Hydrologic Tests at Characterization Wells R-9i, R-13, R-19, R-22, and R-31

Hydrologic information is essential for environmental efforts at Los Alamos National Laboratory. Testing at new characterization wells being drilled to the regional aquifer (''R wells'') to improve the conceptual hydrogeologic model of the Pajarito Plateau is providing such information. Drilling has been by air-rotary casing-advance or open-hole methods. Most wells are completed with multiple screens. After their construction, wells were rigorously developed by wire-brushing, bailing, followed by surging, swabbing, or jetting, and finally by pumping. These methods are effective based on field-parameter measurements and comparison of results of hydrologic testing at well R-31 before and after complete well development. We conducted field tests on various zones of saturation penetrated by the R wells to collect data needed for determining hydraulic properties. This document provides details of the design and execution of testing as well as an analysis of data for five of the new wells: R-9i, R-13, R-19, R-22, and R-31. One well was evaluated by a pumping test (R-13), another was evaluated by both straddle-packer/injection and pumping tests (R-9i), and the rest were evaluated by injection tests alone (R-19, R-22, R-31). Testing was constrained by the regional setting (complex geology and multiple zones of saturation) and well construction (multiscreen completion and the small diameter of the production casing). Packers are required for testing multiscreen wells. The small diameter of the production casing not only precludes the use of a slugger but also limits the capacity of pumps that can be used in testing, especially for the depths involved in the R wells. For example, pumping at a maximum rate of 19 gallons per minute did not significantly stress the regional aquifer at R-13. Although not slug tests, the injection tests are comparable in several ways, and analysis of data by slugtest methods is appropriate. Despite constraints, the results obtained appear valid based on (1) the care taken during test implementation and data analysis, (2) comparison of results for initial and repeated tests obtained by the same analytical method, (3) comparison of results obtained for a given test by different analytical methods, (4) comparison of results with values determined by geophysical logging in the wells and pumping tests of the same geologic units elsewhere on the plateau, and (5) comparison with hydraulic properties commonly reported for similar geologic materials outside the area. Significant contributions of this report are not only the documentation of test design, implementation, and analysis but also a comprehensive table showing the distribution of hydraulic properties for the saturated geologic units tested beneath the Pajarito Plateau. We also offer several recommendations based on testing to date. Placing screens across the water table and geologic contacts as well as employing oversized filter packs hinders testing and should be avoided. In addition, we recommend that future testing include some alternative designs and methods. Multiple methods and routine repeat testing for a given screened interval would permit comparison of results

TikiWiki: a tool to support engineering design students in concept generation

For student design engineers, the concept generation stage of the design process is usually one of most creative, but poses problems in handling large amounts of information when developing new ideas. Storing such information digitally potentially makes its retrieval and utilisation quicker and easier - ideal for the inherently spontaneous nature of the concept generation task. There is, however, currently a low use of existing electronic resources amongst undergraduate students. This paper discusses how a group of product design engineering students were encouraged to use TikiWiki, a groupware product, as an integral part of a design project. It was observed that a digital repository has a positive effect on concept generation, despite the logistical problems with moving information into the digital domain. Students were able to better interact with the information, evidenced by hierarchical and well constructed topic information resources, a high number of ‘hits’ on their Wiki pages, clear references to information used in concept design templates and instances of ‘topic-led’ designs where the research carried out by a group clearly influenced design direction. Additionally, students showed a strong preference for browsing the structured Wiki pages they had created rather than searching with keywords, in keeping with the open-ended nature of concept generation

Natural disturbances and the physiognomy of pine savannas : A phenomenological model

Abstract. Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of ‘old-growth’ stands, and what are the implications for ecosystem conservation and restoration? Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the physiognomic structure of Pinus palustris stands. We relate two natural disturbances (tropical storms and fire) that affect different stages of the life cycle to different aspects of the physiognomic structure. We then compare overstorey stand structure and ground cover composition of two old-growth longleaf stands near the extremes of different composite disturbance regimes: the Wade Tract (frequent hurricanes and fire) and the Boyd Tract (infrequent hurricanes and long-term fire exclusion). Results: We predict that tropical storms and fires have different effects on stand physiognomy. Tropical storms are periodic, and sometimes intense, whereas fires are more frequent and less intense. Hurricanes directly influence the overstorey via wind-caused damage and mortality, and indirectly influence the herb layer by altering the spatial distribution of shading and litter accumulation. Fire exerts direct effects on juvenile stages and indirect effects on the herb layer via fine fuel consumption and selective mortality of potential competitors of P. palustris juveniles. These differences in effects of disturbances can result in widely different physiognomies for P. palustris stands. Finally, some global climate change scenarios have suggested that changes may occur in tropical storm and fire regimes, altering frequency and severity. Such changes may greatly affect pine stands, and ultimately entire pine savanna ecosystems. Conclusions: Our phenomenological model of disturbance regimes in Pinus palustris old-growth produces very different physiognomies for different disturbances regimes that reflect natural process and human management actions. This model can be used to derive restoration strategies for pine savannas that are linked to reinstitution of important ecological processes rather than specific physiognomic states

The Reporting on ERAS Compliance, Outcomes, and Elements Research (RECOvER) Checklist: A Joint Statement by the ERAS^® and ERAS^® USA Societies.

