Role of surface states in STM spectroscopy of (111) metal surfaces with Kondo adsorbates

A nearly-free-electron (NFE) model to describe STM spectroscopy of (111) metal surfaces with Kondo impurities is presented. Surface states are found to play an important role giving a larger contribution to the conductance in the case of Cu(111) and Au(111) than Ag(111) surfaces. This difference arises from the farther extension of the Ag(111) surface state into the substrate. The different line shapes observed when Co is adsorbed on different substrates can be explained from the position of the surface band onset relative to the Fermi energy. The lateral dependence of the line shape amplitude is found to be bulk-like for R|| < 4 Amstrongs and surface-like at larger distances, in agreement with experimental data.Comment: 4 pages, 3 eps figure

Divine providence and epidemic cholera : a contribution to the study of secularization of thought in nineteenth century England

The idea of providence was a prominent and pervasive theme in public discourse on subjects of national importance, and upon momentous occasions in nineteenthcentury England. Perceptions of divine involvement and purpose in human affairs embodied in the notion of providence seemed to be at the heart of a religious world view in the Christian tradition, and thus essential elements for study in any historical investigation of religious change. The midcentury years, ostensibly a period of high religious consciousness, provide an opportunity to explore processes which were eventually to lead to the more secular nature of society apparent by the end of the century. The recurring cholera epidemics between 1831 and 1854 were alarming events which provoked reactions throughout society; they provide a means of tracing developments in perceptions of providential involvement in calamitous events during a critical twenty-four year period. Systematic surveys of a broad range of sources, including newspapers, periodicals and sermons were carried out to document the responses of different sections of society, and facilitated investigation of cross-sectional and longitudinal patterns in religious attitudes. It was hypothesised that changing ideas about the nature and extent of providential action in relation to epidemic disease could provide an index of the process of secularization of thought, and thus contribute to the wider debate on secularization. The results vindicated the use of the concept of providence to explore religious consciousness. They have confirmed the mid-nineteenth century to be a critical period for religious change. Analysis of religious perceptions of cholera at three points in time produced a complex picture of changing attitudes, including an unexpected peaking of providential interpretations by some observers during the second epidemic. However, the variation between different sources and social groups did not obscure a significant longer-term trend of decline in providential attitudes, consistent with a secularization of thought during the quarter of a century studied

FIELD TESTING OF REMOTE SENSOR GAS LEAK DETECTION SYSTEMS FINAL REPORT

The natural gas pipeline industry routinely checks their pipeline right-of-ways to ensure that leaks are detected. Pipeline companies use various processes to detect signs of leaking pipes, including using vehicles or low-flying aircraft. The leak detection methods range from directly sensing the gas to looking for indirect signs of leakage. The U.S. Department of Energy (DOE) and the U.S. Department of Transportation’s Office of Pipeline Safety (OPS) have provided funding to several commercial companies and research laboratories to develop advanced remote sensor systems to provide high quality, cost-effective leak detection information. To aid in the development and availability of these remote detection systems, the DOE funded a project to conduct field testing of five remote sensor leak detection systems. OPS provided co-funding for this project. The five systems chosen to be included in the field test were being developed by En’Urga Inc., ITT Industries, Inc., LaSen, Inc., Lawrence Livermore National Laboratories, and Physical Sciences Inc. The technologies included passive infrared multi-spectral scanning, laser-based differential absorption LIDAR (Light Detection and Ranging), hyperspectral imaging, and tunable diode laser absorption spectroscopy. The sensor systems were mounted in an unmodified automobile, a helicopter, or a fixed-wing aircraft. A “virtual pipeline,” that simulated conditions of an actual pipeline was created at the Rocky Mountain Oilfield Testing Center field site at NPR-3, north of Casper, Wyoming. The pipeline route was approximately 7.5 miles long and was marked by 14 direction change markers and 22 sets of road crossing markers. Fifteen leak sites, which included three types of gas releases, were established along the route, with natural gas leak rates ranging from 1 scfh to 5,000 scfh. One leak site was designated as a “calibration” site, and the location and leak rate for this site were provided to the equipment providers. Leak sites that were designed to cause plant stress were on continuously from August 30, 2004 through September 17, 2004. The remaining leak sites were set daily during the test week of September 13 to 17, 2004. Four equipment providers were scheduled to collect data along the pipeline path twice each test day. One equipment provider, at their request, was scheduled to collect data once each day for one of their platforms and twice during the entire week for their other platform. Reports of the findings for the individual equipment providers were due to Southwest Research Institute® (SwRI®) within two weeks after the testing period and are included in this report as Appendix I. Based on the data provided, leaks at many of the leak sites were successfully detected. Leak rates of 500 scfh or higher were detected at least 50% of the time. Leak rates of 100 scfh were only detected 15% of the time. Leak rates of 15 scfh and 10 scfh were only detected about 5% of the time. The 1-scfh leak was never detected. There were also a large number of “false positive” leak sites identified by the equipment providers. Some of the equipment providers made system improvements during the week including repairing malfunctioning equipment, mechanical modifications to improve performance in field applications, and developing improved data handling schemes. Other modifications have been defined for future work by some of the equipment providers. Improvements for potential future testing efforts have been identified and include improving the pipeline route and adding more leak sites

