150 research outputs found
A system for online beam emittance measurements and proton beam characterization
A system for online measurement of the transverse beam emittance was
developed. It is named PrOBaM (4-Profiler Online Beam
Emittance Measurement) and was conceived to measure the emittance in a fast and
efficient way using the multiple beam profiler method. The core of the system
is constituted by four consecutive UniBEaM profilers, which are based on silica
fibers passing across the beam. The PrOBaM system was
deployed for characterization studies of the 18~MeV proton beam produced by the
IBA Cyclone 18 MeV cyclotron at Bern University Hospital (Inselspital). The
machine serves daily radioisotope production and multi-disciplinary research,
which is carried out with a specifically conceived Beam Transport Line (BTL).
The transverse RMS beam emittance of the cyclotron was measured as a function
of several machine parameters, such as the magnetic field, RF peak voltage, and
azimuthal angle of the stripper. The beam emittance was also measured using the
method based on the quadrupole strength variation. The results obtained with
both techniques were compared and a good agreement was found. In order to
characterize the longitudinal dynamics, the proton energy distribution was
measured. For this purpose, a method was developed based on aluminum absorbers
of different thicknesses, a UniBEaM detector, and a Faraday cup. The results
were an input for a simulation of the BTL developed in the MAD-X software. This
tool allows machine parameters to be tuned online and the beam characteristics
to be optimized for specific applications.Comment: published in Journal of Instrumentatio
Study of the radioactivity induced in air by a 15-MeV proton beam
Radioactivity induced by a 15-MeV proton beam extracted into air was studied at the beam transport line of the 18-MeV cyclotron at the Bern University Hospital (Inselspital). The produced radioactivity was calculated and measured by means of proportional counters located at the main exhaust of the laboratory. These devices were designed for precise assessment of air contamination for radiation protection purposes. The main produced isotopes were 11C, 13N and 14O. Both measurements and calculations correspond to two different irradiation conditions. In the former, protons were allowed to travel for their full range in air. In the latter, they were stopped at the distance of 1.5 m by a beam dump. Radioactivity was measured continuously in the exhausted air starting from 2 min after the end of irradiation. For this reason, the short-lived 14O isotope gave a negligible contribution to the measured activity. Good agreement was found between the measurements and the calculations within the estimated uncertainties. Currents in the range of 120-370 nA were extracted in air for 10-30 s producing activities of 9-22 MBq of 11C and 13N. The total activities for 11C and 13N per beam current and irradiation time for the former and the latter irradiation conditions were measured to be (3.60 ± 0.48) × 10−3 MBq (nA s)−1 and (2.89 ± 0.37) × 10−3 MBq (nA s)−1, respectivel
Inflationary cosmology with scalar field and radiation
We present a simple, exact and self-consistent cosmology with a
phenomenological model of quantum creation of radiation due to decay of the
scalar field. The decay drives a non-isentropic inflationary epoch, which exits
smoothly to the radiation era, without reheating. The initial vacuum for
radiation is a regular Minkowski vacuum. The created radiation obeys standard
thermodynamic laws, and the total entropy produced is consistent with the
accepted value. We analyze the difference between the present model and a model
with decaying cosmological constant previously considered.Comment: 13 pages Latex; to appear Gen. Rel. Gra
One-dimensional Models for Cell Feeding in Micro-channels.
