Perspective of Station Uptime on Modeling and Management of the Base Station Energy Consumption

The network availability of the wireless network can be viewed as broader concept of network reliability. Reliability is a unique quality of wireless network and it is regarded as key parameter for business success of the telecom service providers. The network availability however is often compromised with outages caused by various factors and amongst the factors, inadequate energy at the base stations is the major outage-contributing factor. Due to unreliable electrical grid supply at many base stations, diesel generators are deployed to the stations as an alternative source of energy.  The diesel generators incur high operating expenses. This paper presents a quantitative approach for measurement and estimation of diesel fuel consumption based on uptime hours of various equipments installed at the base station site. It also introduces a new parameter called energy conservation factor, which determines amount of energy transfer to the battery-bank while charging the battery with power from an external source such as grid, diesel generator.  This model while presenting a new management perspective for effective utilization of the conserved energy of the battery-bank also attempts to reduce waste such as fuel losses and pilferages. We also describe how the method introduced in this paper can assist management in planning and preparation of fuel budget for a particular base station or the entire wireless network. Keywords: Wireless network availability; Network reliability; Network outage; Base station site; Conserved energy; Energy conservation facto

Effective Dynamic Range in Measurements with Flash Analog-to-Digital Convertor

Flash Analog to Digital Convertor (FADC) is frequently used in nuclear and particle physics experiments, often as the major component in big multi-channel systems. The large data volume makes the optimization of operating parameters necessary. This article reports a study of a method to extend the dynamic range of an 8-bit FADC from the nominal $\rm{2^8}$ value. By comparing the integrated pulse area with that of a reference profile, good energy reconstruction and event identification can be achieved on saturated events from CsI(Tl) crystal scintillators. The effective dynamic range can be extended by at least 4 more bits. The algorithm is generic and is expected to be applicable to other detector systems with FADC readout.Comment: 19 pages, 1 table, 10 figure

Upper crustal velocity structure beneath the central Lucky Strike Segment from seismic refraction measurements

Geochemistry Geophysics Geosystems, vol. 11, pp. Q05001, 21 pp, 2010International audienceWe present a three-dimensional velocity model of the upper crust around the central volcano of the Lucky Strike Segment, Mid-Atlantic Ridge. The model, constructed from a 3-D array of air gun shots (37.5 m spacing along line and 100 m between lines) to ocean bottom seismometers fired during a 3-D seismic reflection survey, shows an off-axis velocity increase (∼1 km/s), a low-velocity region within the median valley, and a low-velocity anomaly underneath the Lucky Strike volcano. Our observations indicate a porosity decrease of 1%–9% (corresponding to a velocity increase of ∼0.5–1 km/s) over a distance of 8 km from the ridge axis (∼0.7 Ma) and a porosity decrease of 4%–11% (corresponding to a velocity increase of ∼2 km/s) between a depth of 0.5 and 1.75 km below seafloor. A sinusoidal variation in the traveltime residuals indicates the presence of azimuthal anisotropy with cracks aligned approximately along the ridge axis. We favor an interpretation in which upper crustal porosities are created by a combination of magmatic accretion (lava–sheeted dike boundary) and active extension (faults, fractures, and fissures). The porosity variation with depth probably depends on pore space collapse, hydrothermal alteration, and a change of stress accommodation. The off-axis porosities are possibly influenced by both hydrothermal precipitation and the aging of the crust

Heisenberg exchange enhancement by orbital relaxation in cuprate compounds

We calculate the Heisenberg exchange J in the quasi-2D antiferromagnetic cuprates La2CuO4, YBa2Cu3O6, Nd2CuO4 and Sr2CuO2Cl2. We apply all-electron (MC)SCF and non-orthogonal CI calculations to [Cu2O11]18-, [Cu2O9]14-, [Cu2O7]10- and [Cu2O7Cl4]14- clusters in a model charge embedding. The (MC)SCF triplet and singlet ground states are well characterized by Cu2+ (dx2-y2) and O2-. The antiferromagnetic exchange is strongly enhanced by admixing relaxed (MC)SCF triplet and singlet excited states, in which a single electron is transferred from the central O ion to Cu. We ascribe this effect to orbital relaxation in the charge transfer component of the wave function. Close agreement with experiment is obtained.Comment: publishe

