86,977 research outputs found
Personal Papers (MS 80-0002)
No full textLetter from Philip Hambsch to Daniel Kempner discussing his previous trip to Galveston, the temperature during the day, and his current activities and travel plans
Investigation of Mass-TKE Distributions of Fission Fragments from the 235U(n,f)-Reaction in Resonances
No full textThe aim of the present work was to obtain experimental data on the incident neutron energy dependence of the relative weights of the two main asymmetric fission modes, which make up the mass distribution of the 235U(n,f)-reaction. This dependence of the fission modes as a function of incident neutron energy in 235U(n,f) was discovered in Ref. [1]. But so far it is the only measurement where fission mode fluctuations in resonance neutron induced fission were detected. The statistical significance of the data of Ref. [1] below 8 eV was not high enough to draw conclusions on the physical nature of the fluctuations. Based on the progress in fission cross-section and the multi-modal model calculations reported in Ref.[2] it was found reasonable to analyse the data of the measurement reported in Ref. [3]. Measurements of fission fragment (FF) mass and total kinetic energy (TKE) distributions of 235U(n,f) were carried out at the Dubna IBR-30 time of flight spectrometer in the resonance neutron energy range from thermal up to 35 eV. In the energy range from thermal to 8.77 eV individual resonances could be resolved, but for the higher incident neutron energies the resolution degraded due to the rather large (4 s) width of the neutron pulse.
The data analysis was carried out in two steps. At first the experimental difficulties were investigated i.e. the very close proximity to the source, the alignment of the ionisation chamber was checked and necessary improvements were made. At the final step FF mass yield and TKE distributions were evaluated for various incident neutron energy intervals and the difference of these values obtained for thermal and resonance neutron energies was constructed. In contrast to Ref. [1] we realised true relative measurements (with respect to thermal energy). The data analysis confirmed the main characteristics of the asymmetric fission modes obtained in Ref. [1] from thermal neutron induced fission of 235U as well as the scale of the fluctuation of the fission mode weights in different neutron resonances (~15% for the standard I and ~4% for the standard II mode). Some differences between the results of the present work to the results obtained in Ref. [1] could be explained by the worse neutron energy resolution of the present investigation as well as due to the data analysis, where new calibration results obtained after the publication of Ref. [1] were used.
References
1. F.-J. Hambsch, H.-H. Knitter, C. Budtz-Jorgensen, and J.P. Theobald, Nucl. Phys. A491,
56 (1989).
2. F. -J. Hambsch, Proc. 12th Int. Seminar on Interaction of Neutrons with Nuclei (ISINN-12), Dubna, Russia, May 26-29, 2004.
3. Sh. S. Zeinalov, M. Florek, W.I. Furman, V.A. Kriatchkov and Yu. S. Zamyatnin, Proc. 7th Int. Seminar on Interaction of Neutrons with Nuclei (ISINN-7), Dubna, Russia, May 25-28, 1999.JRC.D.5 - Neutron physic
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Measurement of fission yields and isomeric yield ratios at IGISOL
No full textData on fission yields and isomeric yield ratios (IYR) are tools to study the fission process, in particular the generation of angular momentum. We use the IGISOL facility with the Penning trap JYFLTRAP in Jyväskylä, Finland, for such measurements on 232Th and natU targets. Previously published fission yield data from IGISOL concern the 232Th(p,f) and 238U(p,f) reactions at 25 and 50 MeV. Recently, a neutron source, using the Be(p,n) reaction, has been developed, installed and tested. We summarize the results for (p,f) focusing on the first measurement of IYR by direct ion counting. We also present first results for IYR and relative yields for Sn and Sb isotopes in the 128-133 mass range from natU(n,f) based on γ-spectrometry. We find a staggering behaviour in the cumulative yields for Sn and a shift in the independent fission yields for Sb as compared to current evaluations. Plans for the future experimental program on fission yields and IYR measurements are discussed.peerReviewe
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
Mapping the Discipline of the Olympic Games An Author-Cocitation Analysis
No full textThe authors conducted an author cocitation analysis on prominent authors writing about the Olympics during the 1990s. Author cocitation is an established bibliometric technique that can be used to measure the relative similarities of topics written about by the cited authors. This enables a visual representation of the “intellectual space” of the discipline, in this case the Olympics, to be created for the period under review. So core and peripheral research areas are identified, along with their major contributors. The representation appears as a two-dimensional cluster-enhanced map. Subject expertise was then applied to the results to place labels on the generated clusters of authors and their topics
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