553 research outputs found

    Vibration measurement by pulse differential holographic interferometry

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    Technique measures structural deformation of materials subjected to wide range of temperatures and other environmental conditions. Effects of convection currents are eliminated by operating a pulsed laser in double pulse mode that exposes hologram twice in quick succession

    Use of biological reference points for the conservation of atlantic salmon (Salmo salar L.)in the River Lune, North West England.

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    This paper deals with the development and use of biological reference points for salmon conservation on the River Lune, England. The Lune supports recreational and net fisheries with annual catches in the region of 1,000 and 1356 salmon respectively. Using models transported from other river systems, biological reference points exclusive to the Lune were developed; specifically the number of eggs deposited and carrying capacity estimates for age 0+ and 1+ parr. The conservation limit was estimated at 11.9 million eggs and between 1989 and 1998 was exceeded in two years. Comparison of juvenile salmon densities in 1991 and 1997 with estimates of carrying capacity indicated that 0+ and 1+ parr densities were at around 60 % of carrying capacity and may relate to the number of eggs deposited in 1990 and 1996 being approximately 70% of the target value. The paper discusses the management actions taken in order to ensure that the management target of the conservation limit being met four years out of five is delivered. It also discusses the balance between conservation and exploitation and the socio-economic decisions made in order to ensure parity of impacts on the rod and net fisheries. The regulations have been enforced since 1999 and the paper concludes with an assessment of the actions taken to deliver the management targets, over the last five years

    The impact of global nuclear mass model uncertainties on rr-process abundance predictions

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    Rapid neutron capture or `rr-process' nucleosynthesis may be responsible for half the production of heavy elements above iron on the periodic table. Masses are one of the most important nuclear physics ingredients that go into calculations of rr-process nucleosynthesis as they enter into the calculations of reaction rates, decay rates, branching ratios and Q-values. We explore the impact of uncertainties in three nuclear mass models on rr-process abundances by performing global monte carlo simulations. We show that root-mean-square (rms) errors of current mass models are large so that current rr-process predictions are insufficient in predicting features found in solar residuals and in rr-process enhanced metal poor stars. We conclude that the reduction of global rms errors below 100100 keV will allow for more robust rr-process predictions.Comment: 5 pages, 3 figures, invited talk at the 15th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15), to appear in EPJ Web of Conference

    Applications of holography to vibrations, transient response, and wave propagation

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    Applications of holography to vibrations, transient response, and wave propagatio

    The sensitivity of r-process nucleosynthesis to the properties of neutron-rich nuclei

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    About half of the heavy elements in the Solar System were created by rapid neutron capture, or r-process, nucleosynthesis. In the r-process, heavy elements are built up via a sequence of neutron captures and beta decays in which an intense neutron flux pushes material out towards the neutron drip line. The nuclear network simulations used to test potential astrophysical scenarios for the r-process therefore require nuclear physics data (masses, beta decay lifetimes, neutron capture rates, fission probabilities) for thousands of nuclei far from stability. Only a small fraction of this data has been experimentally measured. Here we discuss recent sensitivity studies that aim to determine the nuclei whose properties are most crucial for r-process calculations.Comment: 8 pages, 4 figures, submitted to the Proceedings of the Fifth International Conference on Fission and Properties of Neutron-Rich Nuclei (ICFN5

    Sensitivity of the r-process to nuclear masses

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    The rapid neutron capture process (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. 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. This work is an attempt to determine the most crucial nuclear masses to measure using an r-process simulation code and several mass models (FRDM, Duflo-Zuker, and HFB-21). The most important nuclear masses to measure are determined by the changes in the resulting r-process abundances. Nuclei around the closed shells near N=50, 82, and 126 have the largest impact on r-process abundances irrespective of the mass models used.Comment: 5 pages, 4 figures, accepted in European Physical Journal

    Adiponectin in Cardiovascular Inflammation and Obesity

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    Inflammation is widely known to play a key role in the development and progression of cardiovascular diseases. It is becoming increasingly evident that obesity is linked to many proinflammatory and obesity-associated cardiovascular conditions (e.g., metabolic syndrome, acute coronary syndrome, and congestive heart failure). It has been observed that adipokines play an increasingly large role in systemic and local inflammation. Therefore, adipose tissue may have a more important role than previously thought in the pathogenesis of several disease types. This review explores the recently described role of adiponectin as an immunomodulatory factor and how it intersects with the inflammation associated with both cardiovascular and autoimmune pathologies

    Sensitivity studies for r-process nucleosynthesis in three astrophysical scenarios

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    In rapid neutron capture, or r-process, nucleosynthesis, heavy elements are built up via a sequence of neutron captures and beta decays that involves thousands of nuclei far from stability. Though we understand the basics of how the r-process proceeds, its astrophysical site is still not conclusively known. The nuclear network simulations we use to test potential astrophysical scenarios require nuclear physics data (masses, beta decay lifetimes, neutron capture rates, fission probabilities) for all of the nuclei on the neutron-rich side of the nuclear chart, from the valley of stability to the neutron drip line. Here we discuss recent sensitivity studies that aim to determine which individual pieces of nuclear data are the most crucial for r-process calculations. We consider three types of astrophysical scenarios: a traditional hot r-process, a cold r-process in which the temperature and density drop rapidly, and a neutron star merger trajectory.Comment: 8 pages, 4 figures, submitted to the Proceedings of the International Nuclear Physics Conference (INPC) 201
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