Towards a microscopic description of dimer adsorbates on metallic surfaces

Despite the experimental successes of Scanning Tunneling Microscopy (STM) and the interest in more complex magnetic nanostructures, our present understanding and theoretical description of STM spectra of magnetic adatoms is mainly phenomenological and most often ignores many-body effects. Here, we propose a theory which includes a microscopic description of the wave functions of the substrate and magnetic adatoms together with quantum many-body effects. To test our theory, we have computed the STM spectra of magnetic Cobalt monomers and dimers adsorbed on metallic Copper surfaces and succesfully compared our results to recent available experimental data.Comment: 4 pages, 2 figures, discussion of calculation of RKKY interaction and connection to NRG included. Extended discussion on calculations of the one-electron parameters of Anderson model. Typos correcte

Double layer in ionic liquids: Overscreening vs. crowding

We develop a simple Landau-Ginzburg-type continuum theory of solvent-free ionic liquids and use it to predict the structure of the electrical double layer. The model captures overscreening from short-range correlations, dominant at small voltages, and steric constraints of finite ion sizes, which prevail at large voltages. Increasing the voltage gradually suppresses overscreening in favor of the crowding of counterions in a condensed inner layer near the electrode. The predicted ion profiles and capacitance-voltage relations are consistent with recent computer simulations and experiments on room-temperature ionic liquids, using a correlation length of order the ion size.Comment: 4 pages + supplementary informatio

Bedrock Topography of Maple Park Quadrangle, Kane and DeKalb Counties, Illinois

Relief shown by contours and spot heights"This research was supported in part by the U.S. Geological Survey, National Cooperative Geologic Mapping Program under USGS award number 98HQAG2050."Includes disclaimer, index to adjoining quadrangles, and location mapIncludes bibliographical reference

Rebuilding a foundation of trust: A call to action in creating a safe environment for everyone

Well before the COVID-19 pandemic, incivility and physical threats directed toward healthcare employees and often registered nurses was a growing concern by Chief Nurse Executive (CNE) leaders. In 2019, conversations initiated by The Beryl Institute’s Nurse Executive Council (NEC) to consider how best to achieve a much-needed balance between patient/family and staff safety have now become a critical priority to ensure the safety of everyone receiving and providing health care services. The heart of this work was organized around a set of newly developed ethical precepts designed to guide the exploration of key concepts. A call to action grounded in rebuilding a foundation of trust is proposed. In pursuing future steps to deepen this foundation, and to reaffirm the vital role for nurse leaders and of all in healthcare, we must be willing to engage in dialogue, to ask openly, and question respectfully. We believe healthcare systems and nurse leaders both play a vital role in elevating the humanity on which we will find brighter days ahead. Through a sustained commitment to this aim, we seek to strengthen health care delivery environments that shape physically and psychologically safe environments for everyone. Experience Framework This article is associated with the Culture & Leadership lens of The Beryl Institute Experience Framework (https://www.theberylinstitute.org/ExperienceFramework). Access other PXJ articles related to this lens. Access other resources related to this len

Beneath Illinois roads : from the surface to bedrock

"Surface deposits compiled from Hansel and Johnson (1996), Lineback (1979), and William and Frye (1970)." / Includes col. ill., glacial timetable, and ancillary map. / On verso: "Beneath Illinois roads: from the surface to bedrock," 1 cross section and 5 ancillary maps with text: Land cover -- Surface topography -- Surface deposits -- Bedrock surface -- Bedrock geology. Scale 1:760,320. 1 in. = approx. 12 mi.Ope

Complexities of atomic structure at CdO/MgO and CdO/Al2O3 interfaces

We report the interface structures of CdO thin films on (001)-MgO and (0001)-Al2O3 substrates. Using aberration corrected scanning transmission electron microscopy, we show that epitaxial growth of (001)-CdO∥(001)-MgO occurs with a lattice misfit greater than 10%. A high density of interface misfit dislocations is found to form. In combination with molecular dynamics simulations, we show that dislocation strain fields form and overlap in very thin heterostructures of CdO and MgO (<3 nm). On the c-Al2O3 substrate, we find that CdO grows with a surface normal of [025]. We show that three rotation variants form due to the symmetry of the sapphire surface. These results contribute insights into the epitaxial growth of these rock-salt oxides