609 research outputs found
Dynamic quadrilateral characteristic based distance relays for transmission lines equipped with TCSC
Copyright: © 2021 by the authors. A two-fold adaptive dynamic quadrilateral relay is developed in this research for protecting Thyristor-Controlled Series Compensator (TCSC)-compensated transmission lines (TLs). By investigating a new tilt angle and modifying the Takagi method to recognize the fault zone identifier, the proposed relay adapts its reactive reach and resistive reach separately and independently. The investigated tilt angle and identified fault zone use the TCSC reactance to compensate its effect on the TL parameters and system homogeneity. Excessive tests are simulated by MATLAB on the non-homogenous network, IEEE-9 bus system and further tests are carried out on IEEE-39 bus system in order to generalize and validate the efficiency of the proposed approach. The designed trip boundaries are able to detect wide range of resistive faults under all TCSC modes of operations. The proposed approach is easy to implement as there no need for data synchronization or a high level of computation and filtration. Moreover, the proposed adaptive dynamic relay can be applied for non-homogeneity systems and short as well as long TLs which are either TCSC-compensated or -uncompensated TLs
Higgs production in CP-violating supersymmetric cascade decays: probing the `open hole' at the Large Hadron Collider
A benchmark CP-violating supersymmetric scenario (known as 'CPX-scenario' in
the literature) is studied in the context of the Large Hadron Collider (LHC).
It is shown that the LHC, with low to moderate accumulated luminosity, will be
able to probe the existing `hole' in the - plane, which
cannot be ruled out by the LEP data. We explore the parameter space with
cascade decay of third generation squarks and gluino with CP-violating decay
branching fractions. We propose a multi-channel analysis to probe this
parameter space some of which are background free at an integrated luminosity
of 5-10 fb. Specially, multi-lepton final states (3\l,\, 4\l and like
sign di-lepton) are almost background free and have reach for the
corresponding signals with very early data of LHC for both 14 TeV and 7 TeV
center of mass energy.Comment: 24 pages, 9 figures, references added as in the journal versio
Studies in RF power communication, SAR, and temperature elevation in wireless implantable neural interfaces
Implantable neural interfaces are designed to provide a high spatial and temporal precision control signal implementing high degree of freedom real-time prosthetic systems. The development of a Radio Frequency (RF) wireless neural interface has the potential to expand the number of applications as well as extend the robustness and longevity compared to wired neural interfaces. However, it is well known that RF signal is absorbed by the body and can result in tissue heating. In this work, numerical studies with analytical validations are performed to provide an assessment of power, heating and specific absorption rate (SAR) associated with the wireless RF transmitting within the human head. The receiving antenna on the neural interface is designed with different geometries and modeled at a range of implanted depths within the brain in order to estimate the maximum receiving power without violating SAR and tissue temperature elevation safety regulations. Based on the size of the designed antenna, sets of frequencies between 1 GHz to 4 GHz have been investigated. As expected the simulations demonstrate that longer receiving antennas (dipole) and lower working frequencies result in greater power availability prior to violating SAR regulations. For a 15 mm dipole antenna operating at 1.24 GHz on the surface of the brain, 730 uW of power could be harvested at the Federal Communications Commission (FCC) SAR violation limit. At approximately 5 cm inside the head, this same antenna would receive 190 uW of power prior to violating SAR regulations. Finally, the 3-D bio-heat simulation results show that for all evaluated antennas and frequency combinations we reach FCC SAR limits well before 1 °C. It is clear that powering neural interfaces via RF is possible, but ultra-low power circuit designs combined with advanced simulation will be required to develop a functional antenna that meets all system requirements. © 2013 Zhao et al
CP violation in sbottom decays
We study CP asymmetries in two-body decays of bottom squarks into charginos
and tops. These asymmetries probe the SUSY CP phases of the sbottom and the
chargino sector in the Minimal Supersymmetric Standard Model. We identify the
MSSM parameter space where the CP asymmetries are sizeable, and analyze the
feasibility of their observation at the LHC. As a result, potentially
