93 research outputs found
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On the proliferation resistance of thorium-uranium nuclear fuel
This paper will highlight the historical and potential future uses of 232Th and 233U both in terms of civil and military applications. A brief section on the differences between 233U and 239Pu will be presented and how these could impact proliferation-resistance assessments. Finally, a set of open questions regarding 233U will be presented, some of which will be answered as part of this research project
Hygrometer for Detecting Water in Partially Enclosed Volumes
A portable hygrometer has been devised to implement a pre-existing technique for detecting water trapped in partially enclosed volumes that may be difficult to reach and cannot be examined directly. The technique is based on the fact that eventually the air in such a volume becomes saturated or nearly so. The technique is straightforward: One measures the relative humidity and temperature of both the ambient air and a sample of air from the enclosed volume. If the relative humidity of the sample is significantly greater than that of the ambient air and/or if the sample is at or close to the dew point, then it can be concluded that water is trapped in the volume. Of course, the success of this technique depends on the existence of an access hole through which one can withdraw some air from the enclosed volume
SpaceWire Protocol ID: What Does It Mean To You?
Spacewire is becoming a popular solution for satellite high-speed data buses because it is a simple standard that provides great flexibility for a wide range of system requirements. It is simple in packet format and protocol, allowing users to easily tailor their implementation for their specific application. Some of the attractive aspects of Spacewire that make it easy to implement also make it hard for future reuse. Protocol reuse is difficult because Spacewire does not have a defined mechanism to communicate with the higher layers of the protocol stack. This has forced users of Spacewire to define unique packet formats and define how these packets are to be processed. Each mission writes their own Interface Control Document (ICD) and tailors Spacewire for their specific requirements making reuse difficult. Part of the reason for this habit may be because engineers typically optimize designs for their own requirements in the absence of a standard. This is an inefficient use of project resources and costs more to develop missions. A new packet format for Spacewire has been defined as a solution for this problem. This new packet format is a compliment to the Spacewire standard that will support protocol development upon Spacewire. The new packet definition does not replace the current packet structure, i.e., does not make the standard obsolete, but merely extends the standard for those who want to develop protocols over Spacewire. The Spacewire packet is defined with the first part being the Destination Address, which may be one or more bytes. This is followed by the packet cargo, which is user defined. The cargo is truncated with an End-Of-Packet (EOP) marker. This packet structure offers low packet overhead and allows the user to define how the contents are to be formatted. It also provides for many different addressing schemes, which provide flexibility in the system. This packet flexibility is typically an attractive part of the Spacewire. The new extended packet format adds one new field to the packet that greatly enhances the capability of Spacewire. This new field called the Protocol Identifier (ID) is used to identify the packet contents and the associated processing for the packet. This feature along with the restriction in the packet format that uses the Protocol ID, allows a deterministic method of decoding packets that was not before possible. The first part of the packet is still the Destination Address, which still conforms to the original standard but with one restriction. The restriction is that the first byte seen at the destination by the user needs to be a logical address, independent of the addressing scheme used. The second field is defined as the Protocol ID, which is usually one byte in length. The packet cargo (user defined) follows the Protocol ID. After the packet cargo is the EOP, which defines the end of packet. The value of the Protocol ID is assigned by the Spacewire working group and the protocol description published for others to use. The development of Protocols for Spacewire is currently the area of greatest activity by the Spacewire working group. The first protocol definition by the working group has been completed and is now in the process of formal standardization. There are many other protocols in development for missions that have not yet received formal Protocol ID assignment, but even if the protocols are not formally assigned a value, this effort will provide synergism for future developments
Alliances, assemblages, and affects : three moments of building collective working-class literacies
This article explores how assemblage and affect theories can enable research into the formation of a collective working-class identity, inclusive of written, print, publication, and organizational literacies through the origins of the Federation of Worker Writer and Community Publishers, an organization that expanded its collectivity as new heritages, ethnicities, and immigrant identities altered the organization’s membership and "class" identity
The Powerful Potential of Relationships and Community Writing
The following essay is a collective reflection in which the authors revisit the themes they raise in the edited volume Unsustainable, ask new questions, and suggest, again, that long-term sustainability might not be the most appropriate goal for every university-community partnership. Still, relationships, with all their variability, remain the lifeblood of community writing work. Just as the Conference on Community Writing (CCW) was a welcome opportunity to reconnect with old friends and learn new names, our programs are built on the strength of the relationships we build in the community and on our campuses
Reel Lines
Newsletter discussing fishing in Texas and educational programs offered by the Texas Parks and Wildlife Department
Reel Lines
Newsletter discussing fishing in Texas and educational programs offered by the Texas Parks and Wildlife Department
5\u3csup\u3eth\u3c/sup\u3e Generation vs 4\u3csup\u3eth\u3c/sup\u3e Generation Troponin T in Predicting Major Adverse Cardiovascular Events and All-Cause Mortality in Patients Hospitalized for Non-Cardiac Indications: A Cohort Study
OBJECTIVE: The frequency and implications of an elevated cardiac troponin (4th or 5th generation TnT) in patients outside of the emergency department or presenting with non-cardiac conditions is unclear.
