428 research outputs found
Density of a gas of spin polarized fermions in a magnetic field
For a fermion gas with equally spaced energy levels that is subjected to a
magnetic field, the particle density is calculated. The derivation is based on
the path integral approach for identical particles, in combination with the
inversion techniques for the generating function of the static response
functions. Explicit results are presented for the ground state density as a
function of the magnetic field with a number of particles ranging from 1 to 45.Comment: 9 pages, 8 figures; To appear in Phys. Rev. E on December 1, 2000;
e-mail addresses: [email protected], [email protected],
[email protected], [email protected]
Glassy behavior of molecular crystals: A comparison between results from MD-simulation and mode coupling theory
We have investigated the glassy behavior of a molecular crystal built up with
chloroadamantane molecules. For a simple model of this molecule and a rigid fcc
lattice a MD simulation was performed from which we obtained the dynamical
orientational correlators and the ``self''
correlators , with ,
. Our investigations are for the diagonal correlators
. Since the lattice constant decreases with decreasing
temperature which leads to an increase of the steric hindrance of the
molecules, we find a strong slowing down of the relaxation. It has a high
sensitivity on , . For most , there is a two-step
relaxation process, but practically not for , ,
and . Our results are consistent with the -relaxation
scaling laws predicted by mode coupling theory from which we deduce the glass
transition temperature . From a first principle solution
of the mode coupling equations we find . Furthermore mode
coupling theory reproduces the absence of a two-step relaxation process for
, , and , but underestimates the critical
nonergodicity parameters by about 50 per cent for all other . It is
suggested that this underestimation originates from the anisotropic crystal
field which is not accounted for by mode coupling theory. Our results also
imply that phonons have no essential influence on the long time relaxation
A natural Finsler--Laplace operator
We give a new definition of a Laplace operator for Finsler metric as an
average with regard to an angle measure of the second directional derivatives.
This definition uses a dynamical approach due to Foulon that does not require
the use of connections nor local coordinates. We show using 1-parameter
families of Katok--Ziller metrics that this Finsler--Laplace operator admits
explicit representations and computations of spectral data.Comment: 25 pages, v2: minor modifications, changed the introductio
DETERMINANTS OF MENTAL HEALTH STIGMA AMONG PHARMACY STUDENTS IN AUSTRALIA, BELGIUM, ESTONIA, FINLAND, INDIA AND LATVIA
publishersversionPeer reviewe
Vaccine Willingness and Impact of the COVID-19 Pandemic on Women's Perinatal Experiences and Practices-A Multinational, Cross-Sectional Study Covering the First Wave of the Pandemic.
The COVID-19 pandemic may be of particular concern for pregnant and breastfeeding women. We aimed to explore their beliefs about the coronavirus and COVID-19 vaccine willingness and to assess the impact of the pandemic on perinatal experiences and practices. A multinational, cross-sectional, web-based study was performed in six European countries between April and July 2020. The anonymous survey was promoted via social media. In total, 16,063 women participated (including 6661 pregnant and 9402 breastfeeding women). Most responses were collected from Belgium (44%), Norway (18%) and the Netherlands (16%), followed by Switzerland (11%), Ireland (10%) and the UK (3%). Despite differences between countries, COVID-19 vaccine hesitancy was identified among 40-50% of the respondents at the end of the first wave of the pandemic and was higher among pregnant women. Education level and employment status were associated with vaccine hesitancy. The first wave had an adverse impact on pregnancy experiences and disrupted access to health services and breastfeeding support for many women. In the future, access to health care and support should be maintained at all times. Evidence-based and tailored information on COVID-19 vaccines should also be provided to pregnant and breastfeeding women to avoid unfounded concerns about the vaccines and to support shared decision making in this population
IAEA activities in support of accelerator-based research and applications
Accelerator applications is one of the thematic areas, where the IAEA Physics Section supports IAEA Member States in strengthening their capabilities to adopt and benefit from the use of accelerators. A number of activities are being implemented by the IAEA Physics Section focusing on accelerator-based applications in multiple disciplines, facilitation of access to accelerator facilities, organization of meetings, coordination of joint research projects and capacity building in accelerator-based technologies and techniques. This communication reports on
