8,174 research outputs found
Numerical Simulation on Shoreline Change in Western Region of Badung Regency, Bali, Indonesia
Shoreline change is considered the most dynamic processes in coastal region. Coastal erosion is a global problem where 70% beaches around the world are recessional. Almost all coastal area in Bali is potential to suffer from erosion. Badung Regency in Bali has many beaches that famous as tourism area where from about 64 km shoreline length, 11,5 km were recorded suffered by erosion in 1985 and 12,1 km erosion in 2007. This study aims to determine the value of shoreline changes that occur in western of Badung Regency from 2001 to 2010 based on the predicted wave data using monthly wind data from Ngurah Rai, Tuban, Badung, Bali meteorological station. Shoreline change simulation measured the forward (accretion) or backward (erosion) distance of the shoreline on the East-West direction. Bali has wind patterns that influenced by the Northwest monsoon from November-April and Southeast monsoon from May-October. In 2001-2010, dominant wind in this region was coming from east, southeast, and west. Geographically western coast of Badung influenced by incoming winds from the west, southwest, and south. Wind blow towards the coast in 2001-2010 are dominantly come from the west with wind speed range was about 1,7-4,7 m/s. Simulation indicated that generally shoreline tends to experience accretion in the north and erosion in the south. From 16000 m of study shoreline, along 7100 m of shoreline tend to suffer by erosion. Oppositely, along 8900 m of shoreline tend to have accretion
Numerical Simulation on Shoreline Change in Western Region of Badung Regency, Bali, Indonesia
Shoreline change is considered the most dynamic processes in coastal region. Coastal erosion is a global problem where 70% beaches around the world are recessional. Almost all coastal area in Bali is potential to suffer from erosion. Badung Regency in Bali has many beaches that famous as tourism area where from about 64 km shoreline length, 11,5 km were recorded suffered by erosion in 1985 and 12,1 km erosion in 2007. This study aims to determine the value of shoreline changes that occur in western of Badung Regency from 2001 to 2010 based on the predicted wave data using monthly wind data from Ngurah Rai, Tuban, Badung, Bali meteorological station. Shoreline change simulation measured the forward (accretion) or backward (erosion) distance of the shoreline on the East-West direction. Bali has wind patterns that influenced by the Northwest monsoon from November-April and Southeast monsoon from May-October. In 2001-2010, dominant wind in this region was coming from east, southeast, and west. Geographically western coast of Badung influenced by incoming winds from the west, southwest, and south. Wind blow towards the coast in 2001-2010 are dominantly come from the west with wind speed range was about 1,7-4,7 m/s. Simulation indicated that generally shoreline tends to experience accretion in the north and erosion in the south. From 16000 m of study shoreline, along 7100 m of shoreline tend to suffer by erosion. Oppositely, along 8900 m of shoreline tend to have accretion
Solution of Orthopositronium lifetime Puzzle
The intrinsic decay rate of orthopositronium formed in powder
is measured using the direct correction method such that the time
dependence of the pick-off annihilation rate is precisely determined. The decay
rate of orthopositronium is found to be , which is consistent with our previous measurements with
about twice the accuracy. Results agree well with the QED
prediction, and also with a result reported very recently using nanoporous
film
A XMM-Newton observation during the 2000 outburst of SAX J1808.4-3658
I present a XMM-Newton observation of the accretion driven millisecond X-ray
pulsar SAX J1808.4-3658 during its 2000 outburst. The source was conclusively
detected, albeit at a level of only ~2 x 10^{32} erg/s. The source spectrum
could be fitted with a power-law model (with a photon index of ~2.2), a neutron
star atmosphere model (with a temperature of ~0.2 keV), or with a combination
of a thermal (either a black-body or an atmosphere model) and a power-law
component. During a XMM-Newton observation taken approximately one year later,
the source was in quiescence and its luminosity was a factor of ~4 lower. It is
possible that the source spectrum during the 2000 outburst was softer than its
quiescent 2001 spectrum, however, the statistics of the data do not allow to
make a firm conclusion. The results obtained are discussed in the context of
the 2000 outburst of SAX J1808.4-3658 and the quiescent properties of the
source.Comment: Accepted for publication in ApJ, 15 January 200
Large amplitude oscillation of an erupting filament as seen in EUV, H-alpha and microwave observations