detectable CP asymmetries in sbottom decays are found, which motivates further
detailed experimental studies for probing the SUSY CP phases.Comment: 29 pages, 7 figure
Chemical characterization of some substituted hydroxyapatites
Synthetic multi-substituted hydroxyapatite nano powders containing silicon and or carbonate prepared by a wet chemical method. The process parameters are set up to allow the simultaneous substitution of carbonate and silicon ions in the place of phosphorus. The chemical and structural characterizations of the prepared powders are determined with the aid of; XRF, ICP, XRD and FTIR. The results show that, the ion substitution in the crystal lattice of HA caused a change in the unit cell dimensions and affected the degree of crystallization of the produced powders. The apatite formation abilityy of the prepared discs from the synthesized powders is determined by immersing in SBF solution for different periods. The degree of ion release was determined in the obtained solutions. The examined surface of the immersed discs under SEM and analyzed by CDS showed a more dense HA layer than those of un-substituted ones. The HA with the substituted silicon and carbonate ions, showed the highest solubility with greater rate of ion release, compared with carbonate-free powder. All prepared powders took sodium ion from the SBF solution during immersion, which was not recorded before
Trust Perceptions of Online Travel Information by Different Content Creators: Some Social and Legal Implications
Consumers are increasingly turning to the online
environment to provide information to assist them in
making purchase decisions related to travel products. They
often rely on travel recommendations from different
sources, such as sellers, independent experts and, increasingly,
other consumers. A new type of online content, usergenerated
content (UGC), provides a number of legal and
social challenges to providers and users of that content,
especially in relation to areas such as defamation, misrepresentation
and social embarrassment. This paper reports
research that examined the level of trustworthiness of
online travel information from these different sources. The
study used a survey of Australian travel consumers (n=
12,000) and results support the notion that there are
differences in the level of trust for online travel information
from different sources. Respondents âtended to agreeâ that
they trusted information provided by travel agents, information
from commercial operators and comments made by
travellers on third party websites. However, the highest
level of trust was afforded to information provided on State
government tourism websites. These results suggest that
greater trust is placed in online travel comments when they
are on a specific travel website than when they are on a
more generic social networking website. However, respondents
were ânot sureâ that they trusted comments made by
travellers on weblogs and on social networking sites. Some
88% of respondents that had not visited UGC websites (or
were unsure if they had) indicated that they thought that
UGC would be useful in the future â suggesting that they
feel that any concerns they may have in relation to legal and
social problems resulting from its use will be resolved
Higgs Boson Masses in the Complex NMSSM at One-Loop Level
The Next-to-Minimal Supersymmetric Extension of the Standard Model (NMSSM)
with a Higgs sector containing five neutral and two charged Higgs bosons allows
for a rich phenomenology. In addition, the plethora of parameters provides many
sources of CP violation. In contrast to the Minimal Supersymmetric Extension,
CP violation in the Higgs sector is already possible at tree-level. For a
reliable understanding and interpretation of the experimental results of the
Higgs boson search, and for a proper distinction of Higgs sectors provided by
the Standard Model or possible extensions, the Higgs boson masses have to be
known as precisely as possible including higher-order corrections. In this
paper we calculate the one-loop corrections to the neutral Higgs boson masses
in the complex NMSSM in a Feynman diagrammatic approach adopting a mixed
renormalization scheme based on on-shell and conditions. We study
various scenarios where we allow for tree-level CP-violating phases in the
Higgs sector and where we also study radiatively induced CP violation due to a
non-vanishing phase of the trilinear coupling in the stop sector. The
effects on the Higgs boson phenomenology are found to be significant. We
furthermore estimate the theoretical error due to unknown higher-order
corrections by both varying the renormalization scheme of the top and bottom
quark masses and by adopting different renormalization scales. The residual
theoretical error can be estimated to about 10%
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