211 research outputs found
Virial series for inhomogeneous fluids applied to the Lennard-Jones wall-fluid surface tension at planar and curved walls
We formulate a straightforward scheme of statistical mechanics for
inhomogeneous systems that includes the virial series in powers of the activity
for the grand free energy and density distributions. There, cluster integrals
formulated for inhomogeneous systems play a main role. We center on second
order terms that were analyzed in the case of hard-wall confinement, focusing
in planar, spherical and cylindrical walls. Further analysis was devoted to the
Lennard-Jones system and its generalization the 2k-k potential. For this
interaction potentials the second cluster integral was evaluated analytically.
We obtained the fluid-substrate surface tension at second order for the planar,
spherical and cylindrical confinement. Spherical and cylindrical cases were
analyzed using a series expansion in the radius including higher order terms.
We detected a dependence of the surface tension for the
standard Lennard-Jones system confined by spherical and cylindrical walls, no
matter if particles are inside or outside of the hard-walls. The analysis was
extended to bending and Gaussian curvatures, where exact expressions were also
obtained.Comment: 15 pages, 6 figure
Two hard spheres in a pore: Exact Statistical Mechanics for different shaped cavities
The Partition function of two Hard Spheres in a Hard Wall Pore is studied
appealing to a graph representation. The exact evaluation of the canonical
partition function, and the one-body distribution function, in three different
shaped pores are achieved. The analyzed simple geometries are the cuboidal,
cylindrical and ellipsoidal cavities. Results have been compared with two
previously studied geometries, the spherical pore and the spherical pore with a
hard core. The search of common features in the analytic structure of the
partition functions in terms of their length parameters and their volumes,
surface area, edges length and curvatures is addressed too. A general framework
for the exact thermodynamic analysis of systems with few and many particles in
terms of a set of thermodynamic measures is discussed. We found that an exact
thermodynamic description is feasible based in the adoption of an adequate set
of measures and the search of the free energy dependence on the adopted measure
set. A relation similar to the Laplace equation for the fluid-vapor interface
is obtained which express the equilibrium between magnitudes that in extended
systems are intensive variables. This exact description is applied to study the
thermodynamic behavior of the two Hard Spheres in a Hard Wall Pore for the
analyzed different geometries. We obtain analytically the external work, the
pressure on the wall, the pressure in the homogeneous zone, the wall-fluid
surface tension, the line tension and other similar properties
Density functional approach for inhomogeneous star polymers
We propose microscopic density functional theory for inhomogeneous star
polymers. Our approach is based on fundamental measure theory for hard spheres,
and on Wertheim's first- and second-order perturbation theory for the
interparticle connectivity. For simplicity we consider a model in which all the
arms are of the same length, but our approach can be easily extended to the
case of stars with arms of arbitrary lengths.Comment: 4 pages, 3 figures, submitte
The supreme turbinate and the drainage of the posterior ethmoids: a computed tomographic study
Background: It is generally acknowledged that the posterior ethmoidal cells drain under the superior nasal turbinate (SorNT) or, rarely, under the supreme nasal turbinate (SmeNT), and the sphenoid ostium (SO) opens to the sphenoethmoidal recess. However, detailed relations between these structures are variable, complex and still not clear. There is no reliable data on the prevalence of SmeNT and drainage of the posterior ethmoidal cells under this structure. The aim of this study was to re-evaluate the anatomy of the aforementioned region.
Materials and methods: Multiplanar and three-dimensional reconstruction analysis of 100 thin slice paranasal sinus computed tomography scans.
Results: SmeNT was identified in 77 subjects (136 sides). It formed the ostium to the posterior ethmoidal cell adjacent to the skull base or orbit in 58 subjects (91 sides). This cell drained independently from the remaining posterior ethmoidal cells. The sphenoethmoidal (Onodi) cell drained to supreme meatus in 41 subjects (54 sides), and to superior meatus in 37 subjects (49 sides). SO was always located medial to the posteroinferior attachment of SmeNT, or SorNT (in absence of SmeNT).
