Hard, slick and ready to roll
A self-renewing, exceptionally hard and slick catalyst coating provides unprecedented friction and wear protection in automobile engines and gear boxes
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A self-renewing, exceptionally hard and slick catalyst coating provides unprecedented friction and wear protection in automobile engines and gear boxes
We sought to demonstrate here that hard x-rays can initiate a sequence of acatalytic photochemical reactions with the aim of creating molecular mixtures (O 2 and F 2 ) and then observe the two species react to form OF 2 and with little introduction of heat. Two x-ray Raman scattering (XRS) studies of 1. KBF 4 and 2. a mixture of KBF 4 + KClO 4 pressurized to 3 GPa in a diamond anvil cell (DAC) at ambient temperature at the 16 ID-D undulator beamline at the Advanced Photon Source. The spectrometer collected photons with energy losses around 680 eV near the fluorine K-edge. Fluorine K-edge x-ray Raman spectroscopy demonstrated the clear formation of a new peak near 682 eV energy loss after some 8 hours of irradiation and detection of the KBF 4 /KClO 4 mixture which likely represents OF 2 produced from the following reaction: O 2 +2F 2 → 2OF 2 following irradiation of the mixture to release O 2 and F 2 , respectively, from each constituent.
One or more substitutional elements may be used to reduce the solution treatment temperature and required quench rates for hardening of 60-NITINOL. The advantages of modified NITINOL include that less energy is consumed during the heat treatment process, the material is subjected to less thermal distortion, and less machining is required. Modified NITINOL may have adequate hardness for bearing applications and may display highly elastic behavior.
The planned luminosity increase at the Large Hadron Collider in the coming years has triggered interest in the use of the particles' time of arrival as additional information in specialized detectors to mitigate the impact of pile-up. The required time resolution is of the order of tens of picoseconds, with a spatial granularity of the order of 1 mm. A time measurement at this precision level will also be of interest beyond the LHC and beyond high energy particle physics. We present in this paper the first developments towards a radiation hard Depleted Monolithic Active Pixel Sensor (DMAPS), with high-resolution time measurement capability. The technology chosen is a standard high voltage CMOS process, in conjunction with a high resistivity detector material, which has already proven to efficiently detect particles in tracking applications after several hundred of Mrad of irradiation.
An Associated Particle Imaging (API) system consists of a high vacuum chamber where deuterium ions are accelerated on a tritium-loaded target, resulting in alpha particles and neutrons emitted back-to-back, the latter escaping the chamber and used, for example, for tomography of a high-Z sample. An accurate determination of the alpha position is crucial to determine the trajectory of the neutron. Existing API systems have several limitations which a semiconductor-based API detector placed inside the vacuum chamber should not present. The semiconductor material can be either silicon or diamond. In particular, large and fast signals are generated by the alpha interactions in these materials. A pixelated API detector will measure the time and hit position of the alphas produced in the reaction. However, during the lifetime of the generator, the semiconductor detector will be exposed to an intense flux of alpha particles that will degrade its performance over time. To assess the radiation hardness of silicon and diamond against the alpha particles, we exposed single diodes made of either of the two materials to a 5 MeV alpha flux generated by an 241Am radioactive source. During irradiation, the diodes were biased and mounted on current-sensitive preamplifier boards. We have therefore been able to measure insitu the evolution of the waveforms as the damage was accumulating in their substrates.
As parity-violating electron scattering (PVeS) experiments continue to push the frontiers of precision electro-weak asymmetry measurements, the demands on the experimental techniques and apparatus are also pushed. In particular, the need for higher resolution and radiation-hardness of the main integrating detectors has increased over the successive generations of PVeS experiments. The demand for precise measurement of GHz event rates has pushed the field toward the use of thin quartz Cerenkov light based detectors. We have been designing and testing such thin quartz detectors specifically for the upcoming experiments at Jefferson Lab, PREX-II and CREX, but this work also greatly influences the detector development for several future experiments including MOLLER at Jefferson Lab. These are all PVeS experiments that will use the new thin quartz Cerenkov detector design concept for their main asymmetry measurements (as well as for beam monitoring). The new design concept gives not only significant performance improvements compared to its predecessor from PREX-I, but also we have now thoroughly characterized its operational design and performance using a combination of test-beam data and detailed particle and optical Monte Carlo Geant4 simulations. These activities have culminated in the development and implementation of a "bench-marked" Monte Carlo package, QSIM, which constitutes a powerful design tool for present and future PVeS quartz detectors. The benchmarked simulation can replicate real photoelectron distributions (RMS and Mean) from testbeam data with ~5% precision – limited mainly by the systematic uncertainty of the PMT gain measurements.
An ultra-hard carbon film is formed by the uniaxial compression of thin films of graphene. The graphene films are two or three layers thick (2-L or 3-L). High pressure compression forms a diamond-like film and provides improved properties to the coated substrates.
