1,168 research outputs found

    On the stability of the stochastic parabolic Itô equation with delay and Markovian jump

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    AbstractWe present a new result concerning the stability of the stochastic parabolic Itô equation subject to homogenous white noise. Our main results state that this system is exponentially stable by means of a new Lyapunov–Krasovskii functional and a linear matrix inequality (LMI). A numerical example is exploited to show the usefulness of the derived LMI-based stability

    Collective clusterization effects in light heavy ion reactions

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    The collective clusterization process, proposed for intermediate mass fragments (IMFs, 4<<A≤\le28, 2<<Z≤\le14) emitted from the hot and rotating compound nuclei formed in low energy reactions, is extended further to include also the emission of light particles (LPs, A≤\le4, Z≤\le2) from the fusion-evaporation residues. Both the LPs and IMFs are treated as the dynamical collective mass motion of preformed clusters through the barrier. Compared to IMFs, LPs are shown to have different characteristics, and the predictions of our, so-called, dynamical cluster-decay model are similar to those of the statistical fission model.Comment: 4 pages, 3 figures, Conferenc

    T-dependent RMF Model Applied to Ternary Fission Studies

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    Ternary decay is comparatively a rare phenomenon. The yield distribution for the thermal neutroninduced fission of 236U was investigated within the Temperature-dependent Relativistic Mean Field (TRMF) approach and statistical theory. Binding energy obtained from TRMF for the ground state and at a specific temperature is used to evaluate the fragment excitation energy, which is needed to calculate the nuclear level density. Using the ternary convolution, the yield for α-accompanied fission of 236U* is calculated. Initial results are presented which shows a maximum yield for the fragment pair Tc + Ag +α. Further, the ternary pre-existence probability for the spontaneous fission of 236U was studied considering fixed third fragments of α,10Be and 14C using the area of the overlapping region. No significant change in the yield distribution was observed when fragment deformations are considered. However, the heavy group for the probable pair remains as 132Sn with a change in mass number of the lighter fragment.

    Appearance / Disappearance of Magic Number in Light Nuclei

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    The shell structure of a nucleus is important to study their observed characteristic features. The classic magic numbers are successful in explaining the nuclear properties for nuclei lying near the stability line. The advent of radioactive ion beam facilities has permitted to examine nuclei in their extreme proton to neutron ratio. The light exotic nuclei were found to exhibit unique shell closure behaviour which is different from the medium mass nuclei near the stability line. The two nucleon separation energy difference systematics was used as a probe to study the magic character of light nuclei. New proton and neutron magic numbers were predicted among the available even Z isotopes and even N isotones. For certain systems, the classic magic numbers were found to be non-magic, while for some systems the magic property is retained even at the drip lines. The shell closure behaviour predicted is found to depend on the version of the mass table

    Cluster-decay of hot 56^{56}Ni∗^* formed in 32^{32}S+24^{24}Mg reaction

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    The decay of 56Ni∗^{56}Ni^*, formed in 32S+24Mg^{32}S+^{24}Mg reaction at the incident energies EcmE_{cm}=51.6 and 60.5 MeV, is calculated as a cluster decay process within the Preformed Cluster-decay Model (PCM) of Gupta et al. re-formulated for hot compound systems. The observed deformed shapes of the exit channel fragments are simulated by introducing the neck-length parameter at the scission configuration, which nearly coincides the 56Ni^{56}Ni saddle configuration. This is the only parameter of the model, which though is also defined in terms of the binding energy of the hot compound system and the ground-state binding energies of the various emitted fragments. The calculated s-wave cross sections for nuclear shapes with outgoing fragments separated within nuclear proximity limit (here ∼\sim0.3 fm) can be compared with the experimental data, and the TKEs are found to be in reasonably good agreement with experiments for the angular momentum effects added in the sticking limit for the moment of inertia. Also, some light particle production (other than the statistical evaporation residue, not treated here) is predicted at these energies and, interestingly, 4He^4He, which belongs to evaporation residue, is found missing as a dynamical cluster-decay fragment.Comment: 13 Pages, 12 figure

    A Study of clinical profile, laboratory profile and complications of fever with thrombocytopenia

