2,039 research outputs found

    Archeological Survey of Wildlife Mitigation Lands, Justiceburg Reservoir, Garza County, Texas

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    In order to fulfill its obligations in conjunction with the proposed Jnsticeburg Reservoir project, the City of Lubbock, Texas, is considering the purchase of 2,240 acres in Garza County to serve as wildlife mitigation lands. Prior to the City\u27s final decision to acquire the land, an archeological survey was conducted. The ca. 1,000 acres of incised canyonland and upland margin and ca. 215 acres of selected upland rises were intensively surveyed, while the remaining 1,025 acres of upland flat and low-lying areas were spot checked. Subsurface geomorphic investigations (i.e., backhoe trenching) of the uplands were also conducted. The survey resulted in the documentation of 1 historic and 32 prehistoric archeological sites (1 previously recorded). Of these, the historic site is recommended as eligible for listing on the National Register of Historic Places, and eight prehistoric sites are of unknown eligibility. These nine sites will need special management considerations to prevent impacts from wildlife mitigation use of the land. Historic use of the project area is associated with late nineteenth/early twentieth-century cattle ranching, while all of the prehistoric occupations that can be temporally defined are late Archaic or Late Prehistoric. Most of the cultural activity is clustered around three major freshwater spring complexes. There appears to have been intensive use of these areas during the late Holocene but only ephemeral prehistoric use of the uplands more than 0.5 km away from the springs and stream channels. Geomorphic evidence indicates that extensive root-plow disturbance occurred in many upland areas, but well-preserved archeological deposits are present in portions of the eroded upland margin. Three unique upland depositional environments (playas with associated dunes, channels, and pond deposits) have the potential for preserving buried cultural remains of considerable antiquity as well as providing paleo-environmental data which is lacking at this time

    Archaeological Survey of Southwest Block and Selected Roads and Firebreaks at Camp Maxey, Lamar County, Texas

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    In June, July, and September 1998, The Center for Archaeological Research (CAR) of The University of Texas at San Antonio (UTSA) conducted an archaeological survey of approximately 1,000 acres for the Texas Army National Guard (TXARNG) on Camp Maxey, a TXARNG training facility in north-central Lamar County, Texas, under Sections 106 and 110 of the National Historic Preservation Act and the Antiquities Code of Texas. The TXARNG had identified the 1,000-acre area for possible impact associated with the construction of firebreaks, road improvements, and subsequent military training with tracked and wheeled vehicles. Thirty archaeological sites were found and documented. Twenty-three sites contained a prehistoric component only, five sites contained a historic component only, and two sites contained both a prehistoric and historic component. Based on the results of the pedestrian survey and limited shovel testing, CAR recommends that the following sites are insignificant and therefore ineligible for inclusion in the National Register of Historic Places or for designation as State Archaeological Landmarks: 41LR149, 41LR150, 41LR151, 41LR169, 41LR171, 41LR172, 41LR173, 41LR174, 41LR176, 41LR178, and 41LR179. CAR recommends that because the significance of the following sites is unknown, the TXARNG either avoid further impact to them, or conduct test excavations to determine their significance: 41LR152, 41LR153, 41LR154, 41LR155, 41LR156, 41LR157, 41LR158, 41LR159, 41LR160, 41LR161, 41LR162, 41LR163, 41LR164, 41LR165, 41LR166, 41LR167, 41LR168, 41LR175, and 41LR177

    The Multifragmentation Freeze--Out Volume in Heavy Ion Collisions

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    The reduced velocity correlation function for fragments from the reaction Fe + Au at 100 A~MeV bombarding energy is investigated using the dynamical--statistical approach QMD+SMM and compared to experimental data to extract the Freeze--Out volume assuming simultaneous multifragmentation.Comment: 8 pages; 3 uuencoded figures available with figures command, LateX, UCRL-J-1157

    The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0

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    The All-Sky Automated Survey for Supernovae (ASAS-SN) is working towards imaging the entire visible sky every night to a depth of V~17 mag. The present data covers the sky and spans ~2-5~years with ~100-400 epochs of observation. The data should contain some ~1 million variable sources, and the ultimate goal is to have a database of these observations publicly accessible. We describe here a first step, a simple but unprecedented web interface https://asas-sn.osu.edu/ that provides an up to date aperture photometry light curve for any user-selected sky coordinate. Because the light curves are produced in real time, this web tool is relatively slow and can only be used for small samples of objects. However, it also imposes no selection bias on the part of the ASAS-SN team, allowing the user to obtain a light curve for any point on the celestial sphere. We present the tool, describe its capabilities, limitations, and known issues, and provide a few illustrative examples.Comment: 8 pages, 9 figures, submitted to PAS

