Sample records for r process

  1. Physical conditions for the r-process

    SciTech Connect

    Wanajo, S.; Tachibana, T.; Goriely, S. [Technische Universitaet Muenchen, Excellence Cluster Universe, Boltzmannstr. 2, D-85748 Garching and Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Senior High School of Waseda University, Nerima, Tokyo 177-0044 (Japan); Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium)

    2012-11-12

    Recent works show that the r-process can proceed by competition between neutron capture and {beta}-decay in low temperature environments (< 5 Multiplication-Sign 10{sup 8} K; cold r-process) where photo-disintegration plays no role. This is in contrast to the traditional picture of the r-process in high temperature environments ({approx} 1 Multiplication-Sign 10{sup 9} K; hot r-process) where the (n, {gamma})-({gamma}, n) equilibrium holds. In this study, we explore nucleosynthesis calculations based on a site-independent model to elucidate the physical conditions leading to cold and hot r-processes.

  2. r-Process nucleosynthesis without excess neutrons.

    PubMed

    Meyer, Bradley S

    2002-12-01

    Matter expanding sufficiently rapidly and at high enough entropy per nucleon can enter a heavy-element synthesis regime heretofore unexplored. In this extreme regime, more similar to nucleosynthesis in the early universe than to that typical in stellar explosive environments, there is a persistent disequilibrium between free nucleons and abundant alpha particles, which allows heavy r-process nucleus production even in matter with more protons than neutrons. This observation bears on the issue of the site of the r process, on the variability of abundance yields from r-process events, and on constraints on neutrino physics derived from nucleosynthesis. PMID:12484993

  3. r-Process in Neutron Star Mergers.

    PubMed

    Freiburghaus; Rosswog; Thielemann

    1999-11-10

    The production site of the neutron-rich heavy elements that are formed by rapid neutron capture (the r-process) is still unknown despite intensive research. Here we show detailed studies of a scenario that has been proposed earlier by Lattimer & Schramm, Symbalisty & Schramm, Eichler et al., and Davies et al., namely the merger of two neutron stars. The results of hydrodynamic and full network calculations are combined in order to investigate the relevance of this scenario for r-process nucleosynthesis. Sufficient material is ejected to explain the amount of r-process nuclei in the Galaxy by decompression of neutron star material. Provided that the ejecta consist of matter with a proton-to-nucleon ratio of Ye approximately 0.1, the calculated abundances fit the observed solar r-pattern excellently for nuclei that include and are heavier than the A approximately 130 peak. PMID:10525469

  4. Wavelet Coefficients of Levy Process R. Suyundykov

    E-print Network

    Paris-Sud XI, Université de

    Wavelet Coefficients of Levy Process R. Suyundykov ENAC Dept. MI LMA 7, Avenue Edouard Belin 31055. Abstract--The main object of the paper is to study the wavelet decomposition of Levy processes by wavelets by Haar wavelets. Keywords : Ondelettes, Processus I. INTRODUCTION Estimation of wavelet coefficients

  5. Superheavy elements and r-process

    SciTech Connect

    Panov, I. V., E-mail: Igor.Panov@itep.ru; Korneev, I. Yu. [Institute of Theoretical and Experimental Physics (Russian Federation); Thielemann, F.-K. [Institut fuer Physik der Universitaet Basel (Switzerland)

    2009-06-15

    The probability for the production of superheavy elements in the astrophysical r-process is discussed. The dependence of the estimated superheavy-element yields on input data is estimated. Preliminary calculations revealed that the superheavy-element yields at the instant of completion of the r-process may be commensurate with the uranium yield, but the former depend strongly on the models used to forecast the properties of beta-delayed, neutron-induced, and spontaneous fission. This study is dedicated to the 80th anniversary of V.S. Imshennik's birth.

  6. R e p r i n t e d f r o m Signal Processing 66 (1998) 203-217

    E-print Network

    1998-01-01

    : Signal Theory, Stochastic Processes, Detection and Estimation, Spectral Analysis, Filtering, Signal Technology, Speech Processing, Radar Signal Process- ing, Sonar Signal Processing, Special Signal ProcessingR e p r i n t e d f r o m SIGNAL PROCESSING Signal Processing 66 (1998) 203-217 A noise robust

  7. R. Budiu Interpretation-Based Processing 1 Running Head: INTERPRETATION-BASED PROCESSING

    E-print Network

    , ACT-R #12;R. Budiu Interpretation-Based Processing 2 Abstract We present interpretation implemented in ACT-R (Anderson & Lebiere, 1998). #12;R. Budiu Interpretation-Based Processing 3 Interpretation

  8. Rapid Business Process Discovery (R-BPD)

    NASA Astrophysics Data System (ADS)

    Ghose, Aditya; Koliadis, George; Chueng, Arthur

    Modeling is an important and time consuming part of the Business Process Management life-cycle. An analyst reviews existing documentation and queries relevant domain experts to construct both mental and concrete models of the domain. To aid this exercise, we propose the Rapid Business Process Discovery (R-BPD) framework and prototype tool that can query heterogeneous information resources (e.g. corporate documentation, web-content, code e.t.c.) and rapidly construct proto-models to be incrementally adjusted to correctness by an analyst. This constitutes a departure from building and constructing models toward just editing them. We believe this rapid mixed-initiative modeling will increase analyst productivity by significant orders of magnitude over traditional approaches. Furthermore, the possibility of using the approach in distributed and real-time settings seems appealing and may help in significantly improving the quality of the models being developed w.r.t. being consistent, complete, and concise.

  9. Modeling sentence processing in ACT-R Shravan Vasishth

    E-print Network

    Lewis, Richard

    Modeling sentence processing in ACT-R Shravan Vasishth Department of Computational Linguistics architecture ACT-R. We show that constraints de- fined in ACT-R, specifically, those relat- ing to activation architecture, ACT-R (Anderson et al., 2002) and directly us- ing the constraints provided in ACT-R to account

  10. Astrophysical models of r-process nucleosynthesis: An update

    SciTech Connect

    Qian Yongzhong [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2012-11-12

    An update on astrophysical models for nucleosynthesis via rapid neutron capture, the r process, is given. A neutrino-induced r process in supernova helium shells may have operated up to metallicities of {approx} 10{sup -3} times the solar value. Another r-process source, possibly neutron star mergers, is required for higher metallicities.

  11. History Preserving Process Graphs R.J. van Glabbeek*

    E-print Network

    Pratt, Vaughan

    History Preserving Process Graphs R.J. van that, contrary to what is widely believed, process g* *raphs, or labelled tran- sition systems introduce a class of process graphs obeying the restriction that any* * state not only uniquely

  12. History Preserving Process Graphs R.J. van Glabbeek*

    E-print Network

    Pratt, Vaughan

    History Preserving Process Graphs R.J. van that, contrary to what is widely believed, process g* *raphs, or labeled transition systems, have a class of process graphs obeying the restriction * *that any state not only uniquely characterizes

  13. Fission Properties for R-Process Nuclei

    SciTech Connect

    Erler, J. [Inst. fur Theoretische Physik II, Univ. Erlangen-Numberg, Germany/UTK/ORNL; Langanke, K. [GSI-Darmstadt/Tech. Univ. Darmstadt, Inst. Phys./Frankfurt Inst. Advanced Studies, Germany; Loens, H. P. [GSI-Darmstadt/Tech. Univ. Darmstadt, Inst. Phys.; Martinez-Pinedo, G. [GSI-Darmstadt/Tech. Univ. Darmstadt, Inst. Phys.; Reinhard, P.-G. [Inst. fur Theoretische Physik II, Univ. Erlangen-Numberg, Germany

    2012-01-01

    We present a systematics of fission barriers and fission lifetimes for the whole landscape of superheavy elements (SHE), i.e., nuclei with Z 100. The fission lifetimes are also compared with the -decay half-lives. The survey is based on a self-consistent description in terms of the Skyrme-Hartree-Fock (SHF) approach. Results for various different SHF parametrizations are compared to explore the robustness of the predictions. The fission path is computed by quadrupole constrained SHF. The computation of fission lifetimes takes care of the crucial ingredients of the large-amplitude collective dynamics along the fission path, as self-consistent collective mass and proper quantum corrections. We discuss the different topologies of fission landscapes which occur in the realm of SHE (symmetric versus asymmetric fission, regions of triaxial fission, bimodal fission, and the impact of asymmetric ground states). The explored region is extended deep into the regime of very neutron-rich isotopes as they are expected to be produced in the astrophysical r process.

  14. Prospects for understanding the astrophysical r-process

    SciTech Connect

    Mathews, G.J.; Cowan, J.J.

    1988-07-01

    This paper discusses several recent advances toward a deeper understanding of the still unknown astrophysical site for rapid (r-process) neutron capture nucleosynthesis. The physical constraints on the r-process from the input nuclear data are highlighted and the particular importance of the recent measurements of beta-decay lifetimes along the r-process path is discussed. Astronomical observations of s- and r-process elemental abundances on metal poor halo stars are also discussed, in the context of models for the galactic chemical evolution of heavy-element abundances, as a constraint on the nature of the r-process. On the basis of these constraints it is suggested that the most likely source for the r-process may be from the ejection of core material from low-mass type II supernovae. 27 refs., 1 fig.

  15. The Rare Earth Peak : An Overlooked r-Process Diagnostic

    E-print Network

    Mumpower, M; Surman, R

    2012-01-01

    The astrophysical site or sites responsible for the r-process of nucleosynthesis still remains an enigma. Since the rare earth region is formed in the latter stages of the r-process it provides a unique probe of the astrophysical conditions during which the r-process takes place. We use features of a successful rare earth region in the context of a high entropy r-process (S>100k_B) and discuss the types of astrophysical conditions that produce abundance patterns that best match meteoritic and observational data. Despite uncertainties in nuclear physics input, this method effectively constrains astrophysical conditions.

  16. The K99/R00 and the NIH Grant Process

    E-print Network

    Krstic, Miroslav

    5/29/12 1 The K99/R00 and the NIH Grant Process Pointers on writing a K99/R00 grant and an overview of the NIH review process Pamela Mellon 2012 Pathway to Independence Award K99/R00 · The PI award instructions and 424 forms · Talk over your aims and approaches with colleagues · RFA is at http://grants.nih

  17. r-Process in Prompt Supernova Explosions Revisited

    NASA Astrophysics Data System (ADS)

    Sumiyoshi, K.; Terasawa, M.; Mathews, G. J.; Kajino, T.; Yamada, S.; Suzuki, H.

    2001-12-01

    We reanalyze r-process nucleosynthesis in the neutron-rich ejecta from a prompt supernova explosion of a low-mass (11 Msolar) progenitor. Although it has not yet been established that a prompt explosion can occur, it is not yet ruled out as a possibility for low-mass supernova progenitors. Moreover, there is mounting evidence that a new r-process site may be required. Hence, we assume that a prompt explosion can occur and make a study of r-process nucleosynthesis in the supernova ejecta. To achieve a prompt explosion we have performed a general relativistic hydrodynamic simulation of adiabatic collapse and bounce using a relativistic nuclear-matter equation of state. The electron fraction Ye during the collapse was fixed at the initial-model value. The size of the inner collapsing core was then large enough to enable a prompt explosion to occur in the hydrodynamic calculation. Adopting the calculated trajectories of promptly ejected material, we explicitly computed the burst of neutronization due to electron captures on free protons in the photodissociated ejecta after the passage of the shock. The thermal and compositional evolution of the resulting neutron-rich ejecta originating from near the surface of the proto-neutron star was obtained. These were used in nuclear reaction network calculations to evaluate the products of r-process nucleosynthesis. We find that, unlike earlier studies of nucleosynthesis in prompt supernovae, the amount of r-process material ejected per supernova is quite consistent with observed Galactic r-process abundances. Furthermore, the computed r-process abundances are in good agreement with solar abundances of r-process elements for A>100. This suggests that prompt supernovae are still viable r-process sites. Such events may be responsible for the abundances of the heaviest r-process nuclei.

  18. Sensitivity studies for the main r process: ?-decay rates

    SciTech Connect

    Mumpower, M.; Cass, J.; Passucci, G.; Aprahamian, A. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)] [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Surman, R. [Department of Physics and Astronomy, Union College, Schenectady, New York 12308 (United States)] [Department of Physics and Astronomy, Union College, Schenectady, New York 12308 (United States)

    2014-04-15

    The pattern of isotopic abundances produced in rapid neutron capture, or r-process, nucleosynthesis is sensitive to the nuclear physics properties of thousands of unstable neutron-rich nuclear species that participate in the process. It has long been recognized that the some of the most influential pieces of nuclear data for r-process simulations are ?-decay lifetimes. In light of experimental advances that have pushed measurement capabilities closer to the classic r-process path, we revisit the role of individual ?-decay rates in the r process. We perform ?-decay rate sensitivity studies for a main (A > 120) r process in a range of potential astrophysical scenarios. We study the influence of individual rates during (n, ?)-(?, n) equilibrium and during the post-equilibrium phase where material moves back toward stability. We confirm the widely accepted view that the most important lifetimes are those of nuclei along the r-process path for each astrophysical scenario considered. However, we find in addition that individual ?-decay rates continue to shape the final abundance pattern through the post-equilibrium phase, for as long as neutron capture competes with ? decay. Many of the lifetimes important for this phase of the r process are within current or near future experimental reach.

  19. R-process nucleosynthesis calculations with complete nuclear physics input

    E-print Network

    I. Petermann; A. Arcones; A. Keli?; K. Langanke; G. Martínez-Pinedo; K. -H. Schmidt; W. R. Hix; I. Panov; T. Rauscher; F. -K. Thielemann; N. Zinner

    2008-12-04

    The r-process constitutes one of the major challenges in nuclear astrophysics. Its astrophysical site has not yet been identified but there is observational evidence suggesting that at least two possible sites should contribute to the solar system abundance of r-process elements and that the r-process responsible for the production of elements heavier than Z=56 operates quite robustly producing always the same relative abundances. From the nuclear-physics point of view the r-process requires the knowledge of a large number of reaction rates involving exotic nuclei. These include neutron capture rates, beta-decays and fission rates, the latter for the heavier nuclei produced in the r-process. We have developed for the first time a complete database of reaction rates that in addition to neutron-capture rates and beta-decay half-lives includes all possible reactions that can induce fission (neutron-capture, beta-decay and spontaneous fission) and the corresponding fission yields. In addition, we have implemented these reaction rates in a fully implicit reaction network. We have performed r-process calculations for the neutrino-driven wind scenario to explore whether or not fission can contribute to provide a robust r-process pattern.

  20. Variances in r-process predictions from uncertain nuclear rates

    NASA Astrophysics Data System (ADS)

    Mumpower, Matthew; Surman, Rebecca; Aprahamian, Ani

    2015-04-01

    Rapid neutron capture or ‘r-process’ nucleosynthesisis a critical process for creating approximately half of heavy elements above iron in the Universe. Simulations of the r- process require theoretical calculations of neutron capture and, ?-decay rates for thousands of short-lived nuclei for which no experimental data exists. We explore the impact of uncertainties in theoretical nuclear rates by performing global monte carlo simulations. We show that randomly varying neutron capture and ?-decay rates within current theoretical model uncertainties results in large error bars for r-process predictions. We conclude that the reduction of rate uncertainties either by new measurements or by improved nuclear models will allow for more robust r-process predictions.

  1. Constraints on r-process nucleosynthesis in accretion disks

    NASA Technical Reports Server (NTRS)

    Jin, Liping

    1991-01-01

    Systems in which accretion drives an outflow from a region near a compact object may enrich the interstellar medium in r-process elements. A detailed assessment of the efficacy of this mechanism for the r-process is presented here, taking into account the constraints imposed by typical accretion-disk conditions. It is concluded that r-process elements are unlikely to have been made in this way, largely because the total production is too low, by a factor of about 100,000, to explain the observed abundances.

  2. Impact of nuclear fission on r-process nucleosynthesis and origin of solar r-process elements

    NASA Astrophysics Data System (ADS)

    Shibagaki, Shota; Kajino, Toshitaka; Mathews, Grant J.; Chiba, Satoshi

    2015-02-01

    Binary neutron star mergers (NSMs) are expected to be main production sites of r-process elements. Their ejecta are extremely neutron-rich (Ye<0.1), and the r-process path proceeds along the neutron drip line and enters the region of fissile nuclei. In this situation, although superheavy nuclei may be synthesized and the r-process path may reach the island of stability, those are sensitive to theoretical models of nuclear masses and nuclear fission. In this study, we carry out r-process nucleosynthesis simulations in the NSMs. Our new nuclear reaction network code include new theoretical models of nuclear masses and nuclear fission. Our r-process simulation of a binary NSM shows that the final r-process elemental abundances exhibit flat pattern for A˜110-160, and several fission cycling operate in extremely neutron-rich conditions of the NSM. We find that the combination of the NSMs and the magnetorotational supernovae can reproduce the solar r-process elements. We discuss the validity of this interpretation.

  3. Galactic r-process production: The inhomogeneous approach

    E-print Network

    Wehmeyer, B; Thielemann, F -K

    2015-01-01

    The origin of elements made by the rapid neutron-capture process (r-process) is not fully understood. Different sources have been proposed, e.g., core-collapse supernovae and neutron star mergers. Old metal-poor stars carry the signature of the astrophysical r-process source(s). Europium is the most indicative element to trace the r-process production, since it is mostly made by the r-process and it is easy to observe compared to other heavy r-process elements. In this work we simulate the evolution of europium in our Galaxy with the inhomogeneous chemical evolution model ICE, and we compare our results with spectroscopic observations. We test the most important parameters affecting the chemical evolution of the r-process element Eu: (a) for neutron star mergers the coalescence time scale of the merger and the probability to experience a neutron star merger event after two supernova explosions occurred and formed a double neutron star system ) and (b) for the sub-class of magneto-rotationally driven Supernova...

  4. Neutrino Reactions on 4He and the r-Process

    Microsoft Academic Search

    Bradley S. Meyer

    1995-01-01

    Neutrinos from a Kelvin-Helmholtz--cooling neutron star drive the winds in which the r-process of nucleosynthesis possibly occurs. The neutrinos establish the matter expansion rate, the entropy per baryon, and the neutron richness in the wind material. Some models of the nucleosynthesis in neutrino-driven winds have successfully reproduced the solar r-process isotopic patterns and yields. An effect not previously included in

  5. Barium from a mini r-process in supernovae

    NASA Technical Reports Server (NTRS)

    Heymann, D.

    1983-01-01

    McCulloch and Wasserburg (1978) have reported nonlinear isotopic anomalies in barium for two Ca-Al-rich inclusions of the Allende carbonaceous chondrite, known as EK-1-4-1 and C-1. In an attempt to account for these anomalies, it has been proposed that Ba from an r-process of nucleosynthesis, containing Ba-135 and Ba-137, was injected into the primeval color system but was not totally homogenized. Questions arise in connection with the relations of Xe isotopes in carbonaceous chondrites. This has prompted Heymann and Dziczkaniec (1979, 1980, 1981) to study the formation of r-Xe, r-Kr, and r-Te by the mini r-process which is thought to occur in the O, Ne-rich shells of Type II supernovae. Lee et al. (1979) have studied the formation of r-Ba, r-Nd, and r-Sm by the same process. Certain differences regarding the approaches used by Lee et al. and by Heymann and Dziczkaniec make it necessary to restudy the work of Lee et al. Attention is given to the survival probabilities of nuclear species of interest, taking into accounts the elements Cs, Ba, I, and Xe.

  6. The i-process and CEMP-r/s stars

    E-print Network

    Dardelet, L; Prado, P; Heringer, E; Higgs, C; Jones, S; Denissenkov, P; Venn, K; Bertolli, M; Pignatari, M; Woodward, P; Herwig, F

    2015-01-01

    We investigate whether the anomalous elemental abundance patterns in some of the C-enhanced metal-poor-s+r (CEMP-r/s) stars are consistent with predictions of nucleosynthesis yields from the i-process, a neutron-capture regime at neutron densities intermediate between those typical for the slow (s) and rapid (r) processes. Conditions necessary for the i-process are expected to be met at multiple stellar sites, such as the He-core and He-shell flashes in low-metallicity low-mass stars, super-AGB and post-AGB stars, as well as low-metallicity massive stars. We have found that single-exposure one-zone simulations of the i-process reproduce the abundance patterns in some of the CEMP-r/s stars much better than the model that assumes a superposition of yields from s- and r-process sources. Our previous study of nuclear data uncertainties relevant to the i-process revealed that they could have a significant impact on the i-process yields obtained in our idealized one-zone calculations, leading, for example, to ~0.7d...

  7. R&M 2000 and the Air Force Acquisition Process

    Microsoft Academic Search

    Bernard P. Randolph

    1987-01-01

    This paper discusses the impact of R&M 2000 on the acquisition process. The paper emphasizes the interest level during the acquisition process, and the opportunities created by the proper implementation of advanced technology to improve the reliability and maintainability of systems. The use of electronics in weapon systems may be the way in which weapon systems gain increased capability to

  8. Sensitivity studies for the main r process: nuclear masses

    SciTech Connect

    Aprahamian, A.; Mumpower, M. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States)] [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Bentley, I. [Department of Chemistry and Physics, St. Mary's College, Notre Dame, IN 46556 (United States)] [Department of Chemistry and Physics, St. Mary's College, Notre Dame, IN 46556 (United States); Surman, R. [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)] [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)

    2014-04-15

    The site of the rapid neutron capture process (r process) is one of the open challenges in all of physics today. The r process is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both the uncertainties associated with astrophysical conditions that are needed to allow an r process to occur and a vast lack of knowledge about the properties of nuclei far from stability. One way is to disentangle the nuclear and astrophysical components of the question. On the nuclear physics side, there is great global competition to access and measure the most exotic nuclei that existing facilities can reach, while simultaneously building new, more powerful accelerators to make even more exotic nuclei. On the astrophysics side, various astrophysical scenarios for the production of the heaviest elements have been proposed but open questions remain. This paper reports on a sensitivity study of the r process to determine the most crucial nuclear masses to measure using an r-process simulation code, several mass models (FRDM, Duflo-Zuker, and HFB-21), and three potential astrophysical scenarios.

  9. r-process nucleosynthesis in dynamic helium-burning environments

    NASA Technical Reports Server (NTRS)

    Cowan, J. J.; Cameron, A. G. W.; Truran, J. W.

    1985-01-01

    The results of an extended examination of r-process nucleosynthesis in helium-burning enviroments are presented. Using newly calculated nuclear rates, dynamical r-process calculations have been made of thermal runaways in helium cores typical of low-mass stars and in the helium zones of stars undergoing supernova explosions. These calculations show that, for a sufficient flux of neutrons produced by the C-13 neutron source, r-process nuclei in solar proportions can be produced. The conditions required for r-process production are found to be 10 to the 20th-10 to the 21st neutrons per cubic centimeter for times of 0.01-0.1 s and neutron number densities in excess of 10 to the 19th per cubic centimeter for times of about 1 s. The amount of C-13 required is found to be exceedingly high - larger than is found to occur in any current stellar evolutionary model. It is thus unlikely that these helium-burning environments are responsible for producing the bulk of the r-process elements seen in the solar system.

  10. The r-process in the early Galaxy

    E-print Network

    Jennifer A. Johnson; Michael Bolte

    2002-08-20

    We report Sr, Pd and Ag abundances for a sample of metal-poor field giants and analyze a larger sample of Y, Zr, and Ba abundances. The [Y/Zr] and [Pd/Ag] abundance ratios are similar to those measured for the r-process-rich stars CS 22892-052 and CS 31082-001. The [Pd/Ag] ratio is larger than predicted from the solar-system r-process abundances. The constant[Y/Zr] and [Sr/Y] values in the field stars places strong limits on the contributions of the weak s-process and the main s-process to the light neutron-capture elements. Stars in the globular cluster M 15 possess lower [Y/Zr] values than the field stars. There is a large dispersion in [Y/Ba]. Because the r-process is responsible for the production of the heavy elements in the early Galaxy, these dispersions require varying light-to-heavy ratios in r-process yields.

  11. Nuclear Structure and Setting Constraints on the r-process?

    NASA Astrophysics Data System (ADS)

    Aprahamian, Ani

    2015-04-01

    One of the open questions in all of physics today has to do with the site of the r-process. There are uncertainties associated with the astrophysics, the observations, and the physics of nuclei far from stability. This paper uses existing nuclear physics models and their implied properties for nuclei far from stability to determine the nuclei that have the greatest impact on a given astrophysical scenario. The properties considered are nuclear masses, beta- decay rates, and neutron capture rates individually as well as in a correlated way to identify the most important nuclei in a given r-process trajectory. The ultimate goal is to set some constraints on potential sites of the r-process based on the nuclear properties.

  12. The r-, s-, and p-Processes in Nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Meyer, Bradley S.

    1994-01-01

    Burbidge et al (1957) and Cameron (1957) laid out the framework for our understanding of the formation of the heavy nuclei (those nuclei with mass number A approx. greater than 70). From systematics in the solar system abundance distribution, Burbidge et al determined that the heavy nuclei were formed in three distinct nucleosynthetic processes, which they termed the r-, s-, and p-processes. That we still use these terms today is a credit to the soundness of this work done 37 years ago. We may understand how Burbidge et al and Cameron arrived at their conclusions from Figure 1. One population of nuclei, the s-nuclei, shows an abundance distribution with peaks near mass numbers 87, 138, and 208. These nuclei are made in a slow neutron-capture process, the s-process. A rapid neutron-capture process, the r-process, is responsible for the r-nuclei, whose abundance distribution shows peaks at mass numbers 80, 130, and 195. The p-process is responsible for production of the rarer, more proton-rich heavy isotopes (the p-nuclei) that cannot be made by neutron capture. The first quantitative evaluations of the ideas of Burbidge et al and Cameron came to light in the early 1960s with work on the s-process (Clayton et al 1961, Seeger et al 1965) and the r-process (Seeger et al 1965). These calculations further elucidated the mechanisms for heavy-element formation and showed the plausibility of the framework developed in the 1950s. Subsequent work has focused on determining the astrophysical sites where the r-, s-, and p-processes occurred with the help of improved nuclear details, stellar models, and abundances. A goal of this paper is to review the recent progress astrophysicists, astronomers, and physicists have made in these directions and to point out the problems that remain in our understanding of the formation of the heavy nuclei. Another, perhaps deeper, goal is to to seek some understanding of why there are three major processes available to nature for synthesis of heavy elements. It is impossible for a single paper to cover all relevant aspects of the r-, s-, and p-processes; therefore, where possible, references to other reviews are given. Readers should turn to these reviews for more details. Nevertheless, it is hoped that the present paper gives some flavor for the rich field of heavy-element synthesis.

  13. The r-Process in Black Hole Winds

    E-print Network

    Shinya Wanajo; Hans-Thomas Janka

    2010-06-11

    All the current r-process scenarios relevant to core-collapse supernovae are facing severe difficulties. In particular, recent core-collapse simulations with neutrino transport show no sign of a neutron-rich wind from the proto-neutron star. In this paper, we discuss nucleosynthesis of the r-process in an alternative astrophysical site, "black hole winds", which are the neutrino-driven outflow from the accretion torus around a black hole. This condition is assumed to be realized in double neutron star mergers, neutron star - black hole mergers, or hypernovae.

  14. Rosen’s (M,R) system in process algebra

    PubMed Central

    2013-01-01

    Background Robert Rosen’s Metabolism-Replacement, or (M,R), system can be represented as a compact network structure with a single source and three products derived from that source in three consecutive reactions. (M,R) has been claimed to be non-reducible to its components and algorithmically non-computable, in the sense of not being evaluable as a function by a Turing machine. If (M,R)-like structures are present in real biological networks, this suggests that many biological networks will be non-computable, with implications for those branches of systems biology that rely on in silico modelling for predictive purposes. Results We instantiate (M,R) using the process algebra Bio-PEPA, and discuss the extent to which our model represents a true realization of (M,R). We observe that under some starting conditions and parameter values, stable states can be achieved. Although formal demonstration of algorithmic computability remains elusive for (M,R), we discuss the extent to which our Bio-PEPA representation of (M,R) allows us to sidestep Rosen’s fundamental objections to computational systems biology. Conclusions We argue that the behaviour of (M,R) in Bio-PEPA shows life-like properties. PMID:24237684

  15. Steady flow approximations to the helium r-process

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.; Cowan, J. J.; Klapdor, H. V.; Metzinger, J.; Oda, T.; Truran, J. W.

    1983-01-01

    A steady flow approximation to the r-process is presented and used for numerical experiments with physical quantities to determine the sensitivity of the process to variations in those quantities. The effect of neutron capture cross sections along the capture path and of recently available improved beta decay rates on the r-process are discussed. The peaks in the observed r-process yield curve near mass numbers 80 and 130 are roughly characterized by a neutron number density of 10 to the 20th per cu/cm; the mean beta decay rates are about 10/s, and the freezing time is comparable to or less than 0.1 s. The peak near mass number 195 is roughly characterized by a neutron number density of 10 to the 21st/cm, the mean beta decay rates are about 100/s, and the freezing time is comparable to or less than 0.01 s. The flow path of the steady state r-process is sensitively dependent upon the neutron capture cross sections in the flow network and on the values of the beta decay rates.

  16. Explosive Nucleosynthesis and the Astrophysical rProcess

    E-print Network

    Rauscher, Thomas

    Explosive Nucleosynthesis and the Astrophysical r­Process F.­K. Thielemann 1 , C. Freiburghaus 1 in explosive burning and the role which neutron and/or proton separation energies play. We focus neutron stars after a supernova explosion, followed the expansion of matter with initial entropies

  17. Process rc es r e o re o r s or o ro c o e oor o o s r e s e s

    E-print Network

    Process rc es r e o re o r s or o ro c o e oor o o s r e s e s Abstract str b t r s rts c ab rat r c ss s c s act t s c t s c r at a c r at t act t s a t a a art t t sta rs t r c ss s a ss t a c aract r st c r s bas t c c t a r c ss scr b t r c ss t b a ac t s c ct t r t r c ss act t r s rt a t r

  18. Assessment of advanced coal-gasification processes. [AVCO high throughput gasification in process; Bell High Mass Flux process; CS-R process; and Exxon Gasification process

    SciTech Connect

    McCarthy, J.; Ferrall, J.; Charng, T.; Houseman, J.

    1981-06-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process, Bell Single - Stage High Mass Flux (HMF) Process, Cities Service/Rockwell (CS/R) Hydrogasification Process, and the Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic fluidbed reactor producing all of the raw product methane in the gasifier.

  19. Probabilities of delayed processes for nuclei involved in the r-process

    SciTech Connect

    Panov, I. V., E-mail: Igor.Panov@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation); Korneev, I. Yu.; Lutostansky, Yu. S. [National Research Center Kurchatov Institute (Russian Federation)] [National Research Center Kurchatov Institute (Russian Federation); Thielemann, F.-K. [University of Basel, Institute of Physics (Switzerland)] [University of Basel, Institute of Physics (Switzerland)

    2013-01-15

    Delayed fission, along with induced and spontaneous fission, is responsible for the suppression of the production of superheavy elements both during the r-process and after its completion. Beta-decay strength functions are required for calculating delayed fission. In the present study, respective strength functions are calculated by relying on the theory of finite Fermi systems and by predominantly employing nuclear masses and fission barriers predicted by a generalized Thomas-Fermi model. The probabilities for delayed fission and for the emission of delayed neutrons are calculated for a number of isotopes. On the basis of calculations performed in order to determine the probabilities for delayed processes, it is shown that some of the delayed-fission probabilities calculated thus far were substantially overestimated. The application of these new results to calculating the r-process may change substantially both the r-process path and the yields of superheavy nuclei.

  20. ?-decay spectroscopy for the r-process nucleosynthesis

    SciTech Connect

    Nishimura, Shunji [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Collaboration: RIBF Decay Collaborations

    2014-05-09

    Series of decay spectroscopy experiments, utilizing of high-purity Ge detectors and double-sided silicon-strip detectors, have been conducted to harvest the decay properties of very exotic nuclei relevant to the r-process nucleosynthesis at the RIBF. The decay properties such as ?-decay half-lives, low-lying states, ?-delayed neutron emissions, isomeric states, and possibly Q{sub ?} of the very neutron-rich nuclei are to be measured to give significant constraints in the uncertainties of nuclear properties for the r-process nucleosynthesis. Recent results of ?? spectroscopy study using in-flight fission of {sup 238}U-beam will be presented together with our future perspectives.

  1. Predictions for nuclear properties along the r-process path

    SciTech Connect

    Aprahamian, A.

    1987-10-15

    The uniformity of different nuclear regions as a function of the number of valence protons and neutrons (counted from the nearest closed shell) has been exploited for the parameterization of calculations for nuclei far from stability within the IBA model. Predictions are given for low lying levels, E2 transition rates, and binding energies for nuclei in the r-process path in the A = 150 and A = 190 mass regions. 6 refs., 6 figs.

  2. Explosive nucleosynthesis and the astrophysical r-process

    SciTech Connect

    Thielemann, F.-K.; Freiburghaus, C.; Rauscher, T.; Kolbe, E. [Departement fuer Physik und Astronomie, Univ. Basel, Klinglbergstr. 82, CH-4056 Basel (Switzerland); Pfeiffer, B.; Kratz, K.-L. [Institut fuer Kernchemie, Univ. Mainz, Fritz-Strassmann-Weg 2, D-55099 Mainz (Germany); Cowan, J. J. [Department of Physics and Astronomy, Univ. of Oklahoma, Norman, Oklahoma 73019 (United States)

    1998-12-21

    We give an overview of chemical equilibria in explosive burning and the role which neutron and/or proton separation energies play. We focus then on the rapid neutron-capture process (r-process) which encounters unstable nuclei far from beta-stability with neutron separation energies in the range 1-4 MeV. Its observable features, like the abundances, witness nuclear structure as well as the conditions in the appropriate astrophysical environment. With the remaining lack of a full understanding of its astrophysical origin, parametrized calculations are still necessary. The classical approach is based on (constant) neutron number densities n{sub n} and temperatures T over duration timescales {tau}. Recent investigations, motivated by the neutrino wind scenario from hot neutron stars after a supernova explosion, followed the expansion of matter with initial entropies S and electron fractions Y{sub e} over expansion timescales {tau}. We compare the similarities and differences between the two approaches with respect to resulting abundance features and their relation to solar r-process abundances. Special emphasis is given to the questions (i) whether the same nuclear properties far from stability lead to similar abundance patterns and deficiencies in both approaches and (ii) whether some features can also provide clear constraints on the permitted astrophysical conditions.

  3. Novel technique for constraining r-process (n, ?) reaction rates.

    PubMed

    Spyrou, A; Liddick, S N; Larsen, A C; Guttormsen, M; Cooper, K; Dombos, A C; Morrissey, D J; Naqvi, F; Perdikakis, G; Quinn, S J; Renstrøm, T; Rodriguez, J A; Simon, A; Sumithrarachchi, C S; Zegers, R G T

    2014-12-01

    A novel technique has been developed, which will open exciting new opportunities for studying the very neutron-rich nuclei involved in the r process. As a proof of principle, the ? spectra from the ? decay of ^{76}Ga have been measured with the SuN detector at the National Superconducting Cyclotron Laboratory. The nuclear level density and ?-ray strength function are extracted and used as input to Hauser-Feshbach calculations. The present technique is shown to strongly constrain the ^{75}Ge(n,?)^{76}Ge cross section and reaction rate. PMID:25526121

  4. THE r-PROCESS IN METAL-POOR STARS AND BLACK HOLE FORMATION

    SciTech Connect

    Boyd, R. N. [Physics and Life Sciences, L-050, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Famiano, M. A. [Department of Physics and Joint Institute for Nuclear Astrophysics (JINA), Western Michigan University, 1903 W. Michigan Avenue, Kalamazoo, MI 49008-5252 (United States); Meyer, B. S. [Department of Physics and Astronomy, Clemson University, 118 Kinard Laboratory, Clemson, SC 29634-0978 (United States); Motizuki, Y. [RIKEN Nishina Center, Hirosawa 2-1, Wako 351-0198 (Japan); Kajino, T. [National Astronomical Observatory of Japan, 2-21-1 Mitaka, Tokyo 181-8588 (Japan); Roederer, I. U., E-mail: boyd11@llnl.gov [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2012-01-15

    Nucleosynthesis of heavy nuclei in metal-poor stars is generally thought to occur via the r-process because the r-process is a primary process that would have operated early in the Galaxy's history. This idea is strongly supported by the fact that the abundance pattern in many metal-poor stars matches well the inferred solar r-process abundance pattern in the mass range between the second and third r-process abundance peaks. Nevertheless, a significant number of metal-poor stars do not share this standard r-process template. In this Letter, we suggest that the nuclides observed in many of these stars are produced by the r-process, but that it is prevented from running to completion in more massive stars by collapse to black holes before the r-process is completed, creating a 'truncated r-process', or 'tr-process'. We find that the observed fraction of tr-process stars is qualitatively what one would expect from the initial mass function and that an apparent sharp truncation observed at around mass 160 could result from a combination of collapses to black holes and the difficulty of observing the higher mass rare-earth elements. We test the tr-process hypothesis with r-process calculations that are terminated before all r-process trajectories have been ejected. We find qualitative agreement between observation and theory when black hole collapse and observational realities are taken into account.

  5. Changes in r-process abundances at late times

    SciTech Connect

    Surman, R.; Engel, J.

    2001-09-01

    We explore changes in abundance patterns that occur late in the r process. As the neutrons available for capture begin to disappear, a quasiequilibrium funnel shifts material into the large peaks at A=130 and A=195, and into the rare-earth ''bump'' at A=160. A bit later, after the free-neutron abundance has dropped and beta decay has begun to compete seriously with neutron capture, the peaks can widen. The degree of widening depends largely on neutron-capture rates in a few nuclei near closed neutron shells and relatively close to stability. We identify particular nuclei whose capture rates should be examined experimentally, perhaps at a radioactive beam facility.

  6. The r-process and neutrino-heated supernova ejecta

    NASA Technical Reports Server (NTRS)

    Woosley, S. E.; Wilson, J. R.; Mathews, G. J.; Hoffman, R. D.; Meyer, B. S.

    1994-01-01

    As a neutron star is formed by the collapse of the iron core of a massive star, its Kelvin-Helmholtz evolution is characterized by the release of gravitational binding energy as neutrinos. The interaction of these neutrinos with heated material above the neutron star generates a hot bubble in an atmosphere that is nearly in hydrostatic equilibrium and heated, after approximately 10 s, to an entropy of S/N(sub AS)k greater than or approximately = 400. The neutron-to-proton ratio for material moving outward through this bubble is set by the balance between neutrino and antineutrino capture on nucleons. Because the electron antineutrino spectrum at this time is hotter than the electron neutrino spectrum, the bubble is neutron-rich (0.38 less than or approximately = Y(sub e) less than or approximately = 0.47). Previous work using a schematic model has shown that these conditions are well suited to the production of heavy elements by the r-process. In this paper we have advanced the numerical modeling of a 20 solar mass 'delayed' supernova explosion to the point that we can follow the detailed evolution of material moving through the bubble at the late times appropiate to r-process nucleosynthesis. The supernova model predicts a final kinetic energy for the ejecta of 1.5 x 10(exp 51) ergs and leaves behind a remnant with a baryon mass of 1.50 solar mass (and a gravitational mass of 1.445 solar mass). We follow the thermodynamic and compositional evolution of 40 trajectories in rho(t), T(t), Y(sub e)(t) for a logarithmic grid of mass elements for the last approximately = 0.03 solar mass to be ejected by the proto-neutron star down to the last less than 10(exp -6) solar mass of material expelled at up to approximately = 18 s after core collapse. We find that an excellent fit to the solar r-process abundance distribution is obtained with no adjustable parameters in the nucleosynthesis calculations. Moreover, the abundances are produced in the quantities required to account for the present Galactic abundances. However, at earlier times, this one-dimensional model ejects too much material with entropies S/N(sub A)k approximately 50 and Y(sub e) approximately 0.46. This leads to an acceptable over production of N = 50 nuclei, particularly Sr-88, Y-89, and Zr-90, relative to their solar abundances. We speculate on various means to avoid the early overproduction and/or ejection of N = 50 isotonic nuclei while still producing and ejecting the correct amount of r-process material.

  7. Formation Of The Rare Earth Peak: Gaining Insight Into Late-Time r-Process Dynamics

    E-print Network

    Mumpower, Matthew; Surman, Rebecca

    2011-01-01

    We study the formation and final structure of the rare earth peak ($A\\sim160$) of the $r$-process nucleosynthesis. The rare earth peak forms at late times in the $r$-process after neutron exhaustion (neutron-to-seed ratio unity or R=1) as matter decays back to stability. Since rare earth peak formation does not occur during \

  8. R-Process Freezeout, Nuclear Deformation, and the Rare-Earth Element Peak

    E-print Network

    R. Surman; J. Engel; J. R. Bennett; B. S. Meyer

    1997-01-03

    We use network calculations of r-process nucleosynthesis to explore the origin of the peak in the solar r-process abundance distribution near nuclear mass number A = 160. The peak is due to a subtle interplay of nuclear deformation and beta decay, and forms not in the steady phase of the r-process, but only just prior to freezeout, as the free neutrons rapidly disappear. Its existence should therefore help constrain the conditions under which the r-process occurs and freezes out.

  9. Realistic fission model and the r-process in neutron star mergers

    SciTech Connect

    Shibagaki, S.; Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556, U.S.A. and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-05-09

    About half of heavy elements are considered to be produced by the rapid neutron-capture process, r-process. The neutron star merger is one of the viable candidates for the astrophysical site of r-process nucleosynthesis. Nuclear fission reactions play an important role in the r-process of neutron star mergers. However theoretical predictions about fission properties of neutron-rich nuclei have some uncertainties. Especially, their fission fragment distributions are totally unknown and the phenomenologically extrapolated distribution was often applied to nucleosynthesis calculations. In this study, we have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions. We discuss the effects on the r-process in neutron star mergers from the nuclear fission of heavy neutron-rich actinide elements. We also discuss how variations in the fission fragment distributions affect the abundance pattern.

  10. Neutron-capture elements in the s- and r-process-rich stars: Constraints on neutron-capture nucleosynthesis processes

    E-print Network

    Bo Zhang; Kun Ma; Guide Zhou

    2006-05-14

    The chemical abundances of the very metal-poor double-enhanced stars are excellent information for setting new constraints on models of neutron-capture processes at low metallicity. These stars are known as s+r stars, since they show enhancements of both s-process and r-process elements. The observed abundance ratios for the double-enhanced stars can be explained by those of stars that were polluted by an AGB star and subsequently accreted very significant amounts of r-process material out of an AIC (accretion-induced collapse) or Type 1.5 supernova. In this paper we present for the first time an attempt to fit the elemental abundances observed in the s- and r-rich, very metal-poor stars using a parametric model and suggest a new concept of component coefficients to describe the contributions of the individual neutron-capture processes to double-enhanced stars. We find that the abundance ratios of these stars are best fitted by enrichments of s- and r-process material. The overlap factor in the AGB stars where the observed s-process elements were produced lies between 0.1 and 0.81. Taking into account the dependence of the initial-final mass relations on metallicity, this wide range of values could possibly be explained by a wide range of core-mass values of AGB stars at low metallicity. The component coefficient of the r-process is strongly correlated with the component coefficient of the s-process for the double-enhanced stars. This is significant evidence that the r-process material in double-enhanced stars comes from an AIC or Type 1.5 supernova.

  11. MPCI: An R Package for Computing Multivariate Process Capability Indices

    Microsoft Academic Search

    Edgar Santos-Fernández; Michele Scagliarini

    2012-01-01

    Manufacturing processes are often based on more than one quality characteristic. When these variables are correlated the process capability analysis should be performed using multivariate statistical methodologies. Although there is a growing interest in methods for evaluating the capability of multivariate processes, little attention has been given to developing user friendly software for supporting multivariate capability analysis. In this work

  12. Handling Concept Drift in Process Mining R.P. Jagadeesh Chandra Bose1,2

    E-print Network

    van der Aalst, Wil

    Handling Concept Drift in Process Mining R.P. Jagadeesh Chandra Bose1,2 , Wil M.P. van der Aalst1 to the phenomenon known as concept drift. While cases are being handled, the process itself may be changing in ProM3 and evaluated by analyzing an evolving process. Keywords: process mining, concept drift

  13. r-Java : An r-process Code and Graphical User Interface for Heavy-Element Nucleosynthesis

    E-print Network

    Charignon, Camille; Koning, Nico; Jaikumar, Prashanth; Ouyed, Rachid

    2011-01-01

    We present r-Java, an r-process code for open use, that performs r-process nucleosynthesis calculations. Equipped with a simple graphical user interface, r-Java is capable of carrying out nuclear statistical equilibrium (NSE) as well as static and dynamic r-process calculations for a wide range of input parameters. In this introductory paper, we present the motivation and details behind r-Java, and results from our static and dynamic simulations. Static simulations are explored for a range of neutron irradiation and temperatures. Dynamic simulations are studied with a parameterized expansion formula. Our code generates the resulting abundance pattern based on a general entropy expression that can be applied to degenerate as well as non-degenerate matter, allowing us to track the rapid density and temperature evolution of the ejecta during the initial stages of ejecta expansion. At present, our calculations are limited to the waiting-point approximation. We encourage the nuclear astrophysics community to provi...

  14. r-Java : An r-process Code and Graphical User Interface for Heavy-Element Nucleosynthesis

    E-print Network

    Camille Charignon; Mathew Kostka; Nico Koning; Prashanth Jaikumar; Rachid Ouyed

    2011-04-02

    We present r-Java, an r-process code for open use, that performs r-process nucleosynthesis calculations. Equipped with a simple graphical user interface, r-Java is capable of carrying out nuclear statistical equilibrium (NSE) as well as static and dynamic r-process calculations for a wide range of input parameters. In this introductory paper, we present the motivation and details behind r-Java, and results from our static and dynamic simulations. Static simulations are explored for a range of neutron irradiation and temperatures. Dynamic simulations are studied with a parameterized expansion formula. Our code generates the resulting abundance pattern based on a general entropy expression that can be applied to degenerate as well as non-degenerate matter, allowing us to track the rapid density and temperature evolution of the ejecta during the initial stages of ejecta expansion. At present, our calculations are limited to the waiting-point approximation. We encourage the nuclear astrophysics community to provide feedback on the code and related documentation, which is available for download from the website of the Quark-Nova Project: http://quarknova.ucalgary.ca/

  15. The r-Process in Supersonic Neutrino-Driven Winds: The Roll of Wind Termination Shock

    E-print Network

    Takami Kuroda; Shinya Wanajo; Ken'ichi Nomoto

    2007-09-17

    Recent hydrodynamic studies of core-collapse supernovae imply that the neutrino-heated ejecta from a nascent neutron star develops to supersonic outflows. These supersonic winds are influenced by the reverse shock from the preceding supernova ejecta, forming the wind termination shock. We investigate the effects of the termination shock in neutrino-driven winds and its roll on the r-process. Supersonic outflows are calculated with a semi-analytic neutrino-driven wind model. Subsequent termination-shocked, subsonic outflows are obtained by applying the Rankine-Hugoniot relations. We find a couple of effects that can be relevant for the r-process. First is the sudden slowdown of the temperature decrease by the wind termination. Second is the entropy jump by termination-shock heating, up to several 100NAk. Nucleosynthesis calculations in the obtained winds are performed to examine these effects on the r-process. We find that 1) the slowdown of the temperature decrease plays a decisive roll to determine the r-process abundance curves. This is due to the strong dependences of the nucleosynthetic path on the temperature during the r-process freezeout phase. Our results suggest that only the termination-shocked winds with relatively small shock radii (~500km) are relevant for the bulk of the solar r-process abundances (A~100-180). The heaviest part in the solar r-process curve (A~180-200), however, can be reproduced both in shocked and unshocked winds. These results may help to constrain the mass range of supernova progenitors relevant for the r-process. We find, on the other hand, 2) negligible roles of the entropy jump on the r-process. This is a consequence that the sizable entropy increase takes place only at a large shock radius (~10,000km) where the r-process has already ceased.

  16. New developments in understanding the r-process from observations of metal-poor stars

    NASA Astrophysics Data System (ADS)

    Frebel, Anna

    2015-04-01

    In their atmospheres, old metal-poor Galactic stars retain detailed information about the chemical composition of the interstellar medium at the time of their birth. Extracting such stellar abundances enables us to reconstruct the beginning of the chemical evolution shortly after the Big Bang. About 5% of metal-poor stars with [Fe/H] < - 2 . 5 display in their spectrum a strong enhancement of neutron-capture elements associated with the rapid (r-) nucleosynthesis process that is responsible for the production of the heaviest elements in the Universe. This fortuity provides a unique opportunity of bringing together astrophysics and nuclear physics because these objects act as ``cosmic lab'' for both fields of study. The so-called r-process stars are thought to have formed from material enriched in heavy neutron-capture elements that were created during an r-process event in a previous generation supernova. It appears that the few stars known with this rare chemical signature all follow the scaled solar r-process pattern (for the heaviest elements with 56 <= Z <= 90 that is). This suggests that the r-process is universal - a surprising empirical finding and a solid result that can not be obtained from any laboratory on earth. While much research has been devoted to establishing this pattern, little attention has been given to the overall level of enhancement. New results will be presented on the full extent of r-process element enrichment as observed in metal-poor stars. The challenge lies in determining how the r-process material in the earliest gas clouds was mixed and diluted. Assuming individual r-process events to have contributed the observed r-process elements. We provide empirical estimates on the amount of r-process material produced. This should become a crucial constraint for theoretical nuclear physics models of heavy element nucleosynthesis.

  17. The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries

    Microsoft Academic Search

    M. Arnould; S. Goriely; K. Takahashi

    2007-01-01

    The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of various metallicities, as well as in the solar system.A very large amount of nuclear information is necessary in order to model the r-process. This concerns

  18. International Conference on IEEESignal Processing and Communications R

    E-print Network

    Sharma, Vinod

    , Bangalore SPCOM 2010 July 18-21, 2010 SPCOM 2010 provides a forum for researchers from academia, research Processing Network Information Theory Audio, Speech, Image & Video Signal Processing Sequences & Complexity-hoc and Sensor Networks Next Generation Networking, QoS & Security Multihop and Mesh Networks Vehicular Networks

  19. Cosmochemistry S-and r-process nucleosynthesis

    E-print Network

    Mojzsis, Stephen J.

    Numbers of stable nuclei for odd and even Z and N: Z N A(Z+N) #stable # very long lived Odd Odd Even 4 5 1987A September 16, 2014 #12;H-R diagram and chemistry (Hertzsprung-Russell diagram) L = (Luminosity of the HZ diagram. · When core T = 0.3 x 108 K to 0.8 x 108 K 26Al is an important product THIS NUCLIDE

  20. The r-Process in Metal Poor Stars and Black Hole Formation

    SciTech Connect

    Boyd, R N; Famiano, M A; Meyer, B S; Motizuki, Y; Kajino, T; Roederer, I U

    2011-11-30

    Nucleosynthesis of heavy nuclei in metal-poor stars is generally ascribed to the r-process, as the abundance pattern in many such stars agrees with the inferred Solar r-process abundances. Nonetheless, a significant number of these stars do not share this r-process template. they suggest that many such stars have begun an r-process, but it was prevented from running to completion in more massive stars by collapse to black holes, creating a 'truncated r-process,' or 'tr-process'. The observed fraction of tr-process stars is found to be consistent with expectations from the initial mass function (IMF), and they suggest that an apparent sharp truncation observed at around mass 160 could result from a combination of collapses to black holes and the difficulty of observing the higher mass rare earths. They test the tr-process hypothesis with calculations that are terminated before all r-process trajectories have been ejected. These produce qualitative agreement with observation when both black hole collapse and observational realities are taken into account.

  1. The fundamental role of fission during r-process nucleosynthesis in neutron star mergers

    NASA Astrophysics Data System (ADS)

    Goriely, S.

    2015-02-01

    The rapid neutron-capture process, or r-process, is known to be of fundamental importance for explaining the origin of approximately half of the A > 60 stable nuclei observed in nature. Despite important efforts, the astrophysical site of the r-process remains unidentified. Here we study r-process nucleosynthesis in a material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars. r-process nucleosynthesis during the decompression is known to be largely insensitive to the detailed astrophysical conditions because of efficient fission recycling, producing a composition that closely follows the solar r-abundance distribution for nuclei with mass numbers A > 140. Due to the important role played by fission in such a scenario, the impact of fission is carefully analyzed. We consider different state-of-the-art global models for the determination of the fission paths, nuclear level densities at the fission saddle points and fission fragment distributions. Based on such models, the sensitivity of the calculated r-process abundance distribution is studied. The fission path is found to strongly affect the region of heavy nuclei responsible for the fission recycling, while the fission fragment distribution of nuclei along the A ? 278 isobars defines the abundance pattern of nuclei produced in the 110 ? A ? 170 region. The late capture of prompt fission neutrons is also shown to affect the abundance distribution, and in particular the shape of the third r-process peak around A ? 195.

  2. Relative contributions of the weak, main and fission-recycling r-process

    E-print Network

    S. Shibagaki; T. Kajino; G. J. Mathews; S. Chiba; S. Nishimura; G. Lorusso

    2015-05-09

    There has been a persistent conundrum in attempts to model the nucleosynthesis of heavy elements by rapid neutron capture (the $r$-process). Although the location of the abundance peaks near nuclear mass numbers 130 and 195 identify an environment of rapid neutron capture near closed nuclear shells, the abundances of elements just above and below those peaks are often underproduced by more than an order of magnitude in model calculations. At the same time there is a debate in the literature as to what degree the $r$-process elements are produced in supernovae or the mergers of binary neutron stars. In this paper we propose a novel solution to both problems. We demonstrate that the underproduction of elements above and below the $r$-process peaks characteristic in the main or weak $r$-process events (like magnetohydrodynamic jets or neutrino-driven winds in core-collapse supernovae) can be supplemented via fission fragment distributions from the recycling of material in a neutron-rich environment such as that encountered in neutron star mergers. In this paradigm, the abundance peaks themselves are well reproduced by a moderately neutron rich, main $r$-process environment such as that encountered in the magnetohydrodynamical jets in supernovae supplemented with a high-entropy, weakly neutron rich environment such as that encountered in the neutrino-driven-wind model to produce the lighter $r$-process isotopes. Moreover, we show that the relative contributions to the $r$-process abundances in both the solar-system and metal-poor stars from the weak, main, and fission-recycling environments required by this proposal are consistent with estimates of the relative Galactic event rates of core-collapse supernovae for the weak and main $r$-process and neutron star mergers for the fission-recycling $r$-process.

  3. Modern Information Processing: From Theory to Applications 1 B. Bouchon-Meunier, G. Coletti and R.R. Yager, Editors

    E-print Network

    Utrecht, Universiteit

    tests are uncertain to at least some extent. In the medical domain, for example, an X-ray canModern Information Processing: From Theory to Applications 1 B. Bouchon-Meunier, G. Coletti and R for reasoning with uncertainty in a variety of application domains. A probabilistic network in essence

  4. The impact of nuclear masses near $N=82$ on $r$-process abundances

    E-print Network

    M. Mumpower; D. -L. Fang; R. Surman; M. Beard; A. Aprahamian

    2014-10-27

    We have performed for the first time a complete $r$-process mass sensitivity study in the $N=82$ region. We take into account how an uncertainty in a single nuclear mass propagates to influence important quantities of neighboring nuclei, including Q-values and reaction rates. We demonstrate that nuclear mass uncertainties of $\\pm0.5$ MeV in the $N=82$ region result in up to an order of magnitude local change in $r$-process abundance predictions. We identify key nuclei in the study whose mass has a substantial impact on final $r$-process abundances and could be measured at future radioactive beam facilities.

