI) study used standard Tisch “hi-vol” motors that have a known lifetime of approximately 1 month under constant use; this necessitated monthly maintenance, and it is suggested that, for future deployment in the Arctic, the motors be upgraded to industrial blowers. The BBCSI sampling campaign successfully collected and archived 87 ambient atmospheric PM samples from Barrow, Alaska, from July 2012 to June 2013. Preliminary analysis of the OC and BC concentrations has been completed. This campaign confirmed known trends of high BC lasting from the winter through to spring haze periods and low BC concentrations in the summer. However, the annual OC concentrations had a very different seasonal pattern with the highest concentrations during the summer, lowest concentrations during the fall, and increased concentrations during the winter and spring (Figure 1).

  6. Light ion source studies with a magnetically insulated extraction diode

    International Nuclear Information System (INIS)

    Struckman, C.K.

    1992-01-01

    Light ion sources are currently being studied to assess their ability to drive an inertial confinement fusion reactor. The author has produced a high purity, 1MV, 300A/cm 2 lithium beam using a 200cm 2 extraction geometry, magnetically insulated ion diode. The lithium source was an AC glow discharge cleaned, LiF/Al film active anode. The active anode plasma was formed after 50KA of current was shunted through the anode film for 20ns. The stoichiometry of the resulting ion beam was 65% Li + , 20% Al +2 , and 15% H + . Without the glow discharge cleaning, the ion beam was over 55% hydrogen and only 20% Li + . At the time of the diode's design, extraction diodes were producing poor ion beams: their current efficiency was only 60-70%, and their extracted ion current was radially nonuniform. This diode was the first high efficiency extraction diode, and produced over 200KA of ions with 80-90% ion current efficiency. In addition, by varying the tilt of the applied magnetic field, it was possible to show that the ion current density could be made independent of radius. Since the author was unable to make a Li + beam with a passive anode, he installed an active anode that used an external current to vaporize a thin metal film on the anode surface. Poor beam purity was the most serious problem with active anodes. In order to remove impurities, especially the hydrogen contamination, the author cleaned the anodes with a glow discharge. Al film anodes were cleaned with a 110mA, 33W DC glow discharge, and the LiF/Al film anodes were cleaned with an equivalent AC discharge. The results obtained and a model for the mechanism behind the cleaning process are throughly discussed

  7. 5 MW pulsed spallation neutron source, Preconceptual design study

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    This report describes a self-consistent base line design for a 5 MW Pulsed Spallation Neutron Source (PSNS). It is intended to establish feasibility of design and as a basis for further expanded and detailed studies. It may also serve as a basis for establishing project cost (30% accuracy) in order to intercompare competing designs for a PSNS not only on the basis of technical feasibility and technical merit but also on the basis of projected total cost. The accelerator design considered here is based on the objective of a pulsed neutron source obtained by means of a pulsed proton beam with average beam power of 5 MW, in {approx} 1 {mu}sec pulses, operating at a repetition rate of 60 Hz. Two target stations are incorporated in the basic facility: one for operation at 10 Hz for long-wavelength instruments, and one operating at 50 Hz for instruments utilizing thermal neutrons. The design approach for the proton accelerator is to use a low energy linear accelerator (at 0.6 GeV), operating at 60 Hz, in tandem with two fast cycling booster synchrotrons (at 3.6 GeV), operating at 30 Hz. It is assumed here that considerations of cost and overall system reliability may favor the present design approach over the alternative approach pursued elsewhere, whereby use is made of a high energy linear accelerator in conjunction with a dc accumulation ring. With the knowledge that this alternative design is under active development, it was deliberately decided to favor here the low energy linac-fast cycling booster approach. Clearly, the present design, as developed here, must be carried to the full conceptual design stage in order to facilitate a meaningful technology and cost comparison with alternative designs.

  8. 5 MW pulsed spallation neutron source, Preconceptual design study

    International Nuclear Information System (INIS)

    1994-06-01

    This report describes a self-consistent base line design for a 5 MW Pulsed Spallation Neutron Source (PSNS). It is intended to establish feasibility of design and as a basis for further expanded and detailed studies. It may also serve as a basis for establishing project cost (30% accuracy) in order to intercompare competing designs for a PSNS not only on the basis of technical feasibility and technical merit but also on the basis of projected total cost. The accelerator design considered here is based on the objective of a pulsed neutron source obtained by means of a pulsed proton beam with average beam power of 5 MW, in ∼ 1 μsec pulses, operating at a repetition rate of 60 Hz. Two target stations are incorporated in the basic facility: one for operation at 10 Hz for long-wavelength instruments, and one operating at 50 Hz for instruments utilizing thermal neutrons. The design approach for the proton accelerator is to use a low energy linear accelerator (at 0.6 GeV), operating at 60 Hz, in tandem with two fast cycling booster synchrotrons (at 3.6 GeV), operating at 30 Hz. It is assumed here that considerations of cost and overall system reliability may favor the present design approach over the alternative approach pursued elsewhere, whereby use is made of a high energy linear accelerator in conjunction with a dc accumulation ring. With the knowledge that this alternative design is under active development, it was deliberately decided to favor here the low energy linac-fast cycling booster approach. Clearly, the present design, as developed here, must be carried to the full conceptual design stage in order to facilitate a meaningful technology and cost comparison with alternative designs

  9. A review of output-only structural mode identification literature employing blind source separation methods

    Science.gov (United States)

    Sadhu, A.; Narasimhan, S.; Antoni, J.

    2017-09-01

    Output-only modal identification has seen significant activity in recent years, especially in large-scale structures where controlled input force generation is often difficult to achieve. This has led to the development of new system identification methods which do not require controlled input. They often work satisfactorily if they satisfy some general assumptions - not overly restrictive - regarding the stochasticity of the input. Hundreds of papers covering a wide range of applications appear every year related to the extraction of modal properties from output measurement data in more than two dozen mechanical, aerospace and civil engineering journals. In little more than a decade, concepts of blind source separation (BSS) from the field of acoustic signal processing have been adopted by several researchers and shown that they can be attractive tools to undertake output-only modal identification. Originally intended to separate distinct audio sources from a mixture of recordings, mathematical equivalence to problems in linear structural dynamics have since been firmly established. This has enabled many of the developments in the field of BSS to be modified and applied to output-only modal identification problems. This paper reviews over hundred articles related to the application of BSS and their variants to output-only modal identification. The main contribution of the paper is to present a literature review of the papers which have appeared on the subject. While a brief treatment of the basic ideas are presented where relevant, a comprehensive and critical explanation of their contents is not attempted. Specific issues related to output-only modal identification and the relative advantages and limitations of BSS methods both from theoretical and application standpoints are discussed. Gap areas requiring additional work are also summarized and the paper concludes with possible future trends in this area.

  10. Structural Studies of Archaealthermophilic Adenylate Kinase; TOPICAL

    International Nuclear Information System (INIS)

    Konisky, J.

    2002-01-01

    Through this DOE-sponsored program Konisky has studied the evolution and molecular biology of microbes that live in extreme environments. The emphasis of this work has been the determination of the structural features of thermophilic enzymes that allow them to function optimally at near 100 C. The laboratory has focused on a comparative study of adenylate kinase (ADK), an enzyme that functions to interconvert adenine nucleotides. Because of the close phylogenetic relatedness of members of the Methanococci, differences in the structure of their ADKs will be dominated by structural features that reflect contributions to their optimal temperature for activity, rather than differences due to phylogenetic divergence. We have cloned, sequenced and modeled the secondary structure for several methanococcal ADKs. Using molecular modeling threading approaches that are based on the solved structure for the porcine ADK, we have also proposed a general low resolution three dimensional structure for each of the methanococcal enzymes. These analyses have allowed us to propose structural features that confer hyperthermoactivity to those enzymes functioning in the hyperthermophilic members of the Methanococci. Using protein engineering methodologies, we have tested our hypotheses by examining the effects of selective structural changes on thermoactivity. Despite possessing between 68-81% sequence identity, the methanococcal AKs had significantly different stability against thermal denaturation, with melting points ranging from 69-103 C. The construction of several chimerical AKs by linking regions of the MVO and MJA AKs demonstrated the importance of cooperative interactions between amino- and carboxyl-terminal regions in influencing thermostability. Addition of MJA terminal fragments to the MVO AK increased thermal stability approximately 20 C while maintaining 88% of the mesophilic sequence. Further analysis using structural models suggested that hydrophobic interactions are

  11. Experimental and computational study of thaumasite structure

    Energy Technology Data Exchange (ETDEWEB)

    Scholtzová, Eva, E-mail: Eva.Scholtzova@savba.sk [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Kucková, Lenka; Kožíšek, Jozef [Department of Physical Chemistry, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava (Slovakia); Pálková, Helena [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Tunega, Daniel [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 36 Bratislava (Slovakia); Institute for Soil Science, University of Natural Resources and Life Sciences, Peter-Jordanstrasse 82, A-1190 Wien (Austria)

    2014-05-01

    The structure of thaumasite has been studied experimentally by means of a single crystal X-ray diffraction and FTIR methods, and theoretically using density functional theory (DFT) method. Very good agreement was achieved between calculated and experimental structural parameters. In addition, calculations offered the refinement of the positions of the hydrogen atoms. The detailed analysis of the hydrogen bonds existing in the thaumasite structure has been performed. Several types of hydrogen bonds have been classified. The water molecules coordinating Ca{sup 2+} cation act as proton donors in moderate O-H···O hydrogen bonds formed with CO₃⁻²and SO₄⁻² anions. The multiple O-H···O hydrogen bonds exist among water molecules themselves. Finally, relatively weak hydrogen bonds form water molecules with the OH groups from the coordination sphere of the Si(OH)₆⁻² anion. Further, calculated vibrational spectrum allowed complete assignment of all vibrational modes which are not available from the experimental spectrum that has a complex structure with overlapped bands, especially below 1500 cm⁻¹. Highlights: • The thaumasite structure was studied experimentally and using DFT method. • We used DFT method for the refinement of the positions of hydrogen atoms. • A detailed analysis of the hydrogen bonds was done. • A complete assignment of all bands to particular types of vibrations was done.

  12. Structural study of concentrated micellar solutions

    International Nuclear Information System (INIS)

    Zemb, Thomas

    1985-01-01

    This research thesis reports the study of the structure of concentrated soap-water binary micelles with a comparison of measurements of light, neutrons and X-ray scattering, and the relaxation induced by paramagnetic ions adsorbed at the interface. In the first part, the author discusses the specific sensitivity ranges of different experimental techniques, outlines the resolution which can be obtained with scattering experiments, and proposes a critical analysis of results published in the relevant literature. In a second part, the author discusses the compared results of the application of various techniques (magnetic resonance, X-light and neutron scattering) on the two most used model systems: sodium octanoate and sodium dodecyl sulfate (SDS) in solution. Then, the author addresses the case of ternary systems: study of the influence of the presence of a co-surfactant on the structure, study of the effect of interfacial charge on the micellar structure, use of the same previous quantitative methods to study the disturbances brought to the structure due to the presence of reactants [fr

  13. Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

    Science.gov (United States)

    Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus

    2017-08-01

    At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on

  14. Study theorizes use of geothermal sources for energy in refineries

    NARCIS (Netherlands)

    Golombok, M.; Beintema, K.

    2008-01-01

    Geothermal sources for direct heating can theoretically serve as an alternative source of high-temperature heat in processing plants. Cutting CO2 emissions from a refinery requires reducing the amount of fuel burned. Heat obtained from geothermal energy is more efficiently used for directly powering

  15. Cascading influence of inorganic nitrogen sources on DOM production, composition, lability and microbial community structure in the open ocean.

    Science.gov (United States)

    Goldberg, S J; Nelson, C E; Viviani, D A; Shulse, C N; Church, M J

    2017-09-01

    Nitrogen frequently limits oceanic photosynthesis and the availability of inorganic nitrogen sources in the surface oceans is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface ocean. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM production, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM production and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open ocean. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Sources of International Courts' Legitimacy: A comparative study

    DEFF Research Database (Denmark)

    Godzimirska, Zuzanna; Creamer, Cosette

    Despite ample scholarship on the legitimacy of international legal institutions, existing studies on international courts (ICs) tend to adopt normative or deductive approaches to specify their legitimacy and assess its effects. Very few adopt empirical or inductive approaches and examine the reas......Despite ample scholarship on the legitimacy of international legal institutions, existing studies on international courts (ICs) tend to adopt normative or deductive approaches to specify their legitimacy and assess its effects. Very few adopt empirical or inductive approaches and examine...... of supply-side factors— the features, roles and practices of a court—in assessing its legitimacy, we argue that demand-side factors—namely the characteristics of the evaluating state—also largely determine the sources of an IC’s legitimacy. To support and illustrate this argument, we examine statements...... of members on the operation of three ICs with different institutional designs and roles: the International Court of Justice, the International Criminal Court, and the Appellate Body of the World Trade Organization. We employ supervised learning methods of text classification to identify statements...

  17. Intrabeam scattering studies at the Swiss light source

    CERN Document Server

    Antoniou, F; Aiba, M; Boege, M; Milas, N; Streun, A; Demma, T

    2012-01-01

    The target parameters of modern ultra-low emittance rings are entering into a regime where Intra-beam Scattering (IBS) becomes important and, in the case of linear collider damping rings, even a limitation for the delivered emittances. The Swiss Light Source (SLS) storage ring, as it has achieved a vertical geometrical emittance of around 1 pm at 2.4 GeV [1], and it has the ability to run at even lower energies, and the availability of emittance monitoring diagnostics, is an ideal testbed for IBS studies. Simulations using the classical IBS theories and tracking codes are undertaken in order to explore the possibilities and limitations for IBS measurements at the SLS. In this respect, comparison between the theories and codes is first discussed. The dependence of the output emittances, taking into account the effect of IBS, with respect to energy, bunch charge and zero current vertical and longitudinal emittance is also studied, in order to define the regimes where the IBS effect can be significant. First mea...

  18. Antiprotonic Radioactive Atom for Nuclear Structure Studies

    International Nuclear Information System (INIS)

    Wada, M.; Yamazaki, Y.

    2005-01-01

    A future experiment to synthesize antiprotonic radioactive nuclear ions is proposed for nuclear structure studies. Antiprotonic radioactive nuclear atom can be synthesized in a nested Penning trap where a cloud of antiprotons is prestored and slow radioactive nuclear ions are bunch-injected into the trap. By observing of the ratio of π+ and π- produced in the annihilation process, we can deduce the different abundance of protons and neutrons at the surface of the nuclei. The proposed method would provide a unique probe for investigating the nuclear structure of unstable nuclei

  19. Galaxy evolution and large-scale structure in the far-infrared. II. The IRAS faint source survey

    International Nuclear Information System (INIS)

    Lonsdale, C.J.; Hacking, P.B.; Conrow, T.P.; Rowan-Robinson, M.

    1990-01-01

    The new IRAS Faint Source Survey data base is used to confirm the conclusion of Hacking et al. (1987) that the 60 micron source counts fainter than about 0.5 Jy lie in excess of predictions based on nonevolving model populations. The existence of an anisotropy between the northern and southern Galactic caps discovered by Rowan-Robinson et al. (1986) and Needham and Rowan-Robinson (1988) is confirmed, and it is found to extend below their sensitivity limit to about 0.3 Jy in 60 micron flux density. The count anisotropy at f(60) greater than 0.3 can be interpreted reasonably as due to the Local Supercluster; however, no one structure accounting for the fainter anisotropy can be easily identified in either optical or far-IR two-dimensional sky distributions. The far-IR galaxy sky distributions are considerably smoother than distributions from the published optical galaxy catalogs. It is likely that structure of the large size discussed here have been discriminated against in earlier studies due to insufficient volume sampling. 105 refs

  20. Development of Dynamic Loudspeakers Modified as Incident Pressure Sources for Noise Reductiuon in a Double Panel Structure

    NARCIS (Netherlands)

    Ho, J.H.; Berkhoff, A.P.

    2013-01-01

    This paper presents a modified loudspeaker source for decentralized feedback cavity control in a double panel structure to reduce the noise transmission. The double panel structure con-sists of two panels with air in between and offers the advantages of low weight, low sound transmission at high

  1. Development of dynamic loudspeakers modified as incident pressure sources for noise reduction in a double panel structure

    NARCIS (Netherlands)

    Ho, J.; Berkhoff, Arthur P.; Crocker, Malcolm J.; Pawelczyk, Marek; Paosawatyanyong, Boonchoat

    2013-01-01

    This paper presents a modified loudspeaker source for decentralized feedback cavity control in a double panel structure to reduce the noise transmission. The double panel structure con-sists of two panels with air in between and offers the advantages of low weight, low sound transmission at high

  2. Study and characterization of a phosphorous ion source and development of a emittancemeter suited to multi-beam ion sources

    International Nuclear Information System (INIS)

    Hoang Gia Tuong.

    1982-12-01

    The ionization process which is used is the electronic bombardment. Phosphorus choice for the source experimentation is motivated by its principal destination: ionic implantation. Heavy ion applications are also quoted. Operating conditions allowing good results to be obtained are determined after a study of different parameters such as the electron current, the neutron pressure and the extraction voltage: the ion current obtained is of the order of mA. The source emittance, representing the quality of the ionic beam, is measured by a method suited to multibeam sources [fr

  3. Fast synchrotron X-ray tomography study of the rod packing structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiaodan; Xia Chengjie; Sun Haohua; Wang Yujie [Department of Physics, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2013-06-18

    We present a fast synchrotron X-ray tomography study of the packing structures of rods under tapping. Utilizing the high flux of the X-rays generated from the third-generation synchrotron source, we can complete a tomography scan within several seconds, after which the three-dimensional (3D) packing structure can be obtained for the subsequent structural analysis. Due to the high-energy nature of the X-ray beam, special image processing steps including image phase-retrieval has been implemented. Overall, this study suggests the possibility of acquiring statistically significant static packing structures within a reasonable time scale using high-intensity X-ray sources.

  4. In-source laser spectroscopy of polonium isotopes: From atomic physics to nuclear structure

    CERN Multimedia

    Rothe, S

    2014-01-01

    The Resonance Ionization Laser Ion Source RILIS [1] at the CERN-ISOLDE on-line radioactive ion beam facility is essential for ion beam production for the majority of experiments, but it is also powerful tool for laser spectroscopy of rare isotopes. A series of experiments on in-source laser spectroscopy of polonium isotopes [2, 3] revealed the nuclear ground state properties of 191;211;216;218Po. However, limitations caused by the isobaric background of surface-ionized francium isotopes hindered the study of several neutron rich polonium isotopes. The development of the Laser Ion Source and Trap (LIST) [4] and finally its integration at ISOLDE has led to a dramatic suppression of surface ions. Meanwhile, the RILIS laser spectroscopy capabilities have advanced tremendously. Widely tunable titanium:sapphire (Ti:Sa) lasers were installed to complement the established dye laser system. Along with a new data acquisition system [5], this more versatile laser setup enabled rst ever laser spectroscopy of the radioact...

  5. Optical and structural studies of silver nanoparticles

    International Nuclear Information System (INIS)

    Temgire, M.K.; Joshi, S.S.

    2004-01-01

    Gamma radiolysis method was used to prepare polyvinyl alcohol (PVA) capped silver nanoparticles by optimizing various conditions like metal ion concentration and polymer (PVA) of different molecular weights. The role of different scavengers was also studied. The decrease in particle size was observed with increase in the molecular weight of capping agent. γ-radiolytic method provides silver nanoparticles in fully reduced and highly pure state. XRD (X-ray diffraction) technique confirmed the zero valent state of silver. Optical studies were done using UV-visible spectrophotometer to see the variation of electronic structure of the metal sol. Transmission Electron Microscopic (TEM) studies reveal the fcc geometry. The TEM show clearly split Debye-Scherrer rings. The d values calculated from the diffraction ring pattern are in perfect agreement with the ASTM data. Ag particles less than 10 nm are spherical in shape, whereas the particles above 30 nm have structure of pentagonal biprisms or decahedra, referred to as multiply twinned particles

  6. Clan structure as a source of intermittency in high energy multihadron production

    International Nuclear Information System (INIS)

    Hove, L. van

    1989-01-01

    Recently the systematic study of charged hadron multiplicity distributions in high energy hadronic and leptonic collisions has revealed the general occurrence of negative binomial regularities in symmetric CM rapidity windows and of intermittency in very small windows in the central region. The negative binomial regularities imply a particular form of clustering called clan structure, which embodies all Mueller multiparticle correlations. We show that this clan structure leads to intermittency when the simplest assumptions are made on the behaviour of the clans in very small windows. (orig.)

  7. Stationary chest tomosynthesis using a carbon nanotube x-ray source array: a feasibility study

    International Nuclear Information System (INIS)

    Shan, Jing; Lee, Yueh Z; Lu, Jianping; Zhou, Otto; Tucker, Andrew W; Heath, Michael D; Wang, Xiaohui; Foos, David H

    2015-01-01

    Chest tomosynthesis is a low-dose, quasi-3D imaging modality that has been demonstrated to improve the detection sensitivity for small lung nodules, compared to 2D chest radiography. The purpose of this study is to investigate the feasibility and system requirements of stationary chest tomosynthesis (s-DCT) using a spatially distributed carbon nanotube (CNT) x-ray source array, where the projection images are collected by electronically activating individual x-ray focal spots in the source array without mechanical motion of the x-ray source, detector, or the patient. A bench-top system was constructed using an existing CNT field emission source array and a flat panel detector. The tube output, beam quality, focal spot size, system in-plane and in-depth resolution were characterized. Tomosynthesis slices of an anthropomorphic chest phantom were reconstructed for image quality assessment. All 75 CNT sources in the source array were shown to operate reliably at 80 kVp and 5 mA tube current. Source-to-source consistency in the tube current and focal spot size was observed. The incident air kerma reading per mAs was measured as 74.47 uGy mAs −1 at 100 cm. The first half value layer of the beam was 3 mm aluminum. An average focal spot size of 2.5  ×  0.5 mm was measured. The system MTF was measured to be 1.7 cycles mm −1 along the scanning direction, and 3.4 cycles mm −1 perpendicular to the scanning direction. As the angular coverage of 11.6°–34°, the full width at half maximum of the artifact spread function improved greatly from 9.5 to 5.2 mm. The reconstructed tomosynthesis slices clearly show airways and pulmonary vascular structures in the anthropomorphic lung phantom. The results show the CNT source array is capable of generating sufficient dose for chest tomosynthesis imaging. The results obtained so far suggest an s-DCT using a distributed CNT x-ray source array is feasible. (paper)

  8. Governance Structures of Free/Open Source Software Development : Examining the role of modular product design as a governance mechanism in the FreeBSD Project

    NARCIS (Netherlands)

    Dafermos, G.

    2012-01-01

    My dissertation looks at the Governance Structures of Free/Open Source (FOSS) Development, based on a case study of FreeBSD, a large FOSS project. More specifically, it examines 3 well-known theories. The 1st theory [decreasing returns to scale] holds that increasing the number of persons working

  9. Study of hot electrons in a ECR ion source

    International Nuclear Information System (INIS)

    Barue, C.

    1992-12-01

    The perfecting of diagnosis connected with hot electrons of plasma, and then the behaviour of measured parameters of plasma according to parameters of source working are the purpose of this thesis. The experimental results obtained give new information on hot electrons of an ECR ion source. This thesis is divided in 4 parts: the first part presents an ECR source and the experimental configuration (ECRIS physics, minimafios GHz, diagnosis used); the second part, the diagnosis (computer code of cyclotron emission and calibration); the third part gives experimental results in continuous regime (emission cyclotron diagnosis, bremsstrahlung); the fourth part, experimental results in pulsed regime (emission cyclotron diagnosis, diamagnetism) calibration)

  10. Study on road surface source pollution controlled by permeable pavement

    Science.gov (United States)

    Zheng, Chaocheng

    2018-06-01

    The increase of impermeable pavement in urban construction not only increases the runoff of the pavement, but also produces a large number of Non-Point Source Pollution. In the process of controlling road surface runoff by permeable pavement, a large number of particulate matter will be withheld when rainwater is being infiltrated, so as to control the source pollution at the source. In this experiment, we determined the effect of permeable road surface to remove heavy pollutants in the laboratory and discussed the related factors that affect the non-point pollution of permeable pavement, so as to provide a theoretical basis for the application of permeable pavement.

  11. Interplanetary sources of magnetic storms: A statistical study

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne

    2001-01-01

    Magnetic storms are mainly caused by the occurrence of intense southward magnetic fields in the interplanetary medium. These fields can be formed directly either by ejection of magnetic structures from the Sun or by stream interaction processes during solar wind propagation. In the present study we...... examine 30 years of satellite measurement of the solar wind during magnetic storms, with the aim of estimating the relative importance of these two processes. We use the solar wind proton temperature relative to the temperature expected from the empirical relation to the solar wind speed T......-p/T-exp, together with the speed gradient, and the interplanetary magnetic field azimuth in the ecliptic, in order to distinguish between the two processes statistically. We find that compression due to stream interaction is at least as important as the direct effect of ejection of intense fields, and probably more...

