Fiber optic sensors and spectrometry for the detection of volatile gem-polyhalogenated hydrocarbons

A fiber optic fluorometer utilizing a double-fiber optic probe was constructed. The absolute fluorescence signal and effective collection efficiency are approximately one fifth those of typical cuvette fluorometers and agree with those predicted by theory. A quinine sulfate calibration curve shows linearity from a detection limit of 10 pg/mL to 10 μg/mL. Single- and double-fiber probe configurations were also compared. The double-fiber configuration provided better detection limits due to its superior signal-to-background ratio. A discussion of sensor methodology for the monitoring of reaction intermediates is presented and a simple kinetic model for predicting the time dependent response of such sensors is developed. Two possible mechanisms for the Fujiwara reaction with chloroform are discussed. The effect of pyridine, water, and base concentrations on reaction kinetics was evaluated to develop single-phase Fujiwara reagent mixtures for both fluorometric and spectrophotometric determinations of chloroform. A unique "continuous-exposure" apparatus allowing vapor phase transport of chloroform from an aqueous sample to a conventional cuvette was constructed. The spectrophotometric detection limit for chloroform is 11 ng/mL and the method was shown to be suitable for the analysis of tap water. Two fiber optic chemical sensors (FOCS) for the detection of chloroform were developed. An aliquot of the optimized fluorometric reagent solution is held in contact with the fiber optic probe within a light-tight enclosure and is isolated from a bulk sample by a trapped headspace. One FOCS utilizes 1.3 mL of reagent held in a reservoir and the other utilizes a 10-μL drop of reagent suspended on the sensing tips of the fiber optic probe. Chloroform vapor from the sample migrates into the FOCS and reacts with the reagent to produce a fluorescent reaction intermediate which is monitored at 590 nm; the rate of increase in the fluorescence signal is related to chloroform concentration. Both FOCSs give detection limits better than 0.1 ng/mL. The response and total measurement times are comparable for the two FOCSs, and the duration of the linear response is limited by inner-filter effects. The response to a number of volatile GPHHCs including the trihalomethanes are reported. Analyses of tap water for chloroform with the reservoir FOCS and GC/MS were in excellent agreement

Runoff of Silvicultural Herbicides Applied Using Best Management Practices

Nine small (2.2 to 2.9 ha) and four large (70 to 135 ha) watersheds in East Texas, USA, were instrumented to compare herbicide runoff under different silvicultural systems with best management practices (BMPs). Two treatments were evaluated: conventional, with clearcutting, aerial herbicide site preparation, and hand-applied banded herbaceous release; and intensive, in which subsoiling, aerial fertilization, and a second-year aerial herbicide application were added. Herbicides were applied as operational tank mixes. The highest imazapyr concentration found in stream water was 39 mg L‑1 during the first storm after application (23 days after treatment, DAT) and in-stream concentrations during runoff events dropped to L‑1 in all streams by 150 DAT. The highest hexazinone concentration was 8 mg L‑1 for the banded application and 35 mg L‑1 for the broadcast application the following year and fell to L‑1 in all streams by 140 DAT. The highest sulfometuron methyl concentration found during a runoff event was 4 mg L‑1 and fell to L‑1 in all streams by 80 DAT. About 1 to 2% of applied imazapyr and less than 1% of hexazinone and sulfometuron methyl were measured in storm runoff. Herbicide was found in streams during storm events only (all herbicides wereµg/L in all true baseflow samples), and peak concentrations during runoff events persisted for relatively short times (\u3c 24 h). These results suggest that silvicultural herbicide applications implemented with contemporary BMPs are unlikely to result in chronic exposure of aquatic biota; therefore, herbicide use under these conditions is unlikely to degrade surface waters

Alsea watershed study revisited: unpublished temperature datasets from pre-harvest 2006 to 2010

These data contain temperature readings from dataloggers launched in Deer Creek, Flynn Creek, and Needle Branch from 2006 to 2010. These loggers were apart of the Alsea Watershed Revisisted Study Revisited articles, but the data was incomplete due to logging gaps, temperature spikes, or other issues. The "Thermistor Functionality" datasets indicate whether dataloggers launched in each stream have complete datasets or not. Despite these data not being complete, they help tell the data collection story for the Alsea Watershed Study Revisited

Information Systems Education Journal In this issue: 4. Full Flip, Half Flip and No Flip: Evaluation of Flipping an Introductory Programming Course The Relative Efficacy of Video and Text Tutorials in Online Computing Education 44. Use of Failure in IS De

The Information Systems Education Journal (ISEDJ) is a double-blind peer-reviewed academic journal published reviewed published by ISCAP, Information Systems and Computing Academic Professionals. The first year of publication was 2003. ISEDJ is published online (http://isedj.org). Our sister publication, the Proceedings of EDSIGCon (http://www.edsigcon.org) features all papers, panels, workshops, and presentations from the conference. The journal acceptance review process involves a minimum of three double-blind peer reviews, where both the reviewer is not aware of the identities of the authors and the authors are not aware of the identities of the reviewers. The initial reviews happen before the conference. At that point papers are divided into award papers (top 15%), other journal papers (top 30%), unsettled papers, and non-journal papers. The unsettled papers are subjected to a second round of blind peer review to establish whether they will be accepted to the journal or not. Those papers that are deemed of sufficient quality are accepted for publication in the ISEDJ journal. Currently the target acceptance rate for the journal is under 40%. Information Systems Education Journal is pleased to be listed in the 1st Edition of Cabell's Directory of Publishing Opportunities in Educational Technology and Library Science, in both the electronic and printed editions. Questions should be addressed to the editor at [email protected] or the publisher at [email protected]. Special thanks to members of AITP-EDSIG who perform the editorial and review processes for ISEDJ. AITP Education Special Interest Group (EDSIG) Board of Directors Abstract This paper discusses how cloud computing can be leveraged to add value to academic programs in information systems and other fields by improving financial sustainment models for institutional technology and academic departments, relieving the strain on overworked technology support resources, while adding richness and improving pedagogical delivery of course content. A literature review on cloud definitions and how cloud paradigms are being implemented in academia is conducted. The author suggests that for smaller programs and institutions, cloud hosting of applications, services and platforms in support of information systems programs may be the only financially viable solution to course technology requirements. The impact of transitioning core information systems courses to a cloud paradigm is discussed, and examples of how the transition can improve course content and delivery are provided. Finally, details are presented on how a transition to the cloud is being accomplished in the information systems program of the school of continuing studies at the author's small liberal arts university