We present multiwavelength observations of a large-amplitude oscillation of a polar-crown filament on 15 October 2002, which has been reported by Isobe and Tripathi (Astron. Astrophys. 449, L17, 2006). The oscillation occurred during the slow rise (â1 kmâsâ1) of the filament. It completed three cycles before sudden acceleration and eruption. The oscillation and following eruption were clearly seen in observations recorded by the Extreme-Ultraviolet Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SOHO). The oscillation was seen only in a part of the filament, and it appears to be a standing oscillation rather than a propagating wave. The amplitudes of velocity and spatial displacement of the oscillation in the plane of the sky were about 5 kmâsâ1 and 15â000 km, respectively. The period of oscillation was about two hours and did not change significantly during the oscillation. The oscillation was also observed in Hα by the Flare Monitoring Telescope at the Hida Observatory. We determine the three-dimensional motion of the oscillation from the Hα wing images. The maximum line-of-sight velocity was estimated to be a few tens of kilometers per second, although the uncertainty is large owing to the lack of line-profile information. Furthermore, we also identified the spatial displacement of the oscillation in 17-GHz microwave images from Nobeyama Radio Heliograph (NoRH). The filament oscillation seems to be triggered by magnetic reconnection between a filament barb and nearby emerging magnetic flux as was evident from the MDI magnetogram observations. No flare was observed to be associated with the onset of the oscillation. We also discuss possible implications of the oscillation as a diagnostic tool for the eruption mechanisms. We suggest that in the early phase of eruption a part of the filament lost its equilibrium first, while the remaining part was still in an equilibrium and oscillated
Dark Matter and Collider Phenomenology with two light Supersymmetric Higgs Bosons
Recently, it has been pointed out that two different excesses of events
observed at LEP could be interpreted as the CP-even Higgs bosons of the MSSM
with masses of approximately 98 and 114 GeV. If this is the case, the entire
MSSM Higgs sector is required to be light. In this article, we explore such a
scenario in detail. We constrain the Higgs and supersymmetric spectrum using
physics constraints as well as the magnetic moment of the muon. We then
point out the implications for neutralino dark matter -- next generation direct
detection experiments will be sensitive to all MSSM models with such a Higgs
sector. Finally, we find that all models outside of a very narrow corridor of
the parameter space have a charged Higgs boson which will be observed at the
LHC. In those exceptional models which do not contain an observable charged
Higgs, a light top squark will always be seen at the LHC, and likely at the
Tevatron.Comment: 12 pages, 18 figure
Radial Bargmann representation for the Fock space of type B
Let be the probability and orthogonality measure for the
-Meixner-Pollaczek orthogonal polynomials, which has appeared in
\cite{BEH15} as the distribution of the -Gaussian process (the
Gaussian process of type B) over the -Fock space (the Fock space of
type B). The main purpose of this paper is to find the radial Bargmann
representation of . Our main results cover not only the
representation of -Gaussian distribution by \cite{LM95}, but also of
-Gaussian and symmetric free Meixner distributions on . In
addition, non-trivial commutation relations satisfied by -operators
are presented.Comment: 13 pages, minor changes have been mad
Quasi-Superradiant Soliton State of Matter in Quantum Metamaterials
Strong interaction of a system of quantum emitters (e.g., two-level atoms)
with electromagnetic field induces specific correlations in the system
accompanied by a drastic insrease of emitted radiation (superradiation or
superfluorescence). Despite the fact that since its prediction this phenomenon
was subject to a vigorous experimental and theoretical research, there remain
open question, in particular, concerning the possibility of a first order phase
transition to the superradiant state from the vacuum state. In systems of
natural and charge-based artificial atome this transition is prohibited by
"no-go" theorems. Here we demonstrate numerically a similar transition in a
one-dimensional quantum metamaterial - a chain of artificial atoms (qubits)
strongly interacting with classical electromagnetic fields in a transmission
line. The system switches from vacuum state with zero classical electromagnetic
fields and all qubits being in the ground state to the quasi-superradiant (QS)
phase with one or several magnetic solitons and finite average occupation of
qubit excited states along the transmission line. A quantum metamaterial in the
QS phase circumvents the "no-go" restrictions by considerably decreasing its
total energy relative to the vacuum state by exciting nonlinear electromagnetic
solitons with many nonlinearly coupled electromagnetic modes in the presence of
external magnetic field.Comment: 6 pages, 4 figure
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