4,648 research outputs found

    Jets and Jet Multiplicities in High Energy Photon-Nucleon Inetraction:

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    We discuss the theory of jet events in high-energy photon-proton interactions using a model which gives a good description of the data available on total inelastic γp\gamma p cross sections up to s\sqrt{s}=210 GeV. We show how to calculate the jet cross sections and jet multiplicities and give predictions for these quantities for energies appropriate for experiments at the HERA epep collider and for very high energy cosmic ray observations.Comment: 12 pages + 4 figs, MAD/TH/92-8, submitted to Phys. Rev. D(Rapid Communications), figs. available on request from [email protected]

    Accretion disc-corona and jet emission from the radio-loud narrow-line Seyfert 1 galaxy RX J1633.3+4719

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    We perform X-ray/ultraviolet (UV) spectral and X-ray variability studies of the radio-loud narrow-line Seyfert 1 (NLS1) galaxy RX J1633.3+4719 using XMM-Newton and Suzaku observations from 2011 and 2012. The 0.3-10 keV spectra consist of an ultrasoft component described by an accretion disc blackbody (kT_in = 39.6^{+11.2}_{-5.5} eV) and a power law due to the thermal Comptonization ({\Gamma} = 1.96^{+0.24}_{-0.31}) of the disc emission. The disc temperature inferred from the soft excess is at least a factor of 2 lower than that found for the canonical soft excess emission from radio-quiet NLS1s. The UV spectrum is described by a power law with photon index 3.05^{+0.56}_{-0.33}. The observed UV emission is too strong to arise from the accretion disc or the host galaxy, but can be attributed to a jet. The X-ray emission from RX J1633.3+4719 is variable with fractional variability amplitude FvarF_{\rm var}=13.5±1.0\pm1.0 per cent. In contrast to radio-quiet active galactic nuclei (AGN), X-ray emission from the source becomes harder with increasing flux. The fractional rms variability increases with energy and the rms spectrum is well described by a constant disc component and a variable power-law continuum with the normalization and photon index being anticorrelated. Such spectral variability cannot be caused by variations in the absorption and must be intrinsic to the hot corona. Our finding of possible evidence for emission from the inner accretion disc, jet and hot corona from RX J1633.3+4719 in the optical to X-ray bands makes this object an ideal target to probe the disc-jet connection in AGN.Comment: 12 pages, 11 figures, 3 tables, Published in MNRA

    Monitoring Lateral Deflections of a Berthing Structure During Dredging — A Case Study

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    For one of the major ports in India, a shallow water berth is recently constructed comprising of a diaphragm wall and pile rows to support the deck structure. The soil strata are essentially very soft clay extending to a large depth. Reclaiming land behind this structure created number of problems including mud flow. The structure was constructed after placement of fill required for reclamation. After completion of the structure, when dredging work was undertaken, it was decided to monitor the lateral movements of berths, as the dredging depth increases. For this purpose inclinometer tubes were installed in one of the diaphragm wall panels and another in one of the piles of the structure. The structure is analysed using PLAXIS finite element software and results are compare with field measurements which are in good agreements

    High-energy Atmospheric Muon Flux Expected at India-Based Neutrino Observatory

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    We calculate the zenith-angle dependence of conventional and prompt high-energy muon fluxes at India-Based Neutrino Observatory (INO) depth. This study demonstrates a possibility to discriminate models of the charm hadroproduction including the low-x QCD behaviour of hadronic cross-sections relevant at very high energies.Comment: 10 pages. 8 figures, 3 table

