Microscopic dynamics of supercooled liquids from first principles

Glasses are solid materials whose constituent atoms are arranged in a disordered manner. The transition from a liquid to a glass remains one of the most poorly understood phenomena in condensed matter physics, and still no fully microscopic theory exists that can describe the dynamics of supercooled liquids in a quantitative manner over all relevant time scales. Here we present such a theoretical framework that yields near-quantitative accuracy for the time-dependent correlation functions of a supercooled system over a broad density range. Our approach requires only simple static structural information as input and is based entirely based on first principles. Owing to this first-principles nature, the framework offers a unique platform to study the relation between structure and dynamics in glass-forming matter, and paves the way towards a systematically correctable and ultimately fully quantitative theory of microscopic glassy dynamics

Relaxation Patterns in Supercooled Liquids from Generalized Mode-Coupling Theory

The mode-coupling theory of the glass transition treats the dynamics of supercooled liquids in terms of two-point density correlation functions. Here we consider a generalized, hierarchical formulation of schematic mode-coupling equations in which the full basis of multipoint density correlations is taken into account. By varying the parameters that control the effective contributions of higher-order correlations, we show that infinite hierarchies can give rise to both sharp and avoided glass transitions. Moreover, small changes in the form of the coefficients result in different scaling behaviors of the structural relaxation time, providing a means to tune the fragility in glass-forming materials. This demonstrates that the infinite-order construct of generalized mode-coupling theory constitutes a powerful and unifying framework for kinetic theories of the glass transition

Kaon electromagnetic production: constraints set by new data

The CLAS data on the photo-production of K+ off the proton are utilised to study reaction mechanism of the process in frame of the isobaric approach. The missing D13 resonance is shown to be important for successful description of the data in the whole kinematical region. Constructed models provide satisfactory predictions for the process.Comment: 4 pages, 4 figures, contribution to the VIII International Conference on Hypernuclear & Strange Particle Physics, Jefferson Lab, Virginia, U.S.A., October 14-18, 200

Characterization and Verification Environment for the RD53A Pixel Readout Chip in 65 nm CMOS

The RD53 collaboration is currently designing a large scale prototype pixel readout chip in 65 nm CMOS technology for the phase 2 upgrades at the HL-LHC. The RD53A chip will be available by the end of the year 2017 and will be extensively tested to confirm if the circuit and the architecture make a solid foundation for the final pixel readout chips for the experiments at the HL-LHC. A test and data acquisition system for the RD53A chip is currently under development to perform single-chip and multi-chip module measurements. In addition, the verification of the RD53A design is performed in a dedicated simulation environment. The concept and the implementation of the test and data acquisition system and the simulation environment, which are based on a modular data acquisition and system testing framework, are presented in this work

Generalized mode-coupling theory of the glass transition: schematic results at finite and infinite order

We present an extensive treatment of the generalized mode-coupling theory (GMCT) of the glass transition, which seeks to describe the dynamics of glass-forming liquids using only static structural information as input. This theory amounts to an infinite hierarchy of coupled equations for multi-point density correlations, the lowest-order closure of which is equivalent to standard mode-coupling theory. Here we focus on simplified schematic GMCT hierarchies, which lack any explicit wavevector-dependence and therefore allow for greater analytical and numerical tractability. For one particular schematic model, we derive the unique analytic solution of the infinite hierarchy, and demonstrate that closing the hierarchy at finite order leads to uniform convergence as the closure level increases. We also show numerically that a similarly robust convergence pattern emerges for more generic schematic GMCT models, suggesting that the GMCT framework is generally convergent, even though no small parameter exists in the theory. Finally, we discuss how different effective weights on the high-order contributions ultimately control whether the transition is continuous, discontinuous, or strictly avoided, providing new means to relate structure to dynamics in glass-forming systems

A method for precise charge reconstruction with pixel detectors using binary hit information

A method is presented to precisely reconstruct charge spectra with pixel detectors using binary hit information of individual pixels. The method is independent of the charge information provided by the readout circuitry and has a resolution mainly limited by the electronic noise. It relies on the ability to change the detection threshold in small steps while counting hits from a particle source. The errors are addressed and the performance of the method is shown based on measurements with the ATLAS pixel chip FE-I4 bump bonded to a 230 {\mu}m 3D-silicon sensor. Charge spectra from radioactive sources and from electron beams are presented serving as examples. It is demonstrated that a charge resolution ({\sigma}<200 e) close to the electronic noise of the ATLAS FE-I4 pixel chip can be achieved

How Will Online Affiliate Marketing Networks Impact Search Engine Rankings?

In online affiliate marketing networks advertising web sites offer their affiliates revenues based on provided web site traffic and associated leads and sales. Advertising web sites can have a network of thousands of affiliates providing them with web site traffic through hyperlinks on their web sites. Search engines such as Google, MSN, and Yahoo, consider hyperlinks as a proof of quality and/or reliability of the linked web sites, and therefore use them to determine the relevance of web sites with regard to search queries. In this research we investigate the potential impact of online affiliate marketing networks on the ranking of advertisers’ web sites in search results. This article empirically explores how seven different affiliate marketing networks affect the rankings of the advertising web sites within web search engines. The field study followed intensively seven online affiliate marketing networks for twelve weeks after their launch. The results indicate that newly started affiliate networks effectively improve the rankings of advertising web sites in search engine results. Also, it was found that the effects of affiliate marketing networks on search engine rankings were smaller for advertising web sites operating in highly competitive markets. Another finding was that a growth in visitors coming from search engines was present as a result of the improvement of search engine rankings. Finally, the results indicate that cost-benefit metrics associated with affiliate marketing programs, such as the average marketing cost will decrease when the positive effects of affiliate marketing on search engine rankings are taken into account

Mechanisms Affecting Recruitment of Yellow Perch in Lake Michigan

Report issued on: August 2001INHS Technical Report prepared for Great Lakes Fishery Trus