Lab-on-Chip technology is an emerging tool to obtain, culture and study different kinds of tissue models. In particular, concerning cardiac microtissues, it could be exploited to investigate cellular behavior in response to biomimetic stimulation (e.g., electrical and/or mechanical actuations).Cell culture in microfluidic chip, usually last several days. During this period of time, cells need feeding to stay alive, proliferate and organize. Different configurations and sizes of microchip features can cause non-uniform distribution of nutrients and wastes on chip, which must be taken into account in studying the response of cells to electrical and/or mechanical stimulations. A simple one-dimensional model of diffusion was used to simulate the concentration of a nutrient and a waste in a previously developed microfluidic chip. For quasi-steady processes, analytical solutions were obtained and analyzed
Systems of Geo Positioning of the Mobile Robot
Article is devoted to the analysis of opportunities of electronic instruments, such as a gyroscope, the accelerometer, the magnetometer together, the video system of image identification and system of infrared indicators during creation of system of exact positioning of the mobile robot. Results of testing and the operating algorithms are given. Possibilities of sharing of these devices and their association in a single system are analyzed. Conclusions on development of opportunities and elimination of shortcomings of the received end-to-end system of positioning of the robot are drawn
Software and Hardware Control Robotic Lawnmowers
The article presents a method for forming the trajectory of an automatic lawnmower, describes the architecture of mobile robot control and suggests a method for estimating the productivity of its work
Cosmological quantum entanglement
We review recent literature on the connection between quantum entanglement
and cosmology, with an emphasis on the context of expanding universes. We
discuss recent theoretical results reporting on the production of entanglement
in quantum fields due to the expansion of the underlying spacetime. We explore
how these results are affected by the statistics of the field (bosonic or
fermionic), the type of expansion (de Sitter or asymptotically stationary), and
the coupling to spacetime curvature (conformal or minimal). We then consider
the extraction of entanglement from a quantum field by coupling to local
detectors and how this procedure can be used to distinguish curvature from
heating by their entanglement signature. We review the role played by quantum
fluctuations in the early universe in nucleating the formation of galaxies and
other cosmic structures through their conversion into classical density
anisotropies during and after inflation. We report on current literature
attempting to account for this transition in a rigorous way and discuss the
importance of entanglement and decoherence in this process. We conclude with
some prospects for further theoretical and experimental research in this area.
These include extensions of current theoretical efforts, possible future
observational pursuits, and experimental analogues that emulate these cosmic
effects in a laboratory setting.Comment: 23 pages, 2 figures. v2 Added journal reference and minor changes to
match the published versio
ШЛЯХИ ПОЛІПШЕННЯ ПОКАЗНИКІВ СПЕРМАТОГЕНЕЗУ В КОМПЛЕКСНОМУ ЛІКУВАННІ ЧОЛОВІЧОГО БЕЗПЛІДДЯ
The paper presents the results of a study of changes in sperm indices in patients with impaired spermatogenesis and against the background of treatment with the food additive Xenoderm. As a result of the study, it was revealed that the drug Xenoderm has a high efficacy in the treatment of men with mild violations of the generative function.
The aim – to study the dynamics of changes in semen indices in the treatment of male infertility with Xenoderm.
Material and Methods. To assess the clinical efficacy and safety of a food additive, 21 patients with chronic non-infectious prostatitis and fertility disorders were examined. The study included men aged 21–40 years (mean age 31.4 years) diagnosed with chronic prostatitis and impaired fertility. The disease duration was at least 6 months.
For immunotolerative correction of structural and functional changes in target organs, a tabletting agent was used, made from crushed cryo-lyophilized xenodermal pig substrate, in the form of a food additive Xenoderm produced by the Institute of Biomedical Technologies (Ternopil).
Conclusions. The results of the study indicate the high efficacy of the drug Xenoderm in the treatment of men with mild violations of the generative function, not caused by diseases of the urogenital organs and any form of hypogonadism. Extensive use of the drug Xenoderm should be recommended to improve the reproductive viability of patients with patospermia of marginal and subfertile levels, due to an unexplained cause or associated with an unhealthy lifestyle. It may also be advisable to include the drug Xenoderm in the complex treatment of men with reduced fertility of various etiologies.В работе представлены результаты исследования изменений показателей спермограммы у больных с нарушением сперматогенеза и на фоне лечения пищевой добавкой Ксенодерм. В результате исследования выявлено, что препарат Ксенодерм имеет высокую эффективность в лечении мужчин с нетяжелыми нарушениями генеративной функции.