  5. The Astrophysical r-Process 50 Years after B{sup 2}FH

    SciTech Connect

    Kratz, K.-L.; Pfeiffer, B. [Max-Planck-Institut fuer Chemie, Otto-Hahn-Institut, D-55128 Mainz (Germany); Farouqi, K. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL60637 (United States); Mashonkina, L. I. [Institute of Astronomy, Russian Academy of Science, RU-119017 Moscow (Russian Federation)

    2008-01-24

    Since the historical papers by Burbidge et al. and Cameron 50 years ago, it is generally accepted that half of the chemical elements above Fe are formed in explosive stellar scenarios by a rapid neutron-capture process (the classical ''r-process''). Already from their essential ideas, it became clear that a correct modelling of this nucleosynthesis process requires both, the knowledge of various nuclear properties very far from stability and a detailed description of the astrophysical environments. However, it took about three decades, until in 1986 the first experimental nuclear-physics data on the neutron-magic r-isotopes {sup 80}Zn and {sup 130}Cd could be obtained, which act as key ''waiting points'' in the respective A{approx_equal}80 and 130 peaks of the Solar-System (SS) r-abundances (N{sub r,{center_dot}}). Since then, using steadily improved nuclear data, we have optimized our r-process calculations to reproduce the present observables of the isotopic N{sub r,{center_dot}} ''residuals'', as well as the more recent elemental abundances in ultra-metal-poor, r-process-enriched halo stars. Concerning the latter observations, we support the basic idea about two different types of r-processes. Based on our many years' experience with the site-independent ''waiting-point approach'', we recently have extended our studies to fully dynamical network calculations for the most likely astrophysical r-process scenario, i.e. the high-entropy wind (HEW) of core-collapse type II supernovae (SN II). Again, an excellent reproduction of all observables for the ''main'' r-process has been achieved. However, a major difference is the nucleosynthesis origin of the lighter heavy elements in the 29{<=}Z{<=}45 mass region. Here, the HEW model predicts-instead of a ''weak'' neutron-capture r-process component-a primary rapid charged-particle process. This may explain the recent observations of a non-correlation of these elements with the heavier ''main'' r-process elements.

  6. Efficient Processing of Spatial Joins Using R-Trees

    Microsoft Academic Search

    Thomas Brinkhoff; Hans-Peter Kriegel; Bernhard Seeger

    1993-01-01

    Spatial joins are one of the most important operations for combin- ing spatial objects of several relations. The efficient processing of a spatial join is extremely important since its execution time is super- linear in the number of spatial objects of the participating relations, and this number of objects may be very high. In this paper, we present a first

  7. Learning curves for multi-task Gaussian process Simon R F Ashton

    E-print Network

    Sollich, Peter

    Learning curves for multi-task Gaussian process regression Simon R F Ashton King's College London-task learning. PAC-style bounds for classification [2, 3, 10] in more general multi-task sce- narios exist Department of Mathematics Strand, London WC2R 2LS, U.K. Peter Sollich King's College London Department

  8. Constructs of Process Change Management in ERP Context: A Focus on SAP R\\/3

    Microsoft Academic Search

    Majed Al-Mashari

    2000-01-01

    This paper explores the ERP phenomenon from a process change management (PCM) perspective. A framework is used to highlight the various PCM constructs in the context of SAP R\\/3 implementation. Evidence on how these constructs are operationalized in practice is drawn from a large collection of R\\/3 case studies representing various organizational experiences. The paper provides foundation and recommends several

  9. Beta decay rates for nuclei with 115 < A < 140 for r-process nucleosynthesis

    E-print Network

    Kamales Kar; Soumya Chakravarti; V. R. Manfredi

    2006-03-19

    For r-process nucleosynthesis the beta decay rates for a number of neutron-rich intermediate heavy nuclei are calculated. The model for the beta strength function is able to reproduce the observed half~lives quite well.

  10. r-process nucleosynthesis in the high-entropy supernova bubble

    NASA Technical Reports Server (NTRS)

    Meyer, B. S.; Mathews, G. J.; Howard, W. M.; Woosley, S. E.; Hoffman, R. D.

    1992-01-01

    We show that the high-temperature, high-entropy evacuated region outside the recent neutron star in a core-collapse supernova may be an ideal r-process site. In this high-entropy environment it is possible that most nucleons are in the form of free neutrons or bound into alpha particles. Thus, there can be many neutrons per seed nucleus even though the material is not particularly neutron rich. The predicted amount of r-process material ejected per event from this environment agrees well with that required by simple galactic evolution arguments. When averaged over regions of different neutron excess in the supernova ejecta, the calculated r-process abundance curve can give a good representation of the solar-system r-process abundances as long as the entropy per baryon is sufficiently high. Neutrino irradiation may aid in smoothing the final abundance distribution.

  11. Detection of the Second R-Process Peak Element Tellurium in Metal-Poor Stars

    E-print Network

    Roederer, Ian U.

    Using near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, we detect neutral tellurium in three metal-poor stars enriched by products of r-process nucleosynthesis, ...

  12. Light-Element Reaction Flow and the Conditions for r-Process Nucleosynthesis

    E-print Network

    T. Sasaqui; K. Otsuki; T. Kajino; G. J. Mathews

    2006-03-18

    We deduce new constraints on the entropy per baryon ($s/k$), dynamical timescale ($\\tau_{dyn}$), and electron fraction ($Y_{e}$) consistent with heavy element nucleosynthesis in the r-process. We show that the previously neglected reaction flow throu gh the reaction sequence \\atg (n,$\\gamma$)\\Li~ significantly enhances the production of seed nuclei. We analyze the r-process nucleosynthesis in the context of a schematic exponential wi nd model. We show that fewer neutrons per seed nucleus implies that the entropy per baryon required for successful r-process nucleosynthesis must be more than a factor of two higher than previous estimates. This places new constraints on dynamical mo dels for the r-process.

  13. All-optical packet switching with all-optical header processing and 2R regeneration

    E-print Network

    Wai, Ping-kong Alexander

    CTuF1 All-optical packet switching with all-optical header processing and 2R regeneration L. F. K demonstrate a 1×4 10 Gb/s all-optical packet switch with all-optical header processing and 2R regeneration/s respectively. ©2005 OpticalSocietyof America OCIS codes: (230.1150)All-optical devices; (060.2330) Fiberoptics

  14. The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries

    E-print Network

    M. Arnould; S. Goriely; K. Takahashi

    2007-05-31

    The r-process, or the rapid neutron-capture process, of stellar nucleosynthesis is called for to explain the production of the stable (and some long-lived radioactive) neutron-rich nuclides heavier than iron that are observed in stars of various metallicities, as well as in the solar system. A very large amount of nuclear information is necessary in order to model the r-process. This concerns the static characteristics of a large variety of light to heavy nuclei between the valley of stability and the vicinity of the neutron-drip line, as well as their beta-decay branches or their reactivity. The enormously challenging experimental and theoretical task imposed by all these requirements is reviewed, and the state-of-the-art development in the field is presented. Nuclear-physics-based and astrophysics-free r-process models of different levels of sophistication have been constructed over the years. We review their merits and their shortcomings. For long, the core collapse supernova of massive stars has been envisioned as the privileged r-process location. We present a brief summary of the one- or multidimensional spherical or non-spherical explosion simulations available to-date. Their predictions are confronted with the requirements imposed to obtain an r-process. The possibility of r-nuclide synthesis during the decompression of the matter of neutron stars following their merging is also discussed.

  15. The r-process nucleosynthesis in an expanding hot bubble in supernovae explosion

    NASA Astrophysics Data System (ADS)

    Baruah, Rulee; Duorah, H. L.; Duorah, K.

    2006-08-01

    The r-process is one of the major nucleosynthesis processes responsible for the production of heavy elements beyond iron. Recent models of r-process nucleosynthesis rely on a neutrino-heated bubble developing at late times, which provides both the necessary conditions and the requisite amount of ejected mass for the r-process (Wooseley et al '94) . In the neutrino-driven explosion, only a small amount of matter is heated to the requisite high specific energy and entropy. Meyer et al (1992) first calculated the r-process under conditions appropriate to a neutrino-heated bubble and found that the solar r-process abundances could be replicated. They showed that the hot bubble that forms outside the protoneutron star during a SN explosion may be a viable site for the r-process as long as the entropy per baryon can be made sufficiently high. But in a very neutron rich environment such as a neutron star , the r-process could occur even at low entropy (Cowan and Thielemann, 2004). The high entropy wind is not the correct r-process site , owing to the inherent deficiencies in the abundance pattern below A=110 as well as the problems in obtaining the high entropies in SN II explosions required for producing the massive r-process nuclei up to A ? 195 and beyond ( Freiburghaus et al., 1999). Modelers of r-process nucleosynthesis find the entropy of the expanding matter and the overall n/p ratio to be more useful parameter than the temp and neutron density. We have tried to associate the explosion entropies with the site-independent classical approach (n[n] and T) and thereby compare the results of the two approaches from the abundances at different entropy conditions. We find that en entropy of ? 300 with Y[e] ? 0.45 can lead to a successful r-process. This is in agreement with the r-process abundance peaks at n[n] ? 10^32 cm^-3 and T[9] ? 1.5 . References : 1. Cowan J.J. and Thielemann F. K., Physics Today, 2004 2. Woosley S.E., Wilson J.R., Mathews G. J., Hoffman R.D. and Meyer B.S., 1994, ApJ, 433, 229 3. Takahashi K., Witti J. and Janka H.-Th., 1994, A & A , 286, 857 4. Meyer B. S., Mathews G. J., Howard W. M., Woosley S. E. and Hoffman R.D.,1992, ApJ, 399, 656 5. Freiburghaus C., Rembges J. F., Rauscher T.,Kolbe E., Thielemann F. K., kratz K. L., Pfeiffer B. and Cowan J. J., 1999, ApJ, 516, 381

  16. Stochastic Impulsive Systems Driven by Renewal Processes Jo~ao P. Hespanha and Andrew R. Teel

    E-print Network

    Hespanha, João Pedro

    Stochastic Impulsive Systems Driven by Renewal Processes Jo~ao P. Hespanha and Andrew R. Teel Abstract-- Stochastic impulsive systems are defined by a diffusion process with jumps triggered construct a model for such systems based on jump-diffusion equations and provide Lyapunov-based conditions

  17. Electrochromic Polymers for Easily Processed Devices John R. Reynolds,* Avni A. Argun, Irina Schwendeman,

    E-print Network

    Tanner, David B.

    Electrochromic Polymers for Easily Processed Devices John R. Reynolds,* Avni A. Argun, Irina for electrochromic applications. These polymers exhibit ease of processability and useful mechanical properties (e.g. flexibility). However, the major strength of these organic-based materials is that their electrochromic

  18. The r-process nucleosynthesis during the decompression of neutron star crust material

    SciTech Connect

    Goriely, S. [Institut d'Astronomie et d'Astrophysique, CP-226, Université Libre de Bruxelles, 1050 Brussels (Belgium); Bauswein, A. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece and Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching (Germany); Janka, H.-T. [Max-Planck-Institut für Astrophysik, Postfach 1317, 85741 Garching (Germany); Sida, J.-L.; Lemaître, J.-F.; Panebianco, S. [C.E.A. Saclay, Irfu/Service de Physique Nucléaire, 91191 Gif-sur-Yvette (France); Dubray, N.; Hilaire, S. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2014-05-02

    About half of the nuclei heavier than iron observed in nature are produced by the so-called rapid neutron capture process, or r-process, of nucleosynthesis. The identification of the astrophysics site and the specific conditions in which the r-process takes place remains, however, one of the still-unsolved mysteries of modern astrophysics. Another underlying difficulty associated with our understanding of the r-process concerns the uncertainties in the predictions of nuclear properties for the few thousands exotic neutron-rich nuclei involved, for which essentially no experimental data exist. The present paper emphasizes some important future challenges faced by nuclear physics in this problem, particularly in the determination of the nuclear structure properties of exotic neutron-rich nuclei as well as their radiative neutron capture rates and their fission probabilities. These quantities are particularly relevant to determine the composition of the matter resulting from the r-process. Both the astrophysics and the nuclear physics difficulties are critically reviewed with special attention paid to the r-process taking place during the decompression of neutron star matter following the merging of two neutron stars.

  19. Fission modes of neutron-rich nuclei in the r-process nucleosynthesis

    SciTech Connect

    Tatsuda, S.; Yamamoto, K.; Asano, T.; Ohta, M. [Department of Physics, Konan University, 8-9-1 Okamoto, Kobe658-8501 (Japan); Wada, T. [Kansai Univ. (Japan); Chiba, S.; Koura, H.; Maruyama, T. [JAEA (Japan); Tachibana, T. [Waseda Univ. (Japan); Kajino, T. [NAO (Japan); Sumiyoshi, K. [Numazu College of Technology (Japan); Otsuki, K. [Univ. of Chicago (United States)

    2008-05-21

    The fission fragments mass distribution (FFMD) which is the important nuclear information in the study of the r-process nucleosynthesis is estimated for the neutron-rich nuclei (Z>85) according to the theoretical investigation of the potential energy surface. The details for determining FFMD are discussed. In this paper, the network calculation on the r-process nucleosynthesis is also performed including the data of FFMD. The comparison of the results of the network calculation, with and without the fission processes, is shown.

  20. Isotopic compositions of bismuth, lead, thallium, and mercury from mini r-processing

    NASA Technical Reports Server (NTRS)

    Heymann, D.; Liffman, K.

    1986-01-01

    The yields of stable isotopes of Bi, Pb, Tl and Hg as well as yields of Pb-205 are calculated with a parametrized model for 'mini r-processing' in the Ne, O, C-rich zones of explosive burning in massive stars. The Pb isotopic compositions stand out by their comparatively low Pb-207 yields and by the fact that this r-process variant yields Pb-204 quite abundantly. The average Pb-205/Pb-204 yield ratio of 6.1 is the same order of magnitude as yield ratios deduced for s-processing. The Hg from this mini r-process looks like normal solar-system mercury, but with Hg-196 missing and the light s-isotopes A = 198, 199, 200 and 201 depleted (especially the odd-A species).

  1. Decay of the $r$-process nuclides $^{137, 138, 139}$Sb, and the A=130 solar $r$-process abundance peak

    E-print Network

    Arndt, O; Farouqi, K; Koester, U; Kratz, K-L; Pfeiffer, B; Walters, W B; Hoteling, N; Fedosseev, V; Hennrich, S; Woehr, A; Shergur, J; Hecht, A A

    2011-01-01

    Half-life (T(1/2)) and beta-delayed neutron branching (P(n)) values of 492(25) ms and 49(8)\\%, 350(15) ms and 72(8)\\%, and 93(13) ms and 90(10)\\% for the r-process nuclei (137,138,139)Sb, respectively, have been measured at the CERN On-Line Isotope Mass Separator (ISOLDE) facility by counting beta-delayed neutrons. More precise T(1/2) and P(n) values of 300(15) ms and 27(4)\\%, and 273(7) ms and 50(8)\\% for (136,137)Sn, respectively, have also been measured. The sources were prepared by using the selective ionization of Sb or Sn with the Resonance Ionization Laser Ion Source and the high-resolution mass separator. The new data for Sb isotopes are compared with calculated T(1/2) and P(n) values for both spherical and nonspherical shapes. The data have been incorporated into parametrized nucleosynthesis calculations of the r process in high-entropy winds of core-collapse supernovae in order to study the properties of the A = 130 solar-system r-process abundance peak.

  2. R-Process Nucleosynthesis in Dynamically Ejected Matter of Neutron Star Mergers

    E-print Network

    Stephane Goriely; Andreas Bauswein; H. -Thomas Janka

    2011-08-09

    Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this process has not been identified yet. Here we study r-process nucleosynthesis in material that is dynamically ejected by tidal and pressure forces during the merging of binary neutron stars (NSs) and within milliseconds afterwards. For the first time we make use of relativistic hydrodynamical simulations of such events, defining consistently the conditions that determine the nucleosynthesis, i.e., neutron enrichment, entropy, early density evolution and thus expansion timescale, and ejecta mass. We find that 10^{-3}-10^{-2} solar masses are ejected, which is enough for mergers to be the main source of heavy (A > 140) galactic r-nuclei for merger rates of some 10^{-5} per year. While asymmetric mergers eject 2-3 times more mass than symmetric ones, the exact amount depends weakly on whether the NSs have radii of ~15 km for a "stiff" nuclear equation of state (EOS) or ~12 km for a "soft" EOS. R-process nucleosynthesis during the decompression becomes largely insensitive to the detailed conditions because of efficient fission recycling, producing a composition that closely follows the solar r-abundance distribution for nuclei with mass numbers A > 140. Estimating the light curve powered by the radioactive decay heating of r-process nuclei with an approximative model, we expect high emission in the B-V-R bands for 1-2 days with potentially observable longer duration in the case of asymmetric mergers because of the larger ejecta mass.

  3. PRIMORDIAL r-PROCESS DISPERSION IN METAL-POOR GLOBULAR CLUSTERS

    SciTech Connect

    Roederer, Ian U., E-mail: iur@obs.carnegiescience.edu [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)

    2011-05-01

    Heavy elements, those produced by neutron-capture reactions, have traditionally shown no star-to-star dispersion in all but a handful of metal-poor globular clusters (GCs). Recent detections of low [Pb/Eu] ratios or upper limits in several metal-poor GCs indicate that the heavy elements in these GCs were produced exclusively by an r-process. Re-examining GC heavy element abundances from the literature, we find unmistakable correlations between the [La/Fe] and [Eu/Fe] ratios in four metal-poor GCs (M5, M15, M92, and NGC 3201), only two of which were known previously. This indicates that the total r-process abundances vary from star to star (by factors of 2-6) relative to Fe within each GC. We also identify potential dispersion in two other GCs (M3 and M13). Several GCs (M12, M80, and NGC 6752) show no evidence of r-process dispersion. The r-process dispersion is not correlated with the well-known light element dispersion, indicating that it was present in the gas throughout the duration of star formation. The observations available at present suggest that star-to-star r-process dispersion within metal-poor GCs may be a common but not ubiquitous phenomenon that is neither predicted by nor accounted for in current models of GC formation and evolution.

  4. The impact of uncertain nuclear masses near closed shells on the r-process abundance pattern

    NASA Astrophysics Data System (ADS)

    Mumpower, M.; Surman, R.; Fang, D. L.; Beard, M.; Aprahamian, A.

    2015-03-01

    Calculations of rapid neutron capture nucleosynthesis involve thousands of pieces of nuclear data for which no experimental information is available. Of the nuclear data sets needed for r-process simulations—masses, ? -decay rates, ? -delayed neutron emission probabilities, neutron capture rates, fission probabilities and daughter product distributions, neutrino interaction rates—masses are arguably the most important, because they are a key ingredient in the calculations of all other theoretical quantities. Here, we investigate how uncertainties in nuclear masses translate into uncertainties in the final abundance pattern produced in r-process simulations. We examine the influence of individual mass variations on three types of r-process simulations—a hot wind, cold wind, and neutron star merger r process—with markedly different r-process paths and resulting final abundance patterns. We find the uncertainties in the abundance patterns due to the mass variations exceed the differences due to the astrophysics. This situation can be improved, however, by even modest reductions in mass uncertainties.

  5. Nuclear masses near $N=82$ that influence $r$-process abundances

    E-print Network

    M. Mumpower; R. Surman; M. Beard; D. -L. Fang; A. Aprahamian

    2014-11-14

    Nuclear masses are one of the key ingredients of nuclear physics that go into astrophysical simulations of the $r$ process. Nuclear masses effect $r$-process abundances by entering into calculations of Q-values, neutron capture rates, photo-dissociation rates, beta-decay rates, branching ratios and the properties of fission. Most of the thousands of short-lived neutron-rich nuclei which are believed to participate in the $r$ process lack any experimental verification, thus the identification of the most influential nuclei is of paramount importance. We have conducted mass sensitivity studies near the $N=82$ closed shell in the context of a main $r$-process. Our studies take into account how an uncertainty in a single nuclear mass propagates to influence the relevant quantities of neighboring nuclei and finally to $r$-process abundances. We identify influential nuclei in various astrophysical conditions using the FRDM mass model. We show that our conclusions regarding these key nuclei are still retained when a superposition of astrophysical trajectories is considered.

  6. Misregulation of miR1 processing is associated with heart defects in myotonic dystrophy

    Microsoft Academic Search

    Frédérique Rau; Fernande Freyermuth; Charlotte Fugier; Jean-Philippe Villemin; Marie-Christine Fischer; Bernard Jost; Doulaye Dembele; Geneviève Gourdon; Annie Nicole; Denis Duboc; Karim Wahbi; John W Day; Harutoshi Fujimura; Masanori P Takahashi; Didier Auboeuf; Natacha Dreumont; Denis Furling; Nicolas Charlet-Berguerand

    2011-01-01

    Myotonic dystrophy is an RNA gain-of-function disease caused by expanded CUG or CCUG repeats, which sequester the RNA binding protein MBNL1. Here we describe a newly discovered function for MBNL1 as a regulator of pre-miR-1 biogenesis and find that miR-1 processing is altered in heart samples from people with myotonic dystrophy. MBNL1 binds to a UGC motif located within the

  7. A Functional Interface at the rDNA Connects rRNA Synthesis, Pre-rRNA Processing and Nucleolar Surveillance in Budding Yeast

    PubMed Central

    Leporé, Nathalie; Lafontaine, Denis L. J.

    2011-01-01

    Ribogenesis is a multistep error-prone process that is actively monitored by quality control mechanisms. How ribosomal RNA synthesis, pre-rRNA processing and nucleolar surveillance are integrated is unclear. Nor is it understood how defective ribosomes are recognized. We report in budding yeast that, in vivo, the interaction between the transcription elongation factor Spt5 and Rpa190, the largest subunit of RNA polymerase (Pol) I, requires the Spt5 C-terminal region (CTR), a conserved and highly repetitive domain that is reminiscent of the RNA Pol II C-terminal domain (CTD). We show that this sequence is also required for the interaction between Spt5 and Nrd1, an RNA specific binding protein, and an exosome cofactor. Both the Spt4-Spt5, and the Nrd1-Nab3 complexes interact functionally with Rrp6, and colocalize at the rDNA. Mutations in the RNA binding domain of Nrd1, but not in its RNA Pol II CTD-interacting domain, and mutations in the RRM of Nab3 led to the accumulation of normal and aberrant polyadenylated pre-rRNAs. Altogether these results indicate that Nrd1-Nab3 contributes to recruiting the nucleolar surveillance to elongating polymerases to survey nascent rRNA transcripts. PMID:21949810

  8. Beta-decay spectroscopy relevant to the r-process nucleosynthesis

    SciTech Connect

    Nishimura, Shunji [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Collaboration: RIBF Decay Collaboration

    2012-11-12

    A scientific program of beta-decay spectroscopy relevant to r-process nucleosynthesis has been started using high intensity U-beam at the RIBF. The first results of {beta}-decay half-lives of very neutron-rich Kr to Tc nuclides, all of which lie close to the r-process path, suggest a systematic enhancement of the the {beta}-decay rates of the Zr and Nb isotopes around A110 with respect to the predictions of the deformed quasiparticle-random-phase-approximation model (FRDM + QRPA). An impact of the results on the astrophysical r-process is discussed together with the future perspective of the {beta}-decay spectroscopy with the EURICA.

  9. An expanding vortex site for the r-process in rotating stellar collapse

    NASA Technical Reports Server (NTRS)

    Symbalisty, E. M. D.; Schramm, D. N.; Wilson, J. R.

    1985-01-01

    The astrophysical site of r-process nucleosynthesis is investigated theoretically using two-dimensional expanding-vortex stellar-collapse simulations based on the Eulerian adaptive-mesh MHD code of Symbalisty (1984). The results are presented graphically, and it is found that the classical r-process can be explained as the result of the collapse of the highly rotating iron core of a 15-solar-mass star, in which the angular velocity along the rotation axis reaches a maximum of 1000 rad/s, corresponding to an angular momentum of 3.4 x 10 to the 48th erg/s for the inner 1.5 solar mass. The ejected jets are shown to yield about 0.0004 solar mass per supernova, sufficient to explain the observed abundances of r-process products.

  10. The impact of individual nuclear masses on $r$-process abundances

    E-print Network

    Mumpower, M R; Fang, D -L; Beard, M; Moller, P; Kawano, T; Aprahamian, A

    2015-01-01

    We have performed for the first time a comprehensive study of the sensitivity of $r$-process nucleosynthesis to individual nuclear masses across the chart of nuclides. Using the latest version (2012) of the Finite-Range Droplet Model, we consider mass variations of $\\pm0.5$ MeV and propagate each mass change to all affected quantities, including $Q$-values, reaction rates, and branching ratios. We find such mass variations can result in up to an order of magnitude local change in the final abundance pattern produced in an $r$-process simulation. We identify key nuclei whose masses have a substantial impact on abundance predictions for hot, cold, and neutron star merger $r$-process scenarios and could be measured at future radioactive beam facilities.

  11. The impact of individual nuclear masses on $r$-process abundances

    E-print Network

    M. R. Mumpower; R. Surman; D. -L. Fang; M. Beard; P. Moller; T. Kawano; A. Aprahamian

    2015-05-28

    We have performed for the first time a comprehensive study of the sensitivity of $r$-process nucleosynthesis to individual nuclear masses across the chart of nuclides. Using the latest version (2012) of the Finite-Range Droplet Model, we consider mass variations of $\\pm0.5$ MeV and propagate each mass change to all affected quantities, including $Q$-values, reaction rates, and branching ratios. We find such mass variations can result in up to an order of magnitude local change in the final abundance pattern produced in an $r$-process simulation. We identify key nuclei whose masses have a substantial impact on abundance predictions for hot, cold, and neutron star merger $r$-process scenarios and could be measured at future radioactive beam facilities.

  12. Evidence for supernova injection into the solar nebula and the decoupling of r-process nucleosynthesis

    PubMed Central

    Brennecka, Gregory A.; Borg, Lars E.; Wadhwa, Meenakshi

    2013-01-01

    The isotopic composition of our Solar System reflects the blending of materials derived from numerous past nucleosynthetic events, each characterized by a distinct isotopic signature. We show that the isotopic compositions of elements spanning a large mass range in the earliest formed solids in our Solar System, calcium–aluminum-rich inclusions (CAIs), are uniform, and yet distinct from the average Solar System composition. Relative to younger objects in the Solar System, CAIs contain positive r-process anomalies in isotopes A < 140 and negative r-process anomalies in isotopes A > 140. This fundamental difference in the isotopic character of CAIs around mass 140 necessitates (i) the existence of multiple sources for r-process nucleosynthesis and (ii) the injection of supernova material into a reservoir untapped by CAIs. A scenario of late supernova injection into the protoplanetary disk is consistent with formation of our Solar System in an active star-forming region of the galaxy. PMID:24101483

  13. Inter-partner process learning in collaborative R&D—a case study from the telecommunications industry

    Microsoft Academic Search

    JAN FELLER; ANTERO HIRVENSALO; RIITTA SMEDS

    2005-01-01

    This research sheds light on how and what partner companies in an R&D collaboration relationship can jointly learn to improve their R&D processes. Methodological triangulation is applied: by using the business process simulation method as well as interviews in a two-case study, a set of process improvements for the collaborative R&D process of the case companies is developed. One focus

  14. Observations of the r-Process in Galactic Halo Stars: Successes and Frustrations

    NASA Astrophysics Data System (ADS)

    Sneden, Chris

    2010-11-01

    Our understanding of early Galactic nucleosynthesis was fundamentally changed in the 1980s and 1990s by the serendipitous discovery of a few stars with extremely large abundance enhancements of neutron-capture (Z>30) elements. Detailed spectroscopic analyses of these stars revealed their neutron-capture abundance ratios to be well-matched by the solar-system r-process-only distribution. Subsequent work has significantly sharpened our knowledge of the r-process in low-metallicity Galactic halo stars. Astronomers have found many more r-rich stars and have analyzed them in often excruciating detail; lab atomic physicists have radically altered the quantity and quality of atomic transition data; nuclear experimental physicists have improved reaction rates away from the valley of beta stability; and theoretical nuclear physicists have begun to make realistic r-process abundance predictions. Here I will summarize our observational knowledge of the r-process in stars, trying to distinguish between those results which undoubtedly will stand the test of time, and those still much in need of further development. Suggestions will be given for profitable future studies by astronomers, and requests for vital parallel investigations by physicists.

  15. Neutron Capture on 130Sn during r-Process Freeze-Out

    SciTech Connect

    Beun, Joshua [North Carolina State University; Blackmon, Jeffery C [Louisiana State University; Hix, William Raphael [ORNL; Mclaughlin, Gail C [North Carolina State University; Smith, Michael Scott [ORNL; Surman, Rebecca [Union College

    2009-01-01

    We examine the role of neutron capture on {sup 130}Sn during r-process freeze-out in the neutrino-driven wind environment of the core-collapse supernova. We find that the global r-process abundance pattern is sensitive to the magnitude of the neutron capture cross section of {sup 130}Sn. The changes to the abundance pattern include not only a relative decrease in the abundance of {sup 130}Sn and an increase in the abundance of {sup 131}Sn, but also a shift in the distribution of material in the rare earth and third peak regions.

  16. Beta decay studies of r-process nuclei at the National Superconducting Cyclotron Laboratory

    E-print Network

    J. Pereira; A. Aprahamian; O. Arndt; A. Becerril; T. Elliot; A. Estrade; D. Galaviz; S. Hennrich; P. Hosmer; R. Kessler; K. -L. Kratz; G. Lorusso; P. F. Mantica; M. Matos; F. Montes; P. Santi; B. Pfeiffer; M. Quinn; H. Schatz; F. Schertz; L. Schnorrenberger; E. Smith; B. E. Tomlin; W. Walters; A. Wohr

    2009-01-13

    The impact of nuclear physics on astrophysical r-process models is discussed, emphasizing the importance of beta-decay properties of neutron-rich nuclei. Several r-process motivated beta-decay experiments performed at the National Superconducting Cyclotron Laboratory are presented. The experiments include the measurement of beta-decay half-lives and neutron emission probabilities of nuclei in regions around Ni-78; Se-90; Zr-106 and Rh-120, as well as spectroscopic studies of Pd-120. A summary on the different experimental techniques employed, data analysis, results and impact on model calculations is presented.

  17. The isovector imaginary neutron potential: a key ingredient for the r-process nucleosynthesis

    SciTech Connect

    Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium); Delaroche, J.-P. [DPTA/Service de Physique Nucleaire, CEA/DAM Ile de France, BP 12, 91680 Bruyeres-le-Chatel (France)

    2008-05-12

    The isovector contribution to the imaginary component of the microscopic optical model potential is adjusted on experimental neutron strength function data. Within the Brueckner-Hartree-Fock approximation of Jeukenne-Lejeune-Mahaux, it is shown that experimental data favours a strong isovector component that can have a drastic impact on the radiative neutron capture cross section for neutron-rich nuclei. If confirmed, this result strongly inhibits the resonant capture by exotic nuclei, so that the traditional r-process picture of the fast neutron captures during the nucleosynthesis r-process needs to be revisited in depth.

  18. Neutron capture on 130Sn during r-process freeze-out

    E-print Network

    J. Beun; J. C. Blackmon; W. R. Hix; G. C. McLaughlin; M. S. Smith; R. Surman

    2008-06-24

    We examine the role of neutron capture on 130Sn during r-process freeze-out in the neutrino-driven wind environment of the core-collapse supernova. We find that the global r-process abundance pattern is sensitive to the magnitude of the neutron capture cross section of 130Sn. The changes to the abundance pattern include not only a relative decrease in the abundance of 130Sn and an increase in the abundance of 131Sn, but also a shift in the distribution of material in the rare earth and third peak regions.

  19. Beta Decays of Isotones with Neutron Magic Number of N=126 and R-process Nucleosynthesis

    E-print Network

    Toshio Suzuki; Takashi Yoshida; Toshitaka Kajino; Takaharu Otsuka

    2011-12-16

    Beta decays of the isotones with N=126 are studied by shell model calculations taking into account both the Gamow-Teller (GT) and first-forbidden (FF) transitions. The FF transitions are found to be important to reduce the half-lives, by nearly twice to several times, from those by the GT contributions only. Possible implications of the short half-lives of the waiting point nuclei on the r-process nucleosynthesis during the supernova explosions are discussed. A slight shift of the third peak of the element abundances in the r-process toward higher mass region is found.

  20. WASTE PROCESSING ANNUAL NUCLEAR SAFETY RELATED R AND D REPORT FOR CY2008

    SciTech Connect

    Fellinger, A.

    2009-10-15

    The Engineering and Technology Office of Waste Processing identifies and reduces engineering and technical risks associated with key waste processing project decisions. The risks, and actions taken to mitigate those risks, are determined through technology readiness assessments, program reviews, technology information exchanges, external technical reviews, technical assistance, and targeted technology development and deployment (TDD). The Office of Waste Processing TDD program prioritizes and approves research and development scopes of work that address nuclear safety related to processing of highly radioactive nuclear wastes. Thirteen of the thirty-five R&D approved work scopes in FY2009 relate directly to nuclear safety, and are presented in this report.

  1. Processing effects in aluminum micro-channel tube for brazed R744 heat exchangers

    Microsoft Academic Search

    Gowreesan Vamadevan; Frank F. Kraft

    2007-01-01

    The effects of processing on the mechanical behavior of aluminum alloy micro-channel tubing used in brazed automotive heat exchangers are evaluated in light of the stringent requirements of CO2 (R744 refrigerant) based systems. An apparatus was developed to simulate system operating conditions of pressure and elevated temperature in tube samples. Commercially extruded and processed AA3102 micro-channel tube samples were given

  2. The even-odd systematics in R-process nuclide abundances

    NASA Technical Reports Server (NTRS)

    Marti, K.; Suess, H. E.

    1988-01-01

    The paper reports and discusses solar system N(R) abundances for nuclides A greater than 70, obtained as differences between measured solar system abundances and calculated S-process contributions. The abundance peak at A of about 163 in the rare earth element region reveals properties which are similar to those of the R-process peaks corresponding to magic neutron numbers N = 82 and N = 126. Systematic differences in the N(R) abundances of even-A and odd-A nuclides are restricted to specific mass regions. It is concluded that these differences are most probably related to the properties of nuclear species during beta(-) decay to the stability valley.

  3. Femtosecond pulse processing A . M . W E I N E R

    E-print Network

    Purdue University

    results from this ®eld, drawing upon work by the author. In Sect. 2 we discuss Fourier transform pulseFemtosecond pulse processing A . M . W E I N E R Purdue University, School of Electrical communications, pulse shaping, terahertz radiation, ultrafast optics 1. Introduction A variety of powerful

  4. Analysis of launch site processing effectiveness for the Space Shuttle 26R payload

    Microsoft Academic Search

    C. A. Flores; R. E. Heuser; A. M. Smith

    1991-01-01

    A trend analysis study performed on the problem reports (PRs) recorded during the US Space Shuttle 26R payload processing cycle at Kennedy Space Center is described. The study used defect flow analysis (DFA), which views the PRs as a population of events, and focuses on ways to understand the characteristics of the population as a whole rather than that of

  5. John R. Jones and George A. Schier This chapter considers aspen growth as a process,

    E-print Network

    GROWTH John R. Jones and George A. Schier This chapter considers aspen growth as a process (33 m) tall. The stand was still in- tact but had a very high decay frequency. That study (Jones 1966. Of the 10 plots (Jones 1966, 1967b)in stands 160 years or older, 3 had site indexes that were rather poor

  6. Effects of Beta-Decays of Excited-State Nuclei on the Astrophysical r-Process

    E-print Network

    M. A. Famiano; R. N. Boyd; T. Kajino; K. Otsuki; M. Terasawa; G. J. Mathews

    2008-08-07

    A rudimentary calculation is employed to evaluate the possible effects of beta- decays of excited-state nuclei on the astrophysical r-process. Single-particle levels calculated with the FRDM are adapted to the calculation of beta-decay rates of these excited-state nuclei. Quantum numbers are determined based on proximity to Nilson model levels. The resulting rates are used in an r-process network calculation in which a supernova hot-bubble model is coupled to an extensive network calculation including all nuclei between the valley of stability and the neutron drip line and with masses ABeta-decay rates are included as functional forms of the environmental temperature. While the decay rate model used is simple and phenomenological, it is consistent across all 3700 nuclei involved in the r-process network calculation. This represents an approximate first estimate to gauge the possible effects of excited-state beta-decays on r-process freeze-out abundances.

  7. Long gamma-ray burst as a production site of r-process elements

    SciTech Connect

    Nakamrua, Ko; Harikae, Seiji; Kajino, Toshitaka; Mathews, Grant J. [National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo, 181-8588 (Japan); Quants Research Department, Financial Engineering Division, Mitsubishi UFJ Morgan Stanley Securities Co., Ltd. (Japan); National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo, 181-8588 and Department of Astronomy, School of Science, University of Tokyo, Tokyo, 113-0033 (Japan); Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556 (United States)

    2012-11-12

    We simulated the r-process nucleosynthesis in and around a high entropy jet from a long gamma-ray burst (GRB). Our simulation is based on the collapsar scenario for long GRBs and on relativistic magnetohydrodynamic simulations (Harikae et al. 2009, 2010) including ray-tracing neutrino transport, which describe the development of the black hole accretion disk and the heating of the funnel region to produce a relativistic jet. The time evolution of the jet was then extended to later phase via axi-symmetric special relativistic hydrodynamic simulation to follow the temperature, entropy, electron fraction, and density evolution for representative test particles. The evolution of nuclear abundances from nucleons to heavy nuclei for representative test particle trajectories was solved in a large nuclear reaction network including more than 5000 isotopes. We show that a robust r-process successfully occurs within the collapsar jet outflow and that sufficient mass is ejected within the flow to account for the observed r-process abundance distribution along with the large dispersion in r-process elements observed in metal-poor halo stars.

  8. New fission fragment distributions and r-process origin of the rare-earth elements

    E-print Network

    Goriely, S; Lemaitre, J -F; Panebianco, S; Dubray, N; Hilaire, S; Bauswein, A; Janka, H -Thomas

    2013-01-01

    Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A > 140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular the fission fragment yields determine the creation of 110 140.

  9. ONBOARD IMAGE PROCESSING FOR AUTONOMOUS SPACECRAFT DETECTION OF VOLCANIC PLUMES. D. R. Thompson1,2

    E-print Network

    Schaffer, Steven

    ONBOARD IMAGE PROCESSING FOR AUTONOMOUS SPACECRAFT DETECTION OF VOLCANIC PLUMES. D. R. Thompson1 them requires good luck and many images. This demands a prohibitive fraction of the spacecraft capture. The spacecraft could search these images onboard for plumes and only save the fraction contain

  10. Relative contributions of the weak, main and fission-recycling r-process

    E-print Network

    Shibagaki, S; Mathews, G J; Chiba, S; Nishimura, S; Lorusso, G

    2015-01-01

    There has been a persistent conundrum in attempts to model the nucleosynthesis of heavy elements by rapid neutron capture (the $r$-process). Although the location of the abundance peaks near nuclear mass numbers 130 and 195 identify an environment of rapid neutron capture near closed nuclear shells, the abundances of elements just above and below those peaks are often underproduced by more than an order of magnitude in model calculations. At the same time there is a debate in the literature as to what degree the $r$-process elements are produced in supernovae or the mergers of binary neutron stars. In this paper we propose a novel solution to both problems. We demonstrate that the underproduction of elements above and below the $r$-process peaks characteristic in the main or weak $r$-process events (like magnetohydrodynamic jets or neutrino-driven winds in core-collapse supernovae) can be supplemented via fission fragment distributions from the recycling of material in a neutron-rich environment such as that ...

  11. Sequential Plasma Activated Process for Silicon Direct Bonding M. M. R. Howladera

    E-print Network

    Howlader, Matiar R

    , such as hydrophilic, hydrophobic, fusion, and plasma activation bonding. Hydrophilic surfaces are prepared by cleaning complexities, such as a dip in water or RCA clean, after plasma treatment should be avoided. ThereforeSequential Plasma Activated Process for Silicon Direct Bonding M. M. R. Howladera , T. Sugab , H

  12. Controls on Nitrogen Loss Processes in Chesapeake Bay Sediments Andrew R. Babbin* and Bess B. Ward

    E-print Network

    Ward, Bess

    Controls on Nitrogen Loss Processes in Chesapeake Bay Sediments Andrew R. Babbin* and Bess B. Ward, United States *S Supporting Information ABSTRACT: The flux of fixed nitrogen into the marine environment is increasing as a direct result of anthropogenic nitrogen loading, but the controls on the mechanisms

  13. r-Process nucleosynthesis: Present status and future experiments at the FRS and ESR

    NASA Astrophysics Data System (ADS)

    Dillmann, Iris; Litvinov, Yuri A.

    2011-04-01

    No astrophysical process other than the rapid neutron capture process (r process) is used more often to motivate the necessity of the new-generation radioactive beam facilities with higher beam intensities. In the dawn of these facilities (RIBF at RIKEN, FRIB at Michigan State University, and FAIR in Darmstadt) experiments carried out at the presently existing facilities mark a transition between the past and the future. Two such facilities are the Fragment Separator (FRS) and Experimental Storage Ring (ESR) at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt. Up to now one could only “scratch” the regions where the r process takes place-with the exception of the N=126 region, which remains an experimental “terra incognita”. Owing to the upgrade of the GSI accelerator and to the development of new highly sensitive and efficient detection techniques in view of the future FAIR facility, planned experiments at the FRS and ESR aim at filling this gap, approaching the r-process path also at N=126.

  14. Realistic fission models, new beta-decay half-lives and the r-process in neutron star mergers

    SciTech Connect

    Shibagaki, S.; Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan); Lorusso, G.; Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556 (United States)

    2014-05-02

    Almost half of heavy nuclei beyond iron are considered to be produced by rapid neutron capture process (r-process). This process occurs in the neutron-rich environment such as core-collapse supernovae or neutron star mergers, but the main production site is still unknown. In the r-process of neutron star mergers, nuclear fission reactions play an important role. Also beta-decay half-lives of magic nuclei are crucial for the r-process. We have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions and new beta-decay half-lives for N=82 nuclei measured at RIBF-RIKEN. We investigate the effect of nuclear fission on abundance patterns in the matter ejected from neutron star mergers with two different fission fragment mass distributions. We also discuss how the new experimental beta-decay half-lives affect the r-process.

  15. Realistic fission models, new beta-decay half-lives and the r-process in neutron star mergers

    NASA Astrophysics Data System (ADS)

    Shibagaki, S.; Kajino, T.; Chiba, S.; Lorusso, G.; Nishimura, S.; Mathews, G. J.

    2014-05-01

    Almost half of heavy nuclei beyond iron are considered to be produced by rapid neutron capture process (r-process). This process occurs in the neutron-rich environment such as core-collapse supernovae or neutron star mergers, but the main production site is still unknown. In the r-process of neutron star mergers, nuclear fission reactions play an important role. Also beta-decay half-lives of magic nuclei are crucial for the r-process. We have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions and new beta-decay half-lives for N=82 nuclei measured at RIBF-RIKEN. We investigate the effect of nuclear fission on abundance patterns in the matter ejected from neutron star mergers with two different fission fragment mass distributions. We also discuss how the new experimental beta-decay half-lives affect the r-process.

  16. Half-life of the doubly magic r-process nucleus 78Ni.

    PubMed

    Hosmer, P T; Schatz, H; Aprahamian, A; Arndt, O; Clement, R R C; Estrade, A; Kratz, K-L; Liddick, S N; Mantica, P F; Mueller, W F; Montes, F; Morton, A C; Ouellette, M; Pellegrini, E; Pfeiffer, B; Reeder, P; Santi, P; Steiner, M; Stolz, A; Tomlin, B E; Walters, W B; Wöhr, A

    2005-03-25

    Nuclei with magic numbers serve as important benchmarks in nuclear theory. In addition, neutron-rich nuclei play an important role in the astrophysical rapid neutron-capture process (r process). 78Ni is the only doubly magic nucleus that is also an important waiting point in the r process, and serves as a major bottleneck in the synthesis of heavier elements. The half-life of 78Ni has been experimentally deduced for the first time at the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory at Michigan State University, and was found to be 110(+100)(-60) ms. In the same experiment, a first half-life was deduced for 77Ni of 128(+27)(-33) ms, and more precise half-lives were deduced for 75Ni and 76Ni of 344(+20)(-24) ms and 238(+15)(-18) ms, respectively. PMID:15903849

  17. Cerebral Processing of Prosodic Emotional Signals: Evaluation of a Network Model Using rTMS

    PubMed Central

    Plewnia, Christian; Wildgruber, Dirk

    2014-01-01

    A great number of functional imaging studies contributed to developing a cerebral network model illustrating the processing of prosody in the brain. According to this model, the processing of prosodic emotional signals is divided into three main steps, each related to different brain areas. The present study sought to evaluate parts of the aforementioned model by using low-frequency repetitive transcranial magnetic stimulation (rTMS) over two important brain regions identified by the model: the superior temporal cortex (Experiment 1) and the inferior frontal cortex (Experiment 2). The aim of both experiments was to reduce cortical activity in the respective brain areas and evaluate whether these reductions lead to measurable behavioral effects during prosody processing. However, results obtained in this study revealed no rTMS effects on the acquired behavioral data. Possible explanations for these findings are discussed in the paper. PMID:25171220

  18. CIS Modules Process R&D: Final Technical Report, October 2005 - June 2006

    SciTech Connect

    Tarrant, D. E.; Gay, R. R.

    2006-07-01

    The primary objectives of this subcontract were to: address key near-term technical R&D issues for continued improvement in thin-film PV products; continue process development for increased production capacity; pursue long-term R&D contributing to progress toward the MYTP goals for 2020 to increase the conversion efficiency to 15% and reduce module manufacturing costs to less than $50/m2, thus enabling PV systems with a 30-year lifetime at an installed cost of under $2.00/W; and advance the understanding of the requirements needed to achieve better thin-film PV cell and module performance, greater reliability and market acceptance, and investigate materials systems and new devices that can improve the cost/performance ratio of future thin-film PV factories. The demonstrated and maintained high production yield is a major accomplishment supporting attractive cost projections for CIS. Process R&D at successive levels of CIS production has led to the continued demonstration of the prerequisites for commitment to large-scale commercialization. Process and packaging R&D during this and previous subcontracts has demonstrated the potential for further cost and performance improvements.

  19. Rrp5 Binding at Multiple Sites Coordinates Pre-rRNA Processing and Assembly

    PubMed Central

    Lebaron, Simon; Segerstolpe, Åsa; French, Sarah L.; Dudnakova, Tatiana; de lima Alves, Flavia; Granneman, Sander; Rappsilber, Juri; Beyer, Ann L.; Wieslander, Lars; Tollervey, David

    2013-01-01

    Summary In vivo UV crosslinking identified numerous preribosomal RNA (pre-rRNA) binding sites for the large, highly conserved ribosome synthesis factor Rrp5. Intramolecular complementation has shown that the C-terminal domain (CTD) of Rrp5 is required for pre-rRNA cleavage at sites A0–A2 on the pathway of 18S rRNA synthesis, whereas the N-terminal domain (NTD) is required for A3 cleavage on the pathway of 5.8S/25S rRNA synthesis. The CTD was crosslinked to sequences flanking A2 and to the snoRNAs U3, U14, snR30, and snR10, which are required for cleavage at A0–A2. The NTD was crosslinked to sequences flanking A3 and to the RNA component of ribonuclease MRP, which cleaves site A3. Rrp5 could also be directly crosslinked to several large structural proteins and nucleoside triphosphatases. A key role in coordinating preribosomal assembly and processing was confirmed by chromatin spreads. Following depletion of Rrp5, cotranscriptional cleavage was lost and preribosome compaction greatly reduced. PMID:24239293

  20. Beta-decay rates of nuclei in ground and excited states and effects on the r-process of nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Famiano, Michael Andrew

    2001-06-01

    Roughly half of all nuclei with mass A > 70 and nearly all of the rare earth elements are produced by two process of neutron capture on lighter nuclei. These processes are called the rapid, or r-, process, and the slow, or s-, process, their names indicative of the rate of neutron captures relative to the stabilizing ?- decays. The r-process must necessarily exist in an environment of high neutron flux. Therefore, nuclei produced in the r-process, which are the progenitors of the stable nuclei observed today, fall along a locus in the very neutron rich region of the isotopic chart known as the r-process path. Progression along the r-process path occurs through a sequence of neutron captures and ?-decays. Since neutron captures are very fast, the r-process is primarily limited by ?-decays. The very neutron-rich nuclei along the r-process path are, for the most part, beyond the reach of experimental physics, despite their importance to modern nuclear astrophysics. Of primary importance in an analysis of r-process nucleosynthesis are the ?-decay half-lives. An alteration in the half-lives can change the path and pace of the r-process. Difficulties in current r-process predictions include the difficulty of current models to manufacture sufficient nuclei in the mass region A~200 region. However, the inclusion of excited state ?-decays may resolve this difficulty by allowing a population of nuclei along the r-process path to speed up the r-process, so that it can move rapidly to the higher masses. The problem is further complicated by the lack of knowledge of many of the r-process progenitor nuclei; indeed, many have not been studied. The theoretical problem of ?-decays of excited state nuclei as well as the production of high mass nuclei via an r-process are both attacked in this work, the results of which are mutually supportive. Future experimentation is discussed as a final note.

  1. The r-process nucleosynthesis during the decompression of neutronised matter

    SciTech Connect

    Goriely, S.; Chamel, N. [IAA-ULB, Campus de la Plaine, CP 226, 1050 Brussels (Belgium); Pearson, J. M. [Dept. de Physique, Universite de Montreal, Montreal (Quebec), H3C 3J7 (Canada)

    2011-10-28

    The rapid neutron-capture process, or r-process, is known to be of fundamental importance for explaining the origin of approximately half of the A>60 stable nuclei observed in nature. In recent years nuclear astrophysicists have developed more and more sophisticated r-process models, eagerly trying to add new astrophysical or nuclear physics ingredients to explain the solar system composition in a satisfactory way.We show here that the decompression of the neutron star matter may provide suitable conditions for a robust r-processing. After decompression, the inner crust material gives rise to an abundance distribution for A>130 nuclei similar to the one observed in the solar system. Similarly, the outer crust if heated at a temperature of about 8 10{sup 9} K before decompression is made of exotic neutron-rich nuclei with a mass distribution close to the 80{<=}A{<=}130 solar one. During the decompression, the free neutrons (initially liberated by the high temperatures) are re-captured leading to a final pattern similar to the solar system distribution.

  2. The History of R-Process Enrichment in the Milky Way

    NASA Astrophysics Data System (ADS)

    Shen, Sijing; Cooke, Ryan J.; Ramirez-Ruiz, Enrico; Madau, Piero; Mayer, Lucio; Guedes, Javiera

    2015-07-01

    We investigate the production sites and the enrichment history of r-process elements in the Galaxy, as traced by the [Eu/Fe] ratio, using the high resolution, cosmological zoom-in simulation “Eris.” At z = 0, Eris represents a close analog to the Milky Way, making it the ideal laboratory to understand the chemical evolution of our Galaxy. Eris formally traces the production of oxygen and iron due to supernovae (SNe) Ia and SNe II. We include in post-processing the production of r-process elements from compact binary mergers. Unlike previous studies, we find that the nucleosynthetic products from compact binary mergers can be incorporated into stars of very low metallicity and at early times, even with a minimum delay time of 100 Myr. This conclusion is relatively insensitive to modest variations in the merger rate, minimum delay time, and the delay time distribution. By implementing a first-order prescription for metal mixing, we can further improve the agreement between our model and the data for the chemical evolution of both [?/Fe] and [Eu/Fe]. We argue that compact binary mergers could be the dominant source of r-process nucleosynthesis in the Galaxy.

  3. Dynamical r-process studies within the neutrino-driven wind scenario and its sensitivity to the nuclear physics input

    NASA Astrophysics Data System (ADS)

    Arcones, A.; Martínez-Pinedo, G.

    2011-04-01

    We use results from long-time core-collapse supernovae simulations to investigate the impact of the late time evolution of the ejecta and of the nuclear physics input on the calculated r-process abundances. Based on the latest hydrodynamical simulations, heavy r-process elements cannot be synthesized in the neutrino-driven winds that follow the supernova explosion. However, by artificially increasing the wind entropy, elements up to A=195 can be made. In this way one can reproduce the typical behavior of high-entropy ejecta where the r process is expected to occur. We identify which nuclear physics input is more important depending on the dynamical evolution of the ejecta. When the evolution proceeds at high temperatures (hot r process), an (n,?)?(?,n) equilibrium is reached, while at low temperatures (cold r process) there is a competition between neutron captures and beta decays. In the first phase of the r process, while enough neutrons are available, the most relevant nuclear physics inputs are the nuclear masses for the hot r process and the neutron capture and beta-decay rates for the cold r process. At the end of this phase, the abundances follow a steady beta flow for the hot r process and a steady flow of neutron captures and beta decays for the cold r process. After neutrons are almost exhausted, matter decays to stability and our results show that in both cases neutron captures are key for determining the final abundances, the position of the r-process peaks, and the formation of the rare-earth peak. In all the cases studied, we find that the freeze-out occurs in a time scale of several seconds.

  4. Dynamical r-process studies within the neutrino-driven wind scenario and its sensitivity to the nuclear physics input

    SciTech Connect

    Arcones, A. [Institut fuer Kernphysik, Technische Universitaet Darmstadt, D-64289 Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany); Martinez-Pinedo, G. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, D-64291 Darmstadt (Germany)

    2011-04-15

    We use results from long-time core-collapse supernovae simulations to investigate the impact of the late time evolution of the ejecta and of the nuclear physics input on the calculated r-process abundances. Based on the latest hydrodynamical simulations, heavy r-process elements cannot be synthesized in the neutrino-driven winds that follow the supernova explosion. However, by artificially increasing the wind entropy, elements up to A=195 can be made. In this way one can reproduce the typical behavior of high-entropy ejecta where the r process is expected to occur. We identify which nuclear physics input is more important depending on the dynamical evolution of the ejecta. When the evolution proceeds at high temperatures (hot r process), an (n,{gamma})<-->({gamma},n) equilibrium is reached, while at low temperatures (cold r process) there is a competition between neutron captures and beta decays. In the first phase of the r process, while enough neutrons are available, the most relevant nuclear physics inputs are the nuclear masses for the hot r process and the neutron capture and beta-decay rates for the cold r process. At the end of this phase, the abundances follow a steady beta flow for the hot r process and a steady flow of neutron captures and beta decays for the cold r process. After neutrons are almost exhausted, matter decays to stability and our results show that in both cases neutron captures are key for determining the final abundances, the position of the r-process peaks, and the formation of the rare-earth peak. In all the cases studied, we find that the freeze-out occurs in a time scale of several seconds.

  5. The Evolutionarily Conserved Protein LAS1 Is Required for Pre-rRNA Processing at Both Ends of ITS2

    PubMed Central

    Schillewaert, Stéphanie; Wacheul, Ludivine; Lhomme, Frédéric

    2012-01-01

    Ribosome synthesis entails the formation of mature rRNAs from long precursor molecules, following a complex pre-rRNA processing pathway. Why the generation of mature rRNA ends is so complicated is unclear. Nor is it understood how pre-rRNA processing is coordinated at distant sites on pre-rRNA molecules. Here we characterized, in budding yeast and human cells, the evolutionarily conserved protein Las1. We found that, in both species, Las1 is required to process ITS2, which separates the 5.8S and 25S/28S rRNAs. In yeast, Las1 is required for pre-rRNA processing at both ends of ITS2. It is required for Rrp6-dependent formation of the 5.8S rRNA 3? end and for Rat1-dependent formation of the 25S rRNA 5? end. We further show that the Rat1-Rai1 5?-3? exoribonuclease (exoRNase) complex functionally connects processing at both ends of the 5.8S rRNA. We suggest that pre-rRNA processing is coordinated at both ends of 5.8S rRNA and both ends of ITS2, which are brought together by pre-rRNA folding, by an RNA processing complex. Consistently, we note the conspicuous presence of ?7- or 8-nucleotide extensions on both ends of 5.8S rRNA precursors and at the 5? end of pre-25S RNAs suggestive of a protected spacer fragment of similar length. PMID:22083961

  6. Physics and Process Modeling (PPM) and Other Propulsion R and T. Volume 1; Materials Processing, Characterization, and Modeling; Lifting Models

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This CP contains the extended abstracts and presentation figures of 36 papers presented at the PPM and Other Propulsion R&T Conference. The focus of the research described in these presentations is on materials and structures technologies that are parts of the various projects within the NASA Aeronautics Propulsion Systems Research and Technology Base Program. These projects include Physics and Process Modeling; Smart, Green Engine; Fast, Quiet Engine; High Temperature Engine Materials Program; and Hybrid Hyperspeed Propulsion. Also presented were research results from the Rotorcraft Systems Program and work supported by the NASA Lewis Director's Discretionary Fund. Authors from NASA Lewis Research Center, industry, and universities conducted research in the following areas: material processing, material characterization, modeling, life, applied life models, design techniques, vibration control, mechanical components, and tribology. Key issues, research accomplishments, and future directions are summarized in this publication.