Conclusions: Patients with divergent drainage of the posterior ethmoids (with posterior ethmoidal cell draining to the supreme meatus) may require more extensive surgery to avoid persistence or recurrence of inflammatory disease. SmeNT is more common than thought, but due to its posterior and superior location to SorNT, it is rarely seen intraoperatively. If SmeNT is present, SO is always located medial to its posteroinferior attachment. (Folia Morphol 2018; 77, 1: 110–115
Metric gravity theories and cosmology:II. Stability of a ground state in f(R) theories
A fundamental criterion of viability of any gravity theory is existence of a
stable ground-state solution being either Minkowski, dS or AdS space. Stability
of the ground state is independent of which frame is physical. In general, a
given theory has multiple ground states and splits into independent physical
sectors. All metric gravity theories with the Lagrangian being a function of
Ricci tensor are dynamically equivalent to Einstein gravity with a source and
this allows us to study the stability problem using methods developed in GR. We
apply these methods to f(R) theories. As is shown in 13 cases of Lagrangians
the stability criterion works simply and effectively whenever the curvature of
the ground state is determined. An infinite number of gravity theories have a
stable ground state and further viability criteria are necessary.Comment: A modified and expanded version of a second part of the paper which
previously appeared as gr-qc/0702097v1. The first, modified part is now
published as gr-qc/0702097v2 and as a separate paper in Class. Qu. Grav. The
present paper matches the published versio
Inflation in Multidimensional Quantum Cosmology
We extend to multidimensional cosmology Vilenkin's prescription of tunnelling
from nothing for the quantum origin of the observable Universe. Our model
consists of a -dimensional spacetime of topology , with a scalar field (``chaotic inflaton'') for the
matter component. Einstein gravity and Casimir compactification are assumed.
The resulting minisuperspace is 3--dimensional. Patchwise we find an
approximate analytic solution of the Wheeler--DeWitt equation through which we
discuss the tunnelling picture and the probability of nucleation of the
classical Universe with compactifying extra dimensions. Our conclusion is that
the most likely initial conditions, although they do not lead to the
compactification of the internal space, still yield (power-law) inflation for
the outer space. The scenario is physically acceptable because the inner space
growth is limited to in 100 e-foldings of inflation, starting
from the Planck scale.Comment: RevTeX, 30 pages, 4 figures available via fax on request to
[email protected], submitted to Phys. Rev.
Recommended from our members
A mechanochemical strategy for IRMOF assembly based on pre-designed oxo-zinc precursors.
We demonstrate a mechanochemical strategy that allowed the first successful mechanosynthesis of IRMOFs based on an oxo-centred secondary building unit (SBU). The presented study indicates that controlling the acid-base relationship between reagents is key to mechanochemical synthesis of IRMOFs, revealing a pre-assembled oxo-zinc amidate cluster as an efficient precursor for IRMOF mechanosynthesis.The authors would like to acknowledge the project operated within the Foundation for Polish Science Team Programme co-financed by the EU ‘‘European Regional Development Fund’’ TEAM/2011–7/8, and the European Union in the framework of Regional Development Fund through the Joint UW and WUT International PhD Program of Foundation for Polish Science – “Towards Advanced Functional Materials and Novel Devices” (MPD/2010/4) (D.P.) for financial support.This is the accepted manuscript. The final version was published in Chemical Communications and is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/CC/c4cc09917f#!divAbstract
Dimensions of aging and their influence on physical activity = Wymiary starzenia i ich wpływ na aktywność fizyczną
Podhorecka M., Główczewska J., Ciesielska N., Gębka D., Sokołowski R., Szymańska A., Jagielski D., Zukow W. Dimensions of aging and their influence on physical activity = Wymiary starzenia i ich wpływ na aktywność fizyczną. Journal of Education, Health and Sport. 2015;5(12):230-239. ISSN 2391-8306. DOIhttp://dx.doi.org/10.5281/zenodo.35365http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%2812%29%3A230-239http://pbn.nauka.gov.pl/works/680050Formerly Journal of Health Sciences. ISSN 1429-9623 / 2300-665X. Archives 2011–2014http://journal.rsw.edu.pl/index.php/JHS/issue/archive Deklaracja.Specyfika i zawartość merytoryczna czasopisma nie ulega zmianie.Zgodnie z informacją MNiSW z dnia 2 czerwca 2014 r., że w roku 2014 nie będzie przeprowadzana ocena czasopism naukowych; czasopismo o zmienionym tytule otrzymuje tyle samo punktów co na wykazie czasopism naukowych z dnia 31 grudnia 2014 r. The journal has had 5 points in Ministry of Science and Higher Education of Poland parametric evaluation. Part B item 1089. (31.12.2014).