110,496 research outputs found
Variability of Millennial-Scale Trends in the Geomagnetic Axial Dipole
The historical trend in the axial dipole is sufficient to reverse the field in less than 2 kyr. Assessing the prospect of an imminent polarity reversal depends on the probability of sustaining the historical trend for long enough to produce a reversal. We use a stochastic model to predict the variability of trends for arbitrary time windows. Our predictions agree well with the trends computed from paleomagnetic models. Applying these predictions to the historical record shows that the current trend is likely due to natural variability. Furthermore, an extrapolation of the current trend for the next 1 to 2 kyr is highly unlikely. Instead, we compute the trend and time window needed to reverse the field with a specified probability. We find that the dipole could reverse in the next 20 kyr with a probability of 2%
Design and Development of an Airblast Atomiser for the KAVERI engine and the sectoral combustor tests
This report deals with the design and development
of an airblast atomiser for application in the KAVERI
engine. Five atomisers of the chosen design were
fabricated and tested at ambient conditions to determine
the fuel spray SMD, patternation, cone angle
and atomiser flow number. The atomiser performance
parameters specified were achieved and hot tests
carried out in the 90° combustor sector. The combustor
pressure loss, exit temperature distribution, ignition
and stability limits were evaluate
The Organic Research Centre; Elm Farm Bulletin 84 July 2006
Regular bulletin with technical updates of the Organic Advisory Service
Issue contains:
Battling on for Avian Flu preventive vaccination; Organic Colombian Blacktail eggs;
UK Co-existence - GMOand non-GMO crops; Aspects of Poultry Behaviour; CAP in the service of biodiversity; Seeing the Wood, the Trees and the Catch 22; Beware of organic market "statistics"; A central role in energy review
Elm Farm Organic Research Centre Bulletin 83 April 2006
Regular bulleting with technical updates from Organic Advisory Service
Issue contains:
Testing for Tolerance - a pragmatic view GM Debate
Vaccination nation - to jab or not to jab Future shape of OCIS
Evolutionary wheat makes the grade? NIAB tracks health of organic cereal seed
Stopping erosion of soil quality - the organic way
Care needed to halt butterfly collapse
Aspects of poultry behaviour: How free range is free range?
On choosing an organic wheat A local education challenge
New Wakelyns Science Building Organic vegetable market growt
Clinical impact of “in-treatment” wall motion abnormalities in hypertensive atients with left ventricular hypertrophy: the LIFE Study.
Seismo-electromagnetic phenomena in the western part of the Eurasia-Nubia plate boundary
This paper presents a future research plan that aims to monitor Seismo-electromagnetic (SEM) phenomena in the western part of the Eurasia-Nubia plate boundary (WENP). This region has a significant tectonic activity [1] combined with relatively low electromagnetic noise levels and for that reason presents the possibility to perform high quality SEM measurements.
Further, it is known that low-frequency [ultra (ULF), very (VLF), and low-frequencies (LF)] electromag- netic (EM) waves produce more convincing earthquake precursors (compared to higher frequencies) because of less contamination, large skin depth, and low attenuation [2]. Thus, two SEM effects will be considered: ULF electromagnetic field emissions [3], and VLF/LF radio broadcastings [4].
With respect to the ULF measurements, as a start, three ULF sensors are planned to be installed in the South of Iberian Peninsula supported by the existing networks of seismic research stations. Subsequent devel- opment of this initial plan could result in the implementation of a lager ULF monitoring network not only in the Iberian Peninsula, but also in the rest of Europe. Possible integration in the SEGMA array is now under consideration. Another perspective is to use a portable station to track seismic events.
Regarding the VLF/LF radio broadcastings, a receiver is planned to be mounted in University of Évora. Radio signals from up to 10 transmitters (in these bands) of interest to study the seismic activity in the WENP region will be monitored. Actually, the radio path from the transmitter to the receiver should cross the epicentral area, therefore two possible transmitters are the ones installed in Monaco (France) and Sicily (Italy). Furthermore, the system will integrate the INFREP network and in this context it will not be restricted to WENP region.
With the development of these research plans we aim to collect novel SEM data emerging from the seis- mic activity in the WENP region. We expect to address the time variations of EM properties of the crust/plate in relation with the strain field, and in space in relation with composition and temperature and stress fields. Further, the interplay between atmospheric (and solar) perturbations with crust perturbations will be monitored, to observe geomagnetic perturbations at different locations. Our study will be focused in the analyses of low magnitude earthquakes with M =< 4, these events are frequent in the WENP region, but have been almost completely disregarded in literature [5,6].
[1] J. Borges, A. J. S. Fitas, M. Bezzeghoud, and P. Teves-Costa, Tectonophysics 337, 373 (2001). [2] V. Chauhan, O.P. Singh, V. Kushwah, V. Singh, B. Singh, Journal of Geodynamics 48, 68 (2009). [3] L. Telesca, V. Lapenna, M. Macchiato, and K. Hattori, Earth and Planet. Science Lett. 268, 219 (2008)
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