12,864 research outputs found
Role of the developing nations in the development and optimal use of space technology
The economic and social factors are discussed which play a role in the advancement of space technology in developing nations. It is concluded that mutual collaboration between developed and developing nations is the basic element which will allow developing nations to take part in space experiments and research
The high-excitation planetary nebulae: NGC 3918 and IC 2448
International Ultraviolet Exploration observations of NGC 3918 and IC 2448 are presented. Combining these observations with data in the optical range and computed model structure, the chemical composition for these objects is derived. For NGC 3918 log C = -3.02, log N = -3.61 and log 0 = -3.22; while for IC 2448 log C = -3.44, log N = -81 and log 0 = 3.54
Off-Mass-Shell N Scattering and
We adapt the off-shell N amplitude of the Tucson-Melbourne three-body
force to the half-off-shell amplitude of the pion rescattering contribution to
near threshold. This {\em pion} rescattering contribution,
together with the impulse term, provides a good description of the data when
the half-off-shell amplitude is linked to the phenomenological invariant
amplitudes obtained from meson factory N scattering data.Comment: 3 pages, contributed to STORRI99, Bloomington, Indiana, September
199
Public Health England's recovery tools: potential teaching resources?
The file attached to this record is the author's final peer reviewed version.Training to combat chemical and radiation accidents, incidents or attacks is critical for health professionals
due to recent events involving these hazards or their use as unconventional weapons, such as the use of
the nerve agent novichok in Salisbury, UK. Health professionals need to have appropriate knowledge and
skills to effectively respond to future events involving any of these substances, which requires a rapid and
coordinated response from different professionals to protect the environment and minimise the number of
people exposed and reduce morbidity and mortality. However, despite chemical and radiation incidents
becoming increasingly prevalent, literature reviews have shown that there is a lack of teaching of
appropriate competences to face future crises in Europe, particularly amongst clinicians and other health
professionals that would be part of the initial response. Thus, De Montfort University (DMU, UK) in
collaboration with different academics from the University of Alcalá (Spain) and researchers from Public
Health England (PHE) with comprehensive experience in environmental decontamination and restoration,
have created a short training course for providing undergraduate/postgraduate students with basic skills
to respond to chemical incidents, basic skills that are based on the major competences recently identified
by the European Commission [1]. This novel training has been tested with students from different
backgrounds in various European universities, recording high degrees of acquisition of the various basic
competences that we developed to initially respond to chemical events [2]. To develop the practical part
of this chemical training, we have incorporated the novel guidance and methodology developed by PHE
to successfully tailor a protection and recovery response to any incident involving chemical substances,
which is available in the “UK Recovery Handbook for Chemical Incidents” [3] and its web-based tools:
“Chemical Recovery Navigation Tool” (CRNT, [4]) and “Chemical Recovery Record Form” (CRRF, [5]).
These innovative resources aid the user to select effective protection, decontamination and restoration
techniques or strategies from a pool of up-to-date options applicable to different environments according
to the physicochemical properties of the chemical(s) involved and the area affected. The CRNT is
accompanied by the CRRF, which facilitates collection and analysis of the necessary data to inform
decisions, and an e-learning resource named “Chemical Recovery: Background” (CRB, [6]), which could
facilitate the learning of environmental decontamination and restoration. We are currently developing a
short training course to cover minor radiation incidents; this radiation training will follow the same methods
used to develop the chemical training, but with the specific PHE recovery tools to tackle such events,
specifically the “UK Recovery Handbooks for Radiation Incidents” [7] and its associated web-based tools
“Radiation Recovery Navigation Tool” (Rad RNT, [8]), one for each environment: food production systems,
inhabited areas and drinking water supplies. This communication will explore the use of the PHE’s
Recovery Navigation Tools as potential resources to facilitate the acquisition of basic knowledge to tailor
protection and recovery interventions for minor chemical and radiation incidents to protect the public
Galactic Planetary Nebulae with Wolf-Rayet Nuclei III. Kinematical Analysis of a Large Sample of Nebulae
Expansion velocities (Vexp) of different ions and line widths at the base of
the lines are measured and analyzed for 24 PNe with [WC]-type nuclei (WRPNe), 9
PNe ionized by WELS (WLPNe) and 14 ordinary PNe. A comparative study of the
kinematical behavior of the sample clearly demonstrates that WRPNe have in
average 40-45% larger Vexp, and possibly more turbulence than WLPNe and
ordinary PNe. WLPNe have velocity fields very much alike the ones of ordinary
PNe, rather than the ones of WRPNe. All the samples (WRPNe, WLPNe and ordinary
PNe) show expansion velocities increasing with age indicators, for example
is larger for low-density nebulae and also it is larger for nebulae
around high-temperature stars. This age effect is much stronger for evolved
WRPNe, suggesting that the [WC] winds have been accelerating the nebulae for a
long time, while for non-WRPNe the acceleration seems to stop at some point
when the star reaches a temperature of about 90,000-100,000 K. Non-WR nebulae
reach a maximum Vexp < 30 km/s while evolved WRPNe reach maximum Vexp of about
40 km/s. For all kind of objects (WRPNe and non-WRPNe) it is found that in
average Vexp(N+) is slightly larger than Vexp(O++), indicating that the nebulae
present acceleration of the external shells.Comment: 20 pages, 11 fig. To appear in Revista Mexicana de Astronomia y
Astrofisica, April 200
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