4,258 research outputs found
Comparison of alternative laboratory dowel bar testing procedures
The objective of this study was to evaluate the performance of a modified version of the AASHTO T253 dowel bar test procedure. The modified AASHTO test was developed based upon comparisons to previous ISU projects and was compared to an alternate cantilevered dowel bar test. The dowel bar tests were conducted for the purpose of finding a preferred method of obtaining the Modulus of Dowel Support, k0. The series of tests included 54 modified AASHTO specimens and 18 cantilever specimens. Six different dowel bar types were included in the laboratory tests. The bar shapes were both round and elliptical. The dowel bars were made of epoxy-coated steel, stainless steel, and glass fiber-reinforced polymer (GFRP).;The study was conducted in the Iowa State University Structural Engineering Laboratories. The data gathered from the laboratory tests was analyzed using modified theories developed by Timoshenko and Friberg.;The results in this study determined that the modified AASHTO test was superior to the experimental cantilever test in both accuracy and precision for the determination of k0. Recommendations are given for an improved AASHTO T253 procedure. Recommendations for further research regarding the determination of k0 are noted at the end of this study
The canons of the orthodox church and the application of ‘economy’ to current infringements
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Planning Related to the Curation and Processing of Returned Martian Samples
The Astromaterials Acquisition and Curation Office (henceforth referred to herein as NASA Curation Office) at NASA Johnson Space Center (JSC) is responsible for curating all of NASAs extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10E Curation of Extraterrestrial Materials, JSC is charged with the curation of all extraterrestrial material under NASA control, including future NASA missions. The Directive goes on to define Curation as including documentation, preservation, preparation, and distribution of samples for research, education, and public outreach. Here we describe some of the ongoing planning efforts in curation as they pertain to the return of martian samples in a future, as of yet unplanned, mission
Notes on Recent Cases
Notes on recent cases by Marc Wonderlin, Francis T. Ready, Walter E. Parent, J. R. Harrington, James A. Allan, D. M. Donahue, J. J. Canty, J. S. Angelino, Henry Hasley, and John P. Berscheid
The Acquisition, Containment, and Curation of Mars Samples on Earth
The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (henceforth AACO) is responsible for receiving and curating all of NASAs extraterrestrial samples, current and future (as per NASA Policy Directive (NPD) 7100.10E Curation of Extraterrestrial Materials). As such, the AACO coordinates sample capture, containment, and transportation to the curation facility as well as documents, preserves, prepares, and distributes all of the samples within NASAs astromaterial collections for research, education, and public outreach. Since the lunar rock and soil samples returned during the Apollo Program, NASAs first Class V Restricted Earth Return Missions, the AACO curates six other astromaterials collections. Lessons learned from each collection and respective missions (e.g. Apollo, Genesis, Stardust) as well as advancements in science and technology have informed the AACOs plan for acquiring and curating Martian samples. Given the nature of the collection, a mobile and modular facility is recommended. The two broad requirements a Mars sample facility must maintain are: 1) the ability to contain the samples to protect the public from exposure of an unknown unknown biological agent and 2) ensure the scientific integrity of the samples are maintained (while maximizing scientific outcome). Although Apollo samples were eventually deemed safe and released to the scientific community for evaluation, there is no guarantee that this will be the case for Martian samples. Therefore, the facility in which the samples will be contained and investigated must be modular and able to accommodate an array of instrumentation that could be highly variable depending on the initial scientific outcomes. Furthermore, in order to facilitate proper sample capture and containment upon landing as well as sample distribution to other laboratories with proper containment, a mobile facility is a valuable investment
Interface Roughening in a Hydrodynamic Lattice-Gas Model with Surfactant
Using a hydrodynamic lattice-gas model, we study interface growth in a binary
fluid with various concentrations of surfactant. We find that the interface is
smoothed by small concentrations of surfactant, while microemulsion droplets
form for large surfactant concentrations. To assist in determining the
stability limits of the interface, we calculate the change in the roughness and
growth exponents and as a function of surfactant concentration
along the interface.Comment: 4 pages with 4 embedded ps figures. Requires psfig.tex. Will appear
in PRL 14 Oct 199
Mobile/Modular BSL-4 Containment Facilities Integrated into a Curation Receiving Laboratory for Restricted Earth Return Missions
