655 research outputs found
Multimeson production in pp interactions as a background for eta and eta' decays
Multimeson production in pp interactions comprises important background for
eta, omega and eta' mesons production experiments and for the studies of their
decays planned with WASA detector at COSY. The available information about the
reactions is summarized and the need for efforts to describe the processes is
stressed.Comment: Proceedings of MENU07 Conference Julich, Germany 200
Red giants from the Pennsylvania - Torun Planet Search
The main goal of the Pennsylvania - Torun Planet Search (PTPS) is detection
and characterization of planets around evolved stars using the high-accuracy
radial velocity (RV) technique. The project is performed with the 9.2 m
Hobby-Eberly Telescope. To determine stellar parameters and evolutionary status
for targets observed within the survey complete spectral analysis of all
objects is required. In this paper we present the atmospheric parameters
(effective temperatures, surface gravities, microturbulent velocities and
metallicities) of a subsample of Red Giant Clump stars using strictly
spectroscopic methods based on analysis of equivalent widths of Fe I and Fe II
lines. It is shown that our spectroscopic approach brings reliable and
consistent results.Comment: 3 pages, 2 figures, proceeding of the conference "New Technologies
for Probing the Diversity of Brown Dwarfs and Exoplanets" (Shangai, China,
July 19-24, 2009), to appear in EPJ Web of Conference
ДОСЛІДЖЕННЯ СПРИЙНЯТТЯ ПРОБЛЕМИ НЕПОВНОСПРАВНОСТІ МЕДИЧНИМИ ПРАЦІВНИКАМИ
The disability problem is an important issue that paramedics also face. Their attitudes and knowledge about this phenomenon may largely depend on the contact they make with a disabled person, and this in turn will be reflected in the activities that will be performed by the rescuer. The very method of collecting medical history is important in further rescue proceedings. The paper presents a variety of aspects in the approach to disability expressed in tests carried out on paramedics. The intention of the authors was to signal the problem of disability and attempt to make a preliminary assessment of the subjective attitudes of medical students towards people with disabilities. This study is a preliminary report, and the leitmotiv of this publication is the willingness to interest the subject of other researchers and to share already available results. Statistical analysis shows that among the causes of disability, the most common are damage and diseases of the musculoskeletal system – 46.5% in second place are cardiovascular diseases – 45.5%, and neurological diseases to which we want to devote broad attention are in third place in this statistical and constitute 23.9%. The study was conducted in May 2019 in a group of 60 students (30 women and 30 men) aged 20-22 attending medical universities in the Kuyavian-Pomeranian Voivodeship. The research tool was the author's own survey containing closed questions. Participation in the study was voluntary and anonymous. The respondents were asked about demographic data: the perception of the disabled, knowledge of problems related to the disabled and ways of supporting the disabled. The results were developed using Microsoft Excel 2010 from the Windows 7 package, using the appropriately available spreadsheet functions. The obtained results justify the careful conclusion that the problem of disability, seen through the eyes of medical university students, is not only noticed but assessed by them. Students very emphatically referred to the problem of disabled people taken up in the article.Досить часто медичним працівникам у своїй роботі доводиться стикатися із неповносправними людьми. Те, як медики сприймають і розуміють цю проблему, визначає їх спілкування із неповносправними пацієнтами, що, в свою чергу, впливає на рівень наданої допомоги, адже він залежить від якості збору інформації про хворобу. У роботі висвітлено низку особливостей сприйняття медичними працівниками проблеми неповносправності, визначених за результатами проведення опитувань. Цією роботою автори ставлять за мету нагадати усім про проблему неповносправності та дослідити субєктивне ставлення студентів медичних спеціальностей до неповносправних людей. Лейтмотивом проведених досліджень є також бажання привернути увагу інших дослідників та спонукати їх поділитися результатами подібних досліджень у цій області. Аналіз статистики показує, що причиною неповносправності у 46,5% випадків є вади опорно-рухового апарату, у 45,5% – серцево-судинні хвороби і у 23,9% випадків – неврологічні проблеми (саме вони і потребують найбільшої уваги). Дослідження були проведені у травні 2019 року з групою із 60 студентів (30 чоловіків і 30 жінок) віком 20-22 роки, що навчаються у медичних закладах освіти Куявсько-Поморського воєводства.Для дослідження було використано анкетування. Усі запитання були розроблені авторами і потребували відповіді «так» або «ні». Участь у анкетуванні була добровільною і анонімною. Респондентів запитували про ставлення до неповносправних осіб, розуміння їх проблем, вміння надання допомоги та підтримки. Обробку результатів проводили за допогою табличного редактора Microsoft Excel 2010 (Windows 7). За результатами досліджень можна обережно зробити висновок, що студенти медичних спеціальностей не тільки розуміють проблеми неповносправних людей, а й переймаються ними і проявляють емпатію
The Penn State - Toru\'n Planet Search: target characteristics and recent results
More than 450 stars hosting planets are known today but only approximately 30
planetary systems were discovered around stars beyond the Main Sequence. The
Penn State-Toru\'n Planet Search, putting an emphasis on extending studies of
planetary system formation and evolution to intermediate-mass stars, is
oriented towards the discoveries of substellar-mass companions to a large
sample of evolved stars using high-precision radial velocity technique. We
present the recent status of our survey and detailed characteristic for ~350
late type giant stars, i.e. the new results of radial velocity analysis and
stellar fundamental parameters obtained with extensive spectroscopic method.
