4,562 research outputs found
Accurate time-domain gravitational waveforms for extreme-mass-ratio binaries
The accuracy of time-domain solutions of the inhomogeneous Teukolsky equation
is improved significantly. Comparing energy fluxes in gravitational waves with
highly accurate frequency-domain results for circular equatorial orbits in
Schwarzschild and Kerr, we find agreement to within 1% or better, which we
believe can be even further improved. We apply our method to orbits for which
frequency-domain calculations have a relative disadvantage, specifically
high-eccentricity (elliptical and parabolic) "zoom-whirl" orbits, and find the
energy fluxes, waveforms, and characteristic strain in gravitational waves.Comment: 6 pages, 9 figures, 2 tables; Changes: some errors corrected.
Comparison with Frequency-domain now done in stronger fiel
Method of producing high T(subc) superconducting NBN films
Thin films of niobium nitride with high superconducting temperature (T sub c) of 15.7 K are deposited on substrates held at room temperature (approx 90 C) by heat sink throughout the sputtering process. Films deposited at P sub Ar 12.9 + or - 0.2 mTorr exhibit higher T sub c with increasing P sub N2,I with the highest T sub c achieved at P sub n2,I= 3.7 + or - 0.2 mTorr and total sputtering pressure P sub tot = 16.6 + or - 0.4. Further increase of N2 injection starts decreasing T sub c
The Deuteron Spin Structure Functions in the Bethe-Salpeter Approach and the Extraction of the Neutron Structure Function
The nuclear effects in the spin-dependent structure functions and
are calculated in the relativistic approach based on the Bethe-Salpeter
equation with a realistic meson-exchange potential.
The results of calculations are compared with the non-relativistic
calculations. The problem of extraction of the neutron spin structure function,
, from the deuteron data is discussed.Comment: (Talk given at the SPIN'94 International Symposium, September 15-22,
1994, Bloomington, Indiana), 6 pages, 5 figures, Preprint Alberta Thy 29-9
Electronic structure and chemical bonding of 3d-metal dimers ScX, X=Sc-Zn
The electronic and geometrical structures of the ground and excited states of the homonuclear Sc2, mixed ScTi, ScV, ScCr, ScMn, ScFe, ScCo, ScNi, ScCu, and ScZn 3d-metal dimers and their anions have been calculated using the density functional theory with generalized gradient approximation for the exchange-correlation potential. The ground states of the neutral dimers are found to be 5ÎŁâuâ(Sc2), 6ÎŁ+â(ScTi), 7ÎŁ+â(ScV), 4ÎŁ+â(ScCr), 3ÎŁ+â(ScMn), 2Î(ScFe), 1ÎŁ+â(ScCo), 2ÎŁ+â(ScNi), 3Î(ScCu), and 4ÎŁ+â(ScZn). A natural bond analysis reveals an antiferrimagnetic spin coupling in the ground states of ScCr, ScMn, and ScFe. This is due to the electron transfer from Sc to the opposite atom and specific bond formations. While each dimer has a unique chemical bonding pattern, most curious is the localization of two 4s electrons at both atomic sites in the ground 5ÎŁâu state of Sc2, which leads to formation of two lone pairs and the bonding scheme: (3d+3d)3α(4s+4s)1ÎČ. No appreciable sd hybridization is found for the ground states of the ScX dimers except for ScNi. Even though the electron affinities of the ScX dimers are relatively low and do not exceed 1 eV, each ScXâ (except ScCoâ) possesses at least two states stable towards detachment of an extra electron
Gastrointestinal symptom severity in irritable bowel syndrome, inflammatory bowel disease and the general population
BackgroundIrritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) patients report similar gastrointestinal (GI) symptoms, yet comparisons of symptom severity between groups and with the general population (GP) are lacking.MethodsWe compared PatientâReported Outcomes Measurement Information System (PROMISÂź) GI symptom scales measuring gastroâesophageal reflux (GER), disrupted swallowing, diarrhea, bowel incontinence, nausea/vomiting, constipation, belly pain, and gas/bloating in: (i) USA GP sample, (ii) IBS patients, and (iii) IBD patients from tertiary care and community populations. Symptom severity scores were based on Tâscore metric with mean 50±10 (standard deviation) relative to the GP.Key ResultsOf 1643 patients enrolled, there were 253 IBS patients (68% F, mean age 45±15 years), 213 IBD patients (46% F, mean age 41±14 years), and 1177 GP subjects (57% F, mean age 46±16 years). IBS patients reported greater severity of GER, disrupted swallowing, nausea/vomiting, belly pain, gas/bloating, and constipation symptoms than their IBD counterparts (all P<.05). Compared to the GP, IBD patients had worse belly pain, gas/bloating, diarrhea, and bowel incontinence, but less severe GER and disrupted swallowing (all P<.05), and IBS patients had more severe nausea/vomiting, belly pain, gas/bloating, and constipation (all P<.05). Women had more severe belly pain and gas/bloating than men, whereas men had more severe bowel incontinence (all P<.05).Conclusion & InferencesIBS and IBD are associated with more severe GI symptoms compared to the GP excluding esophageal symptoms. Unlike IBD, IBS is not characterized by observable GI inflammation but patients report more severe upper and lower GI symptoms.The PROMIS GI scales were used to determine gastrointestinal symptoms severity in patients. Unlike IBD, IBS is not characterized by observable gastrointestinal inflammation, but patients report more severe upper and lower gastrointestinal symptoms.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/1/nmo13003.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136712/2/nmo13003_am.pd
Phase transition in the 3-D massive Gross-Neveu model
We consider the 3-dimensional massive Gross-Neveu model at finite temperature
as an effective theory for strong interactions. Using the Matsubara imaginary
time formalism, we derive a closed form for the renormalized -dependent
four-point function. This gives a singularity, suggesting a phase transition.
Considering the free energy we obtain the -dependent mass, which goes to
zero for some temperature. These results lead us to the conclusion that there
is a second-order phase transition.Comment: 06 pages, 02 figures, LATE
- âŠ