  12. Interplanetary sources to magnetic storms - A statistical study

    DEFF Research Database (Denmark)

    Vennerstrøm, Susanne

    2001-01-01

    Magnetic storms are mainly caused by the occurrence of intense southward magnetic fields in the interplanetary medium. These fields can be formed directly either by ejection of magnetic structures from the Sun or by stream interaction processes during solar wind propagation. In the present study we...... examine 30 years of satellite measurement of the solar wind during magnetic storms, with the aim of estimating the relative importance of these two processes. We use the solar wind proton temperature relative to the temperature expected from the empirical relation to the solar wind speed Tp/Texp, together...... with the speed gradient, and the interplanetary magnetic field azimuth in the ecliptic, in order to distinguish between the two processes statistically. We find that compression due to stream interaction is at least as important as the direct effect of ejection of intense fields, and probably more so. Only...

  13. Barrow Black Carbon Source and Impact Study Final Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Tate [Baylor Univ., Waco, TX (United States)

    2014-07-01

    The goal of the Barrow Black Carbon Source and Impact (BBCSI) Study was to characterize the concentration and isotopic composition of carbonaceous atmospheric particulate matter (PM) at the Atmospheric Radiation Measurement site in Barrow, AK. The carbonaceous component was characterized via measurement of the organic and black carbon (OC and BC) components of the total PM. To facilitate complete characterization of the particulate matter, filter-based collections were used, including a medium volume PM2.5 sampler and a high volume PM10 sampler. Thirty-eight fine (PM2.5) and 49 coarse (PM10) particulate matter fractions were collected at weekly and bi-monthly intervals. The PM2.5 sampler operated with minimal maintenance during the 12 month campaign. The PM10 sampler used for the BBCSI used standard Tisch hi-vol motors which have a known lifetime of ~1 month under constant use; this necessitated monthly maintenance and it is suggested that the motors be upgraded to industrial blowers for future deployment in the Arctic. The BBCSI sampling campaign successfully collected and archived 87 ambient atmospheric particulate matter samples from Barrow, AK from July 2012 to June 2013. Preliminary analysis of the organic and black carbon concentrations has been completed. This campaign confirmed known trends of high BC lasting from the winter through to spring haze periods and low BC concentrations in the summer.

  14. Studies of IRAS sources at high galactic latitudes

    International Nuclear Information System (INIS)

    Rowan-Robinson, M.; Helou, G.; Walker, D.

    1987-01-01

    A detailed study has been carried out of a complete sample of IRAS 25-, 60- and 100-μm sources identified with galaxies brighter than 14.5 mag at b > 60 0 . Redshifts are available for virtually all these galaxies. The 60- and 100-μm luminosities are well correlated with the corrected absolute magnitude Msub(B), the 25-μm luminosity less well so. There is a clear correlation of the ratio of far-infrared luminosity to optical luminosity, Lsub(FIR)/Lsub(B), with 100 μm/60 μm colour, in the sense that the more luminous infrared galaxies are warmer. This behaviour can be modelled as a mixture of a normal 'disc' component and a starburst component. There is no significant difference in the distribution of Lsub(FIR)/Lsub(B) versus 100 μm/60 μm colour for edge-on and face-on spirals, showing that the adopted internal extinction correction is a good approximation. (author)

  15. NATO Advanced Study Institute on Physics of New Laser Sources

    CERN Document Server

    Arecchi, F; Mooradian, Aram; Sona, Alberto

    1985-01-01

    This volume contains the lectures and seminars presented at the NATO Advanced Study Institute on "Physics of New Laser Sources", the twelfth course of the Europhysics School of Quantum Electronics, held under the supervision of the Quantum Electronics Division of the European Physical Society. The Institute was held at Centro "I Cappuccini" San Miniato, Tuscany, July 11-21, 1984. The Europhysics School of Quantum Electronics was started in 1970 with the aim of providing instruction for young researchers and advanced students already engaged in the area of quantum electronics or for those wishing to switch into this area after working previously in other areas. From the outset, the School has been under the direction of Prof. F. T. Arecchi, then at the University of Pavia, now at the University of Florence, and Dr. D. Roess of Heraeus, Hanau. In 1981, Prof. H. Walther, University of Munich and Max-Planck Institut fur Quantenoptik joined as co-director. Each year the Directors choose a subj~ct of particular int...

  16. Radiation damage studies of nuclear structural materials

    International Nuclear Information System (INIS)

    Barat, P.

    2012-01-01

    Maximum utilization of fuel in nuclear reactors is one of the important aspects for operating them economically. The main hindrance to achieve this higher burnups of nuclear fuel for the nuclear reactors is the possibility of the failure of the metallic core components during their operation. Thus, the study of the cause of the possibility of failure of these metallic structural materials of nuclear reactors during full power operation due to radiation damage, suffered inside the reactor core, is an important field of studies bearing the basic to industrial scientific views.The variation of the microstructure of the metallic core components of the nuclear reactors due to radiation damage causes enormous variation in the structure and mechanical properties. A firm understanding of this variation of the mechanical properties with the variation of microstructure will serve as a guide for creating new, more radiation-tolerant materials. In our centre we have irradiated structural materials of Indian nuclear reactors by charged particles from accelerator to generate radiation damage and studied the some aspects of the variation of microstructure by X-ray diffraction studies. Results achieved in this regards, will be presented. (author)

  17. Source separation of household waste: A case study in China

    International Nuclear Information System (INIS)

    Zhuang Ying; Wu Songwei; Wang Yunlong; Wu Weixiang; Chen Yingxu

    2008-01-01

    A pilot program concerning source separation of household waste was launched in Hangzhou, capital city of Zhejiang province, China. Detailed investigations on the composition and properties of household waste in the experimental communities revealed that high water content and high percentage of food waste are the main limiting factors in the recovery of recyclables, especially paper from household waste, and the main contributors to the high cost and low efficiency of waste disposal. On the basis of the investigation, a novel source separation method, according to which household waste was classified as food waste, dry waste and harmful waste, was proposed and performed in four selected communities. In addition, a corresponding household waste management system that involves all stakeholders, a recovery system and a mechanical dehydration system for food waste were constituted to promote source separation activity. Performances and the questionnaire survey results showed that the active support and investment of a real estate company and a community residential committee play important roles in enhancing public participation and awareness of the importance of waste source separation. In comparison with the conventional mixed collection and transportation system of household waste, the established source separation and management system is cost-effective. It could be extended to the entire city and used by other cities in China as a source of reference

  18. Comparative study of wild edible mushrooms as sources of antioxidants.

    Science.gov (United States)

    Witkowska, Anna M; Zujko, Małgorzata E; Mirończuk-Chodakowska, Iwona

    2011-01-01

    The purpose of the study was to explore sixteen of the most popular edible species of wild-growing mushrooms as potential sources of antioxidants. Among the mushrooms tested, the highest total polyphenol contents, exceeding 100 mg/100 g fresh mass, were found in five mushrooms: Boletus chrysenteron, B. edulis, Leccinum scabrum, L. aurantiacum, and Macrolepiota procera. Antioxidant activity was measured with the FRAP, TEAC, DPPH scavenging ability and ferrous ions chelating ability assays. Results of the study show that wild mushrooms vary according to their antioxidant properties. The highest FRAP potentials, exceeding 1 mmol/100 g, were found in five species ofBoletales: Boletus edulis, B. chrysenteron, Leccinum scabrum, L. aurantiacum, and Suillus grevillei. TEAC values were from 1.07 to 4.01 mmol/100 g fresh mass. High TEAC values (>2.3 mmol/100 g) were found in Leccinum scabrum, L. aurantiacum, Macrolepiota procera, Boletus chrysenteron, and B. edulis. The DPPH radical scavenging effectiveness of mushroom extracts, expressed as EC50 values, was in range 2.91-13.86 mg/mL. Scavenging ability was the highest for B. edulis and B. chrysenteron. The metal chelating ability of mushroom extracts expressed as ECso values of chelating ability on ferrous ions were from 8.02 mg/mL in Cantharellus cibarius to 12.10 mg/mL in Suillus luteus. Among the mushrooms tested, Boletus chrysenteron and B. edulis were characterized by high scores of polyphenol contents and antioxidant activity in the FRAP, TEAC, and DPPH assays. These results place these culinary species of wild-growing mushrooms among products with considerable antioxidant potential.

  19. Materials compatibility studies for the Spallation Neutron Source

    International Nuclear Information System (INIS)

    DiStefano, J.R.; Pawel, S.J.; Manneschmidt, E.T.

    1998-01-01

    The Spallation Neutron Source (SNS) is a high power facility for producing neutrons that utilizes flowing liquid mercury inside an austenitic stainless steel container as the target for a 1.0 GeV proton beam. Type 316 SS has been selected as the container material for the mercury and consequences of exposure of 316 SS to radiation, thermal shock, thermal stress, cavitation and hot, flowing mercury are all being addressed by R and D programs. In addition, corrosion studies also include evaluation of Inconel 718 because it has been successfully used in previous spallation neutron systems as a window material. Two types of compatibility issues relative to 316 SS/mercury and Inconel 718/mercury are being examined: (1) liquid metal embrittlement (LME) and (2) temperature gradient mass transfer. Studies have shown that mercury does not easily wet type 316 SS below 275 C. In the LME experiments, attempts were made to promote wetting of the steel by mercury either by adding gallium to the mercury or coating the specimen with a tin-silver solder that the mercury easily wets. The latter proved more reliable in establishing wetting, but there was no evidence of LME in any of the constant extension rate tensile tests either at 23 or 100 C. Inconel 718 also showed no change in room temperature properties when tested in mercury or mercury-gallium. However, there was evidence that the fracture was less ductile. Preliminary evaluation of mass transfer of either type 316 SS or Inconel 718 in mercury or mercury-gallium at 350 C (maximum temperature) did not reveal significant effects. Two 5,000 h thermal convection loop tests of type 316 SS are in progress, with specimens in both hot and cold test regions, at 300 and 240 C, respectively

  20. Dietary sources of sugars in adolescents' diet: the HELENA study.

    Science.gov (United States)

    Mesana, M I; Hilbig, A; Androutsos, O; Cuenca-García, M; Dallongeville, J; Huybrechts, I; De Henauw, S; Widhalm, K; Kafatos, A; Nova, E; Marcos, A; González-Gross, M; Molnar, D; Gottrand, F; Moreno, L A

    2018-03-01

    To report dietary sugars consumption and their different types and food sources, in European adolescents. Food consumption data of selected groups were obtained from 1630 adolescents (45.6% males, 12.5-17.5 years) from the HELENA study using two nonconsecutive 24-h recalls. Energy intake, total sugars and free sugars were assessed using the HELENA-DIAT software. Multiple regression analyses were performed adjusting for relevant confounders. Total sugars intake (137.5 g/day) represented 23.6% and free sugars (110.1 g/day), 19% of energy intake. Girls had significantly lower intakes of energy, carbohydrates, total sugars and free sugars. 94% of adolescents had a consumption of free sugars above 10% of total energy intake. The main food contributor to free sugars was 'carbonated, soft and isotonic drinks,' followed by 'non-chocolate confectionary' and 'sugar, honey, jam and syrup.' Older boys and girls had significantly higher intakes of free sugars from 'cakes, pies and biscuits.' Free sugars intake was negatively associated with low socioeconomic status for 'non-chocolate confectionary' and 'sugar, honey and jam' groups; with low maternal educational level for carbonated and 'soft drinks,' 'sugar, honey and jam,' 'cakes and pies' and 'breakfast cereals' groups; and with high paternal educational level for 'carbonated and soft drinks' and 'chocolates' group. The majority (94%) of studied adolescents consumed free sugars above 10% of daily energy intake. Our data indicate a broad variety in foods providing free sugars. Continued efforts are required at different levels to reduce the intake of free sugars, especially in families with a low educational level.

  1. Study of a microwave power source for a two-beam accelerator

    International Nuclear Information System (INIS)

    Houck, T.L.

    1994-01-01

    A theoretical and experimental study of a microwave power source suitable for driving a linear e + e - collider is reported. The power source is based on the Relativistic Klystron Two-Beam Accelerator (RK-TBA) concept, is driven by a 5-MeV, 1-kA induction accelerator electron beam, and operates at X-band frequencies. The development of a computer code to simulate the transverse beam dynamics of an intense relativistic electron beam transiting a system of microwave resonant structures is presented. This code is time dependent with self-consistent beam-cavity interactions and uses realistic beam parameters. Simulations performed with this code are compared with analytical theory and experiments. The concept of spacing resonant structures at distances equal to the betatron wavelength of the focusing system to suppress the growth of transverse instabilities is discussed. Simulations include energy spread over the beam to demonstrate the effect of Landau damping and establish the sensitivity of the betatron wavelength spacing scheme to errors in the focusing system. The design of the Reacceleration Experiment is described in detail and includes essentially all the issues related to a full scale RK-TBA microwave source. A total combined power from three output structures in excess of 170 MW with an amplitude stability of ±4% over a 25 ns pulse was achieved. The results of the experiment are compared to simulations used during the design phase to validate the various codes and methods used. The primary issue for the RK-TBA concept is identified as transverse beam instability associated with the excitation of higher order modes in the resonant structures used for extracting microwave power from the modulated beam. This work represents the first successful experimental demonstration of repeated cycles of microwave energy extraction from and reacceleration of a modulated beam

  2. Positron Studies of Oxide-Semiconductor Structures

    OpenAIRE

    Uedono , A.; Wei , L.; Kawano , T.; Tanigawa , S.; Suzuki , R.; Ohgaki , H.; Mikado , T.

    1995-01-01

    The annihilation characteristics of positrons in SiO2 films grown on Si substrates were studied by using monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of incident positron energy for SiO2/Si structures fabricated by various oxidation techniques. From the measurements, it was found that the formation probability of positronium (Ps) atoms in SiO2 films strongly depends on the growth condition...

  3. The PROTEUS Experiment: Active Source Seismic Imaging of the Crustal Magma Plumbing Structure of the Santorini Arc Volcano

    Science.gov (United States)

    Hooft, E. E. E.; Morgan, J. V.; Nomikou, P.; Toomey, D. R.; Papazachos, C. V.; Warner, M.; Heath, B.; Christopoulou, M. E.; Lampridou, D.; Kementzetzidou, D.

    2016-12-01

    The goal of the PROTEUS seismic experiment (Plumbing Reservoirs Of The Earth Under Santorini) is to examine the entire crustal magma plumbing system beneath a continental arc volcano and determine the magma geometry and connections throughout the crust. These physical parameters control magma migration, storage, and eruption and inform the question of how physical and chemical processing of magma at arc volcanoes forms the andesitic rock compositions that dominate the lower continental crust. These physical parameters are also important to understand volcanic-tectonic interactions and geohazards. Santorini is ideal for these goals because the continental crust has been thinned by extension and so the deep magmatic system is more accessible, also it is geologically well studied. Since the volcano is a semi-submerged, it was possible to collect a unique 3D marine-land active source seismic dataset. During the PROTEUS experiment in November-December of 2015, we recorded 14,300 marine sound sources from the US R/V Langseth on 89 OBSIP short period ocean bottom seismometers and 60 German and 5 Greek land seismometers. The experiment was designed for high-density spatial sampling of the seismic wavefield to allow us to apply two state-of-the-art 3D inversion methods: travel time tomography and full waveform inversion. A preliminary travel time tomography model of the upper crustal seismic velocity structure of the volcano and surrounding region is presented in an accompanying poster. We also made marine geophysical maps of the seafloor using multi-beam bathymetry and of the gravity and magnetic fields. The new seafloor map reveals the detailed structure of the major fault system between Santorini and Amorgos, of associated landslides, and of newly discovered volcanic features. The PROTEUS project will provide new insights into the structure of the whole crustal magmatic system of a continental arc volcano and its evolution within the surrounding tectonic setting.

  4. A photon source model based on particle transport in a parameterized accelerator structure for Monte Carlo dose calculations.

    Science.gov (United States)

    Ishizawa, Yoshiki; Dobashi, Suguru; Kadoya, Noriyuki; Ito, Kengo; Chiba, Takahito; Takayama, Yoshiki; Sato, Kiyokazu; Takeda, Ken

    2018-05-17

    An accurate source model of a medical linear accelerator is essential for Monte Carlo (MC) dose calculations. This study aims to propose an analytical photon source model based on particle transport in parameterized accelerator structures, focusing on a more realistic determination of linac photon spectra compared to existing approaches. We designed the primary and secondary photon sources based on the photons attenuated and scattered by a parameterized flattening filter. The primary photons were derived by attenuating bremsstrahlung photons based on the path length in the filter. Conversely, the secondary photons were derived from the decrement of the primary photons in the attenuation process. This design facilitates these sources to share the free parameters of the filter shape and be related to each other through the photon interaction in the filter. We introduced two other parameters of the primary photon source to describe the particle fluence in penumbral regions. All the parameters are optimized based on calculated dose curves in water using the pencil-beam-based algorithm. To verify the modeling accuracy, we compared the proposed model with the phase space data (PSD) of the Varian TrueBeam 6 and 15 MV accelerators in terms of the beam characteristics and the dose distributions. The EGS5 Monte Carlo code was used to calculate the dose distributions associated with the optimized model and reference PSD in a homogeneous water phantom and a heterogeneous lung phantom. We calculated the percentage of points passing 1D and 2D gamma analysis with 1%/1 mm criteria for the dose curves and lateral dose distributions, respectively. The optimized model accurately reproduced the spectral curves of the reference PSD both on- and off-axis. The depth dose and lateral dose profiles of the optimized model also showed good agreement with those of the reference PSD. The passing rates of the 1D gamma analysis with 1%/1 mm criteria between the model and PSD were 100% for 4

  5. Pinon Pine Tree Study, Los Alamos National Laboratory: Source document

    International Nuclear Information System (INIS)

    Gonzales, G.J.; Fresquez, P.R.; Mullen, M.A.; Naranjo, L. Jr.

    2000-01-01

    One of the dominant tree species growing within and around Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis) tree. Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food--the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of 3 H, 137 Cs, 90 Sr, tot U, 238 Pu, 239,240 Pu, and 241 Am in soils (0- to 12-in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) concentrations of radionuclides in PPN collected in 1977 to present data, (3) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (4) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of 3 H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 microSv). Soil-to-nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables

  6. A study of γ-ray source for the transmutation

    International Nuclear Information System (INIS)

    Nomura, Masahiro; Takahashi, Hiroshi.

    1996-07-01

    PNC is developing high power CW electron linac for various applications, those are the transmutation of the fission products, Free Electron Laser (FEL), the positron source and so on. Especially, the transmutation by the electron linac has been studied for several years. As the results, high flux and high energy γ-ray (∼15 MeV) is required, one of the big problems is that plenty of transmutation energy is needed and the narrow γ-ray energy spectrum can reduce the transmutation energy. The γ-rays can be produced by synchrotron radiation, FEL and laser compton scattering. Those methods were described briefly and compared. As a result, the laser compton scattering is one of the good methods to produce high energy γ-ray. However the cross section between electron and photon is small and the scattered photon energy spectrum is not so narrow that the transmutation energy is reduced drastically. To enhance the interaction between electron and photon, the super cavity is proposed. And some experiments are in progress. To reduce the transmutation energy, scattered electron must be reused by the storage ring. If the scattered electrons are not used for producing γ-ray, the efficiency is less than 1%. In our system, the efficiency can be increased to 20% by reusing scattered electrons. But this efficiency is still low. To increase the efficiency, the RF bucket must be enlarged. If the momentans compaction factor α can be reduced, the RF bucket can be enlarged. And the storage ring must be designed to have small value of the α. The electron energy dependency of efficiency is investigated, too. In short word, it is difficult to increase the efficiency drastically by changing electron energy. This work was conducted as a part of the collaboration work between PNC and BNL. (author)

  7. The effect of structure and a secondary carbon source on the microbial degradation of chlorophenoxy acids.

    Science.gov (United States)

    Evangelista, S; Cooper, D G; Yargeau, V

    2010-05-01

    Pseudomonas putida, Aspergillus niger, Bacillus subtilis, Pseudomonas fluorescens, Sphingomonas herbicidovorans and Rhodococcus rhodochrous growing on glucose in a medium containing one of three chlorophenoxy acids at a concentration of 0.1 g L(-1) (clofibric acid, (R)-2-(4-chloro-2-methylphenoxy)propionic acid (mecoprop or MCPP) and 4-chloro-2-methylphenoxyacetic acid (MCPA)) degraded these compounds to varying degrees; from nonmeasurable to almost complete removal. These results with the addition of glucose (2.5 g L(-1)) as an easy to use carbon source indicated the formation of metabolites different from results reported in the literature for growth studies in which the chlorophenoxy acid was the sole carbon source. The metabolite, 4-chloro-2-methylphenol, which had been reported previously, was only observed in trace amounts for MCPP and MCPA in the presence of S. herbicidovorans and glucose. In addition, three other compounds (M1, M3 and M4) were observed. It is suggested that these unidentified metabolites resulted from ring opening of the metabolite 4-chloro-2-methylphenol (M2). The rate of biodegradation of the chlorophenoxy acids was influenced by the degree of steric hindrance adjacent to the internal oxygen bond common to all three compounds. The most hindered compound, clofibric acid, was converted to ethyl clofibrate by R. rhodochrous but was not degraded by any microorganisms studied. The more accessible internal oxygen bonds of the other two chlorophenoxy acids, MCPP and MCPA, were readily broken by S. herbicidovorans. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  8. Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone.

    Directory of Open Access Journals (Sweden)

    Mary Higby Schweitzer

    Full Text Available Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures.

  9. Testing the Hypothesis of Biofilm as a Source for Soft Tissue and Cell-Like Structures Preserved in Dinosaur Bone

    Science.gov (United States)

    2016-01-01

    Recovery of still-soft tissue structures, including blood vessels and osteocytes, from dinosaur bone after demineralization was reported in 2005 and in subsequent publications. Despite multiple lines of evidence supporting an endogenous source, it was proposed that these structures arose from contamination from biofilm-forming organisms. To test the hypothesis that soft tissue structures result from microbial invasion of the fossil bone, we used two different biofilm-forming microorganisms to inoculate modern bone fragments from which organic components had been removed. We show fundamental morphological, chemical and textural differences between the resultant biofilm structures and those derived from dinosaur bone. The data do not support the hypothesis that biofilm-forming microorganisms are the source of these structures. PMID:26926069

  10. Hyperfine structure studies with the COMPLIS facility

    CERN Document Server

    Crawford, J E; Le Blanc, F; Lunney, M D; Obert, J; Oms, J; Putaux, J C; Roussière, B; Sauvage, J; Zemlyanoi, S G; Verney, D; Pinard, J; Cabaret, L A; Duong, H T; Huber, G; Krieg, M; Sebastian, V; Girod, M; Peru, S; Genevey, J; Ibrahim, F; Lettry, Jacques

    1998-01-01

    COMPLIS is an experimental facility designed to carry out spectroscopic studies on radioisotopes produced by disintegration of elements available at CERN's Booster-ISOLDE on-line isotope separator. During recent series of experimental runs, hyperfine structure measurements have yielded information on nuclear moments and deformations of platinum and iridium isotopes, For the first time, population by alpha -decay from Hg was exploited to investigate /sup 178/-/sup 181/Pt-the most neutron-deficient Pt isotopes yet studied. Successful measurements have recently been carried out on /sup 182-189/Ir. (10 refs).

  11. Global sourcing risk management approaches: A study of small clothing and textile retailers in Gauteng

    Directory of Open Access Journals (Sweden)

    Wesley Niemann

    2018-02-01

    Full Text Available Background: Global sourcing has increased as buyers searched for new markets that offered better pricing, quality, variety and delivery lead times than their local markets. However, the increase in global sourcing has also exposed businesses to many supply risks. Purpose: The purpose of this descriptive qualitative study was to explore the global sourcing supply risks encountered by small clothing and textile retailers in Gauteng and to determine what supply risk identification and management approaches they utilise. Method: This study utilised semi-structured interviews conducted with 12 small clothing and textile retail owners. Results: The study found that the three major supply risks encountered by these retailers were fluctuating exchange rates, communication barriers and costly and complicated logistics, which included high customs costs. Furthermore, although aware of the supply risks, none of the small clothing and textile retailers had formal identification and management approaches in place. Instead, risks are dealt with at the sole discretion of the owner as and when they occur. The study also found that informal identification and management approaches were being applied by some of the retailers. These included factoring exchange rate fluctuations into the profit margins and using translators to combat communication barriers. Contribution: The study is one of the first empirical studies conducted on global supply risks and the associated identification and management approaches in the South African small business context, specifically focused on clothing and textile retailers. Conclusion: Small clothing and textile retailers need to proactively identify and manage global sourcing risk using the identified approaches in order to reduce and mitigate potential supply disruptions.

  12. AN ANALYSIS OF THE ORGANIZATIONAL STRUCTURE AND THE PROCESS TO ADOPT GLOBAL SOURCING

    Directory of Open Access Journals (Sweden)

    Moema Pereira Nunes

    2016-03-01

    Full Text Available This study analyze the adoption of GS by Brazilian companies in terms of organizational structure and process of GS in order to identify what is differencing the experience of these companies and the previously knowledge related with GS. A case-based qualitative research was developed. Four Brazilian companies were investigated. Data were collect interviews and a content analysis was made. Regarding the organizational structure, it was identified that the firm’s industry sector influence in the adoption of GS. It confirms the assumption that the environment plays an important role in emerging countries. The need of innovation and the geographic concentration in an industry sector were identified as influences in the organizational structure to adopt GS. The need of scale in the purchasing process was perceived as an influence in the process of GS. The investigated companies presented a non-structure process of GS, what reduce the opportunity to learn with GS as part of the process may not be monitored.

