1,233 research outputs found
ECONOMIC IMPLICATIONS OF DISCONTINUING THE TEXAS HIGH PLAINS BOLL WEEVIL SUPPRESSION PROGRAM
Crop Production/Industries,
Corinth Excavations Archaeological Manual
“The publication of the Corinth Excavation Manual offers us a unique view into real-life archaeological practice on one of the most important Classical sites in the Mediterranean.” Adam Rabinowitz, Associate Professor and Assistant Director, Institute of Classical Archaeology, University of Texas, Austin
The Corinth Excavations Archaeological Manual is the first major field manual published from an American excavation in Greece and among a very small number of manuals published from the Eastern Mediterranean in the last generation. The appearance of this book is timely, however, as there is a growing interest in field methods and the history of excavation practices throughout the discipline of archaeology. Moreover, Corinth Excavations has long held a special place in American archaeology in Greece as the primary training excavation for graduate students associated with the American School of Classical Studies at Athens. As a result, the field manual has had a particular influence among American excavators and projects in Greece, among Mediterranean archaeologists, and in archaeology classrooms.
Published as a technical field manual, an archival document, and a key statement of practice from a major excavation, the Corinth Excavations Archaeological Manual presents a guide for daily procedures at the Corinth Excavations, a complete record of documentation forms used in the field, and a practical glimpse into the functioning of a complex, major, project. The manual is a landmark text appropriate for the university student, the scholar of methodology, and the working field archaeologist.
“The Corinth manual has grown over the years into a comprehensive and authoritative guide to open-area, stratigraphic excavation, covering everything from excavation of pits, wells, and robbing trenches to the removal of deposits to inventorying objects in the museum. ” David Pettegrew, Associate Professor, Messiah College and author of The Isthmus of Corinth (2016).
All of the authors have worked on the excavations at Corinth in various capacities. This manual was developed under the directorship of Dr. Guy Sanders by former field directors Alicia Carter Johnson and Dr. Sarah James. Additional contributions come from past and present Corinth staff including assistant director Dr. Ioulia Tzonou-Herbst, architect James Herbst, conservator Nicol Anastasatou, and archaeologist Katerina Ragkou. The authors would also like to recognize the contributions of the many students from the American School of Classical Studies at Athens who offered valuable feedback on earlier versions of this manual over the past 10 years.https://commons.und.edu/press-books/1005/thumbnail.jp
Tracing Nitrogen in Volcanic and Geothermal Volatiles from the Nicaraguan Volcanic Front
We report new chemical and isotopic data from 26 volcanic and geothermal gases, vapor condensates, and thermal water samples,
collected along the Nicaraguan volcanic front. The samples were analyzed for chemical abundances and stable isotope compositions,
with a focus on nitrogen abundances and isotope ratios. These data are used to evaluate samples for volatile contributions from magma,
air, air-saturated water, and the crust. Samples devoid of crustal contamination (based upon He isotope composition) but slightly contaminated
by air or air-saturated water are corrected using N2/Ar ratios in order to obtain primary magmatic values, composed of contributions
from upper mantle and subducted hemipelagic sediment on the down-going plate. Using a mantle endmember with
d15N= 5&and N2/He = 100 and a subducted sediment component with d15N=+7& and N2/He = 10,500, the average sediment contribution
to Nicaraguan volcanic and geothermal gases was determined to be 71%. Most of the gases were dominated by sediment-derived
nitrogen, but gas from Volca´n Mombacho, the southernmost sampling location, had a mantle signature (46% from subducted
sediment, or 54% from the mantle) and an affinity with mantle-dominated gases discharging from Costa Rica localities to the south. High
CO2/N2 exc. ratios (N2 exc. is the N2 abundance corrected for contributions from air) in the south are similar to those in Costa Rica, and
reflect the predominant mantle wedge input, whereas low ratios in the north indicate contribution by altered oceanic crust and/or preferential
release of nitrogen over carbon from the subducting slab. Sediment-derived nitrogen fluxes at the Nicaraguan volcanic front,
estimated by three methods, are 7.8 · 108 mol N/a from 3He flux, 6.9 · 108 mol/a from SO2 flux, and 2.1 · 108 and 1.3 · 109 mol/a from
