The Glass Ceiling and Persons With Disabilities

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Characterization of mineral dust emitted from an actively retreating glacier in Yukon, Canada

La poussière minérale atmosphérique émise dans les régions arctiques peut modifier de manière significative le bilan énergétique de l'atmosphère nordique en diffusant et en absorbant la radiation. La poussière joue également un rôle important dans le cycle biogéochimique des métaux et peut avoir des effets négatifs sur la qualité de l'air et la santé publique. L'impact des sources de poussière du Nord sur l'atmosphère et l'environnement peut changer rapidement, car le réchauffement du climat dans le Nord peut augmenter la production de poussière minérale et peut affecter les régions d'origine. Cependant, à l'heure actuelle, l'impact de ces changements est difficile à évaluer, car très peu d'études scientifiques effectuent des mesures directes des émissions de poussières minérales ainsi que des propriétés chimiques et microphysiques des poussières minérales dans les régions arctiques. Pour combler cette lacune, nous avons fait des mesures de la poussière minérale en juin 2017 et en mai 2018 près de l'Ä’äy Chù (rivière Slims), dans une vallée proglaciale du Yukon, qui est un site important des émissions de la poussière. Le changement climatique a eu de lourdes conséquences sur la vallée d'Ä'äy Chù. Le retrait rapide du glacier Kaskawulsh laissant le lit de la rivière exposé augmentant ainsi potentiellement sa surface érodable qui peut produire de la poussière. Nous avons collecté des échantillons d’aérosols (PM10 et poussières minérales déposées) dans toute la vallée Ä’äy Chù et avons enregistré des données météorologiques afin d’établir un lien entre des facteurs environnementaux et l’émission de poussières. Nous avons également utilisé une méthode quantitative pour analyser les métaux traces dans les poussières minérales par spectrométrie de masse à plasma à couplage inductif (ICP-MS) afin de quantifier les métaux traces dans les échantillons de PM10, du sol et de poussières minérales déposées. Notre étude est la première à mener une caractérisation chimique et microphysique des poussières minérales émises directement par une source de poussière de haute latitude au Canada. L'analyse des données obtenues par un compteur de particules optiques (OPC) a indiqué à quelle heure des événements de poussière se sont produits pendant la journée, tandis qu'une analyse gravimétrique d'échantillons de filtres a montré des concentrations ambiantes entre 240 µg / m³ et 3 950 µg / m³ à la source des poussières. En outre, les seuils de qualité de l’air de l’Organisation de la Santé Mondial (OSM) ont été dépassés aux sites proches de la source de poussière, notamment au centre des visiteurs Thachäl Dhäl géré par Parcs Canada et à un site situé à proximité de la route de l’Alaska. Nous n'avons pas réussi à analyser nos échantillons en utilisant l'ablation au laser ICP-MS et l'ICP-MS à particule unique. Néanmoins, nous avons validé avec succès un protocole d'analyse ICP-MS d'échantillons digérés et avons ainsi pu appliquer cette technique à l'analyse de nos échantillons. L’analyse de la composition élémentaire par ICP-MS a révélé l’enrichissement en échantillons de PM10 de la composition des éléments mineurs et des éléments traces par rapport aux sols, généralement par un facteur de 1,5 à 2. De plus, une analyse SEM / EDS a démontré que les poussières émises se composent principalement de particules non sphériques composées d'agrégats minéraux d'argile aluminosilicate. Enfin, nous avons calculé le flux vertical de masse de particules, et nous avons utilisés le flux, la distribution de taille et la composition du PM10 afin d’évaluer plusieurs théories relatives au mécanisme prédominant d'émission de poussière qui se produit dans la vallée d'Ä'äy Chù.Airborne mineral dust emitted in Arctic regions can significantly alter the energy balance of the Northern atmosphere through scattering and absorption of radiation; dust also plays an important role in the biogeochemical cycling of metals and can have deleterious effects on air quality and public health. The impact of northern dust sources on the atmosphere and environment may change rapidly, as warming temperatures in the North can increase mineral dust production and source regions by inducing topographical changes due to rapid glacier ablation. However, at present, the impact of such changes is difficult to evaluate because there are very few scientific studies that perform direct field measurements of mineral dust emissions as well as of mineral dust chemical and microphysical properties in Arctic regions. To address this knowledge gap, we performed mineral dust measurement campaigns in June 2017 and May 2018 near the Ä’äy Chù (Slims River), within a proglacial valley in Yukon, Canada that has exhibited strong dust emissions. The Ä’äy Chù Valley has been impacted heavily by climate change, as the rapid retreat of the adjacent Kaskawulsh glacier, recently routed waters away from the river valley, leaving the riverbed exposed and thus potentially increasing its dust-producing erodible surface area. We have collected aerosol samples (PM10 and deposited mineral dust) throughout the Ä’äy Chù Valley, and have recorded weather data to establish a link between environmental factors and the emission of dust. We have also employed an efficient, quantitative method for analysis of trace metals in mineral dust via inductively coupled plasma mass spectrometry (ICP-MS) to quantify trace metals in PM10 samples, soil and in deposited mineral dust samples. Ours is the first field campaign to provide chemical and microphysical characterization of mineral dust emitted directly from a high-latitude dust source in Canada. Analysis of data obtained by an optical particle counter (OPC) indicated dust events occurred during both daylight and non-daylight hours, while gravimetric analysis of filter samples found ambient concentrations ranging between 240 µg/m3 and 3950 µg/m3 at the dust source during the course of the dust observation campaign. Furthermore, air quality thresholds of the World Health Organization (WHO) were exceeded at sites near the dust source, including at the Thachäl Dhäl Visitor’s Center run by Parks Canada and a site next to the Alaska Highway. We were unable to successfully analyze our samples using laser ablation ICP-MS and single particle ICP-MS. Nevertheless, we successfully validated a protocol for performing ICP-MS analysis of digested samples and were thus able to apply this technique to the analysis of our samples. Analysis of elemental composition via ICP-MS has revealed enrichment of minor and trace element content in ambient air samples as compared to soils and dust deposition, generally by a factor of 1.5 to 2. Moreover, SEM/EDS analysis has demonstrated that the emitted dust primarily consists of non-spherical particles composed of aluminosilicate clay mineral aggregates. Finally, we have calculated the vertical flux of particulate mass, and have used the flux, the size distribution, and the composition of both PM10 and soil samples to evaluate several theories related to the predominant dust emission mechanism that occurs in the Ä’äy Chù Valley