Measurement of the Intrinsic Radiopurity of Cs-137/U-235/U-238/Th-232 in CsI(Tl) Crystal Scintillators

The inorganic crystal scintillator CsI(Tl) has been used for low energy neutrino and Dark Matter experiments, where the intrinsic radiopurity is an issue of major importance. Low-background data were taken with a CsI(Tl) crystal array at the Kuo-Sheng Reactor Neutrino Laboratory. The pulse shape discrimination capabilities of the crystal, as well as the temporal and spatial correlations of the events, provide powerful means of measuring the intrinsic radiopurity of Cs-137 as well as the U-235, U-238 and Th-232 series. The event selection algorithms are described, with which the decay half-lives of Po-218, Po-214, Rn-220, Po-216 and Po-212 were derived. The measurements of the contamination levels, their concentration gradients with the crystal growth axis, and the uniformity among different crystal samples, are reported. The radiopurity in the U-238 and Th-232 series are comparable to those of the best reported in other crystal scintillators. Significant improvements in measurement sensitivities were achieved, similar to those from dedicated massive liquid scintillator detector. This analysis also provides in situ measurements of the detector performance parameters, such as spatial resolution, quenching factors, and data acquisition dead time.Comment: 28 pages, 12 figure

Structural, Electronic, and Magnetic Properties of MnO

We calculate the structural, electronic, and magnetic properties of MnO from first principles, using the full-potential linearized augmented planewave method, with both local-density and generalized-gradient approximations to exchange and correlation. We find the ground state to be of rhombohedrally distorted B1 structure with compression along the [111] direction, antiferromagnetic with type-II ordering, and insulating, consistent with experiment. We show that the distortion can be understood in terms of a Heisenberg model with distance dependent nearest-neighbor and next-nearest-neighbor couplings determined from first principles. Finally, we show that magnetic ordering can induce significant charge anisotropy, and give predictions for electric field gradients in the ground-state rhombohedrally distorted structure.Comment: Submitted to Physical Review B. Replaced: regenerated figures to resolve font problems in automatically generated pd

Shell-model calculations of neutrino scattering from 12C

Neutrino reaction cross-sections, $(\nu_\mu,\mu^-)$, $(\nu_e,e^-)$, $\mu$-capture and photoabsorption rates on $^{12}$C are computed within a large-basis shell-model framework, which included excitations up to $4\hbar\omega$. When ground-state correlations are included with an open $p$-shell the predictions of the calculations are in reasonable agreement with most of the experimental results for these reactions. Woods-Saxon radial wave functions are used, with their asymptotic forms matched to the experimental separation energies for bound states, and matched to a binding energy of 0.01 MeV for unbound states. For comparison purposes, some results are given for harmonic oscillator radial functions. Closest agreement between theory and experiment is achieved with unrestricted shell-model configurations and Woods-Saxon radial functions. We obtain for the neutrino-absorption inclusive cross sections: $\bar{\sigma} = 13.8 \times 10^{-40}$ cm$^2$ for the $(\nu_{\mu},\mu^{-})$ decay-in-flight flux in agreement with the LSND datum of $(12.4 \pm 1.8) \times 10^{-40}$ cm$^2$; and $\bar{\sigma} = 12.5 \times 10^{-42}$ cm$^2$ for the $(\nu_{e},e^{-})$ decay-at-rest flux, less than the experimental result of $(14.4 \pm 1.2) \times 10^{-42}$ cm$^2$.Comment: 19 pages. ReVTeX. No figure

Solar Hydrogen Burning and Neutrinos

We summarize the current status of laboratory measurements of nuclear cross sections of the pp chain and CN cycle. We discuss the connections between such measurements, predictions of solar neutrino fluxes, and the conclusion that solar neutrinos oscillate before reaching earth.Comment: 34 pages, 6 figure

First Observation of Coherent π0\pi^0 Production in Neutrino Nucleus Interactions with Eν<E_{\nu}< 2 GeV

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $\pi^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $\pi^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $\pi^0$ production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 $\pm$1.1 (stat) $\pm$2.5 (sys))% of all exclusive NC $\pi^0$ production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for $\nu_{\mu} \to \nu_e$ oscillations.Comment: Submitted to Phys. Lett.