Archaeological Survey of the Proposed Crawford Memorial Park Improvements Dallas County, Texas

The City of Dallas is proposing to improve the existing Crawford Memorial Park in central-southeastern Dallas County, Texas. DIPS Environmental, Inc., contracted with AR Consultants, Inc. to conduct an intensive archaeological survey of Crawford Memorial Park under the authority of Texas Antiquities Permit number 8747. Crawford Memorial Park totals approximately 265 acres. However, modern landscape modifications including a number of sports fields, the Crawford Aquatic Center, parking lots, cement walking paths, a playground, pavilion, bathrooms, and a City of Dallas Park and Recreation Maintenance Facility exist within the park boundary and project area. As Crawford Memorial Park has never been surveyed for archaeological resources, the area of the park where these modern landscape modifications have occurred, approximately 105 acres, was subject to a reconnaissance pedestrian survey without shovel testing. Approximately 160 acres of Crawford Memorial Park was subject to an intensive pedestrian survey with shovel testing. In total, 57 shovel tests were excavated during the systematic field inspection on March 5-6, 11, 14, and 19-20, 2019. The archaeological potential for prehistoric and historic cultural resources had been considered low except for a known earthen berm and floodwater overflow feature that was constructed to dam the old Prairie Creek channel in 1961. This historic site, 41DL549, was the only site recorded during survey. Apart from 41DL549 no cultural resources were identified in the shovel tests or on the surface. Given the results of this survey, AR Consultants, Inc. recommends that further cultural resource investigations are unnecessary for this project, and requests that the Texas Historical Commission and the Fort Worth District of the U.S. Army Corps of Engineers concur with this recommendation. The field notes, photographs, and photo logs are curated at the Center for Archaeological Studies at Texas State University in San Marcos, Texas

Archaeological Survey of the Proposed Crawford Memorial Park Improvements Dallas County, Texas

The City of Dallas is proposing to improve the existing Crawford Memorial Park in central-southeastern Dallas County, Texas. DIPS Environmental, Inc., contracted with AR Consultants, Inc. to conduct an intensive archaeological survey of Crawford Memorial Park under the authority of Texas Antiquities Permit number 8747. Crawford Memorial Park totals approximately 265 acres. However, modern landscape modifications including a number of sports fields, the Crawford Aquatic Center, parking lots, cement walking paths, a playground, pavilion, bathrooms, and a City of Dallas Park and Recreation Maintenance Facility exist within the park boundary and project area. As Crawford Memorial Park has never been surveyed for archaeological resources, the area of the park where these modern landscape modifications have occurred, approximately 105 acres, was subject to a reconnaissance pedestrian survey without shovel testing. Approximately 160 acres of Crawford Memorial Park was subject to an intensive pedestrian survey with shovel testing. In total, 57 shovel tests were excavated during the systematic field inspection on March 5-6, 11, 14, and 19-20, 2019. The archaeological potential for prehistoric and historic cultural resources had been considered low except for a known earthen berm and floodwater overflow feature that was constructed to dam the old Prairie Creek channel in 1961. This historic site, 41DL549, was the only site recorded during survey. Apart from 41DL549 no cultural resources were identified in the shovel tests or on the surface. Given the results of this survey, AR Consultants, Inc. recommends that further cultural resource investigations are unnecessary for this project, and requests that the Texas Historical Commission and the Fort Worth District of the U.S. Army Corps of Engineers concur with this recommendation. The field notes, photographs, and photo logs are curated at the Center for Archaeological Studies at Texas State University in San Marcos, Texas

Archaeological Survey Of The Proposed Grapevine Aerial SS Repair Tarrant County, Texas

