A comprehensive study of optical transitions in direct bandgap Ge0.875Sn0.125 group IV alloys via photoluminescence measurements as a function of temperature, compressive strain and excitation power is performed. The analysis of the integrated emission intensities reveals a strain-dependent indirect-to-direct bandgap transition, in good agreement with band structure calculations based on 8 band...

The impulsive riveting method is described as the punching and joining of sheet metal carried out using the impulsive energy of a weight accelerated by an air compressor. Parts are held together between the rivet and rivet-holder. A hole is made in the sheets by the high speed collision of rivet and a weight (approximately 100 m/s or more). Another method, punch riveting, joins the sheets by pr...

We propose statistical learning methods for approximating implicit surfaces and computing dense 3D deformation fields. Our approach is based on Support Vector (SV) Machines, which are state of the art in machine learning. It is straightforward to implement and computationally competitive; its parameters can be automatically set using standard machine learning methods. The surface approximation ...

Mechanical oscillators can be optically cooled using a technique known as optical-cavity back-action. Cooling of composite metal–semiconductor mirrors, dielectric mirrors and dielectric membranes has been demonstrated. Here we report cavity cooling of mechanical modes in a high-quality-factor and optically active semiconductor nanomembrane. The cooling is a result of electron–hole generation by...

The gravitational-wave spectrum emitted by a non-axisymmetric torus rotating at an angular velocity ΩT , is derived in terms of a structure function representing a combination of sausage-tilt modes in the torus in the limit of an incompressible fluid. The analysis of the gravitational-wave spectrum is then applied to a model proposed recently, in which a highly magnetized torus interacts with a...

Both intrinsic and extrinsic charge transport properties of methylammonium lead triiodide perovskites are investigated from first-principles. The weak electron-phonon couplings are revealed, with the largest deformation potential (~ 5 eV) comparable to that of single layer graphene. The intrinsic mobility limited by the acoustic phonon scattering is as high as a few thousands cm(2) V(-1) s(-1) ...

We study the addition of an irrelevant operator to the N = 4 supersymmetric large N SU(N) gauge theory, in the presence of finite temperature, T . In the supergravity dual, the effect of the operator is known to correspond to a deformation of the AdS5 × S5 “throat” which restores the asymptotic ten dimensional Minkowski region of spacetime, completing the full D3–brane solution. The system at n...

0013-7944/$ see front matter 2012 Elsevier Ltd http://dx.doi.org/10.1016/j.engfracmech.2012.04.030 ⇑ Corresponding author. Tel.: +1 858 534 5930; fa E-mail addresses: [email protected] (C. Nielsen) The fracture behavior of poly(methyl methacrylate) (PMMA) is studied using double cleavage drilled compression (DCDC) experiments. Increasing sample thickness is found to increase the stresses requir...

We investigate the possibility of extending non-extreme black hole solutions made of intersecting M-branes to those with two non-extreme deformation parameters, similar to Reissner-Nordstrøm solutions. General analysis of possible solutions is carried out to reduce the problem of solving field equations to a simple algebraic one for static spherically-symmetric case in D dimensions. The results...

The properties of a semiconductor are drastically modified when the crystal point group symmetry is broken under an arbitrary strain. We investigate the family of semiconductors consisting of GaAs, GaSb, InAs and InSb, considering their electronic band structure and deformation potentials subject to various strains based on hybrid density functional theory. Guided by these first-principles resu...