87,371 research outputs found
Air pollution at Rochester, NY: Long-term trends and multivariate analysis of upwind SO2 source impacts
No full textThere have been many changes in the air pollutant sources in the northeastern United States since 2001. To assess the effect of these changes, trend analyses of the monthly average values were performed on PM2.5 and its components including major ions, elemental carbon (EC), organic carbon (OC), and gaseous pollutant concentrations measured between 2001 (in some cases 1999) and 2015 at the NYS Department of Environmental Conservation sites in Rochester, NY. Mann-Kendall regression with Sen's slope was applied to estimate the trends and seasonality. Using piecewise regression, significant reductions in the air pollution of Rochester area were observed between 2008 and 2010 when a 260 MW coal-fired power plant was decommissioned, new heavy-duty diesel trucks had to be equipped with catalytic regenerator traps, and the economic recession that began in 2008 reduced traffic and other activities. The monthly average PM2.5 mass showed a downward trend (− 5 μg/m3; − 41%) in Rochester between 2001 and 2015. This change is largely due to reductions in particulate sulfate that showed a 65% decrease. The sulfate concentrations were compared to changes in SO2 emissions in seventeen upwind source domains, and other systematic changes by multivariate linear regression. Selectivity ratio obtained from target projection discriminated the most important source domains that are SO2 emissions from Georgia for winter, North Carolina for transition (spring and fall) and Ohio along with other influences for summer. North Carolina and Michigan were identified as the main sources for entire period. These observations suggest that any further reductions in the specified regional SO2 emissions would result in a proportional decrease in sulfate in Rochester
Multivariate analysis of upwind SO2 emission influences on air pollution in Rochester, NY
No full textInfluence of ultrasonic vibration on the microstructure and texture evolution of AZ91 magnesium alloy during ultrasonic-assisted friction stir welding
No full textThe aim of this work is to investigate the influence of ultrasonic vibration on the microstructure and texture evolution in ultrasonic-assisted friction stir welding (UaFSW) of AZ91 Mg alloy. Ultrasonic vibration with an amplitude of 15 μm induced to the weld line perpendicularly to the welding direction. A scanning electron microscopy equipped with electron backscattered diffraction (EBSD) was used to investigate the microstructure and texture changes of the joints. A high fraction of low-angle grain boundaries (LAGBs) was observed during the occurrence of dynamic recovery (DRV) in thermomechanically affected zones (TMAZs) of welded specimens. Statistical analysis from the grain boundaries of the stir zone (SZ) revealed that the fraction of high-angle grain boundaries (HAGBs) in the SZ of UaFSW joint is higher than that of the FSW joint. The results along with the formation of simple shear texture components in the SZ of welds imply that continuous dynamic recrystallization (CDRX) is responsible for grain refinement in the SZs. Moreover, vibration associated with UaFSW assisted the DRV and CDRX mechanisms and increases the intensity of the developed texture in the SZ of the UaFSW joint
The Air Pollution at Rochester: Long-Term Trends
No full textThere have been a number of changes in the sources of air pollutant in the northeastern United States since 2001. Trend analyses of monthly averages were performed on PM 2.5, ionic species, elemental carbon (EC), organic carbon (OC) and gaseous pollutants collected between 2001 and 2015 for NYS Department of Environmental Conservation sites in Rochester. Non-parametric (Mann-Kendall regression with Sen’s slope) and parametric (weighted linear and non-linear regressions) approaches were applied to estimate the trends and seasonality. We fitted the different models to monthly averages of each species for each month over the 15 years of available data. Separating the data by month removes their seasonal dependence. The unequal number of attainable samples averaged to provide monthly asset value was accounted for by weighting each month proportional to its number of available daily concentration values. Sulfate and nitrate showed downward trends. For almost all of the species over the whole, the weighted linear parametric modeling yielded steeper slopes than the non-parametric Mann-Kendall approach. For sulfate, the slopes = -0.20 and -0.15 μg m -3 year -1, respectively. These trends will be compared to changes in emissions in the upwind source domain
Dissimilar friction stir welding of AISI 430 ferritic and AISI 304L austenitic stainless steels
No full textDissimilar joints of AISI 430 ferritic and AISI 304L austenitic stainless steels were produced by friction stir welding process. A sound and defect-free joint was obtained at 1 mm tool offset towards the ferritic sample located in the advancing side, and at rotational and welding speeds of 560 rpm and 50 mm/min, respectively. The XRD measurements revealed the presence of approximately equal volume fractions of ferrite (51%) and austenite (49%) phases in the stir zone (SZ). The formation of low-angle grain boundaries through the occurrence of dynamic recovery along with the presence of shear texture components in both constituent phases of ferrite and austenite in the SZ approved the occurrence of continuous dynamic recrystallization throughout the evolved microstructure. Moreover, microstructural observations showed the formation of necklace structure through the microstructure of ferrite in the SZ. Taylor map approved the strain localization in the ferrite phase. Micro-hardness measurement indicated that the hardness value is increased in the SZ. The result of tensile test showed that fracture occurred from less ductile ferritic base metal. © 2020, Wroclaw University of Science and Technology
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Cosmological tests of an axiverse-inspired quintessence field
No full textInspired by the string axiverse idea, it has been suggested that the recent transition from decelerated to accelerated cosmic expansion is driven by an axion-like quintessence field with a sub-Planckian decay constant. The scenario requires that the axion field be rather near the maximum of its potential but is less finely tuned than other explanations of cosmic acceleration. The model is parametrized by an axion decay constant f, the axion mass m, and an initial misalignment angle |θi| which is close to π. In order to determine the m and θi values consistent with observations, these parameters are mapped onto observables: the Hubble parameter H(z) at an angular-diameter distance dA(z) to redshift z=0.57, as well as the angular sound horizon of the cosmic microwave background (CMB). Measurements of the baryon acoustic oscillation (BAO) scale at z≃0.57 by the BOSS survey and Planck measurements of CMB temperature anisotropies are then used to probe the {m,f,θi} parameter space. With current data, CMB constraints are the most powerful, allowing a fraction of only ∼0.2 of the parameter-space volume. Measurements of the BAO scale made using the SPHEREx or SKA experiments could go further, observationally distinguishing all but ∼10-2 or ∼10-5 of the parameter-space volume (allowed by simple priors) from the ΛCDM model
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
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