1,037 research outputs found
Extra Higgs Boson and as Portals to Signatures of Heavy Neutrinos at the LHC
In this paper, we discuss the potential of observing heavy neutrino ()
signatures of a enlarged Standard Model (SM) encompassing three
heavy Majorana neutrinos alongside the known light neutrino states at the Large
Hadron Collider (LHC). We exploit the theoretical decay via a pair of heavy
(non-SM-like) Higgs boson and production followed by and decays, ultimately
yielding a signature and, depending upon how boosted
the final state objects are, we define different possible selections aimed at
improving the signal to background ratio in LHC Run 2 data for a wide range of
heavy neutrino masses.Comment: 31 pages, 10 figures. arXiv admin note: text overlap with
arXiv:1612.0597
Productivity of Florida Springs: Second annual report to Biology Branch, Office of Naval Research progress from January 1 to December 31, 1954
Production measurements at different times of the year indicate a linear relationship of light intensity and overall production at about 8% of the visible light energy reaching plant level. Measurements of a coral reef at Eniwetok indicate 6%. Further evidence of breeding at all seasons but with a quantitative pulse in the seasons of maximum light indicates that the seasonal fluctuation in primary production is routed through reproduction rather than through major changes in populations. The succession of plants and anmals of the aufwuchs has been shown with glass slides and counts from Sagittaria blades. Losss of oxygen bubbles during the day and emergence of aquatic insects at night have been measured with funnels. Bell jar measurements are reported for bacterial metabolism on mud surfaces. pH determined CO2 uptake agrees with titration determinations. A few rough estimates of herbivore production have been made from caged snails, aufwuchs succession, and fish tagging. Nitrate uptake a night by aufwuchs communities has been confirmed in a circulating microcosm experiment as well as in bell jars in the springs. Distributions of oxygen and organisms have been used to criticize the saprobe stream classification system. Theoretical consideration of maximum photosynthetic rates in teh literature data indicates logarithmic rate variation inversely with organismal size just as for respiratory metabolism. Extreme pyramid shapes are thus shown for communities in which organismal size decreases up the food chain and for other communities with the same energy influx but with organismal size increasing up the food chain. Literature data is used to further demonstrate the validity of the optimum efficiency-maximum power principle for photosynthesis. Work on plants by Dr. Delle Natelson indicates essential stability of aquatic plant communities after 3 years and about 10-20% reproducibility in previous biomass estimates by Davis. Work on an animal picture of the fishery characteristics by Caldwell, Barry, and Odum is half completed. The study of aquatic insects in relationship to spring gradients by W.C. Sloan has been completed an an M.S. thesis. J. Yount has begun a study of affect of total productivity on community composition using aufwuchs organisms on glass slides placed in different current and light conditions in Silver Springs. (49pp.
Adaptive Resolution Simulation (AdResS): A Smooth Thermodynamic and Structural Transition from Atomistic to Coarse Grained Resolution and Vice Versa in a Grand Canonical Fashion
The AdResS method in molecular dynamics (MD) allows, in a grand canonical (GC) fashion, to change on-the-fly the number of degrees of freedom of a system, allowing to pass from atomistic (AT) to coarse-grained (CG) resolution and vice versa as a function of the position of the molecule in the simulation box. The coupling of resolutions is made in a thermodynamically consistent way, though in the current formulation, in the region where the molecule changes resolution, neither thermodynamic nor structural properties can be preserved. Here we propose an extension of the method where basic thermodynamic and structural properties can be systematically controlled also in the transition region; this assures a very smooth change from one molecular representation to the other. Moreover, we provide a rigorous argument which shows that if in the region where the molecules change resolution the radial distribution function (RDF) is the same as in the AT and CG region, then the AT region is, from the statistical point of view, equivalent to a subsystem embedded in a larger full AT system, at least up to a second order approximation
Quality Control Procedures for HTGR Fuel Element Components
The growing use of nuclear reactors for the production of electric power throughout the world, and the consequent increase in the number of nuclear fuel manufacturers, is giving enhanced importance to the consideration of quality assurance in the production of nuclear fuels. The fuel is the place, where the radioactive fission products are produced in the reactor and, therefore, the integrity of the fuel is of utmost importance. The first and most fundamental means of insuring that integrity is through the exercise of properly designed quality assurance programmes during the manufacture of the fuel and other fuel element components. The International Atomic Energy Agency therefore conducted an International Seminar on Nuclear Fuel Quality Assurance in Oslo, Norway from 24 till 28 May, 1976. The seminar was addressed to a wider audience and was, with its educational content, of interest in those countries newly entering the field as well as in those with established nuclear fuel fabrication capabilities. This KFA report contains a paper which was distributed preliminary during the seminar'and - in the second part - the text of the oral presentation. The tables and figures were presented as slides. The paper gives a summary of the procedures available in the present state for the production control of HTGR core materials and of the meaning of the particular properties for reactor operation. The work was partly sponsored by the Bundesministerium fĂźr Forschung und Technologie of the Federal Republic of Germany as well as by the Government of North-Rhine-Westfalia
On the upper bound of the electronic kinetic energy in terms of density functionals
We propose a simple density functional expression for the upper bound of the
