Water facilities in retrospect and prospect: An illuminating tool for vehicle design

Water facilities play a fundamental role in the design of air, ground, and marine vehicles by providing a qualitative, and sometimes quantitative, description of complex flow phenomena. Water tunnels, channels, and tow tanks used as flow-diagnostic tools have experienced a renaissance in recent years in response to the increased complexity of designs suitable for advanced technology vehicles. These vehicles are frequently characterized by large regions of steady and unsteady three-dimensional flow separation and ensuing vortical flows. The visualization and interpretation of the complicated fluid motions about isolated vehicle components and complete configurations in a time and cost effective manner in hydrodynamic test facilities is a key element in the development of flow control concepts, and, hence, improved vehicle designs. A historical perspective of the role of water facilities in the vehicle design process is presented. The application of water facilities to specific aerodynamic and hydrodynamic flow problems is discussed, and the strengths and limitations of these important experimental tools are emphasized

Application of the Recovery Potential Screening Tool in the Matagorda Bay Watershed

The State of Texas currently contains 568 water bodies considered impaired due to excessive pollutant loading. Of these, approximately 48% are impaired due to elevated levels of fecal indicator bacteria from animals, birds and humans. Once impaired, efforts to restore water quality must be undertaken. This large number of bacteria impairments leaves the State with a sizable task ahead and presents a range of restoration challenges. Restoring all of these impaired water bodies is costly and resource intensive, thus prioritizing future water quality restoration efforts is a means to efficiently allocate available resources and achieve timely restoration results. The U.S. Environmental Protection Agency (EPA) developed the Recovery Potential Screening (RPS) tool to help prioritize water body restoration planning efforts (Norton et al. 2009). Built as a technical aid for states and government agencies, the RPS tool provides a systematic approach for comparing the relative restorability of water bodies. When employed and supplied with sufficient data, this tool can aid groups and entities considering restoration efforts determine which water bodies have the highest likelihood of successful water quality restoration based on characteristics of the local watershed (U.S. EPA 2014)

Basin Approach to Address Bacterial Impairments in Basins 15, 16, and 17

In the 2012 Texas Integrated Report and 303(d) List, approximately 48% of the 568 impaired water bodies were caused by high bacteria levels. Once a water body has been listed, the Clean Water Act requires action to be undertaken to restore water quality in that water body. Several options exist to achieve this, which include additional monitoring, a standards assessment, development of a total maximum daily load (TMDL) or development of another watershed based plan such as a watershed protection plan. Traditionally, impairments have been addressed one at a time. In order to more efficiently address similar impairments within the same basin, more efficiently distribute resources, and with the hopes of preventing future listings within the same watershed, a new basin wide approach is being implemented in the Texas River Basins 15 (Colorado – Lavaca), 16 (Lavaca), and 17 (Lavaca Guadalupe). These watersheds, collectively referred to as the Matagorda Bay watershed have five water body assessment units impaired for elevated levels of fecal indicator bacteria: Carancahua Bay, Arenosa Creek, Tres Palacios Creek and two segments of the Lavaca River. This report discusses the current and historical state of the study area and focuses on describing the physical, hydrological, climatic, and demographic conditions as well as potential sources of pollution. Information presented will be used in future water quality analysis and will assist in determining how to address bacteria impairments in the watershed. Information is compiled on a watershed level, summarizing all three basins, as well as within each basin where appropriate

Observation of the Cabibbo-suppressed decay Xi_c+ -> p K- pi+

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi_c+ -> p K- pi+. We observe 150 +- 22 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma- beam. The branching fractions of the decay relative to the Cabibbo-favored Xi_c+ -> Sigma+ K- pi+ and Xi_c+ -> X- pi+ pi+ are measured to be B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> Sigma+ K- pi+) = 0.22 +- 0.06 +- 0.03 and B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> X- pi+ pi+) = 0.20 +- 0.04 +- 0.02, respectively.Comment: 5 pages, RevTeX, 3 figures (postscript), Submitted to Phys. Rev. Let

First Observation of the Doubly Charmed Baryon Xi_cc^+

We observe a signal for the doubly charmed baryon Xi_cc^+ in the charged decay mode Xi_cc^+ --> Lambda_c^+ K- pi+ in data from SELEX, the charm hadro-production experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1 +/- 0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is (3519 +/- 1) MeV/c^2. The Gaussian mass width of this state is 3MeV/c^2, consistent with resolution; its lifetime is less than 33fsec at 90% confidence.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter

First Measurement of pi e -> pi e gamma Pion Virtual Compton Scattering

Pion Virtual Compton Scattering (VCS) via the reaction pi e --> pi e gamma was observed in the Fermilab E781 SELEX experiment. SELEX used a 600 GeV/c pi- beam incident on target atomic electrons, detecting the incident pi- and the final state pi-, electron and gamma. Theoretical predictions based on chiral perturbation theory are incorporated into a Monte Carlo simulation of the experiment and are compared to the data. The number of reconstructed events (9) and their distribution with respect to the kinematic variables (for the kinematic region studied) are in reasonable accord with the predictions. The corresponding pi- VCS experimental cross section is sigma=38.8+-13 nb, in agreement with the theoretical expectation sigma=34.7 nb.Comment: 10 pages, 12 figures, 4 tables, 25 references, SELEX home page is http://fn781a.fnal.gov/, revised July 21, 2002 in response to journal referee Comment

Measurement of direct photon production at Tevatron fixed target energies

Measurements of the production of high transverse momentum direct photons by a 515 GeV/c piminus beam and 530 and 800 GeV/c proton beams in interactions with beryllium and hydrogen targets are presented. The data span the kinematic ranges of 3.5 < p_T < 12 GeV/c in transverse momentum and 1.5 units in rapidity. The inclusive direct-photon cross sections are compared with next-to-leading-order perturbative QCD calculations and expectations based on a phenomenological parton-k_T model.Comment: RevTeX4, 23 pages, 32 figures, submitted to Phys. Rev.

de Broglie waves as the "Bridge of Becoming" between quantum theory and relativity

It is hypothesized that de Broglie's 'matter waves' provide a dynamical basis for Minkowski spacetime in an antisubstantivalist or relational account. The relativity of simultaneity is seen as an effect of the de Broglie oscillation together with a basic relativity postulate, while the dispersion relation from finite rest mass gives rise to the differentiation of spatial and temporal axes. Thus spacetime is seen as not fundamental, but rather as emergent from the quantum level. A result by Solov'ev which demonstrates that time is not an applicable concept at the quantum level is adduced in support of this claim. Finally, it is noted that de Broglie waves can be seen as the "bridge of becoming" discussed by Elitzur and Dolev (2005).Comment: Forthcoming in Foundations of Science; reference added to recent work of Dolc

Evidence for Parton kT Effects in High pT Particle Production

Inclusive pizero and direct-photon cross sections in the kinematic range 3.5 < pT < 12 GeV/c with central rapidities are presented for 530 and 800 GeV/c proton beams and a 515 GeV/c pi- beam incident on beryllium targets. Current Next-to-Leading-Order perturbative QCD calculations fail to adequately describe the data for conventional choices of scales. Kinematic distributions from these hard scattering events provide evidence that the interacting partons carry significant initial-state parton transverse momentum (kT). Incorporating these kT effects phenomenologically greatly improves the agreement between calculations and the measured cross sections.Comment: 11 pages including 6 pages of figures with caption