U.S. government agencies, particularly the Dept. of Energy, need robotic tools to handle and inspect high-consequence materials - materials for which mishandling would result in great risk to both application operators and the general public. The remediation and documentation of nuclear waste has become a problem of national significance and it cannot be addressed without robotic tools. The use of robots bypasses the danger and decreases the preparation time to handle harmful materials. In the 1980's and 90's, the US Dept. of Energy (DOE) invested heavily in robotic technologies as part of a comprehensive program of research and development aimed at enabling safer and more efficient cleanup of nuclear waste sites. For the next generation of harder, more complex clean-up problems, there is a clear need for more R and D. There is a clear need for flexible, quickly deployable robotic technologies that can be configured to respond to unforeseen situations -- or can be purpose-built for planned activities -- while keeping human workers safe, yet effective. Modularity and inter-operability are core capabilities for inspection tasks in contaminated facilities with a large variety of inspection problems. With any tool, familiarity breeds ingenuity, and ingenuity leads to new innovations in efficiency, effectiveness, safety, and performance. For example, the simple screwdriver can be held fourteen different ways by an experienced machinist who knows exactly what he or she wants to accomplish at any given moment. As a tool, robots are no different. To maximize the efficiency, effectiveness, safety and performance, redeployment and reuse of familiar tools is essential. Modularity can assist with re-deployment and modularity manifests itself in both hardware and software. In some applications of inspection of high-consequence materials, a common concern has been the simplicity of the tool -- often correlated with cost (which is not always accurate) -- in case it becomes unrecoverable. In the case of robots, which have complex user interfaces and complex dynamics of interaction, the lack of familiarity can lead to clumsy operations and reduced accumulation of knowledge. As a result, while incremental successes may be achieved with sequential uses of different robots, there often is little knowledge gain that is generalizable across multiple uses. Total cost often goes down when a more sophisticated, but more familiar tool, can be used more frequently.An example is the inspection of the H-Canyon Exhaust Air Tunnel at the Savannah River Site nuclear waste facility in the United States [1]. This is a particularly nasty environment, due to the acidic gases, large amounts of erosion and debris, and wet, mucky puddles. Over the past twelve years, six inspections have been attempted with five different robotic vehicles. In fact, these inspections have been successful with their limited, but progressively increasing objectives, although most robots have been abandoned in the tunnel. While each vehicle has cost less than $75,000 (the sacrificial part), the total costs of development have been much higher. The robots used to investigate changed much from iteration to iteration and it is not clear a strong body of generalizable expertise was built up across trials. The authors of this study demonstrated the combination of two types of modular, serpentine, re-configurable robots for locomotion over complex terrains and the inspection of hard-to-reach areas. The MOTHERSHIP is a tread/limb/serpentine hybrid robot design for locomotion over complex terrains, while the CMU snake robot provides highly articulated inspection of highly confined spaces. The demonstration at the Portsmouth Gaseous Diffusion Plant involves a combination of the two whereby gross locomotion is achieved with the MOTHERSHIP and the CMU Snake deploys a sensor package to gather data from behind and under obstacles. Although statically configured in its present state, the combined robot is built of individual modules for which reconfiguration has been demonstrated in both labs at Purdue and CMU. In future work, much higher degrees of reconfiguration and re-purposing of both software and hardware are easily achievable with these unique platforms. (authors)
The Aspo Hard Rock Laboratory (HRL), located in the Simpevarp area in the municipality of Oskarshamn in Sweden, Figure 1, constitutes an important part of the Swedish Nuclear Fuel and Waste Management (SKB) work with design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Most of the research has concerned with processes of importance for the long-term safety of a future final repository and the capability to model the processes taking place at repository depth. Demonstration addresses the performance of the engineered barriers and practical means of constructing a repository and emplacing the canisters containing spent fuel. SKB will in the coming years more focus on using the Aspo HRL for demonstrating technology for and function of important parts of the repository system before constructing and operate the spent nuclear fuel repository in Forsmark. Aspo HRL includes both a research village with office space for 100 persons and different laboratories, e.g. Chemistry and Material Science Laboratory and Bentonite Laboratory, and an underground research laboratory to a depth of 460 m. The Aspo HRL is also open for other organisations to be used for their own projects and experiments not only related to nuclear waste management research. (authors)
Between the bookends of World War II and the Cold War, numerous cycles of up-sizing, down-sizing, and right sizing resulted in changing needs for federal real property to support government missions. The end of the Cold War has yielded many opportunities for reuse of federal facilities as defense-related property needs have been lessened. These federal facilities have both a historic and an environmental legacy, from radionuclides to unexploded ordnance to landfills and everything in between. Private-sector manufacturing sites have been especially affected by changing market demands. Obsolescence and advancing technologies have made the 'have to have it' product into the 'what was that for?' The result has been thousands of hectares (acres) of contaminated land throughout the country. While site histories go back in time, it is the environmental cleanup contaminants that have the ability to go forward in time and influence the future use of a site. Demonstrating that property conditions are protective of human health and the environment facilitates reuse options for these properties. Site reuse creates land for communities to attract businesses, grow their tax bases, add open space, and