CO2 fluxes calculated from 3He and SO2, respectively. These flux results are higher than previous estimates for Central America, reflecting
the high sediment-derived volatile contribution and the high nitrogen content of geothermal and volcanic gases in Nicaragua. The
fluxes are also similar to but higher than estimated hemipelagic nitrogen inputs at the trench, suggesting addition of N from altered oceanic
basement is needed to satisfy these flux estimates. The similarity of the calculated input of N via the trench to our calculated outputs
suggests that little or none of the subducted nitrogen is being recycled into the deeper mantle, and that it is, instead, returned to the
surface via arc volcanism
Development of a superhydrophobic polyurethane-based coating from a two-step plasma-fluoroalkyl silane treatment
A method of achieving a superhydrophobic surface based upon a highly filled polyurethane (PU) paint coating has been demonstrated through the use of a combined oxygen/argon plasma pretreatment and a fluoroalkyl silane (FAS) final treatment. The combined plasma-FAS treated PU surface has been investigated and characterised using: field emission gun secondary electron microscope (FEG-SEM); X-ray photoelectron spectroscopy (XPS); energy-dispersive X-ray spectroscopy (EDX); water contact angle analysis (WCA); atomic force microscopy (AFM), and; Fourier transform infrared spectroscopy (FTIR). It was found that the oxygen/argon plasma treatment increased both the surface roughness (Ra) and surface free energy (SFE) of the PU paint coating from approximately 60-320 nm, and, from ~52 to ~80 mN/m respectively. It was also found that the plasma process created a multiscale roughened texture through the process of differential ablation between the PU polymer and the barium sulphate solid content, which is present in the paint as an extender, and other additives. In addition, the process also imparted favourable polar groups into the PU surface from the ionised and radical oxygen species in the plasma. When the FAS coating was subsequently applied to the PU without prior plasma treatment, there was a significant increases in water contact angles. This parameter increased from approximately 60°on untreated PU to around 130°with FAS applied. In this case, the SFE decreased to ~7.5 mN/m and showed 42.0 at% fluorine present as indicated by XPS. However, subsequently applying the FAS polymer after plasma pretreatment takes advantage of the known synergistic relationship that exists between surface roughness and low surface free energy coatings. The two processes combined to create superhydrophobicity with a surface that exhibited water contact angles up to 153.1°. With this optimised process, the apparent SFE was 0.84 mN/m with a more highly fluorinated surface present. In this case 47.2 at% surface fluorine was observed by XPS. In addition to changes in SFE, plasma treatment was also observed to alter levels of surface gloss and colour. After exposure to 600 s of plasma gloss levels are shown to reduce from values of from ~50 to ~21 (GU), with small but significant corresponding increases in the lightness and yellowness of the surface
Inherent thermometry in a hybrid superconducting tunnel junction
We discuss inherent thermometry in a Superconductor - Normal metal -
Superconductor tunnel junction. In this configuration, the energy selectivity
of single-particle tunneling can provide a significant electron cooling,
depending on the bias voltage. The usual approach for measuring the electron
temperature consists in using an additional pair of superconducting tunnel
junctions as probes. In this paper, we discuss our experiment performed on a
different design with no such thermometer. The quasi-equilibrium in the central
metallic island is discussed in terms of a kinetic equation including injection
and relaxation terms. We determine the electron temperature by comparing the
micro-cooler experimental current-voltage characteristic with isothermal
theoretical predictions. The limits of validity of this approach, due to the
junctions asymmetry, the Andreev reflection or the presence of sub-gap states
are discussed
Radiation- and Bound-Mode Propagation in Rectangular, Multimode Dielectric, Channel Waveguides With Sidewall Roughness
Characterisation of seasonal temperature variation in a shallow, urban aquifer: implications for the sustainable development of ground source heating systems
Groundwater thermally enhanced by the Urban Heat Island effect can be utilised by ground source heating
systems (GSHSs). However, the near subsurface is subject to seasonal temperature variation reflected in shallow
groundwater that can differ by several degrees throughout the year. To sustainably manage the near surface
thermal resource an understanding of factors which control variation in groundwater temperature and how these
are transmitted through the aquifer is needed.