the currently implemented activities together with those planned for the near future
Remote Laboratory for E-Learning of Systems on Chip and Their Applications to Nuclear and Scientific Instrumentation
Configuring and setting up a remote access laboratory for an advanced online school on fully programmable System-on-Chip (SoC) proved to be an outstanding challenge. The school, jointly organized by the International Centre for Theoretical Physics (ICTP) and the International Atomic Energy Agency (IAEA), focused on SoC and its applications to nuclear and scientific instrumentation and was mainly addressed to physicists, computer scientists and engineers from developing countries. The use of e-learning tools, which some of them adopted and others developed, allowed the school participants to directly access both integrated development environment software and programmable SoC platforms. This facilitated the follow-up of all proposed exercises and the final project. During the four weeks of the training activity, we faced and overcame different technology and communication challenges, whose solutions we describe in detail together with dedicated tools and design methodology. We finally present a summary of the gained experience and an assessment of the results we achieved, addressed to those who foresee to organize similar initiatives using e-learning for advanced training with remote access to SoC platforms
Barriers to medication counselling for people with mental health disorders : A six country study
Provision of medication information may improve adherence and prevent medication related problems. People with mental health disorders commonly receive less medication counselling from pharmacists than people with other common long term and persistent disorders. Objective: The objective of this study was to compare and contrast barriers pharmacy students perceive toward providing medication counselling for people with mental health disorders in Australia, Belgium, Estonia, Finland, India and Latvia. Methods: Barriers identified by third-year pharmacy students as part of the International Pharmacy Students' Health Survey were content analysed using a directed approach. Students' responses were categorised as pharmacist related, patient related, health-system related, or social or cultural related. Quantitative data were analysed using SPSS version 14.0. Results: Survey instruments were returned by 649 students. Of the respondents, 480 identified one or more barriers to medication counselling for people with mental health disorders. Patient related factors accounted for between 25.3% and 36.2% of barriers identified by the pharmacy students. Pharmacist related factors accounted for between 17.6% and 45.1% of the barriers identified by the pharmacy students. Students in India were more likely to attribute barriers to pharmacist and social and cultural related factors, and less likely to healthsystem related factors, than students studying in other countries. Conclusion: The nature of barriers identified by pharmacy students differed according to the country in which they studied. Undergraduate and postgraduate pharmacy education programs may need to be amended to address common misconceptions among pharmacy students.publishersversionPeer reviewe
A Mission to Explore the Pioneer Anomaly
The Pioneer 10 and 11 spacecraft yielded the most precise navigation in deep
space to date. These spacecraft had exceptional acceleration sensitivity.
However, analysis of their radio-metric tracking data has consistently
indicated that at heliocentric distances of astronomical units,
the orbit determinations indicated the presence of a small, anomalous, Doppler
frequency drift. The drift is a blue-shift, uniformly changing with a rate of
Hz/s, which can be interpreted as a
constant sunward acceleration of each particular spacecraft of . This signal has become known as the Pioneer
anomaly. The inability to explain the anomalous behavior of the Pioneers with
conventional physics has contributed to growing discussion about its origin.
There is now an increasing number of proposals that attempt to explain the
anomaly outside conventional physics. This progress emphasizes the need for a
new experiment to explore the detected signal. Furthermore, the recent
extensive efforts led to the conclusion that only a dedicated experiment could
ultimately determine the nature of the found signal. We discuss the Pioneer
anomaly and present the next steps towards an understanding of its origin. We
specifically focus on the development of a mission to explore the Pioneer
Anomaly in a dedicated experiment conducted in deep space.Comment: 8 pages, 9 figures; invited talk given at the 2005 ESLAB Symposium
"Trends in Space Science and Cosmic Vision 2020", 19-21 April 2005, ESTEC,
Noordwijk, The Netherland
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