Semi-Empirical Technique for Computation of Glass Density

We present a semi-empirical technique for computation of glass density based on the enthalpy landscape approach. The technique incorporates thermal history and entropy effects into a scaling factor, which is determined using a computed enthalpy versus volume curve and a single experimental density value. We demonstrate the technique on a series of calcium aluminosilicate glasses.     

Carlo DTS: A Monte Carlo code for the dual thin scintillator neutron detector

A Monte Carlo code called CARLO DTS, developed for the efficiency and proton recoil spectra calculation of the Dual Thin Scintillator (DTS) neutron detector is described. The code CARLO DTS covers the neutron energy range between 1 and 20 MeV. The cross sections and angular distributions were taken from the ENDF/B-V data file for the nuclear reactions involved: H(n.n)H, C(n,n)C and inelastic scattering, (n,), (n,n′)3 reactions on carbon-12. The theoretical calculations are compared to experimental results at two neutron energies, namely:2.446 and 14.04 MeV, obtained by means of the Time Correlated Associated Particle Technique.     

Modeling secondary electron images for linewidth measurement by critical dimension scanning electron microscopy

Modeling of critical dimensions scanning electron microscopy with sub-nanometer uncertainty is required to provide a metrics and to avoid yield loss in the processing of advanced CMOS technologies. In this paper, a new approach is proposed, which includes a new Monte Carlo scheme, a new Monte Carlo code, as well as the coupling with electrostatic fields to take into account self-charging effects.     

Glassy models for granular systems

We briefly review some simple lattice models, introduced recently to study granular systems based on the similarities with glassy systems. The basic common ingredient, partially responsible for the complex behavior shown, is geometric frustration due to steric hindrance. Received: 30 March 2000     

Assessment of the Analytical Capabilities of Scanning Capacitance and Scanning Spreading Resistance Microscopy Applied to Semiconductor Devices

In this work we compare the performance of Scanning Capacitance Microscopy and Scanning Spreading Resistance Microscopy for the characterization of doping profiles in semiconductor devices. Particular attention is devoted to parameters of paramount importance for the failure analysis and the characterization of silicon devices, like the quantitative one-dimensional profiling accuracy, the electrical junction delineation and the two-dimensional sub-micron imaging capability.     

Isotopic Effect on the Kinetics of the Belousov-Zhabotinsky Reaction

In this work we present results about the deuterium isotope effect on the global kinetics of a Belousov-Zhabotinsky reaction in batch conditions. A nonlinear dependence of the Induction Period upon the percentage of deuterated reactants was found. The isotopic effect on the bromination reaction of malonic acid was evaluated.     

Through a Glass,Darkly: Dispelling Three Common Misconceptions in Glass Science

The field of glass science is at a critical juncture. With many recent advances in theoretical glass physics, computational capabilities, and processing and characterization technology, there has surely never been a more exciting time to be a glass scientist. However, much of our current glass science education focuses on concepts that have been rejected based on a combination of rigorous theory and experimental observations. In this article, I review three common misconceptions often taught in glass science curricula, viz., the Kauzmann paradox, the divergence of supercooled liquid dynamics, and the notion of residual entropy. In each case, there is now ample experimental and theoretical evidence disproving these concepts. These topics are misleading and confusing to students in the field, and I argue that a better use of the students’ time would be to focus on building a rigorous foundation in the underlying physics, chemistry, and mathematics of glass. Such a rigorous foundation is necessary for students to be successful in the high-technology jobs of the future and to discover the next great advances in glass science and technology.     

Interaction of the σ2 Receptor Ligand PB28 with the Human Nucleosome: Computational and Experimental Probes of Interaction with the H2A/H2B Dimer

Sigma‐2 (σ₂) binding sites are an emerging target for anti‐neoplastic agents due to the strong apoptotic effect exhibited by σ₂ agonists in vitro and the overexpression of these sites in tumor cells. Nonetheless, no σ₂ receptor protein has been identified. Affinity chromatography using the high‐affinity σ₂ ligand PB28 and human SK‐N‐SH neuroblastoma cells was previously utilized to identify σ₂ ligand binding proteins, specifically histones H1, H2A, H2B, and H3.3a. To rationalize this finding, homology modeling and automated docking studies were employed to probe intermolecular interactions between PB28 and human nucleosomal proteins. These studies predicted interaction of PB28 with the H2A/H2B dimer at a series of sites previously found to be implicated in chromatin compaction and nucleosomal assembly. To experimentally verify this prediction, a competitive binding assay was performed on the reconstituted H2A/H2B dimer using [³H]PB28 as radioligand, and an IC₅₀ value of 0.50 nM was determined for PB28 binding. In addition, [³H]PB28 was found to accumulate with up to a fivefold excess in nuclear fractions over cytosolic fractions of SK‐N‐SH and MCF7 cells, indicating that PB28 is capable of entering the nucleus to interact with histone proteins. In conjunction with computational results, these data suggest that PB28 may exert its cytotoxic effect through direct interaction with nuclear material.