We show that even in relatively small urban areas (Cardiff, U.K., situated on a shallow gravel aquifer) the
Zone of Seasonal Fluctuation (ZSF) can vary in depth by 8m. GSHSs are more efficient if they are sited below the
ZSF, where temperatures are more stable.
In Spring 2014, 48 groundwater monitoring boreholes were profiled at a 1m resolution to measure groundwater
temperature across Cardiff. These were reprofiled that Autumn and compared to the Spring temperatures,
defining the ZSF. The average depth to the base of the ZSF was 9.5mbgl but ranged from 7.1-15.5mbgl.
The amplitude of the differences between Spring and Autumn temperatures also varied. To better understand
the high spatial variability 60 boreholes were instrumented with in situ temperature loggers, recording at
half-hourly intervals. The first year’s data revealed the amplitudes of temperature variation within boreholes with
loggers at similar depths were not always consistent. It was also noted that lag times between air temperature and
groundwater temperature were not uniform across the sites. The data also showed that where gravels occurred at
shallower depths the ZSF tended to be shallower and lag times shorter.
The wide spatial variability of the ZSF may be partially explained by differing landuse. Those boreholes in
open, grassed areas showed a deeper ZSF than those in built-up areas but built-up areas generally showed
the greatest variation between Spring and Autumn temperature profiles, suggesting heat loss from buildings
and underground infrastructure plays a part. Natural and anthropogenic factors affecting spatial and temporal
groundwater temperatures, either separately or in combination, that have been considered in this study include
landuse, depth, lithology/lithostratigraphy, material properties, hydrogeological setting, thermal conductivity,
buried infrastructure, land surface temperature, weather effects and solar radiation.
This study shows that urban groundwater temperatures can vary greatly across a small area, which has implications
for the successful development, and long-term performance of open- and closed-loop GSHSs, and the
environmental regulation of these systems. Key to the effective wide-scale use of GSHSs is an understanding
of the hydrogeological setting, chiefly how heat is transferred across the aquifer. This study attempts to provide
insight into an array of factors which determine heat transfer in the ZSF
The association of attitudes about contraceptives with contraceptive use in a random sample of Colorado women
Context
Research regarding unintended pregnancy often focuses on how women make decisions about whether or not to use contraceptives, and structural barriers to contraception. Less research examines how multidimensional attitudinal characteristics may be associated with effective contraceptive use.
Methods
In fall 2007, we conducted a random telephone survey of 801 sexually active women in Colorado to assess associations of the attitudinal dimensions of Planning, Partner Communication, and Stigma and Misinformation with contraceptive use. We also examine demographic differences on hypothesized predictors.
Results
Stigma and Misinformation is higher in Latina women, women on Medicaid or with no insurance, women with less than a college degree, and women living in small towns or rural areas. Partner Communication attitudes are most positive among those with a bachelor's degree, and those with less than a high school degree, while they are most negative among those living in small towns and rural areas. In multivariate analysis, planning to use contraceptives is associated with greater likelihood of more effective contraceptive use. Higher levels of planning and partner communication are associated with greater likelihood of any contraceptive use.
Discussion
In addition to addressing structural barriers to contraception, interventions to address the need to plan for contraception are vital to mitigate the high prevalence of unintended pregnancies in the United States
On the third critical field in Ginzburg-Landau theory
Using recent results by the authors on the spectral asymptotics of the
Neumann Laplacian with magnetic field, we give precise estimates on the
critical field, , describing the appearance of superconductivity in
superconductors of type II. Furthermore, we prove that the local and global
definitions of this field coincide. Near only a small part, near the
boundary points where the curvature is maximal, of the sample carries
superconductivity. We give precise estimates on the size of this zone and decay
estimates in both the normal (to the boundary) and parallel variables
RCPE UK consensus conference on 'Approaching the comprehensive management of atrial fibrillation: evolution or revolution?'
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