The City of Grapevine is proposing to repair an aerial sanitary sewer across Big Bear Creek in Tarrant County, Texas. The project area is located on the south side of a horseshoe bend in the floodplain of Big Bear Creek, north of Western Oaks Drive and west of Texas State Highway 121. AR Consultants, Inc. (ARC) conducted the intensive pedestrian archaeological survey in an area approximately 50-meters by 25-meters (0.3-acres) on June 8, 2018. Four shovel tests were excavated within the project area during the systematic field inspection. The archaeological potential for prehistoric and historic cultural resources was considered low. During survey, no cultural resources were identified in the shovel tests or found on the surface. Given the results of this survey, AR Consultants, Inc. recommends that further cultural resource investigations are unnecessary for this project, and requests that the Texas Historical Commission and the Fort Worth District of the U.S. Army Corps of Engineers concur with this recommendation. The field notes, photographs, and photo logs will be curated with the Center for Archaeological Studies at Texas State University in San Marcos, Texas

Quantum optical signal processing in diamond

Controlling the properties of single photons is essential for a wide array of emerging optical quantum technologies spanning quantum sensing, quantum computing, and quantum communications. Essential components for these technologies include single photon sources, quantum memories, waveguides, and detectors. The ideal spectral operating parameters (wavelength and bandwidth) of these components are rarely similar; thus, frequency conversion and spectral control are key enabling steps for component hybridization. Here we perform signal processing of single photons by coherently manipulating their spectra via a modified quantum memory. We store 723.5 nm photons, with 4.1 nm bandwidth, in a room-temperature diamond crystal; upon retrieval we demonstrate centre frequency tunability over 4.2 times the input bandwidth, and bandwidth modulation between 0.5 to 1.9 times the input bandwidth. Our results demonstrate the potential for diamond, and Raman memories in general, to be an integrated platform for photon storage and spectral conversion.Comment: 6 pages, 4 figure

Storage and retrieval of ultrafast single photons using a room-temperature diamond quantum memory

We report the storage and retrieval of single photons, via a quantum memory, in the optical phonons of room-temperature bulk diamond. The THz-bandwidth heralded photons are generated by spontaneous parametric downconversion and mapped to phonons via a Raman transition, stored for a variable delay, and released on demand. The second-order correlation of the memory output is $g^{(2)}(0) = 0.65 \pm 0.07$, demonstrating preservation of non-classical photon statistics throughout storage and retrieval. The memory is low-noise, high-speed and broadly tunable; it therefore promises to be a versatile light-matter interface for local quantum processing applications.Comment: 6 pages, 4 figure

Storage of polarization-entangled THz-bandwidth photons in a diamond quantum memory

Bulk diamond phonons have been shown to be a versatile platform for the generation, storage, and manipulation of high-bandwidth quantum states of light. Here we demonstrate a diamond quantum memory that stores, and releases on demand, an arbitrarily polarized $\sim$250 fs duration photonic qubit. The single-mode nature of the memory is overcome by mapping the two degrees of polarization of the qubit, via Raman transitions, onto two spatially distinct optical phonon modes located in the same diamond crystal. The two modes are coherently recombined upon retrieval and quantum process tomography confirms that the memory faithfully reproduces the input state with average fidelity $0.784\pm0.004$ with a total memory efficiency of $(0.76\pm0.03)\%$. In an additional demonstration, one photon of a polarization-entangled pair is stored in the memory. We report that entanglement persists in the retrieved state for up to 1.3 ps of storage time. These results demonstrate that the diamond phonon platform can be used in concert with polarization qubits, a key requirement for polarization-encoded photonic processing

An evaluation of silicon carbide unipolar technologies for electric vehicle drive-trains

Voltage sourced converters (VSCs) in electric vehicle (EV) drive-trains are conventionally implemented by silicon Insulated Gate Bipolar Transistors (IGBTs) and p-i-n diodes. The emergence of SiC unipolar technologies opens up new avenues for power integration and energy conversion efficiency. This paper presents a comparative analysis between 1.2-kV SiC MOSFET/Schottky diodes and silicon IGBT/p-i-n diode technologies for EV drive-train performance. The switching performances of devices have been tested between -75 °C and 175 °C at different switching speeds modulated by a range of gate resistances. The temperature impact on the electromagnetic oscillations in SiC technologies and reverse recovery in silicon bipolar technologies is analyzed, showing improvements with increasing temperature in SiC unipolar devices whereas those of the silicon-bipolar technologies deteriorate. The measurements are used in an EV drive-train model as a three-level neutral point clamped VSC connected to an electric machine where the temperature performance, conversion efficiency and the total harmonic distortion is studied. At a given switching frequency, the SiC unipolar technologies outperform silicon bipolar technologies showing an average of 80% reduction in switching losses, 70% reduction in operating temperature and enhanced conversion efficiency. These performance enhancements can enable lighter cooling and more compact vehicle systems

