2,254 research outputs found
Approximate black hole binary spacetime via asymptotic matching
We construct a fully analytic, general relativistic, nonspinning black hole
binary spacetime that approximately solves the vacuum Einstein equations
everywhere in space and time for black holes sufficiently well separated. The
metric is constructed by asymptotically matching perturbed Schwarzschild
metrics near each black hole to a two-body post-Newtonian metric far from them,
and a two-body post-Minkowskian metric farther still. Asymptotic matching is
done without linearizing about a particular time slice, and thus it is valid
dynamically and for all times, provided the binary is sufficiently well
separated. This approximate global metric can be used for long dynamical
evolutions of relativistic magnetohydrodynamical, circumbinary disks around
inspiraling supermassive black holes to study a variety of phenomena.Comment: 17 pages, 8 figures, 1 table. Appendix added to match published
versio
Pengaruh Aromaterapi Rosemary Terhadap Atensi
Latar belakang : Aromaterapi merupakan suatu metode pengobatan alternatif berupa media bau-bauan yang berasal dari bahan tanaman mudah menguap. Selain berperan sebagai media relaksasi, aromaterapi juga memiliki pengaruh yang positif terhadap beberapa fungsi kognitif. Salah satu parameter untuk mengevaluasi kemampuan kognisi adalah atensi. Atensi merupakan suatu USAha pemusatan pikiran terhadap suatu objek untuk menghadapi objek tersebut dimana melibatkan berbagai macam aspek psikologis dan neurologis. Atensi terdiri dari tiga aspek, yaitu alerting, orienting, dan executive attention.Tujuan : Mengetahui pemberian aromaterapi rosemary terhadap peningkatan atensi.Metode : Penelitian ini menggunakan metode eksperimental murni. Sampel penelitian adalah mahasiswa Fakultas Kedokteran Undip (n=20) yang diukur atensinya menggunakan software Attention Network Test sebelum dan sesudah diberikan paparan aromaterapi Rosemary selama ± 30 menit. Atensi antara sebelum dan sesudah bermain video game dianalisis menggunakan uji T berpasangan, sedangkan Perubahan atensi antar kelompok dianalisis dengan menggunakan uji T tidak berpasangan.Hasil : Ditemukan rerata peningkatan atensi pada fungsi alerting subjek penelitian yang diberikan paparan aromaterapi rosemary selama ± 30 menit dari 47,77 ± 21,77 ms menjadi 29,00 ± 6,14 ms dengan p = 0,001 (p < 0,05).Kesimpulan : Pemberian paparan aromaterapi rosemary dapat meningkatkan atensi pada fungsi alerting
Testing minimal lepton flavor violation with extra vector-like leptons at the LHC
Models of minimal lepton flavor violation where the seesaw scale is higher
than the relevant flavor scale predict that all lepton flavor violation is
proportional to the charged lepton Yukawa matrix. If extra vector-like leptons
are within the reach of the LHC, it will be possible to test the resulting
predictions in ATLAS/CMS.Comment: 19 pages, 8 figure
Study of Conformally Flat Initial Data for Highly Spinning Black Holes and their Early Evolutions
We study conformally-flat initial data for an arbitrary number of spinning
black holes with exact analytic solutions to the momentum constraints
constructed from a linear combination of the classical Bowen-York and conformal
Kerr extrinsic curvatures. The solution leading to the largest intrinsic spin,
relative to the ADM mass of the spacetime epsilon_S=S/M^2_{ADM}, is a
superposition with relative weights of Lambda=0.783 for conformal Kerr and
(1-Lambda)=0.217 for Bowen-York. In addition, we measure the spin relative to
the initial horizon mass M_{H_0}, and find that the quantity chi=S/M_{H_0}^2
reaches a maximum of \chi^{max}=0.9856 for Lambda=0.753. After equilibration,
the final black-hole spin should lie in the interval 0.9324<chi_{final}<0.9856.
