9,531 research outputs found
The Performance of CRTNT Fluorescence Light Detector for Sub-EeV Cosmic Ray Observation
Cosmic Ray Tau Neutrino Telescopes (CRTNT) using for sub-EeV cosmic ray
measurement is discussed. Performances of a stereoscope configuration with a
tower of those telescopes plus two side-triggers are studied. This is done by
using a detailed detector simulation driven by Corsika. Detector aperture as a
function of shower energy above 10^17 eV is calculated. Event rate of about 20k
per year for the second knee measurement is estimated. Event rate for cross
calibration with detectors working on higher energy range is also estimated.
Different configurations of the detectors are tried for optimization.Comment: 5 pages, 4 figures, submitted to HEP & N
Rotation of the pinning direction in the exchange bias training effect in polycrystalline NiFe/FeMn bilayers
For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively
Lanczos algorithm with Matrix Product States for dynamical correlation functions
The density-matrix renormalization group (DMRG) algorithm can be adapted to
the calculation of dynamical correlation functions in various ways which all
represent compromises between computational efficiency and physical accuracy.
In this paper we reconsider the oldest approach based on a suitable
Lanczos-generated approximate basis and implement it using matrix product
states (MPS) for the representation of the basis states. The direct use of
matrix product states combined with an ex-post reorthogonalization method
allows to avoid several shortcomings of the original approach, namely the
multi-targeting and the approximate representation of the Hamiltonian inherent
in earlier Lanczos-method implementations in the DMRG framework, and to deal
with the ghost problem of Lanczos methods, leading to a much better convergence
of the spectral weights and poles. We present results for the dynamic spin
structure factor of the spin-1/2 antiferromagnetic Heisenberg chain. A
comparison to Bethe ansatz results in the thermodynamic limit reveals that the
MPS-based Lanczos approach is much more accurate than earlier approaches at
minor additional numerical cost.Comment: final version 11 pages, 11 figure
Fluctuations of Matrix Entries of Regular Functions of Wigner Matrices
We study the fluctuations of the matrix entries of regular functions of
Wigner random matrices in the limit when the matrix size goes to infinity. In
the case of the Gaussian ensembles (GOE and GUE) this problem was considered by
A.Lytova and L.Pastur in J. Stat. Phys., v.134, 147-159 (2009). Our results are
valid provided the off-diagonal matrix entries have finite fourth moment, the
diagonal matrix entries have finite second moment, and the test functions have
four continuous derivatives in a neighborhood of the support of the Wigner
semicircle law.Comment: minor corrections; the manuscript will appear in the Journal of
Statistical Physic
КВАРЦ. УЛЬТРАФІОЛЕТОВЕ ВИПРОМІНЮВАННЯ. ОЗОН. ВПЛИВ НА ВІРУС COVID-19
The article analyzes the effect of ultraviolet radiation, quartz and ozone on microorganisms and the impact on the human body. It is explained that due to the deactivation of DNA of bacteria viruses and other pathogenic microorganisms their ability to reproduce and cause disease is impaired which makes it advisable to use ultraviolet for disinfection, especially during a viral epidemic such as COVID-19.У статті проаналізовано вплив ультрафіолетового випромінювання, кварцу та озону як на людський організм, так і на мікроорганізми. Пояснено, що внаслідок дезактивації ДНК бактерій, вірусів та інших патогенних мікроорганізмів руйнується їх здатність до розмноження та виникнення хвороби, що робить доцільним використання ультрафіолетового випромінювання з метою дезінфекції, особливо в період такої вірусної епідемії, як COVID-19
СИНДРОМ СУХОГО ОКА
The article analyzes the etiology of the appearance and methods of treatment of dry eye syndrome.У статті проаналізовано етіологію виникнення синдрому сухого ока та методи лікування захворювання
A COMPARATIVE STUDY OF THE PHYTOCHEMICALS, ANTIOXIDANT AND ANTIBACTERIAL POTENTIAL OF METHANOLIC EXTRACTS OF TRICHOSANTHES CUCUMERINA (L.) VAR. CUCUMERINA UNDER IN VITRO CULTURE AND NATURAL CONDITIONS
