An Isolated Stellar-Mass Black Hole Detected Through Astrometric Microlensing

We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry of the source star of the long-duration (t_E ~ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462, in the direction of the Galactic bulge. HST imaging, conducted at eight epochs over an interval of six years, reveals a clear relativistic astrometric deflection of the background star's apparent position. Ground-based photometry shows a parallactic signature of the effect of the Earth's motion on the microlensing light curve. Combining the HST astrometry with the ground-based light curve and the derived parallax, we obtain a lens mass of 7.1 +/- 1.3 M_Sun and a distance of 1.58 +/- 0.18 kpc. We show that the lens emits no detectable light, which, along with having a mass higher than is possible for a white dwarf or neutron star, confirms its BH nature. Our analysis also provides an absolute proper motion for the BH. The proper motion is offset from the mean motion of Galactic-disk stars at similar distances by an amount corresponding to a transverse space velocity of ~45 km/s, suggesting that the BH received a modest natal 'kick' from its supernova explosion. Previous mass determinations for stellar-mass BHs have come from radial-velocity measurements of Galactic X-ray binaries, and from gravitational radiation emitted by merging BHs in binary systems in external galaxies. Our mass measurement is the first ever for an isolated stellar-mass BH using any technique

DETC2005-84021 FREE VIBRATION ANALYSIS OF CIRCULAR FGM PLATE HAVING VARIABLE THICKNESS UNDER AXISYMMETRIC CONDITION BY FINITE ELEMENT METHOD

ABSTRACT This study presents the free vibration analysis of circular plate having variable thickness made of functionally-graded material. The boundary conditions of the plate is either simply supported or clamped. Dynamic equations were obtained using energy method based on Love-Kichhoff hypothesis and Sander's non-linear strain-displacement relation for thin plates. The finite element method is used to determine the natural frequencies. The results obtained show good agreement with known analytical data. The effects of thickness variation and Poisson's ratio are investigated by calculating the natural frequencies. These effects are found not to be the same for simply supported and clamped plates

Biomacromolecular Journal Pre-Clinical and Clinical Data Confirm the Anticancer Effect of Deuterium Depletion

ABSTRACT The two stable isotopes of hydrogen, protium ( H ratio in the cells is proposed as the key mechanism to regulate cell growth

HT2008-56478 HEAT TRANSFER ENHANCEMENT IN TRIANGULAR FIN

ABSTRACT Fins are widely utilized in many industrial applications for example, fins are used in air cooled finned tube heat exchangers like car radiators, heat rejection devices, refrigeration systems and in condensing central heat exchangers. In this paper, heat transfer inside the fin system composed of a primary rectangular fin with a number of rectangular fins (secondary fins), which are attached on its surface, is modeled and analyzed numerically. The length of the secondary fins decreases linearly from the base of the primary fin to its tip. This modified triangular fin is a kind of improved tree fin networks. The effectiveness of the modified triangular fin is compared with the effectiveness of triangular fin which is calculated analytically. The results show that adding secondary fins increases the effectiveness of triangular fin significantly. Also, it is found that increasing the number of secondary fins in a constant length of primary fin will increase the effectiveness. In addition, by comparing the results it can be concluded that by shortening the length of the primary fin in modified triangular fin, the effectiveness will increase significantly to the contrary of the triangular fin, so smaller heat exchangers can be built by using the modified triangular fin. It is found that in a constant length of primary fin, there is an optimum thickness of secondary fins which maximize the effectiveness of the fin. INTRODUCTION The principle goal in improving the performance of existing thermal systems or in the design of new ones is to enhance heat transfer between hot or cold surfaces and the transport fluid. As such, several methods were proposed in the literature to achieve this task. These methods can be classifie

Additional files of Tandem repeats ubiquitously flank and contribute to translation initiation sites

Additional file 1 Additional Table 1. The number of genes, transcripts and extracted TRs for each species. The rows of the table are sorted from large to small, based on the ratio of the number of TRs to the number of genes and transcripts in each species

Tallo database

The Tallo database (v1.0.0) is a collection of 498,838 georeferenced and taxonomically standardized records of individual trees for which stem diameter, height and/or crown radius have been measured. Data were compiled from 61,856 globally distributed sites and include measurements for 5,163 tree species. For a full description of the database, see: Jucker et al. (2022) Tallo – a global tree allometry and crown architecture database. Global Change Biology, https://doi.org/10.1111/gcb.16302. If using the Tallo database in your work please cite the original publication listed above, as well as this repository using the corresponding DOI (10.5281/zenodo.6637599)