The Pantano Longarini shipwreck: a reanalysis

A late antique shipwreck was excavated in the Pantano Longarini marsh in the southeastern corner of Sicily in the 1960s. Despite its excellent preservation, problematic circumstances surrounding its excavation and publication have resulted in scholars ignoring or misinterpreting it. The majority of the data, including original field notes and documentation, are lost, and the drawings, plans, and photographs that remain are sometimes inconsistent and incomplete. My research reanalyzes the remains of this ship to determine how the Sicilians adapted to their marine and economic conditions within the turbulent socio-economic and political climate of late antiquity. The Pantano Longarini shipwreck demonstrates early stages in a shift from the tradition of plank-based construction to the modern system of reliance on an internal framework for structural support. Contemporary wrecks provide parallels, but unique elements distinguish this ship from those typically studied. Extremely thick timbers, a relatively flat bottom and bow and stern ramps argue that the Pantano Longarini ship was designed to carry bulk loads. Although the ship was originally reported as an extremely advanced ship, the present analysis points to a different type of watercraft: a coastal barge. Correctly identifying the Pantano Longarini ship allows us to gather information about the needs of its builders, as well as extends our knowledge of shipping and ship construction in the seventh century

Light Nonaqueous-Phase Liquid Hydrocarbon Weathering at some JP-4 Fuel Release Sites

A fuel weathering study was conducted for database entries to estimate natural light, nonaqueousphase liquid weathering and source-term reduction rates for use in natural attenuation models. A range of BTEX weathering rates from mobile LNAPL plumes at eight field sites with known release dates was documented. Freephase fuel BTEX weathering rates varied among sites and were influenced by many factors. First-order weathering rate for five JP-4 fuel sites was 16%/year. Benzene and toluene exhibited higher weathering rates than ethylbenzene and xylene, as expected, because of higher water solubility. The primary weathering mechanism of mobile LNAPL was dissolution. Meaningful determination of mobile LNAPL weathering rates for BTEX in the fuels was difficult because of the large ranges of initial BTEX values

Geophysical Characterization, Redox Zonation, and Contaminant Distribution at a Groundwater/Surface Water Interface

Three transects along a groundwater/surface water interface were characterized for spatial distributions of chlorinated aliphatic hydrocarbons and geochemical conditions to evaluate the natural bioremediation potential of this environmental system. Partly on the basis of ground penetrating radar measurements, a conductive sediment layer was detected from the shore out to at least 300 m offshore which exhibited gradients in redox pairs and contaminant profiles. The cis-Dichloroethene and 1-chloroethene were predominant in the presence of elevated methane and ferrous iron concentrations and depressed sulfate and aquifer solids-bound iron concentrations. The shallow monitoring points were generally hypoxic to aerobic and exhibited values of specific conductance reflective of near-shore lake water, indicating reoxygenation of the contaminant plume due to wave infiltration. The barge transect yielded trace contaminant concentrations and showed evidence of sulfate reduction. These analyses contributed to the understanding of processes affecting contaminant fate and transport at near-shore mixing zones

Methane Occurrences in Aquifers Overlying the Barnett Shale Play with a Focus on Parker County, Texas

Clusters of elevated methane concentrations in aquifers overlying the Barnett Shale play have been the focus of recent national attention as they relate to impacts of hydraulic fracturing. The objective of this study was to assess the spatial extent of high dissolved methane previously observed on the western edge of the play (Parker County) and to evaluate its most likely source. A total of 509 well water samples from 12 counties (14,500 km2) were analyzed for methane, major ions, and carbon isotopes. Most samples were collected from the regional Trinity Aquifer and show only low levels of dissolved methane (85% of 457 unique locations 20 mg/L) are limited to a few spatial clusters. The Parker County cluster area includes historical vertical oil and gas wells producing from relatively shallow formations and recent horizontal wells producing from the Barnett Shale (depth of â ¼1500 m). Lack of correlation with distance to Barnett Shale horizontal wells, with distance to conventional wells, and with well density suggests a natural origin of the dissolved methane. Known commercial very shallow gas accumulations (<200 m in places) and historical instances of water wells reaching gas pockets point to the underlying Strawn Group of Paleozoic age as the main natural source of the dissolved gas.Article impact statement: Dissolved methane in aquifers over the Barnett play is infrequent, thermogenic but natural, and related to localized shallow gas accumulations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/1/gwat12508-sup-0001-supinfo.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/2/gwat12508_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137724/3/gwat12508.pd

A water column study of methane around gas flares located at the West Spitsbergen continental margin

