103 research outputs found
Exploring Computer Science: Coding Can Be Fun
The focus of this project is to adopt a course/curriculum that builds interest in computer science and appeals to high school students through a variety of programs and activities. One of our goals is to increase interest in computer science among high school students especially minority and female students. Students will learn how to use programming languages, utilize higher level problem solving and program robots using the skills they acquired. The course, Exploring Computer Science, gives students the opportunity to learn a variety of computer science topics and have fun doing it
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Physical Properties Models for Simulation of Processes to Treat INEEL Tank Farm Waste: Thermodynamic Equilibrium
A status is presented of the development during FY2002 of a database for physical properties models for the simulation of the treatment of Sodium-Bearing Waste (SBW) at the Idaho National Engineering and Environmental Laboratory. An activity coefficient model is needed for concentrated, aqueous, multi-electrolyte solutions that can be used by process design practitioners. Reasonable first-order estimates of activity coefficients in the relevant media are needed rather than an incremental improvement in theoretical approaches which are not usable by practitioners. A comparison of the Electrolyte Non-Random Two-Liquid (ENRTL) and Pitzer ion-interaction models for the thermodynamic representation of SBW is presented. It is concluded that Pitzer's model is superior to ENRTL in modeling treatment processes for SBW. The applicability of the Pitzer treatment to high concentrations of pertinent species and to the determination of solubilities and chemical equilibria is addressed. Alternate values of Pitzer parameters for HCl, H2SO4, and HNO3 are proposed, applicable up to 16m, and 12m, respectively. Partial validation of the implementation of Pitzer's treatment within the commercial process simulator ASPEN Plus was performed
ACMiner: Extraction and Analysis of Authorization Checks in Android's Middleware
Billions of users rely on the security of the Android platform to protect
phones, tablets, and many different types of consumer electronics. While
Android's permission model is well studied, the enforcement of the protection
policy has received relatively little attention. Much of this enforcement is
spread across system services, taking the form of hard-coded checks within
their implementations. In this paper, we propose Authorization Check Miner
(ACMiner), a framework for evaluating the correctness of Android's access
control enforcement through consistency analysis of authorization checks.
ACMiner combines program and text analysis techniques to generate a rich set of
authorization checks, mines the corresponding protection policy for each
service entry point, and uses association rule mining at a service granularity
to identify inconsistencies that may correspond to vulnerabilities. We used
ACMiner to study the AOSP version of Android 7.1.1 to identify 28
vulnerabilities relating to missing authorization checks. In doing so, we
demonstrate ACMiner's ability to help domain experts process thousands of
authorization checks scattered across millions of lines of code
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Simulation of High-Level Waste Treatment Process Trains at Idaho National Engineering and Environmental Laboratory
The purpose of this document is to provide the overall planning framework for the role of simulation in the integration/optimization of treatment process trains for the High Level Waste (HLW) Program at Idaho National Engineering and Environmental Laboratory (INELL). This project involves a TTP (Technical Task Plan ID77WT31, Subtask C) with Savannah River Site (SRS) to jointly develop a simulation tool set that can support flowsheet optimization for HLW treatment trains at INEEL. Despite the commonality between the simulation efforts at SRS and INEEL, the individual work scopes of the two sites are different – that of the INEEL is broader. This document concerns only the scope of the INEEL effort, and it describes the boundaries of several scope-related planning areas for this project INEEL: 1) the objective of the project – the needs (drivers) the simulation efforts are attempting to satisfy, the role simulation results will play in managerial decision making, and the type of issues to be investigated; 2) constraints – higher-level budget forecasts and schedules, legal commitments, customer directives, and other similar forces that a priori define boundary elements; 3) the process domain – the set of chemical and physical operations to be modeled; 4) the model’s life cycle – the phases of the waste treatment’s life cycle that will utilize simulation, i.e., process configuration, design, and/or operations; 5) the types of models involved in the integrated simulation tool set – discrete vs. continuous, deterministic vs. stochastic, etc.; and 6) and targeted users – the downstream activities that may potentially use the simulation results. This document closes with a description of the budget, schedule, and task inter-relationships that result from the determined scope. This document is the cornerstone of the planning process, and many of the software requirements flow directly from the decisions discussed in this document
All-organic and organic-silicon photonic ring micro-resonators
Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated
‘Off With Their Heads’: British Prime Ministers and the Power to Dismiss
The British prime minister’s power to appoint and dismiss ministers is probably his most important single power. This article explores how prime ministers from Macmillan to Blair have used that power. The article considers the criteria that prime ministers use when choosing to appoint or dismiss individuals from office before examining the calculations and miscalculations that prime ministers have made in practice. Finally, the article analyses the way that prime ministers have exercised, in particular, their power to dismiss and finds that Thatcher was far more likely than others to sack cabinet colleagues on ideological or policy grounds. The article emphasizes that prime ministers’ relationships with especially powerful ministers – ‘big beasts of the jungle’ – are crucial to an understanding of British government at the top.</jats:p
All-organic and organic-silicon photonic ring micro-resonators
Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated
Cathelicidin-like Helminth Defence Molecules (HDMs) Absence of Cytotoxic, Anti-microbial and Anti-protozoan Activities Imply a Specific Adaptation to Immune Modulation
Host defence peptides (HDPs) are expressed throughout the animal and plant kingdoms. They have multifunctional roles in the defence against infectious agents of mammals, possessing both bactericidal and immune-modulatory activities. We have identified a novel family of molecules secreted by helminth parasites (helminth defence molecules; HDMs) that exhibit similar structural and biochemical characteristics to the HDPs. Here, we have analyzed the functional activities of four HDMs derived from Schistosoma mansoni and Fasciola hepatica and compared them to human, mouse, bovine and sheep HDPs. Unlike the mammalian HDPs the helminth-derived HDMs show no antimicrobial activity and are non-cytotoxic to mammalian cells (macrophages and red blood cells). However, both the mammalian- and helminth-derived peptides suppress the activation of macrophages by microbial stimuli and alter the response of B cells to cytokine stimulation. Therefore, we hypothesise that HDMs represent a novel family of HDPs that evolved to regulate the immune responses of their mammalian hosts by retaining potent immune modulatory properties without causing deleterious cytotoxic effects. © 2013 Thivierge et al
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