Quantum Spectra of Triangular Billiards on the Sphere

We study the quantal energy spectrum of triangular billiards on a spherical surface. Group theory yields analytical results for tiling billiards while the generic case is treated numerically. We find that the statistical properties of the spectra do not follow the standard random matrix results and their peculiar behaviour can be related to the corresponding classical phase space structure.Comment: 18 pages, 5 eps figure

Optically switched magnetism in photovoltaic perovskite CH3_3NH3_3(Mn:Pb)I3_3

The demand for ever-increasing density of information storage and speed of manipulation boosts an intense search for new magnetic materials and novel ways of controlling the magnetic bit. Here, we report the synthesis of a ferromagnetic photovoltaic CH$_3$NH$_3$(Mn:Pb)I$_3$ material in which the photo-excited electrons rapidly melt the local magnetic order through the Ruderman-Kittel-Kasuya-Yosida interactions without heating up the spin system. Our finding offers an alternative, very simple and efficient way of optical spin control, and opens an avenue for applications in low power, light controlling magnetic devices

Micro-sensor thin-film anemometer

A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique

DeepSRE: Identification of sterol responsive elements and nuclear transcription factors Y proximity in human DNA by Convolutional Neural Network analysis

SREBP1 and 2, are cholesterol sensors able to modulate cholesterol-related gene expression responses. SREBPs binding sites are characterized by the presence of multiple target sequences as SRE, NFY and SP1, that can be arranged differently in different genes, so that it is not easy to identify the binding site on the basis of direct DNA sequence analysis. This paper presents a complete workflow based on a one-dimensional Convolutional Neural Network (CNN) model able to detect putative SREBPs binding sites irrespective of target elements arrangements. The strategy is based on the recognition of SRE linked (less than 250 bp) to NFY sequences according to chromosomal localization derived from TF Immunoprecipitation (TF ChIP) experiments. The CNN is trained with several 100 bp sequences containing both SRE and NF-Y. Once trained, the model is used to predict the presence of SRE-NFY in the first 500 bp of all the known gene promoters. Finally, genes are grouped according to biological process and the processes enriched in genes containing SRE-NFY in their promoters are analyzed in details. This workflow allowed to identify biological processes enriched in SRE containing genes not directly linked to cholesterol metabolism and possible novel DNA patterns able to fill in for missing classical SRE sequences

Micro-sensor thin-film anemometer

A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14 deg half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique

The Inhibition of Mixing in Chaotic Quantum Dynamics

We study the quantum chaotic dynamics of an initially well-localized wave packet in a cosine potential perturbed by an external time-dependent force. For our choice of initial condition and with $\hbar$ small but finite, we find that the wave packet behaves classically (meaning that the quantum behavior is indistinguishable from that of the analogous classical system) as long as the motion is confined to the interior of the remnant separatrix of the cosine potential. Once the classical motion becomes unbounded, however, we find that quantum interference effects dominate. This interference leads to a long-lived accumulation of quantum amplitude on top of the cosine barrier. This pinning of the amplitude on the barrier is a dynamic mechanism for the quantum inhibition of classical mixing.Comment: 20 pages, RevTeX format with 6 Postscript figures appended in uuencoded tar.Z forma

Differential abundance analysis of Procyon and θ Sculptoris: Comparison with abundance patterns of solar‐like pairs

The precision differential abundance (PDA) technique is applied to the mid‐F stars Procyon and θ Scl using spectra from the ESO UVESPOP library. We relate PDA patterns to endogenous processes related to condensation or to exogenous processes connected to Galactic chemical evolution. We employ one‐dimensional LTE models, but emphasize the use of weaker lines (≤20 mÅ) that are typically used in such studies. We compare our results with PDAs of solar‐type stars. Abundances and PDAs are determined for 28 elements: C, N, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, and Gd. A plot of PDAs (θ Scl minus Procyon) versus Z shows a highly significant correlation. Moreover, local substructure of the plot for the elements Ca‐Zn and neutron‐addition elements is similar to that which can be found for solar twins. Our PDA versus Z plot structural shows similarity to plots that can be made from the extensive work of Bedell et al. (2018). That PDA structure and substructure is clearly a function of age.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154353/1/asna202013694.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154353/2/asna202013694_am.pd