298 research outputs found
Study of the time-differentiated particle flux density at various distances from EAS axis
The EAS time structure is studied using the enlarged EAS array of the Moscow State University. The time measurements are made using 22 scintillators which form 13 rectanges of 180x190 sq m size covering the entire array area. The array is triggered by a signal of 4-fold coincidences of the pulses from the detectors forming each of the rectangles. The data were obtained during 2200 hours of the array operation in 1984. A total of 816 showers, to which at least 14 of 22 scintillator detectors responded, were selected among all those detected. The coordinates of the EAS axis in the observation plane and the EAS sizes were determined by the maximum likelihood method using a computer on the assumption that the electron LDF is the NKG form. A total of 492 showers in the interval of EAS size Ne = 5x10 to the 6th power - 2x10 to the 8th power (N bar e = 1.7x 10 to the 7th power) with zenith angles theta or = 45 deg and axes within the array are analyzed
Analysis of nonlinear optical materials properties by simple powder technique
© Published under licence by IOP Publishing Ltd. The article describes a simple technique for comparative analysis of the second harmonic generation properties of new samples and etalon materials by their powders. The effectiveness of the method was tested and and measuring of nonlinear coefficient and damage threshold of the well known materials: KDP, LiIO3, m-nitroaniline was demonstrated. The parameters of the new promising nonlinear material DNPAP were measured
The current status of orbital experiments for UHECR studies
Two types of orbital detectors of extreme energy cosmic rays are being
developed nowadays: (i) TUS and KLYPVE with reflecting optical systems
(mirrors) and (ii) JEM-EUSO with high-transmittance Fresnel lenses. They will
cover much larger areas than existing ground-based arrays and almost uniformly
monitor the celestial sphere. The TUS detector is the pioneering mission
developed in SINP MSU in cooperation with several Russian and foreign
institutions. It has relatively small field of view (+/-4.5 deg), which
corresponds to a ground area of 6.4x10^3 sq.km. The telescope consists of a
Fresnel-type mirror-concentrator (~2 sq.m) and a photo receiver (a matrix of
16x16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite,
and is currently at the final stage of preflight tests. Recently, SINP MSU
began the KLYPVE project to be installed on board of the Russian segment of the
ISS. The optical system of this detector contains a larger primary mirror (10
sq.m), which allows decreasing the energy threshold. The total effective field
of view will be at least +/-14 degrees to exceed the annual exposure of the
existing ground-based experiments. Several configurations of the detector are
being currently considered. Finally, JEM-EUSO is a wide field of view (+/-30
deg) detector. The optics is composed of two curved double-sided Fresnel lenses
with 2.65 m external diameter, a precision diffractive middle lens and a pupil.
The ultraviolet photons are focused onto the focal surface, which consists of
nearly 5000 multi-anode photomultipliers. It is developed by a large
international collaboration. All three orbital detectors have multi-purpose
character due to continuous monitoring of various atmospheric phenomena. The
present status of development of the TUS and KLYPVE missions is reported, and a
brief comparison of the projects with JEM-EUSO is given.Comment: 18 pages; based on the rapporteur talk given by M.I. Panasyuk at
ECRS-2014; v2: a few minor language issues fixed thanks to the editor; to be
published in the proceeding
Bacillus intermedius ribonuclease (BINASE) induces apoptosis in human ovarian cancer cells
© 2014 Elsevier B.V. All rights reserved. The cytotoxic effects of Bacillus intermedius RNase (binase) towards ovarian cancer cells (SKOV3 and OVCAR5) were studied in comparison to normal ovarian epithelial cells (HOSE1 and HOSE2). Binase decreased viability and induced the selective apoptosis of ovarian cancer cells. The apoptosis rate was 50% in SKOV3 and 48% in OVCAR5 cells after 24 h of binase treatment (50 μg/ml). Binase-induced apoptosis in these cell lines was accompanied by caspase-3 activation and poly(ADP-ribose) polymerase fragmentation. Normal ovarian epithelial cells were not affected by binase, except for a slight decrease of HOSE2 cell viability and the appearance of traces of activated caspase-3, but not the poly(ADP-ribose) polymerase 85-kDA fragment. Binase did not induce alteration of EZH2 (enhancer of zeste-homolog-2) protein expression neither, in tumor nor in normal cells. In conclusion, selective binase-induced cell death and apoptosis via poly(ADP-ribose) polymerase fragmentation may serve as a new treatment option against ovarian cancer progression
Thermodynamics and Kinetics of Adduct Formation in Solutions of Bis(N-diisopropoxyphosphinoylthiobenzamido)-copper(II). An ESR Study and Description in Terms of the Donor-Acceptor Model
The equilibrium constants Kad, enthalpies, and entropies of adduct formation, rate constants for adduct formation (kf) and dissociation (kd), and enthalpies and entropies of activation have been calculated for solutions of bis(N-diisopropoxyphosphinoylthiobenzamido)copper(II) (CuL2) in toluene with addition of donor solvents Y (methanol, N,N-dimethylformamide, dimethyl sulfoxide, pyridine, piperidine, diethylamine) over a wide temperature range. The quantities logKad, logkf, and logkd have been found to linearly vary with the donor numbers of the solvents Y; on this basis, an associative character of activation in the formation and dissociation of adducts with copper(II) bischelates has been established for the first time. The constants Kad for CuL2Y are higher than those for other analogous adducts presumably due to the larger fraction of the isomer CuL2Yeq with equatorial coordination of the solvent
Spectroscopy and stimulated emission of Nd3+ in an acentric CsY2F7 host
The results of preliminary spectroscopic studies of new fluoride single-crystal CsY2F7 that is activated by Nd3+ ions are given. Direct evidence for the possibility of application of this ordered material as a laser host is given for the first time to our knowledge. Stimulated emission of Nd3+ ions on the main intermultiplet transition is obtained under both nonselective flash-lamp pumping conditions and continuous Ar ion laser pumping conditions. © 1992 Optical Society of America
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