Movie of the interplanetary magnetic field

Description of movie representing IMP-1 MAGNETOMETER observations of interplanetary magnetic fiel

Disaster Preparedness in the Developing World

Summary This article discusses the significance of disaster resulting from natural phenomena for people and societies in the developing world. It examines the need to develop planning and management techniques and skills so that disaster?prone countries can be ready to meet the challenge of disaster, and thus mitigate the distress which it brings to those least equipped to withstand it. It concludes by making proposals for the expansion of the training of public servants in developing countries to embrace pre?disaster planning and disaster management. It suggests that this is the most rapid, effective and economical way of meeting the disaster threat. Resume Comment se préparer pour les catastrophes dans les pays en voie de développement Cet article étudie ce que représente les catastrophes résultant de phénomènes naturels pour les gens et les sociétés dans les pays en voie de développement. Il examine la nécessité de mettre au point des techniques de planification et de gestion permettant aux pays sujets aux catastrophes à se préparer en vue de la catastrophe, et ainsi réduire la détresse qu'elle entraine chez ceux qui sont le moins bien équipés pour y faire face. L'auteur conclut en proposant quelques mesures pour que la formation des fonctionnaires dans les pays en voie de développement comprenne la planification en vue de l'éventuelle catastrophe et l'organisation en cas de catastrophe. Il suggère que ce serait le moyen le plus rapide, le plus efficace et le plus économique pour faire face aux menaces de catastrophes. Resumen La preparación contra los desastres en el mundo en vias de desarrollo En este artículo se reseña la importancia de los desastres causados por fenómenos naturales para la gente y las sociedades del mundo en vías de desarrollo. Se examina en él la necesidad de desarrollar técnicas de administración y planificación y pericia para que los países con propensión al desastre puedan estar listos para hacer frente a los desastres inminentes y mitigar así las calamidades que acarrean a los que están en peores condiciones para soportarlas. Concluye proponiendo la expansión de la formación de funcionarios públicos en los países en vías de desarrollo para incluir la planificación previa a los desastres y la organización necesaria después de los desastres. Se sugiere que ésta es la manera más rápida, eficaz y económica de hacer frente a la amenaza de desastres

Interplanetary magnetic field IMP-1, motion picture of the transverse components

Motion picture report of IMP-1 magnetometer observations of interplanetary magnetic fiel

A VLT/FLAMES survey for massive binaries in Westerlund 1 IV. Wd1-5 – binary product and a pre-supernova companion for the magnetar CXOU J1647-45?

Context. The first soft gamma-ray repeater was discovered over three decades ago, and was subsequently identified as a magnetar, a class of highly magnetised neutron star. It has been hypothesised that these stars power some of the brightest supernovae known, and that they may form the central engines of some long duration gamma-ray bursts. However there is currently no consenus on the formation channel(s) of these objects.Aims. The presence of a magnetar in the starburst cluster Westerlund 1 implies a progenitor with a mass ≥40 M⊙, which favours its formation in a binary that was disrupted at supernova. To test this hypothesis we conducted a search for the putative pre-SN companion.Methods. This was accomplished via a radial velocity survey to identify high-velocity runaways, with subsequent non-LTE model atmosphere analysis of the resultant candidate, Wd1-5.Results. Wd1-5 closely resembles the primaries in the short-period binaries, Wd1-13 and 44, suggesting a similar evolutionary history, although it currently appears single. It is overluminous for its spectroscopic mass and we find evidence of He- and N-enrichement, O-depletion, and critically C-enrichment, a combination of properties that is difficult to explain under single star evolutionary paradigms. We infer a pre-SN history for Wd1-5 which supposes an initial close binary comprising two stars of comparable (~ 41 M⊙ + 35 M⊙) masses. Efficient mass transfer from the initially more massive component leads to the mass-gainer evolving more rapidly, initiating luminous blue variable/common envelope evolution. Reverse, wind-driven mass transfer during its subsequent WC Wolf-Rayet phase leads to the carbon pollution of Wd1-5, before a type Ibc supernova disrupts the binary system. Under the assumption of a physical association between Wd1-5 and J1647-45, the secondary is identified as the magnetar progenitor; its common envelope evolutionary phase prevents spin-down of its core prior to SN and the seed magnetic field for the magnetar forms either in this phase or during the earlier episode of mass transfer in which it was spun-up.Conclusions. Our results suggest that binarity is a key ingredient in the formation of at least a subset of magnetars by preventing spin-down via core-coupling and potentially generating a seed magnetic field. The apparent formation of a magnetar in a Type Ibc supernova is consistent with recent suggestions that superluminous Type Ibc supernovae are powered by the rapid spin-down of these objects

