816 research outputs found

    Rural Facility Electric Power Quality Analysis

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    This report gives results of a recently completed data collection and analysis project investigating electric power quality of two isolated utility systems in Alaska. This is the second phase of a similar effort reported in 1984 which provided the first comprehensive power quality data from four small Alaskan communities. In this report, second generation instrumentation is described and comprehensive data and data analyses are presented. These data are important because of the increased use throughout Alaska of electrical and electronic equipment that may be damage by power system disturbances.Abstract - iv 1.0 Introduction - 1 1.1 Site descriptions - 1 1.2 Power quality definitions and disturbance analyzzer outputs - 2 2.0 Second Generation Instrumentation - 4 2.1 Hardware - 4 2.2 Software development and utilization - 8 3.0 Power System Disturbance Data - 9 3.1 Kotzebue site - 10 Figure Descriptions - 10 3.1.1 808: - 10 3.1.2 626: - 13 3.1.2.1 Impulse - 13 3.1.2.2 Sag - 16 3.1.2.3 Surge - 18 3.1.2.4 Frequency Disturbances - 21 3.1.2.5 Voltages - 23 Figures K1-K85 - 24-66 3.2 Tazlina site - 67 Figure Descriptions - 67 3.2.1 808: - 67 3.2.2 626: - 71 3.2.2.1 Impulse - 1 3.2.2.2 Sag - 74 3.2.2.3 Surge - 77 3.2.2.4 Frequency Disturbances - 81 3.2.2.5 Voltages - 83 Figures T1 - T102 - 85-135 3.3 Power system disturbance data summary - 136 3.3.1 Kotzebue site - 136 3.3.2 Tazlina site - 142 4.0 Conclusions - 147 5.0 Acknowledgements - 154 6.0 References - 154 7.0 Selected Bibliography - 155 8.0 Appendix

    Displacements analysis of self-excited vibrations in turning

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    The actual research deals with determining by a new protocol the necessary parameters considering a three-dimensional model to simulate in a realistic way the turning process on machine tool. This paper is dedicated to the experimental displacements analysis of the block tool / block workpiece with self-excited vibrations. In connexion with turning process, the self-excited vibrations domain is obtained starting from spectra of two accelerometers. The existence of a displacements plane attached to the tool edge point is revealed. This plane proves to be inclined compared to the machines tool axes. We establish that the tool tip point describes an ellipse. This ellipse is very small and can be considered as a small straight line segment for the stable cutting process (without vibrations). In unstable mode (with vibrations) the ellipse of displacements is really more visible. A difference in phase occurs between the tool tip displacements on the radial direction and on the cutting one. The feed motion direction and the cutting one are almost in phase. The values of the long and small ellipse axes (and their ratio) shows that these sizes are increasing with the feed rate value. The axis that goes through the stiffness center and the tool tip represents the maximum stiffness direction. The maximum (resp. minimum) stiffness axis of the tool is perpendicular to the large (resp. small) ellipse displacements axis. FFT analysis of the accelerometers signals allows to reach several important parameters and establish coherent correlations between tool tip displacements and the static - elastic characteristics of the machine tool components tested

    Masses, Accretion Rates and Inclinations of AGNs

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    We assume that the gravitational instability of standard thin accretion disks leads to the Broad Line Regions (BLRs), the B band luminosity comes from standard thin disk and the motion of BLRs is virial. The central black hole masses, the accretion rates and the disk inclinations to the line of sight for 17 Seyfert 1 galaxies and 17 Palomar-Green (PG) quasars have been calculated. Our results are sensitive to α\alpha parameter of the standard α\alpha disk. With the same values of α\alpha (α=1\alpha=1), calculated central black hole masses for 17 Seyfert 1 galaxies are consistent with that from Kaspi et al. (2000) while that for 17 PG quasars are larger than that from Kaspi et al. (2000) by almost 2 orders of magnitude. Inclinations of 17 Seyfert 1 galaxies are about 6 times larger than that of 17 PG quasars. These inclinations, with a mean value of 32o32^{o} for 17 Seyfert 1 galaxies that agrees well with the result obtained by fitting the iron KαK\alpha lines of Seyfert 1 galaxies observed with ASCA (Nandra et al. 1997) and the result obtained by Wu & Han (2001), provide further support for the orientation-dependent unification scheme of active galactic nuclei. There is a relation between the FWHM of Hβ\beta and the inclination, namely the inclination is smaller in AGNs with smaller FWHM of Hβ\beta. The effect of inclinations in narrow line Seyfert 1 galaxies (NLS1s) should be considered when one studies the physics of NLS1s. (abbreviated)Comment: 9 pages, 9 figures, 4 tables, accepted by A&