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    BACKGROUND : Infection is a common cause of thrombocytopenia. Detection of thrombocytopenia associated with fever helps to narrow differential diagnosis and management of fever. It also helps to know the various complications of thrombocytopenia and its management and outcome of the patient. AIM OF THE STUDY : 1. To study of incidence of various etiological agents for patients getting admitted for fever with thrombocytopenia. 2. To analyse relevant epidemiological data like seasonal variation 3. To analyse the clinical feature among various positive cases. 4. To analyse the investigation done on positive cases. 5. To study the incidence of complication. 6. To analyse about outcome of the patient. METHODS : 100 patients aged > 12 years with fever and thrombocytopenia seen between December 2010 to November 2011 were included for this study. RESULTS: Infection was the commonest cause of thrombocytopenia and dengue was the commonest infection. Bleeding manifestations were seen in 12 % of patients. PetechIae/purpura as the commonest bleeding manifestation followed by gum bleeding. Good recovery was noted in 92% while 8% had mortality. 50% of patients with platelet count below 20,000 does not needed platelet transfusion. CONCLUSIONS : Infections, particularly dengue was the commonest cause of fever with thrombocytopenia. In majority of patients, thrombocytopenia was transient and asymptomatic but in significant number of cases there were bleeding manifestations. Spontaneous bleeding was noted in platelet count of < 20,000/mm3 in majority of patients, petechiae /purpura was seen in platelet count in range of 20,000- 40,000/mm3. On treating the specific cause drastic improvement in platelet count was noted during discharge and further follow-up

    Ultralow Power Energy Harvesting Body Area Network Design: A Case Study

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    Citation: Zheng, C. Y., Kuhn, W. B., & Natarajan, B. (2015). Ultralow Power Energy Harvesting Body Area Network Design: A Case Study. International Journal of Distributed Sensor Networks, 11. doi:10.1155/2015/824705This paper presents an energy harvesting wireless sensor network (EHWSN) architecture designed for use within an astronaut's space suit. The contribution of this work spans both physical (PHY) layer energy harvesting transceiver design and low power medium access control (MAC) solutions. The architecture consists of a star topology with two types of transceiver nodes: a powered gateway radio (GR) node and multiple energy harvesting biosensor radio (BSR) nodes. To demonstrate the feasibility of an EHWSN at the PHY layer, a representative BSR node is implemented. The BSR node is powered by a thermal energy harvesting system (TEHS) which exploits the difference between the temperatures of a space suit's cooling garment and the astronaut's body. It is shown that, through appropriate control of the duty cycle in transmission and receiving modes, it is possible to operate with less than 1 mW generated by the TEHS. This requires ultralow duty cycle which complicates MAC layer design because a BSR node must sleep for more than 99.6% of overall operation time. The challenge for MAC layer design is the inability to predict when the BSR node awakens from sleep mode due to unpredictability of the harvested energy. Therefore, a new feasible MAC layer design, GRI-(gateway radio initialized-) MAC, is proposed and analyzed

    Simulation of fluid flows during growth of organic crystals in microgravity

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    Several counter diffusion type crystal growth experiments were conducted in space. Improvements in crystal size and quality are attributed to reduced natural convection in the microgravity environment. One series of experiments called DMOS (Diffusive Mixing of Organic Solutions) was designed and conducted by researchers at the 3M Corporation and flown by NASA on the space shuttle. Since only limited information about the mixing process is available from the space experiments, a series of ground based experiments was conducted to further investigate the fluid dynamics within the DMOS crystal growth cell. Solutions with density differences in the range of 10 to the -7 to 10 to the -4 power g/cc were used to simulate microgravity conditions. The small density differences were obtained by mixing D2O and H2O. Methylene blue dye was used to enhance flow visualization. The extent of mixing was measured photometrically using the 662 nm absorbance peak of the dye. Results indicate that extensive mixing by natural convection can occur even under microgravity conditions. This is qualitatively consistent with results of a simple scaling analysis. Quantitave results are in close agreement with ongoing computational modeling analysis

    Theoretical and numerical perspectives and field observations for the design and performance evaluation of embankments constructed on soft marine clay

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    In this chapter, a two-demensional plane strain solution is adopted for the embankment analysis, which includes the effects of smear zone caused by mandrel driven vertical drains. The equivalent (transformed) permeability coefficients are incorporated in finite element codes, employing modified Cam-clay theory. Selected numerical studies have been carried out to study the effect of embankment slope, construction rate, and drain spacing on the failure of the soft clay foundation. Finally, the observed and predicted performances of well-instrumented full-scale trial embankments built on soft Malaysian marine clay have been discussed in detail. The predicted results agree with the field measurements
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