Families of Roles: A new theory of occurrent-dependent roles

PublishedRoles are important both theoretically and practically for modelling the world around us. Although many theories of roles have been proposed, there remain aspects which are little understood. In this paper we investigate roles and their contexts from a temporal point of view.We introduce the idea of a family of occurrent-dependent roles as a means to organise prospective and retrospective derived roles around an original role from which they are derived. By this means we account for the existence of groups of similar roles which are difficult to distinguish without a careful analysis of the temporal aspects. Following detailed informal discussion, we present a preliminary formalisation of the key concepts and relations.Air Force Research Laborator

Raman signatures of classical and quantum phases in coupled dots: A theoretical prediction

We study electron molecules in realistic vertically coupled quantum dots in a strong magnetic field. Computing the energy spectrum, pair correlation functions, and dynamical form factor as a function of inter-dot coupling via diagonalization of the many-body Hamiltonian, we identify structural transitions between different phases, some of which do not have a classical counterpart. The calculated Raman cross section shows how such phases can be experimentally singled out.Comment: 9 pages, 2 postscript figures, 1 colour postscript figure, Latex 2e, Europhysics Letters style and epsfig macros. Submitted to Europhysics Letter

Efeitos de diferentes sistemas de cultivo nas propriedades físicas e produtividade do solo.

bitstream/item/40430/1/Boletim-Pesquisa-67-CPATU.pd

Hypersurface homogeneous locally rotationally symmetric spacetimes admitting conformal symmetries

All hypersurface homogeneous locally rotationally symmetric spacetimes which admit conformal symmetries are determined and the symmetry vectors are given explicitly. It is shown that these spacetimes must be considered in two sets. One set containing Ellis Class II and the other containing Ellis Class I, III LRS spacetimes. The determination of the conformal algebra in the first set is achieved by systematizing and completing results on the determination of CKVs in 2+2 decomposable spacetimes. In the second set new methods are developed. The results are applied to obtain the classification of the conformal algebra of all static LRS spacetimes in terms of geometrical variables. Furthermore all perfect fluid nontilted LRS spacetimes which admit proper conformal symmetries are determined and the physical properties some of them are discussed.Comment: 15 pages; to appear in Classical Quantum Gravity; some misprints in Tables 3,5 and in section 4 correcte

Empirical likelihood estimation of the spatial quantile regression

The spatial quantile regression model is a useful and flexible model for analysis of empirical problems with spatial dimension. This paper introduces an alternative estimator for this model. The properties of the proposed estimator are discussed in a comparative perspective with regard to the other available estimators. Simulation evidence on the small sample properties of the proposed estimator is provided. The proposed estimator is feasible and preferable when the model contains multiple spatial weighting matrices. Furthermore, a version of the proposed estimator based on the exponentially tilted empirical likelihood could be beneficial if model misspecification is suspect

A mass-flow-calorimetry system for scaled-up experiments on anomalous heat evolution at elevated temperatures

We have been studying phenomena of anomalous heat evolution from hydrogen-isotope-loaded nanocomposite samples at elevated temperatures as well as at room temperature using a twin absorption system. Recent experiments have used Ni-based nano-composite samples; Pd1 Ni7/ZrO2 ("PNZ"), Ni/ZrO2 ("NZ"), Cu0.081 Ni0.36/ZrO2 ("CNZ") and Cu0.21Ni0.21/ZrO2 ("CNZII"). The results of measurements have been presented in the meetings of the 12th Japan CF-Research Society (JCF12), the 17th International Conference on Condensed Matter Nuclear Science (ICCF17) and the 13th Japan CFResearch Society (JCF13), and have been/will be published in [3], [4] and [5], respectively. These will be summarized, and the time-dependent data will be re-analyzed in another paper by A. Takahashi in this Conference for speculating heat releasing mechanisms during the several-week-lasted phase of D(H)-loading into the nano-composite samples. As will be shown there, a lot of interesting, even astonishing, features are involved; burst-like heat release with anomalously high values of differential heat of sorption (η) reaching ca. 600 eV/atom-H, large values of integrated heat reaching ca. 800 eV/atom-Ni from the CNZ sample absorbing H, and abrupt desorption with absorbed energy of 50 - 80 eV/atom-Ni observed almost exclusively in the first 573-K run for each sample. To confirm the interesting phenomena, repeated measurements with improved signal-to-noise ratio are required. Since the easiest way for this is to increase the sample amount, we have fabricated a reaction chamber with a ten-times-larger volume than in-being one. Another important improvement is a mass flow calorimetry applied to the system using an oil coolant with a boiling point of 390 deg-C. Moreover, to make residual gas mass spectral analysis in A = 1 - 6 amu range, a QMA system is going to be installed in the line of the apparatus. In the presentation we will show the schematics of this new oil-cooling mass-flow calorimetry system for observing anomalous heat evolution in H(D)-gas charging to Ni-based nano-composite samples and for calibration runs using blank alumina sample

