Explicit Euler method for solving time dependent Schr\H{o}dinger equation

Using an explicit Euler substitution it was obtained a system of differential equations, which can be used to find the solution of time-dependent 1-dimentional Schr\H{o}dinger equation for a general form of the time-dependent potential.Comment: 1 page. Accepted for publication in Phys. Rev.

The presidentialization of the Romanian political system: an interplay between structures and contingencies

The peculiarities of post-communist Romania have stirred inquiries regarding the delimitation of the governmental system, the separation of powers and the relations between these. The present analysis addresses the phenomenon labeled the "presidentialization of politics", which designates the adoption of a presidential modus operandi without an actual constitutional option for presidentialism. Since the concept revolves around the highly debated concentration of power in the hands of leaders, the potential presidentialization of the Romanian political system would be investigated by scrutinizing the increased leadership autonomy in three arenas: the executive, the party and the electoral process. Basically, this paper represents a theoretical extension of the presidentialization thesis, aiming at concluding on the phenomenon’s existence and functioning in Romania as encouraged by a series of structural and contingent factors, including the communist legacies and the dysfunctions of the democratic transition

Black hole microstructures in the extremal limit

The microstructure of black holes is a mystery. There is yet no resolution of basic questions such as what the constituent particles are. We work here with black hole thermodynamics (BHT), and the metric geometry of thermodynamics, which connects to interparticle interactions via the invariant thermodynamic Ricci scalar curvature $R$. $R$ may be calculated with BHT. In ordinary thermodynamics (OT), $R$ is positive/negative for interparticle interactions repulsive/attractive. Its magnitude is the correlation length. The basic universality of thermodynamics leads us to expect similar relations for BHT. Our contribution here is motivated by a physical simplification that frequently occurs at low temperatures $T$ in OT: complicated interactions tend to freeze out, leaving only basic quantum statistical interactions, those of ideal Fermi or Bose gasses. Our hope is that similar simplification happens in black holes in the extremal limit, where the BHT temperature $T \to 0$. We evaluate the extremal $R$ for twelve BHT literature models, working with the independent variables mass, angular momentum, charge, and the cosmological constant, $\{M,J,Q,\Lambda\}$, respectively. We allowed only two of these variables to fluctuate at a time, with the other two fixed. $M$ always fluctuated, either $J$ or $Q$ fluctuated, and $\Lambda$ was always fixed. At constant average $M$, $R$ has limiting divergence $R=c\,T^{-1}$, with the nonsingular constant $c$ depending only on $M$ and the two fixed parameters. $c$ is positive for $11/12$ of the models we examined, and negative only for the tidal charged model. The positive sign for $R$ indicates a BHT microstructure composed of particles with repulsive (fermionic) interactions. The limiting BHT expression for $R$ resembles that for 2D and 3D ideal Fermi gasses at constant volume, which also have limiting divergence $R=c\,T^{-1}$, with positive $c$

Review of Non-destructive Testing (NDT) Techniques and their applicability to thick walled composites

A tier 1 automotive supplier has developed a novel and unique kinetic energy recovery storage system for both retro-fitting and OEM application for public transport systems where periodic stop start behaviour is paramount. A major component of the system is a composite flywheel spinning at up to 36,000 rpm (600 Hz). Material soundness is an essential requirement of the flywheel to ensure failure does not occur. The component is particularly thick for a composite being up to 30 mm cross section in some places. The geometry, scale and material make-up pose some challenges for conventional NDT systems. Damage can arise in composite materials during material processing, fabrication of the component or in-service activities among which delamination, cracks and porosity are the most common defects. A number of non-destructive testing (NDT) techniques are effective in testing components for defects without damaging the component. NDT techniques like Ultrasonic Testing, X-Ray, Radiography, Thermography, Eddy current and Acoustic Emission are current techniques for various testing applications. Each of these techniques uses different principles to look into the material for defects. However, the geometry, physical and material properties of the component being tested are important factors in the applicability of a technique. This paper reviews these NDT techniques and compares them in terms of characteristics and applicability to composite parts