2,185 research outputs found
Dual, PhotoâResponsive and RedoxâActive Supramolecular Foldamers
We report on dual, lightâresponsive and redoxâactive foldamers that demonstrate reversible and robust stimuliâinduced behaviour. Herein, UV/Vis, 1H NMR and circular dichroism (CD) spectroscopy and cyclic voltammetry have been used to establish the reversibility and highly robust nature of the lightâ and redoxâdriven behaviour of these new foldamers with minimal levels of fatigue observed even upon multiple cyclic treatments with irradiative/nonâirradiative and oxidative/reductive conditions. This proofâofâconcept work paves the way towards the creation of novel stimuliâresponsive foldamers of increasing sophistication capable of demonstrating reversible and robust responses to multiple distinct stimuli
Dual, PhotoâResponsive and RedoxâActive Supramolecular Foldamers
We report on dual, lightâresponsive and redoxâactive foldamers that demonstrate reversible and robust stimuliâinduced behaviour. Herein, UV/Vis, 1H NMR and circular dichroism (CD) spectroscopy and cyclic voltammetry have been used to establish the reversibility and highly robust nature of the lightâ and redoxâdriven behaviour of these new foldamers with minimal levels of fatigue observed even upon multiple cyclic treatments with irradiative/nonâirradiative and oxidative/reductive conditions. This proofâofâconcept work paves the way towards the creation of novel stimuliâresponsive foldamers of increasing sophistication capable of demonstrating reversible and robust responses to multiple distinct stimuli
Measurements of pernitric acid at the South Pole during ISCAT 2000
The first measurements of pernitric acid at the South Pole were performed during the second Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT 2000). Observed HO2NO2 concentrations averaged 25 pptv. Simple steady-state calculations constrained by measurements show that the lifetime of pernitric acid was largely controlled by dry deposition, with thermal decomposition becoming increasingly important at warmer temperatures. We determined that the pernitric acid equilibrium constant is less uncertain than indicated in the literature. One consequence of pernitric acid deposition to the snow surface is that it is an important sink for both NOx and HOx. Another is that the photochemistry of HO2NO2 in the Antarctic snowpack may be a NOx source in addition to nitrate photolysis. This might be one of the important differences in snow photochemistry between the South Pole and warmer polar sites
Housing Preferences and Choices Among Adults with Mental Illness and Substance Use Disorders: A Qualitative Study
Housing is a crucial issue for adults with severe mental illness and co-occurring substance use disorders, as this population is particularly susceptible to housing instability and homelessness. We interviewed 40 adults with dual disorders, living in either supervised or independent housing arrangements, to examine housing preferences, decision making processes surrounding housing choices, and perceived barriers to housing. We found that many clients indicated their housing preferences had changed over time, and some clients related housing preferences to recovery. Although the majority of clients preferred independent housing, many also described benefits of supervised housing. Clients' current living situations appeared to be driven primarily by treatment provider recommendations and availability of housing. Common barriers to obtaining desired housing were lack of income and information. These findings have implications for supported housing models and approaches to providing housing for clients
Report on Interstate 476 (The Blue Route)
For fifty years Pennsylvanians have been discussing the idea of constructing a new north-south highway in the central part of Delaware County, the suburban county immediately west of the City of Philadelphia. Such a highway originally was conceived as a parkway. The notion never got very far until the mid-1950\u27s. When the federal Interstate Highway System was conceived, a facility in central Delaware County was proposed to connect the Pennsylvania Turnpike (I-276) in Plymouth Meeting, Montgomery County, with the Delaware Expressway (I-95) in Ridley Township, Delaware County. This facility was designated I-476. As conceived, it would constitute the western part of a planned circumferential freeway network around Philadelphia. I-476 is commonly known as the Blue Route and also as the Mid County Expressway.
As an interstate highway project, 90% of the cost of I-476 would be covered by federal interstate highway funds allocated to the Pennsylvania Department of Transportation (PennDOT) by the Federal Highway Administration (FHWA). The remaining 10% of the project\u27s cost would be paid for by PennDOT (either construction bonds or revenues from the State Motor Fund).