  13. Time-Reversal Study of the Hemet (CA) Tremor Source

    Science.gov (United States)

    Larmat, C. S.; Johnson, P. A.; Guyer, R. A.

    2010-12-01

    Since its first observation by Nadeau & Dolenc (2005) and Gomberg et al. (2008), tremor along the San Andreas fault system is thought to be a probe into the frictional state of the deep part of the fault (e.g. Shelly et al., 2007). Tremor is associated with slow, otherwise deep, aseismic slip events that may be triggered by faint signals such as passing waves from remote earthquakes or solid Earth tides.Well resolved tremor source location is key to constrain frictional models of the fault. However, tremor source location is challenging because of the high-frequency and highly-scattered nature of tremor signal characterized by the lack of isolated phase arrivals. Time Reversal (TR) methods are emerging as a useful tool for location. The unique requirement is a good velocity model for the different time-reversed phases to arrive coherently onto the source point. We present results of location for a tremor source near the town of Hemet, CA, which was triggered by the 2002 M 7.9 Denali Fault earthquake (Gomberg et al., 2008) and by the 2009 M 6.9 Gulf of California earthquake. We performed TR in a volume model of 88 (N-S) x 70 (W-E) x 60 km (Z) using the full-wave 3D wave-propagation package SPECFEM3D (Komatitsch et al., 2002). The results for the 2009 episode indicate a deep source (at about 22km) which is about 4km SW the fault surface scarp. We perform STA/SLA and correlation analysis in order to have independent confirmation of the Hemet tremor source. We gratefully acknowledge the support of the U. S. Department of Energy through the LANL/LDRD Program for this work.

  14. Sustainability in Open Source Software Commons: Lessons Learned from an Empirical Study of SourceForge Projects

    Directory of Open Access Journals (Sweden)

    Charles M. Schweik

    2013-01-01

    Full Text Available In this article, we summarize a five-year US National Science Foundation funded study designed to investigate the factors that lead some open source projects to ongoing collaborative success while many others become abandoned. Our primary interest was to conduct a study that was closely representative of the population of open source software projects in the world, rather than focus on the more-often studied, high-profile successful cases. After building a large database of projects (n=174,333 and implementing a major survey of open source developers (n=1403, we were able to conduct statistical analyses to investigate over forty theoretically-based testable hypotheses. Our data firmly support what we call the conventional theory of open source software, showing that projects start small, and, in successful cases, grow slightly larger in terms of team size. We describe the “virtuous circle” supporting conventional wisdom of open source collaboration that comes out of this analysis, and we discuss two other interesting findings related to developer motivations and how team members find each other. Each of these findings is related to the sustainability of these projects.

  15. Positron annihilation spectroscopy in materials structure studies

    International Nuclear Information System (INIS)

    Grafutin, Viktor I; Prokop'ev, Evgenii P

    2002-01-01

    A relatively new method of materials structure analysis - positron annihilation spectroscopy (PAS) - is reviewed. Measurements of positron lifetimes, the determination of positron 3γ- and 2γ-annihilation probabilities, and an investigation of the effects of different external factors on the fundamental characteristics of annihilation constitute the basis for this promising method. The ways in which the positron annihilation process operates in ionic crystals, semiconductors, metals and some condensed matter systems are analyzed. The scope of PAS is described and its prospects for the study of the electronic and defect structures are discussed. The applications of positron annihilation spectroscopy in radiation physics and chemistry of various substances as well as in physics and chemistry of solutions are exemplified. (instruments and methods of investigation)

  16. Structural study of some halogen oxyfluorides

    International Nuclear Information System (INIS)

    Tantot, Georges.

    1976-12-01

    Some halogen oxyfluorides are studied from a structural point of view by vibrational spectroscopy and nuclear magnetic resonance. Force constant and molecular orbital calculations are added to the experimental data. The pyramidal shape of ClO 2 F under its three physical states is confirmed. In the gas and liquid phases an intermolecular association is observed. A similar interaction takes place in ClOF 3 . ClO 3 F has only a solid state transition above 10K. The structures of ClO 2 F and KBrO 2 F 2 are partly determined. The theoretical calculations are well correlated with the experimental data. They suggest a major influence of the ligands [fr

  17. Manufacturing study of beryllium bonded structures

    International Nuclear Information System (INIS)

    Onozuka, M.; Hirai, S.; Kikuchi, K.; Oda, Y.; Shimizu, K.

    2004-01-01

    Manufacturing study has been conducted on Be-bonded structures employed in the first-wall panel of the blanket system for the ITER. For Be tiles bonded to the Cu-Cr-Zr alloy heat sink with stainless-steel cooling pipes, a one-axis hot press with two heating process has been used to bond the three materials. First, Cu-alloy and SS materials are bonded diffusively. Then, Be tiles are bonded to the pre-bonded structure under 20 MPa and at 560 degree C. An Al-Si base interlayer has been used to bond Be to the Cu-Alloy. Because of the limited heat processes using a conventional hot press, the manufacturing cost can be minimized. Using the above bonding techniques, a partial mockup of a blanket first-wall panel with 16 Be tiles (with 50 mm in size) has been successfully manufactured. (author)

  18. Feasibility study of broadband efficient ''water window'' source

    International Nuclear Information System (INIS)

    Higashiguchi, Takeshi; Yugami, Noboru; Otsuka, Takamitsu; Jiang Weihua; Endo, Akira; Li Bowen; Dunne, Padraig; O'Sullivan, Gerry

    2012-01-01

    We demonstrate a table-top broadband emission water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs) in the 2-4 nm region, extending below the carbon K edge (4.37 nm). Arrays resulting from n=4-n=4 transitions are overlaid with n=4-n=5 emission and shift to shorter wavelength with increasing atomic number. An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth plasma UTA source, coupled to multilayer mirror optics.

  19. Harnessing structural darkness in the visible and infrared wavelengths for a new source of light

    KAUST Repository

    Huang, Jianfeng

    2015-10-19

    Engineering broadband light absorbers is crucial to many applications, including energy-harvesting devices and optical interconnects. The performances of an ideal absorber are that of a black body, a dark material that absorbs radiation at all angles and polarizations. Despite advances in micrometre-thick films, the absorbers available to date are still far from an ideal black body. Here, we describe a disordered nanostructured material that shows an almost ideal black-body absorption of 98-99% between 400 and 1,400 nm that is insensitive to the angle and polarization of the incident light. The material comprises nanoparticles composed of a nanorod with a nanosphere of 30 nm diameter attached. When diluted into liquids, a small concentration of nanoparticles absorbs on average 26% more than carbon nanotubes, the darkest material available to date. By pumping a dye optical amplifier with nanosecond pulses of 100 mW power, we harness the structural darkness of the material and create a new type of light source, which generates monochromatic emission (5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses. © 2016 Macmillan Publishers Limited. All rights reserved.

  20. Two-Component Structure of the Radio Source 0014+813 from VLBI Observations within the CONT14 Program

    Science.gov (United States)

    Titov, O. A.; Lopez, Yu. R.

    2018-03-01

    We consider a method of reconstructing the structure delay of extended radio sources without constructing their radio images. The residuals derived after the adjustment of geodetic VLBI observations are used for this purpose. We show that the simplest model of a radio source consisting of two point components can be represented by four parameters (the angular separation of the components, the mutual orientation relative to the poleward direction, the flux-density ratio, and the spectral index difference) that are determined for each baseline of a multi-baseline VLBI network. The efficiency of this approach is demonstrated by estimating the coordinates of the radio source 0014+813 observed during the two-week CONT14 program organized by the International VLBI Service (IVS) in May 2014. Large systematic deviations have been detected in the residuals of the observations for the radio source 0014+813. The averaged characteristics of the radio structure of 0014+813 at a frequency of 8.4 GHz can be calculated from these deviations. Our modeling using four parameters has confirmed that the source consists of two components at an angular separation of 0.5 mas in the north-south direction. Using the structure delay when adjusting the CONT14 observations leads to a correction of the average declination estimate for the radio source 0014+813 by 0.070 mas.

  1. RMG An Open Source Electronic Structure Code for Multi-Petaflops Calculations

    Science.gov (United States)

    Briggs, Emil; Lu, Wenchang; Hodak, Miroslav; Bernholc, Jerzy

    RMG (Real-space Multigrid) is an open source, density functional theory code for quantum simulations of materials. It solves the Kohn-Sham equations on real-space grids, which allows for natural parallelization via domain decomposition. Either subspace or Davidson diagonalization, coupled with multigrid methods, are used to accelerate convergence. RMG is a cross platform open source package which has been used in the study of a wide range of systems, including semiconductors, biomolecules, and nanoscale electronic devices. It can optionally use GPU accelerators to improve performance on systems where they are available. The recently released versions (>2.0) support multiple GPU's per compute node, have improved performance and scalability, enhanced accuracy and support for additional hardware platforms. New versions of the code are regularly released at http://www.rmgdft.org. The releases include binaries for Linux, Windows and MacIntosh systems, automated builds for clusters using cmake, as well as versions adapted to the major supercomputing installations and platforms. Several recent, large-scale applications of RMG will be discussed.

  2. Study on geology and geological structure based on literature studies

    International Nuclear Information System (INIS)

    Funaki, Hironori; Ishii, Eiichi; Yasue, Ken-ichi; Takahashi, Kazuharu

    2005-03-01

    Japan Nuclear Cycle Development Institute (JNC) is proceeding with underground research laboratory (URL) project for the sedimentary rock in Horonobe, Hokkaido. This project is an investigation project which is planned over 20 years. Surface-based investigations (Phase 1) have been conducted for the present. The purposes of the Phase 1 are to construct the geological environment model (geological-structural, hydrogeological, and hydrochemical models) and to confirm the applicability of investigation technologies for the geological environment. The geological-structural model comprises the base for the hydrogeological and hydrochemical models. We constructed the geological-structural model by mainly using data obtained from literature studies. Particulars regarding which data the model is based on and who has performed the interpretation are also saved for traceability. As a result, we explain the understanding of degree and the need of information on stratigraphy and discontinuous structure. (author)

  3. Tax evasion and income source: A comparative experimental study

    NARCIS (Netherlands)

    Gërxhani, K.; Schram, A.J.H.C.

    2006-01-01

    We compare tax evasive behavior in a country in transition from communism to that in a developed economy by running an experiment across distinct social groups in Albania and the Netherlands. Aside from the tax compliance decision, subjects choose a source of income, where one type enables

  4. Principal and experimental study of source of polarized electrons

    International Nuclear Information System (INIS)

    Shang Rencheng; Gao Junfang; Xiao Yuan; Pang Wenning; Deng Jingkang

    1999-01-01

    The getting of polarized electrons was briefly introduced, that is the source of polarized electrons. The measurement of polarization in future, the application of polarized electrons in atomic and molecular physics, condensed physics, biological physics, nuclear and particle physics were discussed

  5. Literature study of source term research for PWRs

    Energy Technology Data Exchange (ETDEWEB)

    Sponton, L.L.; NiIsson, Lars

    2001-04-01

    A literature survey has been carried out in support of ongoing source term calculations with the MELCOR code of some severe accident scenarios for the Swedish Ringhals 2 pressurised water reactor (PWR). The research in the field of severe accidents in power reactors and the source term for subsequent release of radioisotopes was intensified after the Harrisburg accident and has produced a large amount of reports and papers. This survey was therefore limited to research concerning PWR type of reactors and with emphasis on papers related to MELCOR code development. A background is given, relating to some historic documents, and then more recent research after 1990 is reviewed. Of special interest is the ongoing PMbus-programme which is creating new and important results of benefit to the code development and validation of, among others, the MELCOR code. It is concluded that source term calculations involve simulation of many interacting complex physical phenomena, which result in large uncertainties The research has, however, over the years led to considerable improvements Thus has the uncertainty in source term predictions been reduced one to two orders of magnitude from the simpler codes in the early 1980-s to the more realistic codes of today, like MELCOR.

  6. 61 SOURCE-CRITICAL STUDIES IN LUKE-ACTS: IMPLICATIONS ...

    African Journals Online (AJOL)

    HP

    its picture in the human mind.10 Social memory, especially in its wider concept of ... his sources, with special attention to their function and how they influenced Luke‟s narrative discourse. ..... But he also explicitly states his engagement in another dialogue ... some literary dependence without a clear dividing line. To have a ...

  7. Open Source Projects in Software Engineering Education: A Mapping Study

    Science.gov (United States)

    Nascimento, Debora M. C.; Almeida Bittencourt, Roberto; Chavez, Christina

    2015-01-01

    Context: It is common practice in academia to have students work with "toy" projects in software engineering (SE) courses. One way to make such courses more realistic and reduce the gap between academic courses and industry needs is getting students involved in open source projects (OSP) with faculty supervision. Objective: This study…

  8. Literature study of source term research for PWRs

    International Nuclear Information System (INIS)

    Sponton, L.L.; NiIsson, Lars

    2001-04-01

    A literature survey has been carried out in support of ongoing source term calculations with the MELCOR code of some severe accident scenarios for the Swedish Ringhals 2 pressurised water reactor (PWR). The research in the field of severe accidents in power reactors and the source term for subsequent release of radioisotopes was intensified after the Harrisburg accident and has produced a large amount of reports and papers. This survey was therefore limited to research concerning PWR type of reactors and with emphasis on papers related to MELCOR code development. A background is given, relating to some historic documents, and then more recent research after 1990 is reviewed. Of special interest is the ongoing PMbus-programme which is creating new and important results of benefit to the code development and validation of, among others, the MELCOR code. It is concluded that source term calculations involve simulation of many interacting complex physical phenomena, which result in large uncertainties The research has, however, over the years led to considerable improvements Thus has the uncertainty in source term predictions been reduced one to two orders of magnitude from the simpler codes in the early 1980-s to the more realistic codes of today, like MELCOR

  9. Study on a volume-production H- ion source

    International Nuclear Information System (INIS)

    Takama, S.

    1988-01-01

    H - ions formed by volume-production are extracted from a multicuspion source. By applying a large positive bias to the plasma electrode, the ratio I - /I e becomes 1/20. H - ion current of 0.4mA is extracted from a 0.3cm 2 circular aperture at an arc current of 10A. (author)

  10. Quasiballistic heat removal from small sources studied from first principles

    Science.gov (United States)

    Vermeersch, Bjorn; Mingo, Natalio

    2018-01-01

    Heat sources whose characteristic dimension R is comparable to phonon mean free paths display thermal resistances that exceed conventional diffusive predictions. This has direct implications to (opto)electronics thermal management and phonon spectroscopy. Theoretical analyses have so far limited themselves to particular experimental configurations. Here, we build upon the multidimensional Boltzmann transport equation (BTE) to derive universal expressions for the apparent conductivity suppression S (R ) =κeff(R ) /κbulk experienced by radially symmetric 2D and 3D sources. In striking analogy to cross-plane heat conduction in thin films, a distinct quasiballistic regime emerges between ballistic (κeff˜R ) and diffusive (κeff≃κbulk ) asymptotes that displays a logarithmic dependence κeff˜ln(R ) in single crystals and fractional power dependence κeff˜R2 -α in alloys (with α the Lévy superdiffusion exponent). Analytical solutions and Monte Carlo simulations for spherical and circular heat sources in Si, GaAs, Si0.99Ge0.01 , and Si0.82Ge0.18 , all carried out from first principles, confirm the predicted generic tendencies. Contrary to the thin film case, common approximations like kinetic theory estimates κeff≃∑Sωgreyκω and modified Fourier temperature curves perform relatively poorly. Up to threefold deviations from the BTE solutions for sub-100 nm sources underline the need for rigorous treatment of multidimensional nondiffusive transport.

  11. Cougar survival and source-sink structure on Greater Yellowstone's Northern Range

    Science.gov (United States)

    Ruth, T.K.; Haroldson, M.A.; Murphy, K.M.; Buotte, P.C.; Hornocker, M.G.; Quigley, H.B.

    2011-01-01

    We studied survival and causes of mortality of radiocollared cougars (Puma concolor) on the Greater Yellowstone Northern Range (GYNR) prior to (1987–1994) and after wolf (Canis lupus) reintroduction (1998–2005) and evaluated temporal, spatial, and environmental factors that explain variation in adult, subadult, and kitten survival. Using Program MARK and multimodel inference, we modeled cougar survival based on demographic status, season, and landscape attributes. Our best models for adult and independent subadults indicated that females survived better than males and survival increased with age until cougars reached older ages. Lower elevations and increasing density of roads, particularly in areas open to cougar hunting north of Yellowstone National Park (YNP), increased mortality risks for cougars on the GYNR. Indices of ungulate biomass, cougar and wolf population size, winter severity, rainfall, and individual characteristics such as the presence of dependent young, age class, and use of Park or Wilderness were not important predictors of survival. Kitten survival increased with age, was lower during winter, increased with increasing minimum estimates of elk calf biomass, and increased with increasing density of adult male cougars. Using our best model, we mapped adult cougar survival on the GYNR landscape. Results of receiver operating characteristic (ROC) analysis indicated a good model fit for both female (area under the curve [AUC] = 0.81, 95%CI = 0.70–0.92, n = 35 locations) and male cougars (AUC = 0.84, 95%CI = 0.74–0.94, n = 49 locations) relative to hunter harvest locations in our study area. Using minimum estimates of survival necessary to sustain the study population, we developed a source-sink surface and we identify several measures that resource management agencies can take to enhance cougar population management based on a source-sink strategy.

  12. Study on designing of hexapole magnet of ECR ion source

    CERN Document Server

    Sun Liang Ting; Zhao Hong, Wei

    2004-01-01

    Detailed research has been done on the aspects of the design of a Halbach structure permanent hexapole, such as the permanent material adoption, the structure design, the dimension selection, etc. A possible method has been proposed to solve the problem of demagnetization in some magnetic blocks. By optimizing the geometry structure, the magnetic field in the working aperture is made to be the maximum for a certain condition. Some useful codes like POISSON, PERMAG, and TOSCA are used to simulate the sextuple magnetic field. Some useful plots are also presented.

  13. Neutron scattering studies of modulated magnetic structures

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard Soerensen, Steen

    1999-08-01

    This report describes investigations of the magnetic systems DyFe{sub 4}Al{sub 8} and MnSi by neutron scattering and in the former case also by X-ray magnetic resonant scattering. The report is divided into three parts: An introduction to the technique of neutron scattering with special emphasis on the relation between the scattering cross section and the correlations between the scattering entities of the sample. The theoretical framework of neutron scattering experiments using polarized beam technique is outlined. The second part describes neutron and X-ray scattering investigation of the magnetic structures of DyFe{sub 4}Al{sub 8}. The Fe sublattice of the compound order at 180 K in a cycloidal structure in the basal plane of the bct crystal structure. At 25 K the ordering of the Dy sublattice shows up. By the element specific technique of X-ray resonant magnetic scattering, the basal plane cycloidal structure was also found for the Dy sublattice. The work also includes neutron scattering studies of DyFe{sub 4}Al{sub 8} in magnetic fields up to 5 T applied along a <110> direction. The modulated structure at the Dy sublattice is quenched by a field lower than 1 T, whereas modulation is present at the Fe sublattice even when the 5 T field is applied. In the third part of the report, results from three small angle neutron experiments on MnSi are presented. At ambient pressure, a MnSi is known to form a helical spin density wave at temperature below 29 K. The application of 4.5 kbar pressure intended as hydrostatic decreased the Neel temperature to 25 K and changed the orientation of the modulation vector. To understand this reorientation within the current theoretical framework, anisotropic deformation of the sample crystal must be present. The development of magnetic critical scattering with an isotropic distribution of intensity has been studied at a level of detail higher than that of work found in the literature. Finally the potential of a novel polarization

  14. Nucleon structure study by virtual compton scattering

    International Nuclear Information System (INIS)

    Berthot, J.; Bertin, P.Y.; Breton, V.; Fonvielle, H.; Hyde-Wright, C.; Quemener, G.; Ravel, O.; Braghieri, A.; Pedroni, P.; Boeglin, W.U.; Boehm, R.; Distler, M.; Edelhoff, R.; Friedrich, J.; Geiges, R.; Jennewein, P.; Kahrau, M.; Korn, M.; Kramer, H.; Krygier, K.W.; Kunde, V.; Liesenfeld, A.; Merle, K.; Neuhausen, R.; Offermann, E.A.J.M.; Pospischil, T.; Rosner, G.; Sauer, P.; Schmieden, H.; Schardt, S.; Tamas, G.; Wagner, A.; Walcher, T.; Wolf, S.

    1995-01-01

    We propose to study nucleon structure by Virtual Compton Scattering using the reaction p(e,e'p)γ with the MAMI facility. We will detect the scattered electron and the recoil proton in coincidence in the high resolution spectrometers of the hall A1. Compton events will be separated from the other channels (principally π 0 production) by missing-mass reconstruction. We plan to investigate this reaction near threshold. Our goal is to measure new electromagnetic observables which generalize the usual magnetic and electric polarizabilities. (authors). 9 refs., 18 figs., 7 tabs

  15. Studies on HF quadrupole accelerator structures

    International Nuclear Information System (INIS)

    Mueller, J.

    1983-01-01

    The present thesis had the aim to elaborate advantages and disadvantages of existing high frequency resonators in the MHz range regarding their use as RFQ power supply structures and to limit their application ranges. After a short survey over potential and field distributions in the RFQ suitable criteria for the valuation of RFQ resonators are indicated. For the experimentally studied resonators equivalent circuits are presented, in some cases these are theoretically analyzed. Finally the construction of the GSI/Frankfurt proton model as well experiments with the accelerated proton beams are described. (orig.) [de

  16. Study of rock structures by geotomography 5

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Yul; Kim, Yoo Sung; Hyun, Hye Ja [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    Since computerized axial tomography has revolutionized medical x-ray imaging, geotomography has found its big impact in the field of seismic exploration because of its ability to clearly image subsurface velocity structures and attenuation characteristics of the formations. For example, lateral or vertical inhomogeneities may generate distortions in the observed arrival time and/or amplitude of seismic waves. By evaluating such distortions, one can locate the inhomogeneities which may not be detected easily by the conventional surface seismic survey. Recently, seismic geotomography has been used as an efficient aid for solving various, geophysical problems such as evaluating radioactive waste repository, detecting fracture zones in crystalline rocks, dam site investigation, cavity detection and so on. However, application of seismic methods to such environmental problems as above has rarely been conducted, thus many problems including development of suitable equipment and processing facilities still to be attacked. The objectives of this project can be categorized in three major parts. The first is an establishment of the geotomographical processing system on personal computers. This includes the development of an effective routines useful for the first onsets picking. The second is associated with the development of borehole source and receiver systems which provide meaningful data for geotomography. The small and light but powerful borehole acquisition system which is suitable for our field environment is needed to be developed. The third is concerned with the establishment of borehole scanner (televiewer) system for obtaining detailed information about fractures, bedding planes, geothermal reservoirs etc. It is evident that the above mentioned developments should represent our potential of crosshole seismic methods for the exploration of subsurface. The purpose of this investigation is to realize the highly efficient seismic methods i.e. (Abstract Truncated)

  17. Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures.

    Science.gov (United States)

    Schachter, L; Stiebing, K E; Dobrescu, S

    2009-01-01

    The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut für Kernphysik der Universität Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the "MD source" as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an "all stainless steel" ECRIS.

  18. Influence of the electron cyclotron resonance plasma confinement on reducing the bremsstrahlung production of an electron cyclotron resonance ion source with metal-dielectric structures

    International Nuclear Information System (INIS)

    Schachter, L.; Dobrescu, S.; Stiebing, K. E.

    2009-01-01

    The influence of metal-dielectric (MD) layers (MD structures) inserted into the plasma chamber of an electron cyclotron resonance ion source (ECRIS) onto the production of electron bremsstrahlung radiation has been studied in a series of dedicated experiments at the 14 GHz ECRIS of the Institut fuer Kernphysik der Universitaet Frankfurt. The IKF-ECRIS was equipped with a MD liner, covering the inner walls of the plasma chamber, and a MD electrode, covering the plasma-facing side of the extraction electrode. On the basis of similar extracted currents of highly charged ions, significantly reduced yields of bremsstrahlung radiation for the 'MD source' as compared to the standard (stainless steel) source have been measured and can be explained by the significantly better plasma confinement in a MD source as compared to an ''all stainless steel'' ECRIS.

  19. Study on induced radioactivity of China Spallation Neutron Source

    International Nuclear Information System (INIS)

    Wu Qingbiao; Wang Qingbin; Wu Jingmin; Ma Zhongjian

    2011-01-01

    China Spallation Neutron Source (CSNS) is the first High Energy Intense Proton Accelerator planned to be constructed in China during the State Eleventh Five-Year Plan period, whose induced radioactivity is very important for occupational disease hazard assessment and environmental impact assessment. Adopting the FLUKA code, the authors have constructed a cylinder-tunnel geometric model and a line-source sampling physical model, deduced proper formulas to calculate air activation, and analyzed various issues with regard to the activation of different tunnel parts. The results show that the environmental impact resulting from induced activation is negligible, whereas the residual radiation in the tunnels has a great influence on maintenance personnel, so strict measures should be adopted.(authors)

  20. A study of the consistent and the lumped source approximations in finite element neutron diffusion calculations

    International Nuclear Information System (INIS)

    Ozgener, B.; Azgener, H.A.