    Data Recovery at Justiceburg Reservoir (Lake Alan Henry), Garza and Kent Counties, Texas: Phase III, Season 1

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    Phase III data recovery investigations at one historic and three prehistoric sites, augmented by additional survey and off-site geological investigations, were conducted at Lake Alan Henry (formerly Justiceburg Reservoir) on the Double Mountain Fork of the Brazos River in Garza and Kent counties, Texas, during the fall and winter of 1990-1991. Descriptive data from this first of three field seasons of data recovery are presented here in anticipation of a final synthetic report that will relate all the investigations to a series of research design hypotheses. Analysis of surface distributions at 41KT42, a late nineteenth- to early twentieth-century ranch line camp known locally as the Ed Scott Cabin, groups the artifacts into material and functional categories that demonstrate primary and secondary refuse accumulations adjacent to the cabin. The distribution of primary refuse shows kitchen artifacts are spatially distinct from other types that include architectural, firearm, ranching, clothing, and personal items. The primary discard pattern is obfuscated by redistribution attributed to secondary refuse discard. The uppermost of two superimposed hearths at 41GR484, the Grape Creek Bench Site, is radiocarbon dated to 260 B.P. and yielded charcoal identified as Carya sp. Excavations were halt~d at this Late Prehistoric II site because of extremely low artifact recovery. Geoarcheological investigations demonstrate that most of the site has been destroyed by cutbank erosion associated with the meanderings of Grape Creek. At 41KT33, the Late Prehistoric I South Sage Creek Site, stone-lined hearth features dated to 1005 B.P. are surrounded by clusters of artifacts. Petrographic analysis of brownware ceramics suggests affiliations with the local Palo Duro Complex and nonlocally with the Pecos River valley. The Gobbler Creek Bridge Site, 4IGR383, spans the late Archaic and Late Prehistoric I periods. Intact· and dispersed stone-lined hearths radiocarbon dated to 1865-1215 B.P. are surrounded by artifact clusters. Both of the sites appear to have been multifunctional campsites, and repeated occupations are likely. Dense concentrations of fire-cracked rocks at these sites may represent secondary refuse disposal. Lithic analysis indicates extensive use of nonlocal materials derived from Cretaceous formations that occur in the Callahan Divide and Edwards Plateau to the south. Freshwater mussels are the only faunal remains recovered from either of these sites. The meat is presumed to have been consumed as food, while the shells sometimes were made into ornaments. An additional 440 acres of land were surveyed for cultural resources; 360 of these acres were subsequently acquired by the City of Lubbock for use as wildlife mitigation lands. Nine prehistoric archeological sites and one isolated fmd were documented and evaluated for their eligibility for listing on the National Register of Historic Places. Five of these sites are considered to be ineligible for listing on the National Register, and five are potentially eligible for listing. Avoidance is recommended at these five sites, with testing recommended to determine their National Register eligibility if avoidance is not possible. Geological investigations provide information about depositional environments in and near the archeological sites. Two soils buried in the Double Mountain Fork floodplain are radiocarbon dated to 8~00 B.P. and 1700-1300 B.P.; fluvial sediments extend as much as 15 m below these soils in portions of the floodplain. An older terrace previously was identified 18 m above the modem river channel. Current work obtained a terminal date of 8690 B.P. from a buried soil that caps this older terrace. Another radiocarbon date of 3320 B.P. was obtained from fill in a gully that is eroded into the older terrace. These dates bracket an erosional episode when the older terrace was heavily dissected. The erosion coincides with the Altithermal, a period believed to have been characterized by a hot and dry climatic regime

