Analysis of the velocity field of granular hopper flow

We report the analysis of radial characteristics of the flow of granular material through a conical hopper. The discharge is simulated for various orifice sizes and hopper opening angles. Velocity profiles are measured along two radial lines from the hopper cone vertex: along the main axis of the cone and along its wall. An approximate power law dependence on the distance from the orifice is observed for both profiles, although differences between them can be noted. In order to quantify these differences, we propose a Local Mass Flow index that is a promising tool in the direction of a more reliable classification of the flow regimes in hoppers

Applying semantic web technologies to knowledge sharing in aerospace engineering

This paper details an integrated methodology to optimise Knowledge reuse and sharing, illustrated with a use case in the aeronautics domain. It uses Ontologies as a central modelling strategy for the Capture of Knowledge from legacy docu-ments via automated means, or directly in systems interfacing with Knowledge workers, via user-defined, web-based forms. The domain ontologies used for Knowledge Capture also guide the retrieval of the Knowledge extracted from the data using a Semantic Search System that provides support for multiple modalities during search. This approach has been applied and evaluated successfully within the aerospace domain, and is currently being extended for use in other domains on an increasingly large scale

Quantum erasure in the presence of a thermal bath: the effects of system-environment microscopic correlations

We investigate the role of the environment in a quantum erasure setup in the cavity quantum electrodynamics domain. Two slightly different schemes are analyzed. We show that the effects of the environment vary when a scheme is exchanged for another. This can be used to estimate the macroscopic parameters related to the system-environment microscopic correlations.Comment: 10 pages, 2 figure

Sistema físico de produção de leite da UEPAE Porto Velho: análise dos resultados zootécnicos e econômicos referentes ao período de dezembro/84 a setembro/89.

No campo experimental da Unidade de Execução de Pesquisa de Âmbito Estadual de Porto Velho (UEPAE de Porto Velho), da EMBRAPA, em Porto Velho, RO, vem sendo conduzido, desde 1984, um modelo físico de sistema de produção de leite. Este modelo tem por objetivo precípuo viabilizar a atividade leiteira na região, elevando sua produtividade e rentabilidade através da utilização de técnicas integradas de modo que se tomem instrumento de difusão de tecnologia. Atualmente, a produtividade leiteira do rebanho na região é muito baixa, situando-se em tomo de 540 l de leite/vaca/lactação de 180 dias. A partir de um rebanho mestiço Holando x Zebu, com graus de sangue 112,9/16 e 5/8, pretende-se alcançar índices econômicos de produtividade, através de tecnologias que possam ser adotadas pelos produtores locais. Dentre as tecnologias utilizadas destacam-se: inseminação artificial, pastagens diversificadas, pastejo rotacionado, suplementação dos animais com volumosos e concentrados regionais, banco de proteína e desmama precoce. Até o presente, os resultados alcançados vêm superando as metas préestabelecidas, confirmando, desse modo, a eficiência das técnicas aplicadas no sistema.bitstream/item/54885/1/SP210001.pd

Inversion of spinning sound fields

A method is presented for the reconstruction of rotating monopole source distributions using acoustic pressures measured on a sideline parallel to the source axis. The method requires no \textit{a priori} assumptions about the source other than that its strength at the frequency of interest vary sinusoidally in azimuth on the source disc so that the radiated acoustic field is composed of a single circumferential mode. When multiple azimuthal modes are present, the acoustic field can be decomposed into azimuthal modes and the method applied to each mode in sequence. The method proceeds in two stages, first finding an intermediate line source derived from the source distribution and then inverting this line source to find the radial variation of source strength. A far-field form of the radiation integrals is derived, showing that the far field pressure is a band-limited Fourier transform of the line source, establishing a limit on the quality of source reconstruction which can be achieved using far-field measurements. The method is applied to simulated data representing wind-tunnel testing of a ducted rotor system (tip Mach number~0.74) and to control of noise from an automotive cooling fan (tip Mach number~0.14), studies which have appeared in the literature of source identification.Comment: Revised version of paper submitted to JASA; five more figures; expanded content with more discussion of error behaviour and relation to Nearfield Acoustical Holograph

The alignment of the polarization of HAe/Be stars with the interstellar magnetic field

