Portable life support for instrumentation of an offshore platform

A compressor was used to supply air through a nylon hose to the offshore platform field engineer working at the bottom of the piling. Air quality in the pile was sampled periodically for carbon dioxide, carbon monoxide, hydrogen sulfide, and combustible gases by an universal tester and an explosion meter

Data requirements in support of the marine weather service program

Data support activities for the Marine Weather Service Program are outlined. Forecasts, cover anomolous water levels, including sea and swell, surface and breakers, and storm surge. Advisories are also provided for sea ice on the Great Lake and Cook inlet in winter, and in the Bering, Chukchi, and Beaufort Seas in summer. Attempts were made to deal with ocean currents in the Gulf Stream, areas of upwelling, and thermal structure at least down through the mixed layer

Paint Pavement Marking Performance Prediction Model That Includes the Impacts of Snow Removal Operations

The results of this research effort were captured in two manuscripts drafted for publication in peer reviewed journals. The first manuscript validated a previously published model with an expanded data set, updated service life predictions for painted pavement markings using recently released pavement marking retroreflectivity minimums, and incorporated recent cost data to evaluate two alternative methods of compliance with the new retroreflectivity minimums for two-lane roads. The second manuscript developed a new performance prediction model for paint pavement markings that includes the impact of snow removal operations and then applied the model to four real-world roadways to determine if replacement is required. This research determined that each snow plow event degrades paint pavement markings by 3.22 mcd/m2/lux which is more than one month of service life. The work also showed that with no snow fall, an AADT of 4,000, and an RL, Initial of 220 mcd/m2/lux, paint pavement markings have a service life greater than five years on roads with posted speeds less than 55 mph. Finally, the research confirmed that AADT has a small but significant impact on the degradation of painted pavement markings. The results also indicated the developed for North Carolina might be useful in other states

Quikscat measurements of the wind field over the Bering and Chukchi Seas

Thesis (M.S.) University of Alaska Fairbanks, 2008The purpose of this study is to investigate the dynamic wind field and resulting ocean circulation patterns in the Bering and Chukchi Seas. This region forms an important link in global ocean circulation as Bering Strait is a major conduit for water flowing into the Arctic Ocean. The Arctic has been identified as an area sensitive to climate change; thus it is vital to understand how water and energy flow through this region. We first quantify the differences between the winds measured in this region by the Quik Scatterometer (QuikSCAT) and those modeled by the National Centers for Environmental Prediction (NCEP). Although the data sets are well correlated, we find significant discrepancies between these data sets and use linear regressions to correct the NCEP data. The magnitudes of the NCEP wind components are greater than the magnitudes of the QuikSCAT wind components. This creates directional differences between the two data sets at low wind speeds and NCEP speeds that are greater than QuikSCAT speeds at high wind speeds. We next challenge the assumption that the wind field is spatially uniform over the Bering and Chukchi shelves. We produce mean monthly maps of the wind field, surface Ekman transport, and wind variance based upon the 12-hourly QuikSCAT data from July 1999 – May 2007. These maps reveal that the winds are spatially and temporally dynamic in this region. There are several areas and times in which surface Ekman transport is onshore or offshore near the coasts and may engender coastal downwelling and upwelling, respectively. There are also several instances when surface Ekman convergence and divergence may lead to Ekman pumping and suction. We use the entire NCEP record (January 1948 – May 2007) to examine patterns of surface Ekman transport across the shelf break. There was a significant increase in the amount of onshelf surface Ekman transport that coincided with the regime shift that occurred in the Bering Sea in the mid-1970s. We attempt to correlate the time series of surface Ekman cross-shelf transport with several climate indices but find only very weak correlations. The annual surface Ekman freshwater fluxes across the shelf break are iii calculated and found to be very small compared to the total annual freshwater fluxes calculated by Aagaard et al. (2006) and Kinney et al. (2008). To resolve the dominant modes of wind variability we compute hourly, monthly, and annual Complex Empirical Orthogonal Functions (CEOFs) with the QuikSCAT and NCEP data sets. The first modes in each analysis account for more than 60% of the variance. Different aspects of the mode amplitude time series are cross-correlated with climate and indices to produce small but significant correlation coefficients. Finally we calculate Ekman pumping and suction at four locations in the Bering Sea during the spring and summer months of seven years (2000 – 2006). We identify regions and times when Ekman pumping and suction were particularly strong, and perform several runs of a one-dimensional Price-Weller-Pinkel (PWP) vertical mixing model with the QuikSCAT winds, the QuikSCAT winds and a wind-stress-curl term, and the NCEP winds. The results suggest that Ekman suction might facilitate subsequent vertical mixing while Ekman pumping might inhibit subsequent vertical mixing when the winds are generally weak and wind-stress-curl is moderate or strong. The temporal resolution of the QuikSCAT data set is too low to resolve inertial motions at high latitudes. The NCEP data set has higher temporal resolution and is adequate for running the model within this region. We propose interpolating the hourly NWS data collected at St. Paul Island (station PASN) to the QuikSCAT grid using the complex amplitudes and phases from the complex cross-correlations between the two data sets to produce a data set of high temporal and spatial resolution. This would enable researchers to accurately resolve inertial motions and compute wind-stress-curl

