344 research outputs found
Scattering of Dirac particles from non-local separable potentials: the eigenchannel approach
An application of the new formulation of the eigenchannel method [R.
Szmytkowski, Ann. Phys. (N.Y.) {\bf 311}, 503 (2004)] to quantum scattering of
Dirac particles from non-local separable potentials is presented. Eigenchannel
vectors, related directly to eigenchannels, are defined as eigenvectors of a
certain weighted eigenvalue problem. Moreover, negative cotangents of
eigenphase-shifts are introduced as eigenvalues of that spectral problem.
Eigenchannel spinor as well as bispinor harmonics are expressed throughout the
eigenchannel vectors. Finally, the expressions for the bispinor as well as
matrix scattering amplitudes and total cross section are derived in terms of
eigenchannels and eigenphase-shifts. An illustrative example is also provided.Comment: Revtex, 9 pages, 4 figures, published versio
Simulation control facility for temperature control systems
В статье рассмотрена исполнительная часть схемы имитатора объекта контроля для автоматизированных систем контроля температуры, приведена схема исполнительной части, так же рассмотрен расчет точности схемы. Устройство позволяет проводить отладку и проверку системы в лабораторных условиях и на данный момент применяется для проверки автоматизированной системы контроля температуры на АО «НПО автоматики».The article considers the executive part of the circuit simulator object control for automated temperature control systems, a diagram of the executive, also reviewed the accuracy of the calculation scheme. The device allows you to debug and test systems in the laboratory and is currently used to test the automated system to control the temperature of JSC "NPO Automation"
Proposed Search for Mixing in Polarization Phenomena
The and meson mass difference induces the mixing of the
and resonances, the amplitude of which, between the
and thresholds, is large in magnitude, of the order of , and possesses the
phase sharply varying by about 90. We suggest performing the polarized
target experiments on the reaction at high energy in
which the fact of the existence of mixing can be
unambiguously and very easily established through the presence of a strong jump
in the azimuthal asymmetry of the wave production cross section
near the thresholds. The presented estimates of the polarization
effect to be expected in experiment are to a great extent model independent.Comment: RevTeX, 9 pages, 1 figure. A number of typographical and grammatical
errors correcte
Videolaparoscopic surgical treatment of strangulated paraesophageal hiatal hernia (clinical observation)
Relevance. Paraesophageal hiatal hernias are much less common than other types of diaphragmatic hernias. The risk of strangulation in this pathology is about 21 %. It is often very difficult to establish the correct diagnosis in time, because patients are admitted with an atypical clinic of acute cardiological or pulmonary pathology. Usually, the correct diagnosis is established only on the 4th day. Due to late diagnosis, necrosis and perforation of the strangulated organ occur, which causes high mortality; sometimes the correct diagnosis is established only at autopsy.Clinical observation. The patient was admitted to the surgical department on an emergency basis with complaints of intense pain in the lower chest and epigastric region, vomiting of eaten food. From the anamnesis it is known that about a year ago, periodic nausea and vomiting of food eaten began to bother. The last 12 hours before admission to the hospital, pain in the chest and epigastrium intensified, all eaten food came out with vomiting. X-ray diagnosed strangulated paraesophageal hernia of the esophageal opening of the diaphragm. During esophagogastroduodenoscopy it was impossible to pass into the distal parts of the stomach; hyperemia and petechial hemorrhages were detected in the zone of strangulation. Video-laparoscopic reduction of the hernial contents, resection of the hernial sac and anterior diaphragm crurorrhaphy were urgently performed. The early postoperative period was uneventful. The presented clinical observation indicates the promise of using video-endoscopic technologies for diagnosis and treatment of strangulated diaphragmatic hernias. The key to success is the timely establishment of the correct diagnosis. We consider it impractical to perform an antireflux intervention simultaneously in conditions of an acute inflammatory process
Backward asymmetry of the Compton scattering by an isotropic distribution of relativistic electrons: astrophysical implications
The angular distribution of low-frequency radiation after single scattering
by an isotropic distribution of relativistic electrons considerably differs
from the Rayleigh angular function. In particular, the scattering by an
ensemble of ultra-relativistic electrons obeys the law p=1-cos(alpha), where
alpha is the scattering angle; hence photons are preferentially scattered
backwards. We discuss some consequences of this fact for astrophysical
problems. We show that a hot electron-scattering atmosphere is more reflective
than a cold one: the fraction of incident photons which become reflected having
suffered a single scattering event can be larger by up to 50 per cent in the
former case. This should affect the photon exchange between cold accretion