    Links between optical and X-ray light in Scorpius X-1

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    We observed the low-mass X-ray binary Sco X-1 for 12 nights simultaneously using the Rossi X-Ray Timing Explorer and the Otto Struve Telescope at McDonald Observatory at 1-s time-resolution. This is among the most comprehensive simultaneous X-Ray/optical data sets of Sco X-1. Evidence of reprocessing was observed in the form of nine positive, near-zero lag peaks in the cross-correlation function, eight of which were relatively small, and took the shape of piecewise exponential functions. These peaks were initially identified by eye, after which a computational identification scheme was developed to confirm their significance. Based on their short lags (less than 4 s), as well as their occurrence on the flaring branch (FB) and soft apex, the small cross-correlation features are likely to be caused by reprocessing off the outer disc, although the companion could stillmake a contribution to their tails. The Z track was parameterized using a rank number scheme so that the system’s location on the track could be numerically defined. Plotting the results against the optical reveals an increasing step function when moving from the horizontal branch to the normal branch (NB) to the FB, with differential optical levels at ∼0.47, ∼0.57, and ∼1.1, respectively. An additional correlation between Z track location and the optical was found on the upper FB. An optical intensity histogram reveals a transition region between the NB and FB with only intermediate fluxes

    Systematics of Fission Barriers in Superheavy Elements

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    We investigate the systematics of fission barriers in superheavy elements in the range Z = 108-120 and N = 166-182. Results from two self-consistent models for nuclear structure, the relativistic mean-field (RMF) model as well as the non-relativistic Skyrme-Hartree-Fock approach are compared and discussed. We restrict ourselves to axially symmetric shapes, which provides an upper bound on static fission barriers. We benchmark the predictive power of the models examining the barriers and fission isomers of selected heavy actinide nuclei for which data are available. For both actinides and superheavy nuclei, the RMF model systematically predicts lower barriers than most Skyrme interactions. In particular the fission isomers are predicted too low by the RMF, which casts some doubt on recent predictions about superdeformed ground states of some superheavy nuclei. For the superheavy nuclei under investigation, fission barriers drop to small values around Z = 110, N = 180 and increase again for heavier systems. For most of the forces, there is no fission isomer for superheavy nuclei, as superdeformed states are in most cases found to be unstable with respect to octupole distortions.Comment: 17 pages REVTEX, 12 embedded eps figures. corrected abstrac

    A dynamical model of surrogate reactions

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    A new dynamical model is developed to describe the whole process of surrogate reactions; transfer of several nucleons at an initial stage, thermal equilibration of residues leading to washing out of shell effects and decay of populated compound nuclei are treated in a unified framework. Multi-dimensional Langevin equations are employed to describe time-evolution of collective coordinates with a time-dependent potential energy surface corresponding to different stages of surrogate reactions. The new model is capable of calculating spin distributions of the compound nuclei, one of the most important quantity in the surrogate technique. Furthermore, various observables of surrogate reactions can be calculated, e.g., energy and angular distribution of ejectile, and mass distributions of fission fragments. These features are important to assess validity of the proposed model itself, to understand mechanisms of the surrogate reactions and to determine unknown parameters of the model. It is found that spin distributions of compound nuclei produced in 18^{18}O+238^{238}U 16\rightarrow ^{16}O+240^{240*}U and 18^{18}O+236^{236}U 16\rightarrow ^{16}O+238^{238*}U reactions are equivalent and much less than 10\hbar, therefore satisfy conditions proposed by Chiba and Iwamoto (PRC 81, 044604(2010)) if they are used as a pair in the surrogate ratio method.Comment: 17 pages, 5 figure

    Current contraceptive management in Australian general practice: An analysis of BEACH data

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    Objective: To determine current contraceptive management by general practitioners in Australia. Design, setting and participants: Analysis of data from a random sample of 3910 Australian GPs who participated in the Bettering the Evaluation and Care of Health (BEACH) survey, a continuous cross-sectional survey of GP activity, between April 2007 and March 2011. Consultations with female patients aged 12-54 years that involved all forms of contraception were analysed. Main outcome measures: GP and patient characteristics associated with the management of contraception; types of contraception used; rates of encounters involving emergency contraception. Results: Increased age, ethnicity, Indigenous status and holding a Commonwealth Health Care Card were significantly associated with low rates of encounters involving management of contraception. The combined oral contraceptive pill was the most frequently prescribed method of contraception, with moderate prescription of long-acting reversible contraception (LARC), especially among women aged 34-54 years. Rates of consultations concerned with emergency contraception were low, but involved high rates of counselling, advice or education (48%) compared with encounters for general contraception (> 20%). Conclusion: A shift towards prescribing LARC, as recommended in clinical guidelines, has yet to occur in Australian general practice. Better understanding of patient and GP perspectives on contraceptive choices could lead to more effective contraceptive use
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