  7. Hans A. Bethe Prize: Astrophysical, observational and nuclear-physics aspects of r-process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Kratz, Karl-Ludwig

    2014-03-01

    Guided by the Solar System (S.S.) abundance peaks at A ~= 130 and A ~= 195, the basic mechanisms for the rapid neutron-capture process (the r-process) have been known for over 50 years. However, even today, all proposed scenarios and sites face problems with astrophysical conditions as well as with the necessary nuclear-physics input. In my talk, I will describe efforts in experimental and theoretical nuclear-structure data for modeling today's three groups of r-process ``observables'', i.e. the bulk S.S. isotopic abundances, the elemental abundances in metal-poor halo stars, and peculiar isotopic patterns measured in certain cosmic stardust grains. To set a historical basis, I will briefly recall our site-independent ``waiting-point'' model, with superpositions of neutron-density components and the use of the first global, unified nuclear input based on the mass model FRDM(1992). This approach provided a considerable leap forward in the basic understanding of the required astrophysical conditions, as well as of specific shell-structure properties far from stability. Starting in the early millenium, the above simple model has been replaced by more realistic, dynamical parameter studies within the high-entropy wind scenario of core-collapse supernovae, now with superpositions of entropy (S) and electron-fraction (Ye) components. Furthermore, an improved, global set of nuclear-physics data is used today, based on the new mass model FRDM(2012). With this nuclear and astrophysics parameter combination, a new fit to the S.S. r-abundances will be shown, and its improvements and remaining deficiencies in terms of underlying shell structure will be discussed. Concerning the abundance patterns in metal-poor halo stars, an interpretation of the production of ``r-rich'' (e.g. CS 22892-052) and ``r-poor'' (e.g. HD 122563) stars in terms of different (Ye), S combinations will be presented. Finally, for the third group of ``r-observables'', a possible origin of the anomalous Xe-H pattern in presolar nanodiamonds by the ``main'' component of a ``cold'' r-process is suggested.

  8. Neutron single particle structure in 131Sn and the r-process

    SciTech Connect

    Kozub, R. L. [Tennessee Technological University; Bardayan, Daniel W [ORNL; Adekola, Aderemi S [ORNL; Blackmon, Jeff C [ORNL; Chae, K. Y. [University of Tennessee; Chipps, K. [Colorado School of Mines, Golden; Cizewski, J. A. [Rutgers University; Erikson, Luke [Colorado School of Mines, Golden; Hatarik, Robert [Rutgers University; Jones, K. L. [University of Tennessee; Krolas, W. [University of Warsaw; Liang, J Felix [ORNL; Ma, Zhanwen [ORNL; Matei, Catalin [Oak Ridge Associated Universities (ORAU); Moazen, Brian [University of Tennessee; Nesaraja, Caroline D [ORNL; Pain, Steven D [ORNL; Shapira, Dan [ORNL; ShrinerJr., J. F. [Tennessee Technological University; Smith, Michael Scott [ORNL; Swan, T. P. [University of Surrey, UK

    2009-01-01

    Recent calculations suggest that, at late times in the r-process, the rate of neutron capture by {sup 130}Sn has a significant impact on nucleosynthesis. Direct capture into low-lying bound states is likely the dominant reaction in the r-process near the N=82 closed shell, so reaction rates are strongly impacted by the properties of neutron single particle states in this region. In order to investigate these properties, we have acquired (d,p) reaction data in the A{approx}132 region in inverse kinematics using {approx}630 MeV beams (4.85 MeV/u for {sup 130}Sn) and CD{sub 2} targets. An array of Si strip detectors, including SIDAR and an early implementation of the new Oak Ridge Rutgers University Barrel Array (ORRUBA), was used to detect reaction products. Preliminary results for the {sup 130}Sn(d,p){sup 131}Sn experiment are reported.

  9. N=82 shell quenching of the classical r-process "waiting-point" nucleus 130Cd.

    PubMed

    Dillmann, I; Kratz, K-L; Wöhr, A; Arndt, O; Brown, B A; Hoff, P; Hjorth-Jensen, M; Köster, U; Ostrowski, A N; Pfeiffer, B; Seweryniak, D; Shergur, J; Walters, W B

    2003-10-17

    First beta- and gamma-spectroscopic decay studies of the N=82 r-process "waiting-point" nuclide 130Cd have been performed at CERN/ISOLDE using the highest achievable isotopic selectivity. Several nuclear-physics surprises have been discovered. The first one is the unanticipatedly high energy of 2.12 MeV for the [pi g(9/2) multiply sign in circle nu g(7/2)] 1(+) level in 130In, which is fed by the main Gamow-Teller transition. The second surprise is the rather high Q(beta) value of 8.34 MeV, which is in agreement only with recent mass models that include the phenomenon of N=82 shell quenching. Possible implications of these new results on the formation of the A approximately 130 r-process abundance peak are presented. PMID:14611397

  10. Weak Interaction Rates of Nuclei Near the R-Process Paths

    SciTech Connect

    Borzov, I. N.; Cuenca-Garcia, J. J.; Langanke, K.; Martinez-Pinedo, G.; Kelic, A. [Gesellschaft fuer Schwerionenforschung, Darmstadt, D-64291 (Germany); Zinner, N. T. [Institute for Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

    2007-05-22

    Systematic calculations of the beta- and neutrino-induced rates are performed for the nuclei at Z=92-96 approaching the possible r-process paths in vicinity of the spherical neutron shell at N=184. The nuclear ground states are treated self-consistently in the framework of the local energy-density functional (DF) theory. The beta-strength-functions of the Gamow-Teller and first-forbidden decays are calculated within the continuum QRPA approach of the finite Fermi system theory. The beta-decay half-lives and beta-delayed neutron emission probabilities are analyzed simultaneously. Within the same approach the weak interaction rates are calculated for the fission products around Z{approx_equal}50, N=82 forming the A=130 peak in the r-process isotopic abundance. A shell-model study of selected Pd isotopes is performed. An analysis of available experimental data and theoretical predictions from the FRDM is also presented.

  11. {beta}-delayed neutron emission measurements around the third r-process abundance peak

    SciTech Connect

    Caballero-Folch, R.; Cortes, G.; Calvino, F.; Gomez-Hornillos, M. B.; Riego, A. [INTE-DFEN, Universitat Politecnica de Catalunya, Barcelona (Spain); Domingo-Pardo, C.; Tain, J. L.; Agramunt, J.; Rubio, B. [IFIC, CSIC-University of Valencia, Valencia (Spain); Algora, A. [IFIC, CSIC-University of Valencia, Valencia (Spain) and Inst. Nucl. Research, Debrecen (Hungary); Ameil, F.; Farinon, F.; Heil, M.; Knoebel, R.; Kojouharov, I.; Kurcewicz, J.; Kurz, N.; Litvinov, Y.; Mukha, I.; Nociforo, C. [GSI, Darmstadt (Germany); and others

    2013-06-10

    This contribution summarizes an experiment performed at GSI (Germany) in the neutron-rich region beyond N=126. The aim of this measurement is to provide the nuclear physics input of relevance for r-process model calculations, aiming at a better understanding of the third r-process abundance peak. Many exotic nuclei were measured around {sup 211}Hg and {sup 215}Tl. Final ion identification diagrams are given in this contribution. For most of them, we expect to derive halflives and and {beta}-delayed neutron emission probabilities. The detectors used in this experiment were the Silicon IMplantation and Beta Absorber (SIMBA) detector, based on an array of highly segmented silicon detectors, and the BEta deLayEd Neutron (BELEN) detector, which consisted of 30 3He counters embedded in a polyethylene matrix.

  12. The waiting point approximation in R-process calculations. [of astrophysical nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.; Cowan, J. J.; Truran, J. W.

    1983-01-01

    The steady flow approximation to the r-process has been used to evaluate the validity of the waiting point assumption (that, for a given charge number Z, neutron captures become balanced by neutron photodisintegrations) under a variety of conditions. The criterion for the accuracy of the approximation for any set of nuclei with the same value of Z is that the ratio of the total rate of neutron photodisintegration in those nuclei to the total rate of neutron captures should be close to unity. No set of conditions involving neutron production by helium thermonuclear reactions (at temperatures up to 10 to the 9th K) could be found for which the waiting point approximation is useful for all values of Z, and it is recommended that all such r-process calculations not use this approximation. At higher temperatures, such as those characteristic of explosive carbon burning (2 x 10 to the 9th K), the waiting point approximation is much better.

  13. New Precision Mass Measurements of Heavy ^252Cf Fission Fragments Near the r-Process Path

    NASA Astrophysics Data System (ADS)

    van Schelt, J.; Savard, G.; Caldwell, S.; Sternberg, M.; Clark, J. A.; Greene, J. P.; Levand, A. F.; Sun, T.; Zabransky, B. J.; Fallis, J.; Sharma, K. S.; Lascar, D.; Segel, R. E.; Li, G.

    2009-10-01

    Precision mass measurements of nuclides near the astrophysical r-process path are vital to reduce the uncertainties in the relevant neutron separation energies given by mass models, and the consequent abundance predictions. As part of an ongoing program, the Canadian Penning Trap mass spectrometer at Argonne National Laboratory has measured the masses of fission products from a ^252Cf source in a large-volume gas catcher. This has produced 38 new mass measurements of neutron-rich nuclides ranging from Z=51 to 64, many closer to the r-process path than had previously been measured for these elements. Systematic deviations from the AME 2003 are seen over a wide range of elements. The program of mass measurements will continue at the CARIBU upgrade to the ATLAS accelerator at ANL this fall.

  14. arXiv:astro-ph/0301461v231Jan2003 Stellar Sources for Heavy r-Process Nuclei

    E-print Network

    Faraon, Andrei

    . Wasserburg2 ABSTRACT The stellar sites and the complete mechanism of r-process nucleosynthesis are stillarXiv:astro-ph/0301461v231Jan2003 Stellar Sources for Heavy r-Process Nuclei Y.-Z. Qian1 and G. J reactions, nucleosynthesis, abundances -- Galaxy: evo- lution -- Stars: Population II 1. Introduction

  15. THE r-PROCESS IN PROTO-NEUTRON-STAR WIND REVISITED

    SciTech Connect

    Wanajo, Shinya, E-mail: shinya.wanajo@nao.ac.jp [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2013-06-20

    We examine the r-process in the neutrino-driven proto-neutron-star (PNS) wind of core-collapse supernovae in light of the recent findings of massive neutron stars in binaries as well as of an indication of neutron-richness in the PNS ejecta because of the nucleon potential corrections on neutrino opacities. To this end, a spherically symmetric, general relativistic, steady-state wind model is applied for a wide range of PNS masses between 1.2 M{sub Sun} and 2.4 M{sub Sun} with the latter reaching the causality limit. Nucleosynthesis calculations with these PNS models are performed by assuming a time evolution of electron fraction with its minimal value of Y{sub e} = 0.4, which mimics recent hydrodynamical results. The fundamental nucleosynthetic aspect of the PNS wind is found to be the production of Sr, Y, and Zr in quasi-equilibrium and of the elements with A Almost-Equal-To 90-110 by a weak r-process, which can be an explanation for the abundance signatures in r-process-poor Galactic halo stars. PNSs more massive than 2.0 M{sub Sun} can eject heavy r-process elements, however, with substantially smaller amount than what is needed to account for the solar content. PNS winds can be thus the major origin of light trans-iron elements but no more than 10% of those heavier than A {approx} 110, although they may be the sources of the low-level abundances of Sr and Ba found in numerous metal-poor stars if the maximum mass of PNSs exceeds 2.0 M{sub Sun }.

  16. Phenopix: a R package to process digital images of a vegetation cover

    NASA Astrophysics Data System (ADS)

    Filippa, Gianluca; Cremonese, Edoardo; Migliavacca, Mirco; Galvagno, Marta; Morra di Cella, Umberto; Richardson, Andrew

    2015-04-01

    Plant phenology is a globally recognized indicator of the effects of climate change on the terrestrial biosphere. Accordingly, new tools to automatically track the seasonal development of a vegetation cover are becoming available and more and more deployed. Among them, near-continuous digital images are being collected in several networks in the US, Europe, Asia and Australia in a range of different ecosystems, including agricultural lands, deciduous and evergreen forests, and grasslands. The growing scientific interest in vegetation image analysis highlights the need of easy to use, flexible and standardized processing techniques. In this contribution we illustrate a new open source package called "phenopix" written in R language that allows to process images of a vegetation cover. The main features include: (i) define of one or more areas of interest on an image and process pixel information within them, (ii) compute vegetation indexes based on red green and blue channels, (iii) fit a curve to the seasonal trajectory of vegetation indexes and extract relevant dates (aka thresholds) on the seasonal trajectory; (iv) analyze image pixels separately to extract spatially explicit phenological information. The utilities of the package will be illustrated in detail for two subalpine sites, a grassland and a larch stand at about 2000 m in the Italian Western Alps. The phenopix package is a cost free and easy-to-use tool that allows to process digital images of a vegetation cover in a standardized, flexible and reproducible way. The software is available for download at the R forge web site (r-forge.r-project.org/projects/phenopix/).

  17. Integration of marketing domain and R&D domain in NPD design process

    Microsoft Academic Search

    Namwoo Kang; Junyoung Kim

    2007-01-01

    Purpose – To solve the trade-offs between marketing and R&D domains and to minimize information loss in new product development (NPD), this study proposes an integrated design process as a new solution to the interface system between the two domains. Design\\/methodology\\/approach – House of Quality integrated with multivariate statistical analysis is used for determining important design features. These design features

  18. Analysis of launch site processing effectiveness for the Space Shuttle 26R payload

    NASA Technical Reports Server (NTRS)

    Flores, Carlos A.; Heuser, Robert E.; Pepper, Richard E., Jr.; Smith, Anthony M.

    1991-01-01

    A trend analysis study has been performed on problem reports recorded during the Space Shuttle 26R payload's processing cycle at NASA-Kennedy, using the defect-flow analysis (DFA) methodology; DFA gives attention to the characteristics of the problem-report 'population' as a whole. It is established that the problem reports contain data which distract from pressing problems, and that fully 60 percent of such reports were caused during processing at NASA-Kennedy. The second major cause of problem reports was design defects.

  19. The r-process element abundance with a realistic fission fragment mass distribution

    SciTech Connect

    Chiba, S.; Koura, H.; Maruyama, T. [Advanced Science Research Center, JAEA Tokai, Naka, Ibaraki 319-1195 (Japan); Ohta, M.; Tatsuda, S. [Department of Physics, Konan University, 8-9-1 Okamoto, Kobe 658-8501 (Japan); Wada, T. [Department of Pure and Applied Physics, Kansai University, Suita, Osaka 564-8680 (Japan); Tachibana, T. [Senior High School of Waseda University, Tokyo (Japan); Sumiyoshi, K. [Numazu College of Technology, Ooka 3600, Numazu 410-8501 (Japan); Otsuki, K. [GSI Theory Department, Planckstrassel 64291 Darmstadt Germany (Germany); Kajino, T. [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); University of Tokyo (Japan)

    2008-05-21

    Effect of the {beta}-delayed fission in r-process abundance is investigated with a realistic model for the fission fragment mass distribution (FFMD). The data base for the FFMD is constructed based on the two-center shell model and multi-dimensional Langevin calculation. The {beta}-decay rates including neutron emission and {beta}-delayed fission are also newly calculated with 2nd version of the the gross theory. The differences appeared in the final element abundance calculated with and without fission process, with different {beta}-delayed fission rates are demonstrated.

  20. Exploiting Pre-rRNA Processing in Diamond Blackfan Anemia Gene Discovery and Diagnosis

    PubMed Central

    Farrar, Jason E.; Quarello, Paola; Fisher, Ross; O’Brien, Kelly A.; Aspesi, Anna; Parrella, Sara; Henson, Adrianna L.; Seidel, Nancy E.; Atsidaftos, Eva; Prakash, Supraja; Bari, Shahla; Garelli, Emanuela; Arceci, Robert J.; Dianzani, Irma; Ramenghi, Ugo; Vlachos, Adrianna; Lipton, Jeffrey M.; Bodine, David M.; Ellis, Steven R.

    2014-01-01

    Diamond Blackfan anemia (DBA), a syndrome primarily characterized by anemia and physical abnormalities, is one among a group of related inherited bone marrow failure syndromes (IBMFS) which share overlapping clinical features. Heterozygous mutations or single-copy deletions have been identified in 12 ribosomal protein genes in approximately 60% of DBA cases, with the genetic etiology unexplained in most remaining patients. Unlike many IBMFS, for which functional screening assays complement clinical and genetic findings, suspected DBA in the absence of typical alterations of the known genes must frequently be diagnosed after exclusion of other IBMFS. We report here a novel deletion in a child that presented such a diagnostic challenge and prompted development of a novel functional assay that can assist in the diagnosis of a significant fraction of patients with DBA. The ribosomal proteins affected in DBA are required for pre-rRNA processing, a process which can be interrogated to monitor steps in the maturation of 40S and 60S ribosomal subunits. In contrast to prior methods used to assess pre-rRNA processing, the assay reported here, based on capillary electrophoresis measurement of the maturation of rRNA in pre-60S ribosomal subunits, would be readily amenable to use in diagnostic laboratories. In addition to utility as a diagnostic tool, we applied this technique to gene discovery in DBA, resulting in the identification of RPL31 as a novel DBA gene. PMID:25042156

  1. Exploiting pre-rRNA processing in Diamond Blackfan anemia gene discovery and diagnosis.

    PubMed

    Farrar, Jason E; Quarello, Paola; Fisher, Ross; O'Brien, Kelly A; Aspesi, Anna; Parrella, Sara; Henson, Adrianna L; Seidel, Nancy E; Atsidaftos, Eva; Prakash, Supraja; Bari, Shahla; Garelli, Emanuela; Arceci, Robert J; Dianzani, Irma; Ramenghi, Ugo; Vlachos, Adrianna; Lipton, Jeffrey M; Bodine, David M; Ellis, Steven R

    2014-10-01

    Diamond Blackfan anemia (DBA), a syndrome primarily characterized by anemia and physical abnormalities, is one among a group of related inherited bone marrow failure syndromes (IBMFS) which share overlapping clinical features. Heterozygous mutations or single-copy deletions have been identified in 12 ribosomal protein genes in approximately 60% of DBA cases, with the genetic etiology unexplained in most remaining patients. Unlike many IBMFS, for which functional screening assays complement clinical and genetic findings, suspected DBA in the absence of typical alterations of the known genes must frequently be diagnosed after exclusion of other IBMFS. We report here a novel deletion in a child that presented such a diagnostic challenge and prompted development of a novel functional assay that can assist in the diagnosis of a significant fraction of patients with DBA. The ribosomal proteins affected in DBA are required for pre-rRNA processing, a process which can be interrogated to monitor steps in the maturation of 40S and 60S ribosomal subunits. In contrast to prior methods used to assess pre-rRNA processing, the assay reported here, based on capillary electrophoresis measurement of the maturation of rRNA in pre-60S ribosomal subunits, would be readily amenable to use in diagnostic laboratories. In addition to utility as a diagnostic tool, we applied this technique to gene discovery in DBA, resulting in the identification of RPL31 as a novel DBA gene. PMID:25042156

  2. r-Process abundances in metal-poor Galactic halo stars

    NASA Astrophysics Data System (ADS)

    Siqueira-Mello, C.; Barbuy, B.; Spite, M.; Spite, F.; Caffau, E.; Hill, V.; Wanajo, S.; François, P.; Bonifacio, P.; Cayrel, R.

    The site of the r-process is not completely defined, and several models try to explain the origin of the trans-Fe elements. Observed abundances are the best clues to bring some light to this multiplicity of possible mechanisms, and the extremely metal-poor (EMP) Galactic halo stars have a special role in this problem. In this contribution we present the solution of a long-standing problem about the origin of the heavy elements in the metal-poor halo subgiant star HD 140283, and its correlation with the Truran's theory. Next, we describe the results obtained with the EMP r-II star CS 31082-001 in the frame of the ESO Large Program ``First Stars''. Using STIS/HST observations we provide abundances for elements never presented before in this stars, making CS 31082-001 the most complete r-II object studied, with a total of 37 detections of neutron-capture elements. Finally, we present the results obtained from a sample of seven r-I stars, showing how those objects can help us solving the heavy elements problem. Conclusions are also described.

  3. Salinity inhibits post transcriptional processing of chloroplast 16S rRNA in shoot cultures of jojoba (Simmondsia chinesis).

    PubMed

    Mizrahi-Aviv, Ela; Mills, David; Benzioni, Aliza; Bar-Zvi, Dudy

    2005-03-01

    Chloroplast metabolism is rapidly affected by salt stress. Photosynthesis is one of the first processes known to be affected by salinity. Here, we report that salinity inhibits chloroplast post-transcriptional RNA processing. A differentially expressed 680-bp cDNA, containing the 3' sequence of 16S rRNA, transcribed intergenic spacer, exon 1 and intron of tRNA(Ile), was isolated by differential display reverse transcriptase PCR from salt-grown jojoba (Simmondsia chinesis) shoot cultures. Northern blot analysis indicated that although most rRNA appears to be fully processed, partially processed chloroplast 16S rRNA accumulates in salt-grown cultures. Thus, salinity appears to decrease the processing of the rrn transcript. The possible effect of this decreased processing on physiological processes is, as yet, unknown. PMID:15645309

  4. Beta-delayed neutron emission measurements for r-process nuclei

    NASA Astrophysics Data System (ADS)

    Dillmann, Iris

    2014-09-01

    Beta-delayed neutron- (bn-) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the ``rapid neutron-capture process'' (r process). On one hand they lead to a detour of the material beta-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes for r-process nucleosynthesis are not yet experimentally accessible and are located in the ``terra incognita.'' With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of very neutron-rich isotopes at and beyond the border of presently known nuclei. However, reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. The investigation of bn-emitters has recently experienced a renaissance. I will show some recent results from a GSI campaign with the BELEN detector, and introduce the program planned for 2015/16 at RIKEN with the ``BRIKEN'' detector. ``BRIKEN'' (``Beta-delayed neutron measurements at RIKEN for nuclear structure, astrophysics, and applications'') is a worldwide effort which combines 3He-neutron counters from groups in Germany, Japan, Russia, Spain, and the USA and the implantation detector AIDA from the UK to the presently largest and most efficient neutron detection setup. Planned first experiments comprise the first-time measurements of 48 b-delayed one-neutron and 24 b-delayed two-neutron emitters in the regions around doubly-magic 78Ni and 132Sn. Even some b-delayed three-neutron emitters in the heavier mass region will be tackled for the first time.

  5. Chapter for R. Rama (Ed.), Innovation in the food and drink processing industry, Haworth Press Inc, N.Y.

    E-print Network

    Paris-Sud XI, Université de

    1 Chapter for R. Rama (Ed.), Innovation in the food and drink processing industry, Haworth Press Inc, N.Y. Biotech Innovation in Europe's Food and Drink Processing Industry: Promise, Barriers). The next section will discuss the many opportunities for product and process innovation in the food

  6. 1154 D. R. Warren et al. Copyright 2007 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 32, 11541163 (2007)

    E-print Network

    Hall Jr., Robert O.

    2007-01-01

    1154 D. R. Warren et al. Copyright © 2007 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 32, 1154­1163 (2007) DOI: 10.1002/esp Earth Surface Processes and Landforms Earth Surf. Process. Landforms.interscience.wiley.com) DOI: 10.1002/esp.1548 Forest age, wood and nutrient dynamics in headwater streams of the Hubbard Brook

  7. Beta decay rates for r-process for nuclei near neutron number N=82

    E-print Network

    Kamales Kar; Soumya Chakravarti

    2008-12-01

    For r-process nucleosynthesis the beta decay rates of very neutron-rich nuclei are important ingredients. We consider the region around the neutron number N=82 and calculate the half-lives and rates for a number of nuclei. Forms for beta strength functions based on spectral distribution methods are used. The calculated half-lives are first compared to the observed values and then predictions are made for very neutron-rich nuclei close to drip line for which no experimental values are available.

  8. Half-lives of N = 126 Isotones and the r-Process

    SciTech Connect

    Suzuki, Toshio [Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan and Center for Nuclear Study, University of Tokyo, Hirosawa, Wako-shi, Saitama, 351-0198 (Japan); Yoshida, Takashi [Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Utsuno, Yutaka [Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Naka-gun, Ibaraki 319-1195 (Japan)

    2010-08-12

    Beta decays of N = 126 isotones are studied by shell model calculations. Both the Gamow-Teller (GT) and first-forbidden (FF) transitions are taken into account to evaluate the half-lives of the isotones (Z = 64-72) with the use of shell model interactions based on G-matrix. The FF transitions are found to be important to reduce the half-lives by twice to several times of those obtained by the GT contributions only. Possible implications of the short half-lives of the waiting point nuclei on the r-process nucleosynthesis during the supernova explosions are discussed.

  9. Re-187, recycling r-process elements through stars, and the age of the Galaxy.

    NASA Technical Reports Server (NTRS)

    Talbot, R. J., Jr.

    1973-01-01

    The enhanced beta-decay rate of ionized Re-187 in stars has been studied within the context of a detailed numerical model of the production of r-process elements and their recycling through stars during the course of galactic evolution. It is concluded that the enhanced decay rate does not significantly reduce the Re-Os chronometer age for the Galaxy. Consequently, the Re-187 beta-decay half-life and the Os-186/Os-187 neutron cross-section ratio remain as the significant uncertainties in this chronology. Unlike the uncertainties in other chronologies, both are amenable to laboratory measurements.

  10. Fission fragment mass distribution for nuclei in the r-process region

    SciTech Connect

    Tatsuda, S.; Hashizume, K.; Wada, T.; Ohta, M. [Department of Physics, Konan University, 8-9-1 Okamoto, Kobe 658-8501 (Japan); Sumiyoshi, K. [Numazu College of Technology, NAO (Japan); Otsuki, K. [Univ. of Chicago (United States); Kajino, T. [NAO, GUSA, Univ. of Tokyo (Japan); Koura, H.; Chiba, S. [JAEA (Japan); Aritomo, Y. [FLNR (JINR) (United States)

    2007-02-26

    The fission fragment mass distribution is estimated theoretically on about 2000 nuclides which might have a critical role on the r-process nucleosynthesis through fission (Z>85). The mass distribution of fission fragment is derived by considering the location and the depth of valleys of potential energy surface near scission point of nuclei calculated by means of the liquid drop model with the shell energy correction by the Two-Center shell model. The guiding principle of determining the fission mass asymmetry is the behavior of the fission paths from the saddle to the scission point given by the Langevin calculation.

  11. Supernova SN1987A Bound on Neutrino Spectra for R-Process Nucleosynthesis

    E-print Network

    C. J. Horowitz

    2002-01-31

    The neutrino driven wind during a core collapse supernova is an attractive site for r-process nucleosynthesis. The electron fraction $Y_e$ in the wind depends on observable neutrino energies and luminosities. The mean antineutrino energy is limited by supernova SN1987A data while lepton number conservation constrains the ratio of antineutrino to neutrino luminosities. If $Y_e$, in the wind, is to be suitable for rapid neutron capture nucleosynthesis, then the mean electron neutrino energy may be significantly lower then that predicted in present supernova simulations, or there may be new neutrino physics such as oscillations to sterile neutrinos.

  12. Mass measurements beyond the major r-process waiting point 80Zn

    E-print Network

    S. Baruah; G. Audi; K. Blaum; M. Dworschak; S. George; C. Guenaut; U. Hager; F. Herfurth; A. Herlert; A. Kellerbauer; H. -J. Kluge; D. Lunney; H. Schatz; L. Schweikhard; C. Yazidjian

    2008-11-14

    High-precision mass measurements on neutron-rich zinc isotopes 71m,72-81Zn have been performed with the Penning trap mass spectrometer ISOLTRAP. For the first time the mass of 81Zn has been experimentally determined. This makes 80Zn the first of the few major waiting points along the path of the astrophysical rapid neutron capture process where neutron separation energy and neutron capture Q-value are determined experimentally. As a consequence, the astrophysical conditions required for this waiting point and its associated abundance signatures to occur in r-process models can now be mapped precisely. The measurements also confirm the robustness of the N = 50 shell closure for Z = 30 farther from stability.

  13. Mass Measurements beyond the Major r-Process Waiting Point {sup 80}Zn

    SciTech Connect

    Baruah, S.; Herlert, A.; Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Audi, G.; Guenaut, C.; Lunney, D. [CSNSM-IN2P3-CNRS, Universite de Paris Sud, Orsay (France); Blaum, K.; George, S. [GSI, Planckstr. 1, 64291 Darmstadt (Germany); Institut fuer Physik, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Dworschak, M.; Herfurth, F.; Yazidjian, C. [GSI, Planckstr. 1, 64291 Darmstadt (Germany); Hager, U. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), 40014 Jyvaeskylae (Finland); Helsinki Institute of Physics, University of Helsinki, 00014 Helsinki (Finland); Kellerbauer, A. [Physics Department, CERN, 1211 Geneva 23 (Switzerland); Kluge, H.-J. [GSI, Planckstr. 1, 64291 Darmstadt (Germany); Fakultaet fuer Physik und Astronomie, Ruprecht-Karls-Universitaet, 69120 Heidelberg (Germany); Schatz, H. [Department of Physics and Astronomy, NSCL, and JINA, Michigan State University, East Lansing, Michigan 48824 (United States)

    2008-12-31

    High-precision mass measurements on neutron-rich zinc isotopes {sup 71m,72-81}Zn have been performed with the Penning trap mass spectrometer ISOLTRAP. For the first time, the mass of {sup 81}Zn has been experimentally determined. This makes {sup 80}Zn the first of the few major waiting points along the path of the astrophysical rapid neutron-capture process where neutron-separation energy and neutron-capture Q-value are determined experimentally. The astrophysical conditions required for this waiting point and its associated abundance signatures to occur in r-process models can now be mapped precisely. The measurements also confirm the robustness of the N=50 shell closure for Z=30.

  14. Publications Raymond C Smith Carrillo, C. J., R. C. Smith and D. M. Karl (2004). "Processes regulating

    E-print Network

    California at Santa Barbara, University of

    2004-01-01

    Publications ­ Raymond C Smith Carrillo, C. J., R. C. Smith and D. M. Karl (2004). "Processes regulating oxygen and carbon dioxide in surface waters west of the Antarctic Peninsula." Marine Chemistry 84 and interactions with other climatic change factors." Photochemical and Photobiological Sciences 2: 39-50. Smith, R

  15. THE MIT SPOKEN LECTURE PROCESSING PROJECT James R. Glass, Timothy J. Hazen, D. Scott Cyphers, Ken Schutte and Alex Park

    E-print Network

    Hazen, Timothy J.

    THE MIT SPOKEN LECTURE PROCESSING PROJECT James R. Glass, Timothy J. Hazen, D. Scott Cyphers, Ken, Cambridge, Massachusetts, 02476, USA {hazen,jrg,cyphers}@csail.mit.edu Abstract We will demonstrate the MIT

  16. The role of neutron star mergers and core collapse supernovae in r process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Daigne, F.; Vangioni, E.

    2014-12-01

    Recent IR/optical/UV observations and Gamma-ray burst rate determinations at high redshift have led to significant progress in establishing the cosmic evolution of the star formation rate density (SFRD). The SFRD is then used to predict the ionization history of the Universe, and the evolution of the cosmic chemical abundances, supernova rates, etc, as a function of the redshift z. These predictions are done in the framework of the hierarchical model for structure formation. In this context, we focus here our attention on the origin and evolution of a typical r process element: Europium, in two possible sites: core collapse supernovae (SNII) or Neutron Star Mergers (NSM). In the first scenario, there is only one parameter, the yield of Eu produced in these SNII. In the second one, there are three physical parameters, Eu yield, binary star fraction and time delay before the merger. The comparison of our results with available observations of Eu in stars at various metallicities strongly favors the NSM site for the r process. In addition, it allows to put a constraint on the time delay for mergers, which is typically 0.1-0.2 Gyr, and to make an independent prediction for the expected rate of mergers in the horizon of the adv Virgo/Ligo detectors, which we find typically to be of the order of 3 to 10 events per year for NS/NS and NS/BH mergers respectively.

  17. The Most Complete Template for r-process Nucleosynthesis beyond the Solar System

    NASA Astrophysics Data System (ADS)

    Roederer, Ian

    2012-10-01

    We propose to observe two metal-poor stars that present a unique opportunity to expand the chemical inventory to unprecedented levels in an environment beyond the solar system. The proposed observations will allow us to detect several key elements, including arsenic {As, Z=33} and selenium {Se, Z=34}, that cannot be detected from the ground. These elements are key to understanding the nature of the r-process in the first generations of stars that drive chemical evolution of the Galaxy, yet their abundance in the one star where they have been detected is not fully explained by current models. We will use STIS to obtain high-resolution UV spectra from 1900 to 2380 Angstroms in two metal-poor stars enriched with modest but differing amounts of r-process material, HD 108317 and HD 128279. We will perform an abundance analysis and derive abundances or meaningful upper limits for the heavy elements Cu, Zn, Ge, As, Se, Zr, Mo, Cd, Te, Yb, Os, Ir, Pt, and Pb. This work is supported by recent laboratory experiments and theoretical studies that continue to provide data of wider interest to the atomic, nuclear, and astrophysics communities.

  18. A low initial abundance of 247Cm in the early solar system and implications for r-process nucleosynthesis

    Microsoft Academic Search

    Claudine H. Stirling; Alex N. Halliday; Emma-Kate Potter; Morten B. Andersen; Brigitte Zanda

    2006-01-01

    The short-lived nuclide 247Cm is produced by r-process nucleosynthesis. When the presolar nebula formed, 247Cm became isolated from r-process production and its abundance diminished as a result of radioactive decay. Given its short half-life of only ?16 million years, 247Cm is presently extinct, but its former presence should be detectable as small variations in 235U\\/238U in primitive meteoritic material, provided Cm

  19. Process R&D for CIS-Based Thin-Film PV: Final Technical Report, April 2002 - April 2005

    SciTech Connect

    Tarrant, D. E.; Gay, R. R.

    2006-01-01

    The primary objectives of this Shell Solar Industries subcontract are to address key near-term technical R&D issues for continued CIS product improvement; continue process development for increased production capacity; develop processes capable of significantly contributing to DOE 2020 PV shipment goals; advance mid- and longer-term R&D needed by industry for future product competitiveness including improving module performance, decreasing production process costs per watt produced, and improving reliability; and perform aggressive module lifetime R&D directed at developing packages that address the DOE goal for modules that will last up to 30 years while retaining 80% of initial power. These production R&D results, production volume, efficiency, high line yield, and advances in understanding are major accomplishments. The demonstrated and maintained high production yield is a major accomplishment supporting attractive cost projections for CIS. Process R&D at successive levels of CIS production has led to the continued demonstration of the prerequisites for commitment to large-scale commercialization. Process and packaging R&D during this and previous subcontracts has demonstrated the potential for further cost and performance improvements.

  20. Adsorption of Chrysoidine R by using fly ash in batch process.

    PubMed

    Matheswaran, Manickam; Karunanithi, Thirugnanam

    2007-06-25

    This investigation deals with effective utilization of fly ash as adsorbent for the removal of Chrysoidine R from the aqueous solution. The fly ash is a major byproduct generated in coal-based thermal power plants and has good potential for use as an adsorbent. A series of experiments were carried out in a batch adsorption technique to obtain the effect of process variables viz. contact time, pH (2, 4, 6 and 8) initial concentration of the dye (400, 600, 800 and 1000mgL(-1)), amount of the adsorbent (125, 250, 375 and 500mgL(-1)), and temperature (303, 313, 323 and 333K) on adsorption. The concentration of dye was determined by spectrophotometer. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly; higher adsorption percentage was observed at lower concentration of chrysoidine. The adsorption data were analyzed using Langmuir and Freundlich isotherms. The adsorption was found to obey pseudo-first order kinetics. An intra particle diffusion model was used to fit the experimental data. The thermodynamic parameters such as standard change in free energy, enthalpy and entropy of adsorption have been calculated. Adsorption of Chrysoidine R on fly ash was found to be an exothermic reaction. PMID:17141408

  1. ?-decay spectroscopy of r-process nuclei with N = 126 at KISS

    SciTech Connect

    Hirayama, Y.; Watanabe, Y. X.; Imai, N.; Ishiyama, H.; Jeong, S. C.; Miyatake, H.; Oyaizu, M. [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Kim, Y. H. [Seoul National University, Seoul 151-742 (Korea, Republic of); Mukai, M.; Kimura, S. [Tsukuba University, Ibaraki 305-0006 (Japan)

    2014-05-02

    The ?-decay properties of nuclei with N = 126, which are believed to act as progenitors in the rapid neutron capture (r-) process path forming the third peak (A ? 195) in the observed r-abundance element distribution, are considered critical for understanding the production of heavy elements such as gold and platinum at astrophysical sites. We have constructed the KEK Isotope Separation System (KISS), which consists of a gas cell based laser ion source (atomic number selection) and an isotope separation on-line (ISOL) (mass number selection), to produce pure low-energy beams of neutron-rich isotopes around N = 126 and to study their ?-decay properties, which are also of interest for astrophysics. The isotopes of interest will be produced by multi-nucleon transfer reactions in heavy ion collisions (e.g. {sup 136}Xe projectile on {sup 198}Pt target). KISS will allow us to study unknown isotopes produced in weak reaction channels under low background conditions. We successfully extracted the stable {sup 56}Fe beam from KISS at the last commissioning on-line experiment with the extraction efficiency of 0.25% and beam purity of more than 98%. We can access the nuclei with N = 126 and measure their half-lives using the KISS in the case of the extraction efficiency of 0.1%.

  2. ?-decay spectroscopy of r-process nuclei with N = 126 at KISS

    NASA Astrophysics Data System (ADS)

    Hirayama, Y.; Watanabe, Y. X.; Imai, N.; Ishiyama, H.; Jeong, S. C.; Miyatake, H.; Oyaizu, M.; Kim, Y. H.; Mukai, M.; Kimura, S.

    2014-05-01

    The ?-decay properties of nuclei with N = 126, which are believed to act as progenitors in the rapid neutron capture (r-) process path forming the third peak (A ˜ 195) in the observed r-abundance element distribution, are considered critical for understanding the production of heavy elements such as gold and platinum at astrophysical sites. We have constructed the KEK Isotope Separation System (KISS), which consists of a gas cell based laser ion source (atomic number selection) and an isotope separation on-line (ISOL) (mass number selection), to produce pure low-energy beams of neutron-rich isotopes around N = 126 and to study their ?-decay properties, which are also of interest for astrophysics. The isotopes of interest will be produced by multi-nucleon transfer reactions in heavy ion collisions (e.g. 136Xe projectile on 198Pt target). KISS will allow us to study unknown isotopes produced in weak reaction channels under low background conditions. We successfully extracted the stable 56Fe beam from KISS at the last commissioning on-line experiment with the extraction efficiency of 0.25% and beam purity of more than 98%. We can access the nuclei with N = 126 and measure their half-lives using the KISS in the case of the extraction efficiency of 0.1%.

  3. New Fission Fragment Distributions and r-Process Origin of the Rare-Earth Elements

    NASA Astrophysics Data System (ADS)

    Goriely, S.; Sida, J.-L.; Lemaître, J.-F.; Panebianco, S.; Dubray, N.; Hilaire, S.; Bauswein, A.; Janka, H.-T.

    2013-12-01

    Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A?140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular, the fission fragment yields determine the creation of 110?A?170 nuclei. Here, we apply a new scission-point model, called SPY, to derive the fission fragment distribution (FFD) of all relevant neutron-rich, fissioning nuclei. The model predicts a doubly asymmetric FFD in the abundant A?278 mass region that is responsible for the final recycling of the fissioning material. Using ejecta conditions based on relativistic NS merger calculations, we show that this specific FFD leads to a production of the A?165 rare-earth peak that is nicely compatible with the abundance patterns in the Sun and metal-poor stars. This new finding further strengthens the case of NS mergers as possible dominant origin of r nuclei with A?140.

  4. Mass measurements near the $r$-process path using the Canadian Penning Trap mass spectrometer

    E-print Network

    J. Van Schelt; D. Lascar; G. Savard; J. A. Clark; S. Caldwell; A. Chaudhuri; J. Fallis; J. P. Greene; A. F. Levand; G. Li; K. S. Sharma; M. G. Sternberg; T. Sun; B. J. Zabransky

    2012-04-09

    The masses of 40 neutron-rich nuclides from Z = 51 to 64 were measured at an average precision of $\\delta m/m= 10^{-7}$ using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. The measurements, of fission fragments from a $^{252}$Cf spontaneous fission source in a helium gas catcher, approach the predicted path of the astrophysical $r$ process. Where overlap exists, this data set is largely consistent with previous measurements from Penning traps, storage rings, and reaction energetics, but large systematic deviations are apparent in $\\beta$-endpoint measurements. Differences in mass excess from the 2003 Atomic Mass Evaluation of up to 400 keV are seen, as well as systematic disagreement with various mass models.

  5. In search of sustainability: process R&D in light of current pharmaceutical industry challenges.

    PubMed

    Federsel, Hans-Jürgen

    2006-11-01

    Is there a need for a paradigm shift in the pharmaceutical industry? Many researchers think so and take as examples the eroding corporate reputation, a regulatory environment that is harsher than ever, and the request for cheaper drugs from patient organizations and authorities. Process R&D, which interfaces medicinal chemistry and production, has taken on this challenge by increasing the delivery focus early on to ensure timely availability of desired compounds. The quest for lower costs of goods has forced the design of best synthetic routes that, given the molecular complexity, often lead to catalytic methodologies. Applying these methodologies will enable not only the cost element, but also the increasingly important aspects of environmental friendliness, and atom and stage efficiency, to be addressed. PMID:17055405

  6. COPASutils: an R package for reading, processing, and visualizing data from COPAS large-particle flow cytometers.

    PubMed

    Shimko, Tyler C; Andersen, Erik C

    2014-01-01

    The R package COPASutils provides a logical workflow for the reading, processing, and visualization of data obtained from the Union Biometrica Complex Object Parametric Analyzer and Sorter (COPAS) or the BioSorter large-particle flow cytometers. Data obtained from these powerful experimental platforms can be unwieldy, leading to difficulties in the ability to process and visualize the data using existing tools. Researchers studying small organisms, such as Caenorhabditis elegans, Anopheles gambiae, and Danio rerio, and using these devices will benefit from this streamlined and extensible R package. COPASutils offers a powerful suite of functions for the rapid processing and analysis of large high-throughput screening data sets. PMID:25329171

  7. COPASutils: An R Package for Reading, Processing, and Visualizing Data from COPAS Large-Particle Flow Cytometers

    PubMed Central

    Shimko, Tyler C.; Andersen, Erik C.

    2014-01-01

    The R package COPASutils provides a logical workflow for the reading, processing, and visualization of data obtained from the Union Biometrica Complex Object Parametric Analyzer and Sorter (COPAS) or the BioSorter large-particle flow cytometers. Data obtained from these powerful experimental platforms can be unwieldy, leading to difficulties in the ability to process and visualize the data using existing tools. Researchers studying small organisms, such as Caenorhabditis elegans, Anopheles gambiae, and Danio rerio, and using these devices will benefit from this streamlined and extensible R package. COPASutils offers a powerful suite of functions for the rapid processing and analysis of large high-throughput screening data sets. PMID:25329171

  8. Julian, B.R. and G.R. Foulger, Monitoring Geothermal Processes with Microearthquake Mechanisms, Thirty-Fourth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, February 9-

    E-print Network

    Foulger, G. R.

    Julian, B.R. and G.R. Foulger, Monitoring Geothermal Processes with Microearthquake Mechanisms, Thirty- Fourth Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, February 9- 11, 2009. Monitoring Geothermal Processes with Microearthquake Mechanisms Bruce R. Julian, U. S

  9. DETECTION OF ELEMENTS AT ALL THREE r-PROCESS PEAKS IN THE METAL-POOR STAR HD 160617

    SciTech Connect

    Roederer, Ian U. [Carnegie Observatories, Pasadena, CA 91101 (United States); Lawler, James E., E-mail: iur@obs.carnegiescience.edu, E-mail: jelawler@wisc.edu [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2012-05-01

    We report the first detection of elements at all three r-process peaks in the metal-poor halo star HD 160617. These elements include arsenic and selenium, which have not been detected previously in halo stars, and the elements tellurium, osmium, iridium, and platinum, which have been detected previously. Absorption lines of these elements are found in archive observations made with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We present up-to-date absolute atomic transition probabilities and complete line component patterns for these elements. Additional archival spectra of this star from several ground-based instruments allow us to derive abundances or upper limits of 45 elements in HD 160617, including 27 elements produced by neutron-capture reactions. The average abundances of the elements at the three r-process peaks are similar to the predicted solar system r-process residuals when scaled to the abundances in the rare earth element domain. This result for arsenic and selenium may be surprising in light of predictions that the production of the lightest r-process elements generally should be decoupled from the heavier r-process elements.

  10. The origins of light and heavy r-process elements identified by chemical tagging of metal-poor stars

    E-print Network

    Tsujimoto, Takuji

    2014-01-01

    Growing interests in neutron star (NS) mergers as the origin of r-process elements have sprouted since the discovery of evidence for the ejection of these elements from a short-duration gamma-ray burst. The hypothesis of a NS merger origin is reinforced by a theoretical update of nucleosynthesis in NS mergers successful in yielding r-process nuclides with A>130. On the other hand, whether the origin of light r-process elements are associated with nucleosynthesis in NS merger events remains unclear. We find a signature of nucleosynthesis in NS mergers from peculiar chemical abundances of stars belonging to the Galactic globular cluster M15. This finding combined with the recent nucleosynthesis results implies a potential diversity of nucleosynthesis in NS mergers. Based on these considerations, we are successful in the interpretation of an observed correlation between [light r-process/Eu] and [Eu/Fe] among Galactic halo stars and accordingly narrow down the role of supernova nucleosynthesis in the r-process pr...

  11. Mass Measurements of Heavy ^252Cf Fission Fragments Near the r-Process Path with the Canadian Penning Trap

    NASA Astrophysics Data System (ADS)

    van Schelt, J.; Lascar, D.; Savard, G.; Clark, J. A.; Greene, J. P.; Levand, A. F.; Sun, T.; Zabransky, B. J.; Caldwell, S.; Sternberg, M.; Fallis, J.; Sharma, K. S.; Segel, R. E.; Li, G.

    2010-02-01

    Precision mass measurements of nuclides near the astrophysical r-process path are vital to reduce the uncertainties in the relevant neutron separation energies and the consequent abundance predictions. Before moving to CARIBU, the Canadian Penning Trap mass spectrometer at Argonne National Laboratory undertook a series of mass measurements of spontaneous fission products from a 150 ?Ci ^252Cf source in a previous large-volume gas catcher. Masses of 38 neutron-rich nuclides ranging from Z=51 to 64 were measured, many of which were closer to the r-process path than had previously been measured for these elements. Systematic deviations from the AME 2003 are seen over a wide range of elements, and possible effects of these deviations on the r process will be discussed. These measurements are being extended to even higher neutron excess at CARIBU. )

  12. Impact of weak interactions of free nucleons on the r-process in dynamical ejecta from neutron-star mergers

    E-print Network

    Goriely, Stephane; Just, Oliver; Pllumbi, Else; Janka, Hans-Thomas

    2015-01-01

    We investigate beta-interactions of free nucleons and their impact on the electron fraction (Y_e) and r-process nucleosynthesis in ejecta characteristic of binary neutron star mergers (BNSMs). For that we employ trajectories from a relativistic BNSM model to represent the density-temperature evolutions in our parametric study. In the high-density environment, positron captures decrease the neutron richness at the high temperatures predicted by the hydrodynamic simulation. Circumventing the complexities of modelling three-dimensional neutrino transport, (anti)neutrino captures are parameterized in terms of prescribed neutrino luminosities and mean energies, guided by published results and assumed as constant in time. Depending sensitively on the adopted neutrino-antineutrino luminosity ratio, neutrino processes increase Y_e to values between 0.25 and 0.40, still allowing for a successful r-process compatible with the observed solar abundance distribution and a significant fraction of the ejecta consisting of r...

  13. Near-UV Observations of HD221170: New Insights into the Nature of r-Process-Rich Stars

    E-print Network

    Inese I. Ivans; Jennifer Simmerer; Christopher Sneden; James E. Lawler; John J. Cowan; Roberto Gallino; Sara Bisterzo

    2006-04-08

    Employing high resolution spectra obtained with the near-UV sensitive detector on the Keck I HIRES, supplemented by data obtained with the McDonald Observatory 2-d coude, we have performed a comprehensive chemical composition analysis of the bright r-process-rich metal-poor red giant star HD221170. Analysis of 57 individual neutral and ionized species yielded abundances for a total of 46 elements and significant upper limits for an additional five. Model stellar atmosphere parameters were derived with the aid of ~200 Fe-peak transitions. From more than 350 transitions of 35 neutron-capture (Z > 30) species, abundances for 30 neutron-capture elements and upper limits for three others were derived. Utilizing 36 transitions of La, 16 of Eu, and seven of Th, we derive ratios of log epsilon(Th/La) = -0.73 (sigma = 0.06) and log epsilon(Th/Eu) = -0.60 (sigma = 0.05), values in excellent agreement with those previously derived for other r-process-rich metal-poor stars such as CS22892-052, BD+17 3248, and HD115444. Based upon the Th/Eu chronometer, the inferred age is 11.7 +/- 2.8 Gyr. The abundance distribution of the heavier neutron-capture elements (Z >= 56) is fit well by the predicted scaled solar system r-process abundances, as also seen in other r-process-rich stars. Unlike other r-process-rich stars, however, we find that the abundances of the lighter neutron-capture elements (37 < Z < 56) in HD221170 are also statistically in better agreement with the abundances predicted for the scaled solar r-process pattern.

  14. New Rare Earth Element Abundance Distributions for the Sun and Five r-Process-Rich Very Metal-Poor Stars

    E-print Network

    Sneden, Christopher; Cowan, John J; Ivans, Inese I; Hartog, Elizabeth A Den

    2009-01-01

    We have derived new abundances of the rare-earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant stars. The photospheric values for all five elements are in good agreement with meteoritic abundances. For the low metallicity sample, these abundances have been combined with new Ce abundances from a companion paper, and reconsideration of a few other elements in individual stars, to produce internally-consistent Ba, rare-earth, and Hf (56<= Z <= 72) element distributions. These have been used in a critical comparison between stellar and solar r-process abundance mixes.

  15. s- and r-process element abundances in the CMD of 47 Tucanae using the Robert Stobie Spectrograph on SALT

    E-print Network

    C. C. Worley; P. L. Cottrell; E. C. Wylie de Boer

    2008-02-04

    A recent study by Wylie et al 2006 has revealed that s-process element abundances are enhanced relative to iron in both red giant branch and asymptotic giant branch stars of 47 Tucanae. A more detailed investigation into s-process element abundances throughout the colour-magnitude diagram of 47 Tucanae is vital in order to determine whether the observed enhancements are intrinsic to the cluster. This paper explores this possibility through observational and theoretical means. The visibility of s- and r-process element lines in synthetic spectra of giant and dwarf stars throughout the colour magnitude diagram of 47 Tucanae has been explored. It was determined that a resolving power of 10 000 was sufficient to observe s-process element abundance variations in globular cluster giant branch stars. These synthetic results were compared with the spectra of eleven 47 Tucanae giant branch stars observed during the performance verification of the Robert Stobie Spectrograph on the Southern African Large Telescope. Three s-process elements, Zr, Ba, Nd, and one r-process element, Eu, were investigated. No abundance variations were found such that [X/Fe] = 0.0 +/- 0.5 dex. It was concluded that this resolving power, R ~ 5000, was not sufficient to obtain exact abundances but upper limits on the s-process element abundances could be determined.

  16. Dyskerin Ablation in Mouse Liver Inhibits rRNA Processing and Cell Division? ‡

    PubMed Central

    Ge, Jingping; Rudnick, David A.; He, Jun; Crimmins, Dan L.; Ladenson, Jack H.; Bessler, Monica; Mason, Philip J.

    2010-01-01

    Dyskerin is a component of small nucleolar ribonucleoprotein complexes and acts as a pseudouridine synthase to modify newly synthesized ribosomal, spliceosomal, and possibly other RNAs. It is encoded by the DKC1 gene, the gene mutated in X-linked dyskeratosis congenita, and is also part of the telomerase complex. The yeast ortholog, Cbf5, is an essential protein, but in mammals the effect of dyskerin ablation at the cellular level is not known. Here we show that mouse hepatocytes can survive after induction of a Dkc1 deletion. In the absence of dyskerin, rRNA processing is inhibited with the accumulation of large precursors, and fibrillarin does not accumulate in nucleoli. A low rate of apoptosis is induced in the hepatocytes, which show an induction of the p53-dependent cell cycle checkpoint pathway. Signs of liver damage including an increase in serum alanine aminotransferase activity and a disordered structure at the histological and macroscopic levels are observed. In response to carbon tetrachloride administration, when wild-type hepatocytes mount a rapid proliferative response, those without dyskerin do not divide. We conclude that hepatocytes can survive without dyskerin but that the role of dyskerin in RNA modification is essential for cellular proliferation. PMID:19917719

  17. Discovery of HE 1523-0901, a Strongly r-Process Enhanced Metal-Poor Star with Detected Uranium

    E-print Network

    Anna Frebel; Norbert Christlieb; John E. Norris; Christopher Thom; Timothy C. Beers; Jaehyon Rhee

    2007-03-15

    We present age estimates for the newly discovered very r-process enhanced metal-poor star HE 1523-0901 ([Fe/H]=-2.95) based on the radioactive decay of Th and U. The bright (V=11.1) giant was found amongst a sample of bright metal-poor stars selected from the Hamburg/ESO survey. From an abundance analysis of a high-resolution (R=75,000) VLT/UVES spectrum we find HE 1523-0901 to be strongly overabundant in r-process elements ([r/Fe]=1.8). The abundances of heavy neutron-capture elements (Z>56) measured in HE 1523-0901 match the scaled solar r-process pattern extremely well. We detect the strongest optical U line at 3859.57 A. For the first time, we are able to employ several different chronometers, such as the U/Th, U/Ir, Th/Eu and Th/Os ratios to measure the age of a star. The weighted average age of HE 1523-0901 is 13.2 Gyr. Several sources of uncertainties are assessed in detail.

  18. Salinity inhibits post transcriptional processing of chloroplast 16S rRNA in shoot cultures of jojoba ( Simmondsia chinesis )

    Microsoft Academic Search

    Ela Mizrahi-Aviv; David Mills; Aliza Benzioni; Dudy Bar-Zvi

    2005-01-01

    Chloroplast metabolism is rapidly affected by salt stress. Photosynthesis is one of the first processes known to be affected by salinity. Here, we report that salinity inhibits chloroplast post-transcriptional RNA processing. A differentially expressed 680-bp cDNA, containing the 3' sequence of 16S rRNA, transcribed intergenic spacer, exon 1 and intron of tRNAIle, was isolated by differential display reverse transcriptase PCR

  19. Characterization of miR-218/322-Stxbp1 pathway in the process of insulin secretion.

    PubMed

    Lang, Hongmei; Ai, Zhihua; You, Zhiqing; Wan, Yong; Guo, Wei; Xiao, Jie; Jin, Xiaolan

    2015-02-01

    MicroRNAs (miRNAs) have been implicated in a variety of physiological processes, however, the function of miRNAs in insulin secretion and type 2 diabetes is still unclear. Stxbp1 plays an essential role in exocytosis, and is crucial for insulin secretion. In this study, we focused on the molecular mechanism of Stxbp1 in insulin secretion by identifying its upstream regulators: miR-218 and miR-322. The expression of Stxbp1 was significantly increased in isolated mouse islets exposed to high levels of glucose within 1?h; while two of its predicted upstream miRNAs were found to be downregulated. Further study found that miR-218 and miR-322 directly interact with Stxbp1 by targeting the 3'UTR of its mRNA. MIN6 cells overexpressing the two miRNAs showed a sharp decline in insulin secretion and a decreased sensitivity to glucose; while the inhibition of the two miRNAs promoted insulin secretion. However, islets treated with prolonged high levels of glucose, which is known as glucolipotoxicity, displayed relatively high expression of miR-218 and miR-322, and a reduced level of expression of Stxbp1 accompanied by the blocking of insulin secretion. In summary, this study identified a pathway consisting of miR-218/322 and Stxbp1 in insulin secretion, contributing to a network of ?-cell function involving miRNA. PMID:25489007

  20. Annales Univ. Sci. Budapest de R. Eotvos nom. Sectio Math. 2 (1959), pp. 139146. ON SECONDARY PROCESSES GENERATED BY

    E-print Network

    1959-01-01

    Annales Univ. Sci. Budapest de R. E¨otv¨os nom. Sectio Math. 2 (1959), pp. 139­146. ON SECONDARY PROCESSES GENERATED BY RANDOM POINT DISTRIBUTIONS Andr´as Pr´ekopa (Budapest) Mathematical Institute, E¨otv¨os Lor´and University, Budapest Received: May 15, 1959 Introduction In the paper [3] we have given

  1. The New Digital Engineering Design and Graphics Process R E. Barr, T. J. Krueger, and T. A. Aanstoos

    E-print Network

    Ben-Yakar, Adela

    The New Digital Engineering Design and Graphics Process R E. Barr, T. J. Krueger, and T. A for the educational setting. I. INTRODUCTION The discipline of Engineering Design Graphics has been a cornerstone to solve graphical problems. The field has gone from using drafting boards, to computer-aided design

  2. New Nuclear Reaction Flow during r-Process Nucleosynthesis in Supernovae: Critical Role of Light Neutron-Rich Nuclei

    E-print Network

    M. Terasawa; K. Sumiyoshi; T. Kajino; G. J. Mathews; I. Tanihata

    2001-07-19

    We study the role of light neutron-rich nuclei during r-process nucleosynthesis in supernovae. Most previous studies of the r-process have concentrated on the reaction flow of heavy unstable nuclei. Although the nuclear reaction network includes a few thousand heavy nuclei, only limited reaction flow through light-mass nuclei near the stability line has been used in those studies. However, in a viable scenario of the r-process in neutrino-driven winds, the initial condition is a high-entropy hot plasma consisting of neutrons, protons, and electron-positron pairs experiencing an intense flux of neutrinos. In such environments light-mass nuclei as well as heavy nuclei are expected to play important roles in the production of seed nuclei and r-process elements. Thus, we have extended our fully implicit nuclear reaction network so that it includes all nuclei up to the neutron drip line for Z $ \\leq 10$, in addition to a larger network for Z $ \\geq 10$. In the present nucleosynthesis study, we utilize a wind model of massive SNeII explosions to study the effects of this extended network. We find that a new nuclear-reaction flow path opens in the very light neutron-rich region. This new nuclear reaction flow can change the final heavy-element abundances by as much as an order of magnitude.