    1991-01-01

    In finite element formulations for the solution of the within-group neutron diffusion equation, two different treatments are possible for the group source term: the consistent source approximation (CSA) and the lumped source approximation (LSA). CSA results in intra-group scattering and fission matrices which have the same nondiagonal structure as the global coefficient matrix. This situation might be regarded as a disadvantage, compared to the conventional (i.e. finite difference) methods where the intra-group scattering and fission matrices are diagonal. To overcome this disadvantage, LSA could be used to diagonalize these matrices. LSA is akin to the lumped mass approximation of continuum mechanics. We concentrate on two different aspects of the source approximations. Although it has been reported that LSA does not modify the asymptotic h 2 convergence behaviour for linear elements, the effect of LSA on convergence of higher degree elements has not been investigated. Thus, we would be interested in determining, p, the asymptotic order of convergence, in: Δk |k eff (analytical) -k eff (finite element)| = Ch p (1) for finite element approximations of varying degree (N) with both of the source approximations. Since (1) is valid in the asymptotic limit, we must use ultra-fine meshes and quadruple precision arithmetic. For our order of convergence study, we used infinite cylindrical geometry with azimuthal symmetry. Hence, the effects of singularities remain uninvestigated. The second aspect we dwell on is the performance of LSA in bilinear 3-D finite element calculations, compared to CSA. LSA has been used quite extensively in 1- and 2-D even-parity transport and diffusion calculations. In this work, we will try to assess the relative merits of LSA and CSA in 3-D problems. (author)

  1. Recommendation of ruthenium source for sludge batch flowsheet studies

    Energy Technology Data Exchange (ETDEWEB)

    Woodham, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-09-13

    Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate, conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.

  2. In-Source Laser Spectroscopy with the Laser Ion Source and Trap: First Direct Study of the Ground-State Properties of ^{217,219}Po

    Directory of Open Access Journals (Sweden)

    D. A. Fink

    2015-02-01

    Full Text Available A Laser Ion Source and Trap (LIST for a thick-target, isotope-separation on-line facility has been implemented at CERN ISOLDE for the production of pure, laser-ionized, radioactive ion beams. It offers two modes of operation, either as an ion guide, which performs similarly to the standard ISOLDE resonance ionization laser ion source (RILIS, or as a more selective ion source, where surface-ionized ions from the hot ion-source cavity are repelled by an electrode, while laser ionization is done within a radio-frequency quadrupole ion guide. The first physics application of the LIST enables the suppression of francium contamination in ion beams of neutron-rich polonium isotopes at ISOLDE by more than 1000 with a reduction in laser-ionization efficiency of only 20. Resonance ionization spectroscopy is performed directly inside the LIST device, allowing the study of the hyperfine structure and isotope shift of ^{217}Po for the first time. Nuclear decay spectroscopy of ^{219}Po is performed for the first time, revealing its half-life, α-to-β-decay branching ratio, and α-particle energy. This experiment demonstrates the applicability of the LIST at radioactive ion-beam facilities for the production and study of pure beams of exotic isotopes.

  3. Overview of receptor-based source apportionment studies for speciated atmospheric mercury

    OpenAIRE

    Cheng, I.; Xu, X.; Zhang, L.

    2015-01-01

    Receptor-based source apportionment studies of speciated atmospheric mercury are not only concerned with source contributions but also with the influence of transport, transformation, and deposition processes on speciated atmospheric mercury concentrations at receptor locations. Previous studies applied multivariate receptor models including principal components analysis and positive matrix factorization, and back trajectory receptor models including potential source contri...

  4. Structure study in the 19C halo

    International Nuclear Information System (INIS)

    Angelique, J.C.; Le Brun, C.; Liegard, E.; Marques, F.M.; Orr, N.A.

    1997-01-01

    The halo nuclei are nuclei which have one or more neutrons (or protons) with very weak binding energy what results in a spatial extension beyond the core containing the other nucleons. This important spatial extension is related via the Heisenberg principle to a narrow momentum distribution which signs the halo structure of the nucleus under consideration. To extend our understanding of this phenomenon an experiment has been carried out with the DEMON multidetector in the frame of the collaboration E133. The subject was the study of 19 C, a nucleus susceptible of having a neutron halo due to the low binding energy of its last neutron (S n = 240 ± 100 keV). The 19 C secondary beam was produced by fragmentation of a primary 40 Ar beam in a carbon target between the two solenoids of SISSI and than directed to a GANIL experimental room. A silicon detector telescope was used to detect the charged particles issued from the reaction of 19 C nuclei with the tantalum target while the DEMON detection modular assembly separated by four meters from the target allowed the neutron detection between 0 and 42 degrees. The first results of this analysis are favorable to a halo structure for this nucleus for the reaction channel in which the 18 C core is destroyed. We have compared the angular distribution of the neutrons of 19 C with those obtained from the breakup reactions of other exotic nuclei ( 21 N, 22 O and 24 F) but having no halo structure. A net different behavior of these nuclei indicate a clear difference in structure. Actually, the 19 C distribution corresponds to the superposition of a broad distribution and narrow distribution. The last one having width of 42 ± 12 MeV/c, compatible with an important spatial extension, corresponds to neutrons coming from the halo. It is argued that the model in which the halo neutron moves on a s orbital cannot described the structure of 19 C halo. A more adequate description would be a mixture of s and d orbitals which would also

  5. Tragacanth Gum: Structural Composition, Natural Functionality and Enxymatic Conversion as Source of Potential Prebiotic Activity

    DEFF Research Database (Denmark)

    Ahmadi Gavlighi, Hassan

    very high viscosities when in aqueous solution, and is described as a complex, highly branched, heterogeneous hydrophilic polysaccharide. The gum contains pectinaceous arabinogalactans and fucose-substituted xylogalacturonans. The objective of this PhD study were to evaluate tragacanth samples from six...... and fractionated by centrifugation to soluble and insoluble. To examine correlation between composition structure, sugar composition and methoxyl and acetyl content was determined. The six gum samples varied with respect totheir levels and ratios of water-soluble and water-swellable fractions, their monosaccharide...

  6. Study of the partonic structure of the helium nucleus

    International Nuclear Information System (INIS)

    Perrin, Y.

    2012-01-01

    The structure of the nucleons and of the nuclei was actively studied during the twentieth century through electron elastic scattering (measuring the electromagnetic form factors) and deep inelastic electron scattering (measuring the parton distributions). The formalism of generalized parton distributions (GPD) achieved the unification of the form factors and the parton distributions. This link gives a source of information about parton dynamics, such as the distribution of nuclear forces and orbital momentum inside hadrons. The easiest experimental access to the GPD is the deeply virtual Compton scattering (DVCS), which corresponds to the hard electroproduction of a real photon. While several experiments focussed on DVCS off the nucleon, only a few experiments studied DVCS off a nuclear target. This thesis deals with the study of the coherent channel of DVCS off helium 4, with the aim of extracting the real and imaginary parts of the Compton form factor thanks to the beam spin asymmetry. (author)

  7. Source apportionment studies on particulate matter in Beijing/China

    Science.gov (United States)

    Suppan, P.; Shen, R.; Shao, L.; Schrader, S.; Schäfer, K.; Norra, S.; Vogel, B.; Cen, K.; Wang, Y.

    2013-05-01

    More than 15 million people in the greater area of Beijing are still suffering from severe air pollution levels caused by sources within the city itself but also from external impacts like severe dust storms and long range advection from the southern and central part of China. Within this context particulate matter (PM) is the major air pollutant in the greater area of Beijing (Garland et al., 2009). PM did not serve only as lead substance for air quality levels and therefore for adverse health impact effects but also for a strong influence on the climate system by changing e.g. the radiative balance. Investigations on emission reductions during the Olympic Summer Games in 2008 have caused a strong reduction on coarser particles (PM10) but not on smaller particles (PM2.5). In order to discriminate the composition of the particulate matter levels, the different behavior of coarser and smaller particles investigations on source attribution, particle characteristics and external impacts on the PM levels of the city of Beijing by measurements and modeling are performed: a) Examples of long term measurements of PM2.5 filter sampling in 2010/2011 with the objectives of detailed chemical (source attribution, carbon fraction, organic speciation and inorganic composition) and isotopic analyses as well as toxicological assessment in cooperation with several institutions (Karlsruhe Institute of Technology (IfGG/IMG), Helmholtz Zentrum München (HMGU), University Rostock (UR), Chinese University of Mining and Technology Beijing, CUMTB) will be discussed. b) The impact of dust storm events on the overall pollution level of particulate matter in the greater area of Beijing is being assessed by the online coupled comprehensive model system COSMO-ART. First results of the dust storm modeling in northern China (2011, April 30th) demonstrates very well the general behavior of the meteorological parameters temperature and humidity as well as a good agreement between modeled and

  8. Experimental study on cesium immobilization in struvite structures

    International Nuclear Information System (INIS)

    Wagh, Arun S.; Sayenko, S.Y.; Shkuropatenko, V.A.; Tarasov, R.V.; Dykiy, M.P.; Svitlychniy, Y.O.; Virych, V.D.; Ulybkina, E.A.

    2016-01-01

    Graphical abstract: X-ray diffraction patterns of Ceramicrete forms, green representing struvite-K, and red, struvite-(K,Cs) with 10 wt.% CsCl in it. Cs substitutes partially for K, which immobilizes Cs at room temperature by the acid–base reaction. - Highlights: • Struvite structure of Ceramicrete is an excellent host of radioactive cesium. • The volatility problem of cesium can be avoided by this method. • This method can be used to produce cesium waste forms in ambient conditions. • It can also be used to pretreat cesium in glass vitrification technology. • It also provides a method to produce safe sealed radioactive sources of cesium. - Abstract: Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources.

  9. Experimental study on cesium immobilization in struvite structures

    Energy Technology Data Exchange (ETDEWEB)

    Wagh, Arun S., E-mail: asw@anl.gov [Environmental Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, IL 60439 (United States); Sayenko, S.Y.; Shkuropatenko, V.A.; Tarasov, R.V.; Dykiy, M.P.; Svitlychniy, Y.O.; Virych, V.D.; Ulybkina, E.A. [National Science Center, Kharkov Institute of Physics and Technology, Kharkov (Ukraine)

    2016-01-25

    Graphical abstract: X-ray diffraction patterns of Ceramicrete forms, green representing struvite-K, and red, struvite-(K,Cs) with 10 wt.% CsCl in it. Cs substitutes partially for K, which immobilizes Cs at room temperature by the acid–base reaction. - Highlights: • Struvite structure of Ceramicrete is an excellent host of radioactive cesium. • The volatility problem of cesium can be avoided by this method. • This method can be used to produce cesium waste forms in ambient conditions. • It can also be used to pretreat cesium in glass vitrification technology. • It also provides a method to produce safe sealed radioactive sources of cesium. - Abstract: Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid–base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources.

  10. Seismic velocity structure and microearthquake source properties at The Geysers, California, geothermal area

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, D.R.

    1986-12-01

    The method of progressive hypocenter-velocity inversion has been extended to incorporate S-wave arrival time data and to estimate S-wave velocities in addition to P-wave velocities. S-wave data to progressive inversion does not completely eliminate hypocenter-velocity tradeoffs, but they are substantially reduced. Results of a P and S-wave progressive hypocenter-velocity inversion at The Geysers show that the top of the steam reservoir is clearly defined by a large decrease of V/sub p//V/sub s/ at the condensation zone-production zone contact. The depth interval of maximum steam production coincides with minimum observed V/sub p//V/sub s/, and V/sub p//V/sub s/ increses below the shallow primary production zone suggesting that reservoir rock becomes more fluid saturated. The moment tensor inversion method was applied to three microearthquakes at The Geysers. Estimated principal stress orientations were comparable to those estimated using P-wave firstmotions as constraints. Well constrained principal stress orientations were obtained for one event for which the 17 P-first motions could not distinguish between normal-slip and strike-slip mechanisms. The moment tensor estimates of principal stress orientations were obtained using far fewer stations than required for first-motion focal mechanism solutions. The three focal mechanisms obtained here support the hypothesis that focal mechanisms are a function of depth at The Geysers. Progressive inversion as developed here and the moment tensor inversion method provide a complete approach for determining earthquake locations, P and S-wave velocity structure, and earthquake source mechanisms.

  11. Studies on metal-dielectric plasmonic structures.

    Energy Technology Data Exchange (ETDEWEB)

    Chettiar, Uday K. (Purdue University, West Lafayette, IN); Liu, Zhengtong (Purdue University, West Lafayette, IN); Thoreson, Mark D. (Purdue University, West Lafayette, IN); Shalaev, Vladimir M. (Purdue University, West Lafayette, IN); Drachev, Vladimir P. (Purdue University, West Lafayette, IN); Pack, Michael Vern; Kildishev, Alexander V. (Purdue University, West Lafayette, IN); Nyga, Piotr (Purdue University, West Lafayette, IN)

    2010-01-01

    The interaction of light with nanostructured metal leads to a number of fascinating phenomena, including plasmon oscillations that can be harnessed for a variety of cutting-edge applications. Plasmon oscillation modes are the collective oscillation of free electrons in metals under incident light. Previously, surface plasmon modes have been used for communication, sensing, nonlinear optics and novel physics studies. In this report, we describe the scientific research completed on metal-dielectric plasmonic films accomplished during a multi-year Purdue Excellence in Science and Engineering Graduate Fellowship sponsored by Sandia National Laboratories. A variety of plasmonic structures, from random 2D metal-dielectric films to 3D composite metal-dielectric films, have been studied in this research for applications such as surface-enhanced Raman sensing, tunable superlenses with resolutions beyond the diffraction limit, enhanced molecular absorption, infrared obscurants, and other real-world applications.

  12. A Comparison of FDM Structural Layouts and Implementation of an Open-Source Arm-Based System

    Directory of Open Access Journals (Sweden)

    Pollard David

    2018-01-01

    Full Text Available Fused Deposition Modelling (FDM is a manufacturing process to build components in a layer-by-layer approach through extrusion of polymers from a movable nozzle, allowing for significantly higher degrees of complexity over machined parts. Current FDM systems typically use actuation provided through a gantry or delta structural layout, operating through depositing successive planar layers in a 2.5D process; it has been shown in numerous studies the bonding between layers has significantly lower strength than the homogeneous material or in-plane properties - an issue which can be mitigated through the deposition of curved layers. This paper compares four differing structural layouts of FDM systems (gantry, delta, Stewart Platform, and arm-based to identify the key advantages of an arm-based method as the increased workspace and manipulability enabling “Additive Finalisation” of components, and suitability for curved layer FDM. Details are then presented of the open-source implementation and evaluation of a 6 degree-of-freedom arm-based FDM printer at the University of Bristol.

  13. Overview of the Lombardy Region (I) Source Apportionment Study

    Science.gov (United States)

    Larsen, B. R.

    2009-04-01

    The Lombardia Region (RL) is situated in the central part of the Po Plain (I) where the mesoscale climatological conditions are determined to a high degree by the orographical characteristics of this area. Encirclement from three sides (North, West and South) by the mountain chains contributes greatly to the climatological peculiarities that are related from the physical point of view to the dynamic of the air mass in this region. The adverse anemological regime and the persistence of atmospheric stability result in low wind speeds, inversion of the temperature, and shallow inversion layers. Due to these particular geographical and the meteorological conditions associated with a high population density (9 million inhabitants) and the connected anthropogenic activities, RL is one of Europe's most polluted regions with regard to PM and photochemical smog. The 24 hours EU air quality limit for PM10 of 50 ug/m3 is exceeded up to 180 days per year and the yearly limit of 40 ug/m3 is in breach for most urban/urban background areas. In order to efficiently plan abatement strategies, quantitative information is required on the pollution sources and available emission inventories need to be compared with source apportionment results derived by receptor modeling of the chemical composition of PM10 in ambient air and in source emissions. The European Commission Joint Research Centre (JRC) has embarked on a major integrated project in RL (2006-2010) in collaboration with the air quality authorities (ARPA) to support the design of appropriate air quality and emission reduction strategies in this area. The present paper presents the first results of this project, carried out during typical winter episodes in 2007 at ten measurement stations distributed over the entire RL. The source contributions to PM10 and the associated air toxics (benzo[a]pyrene, Pb, Ni, Cd and As) have been quantified by Chemical Mass Balance and Positive Matrix Factorization based upon the chemical

  14. Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim

    2016-08-01

    Amy Eisses, Annie M. Kell, Graham Kent, Neal W. Driscoll, Robert E. Karlin, Robert L. Baskin, John N. Louie, Kenneth D. Smith, Sathish Pullammanappallil, 2011, Marine and land active-source seismic investigation of geothermal potential, tectonic structure, and earthquake hazards in Pyramid Lake, Nevada: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract NS14A-08.

  15. Science Study Aids 3: Carbohydrates - Nature's Energy Source.

    Science.gov (United States)

    McConnell, Bill

    This publication is the third of a series of seven supplementary investigative materials for use in secondary science classes providing up-to-date research-related investigations. This unit is structured for grade levels 7 through 12. It is concerned with the role of carbohydrates as important nutrients for consumers. This guide will enable…

  16. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    International Nuclear Information System (INIS)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G.; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E.

    2016-01-01

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  17. Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Michael E.; Chapman, David J.; White, Thomas G. [Imperial College London, London (United Kingdom); Drakopoulos, Michael [Diamond Light Source, I12 Joint Engineering, Environmental, Processing (JEEP) Beamline, Didcot, Oxfordshire (United Kingdom); Rack, Alexander [European Synchrotron Radiation Facility, Grenoble (France); Eakins, Daniel E., E-mail: d.eakins@imperial.ac.uk [Imperial College London, London (United Kingdom)

    2016-03-24

    Scintillator performance in time-resolved, hard, indirect detection X-ray studies on the sub-microsecond timescale at synchrotron light sources is reviewed, modelled and examined experimentally. LYSO:Ce is found to be the only commercially available crystal suitable for these experiments. The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits)

  18. Thermal Analysis of AlGaN/GaN High-Electron-Mobility Transistor and Its RF Power Efficiency Optimization with Source-Bridged Field-Plate Structure.

    Science.gov (United States)

    Kwak, Hyeon-Tak; Chang, Seung-Bo; Jung, Hyun-Gu; Kim, Hyun-Seok

    2018-09-01

    In this study, we consider the relationship between the temperature in a two-dimensional electron gas (2-DEG) channel layer and the RF characteristics of an AlGaN/GaN high-electron-mobility transistor by changing the geometrical structure of the field-plate. The final goal is to achieve a high power efficiency by decreasing the channel layer temperature. First, simulations were performed to compare and contrast the experimental data of a conventional T-gate head structure. Then, a source-bridged field-plate (SBFP) structure was used to obtain the lower junction temperature in the 2-DEG channel layer. The peak electric field intensity was reduced, and a decrease in channel temperature resulted in an increase in electron mobility. Furthermore, the gate-to-source capacitance was increased by the SBFP structure. However, under the large current flow condition, the SBFP structure had a lower maximum temperature than the basic T-gate head structure, which improved the device electron mobility. Eventually, an optimum position of the SBFP was used, which led to higher frequency responses and improved the breakdown voltages. Hence, the optimized SBFP structure can be a promising candidate for high-power RF devices.

  19. From laser-plasma accelerators to femtosecond X-ray sources: study, development and applications

    International Nuclear Information System (INIS)

    Corde, S.

    2012-01-01

    During the relativistic interaction between a short and intense laser pulse and an underdense plasma, electrons can be injected and accelerated up to hundreds of MeV in an accelerating structure formed in the wake of the pulse: this is the so-called laser-plasma accelerator. One of the major perspectives for laser-plasma accelerators resides in the realization of compact sources of femtosecond x-ray beams. In this thesis, two x-ray sources was studied and developed. The betatron radiation, intrinsic to laser-plasma accelerators, comes from the transverse oscillations of electrons during their acceleration. Its characterization by photon counting revealed an x-ray beam containing 10"9 photons, with energies extending above 10 keV. We also developed an all-optical Compton source producing photons with energies up to hundreds of keV, based on the collision between a photon beam and an electron beam. The potential of these x-ray sources was highlighted by the realization of single shot phase contrast imaging of a biological sample. Then, we showed that the betatron x-ray radiation can be a powerful tool to study the physics of laser-plasma acceleration. We demonstrated the possibility to map the x-ray emission region, which gives a unique insight into the interaction, permitting us for example to locate the region where electrons are injected. The x-ray angular and spectral properties allow us to gain information on the transverse dynamics of electrons during their acceleration. (author)

  20. Uncovering the social deficits in the autistic brain.A Source-Based Morphometric study

    Directory of Open Access Journals (Sweden)

    Alessandro Grecucci

    2016-08-01

    Full Text Available Autism is a neurodevelopmental disorder that mainly affects social interaction and communication. Evidence from behavioral and functional MRI studies supports the hypothesis that dysfunctional mechanisms involving social brain structures play a major role in autistic symptomatology. However, the investigation of anatomical abnormalities in the brain of people with autism has led to inconsistent results. We investigated whether specific brain regions, known to display functional abnormalities in autism, may exhibit mutual and peculiar patterns of covariance in their grey-matter concentrations. We analyzed structural MRI images of 32 young men affected by autistic disorder (AD and 50 healthy controls. Controls were matched for sex, age, handedness. IQ scores were also monitored to avoid confounding. A multivariate Source-Based Morphometry (SBM was applied for the first time on AD and controls to detect maximally independent networks of gray matter. Group comparison revealed a gray-matter source that showed differences in AD compared to controls. This network includes broad temporal regions involved in social cognition and high-level visual processing, but also motor and executive areas of the frontal lobe. Notably, we found that gray matter differences, as reflected by SBM, significantly correlated with social and behavioral deficits displayed by AD individuals and encoded via the Autism Diagnostic Observation Schedule scores. These findings provide support for current hypotheses about the neural basis of atypical social and mental states information processing in autism.

  1. Sensitivity of metrics of phylogenetic structure to scale, source of data and species pool of hummingbird assemblages along elevational gradients.

    Directory of Open Access Journals (Sweden)

    Sebastián González-Caro

    Full Text Available Patterns of phylogenetic structure of assemblages are increasingly used to gain insight into the ecological and evolutionary processes involved in the assembly of co-occurring species. Metrics of phylogenetic structure can be sensitive to scaling issues and data availability. Here we empirically assess the sensitivity of four metrics of phylogenetic structure of assemblages to changes in (i the source of data, (ii the spatial grain at which assemblages are defined, and (iii the definition of species pools using hummingbird (Trochilidae assemblages along an elevational gradient in Colombia. We also discuss some of the implications in terms of the potential mechanisms driving these patterns. To explore how source of data influence phylogenetic structure we defined assemblages using three sources of data: field inventories, museum specimens, and range maps. Assemblages were defined at two spatial grains: coarse-grained (elevational bands of 800-m width and fine-grained (1-km(2 plots. We used three different species pools: all species contained in assemblages, all species within half-degree quadrats, and all species either above or below 2000 m elevation. Metrics considering phylogenetic relationships among all species within assemblages showed phylogenetic clustering at high elevations and phylogenetic evenness in the lowlands, whereas those metrics considering only the closest co-occurring relatives showed the opposite trend. This result suggests that using multiple metrics of phylogenetic structure should provide greater insight into the mechanisms shaping assemblage structure. The source and spatial grain of data had important influences on estimates of both richness and phylogenetic structure. Metrics considering the co-occurrence of close relatives were particularly sensitive to changes in the spatial grain. Assemblages based on range maps included more species and showed less phylogenetic structure than assemblages based on museum or field

  2. STUDIES OF SHADING LEVELS AND NUTRITION SOURCES ON GROWTH, YIELD

    Directory of Open Access Journals (Sweden)

    Edi Purwanto

    2011-10-01

    Full Text Available Growth and biochemical content of medicinal crops are influenced by agroecosystems characteristics . The objective of this research was to determine the optimum shading level and type of fertilizer as sources of nutrition on the growth, yield, and andrographolide content of sambiloto. The experiment used Split Plot Design with basic design of Randomized Complete Block Design arranged with two treatment factors, with three replications. The first factor as the main plot was shading levels, namely without shading, 25% shading, 50% shading, and 75% shading. The second factor as the sub plot was sources of nutrition reprented by type of fertilizer, namely NPK fertilizer, cow stable fertilizer, and compost fertilizer. The result of research indicated that shading level and the kind of nutrition influenced some growth and yield variables such as number of leaves, number of branches, plant height, plant dry weight and simplisia weight, and andrographolide content. Interaction of shading level at 25% and straw compost fertilizer performed best in growth characteristics, while the highest andrographolide content resulted from the treatment combination of 50% shading level and straw compost fertilizer.

  3. Study of Coal Burst Source Locations in the Velenje Colliery

    Directory of Open Access Journals (Sweden)

    Goran Vižintin

    2016-06-01

    Full Text Available The Velenje coal mine (VCM is situated on the largest Slovenian coal deposit and in one of the thickest layers of coal known in the world. The thickness of the coal layer causes problems for the efficiency of extraction, since the majority of mining operations is within the coal layer. The selected longwall coal mining method with specific geometry, increasing depth of excavations, changes in stress state and naturally given geomechanical properties of rocks induce seismic events. Induced seismic events can be caused by caving processes, blasting or bursts of coal or the surrounding rock. For 2.5D visualization, data of excavations, ash content and calorific value of coal samples, hanging wall and footwall occurrence, subsidence of the surface and coal burst source locations were collected. Data and interpolation methods available in software package Surfer®12 were statistically analyzed and a Kriging (KRG interpolation method was chosen. As a result 2.5D visualizations of coal bursts source locations with geomechanical properties of coal samples taken at different depth in the coal seam in the VCM were made with data-visualization packages Surfer®12 and Voxler®3.

