1,830 research outputs found
Finding the optimum activation energy in DNA breathing dynamics: A Simulated Annealing approach
We demonstrate how the stochastic global optimization scheme of Simulated
Annealing can be used to evaluate optimum parameters in the problem of DNA
breathing dynamics. The breathing dynamics is followed in accordance with the
stochastic Gillespie scheme with the denaturation zones in double stranded DNA
studied as a single molecule time series. Simulated Annealing is used to find
the optimum value of the activation energy for which the equilibrium bubble
size distribution matches with a given value. It is demonstrated that the
method overcomes even large noise in the input surrogate data.Comment: 9 pages, 4 figures, iop article package include
Optimal operating conditions and characteristics of acetone/CaF_2 detector for inverse photoemission spectroscopy
Performance and characteristics of a band-pass photon detector using acetone
gas and CaF_2 window (acetone/CaF_2) have been studied and compared with an
ethanol/MgF_2 detector. The optimal operating conditions are found to be 4 mbar
acetone pressure and 745+/-20 V anode voltage. The count rate obtained by us is
about a factor of 3 higher than what has been reported earlier for the acetone
detector. Unlike other gas filled detectors, this detector works in the
proportional region with very small dead time (4 micro sec). A detector
band-pass of 0.48+/-0.01 eV FWHM is obtained.Comment: Review of Scientific Instruments 76, 066102 (2005
Low-Mass Dileptons at the CERN-SpS: Evidence for Chiral Restoration?
Using a rather complete description of the in-medium spectral function
- being constrained by various independent experimental information - we
calculate pertinent dilepton production rates from hot and dense hadronic
matter. The strong broadening of the resonance entails a reminiscence to
perturbative annihilation rates in the vicinity of the phase
boundary. The application to dilepton observables in Pb(158AGeV)+Au collisions
- incorporating recent information on the hadro-chemical composition at
CERN-SpS energies - essentially supports the broadening scenario. Possible
implications for the nature of chiral symmetry restoration are outlined.Comment: 6 pages ReVTeX including 5 eps-figure
Diazotrophic activity and ferric phosphate mineralizing ability in estuarine sulfate reducing bacteria
Twenty strainsofsulfate reducing bacteria were isolated from water and sediments of Cochin backwaters,
India. Five of them were identified as Desulfovibrio desulfuricans and fifteen as Desulfotomaculum orientis. All the Desulfovibrio were isolated from sediments whereas Desulfotomaculum was present in both water and sediment. All the bacteria grew at pH of slightly alkaline reaction and lowered the Eh from -105 to - 270 m V of the growth medium. Complete reduction of sulfate to sulfide by the bacteria was evidenced by blackening of Post gate culture media. All isolates were able to fix dinitrogen in anaerobic N-free modified
Postgate broth. In addition to nitrogen fixing ability, 5 of the Desulfotomaculum and 3 of the Desulfovibrio were able to produce soluble phosphorus in growth medium from insoluble FePO4. A scheme for FePO4 mineralization in marine and estuarine sediments has been proposed
Chitinolytic bacteria in Penaeus indicus
Quantitative distribution of chitinolytic bacteria from the hepatopancreas, stomach and intestine of a
commercially important marine prawn Penaeus indicus was studied. Twenlyfive representative bacteria
were isolated from colonies forming well defined clear zones on chitin agar medium and were identified.
Eighteen of the isolates were members of the genus Vibrio and the rest were members of the genus
Pseudomonas
Influence of Ni doping on the electronic structure of Ni_2MnGa
The modifications in the electronic structure of Ni_{2+x}Mn_{1-x}Ga by Ni
doping have been studied using full potential linearized augmented plane wave
method and ultra-violet photoemission spectroscopy. Ni 3d related electron
states appear due to formation of Ni clusters. We show the possibility of
changing the minority-spin DOS with Ni doping, while the majority-spin DOS
remains almost unchanged. The total magnetic moment decreases with excess Ni.
The total energy calculations corroborate the experimentally reported changes
in the Curie temperature and the martensitic transition temperature with x.Comment: 4 pages, 4 figures, accepted in Phys. Rev.
Local simulation of singlet statistics for restricted set of measurement
The essence of Bell's theorem is that, in general, quantum statistics cannot
be reproduced by local hidden variable (LHV) model. This impossibility is
strongly manifested while analyzing the singlet state statistics for Bell-CHSH
violations. In this work, we provide various subsets of two outcome POVMs for
which a local hidden variable model can be constructed for singlet state.Comment: 2 column, 5 pages, 4 figures, new references, abstract modified,
accepted in JP
Implementing Man-in-the-Middle Attack to Investigate Network Vulnerabilities in Smart Grid Test-bed
The smart-grid introduces several new data-gathering, communication, and
information-sharing capabilities into the electrical system, as well as
additional privacy threats, vulnerabilities, and cyber-attacks. In this study,
Modbus is regarded as one of the most prevalent interfaces for control systems
in power plants. Modern control interfaces are vulnerable to cyber-attacks,
posing a risk to the entire energy infrastructure. In order to strengthen
resistance to cyber-attacks, this study introduces a test bed for
cyber-physical systems that operate in real-time. To investigate the network
vulnerabilities of smart power grids, Modbus protocol has been examined
combining a real-time power system simulator with a communication system
simulator and the effects of the system presented and analyzed. The goal is to
detect the vulnerability in Modbus protocol and perform the Man-in-the-middle
attack with its impact on the system. This proposed testbed can be evaluated as
a research model for vulnerability assessment as well as a tool for evaluating
cyber-attacks and enquire into any detection mechanism for safeguarding and
defending smart grid systems from a variety of cyberattacks. We present here
the preliminary findings on using the testbed to identify a particular MiTM
attack and the effects on system performance. Finally, we suggest a cyber
security strategy as a solution to address such network vulnerabilities and
deploy appropriate countermeasures.Comment: 7 pages, 10 figures, Conference paper, Accepted in publication for
2023 IEEE World AI IoT Congress (AIIoT
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