Enhanced recovery after surgery (ERAS) programs are multimodal care pathways designed to minimize the physiological and psychological impact of surgery for patients. Increased compliance with ERAS guidelines is associated with improved patient outcomes across surgical types. As ERAS programs have proliferated, an unintentional effect has been significant variation in how ERAS-related studies are reported in the literature. To improve the quality of ERAS reporting, ERAS <sup>®</sup> USA and the ERAS <sup>®</sup> Society launched an effort to create an instrument to assist authors in manuscript preparation. Criteria to include were selected by a combination of literature review and expert opinion. The final checklist was refined by group consensus. The Societies present the Reporting on ERAS Compliance, Outcomes, and Elements Research (RECOvER) Checklist. The tool contains 20 items including best practices for reporting clinical pathways, compliance auditing, and formatting guidelines. The RECOvER Checklist is intended to provide a standardized framework for the reporting of ERAS-related studies. The checklist can also assist reviewers in evaluating the quality of ERAS-related manuscripts. Authors are encouraged to include the RECOvER Checklist when submitting ERAS-related studies to peer-reviewed journals

Vertically Self-Gravitating ADAFs in the Presence of Toroidal Magnetic Field

Force due to the self-gravity of the disc in the vertical direction is considered to study its possible effects on the structure of a magnetized advection-dominated accretion disc. We present steady-sate self similar solutions for the dynamical structure of such a type of the accretion flows. Our solutions imply reduced thickness of the disc because of the self-gravity. It also imply that the thickness of the disc will increase by adding the magnetic field strength.Comment: Accepted for publication in Astrophysics and Space Science

Comparison of temperature-dependent calibration methods of an instrument to measure OH and HO₂ radicals using laser-induced fluorescence spectroscopy

Laser-induced fluorescence (LIF) spectroscopy has been widely applied to fieldwork measurements of OH radicals and HO2, following conversion to OH, over a wide variety of conditions, on different platforms and in simulation chambers. Conventional calibration of HOx (OH + HO2) instruments has mainly relied on a single method, generating known concentrations of HOx from H2O vapour photolysis in a flow of zero air impinging just outside the sample inlet (SHOx = CHOx . [HOx ], where SHOx is the observed signal and CHOx is the calibration factor). The fluorescence assay by gaseous expansion (FAGE) apparatus designed for HOx measurements in the Highly Instrumented Reactor for Atmospheric Chemistry (HIRAC) at the University of Leeds has been used to examine the sensitivity of FAGE to external gas temperatures (266–348 K). The conventional calibration methods give the temperature dependence of COH (relative to the value at 293 K) of (0.0059±0.0015) K−1 and CHO2 of (0.014±0.013) K−1. Errors are 2σ . COH was also determined by observing the decay of hydrocarbons (typically cyclohexane) caused by OH reactions giving COH (again, relative to the value at 293 K) of (0.0038 ± 0.0007) K−1. Additionally, CHO2 was determined based on the second-order kinetics of HO2 recombination with the temperature dependence of CHO2 , relative to 293 K being (0.0064 ± 0.0034) K−1. The temperature dependence of CHOx depends on the HOx number density, quenching, the relative population of the probed OH rotational level and HOx transmission from the inlet to the detection axis. The first three terms can be calculated and, in combination with the measured values of CHOx, show that HOx transmission increases with temperature. Comparisons with other instruments and the implications of this work are discussed

Relation Between Chiral Susceptibility and Solutions of Gap Equation in Nambu--Jona-Lasinio Model

We study the solutions of the gap equation, the thermodynamic potential and the chiral susceptibility in and beyond the chiral limit at finite chemical potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation between the chiral susceptibility and the thermodynamic potential in the NJL model. We find that the chiral susceptibility is a quantity being able to represent the furcation of the solutions of the gap equation and the concavo-convexity of the thermodynamic potential in NJL model. It indicates that the chiral susceptibility can identify the stable state and the possibility of the chiral phase transition in NJL model.Comment: 21 pages, 6 figures, misprints are correcte

Search for Neutral Higgs Bosons of the Minimal Supersymmetric Standard Model in e+e- Interactions at \sqrt{s} = 189 GeV

A search for the lightest neutral scalar and neutral pseudoscalar Higgs bosons in the Minimal Supersymmetric Standard Model is performed using 176.4 pb^-1 of integrated luminosity collected by L3 at a center-of-mass energy of 189 GeV. No signal is observed, and the data are consistent with the expected Standard Model background. Lower limits on the masses of the lightest neutral scalar and pseudoscalar Higgs bosons are given as a function of tan(beta). Lower mass limits for tan(beta)>1 are set at the 95% confidence level to be m_h > 77.1 GeV and m_A > 77.1 GeV