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New modes of everyday communication--textual, visual, audio and video--are already part of almost every high school and college student's social life. Can such social networking principles be effective in an educational setting? In this article, the author describes how the students at his school, Rhode Island School of Design (RISD), are provided with opportunities to share their work through a new generation of Web 2.0 solutions that are easier to use, more engaging, and have an increasing impact upon collaboration and communication in the classroom than complex technologies of the past. Technologies adopted in schools today, including blogs, wikis, social networking, and online learning communities, are keeping teachers and students connected in and out of class. They are creating opportunities for groups to share, collaborate, showcase and grow together. In addition, they allow exchange of information and ideas not only within the confines of a classroom, but across schools, districts, states and the world.

Oil spill forensic investigations are often challenging due to many confounding variables such as sample weathering, oil composition complexities, and the quality or quantity of collected materials, but the difficulty is further compounded when dealing with mixed oils. In this case, well-established oil fingerprinting techniques become inadequate, including gas chromatography-flame ionization detection (GC/FID) and gas chromatography-mass spectrometry (GC/MS) diagnostic ratio analysis. In dealing with mixtures of highly refined lubricating (lube) oils, GC/FID analysis often yields inconclusive results, while diagnostic ratio analysis can be compromised by missing or low response biomarker compounds. The present study explored the feasibility of addressing the challenges of mixed lube oil analysis through a multi-tiered analytical approach. This analysis supplemented traditional GC/FID and GC/MS diagnostic ratio analyses with multivariate statistics to rapidly screen large data sets. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) proved to be effective and intuitive qualitative methods for visualizing, differentiating, and characterizing four highly similar lube oil mixtures. Non-linear mixing patterns that were significant in the diagnostic ratio analysis were far less evident through LDA. Overall, these findings lay the groundwork for promising future study involving multivariate statistical approaches to complex mixed oil forensic cases. [ABSTRACT FROM AUTHOR]

Observations made for the analysis of the oil spill dispersant tracer dioctyl sulfosuccinate (DOSS) during LC50 toxicity testing, highlighted a stability issue for this tracer compound in seawater. A liquid chromatography high-resolution quadrupole time-of-flight mass spectrometry (LC/QToF) was used to confirm monooctyl sulfosuccinate (MOSS) as the only significant DOSS breakdown product, and not the related isomer, 4-(2-ethylhexyl) 2-sulfobutanedioate. Combined analysis of DOSS and MOSS was shown to be applicable to monitoring of spill dispersants Corexit® EC9500A, Finasol OSR52, Slickgone NS, and Slickgone EW. The unassisted conversion of DOSS to MOSS occurred in all four oil spill dispersants solubilized in seawater, although differences were noted in the rate of MOSS formation. A marine microcosm study of Corexit EC9500A, the formulation most rapid to form MOSS, provided further evidence of the stoichiometric conversion of DOSS to MOSS under conditions relevant to real world dilbit spill. Results supported combined DOSS and MOSS analysis for the monitoring of spill dispersant in a marine environment, with a significant extension of sample collection time by 10 days or longer in cooler conditions. Implications of the unassisted formation of MOSS and combined DOSS:MOSS analysis are discussed in relation to improving dispersant LC50 toxicity studies. [ABSTRACT FROM AUTHOR]

A saponification extraction method with gas chromatography pseudo-MRM (pMRM) mass spectrometry detection was developed for the determination of 50 total polycyclic aromatic hydrocarbons (TPAH50, a combination of parent and alkylated homologues) in biota. The method was aimed at monitoring and identification of potential TPAH contaminants in bitumen impacted environments. Alkylated PAHs were determined by multi-level, quantitative calibration using parent PAHs. The developed and thoroughly validated method required only one injection for TPAH50 analysis which represents significant saving of time and expensive authentic alkylated standards. The current method was tested with certified reference mussel tissue NIST 1974c and performed well. In a comparison study, the method reached a limit of quantitation (LOQ) for the TPAH50 between 0.1 and 0.2 ng g−1, while the QuEChERs enhanced matrix removal – lipid (EMR) kit produced by Agilent showed an LOQ of 5–10 ng g−1. The current method relied on response factors (RF) for the quantitation of alkylated PAHs determined against parent PAHs. These RFs were shown to be stable and consistent over the course of 1 year, during which over 200 routine environmental biota monitoring samples were analyzed. The environmental biota monitoring samples analyzed include muscle, carcass and liver, with an average total PAH50 concentration of 13, 90 and 135 ng g−1, respectively. Results show significant differences in the distributions of 1 ringed, 2 ringed, 3 ringed, 4 ringed, and 5+ ringed TPAHs between the types of biota samples. [ABSTRACT FROM AUTHOR]