  4. A study about ions sources for solids and gases

    International Nuclear Information System (INIS)

    Perez Z, E.

    1975-01-01

    Description of the different ways of obtaining ions and the causes which limits their production is covered among the various possible combinations of parameters involved in any source in order to obtain the maximum current of ions, the following were selected: filament current against: focusing voltage and accelerating voltage, establishing also a ions current relationship between detectors. In the first pair of parameters, the increase of the accelerating voltage produced the increase of the ionization current and similarly in the second and third pair of parameters the increase of the filament current and pression respectively produced the same effect. During the separation between the discharge camera and lens it was observed that to each variation in the extraction voltage corresponded an equal variation in the focusing voltage. Finally a relationship was established in the ions current between grating and detector in order to determine the more appropriate distance between the camera and the focusing lens. The increase of the ionization current when the accelerating voltage, the magnetic field and the gas pressure are increased is interpreted as a physical fact; the efficiency of a source is considered. (author)

  5. Bi-resonant structure with piezoelectric PVDF films for energy harvesting from random vibration sources at low frequency

    DEFF Research Database (Denmark)

    Liang, Shanshan; Crovetto, Andrea; Peng, Zhuoteng

    2016-01-01

    and experiments with piezoelectric elements show that the energy harvesting device with the bi-resonant structure can generate higher power output than that of the sum of the two separate devices from random vibration sources at low frequency, and hence significantly improves the vibration-to- electricity......This paper reports on a bi-resonant structure of piezoelectric PVDF films energy harvester (PPEH), which consists of two cantilevers with resonant frequencies of 15 Hz and 22 Hz. With increased acceleration, the vibration amplitudes of the two cantilever-mass structures are increased and collision...

  6. Capital Structure of Internet Companies: Case Study

    OpenAIRE

    Miglo, Anton; Liang, Shuting; Lee, Zhenting

    2014-01-01

    We analyze the financing decisions and capital structure of internet companies and relate observed findings to the common capital structure theories. Large internet companies usually have low debt and small internet companies have high debt. We find that the trade-off theory of capital structure, pecking order theory, market timing theory and other theories cannot individually explain a firm’s capital structure. However, they can compliment each other in describing some patterns of observed b...

  7. The Guarda structure (Portugal): Impact structure or not? Microstructural studies of Quartz, Zircon and Monazite

    NARCIS (Netherlands)

    Zalinge, M.E. van; Hamers, M.F.; Drury, M.R.

    2012-01-01

    The Guarda Structure in north-eastern Portugal has been proposed as a potential impact structure. We have studied the structure in detail, but no field or microscopic evidence has been found to support the impact hypothesis

  8. Structural studies of supported tin catalysts

    Science.gov (United States)

    Nava, Noel; Viveros, Tomás

    1999-11-01

    Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Mössbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied.

  9. Structural studies of supported tin catalysts

    International Nuclear Information System (INIS)

    Nava, Noel; Viveros, Tomas

    1999-01-01

    Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Moessbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO 2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied

  10. Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs

    International Nuclear Information System (INIS)

    Hogsden, Kristy L.; Harding, Jon S.

    2012-01-01

    We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. - Highlights: ► Food webs in acid mine drainage impacted streams are small and extremely simplified. ► Conductivity explained differences in food web properties between streams. ► Number of links and web size accounted for much dissimilarity between food webs. ► Food web structure was comparable in naturally acidic and circumneutral streams. - Food web structure differs in streams with anthropogenic and natural sources of acidity and metals.

  11. Source Authenticity in the UMLS – A Case Study of the Minimal Standard Terminology

    Science.gov (United States)

    Elhanan, Gai; Huang, Kuo-Chuan; Perl, Yehoshua

    2010-01-01

    As the UMLS integrates multiple source vocabularies, the integration process requires that certain adaptation be applied to the source. Our interest is in examining the relationship between the UMLS representation of a source vocabulary and the source vocabulary itself. We investigated the integration of the Minimal Standard Terminology (MST) into the UMLS in order to examine how close its UMLS representation is to the source MST. The MST was conceived as a “minimal” list of terms and structure intended for use within computer systems to facilitate standardized reporting of gastrointestinal endoscopic examinations. Although the MST has an overall schema and implied relationship structure, many of the UMLS integrated MST terms were found to be hierarchically orphaned, and with lateral relationships that do not closely adhere to the source MST. Thus, the MST representation within the UMLS significantly differs from that of the source MST. These representation discrepancies may affect the usability of the MST representation in the UMLS for knowledge acquisition. Furthermore, they pose a problem from the perspective of application developers. While these findings may not necessarily apply to other source terminologies, they highlight the conflict between preservation of authentic concept orientation and the UMLS overall desire to provide fully specified names for all source terms. PMID:20692366

  12. Anthropogenic and natural sources of acidity and metals and their influence on the structure of stream food webs.

    Science.gov (United States)

    Hogsden, Kristy L; Harding, Jon S

    2012-03-01

    We compared food web structure in 20 streams with either anthropogenic or natural sources of acidity and metals or circumneutral water chemistry in New Zealand. Community and diet analysis indicated that mining streams receiving anthropogenic inputs of acidic and metal-rich drainage had much simpler food webs (fewer species, shorter food chains, less links) than those in naturally acidic, naturally high metal, and circumneutral streams. Food webs of naturally high metal streams were structurally similar to those in mining streams, lacking fish predators and having few species. Whereas, webs in naturally acidic streams differed very little from those in circumneutral streams due to strong similarities in community composition and diets of secondary and top consumers. The combined negative effects of acidity and metals on stream food webs are clear. However, elevated metal concentrations, regardless of source, appear to play a more important role than acidity in driving food web structure. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Optimisation studies for a moderator on a pulsed neutron source

    International Nuclear Information System (INIS)

    Picton, D.J.; Ross, D.K.; Taylor, A.D.

    1982-01-01

    Having reviewed general aspects of moderator design for pulsed neutron sources, calculations are presented on a number of aspects of moderator optimization. Results of time-independent calculations on metal hydride moderators and a detailed method of evaluating moderated pulse intensities and time distributions, are given. Using computer codes, neutron cross-sections have been calculated from vibrational frequency distributions and time-dependent moderator calculations performed by Monte Carlo methods. The choice of an ambient moderator material and the optimum configuration of heterogeneous poisoning are examined and evaluations of liquid-nitrogen-cooled moderators are presented. Conclusions are drawn concerning the relative merits of cooled and poisoned moderators and an evaluation presented of solid methane at 20 K as a moderator for the production of cold neutrons. (U.K.)

  14. Capitalization of renewable energy sources: Romanian case studies

    International Nuclear Information System (INIS)

    Voronca, Mihai-Marius; Cruceru, Mihai

    2007-01-01

    One of the major challenges of the recent integration of Romania in the European Union is the extension of use, at national scale, of Renewable Energy Sources (RES). Targeting private operators and municipalities, authors have as objective to deliver an investigation on the interesting 'Acquis' in financing and implementing RES projects in Romania. Using as method of investigation the accurate screening of their experience as well as the extended international experience in the field, authors have reviewed in the present paper different possibilities in RES investment financing, frequent obstacles and barriers, and ways for overcoming them. Recent results are motivating authors to consider the national experience of an encouraging success and to act towards the capitalization of such investments replication potential to a national and regional scale. (authors)

  15. Study on analysis from sources of error for Airborne LIDAR

    Science.gov (United States)

    Ren, H. C.; Yan, Q.; Liu, Z. J.; Zuo, Z. Q.; Xu, Q. Q.; Li, F. F.; Song, C.

    2016-11-01

    With the advancement of Aerial Photogrammetry, it appears that to obtain geo-spatial information of high spatial and temporal resolution provides a new technical means for Airborne LIDAR measurement techniques, with unique advantages and broad application prospects. Airborne LIDAR is increasingly becoming a new kind of space for earth observation technology, which is mounted by launching platform for aviation, accepting laser pulses to get high-precision, high-density three-dimensional coordinate point cloud data and intensity information. In this paper, we briefly demonstrates Airborne laser radar systems, and that some errors about Airborne LIDAR data sources are analyzed in detail, so the corresponding methods is put forwarded to avoid or eliminate it. Taking into account the practical application of engineering, some recommendations were developed for these designs, which has crucial theoretical and practical significance in Airborne LIDAR data processing fields.

  16. Experimental Study of a Positron\\\\ Source Using Channeling

    CERN Multimedia

    Gavrykov, V; Kulibaba, V; Baier, V; Beloborodov, K; Bojenok, A; Bukin, A; Burdin, S; Dimova, T; Druzhinin, V; Dubrovin, M; Seredniakov, S; Shary, V; Strakhovenko, V; Keppler, P; Major, J; Bogdanov, A V; Potylitsin, A; Vnoukov, I; Artru, X; Lautesse, P; Poizat, J-C; Remillieux, J

    2002-01-01

    Many simulations have predicted that the yield of positrons, resulting from the interaction of fast electrons in a solid target, increases if the target is a crystal oriented with a major axis parallel to the electron beam. Tests made at Orsay and Tokyo confirmed these expectations. The experiment WA 103 concerns the determination of the main characteristics (emittance, energy spread) of a crystal positron source which could replace advantageously the conventional positron converters foreseen in some linear collider projects. The main element of the set-up is a magnetic spectrometer, using a drift chamber, where the positron trajectories are reconstructed (see Figure 1) A first run has been operated in july 2000 and the first results showed, as expected, a significant enhancement in photon and positron generation along the $$ axis of the tungsten crystal. Indications about a significant increase in the number of soft photons and positrons were also gathered : this point is of importance for the positron colle...

  17. Assessment of the content, structure, and source of soil dissolved organic matter in the coastal wetlands of Jiaozhou Bay, China

    Science.gov (United States)

    Xi, Min; Zi, Yuanyuan; Wang, Qinggai; Wang, Sen; Cui, Guolu; Kong, Fanlong

    2018-02-01

    The contents and the spectral analysis of dissolved organic matter (DOM) in four typical wetlands, such as naked tidal, suaeda salsa, reed and spartina, were conducted to investigate the content, structure, and source of DOM in coastal wetland soil. The soil samples were obtained from Jiaozhou Bay in January, April, July, and October of 2014. Results showed that the DOM contents in soil of four typical wetland were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in horizontal direction, and decreased with the increase of soil depth on vertical section. In addition, the DOM contents changed with the seasons, in order of spring > summer > autumn > winter. The structural characteristics of DOM in Jiaozhou Bay wetland, such as aromaticity, hydrophobicity, molecular weight, polymerization degree of benzene ring carbon frame structure and so on were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in the horizontal direction. On the vertical direction, they showed a decreasing trend with the increase of soil depth. The results of three dimensional fluorescence spectra and fluorescence spectrum parameters (FI, HIX, and BIX) indicated that the DOM in Jiaozhou Bay was mainly derived from the biological activities. The contents and structure of DOM had certain relevance, but the contents and source as well as the structure and source of DOM had no significant correlation. The external pollution including domestic sewage, industrial wastewater, and aquaculture sewage affected the correlation among the content, structure and source of DOM by influencing the percentage of non-fluorescent substance in DOM and disturbing the determination of protein-like fluorescence.

  18. Integrated analysis of multiple data sources reveals modular structure of biological networks

    International Nuclear Information System (INIS)

    Lu Hongchao; Shi Baochen; Wu Gaowei; Zhang Yong; Zhu Xiaopeng; Zhang Zhihua; Liu Changning; Zhao, Yi; Wu Tao; Wang Jie; Chen Runsheng

    2006-01-01

    It has been a challenging task to integrate high-throughput data into investigations of the systematic and dynamic organization of biological networks. Here, we presented a simple hierarchical clustering algorithm that goes a long way to achieve this aim. Our method effectively reveals the modular structure of the yeast protein-protein interaction network and distinguishes protein complexes from functional modules by integrating high-throughput protein-protein interaction data with the added subcellular localization and expression profile data. Furthermore, we take advantage of the detected modules to provide a reliably functional context for the uncharacterized components within modules. On the other hand, the integration of various protein-protein association information makes our method robust to false-positives, especially for derived protein complexes. More importantly, this simple method can be extended naturally to other types of data fusion and provides a framework for the study of more comprehensive properties of the biological network and other forms of complex networks

  19. Bacterial community composition and structure in an Urban River impacted by different pollutant sources.

    Science.gov (United States)

    Ibekwe, A Mark; Ma, Jincai; Murinda, Shelton E

    2016-10-01

    Microbial communities in terrestrial fresh water are diverse and dynamic in composition due to different environmental factors. The goal of this study was to undertake a comprehensive analysis of bacterial composition along different rivers and creeks and correlate these to land-use practices and pollutant sources. Here we used 454 pyrosequencing to determine the total bacterial community composition, and bacterial communities that are potentially of fecal origin, and of relevance to water quality assessment. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity, abundance, and community composition. Detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were used to correlate bacterial composition in streams and creeks to different environmental parameters impacting bacterial communities in the sediment and surface water within the watershed. Bacteria were dominated by the phyla Proteobacteria, Bacteroidetes, Acidobacteria, and Actinobacteria, with Bacteroidetes significantly (PPCoA and DCA showed that bacterial composition in sediment and surface water was significantly different (Pmicrobial community compositions were influenced by several environmental factors, and pH, NO2, and NH4 were the major environmental factors driving FIB in surface water based on CCA analysis, while NO3 was the only factor in sediment. Published by Elsevier B.V.

  20. Forward Modeling of Large-scale Structure: An Open-source Approach with Halotools

    Science.gov (United States)

    Hearin, Andrew P.; Campbell, Duncan; Tollerud, Erik; Behroozi, Peter; Diemer, Benedikt; Goldbaum, Nathan J.; Jennings, Elise; Leauthaud, Alexie; Mao, Yao-Yuan; More, Surhud; Parejko, John; Sinha, Manodeep; Sipöcz, Brigitta; Zentner, Andrew

    2017-11-01

    We present the first stable release of Halotools (v0.2), a community-driven Python package designed to build and test models of the galaxy-halo connection. Halotools provides a modular platform for creating mock universes of galaxies starting from a catalog of dark matter halos obtained from a cosmological simulation. The package supports many of the common forms used to describe galaxy-halo models: the halo occupation distribution, the conditional luminosity function, abundance matching, and alternatives to these models that include effects such as environmental quenching or variable galaxy assembly bias. Satellite galaxies can be modeled to live in subhalos or to follow custom number density profiles within their halos, including spatial and/or velocity bias with respect to the dark matter profile. The package has an optimized toolkit to make mock observations on a synthetic galaxy population—including galaxy clustering, galaxy-galaxy lensing, galaxy group identification, RSD multipoles, void statistics, pairwise velocities and others—allowing direct comparison to observations. Halotools is object-oriented, enabling complex models to be built from a set of simple, interchangeable components, including those of your own creation. Halotools has an automated testing suite and is exhaustively documented on http://halotools.readthedocs.io, which includes quickstart guides, source code notes and a large collection of tutorials. The documentation is effectively an online textbook on how to build and study empirical models of galaxy formation with Python.

  1. Forward Modeling of Large-scale Structure: An Open-source Approach with Halotools

    Energy Technology Data Exchange (ETDEWEB)

    Hearin, Andrew P.; Campbell, Duncan; Tollerud, Erik; Behroozi, Peter; Diemer, Benedikt; Goldbaum, Nathan J.; Jennings, Elise; Leauthaud, Alexie; Mao, Yao-Yuan; More, Surhud; Parejko, John; Sinha, Manodeep; Sipöcz, Brigitta; Zentner, Andrew

    2017-10-18

    We present the first stable release of Halotools (v0.2), a community-driven Python package designed to build and test models of the galaxy-halo connection. Halotools provides a modular platform for creating mock universes of galaxies starting from a catalog of dark matter halos obtained from a cosmological simulation. The package supports many of the common forms used to describe galaxy-halo models: the halo occupation distribution, the conditional luminosity function, abundance matching, and alternatives to these models that include effects such as environmental quenching or variable galaxy assembly bias. Satellite galaxies can be modeled to live in subhalos or to follow custom number density profiles within their halos, including spatial and/or velocity bias with respect to the dark matter profile. The package has an optimized toolkit to make mock observations on a synthetic galaxy population—including galaxy clustering, galaxy–galaxy lensing, galaxy group identification, RSD multipoles, void statistics, pairwise velocities and others—allowing direct comparison to observations. Halotools is object-oriented, enabling complex models to be built from a set of simple, interchangeable components, including those of your own creation. Halotools has an automated testing suite and is exhaustively documented on http://halotools.readthedocs.io, which includes quickstart guides, source code notes and a large collection of tutorials. The documentation is effectively an online textbook on how to build and study empirical models of galaxy formation with Python.

  2. Time-resolved hard x-ray studies using third-generation synchrotron radiation sources (abstract)

    International Nuclear Information System (INIS)

    Mills, D.M.

    1992-01-01

    The third-generation, high-brilliance, synchrotron radiation sources currently under construction will usher in a new era of x-ray research in the physical, chemical, and biological sciences. One of the most exciting areas of experimentation will be the extension of static x-ray scattering and diffraction techniques to the study of transient or time-evolving systems. The high repetition rate, short-pulse duration, high-brilliance, variable spectral bandwidth, and large particle beam energies of these sources make them ideal for hard x-ray, time-resolved studies. The primary focus of this presentation will be on the novel instrumentation required for time-resolved studies such as optics which can increase the flux on the sample or disperse the x-ray beam, detectors and electronics for parallel data collection, and methods for altering the natural time structure of the radiation. This work is supported by the U.S. Department of Energy, BES-Materials Science, under Contract No. W-31-109-ENG-38

  3. Larix decidua Bark as a Source of Phytoconstituents: An LC-MS Study

    Directory of Open Access Journals (Sweden)

    Valeria Baldan

    2017-11-01

    Full Text Available Larix decidua bark is a waste of the timber industry and is widely diffused in Northern Italy. This material can be considered a good source of antioxidants and phytoconstituents with possible use in cosmetic or nutraceutical products. In this study, simple extraction of larch bark was performed using mixtures of ethanol/water. Furthermore, the phytochemical composition of larch bark extract was studied using LC-MSn methods and the main constituents were identified as flavonoids, spiro-polyphenols, and procyanidins. To confirm the identification by LC-MS semi-preparative HPLC was performed in order to isolate the main constituents and verify the structures by 1H-NMR. Antioxidant properties were studied using an in vitro approach combining DPPH assay and LC-MS in order to establish different roles of the various classes of phytochemicasl of the extract. DPPH activity of some of the isolated compounds was also assessed. The overall results indicate this waste material as a good source of antioxidant compounds, mainly procyanidins, whichresulted the most active constituents in the DPPH assay.

  4. Radiofrequency Electromagnetic Radiation and Memory Performance: Sources of Uncertainty in Epidemiological Cohort Studies.

    Science.gov (United States)

    Brzozek, Christopher; Benke, Kurt K; Zeleke, Berihun M; Abramson, Michael J; Benke, Geza

    2018-03-26

    Uncertainty in experimental studies of exposure to radiation from mobile phones has in the past only been framed within the context of statistical variability. It is now becoming more apparent to researchers that epistemic or reducible uncertainties can also affect the total error in results. These uncertainties are derived from a wide range of sources including human error, such as data transcription, model structure, measurement and linguistic errors in communication. The issue of epistemic uncertainty is reviewed and interpreted in the context of the MoRPhEUS, ExPOSURE and HERMES cohort studies which investigate the effect of radiofrequency electromagnetic radiation from mobile phones on memory performance. Research into this field has found inconsistent results due to limitations from a range of epistemic sources. Potential analytic approaches are suggested based on quantification of epistemic error using Monte Carlo simulation. It is recommended that future studies investigating the relationship between radiofrequency electromagnetic radiation and memory performance pay more attention to treatment of epistemic uncertainties as well as further research into improving exposure assessment. Use of directed acyclic graphs is also encouraged to display the assumed covariate relationship.

  5. Radiofrequency Electromagnetic Radiation and Memory Performance: Sources of Uncertainty in Epidemiological Cohort Studies

    Directory of Open Access Journals (Sweden)

    Christopher Brzozek

    2018-03-01

    Full Text Available Uncertainty in experimental studies of exposure to radiation from mobile phones has in the past only been framed within the context of statistical variability. It is now becoming more apparent to researchers that epistemic or reducible uncertainties can also affect the total error in results. These uncertainties are derived from a wide range of sources including human error, such as data transcription, model structure, measurement and linguistic errors in communication. The issue of epistemic uncertainty is reviewed and interpreted in the context of the MoRPhEUS, ExPOSURE and HERMES cohort studies which investigate the effect of radiofrequency electromagnetic radiation from mobile phones on memory performance. Research into this field has found inconsistent results due to limitations from a range of epistemic sources. Potential analytic approaches are suggested based on quantification of epistemic error using Monte Carlo simulation. It is recommended that future studies investigating the relationship between radiofrequency electromagnetic radiation and memory performance pay more attention to treatment of epistemic uncertainties as well as further research into improving exposure assessment. Use of directed acyclic graphs is also encouraged to display the assumed covariate relationship.

  6. Statistical spectroscopic studies in nuclear structure physics

    International Nuclear Information System (INIS)

    Halemane, T.R.

    1979-01-01

    The spectral distribution theory establishes the centroid and width of the energy spectrum as quantities of fundamental importance and gives credence to a geometry associated with averages of the product of pairs of operators acting within a model space. Utilizing this fact and partitioning the model space according to different group symmetries, simple and physically meaningful expansions are obtained for the model interactions. In the process, a global measure for the goodness of group symmetries is also developed. This procedure could eventually lead to a new way of constructing model interactions for nuclear structure studies. Numerical results for six (ds)-shell interactions and for scalar-isospin, configuration-isospin, space symmetry, supermultiplet and SU(e) x SU(4) group structures are presented. The notion of simultaneous propagation of operator averages in the irreps of two or more groups (not necessarily commuting) is also introduced. The non-energy-weighted sum rule (NEWSR) for electric and magnetic multipole excitations in the (ds)-shell nuclei 20 Ne, 24 Mg, 28 Si, 32 S, and 36 Ar are evaluated. A generally applicable procedure for evaluating the eigenvalue bound to the NEWSR is presented and numerical results obtained for the said excitations and nuclei. Comparisons are made with experimental data and shell-model results. Further, a general theory is given for the linear-energy-weighted sum rule (LEWSR). When the Hamiltonian is one-body, this has a very simple form (expressible in terms of occupancies) and amounts to an extension of the Kurath sum rule to other types of excitations and to arbitrary one-body Hamiltonians. Finally, we develop a statistical approach to perturbation theory and inverse-energy-weighted sum rules, and indicate some applications

  7. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    1992-01-01

    The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of 16 O(e,e'p), 12 C(e,e'pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in 12 C(e,e'p 0 ) and 16 O(e,e'p 0 ), comparison of the 12 C(e, e'p 0 ) and 16 O(e,e'p 3 ) reactions, quadrupole strength in the 16 O(e,e'α 0 ) reaction, quadrupole strength in the 12 C(e,e'α) reaction, analysis of the 12 C(e,e'p 1 ) and 16 O(e,e'p 3 ) angular distributions, analysis of the 40 Ca(e,e'x) reaction at low q, analysis of the higher-q 12 C(e,e'x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments)

  8. Harnessing structural darkness in the visible and infrared wavelengths for a new source of light

    KAUST Repository

    Huang, Jianfeng; Liu, Changxu; Zhu, Yihan; Masala, Silvia; Alarousu, Erkki; Han, Yu; Fratalocchi, Andrea

    2015-01-01

    source, which generates monochromatic emission (5 nm wide) without the need for any resonance. This is achieved through the dynamics of light condensation in which all absorbed electromagnetic energy spontaneously generates single-colour energy pulses

  9. Development of a Laser-Powered Dielectric Structure-Based Accelerator as a Stand-Alone Particle Source

    International Nuclear Information System (INIS)

    Yoder, R. B.; Travish, G.; Arab, E. R.; Fong, D.; Hoyer, Z.; Lacroix, U. H.; Vartanian, N.; Rosenzweig, J. B.

    2010-01-01

    An experimental program to develop and build a dielectric-based slab-symmetric structure (the micro-accelerator platform, or MAP) for generating and accelerating low-energy electrons is underway at UCLA and Manhattanville College. This optical acceleration structure is effectively a resonant cavity powered by a side-coupled laser, and has applications as a radiation source for medicine or industry. We present recent experimental and computational results on the accelerator, and progress toward its incorporation into a self-contained particle source. Such a particle source would incorporate a micron-scale electron emitter and a non-relativistic capture region to enable self-injection into the synchronous field within the accelerator. A prototype of the accelerator itself has been constructed from candidate dielectric materials using micromanufacturing techniques; the current status of the testing program is described. A novel electron emitter incorporating pyroelectric crystals with field-enhancing tips has been demonstrated to produce steady currents; the results are dependent on tip geometry, and appear suitable for injection into a microstructure. Extension of the MAP concept to non-relativistic velocities, as in the stand-alone source, requires a tapered structure that gives rise to numerous complications including beam defocusing and manufacturing challenges; approaches for addressing these complications are mentioned.

