Analysis of air quality management with emphasis on transportation sources

The current environment and practices of air quality management were examined for three regions: Denver, Phoenix, and the South Coast Air Basin of California. These regions were chosen because the majority of their air pollution emissions are related to mobile sources. The impact of auto exhaust on the air quality management process is characterized and assessed. An examination of the uncertainties in air pollutant measurements, emission inventories, meteorological parameters, atmospheric chemistry, and air quality simulation models is performed. The implications of these uncertainties to current air quality management practices is discussed. A set of corrective actions are recommended to reduce these uncertainties

A Mid-Infrared Galaxy Atlas (MIGA)

A mid-infrared atlas of part of the Galactic plane ($75^\circ < l < 148^\circ, b = \pm6^\circ$) has been constructed using HIRES processed infrared data to provide a mid-infrared data set for the Canadian Galactic Plane Survey (CGPS). The addition of this data set to the CGPS will enable the study of the emission from the smallest components of interstellar dust at an angular resolution comparable to that of the radio, millimetre, and far-infrared data in the CGPS. The Mid-Infrared Galaxy Atlas (MIGA) is a mid-infrared (12 $\mu$m and 25 $\mu$m) counterpart to the far-infrared IRAS Galaxy Atlas (IGA), and consists of resolution enhanced ($\sim 0.5'$ resolution) HIRES images along with ancillary maps. This paper describes the processing and characteristics of the atlas, the cross-beam simulation technique used to obtain high-resolution ratio maps, and future plans to extend both the IGA and MIGA.Comment: 38 pages (including 15 tables), 13 figures (8 dithered GIF and 5 EPS). Submitted to Astrophysical Journal Supplement Series. A preprint with higher resolution figures is available at http://www.cita.utoronto.ca/~kerton/publications.htm

Factors Influencing Consumer Likelihood of Purchasing a Flexible-Fuel or Hybrid Automobile

Developing fuels and vehicles that reduce our reliance on fossil fuels has become a priority due to the threat of global climate change and desire for reduced dependence on oil imports. Flexible-fuel vehicles that can run on ethanol/gasoline blends of up to 85% ethanol and hybrid electric vehicles present two such opportunities. While production of both flexible-fuel and hybrid vehicles is increasing, there is still a great deal of uncertainty about how consumers will respond to these products. To address this uncertainty, data was collected through an online survey of automobile owners that asked respondents how likely they were to choose either a flexible-fuel or hybrid vehicle as their next vehicle. A bivariate probit model was used to jointly analyze responses to these two questions. The results show that, while there was some overlap in the factors correlated with perceived likelihood of choosing one of these two types of automobiles, there were also clear differences. These results should benefit policymakers, marketers and academics seeking a better understanding of the respective markets for these vehicles.flexible-fuel vehicles, ethanol, E85, hybrid electric vehicles, Demand and Price Analysis, Environmental Economics and Policy, Resource /Energy Economics and Policy,

EFFECTS OF RISK ON OPTIMAL NITROGEN FERTILIZATION DATES IN WINTER WHEAT PRODUCTION AS AFFECTED BY DISEASE AND NITROGEN SOURCE

Optimal fertilization dates were found for two nitrogen sources in the presence of two diseases for wheat farmers with different risk preferences. Risk was independent of fertilization date. Ammonium Nitrate and Urea-Ammonium Nitrate did not affect risk differently. Ammonium Nitrate applied on March 9 was optimal regardless of risk preferences.Crop Production/Industries,

EFFECTS OF RISK, DISEASE, AND NITROGEN SOURCE ON OPTIMAL NITROGEN FERTILIZATION RATES IN WINTER WHEAT PRODUCTION

Interactions among nitrogen (N) fertilization rate, N source, and disease severity can affect mean yield and yield variance in conservation tillage wheat production. A Just-Pope model was used to evaluate the effects of N rate, N source, and disease on the spring N-fertilization decision. Ammonium nitrate (AN) was the utility-maximizing N source regardless of risk preferences. The net-return-maximizing AN rate was 92 lb N/acre, providing $0.52/acre higher net returns than the best alternative N source (urea). If a farmer could anticipate a higher than average Take-All infection, the difference in optimal net-returns between AN and urea would increase to$35.11/acre.Crop Production/Industries,

Effects of cochlear implantation on binaural hearing in adults with unilateral hearing loss