    Theoretical Directional and Modulated Rates for Direct SUSY Dark Matter Detection

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    Exotic dark matter together with the vacuum energy (cosmological constant) seem to dominate in the flat Universe. Thus direct dark matter detection is central to particle physics and cosmology. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). Furthermore from the knowledge of the density and velocity distribution of the LSP, the quark substructure of the nucleon and the nuclear structure (form factor and/or spin response function), one is able to evaluate the event rate for LSP-nucleus elastic scattering. The thus obtained event rates are, however, very low. So it is imperative to exploit the two signatures of the reaction, namely the modulation effect, i.e. the dependence of the event rate on the Earth's motion, and the directional asymmetry, i.e. the dependence of the rate on the the relative angle between the direction of the recoiling nucleus and the sun's velocity. These two signatures are studied in this paper employing various velocity distributions and a supersymmetric model with universal boundary conditions at large tan(beta).Comment: 11 LATEX pages, 1 table and 4 ps figures included. Paper presented in DARK2002, Fourth Heidelberg International Conference on Dark Matter in Astro- and Particle Physics, Cape Town, South Africa, 4-9 February, 2002, to appear in the proceedings (to be published by Springer Verlag

    Dark matter and Colliders searches in the MSSM

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    We study the complementarity between dark matter experiments (direct detection and indirect detections) and accelerator facilities (the CERN LHC and a s=1\sqrt{s}= 1 TeV e+e−e^+e^- Linear Collider) in the framework of the constrained Minimal Supersymmetric Standard Model (MSSM). We show how non--universality in the scalar and gaugino sectors can affect the experimental prospects to discover the supersymmetric particles. The future experiments will cover a large part of the parameter space of the MSSM favored by WMAP constraint on the relic density, but there still exist some regions beyond reach for some extreme (fine tuned) values of the supersymmetric parameters. Whereas the Focus Point region characterized by heavy scalars will be easily probed by experiments searching for dark matter, the regions with heavy gauginos and light sfermions will be accessible more easily by collider experiments. More informations on both supersymmetry and astrophysics parameters can be thus obtained by correlating the different signals.Comment: 25 pages, 10 figures, corrected typos and reference adde

    GEMINI 3D spectroscopy of BAL+IR+Fe II QSOs: II. IRAS 04505-2958 an explosive QSO with hypershell and a new scenario for galaxy formation and galaxy end

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    From a study of BAL + IR + Fe II QSOs (using deep Gemini GMOS-IFU spectroscopy) new results are presented: for IRAS 04505-2958. Specifically, we have studied in detail the out flow (OF) process and their associated structures, mainly at two large galactic scales: (i) two blobs/shells (S1, S2) at radius r = 1.1 and 2.2 kpc; and (ii) an external hypergiant shell (S3) at r = 11 kpc. In addition, the presence of two very extended hypergiant shells (S4, S5) at r = 80 kpc is discussed. From this GMOS study the following main results were obtained: (i) For the external hypergiant shell S3 the kinematics GMOS maps of the ionized gas show very similar features to those observed for the prototype of exploding external supergiant shell: in NGC 5514. (ii) The main knots K1, K2 and K3 -of this hypergiant shell S3- show a stellar population and emission line ratios associated with the presence of a starburst + OF/shocks. (iii) The internal shells S1 and S2 show structures, OF components and properties very similar to those detected in the nuclear shells of Mrk 231. (iv) The shells S1+S2 and S3 are aligned at PA = 131: i.e. suggesting that the OF process is in the blow-out phase with bipolar structure. In addition, the shells S4 and S5 (at 80-100 kpc scale) are aligned at PA = 40, i.e.: a bipolar OF perpendicular to the internal OF. Finally, the generation of UHE cosmic rays and neutrino/ dark-matter -associated with HyNe in BAL + IR + Fe II QSOs- is discussed.Comment: Submitted MNRAS, 81 pages, 25 Figure