  10. A comparison study on various low energy sources in interstitial prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Mahdi Bakhshabadi

    2016-02-01

    Full Text Available Purpose: Low energy sources are routinely used in prostate brachytherapy. 125 I is one of the most commonly used sources. Low energy 131 Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125 I, 103 Pd, and 131 Cs sources in interstitial brachytherapy of prostate. Material and methods: ProstaSeed 125 I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103 Pd and 131 Cs were simulated with the same geometry as the ProstaSeed 125 I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results : Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131 Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103 Pd source. Conclusions : The higher initial absolute dose in cGy/(h.U of 131 Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103 Pd source are advantages of this later brachytherapy source. Based on the total dose the 125 I source has advantage over the others due to its longer half-life.

  11. A comparison study on various low energy sources in interstitial prostate brachytherapy.

    Science.gov (United States)

    Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

    2016-02-01

    Low energy sources are routinely used in prostate brachytherapy. (125)I is one of the most commonly used sources. Low energy (131)Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of (125)I, (103)Pd, and (131)Cs sources in interstitial brachytherapy of prostate. ProstaSeed (125)I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of (103)Pd and (131)Cs were simulated with the same geometry as the ProstaSeed (125)I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, (131)Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the (103)Pd source. The higher initial absolute dose in cGy/(h.U) of (131)Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the (103)Pd source are advantages of this later brachytherapy source. Based on the total dose the (125)I source has advantage over the others due to its longer half-life.

  12. Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

    Science.gov (United States)

    Moskal, Aurelie; Pisa, Pedro T; Ferrari, Pietro; Byrnes, Graham; Freisling, Heinz; Boutron-Ruault, Marie-Christine; Cadeau, Claire; Nailler, Laura; Wendt, Andrea; Kühn, Tilman; Boeing, Heiner; Buijsse, Brian; Tjønneland, Anne; Halkjær, Jytte; Dahm, Christina C; Chiuve, Stephanie E; Quirós, Jose R; Buckland, Genevieve; Molina-Montes, Esther; Amiano, Pilar; Huerta Castaño, José M; Gurrea, Aurelio Barricarte; Khaw, Kay-Tee; Lentjes, Marleen A; Key, Timothy J; Romaguera, Dora; Vergnaud, Anne-Claire; Trichopoulou, Antonia; Bamia, Christina; Orfanos, Philippos; Palli, Domenico; Pala, Valeria; Tumino, Rosario; Sacerdote, Carlotta; de Magistris, Maria Santucci; Bueno-de-Mesquita, H Bas; Ocké, Marga C; Beulens, Joline W J; Ericson, Ulrika; Drake, Isabel; Nilsson, Lena M; Winkvist, Anna; Weiderpass, Elisabete; Hjartåker, Anette; Riboli, Elio; Slimani, Nadia

    2014-01-01

    Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses. We identified nutrient patterns from food frequency questionnaires (FFQ) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study and used 24-hour dietary recall (24-HDR) data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA) was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312). Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436) provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC) 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores. The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research opportunities and

  13. Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

    Directory of Open Access Journals (Sweden)

    Aurelie Moskal

    Full Text Available Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses.We identified nutrient patterns from food frequency questionnaires (FFQ in the European Prospective Investigation into Cancer and Nutrition (EPIC Study and used 24-hour dietary recall (24-HDR data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312. Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436 provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores.The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research

  14. A Numerical Study on the Excitation of Guided Waves in Rectangular Plates Using Multiple Point Sources

    Directory of Open Access Journals (Sweden)

    Wenbo Duan

    2017-12-01

    Full Text Available Ultrasonic guided waves are widely used to inspect and monitor the structural integrity of plates and plate-like structures, such as ship hulls and large storage-tank floors. Recently, ultrasonic guided waves have also been used to remove ice and fouling from ship hulls, wind-turbine blades and aeroplane wings. In these applications, the strength of the sound source must be high for scanning a large area, or to break the bond between ice, fouling and plate substrate. More than one transducer may be used to achieve maximum sound power output. However, multiple sources can interact with each other, and form a sound field in the structure with local constructive and destructive regions. Destructive regions are weak regions and shall be avoided. When multiple transducers are used it is important that they are arranged in a particular way so that the desired wave modes can be excited to cover the whole structure. The objective of this paper is to provide a theoretical basis for generating particular wave mode patterns in finite-width rectangular plates whose length is assumed to be infinitely long with respect to its width and thickness. The wave modes have displacements in both width and thickness directions, and are thus different from the classical Lamb-type wave modes. A two-dimensional semi-analytical finite element (SAFE method was used to study dispersion characteristics and mode shapes in the plate up to ultrasonic frequencies. The modal analysis provided information on the generation of modes suitable for a particular application. The number of point sources and direction of loading for the excitation of a few representative modes was investigated. Based on the SAFE analysis, a standard finite element modelling package, Abaqus, was used to excite the designed modes in a three-dimensional plate. The generated wave patterns in Abaqus were then compared with mode shapes predicted in the SAFE model. Good agreement was observed between the

  15. Studies of coal structure using carbene chemistry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The object of this grant was to react coal, derivatized forms of coal, and solvent swelled coal with carbenes (divalent carbon species) under mild conditions. These carbenes were to be prepared by treating the coal with several diazo compounds and then thermally decomposing them at relatively low temperatures (80--130{degree}C). The carbenes were to be chosen to show varying selectively toward aromatic rings containing heteroatom functionalities and toward polynuclear aromatic systems. In some instances, where selectivities toward aromatic and heteroaromatic ring systems were not known, model studies were to be carried out. Because of the generally mild conditions employed and the good selectivity anticipated, and actually observed with one particular system, it was expected that this methodology would provide structural information about the coal, along with data on the extent of occurrence and type of aromatic systems. After carbene reactions, treatment of the coal samples was to include extractions and thermolysis. Physical studies included thermogravimetric analysis, diffuse reflectance FT-IR spectroscopy, NMR ({sup 1}H and {sup 13}C) spectroscopy, gas chromatography, GC/MS and GC/FT-IR. 7 figs., 10 tabs.

  16. Simulation study of dynamo structure in reversed field pinch

    International Nuclear Information System (INIS)

    Nagata, A.; Sato, K.I.; Ashida, H.; Amano, T.

    1992-10-01

    The dynamo structure in the reversed field pinch (RFP) is studied through the nonlinear dynamics of single-helicity mode. Simulation is concentrated upon the physical structure of nonlinear interactions of the plasma flow and magnetic fluctuation. The result indicates that when the initial equilibrium profile is deformed by resistive diffusion, the radial flow is driven near the core of the plasma. As this flow forms a vortex structure and magnetic fluctuation grows radially, the dynamo electric field is spirally induced just inside the reversal surface and then the toroidal flux is increased. This dynamo electric field correlates to nonlinear evolution of the kinetic energy of m=1 mode, and the increase of the toroidal flux is originated in the growth process of the magnetic energy of this mode. Consequently, the RFP configuration can be sustained by the single-helicity evolution of m=1 mode alone, and the electric field induced by the interactions of the toroidal velocity and the radial magnetic field is the most dominant source on the dynamo action. (author)

  17. Experimental study on cesium immobilization in struvite structures.

    Science.gov (United States)

    Wagh, Arun S; Sayenko, S Y; Shkuropatenko, V A; Tarasov, R V; Dykiy, M P; Svitlychniy, Y O; Virych, V D; Ulybkina, Е А

    2016-01-25

    Ceramicrete, a chemically bonded phosphate ceramic, was developed for nuclear waste immobilization and nuclear radiation shielding. Ceramicrete products are fabricated by an acid-base reaction between magnesium oxide and mono potassium phosphate that has a struvite-K mineral structure. In this study, we demonstrate that this crystalline structure is ideal for incorporating radioactive Cs into a Ceramicrete matrix. This is accomplished by partially replacing K by Cs in the struvite-K structure, thus forming struvite-(K, Cs) mineral. X-ray diffraction and thermo-gravimetric analyses are used to confirm such a replacement. The resulting product is non-leachable and stable at high temperatures, and hence it is an ideal matrix for immobilizing Cs found in high-activity nuclear waste streams. The product can also be used for immobilizing secondary waste streams generated during glass vitrification of spent fuel, or the method described in this article can be used as a pretreatment method during glass vitrification of high level radioactive waste streams. Furthermore, it suggests a method of producing safe commercial radioactive Cs sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. A study of human DPOAE fine structure

    DEFF Research Database (Denmark)

    Reuter, Karen; Hammershøi, Dorte

    height and ripple prevalence. Temporary changes of the DPOAE fine structure are analyzed by measuring DPOAE both before and after exposing some of the subjects to an intense sound. The characteristic patterns of fine structure can be found in the DPOAE of all subjects, though they are individual and vary...... fine structures are obtained from 74 normalhearing humans using primary levels of L1/L2=65/45 dB. The subjects belong to groups with different age and exposure history. A classification algorithm is developed, which quantifies the fine structure by the parameters ripple place, ripple width, ripple...

  19. Isotope studies of UK tufa deposits and associated source waters

    International Nuclear Information System (INIS)

    Thorpe, P.M.

    1981-12-01

    Tufa is a secondary deposit of calcium carbonate precipitated from springs and streams. Previous attempts to date tufa deposits directly with 14 C have had limited success. The major problem is to quantify the amount of carbon incorporated in tufa, derived from the dissolution of carbonate bedrock, essentially free of 14 C. The isotopic composition of tufa-depositing streamwaters is similar to that of water recharging aquifers. The 14 C levels of recent tufa layers, at three sites, were similar to those of the source waters. 14 C dates from tufa at these sites suggested a Postglacial origin when corrected for bedrock carbon dilution of 16 to 24%. This dilution was overestimated by consideration of carbon mass balance using characteristic stable carbon isotope compositions (delta 13 C) for the biogenic and bedrock components. This method of correction is often applied to 14 C dates from groundwaters. The carbon isotope composition of spring waters supplying the tufa-depositing streams was realistically explained by a two stage process of carbonate dissolution under open and then closed conditions with respect to gaseous carbon dioxide. Seasonal variations in the 14 C and delta 13 C composition of stream and spring waters, downstream increases in 14 C and delta 13 C and seasonal variations in the oxygen and hydrogen isotopic composition of rainfall are explained. (author)

  20. COMPARATIVE STUDY OF LUNAR ROUGHNESS FROM MULTI - SOURCE DATA

    Directory of Open Access Journals (Sweden)

    Y. Lou

    2017-07-01

    Full Text Available The lunar terrain can show its collision and volcanic history. The lunar surface roughness can give a deep indication of the effects of lunar surface magma, sedimentation and uplift. This paper aims to get different information from the roughness through different data sources. Besides introducing the classical Root-mean-square height method and Morphological Surface Roughness (MSR algorithm, this paper takes the area of the Jurassic mountain uplift in the Sinus Iridum and the Plato Crater area as experimental areas. And then make the comparison and contrast of the lunar roughness derived from LRO's DEM and CE-2 DOM. The experimental results show that the roughness obtained by the traditional roughness calculation method reflect the ups and downs of the topography, while the results obtained by morphological surface roughness algorithm show the smoothness of the lunar surface. So, we can first use the surface fluctuation situation derived from RMSH to select the landing area range which ensures the lands are gentle. Then the morphological results determine whether the landing area is suitable for the detector walking and observing. The results obtained at two different scales provide a more complete evaluation system for selecting the landing site of the lunar probe.

  1. Linac Coherent Light Source (LCLS) design study report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The Stanford Linear Accelerator Center (SLAC), in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the self-amplified spontaneous emission (SASE) mode in the wavelength range 1.5--15 {angstrom}. This FEL, called Linac Coherent Light Source (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. In this report, the Design Team has established performance parameters for all the major components of the LCLS and developed a layout of the entire system. Chapter 1 is the Executive Summary. Chapter 2 (Overview) provides a brief description of each of the major sections of the LCLS, from the rf photocathode gun, through the experimental stations and electron beam dump. Chapter 3 describes the scientific case for the LCLS. Chapter 4 provides a review of the principles of the FEL physics that the LCLS is based on, and Chapter 5 discusses the choice of the system's physical parameters. Chapters 6 through 10 describe in detail each major element of the system. Chapters 11 through 13 respectively cover undulator controls, mechanical alignment, and radiation issues.

  2. Dynamic sheath studies in plasma source ion implantation

    International Nuclear Information System (INIS)

    Schever, J.T.; Shamim, M.; Conrad, J.R.

    1990-01-01

    Plasma Source Ion Implantation (PSII) is a non-line-of-sight method for materials processing in which a target is immersed in a plasma and pulse biased to a high negative voltage (∼ 50 kV). A model of the dynamic sheath which forms under these conditions has been developed and applied to planar, cylindrical and spherical geometries. This model assumes that the transient sheath obeys the Child-Langmuir law for space charge limited emission at each instant during the propagation. Ions uncovered by the propagating sheath edge supply the space charge limited current. This yields an equation relating sheath edge velocity to position, which can be integrated to obtain the sheath edge position as a function of time. The same procedure used in cylindrical and spherical geometry results in a similar equation which must be integrated numerically. Comparison of results of experimental measurements, our model and simulation will be presented for the dynamic sheath edge position and target current waveform. Measurements of implanted dose uniformity of wedge shaped targets are also presented

  3. Microjet burners for molecular-beam sources and combustion studies

    Science.gov (United States)

    Groeger, Wolfgang; Fenn, John B.

    1988-09-01

    A novel microjet burner is described in which combustion is stabilized by a hot wall. The scale is so small that the entire burner flow can be passed through a nozzle only 0.2 mm or less in diameter into an evacuated chamber to form a supersonic free jet with expansion so rapid that all collisional processes in the jet gas are frozen in a microsecond or less. This burner can be used to provide high-temperature source gas for free jet expansion to produce intense beams of internally hot molecules. A more immediate use would seem to be in the analysis of combustion products and perhaps intermediates by various kinds of spectroscopies without some of the perturbation effects encountered in probe sampling of flames and other types of combustion devices. As an example of the latter application of this new tool, we present infrared emission spectra for jet gas obtained from the combustion of oxygen-hydrocarbon mixtures both fuel-rich and fuel-lean operation. In addition, we show results obtained by mass spectrometric analysis of the combustion products.

  4. Linac Coherent Light Source (LCLS) design study report

    International Nuclear Information System (INIS)

    1998-04-01

    The Stanford Linear Accelerator Center (SLAC), in collaboration with Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and the University of California at Los Angeles, is proposing to build a Free-Electron-Laser (FEL) R and D facility operating in the self-amplified spontaneous emission (SASE) mode in the wavelength range 1.5--15 angstrom. This FEL, called Linac Coherent Light Source (LCLS), utilizes the SLAC linac and produces sub-picosecond pulses of short wavelength x-rays with very high peak brightness and full transverse coherence. In this report, the Design Team has established performance parameters for all the major components of the LCLS and developed a layout of the entire system. Chapter 1 is the Executive Summary. Chapter 2 (Overview) provides a brief description of each of the major sections of the LCLS, from the rf photocathode gun, through the experimental stations and electron beam dump. Chapter 3 describes the scientific case for the LCLS. Chapter 4 provides a review of the principles of the FEL physics that the LCLS is based on, and Chapter 5 discusses the choice of the system's physical parameters. Chapters 6 through 10 describe in detail each major element of the system. Chapters 11 through 13 respectively cover undulator controls, mechanical alignment, and radiation issues

  5. XTALOPT: An open-source evolutionary algorithm for crystal structure prediction

    Science.gov (United States)

    Lonie, David C.; Zurek, Eva

    2011-02-01

    The implementation and testing of XTALOPT, an evolutionary algorithm for crystal structure prediction, is outlined. We present our new periodic displacement (ripple) operator which is ideally suited to extended systems. It is demonstrated that hybrid operators, which combine two pure operators, reduce the number of duplicate structures in the search. This allows for better exploration of the potential energy surface of the system in question, while simultaneously zooming in on the most promising regions. A continuous workflow, which makes better use of computational resources as compared to traditional generation based algorithms, is employed. Various parameters in XTALOPT are optimized using a novel benchmarking scheme. XTALOPT is available under the GNU Public License, has been interfaced with various codes commonly used to study extended systems, and has an easy to use, intuitive graphical interface. Program summaryProgram title:XTALOPT Catalogue identifier: AEGX_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEGX_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL v2.1 or later [1] No. of lines in distributed program, including test data, etc.: 36 849 No. of bytes in distributed program, including test data, etc.: 1 149 399 Distribution format: tar.gz Programming language: C++ Computer: PCs, workstations, or clusters Operating system: Linux Classification: 7.7 External routines: QT [2], OpenBabel [3], AVOGADRO [4], SPGLIB [8] and one of: VASP [5], PWSCF [6], GULP [7]. Nature of problem: Predicting the crystal structure of a system from its stoichiometry alone remains a grand challenge in computational materials science, chemistry, and physics. Solution method: Evolutionary algorithms are stochastic search techniques which use concepts from biological evolution in order to locate the global minimum on their potential energy surface. Our evolutionary algorithm, XTALOPT, is freely

  6. Protein structure similarity clustering (PSSC) and natural product structure as inspiration sources for drug development and chemical genomics

    NARCIS (Netherlands)

    Dekker, Frank J; Koch, Marcus A; Waldmann, Herbert; Dekker, Frans

    Finding small molecules that modulate protein function is of primary importance in drug development and in the emerging field of chemical genomics. To facilitate the identification of such molecules, we developed a novel strategy making use of structural conservatism found in protein domain

  7. An overview of studies in structural mechanics

    International Nuclear Information System (INIS)

    Guilbaud, D.; Blay, N.; Broc, D.; Chaudat, T.; Feau, C.; Sollogoub, P.; Wang, F.; Baj, F.; Bung, H.; Combescure, D.; Lepareux, M.; Phalippou, C.; Bentejac, F.; Hourdequin, N.; Laporte, T.; Millard, A.; Nicolas, L.; Chapuliot, S.; Fissolo, A.; Gourdin, C.; Kayser, Y.; Marie, S.; Reytier, M.; Yuritzinn, T.; Magnaud, J.P.; Braillard, O.; Collard, B.; Gobillot, G.; Mori, V.; Vallory, J.; Pascal-Ribot, S.; Pluyette, E.; Berton, M.N.; Cabrillat, M.T.; Lejeail, Y.

    2006-01-01

    The present report gives an overview of the ongoing research programmes in structural mechanics at CEA/DEN. On the whole, these contributions are well representative of the research work performed, more oriented by engineering concerns than driven by pure academic goals. Fundamentally, the developed knowledge results in new methods and improved engineering and computational tools that can be used for CEA needs and transferred to industrial clients and partners. Basic research is carried out with the help of university laboratories, what allows CEA teams to identify the underlying problems and to address them in an adequate manner. Confrontation with other viewpoints and backgrounds takes place in international cooperative actions conducted with academic or industrial research centres, often giving rise to benchmarks. Due to the wide range of problems submitted to CEA/DEN, the R and D topics are numerous and the effort devoted to each of them is limited and sometimes not continuous. Basic research is of course more limited and needs thorough preparation in order to ensure that the key questions, which lock the progress, are really addressed.. Before to end, it is worth mentioning two original research actions which have begun: -) identification of medium state and representation of its variability by a probabilistic approach: this original approach couples inverse method an probability to obtain non directly measurable value from global effect on structures (for example deduce damage from the displacement of a loaded beam) and should be applied to non destructive identification of present state of nuclear reactor enclosures, -) a program of numerical simulations of fluid-elastic instability of a tube bundle submitted to cross flow has been initiated with an Arbitrary Lagrangian Eulerian -ALE- finite element method to obtain a better knowledge and understanding of the phenomenon. From these simulations, the evolutions of pressure and velocity fields close to fluid

  8. The 1946 Unimak Tsunami Earthquake Area: revised tectonic structure in reprocessed seismic images and a suspect near field tsunami source

    Science.gov (United States)

    Miller, John J.; von Huene, Roland E.; Ryan, Holly F.

    2014-01-01

    In 1946 at Unimak Pass, Alaska, a tsunami destroyed the lighthouse at Scotch Cap, Unimak Island, took 159 lives on the Hawaiian Islands, damaged island coastal facilities across the south Pacific, and destroyed a hut in Antarctica. The tsunami magnitude of 9.3 is comparable to the magnitude 9.1 tsunami that devastated the Tohoku coast of Japan in 2011. Both causative earthquake epicenters occurred in shallow reaches of the subduction zone. Contractile tectonism along the Alaska margin presumably generated the far-field tsunami by producing a seafloor elevation change. However, the Scotch Cap lighthouse was destroyed by a near-field tsunami that was probably generated by a coeval large undersea landslide, yet bathymetric surveys showed no fresh large landslide scar. We investigated this problem by reprocessing five seismic lines, presented here as high-resolution graphic images, both uninterpreted and interpreted, and available for the reader to download. In addition, the processed seismic data for each line are available for download as seismic industry-standard SEG-Y files. One line, processed through prestack depth migration, crosses a 10 × 15 kilometer and 800-meter-high hill presumed previously to be basement, but that instead is composed of stratified rock superimposed on the slope sediment. This image and multibeam bathymetry illustrate a slide block that could have sourced the 1946 near-field tsunami because it is positioned within a distance determined by the time between earthquake shaking and the tsunami arrival at Scotch Cap and is consistent with the local extent of high runup of 42 meters along the adjacent Alaskan coast. The Unimak/Scotch Cap margin is structurally similar to the 2011 Tohoku tsunamigenic margin where a large landslide at the trench, coeval with the Tohoku earthquake, has been documented. Further study can improve our understanding of tsunami sources along Alaska’s erosional margins.

  9. Space-time structure of neutron and X-ray sources in a plasma focus

    International Nuclear Information System (INIS)

    Bostick, W.H.; Nardi, V.; Prior, W.

    1977-01-01

    Systematic measurements with paraffin collimators of the neutron emission intensity have been completed on a plasma focus with a 15-20 kV capacitor bank (hollow centre electrode; discharge period T approximately 8 μs; D 2 filling at 4-8 torr). The space resolution was 1 cm or better. These data indicate that at least 70% of the total neutron yield originates within hot-plasma regions where electron beams and high-energy D beams (approximately > 0.1-1 MeV) are produced. The neutron source is composed of several (approximately > 1-10) space-localized sources of different intensity, each with a duration approximately less than 5 ns (FWHM). Localized neutron sources and hard (approximately > 100 keV) X-ray sources have the same time multiplicity and are usually distributed in two groups over a time interval 40-400 ns long. By the mode of operation used by the authors one group of localized sources (Burst II) is observed 200-400 ns after the other group (Burst I) and its space distribution is broader than for Burst I. The maximum intensity of a localized source of neutrons in Burst I is much higher than the maximum intensity in Burst II. Secondary reactions T(D,n) 4 He (from the tritium produced only by primary reactions in the same discharge; no tritium was used in filling the discharge chamber) are observed in a time coincidence with the strongest D-D neutron pulse of Burst I. The neutron signal from a localized source with high intensity has a relatively long tail of small amplitude (area tail approximately less than 0.2 X area peak). This tail can be generated by the D-D reactions of the unconfined part of an ion beam in the cold plasma. Complete elimination of scattered neutrons on the detector was achieved in these measurements. (author)

  10. Monte Carlo simulations and radiation dosimetry measurements of 142Pr capillary tube-based radioactive implant (CTRI). A new structure for brachytherapy sources

    International Nuclear Information System (INIS)

    Bakht, M.K.; Haddadi, A.; Sadeghi, M.; Ahmadi, S.J.; Sadjadi, S.S.; Tenreiro, C.

    2013-01-01

    Previously, a promising β - -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142 Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of β - -emitting radioisotopes such as 142 Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141 Pr(n, γ) 142 Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic radiochromic film. In addition, the dose rate distribution of 142 Pr CTRI was calculated by modeling 142 Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142 Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142 Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142 Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142 Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142 Pr glass seed. (author)

  11. Progress report on nuclear structure studies

    International Nuclear Information System (INIS)

    Walters, W.B.

    1991-01-01

    In this report, new results are reported for the decay and nuclear orientation of 114,116 I and 114 Sb as well as data for the structure of daughter nuclides 114,116 Te. New results for IBM-2 calculations for the structure of 126 Xe are also reported. 6 figs., 5 tabs

  12. Comparative study of surrogate models for groundwater contamination source identification at DNAPL-contaminated sites

    Science.gov (United States)

    Hou, Zeyu; Lu, Wenxi

    2018-05-01

    Knowledge of groundwater contamination sources is critical for effectively protecting groundwater resources, estimating risks, mitigating disaster, and designing remediation strategies. Many methods for groundwater contamination source identification (GCSI) have been developed in recent years, including the simulation-optimization technique. This study proposes utilizing a support vector regression (SVR) model and a kernel extreme learning machine (KELM) model to enrich the content of the surrogate model. The surrogate model was itself key in replacing the simulation model, reducing the huge computational burden of iterations in the simulation-optimization technique to solve GCSI problems, especially in GCSI problems of aquifers contaminated by dense nonaqueous phase liquids (DNAPLs). A comparative study between the Kriging, SVR, and KELM models is reported. Additionally, there is analysis of the influence of parameter optimization and the structure of the training sample dataset on the approximation accuracy of the surrogate model. It was found that the KELM model was the most accurate surrogate model, and its performance was significantly improved after parameter optimization. The approximation accuracy of the surrogate model to the simulation model did not always improve with increasing numbers of training samples. Using the appropriate number of training samples was critical for improving the performance of the surrogate model and avoiding unnecessary computational workload. It was concluded that the KELM model developed in this work could reasonably predict system responses in given operation conditions. Replacing the simulation model with a KELM model considerably reduced the computational burden of the simulation-optimization process and also maintained high computation accuracy.

