Archaeological Investigations for FEMA Phase I Master Plan Drainage Improvements, City of Buda, Hays County, Texas

Archaeologists from the Center for Archaeological Studies (CAS) at Texas State University conducted an intensive pedestrian survey including the excavation of 1 mechanical trench and 13 shovel tests along a proposed drainage easement northwest and west-southwest of FM 2770 (also known as Jack C. Hays Trail) in Buda, Texas, from May 14–15, 2018. The survey was executed in order to assess the project area for potential impacts to cultural resources in advance of the installation of a proposed new outfall channel and culvert under FM 2770 in order to divert excess flow from the unnamed tributary of Onion Creek in the City of Buda. Work was carried out by CAS archaeologists Jodi Jacobson and Victoria Pagano under Texas Antiquities Permit Number 8407, assigned to Principal Investigator Jacob Hooge. The area of potential effects (APE) includes a narrow drainage easement no more than 1,600 linear feet, a construction easement width not to exceed 180 feet, with depths not likely to exceed 14.5 feet for a total project acreage of 6.7 acres The project area extends approximately 400 linear feet northwest of FM 2770 and approximetely1,100 linear feet east-southeast. While planned for city acquisition, the property was privately owned and undeveloped at the time of survey. During survey a total of four positive shovel tests with non-diagnostic lithic flakes were encountered, two of which also contained clear bottle glass. Flakes were limited to the upper 70 centimeters (cm) of one of the positive shovel tests and limited to the upper 50 cm of the remaining three. The bottle glass was identified mixed within and even at levels below the flakes in two of the tests with presence depths of historic context not exceeding 50 cm, with an additional surficial scattering of some 20th century mixed with modern mostly surficial trash debris. Given the disturbance, all prehistoric deposits within the project area would be lacking in integrity. CAS recommends that site 41HY548 within the project boundaries would be ineligible for inclusion in the National Register of Historic Places due to lack of integrity of association, setting, or material based on the mixed nature of the deposits, as well as a lack to provide new or additional information. CAS recommends full regulatory clearance for the proposed project

On absolute Galois splitting fields of central simple algebras

A splitting field of a central simple algebra is said to be absolute Galois if it is Galois over some fixed subfield of the centre of the algebra. The paper provides an existence theorem for such fields over global fields with enough roots of unity. As an application, all twisted function fields and all twisted Laurent series rings over symbol algebras (or p-algebras) over global fields are crossed products. A closely related statement holds for division algebras over Henselian valued fields with global residue field. The existence of absolute Galois splitting fields in central simple algebras over global fields is equivalent to a suitable generalization of the weak Grunwald-Wang Theorem, which is proved to hold if enough roots of unity are present. In general, it does not hold and counter examples have been used in noncrossed product constructions. This paper shows in particular that a certain computational difficulty involved in the construction of explicit examples of noncrossed product twisted Laurent series rings can not be avoided by starting the construction with a symbol algebra.Comment: 12 pages (A4); to appear in J. Number Theory (2007

Export efficiency of black carbon aerosol in continental outflow: Global implications

We use aircraft observations of Asian outflow from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) mission over the NW Pacific in March–April 2001 to estimate the export efficiency of black carbon (BC) aerosol during lifting to the free troposphere, as limited by scavenging from the wet processes (warm conveyor belts and convection) associated with this lifting. Our estimate is based on the enhancement ratio of BC relative to CO in Asian outflow observed at different altitudes and is normalized to the enhancement ratio observed in boundary layer outflow (0–1 km). We similarly estimate export efficiencies of sulfur oxides (SO x = SO2(g) + fine SO4 2−) and total inorganic nitrate (HNO3 T = HNO3(g) + fine NO3 −) for comparison to BC. Normalized export efficiencies for BC are 0.63–0.74 at 2–4 km altitude and 0.27–0.38 at 4–6 km. Values at 2–4 km altitude are higher than for SO x (0.48–0.66) and HNO3 T (0.29–0.62), implying that BC is scavenged in wet updrafts but not as efficiently as sulfate or nitrate. Simulation of the TRACE-P period with a global three-dimensional model (GEOS-CHEM) indicates that a model timescale of 1 ± 1 days for conversion of fresh hydrophobic to hydrophilic BC provides a successful fit to the export efficiencies observed in TRACE-P. The resulting mean atmospheric lifetime of BC is 5.8 ± 1.8 days, the global burden is 0.11 ± 0.03 Tg C, and the decrease in Arctic snow albedo due to BC deposition is 3.1 ± 2.5%.Earth and Planetary Science