We perform full numerical evolutions to compute the energy radiated and the
final horizon mass and spin. We find that the black hole settles to a final
spin of chi_{final}^{max}=0.935 when Lambda=0.783. We also study the evolution
of the apparent horizon structure of this "maximal" black hole in detail.Comment: 9 pages, 8 figure
Perturbative effects of spinning black holes with applications to recoil velocities
Recently, we proposed an enhancement of the Regge-Wheeler-Zerilli formalism
for first-order perturbations about a Schwarzschild background that includes
first-order corrections due to the background black-hole spin. Using this
formalism, we investigate gravitational wave recoil effects from a spinning
black-hole binary system analytically. This allows us to better understand the
origin of the large recoils observed in full numerical simulation of spinning
black hole binaries.Comment: Proceedings of Theory Meets Data Analysis at Comparable and Extreme
Mass Ratios (NRDA/Capra 2010), Perimeter Institute, June 2010 - 12 page
Gambaran Peresepan Digoksin Pada Pasien Gagal Jantung Yang Dirawat Jalan Di RSUP Dr. Kariadi Semarang
ABSTRACKBackground Heart failure is a clinical syndrome caused by abnormalitiesof cardiac structure or function. The prevalence of heart failure is increasing andcaused loss of quality of life. Heart failure treatment guidelines has beenprepared to guide medical treatment and doctors in providing treatmentrecommendations. There are various classes of drugs used in the treatment ofheart failure, one of which is digoxin. Nowadays it has been discovered that notall heart failure patients should be given digoxin.Aim To know wether the prescripction of digoxin in heart failure outpatientof dr. Kariadi Semarang Central Hospital is in conformity with the guidelines forthe treatment of heart failure that used Internationally.Methods This was a descriptive study. Research data were the medicalrecords of outpatient heart failure patients who received digoxin therapy in dr.Kariadi Semarang Central Hospital in January 2011 to December 2011 andcomplemented by the data of ECG and echocardiography. Data were collectedwith a total sampling method. In this study, the administration of digoxin followedheart failure guidelines issued by the European Society of Cardiology (ESC) andAmerican Heart Association (AHA), the heart failure patients with atrialfibrillation (AF) or patients with sinus rhythm but with left ventricle ejectionfraction (LVEF) ≤ 40%. Digoxin was indicated for heart failure patients with AFor patients with sinus rhythm but with the left ventricular ejection fraction (LVEF)≤ 40%Results There were 121 patients who received digoxin therapy, 74 patients(61,2%) received digoxin therapy with proper indications. The reason forprescribing digoxin were atrial fibrillation (n = 18, 14.9%), LVEF ≤40% (n = 21,17.4%), or both (n = 35, 28.9%). Forty six patients (38.0%) received digoxintherapy,without proper indications.Conclusion There were 61,2% patients who received digoxin therapy withapropriate indication and 38,8% patients with inappropriate indications
Volatility of Linear and Nonlinear Time Series
Previous studies indicate that nonlinear properties of Gaussian time series
with long-range correlations, , can be detected and quantified by studying
the correlations in the magnitude series , i.e., the ``volatility''.
However, the origin for this empirical observation still remains unclear, and
the exact relation between the correlations in and the correlations in
is still unknown. Here we find analytical relations between the scaling
exponent of linear series and its magnitude series . Moreover, we
find that nonlinear time series exhibit stronger (or the same) correlations in
the magnitude time series compared to linear time series with the same
two-point correlations. Based on these results we propose a simple model that
generates multifractal time series by explicitly inserting long range
correlations in the magnitude series; the nonlinear multifractal time series is
generated by multiplying a long-range correlated time series (that represents
the magnitude series) with uncorrelated time series [that represents the sign
series ]. Our results of magnitude series correlations may help to
identify linear and nonlinear processes in experimental records.Comment: 7 pages, 5 figure
Baryogenesis from the Kobayashi-Maskawa Phase
The Standard Model fulfills the three Sakharov conditions for baryogenesis.
The smallness of quark masses suppresses, however, the CP violation from the
Kobayashi-Maskawa phase to a level that is many orders of magnitude below what
is required to explain the observed baryon asymmetry. We point out that if, as
a result of time variation in the Yukawa couplings, quark masses were large at
the time of the electroweak phase transition, then the Kobayashi-Maskawa
mechanism could be the source of the asymmetry. The Froggatt-Nielsen mechanism
provides a plausible framework where the Yukawa couplings could all be of order
one at that time, and settle to their present values before nucleosynthesis.
The problems related to a strong first order electroweak phase transition may
also be alleviated in this framework. Our scenario reveals a loophole in the
commonly held view that the Kobayashi-Maskawa mechanism cannot be the dominant
source of CP violation to play a role in baryogenesis.Comment: 4 page
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