A precise determination of angular momentum in the black hole candidate GRO J1655-40

We note that the recently discovered 450 Hz frequency in the X-ray flux of the black hole candidate GRO J1655-40 is in a 3:2 ratio to the previously known 300 Hz frequency of quasi-periodic oscillations (QPO) in the same source. If the origin of high frequency QPOs in black hole systems is a resonance between orbital and epicyclic motion of accreting matter, as suggested previously, the angular momentum of the black hole can be accurately determined, given its mass. We find that the dimensionless angular momentum is in the range $0.2<j<0.65$ if the mass is in the (corresponding) range of 5.5 to 7.9 solar masses

Black hole accretion: theoretical limits and observational implications

Recently, the issue of the role of the Eddington limit in accretion discs became a matter of debate. While the classical (spherical) Eddington limit is certainly an over-simplification, it is not really clear how to treat it in a flattened structure like an accretion disc. We calculate the critical accretion rates and resulting disc luminosities for various disc models corresponding to the classical Eddington limit by equating the attractive and repulsive forces locally. We also discuss the observational appearance of such highly accreting systems by analyzing their spectral energy distributions. Our calculations indicate that the allowed mass accretion rates differ considerably from what one expects by applying the Eddington limit in its classical form, while the luminosities only weakly exceed their classical equivalent. Depending on the orientation of the disc relative to the observer, mild relativistic beaming turns out to have an important influence on the disc spectra. Thus, possible super-Eddington accretion, combined with mild relativistic beaming, supports the idea that ultraluminous X-ray sources host stellar mass black holes and accounts partially for the observed high temperatures of these objects.Comment: to appear in "Black Holes: from Stars to Galaxies" Proceedings IAU Symp. No. 238, eds. V. Karas & G. Matt; 4 pages, 2 figures, needs iaus.cl

In a Place of a Foreword

In Place of a Foreword: Mathematics like poetry : Andrzej Lasota 1932-2006

Professor Andrzej Lasota

Wspomnienia o Profesorze Andrzeju Lasocie

Tatalaksana Pemeliharaan Ayam Ras Petelur Periode Layer Di Populer Farm Desa Kuncen Kecamatan Mijen Kota Semarang

Report compiled to executed Field in Popular Farm Country Kuncen District Mijen Town Semarang to obtain;get knowledge, ability and skilled about management conservancy of petelur race chicken specially layer period. Used items Farm owning layer chicken counted 47.630 tail, what consist of two strain that is New Lohman Platinum and Isa Brown. Used by Method is to 1) conducting all routine activity 2) doing record-keeping of done data with interview, direct perception, activity note and also recording company of ranch. Data in field indicate that cage building in Popular Farm most of all using W type, what aim to be can load more population. passed to feed chicken represent result from mixing alone which is based to the protein content with rate 18% per ton for the period of Grower and 19% per ton for the period of Layer. Giving of Feed, twice one day that is morning at 08.00 WIB counted 50% and daytime at 13.00 WIB counted 50%. Drinking water given ad libitum. Place feed form is " through feeder" long type and place drink is " through drinker" made long type from PVC paralon pipe. Consume ransum at layer period between 115 -120 head/gr/day and its mean 116 head/gr/day. Egg productivity in Popular Farm have fulfilled standart that was about 93% ( Isa Brown pullet standart) in B1 cage, B2, H, I, J, K And L, because of given feed is goodness and have as according to requirement chicken nutrition

Approximating invariant densities of metastable systems

We consider a piecewise smooth expanding map of the interval possessing two invariant subsets of positive Lebesgue measure and exactly two ergodic absolutely continuous invariant probability measures (ACIMs). When this system is perturbed slightly to make the invariant sets merge, we describe how the unique ACIM of the perturbed map can be approximated by a convex combination of the two initial ergodic ACIMs.Comment: 19 pages, 6 figure

Equivariant ZFA with Choice: a position paper

We propose Equivariant ZFA with Choice as a foundation for nominal techniques that is stronger than ZFC and weaker than FM, and why this may be particularly helpful in the context of automated reasoning.Comment: In ARW 201

Medytacyjne przedstawienia Boga w twórczości J. Kirka Richardsa

Współczesny artysta Kirk Richards, pomimo tego, że jest wyznania mormońskiego, wzorując się na twórczości Carla Heinricha Blocha, tworzy obrazy ukazujące oblicza Boga, będące wynikiem rozważania i medytacji Słowa Bożego

Fibroblastic polyp of the colon: clinicopathological analysis of 10 cases with emphasis on its common association with serrated crypts

: To describe the clinical and pathological features of 10 further cases of fibroblastic polyps (FP), a recently described, distinctive type of colorectal mucosal polyp. Methods and results : The patients were seven women and three men with ages ranging from 44 to 63 years. The lesions ranged in size from 2 to 4 mm. Eight of the polyps were located in the sigmoid colon. Five cases were associated with hyperplastic polyps. Histologically, FP displayed bland, plump spindle cells with oval nuclei arranged as bundles parallel to the surface or as haphazardly orientated sheets with a focal periglandular or perivascular concentric arrangement. Eight polyps represented mixed fibroblastic/hyperplastic polyps as they contained serrated (hyperplastic) crypts. Immunohistochemically, all cases were positive for vimentin and negative for desmin, smooth-muscle actin, h-caldesmon, S100 protein, c-Kit, epithelial membrane antigen, cytokeratin AE1/3, CD34, CD68, COX-2, and factor XIIIa. Ultrastructural examination supported the fibroblastic nature of the tumour cells. Conclusions : FP is a distinctive type of benign mucosal colorectal polyp characterized by its distal location, small size, frequent association with hyperplastic polyps, distinct morphological appearance and typical immunonegativity for markers of specific differentiation. FP with serrated crypts (mixed fibroblastic/hyperplastic polyp) represents a frequent variant of this lesion. Pathologists should recognize FP and discriminate it from other types of colorectal polyps.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72181/1/j.1365-2559.2006.02357.x.pd