Effect of matrix parameters on mesoporous matrix based quantum computation

We present a solid state implementation of quantum computation, which improves previously proposed optically driven schemes. Our proposal is based on vertical arrays of quantum dots embedded in a mesoporous material which can be fabricated with present technology. We study the feasibility of performing quantum computation with different mesoporous matrices. We analyse which matrix materials ensure that each individual stack of quantum dots can be considered isolated from the rest of the ensemble-a key requirement of our scheme. This requirement is satisfied for all matrix materials for feasible structure parameters and GaN/AlN based quantum dots. We also show that one dimensional ensembles substantially improve performances, even of CdSe/CdS based quantum dots

Sewage, Septage and faecal sludge management profile in Ho district of Ghana

The paper presents the sewage, septage and faecal sludge management profile in the Ho District of Ghana. The excreta handling facilities available in Ho District are water closet systems, KVIP, pan/bucket latrines and public latrines. About 71 per cent of the population, especially people in the densely populated and low income communities, depend on pit/KVIP/public latrines, and about 16 per cent of the population have no access to toilet facilities. Due to inadequate sanitation vehicles and equipment the District Assembly faces a lot of difficulties in the collection of septage and faecal sludges. The SS, BOD and faecal coliform of the septage were 70 mg/l, 320 mg/l and 3.0 million counts/100 ml while the SS, BOD and faecal coliform of the raw sewage were 40 mg/l, 300 mg/l and 11 million counts/100 ml. There is the need for a definite and well coordinated effort by the agencies involved to properly manage the sewage, septage and faecal matter in the Ho District if the adverse effects of liquid waste on public health and environment are to be minimized, and a clean and healthy environment in the District is to be ensured. Résumé Cet article présente le profil de gestion des eaux d'égout, de septage, et des vidanges fécales dans le district de Ho du Ghana. Les équipements de manutention d'excrétions disponibles dans le district de Ho sont les systèmes de W-C, KVIP, les latrine à cuvettes/seaux et les latrines publiques. A peu près 71 % de la population surtout les gens dans les communautés densément peuplées et à faible revenu dépendent de latrines à fosses/KVIPL/ publiques et à peu près 16 % de la population n'ont pas d'accès aux toilettes sanitaires. En raison d'insuffisance de voitures sanitaires et d'équipments l'Assemblée du District recontre beaucoup de difficultés dans l'évacuation de septage et des vidanges fécales. Les solides en suspension (SS), la démande d'oxygène biochimique (DOB) et le coliforme fécale du septage étaient 70 mg/l, 320 mg/l et 3.0 million de comptes/100 ml alors que SS, DOB et le coliforme fécale des eaux d'égout non traitées étaient 40 mg/l, 300 mg/l et 11 million de comptes /100 ml. Il y a la nécessité pour un effort précis et bien coordonné par les agences concernées de gérer proprement les eaux d'égout, le septage et la matière fécale dans le district de Ho si les effets défavorables de liquides usées sur la santé publique des habitants et l'environnement doivent être réduit au minimum, et si un environnement propre et sain pour les gens du district doit être assuré. Ghana Journal of Science Vol. 46 2006: pp. 91-9

Mesoporous matrices for quantum computation with improved response through redundance

We present a solid state implementation of quantum computation, which improves previously proposed optically driven schemes. Our proposal is based on vertical arrays of quantum dots embedded in a mesoporous material which can be fabricated with present technology. The redundant encoding typical of the chosen hardware protects the computation against gate errors and the effects of measurement induced noise. The system parameters required for quantum computation applications are calculated for II-VI and III-V materials and found to be within the experimental range. The proposed hardware may help minimize errors due to polydispersity of dot sizes, which is at present one of the main problems in relation to quantum dot-based quantum computation. (c) 2007 American Institute of Physics

The Onset of Nuclear Structure Effects in Near-Barrier Elastic Scattering of Weakly-Bound Nuclei: 6^6He and 6^6Li Compared