A FDA clinical trial was carried out to evaluate the potential benefit of cochlear implant (CI) use for adults with unilateral moderate-to-profound sensorineural hearing loss. Subjects were 20 adults with moderate-to-profound unilateral sensorineural hearing loss and normal or near-normal hearing on the other side. A MED-EL standard electrode was implanted in the impaired ear. Outcome measures included: (a) sound localization on the horizontal plane (11 positions, −90° to 90°), (b) word recognition in quiet with the CI alone, and (c) masked sentence recognition with the target at 0° and the masker at −90°, 0°, or 90°. This battery was completed preoperatively and at 1, 3, 6, 9, and 12 months after CI activation. Normative data were also collected for 20 age-matched control subjects with normal or near-normal hearing bilaterally. The CI improved localization accuracy and reduced side bias. Word recognition with the CI alone was similar to performance of traditional CI recipients. The CI improved masked sentence recognition when the masker was presented from the front or from the side of normal or near-normal hearing. The binaural benefits observed with the CI increased between the 1- and 3-month intervals but appeared stable thereafter. In contrast to previous reports on localization and speech perception in patients with unilateral sensorineural hearing loss, CI benefits were consistently observed across individual subjects, and performance was at asymptote by the 3-month test interval. Cochlear implant settings, consistent CI use, and short duration of deafness could play a role in this result

Metrological characterization of the pulsed Rb clock with optical detection

We report on the implementation and the metrological characterization of a vapor-cell Rb frequency standard working in pulsed regime. The three main parts that compose the clock, physics package, optics and electronics, are described in detail in the paper. The prototype is designed and optimized to detect the clock transition in the optical domain. Specifically, the reference atomic transition, excited with a Ramsey scheme, is detected by observing the interference pattern on a laser absorption signal. \ The metrological analysis includes the observation and characterization of the clock signal and the measurement of frequency stability and drift. In terms of Allan deviation, the measured frequency stability results as low as $1.7\times 10^{-13} \ \tau^{-1/2}$, $\tau$ being the averaging time, and reaches the value of few units of $10^{-15}$ for $\tau=10^{4}$ s, an unprecedent achievement for a vapor cell clock. We discuss in the paper the physical effects leading to this result with particular care to laser and microwave noises transferred to the clock signal. The frequency drift, probably related to the temperature, stays below $10^{-14}$ per day, and no evidence of flicker floor is observed. \ We also mention some possible improvements that in principle would lead to a clock stability below the $10^{-13}$ level at 1 s and to a drift of few units of $10^{-15}$ per day

Interstellar Turbulence: II. Energy Spectra of Molecular Regions in the Outer Galaxy

The multivariate tool of Principal Component Analysis (PCA) is applied to 23 fields in the FCRAO CO Survey of the Outer Galaxy. PCA enables the identification of line profile differences which are assumed to be generated from fluctuations within a turbulent velocity field. The variation of these velocity differences with spatial scale within a molecular region is described by a singular power law, delta v= c L^alpha which can be used as a powerful diagnostic to turbulent motions. For the ensemble of 23 fields, we find a mean value alpha = 0.62 +- 0.11. From a recent calibration of this method using fractal Brownian motion simulations (Brunt & Heyer 2001), the measured velocity difference-size relationship corresponds to an energy spectrum, E(k), which varies as k^-beta, where beta = 2.17 +- 0.31. We compare our results to both decaying and forced hydrodynamic simulations of turbulence. We conclude that energy must be continually injected into the regions to replenish that lost by dissipative processes such as shocks. The absence of large, widely distributed shocks within the targeted fields suggests that the energy is injected at spatial scales less than several pc.Comment: 24 pages, 10 figures, accepted by Ap

AXS Vecta 0.071–0.074 Inch Aspiration Catheters for Mechanical Thrombectomy: Case Series and Literature Review

Aspiration catheters are widely used for thrombectomy either alone or in combination with a stent-retriever, with a distal inner diameter and trackability keys to their success. In an illustrative case series, we report our clinical experience with AXS Vecta (Stryker Neurovascular, Fremont, CA, USA), available in both 0.071-inch and 0.074-inch distal inner diameters, including the first 2 Vecta 74 cases reported. A literature review on AXS Vecta is also provided. In our series, 9 thrombectomies were performed (Vecta 71: 2 M1, 5 M2 occlusions; Vecta 74: 1 M1 and 1 ICA-terminus occlusion). The AXS Vecta was successfully delivered to the target site in all cases. In 7 of 9 cases, the catheter was delivered over a Tenzing 7 delivery catheter (Route 92 Medical, San Mateo, CA, USA). For 2 of 9 combination approach cases, Vecta was delivered using the stent-retriever wire as a rail. The median improvement in NIHSS score during hospitalization was 9 (IQR 5–12). Successful mTICI 2C or 3 recanalization was achieved in 8 of 9 (89%) patients after a median 2 (IQR 1–2) passes. Our median groin-to-reperfusion time was 23 (IQR 12.5–32) minutes, with no procedural complications. Two previous clinical studies of a total of 29 patients treated with Vecta 71 reported successful mTICI 2b–3 recanalization in 89–90% of cases. The Median groin-to-reperfusion time was 30 minutes. Complications were seen in 2 of 29 (6.9%) cases (vessel perforation and/or intracerebral hemorrhage). These data support the efficacy, deliverability, and safety of AXS Vecta for mechanical thrombectomy