Time-driven and event-driven control models are two fundamental design paradigms applied in distributed control systems for synchronizing decentralized activities. This paper proposes a unified architecture for combining both approaches. The combination offers the best of both worlds’ properties, such as the expressiveness of event-driven programming and the determinism of time-driven logic. The foundations of this symbiosis are the IEC 61499 Function Block standard providing event-driven distributed control architecture and the IEEE 1588 Precision Time Protocol establishing the basis for highly-accurate time synchronization. The proposed time-complemented event-driven distributed control model aims at improving the modularity and flexibility of automation software with satisfactory control performance. The new control model has been compared with conventional centralized and distributed control approaches analytically and by simulation. The comparison results reveal that the proposed control model is efficient and flexible. Finally, a reference example has been used to demonstrate merits of the new approach. [ABSTRACT FROM AUTHOR]

This paper presents a novel model-driven software architecture for systems with high degree of redundancy and modularity of the equipment. The architecture is based on totally decentralized control. It combines adaptability and robustness of multi-agent control architectures with portability and interoperability benefits of IEC 61499 function block architecture. The architecture has been successfully proven feasible on a number of field trials, including modeling and implementation of a medium-scale airport baggage handling control. Deployment was done on distributed networks consisting of configurations ranging from a few to dozens of communicating control nodes. The work confirmed the ability to deliver similar functional characteristics as centralized systems but in a distributed implementation. Performance testing and development verified sufficient performance and software life-cycle benefits. [ABSTRACT FROM PUBLISHER]

Sulfur anions and their derivatives have long been recognized for their high selectivity and reactivity toward Pb2+ ions and formation of highly absorptive yet water-insoluble compounds with both acid and base media. This phenomenon has been used for qualitative analysis of lead ions in water. We demonstrate a new method to quantitatively determine the Pb2+ concentration in the range of 0.5-500 ppm in water using colorimetric measurement, based on forming "soluble" lead sulfide in water enhanced with non-precious-metal nanoparticles. This method has inherent high selectivity for lead over other alkali-metal and alkaline-earth-metal ions. The colorimetric measurements of the absorptive solutions provide accurate determination of the lead concentration in water comparable to that measured using inductively coupled plasma mass spectrometry. To our knowledge, this is the simplest, lowest cost, and easiest-to-use method for detecting and determining the lead concentration in water. [ABSTRACT FROM AUTHOR]

• Unassisted stoichiometric degradation of DOSS to monooctyl sulfosuccinate 2 (MOSS). • LC/QToF method for DOSS and MOSS as dual tracers for oil spill dispersant. • Dispersant plus dilbit in seawater microcosm study of DOSS conversion to MOSS. • Extension of environmental seawater sample collection time. A high resolution mass spectrometry method was developed for the environmental impact monitoring of oil spill dispersants. Previously reported instability of dioctyl sulfosuccinate (DOSS) dispersant tracer was addressed by the new procedure. The method monitors both DOSS and its degradation product, monooctyl sulfosuccinate (MOSS), by liquid chromatography time-of-flight mass spectrometry. The related isomer, 4-(2-ethylhexyl) 2-sulfobutanedioate, was chromatographically resolved from MOSS but was not a product of DOSS degradation. Using this direct injection method (10 μL), the practical lower limit of quantitation was 0.5 nM for each analyte, a concentration equivalent to 0.22 ng mL−1, or 0.30 ng mL−1 including initial dilution factor with acetonitrile. The method was shown applicable to analysis of the dispersants Corexit® EC9500 A, Finasol OSR 52, Slickgone NS, and Slickgone EW for which DOSS is an active ingredient. A marine microcosm study of Corexit EC9500A, together with diluted bitumen (dilbit), at 15 ± 1 °C, provided evidence of the stoichiometric conversion of DOSS to MOSS under conditions reflecting a western Canadian marine environment. The advantage of the developed method is in its ability to extend environmental seawater sample collection time from 4 days for DOSS alone, to 14 days when both DOSS and MOSS are simultaneously analysed and results combined. The collection time is likely extended beyond the 14 day period with cooler temperatures. Preservation of collected seawater samples using sodium hydroxide, converting DOSS into MOSS in situ , was rejected due to stability issues. Addition of disodium ethylenediaminetetraacetic acid did not improve hold times, thus eliminating the theory of cation induced micelle effects causing DOSS loss. [ABSTRACT FROM AUTHOR]

Sulfur anions and their derivatives have long been recognized for their high selectivity and reactivity toward Pb(2+) ions and formation of highly absorptive yet water-insoluble compounds with both acid and base media. This phenomenon has been used for qualitative analysis of lead ions in water. We demonstrate a new method to quantitatively determine the Pb(2+) concentration in the range of 0.5-500 ppm in water using colorimetric measurement, based on forming "soluble" lead sulfide in water enhanced with non-precious-metal nanoparticles. This method has inherent high selectivity for lead over other alkali-metal and alkaline-earth-metal ions. The colorimetric measurements of the absorptive solutions provide accurate determination of the lead concentration in water comparable to that measured using inductively coupled plasma mass spectrometry. To our knowledge, this is the simplest, lowest cost, and easiest-to-use method for detecting and determining the lead concentration in water.