Thickness Dependent Growth of Epitaxial Iron Silicide Nanoobjects on Si (001)

Strain-induced, self-assembled iron silicide nanostructures were grown on Si(001) substrate by conventional Fe evaporation and subsequent annealing. The initial Fe thickness was in the 0.1-6.0 nm range and the annealing temperature was 850 °C. The formed phases and structures were characterized by reflection high energy electron diffraction, and scanning electron microscopy. The electrical characteristics were investigated by I-V and C-V measurements, and by DLTS. The samples show silicide nanostructure formation in the whole thickness range. The shape of the nanostructures varied from rod like to triangular and quadratic depending on the initial Fe thickness. The size distribution of the formed iron silicide nanoobjects was not homogeneous, but they were oriented in square directions on Si(001). Higher thickness resulted in increased particles size. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3518

R&D results on a CsI-TTGEM based photodetector

The very high momentum particle identification detector proposed for the ALICE upgrade is a focusing RICH using a C4F10 gaseous radiator. For the detection of Cherenkov photons, one of the options currently under investigation is to use a CsI coated Triple-Thick-GEM (CsI-TTGEM) with metallic or resistive electrodes. We will present results from the laboratory studies as well as preliminary results of beam tests of a RICH detector prototype consisting of a CaF2 radiator coupled to a 10x10 cm2 CsI-TTGEM equipped with a pad readout and GASSIPLEX-based front-end electronics. With such a prototype the detection of Cherenkov photons simultaneously with minimum ionizing particles has been achieved for the first time in a stable operation mode

Electronic Transport in the Oxygen Deficient Ferromagnetic Semiconducting TiO2−δ_{2-\delta}

TiO$_{2-\delta}$ films were deposited on (100) Lanthanum aluminates LaAlO$_{3}$ substrates at a very low oxygen chamber pressure $P\approx 0.3$ mtorr employing a pulsed laser ablation deposition technique. In previous work, it was established that the oxygen deficiency in these films induced ferromagnetism. In this work it is demonstrated that this same oxygen deficiency also gives rise to semiconductor titanium ion impurity donor energy levels. Transport resistivity measurements in thin films of TiO$_{2-\delta}$ are presented as a function of temperature and magnetic field. Magneto- and Hall- resistivity is explained in terms of electronic excitations from the titanium ion donor levels into the conduction band.Comment: RevTeX4, Four pages, Four Figures in ^.eps forma

Sampling, Intervention, Prediction, Aggregation: A Generalized Framework for Model-Agnostic Interpretations

Model-agnostic interpretation techniques allow us to explain the behavior of any predictive model. Due to different notations and terminology, it is difficult to see how they are related. A unified view on these methods has been missing. We present the generalized SIPA (sampling, intervention, prediction, aggregation) framework of work stages for model-agnostic interpretations and demonstrate how several prominent methods for feature effects can be embedded into the proposed framework. Furthermore, we extend the framework to feature importance computations by pointing out how variance-based and performance-based importance measures are based on the same work stages. The SIPA framework reduces the diverse set of model-agnostic techniques to a single methodology and establishes a common terminology to discuss them in future work

Communications Biophysics

Contains reports on three research projects.United States Air Force (Contract AF19(604)-4112

Heavy Flavor Probes of Quark Matter

A brief survey of the role of heavy flavors as a probe of the state of matter produced by high energy heavy ion collisions is presented. Specific examples include energy loss, initial state gluon saturation, thermalization and flow. The formation of quarkonium bound states from interactions in which multiple heavy quark-antiquark pairs are initially produced is examined in general. Results from statistical hadronization and kinetic models are summarized. New predictions from the kinetic model for J/Psi at RHIC are presented.Comment: Based on invited plenary talk at Strange Quark Matter 2004, Cape Town, South Africa, September 15-20, 2004, references completed, published in J. Phys. G: Nucl. Part. Phys. 31 (2005) S641-S64

Plant roots steer resilience to perturbation of river floodplains

Freshwater ecosystems along river floodplains host among the greatest biodiversity on Earth and are known to respond to anthropic pressure. For water impounded systems, resilience to changes in the natural flow regime is believed to be bi-directional. Whether such resilience prevents the system from returning to pristine conditions after the flow regime changes reverse is as yet unclear, though widely documented. In this work we show that temporal irreversibility of river floodplains to recover their status may be explained by the dynamics of riparian water-tolerant plant roots. Our model is a quantitative tool that will benefit scientists and practitioners in predicting the impact of changing flow regimes on long-term river floodplain dynamics

Relativistic Viscous Fluid Dynamics and Non-Equilibrium Entropy

Fluid dynamics corresponds to the dynamics of a substance in the long wavelength limit. Writing down all terms in a gradient (long wavelength) expansion up to second order for a relativistic system at vanishing charge density, one obtains the most general (causal) equations of motion for a fluid in the presence of shear and bulk viscosity, as well as the structure of the non-equilibrium entropy current. Requiring positivity of the divergence of the non-equilibrium entropy current relates some of its coefficients to those entering the equations of motion. I comment on possible applications of these results for conformal and non-conformal fluids.Comment: 25 pages, no figures; v2: matches published versio