4,176 research outputs found
Parallel J-W Monte Carlo Simulations of Thermal Phase Changes in Finite-size Systems
The thermodynamic properties of 59 TeF6 clusters that undergo
temperature-driven phase transitions have been calculated with a canonical
J-walking Monte Carlo technique. A parallel code for simulations has been
developed and optimized on SUN3500 and CRAY-T3E computers. The Lindemann
criterion shows that the clusters transform from liquid to solid and then from
one solid structure to another in the temperature region 60-130 K.Comment: 4 pages, 5 figures; presented at the conference on computational
physics, Aachen (2001) accepted for publication in Comp.Phys.Com
What My Muffin Top Has To Say To You
My name is Hannah, and I have a confession to make. I hate working out—none of that sweat, panting, exhaustion, and sore muscles for me, no thank you. I’m embarrassed to go to a gym because I assume that everyone judges my speed, pacing, and weight lifting. I try to encourage myself by shopping for brightly colored running shorts and funky sports bras, but, honestly, it’s a fruitless endeavor. Because at the end of the day, I just don’t like to exercise.
So why do I do it?
Because I want to be skinny. [excerpt
Culture Shock
Take one week living in our culture:
Monday: A student quotes other students on Overheard at Gettysburg.
“In the commons at 8:50am. Two girls. Completely serious.
Girl 1: Have you been outside? Girl 2: Yea! It’s rape weather. Girl 1: I know. A girl could totally get raped out there.” [excerpt
Significant Interpretations of Developing Structures of the Ministry-1880-1970
A historical study of the Church\u27s ministry soon discloses a great deal of variety in the ministerial office. As Niebuhr and Williams remind us in their historical survey of the Protestant ministry, while there are a number of aspects of ministry that are agreed upon and shared in the various historic churches, there are also divergent interpretations regarding the nature and essence of the ministerial office
The Role of Multiplicity in Disk Evolution and Planet Formation
The past decade has seen a revolution in our understanding of protoplanetary
disk evolution and planet formation in single star systems. However, the
majority of solar-type stars form in binary systems, so the impact of binary
companions on protoplanetary disks is an important element in our understanding
of planet formation. We have compiled a combined multiplicity/disk census of
Taurus-Auriga, plus a restricted sample of close binaries in other regions, in
order to explore the role of multiplicity in disk evolution. Our results imply
that the tidal influence of a close (<40 AU) binary companion significantly
hastens the process of protoplanetary disk dispersal, as ~2/3 of all close
binaries promptly disperse their disks within <1 Myr after formation. However,
prompt disk dispersal only occurs for a small fraction of wide binaries and
single stars, with ~80%-90% retaining their disks for at least ~2--3 Myr (but
rarely for more than ~5 Myr). Our new constraints on the disk clearing
timescale have significant implications for giant planet formation; most single
stars have 3--5 Myr within which to form giant planets, whereas most close
binary systems would have to form giant planets within <1 Myr. If core
accretion is the primary mode for giant planet formation, then gas giants in
close binaries should be rare. Conversely, since almost all single stars have a
similar period of time within which to form gas giants, their relative rarity
in RV surveys indicates either that the giant planet formation timescale is
very well-matched to the disk dispersal timescale or that features beyond the
disk lifetime set the likelihood of giant planet formation.Comment: Accepted to ApJ; 15 pages, 3 figures, 3 tables in emulateapj forma
The physical activity levels among people living with human immunodeficiency virus/acquired immunodeficiency syndrome receiving high active antiretroviral therapy in Rwanda
The accessibility of high active antiretroviral therapy (HAART) for local human immunodeficiency virus (HIV) patients is improving in Rwanda. It is well known that this therapy is associated with serious adverse effects, such as metabolic and morphologic changes. One of the recommended preventive modalities for these complications is participation in physical activity. The current study aims to determine the anthropometric profile and physical activity levels among people living with HIV and receiving HAART in Kigali, Rwanda. The study was a cross-sectional, descriptive quantitative survey. The participant’s levels of physical activity participation and their association with anthropometric profiles were measured, using a structured self-administered questionnaire for 407 clients passing through the clinics. Of the participants, approximately 70% were inactive and in addition, 40% were obese and 43% overweight. Obesity was found to be strongly associated with inactivity. Lack of motivation, and time as well as fear of worsening the disease were found to be barriers to participation in physical activity.Keywords: HIV, AIDS, physical inactivity, Rwanda, HAAR
Exoplanets imaging with a Phase-Induced Amplitude Apodization Coronagraph - I. Principle
Using 2 aspheric mirrors, it is possible to apodize a telescope beam without
losing light or angular resolution: the output beam is produced by
``remapping'' the entrance beam to produce the desired light intensity
distribution in a new pupil. We present the Phase-Induced Amplitude Apodization
Coronagraph (PIAAC) concept, which uses this technique, and we show that it
allows efficient direct imaging of extrasolar terrestrial planets with a
small-size telescope in space. The suitability of the PIAAC for exoplanet
imaging is due to a unique combination of achromaticity, small inner working
angle (about 1.5 ), high throughput, high angular resolution and
large field of view. 3D geometrical raytracing is used to investigate the
off-axis aberrations of PIAAC configurations, and show that a field of view of
more than 100 in radius is available thanks to the correcting
optics of the PIAAC. Angular diameter of the star and tip-tilt errors can be
compensated for by slightly increasing the size of the occulting mask in the
focal plane, with minimal impact on the system performance. Earth-size planets
at 10 pc can be detected in less than 30s with a 4m telescope. Wavefront
quality requirements are similar to classical techniques.Comment: 35 pages, 16 figures, Accepted for publication in Ap
The physical activity levels among people living with human immunodeficiency virus/acquired immunodeficiency syndrome receiving high active antiretroviral therapy in Rwanda
The accessibility of high active antiretroviral therapy (HAART) for local human immunodeficiency virus (HIV) patients is improving in Rwanda. It is well known that this therapy is associated with serious adverse effects, such as metabolic and morphologic changes. One of the recommended preventive modalities for these complications is participation in physical activity. The current study aims to determine the anthropometric profile and physical activity levels among people living with
HIV and receiving HAART in Kigali, Rwanda. The study was a cross-sectional, descriptive quantitative survey. The participant’s levels of physical activity participation and their association with anthropometric profiles were measured, using a structured self-administered questionnaire for 407 clients passing through the clinics. Of the participants, approximately 70% were inactive and in addition, 40% were obese and 43% overweight. Obesity was found to be strongly associated with inactivity. Lack of
motivation, and time as well as fear of worsening the disease were found to be barriers to participation in physical activity.Department of HE and Training approved lis
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