A multi-objective, hub-and-spoke model to design and manage biofuel supply chains

In this paper we propose a multi-objective, mixed integer linear programming model to design and manage the supply chain for biofuels. This model captures the trade-offs that exist between costs, environmental and social impacts of delivering biofuels. The in-bound supply chain for biofuel plants relies on a hub-and-spoke structure which optimizes transportation costs of biomass. The model proposed optimizes the CO2 style= position: relative; tabindex= 0 id= MathJax-Element-1-Frame \u3eCO2 emissions due to transportation-related activities in the supply chain. The model also optimizes the social impact of biofuels. The social impacts are evaluated by the number of jobs created. The multi-objective optimization model is solved using an augmented ϵ style= position: relative; tabindex= 0 id= MathJax-Element-2-Frame \u3eϵ-constraint method. The method provides a set of Pareto optimal solutions. We develop a case study using data from the Midwest region of the USA. The numerical analyses estimates the quantity and cost of cellulosic ethanol delivered under different scenarios generated. The insights we provide will help policy makers design policies which encourage and support renewable energy production

Single ion heat engine with maximum efficiency at maximum power

We propose an experimental scheme to realize a nano heat engine with a single ion. An Otto cycle may be implemented by confining the ion in a linear Paul trap with tapered geometry and coupling it to engineered laser reservoirs. The quantum efficiency at maximum power is analytically determined in various regimes. Moreover, Monte Carlo simulations of the engine are performed that demonstrate its feasibility and its ability to operate at maximum efficiency of 30% under realistic conditions.Comment: 5 pages, 3 figure

Summary of the cloud chemistry modeling intercomparison: Photochemical box model simulation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94892/1/jgrd10037.pd

Measurement errors in body size of sea scallops (Placopecten magellanicus) and their effect on stock assessment models

Body-size measurement errors are usually ignored in stock assessments, but may be important when body-size data (e.g., from visual sur veys) are imprecise. We used experiments and models to quantify measurement errors and their effects on assessment models for sea scallops (Placopecten magellanicus). Errors in size data obscured modes from strong year classes and increased frequency and size of the largest and smallest sizes, potentially biasing growth, mortality, and biomass estimates. Modeling techniques for errors in age data proved useful for errors in size data. In terms of a goodness of model fit to the assessment data, it was more important to accommodate variance than bias. Models that accommodated size errors fitted size data substantially better. We recommend experimental quantification of errors along with a modeling approach that accommodates measurement errors because a direct algebraic approach was not robust and because error parameters were diff icult to estimate in our assessment model. The importance of measurement errors depends on many factors and should be evaluated on a case by case basis

Lorentz Symmetry breaking studies with photons from astrophysical observations

Lorentz Invariance Violation (LIV) may be a good observational window on Quantum Gravity physics. Within last few years, all major Gamma-ray experiments have published results from the search for LIV with variable astrophysical sources: gamma-ray bursts with detectors on-board satellites and Active Galactic Nuclei with ground-based experiments. In this paper, the recent time-of-flight studies with unpolarized photons published from the space and ground based observations are reviewed. Various methods used in the time delay searches are described, and their performance discussed. Since no significant time-lag value was found within experimental precision of the measurements, the present results consist of 95% confidence cevel limits on the Quantum Gravity scale on the linear and quadratic terms in the standard photon dispersion relations.Comment: 22 pages, 9 figures. V2 match the published version. Invited review talk to the 2nd International Colloquium "Scientific and Fundamental Aspects of the Galileo Programme", 14-16 october 2009, Padua, Ital