We present a study of the correlation between the direction of the symmetry axis of the circumstellar material around intermediate mass young stellar objects and that of the interstellar magnetic field. We use CCD polarimetric data on 100 Herbig Ae/Be stars. A large number of them shows intrinsic polarization, which indicates that their circumstellar envelopes are not spherical. The interstellar magnetic field direction is estimated from the polarization of field stars. There is an alignment between the position angle of the Herbig Ae/Be star polarization and that of the field stars for the most polarized objects. This may be an evidence that the ambient interstellar magnetic field plays a role in shaping the circumstellar material around young stars of intermediate mass and/or in defining their angular momentum axis.Comment: ApJ accepte

Seismic vulnerability of churches in Faial and Pico islands, Azores

Earthquakes represent one of the main cause of serious damage and loss of historic and architectural heritage. Interventions to preserve these building should start with a careful knowledge and assessment of their seismic vulnerability, in order to support any needed retrofitting and strengthening measures. This paper proposes a procedure to register and diagnose of the level of damage on churches after the occurrence of an earthquake, and also to assess the seismic vulnerability of this type of construction. This procedure was applied to sixteen churches in the Azores islands which were hit by the July 9th 1998 earthquake. Belfries of church towers are elements with a particular seismic vulnerability. For this reason, and based on the Italian methodology proposed by the Linee Guida (2006), it is applied to belfries of two churches from Pico (Azores), a simplified mechanical model for assessment of seismic vulnerability of this type of structures

Control of state and state entanglement with a single auxiliary subsystem

We present a strategy to control the evolution of a quantum system. The novel aspect of this protocol is the use of a \emph{single auxiliary subsystem}. Two applications are given, one which allows for state preservation and another which controls the degree of entanglement of a given initial state

Effect Of Inhibition Of Nitric Oxide Synthase On Blood Pressure And Renal Sodium Handling In Renal Denervated Rats.

The role of sympathetic nerve activity in the changes in arterial blood pressure and renal function caused by the chronic administration of N G-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, was examined in sham and bilaterally renal denervated rats. Several studies have demonstrated that sympathetic nerve activity is elevated acutely after L-NAME administration. To evaluate the role of renal nerve activity in L-NAME-induced hypertension, we compared the blood pressure response in four groups (N = 10 each) of male Wistar-Hannover rats weighing 200 to 250 g: 1) sham-operated vehicle-treated, 2) sham-operated L-NAME-treated, 3) denervated vehicle-treated, and 4) denervated L-NAME-treated rats. After renal denervation or sham surgery, one control week was followed by three weeks of oral administration of L-NAME by gavage. Arterial pressure was measured weekly in conscious rats by a tail-cuff method and renal function tests were performed in individual metabolic cages 0, 7, 14 and 21 days after the beginning of L-NAME administration. L-NAME (60 mg kg-1 day-1) progressively increased arterial pressure from 108 +/- 6.0 to 149 +/- 12 mmHg (P<0.05) in the sham-operated group by the third week of treatment which was accompanied by a fall in creatinine clearance from 336 +/- 18 to 222 +/- 59 microl min-1 100 g body weight-1 (P<0. 05) and a rise in fractional urinary sodium excretion from 0.2 +/- 0. 04 to 1.62 +/- 0.35% (P<0.05) and in sodium post-proximal fractional excretion from 0.54 +/- 0.09 to 4.7 +/- 0.86% (P<0.05). The development of hypertension was significantly delayed and attenuated in denervated L-NAME-treated rats. This was accompanied by a striking additional increase in fractional renal sodium and potassium excretion from 0.2 +/- 0.04 to 4.5 +/- 1.6% and from 0.1 +/- 0.015 to 1.21 +/- 0.37%, respectively, and an enhanced post-proximal sodium excretion compared to the sham-operated group. These differences occurred despite an unchanged creatinine clearance and Na+ filtered load. These results suggest that bilateral renal denervation delayed and attenuated the L-NAME-induced hypertension by promoting an additional decrease in tubule sodium reabsorption in the post-proximal segments of nephrons. Much of the hypertension caused by chronic NO synthesis inhibition is thus dependent on renal nerve activity.33347-5