  3. OPTIMIZATION OF THE DEHYDRATION PROCESS FOR TWO BIOTYPES OF LUCUMA (Pouteria lúcuma (R & P) KUNTZE) USING THE RESPONSE SURFACE METHODOLOGY

    Microsoft Academic Search

    Marianela Inga

    Lucuma (Pouteria lucuma (R and P) Kuntze) is a native fruit of Peru. Lucuma flavor and color are appreciated in ice cream preparation. The carotene content gives to lucuma pulp a coloration between light yellow and intense orange. Frozen pulp and lucuma meal are two forms for its commercialization. In this research the objective was the optimization of dehydration process

  4. A low initial abundance of 247Cm in the early solar system and implications for r-process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Stirling, Claudine H.; Halliday, Alex N.; Potter, Emma-Kate; Andersen, Morten B.; Zanda, Brigitte

    2006-11-01

    The short-lived nuclide 247Cm is produced by r-process nucleosynthesis. When the presolar nebula formed, 247Cm became isolated from r-process production and its abundance diminished as a result of radioactive decay. Given its short half-life of only ˜ 16 million years, 247Cm is presently extinct, but its former presence should be detectable as small variations in 235U/ 238U in primitive meteoritic material, provided Cm was chemically fractionated from U at the time these solid objects formed. The magnitude of U isotopic anomalies in meteorites can thus be used to elucidate the timing and character of the last r-process nucleosynthetic event for input into models describing the formation and evolution of the early solar system. Here we report coupled U isotopic determinations and Nd/U proxy measurements for Cm/U in a series of acid-etched leachates and mineral assemblages extracted from meteorites containing primitive phases expected to show strong Cm-U fractionations. Using multiple-collector ICPMS, we are able to determine 235U/ 238U with 2 ? analytical uncertainties of ± 1 epsilon (1 epsilon = 1 part in 10,000) on sample sizes consisting of < 3 ng of 238U and < 20 pg of 235U. A double-spiking procedure using a mixed 236U- 233U spike was employed to allow instrumental mass fractionation to be reliably corrected internally and at high precision. Uranium isotopic results for almost 40 different phases show no resolvable deviations in 235U/ 238U from the chondritic value, at the ˜ 1-2 epsilon level. These data supplement our previous observations for a suite of bulk meteorite samples [C.H. Stirling, A.N. Halliday, D. Porcelli, In search of live 247Cm in the early solar system, Geochim. Cosmochim. Acta 69 (2005) 1059-1071] and provide evidence for a solar system initial 247Cm/ 235U of < 8 × 10 - 5 . Such a low value is difficult to explain without a long time-scale of ˜ 2.3 × 10 8 years between the last actinide producing r-process event and the formation of the solar system. As such it is difficult to reconcile with a model of actinide production in the same r-process forming event as 182Hf with a half-life of 8.9 My [G.J. Wasserburg, M. Busso, R. Gallino, Abundances of actinides and short-lived nonactinides in the interstellar medium: Diverse supernova sources for the r-processes, Astrophys. J. 466 (1996) L109-L113]. The alternative models of 182Hf production via a neutron-rich fast s-process, occurring, for example, in the helium burning shell in a 25 solar mass star during explosive nucleosynthesis [G.J. Wasserburg, M. Busso, R. Gallino, Abundances of actinides and short-lived nonactinides in the interstellar medium: Diverse supernova sources for the r-processes, Astrophys. J. 466 (1996) L109-L113], or via a distinct r-process event that is separate from actinide production [G.J. Wasserburg, M. Busso, R. Gallino, K.M. Nollet, Short-lived nuclei in the early solar system: Possible AGB sources, Nucl. Phys. A (in press)], may provide a viable explanation. However, further studies are also required to assess the veracity of Cm-U systematics, which are critically dependent on the suitability of using Nd and the light rare earth elements (LREEs) as a chemical proxy for Cm.

  5. The Human Nucleolar Protein FTSJ3 Associates with NIP7 and Functions in Pre-rRNA Processing

    PubMed Central

    Morello, Luis G.; Coltri, Patricia P.; Quaresma, Alexandre J. C.; Simabuco, Fernando M.; Silva, Tereza C. L.; Singh, Guramrit; Nickerson, Jeffrey A.; Oliveira, Carla C.; Moore, Melissa J.; Zanchin, Nilson I. T.

    2011-01-01

    NIP7 is one of the many trans-acting factors required for eukaryotic ribosome biogenesis, which interacts with nascent pre-ribosomal particles and dissociates as they complete maturation and are exported to the cytoplasm. By using conditional knockdown, we have shown previously that yeast Nip7p is required primarily for 60S subunit synthesis while human NIP7 is involved in the biogenesis of 40S subunit. This raised the possibility that human NIP7 interacts with a different set of proteins as compared to the yeast protein. By using the yeast two-hybrid system we identified FTSJ3, a putative ortholog of yeast Spb1p, as a human NIP7-interacting protein. A functional association between NIP7 and FTSJ3 is further supported by colocalization and coimmunoprecipitation analyses. Conditional knockdown revealed that depletion of FTSJ3 affects cell proliferation and causes pre-rRNA processing defects. The major pre-rRNA processing defect involves accumulation of the 34S pre-rRNA encompassing from site A? to site 2b. Accumulation of this pre-rRNA indicates that processing of sites A0, 1 and 2 are slower in cells depleted of FTSJ3 and implicates FTSJ3 in the pathway leading to 18S rRNA maturation as observed previously for NIP7. The results presented in this work indicate a close functional interaction between NIP7 and FTSJ3 during pre-rRNA processing and show that FTSJ3 participates in ribosome synthesis in human cells. PMID:22195017

  6. The Role of Fission in Neutron Star Mergers and its Impact on the r-Process Peaks

    E-print Network

    Marius Eichler; Almudena Arcones; Alexandra Kelic; Oleg Korobkin; Karlheinz Langanke; Tomislav Marketin; Gabriel Martinez-Pinedo; Igor V. Panov; Thomas Rauscher; Stephan Rosswog; Christian Winteler; Nikolaj T. Zinner; Friedrich-Karl Thielemann

    2015-05-29

    Comparing observational abundance features with nucleosynthesis predictions of stellar evolution or explosion simulations can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. We test the abundance features of r-process nucleosynthesis calculations for the dynamical ejecta of neutron star merger simulations based on three different nuclear mass models: The Finite Range Droplet Model (FRDM), the (quenched version of the) Extended Thomas Fermi Model with Strutinsky Integral (ETFSI-Q), and the Hartree-Fock-Bogoliubov (HFB) mass model. We make use of corresponding fission barrier heights and compare the impact of four different fission fragment distribution models on the final r-process abundance distribution. In particular, we explore the abundance distribution in the second r-process peak and the rare-earth sub-peak as a function of mass models and fission fragment distributions, as well as the origin of a shift in the third r-process peak position. The latter has been noticed in a number of merger nucleosynthesis predictions. We show that the shift occurs during the r-process freeze-out when neutron captures and {\\beta}-decays compete and an (n,{\\gamma})-({\\gamma},n) equilibrium is not maintained anymore. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of {\\beta}-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well.

  7. Edinburgh Research Explorer Rrp5 binding at multiple sites coordinates pre-rRNA processing

    E-print Network

    Millar, Andrew J.

    .T., unpublished data). NTC occurs when the transcribing polymerase has traveled into the 50 region of the 25S rDNA of the 35S pre-rRNA (released transcript cleavage; RTC) or cotran- scriptionally on the nascent transcript (nascent transcript cleav- age; NTC) (Kos and Tollervey, 2010; Osheim et al., 2004) (K. Axt and D

  8. Expression of mouse and frog rRNA genes: transcription and processing

    Microsoft Academic Search

    Barbara Sollner-Webb; Louise Pape; Kenneth Ryan; Edward B. Mougey; Regina Poretta; Emil Nikolov; Mark H. Paalman; Inara Lazdins; Cathy Martin

    1991-01-01

    This article summarizes a number of lines of investigation of rRNA gene expression that are ongoing in the laboratory. These studies focus on mouse and frog, two distant vertebrate species. One major conclusion is that the basic properties of rRNA gene expression appear remarkably well conserved in evolution, with only relatively minor perturbations between frog and mouse, contrary to the

  9. Consultative Processes in a Small Democracy: D.A.R.E. New Zealand.

    ERIC Educational Resources Information Center

    Sanders, Owen

    This paper outlines the approach to drug abuse education being taken by D.A.R.E. (Drug Abuse Resistance Education) New Zealand, a distinctly indigenous response characterized by a consultative association involving the police, the schools, and the community. A key feature of D.A.R.E. New Zealand is the extent to which parents and the wider…

  10. R&D activities in airborne SAR image processing\\/analysis at Lockheed Martin Canada

    Microsoft Academic Search

    Langis Gagnon; H. Oppenheim; Pierre Valin

    1998-01-01

    We give an overview of some R&D projects in SAR imagery at Lockheed Martin Canada. These projects are motivated by airborne surveillance applications such as the landmass and coastal surveillance missions of the Canadian CP-140 (Aurora) aircraft. The activities reviewed here are: (1) R&D supports to CP-140 Spotlight SAR upgrade, (2) fast multiresolution prescreening filter for CFAR detection, (3) comparison

  11. Inhibitory repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex modulates early affective processing.

    PubMed

    Zwanzger, Peter; Steinberg, Christian; Rehbein, Maimu Alissa; Bröckelmann, Ann-Kathrin; Dobel, Christian; Zavorotnyy, Maxim; Domschke, Katharina; Junghöfer, Markus

    2014-11-01

    The dorsolateral prefrontal cortex (dlPFC) has often been suggested as a key modulator of emotional stimulus appraisal and regulation. Therefore, in clinical trials, it is one of the most frequently targeted regions for non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS). In spite of various encouraging reports that demonstrate beneficial effects of rTMS in anxiety disorders, psychophysiological studies exploring the underlying neural mechanisms are sparse. Here we investigated how inhibitory rTMS influences early affective processing when applied over the right dlPFC. Before and after rTMS or sham stimulation, subjects viewed faces with fearful or neutral expressions while whole-head magnetoencephalography (MEG) was recorded. Due to the disrupted functioning of the right dlPFC, visual processing in bilateral parietal, temporal, and occipital areas was amplified starting at around 90 ms after stimulus onset. Moreover, increased fear-specific activation was found in the right TPJ area in a time-interval between 110 and 170 ms. These neurophysiological effects were reflected in slowed reaction times for fearful, but not for neutral faces in a facial expression identification task while there was no such effect on a gender discrimination control task. Our study confirms the specific and important role of the dlPFC in regulation of early emotional attention and encourages future clinical research to use minimal invasive methods such as transcranial magnetic (TMS) or direct current stimulation (tDCS). PMID:25019678

  12. Search for spin-orbit-force reduction at {sup 106,108}Zr around r-process path

    SciTech Connect

    Sumikama, T.; Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Watanabe, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); and others

    2012-11-12

    Shell gap at the magic number N= 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N= 82 and a new shell closure at N70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, {sup 110}Zr(Z = 40,N = 70). We performed {beta}-{gamma} and isomer spectroscopy at RIBF to observe low-lying states in {sup 106,108}Zr. The present results indicate a well deformed shape for {sup 106,108}Zr. The drastic reduction of the spin-orbit force most likely does not occur around {sup 110}Zr on an r-process path.

  13. Search for spin-orbit-force reduction at 106,108Zr around r-process path

    NASA Astrophysics Data System (ADS)

    Sumikama, T.; Yoshinaga, K.; Watanabe, H.; Nishimura, S.; Miyashita, Y.; Yamaguchi, K.; Sugimoto, K.; Chiba, J.; Li, Z.; Baba, H.; Berryman, J. S.; Blasi, N.; Bracco, A.; Camera, F.; Doornenbal, P.; Go, S.; Hashimoto, T.; Hayakawa, S.; Hinke, C.; Ideguchi, E.; Isobe, T.; Ito, Y.; Jenkins, D. G.; Kawada, Y.; Kobayashi, N.; Kondo, Y.; Krücken, R.; Kubono, S.; Lorusso, G.; Nakano, T.; Kurata-Nishimura, M.; Odahara, A.; Ong, H. J.; Ota, S.; Podolyák, Zs.; Sakurai, H.; Scheit, H.; Steiger, K.; Steppenbeck, D.; Takano, S.; Takashima, A.; Tajiri, K.; Teranishi, T.; Wakabayashi, Y.; Walker, P. M.; Wieland, O.; Yamaguchi, H.

    2012-11-01

    Shell gap at the magic number N = 82 is important to reproduce the 2nd peak of r-process abundance. If a spin-orbit force is reduced in a very neutron-rich region, a shell quenching at N = 82 and a new shell closure at N = 70 are predicted. A shell evolution by the spin-orbit-force reduction can be searched for through the shape evolution of Zr isotopes around an expected double magic nuclei, 110Zr(Z = 40,N = 70). We performed ?-? and isomer spectroscopy at RIBF to observe low-lying states in 106,108Zr. The present results indicate a well deformed shape for 106,108Zr. The drastic reduction of the spin-orbit force most likely does not occur around 110Zr on an r-process path.

  14. Half-life of Zn80 - The first measurement for an r-process waiting-point nucleus

    Microsoft Academic Search

    R. L. Gill; R. F. Casten; D. D. Warner; A. Piotrowski; H. Mach; John Hill; F. K. Wohn; J. A. Winger; R. Moreh

    1986-01-01

    The first measurement of beta decay in Zn-80, a critical N = 50 waiting-point nucleus in the evaluation of different models of r-process environments and exposure times, is reported. Using the TRISTAN mass separator on line to the Brookhaven high-flux beam reactor, a half-life of 0.55 + or - 0.02 was measured for the neutron-rich fission product nucleus Zn-80(50). A

  15. R-Process Nucleosynthesis in Neutrino-Driven Winds:. Treatment of the Injection Region and Requirements on Neutrino Emission

    Microsoft Academic Search

    A. W. Steiner; Y.-Z. Qian

    2004-01-01

    During the Kelvin-Helmholtz cooling phase of a protoneutron star, the intense neutrino flux of the protoneutron star drives a wind by depositing energy in the overlying material. It has been proposed that this neutrino-driven wind is a likely site for the r-process. We reexamine the physical conditions in the wind by paying particular attention to the injection region. We emphasize

  16. Uranium lines in the spectra of peculiar A stars - A search for recent r-process events

    NASA Technical Reports Server (NTRS)

    Cowley, C. R.; Adelman, S. J.

    1975-01-01

    Uranium wavelengths in the spectra of Ap stars are studied to see if they give any indication of a recent r-process event. It is concluded that there is no credible evidence for an admixture of uranium-235 in these stars, which would imply such an event. The evidence, though negative, is badly confused by blending of lines, and a final judgement must wait for an observational clarification of the situation.

  17. Probing the Site for r-Process Nucleosynthesis with Abundances of Barium and Magnesium in Extremely Metal-poor Stars.

    PubMed

    Tsujimoto; Shigeyama; Yoshii

    2000-03-01

    We suggest that if the astrophysical site for r-process nucleosynthesis in the early Galaxy is confined to a narrow mass range of Type II supernova (SN II) progenitors, with a lower mass limit of Mms=20 M middle dot in circle, a unique feature in the observed distribution of [Ba/Mg] versus [Mg/H] for extremely metal-poor stars can be adequately reproduced. We associate this feature, a bifurcation of the observed elemental ratios into two branches in the Mg abundance interval -3.7processes. The first branch, which we call the y-branch, is associated with the production of Ba and Mg from individual massive supernovae. The derived mass of Ba synthesized in SNe II is 8.5x10-6 M middle dot in circle for Mms=20 M middle dot in circle and 4.5x10-8 M middle dot in circle for Mms=25 M middle dot in circle. We conclude that SNe II with Mms approximately 20 M middle dot in circle are the dominant source of r-process nucleosynthesis in the early Galaxy. An SN-induced chemical evolution model with this Mms-dependent Ba yield creates the y-branch, reflecting the different nucleosynthesis yields of [Ba/Mg] for each SN II with Mms greater, similar20 M middle dot in circle. The second branch, which we call the i-branch, is associated with the elemental abundance ratios of stars which were formed in the dense shells of the interstellar medium swept up by SNe II with Mms<20 M middle dot in circle that do not synthesize r-process elements, and it applies to stars with observed Mg abundances in the range &sqbl0;Mg&solm0;H&sqbr0;<-2.7. The Ba abundances in these stars reflect those of the interstellar gas at the (later) time of their formation. The existence of a [Ba/Mg] i-branch strongly suggests that SNe II that are associated with stars of progenitor mass Mmsr-process elements. We predict the existence of this i-branch for other r-process elements, such as europium (Eu), to the extent that their production site is in common with Ba. PMID:10673408

  18. Rolling Deck to Repository (R2R): Programmatic Quality Assessment and Processing of Marine Gravity and Magnetic Data and Associated Metadata

    NASA Astrophysics Data System (ADS)

    Morton, J. J.; Ferrini, V.; O'hara, S. H.; Arko, R. A.; Carbotte, S. M.; Coakley, B.

    2011-12-01

    With its global capability and diverse array of sensors, the U.S. academic research fleet is an integral component of ocean exploration. The Rolling Deck to Repository (R2R) Program provides a central shore-side gateway for underway data from the U.S. academic research fleet, with the primary goal of preserving and documenting routine underway data. Programmatic tools for Quality Assessment (QA) of multiple underway data types are being developed to provide prompt feedback to shipboard operators and inform down-stream science users. QA tools are being developed in object oriented PHP with modular components that can be distributed for use by the community. Programmatic data processing (DP) tools for select data types are also being developed. We report on recent progress with QA and DP tools developed for underway gravity and magnetics data. For magnetics data, DP includes despiking and removal of bad data, merging with navigation, turn removal, calculation of a layback position, and removal of the IGRF to produce a magnetic anomaly. For gravity data, DP involves merging with navigation, corrections for speed and heading (Eötvös) and latitude, some basic filtering, removing bad data, subsampling, and drift corrections. All of these tools follow a programmatic workflow that requires minimal human intervention. Advanced processing which requires human intervention is left to the science user. These tools make use of metadata specific to each device and data type, as well as customizable thresholds and processing parameters. The full suite of metadata that describes each data set, the quality assessment parameters and results, as well as processing steps will accompany the data being submitted to the National Geophysical Data Center. In addition to QA reports for raw data files, day plots are also produced at each step to allow for quick observation and verification of the data quality and processing steps. These plots will also be delivered with the data files. The result of data processing for gravity and magnetics data is a quality assessed multiplexed file (MGD77T). In addition, web tools are being developed to provide science users and operators with a quick and intuitive interface for reviewing QA results.

  19. Barkowsky, T. (2001). Mental processing of geographic knowledge. In D. R. Montello (Ed.), Spatial Information Theory -Foundations of Geographic Information Science (pp. 371-386).

    E-print Network

    Bremen, Universität

    2001-01-01

    Barkowsky, T. (2001). Mental processing of geographic knowledge. In D. R. Montello (Ed.), Spatial is elaborated. After a short review of conceptions on mental processing of spatial knowledge from psychology, 1993). Processing geographic information can be described as a mental construction process in memory

  20. Nine new metal-poor stars on the subgiant and red horizontal branches with high levels of r-process enhancement

    NASA Astrophysics Data System (ADS)

    Roederer, Ian U.; Cowan, John J.; Preston, George W.; Shectman, Stephen A.; Sneden, Christopher; Thompson, Ian B.

    2014-12-01

    We report the discovery of nine metal-poor stars with high levels of r-process enhancement (+0.81 ? [Eu/Fe] ? +1.13), including six subgiants and three stars on the red horizontal branch. We also analyse four previously known r-process-enhanced metal-poor red giants. From this sample of 13 stars, we draw the following conclusions. (1) High levels of r-process enhancement are found in a broad range of stellar evolutionary states, reaffirming that this phenomenon is not associated with a chemical peculiarity of red giant atmospheres. (2) Only 1 of 10 stars observed at multiple epochs shows radial-velocity variations, reaffirming that stars with high levels of r-process enhancement are not preferentially found among binaries. (3) Only 2 of the 13 stars are highly enhanced in C and N, indicating that there is no connection between high levels of r-process enhancement and high levels of C and N. (4) The dispersions in [Sr/Ba] and [Sr/Eu] are larger than the dispersions in [Ba/Eu] and [Yb/Eu], suggesting that the elements below the second r-process peak do not always scale with those in the rare Earth domain, even within the class of highly-r-process-enhanced stars. (5) The light-element (12 ? Z ? 30) abundances of highly-r-process-enhanced stars are indistinguishable from those with normal levels of r-process material at the limit of our data, 3.5 per cent (0.015 dex) on average. The nucleosynthetic sites responsible for the large r-process enhancements did not produce any detectable light-element abundance signatures distinct from normal core-collapse supernovae.

  1. PAL[R] Services Being Measured through Scientifically-Based Evaluation Process

    ERIC Educational Resources Information Center

    Perspectives in Peer Programs, 2007

    2007-01-01

    In January 2006, PAL[R] Peer Assistance and Leadership, a Promising Prevention Program of Workers Assistance Program, Inc. (WAP), received a $30,000 grant from the Center for Substance Abuse Prevention (CSAP) in order to be scientifically-evaluated on the outcomes and effectiveness of its programs and services. According to the grant, the…

  2. Low-mass supernovae in the early Galactic halo: source of the double r/s-process enriched halo stars?

    E-print Network

    Albert A. Zijlstra

    2003-12-18

    Several stars at the low-metallicity extreme of the Galactic halo ([Fe/H]=-2.5) show strong enhancements of both s-process and r-process elements. The presence of s-process elements in main-sequence stars is explained via mass transfer from an AGB companion star in a binary system. r-Process elements originate in type-II supernovae and also require mass transfer. It is however unclear how pollution by both an AGB star and a supernova could have occured. Here I show that the initial--final-mass relation steepens at low metallicity, due to low mass-loss efficiency. This may cause the degenerate cores of low-Z, high-mass AGB stars to reach the Chandresekhar mass, leading to an Iben & Renzini-type-1.5 supernova. Such supernovae can explain both the enhancement patterns and the metallicity dependence of the double-enhanced halo stars. Reduced mass loss efficiency predicts more massive remnants in metal-poor globular clusters. The evidence for a high M/L population in the cores of globular clusters is briefly discussed.

  3. Windings of Planar Stable Processes R. A. Doney & D. A. Korshunov

    E-print Network

    Sidorov, Nikita

    provide a new easy proof, we obtain some limit Theorems for the exit time from a cone of stable processes processes, windings, exit time from a cone, Spitzer's Theorem, skew-product representation, Lamperti, an aspect which has already been investigated e.g. by Doney [Don04] Probability and Statistics Group

  4. DD3R zeolite membranes in separation and catalytic processes: Modelling and application

    Microsoft Academic Search

    J. Van den Bergh

    2010-01-01

    Around 2004 the annual energy consumption of the Dutch (petro-)chemical industry was estimated to be 460 PJ of which 200 PJ could be allocated to separation processes [1]. In 2009, 15% of the global energy consumption was required for separation and purification processes to produce commodities. Moreover, it is expected that in 2040 the global commodity demand is three times

  5. Processing of double-R-loops in (CAG)·(CTG) and C9orf72 (GGGGCC)·(GGCCCC) repeats causes instability

    PubMed Central

    Reddy, Kaalak; Schmidt, Monika H.M.; Geist, Jaimie M.; Thakkar, Neha P.; Panigrahi, Gagan B.; Wang, Yuh-Hwa; Pearson, Christopher E.

    2014-01-01

    R-loops, transcriptionally-induced RNA:DNA hybrids, occurring at repeat tracts (CTG)n, (CAG)n, (CGG)n, (CCG)n and (GAA)n, are associated with diseases including myotonic dystrophy, Huntington's disease, fragile X and Friedreich's ataxia. Many of these repeats are bidirectionally transcribed, allowing for single- and double-R-loop configurations, where either or both DNA strands may be RNA-bound. R-loops can trigger repeat instability at (CTG)·(CAG) repeats, but the mechanism of this is unclear. We demonstrate R-loop-mediated instability through processing of R-loops by HeLa and human neuron-like cell extracts. Double-R-loops induced greater instability than single-R-loops. Pre-treatment with RNase H only partially suppressed instability, supporting a model in which R-loops directly generate instability by aberrant processing, or via slipped-DNA formation upon RNA removal and its subsequent aberrant processing. Slipped-DNAs were observed to form following removal of the RNA from R-loops. Since transcriptionally-induced R-loops can occur in the absence of DNA replication, R-loop processing may be a source of repeat instability in the brain. Double-R-loop formation and processing to instability was extended to the expanded C9orf72 (GGGGCC)·(GGCCCC) repeats, known to cause amyotrophic lateral sclerosis and frontotemporal dementia, providing the first suggestion through which these repeats may become unstable. These findings provide a mechanistic basis for R-loop-mediated instability at disease-associated repeats. PMID:25147206

  6. FLEXIBLE APPLICATION OF THE JLAB PANSOPHY INFORMATION SYSTEM FOR PROJECT REPORTS, PROCESS MONITORING, AND R&D SAMPLE TRACKING

    SciTech Connect

    Valerie Bookwalter; Bonnie Madre; Charles Reece

    2008-02-12

    The use and features of the JLab SRF Institute IT system Pansophy1,2 continue to expand. In support of the cryomodule rework project for CEBAF a full set of web-based travelers has been implemented and an integrated set of live summary reports has been created. A graphical user interface within the reports enables navigation to either higher-level summaries or drill-down to the original source data. In addition to collection of episodic data, Pansophy is now used to capture, coordinate, and display continuously logged process parameter that relate to technical water systems and clean room environmental conditions. In a new expansion, Pansophy is being used to collect and track process and analytical data sets associated with SRF material samples that are part of the surface creation, processing, and characterization R&D program.

  7. Chemistry of the Sagittarius dwarf galaxy: A top-light initial mass function, outflows, and the R-process

    SciTech Connect

    McWilliam, Andrew [The Observatories of the Carnegie Institute of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Wallerstein, George; Mottini, Marta, E-mail: andy@obs.carnegiescience.edu, E-mail: walleg@u.washington.edu [Astronomy Department, University of Washington, Seattle, WA 98195 (United States)

    2013-12-01

    From chemical abundance analysis of stars in the Sagittarius dwarf spheroidal galaxy (Sgr), we conclude that the ?-element deficiencies cannot be due to the Type Ia supernova (SN Ia) time-delay scenario of Tinsley. Instead, the evidence points to low [?/Fe] ratios resulting from an initial mass function (IMF) deficient in the highest mass stars. The critical evidence is the 0.4 dex deficiency of [O/Fe], [Mg/Fe], and other hydrostatic elements, contrasting with the normal trend of r-process [Eu/Fe] {sub r} with [Fe/H]. Supporting evidence comes from the hydrostatic element (O, Mg, Na, Al, Cu) [X/Fe] ratios, which are inconsistent with iron added to the Milky Way (MW) disk trends. Also, the ratio of hydrostatic to explosive (Si, Ca, Ti) element abundances suggests a relatively top-light IMF. Abundance similarities with the LMC, Fornax, and IC 1613 suggest that their ?-element deficiencies also resulted from IMFs lacking the most massive SNe II. The top-light IMF, as well as the normal trend of r-process [Eu/Fe] {sub r} with [Fe/H] in Sgr, indicates that massive SNe II (?30 M {sub ?}) are not major sources of r-process elements. High [La/Y] ratios, consistent with leaky-box chemical evolution, are confirmed but ?0.3 dex larger than theoretical asymptotic giant branch (AGB) predictions. This suggests that a substantial increase in the theoretical {sup 13}C pocket in low-mass AGB stars is required. Sgr has the lowest [Rb/Zr] ratios known, consistent with pollution by low-mass (?2 M {sub ?}) AGB stars near [Fe/H] = –0.6, likely resulting from leaky-box chemical evolution. The [Cu/O] trends in Sgr and the MW suggest that Cu yields increase with both metallicity and stellar mass, as expected from Cu production by the weak s-process in massive stars. Finally, we present an updated hyperfine splitting line list, an abundance analysis of Arcturus, and further develop our error analysis formalism.

  8. Synthetic lethality with fibrillarin identifies NOP77p, a nucleolar protein required for pre-rRNA processing and modification.

    PubMed Central

    Bergès, T; Petfalski, E; Tollervey, D; Hurt, E C

    1994-01-01

    The nucleolar protein fibrillarin (encoded by the NOP1 gene in yeast), is required for many post-transcriptional steps in yeast ribosome synthesis. A screen for mutations showing synthetic lethality with a temperature sensitive nop1-5 allele led to the identification of the NOP77 gene. NOP77 is essential for viability and encodes a nucleolar protein with a predicted molecular weight of 77 kDa. Depletion of NOP77p impairs both the processing and methylation of the pre-rRNA. The processing defect is greatest for the pathway leading to 25S rRNA synthesis, and is distinctly different from that observed for mutations in other nucleolar components. NOP77p contains three canonical RNA recognition motifs (RRMs), suggesting that it is an RNA binding protein. The NOP77 allele which complements the synthetic lethal nop1 strains has an alanine at position 308, predicted to lie in helix alpha 1 of RRM3, whereas the non-complementing nop77-1 allele contains a proline at the corresponding position. We propose that NOP77p mediates specific interactions between NOP1p and the pre-rRNA. Images PMID:8039506

  9. Improving R&D processes by an ISO 9001-based Quality Management System

    Microsoft Academic Search

    Antti Auer; Jukka Karjalainen; Veikko Seppänen

    1996-01-01

    This paper presents practical experience in planning, implementing, and adopting a Quality Management System (QMS) for embedded systems development at VTT Electronics. The main objective for the development of the QMS was to make it practical for real-life embedded systems research and development (R&D) projects. We have applied the ISO 9001 standard and ISO 9000–3 guidelines in building the quality

  10. EPA'S POLLUTION PREVENTION R&D APPROACHES AND INSIGHTS INTO THECHEMICAL PROCESS INDUSTRY

    EPA Science Inventory

    Chemical Engineers face major research challenges associated withthe imperative to protect and improve the environment. hesechallenges include designing optimal, less polluting chemicalplants and processes, improving air quality through research,managing hazardous wastes responsi...

  11. A Methodology for Exposing Process Risk in Emergent System VICTOR R. BASILI, University of Maryland at College Park and the Fraunhofer

    E-print Network

    Basili, Victor R.

    unstated, assumptions: Assumption 1. The process is capable of achieving the property and mitigatingA Methodology for Exposing Process Risk in Emergent System Properties VICTOR R. BASILI, University changes are difficult and costly to implement. In this paper, we propose the Process Risk Assessment (PRA

  12. The neutron long counter NERO for studies of beta-delayed neutron emission in the r-process

    E-print Network

    J. Pereira; P. Hosmer; G. Lorusso; P. Santi; A. Couture; J. Daly; M. Del Santo; T. Elliot; J. Goerres; C. Herlitzius; K. -L. Kratz; L. O. Lamm; H. Y. Lee; F. Montes; M. Ouellette; E. Pellegrini; P. Reeder; H. Schatz; F. Schertz; L. Schnorrenberger; K. Smith; E. Stech; E. Strandberg; C. Ugalde; M. Wiescher; A. Woehr

    2010-07-28

    The neutron long counter NERO was built at the National Superconducting Cyclotron Laboratory (NSCL), Michigan State University, for measuring beta-delayed neutron-emission probabilities. The detector was designed to work in conjunction with a beta-decay implantation station, so that beta decays and beta-delayed neutrons emitted from implanted nuclei can be measured simultaneously. The high efficiency of about 40%, for the range of energies of interest, along with the small background, are crucial for measuring beta-delayed neutron emission branchings for neutron-rich r-process nuclei produced as low intensity fragmentation beams in in-flight separator facilities.

  13. GPS-R L1 interference signal processing for soil moisture estimation: an experimental study

    NASA Astrophysics Data System (ADS)

    Yan, Songhua; Li, Zhengyong; Yu, Kegen; Zhang, Kefei

    2014-12-01

    Global positioning system reflectometry (GPS-R) is an emerging area of GPS applications in microwave remote sensing using multipath reflected signals. Soil moisture estimation is one of the many potential applications of the GPS-R technique. The focus of this study is on investigating the feasibility of soil moisture estimation based on GPS L1 band interference signals which can be readily captured using a low-cost off-the-shelf L1-band GPS receiver. The theoretical background is studied, and the field experiments conducted are described. Power spectrum analysis is performed on the received interference signals to determine the interference signal frequency variation, and cosine similarity is applied to identify the initial phase change. Data collected at a number of continuously operating GPS stations are also analyzed. The results demonstrate that both interference signal frequency and phase have changed significantly after rainfalls occurred. That is, it is possible to estimate soil moisture by analyzing the frequency change and phase shift. However, it is also observed that the phase shift is inconsistent in some cases. Ongoing work will focus on figuring out the source of the inconsistency so that reliable estimation of soil moisture can be achieved.

  14. A new tool for studying GNSS-R signals for applications in surface hydrology processes

    NASA Astrophysics Data System (ADS)

    Roussel, Nicolas; Frappart, Frédéric; Ramillien, Guillaume; Desjardins, Camille; Gegout, Pascal; Biancale, Richard; Perosanz, Félix

    2013-04-01

    Receiving Global Navigation Satellite System (GNSS) signals that are reflected off the surface, together with directly received GNSS signals makes possible the monitoring of the water level variations over land and ocean. In the context of the development of a new GNSS-R research activity at GRGS in Toulouse, we have built a simulator for modeling the trajectories of GNSS electromagnetic waves that are reflected on the surface of the Earth (i.e., water and soil), as realistic as possible, once the satellite constellation is known by orbit ephemeris, and the position of the receiver is fixed for a peculiar time session. It includes the possible masking of the terrestrial topography that may cancel the reception of GNSS satellites. Atmospheric delay effects derived from mapping functions are also taken into account for both direct and reflected signals. Our simulator helps us for determining the availability and geographical locations at an accuracy lesser than 10 cm of the specular reflection points, and thus selecting an optimal site for getting meaningful GNSS-R observations. In the future, analysis of the reflected waveforms proposed by our simulator would allow us to estimate other parameters such as significant ocean wave height, surface wind speed and soil moisture content.

  15. R and D investment strategies for condition-based maintenance: An economic model to assist process, plant, and management in the decision making process

    SciTech Connect

    Allgood, G.O.

    1998-04-01

    In today`s manufacturing environment, systems and equipment are being asked to perform at levels not thought possible a decade ago. The intent is to push process operations, product quality, and equipment reliability, availability, and maintainability to unprecedented levels while maintaining budgetary structures consistent with cost reduction initiatives. In light of this, there is a demand to reduce operational and support costs and eliminate or minimize any new capital investments in plant equipment while increasing process efficiency and revenues. In short, manufacturers are trying to invoke new measures to ensure plant performance while minimizing costs and extending operational life of new and/or aging equipment. The only way this can be accomplished is by developing new and innovating approaches in condition-based maintenance. To achieve this while adhering to strict economic constraints requires the development of new sensors, systems, and methods for interrogating, diagnosing, and controlling systems. The old adage, business as usual, will not suffice in this new way of thinking. What will be required is an investment strategy that mitigates R and D risks by developing economic indicators (operational and costs) that qualify the ability of a proposed technology to meet the functional and operational needs of a process. The strategy must, therefore, internalize a methodology and approach that provides control points in the development and implementation cycle. An integral part of this is an economic model that provides a break-even analysis and sensor and system performance assessment based on the concentration of losses and the ability of a proposed sensor to meet systematic needs. This model then becomes a tool for strategizing continued research and development (R and D) for any proposed technology.

  16. Modeling elastic and plastic deformations in nonequilibrium processing using phase field crystals K. R. Elder1

    E-print Network

    Elder, Ken

    Modeling elastic and plastic deformations in nonequilibrium processing using phase field crystals K November 2004) A continuum field theory approach is presented for modeling elastic and plastic deformation the construction of a phase field model for the dynamics of crystal growth that includes elastic and plastic

  17. arXiv:astroph/0101440 Halo Star Abundances and rProcess Synthesis

    E-print Network

    Cowan, John

    the star formation and nucleosynthesis history of Galactic matter. Of particular interest are the heavy element compositions of extremely metal­deficient stars. At metallicities [Fe/H] Ÿ ­2.5, stellar abundance the intermediate mass stars that provide the site for s­process nucleosynthesis during the AGB phase

  18. Planning for Education: People and Processes. School Planning Guide Series -- 1R.

    ERIC Educational Resources Information Center

    Pearson, Douglas L.

    In the process of planning for the needs of all students, local school officials could use a linear planning guide. Such a procedure calls for moving through several phases: preparation for planning, analysis of the situation, development of alternatives, selection of a plan, implementation of the plan, and evaluation of the plan and of the…

  19. Point processes, spatialtemporal Frederic Paik Schoenberg, David R. Brillinger & Peter Guttorp

    E-print Network

    Schoenberg, Frederic Paik (Rick)

    spatial coordinates, e.g. longitude, latitude, and height or depth, though sometimes only one or two of wildfires occurring between 1876 and 1996 in Los Angeles County, CA, recorded by the Los Angeles County. Attention is typically restricted to points in some time interval [T0, T1], and to processes with only

  20. FPGA based image processing with R-fuctions and the curvelet transform 

    E-print Network

    Wisinger, John L.

    2003-01-01

    of their implementation is quite a drain on standard microprocessors. It is for this reason that an FPGA implementation was developed. By offloading some of the processing work into a properly configured FPGA, speeds can be achieved in excess of one hundred times faster...

  1. Separation and recovery process R&D to enhance automotive materials recycling

    SciTech Connect

    Daniels, E.J.

    1994-05-01

    Since 1976, the sales-weighted curb-weight of cars and light trucks sold in the United States has decreased by almost 800 pounds. Vehicle weight reduction has, of course, provided for a significant increase in US fleet fuel economy, from 17 to 27 miles per gallon. However, achievement of the weight reduction and concomitant increase in fuel economy was brought about, in part, by the substitution of lighter-weight materials, such as thinner-gauge coated sheet-steels replacing heavy-gauge noncoated sheet-steels and new aluminum alloys replacing steel as well as the increased use of plastics replacing metals. Each of these new materials has created the need for new technology for materials recycling. This paper highlights some of the R&D being conducted at Argonne National Laboratory to develop technology that will enhance and minimize the cost of automotive materials recycling.

  2. Genetic identification of Arabidopsis RID2 as an essential factor involved in pre-rRNA processing.

    PubMed

    Ohbayashi, Iwai; Konishi, Mineko; Ebine, Kazuo; Sugiyama, Munetaka

    2011-07-01

    A temperature-sensitive mutant of Arabidopsis, root initiation defective 2-1 (rid2-1), is characterized by peculiar defects in callus formation. To gain insights into the requirements for the reactivation of cell division, we analyzed this mutant and isolated the gene responsible, RID2. The phenotypes of rid2-1 in tissue culture and in seedlings indicated that the rid2 mutation has various (acute and non-acute) inhibitory effects on different aspects of cell proliferation. This suggests that the RID2 function is not directly involved in every cycle of cell division, but is related to 'vitality', supporting cell proliferation. The rid2-1 mutation was shown to cause nucleolar vacuolation and excessive accumulation of various intermediates of pre-rRNA processing. Positional cloning of the RID2 gene revealed that it encodes an evolutionarily conserved methyltransferase-like protein, which was found to localize in the nucleus, with accumulation being most evident in the nucleolus. It can be inferred from these findings that RID2 contributes to the nucleolar activity for pre-rRNA processing, probably through some methylation reaction. PMID:21401745

  3. New Half-lives of r-process Zn and Ga Isotopes Measured with Electromagnetic Separation

    SciTech Connect

    Madurga, M [University of Tennessee, Knoxville (UTK); Surman, Rebecca [Union College; Borzov, Ivan N [ORNL; Grzywacz, R. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Rykaczewski, Krzysztof Piotr [ORNL; Gross, Carl J [ORNL; Miller, D [University of Tennessee, Knoxville (UTK); Stracener, Daniel W [ORNL; Batchelder, Jon Charles [ORNL; Brewer, N.T. [Vanderbilt University; Cartegni, L. [University of Tennessee, Knoxville (UTK); Hamilton, J. H. [Vanderbilt University; Hwang, J. K. [Vanderbilt University; Liu, S. H. [Vanderbilt University; Ilyushkin, S. [Mississippi State University (MSU); Karny, M. [University of Warsaw; Korgul, A. [Joint Institute for Heavy Ion Research, Oak Ridge; Krolas, W. [Joint Institute for Heavy Ion Research, Oak Ridge; Kuzniak, A. [University of Tennessee, Knoxville (UTK); Mazzocchi, C. [University of Warsaw; Mendez, II, Anthony J [ORNL; Miernik, K. [Oak Ridge National Laboratory (ORNL); Padgett, Stephen [University of Tennessee, Knoxville (UTK); Paulauskas, S. [University of Tennessee, Knoxville (UTK); Ramayya, A. V. [Vanderbilt University; Winger, J. A. [Oak Ridge Associated Universities (ORAU); Wolinska-Cichocka, Marzena [ORNL; Zganjar, E. F. [Louisiana State University

    2012-01-01

    The {beta} decays of neutron-rich nuclei near the doubly magic {sup 78}Ni were studied at the Holifield Radioactive Ion Beam Facility using an electromagnetic isobar separator. The half-lives of {sup 82}Zn (228 {+-} 10 ms), {sup 83}Zn (117 {+-} 20 ms), and {sup 85}Ga (93 {+-} 7 ms) were determined for the first time. These half-lives were found to be very different from the predictions of the global model used in astrophysical simulations. A new calculation was developed using the density functional model, which properly reproduced the new experimental values. The robustness of the new model in the {sup 78}Ni region allowed us to extrapolate data for more neutron-rich isotopes. The revised analysis of the rapid neutron capture process in low entropy environments with our new set of measured and calculated half-lives shows a significant redistribution of predicted isobaric abundances strengthening the yield of A > 140 nuclei.

  4. RRP20, a component of the 90S preribosome, is required for pre-18S rRNA processing in Saccharomyces cerevisiae

    PubMed Central

    Senapin, Saengchan; Desmond Clark-Walker, G.; Jie Chen, Xin; Séraphin, Bertrand; Daugeron, Marie-Claire

    2003-01-01

    A strain of Saccharomyces cerevisiae, defective in small subunit ribosomal RNA processing, has a mutation in YOR145c ORF that converts Gly235 to Asp. Yor145c is a nucleolar protein required for cell viability and has been reported recently to be present in 90S pre-ribosomal particles. The Gly235Asp mutation in YOR145c is found in a KH-type RNA-binding domain and causes a marked deficiency in 18S rRNA production. Detailed studies by northern blotting and primer extension analyses show that the mutant strain impairs the early pre-rRNA processing cleavage essentially at sites A1 and A2, leading to accumulation of a 22S dead-end processing product that is found in only a few rRNA processing mutants. Furthermore, U3, U14, snR10 and snR30 snoRNAs, involved in early pre-rRNA cleavages, are not destabilized by the YOR145c mutation. As the protein encoded by YOR145c is found in pre-ribosomal particles and the mutant strain is defective in ribosomal RNA processing, we have renamed it as RRP20. PMID:12736301

  5. Unit operations used to treat process and/or waste streams at nuclear power plants. [R

    SciTech Connect

    Godbee, H.W.; Kibbey, A.H.

    1980-01-01

    Estimates are given of the annual amounts of each generic type of LLW (i.e., Government and commerical (fuel cycle and non-fuel cycle)) that is generated at LWR plants. Many different chemical engineering unit operations used to treat process and/or waste streams at LWR plants include adsorption, evaporation, calcination, centrifugation, compaction, crystallization, drying, filtration, incineration, reverse osmosis, and solidification of waste residues. The treatment of these various streams and the secondary wet solid wastes thus generated is described. The various treatment options for concentrates or solid wet wastes, and for dry wastes are discussed. Among the dry waste treatment methods are compaction, baling, and incineration, as well as chopping, cutting and shredding. Organic materials (liquids (e.g., oils or solvents) and/or solids), could be incinerated in most cases. The filter sludges, spent resins, and concentrated liquids (e.g., evaporator concentrates) are usually solidified in cement, or urea-formaldehyde or unsaturated polyester resins prior to burial. Incinerator ashes can also be incorporated in these binding agents. Asphalt has not yet been used. This paper presents a brief survey of operational experience at LWRs with various unit operations, including a short discussion of problems and some observations on recent trends.

  6. Apollo(R) Thin Film Process Development: Final Technical Report, April 1998 - April 2002

    SciTech Connect

    Cunningham, D.W.

    2002-10-01

    BP Solar first started investigative work on CdTe photovoltaics in 1986. The module product name chosen for the CdTe devices is Apollo. The deposition method chosen was electrochemical deposition due to its simplicity and good control of stoichiometric composition. The window layer used is CdS, produced from a chemical-bath deposition. Initial work focused on increasing photovoltaic cell size from a few mm2 to 900 cm2. At BP Solar's Fairfield plant, work is focused on increasing semiconductor deposition to 1 m2. The primary objective of this subcontract is to establish the conditions required for the efficient plating of CdS/CdTe on large-area, transparent conducting tin-oxide-coated glass superstrate. The initial phase concentrates on superstrate sizes up to 0.55 m2. Later phases will include work on 0.94 m2 superstrates. The tasks in this subcontract have been split into four main categories: (1) CdS and CdTe film studies; (2) Enhanced laser processing; (3) Outdoor testing program for the Apollo module; and (4) Production waste abatement and closed loop study.

  7. Journal of Ceramic Processing Research. Vol. 12, No. 6, pp. 691~694 (2011) J O U R N A L O F

    E-print Network

    Volinsky, Alex A.

    2011-01-01

    Journal of Ceramic Processing Research. Vol. 12, No. 6, pp. 691~694 (2011) 691 J O U R N A L O F Ceramic Processing Research Microstructure and quality of SiC foam filters for casting Fengzhang Rena quality indicator of ceramic foam filters used in metal casting. Maximum compressive strain at high

  8. Harteneck, M. and Stewart, R.W. Adaptive Digital Signal Processing JAVA Teaching Tool. IEEE Transactions on Education, 44 (2). pp. 200-201. ISSN 0018-9359

    E-print Network

    Mignotte, Max

    Harteneck, M. and Stewart, R.W. Adaptive Digital Signal Processing JAVA Teaching Tool. IEEE Administrator: eprints@cis.strath.ac.uk #12;Adaptive Digital Signal Processing JAVA Teaching Tool M. Harteneck, November 1999 Abstract This publication presents a JAVA program for teaching the rudiments of adaptive

  9. 1964 A. Talebi, R. Uijlenhoet and P. A. Troch Copyright 2008 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 33, 19641976 (2008)

    E-print Network

    Troch, Peter

    2008-01-01

    1964 A. Talebi, R. Uijlenhoet and P. A. Troch Copyright © 2008 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 33, 1964­1976 (2008) DOI: 10.1002/esp Earth Surface Processes and Landforms Earth Surf shape, profile curvature of surface and bedrock, and soil depth. To investigate the stability of complex

  10. Discovery of a strongly r-process enhanced extremely metal-poor star LAMOST J110901.22+075441.8

    E-print Network

    Li, Haining; Honda, Satoshi; Zhao, Gang; Christlieb, Norbert; Suda, Takuma

    2015-01-01

    We report the discovery of an extremely metal-poor (EMP) giant, LAMOST J110901.22+075441.8, which exhibits large excess of r-process elements with [Eu/Fe] ~ +1.16. The star is one of the newly discovered EMP stars identified from LAMOST low-resolution spectroscopic survey and the high-resolution follow-up observation with the Subaru Telescope. Stellar parameters and elemental abundances have been determined from the Subaru spectrum. Accurate abundances for a total of 23 elements including 11 neutron-capture elements from Sr through Dy have been derived for LAMOST J110901.22+075441.8. The abundance pattern of LAMOST J110901.22+075441.8 in the range of C through Zn is in line with the "normal" population of EMP halo stars, except that it shows a notable underabundance in carbon. The heavy element abundance pattern of LAMOST J110901.22+075441.8 is in agreement with other well studied cool r-II metal-poor giants such as CS 22892-052 and CS 31082-001. The abundances of elements in the range from Ba through Dy well...

  11. Hsa-miR-520d induces hepatoma cells to form normal liver tissues via a stemness-mediated process.

    PubMed

    Tsuno, Satoshi; Wang, Xinhui; Shomori, Kohei; Hasegawa, Junichi; Miura, Norimasa

    2014-01-01

    The human ncRNA gene RGM249 regulates the extent of differentiation of cancer cells and the conversion of 293FT cells to hiPSCs. To identify the factors underlying this process, we investigated the effects of lentivirally inducing miR-520d expression in 293FT and HLF cells in vitro. Subsequently, we evaluated tumor formation in a xenograft model. Transformed HLF cells were Oct4 and Nanog positive within 24?h, showed p53 upregulation and hTERT downregulation, and mostly lost their migration abilities. After lentiviral infection, the cells were intraperitoneally injected into mice, resulting in benign teratomas (6%), the absence of tumors (87%) or differentiation into benign liver tissues (7%) at the injection site after 1 month. We are the first to demonstrate the loss of malignant properties in cancer cells in vivo through the expression of a single microRNA (miRNA). This miRNA successfully converted 293FT and hepatoma cells to hiPSC-like cells. The regulation of malignancy by miR-520d appears to be through the conversion of cancer cells to normal stem cells, maintaining p53 upregulation. PMID:24458129

  12. Electromagnetic transients and r-process nucleosynthesis from the disk wind outflows of neutron star merger remnants

    NASA Astrophysics Data System (ADS)

    Fernandez, Rodrigo; Kasen, Daniel; Quataert, Eliot; Metzger, Brian; Schwab, Josiah; Rosswog, Stephan

    2015-04-01

    The remnant accretion disk formed in binaries that involve neutron stars and/or black holes is a source of non-relativistic ejecta. The outflow is launched on a viscous and/or thermal timescale, and can provide an amount of material comparable to that in the dynamical ejecta. I will present work aimed at characterizing the properties of these winds through two-dimensional, time-dependent hydrodynamic simulations that include the relevant physics needed to follow the ejecta composition. In particular, I will focus on the effect of the spin of a promptly-formed black hole remnant on the wind, and on the interaction of the disk wind with the dynamical ejecta. I will discuss the implications of these results for the optical/IR signal from these events and for the origin of r-process elements in the Galaxy.

  13. Pre-processing of Fourier transform infrared spectra by means of multivariate analysis implemented in the R environment.

    PubMed

    Banas, Krzysztof; Banas, Agnieszka; Gajda, Mariusz; Pawlicki, Bohdan; Kwiatek, Wojciech M; Breese, Mark B H

    2015-04-21

    Pre-processing of Fourier transform infrared (FTIR) spectra is typically the first and crucial step in data analysis. Very often hyperspectral datasets include the regions characterized by the spectra of very low intensity, for example two-dimensional (2D) maps where the areas with only support materials (like mylar foil) are present. In that case segmentation of the complete dataset is required before subsequent evaluation. The method proposed in this contribution is based on a multivariate approach (hierarchical cluster analysis), and shows its superiority when compared to the standard method of cutting-off by using only the mean spectral intensity. Both techniques were implemented and their performance was tested in the R statistical environment - open-source platform - that is a favourable solution if the repeatability and transparency are the key aspects. PMID:25723954

  14. The New Model of Chemical Evolution of r-process Elements Based on the Hierarchical Galaxy Formation. I. Ba and Eu

    NASA Astrophysics Data System (ADS)

    Komiya, Yutaka; Yamada, Shimako; Suda, Takuma; Fujimoto, Masayuki Y.

    2014-03-01

    We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy r-process elements, Ba and Eu, of extremely metal-poor (EMP) stars and give constraints on their astronomical sites. Our models take into account changes of the surface abundances of EMP stars by the accretion of interstellar medium (ISM). We also consider metal-enrichment of intergalactic medium by galactic winds and the resultant pre-enrichment of proto-galaxies. The trend and scatter of the observed r-process abundances are well reproduced by our hierarchical model with ~10% of core-collapse supernovae in low-mass end (~10 M ?) as a dominant r-process source and the star formation efficiency of ~10-10 yr-1. For neutron star mergers as an r-process source, their coalescence timescale has to be ~107 yr, and the event rates ~100 times larger than currently observed in the Galaxy. We find that the accretion of ISM is a dominant source of r-process elements for stars with [Ba/H] < -3.5. In this model, a majority of stars at [Fe/H] < -3 are formed without r-process elements, but their surfaces are polluted by the ISM accretion. The pre-enrichment affects ~4% of proto-galaxies, and yet, is surpassed by the ISM accretion in the surface of EMP stars.

  15. The long-term evolution of neutron star merger remnants - I. The impact of r-process nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Rosswog, S.; Korobkin, O.; Arcones, A.; Thielemann, F.-K.; Piran, T.

    2014-03-01

    We follow the long-term evolution of the dynamic ejecta of neutron star mergers for up to 100 years and over a density range of roughly 40 orders of magnitude. We include the nuclear energy input from the freshly synthesized, radioactively decaying nuclei in our simulations and study its effects on the remnant dynamics. Although the nuclear heating substantially alters the long-term evolution, we find that running nuclear networks over purely hydrodynamic simulations (i.e. without heating) yields actually acceptable nucleosynthesis results. The main dynamic effect of the radioactive heating is to quickly smooth out inhomogeneities in the initial mass distribution, subsequently the evolution proceeds self-similarly and after 100 years the remnant still carries the memory of the initial binary mass ratio. We also explore the nucleosynthetic yields for two mass ejection channels. The dynamic ejecta very robustly produce `strong' r-process elements with A > 130 with a pattern that is essentially independent of the details of the merging system. From a simple model we find that neutrino-driven winds yield `weak' r-process contributions with 50 < A < 130 whose abundance patterns vary substantially between different merger cases. This is because their electron fraction, set by the ratio of neutrino luminosities, varies considerably from case to case. Such winds do not produce any 56Ni, but a range of radioactive isotopes that are long-lived enough to produce a second, radioactively powered electromagnetic transient in addition to the `macronova' from the dynamic ejecta. While our wind model is very simple, it nevertheless demonstrates the potential of such neutrino-driven winds for electromagnetic transients and it motivates further, more detailed neutrino-hydrodynamic studies. The properties of the mentioned transients are discussed in more detail in a companion paper.

  16. atBRX1-1 and atBRX1-2 are involved in an alternative rRNA processing pathway in Arabidopsis thaliana.

