13,335 research outputs found
An Examination of an Effective Peer Evaluation Process
This student, peer evaluation process for mid-sized groups was developed to allow for assessment of individual performance in a high-stakes, team project. The objective is to ensure, as much as possible, the grades being assigned are being earned
Millimeter wave propagation measurements using the ATS 5 satellite
The ATS 5 millimeter wave propagation experiment determines long- and short-term attenuation statistics of operational millimeter wavelength earthspace links as functions of defined meteorological conditions. A preliminary analysis of results with 15 GHz downlink and 32 GHz uplink frequency bands indicates that both frequency bands exhibit an excellent potential for utilization in reliable high data rate earth-space communications systems
ATS-5 millimeter wave propagation measurements
Long term experimental measurements to determine the propagation characteristics of 15 and 32 GHz earth-space links and to evaluate performance characteristics of operational millimeter wave systems are reported. The ATS 5 millimeter wave experimental link experienced attenuation and fading characteristics as a function of rainfall rate and other meteorological parameters. A method of site selection for the lowest attenuation rainfall rate improved reception tremendously
Propagation handbook, frequencies above 10 GHz
The progress and accomplishments in the developmet of the Fourth Edition of the NASA Propagation Effects Handbook for Satellite Systems Design, for frequencies 10 to 100 GHz, NASA Reference Publication 1082(04), dated May 1988, prepared by Westighouse Electric Corporation for the Jet Propulsion Laboratory are discussed
Considerations on reduction of indoor air pollution from radioactive emissions from building materials and the ground
The goal of this paper is to study the reduction of health risks from indoor radioactive pollutants, as thoron emissions from common building materials, and radon emission from both building materials and the ground. In particular, when dealing with the indoor environment, one of the most important hazard is represented by radon gas, considered by the World Health Organization (WHO) as the second largest cause of lung cancer, cigarette smoke being the first. Such a radioactive gas belongs to the natural radioactive background of radiation, and its presence all over the world is unavoidable.
Radon gas density varies due to microclimatic factors such as temperature, air pressure, humidity and changes in ground layers. Radon gas emerges from the ground and penetrates building basements, accumulating itself into the indoor air, and being breathed in by people. Taking care of the airtightness of windows allows the radon concentration to build up, in some cases beyond reference levels, together with other chemical pollutants, i.e. combustion residues and solvents. The EU Basic Safety Standards, stated in the Council Directive 2013/59/Euratom, based on the last recommendations from the International Commission on Radiological Protection (ICRP) and from WHO, are focusing on risks related to radon gas concentration inside dwellings and working places. On considering that Council Directive 2013/59 Euratom has to be transposed into law by each EU Member State by February 2018, it is recommended that radon issues have to be considered during the design phase of the building construction. For NZEB applications a special attention is requested when energy consumption is reduced lower and lower by taking care of airtightness. In such a case, indoor pollutants (chemical, radioactive, particulate, etc.) can significantly accumulate beyond safe levels.
This paper describes measurements and remedial actions of study cases, focusing on public and domestic environments
Recommended from our members
Effective Organisational Communication: Perspectives, principles and practices (4th edition)
Effective Organisational Communication gives students from all backgrounds the tools to communicate both within and between organisations of all kinds. With thorough coverage of the theoretical background of organisational communication, as well as practical content that helps readers develop their own communication skills, this is the perfect resource for those who want to improve their ability to work effectively with others.
This heavily revised fourth edition reflects the rapidly changing world of organisational communication, with a special focus on social media and recent developments in advertising, PR and social marketing.
Features to aid learning include:
ā¢ Real-world case studies from organisations of all kinds bring the topics alive.
ā¢ āFace to faceā case studies connect concepts and issue with typical everyday communication challenges found at university and work.
ā¢ Up to the minute coverage of international and inter-cultural communication and emerging technologies.
ā¢ Web links provide a starting point for research and further study on key issues in each chapter.
āThere is something refreshing about this text that derives from the breadth of the issues and perspectives addressed in the first half of the book, the worldview advanced through a willingness to engage with the complexity of organisations and communication, and the authors' rich yet succinct style of writing. They have managed to create a comprehensive text that addresses both the conceptual and the practical requirements of students, and even make topics like āmeetingsā, āemailā, and āreport writingā both instructive and engaging.
The book is rich with valuable insights into the patterns, unpredictability and nuances of organisational communication. It is surprisingly thorough in its coverage of the topics one might expect, as well as many that come as a pleasing surprise. It avoids an instrumental focus and didacticism, but continuously provides guidance for effective practice.ā
Journal of Communication Management (2010
Stability of a granular layer on an inclined "fakir plane"
We present here experimental results on the effect of a forest of cylinder
obstacles (nails) on the stability of a granular layer over a rough incline, in
a so-called "fakir plane" configuration. The nail forest is found to increase
the stability of the layer, the more for the densest array, and such an effect
is recovered by a simple model taking into account the additional friction
force exerted by the pillar forest onto the granular layer
Traveling-wave tube circuit simplifies microwave relay
Circuit with a sawtooth-modulated traveling-wave tube, which acts as a frequency converter and as an amplifier, simplifies microwave transmission. Lower power losses and reduced size and weight are also realized in this circuit
- ā¦