  13. Comparison of silver and molybdenum microfocus X-ray sources for single-crystal structure determination.

    Science.gov (United States)

    Krause, Lennard; Herbst-Irmer, Regine; Sheldrick, George M; Stalke, Dietmar

    2015-02-01

    The quality of diffraction data obtained using silver and molybdenum microsources has been compared for six model compounds with a wide range of absorption factors. The experiments were performed on two 30 W air-cooled Incoatec IµS microfocus sources with multilayer optics mounted on a Bruker D8 goniometer with a SMART APEX II CCD detector. All data were analysed, processed and refined using standard Bruker software. The results show that Ag  K α radiation can be beneficial when heavy elements are involved. A numerical absorption correction based on the positions and indices of the crystal faces is shown to be of limited use for the highly focused microsource beams, presumably because the assumption that the crystal is completely bathed in a (top-hat profile) beam of uniform intensity is no longer valid. Fortunately the empirical corrections implemented in SADABS , although originally intended as a correction for absorption, also correct rather well for the variations in the effective volume of the crystal irradiated. In three of the cases studied (two Ag and one Mo) the final SHELXL R 1 against all data after application of empirical corrections implemented in SADABS was below 1%. Since such corrections are designed to optimize the agreement of the intensities of equivalent reflections with different paths through the crystal but the same Bragg 2θ angles, a further correction is required for the 2θ dependence of the absorption. For this, SADABS uses the transmission factor of a spherical crystal with a user-defined value of μ r (where μ is the linear absorption coefficient and r is the effective radius of the crystal); the best results are obtained when r is biased towards the smallest crystal dimension. The results presented here suggest that the IUCr publication requirement that a numerical absorption correction must be applied for strongly absorbing crystals is in need of revision.

  14. Effect of calcium source on structure and properties of sol-gel derived bioactive glasses.

    Science.gov (United States)

    Yu, Bobo; Turdean-Ionescu, Claudia A; Martin, Richard A; Newport, Robert J; Hanna, John V; Smith, Mark E; Jones, Julian R

    2012-12-18

    The aim was to determine the most effective calcium precursor for synthesis of sol-gel hybrids and for improving homogeneity of sol-gel bioactive glasses. Sol-gel derived bioactive calcium silicate glasses are one of the most promising materials for bone regeneration. Inorganic/organic hybrid materials, which are synthesized by incorporating a polymer into the sol-gel process, have also recently been produced to improve toughness. Calcium nitrate is conventionally used as the calcium source, but it has several disadvantages. Calcium nitrate causes inhomogeneity by forming calcium-rich regions, and it requires high temperature treatment (>400 °C) for calcium to be incorporated into the silicate network. Nitrates are also toxic and need to be burnt off. Calcium nitrate therefore cannot be used in the synthesis of hybrids as the highest temperature used in the process is typically 40-60 °C. Therefore, a different precursor is needed that can incorporate calcium into the silica network and enhance the homogeneity of the glasses at low (room) temperature. In this work, calcium methoxyethoxide (CME) was used to synthesize sol-gel bioactive glasses with a range of final processing temperatures from 60 to 800 °C. Comparison is made between the use of CME and calcium chloride and calcium nitrate. Using advanced probe techniques, the temperature at which Ca is incorporated into the network was identified for 70S30C (70 mol % SiO(2), 30 mol % CaO) for each of the calcium precursors. When CaCl(2) was used, the Ca did not seem to enter the network at any of the temperatures used. In contrast, Ca from CME entered the silica network at room temperature, as confirmed by X-ray diffraction, (29)Si magic angle spinning nuclear magnetic resonance spectroscopy, and dissolution studies. CME should be used in preference to calcium salts for hybrid synthesis and may improve homogeneity of sol-gel glasses.

  15. Band structure studies of actinide systems

    International Nuclear Information System (INIS)

    Koelling, D.D.

    1976-01-01

    The nature of the f-orbitals in an actinide system plays a crucial role in determining the electronic properties. It has long been realized that when the actinide separation is small enough for the f-orbitals to interact directly, the system will exhibit itinerant electron properties: an absence of local moment due to the f-orbitals and sometimes even superconductivity. However, a number of systems with the larger actinide separation that should imply local moment behavior also exhibit intinerant properties. Such systems (URh 3 , UIr 3 , UGe 3 , UC) were examined to learn something about the other f-interactions. A preliminary observation made is that there is apparently a very large and ansiotropic mass enhancement in these systems. There is very good reason to believe that this is not solely due to large electron--electron correlations but to a large electron--phonon interaction as well. These features of the ''non-magnetic'', large actinide separation systems are discussed in light of our results to date. Finally, the results of some recent molecular calculations on actinide hexafluorides are used to illustrate the shielding effects on the intra-atomic Coulomb term U/sub f-f/ which would appear in any attempt to study the formation of local moments. As one becomes interested in materials for which a band structure is no longer an adequate model, this screened U/sub ff/ is the significant parameter and efforts must be made to evaluate it in solid state systems

  16. Research Sources and Microforms in Black Studies: An Annotated Bibliography.

    Science.gov (United States)

    Ridinger, Robert B. Marks

    1985-01-01

    Analyzes 93 reference works and 23 microform collections concerning the Black American experience in 13 subject areas of the social sciences (anthropology, biography, race relations and civil rights, the Black church, communication studies, economics, education, dance, genealogy, Black history, sports, women's studies, and literature and language)…

  17. Evaluation of the drain—source voltage effect on AlGaAs/InGaAs PHEMTs thermal resistance by the structure function method

    International Nuclear Information System (INIS)

    Ma Lin; Feng Shiwei; Zhang Yamin; Deng Bing; Yue Yuan

    2014-01-01

    The effect of drain—source voltage on AlGaAs/InGaAs PHEMTs thermal resistance is studied by experimental measuring and simulation. The result shows that AlGaAs/InGaAs PHEMTs thermal resistance presents a downward trend under the same power dissipation when the drain—source voltage (V DS ) is decreased. Moreover, the relatively low V DS and large drain—source current (I DS ) result in a lower thermal resistance. The chip-level and package-level thermal resistance have been extracted by the structure function method. The simulation result indicated that the high electric field occurs at the gate contact where the temperature rise occurs. A relatively low V DS leads to a relatively low electric field, which leads to the decline of the thermal resistance. (semiconductor devices)

  18. Synchrotron X-Ray Microdiffraction Studies of Electromigration in Interconnect lines at the Advanced Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Nobumichi; Chen, Kai; Kunz, Martin

    2009-12-01

    Synchrotron polychromatic X-ray microdiffraction is a particularly suitable technique to study in situ the effect of electromigration in metal interconnects as add spatial resolution to grain orientation and strain sensitivity. This technique has been extensively used at the Advanced Light Source to monitor changes in aluminum and copper interconnect test structures while high-density current is passed into them during accelerated tests at elevated temperature. One of the principal findings is the observation of electromigration-induced plasticity in the metal lines that appear during the very early stages of electromigration. In some of the lines, high density of geometrically necessary dislocation are formed leading to additional diffusion paths causing an enhancement of electromigration effect at test temperature.

  19. Structural Studies of Biomass Degrading Enzyme Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lunin, Vladimir V.; Alahuhta, Markus; Brunecky, Roman; Donohoe, Bryon; Xu, Qi; Bomble, Yannick J.; Himmel, Michael E.

    2014-08-05

    Renewable energy today comprises wind, photovoltaics, geothermal, and biofuels. Biomass is the leading source of renewable, sustainable energy used for the production of liquid transportation fuels. While the focus is shifting today from the ethanol towards next generation or advanced biofuels the real challenge however remains the same: reducing the recalcitrance of biomass to deconstruction, which yields the sugars needed for further processing.

  20. Source identification in acoustics and structural mechanics using Sierra/SD.

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Timothy Francis; Aquino, Wilkins [Duke University Durham, NC; Ross, Michael

    2013-03-01

    In this report we derive both time and frequency-domain methods for inverse identification of sources in elastodynamics and acoustics. The inverse/design problem is cast in a PDE-constrained optimization framework with efficient computation of gradients using the adjoint method. The implementation of source inversion in Sierra/SD is described, and results from both time and frequency domain source inversion are compared to actual experimental data for a weapon store used in captive carry on a military aircraft. The inverse methodology is advantageous in that it provides a method for creating ground based acoustic and vibration tests that can reduce the actual number of flight tests, and thus, saving costs and time for the program.

  1. Far-infrared observations of Sagittarius B2 - reconsideration of source structure

    International Nuclear Information System (INIS)

    Thronson, H.A. Jr.; Harper, D.A.; Yerkes Observatory, Williams Bay, WI)

    1986-01-01

    New moderate-angular-resolution far-infrared observations of the Sagittarius B2 star-forming region are presented, discussed, and compared with recent radio molecular and continuum observations of this source. In contrast to previous analyses, its far-infrared spectrum is interpreted as the result of a massive frigid cloud overlying a more-or-less normal infrared source, a natural explanation for the object's previously-noted peculiarities. The characteristics derived for the obscuring cloud are similar to those found for the W51 MAIN object. Both sources have high sub-millimeter surface brightness, a high ratio of sub-millimeter to far-infrared flux, and numerous regions of molecular maser emission. 28 references

  2. Emittance study of a 28 GHz electron cyclotron resonance ion source for the Rare Isotope Science Project superconducting linear accelerator.

    Science.gov (United States)

    Park, Bum-Sik; Hong, In-Seok; Jang, Ji-Ho; Jin, Hyunchang; Choi, Sukjin; Kim, Yonghwan

    2016-02-01

    A 28 GHz electron cyclotron resonance (ECR) ion source is being developed for use as an injector for the superconducting linear accelerator of the Rare Isotope Science Project. Beam extraction from the ECR ion source has been simulated using the KOBRA3-INP software. The simulation software can calculate charged particle trajectories in three dimensional complex magnetic field structures, which in this case are formed by the arrangement of five superconducting magnets. In this study, the beam emittance is simulated to understand the effects of plasma potential, mass-to-charge ratio, and spatial distribution. The results of these simulations and their comparison to experimental results are presented in this paper.

  3. The 2012 Ferrara seismic sequence: Regional crustal structure, earthquake sources, and seismic hazard

    Science.gov (United States)

    Malagnini, Luca; Herrmann, Robert B.; Munafò, Irene; Buttinelli, Mauro; Anselmi, Mario; Akinci, Aybige; Boschi, E.

    2012-10-01

    Inadequate seismic design codes can be dangerous, particularly when they underestimate the true hazard. In this study we use data from a sequence of moderate-sized earthquakes in northeast Italy to validate and test a regional wave propagation model which, in turn, is used to understand some weaknesses of the current design spectra. Our velocity model, while regionalized and somewhat ad hoc, is consistent with geophysical observations and the local geology. In the 0.02-0.1 Hz band, this model is validated by using it to calculate moment tensor solutions of 20 earthquakes (5.6 ≥ MW ≥ 3.2) in the 2012 Ferrara, Italy, seismic sequence. The seismic spectra observed for the relatively small main shock significantly exceeded the design spectra to be used in the area for critical structures. Observations and synthetics reveal that the ground motions are dominated by long-duration surface waves, which, apparently, the design codes do not adequately anticipate. In light of our results, the present seismic hazard assessment in the entire Pianura Padana, including the city of Milan, needs to be re-evaluated.

  4. A compact hard X-ray source for medical imaging and biomolecular studies

    International Nuclear Information System (INIS)

    Cline, D.B.; Green, M.A.; Kolonko, J.

    1995-01-01

    There are a large number of synchrotron light sources in the world. However, these sources are designed for physics, chemistry, and engineering studies. To our knowledge, none have been optimized for either medical imaging or biomolecular studies. There are special needs for these applications. We present here a preliminary design of a very compact source, small enough for a hospital or a biomolecular laboratory, that is suitable for these applications. (orig.)

  5. Fusing Open Source Intelligence and Handheld Situational Awareness - Benghazi Case Study

    Science.gov (United States)

    2014-10-01

    1 DM-0001694 Fusing Open Source Intelligence and Handheld Situational Awareness Benghazi Case Study Jeff Boleng, PhD Marc Novakouski Gene...command and control element at the CIA compound that would have been monitoring OSINT and other sources of intelligence before the attack and... Source Intelligence and Handheld Situational Awareness - Benghazi Case Study 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  6. Electronic structure studies of fullerites and fullerides

    International Nuclear Information System (INIS)

    Merkel, M.; Sohmen, E.; Masaki, A.; Romberg, H.; Alexander, M.; Knupfer, M.; Golden, M.S.; Adelmann, P.; Renker, B.; Fink, J.

    1993-01-01

    The electronic structure of fullerites and fullerides has been investigated by high-resolution photoemission and by high-energy electron energy-loss spectroscopy in transmission. Information on the occupied Π and σ bands, on the unoccupied Π * and σ * bands, and on the joint density of states has been obtained. In particular, we report on the changes of the electronic structure of fullerides as a function of dopant concentration. (orig.)

  7. Status of the dibaryon structure studies

    International Nuclear Information System (INIS)

    Willis, N.; Comets, M.P.; Le Bornec, Y.; Loireleux, E.; Tatischeff, B.

    1989-01-01

    The results of recently performed experiments on the B=2 structures concerning the 0,1 and 2 isospin different states are presented. Experimental data and theoretical models are considered. In the T=1 channel, the existence of narrow states, above the πNN threshold, is established. The results from T=0.2 channels are quite difficult to analyse. Present calculations do not allow the prediction of which of the observables are affected by such structures [fr

  8. Research activities on structure materials of spallation neutron source at SINQ

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, G.S.; Dai, Y. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    With the growing interests on powerful spallation neutron sources, especially with liquid metal targets, and accelerator driven energy systems, spallation materials science and technology have been received wide attention. At SINQ, material research activities are focused on: a) liquid metal corrosion; b) radiation damage; and c) interaction of corrosion and radiation damage. (author) 1 fig., refs.

  9. European database on indoor air pollution sources in buildings: Current status of database structure and software

    NARCIS (Netherlands)

    Molina, J.L.; Clausen, G.H.; Saarela, K.; Plokker, W.; Bluyssen, P.M.; Bishop, W.; Oliveira Fernandes, E. de

    1996-01-01

    the European Joule II Project European Data Base for Indoor Air Pollution Sources in Buildings. The aim of the project is to produce a tool which would be used by designers to take into account the actual pollution of the air from the building elements and ventilation and air conditioning system

  10. Probabilistic M/EEG source imaging from sparse spatio-temporal event structure

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Attias, Hagai T.; Wipf, David

    While MEG and EEG source imaging methods have to tackle a severely ill-posed problem their success can be stated as their ability to constrain the solutions using appropriate priors. In this paper we propose a hierarchical Bayesian model facilitating spatio-temporal patterns through the use of bo...

  11. A monolithic relativistic electron beam source based on a dielectric laser accelerator structure

    International Nuclear Information System (INIS)

    McNeur, Josh; Carranza, Nestor; Travish, Gil; Yin Hairong; Yoder, Rodney

    2012-01-01

    Work towards a monolithic device capable of producing relativistic particle beams within a cubic-centimeter is detailed. We will discuss the Micro-Accelerator Platform (MAP), an optical laser powered dielectric accelerator as the main building block of this chip-scale source along with a field enhanced emitter and a region for sub-relativistic acceleration.

  12. Integrated source and channel encoded digital communication system design study

    Science.gov (United States)

    Alem, W. K.; Huth, G. K.; Simon, M. K.

    1978-01-01

    The particular Ku-band carrier, PN despreading, and symbol synchronization strategies, which were selected for implementation in the Ku-band transponder aboard the orbiter, were assessed and evaluated from a systems performance viewpoint, verifying that system specifications were met. A study was performed of the design and implementation of tracking techniques which are suitable for incorporation into the Orbiter Ku-band communication system. Emphasis was placed on maximizing tracking accuracy and communication system flexibility while minimizing cost, weight, and system complexity of Orbiter and ground systems hardware. The payload communication study assessed the design and performance of the forward link and return link bent-pipe relay modes for attached and detached payloads. As part of this study, a design for a forward link bent-pipe was proposed which employs a residual carrier but which is tracked by the existing Costas loop.

  13. Studies on characteristics of water sources around Kaiga project area

    International Nuclear Information System (INIS)

    Prakash, T.R.; Krishna Bhat, D.; Thimme Gowda, B.; Sherigara, B.S.; Abdul Khadar, A.M.

    1995-01-01

    A systematic and detailed study of characteristics of ground water, Kali river water and rain water samples around Kaiga project area has been undertaken. The analysis of a large number of parameters revealed that the ground waters and Kali river water are of calcium-bicarbonate type as indicated by Romani's modified Hill Piper diagram. The ionic impurities in ground waters and Kali river water are well within the Indian Drinking Water Specifications. The results obtained would serve as base line data for future impact studies. (author). 6 refs., 1 tab

  14. Spatial variation of ground motion in a regional crystal structure using 3-d propagator matrix method and Haskell source model

    International Nuclear Information System (INIS)

    Jaekwan Kim; Jhinwung Kim; Koh, H.M.; Kwon, K.

    1993-01-01

    Variation of seismic wave field in a multi-layered attenuating elastic half space is studied by the propagator matrix method and a point source model with the fault slip function of Haskell type. Accelerations, displacements and their frequency contents due to a vertical dip-slip point source buried in the underlain half space are presented. Also included are responses of the same layered half space model to the plane wave obliquely incident from the half space for the purpose of comparison with those due to a dip-slip point source. (author)

  15. T Plant source aggregate area management study report

    International Nuclear Information System (INIS)

    1992-11-01

    The US Department of Energy (DOE) Hanford Site in Washington State is organized into numerically designated operational areas including the 100, 200, 300, 400, 600, and 1100 Areas. The US Environmental Protection Agency (EPA), in November 1989, included the 200 Areas of the Hanford Site on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980. Inclusion on the NPL initiates the Remedial Investigation (RI) and Feasibility Study (FS) process for characterizing the nature and extent of contamination, assessing risks to human health and the environment, and selection of remedial actions. This report presents the results of an aggregate area management study (AAMS) for the T Plant Aggregate Area located in the 200 Areas. The study provides the basis for initiating RI/FS under CERCLA or under the Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS). This report also integrates RCRA treatment, storage, or disposal (TSD) closure activities with CERCLA and RCRA past-practice investigations

  16. Z Plant source aggregate area management study report

    International Nuclear Information System (INIS)

    1992-10-01

    The US Department of Energy (DOE) Hanford Site in Washington State is or into numerically designated operational areas including the 100, 200, 300, 400, 600, and 1100 Areas. The US Environmental Protection Agency (EPA), in November 1989, included the 200 Areas of the Hanford Site on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980. Inclusion on the NPL initiates the Remedial Investigation (RI) and Feasibility Study (FS) process for characterizing the nature and extent of contamination, assessing risks to human health and the environment, and selection of remedial actions. This report presents the insults of an aggregate area management study (AAMS) for the Z Plant Aggregate Area located m the 200 Areas. The study provides the basis for initiating RIIFS under CERCLA or under the Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS). This report also integrates RCRA treatment, storage, or disposed (TSD) closure activities with CERCLA and RCRA past-practice investigations

  17. U Plant source aggregate area management study report

    International Nuclear Information System (INIS)

    1992-09-01

    The US Department of Energy (DOE) Hanford Site in Washington State is organized into numerically designated operational areas including the 100, 200, 300, 400, 600, and 1100 Areas. The US Environmental Protection Agency (EPA), in November 1989, included the 200 Areas of the Hanford Site on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980. Inclusion on the NPL initiates the Remedial Investigation (RI) and Feasibility Study (FS) process for characterizing the nature and extent of contamination, assessing risks to human health and the environment, and selection of remedial actions. This report presents the results of an aggregate area management study (AAMS) for the U Plant Aggregate Area located in the 200 Areas. The study provides the basis for initiating RI/FS under CERCLA or under the Resource Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS). This report also integrates RCRA treatment, storage, or disposal (TSD) closure activities with CERCLA and RCRA past-practice investigations

  18. B Plant source aggregate area management study report

    International Nuclear Information System (INIS)

    1993-03-01

    The US Department of Energy (DOE) Hanford Site in Washington state is organized into numerically designated operational areas including the 100, 200, 300, 400, 600, and 100 Areas (Figure 1--1). The US Environmental Protection Agency (EPA), in November 1989, included the 200 Areas of the Hanford KLSite on the National Priorities List (NPL), included the 200 Areas of the Hanford Site on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation and Liability Act of Feasibility Study (FS) process for characterizing the nature and extent of contamination, assessing risks to human health and the environment, and selection of remedial actions. This report presents the results of an aggregate area management study (AIMS) for the B Plant Aggregate Area located in the 200 Areas. The study provides the basis for initiating RI/FS under CERCLA or under the Resource which contain reactor fuel processing and waste management Conservation and Recovery Act (RCRA) Facility Investigations (RFI) and Corrective Measures Studies (CMS). This report also integrates RCRA treatment, storage or disposal (TSD) closure activities with CERCLA and RCRA past-practice investigations

  19. SOURCES OF PROFESSIONALISM, A STUDY OF HIGH SCHOOL TEACHERS.

    Science.gov (United States)

    COLOMBOTOS, JOHN L.

    AN INVESTIGATION WAS CONDUCTED OF THE DISTINCTIVE CHARACTERISTICS OF HIGH SCHOOL TEACHERS AS CONTRASTED WITH THEIR PEERS IN A BUSINESS ORGANIZATION. THE EFFECT OF THIS DISTINCTIVENESS ON THE PERSONAL NATURE OF TENSIONS AND CONFLICTS ASSOCIATED WITH JOB PERFORMANCE, CAREER GOALS, AND CAREER PATTERNS WAS ALSO STUDIED. ITS GENERAL OBJECTIVE WAS TO…

  20. Hybrid Wing Body Shielding Studies Using an Ultrasonic Configurable Fan Artificial Noise Source Generating Simple Modes

    Science.gov (United States)

    Sutliff, Daniel, L.; Brown, Clifford, A.; Walker, Bruce, E.

    2012-01-01

    An Ultrasonic Configurable Fan Artificial Noise Source (UCFANS) was designed, built, and tested in support of the Langley Research Center s 14- by 22-Foot wind tunnel test of the Hybrid Wing Body (HWB) full three-dimensional 5.8 percent scale model. The UCFANS is a 5.8 percent rapid prototype scale model of a high-bypass turbofan engine that can generate the tonal signature of candidate engines using artificial sources (no flow). The purpose of the test was to provide an estimate of the acoustic shielding benefits possible from mounting the engine on the upper surface of an HWB aircraft and to provide a database for shielding code validation. A range of frequencies, and a parametric study of modes were generated from exhaust and inlet nacelle configurations. Radiated acoustic data were acquired from a traversing linear array of 13 microphones, spanning 36 in. Two planes perpendicular to the axis of the nacelle (in its 0 orientation) and three planes parallel were acquired from the array sweep. In each plane the linear array traversed five sweeps, for a total span of 160 in. acquired. The resolution of the sweep is variable, so that points closer to the model are taken at a higher resolution. Contour plots of Sound Pressure Level, and integrated Power Levels are presented in this paper; as well as the in-duct modal structure.

  1. Childhood vesicoureteral reflux studies: registries and repositories sources and nosology.

    Science.gov (United States)

    Chesney, Russell W; Patters, Andrea B

    2013-12-01

    Despite several recent studies, the advisability of antimicrobial prophylaxis and certain imaging studies for urinary tract infections (UTIs) remains controversial. The role of vesicoureteral reflux (VUR) on the severity and re-infection rates for UTIs is also difficult to assess. Registries and repositories of data and biomaterials from clinical studies in children with VUR are valuable. Disease registries are collections of secondary data related to patients with a specific diagnosis, condition or procedure. Registries differ from indices in that they contain more extensive data. A research repository is an entity that receives, stores, processes and/or disseminates specimens (or other materials) as needed. It encompasses the physical location as well as the full range of activities associated with its operation. It may also be referred to as a biorepository. This report provides information about some current registries and repositories that include data and samples from children with VUR. It also describes the heterogeneous nature of the subjects, as some registries and repositories include only data or samples from patients with primary reflux while others also include those from patients with syndromic or secondary reflux. Copyright © 2012 Journal of Pediatric Urology Company. All rights reserved.

  2. The Diamond Light Source and the challenges ahead for structural biology: some informal remarks.

    Science.gov (United States)

    Ramakrishnan, V

    2015-03-06

    The remarkable advances in structural biology in the past three decades have led to the determination of increasingly complex structures that lie at the heart of many important biological processes. Many of these advances have been made possible by the use of X-ray crystallography using synchrotron radiation. In this short article, some of the challenges and prospects that lie ahead will be summarized. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Control source development for reduction of noise transmitted through a double panel structure

    OpenAIRE

    Ho, J.