Strobe Traffic Lights Warn of Approaching Emergency Vehicles

Strobe-enhanced traffic signals have been developed to aid in the preemption of road intersections for emergency vehicles. The strobe-enhanced traffic signals can be incorporated into both new and pre-existing traffic-control systems in which the traffic-signal heads are of a relatively new type based on arrays of light-emitting diodes (LEDs). The strobe-enhanced traffic signals offer a less expensive, less complex alternative to a recently developed system of LED-based warning signs placed next to traffic signals. Because of its visual complexity, the combination of traffic signals and warning signs is potentially confusing to motorists. The strobe-enhanced traffic signals present less visual clutter. In a given traffic-signal head, the strobe-enhanced traffic signal is embedded in the red LED array of the stop signal. Two strobe LED strips one horizontal and one vertical are made capable of operating separately from the rest of the red LED matrix. When no emergency vehicle is approaching, the red LED array functions as a normal stop signal: all the red LEDs are turned on and off together. When the intersection is to be preempted for an approaching emergency vehicle, only the LEDs in one of the strobe strips are lit, and are turned on in a sequence that indicates the direction of approach. For example (see figure), if an emergency vehicle approaches from the right, the strobe LEDs are lit in a sequence moving from right to left. Important to the success of strobe-enhanced traffic signals is conformance to city ordinances and close relation to pre-existing traffic standards. For instance, one key restriction is that new icons must not include arrows, so that motorists will not confuse new icons with conventional arrows that indicate allowed directions of movement. It is also critical that new displays like strobe-enhanced traffic signals be similar to displays used in traffic-control systems in large cities. For example, Charleston, South Carolina uses horizontal strobes on red traffic lights to alert motorists and thereby help motorists not to miss red lights. The one significant potential disadvantage of strobe-enhanced traffic lights is initial unfamiliarity on the part of motorists

Roadside-based communication system and method

A roadside-based communication system providing backup communication between emergency mobile units and emergency command centers. In the event of failure of a primary communication, the mobile units transmit wireless messages to nearby roadside controllers that may take the form of intersection controllers. The intersection controllers receive the wireless messages, convert the messages into standard digital streams, and transmit the digital streams along a citywide network to a destination intersection or command center

Cellular-based preemption system

A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications

Hybrid Aerial/Rover Vehicle

A proposed instrumented robotic vehicle called an "aerover" would fly, roll along the ground, and/or float on bodies of liquid, as needed. The aerover would combine features of an aerobot (a robotic lighter-than-air balloon) and a wheeled robot of the "rover" class. An aerover would also look very much like a variant of the "beach-ball" rovers. Although the aerover was conceived for use in scientific exploration of Titan (the largest moon of the planet Saturn), the aerover concept could readily be adapted to similar uses on Earth