The Effect of High-Intensity and Moderate-Intensity Exercise on Enjoyment and General Mood

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Crushed Stone Aggregate Resources of Indiana

Indiana Geological Survey Bulletin 42-HMineral aggregate is an aggregation of mineral material, such as crushed rock, expanded shale, perlite, sand and gravel, shells, or slag. It is sometimes bound with such material as cement or asphalt or is sometimes not bound for use as filter stone, flux stone, railroad ballast, riprap, or road metal. Crushed limestone and dolomite, sand and gravel, slag, perlite, and expanded shale are the main natural and fabricated aggregates currently used in Indiana. Some aggregate, such as sand and gravel, requires little or no processing and can be used almost as it is mined, but rock must be crushed and sorted into various desired sizes before it can be used. Many types of rocks can be used for crushed stone aggregate, but limestone and dolomite are used exclusively in Indiana (pl. 1). In this report crushed stone is synonymous with crushed limestone and dolomite. Each type of aggregate has a distinct advantage with respect to cost and availability or to a specific use for which one type is more suited than another. The advantages of crushed limestone and dolomite are that they can be crushed and sized to meet most specifications, the materials are clean and angular and bind well with cementing mixtures, a uniform lithologic composition can be maintained with little or no selective quarrying in many areas, and they are available at low cost in most counties in Indiana. Crushed stone is one of Indiana’s most important mineral commodities, ranking third in annual value behind coal and cement. During 1969 crushed stone production in Indiana totaled 25, 516,000 tons and was valued at $34,418,000.Indiana Department of Natural Resource

Cam Design Projects in an Advanced CAD Course for Mechanical Engineers

The objective of this paper is to present applications of solid modeling aimed at modeling of complex geometries such as splines and blended surfaces in advanced CAD courses. These projects, in CAD-based Mechanical Engineering courses, are focused on the use of the CAD system to solve design problems for applications in machine design, namely the geometric and mechanical design of cam mechanisms

Measurements of Isoprene-Derived Organosulfates in Ambient Aerosols by Aerosol Time-of-Flight Mass Spectrometry—Part 2: Temporal Variability and Formation Mechanisms

Organosulfate species have recently gained attention for their potentially significant contribution to secondary organic aerosol (SOA); however, their temporal behavior in the ambient atmosphere has not been probed in detail. In this work, organosulfates derived from isoprene were observed in single particle mass spectra in Atlanta, GA during the 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) and the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS). Real-time measurements revealed that the highest organosulfate concentrations occurred at night under a stable boundary layer, suggesting gas-to-particle partitioning and subsequent aqueous-phase processing of the organic precursors played key roles in their formation. Further analysis of the diurnal profile suggests possible contributions from multiple production mechanisms, including acid-catalysis and radical-initiation. This work highlights the potential for additional SOA formation pathways in biogenically influenced urban regions to enhance the organic aerosol burden

Measurements of Isoprene-Derived Organosulfates in Ambient Aerosols by Aerosol Time-of-Flight Mass Spectrometry - Part 1: Single Particle Atmospheric Observations in Atlanta

Organosulfate species have recently been identified as a potentially significant class of secondary organic aerosol (SOA) species, yet little is known about their behavior in the atmosphere. In this work, organosulfates were observed in individual ambient aerosols using single particle mass spectrometry in Atlanta, GA during the 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) and the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS). Organosulfates derived from biogenically produced isoprene were detected as deprotonated molecular ions in negative-ion spectra measured by aerosol time-of-flight mass spectrometry; comparison to high-resolution mass spectrometry data obtained from filter samples corroborated the peak assignments. The size-resolved chemical composition measurements revealed that organosulfate species were mostly detected in submicrometer aerosols and across a range of aerosols from different sources, consistent with secondary reaction products. Detection of organosulfates in a large fraction of negative-ion ambient spectra − ca. 90−95% during ANARChE and ~65% of submicrometer particles in AMIGAS − highlights the ubiquity of organosulfate species in the ambient aerosols of biogenically influenced urban environments

Bostonia. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Hybrid Quantum and Classical Mechanical Monte Carlo Simulations of the Interaction of Hydrogen Chloride with Solid Water Clusters

Monte Carlo simulations using a hybrid quantum and classical mechanical potential were performed for crystal and amorphous-like HCl-water(n) clusters The subsystem composed by HCl and one water molecule was treated within Density Functional Theory, and a classical force field was used for the rest of the system. Simulations performed at 200 K suggest that the energetic feasibility of HCl dissociation strongly depends on its initial placement within the cluster. An important degree of ionization occurs only if HCl is incorporated into the surface. We observe that local melting does not play a crucial role in the ionization process.Comment: 14 Latex pages with 4 postscript figures, to appear in Chem. Phys. Let