14,191 research outputs found
Studies of ''soft tooling'' for a semi- toroidal test tank Final report
Unfeasibility of soft tooling for semi-toroidal test tan
Entropy of Contracting Universe in Cyclic Cosmology
Following up a recent proposal \cite{BF} for a cyclic model based on phantom
dark energy, we examine the content of the contracting universe (cu) and its
entropy . We find that beyond dark energy the universe contains on
average zero or at most a single photon which if present immediately after
turnaround has infinitesimally energy which subsequently blue shifts to produce
pairs. These statements are independent of the equation of state
of dark energy provided . Thus and
if observations confirm the entropy problem is solved. We discuss
the absence of a theoretical lower bound on , then
describe an anthropic fine tuning argument that renders unlikely extremely
small . The present bound already implies a time
until turnaround of Gy.Comment: 5 pages late
Communication to the World Food Conference: Plant Nutrients
27 September 1974 letter from CGIAR Chairman Warren C. Baum to World Food Conference Secretary General Sayed Marei on the work being done on plant nutrients at CGIAR centers and proposals being considered by the CGIAR and its TAC. Agenda document presented at CGIAR meeting, October 1974
CGIAR: How it all Began
This report is a brief summary of events leading to the formation of the CGIAR in 1971, as extracted from the the first two chapters of "Partners Against Hunger" by Warren Baum. This summary is also included in the CGIAR's 1985 annual report
Extended emission around GPS radio sources
Extended radio emission detected around a sample of GHz Peaked Spectrum (GPS)
radio sources is discussed. Evidence for extended emission which is related to
the GPS source is found in 6 objects out of 33. Three objects are associated
with quasars with core-jet pc-scale morphology, and three are identified with
galaxies with symmetric (CSO) radio morphology. We conclude that the core-jet
GPS quasars are likely to be beamed objects with a continuous supply of energy
from the core to the kpc scale. It is also possible that low surface brightness
extended radio emission is present in other GPS quasars but the emission is
below our detection limit due to the high redshifts of the objects. On the
other hand, the CSO/galaxies with extended large scale emission may be
rejuvenated sources where the extended emission is the relic of previous
activity. In general, the presence of large scale emission associated with GPS
galaxies is uncommon, suggesting that in the context of the recurrent activity
model, the time scale between subsequent bursts is in general longer than the
radiative lifetime of the radio emission from the earlier activity.Comment: 18 paged, 18 figures, accepted for publication on A&
Cryptocurrency Fraud: A Look Into The Frontier of Fraud
This research project was conducted to look into what sort of frauds can be committed to steal unsuspecting investors’ cryptocurrencies. The inspiration for this research came in the form of the fact that millions of dollars are lost to cryptocurrency fraud each day, and many of these frauds are successful due to the public’s naivete towards the dangers of investing in cryptocurrencies. After researching many different cryptocurrency fraud cases, the frauds could be categorized into four major categories. These categories include Ponzi schemes, fake initial coin offering schemes, pump and dump schemes as well as cryptocurrency theft
The Properties and Gaseous Environments of Powerful Classical Double Radio Galaxies
The properties of a sample of 31 very powerful classical double radio
galaxies with redshifts between zero and 1.8 are studied. The source
velocities, beam powers, ambient gas densities, total lifetimes, and total
outflow energies are presented and discussed. The rate of growth of each side
of each source were obtained using a spectral aging analysis. The beam power
and ambient gas density were obtained by applying the strong shock jump
conditions to the ends of each side of the source. The total outflow lifetime
was obtained by applying the power-law relationship between the beam power and
the total source lifetime derived elsewhere for sources of this type, and the
total outflow energy was obtained by combining the beam power and the total
source lifetime. Composite profiles were constructed by combining results
obtained from each side of each source. The composite profiles indicate that
the ambient gas density falls with distance from the central engine. The source
velocities, beam powers, total lifetimes, and total energies seem to be
independent of radio source size. This is consistent with the standard model in
which each source grows at a roughly constant rate during which time the
central engine puts out a roughly constant beam power. The fact that the total
source lifetimes and energies are independent of radio source size indicates
that the sources are being sampled at random times during their lifetimes.Comment: 7 pages, 5 figures, to appear in "Extragalactic Jets: Theory and
Observation from Radio to Gamma Ray", eds. T. A. Rector and D. S. De Young,
ASP conference series, Replaced version has minor textual correction
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