kinetic energy for electronic systems. Such a functional is valid in the limit
of slowly varying density, its validity outside this regime is discussed by
making a comparison with upper bounds obtained in previous work. The advantages
of the functional proposed for applications to realistic systems is briefly
discussed.Comment: 10 pages, no figure
Grand-canonical-like molecular-dynamics simulations by using an adaptive-resolution technique
n this work, we provide a detailed theoretical analysis, supported by numerical tests, of the reliability of the adaptive resolution simulation (AdResS) technique in sampling the Grand Canonical ensemble. We demonstrate that the correct density and radial distribution functions in the hybrid region, where molecules change resolution, are two necessary conditions for considering the atomistic and coarse-grained regions in AdResS equivalent to subsystems of a full atomistic system with an accuracy up to the second order with respect to the probability distribution of the system. Moreover, we show that the work done by the thermostat and a thermodynamic force in the transition region is formally equivalent to balance the chemical potential difference between the different resolutions. From these results follows the main conclusion that the atomistic region exchanges molecules with the coarse-grained region in a Grand Canonical fashion with an accuracy up to (at least) second order. Numerical tests, for the relevant case of liquid water at ambient conditions, are carried out to strengthen the conclusions of the theoretical analysis. Finally, in order to show the computational convenience of AdResS as a Grand Canonical set up, we compare our method to the Insertion Particle Method (IMP) in its most efficient computational implementation. This fruitful combination of theoretical principles and numerical evidence candidates the adaptive resolution technique as a natural, general and efficient protocol for Grand Canonical Molecular Dynamics for the case of large systems
Comments on Anomaly Cancellations by Pole Subtractions and Ghost Instabilities with Gravity
We investigate some aspects of anomaly cancellation realized by the
subtraction of an anomaly pole, stressing on some of its properties in
superspace. In a local formulation these subtractions can be described in terms
of a physical scalar, an axion and related ghosts. They appear to be necessary
for the unitarization of the theory in the ultraviolet, but they may generate
an infrared instability of the corresponding effective action, signalled by
ghost condensation. In particular the subtraction of the superanomaly multiplet
by a pole in superspace is of dubious significance, due to the different nature
of the chiral and conformal anomalies. In turn, this may set more stringent
constraints on the coupling of supersymmetric theories to gravity.Comment: 18 pages. Revised version. To appear in "Classical and Quantum
Gravity
High-Order Numerical Method for 1D Non-local Diffusive Equation
In this paper we present a non-local numerical scheme based on the Local
Discontinuous Galerkin method for a non-local diffusive partial differential
equation with application to traffic flow. In this model, the velocity is
determined by both the average of the traffic density as well as the changes in
the traffic density at a neighborhood of each point. We discuss nonphysical
behaviors that can arise when including diffusion, and our measures to prevent
them in our model. The numerical results suggest that this is an accurate
method for solving this type of equation and that the model can capture desired
traffic flow behavior. We show that computation of the non-local convolution
results in complexity, but the increased computation time
can be mitigated with high-order schemes like the one proposed.Comment: 17 pages and 8 figure
Urban Blasting Vibrations: Case Histories of Vibration Monitoring in New York City
This paper summarizes the monitoring experienced gained from several urban rock blasting projects in New York City and one just beyond the city limits. The majority of the experience was gained on the new South Ferry Terminal Structural Box project that included a new subway terminal station and section of tunnel on the number 1-line subway located in Battery Park in Lower Manhattan. The paper will review lessons learned and the limitations of using âoff-the-shelfâ seismographs for near-field blast monitoring. We allege that standard and widely available seismograph equipment is not generally utilized to its fullest potential, and that alternative forms of monitoring are often overlooked in favor of criteria based on peak particle velocity alone. The new South Ferry Terminal tunnel and station comprised a 1,300 ft long excavation varying in width from 25 to 60 ft and 20 to 50 ft in depth. The excavation necessitated blasting adjacent to and underneath existing subway lines at several locations. A separate project currently underway and at a site located north of New York City, is also mentioned due to its wider variation of blast parameters relative to the more typical âurbanâ blast projects of New York City
Rhythmic tapping to a moving beat motion kinematics overrules natural gravity
beat induction is the cognitive ability that allows humans to listen to a regular pulse in music and move in synchrony with it. although auditory rhythmic cues induce more consistent synchronization than flashing visual metronomes, this auditory-visual asymmetry can be canceled by visual moving stimuli. here, we investigated whether the naturalness of visual motion or its kinematics could provide a synchronization advantage over flashing metronomes. Subjects were asked to tap in sync with visual metronomes defined by vertically accelerating/decelerating motion, either congruent or not with natural gravity; horizontally accelerating/decelerating motion; or flashing stimuli. we found that motion kinematics was the predominant factor determining rhythm synchronization, as accelerating moving metronomes in any cardinal direction produced more precise and predictive tapping than decelerating or flashing conditions. our results support the notion that accelerating visual metronomes convey a strong sense of beat, as seen in the cueing movements of an orchestra director
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