Diferencijalni udarni presjeci za rašprsenje elektrona atomima iterbija

Electron scattering by ytterbium atom is studied at energies 10, 20, 40, 60 and 80 eV, by applying a parameter-free complex optical potential. The real part of the complex optical potential includes the static potential Vst(r), the polarization potential Vpol(r) that consists of the short range correlation and long-range polarization effects and Vex(r) term consisting of electron exchange interaction which is modelled by assuming the electron charge cloud as a free electron gas. The loss of flux into the inelastic channels is included via a phenomenological absorption potential. Our results are compared with the recent experimental measurements.Proučavamo raspršenje elektrona na enegijama 10, 20, 40, 60 i 80 eV primjenom bezparametarskog kompleksnog optičkog potencijala. Realni dio optičkog potencijala uključuje statički potencijal Vst(r), polarizacijski potencijal Vpol(r) koji se sastoji od kratko-dosežnih korelacija i dugo-dosežnih polarizacijskih efekata i član Vex(r) koji se sastoji od elektronskog međudjelovanja izmjene, a izražen je pretpostavivši oblak elektronskog naboja kao slobodan elektronski plin. Gubitak toka u neelastične kanale uključuje se preko fenomenološkog apsorpcijskog potencijala. Postignuti ishodi uspoređuju se s nedavnim eksperimentalnim podacima

Ukupni (elastični i neelastični) udarni presjeci raspršenja elektrona na molekulama N2O, CF4, NO I F2

Electron impact total (elastic + inelastic) cross sections and total ionization cross sections are calculated for N2O, CF4, NO and F2 molecules from the thresholds to 5 keV. A model complex optical potential is calculated for each collision system from the corresponding molecular wave function at the Hartree-Fock level. The resulting complex optical potential, free from any adjustable parameter, is treated exactly in a variable-phase approach to calculate scattering complex phase shifts and the total cross sections. The present results are found to be consistent with the existing experimental measurements.Izračunali smo ukupne elektronske sudarne (elastične i neelastične) i ukupne ionizacijske udarne presjeke za molekule N2O, CF4, NO i F2 za energije od praga do 5 keV. Modelske kompleksne optičke potencijale smo izračunali za svaki sustav na osnovi odgovarajućih molekulskih Hartree-Fockovih valnih funkcija. Postignute optičke potencijale, bez parametara za podešavanje, primijenili smo egzaktno s promjenljivim fazama u računima kompleksnih faznih pomaka i ukupnih udarnih presjeka. Ishodi računa su u skladu s dostupnim rezultatima mjerenja

Paraconductivity of K-doped SrFe2As2 superconductor

Paraconductivity of the optimally K-doped SrFe2As2 superconductor is investigated within existing fluctuation mechanisms. The in-plane excess conductivity has been measured in high quality single crystals, with a sharp superconducting transition at Tc=35.5K and a transition width less than 0.3K. The data have been also acquired in external magnetic field up to 14T. We show that the fluctuation conductivity data in zero field and for temperatures close to Tc, can be explained within a three-dimensional Lawrence-Doniach theory, with a negligible Maki-Thompson contribution. In the presence of the magnetic field, it is shown that paraconductivity obeys the three-dimensional Ullah-Dorsey scaling law, above 2T and for H||c. The estimated upper critical field and the coherence length nicely agree with the available experimental data.Comment: 12 pages, 5 figure

UC-401 Website Hardening and Ethical Hacking

This project is to showcase a real life scenario of securing a theoretical business website on Red Hat Linux, Apache, MariaDB, and PHP hosted in a virtual machine. The project objective is for a team to research ways to secure the theoretical business website, develop and implement security policies, and perform a red/blue team exercise. This project is a way for a team to exercise ethical hacking in a closed environment to obtain experience

A Theory of Sampling for Continuous-time Metric Temporal Logic

This paper revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of Metric Temporal Logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to "flat" formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete-time, resulting in an automated partial practically-efficient discretization technique.Comment: Revised version, 43 pages