Moreover, in the future we will make an attempt to perform the statistical
study of our sample and searching the correlations between the existence of
substellar objects and stellar atmospheric parameters according to previous
works which investigated the planetary companion impact on the evolution of the
host stars.Comment: 7 pages, 5 figures, proceeding of the conference "Planetary Systems
beyond the Main Sequence" (Bamberg, Germany, August 11-14, 2010) edited by S.
Schuh, H. Drechsel and U. Heber, AIP Conference Series, part of
PlanetsbeyondMS/2010 proceedings http://arxiv.org/html/1011.660
Frequency-Domain Modeling of OFDM Transmission with Insufficient Cyclic Prefix using Toeplitz Matrices
A novel mathematical framework is proposed to model Intersymbol Interference
(ISI) phenomenon in wireless communication systems based on Orthogonal
Frequency Division Multiplexing (OFDM) with or without cyclic prefix. The
framework is based on a new formula to calculate the Fast Fourier Transform
(FFT) of a triangular Toeplitz matrix, which is derived and proven in this
paper. It is shown that distortion inducted by the ISI from a given subcarrier
is the most significant for the closest subcarriers and the contribution decays
as the distance between subcarriers grows. According to numerical experiments,
knowledge of ISI coefficients concentrated around the diagonal of Channel
Frequency Response (CFR) matrix improves the receiver's error floor
significantly. The potential use of the framework for real-time frequency
domain channel simulation was also investigated and demonstrated to be more
efficient than conventional time domain Tapped Delay Line (TDL) model when a
number of simulated users is high.Comment: Conference: IEEE VTC-Fall 2018, 5 pages, 3 figure
CERTAIN MODIFICATIONS OF AITKEN'S ACCELERATOR FOR SLOWLY CONVERGENT SEQUENCES
The paper presents three modifications of the Aitken accelerator for slowly or irregularly
convergent sequences. The first proposal, based on backward extension of a sequence,
is particularly useful if a small number of regular sequence terms is known. The next
two procedures - integral exponential and hyperbolic - can be applied to sequences with
irregular or disturbed convergence. Numerical examples show essential error reduction of
the limit of sequences under consideration
Planets Around the K-Giants BD+20 274 and HD 219415
We present the discovery of planet-mass companions to two giant stars by the
ongoing Penn State- Toru\'n Planet Search (PTPS) conducted with the 9.2 m
Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274,
has a 4.2 MJ minimum mass planet orbiting the star at a 578-day period and a
more distant, likely stellar-mass companion. The best currently available model
of the planet orbiting the K0-giant HD 219415 points to a Jupiter-mass
companion in a 5.7-year, eccentric orbit around the star, making it the longest
period planet yet detected by our survey. This planet has an amplitude of
\sim18 m/s, comparable to the median radial velocity (RV) "jitter", typical of
giant stars.Comment: 5 figures, 13 pages, accepted by the Astrophysical Journal. arXiv
admin note: substantial text overlap with arXiv:1110.164
Phonon-induced and phonon-free superconductivity in correlated systems : Eliashberg equations for the two-dimensional Hubbard model
The problem of phonon-induced and phonon-free superconductivity in the two-dimensional Hubbard model has been addressed. We have generalized the Eliashberg equations to account for both on-site and intersite
pairing and consider the electron–electron and electron-phonon channel on an equal footing. This approach allows for the discussion of pairing and depairing properties of the local repulsive interaction. We demonstrate the possibility of cooperation between electron-phonon and electron–electron interaction in the stabilization of the d-wave superconductivity, in particular close to the experimental value of optimal doping ( ≃ 0.15). We have
also discussed the problem of phonon-induced superconductivity in the two-dimensional Hubbard model close to the metal-insulator transition. Here, the Coulomb correlations have been incorporated within the Hubbard I
approximation whereas the superconductivity is treated by the Eliashberg scheme. The results support the view that a d-wave component dominates in the gap function
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