METHODS: Consecutive patients aged 18 years or older admitted for a primary non-cardiac condition who had the 4th generation TnT drawn had the 5th generation TnT run on the residual blood sample. Primary and secondary outcomes were all-cause mortality (ACM) and major adverse cardiovascular events (MACE) respectively at 1 year.
RESULTS: 918 patients were included (mean age 59.8 years, 55% male) in the cohort. 69% had elevated 5th generation TnT while 46% had elevated 4th generation TnT. 5th generation TnT was more sensitive and less specific than 4th generation TnT in predicting both ACM and MACE. The sensitivities for the 5th generation TnT assay were 85% for ACM and 90% for MACE rates, compared to 65% and 70% respectively for the 4th generation assay. 5th generation TnT positive patients that were missed by 4th generation TnT had a higher risk of ACM (27.5%) than patients with both assays negative (27.5% vs 11.1%, p\u3c 0.001), but lower than patients who had both assay positive (42.1%). MACE rates were not better stratified using the 5th generation TnT assay.
CONCLUSIONS: In patients admitted for a non-cardiac condition, 5th generation TnT is more sensitive although less specific in predicting MACE and ACM. 5th generation TnT identifies an intermediate risk group for ACM previously missed with the 4th generation assay
A Simplified Approach to Operational InSAR Monitoring of Volcano Deformation in Low- and Middle-Income Countries: Case Study of Rabaul Caldera, Papua New Guinea
The primary goal of operational volcano monitoring is the timely identification of volcanic unrest. This provides critical information to decision makers tasked with mitigating the societal impacts of volcanic eruptions. Volcano deformation is recognized as a key indicator of unrest at many active volcanoes and can be used to provide insight into the depth and geometry of the magma source. Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique that has detected deformation at many volcanoes globally, but most often with hindsight. To date, the use of InSAR for operational volcano monitoring has been limited to a few cases and only in high income countries. Yet a vast number of active volcanoes are located in low- and middle-income countries (LMICs), where resources for operational monitoring are constrained. In these countries, InSAR could provide deformation monitoring at many active volcanoes, including those that have no existing ground monitoring infrastructure. Several barriers combine to make uptake of InSAR into operational volcano monitoring difficult in most countries, but particularly in resource-constrained environments. To overcome some of these limiting factors, we propose a simplified processing chain to better incorporate InSAR and Global Navigation Satellite Systems (GNSS) data into the decision-making process at volcano observatories. To combine the InSAR and GNSS data we use a joint modelling procedure that infers volume changes of a spherical source beneath the volcano. The benefits of our approach for operational use include that the algorithm is computationally lightweight and can be run quickly on a standard desktop or laptop PC. This enables a volcano observatory to interpret geodetic data in a timely fashion, and use the information as part of frequent reporting procedures. To demonstrate our approach we combine ALOS-PALSAR InSAR data and continuous GNSS data from the Rabaul Caldera, Papua New Guinea between 2007 and 2011. Joint inversion of the two datasets indicates volume loss of ~1 × 107 m3 (deflation) occurring between February 2008 and November 2009, followed by volume gain of ~2.5 × 106 m3 (inflation) until February 2011 in a magma body situated ~1.5 km beneath the caldera
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