9,378 research outputs found
Fate of Electromagnetic Field on the Cracking of PSR J1614-2230 in Quadratic Regime
In this paper, we study the cracking of compact object PSR J1614-2230 in
quadratic regime with electromagnetic field. For this purpose, we develop a
general formalism to determine the cracking of charged compact objects. We
apply the local density perturbations to the hydrostatic equilibrium equation
as well as all the physical variables involve in the model. We plot the force
distribution function against radius of the star with different values of model
parameters both with and without charge. It is found that PSR J1614-2230
remains stable (no cracking) corresponding to different values of parameters
when charge is zero, while it exhibit cracking (unstable) when charge is
introduced. We conclude that stability region increases as amount of charge
increases.Comment: 21 pages, 8 figures, version to appear in advances in high energy
physic
Measurement of single event upsets in the ALICE-TPC front-end electronics
The Time Projection Chamber of the ALICE experiment at the CERN Large Hadron
Collider features highly integrated on-detector read-out electronics. It is
following the general trend of high energy physics experiments by placing the
front-end electronics as close to the detector as possible -- only some 10 cm
away from its active volume. Being located close to the beams and the
interaction region, the electronics is subject to a moderate radiation load,
which allowed us to use commercial off-the-shelf components. However, they
needed to be selected and qualified carefully for radiation hardness and means
had to be taken to protect their functionality against soft errors, i.e. single
event upsets.
Here we report on the first measurements of LHC induced radiation effects on
ALICE front-end electronics and on how they attest to expectations
Study of polytropes with Generalized polytropic Equation of State
The aim of this paper is to discuss the theory of Newtonian and relativistic
polytropes with generalized polytropic equation of state. For this purpose, we
formulated the general framework to discuss the physical properties of
polytrops with anisotropic inner fluid distribution under conformally flat
condition in the presence of charge. We investigate the stability of these
polytrops in the vicinity of generalized polytropic equation through
Tolman-mass. It is concluded that one of the derived models is physically
acceptable.Comment: 21 pages, 3 figure
Energy Consumption Rate based Stable Election Protocol (ECRSEP) for WSNs
In recent few yearsWireless Sensor Networks (WSNs) have seen an increased
interest in various applications like border field security, disaster
management and medical applications. So large number of sensor nodes are
deployed for such applications, which can work autonomously. Due to small power
batteries in WSNs, efficient utilization of battery power is an important
factor. Clustering is an efficient technique to extend life time of sensor
networks by reducing the energy consumption. In this paper, we propose a new
protocol; Energy Consumption Rate based Stable Election Protocol (ECRSEP). Our
CH selection scheme is based on the weighted election probabilities of each
node according to the Energy Consumption Rate (ECR) of each node. We compare
results of our proposed protocol with Low Energy Adaptive Clustering Hierarchy
(LEACH), Distributed Energy Efficient Clustering (DEEC), Stable Election
Protocol (SEP), and Enhanced SEP(ESEP). Our simulation results show that our
proposed protocol, ECRSEP outperforms all these protocols in terms of network
stability and network lifetime
Inflation in Supersymmetric SU(5)
We analyze the adjoint field inflation in supersymmetric (SUSY) SU(5) model.
In minimal SUSY SU(5) hybrid inflation monopoles are produced at the end of
inflation. We therefore explore the non-minimal model of inflation based on
SUSY SU(5), like shifted hybrid, which provides a natural solution for the
monopole problem. We find that the supergravity corrections with non-minimal
Kahler potential are crucial to realize the central value of the scalar
spectral index n_s ~ 0.96 consistent with the seven year WMAP data. The tensor
to scalar ratio r is quite small, taking on values r < 10^{-5}. Due to
R-symmetry massless SU(3) octet and SU(2) triplet Higgs bosons are present and
could spoil for gauge coupling unification. To keep gauge coupling unification
intact, light vector-like particles are added which are expected to be observed
at LHC.Comment: 16 page
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An unusual cause of gynaecomastia in a male
Summary: Beta-human chorionic gonadotropin (βhCG) is normally produced by syncytiotrophoblasts of the placenta during pregnancy and aids embryo implantation. However, it is also secreted in varying amounts in non-pregnant conditions commonly heralding a neoplastic process. We present a case of 50-year-old man, who presented with bilateral gynaecomastia with elevated testosterone, oestradiol, suppressed gonadotropins with progressively increasing levels of human chorionic gonadotropin (hCG). Biochemical and radiological investigations including ultrasonography of testes, breast tissue, MRI pituitary and CT scan full body did not identify the source of hCG. FDG PET scan revealed a large mediastinal mass with lung metastasis. Immunostaining and histological analysis confirmed the diagnosis of primary choriocarcinoma of the mediastinum. It is highly aggressive and malignant tumor with poor prognosis. Early diagnosis and management are essential for the best outcome. Learning Points: High βhCG in a male patient or a non-pregnant female suggests a paraneoplastic syndrome. In the case of persistently positive serum hCG, exclude immunoassay interference by doing the urine hCG as heterophilic antibodies are not present in the urine. Non-gestational choriocarcinoma is an extremely rare trophoblastic tumor and should be considered in young men presenting with gynaecomastia and high concentration of hCG with normal gonads. A high index of suspicion and extensive investigations are required to establish an early diagnosis of extra-gonadal choriocarcinoma. Early diagnosis is crucial to formulate optimal management strategy and to minimize widespread metastasis for best clinical outcome
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