The elastic scattering of the halo nucleus $^6$He from heavy targets at incident energies near the Coulomb barrier displays a marked deviation from the standard Fresnel-type diffraction behavior. This deviation is due to the strong Coulomb dipole breakup coupling produced by the Coulomb field of the heavy target, a specific feature of the nuclear structure of $^6$He. We have performed Continuum Discretized Coupled Channels calculations for the elastic scattering of $^{6}$He and $^6$Li from $^{58}$Ni, $^{120}$Sn, $^{144}$Sm, $^{181}$Ta and $^{208}$Pb targets in order to determine the range of $Z_{\mathrm T}$ where this nuclear-structure specific coupling effect becomes manifest. We find that the strong Coulomb dipole breakup coupling effect is only clearly experimentally distinguishable for targets of $Z_{\mathrm T} \approx 80$.Comment: 10 pages with 3 figure

A comparative analysis of faunal remains from some roman and native sites in northern England

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Sum rule of the correlation function

We discuss a sum rule satisfied by the correlation function of two particles with small relative momenta. The sum rule, which results from the completeness condition of the quantum states of the two particles, is first derived and then we check how it works in practice. The sum rule is shown to be trivially satisfied by free particle pair, and then there are considered three different systems of interacting particles. We discuss a pair of neutron and proton in the s-wave approximation and the case of the so-called hard spheres with the phase shifts taken into account up to l=4. Finally, the Coulomb system of two charged particles is analyzed.Comment: 18 pages, 18 figures, revised, to appear in Phys. Rev.

The Effect of the Hall Term on the Nonlinear Evolution of the Magnetorotational Instability: I. Local Axisymmetric Simulations

The effect of the Hall term on the evolution of the magnetorotational instability (MRI) in weakly ionized accretion disks is investigated using local axisymmetric simulations. First, we show that the Hall term has important effects on the MRI when the temperature and density in the disk is below a few thousand K and between 10^13 and 10^18 cm^{-3} respectively. Such conditions can occur in the quiescent phase of dwarf nova disks, or in the inner part (inside 10 - 100 AU) of protoplanetary disks. When the Hall term is important, the properties of the MRI are dependent on the direction of the magnetic field with respect to the angular velocity vector \Omega. If the disk is threaded by a uniform vertical field oriented in the same sense as \Omega, the axisymmetric evolution of the MRI is an exponentially growing two-channel flow without saturation. When the field is oppositely directed to \Omega, however, small scale fluctuations prevent the nonlinear growth of the channel flow and the MRI evolves into MHD turbulence. These results are anticipated from the characteristics of the linear dispersion relation. In axisymmetry on a field with zero-net flux, the evolution of the MRI is independent of the size of the Hall term relative to the inductive term. The evolution in this case is determined mostly by the effect of ohmic dissipation.Comment: 31 pages, 3 tables, 12 figures, accepted for publication in ApJ, postscript version also available from http://www.astro.umd.edu/~sano/publications

Assessment of Grazing Procedures in the Evaluation of Plant Breeding Material

Four stocking densities (2, 3, 5 and 9 sheep/18 m2 for one hour) and two times of grazing (morning or evening) were imposed on a spaced plant nursery of nine red clover (Trifolium pratense L.) populations of varying growth habit, in order to optimize measurement of sheep grazing preference. Plant height, spread and leafiness were measured before and after each of three grazings. Sheep preference was viewed multivariately, using combined measurements of these plant characteristics. MANOVA revealed that the effect of stocking density was significant (P-0.05), but that of time of grazing was not. The plant, population and overall heritabilities were non-significant (P\u3e0.05) for before-and-after grazing differences for all characteristics, and also for leafiness after grazing. Overall heritabilities for after-grazing spread and height were significant at 0.37 and 0.30, respectively. Sampling reliability at the 5 sheep/18 m2 stocking density was 94%, which was superior to the lower grazing intensities; this stocking density was considered to be the best for subsequent evaluation work. Either morning or evening grazings could be used