Background light measurements at the DUMAND site

Ambient light intensities at the DUMAND site, west of the island of Hawaii were measured around the one photoelectron level. Throughout the water column between 1,500m and 4,700m, a substantial amount of stimulateable bioluminescence is observed with a ship suspended detector. But non-stimulated bioluminescence level is comparable, or less than, K sup 40 background, when measured with a bottom tethered detector typical of a DUMAND optical module

Identification problems of muon and electron events in the Super-Kamiokande detector

In the measurement of atmospheric nu_e and nu_mu fluxes, the calculations of the Super Kamiokande group for the distinction between muon-like and electronlike events observed in the water Cerenkov detector have initially assumed a misidentification probability of less than 1 % and later 2 % for the sub-GeV range. In the multi-GeV range, they compared only the observed behaviors of ring patterns of muon and electron events, and claimed a 3 % mis-identification. However, the expressions and the calculation method do not include the fluctuation properties due to the stochastic nature of the processes which determine the expected number of photoelectrons (p.e.) produced by muons and electrons. Our full Monte Carlo (MC) simulations including the fluctuations of photoelectron production show that the total mis-identification rate for electrons and muons should be larger than or equal to 20 % for sub-GeV region. Even in the multi-GeV region we expect a mis-identification rate of several % based on our MC simulations taking into account the ring patterns. The mis-identified events are mostly of muonic origin.Comment: 17 pages, 12 figure

Hubbard band or oxygen vacancy states in the correlated electron metal SrVO3_3?

We study the effect of oxygen vacancies on the electronic structure of the model strongly correlated metal SrVO$_3$. By means of angle-resolved photoemission (ARPES) synchrotron experiments, we investigate the systematic effect of the UV dose on the measured spectra. We observe the onset of a spurious dose-dependent prominent peak at an energy range were the lower Hubbard band has been previously reported in this compound, raising questions on its previous interpretation. By a careful analysis of the dose dependent effects we succeed in disentangling the contributions coming from the oxygen vacancy states and from the lower Hubbard band. We obtain the intrinsic ARPES spectrum for the zero-vacancy limit, where a clear signal of a lower Hubbard band remains. We support our study by means of state-of-the-art ab initio calculations that include correlation effects and the presence of oxygen vacancies. Our results underscore the relevance of potential spurious states affecting ARPES experiments in correlated metals, which are associated to the ubiquitous oxygen vacancies as extensively reported in the context of a two-dimensional electron gas (2DEG) at the surface of insulating $d^0$ transition metal oxides.Comment: Manuscript + Supplemental Material, 12 pages, 9 figure

VLA Observations of H2O Masers in the Class 0 Protostar S106 FIR: Evidence for a 10 AU-Scale Accelerating Jet-like Flow

We conducted VLA observations at 0".06 resolution of the 22 GHz water masers toward the Class 0 source S106 FIR (d=600 pc; 15" west of S106-IRS4) on two epochs separated by ~3 months. Two compact clusters of the maser spots were found in the center of the submillimeter core of S106 FIR. The separation of the clusters was ~80 mas (48 AU) along P. A. = 70 degrees and the size of each cluster was ~20 mas x 10 mas. The western cluster, which had three maser components, was 7.0 km/s redshifted with respect to the ambient cloud velocity. Each component was composed of a few spatially localized maser spots and was aligned on a line connecting the clusters. We found relative proper motions of the components with ~30 mas/yr (18 AU/yr) along the line. In addition, a series of single-dish observations show that the maser components drifted with a radial acceleration of ~1 km/s/yr. These facts indicate that the masers could be excited by a 10 AU-scale jet-like accelerating flow ejected from an assumed protostar located between the two clusters. The outflow size traced by the masers was 50 AU x 5 AU after correction for an inclination angle of 10 degrees which was derived from the relative proper motions and radial velocities of the maser components. The three-dimensional outflow velocity ranged from 40 to 70 km/s assuming symmetric motions for the blue and red components. Since no distinct CO molecular outflows have been detected so far, we suggest that S106 FIR is an extremely young protostar observed just after the onset of outflowing activity.Comment: 24 pages, 6 figures, No. 5 color. Accepted, Astrophysical Journa