Цель – изучение динамики изменений показателей спермограммы при лечении мужского бесплодия препаратом Ксенодерм.
Материал и методы. Для оценки клинической эффективности и безопасности пищевой добавки обследован 21 пациент с хроническим неинфекционным простатитом и нарушением фертильности. В исследование вошли мужчины в возрасте 21–40 лет (средний возраст 31,4 года) с диагностированным хроническим простатитом и нарушением фертильности. Длительность заболевания составляла не менее 6 месяцев.
Для иммунотолеративной коррекции структурно-функциональных изменений в органах-мишенях использовано таблетированное средство, изготовленное из измельченного криолиофилизованого ксенодермального субстрата свиньи, в виде пищевой добавки Ксенодерм производства Института биомедицинских технологий (г. Тернополь).
Выводы. Результаты исследования свидетельствуют о высокой эффективности препарата Ксенодерм при лечении мужчин с нетяжелыми нарушениями генеративной функции, не обусловленными заболеваниями мочеполовых органов и любыми формами гипогонадизма. Широкое использование препарата Ксенодерм следует рекомендовать для улучшения репродуктивной состоятельности пациентов с патоспермией предельного и субфертильного уровней, обусловленной невыясненной причиной или связанной с нездоровым образом жизни. Также может быть целесообразным включение препарата Ксенодерм в комплексное лечение мужчин со сниженной фертильностью различной этиологии.В роботі представлені результати дослідження змін показників спермограми у хворих із порушенням сперматогенезу і на фоні лікування харчовою добавкою Ксенодерм. У результаті дослідження виявлено, що препарат Ксенодерм має високу ефективність у лікуванні чоловіків із нетяжкими порушеннями генеративної функції.
Мета – вивчення динаміки змін показників спермограми при лікуванні чоловічого безпліддя препаратом Ксенодерм.
Матеріал і методи. Для оцінки клінічної ефективності та безпечності харчової добавки обстежено 21 пацієнта з хронічним неінфекційним простатитом і порушенням фертильності. В дослідження увійшли чоловіки у віці 21–40 років (середній вік 31,4 роки) з діагностованим хронічним простатитом і порушенням фертильності. Тривалість захворювання складала не менше 6 місяців.
Для імунотолеративної корекції структурно-функціональних змін в органах-мішенях використовували таблетований засіб, виготовлений із подрібненого кріоліофілізованого ксенодермального субстрату свині у вигляді харчової добавки Ксенодерм виробництва Інституту біомедичних технологій (м. Тернопіль).
Висновки. Результати дослідження свідчать про високу ефективність препарату Ксенодерм при лікуванні чоловіків із нетяжкими порушеннями генеративної функції, які не зумовлені захворюваннями сечостатевих органів та будь-якими формами гіпогонадизму. Широке використання препарату Ксенодерм слід рекомендувати для поліпшення репродуктивної спроможності пацієнтів із патоспермією граничного і субфертильного рівнів з нез’ясованої причини або пов’язаної з нездоровим способом життя. Також може бути доцільним включення препарату Ксенодерм у комплексне лікування чоловіків зі зниженою фертильністю різної етіології
Particle creation, renormalizability conditions and the mass-energy spectrum in gravity theories of quadratic Lagrangians
Massive scalar particle production, due to the anisotropic evolution of a
five-dimensional spacetime, is considered in the context of a quadratic
Lagrangian theory of gravity. Those particles, corresponding to field modes
with non-vanishing momentum component along the fifth dimension, are created
mostly in the neighbourhood of a singular epoch where only their high-frequency
behaviour is of considerable importance. At the 1-loop approximation level,
general renormalizability conditions on the physical quantities relevant to
particle production are derived and discussed. Exact solutions of the resulting
Klein-Gordon field equation are obtained and the mass-energy spectrum
attributed to the scalar field due to the cosmological evolution is being
investigated further. Finally, analytic expressions regarding the number and
the energy density of the created particles at late times, are also derived and
discussed.Comment: LaTeX file, 23 page
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