92 research outputs found
Using of polymeric materials to defeat of lightly armored and easily vulnerable targets. Mathematical modeling
The article deals with the possibility of increasing the damaging effects of small-caliber artillery ammunition in the fuel tanks of aircraft and helicopters. A comparison of the results of the calculation of the probability of the incendiary effect of strikers based on fluoropolymers on diesel fuel was made. The calculations of the probabilities of fuel ignition by the method of 'Fragmented criterion'. As a result of the calculations, it was revealed that this method is not suitable for this type of problem statement. A combined methodology has been developed for calculating the probability of fuel ignition, taking into account the ongoing chemical reaction between fluoropolymers and aluminum. All components of the passing heat release process are taken into account - the impactor deformation energy, the impactor braking energy in the fuel, the chemical energy of the reaction undergoing. The energy of the ongoing chemical reaction was taken into account using thermochemistry methods. © Published under licence by IOP Publishing Ltd
Increasing the effectiveness of combined strikers in the defeat of lightly armored targets
The article deals with the possibility of increasing the damaging effects of small-caliber artillery ammunition in the fuel tanks of aircraft and helicopters. A comparison of the results of the calculation of the probability of the incendiary effect of strikers based on fluoropolymers on diesel fuel was made. The calculations were carried out using the methods of “Fragment Criterion” and “Energy Balance”. © 2021 Institute of Physics Publishing. All rights reserved
Using of polymeric materials to defeat of lightly armored and easily vulnerable targets. Theory and experiments
Small caliber artillery plays an important role in the destruction of lightly armored and easily vulnerable equipment. Currently, a search is underway to increase its damaging effect. The article deals with the possibility of increasing the damaging effects of small-caliber artillery ammunition in the fuel tanks of aircraft and helicopters. The physicochemical properties of fluoropolymer materials are considered. The process of thermodynamic decomposition of a fluoropolymer is considered. The results of experiments on the interaction of fluoroplastic and aluminum / titanium alloys are analyzed. Pictures of changes in the titanium wet structure under the impact of ammunition including fluoroplastic are shown. The Ballistic Stand installation was designed to evaluate the incendiary effect of fluoropolymer materials. Several possible designs of projectiles containing fluoroplastic are selected to evaluate their structural characteristics for incendiary effect. A comparison of the results of the calculation of the probability of the incendiary effect of strikers based on fluoropolymers on diesel fuel was made. © Published under licence by IOP Publishing Ltd
High statistic measurement of the K- -> pi0 e- nu decay form-factors
The decay K- -> pi0 e- nu is studied using in-flight decays detected with the
ISTRA+ spectrometer. About 920K events are collected for the analysis. The
lambda+ slope parameter of the decay form-factor f+(t) in the linear
approximation (average slope) is measured: lambda+(lin)= 0.02774 +-
0.00047(stat) +- 0.00032(syst). The quadratic contribution to the form-factor
was estimated to be lambda'+ = 0.00084 +- 0.00027(stat) +- 0.00031(syst). The
linear slope, which has a meaning of df+(t)/dt|_{t=0} for this fit, is lambda+
= 0.02324 +- 0.00152(stat) +- 0.00032(syst). The limits on possible tensor and
scalar couplings are derived: f_{T}/f_{+}(0)=-0.012 +- 0.021(stat) +-
0.011$(syst), f_{S}/f_{+}(0)=-0.0037^{+0.0066}_{-0.0056}(stat) +- 0.0041(syst).Comment: 11 pages, 8 figures. Accepted by Phys.Lett.
Search for light pseudoscalar sgoldstino in K- decays
A search for the light pseudoscalar sgoldstino production in the three body
K- decay K-->pipi0P has been performed with the ISTRA+ detector exposed to the
25 GeV negative secondary beam of the U70 proton synchrotron. No signal is
seen. An upper limit for the branching ratio Br(K->pipi0P), at 90% confidence
level, is found to be around 9*10**-6 in the effective mass m(P) range from 0
till 200 MeV, excluding the region near m(pi0) where it degrades to 3.5*10**-5.Comment: 10 pages, LATEX, 8 EPS figures, revised version, to be published in
Phys.Lett.
Acute complicated anaerobic paraproctitis: a case from practice
Anaerobic paraproctitis is a life-threatening disease, accompanied by a high mortality rate, requiring absolutely innovative diagnostic and therapeutic approaches. The development of acute paraproctitis is brought about by a number of predisposing factors: weakening of the immune system due to concurrent acute or chronical infection, microcirculation disorders, gastrointestinal disorders, complications of hemorrhoids, fissures, cryptitis. Not infrequently acute paraproctitis is complicated by Fournier’s gangrene.
Objectives. To describe the clinical case of acute anaerobic non-clostridial paraproctitis.
Material and methods. The paper presents a patient with suspected anaerobic non-clostridial paraproctitis.
Results. We managed to control the process. The patient was discharged in a satisfactory condition for the outpatient treatment.
Conclusions. As a result of complex treatment of the patient with symptoms of acute anaerobic non-clostridial paraproctitis, including a wide dissection of purulent streaks and antibiotic therapy, it was possible to stop the given disease
Experimental study of direct photon emission in K- --> pi- pi0 gamma decay using ISTRA+ detector
The branching ratio in the charged-pion kinetic energy region of 55 to 90 MeV
for the direct photon emission in the K- --> pi- pi0 gamma decay has been
measured using in-flight decays detected with the ISTRA+ setup operating in the
25 GeV/c negative secondary beam of the U-70 PS. The value
Br(DE)=[0.37+-0.39(stat)+-0.10(syst)]*10^(-5) obtained from the analysis of 930
completely reconstructed events is consistent with the average value of two
stopped-kaon experiments, but it differs by 2.5 standard deviations from the
average value of three in-flight-kaon experiments. The result is also compared
with recent theoretical predictions.Comment: 13 pages, 8 figure
Glass-Coated Beryllium Mirrors for the LHCb RICH1 Detector
The design, manufacture and testing of lightweight glass-coated beryllium spherical converging mirrors for the RICH1 detector of LHCb are described. The mirrors need to be lightweight to minimize the material budget and fluorocarbon-compatible to avoid degradation in the RICH1 C4F10 gas radiator. Results of the optical measurements for the small-sized prototypes and for the first full-sized prototype mirror are reported
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