disks and hot coronae or ADAF flows in the vicinity of relativistic compact
objects; as well as the rate of cooling (through multiple inverse-Compton
scattering of seed photons supplied from outside) of optically thick clouds of
relativistic electrons in compact radiosources. The forward-backward scattering
asymmetry also causes spatial diffusion of photons to proceed slower in hot
plasma than in cold one, which is important for the shapes of Comptonization
spectra and the time delays between soft and hard radiations coming from
variable X-ray sources.Comment: 20 pages, 3 figures, to appear in Astronomy Letters, added reference
Need for the Development of Dialectical Thinking in Pharmaceutical Personnel to Improve Their Performance in the Pharmacovigilance System
The pharmacovigilance system aimed at ensuring the safety of medicines has been functioning in Russia since 1997. However, at the moment, an important part of this system, pharmacy organisations, is not sufficiently involved in pharmacovigilance activities. Pharmacy personnel may be not prepared to collect information on adverse reactions associated with the use of medicinal products and submit it to regulatory authorities. The reason is not only that their knowledge of pharmacovigilance is insufficient, but also that little attention is paid in the educational process to the development of dialectical thinking, which is necessary for successful problem-solving. The available literature does not cover the importance of dialectical thinking as a professional competency of a pharmacy employee sufficiently well.The aim of the study was to substantiate the need in the development of dialectical thinking in employees of pharmacy organisations in order to increase their participation in the pharmacovigilance system.Materials and methods: 166 employees of pharmacies in Kazan were surveyed on the implementation of pharmacovigilance in pharmacy organisations. The authors used Spearman’s rank correlation coefficient to assess the extent of association between the variables identified in the survey (pharmacy’s standing in the pharmacovigilance system, respondents’ competence in pharmacovigilance, their familiarity with pharmacovigilance documentation, adverse reaction reporting, and so forth).Results: the majority of respondents perceive the importance of pharmacies for the pharmacovigilance system as medium (46.99%) and low (17.47%); the same is true for the level of pharmacovigilance development in pharmacies (45.63 and 27.5% of the respondents respectively). According to the correlation analysis, pharmacy employees do not associate the level of pharmacovigilance development in their pharmacy with their competence, which is characteristic of a dialectical failure. Most respondents tend to exaggerate the role of executive authorities, medical organisations, and pharmaceutical companies in the pharmacovigilance system and underestimate the role of pharmacies and pharmacy staff (only 17.62% of the respondents assign this role to pharmacies), which may be the reason for failing to fulfil pharmacovigilance duties and passing the responsibility to other parties to the circulation of medicinal products.Conclusions: according to the consolidated results, pharmacy employees may not consider themselves to be leading implementers of legislative initiatives, causally related to the effectiveness of pharmacovigilance system as a whole. Consequently, there is a need to form dialectical thinking in pharmacy employees within the framework of educational programmes. It will contribute to the development of reflection on their efforts in ensuring the safety of medicines and increase the effectiveness of their participation in pharmacovigilance activities
Heating of gas inside radio sources to mildly relativistic temperatures via induced Compton scattering
Measured values of the brightness temperature of low-frequency synchrotron
radiation emitted by powerful extragalactic sources reach 10^11--10^12 K. If
some amount of nonrelativistic ionized gas is present within such sources, it
should be heated as a result of induced Compton scattering of the radiation. If
this heating is counteracted by cooling due to inverse Compton scattering of
the same radio radiation, then the plasma can be heated up to mildly
relativistic temperatures kT~10--100 keV. The stationary electron velocity
distribution can be either relativistic Maxwellian or quasi-Maxwellian (with
the high-velocity tail suppressed), depending on the efficiency of Coulomb
collisions and other relaxation processes. We derive several easy-to-use
approximate expressions for the induced Compton heating rate of mildly
relativistic electrons in an isotropic radiation field, as well as for the
stationary distribution function and temperature of electrons. We also give
analytic expressions for the kernel of the integral kinetic equation (one as a
function of the scattering angle and another for the case of an isotropic
radiation field), which describes the redistribution of photons in frequency
caused by induced Compton scattering in thermal plasma. These expressions can
be used in the parameter range hnu<< kT<~ 0.1mc^2 (the formulae earlier
published in Sazonov, Sunyaev, 2000 are less accurate).Comment: 22 pages, 7 figures, submitted to Astronomy Letter
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