Measurements of gas-phase and particle-phase water-soluble organic carbon

The sources, sinks, and overall importance of water-soluble organic carbon (WSOC) in the atmosphere are not well understood. To better address this lack of knowledge, measurements of WSOC in both the gas (WSOC G) and particulate WSOCP phases were made using a newly developed technique during five research campaigns. Part 1 of this thesis investigates atmospheric and firn-air WSOC related to the post-depositional processing of organic compounds within Arctic snow during a research campaign at Summit, Greenland. Part 2 of this thesis highlights the discovery that at all locations where data were collected, WSOCG concentrations are significantly larger than those of WSOCP. A clear and consistent result from all five research campaigns is that WSOCG concentrations are significantly larger than those of WSOC P. The average values of the fractions of WSOCG compared to the total WSOC (fg) for the five campaigns ranged from 0.64 to 0.93. This variation in fg implies that significant differences in WSOC phase partitioning exist between locations, despite the consistent predominance of WSOCG. During the two longest campaigns, in Houston, Texas, and Summit, Greenland, a similar, repeatable diurnal pattern was observed with minimum values for fg occurring at night. This behavior is attributed, at least in part, to temperature related gas-to-particle partitioning. These trends suggest that the measured WSOCG and WSOCP are related and potentially comprised of similar groups of organic species, at least at certain times. This finding and observed fg values greater than 0.5 indicate that a large amount of organic material that participates in aerosol processes is not taken into account by aerosol measurements alone

31st Plenary Meeting Report Of the Scientific, Technical and Economic Committee for Fisheries (PLEN-09-02)

The Scientific, Technical and Economic Committee for Fisheries hold its 31st plenary on 13-17 July 2009 in Copenhagen. The terms of reference included both issues assessments of STECF working group reports and additional requests submitted to the STECF by the Commission. Topics dealt with ranged from fisheries economics to management plan evaluation issues.JRC.DG.G.4-Maritime affair

Particulate and water-soluble carbon measured in recent snow at Summit, Greenland

Water-soluble organic carbon (WSOC), waterinsoluble particulate organic carbon (WIOC), and particulate elemental carbon (EC) were measured simultaneously for the first time on the Greenland Ice Sheet in surface snow and in a 3-meter snow pit. Snow pit concentrations reveal that, on average, WSOC makes up the majority (89%) of carbonaceous species, followed by WIOC (10%) and EC (1%). The enhancement of OC relative to EC (ratio 99:1) in Greenland snow suggests that, along with atmospheric particulate matter, gaseous organics contribute to snow-phase OC. Comparison of summer surface snow concentrations in 2006 with past summer snow pit layers (2002 – 2005) found a significant depletion in WSOC (20 – 82%) and WIOC (46 – 65%) relative to EC for 3 of the 4 years. The apparent substantial loss of WSOC and WIOC in aged snow suggests that post-depositional processes, such as photochemical reactions, need to be considered in linking ice core records of organics to atmospheric concentrations. Citation: Hagler, G. S. W., M. H. Bergin, E. A. Smith, J. E. Dibb, C. Anderson, and E. J. Steig (2007), Particulate and water-soluble carbon measured in recent snow at Summit, Greenland, Geophys. Res. Lett., 34, L16505, doi:10.1029/2007GL030110

Marshall University Music Department Presents the MU Guitar Ensemble

https://mds.marshall.edu/music_perf/1280/thumbnail.jp

Tu quoque arguments, subjunctive inconsistency, and questions of relevance

Tu quoque arguments regard inconsistencies in some speaker‘s performance. Most tu quoque arguments depend on actual inconsistencies. However, there are forms of tu quoque arguments that key, instead, on the conflicts a speaker would have, were some crucial contingent fact different. These, we call subjunctive tu quoque arguments. Finally, there are cases wherein the counterfactual inconsistencies of a speaker are relevant to the issue

Packaging a liquid metal ESD with micro-scale Mercury droplet.

A liquid metal ESD is being developed to provide electrical switching at different acceleration levels. The metal will act as both proof mass and electric contact. Mercury is chosen to comply with operation parameters. There are many challenges surrounding the deposition and containment of micro scale mercury droplets. Novel methods of micro liquid transfer are developed to deliver controllable amounts of mercury to the appropriate channels in volumes under 1 uL. Issues of hermetic sealing and avoidance of mercury contamination are also addressed

Thermal-stress modeling of an optical microphone at high temperature.

To help determine the capability range of a MEMS optical microphone design in harsh conditions computer simulations were carried out. Thermal stress modeling was performed up to temperatures of 1000 C. Particular concern was over stress and strain profiles due to the coefficient of thermal expansion mismatch between the polysilicon device and alumina packaging. Preliminary results with simplified models indicate acceptable levels of deformation within the device

A Comparison of the Microcirculation in Rat Spinotrapezius Muscle and Muscle Fascia

The microcirculation in rat spinotrapezius muscle and muscle fascia is investigated using a computational approach. The simulations are based on a realistic microvascular network structure obtained from microscope observations and consider both blood rheology and vessel elasticity. An improved model for the apparent viscosity of blood is developed to take the shear thinning nature of blood into account. Capillary bundles of muscle tissue are composed of vessels that mainly follow the direction of muscle fibers. In muscle fascia, however, the capillary vessels form a mesh like network without a preferred direction. This structural difference leads to significant differences in the microcirculation. In the muscle fascia, vessel length, velocity, and shear rate follow a lognormal distribution. In muscle, however, the data does not support a lognormal distribution. For both networks, the hematocrit follows an approximately normal distribution