Bialgebras for structural operational semantics: An introduction

Bialgebras and distributive laws are an abstract, categorical framework to study various flavors of structural operational semantics. This paper aims to introduce the reader to the basics of bialgebras for operational semantics, and to sketch the state of the art in this research area.     

Foreign-body appendicitis

The authors report the case of a 9-year-old boy who had a needle in his appendix. The contrast between absence of clinical symptoms and clear inflammatory changes of the appendix is noted. The authors recommend appendectomy for patients with pointed foreign bodies in the appendix to avoid inflammation and perforation.     

Development and Production of Array Barrier Detectors at SCD

XBn or XBp barrier detectors exhibit diffusion-limited dark currents comparable with mercury cadmium telluride Rule-07 and high quantum efficiencies. In 2011, SemiConductor Devices (SCD) introduced “HOT Pelican D”, a 640 × 512/15-μm pitch InAsSb/AlSbAs XBn mid-wave infrared (MWIR) detector with a 4.2-μm cut-off and an operating temperature of ～150 K. Its low power (～3 W), high pixel operability (>99.5%) and long mean time to failure make HOT Pelican D a highly reliable integrated detector-cooler product with a low size, weight and power. More recently, “HOT Hercules” was launched with a 1280 × 1024/15-μm format and similar advantages. A 3-megapixel, 10-μm pitch version (“HOT Blackbird”) is currently completing development. For long-wave infrared applications, SCD’s 640 × 512/15-μm pitch “Pelican-D LW” XBp type II superlattice (T2SL) detector has a ～9.3-μm cut-off wavelength. The detector contains InAs/GaSb and InAs/AlSb T2SLs, and is fabricated into focal plane array (FPA) detectors using standard production processes including hybridization to a digital silicon read-out integrated circuit (ROIC), glue underfill and substrate thinning. The ROIC has been designed so that the complete detector closely follows the interfaces of SCD’s MWIR Pelican-D detector family. The Pelican-D LW FPA has a quantum efficiency of ～50%, and operates at 77 K with a pixel operability of >99% and noise equivalent temperature difference of 13 mK at 30 Hz and F/2.7.     

Accessibility of information about goals during the processing of narrative texts.

Used a probe procedure to show that a goal established earlier in a text is active in memory at the point of its achievement. An initial experiment demonstrated that a goal category (began an investigation to nab the THIEF) is accessible, relative to a control condition, following the processing of a goal-achievement sentence (had the PURSER brought to his office). The remaining experiments provided evidence against several explanations of this result: (1) that the goal category's accessibility is due to an advantage in the strength of its initial encoding; (2) that the goal category is maintained in memory from the point at which the goal is established; or (3) that the goal category is reinstated at the point of goal achievement as the result of a high-level inference. The results suggest that the goal category is reinstated as the result of a low-level inference similar to the type that links an anaphor and its antecedent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling InAs/GaSb and InAs/InAsSb Superlattice Infrared Detectors

InAs/GaSb and InAs/InAsSb type II superlattices have been proposed as promising alternatives to HgCdTe for the photon-absorbing layer of an infrared detector. When combined with a barrier layer based on an InAs/AlSb superlattice or an AlSbAs alloy, respectively, they can be used to make diffusion-limited “barrier” detectors with very low dark currents. In this work we compare theoretical simulations with experimental bandgap and photoabsorption data for such superlattices, spanning from the mid to the long-wave infra-red (2.3–12 μm). The spectral response of detectors based on these materials is also simulated. The simulations are based on a version of the k · p model developed by one of the authors, which takes interface contributions and bandgap bowing into account. Our results provide a way of assessing the relative merits of InAs/GaSb and InAs/InAsSb superlattices as potential detector materials.