    PubMed

    Weis, Benjamin L; Palm, Denise; Missbach, Sandra; Bohnsack, Markus T; Schleiff, Enrico

    2015-03-01

    Ribosome biogenesis is an essential process in all organisms. In eukaryotes, multiple ribosome biogenesis factors (RBFs) act in the processing of ribosomal (r)RNAs, assembly of ribosomal subunits and their export to the cytoplasm. We characterized two genes in Arabidopsis thaliana coding for orthologs of yeast BRX1, a protein involved in maturation of the large ribosomal subunit. Both atBRX1 proteins, encoded by AT3G15460 and AT1G52930, respectively, are mainly localized in the nucleolus and are ubiquitously expressed throughout plant development and in various tissues. Mutant plant lines for both factors show a delay in development and pointed leaves can be observed in the brx1-2 mutant, implying a link between ribosome biogenesis and plant development. In addition, the pre-rRNA processing is affected in both mutants. Analysis of the pre-rRNA intermediates revealed that early processing steps can occur either in the 5' external transcribed spacer (ETS) or internal transcribed spacer 1 (ITS1). Interestingly, we also find that in xrn2 mutants, early processing events can be bypassed and removal of the 5' ETS is initiated by cleavage at the P' processing site. While the pathways of pre-rRNA processing are comparable to those of yeast and mammalian cells, the balance between the two processing pathways is different in plants. Furthermore, plant-specific steps such as an additional processing site in the 5' ETS, likely post-transcriptional processing of the early cleavage sites and accumulation of a 5' extended 5.8S rRNA not observed in other eukaryotes can be detected. PMID:25605960

  17. Parallel processing of real-time dynamic systems simulation on OSCAR (Optimally SCheduled Advanced multiprocessoR)

    NASA Technical Reports Server (NTRS)

    Kasahara, Hironori; Honda, Hiroki; Narita, Seinosuke

    1989-01-01

    Parallel processing of real-time dynamic systems simulation on a multiprocessor system named OSCAR is presented. In the simulation of dynamic systems, generally, the same calculation are repeated every time step. However, we cannot apply to Do-all or the Do-across techniques for parallel processing of the simulation since there exist data dependencies from the end of an iteration to the beginning of the next iteration and furthermore data-input and data-output are required every sampling time period. Therefore, parallelism inside the calculation required for a single time step, or a large basic block which consists of arithmetic assignment statements, must be used. In the proposed method, near fine grain tasks, each of which consists of one or more floating point operations, are generated to extract the parallelism from the calculation and assigned to processors by using optimal static scheduling at compile time in order to reduce large run time overhead caused by the use of near fine grain tasks. The practicality of the scheme is demonstrated on OSCAR (Optimally SCheduled Advanced multiprocessoR) which has been developed to extract advantageous features of static scheduling algorithms to the maximum extent.

  18. Surface processes in microgravity for landing and sampling site selection of asteroid missions-Suggestions for MarcoPolo-R

    NASA Astrophysics Data System (ADS)

    Kereszturi, Akos

    2014-10-01

    Surface properties of small asteroids are reviewed in this work focusing on microgravity related processes in order to give constrains for targeting sample acquisition by next missions, especially for MarcoPolo-R proposed by ESA. Based on our current knowledge and the planned capabilities of this mission, good chance exists to get answers for the following basic questions. Formation method of nanophase iron and amorphous ingredients in the regolith could be determined, surface particle size and regolith density estimation would also be gained, and with extrapolation to the rest of the surface, knowledge on transport processes, ages and results of cratering under special gravity-strength regime will be improved. Searching for fresh material on asteroid surface in general requires sophisticated effort, as small craters often do not produce much ejecta in microgravity, but the bright annuli around them could be the result of local surface disturbance, while slopes often exhibit fresh material. To identify these locations high albedo, bluer colour and occasionally the depth of 1 ?m absorption band could be useful as they often change parallel to each other. To identify the best area for sample acquisition addresses a strategic question: while smooth terrains with easy navigation and sample acquisition provide strongly weathered fine grains; steeper terrains give access to less weathered, material more representative for the whole asteroid, but navigation and mechanical sampling rise difficulties there.

  19. Explosive Nucleosynthesis of Weak r-Process Elements in Extremely Metal-Poor Core-Collapse Supernovae

    E-print Network

    N. Izutani; H. Umeda; N. Tominaga

    2008-10-31

    There have been attempts to fit the abundance patterns of extremely metal-poor stars with supernova nucleosynthesis models for the lighter elements than Zn. On the other hand, observations have revealed that the presence of EMP stars with peculiarly high ratio of "weak r-process elements" Sr, Y and Zr. Although several possible processes were suggested for the origin of these elements, the complete solution for reproducing those ratios is not found yet. In order to reproduce the abundance patterns of such stars, we investigate a model with neutron rich matter ejection from the inner region of the conventional mass-cut. We find that explosive nucleosynthesis in a high energy supernova (or "hypernova") can reproduce the high abundances of Sr, Y and Zr but that the enhancements of Sr, Y and Zr are not achieved by nucleosynthesis in a normal supernova. Our results imply that, if these elements are ejected from a normal supernova, nucleosynthesis in higher entropy flow than that of the supernova shock is required.

  20. j : r " , r { ' , : . r ' . ' . r : r ,r , r r r , l\\ , r l r r l i r e V r j r r t " : , \\ , : r t l r r r r i c ,rry'.,n:. ,rii,r r ln( y' r ainQ uallr v-/ t ' lllSAf : / r r

    E-print Network

    Short, Daniel

    a \\i \\/{ t t t , l r , t . j : r " , r { ' , : . r ' . ' . r : r ,r , r r r , l\\ , r l r r l i r e V r j r r t " : , \\ , : r t l r r r r i c ,rry'.,n:. ,rii,r r ln( y' r ainQ uallr v- / t ' lllSAf : / r r I r r , i r . t .l . r r l : / t . 1 : 1 . . [.t.,h',.; r lVr r! L: ( ] . \\ l] r . l) . L: . \\ x

  1. ?-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.

    PubMed

    Lorusso, G; Nishimura, S; Xu, Z Y; Jungclaus, A; Shimizu, Y; Simpson, G S; Söderström, P-A; Watanabe, H; Browne, F; Doornenbal, P; Gey, G; Jung, H S; Meyer, B; Sumikama, T; Taprogge, J; Vajta, Zs; Wu, J; Baba, H; Benzoni, G; Chae, K Y; Crespi, F C L; Fukuda, N; Gernhäuser, R; Inabe, N; Isobe, T; Kajino, T; Kameda, D; Kim, G D; Kim, Y-K; Kojouharov, I; Kondev, F G; Kubo, T; Kurz, N; Kwon, Y K; Lane, G J; Li, Z; Montaner-Pizá, A; Moschner, K; Naqvi, F; Niikura, M; Nishibata, H; Odahara, A; Orlandi, R; Patel, Z; Podolyák, Zs; Sakurai, H; Schaffner, H; Schury, P; Shibagaki, S; Steiger, K; Suzuki, H; Takeda, H; Wendt, A; Yagi, A; Yoshinaga, K

    2015-05-15

    The ?-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A?130) and the rare-earth-element (A?160) abundance peaks may result from the freeze-out of an (n,?)?(?,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events. PMID:26024165

  2. p-SMAD2/3 and DICER promote pre-miR-21 processing during pressure overload-associated myocardial remodeling.

    PubMed

    García, Raquel; Nistal, J Francisco; Merino, David; Price, Nathan L; Fernández-Hernando, Carlos; Beaumont, Javier; González, Arantxa; Hurlé, María A; Villar, Ana V

    2015-07-01

    Transforming growth factor-? (TGF-?) induces miR-21 expression which contributes to fibrotic events in the left ventricle (LV) under pressure overload. SMAD effectors of TGF-? signaling interact with DROSHA to promote primary miR-21 processing into precursor miR-21 (pre-miR-21). We hypothesize that p-SMAD-2 and -3 also interact with DICER1 to regulate the processing of pre-miR-21 to mature miR-21 in cardiac fibroblasts under experimental and clinical pressure overload. The subjects of the study were mice undergoing transverse aortic constriction (TAC) and patients with aortic stenosis (AS). In vitro, NIH-3T3 fibroblasts transfected with pre-miR-21 responded to TGF-?1 stimulation by overexpressing miR-21. Overexpression and silencing of SMAD2/3 resulted in higher and lower production of mature miR-21, respectively. DICER1 co-precipitated along with SMAD2/3 and both proteins were up-regulated in the LV from TAC-mice. Pre-miR-21 was isolated bound to the DICER1 maturation complex. Immunofluorescence analysis revealed co-localization of p-SMAD2/3 and DICER1 in NIH-3T3 and mouse cardiac fibroblasts. DICER1-p-SMAD2/3 protein-protein interaction was confirmed by in situ proximity ligation assay. Myocardial up-regulation of DICER1 constituted a response to pressure overload in TAC-mice. DICER mRNA levels correlated directly with those of TGF-?1, SMAD2 and SMAD3. In the LV from AS patients, DICER mRNA was up-regulated and its transcript levels correlated directly with TGF-?1, SMAD2, and SMAD3. Our results support that p-SMAD2/3 interacts with DICER1 to promote pre-miR-21 processing to mature miR-21. This new TGF?-dependent regulatory mechanism is involved in miR-21 overexpression in cultured fibroblasts, and in the pressure overloaded LV of mice and human patients. PMID:25887159

  3. Influence of the nature of the R group on the hydrolysis and condensation process of trifunctional silicon alkoxides, R-Si(OR{prime}){sub 3}

    SciTech Connect

    Delattre, L.; Babonneau, F. [Univ. Pierre et Marie Curie, Paris (France). Chimie de la Matiere Condensee

    1994-12-31

    The hydrolysis and condensation reactions of three trifunctional silicon alkoxides, R-Si(OEt){sub 3}, with various R alkyl chains (R = CH{sub 3}, C{sub 2}H{sub 5}, C{sub 8}H{sub 17}), was followed by {sup 29}Si and {sup 1}H Nuclear Magnetic Resonance. The condensation reactions are faster for methyltriethoxysilane and the degree of condensation of the system is higher. The other two systems have similar behaviors during the first hours, with lowest degree of condensation. The condensation reactions slow down for the octyltriethoxysilane, due to the presence of the long alkyl chains which prevent condensation reactions between oligomeric species. The influence of the addition of tetraethoxysilane (TEOS) was studied: for all three systems, the degree of condensation of the network is higher, indicating the role of cross-linking played by TEOS.

  4. Microbial succession in the traditional Chinese Luzhou-flavor liquor fermentation process as evaluated by SSU rRNA profiles.

    PubMed

    Xiang, Wenliang; Li, Ke; Liu, Seng; Xing, Yage; Li, Mingyuan; Che, Zhenming

    2013-03-01

    The community succession of microbes inhabited in the fermenting lees of Luzhou-flavor liquor was investigated based on small-subunit rRNA culture independent method. All sequences recovered from fermenting lees respectively fell into the genera of Lactobacillus, Streptococcus, Bacillus, Staphylococcus, Clostridium, Pelobacter, Actobacter, Serratia, Burkholderia, Rhodoccous, Corynebacterium, Arthrobacter, Microbacterium, Curtobacterium, Leptotrichia, Methanocuuleus, Saccharomyces, Zygosaccharomyces, Saccharomycopsis, Pichia, Talaromyces, Aspergillus, Eurotium, Fomitopsis and Trichosporon. The fungal Pichia, Saccharomycopsis and Talaromyces were most abundant in the lees fermented for 1 day, the fungal Eurotium and the bacteria Burkholderia, Streptococcus and Lactobacillus were dominant in the lees fermented for 7 days, only the bacteria Lactobacillus, Burkholderia were prevalent in the lees fermented for 60 days. Most genera almost existed in the fermenting lees, while their distributions were significantly different in 1, 7 and 60 days fermented lees. The prokaryotic community similarity coefficient was from 0.5000 to 0.5455 and followed to 0.1523, and that of eukaryotic community was from 0.5466 to 0.5259 and to 0.3750 when compared at species level. These results suggested that many microbes in lees have community successions associated with fermenting and that such successions maybe contribute the fermentation process of Luzhou-flavor liquor and is main reasons that the characteristic flavor factors are produced. PMID:23180546

  5. R. Battiti, M. Conti, and R. Lo Cigno (Eds.): WONS 2004, LNCS 2928, pp. 227240, 2004. IFIP International Federation for Information Processing 2004

    E-print Network

    Weske, Mathias

    Extensions Robert Hirschfeld, Katsuya Kawamura, and Hendrik Berndt DoCoMo Communications Laboratories, Future Networking Lab, Landsberger Strasse 308-312, 80687 Munich, Germany {hirschfeld, kawamura, berndt computing. Mobile communication systems that #12;228 R. Hirschfeld, K. Kawamura, and H. Berndt can

  6. I N S T I T U T F R I N F O R M A T I K Flexible Process-Tool-Integration

    E-print Network

    , Software Development Process, V-Modell XT, Microsoft Office, Microsoft Sharepoint, Microsoft Team: SharePoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.3.3. Tool Provider: TFS . . . . . . . . . . . . . . . . . . . . . . . . .

  7. Eytan, R. I. and M. E. Hellberg. 2010. Nuclear and mitochondrial sequence data reveal and conceal different demographic histories and population genetic processes in Caribbean reef

    E-print Network

    Hellberg, Michael E.

    Eytan, R. I. and M. E. Hellberg. 2010. Nuclear and mitochondrial sequence data reveal and conceal different demographic histories and population genetic processes in Caribbean reef fishes. Evolution, in press. Mitochondrial and nuclear sequence data should recover historical demographic events at different

  8. Ozonation attenuates the steroidogenic disruptive effects of sediment free oil sands process water in the H295R cell line.

    PubMed

    He, Yuhe; Wiseman, Steve B; Zhang, Xiaowei; Hecker, Markus; Jones, Paul D; El-Din, Mohamed Gamal; Martin, Jonathan W; Giesy, John P

    2010-07-01

    There is concern regarding oil sands process water (OSPW) produced by the oil sands industry in Alberta, Canada. Little is known about the potential for OSPW, and naphthenic acids (NAs), which are the primary persistent and toxic constituents of OSPW, to affect endocrine systems. Although ozonation significantly reduces concentrations of NAs and OSPW toxicity, it was hypothesized that oxidation of OSPW might produce hydroxylated products with steroidogenic activity. Therefore, untreated and ozone treated OSPW were examined for effects on sex steroid production using the H295R Steroidogenesis Assay. Untreated OSPW significantly decreased testosterone (T) and increased 17beta-estradiol (E2) concentrations at OSPW dilutions greater or equal to 10-fold. This effect was mainly due to decreased E2 metabolism. Analysis of CYP19A (aromatase) mRNA abundance and enzyme activity suggested that induction of this enzyme activity may have also contributed to these effects. Reduction of parent NA concentrations by 24% or 85% decreased the effect of OSPW on E2 production. Although T production remained significantly reduced in cells exposed to ozone treated OSPW, the effect was diminished. Aromatase mRNA abundance and enzyme activity were significantly greater in cells exposed to ozone treated OSPW, however the magnitude was less than in cells exposed to untreated OSPW. No change of E2 metabolism was observed in cells exposed to ozone treated OSPW, which may account for recovery of E2 levels. The results indicate that OSPW exposure can decrease E2 and T production, but ozonation is an effective treatment to reduce NA concentrations in OSPW without increasing affects on steroidogenesis. PMID:20466405

  9. Determination of effective rAAV-mediated gene transfer conditions to support chondrogenic differentiation processes in human primary bone marrow aspirates.

    PubMed

    Rey-Rico, A; Frisch, J; Venkatesan, J K; Schmitt, G; Madry, H; Cucchiarini, M

    2015-01-01

    The genetic modification of freshly aspirated bone marrow may provide convenient tools to enhance the regenerative capacities of cartilage defects compared with the complex manipulation of isolated progenitor cells. In the present study, we examined the ability and safety of recombinant adeno-associated virus (rAAV) serotype 2 vectors to deliver various reporter gene sequences in primary human bone marrow aspirates over time without altering the chondrogenic processes in the samples. The results demonstrate that successful rAAV-mediated gene transfer and expression of the lacZ and red fluorescent protein marker genes were achieved in transduced aspirates at very high efficiencies (90-94%) and over extended periods of time (up to 125 days) upon treatment with hirudin, an alternative anticoagulant that does not prevent the adsorption of the rAAV-2 particles at the surface of their targets compared with heparin. Application of rAAV was safe, displaying neither cytotoxic nor detrimental effects on the cellular and proliferative activities or on the chondrogenic processes in the aspirates especially using an optimal dose of 0.5?mg?ml(-1) hirudin, and application of the potent SOX9 transcription factor even enhanced these processes while counteracting hypertrophic differentiation. The current findings demonstrate the clinical value of this class of vector to durably and safely modify bone marrow aspirates as a means to further develop convenient therapeutic approaches to improve the healing of cartilage defects. PMID:25338919

  10. A Novel “Oxygen-induced” Greening Process in a Cyanobacterial Mutant Lacking the Transcriptional Activator ChlR Involved in Low-oxygen Adaptation of Tetrapyrrole Biosynthesis*

    PubMed Central

    Aoki, Rina; Hiraide, Yuto; Yamakawa, Hisanori; Fujita, Yuichi

    2014-01-01

    ChlR activates the transcription of the chlAII-ho2-hemN operon in response to low-oxygen conditions in the cyanobacterium Synechocystis sp. PCC 6803. Three genes in the operon encode low-oxygen-type enzymes to bypass three oxygen-dependent reactions in tetrapyrrole biosynthesis. A chlR-lacking mutant, ?chlR, shows poor photoautotrophic growth due to low chlorophyll (Chl) content under low-oxygen conditions, which is caused by no induction of the operon. Here, we characterized the processes of etiolation of ?chlR cells in low-oxygen conditions and the subsequent regreening of the etiolated cells upon exposure to oxygen, by HPLC, Western blotting, and low-temperature fluorescence spectra. The Chl content of the etiolated ?chlR cells incubated under low-oxygen conditions for 7 days was only 10% of that of the wild-type with accumulation of almost all intermediates of the magnesium branch of Chl biosynthesis. Both photosystem I (PSI) and photosystem II (PSII) were significantly decreased, accompanied by a preferential decrease of antenna Chl in PSI. Upon exposure to oxygen, the etiolated ?chlR cells resumed to produce Chl after a short lag (?2 h), and the level at 72 h was 80% of that of the wild-type. During this novel “oxygen-induced” greening process, the PSI and PSII contents were largely increased in parallel with the increase in Chl contents. After 72 h, the PSI content reached ?50% of the wild-type level in contrast to the full recovery of PSII. ?chlR provides a promising alternative system to investigate the biogenesis of PSI and PSII. PMID:24297184

  11. E. H. Adelson | C. H. Anderson | J. R. Bergen | P. J. Burt | J. M. Ogden Pyramid methods in image processing

    E-print Network

    processing The image pyramid offers a flexible, convenient multiresolution format that mirrors the multiple scales of processing in the human visual system. Digital image processing is being used in many domains. But digital image processing is still in a developing state. In all of the areas just mentioned, many

  12. Peripheral and/or central effects of racemic-, S(+)- and R(?)-flurbiprofen on inflammatory nociceptive processes: a c-Fos protein study in the rat spinal cord

    PubMed Central

    Buritova, Jaroslava; Besson, Jean-Marie

    1998-01-01

    We have evaluated the effects of intravenous or intraplantar racemic-, S(+)- and R(?)-flurbiprofen on both the carrageenan-evoked peripheral oedema and spinal c-Fos immunoreactivity, an indirect index of neurons involved in spinal nociceptive processes. Three hours after intraplantar injection of carrageenan (6?mg in 150??l of saline) in awake rats, a peripheral oedema and numerous c-Fos protein-like immunoreactive (c-Fos-LI) neurons in L4–L5 segments were observed. c-Fos-LI neurons were essentially located in the superficial (I–II) and deep (V–VI) laminae of the dorsal horn. Intravenous racemic-flurbiprofen (0.3, 3 and 9 ?mg?kg?1) dose-relatedly reduced the carrageenan-evoked oedema and spinal c-Fos expression (r=0.64, r=0.88 and r=0.84 for paw diameter, ankle diameter and number of c-Fos-LI neurons; P<0.05, P<0.001 and P<0.001 respectively). Similar effects to those of intravenous racemic-flurbiprofen were obtained with intravenous S(+)-flurbiprofen (0.3, 3 and 9?mg?kg?1) which dose-relatedly reduced the number of c-Fos-LI neurons (r=0.69, P<0.01) and diameters of paw and ankle (r=0.56 and r=0.52 respectively, P<0.05 for both). For the dose of 0.3?mg?kg?1 i.v., R(?)-flurbiprofen did not modify the number of c-Fos-LI neurons and produced a weak reduction of oedema at only the ankle level (23±12% reduction, P<0.05). However, a ten times higher dose of R(?)-flurbiprofen (3?mg?kg?1 i.v.) was necessary to obtain effects comparable to those of S(+)- or racemic-flurbiprofen (0.3?mg?kg?1 i.v.). Intraplantar racemic-flurbiprofen (1, 10 and 30??g) dose-relatedly reduced the carrageenan-enhanced ankle diameter (r=0.81, P<0.001) and the number of c-Fos-LI neurons in L4–L5 segments (r=0.83, P<0.001), with a 60±3% reduction of the number of c-Fos-LI neurons (P<0.001), and 30±3 and 67±7% reduction of paw and ankle diameter respectively (P<0.001 for both) for the dose of 30??g. For intraplantar S(+)-flurbiprofen (1, 10 and 30 ??g) the dose-related effects (r=0.77, r=0.60 and r=0.59 for c-Fos-LI neurons, paw and ankle diameters respectively, P<0.001, P<0.01 and P<0.01) were similar to those of racemic-flurbiprofen. In contrast, intraplantar R(?)-flurbiprofen (1, 10 and 30??g) did not have detectable effects on all studied parameters. The present study provides clear evidence for potent anti-inflammatory and antinociceptive effects of both intravenous or intraplantar racemic- and S(+)-flurbiprofen. These results further demonstrate marked anti-inflammatory and antinociceptive effects of intravenous, but not intraplantar, R(?)-flurbiprofen. These results suggest that the main site of action of racemic- and S(+)-flurbiprofen is in the periphery and indicate that the site of action of R(?)-flurbiprofen is mainly of central origin. PMID:9776348

  13. Liouville-space R-matrix-Floquet description of atomic radiative processes involving autoionizing states in the presence of intense electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Jacobs, V. L.; Burke, P. G.; Potvliege, R. M.

    2014-01-01

    A reduced-density-operator description is developed for coherent optical phenomena in many-electron atomic systems, utilizing a Liouville-space, multiple-mode Floquet-Fourier representation. The Liouville-space formulation provides a natural generalization of the ordinary Hilbert-space (Hamiltonian) R-matrix-Floquet method, which has been developed for multi-photon transitions and laser-assisted electron-atom collision processes. In these applications, the R-matrix-Floquet method has been demonstrated to be capable of providing an accurate representation of the complex, multi-level structure of many-electron atomic systems in bound, continuum, and autoionizing states. The ordinary Hilbert-space (Hamiltonian) formulation of the R-matrix-Floquet method has been implemented in highly developed computer programs, which can provide a non-perturbative treatment of the interaction of a classical, multiple-mode electromagnetic field with a quantum system. This quantum system may correspond to a many-electron, bound atomic system and a single continuum electron. However, including pseudo-states in the expansion of the many-electron atomic wave function can provide a representation of multiple continuum electrons. The ‘dressed’ many-electron atomic states thereby obtained can be used in a realistic non-perturbative evaluation of the transition probabilities for an extensive class of atomic collision and radiation processes in the presence of intense electromagnetic fields. In order to incorporate environmental relaxation and decoherence phenomena, we propose to utilize the ordinary Hilbert-space (Hamiltonian) R-matrix-Floquet method as a starting-point for a Liouville-space (reduced-density-operator) formulation. To illustrate how the Liouville-space R-matrix-Floquet formulation can be implemented for coherent atomic radiative processes, we discuss applications to electromagnetically induced transparency, as well as to related pump-probe optical phenomena, and also to the unified description of radiative and dielectronic recombination in electron-ion beam interactions and high-temperature plasmas.

  14. An end-to-end system in support of a broad scope of GOES-R sensor and data processing study

    NASA Astrophysics Data System (ADS)

    Huang, Hung-Lung

    2005-08-01

    The mission of NOAA's Geostationary Operational Environmental Satellite System (GOES) R series satellites, in the 2012 time frame, is to provide continuous, near real-time meteorological, oceanographic, solar, and space environment data that supports NOAA's strategic mission goals. It presents an exciting opportunity to explore new instruments, satellite designs, and system architectures utilizing new communication and instrument technologies in order to meet the ever-increasing demands made of Earth observation systems by national agencies and end users alike. The GOES-R sensor suite includes a 16 spectral band Advanced Baseline Imager (ABI), an approximately 1500 high spectral resolution band Hyperspectral Environmental Suite (HES), plus other sensors designed to detect lightning and to explore the ocean, solar and space environment. The Cooperative Institute for Meteorological Satellite Studies (CIMSS) as part of the Space Science and Engineering Center (SSEC) of the University of Wisconsin-Madison, the long time partner of NOAA, has developed the first operational end-to-end processing system for GOES. Based on this heritage, and with recent support from the NASA/NOAA Geosynchrous Imaging FTS (GIFTS) project, the Navy's Multiple University Research Initiative (MURI), and NOAA's GOES-R Risk Reduction program, SSEC has built a near-complete end-to-end system that is capable of simulating sensor measurements from top of atmosphere radiances, raw sensor data (level 0) through calibrated and navigated sensor physical measurements (level 1) to the processed products (level 2). In this paper, the SSEC Hyperspectral Imaging and Sounding Simulator and Processor (HISSP) will be presented in detail. HISSP is capable of demonstrating most of the processing functions such as data compression/decompression, sensor calibration, data processing, algorithm development, and product generation. In summary, HISSP is an end-to-end system designed to support both government and industry for the GOES-R system and their related broad scope of acquisition activities.

  15. Variation of satellite intensity factors with n for 1 s sup 2. epsilon. l r arrow 1 s 2 pnl r arrow 1 s sup 2 nl dielectronic-recombination processes in heliumlike ions

    SciTech Connect

    Karim, K.R. (Department of Physics, Illinois State University, Normal, Illinois 61761 (USA)); Bhalla, C.P. (Department of Physics, Cardwell Hall, Kansas State University, Manhattan, Kansas 66506 (USA))

    1991-01-01

    Satellite intensity factors {ital F}{sub 2}{sup *}({ital s}{minus}{ital f}) have been calculated for the 1{ital s}{sup 2}{epsilon}{ital l}{r arrow}1{ital s}2{ital pnl}{r arrow}1{ital s}{sup 2}{ital nl} dielectronic-recombination processes of heliumlike Ne, Si, Ar, Ti, Cr, and Ni. The relevant atomic parameters have been calculated explicitly for all intermediate resonance states {vert bar}{ital s}{r angle}={vert bar}1{ital s}2{ital pnlSLJ}{r angle} with {ital n}=2--8 and {ital l}=0--6 in the intermediate-coupling scheme. The 1/{ital n}{sup 3} scaling, which has often been used in extrapolating {ital F}{sub 2}{sup *}({ital s}{minus}{ital f}) for {ital n}{ge}4, is tested against these values of {ital F}{sub 2}{sup *}({ital s}{minus}{ital f}).

  16. ? -Decay Half-Lives of 110 Neutron-Rich Nuclei across the N =82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process

    NASA Astrophysics Data System (ADS)

    Lorusso, G.; Nishimura, S.; Xu, Z. Y.; Jungclaus, A.; Shimizu, Y.; Simpson, G. S.; Söderström, P.-A.; Watanabe, H.; Browne, F.; Doornenbal, P.; Gey, G.; Jung, H. S.; Meyer, B.; Sumikama, T.; Taprogge, J.; Vajta, Zs.; Wu, J.; Baba, H.; Benzoni, G.; Chae, K. Y.; Crespi, F. C. L.; Fukuda, N.; Gernhäuser, R.; Inabe, N.; Isobe, T.; Kajino, T.; Kameda, D.; Kim, G. D.; Kim, Y.-K.; Kojouharov, I.; Kondev, F. G.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Lane, G. J.; Li, Z.; Montaner-Pizá, A.; Moschner, K.; Naqvi, F.; Niikura, M.; Nishibata, H.; Odahara, A.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Sakurai, H.; Schaffner, H.; Schury, P.; Shibagaki, S.; Steiger, K.; Suzuki, H.; Takeda, H.; Wendt, A.; Yagi, A.; Yoshinaga, K.

    2015-05-01

    The ? -decay half-lives of 110 neutron-rich isotopes of the elements from Rb 37 to Sn 50 were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r -process calculations and reinforce the notion that the second (A ?130 ) and the rare-earth-element (A ?160 ) abundance peaks may result from the freeze-out of an (n ,? )?(? ,n ) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r -process events.

  17. A Content-Process Model for Training Educational R&D Practitioner, Diffuser, and Developer Teams. Final Report.

    ERIC Educational Resources Information Center

    Miskel, Cecil G.

    This document presents a pilot training program which developed, diffused, and evaluated the application of a selected group of research and development (R&D) techniques for planning and initiating change in the public schools. The training model resulted from suggestions of an interdisciplinary development team at the University of Kansas. The…

  18. Kinetic Phases in the Electron Transfer from P+ Associated Processes in Rhodobacter sphaeroides R-26 Reaction Centers

    E-print Network

    Li, Jiali

    to form P+QAQB - was measured in Rhodobacter sphaeroides R-26 reaction centers (RCs) where the native little or no electron transfer occurs at 200-600 µs (3) in MQAUQB RCs. The 80-µs rate has been previously and 30 °C. In isolated RCs with UQA, if there is any fast component, it appears to be faster and less

  19. ACToR Chemical Structure processing using Open Source ChemInformatics Libraries (FutureToxII)

    EPA Science Inventory

    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 ove...

  20. Activation of BlaR1 protein of methicillin-resistant Staphylococcus aureus, its proteolytic processing, and recovery from induction of resistance.

    PubMed

    Llarrull, Leticia I; Toth, Marta; Champion, Matthew M; Mobashery, Shahriar

    2011-11-01

    The fates of BlaI, the gene repressor protein for the bla operon, BlaR1, the ?-lactam sensor/signal transducer, and PC1 ?-lactamase in four strains of Staphylococcus aureus upon exposure to four different ?-lactam antibiotics were investigated as a function of time. The genes for the three proteins are encoded by the bla operon, the functions of which afford inducible resistance to ?-lactam antibiotics in S. aureus. BlaR1 protein is expressed at low copy number. Acylation of the sensor domain of BlaR1 by ?-lactam antibiotics initiates signal transduction to the cytoplasmic domain, a zinc protease, which is activated and degrades BlaI. This proteolytic degradation derepresses transcription of all three genes, resulting in inducible resistance. These processes take place within minutes of exposure to the antibiotics. The BlaR1 protein was shown to undergo fragmentation in three S. aureus strains within the time frame relevant for manifestation of resistance and was below the detection threshold in the fourth. Two specific sites of fragmentation were identified, one cytoplasmic and the other in the sensor domain. This is proposed as a means for turnover, a process required for recovery from induction of resistance in S. aureus in the absence of the antibiotic challenge. In S. aureus not exposed to ?-lactam antibiotics (i.e. not acylated by antibiotic) the same fragmentation of BlaR1 is still observed, including the shedding of the sensor domain, an observation that leads to the conclusion that the sites of proteolysis might have evolved to predispose the protein to degradation within a set period of time. PMID:21896485

  1. Information Processing, Evaluation, and Utilization: The Role of Academic Libraries in Research and Development (R&D) in Zambia.

    ERIC Educational Resources Information Center

    Lundu, Maurice C.

    1985-01-01

    Analyzes and applies Bettman's information processing theory of consumer choice to information processing, evaluation, and utilization by academic libraries in Zambia to support research and development activities. Certain Zambian cultural and sociopsychological aspects and attitudes that could affect the evaluation and utilization of information…

  2. Approaches to pre-formulation R and D for phytopharmaceuticals emanating from herb based traditional Ayurvedic processes

    PubMed Central

    Anantha, Narayana D. B.

    2013-01-01

    Botanicals constitute a large part of the drugs from the traditional medicine (TM) and ethno medicine (EM) known for their history of safe use (HOSU). Phytopharmaceuticals having a base of such origin offer high advantages as they come with safety profiles, and often allow extrapolation of the HOSU data, under certain circumstances. However, while current pharmaceutical technologies are being adopted by the industry to make phytopharmaceuticals with such origin, there is a need for preformulation research and development (R and D) during formulation. Some suggestions for R and D studies in case of aqueous extracts known in Ayurveda, converted on an industrial scale to obtain a phytopharmaceutical, and formulated as a solid dosage form (granules, tablets, or capsules) are discussed. PMID:23741154

  3. Experiments with a methodology to model the role of R&D expenditures in energy technology learning processes; first results

    Microsoft Academic Search

    Asami Miketa; Leo Schrattenholzer

    2004-01-01

    This paper presents the results of using a stylized optimization model of the global electricity supply system to analyze the optimal research and development (R&D) support for an energy technology. The model takes into account the dynamics of technological progress as described by a so-called two-factor learning curve (2FLC). The two factors are cumulative experience (“learning by doing”) and accumulated

  4. Compact Ku-Band T/R Module for High-Resolution Radar Imaging of Cold Land Processes

    NASA Technical Reports Server (NTRS)

    Andricos, Constantine; Yueh, Simon H.; Krimskiy, Vladimir A.; Rahmat-Samii, Yahya

    2010-01-01

    Global measurement of terrestrial snow cover is critical to two of the NASA Earth Science focus areas: (1) climate variability and change and (2) water and energy cycle. For radar backscatter measurements, Ku-band frequencies, scattered mainly within the volume of the snowpack, are most suitable for the SWE (snow-water equivalent) measurements. To isolate the complex effects of different snowpack (density and snowgrain size), and underlying soil properties and to distinctly determine SWE, the space-based synthetic aperture radar (SAR) system will require a dual-frequency (13.4 and 17.2 GHz) and dual polarization approach. A transmit/receive (T/R) module was developed operating at Ku-band frequencies to enable the use of active electronic scanning phased-array antenna for wide-swath, high-resolution SAR imaging of terrestrial snow cover. The T/R module has an integrated calibrator, which compensates for all environmental- and time-related changes, and results in very stable power and amplitude characteristics. The module was designed to operate over the full frequency range of 13 to 18 GHz, although only the two frequencies, 13.4 GHz and 17.2 GHz, will be used in this SAR radar application. Each channel of the transmit module produces > 4 W (35 dbm) over the operating bandwidth of 20 MHz. The stability requirements of <0.1 dB receive gain accuracy and <0.1 dB transmit power accuracy over a wide temperature range are achieved using a self-correction scheme, which does real-time amplitude calibration so that the module characteristics are continually corrected. All the calibration circuits are within the T/R module. The timing and calibration sequence is stored in a control FPGA (field-programmable gate array) while an internal 128K 8bit high-speed RAM (random access memory) stores all the calibration values. The module was designed using advanced components and packaging techniques to achieve integration of the electronics in a 2 x6.5x1-in. (5x17x2.5-cm) package. The module size allows 4 T/R modules to feed the 16 16-element subarray on an antenna panel. The T/R module contains four transmit channels and eight receive channels (horizontal and vertical polarizations).

  5. The Mutual Exclusion Problem for Unreliable Processes: Preliminary Rt~port Ronald L. Rivest 'and Vaughan R. Pratt

    E-print Network

    Rivest, Ronald L.

    as a subroutine. and is not quite as. elegant as the two-process solution. Introduction I n thi~ introduction we first make precise the model of paraUel compul alion that we are using, and 'then specify carefully

  6. A KINETIC MODEL FOR H2O2/UV PROCESS IN A COMPLETELY MIXED BATCH REACTOR. (R825370C076)

    EPA Science Inventory

    A dynamic kinetic model for the advanced oxidation process (AOP) using hydrogen peroxide and ultraviolet irradiation (H2O2/UV) in a completely mixed batch reactor (CMBR) is developed. The model includes the known elementary chemical and photochemical reac...

  7. MEMBRANE-MODERATED STRIPPING PROCESS FOR REMOVING VOCS FROM WATER IN A COMPOSITE HOLLOW FIBER MODULE. (R825511C027)

    EPA Science Inventory

    The "stripmeation" process for removing volatile organic compounds (VOCs) from water has been introduced and studied. An aqueous solution of the VOC is passed through the bores of hydrophobic microporous polypropylene hollow fibers having a plasma polymerized silicone ...

  8. NOL11, Implicated in the Pathogenesis of North American Indian Childhood Cirrhosis, Is Required for Pre-rRNA Transcription and Processing

    PubMed Central

    Freed, Emily F.; Prieto, José-Luis; McCann, Kathleen L.; McStay, Brian; Baserga, Susan J.

    2012-01-01

    The fundamental process of ribosome biogenesis requires hundreds of factors and takes place in the nucleolus. This process has been most thoroughly characterized in baker's yeast and is generally well conserved from yeast to humans. However, some of the required proteins in yeast are not found in humans, raising the possibility that they have been replaced by functional analogs. Our objective was to identify non-conserved interaction partners for the human ribosome biogenesis factor, hUTP4/Cirhin, since the R565W mutation in the C-terminus of hUTP4/Cirhin was reported to cause North American Indian childhood cirrhosis (NAIC). By screening a yeast two-hybrid cDNA library derived from human liver, and through affinity purification followed by mass spectrometry, we identified an uncharacterized nucleolar protein, NOL11, as an interaction partner for hUTP4/Cirhin. Bioinformatic analysis revealed that NOL11 is conserved throughout metazoans and their immediate ancestors but is not found in any other phylogenetic groups. Co-immunoprecipitation experiments show that NOL11 is a component of the human ribosomal small subunit (SSU) processome. siRNA knockdown of NOL11 revealed that it is involved in the cleavage steps required to generate the mature 18S rRNA and is required for optimal rDNA transcription. Furthermore, abnormal nucleolar morphology results from the absence of NOL11. Finally, yeast two-hybrid analysis shows that NOL11 interacts with the C-terminus of hUTP4/Cirhin and that the R565W mutation partially disrupts this interaction. We have therefore identified NOL11 as a novel protein required for the early stages of ribosome biogenesis in humans. Our results further implicate a role for NOL11 in the pathogenesis of NAIC. PMID:22916032

  9. x : N. (r : {N | (((r r) x) x < (r + 1) (r + 1))}) x:N. (r:{N| (((r * r) x) x < (r + 1) * (r + 1))})

    E-print Network

    x : N. (r : {N | (((r r) x) x r + 1) (r + 1))}) x:N. (r:{N| (((r * r) x) x r + 1) * (r + 1))}) | BY (DivNatInduction 4 · THEN Auto) |\\ | r:{N| (((r * r) 0) 0 r + 1) * (r + 1))} | | 1 BY (With 0 (D 0)· THEN Auto') \\ 1. x: N+ 2. r:{N| (((r * r) (x ÷ 4)) x ÷ 4 r + 1) * (r + 1))} r

  10. The Astrophysical {ital r}-Process: A Comparison of Calculations following Adiabatic Expansion with Classical Calculations Based on Neutron Densities and Temperatures

    SciTech Connect

    Freiburghaus, C. [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States)] [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); Rembges, J.; Rauscher, T. [Departement fuer Physik und Astronomie, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)] [Departement fuer Physik und Astronomie, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Kolbe, E. [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States)] [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); Thielemann, F. [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States)] [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); [Departement fuer Physik und Astronomie, Universitaet Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Kratz, K.; Pfeiffer, B. [Institut fuer Kernchemie, Universitaet Mainz, Fritz-Strassmann-Weg 2, D-55099 Mainz (Germany)] [Institut fuer Kernchemie, Universitaet Mainz, Fritz-Strassmann-Weg 2, D-55099 Mainz (Germany); Cowan, J.J. [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States)] [Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, CA 93106-4030 (United States); [Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    1999-05-01

    The rapid neutron-capture process ({ital r}-process) encounters unstable nuclei far from {beta}-stability. Therefore its observable features, like the abundances, witness (still uncertain) nuclear structure as well as the conditions in the appropriate astrophysical environment. With the remaining lack of a full understanding of its astrophysical origin, parameterized calculations are still needed. We consider two approaches: (1) the classical approach is based on (constant) neutron number densities n{sub n} and temperatures {ital T} over duration timescales {tau}; (2) recent investigations, motivated by the neutrino wind scenario from hot neutron stars after a supernova explosion, followed the expansion of matter with initial entropies {ital S} and electron fractions Y{sub e} over expansion timescales {tau}. In the latter case the freezeout of reactions with declining temperatures and densities can be taken into account explicitly. We compare the similarities and differences between the two approaches with respect to resulting abundance features and their relation to solar {ital r}-process abundances, applying for the first time different nuclear mass models in entropy-based calculations. Special emphasis is given to the questions of ({ital a}) whether the same nuclear properties far from stability lead to similar abundance patterns and possible deficiencies in (1) and (2), and ({ital b}) whether some features can also provide clear constraints on the astrophysical conditions in terms of permitted entropies, Y{sub e} values, and expansion timescales in (2). This relates mostly to the A{lt}110 mass range, where a fit to solar {ital r}-abundances in high-entropy supernova scenarios seems to be hard to attain. Possible low-entropy alternatives are presented. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

  11. Novel Magnetically Fluidized Bed Reactor Development for the Looping Process: Coal to Hydrogen Production R&D

    SciTech Connect

    Mei, Renwei; Hahn, David; Klausner, James; Petrasch, Jorg; Mehdizadeh, Ayyoub; Allen, Kyle; Rahmatian, Nima; Stehle, Richard; Bobek, Mike; Al-Raqom, Fotouh; Greek, Ben; Li, Like; Chen, Chen; Singh, Abhishek; Takagi, Midori; Barde, Amey; Nili, Saman

    2013-09-30

    The coal to hydrogen project utilizes the iron/iron oxide looping process to produce high purity hydrogen. The input energy for the process is provided by syngas coming from gasification process of coal. The reaction pathways for this process have been studied and favorable conditions for energy efficient operation have been identified. The Magnetically Stabilized Porous Structure (MSPS) is invented. It is fabricated from iron and silica particles and its repeatable high performance has been demonstrated through many experiments under various conditions in thermogravimetric analyzer, a lab-scale reactor, and a large scale reactor. The chemical reaction kinetics for both oxidation and reduction steps has been investigated thoroughly inside MSPS as well as on the surface of very smooth iron rod. Hydrogen, CO, and syngas have been tested individually as the reducing agent in reduction step and their performance is compared. Syngas is found to be the most pragmatic reducing agent for the two-step water splitting process. The transport properties of MSPS including porosity, permeability, and effective thermal conductivity are determined based on high resolution 3D CT x-ray images obtained at Argonne National Laboratory and pore-level simulations using a lattice Boltzmann Equation (LBE)-based mesoscopic model developed during this investigation. The results of those measurements and simulations provide necessary inputs to the development of a reliable volume-averaging-based continuum model that is used to simulate the dynamics of the redox process in MSPS. Extensive efforts have been devoted to simulate the redox process in MSPS by developing a continuum model consist of various modules for conductive and radiative heat transfer, fluid flow, species transport, and reaction kinetics. Both the Lagrangian and Eulerian approaches for species transport of chemically reacting flow in porous media have been investigated and verified numerically. Both approaches lead to correct prediction of hydrogen production rates over a large range of experimental conditions in the laboratory scale reactor and the bench-scale reactor. In the economic analysis, a comparison of the hydrogen production plants using iron/iron oxide looping cycle and the conventional process has been presented. Plant configurations are developed for the iron/iron oxide looping cycle. The study suggests a higher electric power generation but a lower hydrogen production efficiency comparing with the conventional process. Additionally, it was shown that the price of H{sub 2} obtained from our reactor can be as low as $1.7/kg, which is 22% lower than the current price of the H{sub 2} obtained from reforming plants.

  12. Beta-decay half-lives and beta-delayed neutron emisison probabilities of nuclei in the region A. 110, relevant for the r-process

    SciTech Connect

    Moller, Peter [Los Alamos National Laboratory; Pereira, J [MSU; Hennrich, S [MSU; Aprahamian, A [UNIV OF NOTRE DAME; Arndt, O [GERMANY; Becerril, A [MSU; Elliot, T [MSU; Estrade, A [MSU; Galaviz, D [MSU; Kessler, R [UNIV MAINZ; Kratz, K - L [GERMANY; Lorusso, G [MSU; Mantica, P F [MSU; Matos, M [MSU; Montes, F [MSU; Pfeiffer, B [UNIV MAINZ; Schatz, F [MSU; Schnorrenberger, L [GERMANY; Smith, E [MSU; Stolz, A [MSU; Quinn, M [UNIV OF NOTRE DAME; Walters, W B [UNIV OF MARYLAND; Wohr, A [UNIV OF NOTRE DAME

    2009-01-01

    Measurements of the {beta}-decay properties of A {approx}< 110 r-process nuclei have been completed at the National Superconducting Cyclotron Laboratory, at Michigan State University. {beta}-decay half-lives for {sup 105}Y, {sup 106,107}Zr and {sup 108,111}Mo, along with ,B-delayed neutron emission probabilities of 104Y, 109,11OMo and upper limits for 105Y, 103-107Zr and 108,111 Mo have been measured for the first time. Studies on the basis of the quasi-random phase approximation are used to analyze the ground-state deformation of these nuclei.

  13. Beta-decay half-lives and beta-delayed neutron emission probabilities of nuclei in the region below A=110, relevant for the r-process

    E-print Network

    J. Pereira; S. Hennrich; A. Aprahamian; O. Arndt; A. Becerril; T. Elliot; A. Estrade; D. Galaviz; R. Kessler; K. -L. Kratz; G. Lorusso; P. F. Mantica; M. Matos; P. Moller; F. Montes; B. Pfeiffer; H. Schatz; F. Schertz; L. Schnorrenberger; E. Smith; A. Stolz; M. Quinn; W. B. Walters; A. Wohr

    2009-02-10

    Measurements of the beta-decay properties of r-process nuclei below A=110 have been completed at the National Superconducting Cyclotron Laboratory, at Michigan State University. Beta-decay half-lives for Y-105, Zr-106,107 and Mo-111, along with beta-delayed neutron emission probabilities of Y-104, Mo-109,110 and upper limits for Y-105, Zr-103,104,105,106,107 and Mo-108,111 have been measured for the first time. Studies on the basis of the quasi-random phase approximation are used to analyze the ground-state deformation of these nuclei.

  14. r.avaflow: An advanced open source computational framework for the GIS-based simulation of two-phase mass flows and process chains

    NASA Astrophysics Data System (ADS)

    Mergili, Martin; Fischer, Jan-Thomas; Fellin, Wolfgang; Ostermann, Alexander; Pudasaini, Shiva P.

    2015-04-01

    Geophysical mass flows stand for a broad range of processes and process chains such as flows and avalanches of snow, soil, debris or rock, and their interactions with water bodies resulting in flood waves. Despite considerable efforts put in model development, the simulation, and therefore the appropriate prediction of these types of events still remains a major challenge in terms of the complex material behaviour, strong phase interactions, process transformations and the complex mountain topography. Sophisticated theories exist, but they have hardly been brought to practice yet. We fill this gap by developing a novel and unified high-resolution computational tool, r.avaflow, representing a comprehensive and advanced open source GIS simulation environment for geophysical mass flows. Based on the latest and most advanced two-phase physical-mathematical models, r.avaflow includes the following features: (i) it is suitable for a broad spectrum of mass flows such as rock, rock-ice and snow avalanches, glacial lake outburst floods, debris and hyperconcentrated flows, and even landslide-induced tsunamis and submarine landslides, as well as process chains involving more than one of these phenomena; (ii) it accounts for the real two-phase nature of many flow types: viscous fluids and solid particles are considered separately with advanced mechanics and strong phase interactions; (iii) it is freely available and adoptable along with the GRASS GIS software. In the future, it will include the intrinsic topographic influences on the flow dynamics and morphology as well as an advanced approach to simulate the entrainment and deposition of solid and fluid material. As input r.avaflow needs information on (a) the mountain topography, (b) the material properties and (c) the spatial distribution of the solid and fluid release masses or one or more hydrographs of fluid and solid material. We demonstrate the functionalities and performance of r.avaflow by using some generic and real-world examples including a channelized debris flow with hydrograph input, and a rock avalanche impacting a reservoir, triggering a flood wave overtopping and eroding the dam. Project web site: http://www.avaflow.org/

  15. Static and fatigue testing of full-scale fuselage panels fabricated using a Therm-X(R) process

    NASA Technical Reports Server (NTRS)

    Dinicola, Albert J.; Kassapoglou, Christos; Chou, Jack C.

    1992-01-01

    Large, curved, integrally stiffened composite panels representative of an aircraft fuselage structure were fabricated using a Therm-X process, an alternative concept to conventional two-sided hard tooling and contour vacuum bagging. Panels subsequently were tested under pure shear loading in both static and fatigue regimes to assess the adequacy of the manufacturing process, the effectiveness of damage tolerant design features co-cured with the structure, and the accuracy of finite element and closed-form predictions of postbuckling capability and failure load. Test results indicated the process yielded panels of high quality and increased damage tolerance through suppression of common failure modes such as skin-stiffener separation and frame-stiffener corner failure. Finite element analyses generally produced good predictions of postbuckled shape, and a global-local modelling technique yielded failure load predictions that were within 7% of the experimental mean.

  16. A study on control of accumulators in web processing lines Prabhakar R. Pagilla, Inderpal Singh, and Ramamurthy V. Dwivedula

    E-print Network

    Pagilla, Prabhakar R.

    in the process section in the case of aluminum and steel webs, and printing, perforating, and laminating less than its width can be described as a web. Plastic wrap, paper, film, and aluminum strip leveller, and an en- try accumulator. Operations such as wash, coat, and quench on the web are performed

  17. Ozonation attenuates the steroidogenic disruptive effects of sediment free oil sands process water in the H295R cell line

    Microsoft Academic Search

    Yuhe He; Steve B. Wiseman; Xiaowei Zhang; Markus Hecker; Paul D. Jones; Mohamed Gamal El-Din; Jonathan W. Martin; John P. Giesy

    2010-01-01

    There is concern regarding oil sands process water (OSPW) produced by the oil sands industry in Alberta, Canada. Little is known about the potential for OSPW, and naphthenic acids (NAs), which are the primary persistent and toxic constituents of OSPW, to affect endocrine systems. Although ozonation significantly reduces concentrations of NAs and OSPW toxicity, it was hypothesized that oxidation of

  18. A MECHANISTIC MODEL FOR ESTIMATING VOC EMISSIONS FROM INDUSTRIAL PROCESS DRAINS PART I: THE UNDERLYING CHANNEL. (R823335)

    EPA Science Inventory

    Recent research has indicated the potential for emissions of volatile organic compound (VOCs) from industrial process drains, and a need for better understanding of the mass transfer kinetics associated with such emissions. rn this study, a two-zone model was developed in a...

  19. Co-production of light p-, s- and r-process isotopes in the high-entropy wind of type II supernovae

    E-print Network

    Farouqi, K; Pfeiffer, B

    2009-01-01

    We have performed large-scale nucleosynthesis calculations within the high-entropy-wind (HEW) scenario of type II supernovae. The primary aim was to constrain the conditions for the production of the classical "p-only" isotopes of the light trans-Fe elements. We find, however, that for electron fractions in the range 0.458 $\\le$ Y$_e$ $\\le$ 0.478, sizeable abundances of p-, s- and r-process nuclei between $^{64}$Zn and $^{98}$Ru are coproduced in the HEW at low entropies (S $\\le$ 100) by a primary charged-particle process after an $\\alpha$-rich freezeout. With the above Y$_e$ -- S correlation, most of the predicted isotopic abundance ratios within a given element (e.g. $^{64}$Zn(p)/$^{70}$Zn(r) or $^{92}$Mo(p)/$^{94}$Mo(p)), as well as of neighboring elements (e.g. $^{70}$Ge(s+p)/$^{74}$Se(p) or $^{74}$Se(p)/$^{78}$Kr(p)) agree with the observed Solar-System ratios. Taking the Mo isotopic chain as a particularly challenging example, we show that our HEW model can account for the production of all 7 stable iso...

  20. Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario

    E-print Network

    Ishimaru, Yuhri; Prantzos, Nikos

    2015-01-01

    Binary mergers (NSMs) of double neutron star (and black hole-neutron star) systems are suggested to be major sites of r-process elements in the Galaxy by recent hydrodynamical and nucleosynthesis studies. It has been pointed out, however, that the estimated long lifetimes of neutron star binaries are in conflict with the presence of r-process-enhanced halo stars at metallicities as low as [Fe/H] ~ -3. To resolve this problem, we examine the role of NSMs in the early Galactic chemical evolution on the assumption that the Galactic halo was formed from merging sub-halos. We present simple models for the chemical evolution of sub-halos with total final stellar masses between 10^4 M_solar and 2 x 10^8 M_solar. Typical lifetimes of compact binaries are assumed to be 100 Myr (for 95% of their population) and 1 Myr (for 5%), according to recent binary population synthesis studies. The resulting metallcities of sub-halos and their ensemble are consistent with the observed mass-metallicity relation of dwarf galaxies in...

  1. NanoStringNorm: an extensible R package for the pre-processing of NanoString mRNA and miRNA data

    PubMed Central

    Waggott, Daryl; Chu, Kenneth; Yin, Shaoming; Wouters, Bradly G.; Liu, Fei-Fei; Boutros, Paul C.

    2012-01-01

    Motivation: The NanoString nCounter Platform is a new and promising technology for measuring nucleic acid abundances. It has several advantages over PCR-based techniques, including avoidance of amplification, direct sequence interrogation and digital detection for absolute quantification. These features minimize aspects of experimental error and hold promise for dealing with challenging experimental conditions such as archival formalin-fixed paraffin-embedded samples. However, systematic inter-sample technical artifacts caused by variability in sample preservation, bio-molecular extraction and platform fluctuations must be removed to ensure robust data. Results: To facilitate this process and to address these issues for NanoString datasets, we have written a pre-processing package called NanoStringNorm in the R statistical language. Key features include an extensible environment for method comparison and new algorithm development, integrated gene and sample diagnostics, and facilitated downstream statistical analysis. The package is open-source, is available through the CRAN package repository, includes unit-tests to ensure numerical accuracy, and provides visual and numeric diagnostics. Availability: http://cran.r-project.org/web/packages/NanoStringNorm Contact: paul.boutros@oicr.on.ca Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22513995

  2. Assessing the reliability and validity of the Revised Two Factor Study Process Questionnaire (R-SPQ2F) in Ghanaian medical students

    PubMed Central

    2014-01-01

    Purpose: We investigated the validity and reliability of the Revised Two Factor Study Process Questionnaire (R-SPQ2F) in preclinical students in Ghana. Methods: The R-SPQ2F was administered to 189 preclinical students of the University for Development Studies, School of Medicine and Health Sciences. Both descriptive and inferential statistics with Cronbach’s alpha test and factor analysis were done. Results: The mean age of the students was 22.69± 0.18years, 60.8% (n=115) were males and 42.3% (n=80) were in their second year of medical training. The students had higher mean deep approach scores (31.23±7.19) than that of surface approach scores (22.62±6.48). Findings of the R-SPQ2F gave credence to a solution of two-factors indicating deep and surface approaches accounting for 49.80% and 33.57%, respectively, of the variance. The scales of deep approach (Cronbach’s alpha, 0.80) and surface approach (Cronbach’s alpha, 0.76) and their subscales demonstrated an internal consistency that was good. The factorial validity was comparable to other studies. Conclusion: Our study confirms the construct validity and internal consistency of the R-SPQ2F for measuring approaches to learning in Ghanaian preclinical students. Deep approach was the most dominant learning approach among the students. The questionnaire can be used to measure students’ approaches to learning in Ghana and in other African countries. PMID:25112447

  3. {beta}-Decay Half-Lives of Very Neutron-Rich Kr to Tc Isotopes on the Boundary of the r-Process Path: An Indication of Fast r-Matter Flow

    SciTech Connect

    Nishimura, S.; Li, Z.; Watanabe, H.; Kurata-Nishimura, M.; Baba, H.; Doornenbal, P.; Isobe, T.; Sakurai, H.; Scheit, H.; Steppenbeck, D. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yoshinaga, K. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Sumikama, T.; Miyashita, Y.; Chiba, J.; Nakano, T.; Sugimoto, K.; Takano, S. [Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Tachibana, T. [4 Senior High School of Waseda University, Nerima Tokyo 177-0044 (Japan); Yamaguchi, K.; Odahara, A. [Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043 (Japan)

    2011-02-04

    The {beta}-decay half-lives of 38 neutron-rich isotopes from {sub 36}Kr to {sub 43}Tc have been measured; the half-lives of {sup 100}Kr, {sup 103-105}Sr, {sup 106-108}Y, {sup 108-110}Zr, {sup 111,112}Nb, {sup 112-115}Mo, and {sup 116,117}Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A{approx_equal}110 region. A revised model based on the second generation gross theory of {beta} decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted.