    2014-01-01

    A double panel structure, which consists of two panels with air in between, is widely adopted in many applications such as aerospace, automotive industries, and buildings due to its low sound transmission at high frequencies, low heat transmission, and low weight. Nevertheless, the resonance of the cavity and the poor sound transmission loss at low frequencies limit the double panel’s noise control performance. Applying active structural acoustic control to the panels or active noise control ...

  4. Experimental study on a cold neutron source of solid methylbenzene

    Energy Technology Data Exchange (ETDEWEB)

    Utsuro, M; Sugimoto, M; Fujita, Y [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.

    1975-10-01

    An experimental study to produce cold neutrons with low temperature solid mesitylene as cold moderator in liquid helium and liquid nitrogen cryostats is reported. Measured cold neutron spectra by using an electron linac and time-of-flight method shows that this material is a better cold moderator than light water ice, giving the cold neutron output not so much inferior to that of solid methane in the temperature range above about 20 K and in the neutron energy region above about 1 MeV.

  5. In Silico Analysis for the Study of Botulinum Toxin Structure

    Science.gov (United States)

    Suzuki, Tomonori; Miyazaki, Satoru

    2010-01-01

    Protein-protein interactions play many important roles in biological function. Knowledge of protein-protein complex structure is required for understanding the function. The determination of protein-protein complex structure by experimental studies remains difficult, therefore computational prediction of protein structures by structure modeling and docking studies is valuable method. In addition, MD simulation is also one of the most popular methods for protein structure modeling and characteristics. Here, we attempt to predict protein-protein complex structure and property using some of bioinformatic methods, and we focus botulinum toxin complex as target structure.

  6. Monochromator on a synchrotron undulator source for liquid surface studies

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Freund, A.K.

    1992-01-01

    For liquid surface studies a monochromatic beam of relative bandwidth between 0.1% and 1% at a variable angle in the vertical plane between 0-degrees and 10-degrees is needed. The beam should be like a sheet some tens of mu-m thick and some mm wide, and as intense as possible. We discuss a monoch......For liquid surface studies a monochromatic beam of relative bandwidth between 0.1% and 1% at a variable angle in the vertical plane between 0-degrees and 10-degrees is needed. The beam should be like a sheet some tens of mu-m thick and some mm wide, and as intense as possible. We discuss......% of the useful x rays, in full agreement with diffraction theory including secondary extinction. Heat load experiments reported elsewhere in this conference prove that Be crystals can withstand high beam power density and that the thermal deformation is small compared to the mosaic spread. The results...... of the flux calculations are most encouraging: a gain of order 10(3) to 10(4) can be expected as compared to existing liquid surface spectrometers....

  7. Structure/Property Relationships of Cyanate Ester Resins from Renewable Sources

    Science.gov (United States)

    2013-04-11

    derived from lignin . These materials possess favorable thermal and water uptake properties with dry glass transition temperatures above 200°C and wet...Differential scanning calorimetry showed that resins with more sterically restrictive bridge groups between the reactive moieties cure more slowly...distribution is unlimited. Creosol as a Monomer Source 7 • Input material cost is an important consideration for cyanate ester resins • Lignin is

  8. To study the municipal solid waste as an energy source

    International Nuclear Information System (INIS)

    Ahmed, Z.; Khan, M.M.

    2005-01-01

    The solid waste management is a very complicated specially when it must be environmental friendly. In the present life, power energy is being more expensive than ever before and human off spring is struggling td acquire cheap ways of getting energy. At the same time, he is facing another problem of waste disposal pollution in the environment, which is a by-product of his industries and population, and when it would be hazardous to life, it will be a more serious problem. In this study, an idea is made to use garbage as an alternate fuel and the analysis of ingredients is done to compare it with the usual fuel i.e. coal. On the other hand, municipal waste (garbage) disposal will be automatically solved. (author)

  9. Molecular Chemical Structure of Barley Proteins Revealed by Ultra-Spatially Resolved Synchrotron Light Sourced FTIR Microspectroscopy: Comparison of Barley Varieties

    International Nuclear Information System (INIS)

    Yu, P.

    2007-01-01

    Barley protein structure affects the barley quality, fermentation, and degradation behavior in both humans and animals among other factors such as protein matrix. Publications show various biological differences among barley varieties such as Valier and Harrington, which have significantly different degradation behaviors. The objectives of this study were to reveal the molecular structure of barley protein, comparing various varieties (Dolly, Valier, Harrington, LP955, AC Metcalfe, and Sisler), and quantify protein structure profiles using Gaussian and Lorentzian methods of multi-component peak modeling by using the ultra-spatially resolved synchrotron light sourced Fourier transform infrared microspectroscopy (SFTIRM). The items of the protein molecular structure revealed included protein structure α-helices, β-sheets, and others such as β-turns and random coils. The experiment was performed at the National Synchrotron Light Source in Brookhaven National Laboratory (BNL, US Department of Energy, NY). The results showed that with the SFTIRM, the molecular structure of barley protein could be revealed. Barley protein structures exhibited significant differences among the varieties in terms of proportion and ratio of model-fitted α-helices, β-sheets, and others. By using multi-component peaks modeling at protein amide I region of 1710-1576 cm -1 , the results show that barley protein consisted of approximately 18-34% of α-helices, 14-25% of β-sheets, and 44-69% others. AC Metcalfe, Sisler, and LP955 consisted of higher (P 0.05). The ratio of α-helices to others (0.3 to 1.0, P < 0.05) and that of β-sheets to others (0.2 to 0.8, P < 0.05) were different among the barley varieties. It needs to be pointed out that using a multi-peak modeling for protein structure analysis is only for making relative estimates and not exact determinations and only for the comparison purpose between varieties. The principal component analysis showed that protein amide I Fourier

  10. Conceptual source design and dosimetric feasibility study for intravascular treatment: a proposal for intensity modulated brachytherapy

    International Nuclear Information System (INIS)

    Kim, Si Yong; Han, Eun Young; Palta, Jatinder R.; Ha, Sung W.

    2003-01-01

    To propose a conceptual design of a novel source for intensity modulated brachytherapy. The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a 90 Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quarter of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter

  11. Conceptual source design and dosimetric feasibility study for intravascular treatment: a proposal for intensity modulated brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Si Yong; Han, Eun Young; Palta, Jatinder R. [College of Medicine, Florida Univ., Florida (United States); Ha, Sung W. [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    2003-06-01

    To propose a conceptual design of a novel source for intensity modulated brachytherapy. The source design incorporates both radioactive and shielding materials (stainless steel or tungsten), to provide an asymmetric dose intensity in the azimuthal direction. The intensity modulated intravascular brachytherapy was performed by combining a series of dwell positions and times, distributed along the azimuthal coordinates. Two simple designs for the beta-emitting sources, with similar physical dimensions to a {sub 90}Sr/Y Novoste Beat-Cath source, were considered in the dosimetric feasibility study. In the first design, the radioactive and materials each occupy half of the cylinder and in the second, the radioactive material occupies only a quarter of the cylinder. The radial and azimuthal dose distributions around each source were calculated using the MCNP Monte Carlo code. The preliminary hypothetical simulation and optimization results demonstrated the 87% difference between the maximum and minimum doses to the lumen wall, due to off-centering of the radiation source, could be reduced to less than 7% by optimizing the azimuthal dwell positions and times of the partially shielded intravascular brachytherapy sources. The novel brachytherapy source design, and conceptual source delivery system, proposed in this study show promising dosimetric characteristics for the realization of intensity modulated brachytherapy in intravascular treatment. Further development of this concept will center on building a delivery system that can precisely control the angular motion of a radiation source in a small-diameter catheter.

  12. Optimization study of normal conductor tokamak for commercial neutron source

    Science.gov (United States)

    Fujita, T.; Sakai, R.; Okamoto, A.

    2017-05-01

    The optimum conceptual design of tokamak with normal conductor coils was studied for minimizing the cost for producing a given neutron flux by using a system code, PEC. It is assumed that the fusion neutrons are used for burning transuranics from the fission reactor spent fuel in the blanket and a fraction of the generated electric power is circulated to opearate the tokamak with moderate plasma fusion gain. The plasma performance was assumed to be moderate ones; {β\\text{N}}~∼ ~3{--}4 in the aspect ratio A~=~2{--}3 and {{H}98y2}~=~1 . The circulating power is an important factor affecting the cost. Though decreasing the aspect ratio is useful to raise the plasma beta and decrease the toroidal field, the maximum field in the coil starts to rise in the very low aspect ratio range and then the circulating power increases with decrease in the plasma aspect ratio A below A~∼ ~2 , while the construction cost increases with A . As a result, the cost per neutron has its minimum around A~∼ ~2.2 , namely, between ST and the conventional tokamak. The average circulating power fraction is expected to be ~51%.

  13. Structural Studies of Some Binaphthyl Derivatives

    DEFF Research Database (Denmark)

    Thorup, Niels; Bjørnholm, T.; Bechgaard, K.

    1996-01-01

    Crystal structures of several 1,1'-binaphthyl derivatives have been determined. In particular compounds which at the 2,2' positions have either identical ethoxy groups or a closed bridged ether and furthermore have identical substitution at the 6,6' positions. The latter groups may be Br, CHO, CN...

  14. STRUCTURAL STUDY AND INVESTIGATION OF NMR TENSORS ...

    African Journals Online (AJOL)

    theory. The structural and vibrational properties of dopamine-4-N7GUA and ... There is evidence, however, that DA is involved in the ... spectra to the results of ab initio gauge-invariant atomic orbital (GIAO) [14-17] and continuous- ..... Nicholls, G. Proteins, transmitter & synapses, Blackwell Scientific Publication: Scotland;.

  15. Structural, optical and photoluminescence study of nanocrystalline

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 37; Issue 3. Structural, optical ... Orientation along plane (200) decreases continuously as molar concentration of SnO2 increases. Dislocation density along plane (110) also decreases as molar concentration increases except 0.4 M SnO2 thin film. Scanning electron ...

  16. Optical and structural study of BST multilayers

    Czech Academy of Sciences Publication Activity Database

    Železný, Vladimír; Chvostová, Dagmar; Pajasová, Libuše; Jelínek, Miroslav; Kocourek, Tomáš; Daniš, S.; Valvoda, V.

    2010-01-01

    Roč. 12, č. 3 (2010), 538-541 ISSN 1454-4164 R&D Projects: GA ČR GA202/07/0591 Institutional research plan: CEZ:AV0Z10100522; CEZ:AV0Z10100520 Keywords : ellipsometry * structure * ferroelectric multilayers Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

  17. Studies of the contributions of nonpoint terrestrial sources to mineral water quality

    International Nuclear Information System (INIS)

    Huff, D.D.

    1977-05-01

    The contributions of nonpoint sources of water quality constituents represent a background loading rate that will not be reduced easily. Consequently, those contributions may have a dominant effect on aquatic ecosystems once point sources have been controlled. Modeling studies conducted at the Tennessee Valley Authority and Oak Ridge National Laboratory represent contrasting approaches that highlight some of the possibilities for predicting nonpoint source inputs to aquatic systems

  18. Design of end magnetic structures for the Advanced Light Source wigglers

    International Nuclear Information System (INIS)

    Humphries, D.; Akre, J.; Hoyer, E.; Marks, S.; Minamihara, Y.; Pipersky, P.; Plate, D.; Schlueter, R.

    1995-01-01

    The vertical magnetic structures for the Advanced Light planar wiggler and 20 cm period elliptical hybrid permanent magnet design. The ends of these structures are characterized by diminishing scalar potential distributions the poles which control beam trajectories. They incorporate electromagnetic correction coils to dynamically correct for variations in the first integral of the field as a function of gap. A permanent magnet trim mechanism is incorporated to minimize the transverse integrated error field distribution. The ends were designed using analytic and computer modeling techniques. The design and modeling results are presented

  19. Is drinking water from 'improved sources' really safe? A case study in the Logone valley (Chad-Cameroon).

    Science.gov (United States)

    Sorlini, S; Palazzini, D; Mbawala, A; Ngassoum, M B; Collivignarelli, M C

    2013-12-01

    Within a cooperation project coordinated by the Association for Rural Cooperation in Africa and Latin America (ACRA) Foundation, water supplies were sampled across the villages of the Logone valley (Chad-Cameroon) mostly from boreholes, open wells, rivers and lakes as well as from some piped water. Microbiological analyses and sanitary inspections were carried out at each source. The microbiological quality was determined by analysis of indicators of faecal contamination, Escherichia coli, Enterococci and Salmonellae, using the membrane filtration method. Sanitary inspections were done using WHO query forms. The assessment confirmed that there are several parameters of health concern in the studied area; bacteria of faecal origins are the most significant. Furthermore, this study demonstrated that Joint Monitoring Programme (JMP) classification and E. coli measurement are not sufficient to state water safety. In fact, in the studied area, JMP defined 'improved sources' may provide unsafe water depending on their structure and sources without E. coli may have Enterococci and Salmonellae. Sanitary inspections also revealed high health risks for some boreholes. In other cases, sources with low sanitary risk and no E. coli were contaminated by Enterococci and Salmonellae. Better management and protection of the sources, hygiene improvement and domestic water treatment before consumption are possible solutions to reduce health risks in the Logone valley.

  20. Ecology and physiology of reed. A literature study for evaluation of reed as an energy source

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerndahl, G.; Egneus, H.

    1980-04-01

    The potentials of reed as an energy source are evaluated. The following subjects are discussed: The structure and life-cycle of reed; Primary production and photosynthesis; important environmental factors for the production; Genetic variation; Competition, succession and parasitism; Human influence like cultivation, harvesting a.o. An extensive list of referencer is given.

  1. Study on Human-structure Dynamic Interaction in Civil Engineering

    Science.gov (United States)

    Gao, Feng; Cao, Li Lin; Li, Xing Hua

    2018-06-01

    The research of human-structure dynamic interaction are reviewed. Firstly, the influence of the crowd load on structural dynamic characteristics is introduced and the advantages and disadvantages of different crowd load models are analyzed. Then, discussing the influence of structural vibration on the human-induced load, especially the influence of different stiffness structures on the crowd load. Finally, questions about human-structure interaction that require further study are presented.

  2. Neural network AE source location apart from structure size and material

    Czech Academy of Sciences Publication Activity Database

    Chlada, Milan; Převorovský, Zdeněk; Blaháček, Michal

    2010-01-01

    Roč. 28, - (2010), s. 99-107 ISSN 0730-0050. [European Conference on Acoustic Emission Testing 2010 /29./. Vídeň, 08.09.2010-10.09.2010] R&D Projects: GA ČR(CZ) GAP104/10/1430; GA MPO(CZ) FR-TI1/274 Institutional research plan: CEZ:AV0Z20760514 Keywords : AE source location * artificial neural network * arrival time profiles Subject RIV: BI - Acoustics http://www.ndt.net/search/abstract.php3?AbsID=10828

  3. Comparison of silver and molybdenum microfocus X-ray sources for single-crystal structure determination

    OpenAIRE

    Krause, Lennard; Herbst-Irmer, Regine; Sheldrick, George M.; Stalke, Dietmar

    2015-01-01

    The quality of diffraction data obtained using silver and molybdenum microsources has been compared for six model compounds with a wide range of absorption factors. The experiments were performed on two 30 W air-cooled Incoatec IµS microfocus sources with multilayer optics mounted on a Bruker D8 goniometer with a SMART APEX II CCD detector. All data were analysed, processed and refined using standard Bruker software. The results show that Ag Kα radiation can be beneficial when heavy elements ...

  4. H- Enhancement Process in a Multicusp Ion Source Operated with a Barium Insert Structure

    Energy Technology Data Exchange (ETDEWEB)

    Leung, K.N.; Van Os, C.F.A.; Kunkel, W.B.

    1990-05-01

    It has been demonstrated that the H{sup -} output current from a small multicusp source can be substantially enhanced if the hydrogen plasma is seeded with barium. Operating with a barium washer insert at the extraction aperture, it is found that the extractable H{sup -} current is increased by a factor of three if the insert bias potential is optimized. By use of a mixture of xenon and hydrogen gas, it is further demonstrated that the positive hydrogen ions are responsible for the observed H{sup -} enhancement.

  5. Aging affects the interaction between attentional control and source memory: an fMRI study.

    Science.gov (United States)

    Dulas, Michael R; Duarte, Audrey

    2014-12-01

    Age-related source memory impairments may be due, at least in part, to deficits in executive processes mediated by the PFC at both study and test. Behavioral work suggests that providing environmental support at encoding, such as directing attention toward item-source associations, may improve source memory and reduce age-related deficits in the recruitment of these executive processes. The present fMRI study investigated the effects of directed attention and aging on source memory encoding and retrieval. At study, participants were shown pictures of objects. They were either asked to attend to the objects and their color (source) or to their size. At test, participants determined if objects were seen before, and if so, whether they were the same color as previously. Behavioral results showed that direction of attention improved source memory for both groups; however, age-related deficits persisted. fMRI results revealed that, across groups, direction of attention facilitated medial temporal lobe-mediated contextual binding processes during study and attenuated right PFC postretrieval monitoring effects at test. However, persistent age-related source memory deficits may be related to increased recruitment of medial anterior PFC during encoding, indicative of self-referential processing, as well as underrecruitment of lateral anterior PFC-mediated relational processes. Taken together, this study suggests that, even when supported, older adults may fail to selectively encode goal-relevant contextual details supporting source memory performance.

  6. Addressing source-induced structural vibrations in an interventional X-ray system

    NARCIS (Netherlands)

    Van Pinxteren, J.A.W.; Vermeulen, J.P.M.B.; van Loon, R.J.A.; van Schothorst, G.; Billington, D.; Phillips, D.

    2017-01-01

    Interventional radiology is a medical discipline, in which imaging equipment is used to diagnose and treat diseases throughout the human body. Dedicated systems, based on X-ray, computed tomography and ultrasound technology, allow for 2D and 3D imaging of (contrast enhanced) physical structures.

  7. Crowd-Sourcing (Semantically) Structured Multilingual Educational Content (CoSMEC)

    Science.gov (United States)

    Tarasowa, Darya; Auer, Sören; Khalili, Ali; Unbehauen, Jörg

    2014-01-01

    The support of multilingual content becomes crucial for educational platforms due to the benefits it offers. In this paper we propose a concept that allows content authors to use the power of the crowd to create (semantically) structured multilingual educational content out of their material. To enable the collaboration of the crowd, we expand our…

  8. 40 CFR 60.2890 - How are these new source performance standards structured?

    Science.gov (United States)

    2010-07-01

    ... standards structured? 60.2890 Section 60.2890 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... standards contain nine major components, as follows: (a) Preconstruction siting analysis. (b) Waste management plan. (c) Operator training and qualification. (d) Emission limitations and operating limits. (e...

  9. Measuring Competence and Dysfunction in Preschool Children: Source Agreement and Component Structure

    Science.gov (United States)

    Klyce, Daniel; Conger, Anthony J.; Conger, Judith Cohen; Dumas, Jean E.

    2011-01-01

    Agreement between parents and teachers on ratings of three domains of behaviors exhibited by preschool children and the structural relations between these domains were measured. Parents and teachers rated the behaviors of a socioeconomically diverse sample of 610 children; ratings were obtained from parents at three time points and from teachers…

  10. Control source development for reduction of noise transmitted through a double panel structure

    NARCIS (Netherlands)

    Ho, J.

    2014-01-01

    A double panel structure, which consists of two panels with air in between, is widely adopted in many applications such as aerospace, automotive industries, and buildings due to its low sound transmission at high frequencies, low heat transmission, and low weight. Nevertheless, the resonance of the

  11. Obtaining source current density related to irregularly structured electromagnetic target field inside human body using hybrid inverse/FDTD method.

    Science.gov (United States)

    Han, Jijun; Yang, Deqiang; Sun, Houjun; Xin, Sherman Xuegang

    2017-01-01

    Inverse method is inherently suitable for calculating the distribution of source current density related with an irregularly structured electromagnetic target field. However, the present form of inverse method cannot calculate complex field-tissue interactions. A novel hybrid inverse/finite-difference time domain (FDTD) method that can calculate the complex field-tissue interactions for the inverse design of source current density related with an irregularly structured electromagnetic target field is proposed. A Huygens' equivalent surface is established as a bridge to combine the inverse and FDTD method. Distribution of the radiofrequency (RF) magnetic field on the Huygens' equivalent surface is obtained using the FDTD method by considering the complex field-tissue interactions within the human body model. The obtained magnetic field distributed on the Huygens' equivalent surface is regarded as the next target. The current density on the designated source surface is derived using the inverse method. The homogeneity of target magnetic field and specific energy absorption rate are calculated to verify the proposed method.

  12. A micromagnetic study of domain structure modeling

    International Nuclear Information System (INIS)

    Matsuo, Tetsuji; Mimuro, Naoki; Shimasaki, Masaaki

    2008-01-01

    To develop a mesoscopic model for magnetic-domain behavior, a domain structure model (DSM) was examined and compared with a micromagnetic simulation. The domain structure of this model is given by several domains with uniform magnetization vectors and domain walls. The directions of magnetization vectors and the locations of domain walls are determined so as to minimize the magnetic total energy of the magnetic material. The DSM was modified to improve its representation capability for domain behavior. The domain wall energy is multiplied by a vanishing factor to represent the disappearance of magnetic domain. The sequential quadratic programming procedure is divided into two steps to improve an energy minimization process. A comparison with micromagnetic simulation shows that the modified DSM improves the representation accuracy of the magnetization process

  13. New complete sample of identified radio sources. Part 2. Statistical study

    International Nuclear Information System (INIS)

    Soltan, A.

    1978-01-01

    Complete sample of radio sources with known redshifts selected in Paper I is studied. Source counts in the sample and the luminosity - volume test show that both quasars and galaxies are subject to the evolution. Luminosity functions for different ranges of redshifts are obtained. Due to many uncertainties only simplified models of the evolution are tested. Exponential decline of the liminosity with time of all the bright sources is in a good agreement both with the luminosity- volume test and N(S) realtion in the entire range of observed flux densities. It is shown that sources in the sample are randomly distributed in scales greater than about 17 Mpc. (author)

  14. The structure and control method of hybrid power source for electric vehicle

    International Nuclear Information System (INIS)

    Li, Maobing; Xu, Hui; Li, Weimin; Liu, Yin; Li, Fade; Hu, Yue; Liu, Li

    2016-01-01

    In this paper, an electric vehicle powertrain configuration is presented, which the lithium-ion battery integrated with ultracapacitors is developed as the hybrid power system to improve the transient performance of an electric vehicle, and to decrease the damage to the battery pack. In the proposed system, a bidirectional direct current/direct current converter is used to couple the ultracapacitors bank to the main battery pack. The energy management strategy based on fuzzy logic for hybrid power system has been proposed to promote the performance of energy flow in the electric vehicle. The experiment results in urban driving cycles show remarkable advantages of the proposed hybrid system configuration and energy management strategy. About 30% of the battery capacity energy is saved while using the hybrid power source. Besides, the voltage and current curves of battery become smoother than that with the single power. - Highlights: • A hybrid power source electric vehicle powertrain configuration is presented. • The energy management strategy based on fuzzy logic is proposed. • The experiment results show remarkable advantages of the configuration and method.

  15. The effect of location of a convective heat source on displacement ventilation: CFD study

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.J.; Holland, D. [Dunham Associates, Inc., Minneapolis, MN (United States). Advanced Technologies Group

    2001-08-01

    Two-dimensional computational simulations are performed to examine the effect of vertical location of a convective heat source on thermal displacement ventilation systems. In this study, a heat source is modeled with seven different heights from the floor (0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 m) in a displacement ventilation environment. The flow and temperature fields in thermal displacement ventilation systems vary depending on the location of the heat source. As the heat source rises, the convective heat gain from the heat source to an occupied zone becomes less significant. This effect changes the temperature field and results in the reduction of the cooling load in the occupied zone. The stratification level is also affected by the heat source location at a given flow rate. (author)

  16. Study of structural colour of Hebomoia glaucippe butterfly wing scales

    Science.gov (United States)

    Shur, V. Ya; Kuznetsov, D. K.; Pryakhina, V. I.; Kosobokov, M. S.; Zubarev, I. V.; Boymuradova, S. K.; Volchetskaya, K. V.

    2017-10-01

    Structural colours of Hebomoia glaucippe butterfly wing scales have been studied experimentally using high resolution scanning electron microscopy. Visualization of scales structures and computer simulation allowed distinguishing correlation between nanostructures on the scales and their colour.

  17. Characteristics of rotating target neutron source and its use in radiation effects studies

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.; Barschall, H.H.; Booth, R.; Wong, C.

    1975-07-01

    The Rotating Target Neutron Source (RTNS) at Lawrence Livermore Laboratory is currently the most intense source of DT fusion neutrons available for the study of radiation effects in materials. This paper will present a brief description of the machine, outline the history of its development and discuss its performance characteristics and its application to CTR materials research. (U.S.)

  18. Manufacturing cost study on the ion sources for the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    A study of the cost of manufacturing 48 ion sources for the Mirror Fusion Test Facility is described. The estimate is built up from individual part costs and assembly operation times for the 80 kV prototype source constructed by LLL and described by LLL drawings furnished during December 1978. Recommendations for cost reduction are made

  19. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.

    1996-10-02

    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.

  20. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    International Nuclear Information System (INIS)

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.

    1996-01-01

    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies