Buth J.M.,University of Minnesota |
Steen P.O.,University of Minnesota |
Sueper C.,Pace Inc |
Blumentritt D.,St. Croix Research |
And 4 more authors.
Environmental Science and Technology | Year: 2010
Triclosan, a widely used antimicrobial, is known to undergo phototransformation in aqueous solution to form 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD). Two sediment cores from a wastewater-impacted depositional zone of the Mississippi River were analyzed for triclosan by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS-Q3) and for a suite of polychlorinated dioxins and furans by high resolution gas chromatography-mass spectrometry (HRGC-MS) to provide evidence of this photoreaction in the environment. 2,8-DCDD was detected at levels that trended with the historical use of triclosan since its introduction in the 1960s. Three other dioxin congeners, 2,3,7-TCDD, 1,2,8-TriCDD, and 1,2,3,8-TCDD, which are known photoproducts of chlorinated derivatives of triclosan, were also detected with similar trend profiles. These four congeners comprised the majority of di- through tetra-chlorinated dioxins. The trend profile of these specific dioxin congeners did not correlate with the trend profile of the higher-chlorinated dioxin homologues or any chlorinated furan homologues, suggesting a unique source. These results are fully consistent with the phototransformation of triclosan and its chlorinated derivatives that form during wastewater chlorine disinfection as the source of 2,8-DCDD, 2,3,7-TriCDD, 1,2,8-TriCDD, and 1,2,3,8-TCDD in this aquatic environment. As the levels of triclosan-derived dioxins increased over time and the total level of chlorinated dioxins decreased, the contribution of triclosan-derived dioxins to the total dioxin pool increased to as high as 31% by mass in recent years, indicating that their contribution to total dioxin toxicity may need consideration. © 2010 American Chemical Society.
Turner C.S.,Pace Inc
IEEE Signal Processing Magazine | Year: 2010
This article presents a computationally fast algorithm for computing logarithms. The algorithm is particularly well suited for implementation using fixed-point processors. © 2010 IEEE.
Anger C.T.,University of Minnesota |
Sueper C.,Pace Inc |
Blumentritt D.J.,University of Minnesota |
McNeill K.,ETH Zurich |
And 2 more authors.
Environmental Science and Technology | Year: 2013
When discharged into surface waters via wastewater effluents, triclosan, the antimicrobial agent in handsoaps, and chlorinated triclosan derivatives (CTDs, formed during disinfection with chlorine) react photochemically to form polychlorinated dibenzo-p-dioxins. To evaluate the historical exposure of waters to these compounds, the levels of triclosan, CTDs, and their derived dioxins were determined in sediment cores collected from wastewater-impacted Minnesota lakes. The accumulation rates and temporal trends of triclosan, CTDs, and dioxins in aquatic sediments were found to be a function of historical wastewater treatment operations and lake system scale. Cores collected from large-scale riverine systems with many wastewater sources recorded increasing concentrations of triclosan, CTDs, and their derived dioxins since the patent of triclosan in 1964. In small-scale lakes with a single wastewater source, the trends were directly attributed to increased triclosan use, local improvements in treatment, and changes in wastewater disinfection since the 1960s. In the lake with no wastewater input, no triclosan or CTDs were detected. Overall, concentrations of triclosan, CTDs, and their dioxins were higher in small-scale systems, reflecting a greater degree of wastewater impact. In cores collected in northern MN, the four dioxins derived from triclosan are present prior to the patent of triclosan, suggesting a secondary source. It is clear, however, that triclosan and CTDs are the dominant source of these congeners after 1965 in systems impacted by wastewater. © 2013 American Chemical Society.
Pace Inc | Date: 2013-10-23
Protective covers and cases for handheld electronic devices, namely, cell phones, portable media players, tablets, personal digital assistants, e-book readers, and computers; protective covers and cases for computers; Peripherals and accessories, namely, Carrying cases, holders, protective cases and stands featuring power supply connectors, adaptors, speakers and battery charging devices, specially adapted for use with handheld digital electronic devices, namely, for computers, laptops, mobile phones, mp3 players, smartphones, tablet computers, notebook computers, and network connection devices; electrical and electronic cabling, connectors, connectivity products and wireless transmission and networking products, namely, connection cables and wireless routers; battery charging and electrical power management devices for computers and home appliance, namely, battery chargers; Video and audio accessories, namely, signal splitters, couplers, and cable connectors; audio and video electricity distribution power consoles; audio and video power and signal filters; electronic switching consoles; signal boosters; computer network hubs, routers and switches; electrical and electronic connectors; connection cables; electronic cables; power wires; telephone wires; digital transmission wires and cables; electrical and electronic plugs; converters; TV and video converters; cable adapters and switches; video transmitters, receivers for audio and video and remote controllers for radios, televisions, stereos; modular electrical, electronic and telephone plugs; coaxial cable, cable adapter plugs; cable splitters; cable connectors; electronic switches; electrical switches; surge protectors; computer cables; computer cable plugs and connectors; electrical voltage suppressors; ribbon extension cables; computer cooling fans; television/computer switches; modems and modem connectors, hubs and adaptors; audio/stereo accessories, namely, stereo cables; headphones; headphone extension cables. stereo plugs and adapters; stereo/mono adapter cables; stereo headphone cords; alternating current adapters; direct current adapters; audio cables; speaker wires and speaker cables; electricity converters and plugs; data transfer switch boxes, computer peripheral sharing devices for enabling a plurality of computers to have shared access to an accessory device or devices such as a printer; computer peripheral sharing devices for enabling a single computer to simultaneously display output on multiple monitors; electrical surge protectors; mouse pads; computer wrist rests; computer mouse wrist rests; computer peripheral devices for permitting wireless transmission of data from computers to peripheral devices and from computer to computer; carrying cases for storing and transporting portable computers and personal data assistants; PCI hardware cards; network interface cards; USB and Ethernet adapters, connectors, controllers, switches, cables and plugs; extension cords; extension cables; mobile power cords; mobile phone and cell phone cases; keyboards; keypads; plug adapters; plug connectors; plug-in connectors; power controllers; power switches; power line transmission machines and apparatus; printer cables; printer hubs; racks and enclosures for computer hardware, computer game mouse; rechargers for portable digital listening devices, portable media players, computers, laptops, cellular phones and mobile phones; wireless transmitters and computer peripherals; uninterruptible power supplies; radio frequency transmitters; telecommunications transmitters; telephone headsets; television transmitters; USB operating software; video transmission apparatus; voltage regulators; voltage stabilizers; voltage stabilizing power supplies; wireless telephony apparatus; wrist rests for use with computers; cables and fibers for the transmission of sounds and images; cables for electrical or optical signal transmission; card reading equipment. computer cursor control devices, namely, computer mouse; converters; computer peripherals; computer networking hubs and switches; computer hardware; computer cases; computer stands; e-reader cases; bags adapted for laptops; Protective sleeves for laptop computers.
Pace Inc | Date: 2016-05-03
Downloadable mobile applications for tracking on-demand service rate of performance on golf courses and alerting users of the rate of performance; and for tracking golfers rates of performance and alerting golfers of their rate of performance.