  4. ?-decay half-lives of very neutron-rich Kr to Tc isotopes on the boundary of the r-process path: an indication of fast r-matter flow.

    PubMed

    Nishimura, S; Li, Z; Watanabe, H; Yoshinaga, K; Sumikama, T; Tachibana, T; Yamaguchi, K; Kurata-Nishimura, M; Lorusso, G; Miyashita, Y; Odahara, A; Baba, H; Berryman, J S; Blasi, N; Bracco, A; Camera, F; Chiba, J; Doornenbal, P; Go, S; Hashimoto, T; Hayakawa, S; Hinke, C; Ideguchi, E; Isobe, T; Ito, Y; Jenkins, D G; Kawada, Y; Kobayashi, N; Kondo, Y; Krücken, R; Kubono, S; Nakano, T; Ong, H J; Ota, S; Podolyák, Zs; Sakurai, H; Scheit, H; Steiger, K; Steppenbeck, D; Sugimoto, K; Takano, S; Takashima, A; Tajiri, K; Teranishi, T; Wakabayashi, Y; Walker, P M; Wieland, O; Yamaguchi, H

    2011-02-01

    The ?-decay half-lives of 38 neutron-rich isotopes from (36)Kr to (43)Tc have been measured; the half-lives of (100)Kr, (103-105)Sr, (106-108)Y, (108-110)Zr, (111,112)Nb, (112-115)Mo, and (116,117)Tc are reported here. The results when compared with previous standard models indicate an overestimation in the predicted half-lives by a factor of 2 or more in the A?110 region. A revised model based on the second generation gross theory of ? decay better predicts the measured half-lives and suggests a more rapid flow of the rapid neutron-capture process (r-matter flow) through this region than previously predicted. PMID:21405387

  5. The Saccharomyces cerevisiae small GTPase, Gsp1p/Ran, is involved in 3' processing of 7S-to-5.8S rRNA and in degradation of the excised 5'-A0 fragment of 35S pre-rRNA, both of which are carried out by the exosome.

    PubMed

    Suzuki, N; Noguchi, E; Nakashima, N; Oki, M; Ohba, T; Tartakoff, A; Ohishi, M; Nishimoto, T

    2001-06-01

    Dis3p, a subunit of the exosome, interacts directly with Ran. To clarify the relationship between the exosome and the RanGTPase cycle, a series of temperature-sensitive Saccharomyces cerevisiae dis3 mutants were isolated and their 5.8S rRNA processing was compared with processing in strains with mutations in a S. cerevisiae Ran homologue, Gsp1p. In both dis3 and gsp1 mutants, 3' processing of 7S-to-5.8S rRNA was blocked at three identical sites in an allele-specific manner. In contrast, the 5' end of 5.8S rRNA was terminated normally in gsp1 and in dis3. Inhibition of 5.8S rRNA maturation in gsp1 was rescued by overexpression of nuclear exosome components Dis3p, Rrp4p, and Mtr4p, but not by a cytoplasmic exosome component, Ski2p. Furthermore, gsp1 and dis3 accumulated the 5'-A0 fragment of 35S pre-rRNA, which is also degraded by the exosome, and the level of 27S rRNA was reduced. Neither 5.8S rRNA intermediates nor 5'-A0 fragments were observed in mutants defective in the nucleocytoplasmic transport, indicating that Gsp1p regulates rRNA processing through Dis3p, independent of nucleocytoplasmic transport. PMID:11404326

  6. Electrochemical mineralization of the azo dye Acid Red 29 (Chromotrope 2R) by photoelectro-Fenton process.

    PubMed

    Almeida, Lucio Cesar; Garcia-Segura, Sergi; Arias, Conchita; Bocchi, Nerilso; Brillas, Enric

    2012-10-01

    The degradation of 100 mL of 244 mg L(-1) of the azo dye Acid Red 29 (AR29) has been studied by photoelectro-Fenton (PEF) using an undivided cell containing a boron-doped diamond (BDD) anode and an air-diffusion cathode under UVA irradiation. The effect of current density, concentration of catalytic Fe(2+) and pH on the process was examined. Quick decolorization and almost total mineralization were achieved due to the synergistic action of UVA light and oxidant hydroxyl radicals formed in the bulk from Fenton's reaction between electrogenerated H(2)O(2) at the cathode and added Fe(2+), as well as in the BDD surface from water oxidation. Optimum PEF conditions were found for 0.5-1.0 mM Fe(2+) and pH 3.0. Comparable electro-Fenton (EF) degradations in the dark yielded much poorer mineralization. The decay kinetics of AR29 followed a pseudo-first-order reaction with similar rate for EF and PEF. The azo dye disappeared much more rapidly than solution color, suggesting the formation of colored conjugated products with ?(max) similar to that of AR29. Ion-exclusion HPLC allowed the detection and quantification of tetrahydroxy-p-benzoquinone, oxalic, oxalacetic, tartronic, tartaric, oxamic, malonic and fumaric acids as intermediates in the PEF process. Oxalic acid, accumulated in large extent, was quickly destroyed by the efficient photolysis of Fe(III)-oxalate complexes with UVA light, whereas tartronic and oxamic acids were the most persistent byproducts because of the larger stability of their Fe(III) complexes. The mineralization of the initial N of the azo dye yielded NH(4)(+) ion and NO(3)(-) ion in smaller proportion. PMID:22854020

  7. Development and evaluation of wastewater-treatment processes at the H-Coal site in Catlettsburg, Kentucky. Volume I. Design summary and R and D task identification

    SciTech Connect

    Oswald, G.E.; Walker, J.F.; Brown, C.H.; Klein, J.A.; Genung, R.K.

    1982-04-01

    The design of a mobile process development unit (PDU) for coal conversion wastewater treatment and an overview of the associated R and D program for its use are described. The PDU consists of three modular units, which can be arranged in various sequences: carbon adsorption, ozonation, and reverse osmosis. Each of the units has a nominal flow capacity of approx. 60 mL of wastewater feed per second (1 gpm). The feed to the PDU will be taken as a sidestream from the existing wastewater treatment system at the H-Coal site. It will have been processed through oil-water separation and distillation stripping, and can be taken both before and after bio-oxidation by an activated sludge process. The ozonation system experimental parameters are ozone contact time, ozone treatment rate, column pressure, and pH. The system will be analyzed as a continuous stirred tank reactor. The calculated results will include ozone reaction, treatment, and absorption rates, contaminant depletion and reaction rates, ozone absorption and contaminant removal efficiencies, and ozone volumetric mass-transfer coefficients. The carbon adsorption system will be operated to obtain bed-depth-service-time (BDST) data for various carbons and operating conditions. The BDST method will yield the rate of carbon exhaustion as well as the minimum depth of carbon required to remove contaminants. Reverse osmosis will be studied to measure dissolved solids rejection efficiency, permeate recovery, and fouling characteristics of various commercially available membranes.

  8. From: Bull, S. & Kay, J. (2013). Open Learner Models as Drivers for Metacognitive Processes, in R. Azevedo & V. Aleven (eds), International Handbook of Metacognition and Learning Technologies, Springer, New York, 349-365.

    E-print Network

    Bull, Susan

    2013-01-01

    From: Bull, S. & Kay, J. (2013). Open Learner Models as Drivers for Metacognitive Processes, in R. Azevedo & V. Aleven (eds), International Handbook of Metacognition and Learning Technologies, Springer, New York, 349-365. Open Learner Models as Drivers for Metacognitive Processes Susan Bull1 and Judy Kay

  9. Fungal diversity in composting process of pig manure and mushroom cultural waste based on partial sequence of large subunit rRNA.

    PubMed

    Cho, Kye Man; Kwon, Eun Ju; Kim, Sung Kyum; Kambiranda, Devaiah M; Math, Reukaradhya K; Lee, Young Han; Kim, Jungho; Yun, Han Dae; Kim, Hoon

    2009-08-01

    Fungal diversity during composting was investigated by culture-independent rDNA sequence analysis. Composting was carried out with pig manure and mushroom cultural waste using a field-scale composter (Hazaka system), and samples were collected at various stages. Based on partial sequence analysis of large subunit (LSU) ribosomal RNA (rRNA) and sequence identity values, a total of 12 different fungal species were found at six sampling sites; Geotrichum sp., Debaryomyces hansenii, Monographella nivalis, Acremonium strictum, Acremonium alternatum, Cladosporium sphaerospermum, Myriangium durosai, Pleurotus eryngii, Malassezia globosa, Malassezia restricta, Rhodotorula glutinis, and Fusarium sporotrichioides. Geotrichum sp. of the class Saccharomycetes was the most predominant fungal species throughout the composting process (185 out of a total of 236 identified clones, or 78.4%), followed by Acremonium strictum (7.6%), Monographella nivalis (5.1%), and Pleurotus eryngii (3.8%). The prevalence of Geotrichum sp. was the lowest (61.1%) at the beginning of composting, and then gradually increased to 92.5% after 10 days of composting. PMID:19734710

  10. Left DLPFC rTMS stimulation reduced the anxiety bias effect or how to restore the positive memory processing in high-anxiety subjects.

    PubMed

    Balconi, Michela; Ferrari, Chiara

    2013-10-30

    In the present research we explored the role of the dorsolateral prefrontal cortex (DLPFC) in memory retrieval process of positive vs. negative emotional stimulus, as a function of the anxiety levels. Anxiety behavior showed a consistent attentional bias toward negative and aversive memories, induced by a right frontal cortical superiority. This effect was analyzed by using a rTMS paradigm that induced a cortical activation of the left DLPFC. Subjects, who were divided in two different groups depending on their anxiety level (high/low-anxiety, State-Trait-Anxiety-Inventory, STAI), were required to perform a task consisting of two experimental phases: an encoding-phase, where some lists composed by positive and negative emotional words were presented to the subjects; and a retrieval-phase, where the old stimuli and new stimuli were presented for a recognition performance. We found that the rTMS stimulation affects the memory retrieval of emotional material. High-anxiety subjects benefit in greater measure from the left DLPFC stimulation with a reduced negative bias. This result suggested that left DLPFC activation favors the memory retrieval of positive emotional information and might limit the "unbalance effect" induced by a right hemispheric superiority at a high level of anxiety. The potentiality of TMS for anxiety behavior modulation was also discussed. PMID:23601793

  11. Yeast polypeptide exit tunnel ribosomal proteins L17, L35 and L37 are necessary to recruit late-assembling factors required for 27SB pre-rRNA processing

    PubMed Central

    Gamalinda, Michael; Jakovljevic, Jelena; Babiano, Reyes; Talkish, Jason; de la Cruz, Jesús; Woolford, John L.

    2013-01-01

    Ribosome synthesis involves the coordinated folding and processing of pre-rRNAs with assembly of ribosomal proteins. In eukaryotes, these events are facilitated by trans-acting factors that propel ribosome maturation from the nucleolus to the cytoplasm. However, there is a gap in understanding how ribosomal proteins configure pre-ribosomes in vivo to enable processing to occur. Here, we have examined the role of adjacent yeast r-proteins L17, L35 and L37 in folding and processing of pre-rRNAs, and binding of other proteins within assembling ribosomes. These three essential ribosomal proteins, which surround the polypeptide exit tunnel, are required for 60S subunit formation as a consequence of their role in removal of the ITS2 spacer from 27SB pre-rRNA. L17-, L35- and L37-depleted cells exhibit turnover of aberrant pre-60S assembly intermediates. Although the structure of ITS2 does not appear to be grossly affected in their absence, these three ribosomal proteins are necessary for efficient recruitment of factors required for 27SB pre-rRNA processing, namely, Nsa2 and Nog2, which associate with pre-60S ribosomal particles containing 27SB pre-rRNAs. Altogether, these data support that L17, L35 and L37 are specifically required for a recruiting step immediately preceding removal of ITS2. PMID:23268442

  12. P h y s i c a l O c e a n o g r a p h y D i v i s i o n Salinity Processes in the Upper Ocean Regional Study (SPURS)

    E-print Network

    P h y s i c a l O c e a n o g r a p h y D i v i s i o n Salinity Processes in the Upper Ocean in the global water cycle. A series of cruises is exploring the salinity maximum region in the Atlantic Ocean the role of large-scale process in driving the upper ocean salinity processes. NOAA/AOML is currently

  13. Introducing the Fission-Fusion Reaction Process: Using a Laser-Accelerated Th Beam to produce Neutron-Rich Nuclei towards the N=126 Waiting Point of the r Process

    E-print Network

    D. Habs; P. G. Thirolf; M. Gross; K. Allinger; J. Bin; A. Henig; D. Kiefer; W. Ma; J. Schreiber

    2010-09-10

    We propose to produce neutron-rich nuclei in the range of the astrophysical r-process around the waiting point N=126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a CH2 layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via the 'hole-boring' mode of laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of 232Th with solid-state density can be generated from a Th layer, placed beneath a deuterated polyethylene foil, both forming the production target. Th ions laser-accelerated to about 7 MeV/u will pass through a thin CH2 layer placed in front of a thicker second Th foil closely behind the production target and disintegrate into light and heavy fission fragments. In addition, light ions (d,C) from the CD2 production target will be accelerated as well to about 7 MeV/u, inducing the fission process of 232Th also in the second Th layer. The laser-accelerated ion bunches with solid-state density, which are about 10^14 times more dense than classically accelerated ion bunches, allow for a high probability that generated fission products can fuse again. In contrast to classical radioactive beam facilities, where intense but low-density radioactive beams are merged with stable targets, the novel fission-fusion process draws on the fusion between neutron-rich, short-lived, light fission fragments both from beam and target. The high ion beam density may lead to a strong collective modification of the stopping power in the target, leading to significant range enhancement. Using a high-intensity laser as envisaged for the ELI-Nuclear Physics project in Bucharest (ELI-NP), estimates promise a fusion yield of about 10^3 ions per laser pulse in the mass range of A=180-190, thus enabling to approach the r-process waiting point at N=126.

  14. Self-association of Trimethylguanosine Synthase Tgs1 is required for efficient snRNA/snoRNA trimethylation and pre-rRNA processing

    PubMed Central

    Boon, Kum-Loong; Pearson, Michael David; Koš, Martin

    2015-01-01

    Trimethylguanosine Synthase catalyses transfer of two methyl groups to the m7G cap of RNA polymerase II transcribed snRNAs, snoRNAs, and telomerase RNA TLC1 to form a 2,2,7-trimethylguanosine cap. While in vitro studies indicate that Tgs1 functions as a monomer and the dimethylation of m7G caps is not a processive reaction, partially methylated sn(o)RNAs are typically not detected in living cells. Here we show that both yeast and human Tgs1p possess a conserved self-association property located at the N-terminus. A disruption of Tgs1 self-association led to a strong reduction of sn(o)RNA trimethylation as well as reduced nucleolar enrichment of Tgs1. Self-association of Tgs1p and its catalytic activity were also prerequisite to bypass the requirement for its accessory factor Swm2p for efficient pre-rRNA processing and snRNA trimethylation. The ability to self-associate might enable Tgs1 to efficiently dimethylate the caps of the targeted RNAs in vivo. PMID:26074133

  15. Cyclodextrin glycosyltransferase production by free cells of Bacillus circulans DF 9R in batch fermentation and by immobilized cells in a semi-continuous process.

    PubMed

    Costa, Hernán; Gastón, Jorgelina Rodríguez; Lara, Julia; Martinez, Camila Ortiz; Moriwaki, Cristiane; Matioli, Graciette; Ferrarotti, Susana Alicia

    2015-06-01

    Cyclodextrin glycosyltransferase (CGTase) catalyzes starch conversion into cyclic or linear oligosaccharides, important industrial products for the complexation of non-polar substances. In this work, conditions to increase CGTase production from Bacillus circulans strain DF 9R were optimized by two systems. On one hand, free cells were grown in batch fermentation experiments to optimize aeration and pH. The highest activity (1.47 ± 0.21 U ml(-1)) was achieved after 48 h of growth, aeration of 1.5 vvm and pH regulated to 7.6. On the other hand, bacterial cells were immobilized on loofa and synthetic sponge, and used for CGTase production in a semi-continuous process. An initial biomass of 30 mg of lyophilized cells and an immobilization time of 24 h with loofa or synthetic sponge were enough to achieve increased production of CGTase: 0.91 ± 0.10 and 0.95 ± 0.11 U ml(-1), respectively. Sponges with immobilized bacteria were reused in 12 successive cycles. Besides, in our conditions, CGTase was not adsorbed onto the supports used for immobilization, which ensured the total recovery of the enzyme from the culture medium. The two CGTase production processes studied showed similar productivity and could be potentially scaled up. PMID:25561345

  16. A precision measurement of the Z{sup 0} lineshape parameters for the process Z{sup 0} {r_arrow} {tau}{sup +}{tau}{sup {minus}}

    SciTech Connect

    Lahmann, R.

    1996-12-31

    In this dissertation, a measurement of the partial decay width of the process Z{sup 0} {r_arrow} {tau}{sup +}{tau}{sup {minus}} using data collected during 1993 and 1994 at the OPAL detector at CERN is described. The cross sections of this process at three center-of-mass energies near the Z{sup 0} resonance were determined, and from a fit to those cross sections, the mass of the Z{sup 0}, its total decay width and its partial decay width into {tau}{sup +}{tau}{sup {minus}} final states were determined as M{sub Z} = 91.183 {+-} 0.020 GeV, {Lambda}{sub tot} = 2.514 {+-} 0.018 GeV and {Lambda}{sub {tau}{tau}} = 84.54 {+-} 0.59 MeV. Using published results for M{sub Z}, and {Lambda}{sub tot} with higher accuracy, a value for the partial decay width of {Lambda}{sub {tau}{tau}} = 84.02 {+-} 0.20 MeV was obtained. Further using published results for the decay width of the Z{sup 0} into quark pair final states, the invisible decay width of the Z{sup 0} was determined as {Lambda}{sub inv} = 496.9 {+-} 4.1 MeV, and the number of neutrino generations was determined as N{sub {nu}} = 2.974 {+-} 0.025(exp) {+-} 0.007 (m{sub top}, M{sub Higgs}). All results were found to be in good agreement with the Standard Model predictions and were consistent with the assumption of lepton universality within the Standard Model framework.

  17. Interpretation of Fracture Toughness and R-Curve Behavior by Direct Observation of Microfracture Process in Ti-Based Dendrite-Containing Amorphous Alloys

    NASA Astrophysics Data System (ADS)

    Jeon, Changwoo; Kim, Choongnyun Paul; Kim, Hyoung Seop; Lee, Sunghak

    2015-04-01

    Fracture properties of Ti-based amorphous alloys containing ductile ? dendrites were explained by directly observing microfracture processes. Three Ti-based amorphous alloys were fabricated by adding Ti, Zr, V, Ni, Al, and Be into a Ti-6Al-4V alloy by a vacuum arc melting method. The effective sizes of dendrites varied from 63 to 104 ?m, while their volume fractions were almost constant within the range from 74 to 76 pct. The observation of the microfracture of the alloy containing coarse dendrites revealed that a microcrack initiated at the amorphous matrix of the notch tip and propagated along the amorphous matrix. In the alloy containing fine dendrites, the crack propagation was frequently blocked by dendrites, and many deformation bands were formed near or in front of the propagating crack, thereby resulting in a zig-zag fracture path. Crack initiation toughness was almost the same at 35 to 36 MPa?m within error ranges in the three alloys because it was heavily affected by the stress applied to the specimen at the time of crack initiation at the crack tip as well as strength levels of the alloys. According to the R-curve behavior, however, the best overall fracture properties in the alloy containing fine dendrites were explained by mechanisms of blocking of the crack growth and crack blunting and deformation band formation at dendrites.

  18. P h y s i c a l O c e a n o g r a p h y D i v i s i o n Salinity Processes in the Upper Ocean Regional Study (SPURS)

    E-print Network

    P h y s i c a l O c e a n o g r a p h y D i v i s i o n Salinity Processes in the Upper Ocean The Salinity Processes in the Upper Ocean Regional Study (SPURS) research effort is actively addressing the essential role of the ocean in the global water cycle. A series of cruises is exploring the salinity maximum

  19. The putative NTPase Fap7 mediates cytoplasmic 20S pre-rRNA processing through a direct interaction with Rps14.

    PubMed

    Granneman, Sander; Nandineni, Madhusudan R; Baserga, Susan J

    2005-12-01

    One of the proteins identified as being involved in ribosome biogenesis by high-throughput studies, a putative P-loop-type kinase termed Fap7 (YDL166c), was shown to be required for the conversion of 20S pre-rRNA to 18S rRNA. However, the mechanism underlying this function has remained unclear. Here we demonstrate that Fap7 is strictly required for cleavage of the 20S pre-rRNA at site D in the cytoplasm. Genetic depletion of Fap7 causes accumulation of only the 20S pre-rRNA, which could be detected not only in 43S preribosomes but also in 80S-sized complexes. Fap7 is not a structural component of 43S preribosomes but likely transiently interacts with them by directly binding to Rps14, a ribosomal protein that is found near the 3' end of the 18S rRNA. Consistent with an NTPase activity, conserved residues predicted to be required for nucleoside triphosphate (NTP) hydrolysis are essential for Fap7 function in vivo. We propose that Fap7 mediates cleavage of the 20S pre-rRNA at site D by directly interacting with Rps14 and speculate that it is an enzyme that functions as an NTP-dependent molecular switch in 18S rRNA maturation. PMID:16287850

  20. R fluids

    E-print Network

    R. Caimmi

    2007-10-20

    A theory of collisionless fluids is developed in a unified picture, where nonrotating figures with anisotropic random velocity component distributions and rotating figures with isotropic random velocity component distributions, make adjoints configurations to the same system. R fluids are defined and mean and rms angular velocities and mean and rms tangential velocity components are expressed, by weighting on the moment of inertia and the mass, respectively. The definition of figure rotation is extended to R fluids. The generalized tensor virial equations are formulated for R fluids and further attention is devoted to axisymmetric configurations where, for selected coordinate axes, a variation in figure rotation has to be counterbalanced by a variation in anisotropy excess and vice versa. A microscopical analysis of systematic and random motions is performed under a few general hypotheses, by reversing the sign of tangential or axial velocity components of an assigned fraction of particles, leaving the distribution function and other parameters unchanged (Meza 2002). The application of the reversion process to tangential velocity components, implies the conversion of random motion rotation kinetic energy into systematic motion rotation kinetic energy. The application of the reversion process to axial velocity components, implies the conversion of random motion translation kinetic energy into systematic motion translation kinetic energy, and the loss related to a change of reference frame is expressed in terms of systematic (imaginary) motion rotation kinetic energy. A procedure is sketched for deriving the spin parameter distribution (including imaginary rotation) from a sample of observed or simulated large-scale collisionless fluids i.e. galaxies and galaxy clusters.

  1. Use of RUse of R--Curves in Characterization of FractureCurves in Characterization of Fracture Process in CementProcess in Cement--Based MaterialsBased Materials

    E-print Network

    Mobasher, Barzin

    of Composites? Inverse Problem: Parameter optimization of stress-crack width response. Input: stress crack widthToughening Due to Fiber Bridging Fiber Debonding and pullout Closing Pressure Crack face stiffness Stress-load deformation Output: R-Curve Response How Do We Estimate Bridging Tractions From The Observed R- Curve Behavior

  2. Overexpression of interleukin-8 receptor 2 (IL-8R2) indicates better prognosis in esophageal adenocarcinoma and squamous cell carcinoma procession.

    PubMed

    Liang, Bing; Zhao, Hui; Che, Jian-Bo; Wang, Hao-Jie; Shi, Gong-Ning

    2014-08-01

    Researches have showed that interleukin family or receptors play a role in many human tumor progressions including esophageal carcinoma. In this study, we examined the expression of interleukin-8 receptor 2 (IL-8R2) and analyze the relationship between it and esophageal carcinoma clinical characteristics. IL-8R2 protein expression was confirmed by immunohistochemistry and immunofluorescence arrays and was analyzed further via Western blot and qRT-PCR analysis in frozen tissues. The correlation between their expression levels and clinical characteristics were evaluated by Mann-Whitney and Kruskal-Wallis test. Via Kaplan-Meier plots and Cox proportional hazard models, overall survival (OS) was analyzed. Compared with normal esophageal tissue, IL-8R2 protein was overexpressed significantly in esophageal cancer (p < 0.05) and was observed both in cytoplasm and nuclear. The lower expression of IL-8R2 protein was observed with higher p staging of esophageal cancer, and the significant association between them was confirmed (p = 0.000), and in advanced p T stage, the similar result was obtained (p = 0.015); however, compared with lymph node metastasis-negative group, it is no significant difference in positive group (p = 0.152). In a Kaplan-Meier analysis, compared with IL-8R2 low expression, IL-8R2 high expression identified a group of patients with the longest OS. Cox proportional hazard models revealed that IL-8R2 predicted long time to OS. The higher expression of IL-8R2 was found in early esophageal carcinoma, which may indicate that IL-8R2 plays an important role and is better prognostic factor in esophageal cancer development. PMID:24972913

  3. An improvement of surface smoothness and lattice match of CeO 2 buffer layers on R-sapphire processed by MOCVD

    Microsoft Academic Search

    I. E. Graboy; N. V. Markov; V. V. Maleev; A. R. Kaul; S. N. Polyakov; V. L. Svetchnikov; H. W. Zandbergen; K.-H. Dahmen

    1997-01-01

    Epitaxial thin films of CeO2 and Ce1?xRxO2? y (R=Y, Nd; x=0–0.32) on R-sapphire were prepared by band flash evaporation MOCVD. It was demonstrated that the smoothness of the films can be improved by a decrease of deposition rate and by post deposition annealing at 1000 °C. The lattice match of buffer layers with R-Al2O3 and YBa2Cu3O7?? was improved by doping

  4. Concentration and pre-purification with ultrafiltration of a R-phycoerythrin solution extracted from macro-algae Grateloupia turuturu: Process definition and up-scaling

    Microsoft Academic Search

    Claire Denis; Anthony Massé; Joël Fleurence; Pascal Jaouen

    2009-01-01

    Grateloupia turuturu, an invasive red macro-alga, represents an unexploited important biomass. A potential use of this seaweed is the production of valuable molecules, such as R-phycoerythrin. Nevertheless, after R-phycoerythrin extraction, protein extract has to be concentrated and pre-purified, which is generally expensive and requires many stages. The present study deals with the feasibility to implement a single stage of ultrafiltration

  5. Fungal Diversity in Composting Process of Pig Manure and Mushroom Cultural Waste Based on Partial Sequence of Large Subunit rRNA

    Microsoft Academic Search

    Hoon Kim; Sung Kyum Kim; Devaiah M Kambiranda; Young Han Lee; Jungho Kim; Han Dae Yun

    2009-01-01

    Fungal diversity during composting was investigated by culture-independent rDNA sequence analysis. Composting was carried out with pig manure and mushroom cultural waste using a field-scale composter (Hazaka system), and samples were collected at various stages. Based on partial sequence analysis of large subunit (LSU) ribosomal RNA (rRNA) and sequence identity values, a total of 12 different fungal species were found

  6. C-C and C-Heteroatom Bond Dissociation Energies in CH3R?C(OH)2: Energetics for Photocatalytic Processes of Organic Diolates on TiO2 Surfaces

    SciTech Connect

    Wang, Tsang-Hsiu; Dixon, David A.; Henderson, Michael A.

    2010-08-26

    The bond energies of a range of gem-diols, CH3R?C(OH)2 (R? = H, F, Cl, Br, CN, NO2, CF3, CH3CH2, CH3CH2CH2, CH3CH2CH2CH2, ((CH3)2)CH, (CH3)3C, ((CH3)2CH)CH2, (CH3CH2)(CH3)CH, C6H5 (CH3CH2)(CH3)CH) which serve as models for binding to a surface have been studied with density functional theory (DFT) and the molecular orbital G3(MP2) methods to provide thermodynamic data for the analysis of the photochemistry of ketones on TiO2. The ultraviolet (UV) photon-induced photodecomposition of adsorbed acetone and 3,3-dimethylbutanone on the rutile TiO2 (110) surface have been investigated with photon stimulated desorption (PSD) and temperature programmed desorption (TPD). The C-CH3 and C-C(R?) bond dissociation energies in CH3R?C(OH)2 were predicted, and our calculated bond dissociation energies are in excellent agreement with the available experimental values. We used a series of isodemic reactions to provide small corrections to the various bond dissociation energies. The calculated bond dissociation energies are in agreement with the observed photodissociation processes except for R? = CF3, suggesting that these processes are under thermodynamic control. For R? = CF3, reaction dynamics also play a role in determining the photodissociation mechanism. The gas phase Brönsted acidities of the gem-diols were calculated. For three molecules, R? = Cl, Br, and NO2, loss of a proton leads to the formation of a complex of acetic acid with the anion Cl-, Br-, and NO2-. The acidities of these three species are very high with the former two having acidities comparable to CF3SO3H. The ketones (R?RC(=O)) are weak Lewis acids except where addition of OH- leads to the dissociation of the complex to form an anion bonded to acetic acid, R' = NO2, Cl, and Br. The X-C bond dissociation energies for a number of X-CO2- species were calculated and these should be useful in correlating with photochemical reactivity studies.

  7. Conformational changes in the 16S rRNA induced by ribosomal proteins in the assembly process of the 30S E. coli subunit

    SciTech Connect

    Mandiyan, V.; Wall, J.S.; Hainfeld, J.F.; Boublik, M.

    1987-05-01

    Conformational changes induced in the 16S rRNA by interactions with ribosomal proteins S4, S8, S15, S17, and S20, were monitored by scanning transmission electron microscopy (STEM) and CD spectroscopy with the aim to clarify the mechanism of rRNA folding during the ribosome assembly. The RNA-protein complexes were prepared by the standard reconstitution procedure and were dialyzed against 60mM KCl, 2mM Mg(OAc)/sub 2/, 10mM Hepes-KOH, pH 7.5. In most combinations the protein binding induced folding of the 16S rRNA into more compact forms evident from the values of radii of gyration, calculated from the mass distribution within the RNA-protein complexes. The most significant conformational changes were observed in the complex of 16S rRNA with proteins S4, S8 and S15. However, even these particles did not show structural similarity to the complete 30S subunits. The CD spectra and melting profiles of the 16S RNA-protein complexes imply a similar net content of ordered secondary structure of 16S RNA but differences in its distribution. These results indicate that interactions of 16S rRNA with five ribosomal proteins involved in the initial steps of ribosome subunit assembly induce conformational changes but not to the same extent as in the complete 30S subunit.

  8. Effective Reuse via Modeling, Managing, and Searching of Business Process Nanjangud C. Narendra, Karthikeyan Ponnalagu, G.R. Gangadharan, Hong-Linh Truong, Schahram Dustdar,

    E-print Network

    Dustdar, Schahram

    Effective Reuse via Modeling, Managing, and Searching of Business Process Assets Nanjangud C not been addressed so far. First, there is a lack of a mechanism for the representation of business process, there is a lack of a technique to determine the extent to which a business process asset could be customized

  9. The Facilitation of Change in Elementary and Secondary Schools--Similarities, Differences, and Interactions about the Process. R&D Report 3218.

    ERIC Educational Resources Information Center

    Stiegelbauer, Suzanne M.; And Others

    The process of change in elementary and secondary schools has been the topic of several major studies conducted during the past 15 years. To date, however, information about the change process in different school settings has not been considered comparatively. This document examines and compares the process of change and the role of the change…

  10. Improved Laboratory Transition Probabilities for Ce II, Application to the Cerium Abundances of the Sun and Five r-process Rich, Metal-Poor Stars, and Rare Earth Lab Data

    E-print Network

    Lawler, J E; Cowan, J J; Ivans, I I; Hartog, E A Den

    2009-01-01

    Recent radiative lifetime measurements accurate to +/- 5% using laser-induced fluorescence (LIF) on 43 even-parity and 15 odd-parity levels of Ce II have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 921 lines of Ce II. This improved laboratory data set has been used to determine a new solar photospheric Ce abundance, log epsilon = 1.61 +/- 0.01 (sigma = 0.06 from 45 lines), a value in excellent agreement with the recommended meteoritic abundance, log epsilon = 1.61 +/- 0.02. Revised Ce abundances have also been derived for the r-process-rich metal-poor giant stars BD+17 3248, CS 22892-052, CS 31082-001, HD 115444 and HD 221170. Between 26 and 40 lines were used for determining the Ce abundance in these five stars, yielding a small statistical uncertainty of 0.01 dex similar to the Solar result. The relative abundances in the metal-poor stars of Ce and Eu, a nearly pure r-process element in the Sun, matches r-process ...

  11. E.R.I.E. and Process Education (With Reference to M:ACOS and SRA-SSLU). A Summary Statement.

    ERIC Educational Resources Information Center

    Ripple, Richard E.

    A summary position statement of the Eastern Regional Institute for Education presents its mission of changing elementary education toward the direction of process education. The first of three basic parts reviews the three completed chapters of a monograph, "What is Process Education? An Emerging Rational Position," in terms of a definition of…

  12. Tracking the interactions of rRNA processing proteins during nucleolar assembly in living Nicole Angelier,* Marc Tramier, Emilie Louvet,* Mat Coppey-Moisan, Tula M. Savino,*

    E-print Network

    Paris-Sud XI, Université de

    Reorganization of the nuclear machinery after mitosis is a fundamental but poorly understood process. Here we condense at the beginning of mitosis and re-assembled at the end of mitosis. During mitosis functions after mitosis, we chose to investigate the assembly of the nucleolar processing machinery in real

  13. Nile: A Query Processing Engine for Data Streams W. G. Aref, A. K. Elmagarmid, M. H. Ali, A. C. Catlin, M. G. Elfeky, M. Eltabak, T. Ghanem, R.

    E-print Network

    Ilyas, Ihab Francis

    Nile: A Query Processing Engine for Data Streams W. G. Aref, A. K. Elmagarmid, M. H. Ali, A. C that allows for the processing of continuous and snap-shot queries over data streams. Specifically of an object-relational database management system to support data streams. Our approach is motivated

  14. MOTIONDEFINED FORM PROCESSING IN HUMAN VISION: A fMRI STUDY, S. Niyogi 1 , J. Reppas 2* , A. Dale 2 , and R. Tootell 2 . MIT Perceptual Science Section,

    E-print Network

    MOTION­DEFINED FORM PROCESSING IN HUMAN VISION: A fMRI STUDY, S. Niyogi 1 , J. Reppas 2* , A. Dale, Charlestown, MA. 2 Purpose. We have studied the processing of motion­defined form in the human brain using condition of uniform motion. The time­averaged motion statistics were identical in the two condi­ tions

  15. CLEAN-ROOM AND C02 -LASER PROCESSING OF ULTRA HIGH-PURITY AL2 0 3 P.A. Morris , R.H. French*, R.L. Coble*, F.N. Tebbe*, U. Chowdhry**

    E-print Network

    Rollins, Andrew M.

    , DE 19898 ABSTRACT Clean-room powder processing, furnace firing, and C02 -laser heating techniques Analyses# (PPM WEIGHT)t 1 2 3 4 5 6 7 8 AL(OH) 3 DIE- DIE+ISO- FURNACE FURNACE FURNACE LASER LASER POWDER

  16. Processing of a composite large subunit rRNA. Studies with chlamydomonas mutants deficient in maturation of the 23s-like rrna.

    PubMed Central

    Holloway, S P; Herrin, D L

    1998-01-01

    (Cr.LSU). Little is known of the cis and trans requirements or of the processing pathway for this essential RNA. Previous work showed that the ribosome-deficient ac20 mutant overaccumulates an unspliced large subunit (LSU) RNA, suggesting that it might be a splicing mutant. To elucidate the molecular basis of the ac20 phenotype, a detailed analysis of the rrn transcripts in ac20 and wild-type cells was performed. The results indicate that processing of the ITSs, particularly ITS-1, is inefficient in ac20 and that ITS processing occurs after splicing. Deletion of the Cr.LSU intron from ac20 also did not alleviate the mutant phenotype. Thus, the primary defect in ac20 is not splicing but most likely is associated with ITS processing. A splicing deficiency was studied by transforming wild-type cells with rrnL genes containing point mutations in the intron core. Heteroplasmic transformants were obtained in most cases, except for P4 helix mutants; these strains grew slowly, were light sensitive, and had an RNA profile indicative of inefficient splicing. Transcript analysis in the P4 mutants also indicated that ITS processing can occur on an unspliced precursor, although with reduced efficiency. These latter results indicate that although there is not an absolutely required order for LSU processing, there does seem to be a preferred order that results in efficient processing in vivo. PMID:9668137

  17. Ultrasonic waves : a tool for gelation process measurements J.-C. Bacri, J.-M. Courdille, J. Dumas and R. Rajaonarison

    E-print Network

    Boyer, Edmond

    L-369 Ultrasonic waves : a tool for gelation process measurements J.-C. Bacri, J.-M. Courdille, J, of a polymeric melt in course of gelation, and its measurement is a sensitive and non destructive method for monitoring the sol-gel transition : the gelation point is accurately determined and the growing of the gel

  18. Test Review: R. W. Keith "SCAN-3 for Adolescents and Adults--Tests for Auditory Processing Disorders". San Antonio, TX: Pearson, 2009

    ERIC Educational Resources Information Center

    Lovett, Benjamin J.; Johnson, Theodore L.

    2010-01-01

    The SCAN-3 is a battery of tasks used for the screening and diagnosis of auditory processing disorder. It is available in two versions, one for children (the SCAN-3: C) and one for adolescents and adults (the SCAN-3: A); the latter version of the SCAN-3 is reviewed in this article, although it is very similar to the child version. The primary…

  19. R. Bestak et al. (Eds.): NETWORKING 2012, Part II, LNCS 7290, pp. 316330, 2012. IFIP International Federation for Information Processing 2012

    E-print Network

    Stojmenovic, Ivan

    ] and Wavelength Division Multiplexing networks [3]. A dominating set (DS) of a given graph G is a set of nodes International Federation for Information Processing 2012 Maximizing Lifetime of Connected-Dominating-Set Sad, Serbia Abstract. Connected-dominating-set (CDS) is a representative technique for constructing

  20. Process for functionalizing alkanes

    DOEpatents

    Bergman, R.G.; Janowicz, A.H.; Periana, R.A.

    1988-05-24

    Process for functionalizing saturated hydrocarbons comprises: (a) reacting said saturated hydrocarbons of the formula: R[sub 1]H wherein H represents a hydrogen atom; and R[sub 1] represents a saturated hydrocarbon radical, with a metal complex of the formula: CpRh[P(R[sub 2])[sub 3

  1. The Earth's magnetosphere is 165 R(sub E) long: Self-consistent currents, convection, magnetospheric structure, and processes for northward interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Fedder, J. A.; Lyon, J. G.

    1995-01-01

    The subject of this paper is a self-consistent, magnetohydrodynamic numerical realization for the Earth's magnetosphere which is in a quasi-steady dynamic equilibrium for a due northward interplanetary magnetic field (IMF). Although a few hours of steady northward IMF are required for this asymptotic state to be set up, it should still be of considerable theoretical interest because it constitutes a 'ground state' for the solar wind-magnetosphere interaction. Moreover, particular features of this ground state magnetosphere should be observable even under less extreme solar wind conditions. Certain characteristics of this magnetosphere, namely, NBZ Birkeland currents, four-cell ionospheric convection, a relatively weak cross-polar potential, and a prominent flow boundary layer, are widely expected. Other characteristics, such as no open tail lobes, no Earth-connected magnetic flux beyond 155 R(sub E) downstream, magnetic merging in a closed topology at the cusps, and a 'tadpole' shaped magnetospheric boundary, might not be expected. In this paper, we will present the evidence for this unusual but interesting magnetospheric equilibrium. We will also discuss our present understanding of this singular state.

  2. Development of a Validated LC Method for Separation of Process-Related Impurities Including the R-enantiomer of S-Pramipexole on Polysaccharide Chiral Stationary Phases.

    PubMed

    Ramisetti, Nageswara Rao; Kuntamukkala, Ramakrishna; Arnipalli, Manikanta Swamy

    2015-07-01

    Despite the availability of a few methods for individual separation of S-pramipexole from its process-related impurities, no common liquid chromatography (LC) method is reported so far in the literature. The present article describes the development of a single-run LC method for simultaneous determination of S-pramipexole and its enantiomeric and process-related impurities on a Chiralpak AD-H (150 x 4.6 mm, 5?m) column using n-hexane/ethanol/n-butylamine (75:25:0.1 v/v/v) as a mobile phase in an isocratic mode of elution at a flow rate of 1.2 ml/min at 30°C. The chromatographic eluents were monitored at a wavelength of 260 nm using a photodiode array detector. Excellent enantioseparation with good resolutions (Rs ? 2.88) and peak shapes (As ? 1.21) for all analytes was achieved. The proposed method was validated according to International Conference Harmonization (ICH) guidelines in terms of accuracy, precision, sensitivity, and linearity. Limits of quantification of impurities (0.25-0.55 ?g/ml) indicate the highest sensitivity achievable by the proposed method. The method has an advantage of selectivity and suitability for routine determination of not only chiral impurity but also all possible related substances in active pharmaceutical ingredients of S-pramipexole. Chirality 27:430-435, 2015. © 2015 Wiley Periodicals, Inc. PMID:25966024

  3. Dynamic mixing processes in spin triads of "breathing crystals" Cu(hfac)(2)L(R): a multifrequency EPR study at 34, 122 and 244 GHz.

    PubMed

    Fedin, Matvey V; Veber, Sergey L; Romanenko, Galina V; Ovcharenko, Victor I; Sagdeev, Renad Z; Klihm, Gudrun; Reijerse, Edward; Lubitz, Wolfgang; Bagryanskaya, Elena G

    2009-08-21

    Spin triads of copper(ii) with two nitroxides are responsible for the magnetic anomalies in a new family of molecular-magnetic compounds called "breathing crystals". We have shown previously that electron paramagnetic resonance (EPR) spectroscopy allows one to investigate the peculiarities of these systems and obtain valuable information on exchange interactions governing the magnetic anomalies. One of the key processes revealed is the dynamic mixing between different spin multiplets that leads to a coalescence of individual EPR lines at high temperatures. The rates of the mixing were found to be fast at EPR frequencies between 9 and 94 GHz. In the present work, we expose the spin triads to higher microwave frequencies of up to 244 GHz in order to reach the conditions of intermediate or slow mixing rates. Three representatives of the family of breathing crystals have been studied. Based on the simulations of EPR data at 34, 122 and 244 GHz, the rates of the mixing processes have been estimated and conclusions on their character and temperature dependence have been drawn. The insights from high-field EPR clarify previously obtained results and aid in the further development of EPR approaches for studying these and similar systems. It is suggested that the static and dynamic Jahn-Teller effects may play an important role in the mechanisms governing the observed spin exchange effects. PMID:19639139

  4. Particles, processes and materials for modern energy needs: Development of a DOE-EPSCoR project in Puerto Rico. Final report for September 30, 1997 - August 31, 2000

    SciTech Connect

    Weiner, Brad R.

    2000-09-29

    Twenty-eight (28) faculty researchers focused on High Energy Particle Physics, Novel Thin Film Materials for Optoelectronic Applications, and Catalytic Processes for Energy Sources and Environmental Detoxification to address problems cited as priorities by the DOE and local agencies. The High Energy Particle Physics cluster has DOE-competitive funding, and the number of cluster investigators who have competitive mainstream funding has increased from 2 to 13 since the inception of the program. In this reporting period, 8 postdoctorals, 38 graduate studnets, and 23 undergraduates were involved in DOE projects, and 191 publications and 238 presentations were generated. The UPR-Arecibo Integrated Science Multi-Use Laboratory provided workshops and other activities that directly impacted 360 teachers and 600 students and indirectly impacted over 25,000 through the enhancement of teachers' skills and knowledge.

  5. A direct interaction between the Utp6 half-a-tetratricopeptide repeat domain and a specific peptide in Utp21 is essential for efficient pre-rRNA processing.

    PubMed

    Champion, Erica A; Lane, Bennett H; Jackrel, Meredith E; Regan, Lynne; Baserga, Susan J

    2008-11-01

    The small subunit (SSU) processome is a ribosome biogenesis intermediate that assembles from its subcomplexes onto the pre-18S rRNA with yet unknown order and structure. Here, we investigate the architecture of the UtpB subcomplex of the SSU processome, focusing on the interaction between the half-a-tetratricopeptide repeat (HAT) domain of Utp6 and a specific peptide in Utp21. We present a comprehensive map of the interactions within the UtpB subcomplex and further show that the N-terminal domain of Utp6 interacts with Utp18 while the HAT domain interacts with Utp21. Using a panel of point and deletion mutants of Utp6, we show that an intact HAT domain is essential for efficient pre-rRNA processing and cell growth. Further investigation of the Utp6-Utp21 interaction using both genetic and biophysical methods shows that the HAT domain binds a specific peptide ligand in Utp21, the first example of a HAT domain peptide ligand, with a dissociation constant of 10 muM. PMID:18725399

  6. GL(m, 2) acting on R(r, m)\\/R(r-1, m)

    Microsoft Academic Search

    Xiang-dong Hou

    1996-01-01

    Let R(r, m) be the rth order Reed-Muller code of length 2m, and let R(r,m)\\/R(r ? 1,m) be the set of all cosets of R(r ? 1,m) in R(r,m). The general linear group GL(m,2) acts on R(r,m)\\/R(r ? 1,m). We compute the numbers of the GL(m,2)-orbits of R(r,m)\\/R(r ? 1,m) for 6 ? m ? 11. This is done through

  7. Curriculum Vitae Howard R. Turtle

    E-print Network

    Crowston, Kevin

    Curriculum Vitae Howard R. Turtle Center for Natural Language Processing Syracuse University · Xiaozhong Liu and Howard Turtle. Real-time User Interest for Real-time Ranking. Journal of the American, and Howard R. Turtle. PIC Matices: a Compu- tationally Tractable Class of Probabilistic Query Operators, ACM

  8. F I S C A L Y E A R 2 0 1 0 A N N U A L R E P O R T E N G I N E E R I N G T O M O R R O W ' S P O U L T R Y I N D U S T R Y

    E-print Network

    Bennett, Gisele

    audio and image signal processing, energy and water conservation, and food safety screening systems L T R Y I N D U S T R Y 2010 ANNUAL REPORT Agricultural Technology Research Program #12;A G R I C U R E V I E W For the Agricultural Technology Research Program (ATRP), fiscal year 2010 was a year

  9. Developments in CD-R

    NASA Astrophysics Data System (ADS)

    Verhoeven, J. A. T.; Mischke, Wlodek S.

    2001-02-01

    A review of recent developments in CD-R technology is given. This covers the physical design principles of the disc together with its production methods. We review all the subsequent manufacturing steps. The relevance of groove replication, substrate conditioning, dye solution and solvents, spinning methods, dye coating process conditions, dye layer drying, sputtering and lacquer coating on the CD-R disc performance are presented. The differences in the recording mechanism for several types of dyes are illustrated. The two modified new phthalocyanine and cyanine processes are described. Some technological implications for higher density recordable formats like DVD-R will be given.

  10. R u t c o r R e p o r t

    E-print Network

    : Supported by DIMACS award (Winter Awards Program, December 2001-January 2002). #12; RRR 16-2002 Page 1 Let G of the form S(n; m) are split graphs in sense of Foldes and Hammer [2]. u u u u u u u u r r r r r r r r r A B

  11. R2R-printed inverted OPV modules - towards arbitrary patterned designs

    NASA Astrophysics Data System (ADS)

    Välimäki, M.; Apilo, P.; Po, R.; Jansson, E.; Bernardi, A.; Ylikunnari, M.; Vilkman, M.; Corso, G.; Puustinen, J.; Tuominen, J.; Hast, J.

    2015-05-01

    We describe the fabrication of roll-to-roll (R2R) printed organic photovoltaic (OPV) modules using gravure printing and rotary screen-printing processes. These two-dimensional printing techniques are differentiating factors from coated OPVs enabling the direct patterning of arbitrarily shaped and sized features into visual shapes and, increasing the freedom to connect the cells in modules. The inverted OPV structures comprise five layers that are either printed or patterned in an R2R printing process. We examined the rheological properties of the inks used and their relationship with the printability, the compatibility between the processed inks, and the morphology of the R2R-printed layers. We also evaluate the dimensional accuracy of the printed pattern, which is an important consideration in designing arbitrarily-shaped OPV structures. The photoactive layer and top electrode exhibited excellent cross-dimensional accuracy corresponding to the designed width. The transparent electron transport layer extended 300 µm beyond the designed values, whereas the hole transport layer shrank 100 µm. We also examined the repeatability of the R2R fabrication process when the active area of the module varied from 32.2 cm2 to 96.5 cm2. A thorough layer-by-layer optimization of the R2R printing processes resulted in realization of R2R-printed 96.5 cm2 sized modules with a maximum power conversion efficiency of 2.1% (mean 1.8%) processed with high functionality.

  12. R2R-printed inverted OPV modules - towards arbitrary patterned designs.

    PubMed

    Välimäki, M; Apilo, P; Po, R; Jansson, E; Bernardi, A; Ylikunnari, M; Vilkman, M; Corso, G; Puustinen, J; Tuominen, J; Hast, J

    2015-05-21

    We describe the fabrication of roll-to-roll (R2R) printed organic photovoltaic (OPV) modules using gravure printing and rotary screen-printing processes. These two-dimensional printing techniques are differentiating factors from coated OPVs enabling the direct patterning of arbitrarily shaped and sized features into visual shapes and, increasing the freedom to connect the cells in modules. The inverted OPV structures comprise five layers that are either printed or patterned in an R2R printing process. We examined the rheological properties of the inks used and their relationship with the printability, the compatibility between the processed inks, and the morphology of the R2R-printed layers. We also evaluate the dimensional accuracy of the printed pattern, which is an important consideration in designing arbitrarily-shaped OPV structures. The photoactive layer and top electrode exhibited excellent cross-dimensional accuracy corresponding to the designed width. The transparent electron transport layer extended 300 µm beyond the designed values, whereas the hole transport layer shrank 100 µm. We also examined the repeatability of the R2R fabrication process when the active area of the module varied from 32.2 cm(2) to 96.5 cm(2). A thorough layer-by-layer optimization of the R2R printing processes resulted in realization of R2R-printed 96.5 cm(2) sized modules with a maximum power conversion efficiency of 2.1% (mean 1.8%) processed with high functionality. PMID:25951787

  13. FINAL REPORT DETERMINATION OF THE PROCESSING RATE OF RPP WTP HLW SIMULANTS USING A DURAMELTER J 1000 VITRIFICATION SYSTEM VSL-00R2590-2 REV 0 8/21/00

    SciTech Connect

    KRUGER AA; MATLACK KS; KOT WK; PEREZ-CARDENAS F; PEGG IL

    2011-12-29

    This report provides data, analysis, and conclusions from a series of tests that were conducted at the Vitreous State Laboratory of The Catholic University of America (VSL) to determine the melter processing rates that are achievable with RPP-WTP HLW simulants. The principal findings were presented earlier in a summary report (VSL-00R2S90-l) but the present report provides additional details. One of the most critical pieces of information in determining the required size of the RPP-WTP HLW melter is the specific glass production rate in terms of the mass of glass that can be produced per unit area of melt surface per unit time. The specific glass production rate together with the waste loading (essentially, the ratio of waste-in to glass-out, which is determined from glass formulation activities) determines the melt area that is needed to achieve a given waste processing rate with due allowance for system availability. As a consequence of the limited amount of relevant information, there exists, for good reasons, a significant disparity between design-base specific glass production rates for the RPP-WTP LAW and HLW conceptual designs (1.0 MT/m{sup 2}/d and 0.4 MT/m{sup 2}/d, respectively); furthermore, small-scale melter tests with HLW simulants that were conducted during Part A indicated typical processing rates with bubbling of around 2.0 MT/m{sup 2}/d. This range translates into more than a factor of five variation in the resultant surface area of the HLW melter, which is clearly not without significant consequence. It is clear that an undersized melter is undesirable in that it will not be able to support the required waste processing rates. It is less obvious that there are potential disadvantages associated with an oversized melter, over and above the increased capital costs. A melt surface that is consistently underutilized will have poor cold cap coverage, which will result in increased volatilization from the melt (which is generally undesirable) and increased plenum temperatures due to increased thermal radiation from the melt surface (which mayor may not be desirable but the flexibility to choose may be lost). Increased volatilization is an issue both in terms of the increased challenge to the off-gas system as well as for the ability to effectively close the recycle loops for volatile species that must be immobilized in the glass product, most notably technetium and cesium. For these reasons, improved information is needed on the specific glass production rates of RPP-WTP HLW streams in DuraMelterJ systems over a range of operating conditions. Unlike the RPP-WTP LAW program, for which a pilot melter system to provide large-scale throughout information is already in operation, there is no comparable HLW activity; the results of the present study are therefore especially important. This information will reduce project risk by reducing the uncertainty associated with the amount of conservatism that mayor may not be associated with the baseline RPP-WTP HLW melter sizing decision. After the submission of the first Test Plan for this work, the RPP-WTP requested revisions to include tests to determine the processing rates that are achievable without bubbling, which was driven by the potential advantages of omitting bubblers from the HLW melter design in terms of reduced maintenance. A further objective of this effort became the determination of whether the basis of design processing rate could be achieved without bubbling. Ideally, processing rate tests would be conducted on a full-scale RPP-WTP melter system with actual HLW materials, but that is clearly unrealistic during Part B1. As a practical compromise the processing rate determinations were made with HL W simulants on a DuraMelter J system at as close to full scale as possible and the DM 1000 system at VSL was selected for that purpose. That system has a melt surface area of 1.2 m{sup 2}, which corresponds to about one-third scale based on the specific glass processing rate of 0.4 MT/m{sup 2}/d assumed in the RPP-WTP HLW conceptual design, but would correspon

  14. Advanced Process Heater

    Microsoft Academic Search

    Tom Briselden; Chris Parrish

    2005-01-01

    The Roadmap for Process Heating Technology (March 16, 2001), identified the following priority R&D needs: Improved performance of high temperature materials; Improved methods for stabilizing low emission flames; Heating technologies that simultaneously reduce emissions, increase efficiency, and increase heat transfer. This Category I award entitled ''Proof of Concept of an Advanced Process Heater (APH) for Steel, Aluminum, and Petroleum Industries

  15. Reduce, Reuse, Recycle (R3 ): a Design

    E-print Network

    Zambreno, Joseph A.

    ) #12;R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3 PE R3

  16. [51] R. Sun, L. Bookman, and S. Shekhar, (eds.) The Working Notes of the AAAI Workshop on Integrating Neural and Symbolic Processes, American Association for Artificial Intelligence, Menlo Park, CA. 1992

    E-print Network

    Varela, Carlos

    . Prince, On Language and Connectionism, in: S. Pinker and J. Mehler (eds.), Con­ nections and Symbols. MIT treatment of connectionism, Behavioral and Brain Sciences, 11, 1­43. 1988. [44] R. Sun, A discrete neural

  17. A pH-based fed-batch process for the production of a chimeric recombinant infectious bursal disease virus (IBDV) structural protein (rVP2H) in insect cells

    Microsoft Academic Search

    Min-Ying Wang; Shyue-Ru Doong

    2000-01-01

    For the production of a rVP2H vaccine, to protect young chickens from infection by an infectious bursal disease virus (IBDV), Trichoplusia ni (Hi-5) cells were cultured in a 500-ml spinner flask to evaluate the productivity of the rVP2H protein. The spinner flask, with a working volume of 500 ml, was equipped with a sparger to bubble the air at a

  18. Oceanography Vol. 19, No. 1, Mar. 200692 BY PI E R R E F. J . L E R MU S I AU X ,

    E-print Network

    Leonard, John J.

    Oceanography Vol. 19, No. 1, Mar. 200692 BY PI E R R E F. J . L E R MU S I AU X , C H I N G S A N G U M DA R , A L E X PA N G , A N D F R A N CO I S L E K I E N Oceanography Vol. 19, No. 1, Mar Uncertainties #12;Oceanography Vol. 19, No. 1, Mar. 2006 93 A multitude of physical and biological processes

  19. The Ratio R dp of the quasielastic nd ? p( nn) to the elastic np ? pn charge-exchange-process yields at the proton emitting angle ? p,lab = 0° over 0.55-2.0 GeV neutron-beam energy region. Comparison of the results with the model-dependent calculations

    NASA Astrophysics Data System (ADS)

    Sharov, V. I.; Morozov, A. A.; Shindin, R. A.; Chernykh, E. V.; Nomofilov, A. A.; Strunov, L. N.

