2,041 research outputs found
Bibliography of El Nino and associated publications
ENGLISH: Citations from the fields of biological, physical and chemical oceanography, meteorology and marine fisheries are used to compile a new bibliography on El Nino phenomena and associated publications. An alphanumeric coding procedure relating this bibliography to a newly microfilmed version of the contents of this bibliography is described. SPANISH: Se emplean las anotaciones del campo biolĂłgico, fĂsico y quĂmico de la oceanografĂa, la rneteorologĂa y la pesca marina para compilar una nueva bibliografĂa sobre el fenĂłmeno del Niño, y publicaciones afines. Se describe el procedimiento de un cĂłdigo alfanumĂ©rico relacionando esta bibliografĂa a una versiĂłn recientemente microfilmada del contenido de Ă©sta.
(PDF contains 53 pages.
Model Checking Tap Withdrawal in C. Elegans
We present what we believe to be the first formal verification of a
biologically realistic (nonlinear ODE) model of a neural circuit in a
multicellular organism: Tap Withdrawal (TW) in \emph{C. Elegans}, the common
roundworm. TW is a reflexive behavior exhibited by \emph{C. Elegans} in
response to vibrating the surface on which it is moving; the neural circuit
underlying this response is the subject of this investigation. Specifically, we
perform reachability analysis on the TW circuit model of Wicks et al. (1996),
which enables us to estimate key circuit parameters. Underlying our approach is
the use of Fan and Mitra's recently developed technique for automatically
computing local discrepancy (convergence and divergence rates) of general
nonlinear systems. We show that the results we obtain are in agreement with the
experimental results of Wicks et al. (1995). As opposed to the fixed parameters
found in most biological models, which can only produce the predominant
behavior, our techniques characterize ranges of parameters that produce (and do
not produce) all three observed behaviors: reversal of movement, acceleration,
and lack of response
Anisotropy of Imbalanced Alfvenic Turbulence in Fast Solar Wind
We present the first measurement of the scale-dependent power anisotropy of
Elsasser variables in imbalanced fast solar wind turbulence. The dominant
Elsasser mode is isotropic at lower spacecraft frequencies but becomes
increasingly anisotropic at higher frequencies. The sub-dominant mode is
anisotropic throughout, but in a scale-independent way (at higher frequencies).
There are two distinct subranges exhibiting different scalings within what is
normally considered the inertial range. The low Alfven ratio and shallow
scaling of the sub-dominant Elsasser mode suggest an interpretation of the
observed discrepancy between the velocity and magnetic field scalings. The
total energy is dominated by the latter. These results do not appear to be
fully explained by any of the current theories of incompressible imbalanced MHD
turbulence.Comment: 5 pages, 2 figure
Junius and Joseph: Presidential Politics and the Assassination of the First Mormon Prophet
""Junius and Joseph examines Joseph Smith's nearly forgotten [1844] presidential bid, the events leading up to his assassination on June 27, 1844, and the tangled aftermath of the tragic incident. It... establishes that Joseph Smith's murder, rather than being the deadly outcome of a spontaneous mob uprising, was in fact a carefully planned military-style execution. It is now possible to identify many of the key individuals engaged in planning his assassination as well as those who took part in the assault on Carthage jail. And furthermore, this study presents incontrovertible evidence that the effort to remove the Mormon leader from power and influence extended well beyond Hancock County [Illinois] (and included prominent Whig politicians as well as the Democratic governor of the state), thereby transforming his death from an impulsive act by local vigilantes into a political assassination sanctioned by some of the most powerful men in Illinois. The circumstances surrounding Joseph Smith's death also serve to highlight the often unrecognized truth that a full understanding of early Mormon history can be gained only when considered in the context of events taking place in American society as a whole."" Beginning with this provocative thesis from the introduction, Wicks and Foister engage in a thorough reexamination of Joseph Smith's 1844 presidential candidacy, its political context and implications, and its probable connection to his murder. While their work asserts controversial conclusions about what and who were behind that murder, its import extends further since it provides unprecedented, detailed portraits of political Mormonism, politics in 1844 Illinois and the Midwest, the web of connections and personalities that linked the two, and the events of June 27. ---Book Review can be found in: The Western Historical Quarterly Winter 2006, by: Stephen C. Taysom
Junius and Joseph: Presidential Politics and the Assassination of the First Mormon Prophet