Giant Fluctuations of Coulomb Drag in a Bilayer System

We have observed reproducible fluctuations of the Coulomb drag, both as a function of magnetic field and electron concentration, which are a manifestation of quantum interference of electrons in the layers. At low temperatures the fluctuations exceed the average drag, giving rise to random changes of the sign of the drag. The fluctuations are found to be much larger than previously expected, and we propose a model which explains their enhancement by considering fluctuations of local electron properties.Comment: 10 pages, 4 figure

Automated design analysis, assembly planning and motion study analysis using immersive virtual reality

Previous research work at Heriot-Watt University using immersive virtual reality (VR) for cable harness design showed that VR provided substantial productivity gains over traditional computer-aided design (CAD) systems. This follow-on work was aimed at understanding the degree to which aspects of this technology were contributed to these benefits and to determine if engineering design and planning processes could be analysed in detail by nonintrusively monitoring and logging engineering tasks. This involved using a CAD-equivalent VR system for cable harness routing design, harness assembly and installation planning that can be functionally evaluated using a set of creative design-tasks to measure the system and users' performance. A novel design task categorisation scheme was created and formalised which broke down the cable harness design process and associated activities. The system was also used to demonstrate the automatic generation of usable bulkhead connector, cable harness assembly and cable harness installation plans from non-intrusive user logging. Finally, the data generated from the user-logging allowed the automated activity categorisation of the user actions, automated generation of process flow diagrams and chronocyclegraphs

Joint Active Passive Sensing using a Radio Frequency System-on-a-Chip based sensor

In this paper we present a dual active and passive radar experimental setup that uses the UCL ARESTOR platform. This is a multi-role RF sensor based on a Xilinx Radio Frequency System on a Chip (RFSoC) device. The system is capable of operating as an active radar, passive radar and wideband electronic surveillance receiver. Experimental results are shown that leverage 2.4 GHz passive radar experiments along with a 5.8 GHz active radar mode that are operating simultaneously observing a target of interest. Details of a bespoke designed RF front-end to access higher frequency bands are included within the paper as well as information on processing pipelines developed within the Field Programmable Gate Array (FPGA). Comparison of the target signature and how both modes could be best utilised are analysed and discussed. The target of interest within this paper is a person walking while being sensing by both modes simultaneously

Radar UAV and Bird Signature comparisons with Micro-Doppler

This chapter reviews the similarities and differences between micro Unmanned Aerial Vehicles (UAVs), also referred to as drones, and bird targets from the signals they present to radar sensors. With the increasing usage of UAV platforms in both military and civilian applications, the demand for the ability to sense drone locations and discriminate them from background clutter and non-drone targets is becoming a vital requirement. A comparable target in size, speed and Radar Cross Section (RCS) is a bird. These are present almost everywhere that radar systems have to operate and have been detected by radar since the early origin of radar engineering. Due to the similarity in radar signature birds can cause common misclassification between them and the priority drone targets which has been identified as a current key challenge in radar sensing. In this chapter radar bird and drone signature research is initially summarised, then a fundamental model that represents the key contributions from drone rotor blades is introduced and compared to real measurements. Laboratory measurements of quadcopter rotor blade signatures with across 4 linear polarisations are then investigated in order to evaluate the trend of Signal-to-Noise-Ratio (SNR) vs. aspect angle. Next bird signatures from two separate radar systems are shown and compared to drone targets also present in the captures which are of comparable size and RCS. The outputs of all research presented are then summarised in the concluding remarks