© The Author (s) 2015;This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland and Radom University in Radom, PolandOpen Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium,provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License(http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited.This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non commercialuse, distribution and reproduction in any medium, provided the work is properly cited.The authors declare that there is no conflict of interests regarding the publication of this paper.Received: 10.11.2015. Revised 25.11.2015. Accepted: 14.12.2015. Dimensions of aging and their influence on physical activityWymiary starzenia i ich wpływ na aktywność fizyczną M. Podhorecka1, J. Główczewska1, N. Ciesielska1, D. Gębka1, R. Sokołowski2, A. Szymańska1, D. Jagielski1, W. Zukow3 1Katedra i Klinika Geriatrii, Collegium Medicum UMK, Toruń, Bydgoszcz, Polska/ Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Department of Geriatrics, Poland2Katedra Higieny, Epidemiologii i Ergonomii , Collegium Medicum UMK, Toruń,Bydgoszcz, Polska/ Nicolaus Copernicus University in Toruń, Collegium Medicum in Bydgoszcz, Department of Hygiene and Epidemiology, Poland3Wydział Kultury Fizycznej, Zdrowia i Turystyki, Uniwersytet Kazimierza Wielkiego w Bydgoszczy, Polska/ Faculty of Physical Education, Health and Tourism, Kazimierz Wielki University, Bydgoszcz, Poland AbstractOld age is a common and a universal phenomenon. It is difficult to define the beginning of the process of aging and entering the period of late adulthood. As time passes, the symptoms of aging become more and more visible. The work presents three dimensions of aging: biological, psychological and social. It demonstrates their influence on physical activity. It shows barriers the elderly people need to overcome or the situations they might be in. It also shows physical activity as one of the main components of the activation process of the elderly.Key words: elderly, physical activity, aging
Percutaneous management of long and diffused coronary lesions using newer generation drug-eluting stents in routine clinical practice : long-term outcomes and complication predictors
Long and diffuse coronary lesions (LDCLs) are routinely subjected to percutaneous
management, but long‑term
clinical outcomes and complication predictors with the use of contemporary
stents and techniques remain undetermined. Long and diffuse coronary lesion was defined as a lesion requiring an implantation
of 30 mm or longer total stent(s) length (TSL) into one coronary artery (bailouts
excluded). There
were 290 LDCL interventions with the use of newer generation drug‑eluting
stents (DESs cobalt chromium
everolimus- or zotarolimus-eluting stents) performed between January 2013 and January 2016. The mean (SD) TSL was 55.5 (16.8) mm. The use of intravascular ultrasound / optical coherence
tomography was 17.1%, rotablation, 6.9%, and noncompliant balloon, 88.9%. The median (range)
follow‑up
duration was 831 (390-1373) days. All‑cause
mortality and cardiac death rates were 11.7%
and 6.9%, respectively. The myocardial infarction (MI) rate was 6.6%, including target‑vessel
MI in 4.1%.
The rate of clinically‑driven
repeat revascularization was 13.8%, and of definite or probable LDCL stent
thrombosis, 7.2%. Overall patient‑oriented
adverse event rate (any death, MI, or repeat revascularization)
was 25.5%, and device‑oriented
rate (cardiac death, target vessel‑MI,
or target lesion restenosis), 13.4%.
Adverse outcome predictors were chronic kidney disease, acute coronary syndrome as an indication for
the procedure, chronic heart failure with reduced left ventricular ejection fraction, multivessel disease,
and coexisting peripheral artery disease, but not lesion‑related
factors, such as bifurcation, calcification,
chronic total occlusion, or TSL. Adverse outcomes following contemporary LDCL management using newer generation
DESs in routine clinical practice are associated with clinical patient characteristics rather than lesion
characteristics or TSL. We identified high‑risk
patient cohorts that may benefit from enhanced surveillance
Absolute properties of BG Ind - a bright F3 system just leaving the Main Sequence
We present photometric and spectroscopic analysis of the bright detached
eclipsing binary BG Ind. The masses of the components are found to be 1.428 +-
0.008 and 1.293 +- 0.008 Msun and the radii to be 2.290+-0.017 and 1.680+-0.038
Rsun for primary and secondary stars, respectively. Spectra- and
isochrone-fitting coupled with color indices calibration yield
[Fe/H]=-0.2+-0.1. At an age of 2.65+-0.20 Gyr BG Ind is well advanced in the
main-sequence evolutionary phase - in fact, its primary is at TAMS or just
beyond it. Together with three similar systems (BK Peg, BW Aqr and GX Gem) it
offers an interesting opportunity to test the theoretical description of
overshooting in the critical mass range 1.2-1.5 Msun.Comment: 8 pages, 5 figures, corrected bugs in author lis
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