    2009-06-01

    Our new experimental results (see, e.g., Preprint JINR no. E1-2008-61 (Dubna, 2008)) on ratio R dp of the quasielastic charge-exchange yield at the proton emitting angle ? p,lab = 0° for the nd ? p( nn) reaction to the elastic np ? pn charge-exchange yield were presented. The measurements were carried out at the Nuclotron of the Veksler and Baldin Laboratory of High Energies of the JINR (Dubna) at the neutron-beam kinetic energies of 0.55, 0.8, 1.0, 1.2, 1.4, 1.8, and 2.0 GeV. In this paper the comparison of the experimental R dp data with the obtained R dp calculations within the impulse approximation by using the invariant-amplitude sets from the GW/VPI phase-shift analysis is made. The R dp values calculated using the set of invariant amplitude data for the elastic np ? pn charge exchange at ? p,CM = 0°, agree with the experimental data. This confirmed the nd ? p( nn) process yield at ? p,CM = 0° is caused by the contribution of the spin-dependent part of the elastic np ? pn charge-exchange reaction. Thus, it has been shown that the obtained experimental R dp results can be used for the Delta-Sigma experimental program to reduce the total ambiguity in the extraction of the amplitude real parts.

  20. 1,2-Dichlorohexafluoro-Cyclobutane (1,2-c-C4F6Cl2, R-316c) a Potent Ozone Depleting Substance and Greenhouse Gas: Atmospheric Loss Processes, Lifetimes, and Ozone Depletion and Global Warming Potentials for the (E) and (Z) stereoisomers

    NASA Technical Reports Server (NTRS)

    Papadimitriou, Vassileios C.; McGillen, Max R.; Smith, Shona C.; Jubb, Aaron M.; Portmann, Robert W.; Hall, Bradley D.; Fleming, Eric L.; Jackman, Charles H.; Burkholder, James B.

    2013-01-01

    The atmospheric processing of (E)- and (Z)-1,2-dichlorohexafluorocyclobutane (1,2-c-C4F6Cl2, R-316c) was examined in this work as the ozone depleting (ODP) and global warming (GWP) potentials of this proposed replacement compound are presently unknown. The predominant atmospheric loss processes and infrared absorption spectra of the R-316c isomers were measured to provide a basis to evaluate their atmospheric lifetimes and, thus, ODPs and GWPs. UV absorption spectra were measured between 184.95 to 230 nm at temperatures between 214 and 296 K and a parametrization for use in atmospheric modeling is presented. The Cl atom quantum yield in the 193 nm photolysis of R- 316c was measured to be 1.90 +/- 0.27. Hexafluorocyclobutene (c-C4F6) was determined to be a photolysis co-product with molar yields of 0.7 and 1.0 (+/-10%) for (E)- and (Z)-R-316c, respectively. The 296 K total rate coefficient for the O(1D) + R-316c reaction, i.e., O(1D) loss, was measured to be (1.56 +/- 0.11) × 10(exp -10)cu cm/ molecule/s and the reactive rate coefficient, i.e., R-316c loss, was measured to be (1.36 +/- 0.20) × 10(exp -10)cu cm/molecule/s corresponding to a approx. 88% reactive yield. Rate coefficient upper-limits for the OH and O3 reaction with R-316c were determined to be <2.3 × 10(exp -17) and <2.0 × 10(exp -22)cu cm/molecule/s, respectively, at 296 K. The quoted uncertainty limits are 2(sigma) and include estimated systematic errors. Local and global annually averaged lifetimes for the (E)- and (Z)-R-316c isomers were calculated using a 2-D atmospheric model to be 74.6 +/- 3 and 114.1 +/-10 years, respectively, where the estimated uncertainties are due solely to the uncertainty in the UV absorption spectra. Stratospheric photolysis is the predominant atmospheric loss process for both isomers with the O(1D) reaction making a minor, approx. 2% for the (E) isomer and 7% for the (Z) isomer, contribution to the total atmospheric loss. Ozone depletion potentials for (E)- and (Z)-R-316c were calculated using the 2-D model to be 0.46 and 0.54, respectively. Infrared absorption spectra for (E)- and (Z)-R-316c were measured at 296 K and used to estimate their radiative efficiencies (REs) and GWPs; 100-year time-horizon GWPs of 4160 and 5400 were obtained for (E)- and (Z)-R-316c, respectively. Both isomers of R-316c are shown in this work to be long-lived ozone depleting substances and potent greenhouse gases.

  1. Modeling Dynamic Tasks: Implications for ACT-R\\/PM

    Microsoft Academic Search

    Frank J. Lee; Michael D. Byrne

    1999-01-01

    ACT-R\\/PM (Byrne & Anderson, 1998) is an extension to the ACT-R (Anderson & Lebiere, 1998) architecture that allows ACT-R to precisely model perceptual and motor processes. While modeling of these processes may not be important in many tasks, it becomes critical in modeling dynamic problem solving tasks. In our presentation, we highlight some important limitations in the current ACT- R\\/PM

  2. Expression of genes for AhR and Nrf2 signal pathways in the retina of OXYS rats during the development of retinopathy and melatonin-induced changes in this process.

    PubMed

    Perepechaeva, M L; Stefanova, N A; Grishanova, A Yu

    2014-08-01

    Modulation of oxidative stress is one of the experimental approaches to the therapy of age-related macular degeneration. Melatonin holds much promise in this respect. It was hypothesized that the efficiency of melatonin in age-related macular degeneration is associated with its ability to modulate gene expression for the AhR and Nrf2 signal pathways. Experiments were performed on premature aging OXYS rats, which serve as a reliable model of age-related macular degeneration in humans. We studied the effect of melatonin on gene mRNA for the AhR and Nrf2 signal pathways. Melatonin was shown to decrease the level of mRNA for AhR-dependent genes of CYP1A2 and CYP1B1 cytochromes in the retina, but had no effect on the content of mRNA for Nrf2-dependent genes in OXYS rats. PMID:25110076

  3. NOAA's GOES R - next generation satellite

    Microsoft Academic Search

    E. J. Miller; M. Madden; R. Reining; J. Linn; L. O'Connor

    2003-01-01

    NOAA's next generation Geostationary Operational Environmental Satellite (GOES) beginning with GOES R is the follow-on to the GOES N-P series. GOES R is being developed for launch in the 2012 time frame to meet new requirements validated through a rigorous screening and verification process. It presents an opportunity to explore new instruments, satellite designs, and system architectures. NOAA's National Environmental

  4. Parallel Processing in Amplitude Analysis

    E-print Network

    Evans, Hal

    Parallel Processing in Amplitude Analysis Lecture 2 of 2 on Parallel Processing Physics 411/610 March 31, 2011 Matt Shepherd #12;M. R. Shepherd Parallel Processing Lecture 2 March 31, 2011 Outline · Theoretical Background · Experimental Technique · Application of Parallel Computing · Method of Maximum

  5. Control in Act-R and Soar

    Microsoft Academic Search

    Todd R. Johnson

    1997-01-01

    This paper compares the Act-R and Soar cognitive architec- tures, focusing on their theories of control. Act-R treats con- trol (conflict resolution) as an automatic process, whereas Soar treats it as a potentially deliberate, knowledge-based process. The comparison reveals that Soar can model ex- tremely flexible control, but has difficulty accounting for probabilistic operator selection and the independent effects of

  6. Arsenite evokes IL-6 secretion, autocrine regulation of STAT3 signaling, and miR-21 expression, processes involved in the EMT and malignant transformation of human bronchial epithelial cells

    SciTech Connect

    Luo, Fei; Xu, Yuan [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Ling, Min [Jiangsu Center for Disease Control and Prevention, Nanjing 211166, Jiangsu (China); Zhao, Yue; Xu, Wenchao [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Liang, Xiao [Mental Health Center of Xuhui-CDC, Shanghai 200232 (China); Jiang, Rongrong; Wang, Bairu [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); Bian, Qian [Jiangsu Center for Disease Control and Prevention, Nanjing 211166, Jiangsu (China); Liu, Qizhan, E-mail: drqzliu@hotmail.com [Institute of Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China); The Key Laboratory of Modern Toxicology, Ministry of Education, School of Public Health, Nanjing Medical University (China)

    2013-11-15

    Arsenite is an established human carcinogen, and arsenite-induced inflammation contributes to malignant transformation of cells, but the molecular mechanisms by which cancers are produced remain to be established. The present results showed that, evoked by arsenite, secretion of interleukin-6 (IL-6), a pro-inflammatory cytokine, led to the activation of STAT3, a transcription activator, and to increased levels of a microRNA, miR-21. Blocking IL-6 with anti-IL-6 antibody and inhibiting STAT3 activation reduced miR-21 expression. For human bronchial epithelial cells, cultured in the presence of anti-IL-6 antibody for 3 days, the arsenite-induced EMT and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates miR-21in an autocrine manner, contributes to the EMT induced by arsenite. These data define a link from inflammation to EMT in the arsenite-induced malignant transformation of HBE cells. This link, mediated through miRNAs, establishes a mechanism for arsenite-induced lung carcinogenesis. - Highlights: • Arsenite evokes IL-6 secretion. • IL-6 autocrine mediates STAT3 signaling and up-regulates miR-21expression. • Inflammation is involved in arsenite-induced EMT.

  7. statistical computing in R 1 R in Sage

    E-print Network

    Verschelde, Jan

    statistical computing in R 1 R in Sage the language and environment R Monte Carlo integration making plots with R in Sage 2 Statistical Computing with R histograms of data fitting linear models 3 computing with R 1 R in Sage the language and environment R Monte Carlo integration making plots with R

  8. Yeast snR30 is a small nucleolar RNA required for 18S rRNA synthesis.

    PubMed Central

    Morrissey, J P; Tollervey, D

    1993-01-01

    Subnuclear fractionation and coprecipitation by antibodies against the nucleolar protein NOP1 demonstrate that the essential Saccharomyces cerevisiae RNA snR30 is localized to the nucleolus. By using aminomethyl trimethyl-psoralen, snR30 can be cross-linked in vivo to 35S pre-rRNA. To determine whether snR30 has a role in rRNA processing, a conditional allele was constructed by replacing the authentic SNR30 promoter with the GAL10 promoter. Repression of snR30 synthesis results in a rapid depletion of snR30 and a progressive increase in cell doubling time. rRNA processing is disrupted during the depletion of snR30; mature 18S rRNA and its 20S precursor underaccumulate, and an aberrant 23S pre-rRNA intermediate can be detected. Initial results indicate that this 23S pre-rRNA is the same as the species detected on depletion of the small nucleolar RNA-associated proteins NOP1 and GAR1 and in an snr10 mutant strain. It was found that the 3' end of 23S pre-rRNA is located in the 3' region of ITS1 between cleavage sites A2 and B1 and not, as previously suggested, at the B1 site, snR30 is the fourth small nucleolar RNA shown to play a role in rRNA processing. Images PMID:8455623

  9. R E S E A R C H A R T I C L E Arbuscular mycorrhizal symbiosis can counterbalance the negative

    E-print Network

    Thioulouse, Jean

    R E S E A R C H A R T I C L E Arbuscular mycorrhizal symbiosis can counterbalance the negative in-6941.2007.00363.x Editor: Karl Ritz Keywords AM symbiosis; plant diversity; catabolic diversity; Eucalyptus. These results highlight the role of AM symbiosis in the processes involved in soil bio-functioning and plant

  10. Separation Process Economics 

    E-print Network

    Barron, T. S.; Wrobel, P. J.

    1985-01-01

    'M Coat Moderate 3. Freeze Crystallization processes Table 4. Curaet.ri.tic. Coat 11...nt H?? a _tal h.at .,,:hanq??urrae. bet....n the proe??a and the r.frig.ra:nt. ? equir?? -.eb.ni.. tor a??pln9 this ."rtae. tr.. he- ice d.po.ita which would...

  11. Test Review: Wagner, R. K., Torgesen, J. K., Rashotte, C. A., & Pearson, N. A., "Comprehensive Test of Phonological Processing-2nd Ed. (CTOPP-2)." Austin, Texas: Pro-Ed

    ERIC Educational Resources Information Center

    Dickens, Rachel H.; Meisinger, Elizabeth B.; Tarar, Jessica M.

    2015-01-01

    The Comprehensive Test of Phonological Processing-Second Edition (CTOPP-2; Wagner, Torgesen, Rashotte, & Pearson, 2013) is a norm-referenced test that measures phonological processing skills related to reading for individuals aged 4 to 24. According to its authors, the CTOPP-2 may be used to identify individuals who are markedly below their…

  12. Form factor of the process {gamma}{sup *}{gamma}{sup *} {r_arrow} {phi}{sup O} at small virtuality of one of the photons and QCD sum rules (II)

    SciTech Connect

    Radyushkin, A.V.; Ruskov, R. [Joint Inst. for Nuclear Research, Moscow (Russian Federation)

    1995-08-01

    QCD sum rules for the form factor F{sub {gamma}*{gamma}*{r_arrow}{pi}{sup 0}}(q{sup 2}{sub 1}, q{sup 2}{sub 2}) are generalized to the region where one of the photons has a small virtuality {vert_bar}q{sup 2}{sub 1}{vert_bar}{much_lt}{vert_bar}q{sup 2}{sub 2}{vert_bar}{ge} 1 GeV{sup 2}. In this range of momentum transfer, additional factorization of short- and long-distance contributions must be performed. The long-distance contribution to the three-point amplitude is factorized into two-point (bilocal) correlation functions of the electromagnetic current and the composite operators of the two lowest twists. The low-energy dependence of the correlation functions is determined from auxiliary QCD sum rules. The sum rule obtained for the form factor is regular in the limit q{sup 2}{sub 1} {r_arrow} 0. The authors estimates for F{sub {gamma}{sup *}}{sub {gamma}{sup *}{r_arrow} {pi}{sup O}} (q{sup 2}{sub 1}=O,q{sup 2}{sub 2}) are in good agreement with available experimental data. 22 refs., 3 figs.

  13. Materials Science and Technology, Volume 15, Materials Science and Technology A Comprehensive Treatment - Volume 15: Processing of Metals and Alloys Cahn,R.W.(ed.)/Haasen,P.(ed.)/Kramer,E.J.(ed.)

    NASA Astrophysics Data System (ADS)

    Cahn, Robert W.

    1996-12-01

    The properties of metals and alloys, and thus their effectiveness in applications, are closely related to the processing methods applied. Metallurgists and other technologists involved with metals and alloys are provided with a unique overview of processing techniques and their effects. From the Contents: Flemings: Solidification Processing. Suryanarayana: Rapid Solidification. Mordike: Surface Modification by Lasers. Arunachalam/Sundaresan: Powder Metallurgy. Koch: Mechanical Milling and Alloying. Follstaedt: Ion Implantation and Ion-Beam Mixing. Pashley: The Epitaxy of Metals. Somekh/Greer: Metallic Multilayers. Humphreys: Recrystallization and Recovery. Cahn: Measurement and Control of Texture. de Bonte/Roos/Celis: Electrodeposition of Metals and Alloys. Sahm/Keller: Solidification Processing Under Microgravity. Siegel: Cluster Assembly of Nanophase Materials.

  14. An R Package Conculsions/Future

    E-print Network

    Diggle, Peter J.

    Processes #12;Motivation Methods An R Package Examples Conculsions/Future Primary Biliary Cirrhosis in Newcastle-Upon-Tyne Primary Biliary Cirrhosis in Newcastle-Upon-Tyne (Aggregated) Gastrointestinal Disease Surveillance Bovine Tuberculosis in Cornwall Spatial Point Process Data · Primary biliary cirrhosis

  15. The Ratio R{sub dp} of the quasielastic nd {yields} p(nn) to the elastic np {yields} pn charge-exchange-process yields at the proton emitting angle {theta}{sub p,lab} = 0 deg. over 0.55-2.0 GeV neutron-beam energy region. Comparison of the results with the model-dependent calculations

    SciTech Connect

    Sharov, V. I., E-mail: sharov@sunhe.jinr.ru; Morozov, A. A.; Shindin, R. A.; Chernykh, E. V.; Nomofilov, A. A.; Strunov, L. N. [Joint Institute for Nuclear Research (Russian Federation)

    2009-06-15

    Our new experimental results (see, e.g., Preprint JINR no. E1-2008-61 (Dubna, 2008)) on ratio R{sub dp} of the quasielastic charge-exchange yield at the proton emitting angle {theta}{sub p,lab} = 0 deg. for the nd {yields} p(nn) reaction to the elastic np {yields} pn charge-exchange yield were presented. The measurements were carried out at the Nuclotron of the Veksler and Baldin Laboratory of High Energies of the JINR (Dubna) at the neutron-beam kinetic energies of 0.55, 0.8, 1.0, 1.2, 1.4, 1.8, and 2.0 GeV. In this paper the comparison of the experimental R{sub dp} data with the obtained R{sub dp} calculations within the impulse approximation by using the invariant-amplitude sets from the GW/VPI phase-shift analysis is made. The R{sub dp} values calculated using the set of invariant amplitude data for the elastic np {yields} pn charge exchange at {theta}{sub p,CM} = 0 deg., agree with the experimental data. This confirmed the nd {yields} p(nn) process yield at {theta}{sub p,CM} = 0 deg. is caused by the contribution of the spin-dependent part of the elastic np {yields} pn charge-exchange reaction. Thus, it has been shown that the obtained experimental R{sub dp} results can be used for the Delta-Sigma experimental program to reduce the total ambiguity in the extraction of the amplitude real parts.

  16. r Human Brain Mapping 31:678693 (2010) r Enhanced Effectiveness in Visuo-Haptic

    E-print Network

    James, Thomas

    2010-01-01

    r Human Brain Mapping 31:678­693 (2010) r Enhanced Effectiveness in Visuo-Haptic Object and haptic object processing. The purpose of the present study was to characterize the underlying neural mecha- nisms for bimodal integration of vision and haptics in these visuo-haptic object-selective brain

  17. Realizability of Point Processes

    Microsoft Academic Search

    T. Kuna; J. L. Lebowitz; E. R. Speer

    2007-01-01

    There are various situations in which it is natural to ask whether a given collection of k functions, ?\\u000a \\u000a j\\u000a (r\\u000a 1,…,r\\u000a \\u000a j\\u000a ), j=1,…,k, defined on a set X, are the first k correlation functions of a point process on X. Here we describe some necessary and sufficient conditions on the ?\\u000a \\u000a j\\u000a ’s for this to be true.

  18. Clementine Sensor Processing System

    NASA Technical Reports Server (NTRS)

    Feldstein, A. A.

    1993-01-01

    The design of the DSPSE Satellite Controller (DSC) is baselined as a single-string satellite controller. The DSC performs two main functions: health and maintenance of the spacecraft; and image capture, storage, and playback. The DSC contains two processors: a radiation-hardened Mil-Std-1750, and a commercial R3000. The Mil-Std-1750 processor performs all housekeeping operations, while the R3000 is mainly used to perform the image processing functions associated with the navigation functions, as well as performing various experiments. The DSC also contains a data handling unit (DHU) used to interface to various spacecraft imaging sensors and to capture, compress, and store selected images onto the solid-state data recorder. The development of the DSC evolved from several key requirements; the DSPSE satellite was to do the following: (1) have a radiation-hardened spacecraft control system and be immune to single-event upsets (SEU's); (2) use an R3000-based processor to run the star tracker software that was developed by SDIO (due to schedule and cost constraints, there was no time to port the software to a radiation-hardened processor); and (3) fly a commercial processor to verify its suitability for use in a space environment. In order to enhance the DSC reliability, the system was designed with multiple processing paths. These multiple processing paths provide for greater tolerance to various component failures. The DSC was designed so that all housekeeping processing functions are performed by either the Mil-Std-1750 processor or the R3000 processor. The image capture and storage is performed either by the DHU or the R3000 processor.

  19. Resveratrol decreases the levels of miR-155 by upregulating miR-663, a microRNA targeting JunB and JunD

    E-print Network

    Paris-Sud XI, Université de

    1 1 Resveratrol decreases the levels of miR-155 by upregulating miR-663, a microRNA targeting Jun downregulates miR-155 through miR-663 Key words: Inflammation; miR-155; monocytes; resveratrol; THP-1 cells hal related to an obvious inflammatory process. Several microRNAs, and especially miR-155, play an essential

  20. An Environment Supporting Visual Information Processing Services

    Microsoft Academic Search

    Eleni Kaldoudi; Marios Zikos; Stelios C. Orphanoudakis

    1997-01-01

    Visual information processing is a rather mature and r ich field. An impressive amount of image and video processing algorithms are currently available fo r a great variety of applications. There is also a considerable number of software packages, either commer cial products or academic shareware, ranging from dedicated systems aiming at solving very specific problems, to open environments designed

  1. On the number of (r,r +1)-factors in an (r,r +1)-factorization of a simple graph

    E-print Network

    Banaji,. Murad

    On the number of (r,r +1)-factors in an (r,r +1)-factorization of a simple graph A. J. W. Hilton,r + 1)-factorization, then the number x of (r,r + 1)-factors in the factorization is bounded above by 1 the vertices lie in the set {d,d +1,...,d +s}. For an integer r 0, an (r,r +1)-factor of a graph G

  2. Thermomechanical Simulation and Processing of Steels, Simpro 08, eds S. K. Chaudhuri, B. K. Jha, S. Srikant, P. K. Maini, A. Deva, R. Datta, Allied Publishers Pvt. Ltd., Kolkata, India, (2008) pages 3-11.

    E-print Network

    Cambridge, University of

    2008-01-01

    of Cambridge, Materials Science and Metallurgy, U.K. Graduate Institute of Ferrous Metallurgy, POSTECH, such as the infamous carbon nanotubes and metal-matrix composites. Keywords : steel, rapid heat treatment, long heat production of steels that the processing time must be reasonable and that the material must have uniform

  3. Studsvik Processing Facility Update

    SciTech Connect

    Mason, J. B.; Oliver, T. W.; Hill, G. M.; Davin, P. F.; Ping, M. R.

    2003-02-25

    Studsvik has completed over four years of operation at its Erwin, TN facility. During this time period Studsvik processed over 3.3 million pounds (1.5 million kgs) of radioactive ion exchange bead resin, powdered filter media, and activated carbon, which comprised a cumulative total activity of 18,852.5 Ci (6.98E+08 MBq). To date, the highest radiation level for an incoming resin container has been 395 R/hr (3.95 Sv/h). The Studsvik Processing Facility (SPF) has the capability to safely and efficiently receive and process a wide variety of solid and liquid Low Level Radioactive Waste (LLRW) streams including: Ion Exchange Resins (IER), activated carbon (charcoal), graphite, oils, solvents, and cleaning solutions with contact radiation levels of up to 400 R/hr (4.0 Sv/h). The licensed and heavily shielded SPF can receive and process liquid and solid LLRWs with high water and/or organic content. This paper provides an overview of the last four years of commercial operations processing radioactive LLRW from commercial nuclear power plants. Process improvements and lessons learned will be discussed.

  4. Genome-Wide Identification and Characterization of R2R3MYB Family in Cucumis sativus

    PubMed Central

    Li, Qiang; Zhang, Cunjia; Li, Jing; Wang, Lina; Ren, Zhonghai

    2012-01-01

    Background The R2R3MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some species, little is known about R2R3MYB genes in cucumber (Cucumis sativus L.). Principal Findings This study has identified 55 R2R3MYB genes in the latest cucumber genome and the CsR2R3MYB family contained the smallest number of identified genes compared to other species that have been studied due to the absence of recent gene duplication events. These results were also supported by genome distribution and gene duplication analysis. Phylogenetic analysis showed that they could be classified into 11 subgroups. The evolutionary relationships and the intron - exon organizations that showed similarities with Arabidopsis, Vitis and Glycine R2R3MYB proteins were also analyzed and suggested strong gene conservation but also the expansions of particular functional genes during the evolution of the plant species. In addition, we found that 8 out of 55 (?14.54%) cucumber R2R3MYB genes underwent alternative splicing events, producing a variety of transcripts from a single gene, which illustrated the extremely high complexity of transcriptome regulation. Tissue-specific expression profiles showed that 50 cucumber R2R3MYB genes were expressed in at least one of the tissues and the other 5 genes showed very low expression in all tissues tested, which suggested that cucumber R2R3MYB genes took part in many cellular processes. The transcript abundance level analysis during abiotic conditions (NaCl, ABA and low temperature treatments) identified a group of R2R3MYB genes that responded to one or more treatments. Conclusions This study has produced a comparative genomics analysis of the cucumber R2R3MYB gene family and has provided the first steps towards the selection of CsR2R3MYB genes for cloning and functional dissection that can be used in further studies to uncover their roles in cucumber growth and development. PMID:23110079

  5. How to formulate image processing applications ?

    E-print Network

    Paris-Sud XI, Université de

    How to formulate image processing applications ? Arnaud Renouf, R´egis Clouard, and Marinette In the last fifty years, a lot of image processing applications have been developed in many fields (medicine in image processing terms has been little studied. Image processing specialists develop their applications

  6. Publications Vaughan R. Pratt

    E-print Network

    Pratt, Vaughan

    on Coalgebraic Methods in Cs (CMCS'03), Elsevier ENTCS 82:1, 1-12, July 2003. Pratt, V.R., "Chu spaces 294:3, 439-471, February 2003. Pratt, V.R., "Event-state duality: the enriched case", Proc. Conf.) Parikh, R., Parida, M. and Pratt, V., "Sock Sorting: An Example of a Vague Algorithm," Logic Journal

  7. R U T C O R R E P O R T

    E-print Network

    RESEARCH REPORT RRR 8-2001, JANUARY, 2001 CONTROL OF MARKET POWER IN ELECTRICITY AUCTIONS Michael HR U T C O R RESEARCH R E P O R T 587&25 5XWJHUV &HQWHU IRU 2SHUDWLRQV 5HVHDUFK 5XWJHUV 8QLYHUVLWUUU CONTROL OF MARKET POWER IN ELECTRICITY AUCTIONS Michael H. Rothkopf a RRR 8-2001, JANUARY, 2001 a RUTCOR

  8. R u t c o r R e p o r t

    E-print Network

    @rutcor.rutgers.edu #12; Rutcor Research Report RRR 43­94, December 1994 MULTIPLE CROSSINGS OF RELIABILITY FUNCTIONSR u t c o r Research R e p o r t RUTCOR ffl Rutgers Center for Operations Research ffl Rutgers­932­5472 Email: rrr@rutcor.rutgers.edu MULTIPLE CROSSINGS OF RELIABILITY FUNCTIONS Alexander K. Kelmans a RRR 43

  9. Factor Analysis Using "R"

    ERIC Educational Resources Information Center

    Beaujean, A. Alexander

    2013-01-01

    "R" (R Development Core Team, 2011) is a very powerful tool to analyze data, that is gaining in popularity due to its costs (its free) and flexibility (its open-source). This article gives a general introduction to using "R" (i.e., loading the program, using functions, importing data). Then, using data from Canivez, Konold, Collins, and Wilson…

  10. [In Process Citation].

    PubMed

    1996-10-18

    M. J. S. Belton, (*) J. W. Head III, A. P. Ingersoll, R. Greeley, A. S. McEwen, K. P. Klaasen, D. Senske, R. Pappalardo, G. Collins, A. R. Vasavada, R. Sullivan, D. Simonelli, P. Geissler, M. H. Carr, M. E. Davies, J. Veverka, P. J. Gierasch, D. Banfield, M. Bell, C. R. Chapman, C. Anger, R. Greenberg, G. Neukum, C. B. Pilcher, R. F. Beebe, J. A. Burns, F. Fanale, W. Ip, T. V. Johnson, D. Morrison, J. Moore, G. S. Orton, P. Thomas, R. A. West The first images of Jupiter, Io, Europa, and Ganymede from the Galileo spacecraft reveal new information about Jupiter's Great Red Spot (GRS) and the surfaces of the Galilean satellites. Features similar to clusters of thunderstorms were found in the GRS. Nearby wave structures suggest that the GRS may be a shallow atmospheric feature. Changes in surface color and plume distribution indicate differences in resurfacing processes near hot spots on Io. Patchy emissions were seen while Io was in eclipse by Jupiter. The outer margins of prominent linear markings (triple bands) on Europa are diffuse, suggesting that material has been vented from fractures. Numerous small circular craters indicate localized areas of relatively old surface. Pervasive brittle deformation of an ice layer appears to have formed grooves on Ganymede. Dark terrain unexpectedly shows distinctive albedo variations to the limit of resolution. M. J. S. Belton, National Optical Astronomy Observatories, 950 North Cherry Ave, Tucson, AZ 85719, USA. J. W. Head III, R. Pappalardo, G. Collins, Department of Geological Science, Brown University, Providence, RI 02912, USA. A. P. Ingersoll and A. R. Vasavada, Department of Geology and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. R. Greeley and R. Sullivan, Department of Geology, Arizona State University, Tempe, AZ 85287-1414, USA. A. S. McEwen, P. Geissler, R. Greenberg, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 87721, USA. K. P. Klaasen, D. Senske, T. V. Johnson, G. S. Orton, R. A. West, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. D. Simonelli, J. Veverka, P. J. Gierasch, D. Banfield, M. Bell, J. A. Burns, P. Thomas, Department of Astronomy, Cornell University, Ithaca, NY 14853, USA. M. H. Carr, U.S. Geological Survey, Menlo Park, CA 94025, USA. M. E. Davies, RAND, Santa Monica, CA 90406, USA. C. R. Chapman, Southwest Research Institute, Boulder, CO 80302, USA. C. Anger, ITTRES Ltd, Calgary, Alberta TIY 5Z6, Canada. G. Neukum, Institute for Planetary Exploration, Deutsche Forschunganstalt für Luft und Raumfahrt, Berlin, Germany. C. B. Pilcher, National Aeronautical and Space Administration, Washington, DC 20546, USA. R. F. Beebe, Department of Astronomy, New Mexico State University, Las Cruces, NM 88003, USA. F. Fanale, Institute for Geophysics, University of Hawaii, Honolulu, HI 96822, USA. W. Ip, Max Planck Institute für Aeronomie, Lindau, Germany. D. Morrison and J. Moore, NASA Ames Research Center, Moffett Field, CA 94035, USA. (*) To whom correspondence should be addressed. E-mail: belton@noao.edu. PMID:17813508

  11. Evolutionary Dynamics of Plant R-Genes

    NSDL National Science Digital Library

    Joy Bergelson (University of Chicago; Department of Ecology and Evolution)

    2001-06-22

    Plant R-genes involved in gene-for-gene interactions with pathogens are expected to undergo coevolutionary arms races in which plant specificity and pathogen virulence continually adapt in response to each other. Lending support to this idea, the solvent-exposed amino acid residues of leucine-rich repeats, a region of R-genes involved in recognizing pathogens, often evolve at unusually fast rates. But within-species polymorphism is also common in R-genes, implying that the adaptive substitution process is not simply one of successive selective sweeps. Here we document these features in available data and discuss them in light of the evolutionary dynamics they likely reflect.

  12. QuasR: quantification and annotation of short reads in R

    PubMed Central

    Gaidatzis, Dimos; Lerch, Anita; Hahne, Florian; Stadler, Michael B.

    2015-01-01

    Summary: QuasR is a package for the integrated analysis of high-throughput sequencing data in R, covering all steps from read preprocessing, alignment and quality control to quantification. QuasR supports different experiment types (including RNA-seq, ChIP-seq and Bis-seq) and analysis variants (e.g. paired-end, stranded, spliced and allele-specific), and is integrated in Bioconductor so that its output can be directly processed for statistical analysis and visualization. Availability and implementation: QuasR is implemented in R and C/C++. Source code and binaries for major platforms (Linux, OS X and MS Windows) are available from Bioconductor (www.bioconductor.org/packages/release/bioc/html/QuasR.html). The package includes a ‘vignette’ with step-by-step examples for typical work ?ows. Contact: michael.stadler@fmi.ch Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25417205

  13. Dielectric Constants of Refrigerants R113, R114, R114B2, R115, R116, and R124

    NASA Astrophysics Data System (ADS)

    Kashiwagi, Hiroshi; Harada, Noboru; Tanaka, Yoshiyuki; Kubota, Hironobu; Makita, Tadashi

    The dielectric constants of six refrigerants have been measured in both gaseous and liquid phases. The fluids used and the experimental ranges of temperature and pressure are as follows : R113 (1, 2, 2- Trichlorotrifluoroethane CClF2CCl2F) : 298.15-423.15K, 0.1-17.3MPa, R1l4 (1, 2- Dichlorotetrafluoroethane CClF2CClF2) : 298.15-423.15K, 0.2-17.2MPa, R114B2 (1, 2- Dibromotetrafluoroethane CBrF2CBrF2) : 298.15-423.15K, 0.2-17.3MPa, R1l5 (Chloropentafluoroethane CClF2CF3) : 298.15 373.15K. O.1-17.1MPa, R1l6 (Hexafluoroethane CF3CF3) : 283.15-373.15 K, 0.2-16.9MPa, R124 (1-Chloro-2, 2, 2, -tetrafluoroethane CHClFCF3) : 273.15 373.15K, 0.1-10.5MPa The measurements were performed using a frequency-counting method on a relative basis with an uncertainty less than ±0.1%.The experimental results are given by polynomial equations. The smoothed value tables are also given for practical convenience. The pressure dependence of dielectric constants in liquid phase is represented by a similar expression to the Tait equation. The effects of pressure, temperature, and density on the dielectric constant and the molar polarization defined by the Clausius-Mossotti relation are discussed in term of polarity of molecules of each refrigerant.

  14. X = X1 . . . Xn Xi R I R V (I)

    E-print Network

    O'Grady, Kieran G.

    . . . R R Spec R p Spec R V (p) Spec R p X X X X X X Y X Y X cod(Y, X) = cod(Y, X) cod(Y, X) (dim Xi -dim Y ) Xi X Y X p C[X] ht(p) = cod(V (p), X) R p Spec R V (p) Spec R R p0 p1 . . . pn p Spec R p) U X U Y = f C[U] (U, f) (U , f ) (V, g) V U U g = f|V = f |V r := dim OX,Y = cod(Y, X). X Y m

  15. DC/AC Student Guide: R2R Ladder Network

    NSDL National Science Digital Library

    Casas, Jesus

    R2R Ladder Networks provide a simple and inexpensive method of converting digital information to an analog signal. The R2R ladder circuit is a very common piece of almost all Digital-to-Analog converters.  By understanding how the R2R ladder system works, a better understanding of Digital-to-Analog converters can be had.

  16. Scientific Processes

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2007-08-01

    In this interactive activity adapted from NOVA, expand your understanding of the scientific process. Watch two videos featuring animations and interviews with scientists, and notice how the processes unfold and vary from one investigation to the other.

  17. strt ts r sr stst rt t s s s r t ssts t rts r ss

    E-print Network

    Boyer, Edmond

    P P strt ts r sr stst rt t s s s r t ssts t rts r ss ttsttrtssttstrts rts s t s s t r sttrs ts rts r rt t st s r t st t s s rt rstrt tqs t rt t t r r t st t s r rt s tst r s t rs s t strt r r s s t r r s t s srt P ts r r rs s r t s s t t t r t st t trt s r r

  18. Variational processes

    Microsoft Academic Search

    J. Zambrini

    A new class of diffusion processes, the Bernstein processes, is introduced in Theoretical Physics. Their dynamical realization, the Variational processes yields a new probabilistic interpretation of the Heat equation, much closer to quantum mechanics than the other known classical analogies, and also a new constructive variational approach to Stochastic Mechanics.

  19. stt rt t Prstt st sttr r str r s

    E-print Network

    Paris-Sud XI, Université de

    stt rt t Prstt st sttr r str r s rtr tétqs ë rsté rrr tr strt r t stt rt t r st sttr tr stt Pr t tt sttr str r s r r s s t rs t rtr t rsts sr tq rts s rs rs rtr stt r st rsss r t s s t sr ts t t rtr rs s rtr t str ts t t t t ssts rs rss tr t tr r st sttr

  20. Rewind S T O R I E S F R O M T H E A R C H I V E S Knowledge Box, 196263

    E-print Network

    Heller, Barbara

    IIT 32 Rewind S T O R I E S F R O M T H E A R C H I V E S Knowledge Box, 1962­63 Numerous IIT people inside, the Knowledge Box was meant to intensify the learning process by deluging the per- son with images projected on the interior walls, ceiling, and floor of the box--an experience that Isaacs felt

  1. A Realization Algorithm for SL2(R[x1, . . . ,xm]) over the Euclidean Domain

    Microsoft Academic Search

    1999-01-01

    Let R be an arbitrary Euclidean domain and A be an n n matrix of determinant 1 whose entries are elements of R. Gaussian elimination process based on Euclidean division algorithm (on R) allows one to write A as a product of elementary matrices over R. Suslin's Stability Theorem states that any n n multivariate polynomial matrix of determinant 1

  2. JOURNAL DE PHYSIQUE Colloque C1, suppl6ment au n"2, Tome 47, f 6 v r i e r 1986 page cl-19

    E-print Network

    Paris-Sud XI, Université de

    s expected t o play a major impact r o l e on the ceramic and glass fabrication processes. "Chemical-ceramics- t r a t e s aqueous solutions. I - INTRODUCTION Ceramic materials with the " f l u o r i t e " type microstructure and thus the elec- t r i c a l conductivity of p o l y c r i s t a l l i n e materials / 3

  3. An analysis of the performances of a vapour compression plant working both as a water chiller and a heat pump using R22 and R417A

    Microsoft Academic Search

    C. Aprea; R. Mastrullo; C. Renno

    2004-01-01

    The aim of this paper is to study the performances of a vapour compression experimental plant working both as a water chiller and as a heat pump, using as refrigerant fluids R22 and its substitute R417A (R125\\/R134a\\/R600 46.6\\/50\\/3.4% in mass). This kind of system is used in industrial processing or air conditioning plants where a supply of refrigerated and heated

  4. Hartwig Hen Lauderdale R

    E-print Network

    Slatton, Clint

    _____________ UR 3520 ­ STRUCTOR: Hartwig Hen Lauderdale R ONE/VOICE MAIL: hhhoch ACHING ASS am Benjamin Lauderdale ducation Cen 577-6378 u Thu: 10:40a- ass: 04/24/12 ERIALS: tment Compu for each sess dologies for a horough For each ass r 24 hours wil d

  5. R&R BIT 2013-2014 pag. 1 Regels en Richtlijnen (R&R)

    E-print Network

    : de beoordeling van een tentamen Artikel 8: eindopdrachten Artikel 9: fraude Artikel 10: cum laude van de examencommissie, of onder bepaalde voorwaarden (zie R&R art. 11 lid 3) aan de examenbevoegde begeleiders van de bachelor- resp. masteropdracht. c. De afhandeling van de 40 EC-regeling (bachelor OER art

  6. ENGINEERING HOWARD R. HUGHES

    E-print Network

    Hemmers, Oliver

    ENGINEERING College of HOWARD R. HUGHES HigHligHts At the Howard R. Hughes College of Engineering is an integral part of engineering studies, we also provide students with a superb technical education and strong of Energy Solar Decathlon 2013. Engineering and architecture students will design then build and operate

  7. Geosciences 466/566 Digital Image Processing

    E-print Network

    Wright, Dawn Jeannine

    Geosciences 466/566 Digital Image Processing Winter 2007 Instructor Dr. Anne Nolin Wilkinson 120 This course focuses on the digital image processing of satellite image data. Topics include: data types, image://my.oregonstate.edu Textbook Jensen, J. R., Digital Image Processing: A Remote Sensing Perspective, 3rd Edition, Prentice Hall

  8. GOES-R product and algorithm development

    Microsoft Academic Search

    Alfred M. Powell Jr.; Mitch Goldberg; Marie Colton

    2005-01-01

    With the launch of GOES-R, the next generation of geostationary environmental monitoring satellites will have gone from the drawing board to on-orbit operations. New products will flow through a processing system that took years to develop and perfect. Around 2012, users will finally get their first taste of the latest remote environmental monitoring products from geostationary orbit. To achieve this

  9. THE THALAMOCORTICAL ALGORITHM Paul R. Adams

    E-print Network

    Adams, Paul R.

    - 1 COMMENTARY THE THALAMOCORTICAL ALGORITHM Paul R. Adams Department of Neurobiology and BehaviorError, Thalamus, Neocortex, Sleep Abbreviations: LGN: lateral geniculate nucleus; LTP: Long Term Potentiation; BCM by a process resetnbling sleep. CONTENTS 1 INTRODUCTION 2 A SKETCH OF THALAMUS AND NEOCORTEX 3 WIRING

  10. Federal R & D Policies Supporting Educational Technology.

    ERIC Educational Resources Information Center

    Blaschke, Charles; And Others

    1989-01-01

    Summarizes factors contributing to successful federal research and development (R&D) funding for educational technology, and provides policy recommendations based on these findings. Topics discussed include the role of industry; public policy issues; legislative initiatives; executive branch administration; staff continuity; procurement process;…

  11. Networks and globalization policies Douglas R. White

    E-print Network

    White, Douglas R.

    9 Networks and globalization policies Douglas R. White 1 This Chapter argues for connecting models of several kinds of macro- and micro-processes as they affect structure and dynamics in the globalization and to loosen assumptions about determinacy in models of networks and globalization. As do many models

  12. Learning and Memory Eric R. Kandel

    E-print Network

    Ulanovsky, Nachum

    biological principles of learning and memory that have emerged from clinical and cognitiveBack 62 Learning and Memory Eric R. Kandel Irving Kupfermann Susan Iversen BEHAVIOR IS THE RESULT the environment alters behavior are learning and memory. Learning is the process by which we acquire knowledge

  13. Signal Processing ] (

    E-print Network

    Paris 7 - Denis Diderot, Université

    consider sparse representations of audio based around the modulated complex lapped transform (MCLT for audio modification. r 2005 Elsevier B.V. All rights reserved. Keywords: Lapped transforms; Overcomplete discrete cosine transform (MDCT) in terms of coding cost and explore the possibility of extending

  14. MiR-221 and miR-130a Regulate Lung Airway and Vascular Development

    PubMed Central

    Mujahid, Sana

    2013-01-01

    Epithelial-mesenchymal interactions play a crucial role in branching morphogenesis, but very little is known about how endothelial cells contribute to this process. Here, we examined how anti-angiogenic miR-221 and pro-angiogenic miR-130a affect airway and vascular development in the fetal lungs. Lung-specific effects of miR-130a and miR-221 were studied in mouse E14 whole lungs cultured for 48 hours with anti-miRs or mimics to miR-130a and miR-221. Anti-miR 221 treated lungs had more distal branch generations with increased Hoxb5 and VEGFR2 around airways. Conversely, mimic 221 treated lungs had reduced airway branching, dilated airway tips and decreased Hoxb5 and VEGFR2 in mesenchyme. Anti-miR 130a treatment led to reduced airway branching with increased Hoxa5 and decreased VEGFR2 in the mesenchyme. Conversely, mimic 130a treated lungs had numerous finely arborized branches extending into central lung regions with diffusely localized Hoxa5 and increased VEGFR2 in the mesenchyme. Vascular morphology was analyzed by GSL-B4 (endothelial cell-specific lectin) immunofluorescence. Observed changes in airway morphology following miR-221 inhibition and miR-130a enhancement were mirrored by changes in vascular plexus formation around the terminal airways. Mouse fetal lung endothelial cells (MFLM-91U) were used to study microvascular cell behavior. Mimic 221 treatment resulted in reduced tube formation and cell migration, where as the reverse was observed with mimic 130a treatment. From these data, we conclude that miR-221 and miR-130a have opposing effects on airway and vascular morphogenesis of the developing lung. PMID:23409087

  15. Shuttle Processing

    NASA Technical Reports Server (NTRS)

    Guodace, Kimberly A.

    2010-01-01

    This slide presentation details shuttle processing flow which starts with wheel stop and ends with launching. The flow is from landing the orbiter is rolled into the Orbiter Processing Facility (OPF), where processing is performed, it is then rolled over to the Vehicle Assembly Building (VAB) where it is mated with the propellant tanks, and payloads are installed. A different flow is detailed if the weather at Kennedy Space Center requires a landing at Dryden.

  16. Released on receipt but intended f o r use

    E-print Network

    Yountain, near Cape Eown, when a moist wind blows i n from the sea. ?omtimes the local topography causes of Permanence, while it is, in r e a l i t y , in constant process of formation on the wind- v?rd sl!! of Crossfell, in the English Lake D i s t r i c t . In the case of a wind bloving athwart a ridge o r mountain

  17. Bacterial Production Lab State variables and processes

    E-print Network

    Vallino, Joseph J.

    Bacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 r (also called bacteria production) B DOM DIN G Time Concentration B G DOM DIN Turnover: [B]/rB U StateI) 8.06 d , Iodine-125 (125I) 60 d Types Helium nuclei Electron Gamma ray For bacterial

  18. Bacterial Production Lab State variables and processes

    E-print Network

    Vallino, Joseph J.

    Helium nuclei Electron Gamma ray For bacterial production, 3H and 14C used. Note, 3H and 14C are weakBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 r (also called bacteria production) B DOM DIN G Time Concentration B G DOM DIN Turnover: [B]/rB U State

  19. Process development

    Microsoft Academic Search

    D. B. Bickler

    1985-01-01

    An overview is given of seven process development activities which were presented at this session. Pulsed excimer laser processing of photovoltaic cells was presented. A different pulsed excimer laser annealing was described using a 50 w laser. Diffusion barrier research focused on lowering the chemical reactivity of amorphous thin film on silicon. In another effort adherent and conductive films were

  20. Peat Processing

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Humics, Inc. already had patented their process for separating wet peat into components and processing it when they consulted NERAC regarding possible applications. The NERAC search revealed numerous uses for humic acid extracted from peat. The product improves seed germination, stimulates root development, and improves crop yields. There are also potential applications in sewage disposal and horticultural peat, etc.

  1. Microchemical Systems (MCS) for Compact Fuel Processing

    E-print Network

    Besser, Ronald S.

    Microchemical Systems (MCS) for Compact Fuel Processing Prof. R.S. Besser Chemical, Biomedical in MCS Understanding Steam Reforming of MeOH as a Model for Thermal Integration Issues in MCS As critical

  2. R for Statistics Rafal Kulik

    E-print Network

    Kulik, Rafal

    R for Statistics Rafal Kulik Department of Mathematics and Statistics University of Ottawa Statistical Society of Ottawa 23 September 2011 Rafal Kulik #12;R for Statistics SSO meeting Plan Rafal Kulik 1 #12;R for Statistics SSO meeting Plan What is R? Rafal Kulik 1 #12;R for Statistics SSO meeting

  3. Clinorotation influences rDNA and NopA100 localization in nucleoli

    Microsoft Academic Search

    M. A. Sobol; F. González-Camacho; V. Rodríguez-Vilariño; E. L. Kordyum; F. J. Medina

    2005-01-01

    The nucleolus is the transcription site of rRNA genes as well as the site of processing and initial packaging of their transcripts. The plant nucleolin homologue NopA100 is involved in the regulation of r-chromatin condensation\\/expansion and rDNA transcription as well as in rRNA processing. We have investigated with immunogold electron microscopy the location of nucleolar DNA and NopA100 in cress

  4. Basic Process Algebra Deadlocking States

    E-print Network

    Srba, Jiri

    and regularity are decidable properties for the class of BPA (or context­free) processes [CHS95, BCS96]. We extend BPA with a deadlocking state obtaining BPA systems. We show that the BPA class is more expressive w.r.t. bisimilarity, but it remains language equivalent to BPA. We prove that bisimilarity

  5. Plans for NOAA's GOES-R Series Satellites

    Microsoft Academic Search

    G. Dittberner; E. Miller; M. Madden; B. Nelson

    NOAA's next generation Geostationary Operational Environmental Satellite (GOES) beginning with GOES R is the follow-on to the GOES N-P series. GOES R is being developed for launch in the 2012 time frame to meet new requirements validated through a rigorous screening and verification process. It presents an opportunity to explore new instruments, satellite designs, and system architectures. NOAA's National Environmental

  6. Ris-R-1490(EN) Technology Foresight and Cleaner

    E-print Network

    of technology 9 4 Technology foresight as a spiral learning process 11 5 Conclusion 14 References 17 Risø-R-1490Risø-R-1490(EN) Technology Foresight and Cleaner Production in a Highly Polluted Industrial Area;Author: Birte Holst Jørgensen and Chris Buckley Title: Technology Foresight and Cleaner Production

  7. Integrative knowledge management to enhance pharmaceutical R&D.

    PubMed

    Marti-Solano, Maria; Birney, Ewan; Bril, Antoine; Della Pasqua, Oscar; Kitano, Hiroaki; Mons, Barend; Xenarios, Ioannis; Sanz, Ferran

    2014-04-01

    Information technologies already have a key role in pharmaceutical research and development (R&D), but achieving substantial advances in their use and effectiveness will depend on overcoming current challenges in sharing, integrating and jointly analysing the range of data generated at different stages of the R&D process. PMID:24687050

  8. R U T C O R R E P O R T

    E-print Network

    the conflict between players. Acknowledgements: Dr Schreider acknowledges SMGS, RMIT University, for providing strategies xi are shares of his activities in industry r. If iraA = be a matrix representing the amount

  9. R Tricks for Kids

    ERIC Educational Resources Information Center

    Braun, W. John; White, Bethany J. G.; Craig, Gavin

    2014-01-01

    Real-world phenomena simulation models, which can be used to engage middle-school students with probability, are described. Links to R instructional material and easy-to-use code are provided to facilitate implementation in the classroom.

  10. Rolling Deck to Repository (R2R): Fleetwide Standard Underway Data Products

    NASA Astrophysics Data System (ADS)

    Sweeney, A. D.; Clark, P. D.; Miller, S. P.; Stocks, K.; Arko, R. A.; Ferrini, V.

    2009-12-01

    The Rolling Deck to Repository (R2R) project was recently launched with the ambitious goal of documenting “routine underway data” from the US academic research fleet and delivering those data to established national archives. Data distributions will be submitted by 18 operating institutions for 30 vessels, from hundreds of cruises per year. R2R will be responsible for digital data collected with instruments that are part of the ship’s permanent equipment and are routinely operated and recorded by the ship’s technicians. Examples include navigation, multibeam, subbottom, gravimeter, magnetics, ADCP, CTD, meteorology, etc. It is anticipated that most underway data will be promptly and publicly released. However R2R will have the ability to securely embargo any specific datasets identified in advance by the chief scientist, for a proprietary hold period of up to two years as mandated by the NSF 04-004 Division of Ocean Sciences Data and Sample Policy. It is important to note that there are data types that R2R will not address. For example, the chief scientist will continue to be responsible for the documentation and archiving of data from specific instruments brought on board by the scientific party, not part of the ship’s standard equipment. Similarly, data collected with National Facility assets including the National Deep Submergence Facility (NDSF), Ocean Bottom Seismograph Instrument Pool (OBSIP) and the National Marine Seismic Facility (NMSF) will continue to be submitted to the appropriate archiving facility directly by those facilities, rather than through R2R. Soon after the shipboard data is received by R2R, the entire original distribution will be safely stored in a deep archive for long-term preservation, and a cataloging process will be undertaken to assemble data sets for delivery to National Data Centers, as described more fully in the invited presentation by Robert Arko, “Rolling Deck to Repository: Technical Design - Experiences and Lessons.” A suite of R2R standard products will be generated for each cruise including (1) Basic Cruise Metadata, (2) Operations Report, and (3) Quality Controlled Navigational Products. Certified R2R navigation will be created at three levels: NavHiRes at the original raw sample rate (usually one sample per second), Nav1Min at a standard 1-minute time interval, and NavControl at a reduced rate appropriate for graphical representation of a cruise at a global or regional scale. These standard data products will be made available for automatic harvesting on www.rvdata.us by repository and data systems, and for download by individual users.

  11. Modulation of in vivo immunoglobulin production by endogenous histamine and H1R and H2R agonists and antagonists.

    PubMed

    Tripathi, Trivendra; Shahid, Mohammad; Khan, Haris M; Negi, Mahendra Pal Singh; Siddiqui, Mashiatullah; Khan, Rahat A

    2010-01-01

    The present study was designed to delineate the immunomodulatory role of histamine receptors (H1R and H2R) and their antibody generation in a rabbit model. Six groups containing 18 rabbits each received either vehicle (sterile distilled water, 1 ml/kg x b.i.d), histamine (100 ?g/kg x b.i.d.), H1R agonist (HTMT, 10 ?g/kg x b.i.d.), H2R agonist (amthamine, 10 ?g/kg x b.i.d.), H1R antagonist (pheniramine, 10 mg/kg x b.i.d.) or H2R antagonist (ranitidine, 10 mg/kg x b.i.d.). All animals were subsequently immunized with an intravenous injection of sheep red blood cells (SRBC). Estimations of total serum immunoglobulins (Igs), immunoglobulin M (IgM) and immunoglobulin G (IgG) were performed by ELISA and hemagglutination assay (HA) at days 0 (pre-immunization), 7, 14, 21, 28 and 58 (post-immunization). Both the ELISA and the HA showed similar production of Igs, IgM and IgG but the results were found comparatively more significant by ELISA as opposed to HA. Results showed that histamine could influence a detectable antibody response to SRBC early (i.e., at day 7), which lasted until day 58. Immunomodulatory processes showed suppression of an Ig generation in the H1R-antagonist group with enhancement in the H2R-antagonist group. The H1R-agonist group showed an increased Ig production in comparison to the H2R-agonist group. The IgM production was inhibited in the H1R-antagonist group as compared to the H2R-antagonist group, and it was also suppressed in H1R-agonist group as compared to H2R-agonist group. IgG production was inhibited in the H1R-antagonist group as opposed to the H2R-antagonist group. In contrast, the H1R-agonist group increased IgG production as compared to the H2R-agonist group. All the results were found to be statistically significant (p < 0.05 or p < 0.01). In conclusion, histamine and its receptor (H1R and H2R) agonists enhance antibody production by triggering the histamine receptors (H1R and H2R), and both the H1R antagonist and the H2R antagonist positively or negatively regulate the antibody production. The findings of this study may have clinical significance. PMID:21098875

  12. Assessment of Advanced Coal Gasification Processes

    NASA Technical Reports Server (NTRS)

    McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

    1981-01-01

    This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

  13. R-modes of neutron stars with the superfluid core

    E-print Network

    Umin Lee; Shijun Yoshida

    2002-11-26

    We investigate the modal properties of the $r$-modes of rotating neutron stars with the core filled with neutron and proton superfluids, taking account of entrainment effects between the superfluids. The stability of the $r$-modes against gravitational radiation reaction is also examined considering viscous dissipation due to shear and a damping mechanism called mutual friction between the superfluids in the core. We find the $r$-modes in the superfluid core are split into ordinary $r$-modes and superfluid $r$-modes, which we call, respectively, $r^o$- and $r^s$-modes. The two superfluids in the core flow together for the $r^o$-modes, while they counter-move for the $r^s$-modes. For the $r^o$-modes, the coefficient $\\kappa_0\\equiv\\lim_{\\Omega\\to 0}\\omega/\\Omega$ is equal to $2m/[l^\\prime(l^\\prime+1)]$, almost independent of the parameter $\\eta$ that parameterizes the entrainment effects between the superfluids, where $\\Omega$ is the angular frequency of rotation, $\\omega$ the oscillation frequency observed in the corotating frame of the star, and $l^\\prime$ and $m$ are the indices of the spherical harmonic function representing the angular dependence of the $r$-modes. For the $r^s$-modes, on the other hand, $\\kappa_0$ is equal to $2m/[l^\\prime(l^\\prime+1)]$ at $\\eta=0$ (no entrainment), and it almost linearly increases as $\\eta$ is increased from $\\eta=0$. The mutual friction in the superfluid core is found ineffective to stabilize the $r$-mode instability caused by the $r^o$-mode except in a few narrow regions of $\\eta$. The $r$-mode instability caused by the $r^s$-modes, on the other hand, is extremely weak and easily damped by dissipative processes in the star.

  14. I I I' I/rnrr!! \\ol c . r r ! l ' r a o $ i n r h r \\ d o { ' r ' h s \\ " r d p ! ' t .

    E-print Network

    Shine, Rick

    ,pec,,latu;: ol lhe -r.l",ndbrLtyof .ne (umercd ,.:d, ,l these animals have bem based upon extrapo lation fromqr creen and King, lqoj). Unfortunately, we know so little abdt the un- derlying biology of most

  15. Transplant Process

    MedlinePLUS

    ... of transplant. Discharge from the hospital Planning to go home The discharge process actually begins weeks before ... you What has to happen before you can go home? For the most part, transplant centers don’ ...