NASA robotic sample return missions designated Category V Restricted Earth Return by the NASA Planetary Protection (PP) Office require sample containment and biohazard testing upon return to Earth. Since the 1960s, sample containment from an unknown extraterrestrial biohazard have been related to the highest containment standards and protocols known to modern science. Today, this is Biosafety Level (BSL) 4 containment. In the U.S., the Biosafety in Microbiological and Biomedical Laboratories publication authored by the U.S. Department of Health and Human Services (HHS): Public Health Service, Centers for Disease Control and Prevention, and the National Institutes of Health houses the primary recommendations, standards, and design requirements for all BSL labs. Past mission concept studies for constructing a NASA Curation Receiving Laboratory with an integrated BSL-4 quarantine and biohazard testing facility have been estimated in the hundreds of millions of dollars (USD). As an alternative option, we have conducted a trade study for constructing a mobile and/or modular sample containment laboratory that would meet all BSL-4 and planetary protection standards and protocols at a fraction of the cost. Mobile and modular BSL-2 and 3 facilities have been successfully constructed and deployed world-wide for government testing of pathogens and pharmaceutical production. Our study showed that a modular BSL-4 construction could result in ~ 90% cost reduction when compared to traditional BSL-4 construction methods without compromising the preservation of the samples or Earth. For the design/construction requirements of a mobile/modular BSL-4 containment, we used the established HHS document standards and protocols for manipulation of agents in Class III Biosafety Cabinets (BSC; i.e., negative pressure gloveboxes) that are currently followed in operational BSL-4 facilities in the U.S
Detailed state of the art review for the different on-line/in-line oil analysis techniques in context of wind turbine gearboxes
The main driver behind developing advanced condition monitoring (CM) systems for the wind energy industry is the delivery of improved asset management regarding the operation and maintenance of the gearbox and other wind turbine components and systems. Current gearbox CM systems mainly detect faults by identifying ferrous materials, water, and air within oil by changes in certain properties such as electrical fields. In order to detect oil degradation and identify particles, more advanced devices are required to allow a better maintenance regime to be established. Current technologies available specifically for this purpose include Fourier transform infrared (FTIR) spectroscopy and ferrography. There are also several technologies that have not yet been or have been recently applied to CM problems. After reviewing the current state of the art, it is recommended that a combination of sensors would be used that analyze different characteristics of the oil. The information individually would not be highly accurate but combined it is fully expected that greater accuracy can be obtained. The technologies that are suitable in terms of cost, size, accuracy, and development are online ferrography, selective fluorescence spectroscopy, scattering measurements, FTIR, photoacoustic spectroscopy, and solid state viscometers
Synthesis 2006
The purpose of this report is to summarize and synthesize activities and achievements of
the CPWF through the end of 2006.
The CPWF is a CGIAR Challenge Program designed to take on the global challenge of
water scarcity and food security. It takes the form of an international, multi-institutional
research-for-development initiative that brings together scientists, development
specialists, and river basin communities in Africa, Asia and Latin America. It seeks to
create and disseminate international public goods (IPGs) helpful in achieving food
security, reducing poverty, improving livelihoods, reducing agriculture–related pollution,
and enhancing environmental security.
This Challenge Program is a three-phase, 15-year endeavor. Several years have passed
since the start of Phase 1 (2003-2008) which began with an inception phase in 2003 and
was followed by full CPWF launch in January 2004. Research projects began field
operations in mid-2004. This synthesis report, then, only describes work carried out in
the first two and a half years of the Program.
During this time, CPWF has conducted its research on water and food in nine
benchmark basins, organized around five different themes. This work is being
implemented through “first call projects”, “basin focal projects”, “small grant projects”
and “synthesis research”. This present report is one example of the latter.
CPWF projects have made considerable progress in developing innovative technologies,
policies and institutions to address water and food issues. Some projects focused on
improving agricultural water productivity. Others focused on developing mechanisms to
inform multi-stakeholder dialogue and negotiation, or explored ways to value water used
to produce ecosystem services. Advances were also made in understanding water-foodpoverty
links, and their regional and global policy context
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