Nelinearna analiza klizišnih procesa pod djelovanjem seizmičkih učinka

This paper investigates the stress-strain state of the slope caused by seismic activity, and taking into account the geometrical and physical nonlinearity.U članku se razmatra stanje naprezanja-deformacija padine prouzročenih seizmičkom aktivnošću uzimajući u obzir geometrijsku i fizičku nelinearnost promatrane sredine

Nelinearna analiza klizišnih procesa pod djelovanjem seizmičkih učinka

This paper investigates the stress-strain state of the slope caused by seismic activity, and taking into account the geometrical and physical nonlinearity.U članku se razmatra stanje naprezanja-deformacija padine prouzročenih seizmičkom aktivnošću uzimajući u obzir geometrijsku i fizičku nelinearnost promatrane sredine

Functioning of linear induction accelerator of electrons LIA-30 in the mode of simultaneous forming and acceleration of 2 - 3 high-current relativistic electron beams

The carried out experimental investigations of LIA-30 accelerator injection system as well as the new data on standard operation modes testing in bremsstrahlung pulse generation made it possible to take a new view of electrophysical processes taking place in the accelerating track. In spite of success achieved in searching for optimal acceleration conditions – namely, limitation of edge steepness and amplitude of injection current pulses, definition of the program of forming voltage pulses that accelerate electrons etc. – there still remains to acute the task of decreasing lateral oscillations of high-current relativistic electron beam along the track as a whole and especially in cathode-anode gap where the influence of longitudinal magnetic field irregularities is most evident. When the magnetic field is limited in the track what is related to technical potentialities, the oscillations decrease in the injection system equipped with a two-beam cathode. Moreover, this process of electron beam acceleration becomes more stable even under conditions of parameter changes in the accelerator subsystem operation

Correlation of Beam Electron and LED Signal Losses under Irradiation and Long-term Recovery of Lead Tungstate Crystals

Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystals recovery from such damage.Comment: 9 pages, 6 figures, LaTeX2

Comparison of Radiation Damage in Lead Tungstate Crystals under Pion and Gamma Irradiation

Studies of the radiation hardness of lead tungstate crystals produced by the Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of Ceramics in China have been carried out at IHEP, Protvino. The crystals were irradiated by a 40-GeV pion beam. After full recovery, the same crystals were irradiated using a $^{137}Cs$ $\gamma$-ray source. The dose rate profiles along the crystal length were observed to be quite similar. We compare the effects of the two types of radiation on the crystals light output.Comment: 10 pages, 8 figures, Latex 2e, 28.04.04 - minor grammatical change

LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter Prototype

We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70 GeV accelerator complex at Protvino, Russia.Comment: 12 pages, 8 figures, LaTeX2e, revised versio

Design and performance of LED calibration system prototype for the lead tungstate crystal calorimeter

A highly stable monitoring system based on blue and red light emitting diodes coupled to a distribution network comprised of optical fibers has been developed for an electromagnetic calorimeter that uses lead tungstate crystals readout with photomultiplier tubes. We report of the system prototype design and on the results of laboratory tests. Stability better than 0.1% (r.m.s.) has been achieved during one week of prototype operation.Comment: 10 pages, 6 figures, LaTeX2

To be folded, to be unfolded or to be aggregated with important functions: application of the directed coaggregation mechanism to combat bacterial communities

One of the reasons for the mortal danger to humans is the ability of pathogenic bacteria to form biofilms. The formation of biofilms is an evolutionarily conservative defense mechanism against adverse conditions. The use of this protection by pathogenic bacteria reduces the effectiveness of the main means of combating them - antibiotics, which complicates the production of new types of drugs. There are two types of antimicrobial agents that are not known antibiotics: nanoparticles and antimicrobial peptides. We demonstrated that peptides synthesized based on the amino acid sequence of proteins and capable of amyloid formation and coaggregation with the whole protein exhibit antimicrobial activity. The ability of peptides to coaggregate with target proteins can help combat biofilm-forming bacterial communities. We evaluated the antimicrobial effects of ten synthesized hybrid peptides, which were obtained based on the sequences of the S1 ribosomal protein of P. aeruginosa and S. aureus. It is important that some peptides demonstrated high antimicrobial activity comparable to the antibiotic gentamicin sulfate against pathogenic strains of MRSA, S. aureus, and P. aeruginosa. These peptides showed no toxicity to eukaryotic cells. Our study demonstrates the promise of hybrid peptides based on the amyloidogenic regions of the S1 ribosomal protein for the development of new antimicrobials against Gram-positive and Gram-negative bacteria resistant to traditional antibiotic.Belgrade : Institute of molecular genetics and genetic engineerin

The history of the development of national traumatology on the example of medical and scientific activities of Saratov Research Institute of Traumatology and Orthopedics (SarNIITO) (1950-1980)

We outlined and described basic directions of national traumatology development at the period of 1950-1980 illustrated by the example of Saratov traumatological school, estimated the contribution of SarNIITO traumatologists into this development at the abovementioned period, depicted syna — one of the founders of acute trauma clinics.</p

Development of a Momentum Determined Electron Beam in the 1 -45 GeV Range

A beam line for electrons with energies in the range of 1 to 45 GeV, low contamination of hadrons and muons and high intensity up to 10^6 per accelerator spill at 27 GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160 micron resolution was able to measure relative electron beam momentum precisely. The resolution sigma_p p was 0.13% at 45 GeV where multiple scattering is negligible. This test beam setup provided the possibility to study properties of lead tungstate crystals (PbWO_4) for the BTeV experiment at Fermilab.Comment: 12 pages, 8 figures; work done by the BTeV Electromagnetic Calorimeter grou