  16. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Robbins, G.A.; Brandes, S.D.; Winschel, R.A.; Burke, F.P.

    1991-11-01

    Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  17. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Robbins, G.A.; Brandes, S.D.; Winschel, R.A.; Burke, F.P.

    1992-03-01

    CONSOL R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  18. Coal liquefaction process streams characterization and evaluation

    SciTech Connect

    Winschel, R.A.; Brandes, S.D.; Robbins, G.A.; Burke, F.P.

    1991-11-01

    Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-field: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.

  19. Anodizing Process

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This anodizing process traces its origin to the 1960's when Reynolds Metals Company, under contract with Goddard Space Flight Center, developed a multipurpose anodizing electrolyte (MAE) process to produce a hard protective finish for spacecraft aluminum. MAE produces a high-density, abrasion-resistant film prior to the coloring step, in which the pores of the film are impregnated with a metallic form of salt. Tru-Color product applications include building fronts, railing, curtain walls, doors and windows.

  20. Flash Flood Processes

    NSDL National Science Digital Library

    2014-09-14

    According to NOAA’s National Weather Service, a flash flood is a life-threatening flood that begins within 6 hours--and often within 3 hours--of a causative event. That causative event can be intense rainfall, the failure of a dam, levee, or other structure that is impounding water, or the sudden rise of water level associated with river ice jams. The “Flash Flood Processes” module offers an introduction to the distinguishing features of flash floods, the underlying hydrologic influences and the use of flash flood guidance (FFG) products. Through use of rich illustrations, animations, and interactions, this module explains the differences between flash floods and general floods and examines the hydrologic processes that impact flash flooding risk. In addition, it provides an introduction to the use of flash flood guidance (FFG) products including derivation from ThreshR and rainfall-runoff curves as well as current strengths and limitations.

  1. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    Sandia

    2009-09-01

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  2. Self-Assembling Process for Fabricating Tailored Thin Films

    ScienceCinema

    None

    2010-01-08

    A simple, economical nanotechnology coating process that enables the development of nanoparticle thin films with architectures and properties unattainable by any other processing method. 2007 R&D 100 winner (SAND2007-1878P)

  3. r-Process Abundance Universality and Actinide Cosmochronology

    E-print Network

    Kaori Otsuki; Grant J. Mathews; Toshitaka Kajino

    2003-06-12

    We review recent observational and theoretical results concerning the presence of actinide nuclei on the surfaces of old halo stars and their use as an age determinant. We present model calculations which show that the observed universality of abundances for 56 = 75 and possibly Z <= 56 as well. This introduces an uncertainty into the use of the Th/Eu chronometer as a means to estimate the ages of the metal deficient stars. We do find, however, that the U/Th ratio is a robust chronometer. This is because the initial production ratio of U to Th is almost independent of the astrophysical nucleosynthesis environment. The largest remaining uncertainties in the U/Th initial production ratio are due to the input nuclear physics models.

  4. CALCIUM TRANSPORT PROCESSES OF LOBSTER HEPATOPANCREATIC MITOCHONDRIA. (R823068)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  5. R&D for graft adsorbents by radiation processing

    NASA Astrophysics Data System (ADS)

    Seko, Noriaki; Tamada, Masao

    Fibrous adsorbent for removal and recovery of metal ions have been synthesized by graft polymerization. In the grafting, the functional groups which have high selectivity against for target metal ions such as Fe, Sc, As, and U are introduced onto nonwoven fabric. When the monomer has a chelate group which makes selective coordination bond to specific these ions, it was directly grafted on the trunk polymer. In the case of precursor monomer having functional groups such as epoxy ring, the grafted trunk fabric is chemically modified. The resultant fibrous adsorbent leads the swift adsorption of metal ions. This property by using fibrous material can reduce the column size of adsorbent in the purification of waste water. The size of purification equipment becomes quite compact and that implies total volume of equipment can reduce. Instead of organic solvent, emulsion system which disperses monomer micelles in water with assistance of surfactant was found to accelerate the graft polymerization. This means the air pollution from organic solvent can be avoided by water system grafting. Furthermore, since the emulsion grafting was highly efficient, the required irradiation dose was considerably lower compared to general organic solvent system. As a result, the emulsion grafting has enormous potential for natural polymer to use as a trunk material for grafting. If a natural polymer such as cellulose can be used, the dependence on petroleum resources, the amount of industrial waste and the generation of carbon dioxide will be reduced to some extent.

  6. Energy Conservation R. D. & D. Programs in High Temperature Processes 

    E-print Network

    Sheneman, R. L.

    1979-01-01

    the metal. The Bonneville Power Administration plans to reduce its power sales to the aluminum industry during the next ten years. The cement industry is rapidly constructing coal-fired kiln capacity. Mandatory reporting and industry wide... removed through the use of additives to a coal-oil-mix fuel substitute Aluminum ingots, plant scrap, purchased new scrap and old scrap are remelted and alloyed by selective charging in the preparation of molten alloy for casting. . ;-:~. Experimental...

  7. EPA 402-R-96-014 STABILIZATION/SOLIDIFICATION PROCESSES

    E-print Network

    Laboratory BWR Boiling Water Reactor CERCLA Comprehensive Environmental Response, Compensation and Liability that these companies have performed. Our next project is to design and develop a test matrix for testing the four S Ed Barth, EPA Office of Research and Development Andrea Faucette, Kaiser-Hill Company, L.L.C. Gary

  8. SPRINT: A new parallel framework for R

    PubMed Central

    Hill, Jon; Hambley, Matthew; Forster, Thorsten; Mewissen, Muriel; Sloan, Terence M; Scharinger, Florian; Trew, Arthur; Ghazal, Peter

    2008-01-01

    Background Microarray analysis allows the simultaneous measurement of thousands to millions of genes or sequences across tens to thousands of different samples. The analysis of the resulting data tests the limits of existing bioinformatics computing infrastructure. A solution to this issue is to use High Performance Computing (HPC) systems, which contain many processors and more memory than desktop computer systems. Many biostatisticians use R to process the data gleaned from microarray analysis and there is even a dedicated group of packages, Bioconductor, for this purpose. However, to exploit HPC systems, R must be able to utilise the multiple processors available on these systems. There are existing modules that enable R to use multiple processors, but these are either difficult to use for the HPC novice or cannot be used to solve certain classes of problems. A method of exploiting HPC systems, using R, but without recourse to mastering parallel programming paradigms is therefore necessary to analyse genomic data to its fullest. Results We have designed and built a prototype framework that allows the addition of parallelised functions to R to enable the easy exploitation of HPC systems. The Simple Parallel R INTerface (SPRINT) is a wrapper around such parallelised functions. Their use requires very little modification to existing sequential R scripts and no expertise in parallel computing. As an example we created a function that carries out the computation of a pairwise calculated correlation matrix. This performs well with SPRINT. When executed using SPRINT on an HPC resource of eight processors this computation reduces by more than three times the time R takes to complete it on one processor. Conclusion SPRINT allows the biostatistician to concentrate on the research problems rather than the computation, while still allowing exploitation of HPC systems. It is easy to use and with further development will become more useful as more functions are added to the framework. PMID:19114001

  9. Ozone friendly binary blends R 32\\/R 134a and the ternary R 407b

    Microsoft Academic Search

    A. Stegou-Sagia; X. Kakatsios; M. Damanakis

    2004-01-01

    The objective of this paper is to present thermodynamic properties and characteristics of the binary refrigerant mixtures R 32\\/R 134a in compositions 20\\/80%, 30\\/70%, 40\\/60% by mass and of the ternary mixture R 407b: 10 wt% R 32+70 wt% R 125+20 wt% R 134a. A computer code has been developed and by use of a Peng–Robinson type equation of state,

  10. Synthesis of Tritium Labeled (R,R)-4-Methoxyfenoterol

    PubMed Central

    Kozocas, Joseph A.; Bupp, James E.; Tanga, Mary J.; Pluhar, Joseph T.; Wainer, Irving W.

    2009-01-01

    The preparation of 2?,4?,6?-[3H3]-(R,R)-4-methoxyfenoterol, a tritium-labeled derivative of (R,R)-4-methoxyfenoterol was demonstrated on a 15 mCi scale providing material with a specific activity of 57 Ci/mmol. PMID:20228869

  11. ?to e in R-symmetric Supersymmetry

    E-print Network

    Ricky Fok; Graham D. Kribs

    2010-11-23

    We demonstrate that mu/e slepton mixing is significantly more restricted than previously thought within the already remarkably flavor-safe R-symmetric supersymmetric standard model. We calculate bounds from mu to e gamma, mu to 3e and, most importantly, mu to e conversion. The process mu to e conversion is significantly more restrictive in R-symmetric models since this process can occur through operators that do not require a chirality-flip. We delineate the allowed parameter space, demonstrating that maximal mixing is rarely possible with weak scale superpartners, while O(0.1) mixing is permitted within most of the space. The best approach to find or rule out mu/e mixing in R-symmetric supersymmetric models is a multi-pronged attack looking at both mu to e conversion as well as mu to e gamma. The redundancy eliminates much of the parameter space where one process, but not both processes, contain amplitudes that accidentally destructively interfere. We briefly discuss implications for searches of slepton flavor violation at the LHC.

  12. Dynamical R-parity violation.

    PubMed

    Csáki, Csaba; Kuflik, Eric; Volansky, Tomer

    2014-04-01

    We present a new paradigm for supersymmetric theories with R-parity violation (RPV). At high scale, R parity is conserved in the visible sector but spontaneously broken in the supersymmetry-breaking sector. The breaking is then dynamically mediated to the visible sector and is manifested via nonrenormalizable operators at low energy. Consequently, RPV operators originate from the Kähler potential rather than the superpotential, and are naturally suppressed by the supersymmetry-breaking scale, explaining their small magnitudes. A new set of nonholomorphic RPV operators is identified and found to often dominate over the standard RPV ones. We study the relevant low-energy constraints arising from baryon-number violating processes, proton decay, and flavor changing neutral currents, which may all be satisfied if a solution to the standard model flavor puzzle is incorporated. The chiral structure of the RPV operators implies new and distinct collider signatures, indicating the need to alter current techniques in searching for RPV at the LHC. PMID:24745404

  13. Sparse unitary operators and repeated entries in the process matrix

    E-print Network

    Vinayak Jagadish; Anil Shaji

    2015-06-12

    We show that quantum processes of low rank are inexorably connected to the dimensions of the environmental state space that the system is in contact with. We also show that the process matrix representing such low rank processes will have only a few distinct entries which goes as O(r^2) (r is the rank) and hence the number of independent measurements needed to characterize the process is greatly reduced.

  14. Macdonald processes

    E-print Network

    Borodin, Alexei

    2011-01-01

    Macdonald processes are probability measures on sequences of partitions defined in terms of nonnegative specializations of the Macdonald symmetric functions and two Macdonald parameters q,t in [0,1). We prove several results about these processes, which include the following. (1) We explicitly evaluate expectations of a rich family of observables for these processes. (2) In the case t=0, we find a Fredholm determinant formula for a q-Laplace transform of the distribution of the last part of the Macdonald-random partition. (3) We introduce Markov dynamics that preserve the class of Macdonald processes and lead to new "integrable" 2d and 1d interacting particle systems. (4) In a large time limit transition, and as q goes to 1, the particles of these systems crystallize on a lattice, and fluctuations around the lattice converge to O'Connell's Whittaker process that describe semi-discrete Brownian directed polymers. (5) This yields a Fredholm determinant for the Laplace transform of the polymer partition function...

  15. Strong and weak gravitational field in $R+?^4/R$ gravity

    E-print Network

    Kh. Saaidi; A. Vajdi; S. W. Rabiei; A. Aghamohammadi; H. Sheikhahmadi

    2012-01-18

    We introduce a new approach for investigating the weak field limit of vacuum field equations in $f(R)$ gravity and we find the weak field limit of $f(R)=R+\\mu ^4/R$ gravity. Furthermore, we study the strong gravity regime in $R+\\mu^{4}/R$ model of $f(R)$ gravity. We show the existence of strong gravitational field in vacuum for such model. We find out in the limit $\\mu\\rightarrow 0$, the weak field limit and the strong gravitational field can be regarded as a perturbed Schwarzschild metric.

  16. Assessment of advanced coal gasification processes

    NASA Technical Reports Server (NTRS)

    Mccarthy, J.; Ferrall, J.; Charng, T.; Houseman, J.

    1981-01-01

    A technical assessment of the following advanced coal gasification processes is presented: high throughput gasification (HTG) process; single stage high mass flux (HMF) processes; (CS/R) hydrogasification process; and the catalytic coal gasification (CCG) process. Each process is evaluated for its potential to produce synthetic natural gas from a bituminous coal. Key similarities, differences, strengths, weaknesses, and potential improvements to each process are identified. The HTG and the HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging, and syngas as the initial raw product gas. The CS/R hydrogasifier is also SRT, but is nonslagging and produces a raw gas high in methane content. The CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier.

  17. r-Java 2.0: the nuclear physics

    E-print Network

    Kostka, M; Shand, Z; Ouyed, R; Jaikumar, P

    2014-01-01

    [Aims:] We present r-Java 2.0, a nucleosynthesis code for open use that performs r-process calculations as well as a suite of other analysis tools. [Methods:] Equipped with a straightforward graphical user interface, r-Java 2.0 is capable of; simulating nuclear statistical equilibrium (NSE), calculating r-process abundances for a wide range of input parameters and astrophysical environments, computing the mass fragmentation from neutron-induced fission as well as the study of individual nucleosynthesis processes. [Results:] In this paper we discuss enhancements made to this version of r-Java, paramount of which is the ability to solve the full reaction network. The sophisticated fission methodology incorporated into r-Java 2.0 which includes three fission channels (beta-delayed, neutron-induced and spontaneous fission) as well as computation of the mass fragmentation is compared to the upper limit on mass fission approximation. The effects of including beta-delayed neutron emission on r-process yield is studi...

  18. R2 Research II R3 Research III

    E-print Network

    Velev, Orlin D.

    Cafe KSC ­ Keystone Science Center P1 ­ Partners I P2 ­ Partners II P3 ­ Partners III R1 ­ Research I Greenway P1 EB3 SH EB2 BTEC U P2 KSC W COT V1 VP V3 V4 R4 R1 R3 R2 V2 T P3 1801 EB1 AC IC U U U U U P P P P

  19. Moisture processes accompanying convective activity

    E-print Network

    Sienkiewicz, Meta Elizabeth

    1981-01-01

    of an Oklahoma squall line by grouping observations with respect to their distance from the surface wind shift line. They explained sources and sinks of moisture in terms of physical processes occur- ring in the area. The calculated moisture sink, however, did... stations partici- pating in AVE VII. ~ 365 ~ Gc 'r ' +562 ~ ' 553 ~ 15; I I ~ 532 ~ 669 1 VGG' ' ~ 10 656 ~ 0! ' . . r' j ~ IOG I +6&1 ~ 11 1 w18 ~ 119 17 , ~ 69 02 & I @363 ~ . F 66 I o &60 ~ 17 . ~ 229 I I I ' ~ 270 ? - . . 01...

  20. Process Technology

    NSDL National Science Digital Library

    This video segment, adapted from ATETV, looks at the Process Technology program at the College of the Mainland and what students will learn in order to succeed in industry. The video explains how the community college accommodates the busy lives of adult non-traditional students while still giving them a well-rounded liberal arts education to make them more marketable to employers. Additionally, the segment explores the various career options for students in process technology programs. Educators will also find a background essay, discussion questions, and standards alignment for the material. Running time for the video is 3:37.

  1. r Human Brain Mapping 30:18661876 (2009) r MINI-REVIEW

    E-print Network

    Moran, Rosalyn

    2009-01-01

    a useful way to test hypotheses about distributed processing in the brain, using electromagnetic data. Humr Human Brain Mapping 30:1866­1876 (2009) r MINI-REVIEW Dynamic Causal Modeling for EEG and MEG/EEG and local field potentials. These studies illustrate how DCM can be used to analyze evoked responses

  2. r e s e a r c h LLLLLinksinksinksinksinks Autumn 2001Volume 10, Number 3

    E-print Network

    Park, Edward

    ), School of Engineering Science, have developed a new technology for underwater 3D acoustic imaging in the imp Policy are the elections of m appointment of the DORE. S SFU Research Expertise Database Goes to existing web-based materi pages, wherever available. R the same processes. "The expertise database w

  3. r Human Brain Mapping 33:19291940 (2012) r Evolution of Crossmodal Reorganization of the

    E-print Network

    2012-01-01

    of the visuo-audio-motor speech processing loop, including Broca's area. Hum Brain Mapp 33:1929­1940, 2012. VC speechreading activates Broca's area in normally hearing subjects (NHS), the activity level elicitedr Human Brain Mapping 33:1929­1940 (2012) r Evolution of Crossmodal Reorganization of the Voice

  4. Dimensionality Reduction in ICA and Rank-(R1, R2, . . . , RN ) Reduction in Multilinear

    E-print Network

    only few sources have significant contributions. Examples are electro-encephalography (EEG), magneto-encephalography (MEG), nuclear magnetic resonance (NMR), hyper-spectral image processing, data analysis, etc. To reduce prewhitening. The L. De Lathauwer holds a permanent research position with the French C.N.R.S.; he also holds

  5. miR-27a and miR-27a* contribute to metastatic properties of osteosarcoma cells

    PubMed Central

    Maximov, Vadim; Galasso, Marco; Khawaled, Saleh; Abou-Sharieha, Samah; Volinia, Stefano; Jones, Kevin B.; Croce, Carlo M.; Aqeilan, Rami I.

    2015-01-01

    Osteosarcoma (OS) is the most common primary malignant bone tumor in adolescents and young adults. The essential mechanisms underlying osteosarcomagenesis and progression continue to be obscure. MicroRNAs (miRNAs) have far-reaching effects on the cellular biology of development and cancer. We recently reported that unique miRNA signatures associate with the pathogenesis and progression of OS. Of particular interest, we found that higher expression of miR-27a is associated with clinical metastatic disease. We report here that overexpression of miR-27a/miR-27a*, a microRNA pair derived from a single precursor, promotes pulmonary OS metastases formation. By contrast, sequestering miR-27a/miR-27a* by sponge technology suppressed OS cells invasion and metastases formation. miR-27a/miR-27a* directly repressed CBFA2T3 expression among other target genes. We demonstrated that CBFA2T3 is downregulated in majority of OS samples and its over expression significantly attenuated OS metastatic process mediated by miR-27a/miR-27a* underscoring CBFA2T3 functions as a tumor suppressor in OS. These findings establish that miR-27a/miR-27a* pair plays a significant role in OS metastasis and proposes it as a potential diagnostic and therapeutic target in managing OS metastases. PMID:25749032

  6. MARGARET R. MULHOLLAND Associate Professor

    E-print Network

    Darby, Dennis

    1 MARGARET R. MULHOLLAND Associate Professor Department of Ocean, Earth and Atmospheric Sciences. Howarth, M. R. Mulholland, M. Paolisso, D. Secor, K. Sellner, D. Wardrop, and R. Wood. 2010. Potential, D. A., M. R. Mulholland, and F. Fu. 2009. Nutrient cycles and marine microbes in a CO2-enriched

  7. Hydrologic Tests at Characterization Wells R-9i, R-13, R-19, R-22, and R-31

    SciTech Connect

    W.J. Stone; S. McLin

    2003-03-01

    Hydrologic information is essential for environmental efforts at Los Alamos National Laboratory. Testing at new characterization wells being drilled to the regional aquifer (''R wells'') to improve the conceptual hydrogeologic model of the Pajarito Plateau is providing such information. Drilling has been by air-rotary casing-advance or open-hole methods. Most wells are completed with multiple screens. After their construction, wells were rigorously developed by wire-brushing, bailing, followed by surging, swabbing, or jetting, and finally by pumping. These methods are effective based on field-parameter measurements and comparison of results of hydrologic testing at well R-31 before and after complete well development. We conducted field tests on various zones of saturation penetrated by the R wells to collect data needed for determining hydraulic properties. This document provides details of the design and execution of testing as well as an analysis of data for five of the new wells: R-9i, R-13, R-19, R-22, and R-31. One well was evaluated by a pumping test (R-13), another was evaluated by both straddle-packer/injection and pumping tests (R-9i), and the rest were evaluated by injection tests alone (R-19, R-22, R-31). Testing was constrained by the regional setting (complex geology and multiple zones of saturation) and well construction (multiscreen completion and the small diameter of the production casing). Packers are required for testing multiscreen wells. The small diameter of the production casing not only precludes the use of a slugger but also limits the capacity of pumps that can be used in testing, especially for the depths involved in the R wells. For example, pumping at a maximum rate of 19 gallons per minute did not significantly stress the regional aquifer at R-13. Although not slug tests, the injection tests are comparable in several ways, and analysis of data by slugtest methods is appropriate. Despite constraints, the results obtained appear valid based on (1) the care taken during test implementation and data analysis, (2) comparison of results for initial and repeated tests obtained by the same analytical method, (3) comparison of results obtained for a given test by different analytical methods, (4) comparison of results with values determined by geophysical logging in the wells and pumping tests of the same geologic units elsewhere on the plateau, and (5) comparison with hydraulic properties commonly reported for similar geologic materials outside the area. Significant contributions of this report are not only the documentation of test design, implementation, and analysis but also a comprehensive table showing the distribution of hydraulic properties for the saturated geologic units tested beneath the Pajarito Plateau. We also offer several recommendations based on testing to date. Placing screens across the water table and geologic contacts as well as employing oversized filter packs hinders testing and should be avoided. In addition, we recommend that future testing include some alternative designs and methods. Multiple methods and routine repeat testing for a given screened interval would permit comparison of results.

  8. R&D in the Federal Budget: FY 1979, R&D, Industry, and the Economy. Research & Development, AAAS Report III.

    ERIC Educational Resources Information Center

    Shapley, Willis H.; Phillips, Don I.

    The federal government's budgeting process for allocating resources to research and development (R&D) is described. The report includes: (1) a review of the FY 1979 R&D budget; (2) a statistical overview of the budget and a critique of the administration's policies on R&D; (3) a general picture of R&D in industry; and (4) a discussion of some of…

  9. Evolution of the miR-290–295/miR-371–373 Cluster Family Seed Repertoire

    PubMed Central

    Wu, Shuang; Aksoy, Munevver; Shi, Jianting; Houbaviy, Hristo Botev

    2014-01-01

    Expression of the mouse miR-290–295 cluster and its miR-371–373 homolog in human is restricted to early embryos, primordial germ cells, the germ line stem cell compartment of the adult testis and to stem cell lines derived from the early embryonic lineages. Sequencing data suggest considerable seed diversification between the seven homologous pre-miRNAs of miR-290–295 but it is not clear if all of the implied miR-290–295 seeds are also conserved in the human miR-371–373 cluster, which consists of only three homologous pre-miRNAs. By employing miRNA target reporters we show that most, if not all, seeds in miR-290–295 are represented in miR-371–373. In the mouse, pre-miR-290, pre-miR-292 and pre-miR-293 express subsets of the miRNA isoforms processed from the single human pre-miR-371. Comparison of the possible miR-290–295/miR-371–373 seed repertoires in placental mammals suggests a model for the evolution of this miRNA cluster family, which would be otherwise difficult to deduce based solely on pre-miRNA sequence comparisons. The conservation of co-expressed seeds that is characteristic of miR-290–295/miR-371–373 should be taken into account in models of the corresponding miRNA-target interaction networks. PMID:25268927

  10. SUPERCRITICAL SIRS EPIDEMIC PROCESSES: FLUCTUATIONS ABOUT ENDEMIC LEVEL

    E-print Network

    Dolgoarshinnykh, Regina

    SUPERCRITICAL SIRS EPIDEMIC PROCESSES: FLUCTUATIONS ABOUT ENDEMIC LEVEL R. G. DOLGOARSHINNYKH Abstract. We describe fluctuations about the endemic level of the supercritical SIRS stochastic epidemic for the SIRS epidemic is R0 = /, and the epidemic processes are supercritical when > . In [ref to LLN] we

  11. Nonlin. Processes Geophys., 14, 131138, 2007 www.nonlin-processes-geophys.net/14/131/2007/

    E-print Network

    Paris-Sud XI, Université de

    Automatic extraction of faults and fractal analysis from remote sensing data R. Gloaguen1, P. R. Marpu1 provided by the objects allow the automatic identification of geolog- ical structures. In this article, we. Digital elevation models and radar data of an area near Lake Magadi (Kenya) have been processed. We

  12. R. Burl Yarberry

    ERIC Educational Resources Information Center

    Nishimoto, Warren

    2007-01-01

    R. Burl Yarberry was born in 1920 in Pueblo, Colorado. He attended public schools in Pueblo and graduated from high school in 1938. After a year attending the Colorado School of Mines, he enlisted in the U.S. Marine Corps and served in the Pacific during World War II. Following his discharge, he earned a BA in English from Western State College of…

  13. Simulation Insights Using "R"

    ERIC Educational Resources Information Center

    Kostadinov, Boyan

    2013-01-01

    This article attempts to introduce the reader to computational thinking and solving problems involving randomness. The main technique being employed is the Monte Carlo method, using the freely available software "R for Statistical Computing." The author illustrates the computer simulation approach by focusing on several problems of…

  14. Reprinted from :r Canadian

    E-print Network

    concrete elements erected in pieces and post-tensioned together by means of high tensile steel bars-produced structural components which had to be shipped by rail to the site and assembled using the post-tensioning erection of a concentrate loading facility using precast concrete in a remote location R. D. KEELER Penner

  15. Avalanche precursors R. Delannay,

    E-print Network

    Gruner, Daniel S.

    Avalanche precursors R. Delannay, Institut de Physique de Rennes, Université de Rennes 1, CNRS UMR at the top of the tray after some avalanches. · 4 or 5 large avalanches then observed during the slow of small "avalanches" which are recorded by a camera.2mm diameter beads #12;N. Nérone et al. Physica A 283

  16. Michael R. Hudec Publications

    E-print Network

    Yang, Zong-Liang

    ., and Porter, M. L., 2001, Structure and evolution of Upheaval Dome: pinched-off salt diapir or meteoritic., 2011, The salt mine: a digital atlas of salt tectonics: The University of Texas at Austin, Bureau., Harrison, H., Peel, Frank, Hudec, M. R., and Perkins, B. F., eds., 1995, Salt, sediment, and hydrocarbons

  17. Northeast Fi Observers r

    E-print Network

    be a rare hould not de rovide guida ip. tocols as fol from the cap pecify am or phone numb r company n. S NUMBER 774-501-741 the schedule nloading, and may start the p rvers should late for a erver would

  18. R u t c o r R e p o r t

    E-print Network

    smaller than or equal to r. Twice-positive sequences are those for which we have ai aj ai-t aj-t = aiaj-t - ajai-t 0. (1.1) for every i ai-1ai+1 . Fekete [4] also, is said to be logconcave if the corresponding probability function is logconcave. While continuous

  19. Process Models for High Performance Telecom Systems

    E-print Network

    Maguire Jr., Gerald Q.

    Process Models for High Performance Telecom Systems S T A F F A N L U N D S T R Ö M Master or asynchronous I/O. In this thesis, some selected process models are analyzed and evaluated for usage in telecom systems. Modern telecom systems have requirements on real-time performance for multimedia service

  20. ACT-R Meets fMRI

    Microsoft Academic Search

    Yulin Qin; Daniel Bothell; John R. Anderson

    2006-01-01

    ACT-R (Adaptive Control of Thought - Rational) is a theory and computational model of human cognitive architecture. It consists\\u000a of a set of modules with their own buffers, each devoted to processing a different kind of information. A production rule\\u000a in the core production system can be fired based on the chunks in these buffers and then it changes the

  1. Signal Processing: Introduction Digital Signal Processing

    E-print Network

    Rimon, Elon

    Signal Processing: Introduction Digital Signal Processing Introduction Areas of Applications signals and processing #12;Signal Processing: Introduction DSP in various disciplines Communication, Finance ( Economic models, Stock market) and many more #12;Signal Processing: Introduction DSP

  2. Fertility Analysis and Recommendations Manager (F.A.R.M.)

    Microsoft Academic Search

    G. A. Kruger; R. E. Karamanos; J. L. Heniy

    1994-01-01

    Farm Analysis and Recommendation Manager (F.A.R.M.) is the computer program which controls the processing of soil samples at Plains Innovative Laboratory Services in Saskatoon, Saskatchewan, Canada. The program controls the flow of samples from reception through drying, grinding, and analytical processes to the printing and faxing of the results. The system prepares all the data sheets with the required standard

  3. A toolkit for parallel image processing J. M. Squyresy

    E-print Network

    Lumsdaine, Andrew

    A toolkit for parallel image processing J. M. Squyresy A. Lumsdainey R. L. Stevensonz y Department and implementation of a parallel image processing software library (the Parallel Image Processing Toolkit). The Toolkit not only supplies a rich set of image processing routines, it is designed principally

  4. Integration, Regulation, and Long-Term Stability of R2 Retrotransposons.

    PubMed

    Eickbush, Thomas H; Eickbush, Danna G

    2015-04-01

    R2 elements are sequence specific non-LTR retrotransposons that exclusively insert in the 28S rRNA genes of animals. R2s encode an endonuclease that cleaves the insertion site and a reverse transcriptase that uses the cleaved DNA to prime reverse transcription of the R2 transcript, a process termed target primed reverse transcription. Additional unusual properties of the reverse transcriptase as well as DNA and RNA binding domains of the R2 encoded protein have been characterized. R2 expression is through co-transcription with the 28S gene and self-cleavage by a ribozyme encoded at the R2 5' end. Studies in laboratory stocks and natural populations of Drosophila suggest that R2 expression is tied to the distribution of R2-inserted units within the rDNA locus. Most individuals have no R2 expression because only a small fraction of their rRNA genes need to be active, and a contiguous region of the locus free of R2 insertions can be selected for activation. However, if the R2-free region is not large enough to produce sufficient rRNA, flanking units - including those inserted with R2 - must be activated. Finally, R2 copies rapidly turnover within the rDNA locus, yet R2 has been vertically maintained in animal lineages for hundreds of millions of years. The key to this stability is R2's ability to remain dormant in rDNA units outside the transcribed regions for generations until the stochastic nature of the crossovers that drive the concerted evolution of the rDNA locus inevitably reshuffle the inserted and uninserted units, resulting in transcription of the R2-inserted units. PMID:26104703

  5. Signal processing

    Microsoft Academic Search

    David M. Norman

    1991-01-01

    The application of signal processing technology to conventional weapons systems can lower operator workloads and enhance kill probabilities, while automating wide-area surveillance, target search and classification, target tracking, and aimpoint selection. Immediate opportunities exist for automatic target cueing in underwater and over-the-horizon targeting, as well as for airborne multiple-target fire control. By embedding the transit\\/receive electronics into conformal aircraft sensor

  6. Vermicomposting Process

    Microsoft Academic Search

    Lawrence K. Wang; Yung-Tse Hung; Kathleen Hung Li

    Vermicomposting is a novel municipal biosolids and solid waste treatment process that uses earthworms (Oligochaete annelids)\\u000a for the biodegradation of the biosolids and\\/or solid waste. This system is alternately called earthworm conversion, vermicomposting,\\u000a vermistabilization, worm composting, or annelidic consumption. The worms maintain aerobic conditions in the organic substances\\u000a while accelerating and enhancing the biological decomposition of the organic substances. The

  7. Renewal Processes

    NSDL National Science Digital Library

    Siegrist, Kyle

    Created by Kyle Siegrist of the University of Alabama-Huntsville, this is an online, interactive lesson on the renewal processes. The resource provides examples, exercises, and applets which include renewal equations and renewal limit theorems. This is the fifteenth of seventeen different statistics lessons presented by Siegrist. This site is broken up much like an online textbook. Each lesson is separable, but together, they form a cohesive look at different aspects of statistics.

  8. Crystal field theory of magnetism in R2Fe14B

    Microsoft Academic Search

    M. Yamada; H. Kato; H. Hiroyoshi; H. Yamamoto; Y. Nakagawa

    1987-01-01

    A systematic study of the spin structure and magnetization process in a series of R2Fe14B (R: rare earth ion) compounds has been made using a combined crystalline electric field (CEF) and molecular field approximation. For the compounds of heavy R, experimental results are explained almost satisfactory in terms of the same set of parameters of CEF and molecular field.

  9. Verification of Sentences Containing Anaphoric Metaphors: An ACT-R Computational Model

    E-print Network

    Verification of Sentences Containing Anaphoric Metaphors: An ACT-R Computational Model Raluca Budiu to Raluca Budiu. #12;Verification of Sentences Containing Anaphoric Metaphors: An ACT-R Computational Model, a more general ACT-R (Anderson & Lebiere, 1998) model of sentence processing that has been used

  10. Hydropyrolysis process

    DOEpatents

    Ullman, Alan Z. (Northridge, CA); Silverman, Jacob (Woodland Hills, CA); Friedman, Joseph (Huntington Beach, CA)

    1986-01-01

    An improved process for producing a methane-enriched gas wherein a hydrogen-deficient carbonaceous material is treated with a hydrogen-containing pyrolysis gas at an elevated temperature and pressure to produce a product gas mixture including methane, carbon monoxide and hydrogen. The improvement comprises passing the product gas mixture sequentially through a water-gas shift reaction zone and a gas separation zone to provide separate gas streams of methane and of a recycle gas comprising hydrogen, carbon monoxide and methane for recycle to the process. A controlled amount of steam also is provided which when combined with the recycle gas provides a pyrolysis gas for treatment of additional hydrogen-deficient carbonaceous material. The amount of steam used and the conditions within the water-gas shift reaction zone and gas separation zone are controlled to obtain a steady-state composition of pyrolysis gas which will comprise hydrogen as the principal constituent and a minor amount of carbon monoxide, steam and methane so that no external source of hydrogen is needed to supply the hydrogen requirements of the process. In accordance with a particularly preferred embodiment, conditions are controlled such that there also is produced a significant quantity of benzene as a valuable coproduct.

  11. HuR/Methyl-HuR and AUF1 regulate the MAT expressed during liver proliferation, differentiation and carcinogenesis

    PubMed Central

    Vázquez-Chantada, Mercedes; Fernández-Ramos, David; Embade, Nieves; Martínez-Lopez, Nuria; Varela-Rey, Marta; Woodhoo, Ashwin; Luka, Zigmund; Wagner, Conrad; Anglim, Paul P.; Finnell, Richard H.; Caballería, Juan; Laird-Offringa, Ite A.; Gorospe, Myriam; Lu, Shelly C; Mato, José M; Martínez-Chantar, M Luz

    2010-01-01

    Background & Aims Hepatic de-differentiation, liver development, and malignant transformation are processes in which the levels of hepatic S-adenosylmethionine (SAMe) are tightly regulated by two genes, MAT1A and MAT2A. MAT1A is expressed in the adult liver, whereas MAT2A expression is primarily extra-hepatic and is strongly associated with liver proliferation. The mechanisms that regulate these expression patterns are not completely understood. In silico analysis of the 3? untranslated region of MAT1A and MAT2A revealed putative binding sites for the RNA-binding proteins AUF1 and HuR, respectively. We investigated the post-transcriptional regulation of MAT1A and MAT2A by AUF1, HuR and methyl-HuR in the aforementioned biological processes. Results During hepatic de-differentiation, the switch between MAT1A and MAT2A coincided with an increase in HuR and AUF1 expression. SAMe treatment altered this homeostasis by shifting the balance of AUF1 and methyl-HuR/HuR, which was identified for the first time as an inhibitor of MAT2A mRNA stability. We also observed a similar temporal distribution and a functional link between HuR, methyl-HuR, AUF1, and MAT1A and MAT2A during the fetal liver development. Immunofluorescent analysis revealed increased levels of HuR and AUF1, and a decrease in methyl-HuR levels in human livers with hepatocellular carcinoma (HCC). Conclusions Our data strongly support a role for AUF1 and HuR/methyl-HuR in liver de-differentiation, development and human HCC progression through the post-translational regulation of MAT1A and MAT2A mRNAs. PMID:20102719

  12. N A S A ' S M I C R O G R A V I T Y R E S E A R C H P R O G R A M National Aeronautics and

    E-print Network

    Waliser, Duane E.

    N A S A ' S M I C R O G R A V I T Y R E S E A R C H P R O G R A M #12;#12;National Aeronautics and Space Administration George C. Marshall Space Flight Center Marshall Space Flight Center, Alabama 35812 NASA/TM ­ 2000-210615 N A S A ' S M I C R O G R A V I T Y R E S E A R C H P R O G R A M A N N U A L R E

  13. R u t c o r R e p o r t

    E-print Network

    1 Introduction One major concern of molecular biology is the sequencing of the human genome and the genomes of other organisms. Unfortunately, sequencing is a slow and error­prone process, and, in the case be used to localize genes and mutations, and can also simplify the sequencing process. A clone's integrity

  14. Investigation on the boiling heat transfer characteristics of R404A and R134a under stratified flow condition

    NASA Astrophysics Data System (ADS)

    Balachander, P.; Raja, B.

    2015-06-01

    An experimental investigation on the flow boiling heat transfer characteristics of R404A and R134a for low mass flux and heat flux conditions in a smooth horizontal tube is reported. Refrigerant saturation temperatures -15, -10, -5 and 0 °C were considered for the flow boiling conditions. The influence of the mass flux, heat flux and saturation temperature on the heat transfer coefficients of R404A and R134a are discussed in detail. The predominant flow pattern for the tested conditions is confirmed to be the stratified-wavy flow. The study revealed that the heat transfer coefficient is a strong function of the heat flux, throughout the flow boiling process, and the nucleate boiling contribution is much higher for R404A compared to that of R134a. The heat transfer characteristic of R404A is compared with that of R134a, to understand their relative performance in low temperature appliances. A modified correlation for the flow boiling heat transfer coefficient of R404A is developed to fit the experimental results of R404A.

  15. Using R via PHP for Teaching Purposes: R-php

    Microsoft Academic Search

    Angelo M. Mineo; Alfredo Pontillo

    2006-01-01

    This paper deals with the R-php statistical software, that is an environment for statistical analysis, freely accessible and attainable through the World Wide Web, based on R. Indeed, this software uses, as \\

  16. Phillip R. Owens, p. 1 Phillip R. Owens

    E-print Network

    Owens, Phillip R.

    Phillip R. Owens, p. 1 Phillip R. Owens Department of Agronomy Purdue University 915 W. State St Assistant Professor Agronomy Department, Purdue University, West Lafayette, IN 1/05 ­ present 60% Research

  17. 1'"":"""":1.R---

    E-print Network

    ofTexas, Energy Office 16. Abstract Automated road and highway maintenance has extremely high~,"FOl~~r~il~l~illrB",RY ,~...'SWUTC/94/60035-2 L000416 4. Title and Subtitle S. Report Date A Model for Evaluating Automation in RoadReport and Period Covered 14. Sponsoring Agency Code Supported by a grant from the Office ofthe Governor ofthe State

  18. R3 fluids

    E-print Network

    R. Caimmi

    2006-07-27

    With regard to large-scale astrophysical systems, the current paper deals with (i) formulation of tensor virial equations from the standpoint of analytical mechanics; (ii) investigation on the role of systematic and random motions for virial equilibrium configurations; (iii) extent to which systematic and random motions are equivalent in changing a fluid shape. The tensor virial equations are formulated using analytical mechanics, and the self potential-energy tensor is shown to be symmetric. The role of systematic and random motions in collisionless, ideal, self-gravitating fluids, is analysed in detail including radial and tangential velocity dispersion on the equatorial plane. R3 fluids are defined as ideal, self-gravitating fluids in virial equilibrium, with systematic rotation around a principal axis of inertia, and ihe related virial equations are formulated. A unified theory of systematic and random motions is developed for R3 fluids, taking into consideration imaginary rotation. The effect of random motion excess is shown to be equivalent to an additional real or imaginary rotation, respectively, inducing flattening or elongation. R3 fluids are found to admit adjoint configurations with isotropic random velocity distribution. Further constraints are established on the amount of random velocity anisotropy along the principal axes, for triaxial configurations. A necessary condition is formulated for the occurrence of bifurcation points from axisymmetric to triaxial configurations in virial equilibrium, which is independent of the anisotropy parameters. In the special case of homeoidally striated Jacobi ellipsoid, some previously known results are reproduced.

  19. Hydrologic Tests at Characterization Wells R-9i, R-13, R-19, R-22, and R-31, Revision 1

    SciTech Connect

    S.G.McLin; W.J. Stone

    2004-06-01

    Hydrologic information is essential for environmental efforts at Los Alamos National Laboratory. Testing at new characterization wells being drilled to the regional aquifer (''R wells'') to improve the conceptual hydrogeologic model of the Pajarito Plateau is providing such information. Field tests were conducted on various zones of saturation penetrated by the R wells to collect data needed for determining hydraulic properties. This document provides details of the design and execution of testing as well as an analysis of data for five new wells: R-9i, R-13, R-19, R-22, and R-31. One well (R-13) was evaluated by a pumping test and the rest (R-9i, R-19, R-22, and R-31) were evaluated by injection tests. Characterization well R-9i is located in Los Alamos Canyon approximately 0.3 mi west of the Route 4/Route 502 intersection. It was completed at a depth of 322 ft below ground surface (bgs) in March 2000. This well was constructed with two screens positioned below the regional water table. Both screens were tested. Screen 1 is completed at about 189-200 ft bgs in fractured basalt, and screen 2 is completed at about 270-280 ft bgs in massive basalt. Specific capacity analysis of the screen 1 data suggests that the fractured basalt has a transmissivity (T) of 589 ft{sup 2}/day and corresponds to a hydraulic conductivity (K) of 7.1 ft/day based on a saturated thickness of 83 ft. The injection test data from the massive basalt near screen 2 were analyzed by the Bouwer-Rice slug test methodology and suggest that K is 0.11 ft/day, corresponding to a T of about 2.8 ft{sup 2}/day based on a saturated thickness of 25 ft. Characterization well R-13 is located in Mortandad Canyon just west of the eastern Laboratory boundary. It was completed at a depth of 1029 ft bgs in February 2002. This well was constructed with one 60-ft long screen positioned about 125 ft below the regional water table. This screen is completed at about 958-1019 ft bgs and straddles the geologic contact between the Puye fanglomerate and unassigned pumiceous units. The specific capacity analysis of a 12 minute pumping test indicates that the Puye fanglomerates near the R-13 screen have a T of 5269 ft{sup 2}/day and correspond to a hydraulic conductivity (K) of 17.6 ft/day based on a saturated thickness of 300 ft. Characterization well R-19 is located east of firing site IJ in Technical Area (TA) 36 on the mesa between Three-mile and Potrillo Canyons. It was completed at a depth of 1885 ft bgs in April 2000. This well was constructed with two screens positioned above the regional water table and five screens positioned below the regional water table. Only the bottom two screens were tested. Screen 6 is completed at about 1727-1734 ft bgs in Puye fanglomerate, and screen 7 is completed at about 1832-1849 ft bgs in Puye fanglomerate. Specific capacity analysis of the screen 6 data suggests that T is about 6923 ft{sup 2}/day and corresponds to a K of 18.6 ft/day based on a saturated thickness of 373 ft. Specific capacity analysis of the screen 7 data suggests that T is about 8179 ft{sup 2}/day and corresponds to a K of 22.0 ft/day based on a saturated thickness of 373 ft. Characterization well R-22 is located on Mesita del Buey between Canada del Buey and Pajarito Canyons immediately east of Material Disposal Area (MDA) G in TA-54. It was completed at a depth of 1489 ft bgs in October 2000. This well was constructed with five screens positioned at or below the regional water table; however, only screens 2-5 were tested. Screen 1 is completed at the regional water table at about 872-914 ft bgs in Cerros del Rio basalt. Screen 2 is completed at about 947-989 ft bgs in Cerros del Rio basalt. Screen 3 is completed at about 1272-1279 ft bgs in Puye fanglomerate. Screen 4 is completed at about 1378-1452 ft bgs in older basalt. Screen 5 is completed at about 1447-1452 ft bgs in older fanglomerate. Bouwer-Rice analyses of the injection-test recovery data suggest K values of 0.04, 0.32, 0.54, and 0.27 ft/day for screens 2, 3, 4, and 5, respectively. These values correspond to

  20. Thee'tale Tits process of Jordan algebras revisited Holger P. Petersson

    E-print Network

    Thee'tale Tits process of Jordan algebras revisited Holger. Geburtstag gewidmet 0. Introduction The 'etale Tits process, which was called the toral Tits process by Petersson-R* *acine [12], may be viewed as a Jordan-theoretical method

  1. Signal processing

    NASA Astrophysics Data System (ADS)

    Norman, David M.

    The application of signal processing technology to conventional weapons systems can lower operator workloads and enhance kill probabilities, while automating wide-area surveillance, target search and classification, target tracking, and aimpoint selection. Immediate opportunities exist for automatic target cueing in underwater and over-the-horizon targeting, as well as for airborne multiple-target fire control. By embedding the transit/receive electronics into conformal aircraft sensor arrays, a 'smart' skin can be created. Electronically scanned phased arrays can be used to yield accurate azimuthal and elevation positions while nullifying EW threats. Attention is given to major development thrusts in algorithm design.

  2. Processing system

    NASA Technical Reports Server (NTRS)

    Hilland, J. E.

    1983-01-01

    To implement the analysis techniques and to provide end-to-end processing, a system was designed with the following capabilities: receive and catalog data from many sources; organize the data on mass storage for rapid access; edit for reasonableness; create new data sets by sorting on parameter, averaging and merging; provide statistical analysis and display tools; and distribute data on demand. Consideration was given to developing a flexible system that could meet immediate workshop needs and respond to future requirements. System architecture and data set details implemented are discussed.

  3. An Activation-Based Model of Sentence Processing as Skilled Memory Retrieval

    E-print Network

    Lewis, Richard

    ­Rational (ACT­R) architecture, and our process model is realized in ACT­R. We present the results of 6 sets free scaling parameter fixed across the simulations; all other parameters were ACT­R defaults; Working memory; ACT-R; Cognitive modeling; Interference; Decay; Activation; Parsing; Syntax; Cognitive

  4. Regulation of the Response Regulator Gene degU through the Binding of SinR/SlrR and Exclusion of SinR/SlrR by DegU in Bacillus subtilis

    PubMed Central

    Yoshikawa, Hirofumi; Chibazakura, Taku

    2014-01-01

    Bacillus subtilis DegU is a response regulator of the DegS-DegU two-component regulatory system. Phosphorylated DegU (DegU-P) controls many genes and biological processes, such as exoprotease and ?-polyglutamic acid production, in addition to the degU gene, by binding to target gene promoters. Nonphosphorylated DegU and low levels of DegU-P are required for swarming motility and genetic competence. The DNA-binding repressors SinR and SlrR are part of a double-negative feedback loop and comprise the epigenetic switch governing biofilm formation. In this study, we found that SinR repressed degU. Furthermore, SlrR, which interacts with SinR through protein-protein interaction, seems to have an active role in degU expression in in vivo lacZ analysis. An in vitro transcription assay supported this observation. An electrophoretic mobility shift assay (EMSA) showed that SinR bound to the degU promoter and that SlrR formed a complex with SinR on the degU promoter. In EMSA, DegU-P excluded the SinR/SlrR complex but not SinR from the degU promoter in the presence of RNA polymerase. These findings suggest that DegU-P interacts with SlrR. In support of this hypothesis, disruption of the slrR gene resulted in decreased degU expression. This newly identified regulatory mechanism for degU is considered to be sequential transcription factor replacement. PMID:24317403

  5. Moisture processes accompanying convective activity 

    E-print Network

    Sienkiewicz, Meta Elizabeth

    1981-01-01

    Moisture Processes Accompanying Convective Activity (December 1981) Meta Elizabeth Sienkiewicz, B. S. , Texas A&M University Chairman of Advisory Committee: Dr, James R. Scoggins A moisture budget analysis was performed on data collected during the AVE... VII (2-3 May 1978) and AVE-SESAME I (10-11 April 1979) experiments. Local rates-of-change of moisture were compared with averaged moisture divergence in the same time period. Results were presented as contoured plots in the horizontal...

  6. Parallel R with the Rmpi and pbdR Libraries

    E-print Network

    Crawford, T. Daniel

    Parallel R with the Rmpi and pbdR Libraries Advanced Research Computing April 22;Advanced Research Compu9ng The Need for Parallelism #12;Advanced Research Compu9ng Parallelism in R · Serial by default ­Excep9on: Built with parallel BLAS (ARC

  7. Efficient separations & processing crosscutting program

    SciTech Connect

    NONE

    1996-08-01

    The Efficient Separations and Processing Crosscutting Program (ESP) was created in 1991 to identify, develop, and perfect chemical and physical separations technologies and chemical processes which treat wastes and address environmental problems throughout the DOE complex. The ESP funds several multiyear tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESP supports applied research and development (R & D) leading to the demonstration or use of these separations technologies by other organizations within the Department of Energy (DOE), Office of Environmental Management.

  8. R-body-producing bacteria.

    PubMed Central

    Pond, F R; Gibson, I; Lalucat, J; Quackenbush, R L

    1989-01-01

    Until 10 years ago, R bodies were known only as diagnostic features by which endosymbionts of paramecia were identified as kappa particles. They were thought to be limited to the cytoplasm of two species in the Paramecium aurelia species complex. Now, R bodies have been found in free-living bacteria and other Paramecium species. The organisms now known to form R bodies include the cytoplasmic kappa endosymbionts of P. biaurelia and P. tetraurelia, the macronuclear kappa endosymbionts of P. caudatum, Pseudomonas avenae (a free-living plant pathogen), Pseudomonas taeniospiralis (a hydrogen-oxidizing soil microorganism), Rhodospirillum centenum (a photosynthetic bacterium), and a soil bacterium, EPS-5028, which is probably a pseudomonad. R bodies themselves fall into five distinct groups, distinguished by size, the morphology of the R-body ribbons, and the unrolling behavior of wound R bodies. In recent years, the inherent difficulties in studying the organization and assembly of R bodies by the obligate endosymbiont kappa, have been alleviated by cloning and expressing genetic determinants for these R bodies (type 51) in Escherichia coli. Type 51 R-body synthesis requires three low-molecular-mass polypeptides. One of these is modified posttranslationally, giving rise to 12 polypeptide species, which are the major structural subunits of the R body. R bodies are encoded in kappa species by extrachromosomal elements. Type 51 R bodies, produced in Caedibacter taeniospiralis, are encoded by a plasmid, whereas bacteriophage genomes probably control R-body synthesis in other kappa species. However, there is no evidence that either bacteriophages or plasmids are present in P. avenae or P. taeniospiralis. No sequence homology was detected between type 51 R-body-encoding DNA and DNA from any R-body-producing species, except C. varicaedens 1038. The evolutionary relatedness of different types of R bodies remains unknown. Images PMID:2651865

  9. Thermodynamic Properties of the Mixtures R23\\/R744 and R41\\/R744 and their Efficiency as Refrigerants

    Microsoft Academic Search

    Aleksandr Vasserman C; Valentine Malchevsky S

    Mixtures of refrigerants are widely used as working substances for refrigerating plants. Among them, mixtures of ozone-safe and natural refrigerants, in particular R23\\/R744 and R41\\/R744, are important. For calculating their thermodynamic properties, we compiled equations of state on the basis of the method in (1). According to this reference, the equation of state for a mixture is presented as a

  10. Physicochemical processes

    SciTech Connect

    Matsumoto, M.R.; Jensen, J.N. [State Univ. of New York, Buffalo, NY (United States); McGinley, P.M. [Univ. of Kentucky, Lexington, KY (United States); Reed, B.E. [West Virginia Univ., Morgantown, WV (United States)

    1993-06-01

    A variety of waste water treatment processes are reported. Destruction of free and organically bound cyanides by alkaline hydrolysis in a pipeline reactor was studied. A bench-scale pilot system combining coagulation, sedimentation, and ultrafiltration to study treatment of animal wastewater was developed. A pilot limestone contactor was evaluated for its ability to treat a low pH, low alkalinity surface water supply for corrosion control, and as a conditioning step for flocculation. Experiments were conducted with a falling film reactor to determine the potential of freeze concentration to treat municipal wastewater for reuse. The effects of reductants and alkali on the sludge quantity from chromium(VI) wastes and the leachability and physical properties of solidified chromium sludge were investigated. Development and experience with a pilot-scale surfactant washing-flushing system to remove polychlorinated biphenyls (PCBs) from contaminated soils was reported.

  11. Hydrogenation process

    SciTech Connect

    Hoxmeier, R.J.

    1990-01-09

    This patent describes a process for selectively hydrogenating the ethylenic unsaturation in a polymer comprising ethylenic unsaturation and cyano groups. It comprises: contacting a polymer comprising polymerized conjugated diene units having ethylenic unsaturation and cyano groups selected from polymerized nitrile units and grafted cyano compounds with hydrogen in a first suitable solvent, and in the presence of a catalyst prepared by combining one or more palladium carboxylates with one or more aluminum compounds, selected from aluminum hydrides and aluminum alkyls, in a second suitable solvent. The second suitable solvent May be the same or different from the first suitable solvent; maintaining the contact for a sufficient period of time permit conversion of at least a portion of the ethylenic unsaturation contained in the polymer; and recovering an at least partially hydrogenated polymer.

  12. Etherification process

    DOEpatents

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1990-08-21

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figs.

  13. Oligomerization process

    DOEpatents

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1991-03-26

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled. 2 figures.

  14. Oligomerization process

    DOEpatents

    Smith, Jr., Lawrence A. (Bellaire, TX); hearn, Dennis (Houston, TX); Jones, Jr., Edward M. (Friendswood, TX)

    1991-01-01

    A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300.degree. F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  15. Etherification process

    DOEpatents

    Smith, Jr., Lawrence A. (Houston, TX); Hearn, Dennis (Houston, TX); Jones, Jr., Edward M. (Friendswood, TX)

    1990-01-01

    A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  16. Incineration process

    SciTech Connect

    Sosnowski, L.

    1988-06-28

    A process is described for coincinerating sewage sludge or toxic liquid chemical waste and a supplemental fuel comprising the steps of: introducing none-gaseous supplemental fuel into an incineration zone at a point intermediate a vertical length of the incineration zone to produce a flame front intermediate the vertical length of the incineration zone; incinerating the introduced non-gaseous supplemental fuel to achieve a combustion temperature approximately between 1800 to 2300 Fahrenheit; dispersing the sewage sludge or toxic liquid chemical waste in relatively small droplets downwardly over the flame front in the incineration zone to evaporate water in the droplets and to destroy toxicity of toxic waste by combustion in the incineration zone; recovering hot incineration off gases from the incineration zone, wherein the mixture of the sewage sludge or toxic liquid chemical waste and the supplemental fuel comprises about 84% trash, 15% tire chips and 1% sewage sludge or liquid chemical waste.

  17. Image Processing

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Electronic Imagery, Inc.'s ImageScale Plus software, developed through a Small Business Innovation Research (SBIR) contract with Kennedy Space Flight Center for use on space shuttle Orbiter in 1991, enables astronauts to conduct image processing, prepare electronic still camera images in orbit, display them and downlink images to ground based scientists for evaluation. Electronic Imagery, Inc.'s ImageCount, a spin-off product of ImageScale Plus, is used to count trees in Florida orange groves. Other applications include x-ray and MRI imagery, textile designs and special effects for movies. As of 1/28/98, company could not be located, therefore contact/product information is no longer valid.

  18. PUBLICATION LIST Joseph R. Manson

    E-print Network

    Manson, Joseph R.

    Phonons", Physical Review Letters 22, 346 (1969). 2. J. R. Manson, V. Celli, and B. DuVall, "Induction by an Exponential Corrugated Potential", Physical Review Letters 43, 1839 (1979). 20. N. Garcia, V. Celli, and J. R", Physical Review B 11, 1066 (1975). 9. B. Gaffney and J. R. Manson, "Energy Accommodation Coefficient

  19. R for Beginners Emmanuel Paradis

    E-print Network

    Watkins, Joseph C.

    of the R Development Core Team for their considerable efforts in developing R and animating the discussion of an object: the indexing system . 26 3.5.5 Accessing the values of an object with names . . . . . . 29 3 on the understanding of how R works, with the aim of a beginner, rather than expert, use. Given that the possibilities

  20. CURRICULUM VITAE R. Cory Watkins

    E-print Network

    Wu, Shin-Tson

    policing: a comparison of the daily activities of community and beat officers, Policing: An International for legitimacy, Police Quarterly. Revise and Resubmit. 2007 Watkins, R. C., Reynolds, K. M., and Eaglin, R., Frank, J., Famega, C., Eck, J. and Watkins, R. C. Managing citizen calls for police service