9,174 research outputs found
A 300 GHz "Always-in-Focus" Focusing System for Target Detection
A focusing system for a 300 GHz radar with 5 m target distance and 10 mm diameter spot size resolution is proposed. The focusing system is based on a Gaussian telescope scheme and its main parameters have been de¬signed using Gaussian beam quasi-optical propagation theory with an in-house developed MATLAB® based analysis tool. Then, this approach has been applied to a real focusing system based on two elliptical mirrors in order to reduce the distortion and cross-polar level and a plane mirror to provide scanning capabilities. The over¬all system has been simulated with a full-wave electromag¬netic simulator and its behavior is presented. With this approach, the focusing system always works "in-focus" since the only mirror that is rotated when scanning is the output plane mirror, so the beam is almost not distorted. The design process, although based in the well-known Gaussian beam quasi-optical propagation theory, provides a fast and accurate method and minimizes the overall size of the mirrors. As a consequence, the size of the focusing system is also reduced
Community Interventions to Improve Cooking Skills and Their Effects on Confidence and Eating Behaviour
Purpose of Review:
Community-based interventions aiming to improve cooking skills are a popular strategy to promote healthy eating. We reviewed current evidence on the effectiveness of these interventions on different confidence aspects and fruit and vegetable intake.
Recent Findings:
Evaluation of cooking programmes consistently report increased confidence in cooking skills in adults across different age groups and settings. The effectiveness of these programmes on modifying eating behaviour is less consistent, but small increases in self-reported consumption of fruit and vegetables are also described. Lack of large samples, randomization and control groups and long-term evaluation are methodological limitations of the evidence reviewed.
Summary:
Cooking skill interventions can have a positive effect on food literacy, particularly in improving confidence on cooking and fruit and vegetable consumption, with vulnerable, low-socieconomic groups gaining more benefits. Consistency across study designs, delivery and evaluation of outcomes both at short and long terms are warranted to draw clearer conclusions on how cooking programmes are contributing to improve diet and health
Multiwavelength study of the starburst galaxy NGC7714. I: Ultraviolet-Optical spectroscopy
We have studied the physical conditions in the central 300 pc of the
proto-typical starburst galaxy NGC 7714. Our analysis is based on ultraviolet
spectroscopy with the HST+GHRS and ground-based optical observations.The data
are interpreted using evolutionary models optimized for young starburst
regions. The massive stellar population is derived in a self-consistent way
using the continuum and stellar absorption lines in the ultraviolet and the
nebular emission line optical spectrum.
The central starburst has an age of about 4.5 Myr, with little evidence for
an age spread. Wolf-Rayet features at the ultraviolet indicates a stellar
population of 2000 Wolf-Rayet stars. The overall properties of the newly
formed stars are quite similar to those derived, e.g., in 30 Doradus. A
standard Salpeter IMF is consistent with all observational constraints. We find
evidence for spatial structure within the central 300 pc sampled. Therefore it
is unlikely that the nucleus of NGC 7714 hosts a single star cluster exceeding
the properties of other known clusters. Contrary to previous suggestions, we
find no evidence for a nuclear supernova rate that would significantly exceed
the total disk-integrated rate. About one supernova event per century is
predicted.Comment: 19 pages, 9 figures in a tar file. Accepted for publication in ApJ,
1999, March, issue 51
Understanding the Success of Government Portals: The Role of Political Leadership, Standards, and a Powerful Centralized IT Agency
Information technologies have become an essential component of government administrative reforms and governance strategies around the world. Although Internet portals are now some of the most mature technologies, they continue to be the most important channel for governments to provide information and services to citizens and other stakeholders. However, studies about government portals still lack the level of detail necessary to better understand the specific variables that affect their success and, more prominently, how these variables intertwine. Based on institutional theory, particularly the technology enactment framework, and one in-depth case study in Mexico, this paper shows how leadership from the governor, the establishment of government-wide rules and standards, and the existence of a powerful centralized IT agency collectively affect the process of enacting a state government website and its potential results. The paper also identifies other variables and discusses some of their interactions and mechanisms of influence
Effect of Sunflower and Marine Oils on Ruminal Microbiota, In vitro Fermentation and Digesta Fatty Acid Profile
Funding This work has been funded by Consejería de Educación, Junta de Castilla y León (research project LE007A07). Acknowledgments We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). Support received from CICYT project AGL2005-04760-C02-02 is gratefully acknowledged.Peer reviewedPublisher PD
- …