    What Role Do Traditional Beliefs Play in Treatment Seeking and Delay for Buruli Ulcer Disease?–Insights from a Mixed Methods Study in Cameroon

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    Victims of Buruli ulcer disease (BUD) frequently report to specialized units at a late stage of the disease. This delay has been associated with local beliefs and a preference for traditional healing linked to a reportedly mystical origin of the disease. We assessed the role beliefs play in determining BUD sufferers' choice between traditional and biomedical treatments.Anthropological fieldwork was conducted in community and clinical settings in the region of Ayos and Akonolinga in Central Cameroon. The research design consisted of a mixed methods study, triangulating a qualitative strand based on ethnographic research and quantitative data obtained through a survey presented to all patients at the Ayos and Akonolinga hospitals (N = 79) at the time of study and in four endemic communities (N = 73) belonging to the hospitals' catchment area.The analysis of BUD sufferers' health-seeking behaviour showed extremely complex therapeutic itineraries, including various attempts and failures both in the biomedical and traditional fields. Contrary to expectations, nearly half of all hospital patients attributed their illness to mystical causes, while traditional healers admitted patients they perceived to be infected by natural causes. Moreover, both patients in hospitals and in communities often combined elements of both types of treatments. Ultimately, perceptions regarding the effectiveness of the treatment, the option for local treatment as a cost prevention strategy and the characteristics of the doctor-patient relationship were more determinant for treatment choice than beliefs.The ascription of delay and treatment choice to beliefs constitutes an over-simplification of BUD health-seeking behaviour and places the responsibility directly on the shoulders of BUD sufferers while potentially neglecting other structural elements. While more efficacious treatment in the biomedical sector is likely to reduce perceived mystical involvement in the disease, additional decentralization could constitute a key element to reduce delay and increase adherence to biomedical treatment

    Shading by Napier Grass Reduces Malaria Vector Larvae in Natural Habitats in Western Kenya Highlands

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    Increased human population in the Western Kenya highlands has led to reclamation of natural swamps resulting in the creation of habitats suitable for the breeding of Anopheles gambiae, the major malaria vector in the region. Here we report on a study to restore the reclaimed swamp and reverse its suitability as a habitat for malaria vectors. Napier grass-shaded and non-shaded water channels in reclaimed sites in Western Kenya highlands were studied for the presence and density of mosquito larvae, mosquito species composition, and daily variation in water temperature. Shading was associated with 75.5% and 88.4% (P < 0.0001) reduction in anopheline larvae densities and 78.1% and 88% (P < 0.0001) reduction in Anopheles gambiae sensu lato (s.l.) densities in two sites, respectively. Shading was associated with a 5.7°C, 5.0°C, and 4.7°C, and 1.6°C, 3.9°C, and 2.8°C (for maximum, minimum, and average temperatures, respectively) reduction (P < 0.0001) in water temperatures in the two locations, respectively. An. gambiae s.l. was the dominant species, constituting 83.2% and 73.1%, and 44.5% and 42.3%, of anophelines in non-shaded and shaded channels, respectively, in the two sites, respectively. An. gambiae sensu stricto (s.s.) constituted the majority (97.4%) of An. gambiae s.l., while the rest (2.6%) comprised of Anopheles arabiensis. Minimum water temperature decreased with increasing grass height (P = 0.0039 and P = 0.0415 for Lunyerere and Emutete sites, respectively). The results demonstrate how simple environmental strategies can have a strong impact on vector densities
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