1,830 research outputs found
Evaluation of high pressure water blast with rotating spray bar for removing paint and rubber deposits from airport runways, and review of runway slipperiness problems created by rubber contamination
A high pressure water blast with rotating spray bar treatment for removing paint and rubber deposits from airport runways is studied. The results of the evaluation suggest that the treatment is very effective in removing above surface paint and rubber deposits to the point that pavement skid resistance is restored to trafficked but uncontaminated runway surface skid resistance levels. Aircraft operating problems created by runway slipperiness are reviewed along with an assessment of the contributions that pavement surface treatments, surface weathering, traffic polishing, and rubber deposits make in creating or alleviating runway slipperiness. The results suggest that conventional surface treatments for both portland cement and asphaltic concrete runways are extremely vulnerable to rubber deposit accretions which can produce runway slipperiness conditions for aircraft operations as or more slippery than many snow and ice-covered runway conditions. Pavement grooving surface treatments are shown to be the least vulnerable to rubber deposits accretion and traffic polishing of the surface treatments examined
A Comparative Study of the ReCellÂŽ Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.
Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCellŽ Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P < .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ⤠.05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG
A direct path to dependable software
What would it take to make software more dependable? Until now, most approaches have been indirect: some practices â processes, tools or techniques â are used that are believed to yield dependable software, and the argument for dependability rests on the extent to which the developers have adhered to them. This article argues instead that developers should produce direct evidence that the software satisfies its dependability claims. The potential advantages of this approach are greater credibility (since the argument is not contingent on the effectiveness of the practices) and reduced cost (since development resources can be focused where they have the most impact)
Re-Instatement Of Pell Grants For Incarcerated Students: Implications For CS Education
The US incarcerates more people, and at a higher rate, than any other country in the worldâpredominantly low-income people of color. Higher education in prison (HEP) has a powerful impact on justice-impacted people, improving their quality of life during incarceration and reducing their likelihood of returning to prison post-release. HEP nearly disappeared in 1994 after Pell Grant eligibility was eliminated for incarcerated students, which was recently reinstated. More computing educators can reach incarcerated students with digital literacy skills, core computing content, and critical analyses of the impacts of computing on society. CS education researchers can also support the growth of CS education in prisons, and influence policies restricting technology infrastructure
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Engaging the Periphery for Visual Communication on Mobile Phones
While mobile phones have become ubiquitous instruments of communication and social interaction, they still require explicit interaction, placing high demands on attention. Engaging the periphery of usersâ attention offers opportunities for awareness and interaction while reducing demands on attention and risks of disruption. We explore the mobile peripheral design space with Emotipix, an application for camera phones that turns the background of the phoneâs display into a place for visual conversations. We conducted an exploratory 2-week user study with 6 pairs and one 4-person group, and found that Emotipix facilitated ongoing social practices. Our study shows that there is an unexploited opportunity to use mobile phones for peripheral awareness. We provide recommendations for managing users â expectations, desires for control, and privacy in mobile peripheral display design. 1
Covert Neurological Symptoms Associated With Silent Infarcts From Midlife to Older Age: The Atherosclerosis Risk in Communities Study
Unrecognized or unreported stroke-like symptoms, called covert symptoms, occur in persons free of clinical stroke. Whether covert symptoms are associated with subclinical brain infarcts (SBI) is unknown. This study examined the association between covert stroke-like symptoms and SBI/stroke in persons with no history of stroke or TIA
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Hot Gas Cleanup Test Facility for Gasification and Pressurized Combustion
Efficiencies in advanced power generation systems such as integrated gasification combined cycle, pressurized fluidized bed combustion and integrated gasification fuel cells can be maximized by feeding hot fuel gas or flue gas to the power block. However, advanced gas turbines have strict particulate requirements to minimize wear on the blades due to the close tolerances used to maximize the efficiency of the turbomachinery. Molten Carbonate Fuel Cells also have strict particulate requirements to prevent blinding of the electrodes. Therefore, one of the main barriers to developing these advanced power generation systems is the removal of particulates in a hot gas stream. Although the development of several high temperature/pressure PCD systems has been ongoing for the past several years, long term operation under realistic conditions for advanced power generation has been limited. The demonstration of reliable operation is critical to the commercialization of PCD technology for advanced power generation. The conceptual design of the Hot Gas Cleanup Test Facility Project was expanded to include additional modules to better address the scope of the Cooperative Agreement with the DOE/METC. The expanded test facility, referred to as the Power Systems Development Facility, will provide a flexible test location in which the development of advanced power system components, the evaluation of advanced turbine and fuel cell configurations, and the integration and control issues of these systems. The facility is intended to provide direct support for upcoming DOE demonstrations of power generation technologies utilizing hot stream cleanup and will provide a resource for rigorous testing and performance assessment of hot stream cleanup devices now being developed with the support of DOE/METC
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