We briefly summarize the observational properties of ultra-compact binaries called AM CVn stars. We analize their outbursts originating from the thermal-viscous instability in helium accretion disc. We present our preliminary results in applying the model of Dwarf Novae outbursts to helium discs. We can calculate models of outbursts of reasonable amplitude of 2 mag with a constant α parameter t...

— I review recent progresses in the dynamics and the evolution of self-gravitating accretion discs. Accretion discs are a fundamental component of several astrophysical systems on very diverse scales, and can be found around supermassive black holes in Active Galactic Nuclei (AGN), and also in our Galaxy around stellar mass compact objects and around young stars. Notwithstanding the specific di...

By a compact packing of the plane by discs, $P$, we mean collection closed discs in with pairwise disjoint interior so that, for every disc $C\in P$, there exists sequence $D_{0},\ldots,D_{m-1}\in P$ that each $D_{i}$ is tangent to both $C$ and $D_{i+1\mod m}.$ We prove, $n\in\mathbb N$, exist only finitely many tuples $(r_{0},r_{1},\ldots,r_{n-1})\in\mathbb{R}^{n}$ $0<r_{0}<r_{1}\ldots<r_{n-1}...

abstract   background: far lateral discal herniation is an uncommon disorder and is difficult to assess by physical examination alone. this study is designed to define clinical and epidemiological findings and to establish the indications of surgical and medical treatment for flldh.   methods: between 2000 and 2005, a total of 2035 patients with lumbar disc herniation underwent surgical discect...

conclusions in this study, we found that in spite of previous beliefs, discopathies were not common etiologies of lbp. thus, even in patients with proven ldh by imaging studies, the physician should perform a thorough evaluation for other causes of lbp to avoid unnecessary lumbar surgeries. results in our study, among 1250 patients with proven ldh by mri, 500 patients (40%) had chronic lbp and ...

Context. In the generally accepted, but poorly documented model, silicate J-type C-stars are binary objects for which the silicate emission originates from a circumbinary or a circumcompanion disc. Aims. We aim at testing this hypothesis by a thorough spectral and spatial observational study of one object: IRAS 18006-3213. Methods. We obtained, analysed and modeled high spatial resolution inter...

BACKGROUND We describe a direct-detection immunoassay that uses high-speed optical interferometry on a biological compact disc (BioCD). METHODS We fabricated phase-contrast BioCDs from 100-mm diameter 1.1-mm thick borosilicate glass disks coated with a 10-layer dielectric stack of Ta2O5/SiO2 that serves as a mirror with a center wavelength at 635 nm. The final layer is a lambda/4 layer of SiO...

The DSHARP survey evidenced the ubiquity of substructure in mm dust distribution large, bright protoplanetary discs. Intriguingly, these datasets have yet higher resolution information that is not recovered a CLEAN image. We first show intrinsic performance algorithm resolution-limited. Then analyzing all 20 sources using 1D, super-resolution code Frankenstein (frank), we accurately fit 1D visi...