In the Arctic Seas, the West Spitsbergen continental margin represents a prominent methane seep area. In this area, free gas formation and gas ebullition as a consequence of hydrate dissociation due to global warming are currently under debate. Recent studies revealed shallow gas accumulation and ebullition of methane into the water column at more than 250 sites in an area of 665 km2. We conducted a detailed study of a subregion of this area, which covers an active gas ebullition area of 175 km2 characterized by 10 gas flares reaching from the seafloor at~245 m up to 50 m water depth to identify the fate of the released gas due to dissolution of methane from gas bubbles and subsequent mixing, transport and microbial oxidation. The oceanographic data indicated a salinity-controlled pycnocline situated ~20 m above the seafloor. A high resolution sampling program at the pycnocline at the active gas ebullition flare area revealed that the methane concentration gradient is strongly controlled by the pycnocline. While high methane concentrations of up to 524 nmol L−1 were measured below the pycnocline, low methane concentrations of less than 20 nmol L−1 were observed in the water column above. Variations in the δ13CCH4 values point to a 13C depleted methane source (~−60‰ VPDB) being mainly mixed with a background values of the ambient water (~−37.5‰ VPDB). A gas bubble dissolution model indicates that ~80% of the methane released from gas bubbles into the ambient water takes place below the pycnocline. This dissolved methane will be laterally transported with the current northwards and most likely microbially oxidized in between 50 and 100 days, since microbial CH4 oxidation rates of 0.78 nmol d−1 were measured. Above the pycnocline, methane concentrations decrease to local background concentration of ~10 nmol L−1. Our results suggest that the methane dissolved from gas bubbles is efficiently trapped below the pycnocline and thus limits the methane concentration in surface water and the air–sea exchange during summer stratification. During winter the lateral stratification breaks down and fractions of the bottom water enriched in methane may be vertically mixed and thus be potentially an additional source for atmospheric methane

THE ECONOMY OF CONFLICT: HOW EAST MEDITERRANEAN TRADE ADAPTED TO CHANGING RULES, ALLEGIANCES AND DEMOGRAPHICS IN THE 10TH - 12TH CENTURIES AD

Seaborne trade increased in quantity and value despite the political and demographic upheaval in the East Mediterranean caused by the ongoing hostilities of the tenth through the twelfth centuries. In order to thrive, trade had to adapt to changing conditions, and thus, the story of the East Mediterranean economy in this period is the story of the modernization of the medieval economy. Critical to this adaptation was the recognition of the interdependence of the economies of all of the major players of the region. The Byzantine Empire, Italian merchant cities, the Islamic states, and the Latin States engaged in various conflicts, but they all depended on each other economically, and they used their unique advantages to enhance their own wealth. The Italian merchant cities traded their naval power for trade rights and other privileges with the Byzantine Empire and the Latin States, while the Muslim states encouraged the Italians to continue trading to overcome their lack of natural resources to manufacture weapons. Not only did the rulers of the time alter their course for economic benefit, but individual merchants altered their behavior, and local markets adapted independently of their central governance. Merchants navigated an obstacle course of moving armies, growing or declining cities, and governmental attempts to impose trade restrictions. Cities rose and fell in population and prominence according to their economic decisions and developed merchant quarters to support trade; evidence for these findings draws from a variety of textual and archaeological sources. In particular, underwater archaeology is opening a new avenue of study that can balance our current views of trade routes, cargos and merchant identities through the identification and exploration of shipwrecks

The Story in the Soil: Toward an Agrarian Rhetoric of Property

The founders of the American republic believed that the institution of private property served as the foundation of a democratic society. James Madison, Thomas Jefferson, and others saw property not only as things the right to which must be protected, but they viewed their right to think for themselves and to communicate those thoughts to others as the most important form of property. The institution of private property was strongly linked with the virtue of phronesis. Madison captured this sentiment stating, as a man is said to have a right to his property, he may be equally said to have a property in his rights. Despite such importance, private property in the United States has been subject to increasing commodification throughout the nation\u27s history. Commodity property views property primarily as a possession and the rights of ownership refer primarily to the right of alienation, that is, the right to buy, sell, trade, and consume that which one owns. Commodity property is not concerned with the relationship between property and other rights, between property and democracy, or between property and communication. This dissertation examines vestiges of an alternative notion, property as propriety, in order to recover the more robust model of public discourse to which it has historically been linked. To that end, the author examines the work of agrarians such as Wendell Berry, which boasts a rich vocabulary regarding property and propriety, and employs this vocabulary to articulate the basic categories and preliminary coordinates of an agrarian rhetoric of property, which asks, what is public discourse like under various property regimes? The author conveys agrarianism\u27s relevance to contemporary debates surrounding property and public communication, arguing that agrarian thought is attentive both to the rhetoric of property claims as well as what Kenneth Burke describes as the recalcitrance of the land. Decorum and related concepts of kairos and propriety mediate between these dimensions and open a space for the cultivation of phronesis. Private property constructed in accordance with objective standards of decorum constitutes what Bakhtin terms a chronotope that propels embodied civic action and fosters healthy practices of public discourse

Sulfur Fertilization for Corn Production on Thurman Loamy Sand

Sandy soils of northeastern Nebraska as represented by the Thurman soil series may be deficient in sulfur as well as in lime, phosphorus, and nitrogen. Objectives of this study include determining the influence of sulfur and nitrogen fertilization on corn plants under greenhouse and field conditions; comparing carriers and application methods of sulfur fertilizer on corn plants under field conditions; diagnosing sulfur requirements of the corn plant. Total plant uptake of sulfur gradually increased throughout the growing season at all locations with the largest increases occurring during ear development in late July to early September. Advisor: H. F. Rhoades