Construction of the Blue Route commenced in 1967 but all conÂstruction on the main stretch of the road--the 16.9 mile section be tween I-95 and the Schuylkill Expressway (I-76)--was halted in 1973. Construction of this portion cannot resume until the project undergoes an environmental impact assessment under the provisions of federal law. The project also must undergo a so-called 4(f) assessment analyzing the facility\u27s impact on parkland and historical resources. The requirements of these federal statutes are summarized in an appenÂdix to this report.
Because of the uncertainty surrounding completion of the Blue Route, and because the project has aroused considerable controversy in Delaware County, U.S. Representative Robert W. Edgar in March 1977 organized a Transportation Advisory Committee to unÂdertake a comprehensive analysis of the project. [...] This report is submitted to the Congressman as the Committee\u27s recommendation
Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures
This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles
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From Archive to GIS: Recovering Spatial Information for Tholos IV at the Palace of Nestor from the Notebooks of Lord William Taylour
This article is a case study in doing new things with old data. In 1953 Lord William Taylour directed the excavation of a monumental vaulted tholos tomb known as 'Tholos IV' at the site of ancient Pylos, Messenia, Greece. The excavation was conducted over two months, during which detailed notes were recorded in three notebooks now kept in the Archives of the American School of Classical Studies at Athens. The formal publication of Tholos IV, however, contains only a basic narrative of the excavation, offering neither precise detail on stratigraphy, object find spots, nor even a complete inventory of small finds. The present study goes back to the original notebooks kept by Taylour and combines the data contained in them with a new digital survey of Tholos IV to produce a comprehensive and accurate 3D GIS model for the excavation. Furthermore, the GIS has been produced in such a way that its dataset is compatible with new excavation data currently generated in the ongoing Palace of Nestor Excavations (PONEX) project, bringing together two excavation campaigns conducted under very different circumstances, methodologies, and recording protocols. Discussion follows on how the production of this GIS deepens our understanding not just of the legacy excavation, but also of the site and its wider landscape.Loyâs contribution to the project in 2018 and 2019 was supported jointly by the Arts and Humanities Research Council (AHRC) and Pembroke College Cambridge, award number AH/L503897/1, with further funding for travel made available by the Louise Taft Semple Fund of the Department of Classics of the University of Cincinnat
The validity of the Landau-Zener model for output coupling of Bose condensates
We investigate the validity of the Landau-Zener model in describing the
output coupling of Bose condensates from magnetic traps by a chirped
radiofrequency field. The predictions of the model are compared with the
numerical solutions of the Gross-Pitaevskii equation. We find a dependence on
the chirp direction, and also quantify the role of gravitation.Comment: 4 pages, Late
Airborne sampling of aerosol particles: Comparison between surface sampling at Christmas Island and P-3 sampling during PEM-Tropics B
Bulk aerosol sampling of soluble ionic compounds from the NASA Wallops Island P-3 aircraft and a tower on Christmas Island during PEM-Tropics B provides an opportunity to assess the magnitude of particle losses in the University of New Hampshire airborne bulk aerosol sampling system. We find that most aerosol-associated ions decrease strongly with height above the sea surface, making direct comparisons between mixing ratios at 30 m on the tower and the lowest flight level of the P-3 (150 m) open to interpretation. Theoretical considerations suggest that vertical gradients of sea-salt aerosol particles should show exponential decreases with height. Observed gradients of Na+ and Mg2+, combining the tower observations with P-3 samples collected below 1 km, are well described by exponential decreases (r values of 0.88 and 0.87, respectively), though the curve fit underestimates average mixing ratios at the surface by 25%. Cascade impactor samples collected on the tower show that \u3e99% of the Na+ and Mg2+mass is on supermicron particles, 65% is in the 1â6 micron range, and just 20% resides on particles with diameters larger than 9 microns. These results indicate that our airborne aerosol sampling probes must be passing particles up to at least 6 microns with high efficiency. We also observed that nss SO42â and NH4+, which are dominantly on accumulation mode particles, tended to decrease between 150 and 1000 m, but they were often considerably higher at the lowest P-3 sampling altitudes than at the tower. This finding is presently not well understood
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