implement sustainability efforts, such as renewables, or set the property aside for future possibilities. A broad range of sites have been made available across the country as a result of federal mission changes and changed economic market conditions affecting private industry. This broad range of properties should have similarly broad recipes for reuse. Even with the constraints of zoning, topographic/natural conditions and use restrictions necessitated by past operations, the pathways to creative, adaptive, and sustainable reuse can be taken by integrating the planning with the remediation or, in a more community-sensitive approach, by integrating the remediation with the planning. Situations do exist where a like-kind use is an ideal reuse option, but a redevelopment of sameness need not be a foregone conclusion. Unlike the operational and imposed environments from which these sites came, with their engineered features often developed in a systematic manner with straight lines and hard edges, they can indeed be transformed into functional, relaxed, and engaging places and be productive again. A site's transformation can begin with how the remediation incorporates sustainable techniques that consider the future use of a site, and how the sustainable remediation can dovetail with the community's reuse plans. Rather than building on Greenfields and extending infrastructure and services to more distant locations, many communities are looking within their already developed footprints for growth possibilities. For some communities this is their only source of growth. Stigmatized and challenged as they may be to reuse, the nation's excess, under-utilized, surplus, and abandoned industrial past presents opportunities well worth considering for improvement to local and regional economies. Communities that are engaged in remediation and reuse planning efforts at these sites have the opportunity to shape their futures, transform their identities and incorporate sustainable practices throughout the process. Unlike the simple name change of a facility, transformative change takes time. Transformative change relies on working partnerships, dedication to achieving something better, open communication, and cooperative planning. It is this type of change that tends to be lasting and tailored to a place. (authors)
In this project irradiated heavy concrete was characterized regarding hard to measure nuclides like Ca-41 using Accelerator Mass Spectrometry (AMS). Concrete samples were irradiated with a known neutron flux and the Ca-41 content was investigated via AMS measurements. The comparison of the results with calculations shows a very good agreement in the Ca-41 content. The project revealed that AMS can be used to characterize irradiated concrete and contributes to improve the methodological basis of the radiological characterization and to extending the validation of nuclide vectors. (authors)
We modify the Standard Model by making the longitudinal component of the photon physical, propagating with small speed $c_L \ll 1$. This modification breaks gauge invariance and Lorentz symmetry, defining a preferred reference frame. No new fields or scales are introduced, and the photon mass is protected by a Galilean higher-form symmetry. The theory has a smooth $c_L\to0$ limit: the new modes decouple from standard matter and ordinary gauge theory predictions are recovered. Experimental constraints are severe. Charged particles Cherenkov-emit these slow modes, experiencing hard recoils against the preferred frame. The recoil rate decreases with $c_L$, but the momentum transfer remains of the order of the particle's momentum. Dark matter detectors, sensitive to keV-scale nuclear recoils, imply an order-of-magnitude bound $c_L \lesssim 10^{-60}$, tens of orders of magnitude stronger than speed-difference bounds. At such values, $c_L$ is better understood as a recoil-rate factor rather than a physically relevant speed. The slow modes, practically fixed in space, make the reference frame a material medium capable of absorbing momentum from charged particles.
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The main objective of the developed software is to reduce the cost per foot during drilling, in other words, optimize the drilling operational parameters in achieving optimum ROP while avoiding critical operational parameters due to either low ROP, drillstring vibration, accelerated cutter wear, or low MSE. The developed software can also be used for post-well analysis to provide insight and lessons learned for future drilling operations. Several functions are available in the software to help the user perform drilling analysis, optimization, and simulation.
We cover the models and statistics associated with single event effects (and total ionizing dose), why we need them, and how to use them: What models are used, what errors exist in real test data, and what the model allows us to say about the DUT will be discussed. In addition, how to use other sources of data such as historical, heritage, and similar part and how to apply experience, physics, and expert opinion to the analysis will be covered. Also included will be concepts of Bayesian statistics, data fitting, and bounding rates.
This work evaluates the effect of a destabilization treatment combined with a subcritical diffusion (SCD) and a subsequent quenching (Q) steps on precipitation of secondary carbides and their influence on the wear properties of HCCI (16%Cr). The destabilization of the austenite at high temperature leads to a final microstructure composed of eutectic and secondary carbides, with an M{sub 7}C{sub 3} nature, embedded in a martensitic matrix. An improved wear resistance was observed in the SCD + Q samples in comparison with the Q one, which was attributed to the size of secondary carbides.
A direct method to calculate the tempering response of a tool steel (H13) that exhibits secondary hardening is presented. Based on the traditional method of presenting tempering response in terms of isothermal tempering, we show that the tempering response for a steel undergoing a non-isothermal tempering schedule can be predicted. Experiments comprised (1) isothermal tempering, (2) non-isothermal tempering pertaining to a relatively slow heating to process-temperature and (3) fast-heating cycles that are relevant to tempering by induction heating. After establishing the tempering response of the steel under simple isothermal conditions, the tempering response can be applied to non-isothermal tempering by using a numerical method to calculate the tempering parameter. Calculated results are verified by the experiments.
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