Can Short-Range Interactions Mediate a Bose Metal Phase in 2D?

We show here based on a 1-loop scaling analysis that short-range interactions are strongly irrelevant perturbations near the insulator-superconductor (IST) quantum critical point. The lack of any proof that short-range interactions mediate physics which is present only in strong coupling leads us to conclude that short-range interactions are strictly irrelevant near the IST quantum critical point. Hence, we argue that no new physics, such as the formation of a uniform Bose metal phase can arise from an interplay between on-site and nearest-neighbour interactions.Comment: 3 pages, 1 .eps file. SUbmitted to Phys. Rev.

The Association between Critical Thinking and Scholastic Aptitude on First-time Pass Rate of the National Physical Therapy Examination

Objectives: 1) To investigate the relationships among critical thinking (CT) abilities, overall academic performance in the Doctorate of Physical Therapy (DPT) program as measured by cumulative grade point average (GPA), and National Physical Therapy Examination (NPTE) licensure scores, and 2) To determine if NPTE scores were significantly different between groups of students who were classified as having low, moderate or high CT abilities. Background: It is well-established that physical therapy practice requires good clinical reasoning skills. Passage of the NPTE is required for licensure. Research to date has been mixed as to whether CT abilities or GPA can predict success on national board licensure examinations such as the NPTE. The conflicting results may be partially due to weak research methodologies, uncontrolled confounders, and the use of non-standardized assessment instruments. Methods and Measures: A convenience sample of 91 DPT students completed a standard assessment of CT abilities three times. Repeated measure (RM) general linear model (GLM) tests were run to determine if mean California Critical Thinking Skills Test (CCTST) scores changed significantly over the course of the DPT program. A Pearson’s correlation matrix was constructed to investigate the relationships among NPTE scores, GPA, and CT. A univariate GLM test was run to determine if there was a statistically significant difference in mean NPTE scores between low, medium, and high CCTST groups. Results: Complete sets of the three CCTST scores were available for 69 students, and NPTE scores were available for 73 graduates. The strongest correlation with the first-time NPTE score was the GPA (r = 0.735, p = 0.001), followed by the CCTST score at Measurement 1 (r = 0.413, p = 0.0001). Graduates who were classified as having low CT abilities had a 100% failure rate on the first attempt for the NPTE, and scored significantly lower on the exam compared to graduates with moderate or high CT abilities (615.33, 634.6, and 652.43, respectively p = 0.0005). Conclusion: Implementing pedagogical practices that foster CT abilities and/or using a CCTST score of 18 or greater as DPT program entry criterion may equate to greater first-time NPTE pass rates for program graduates

Interaction-induced Bose Metal in 2D

We show here that the regularization of the conductivity resulting from the bosonic interactions on the `insulating' (quantum disordered) side of an insulator-superconductor transition in 2D gives rise to a metal with a finite conductivity, $\sigma =(2/\pi) 4 e^2/h$, as temperature tends to zero. The Bose metal is stable to weak disorder and hence represents a concrete example of an interaction-induced metallic phase. Phenomenological inclusion of dissipation reinstates the anticipated insulating behaviour in the quantum-disordered regime. Hence, we conclude that the traditionally-studied insulator-superconductor transition, which is driven solely by quantum fluctuations, corresponds to a superconductor-metal transition. The possible relationship to experiments on superconducting thin films in which a low-temperature metallic phase has been observed is discussed.Comment: A figure has been added and the physics has been clarified. To appear in PR