16,675 research outputs found
Common Errors Found in the Use of Sentence Structure: a Case Study
This study is done to find out: (1) the common errors in the use of sentence structure and (2) the similarities and differences on the types of errors in the use of sentence structure between original draft in the first topic, second topic, and third topic of Written English 4B class English Department in Petra Christian University. The writer chooses the theory of common errors in the use of sentence structure as proposed by Ho (2005). The findings of this study show that there are seven (7) out of eight (8) types of errors that occur in the students' drafts. Fragmented Sentence is the most common error made by the students in their drafts. In addition, there were similarities and differences on the types of errors and the frequency of occurrences of errors among the students. In conclusion, most of the students have understood about the use of sentence structure
Giant Radio Sources
We present multi-frequency VLA observations of two giant quasars, 0437-244
and 1025-229, from the Molonglo Complete Sample. These sources have
well-defined FRII radio structure, possible one-sided jets, no significant
depolarization between 1365 and 4935 MHz and low rotation measure (). The giant sources are defined to be those whose overall
projected size is 1 Mpc. We have compiled a sample of about 50 known
giant radio sources from the literature, and have compared some of their
properties with a complete sample of 3CR radio sources of smaller sizes to
investigate the evolution of giant sources, and test their consistency with the
unified scheme for radio galaxies and quasars. We find an inverse correlation
between the degree of core prominence and total radio luminosity, and show that
the giant radio sources have similar core strengths to the smaller sources of
similar total luminosity. Hence their large sizes are unlikely to be due to
stronger nuclear activity. The degree of collinearity of the giant sources is
also similar to the sample of smaller sources. The luminosity-size diagram
shows that the giant sources are less luminous than our sample of smaller-sized
3CR sources, consistent with evolutionary scenarios where the giants have
evolved from the smaller sources losing energy as they expand to these large
dimensions. For the smaller sources, radiative losses due to synchrotron
radiation is more significant while for the giant sources the equipartition
magnetic fields are smaller and inverse Compton losses with the microwave
background radiation is the dominant process. The radio properties of the giant
radio galaxies and quasars are consistent with the unified scheme.Comment: 14 pages with 12 figures, MNRAS LaTex. Accepted for publication in
MNRAS. Minor changes in the text and couple of references adde
Effects of curvature and interactions on the dynamics of the deconfinement phase transition
We study the dynamics of first-order cofinement-deconfinement phase
transition through nucleation of hadronic bubbles in an expanding quark gluon
plasma in the context of heavy ion collisions for interacting quark and hadron
gas and by incorporating the effects of curvature energy. We find that the
interactions reduce the delay in the phase transition whereas the curvature
energy has a mixed behavior. In contrast to the case of early Universe phase
transition, here lower values of surface tension increase the supercooling and
slow down the hadronization process. Higher values of bag pressure tend to
speed up the transition. Another interesting feature is the start of the
hadronization process as soon as the QGP is created.Comment: LaTeX, 17 pages including 14 postscript figure
Flow reversals in turbulent convection via vortex reconnections
We employ detailed numerical simulations to probe the mechanism of flow
reversals in two-dimensional turbulent convection. We show that the reversals
occur via vortex reconnection of two attracting corner rolls having same sign
of vorticity, thus leading to major restructuring of the flow. Large
fluctuations in heat transport are observed during the reversal due to this
flow reconfiguration. The flow configurations during the reversals have been
analyzed quantitatively using large-scale modes. Using these tools, we also
show why flow reversals occur for a restricted range of Rayleigh and Prandt
numbers
Evolution of primordial planets in relation to the cosmological origin of life
We explore the conditions prevailing in primordial planets in the framework
of the HGD cosmologies as discussed by Gibson and Schild. The initial stages of
condensation of planet-mass H-4He gas clouds in trillion-planet clumps is set
at 300,000 yr (0.3My) following the onset of plasma instabilities when ambient
temperatures were >1000K. Eventual collapse of the planet-cloud into a solid
structure takes place against the background of an expanding universe with
declining ambient temperatures. Stars form from planet mergers within the
clumps and die by supernovae on overeating of planets. For planets produced by
stars, isothermal free fall collapse occurs initially via quasi equilibrium
polytropes until opacity sets in due to molecule and dust formation. The
contracting cooling cloud is a venue for molecule formation and the sequential
condensation of solid particles, starting from mineral grains at high
temperatures to ice particles at lower temperatures, water-ice becomes
thermodynamically stable between 7 and 15 My after the initial onset of
collapse, and contraction to form a solid icy core begins shortly thereafter.
Primordial-clump-planets are separated by ~ 1000 AU, reflecting the high
density of the universe at 30,000 yr. Exchanges of materials, organic molecules
and evolving templates readily occur, providing optimal conditions for an
initial origin of life in hot primordial gas planet water cores when adequately
fertilized by stardust. The condensation of solid molecular hydrogen as an
extended outer crust takes place much later in the collapse history of the
protoplanet. When the object has shrunk to several times the radius of Jupiter,
the hydrogen partial pressure exceeds the saturation vapour pressure of solid
hydrogen at the ambient temperature and condensation occurs.Comment: 14 pages 7 figures SPIE Conference 7819 Instruments, Methods, and
Missions for Astrobiology XIII Proceedings, Aug 3-5, 2010, San Diego, Ed.
Richard B. Hoove
Wideband slotted patch antennas using EBG structures
Copyright @ 2010 IEEEA slotted microstrip patch antenna is designed with Electromagnetic Band gap (EBG) structures. The performance parameters of the presented antenna are then compared with the conventional patch antenna. It is realized that there is a significant increase of bandwidth and better suppression of harmonics than the normal patch antenna. This antenna is thus operating in the frequency band 5 - 6 GHz which is one of the most usable bandwidth regions for wireless applications such as WiMAX, WiFi outdoor, WLAN, Hiperlan/2 and many more. The proposed antenna achieves a gain between 4 to 6 dBi built in FR-4 material
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