Junius and Joseph examines Joseph Smith\u27s nearly forgotten [1844] presidential bid, the events leading up to his assassination on June 27, 1844, and the tangled aftermath of the tragic incident. It... establishes that Joseph Smith\u27s murder, rather than being the deadly outcome of a spontaneous mob uprising, was in fact a carefully planned military-style execution. It is now possible to identify many of the key individuals engaged in planning his assassination as well as those who took part in the assault on Carthage jail. And furthermore, this study presents incontrovertible evidence that the effort to remove the Mormon leader from power and influence extended well beyond Hancock County [Illinois] (and included prominent Whig politicians as well as the Democratic governor of the state), thereby transforming his death from an impulsive act by local vigilantes into a political assassination sanctioned by some of the most powerful men in Illinois. The circumstances surrounding Joseph Smith\u27s death also serve to highlight the often unrecognized truth that a full understanding of early Mormon history can be gained only when considered in the context of events taking place in American society as a whole. Beginning with this provocative thesis from the introduction, Wicks and Foister engage in a thorough reexamination of Joseph Smith\u27s 1844 presidential candidacy, its political context and implications, and its probable connection to his murder. While their work asserts controversial conclusions about what and who were behind that murder, its import extends further since it provides unprecedented, detailed portraits of political Mormonism, politics in 1844 Illinois and the Midwest, the web of connections and personalities that linked the two, and the events of June 27. ---Book Review can be found in: The Western Historical Quarterly Winter 2006, by: Stephen C. Taysom.https://digitalcommons.usu.edu/usupress_pubs/1041/thumbnail.jp
The evolution of inverted magnetic fields through the inner heliosphere
Local inversions are often observed in the heliospheric magnetic field (HMF), but their origins and evolution are not yet fully understood.Parker Solar Probe has recently observed rapid, AlfvĂ©nic, HMF inversions in the inner heliosphere, known as âswitchbacksâ, which have been interpreted as the possible remnants of coronal jets. It has also been suggested that inverted HMF may be produced by near-Sun interchange reconnection; a key process in mechanisms proposed for slow solar wind release. These cases suggest that the source of inverted HMF is near the Sun, and it follows that these inversions would gradually decay and straighten as they propagate out through the heliosphere. Alternatively, HMF inversions could form during solar wind transit, through phenomena such velocity shears, draping over ejecta, or waves and turbulence. Such processes are expected to lead to a qualitatively radial evolution of inverted HMF structures. Using Helios measurements spanning 0.3â1 AU, we examine the occurrence rate of inverted HMF, as well as other magnetic field morphologies, as a function of radial distance r, and find that it continually increases. This trend may be explained by inverted HMF observed between 0.3â1 AU being primarily driven by one or more of the above in-transit processes, rather than created at the Sun. We make suggestions as to the relative importance of these different processes based on the evolution of the magnetic field properties associated with inverted HMF. We also explore alternative explanations outside of our suggested driving processes which may lead to the observed trend
An Experimental Overview of Results Presented at SQM 2006
I have been asked to give an critical overview on the experimental results
shown in the conference with a emphasis of what has been learned and the
challenges that are ahead in trying to understand the physics of the strongly
interacting quark-gluon plasma. I will not try to summarize all of the results
presented, rather I will concentrate primarily on RHIC data from this
conference. Throughout this summary, I will periodically review some of the
previous results for those not familiar with the present state of the field.Comment: 15 pages, 12 Figure
High power diode laser Master Oscillator-Power Amplifier (MOPA)
High power multiple quantum well AlGaAs diode laser master oscillator - power amplifier (MOPA) systems were examined both experimentally and theoretically. For two pass operation, it was found that powers in excess of 0.3 W per 100 micrometers of facet length were achievable while maintaining diffraction-limited beam quality. Internal electrical-to-optical conversion efficiencies as high as 25 percent were observed at an internal amplifier gain of 9 dB. Theoretical modeling of multiple quantum well amplifiers was done using appropriate rate equations and a heuristic model of the carrier density dependent gain. The model gave a qualitative agreement with the experimental results. In addition, the model allowed exploration of a wider design space for the amplifiers. The model predicted that internal electrical-to-optical conversion efficiencies in excess of 50 percent should be achievable with careful system design. The model predicted that no global optimum design exists, but gain, efficiency, and optical confinement (coupling efficiency) can be mutually adjusted to meet a specific system requirement. A three quantum well, low optical confinement amplifier was fabricated using molecular beam epitaxial growth. Coherent beam combining of two high power amplifiers injected from a common master oscillator was also examined. Coherent beam combining with an efficiency of 93 percent resulted in a single beam having diffraction-limited characteristics. This beam combining efficiency is a world record result for such a system. Interferometric observations of the output of the amplifier indicated that spatial mode matching was a significant factor in the less than perfect beam combining. Finally, the system issues of arrays of amplifiers in a coherent beam combining system were investigated. Based upon experimentally observed parameters coherent beam combining could result in a megawatt-scale coherent beam with a 10 percent electrical-to-optical conversion efficiency
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