Combined Description of N‾N\bf{\overline{N}N} Scattering and Annihilation With A Hadronic Model

A model for the nucleon-antinucleon interaction is presented which is based on meson-baryon dynamics. The elastic part is the $G$-parity transform of the Bonn $NN$ potential. Annihilation into two mesons is described in terms of microscopic baryon-exchange processes including all possible combinations of $\pi,\eta,\rho,\omega,a_0,f_0,a_1,f_1,a_2,f_2,K,K^*$. The remaining annihilation part is taken into account by a phenomenological energy- and state independent optical potential of Gaussian form. The model enables a simultaneous description of nucleon-antinucleon scattering and annihilation phenomena with fair quality.Comment: revised version, REVTEX, 9 pages, 10 figures available from this URL ftp://ikp113.ikp.kfa-juelich.de/pub/kph140/nucl-th.9411014.u

Ecology of Neglected Rodent-Borne American Orthohantaviruses

The number of documented American orthohantaviruses has increased significantly over recent decades, but most fundamental research has remained focused on just two of them: Andes virus (ANDV) and Sin Nombre virus (SNV). The majority of American orthohantaviruses are known to cause disease in humans, and most of these pathogenic strains were not described prior to human cases, indicating the importance of understanding all members of the virus clade. In this review, we summarize information on the ecology of under-studied rodent-borne American orthohantaviruses to form general conclusions and highlight important gaps in knowledge. Information regarding the presence and genetic diversity of many orthohantaviruses throughout the distributional range of their hosts is minimal and would significantly benefit from virus isolations to indicate a reservoir role. Additionally, few studies have investigated the mechanisms underlying transmission routes and factors affecting the environmental persistence of orthohantaviruses, limiting our understanding of factors driving prevalence fluctuations. As landscapes continue to change, host ranges and human exposure to orthohantaviruses likely will as well. Research on the ecology of neglected orthohantaviruses is necessary for understanding both current and future threats to human health.Peer reviewe

Coastal sand dunes in the U.S. Pacific Northwest : regional variability in foredune geomorphology and associated physical vulnerability to hazards

Coastal foredunes protect lives, infrastructure, and ecosystems during severe winter storms. In the U.S. Pacific Northwest (PNW), coastal foredune geomorphology is determined by both physical and ecological mechanisms. Before the 1900's, the native plant Elymus mollis was the dominant dune grass and dune morphology was largely determined by sediment supply and other physical factors. The introduction of two different invasive beach grasses in the first half of the 20th century resulted in significant changes to PNW foredune geomorphology. Recent work has shown that the invasive beach grass Ammophila arenaria is associated with taller, narrower foredunes while the grass Ammophila breviligulata is associated with shorter, broader foredunes. We hypothesize that this may impact coastal vulnerability as the taller, narrower foredunes may be more resistant to overtopping, but less resistant to erosion, while the shorter, broader foredunes may be more resistant to erosion, but less resistant to overtopping. The work presented in this thesis is part of a larger, interdisciplinary effort to determine the relative importance of physical and ecological mechanisms in controlling coastal foredune geomorphology and vulnerability in the PNW. Airborne topographic lidar data is used to characterize the regional variability in foredune geomorphology within several littoral cells, subcells, and beaches of the PNW. We present and discuss techniques to automatically and accurately extract foredune morphometric parameters from a lidar elevation data set of the coasts of Oregon and Washington. If the different grass species do affect foredune geomorphology, it is important to understand how managing them might impact coastal vulnerability. Therefore, we use the geomorphological parameters and measured hydrodynamic parameters during a major winter storm to estimate vulnerability to overtopping and erosion at beaches with distinctly different foredunes. Estimates of overtopping and erosion are normalized by the foredune heights and widths to elucidate how the different foredune types, and possibly the associated beach grasses, affect vulnerability. A series of simple foredune erosion models including a geometric model, an equilibrium profile model, and a wave impact model are evaluated for applicability to the PNW coast.Keywords: coastal foredunes, coastal geomorphology, dune erosio