1,722 research outputs found
Oil Pollution in the Coastal Waters off Port Dickson, Straits of Malacca
The petroleum hydrocarbon dist1ibution in the Port Dichson coastal waters was studied over a period of three years
from 1986 to 1989. Generally, there was no significant difference (P > 0.05) of hydrocarbon levels in water among
the sampling stations on each of the sampling dates. However a pronounced fluctuation was found at different
samping dates. Similarly, a pronounced fluctuation of hydrocarbon content in the sediment with different sampling
dates was also detected. The mean hydrocarbon level in the water ranged between 14.69ppb and 150.28 ppb, ESSO
'Tapis A crude oil equivalent (or between 0.77 ppb and 7.87 ppb, chrysene equivalent), while for the sediment it
ranged between 21. 73 mg/kg and 74.50 mg/kgdry sediment, Esso Tapis A crude oil equivalent (or between 1.12
mg/hgand 3. 90 mg/kgdry sediment, chrysene equivalent). The oil pollution level in the PortDickson coastal waters
was comparable or higher than that found in the Exclusive Economic Zone watels off Pahang and Sabah, but was
lower than that detected in the Terengganu and Sanl1uak waters. The saUTce of hydrocarbon pollution in the POTt
Dichsm~ coastal waters was probably from the open sea and the nearby harbour and oil refineries rather than from
land TUn of
Separable Structure of Many-Body Ground-State Wave Function
We have investigated a general structure of the ground-state wave function
for the Schr\"odinger equation for identical interacting particles (bosons
or fermions) confined in a harmonic anisotropic trap in the limit of large .
It is shown that the ground-state wave function can be written in a separable
form. As an example of its applications, this form is used to obtain the
ground-state wave function describing collective dynamics for trapped
bosons interacting via contact forces.Comment: J. Phys. B: At. Mol. Opt. Phys. 33 (2000) (accepted for publication
Carbon fibre tips for scanning probe microscopy based on quartz tuning fork force sensors
We report the fabrication and the characterization of carbon fibre tips for
their use in combined scanning tunnelling and force microscopy based on
piezoelectric quartz tuning fork force sensors. We find that the use of carbon
fibre tips results in a minimum impact on the dynamics of quartz tuning fork
force sensors yielding a high quality factor and consequently a high force
gradient sensitivity. This high force sensitivity in combination with high
electrical conductivity and oxidation resistance of carbon fibre tips make them
very convenient for combined and simultaneous scanning tunnelling microscopy
and atomic force microscopy measurements. Interestingly, these tips are quite
robust against occasionally occurring tip crashes. An electrochemical
fabrication procedure to etch the tips is presented that produces a sub-100 nm
apex radius in a reproducible way which can yield high resolution images.Comment: 14 pages, 10 figure
New Physics Effects in Decays
We present a model-independent analysis of rare B decays, . The effect of possible new physics is written in terms of dimension-6
four-fermi interactions. The lepton number violating scalar- and tensor-type
interactions are included, and they induce decays. We show systematically how the branching ratios and
missing mass-squared spectrum depend on the coefficients of the four-fermi
interactions.Comment: 20 pages with 7 figure
decays in the Left-Right Symmetric Model
We consider decays in the Left-Right Symmetric Model. Values
of observables sensitive to chiral structure such as the polarization
in the decays and the mixing-induced CP
asymmetries in the decays can deviate in the LRSM
significantly from the SM values. The combined analysis of and
as well as can be used to determine the
model parameters.Comment: 16 pages with 7 figures, Version to be published in PR
Faddeev-Jackiw Analysis of Topological Mass Generating Action
We analyze the gauge symmetry of a topological mass generating action in four
dimensions which contains both a vector and a second rank antisymmetric tensor
fields. In the Abelian case, this system induces an effective mass for the
vector gauge field via a topological coupling in the presence of a
kinetic term for the antisymmetric tensor field , while maintaining a gauge
symmetry. On the other hand, for the non-Abelian case the field does not
have a gauge symmetry unless an auxiliary vector field is introduced to the
system. We analyze this change of symmetry in the Faddeev-Jackiw formalism, and
show how the auxiliary vector field enhances the symmetry. At the same time
this enhanced gauge symmetry becomes reducible. We also show this phenomenon in
this analysis.Comment: 20 pages, REVTe
LHC Signature of Mirage Mediation
We study LHC phenomenology of mirage mediation scenario in which anomaly and
modulus contributions to soft SUSY breaking terms are comparable to each other.
A Monte Carlo study of mirage mediation, with model parameters , GeV, , and , is presented. It is
shown that masses of supersymmetric particles can be measured in a model
independent way, providing information on SUSY breaking sector. In particular,
the mass ratio of gluino to the lightest neutralino for the benchmark scenario
is determined to be 1.9 \lesssim m_{\tildeg}/m_{\tilde\chi_1^0} \lesssim 3.1,
well reproducing theoretical input value of which is quite distinctive from the predictions of other SUSY scenarios in which gaugino
masses are unified at the GUT scale. The model parameters of mirage mediation
can be also determined from various kinematic distributions
Short review on metamorphic malware detection in Hidden Markov Models
Metamorphic malware is well known for evading signature-based detection. To cope up with numerous malware which can emerge easily by using open source malware generator, efficient detection in terms of accuracy and runtime performance shall be considered during analysis. Detection strategies such as data mining combine with machine learning have been used by researchers for heuristically detecting malware. In this paper, we present Hidden Markov Model as an efficient metamorphic malware detection tool by exploring the common obfuscation techniques used in malware while reviewing and comparing the different studies that adopt HMM as a detection tool
Thermodynamics of doubly charged CGHS model and D1-D5-KK black holes of IIB supergravity
We study the doubly charged Callan-Giddings-Harvey-Strominger (CGHS) model,
which has black hole solutions that were found to be U-dual to the D1-D5-KK
black holes of the IIB supergravity. We derive the action of the model via a
spontaneous compactification on S^3 of the IIB supergravity on S^1*T^4 and
obtain the general static solutions including black holes corresponding to
certain non-asymptotically flat black holes in the IIB supergravity.
Thermodynamics of them is established by computing the entropy, temperature,
chemical potentials, and mass in the two-dimensional setup, and the first law
of thermodynamics is explicitly verified. The entropy is in precise agreement
with that of the D1-D5-KK black holes, and the mass turns out to be consistent
with the infinite Lorentz boost along the M theory circle that is a part of the
aforementioned U-dual chain.Comment: 21 pages, Revte
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