    Embedded AGN and star formation in the central 80 pc of IC 3639

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    [Abridged] Methods: We use interferometric observations in the NN-band with VLTI/MIDI to resolve the mid-IR nucleus of IC 3639. The origin of the nuclear infrared emission is determined from: 1) the comparison of the correlated fluxes from VLTI/MIDI with the fluxes measured at subarcsec resolution (VLT/VISIR, VLT/ISAAC); 2) diagnostics based on IR fine-structure line ratios, the IR continuum emission, IR bands produced by polycyclic aromatic hydrocarbons (PAH) and silicates; and 3) the high-angular resolution spectral energy distribution. Results: The unresolved flux of IC 3639 is 90±20mJy90 \pm 20\, \rm{mJy} at 10.5μm10.5\, \rm{\mu m}, measured with three different baselines in VLTI (UT1-UT2, UT3-UT4, and UT2-UT3; 4646-58m58\, \rm{m}), making this the faintest measurement so far achieved with mid-IR interferometry. The correlated flux is a factor of 33-44 times fainter than the VLT/VISIR total flux measurement. The observations suggest that most of the mid-IR emission has its origin on spatial scales between 1010 and 80pc80\, \rm{pc} (4040-340mas340\, \rm{mas}). A composite scenario where the star formation component dominates over the AGN is favoured by the diagnostics based on ratios of IR fine-structure emission lines, the shape of the IR continuum, and the PAH and silicate bands. Conclusions: A composite AGN-starburst scenario is able to explain both the mid-IR brightness distribution and the IR spectral properties observed in the nucleus of IC 3639. The nuclear starburst would dominate the mid-IR emission and the ionisation of low-excitation lines (e.g. [NeII]12.8μm_{12.8 \rm{\mu m}}) with a net contribution of 70%\sim 70\%. The AGN accounts for the remaining 30%\sim 30\% of the mid-IR flux, ascribed to the unresolved component in the MIDI observations, and the ionisation of high-excitation lines (e.g. [NeV]14.3μm_{14.3 \rm{\mu m}} and [OIV]25.9μm_{25.9 \rm{\mu m}}).Comment: Accepted for publication in A&

    Classification of EEG signals on standing, walking and running dataset using LSTM-RNN

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    Undoubtedly one of the most important strands of the brain-computer interface (BCI) method is an alternate communication method via brain signals. BCI converts electroencephalogram (EEG) signals from a perception of activity in the brain into user action utilising software and hardware. BCI has piqued the interest of researchers in a wide range of disciplines, such as cognitive science, deep learning, pattern matching, drug treatment medicine, etc. Patients suffering from neuro and cognitive disorders can be assisted through BCI, potentially enabling communication via gestures or just mental imagination. In this paper, a novel combination of Discrete Wavelet Transform (DWT) for extracting the best features and Long Short-Term Memory (LSTM) based Recurrent Neural Network (RNN) is adopted for classifying the EEG signals acquired during standing, walking and running on a treadmill. The dataset used is freely downloaded from Open Science Framework repository. The proposed DWT-LSTMRNN method delivers 96.7% accuracy while classifying four different signals, and thus has the potential to be investigated further on BCI competition datasets that will pave way for a real-time application

    A prospective study of fetomaternal outcome in cases of placenta previa

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    Background: The incidence of placenta previa ranges from 0.5-1% amongst hospital deliveries. Placenta previa is major cause of antepartum haemorrhage and is potentially devastating complication. Obstetric haemorrhage is most common cause for maternal and perinatal morbidity and mortality in India. This study aimed to determine frequency, type of placenta previa, risk factors and adverse fetomaternal outcomes of placenta previa.Methods: This was a prospective study carried out in Department of Obstetrics and Gynaecology, Government Medical College and Sir-T hospital, Bhavnagar from July 2007 to July 2009 to analyze fetomaternal outcome in cases of placenta previa. All patients of placenta previa with gestational age > 28 weeks up to full term were included in the study. All cases were confirmed by Ultrasound examination. All cases were carefully analyzed to find out the incidence, type of placenta previa, its clinical presentation and its outcome in relation to mode of delivery, birth weight, maternal and perinatal morbidity.Results: There was total 50 cases of placenta previa out of 5636 deliveries. The prevalence of placenta previa was 0.88% and was more commonly present among multiparous women (82%). Most common type was type IV placenta previa in 23 (46%) cases followed by type III in 11 (22%) cases. Out of 50 cases, 06 (12%) cases had atonic PPH and 02 (04%) cases underwent peripartum hysterectomy. Most common predisposing factors were age >35 years (04%), multiparity (50%), previous cesarean section (16%) and previous history of abortion (12%). All cases of perinatal mortality were between 28 to 30 weeks weighing between 1-1.5 kg. There was no maternal mortality in this study.Conclusions: Managing a case of placenta previa during pregnancy poses a great challenge to every obstetrician in present day obstetrics due to its increased risk of maternal and perinatal complications

    Heavy boson production through the collision of an ultrahigh-energy neutrino on a target nucleon

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    We discuss W and Z production through the deep inelastic neutrino-nucleon scattering in the context of the standard model SU(3)x SU(2)x U(1) of the strong and electroweak interactions. We find the cross section rates for the process neutrino + nucleon --> lepton(-) + W(+) + X for the case of ultrahigh-energy neutrinos colliding on a target nucleon.Comment: 20 pages, 6 figure
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