Objective: To compare the phytochemicals, antioxidative capacity and antibacterial profile of methanolic extracts of callus and naturally propagated plant species-Trichosanthes cucumerina (L.) var. cucumerina and to optimize an ideal protocol for in vitro callus and shoot induction.Methods: The sterilized seeds of Trichosanthes cucumerina (L.) var. cucumerina were inoculated in half Murashige and Skoog (MS) basal medium devoid of growth hormones to raise aseptic seedlings. Explants from aseptic seedlings used for callus induction in MS medium fortified with varying combinations of N6–Benzyl amino purine (BAP), 1-Naphthalene acetic acid (NAA) and 2,4–Dichlorophenoxy acetic acid (2,4-D). For in vitro soot induction, MS medium supplemented with different concentrations of 2,4-D, BAP and Kinetin-either alone or in combinations were employed. The callus harvested on 21st and 45th days were analyzed for a comparison of the influence of age of callus on the quantity of secondary metabolites. For a comparison with the naturally grown plant, all experiments were carried out with extracts from callus and wild plants. The antioxidant capacity of methanolic extracts was evaluated by 2,2-Diphenyl-1 Picryl Hydrazyl (DPPH) free radical scavenging assay and Ferric Reducing Antioxidant Power (FRAP) analysis. The antibacterial activity of were screened by the agar diffusion method using pathogenic bacteria such as Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and documented through measurement of the diameter of growth inhibition zone (IZ). Results: The results on in vitro culture indicated that MS medium with BAP (0.5 mg/l) and 2,4-D (1 mg/l) was ideal for callus induction. For shoot induction, supplementation of MS medium with BAP-0.5 mg/l, 2,4,D-1.0 mg/l and Kinetin-0.5 mg/l was found to be most favourable. Direct root induction from the callus was found to occur in medium fortified with BAP-0.5 mg/l, 2,4, D-0.5 mg/l and NAA-1.0 mg/l. The phytoconstituents quantified were alkaloids, flavonoids, tannins, phenols and terpenoids and their levels were higher in wild plant in comparison to callus. Naturally grown plant possesses higher free radical scavenging ability and ferric reducing power than callus. Results of antibacterial activity indicated that the Gram-positive strain (Staphylococcus aureus) was more sensitive than the Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). The highest antibacterial activity recorded for naturally propagated plant extract against S. aureus (IZ = 13 mm) and was quite comparable with standard antibiotic cephatoxim (IZ = 20 mm) at 100mg concentration.Conclusion: Results concluded that this overexploited medicinal plant with lesser seed longevity could be successfully propagated by in vitro methods. The phytoconstituents with antioxidative and antibacterial potential were more abundant in naturally propagated plants than undifferentiated callus tissue. The extracts are potent antibacterial agents
Vehicular traffic flow at an intersection with the possibility of turning
We have developed a Nagel-Schreckenberg cellular automata model for
describing of vehicular traffic flow at a single intersection. A set of traffic
lights operating in fixed-time scheme controls the traffic flow. Open boundary
condition is applied to the streets each of which conduct a uni-directional
flow. Streets are single-lane and cars can turn upon reaching to the
intersection with prescribed probabilities. Extensive Monte Carlo simulations
are carried out to find the model flow characteristics. In particular, we
investigate the flows dependence on the signalisation parameters, turning
probabilities and input rates. It is shown that for each set of parameters,
there exist a plateau region inside which the total outflow from the
intersection remains almost constant. We also compute total waiting time of
vehicles per cycle behind red lights for various control parameters.Comment: 8 pages, 17 eps figures, Late
Highly Efficient Q-switched Ho:YLF Laser Pumped by Tm:Fiber Laser
A highly efficient Q-switched Ho:YLF laser pumped by a Tm:fiber laser has been designed and demonstrated. When the pump power is 30 W, the pulse energy is 30mJ at the repetition rate of 100Hz
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