Analytical solution of the peak bending moment of an M boom for membrane deployable structures
Not Available
SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Not Available
The Durable Module Materials Consortium (DuraMAT) launched in November 2016 with five years of funding from the U.S. Department of Energy s (DOE's) Solar Energy Technologies Office (SETO). The program renewed in 2022 for an additional 6 years. DuraMAT is a multi-lab consortium led by the National Renewable Energy Laboratory, with Sandia National Laboratories (Sandia) and Lawrence Berkeley National Laboratory (LBNL) as core research labs. DuraMAT's overarching goal is to accelerate a sustainable, just, and equitable transition to zero-carbon electricity generation by 2035. 2023 has been a wild ride in the solar industry. Photovoltaic (PV) manufacturing is coming back to the United States, and deployment is booming again. DuraMAT has a unique opportunity to support flourishing manufacturing and deployment over the next couple of years.
The OSIRIS-REx sample return capsule's hypersonic re-entry into the atmosphere is a rare opportunity to test a variety of sonic boom source models since the projectile dimensions are well characterized. While the as-flown flight path is unknown, the predicted flight path enables a rough approximation of the source Mach number and location. Six infrasound microphones deployed in the boom carpet along the predicted flight path recorded impulsive signals from the OSIRIS-REx re-entry. Using a suite of atmosphere profiles and the geometric acoustics approximation, we estimate locations with uncertainty estimates along the flight path from which the signals were emitted. Acoustic overpressure and signal duration predictions from Whitham's far field theory, Carlson's simplified sonic boom prediction method, and a drag-dominated hypersonic model are analyzed with uncertainty estimates from the location estimate. While the Carlson simplified sonic boom prediction method could be accurate, our preference is for the drag-dominated source model. Using this source model with an inviscid Burgers's equation solver for propagation, we obtained an excellent match to the recorded data. In conclusion, these results will help better inform future sample return capsule re-entry observation campaigns as well as contribute to a better understanding of high altitude infrasonic sources.
Title: Idaho National Laboratory’s Mobile Hot Cell Transportation: Engineering Solutions for Global Disused Sealed Radioactive Sources. Abstract: The Mobile Hot Cell (MHC), currently under development by Idaho National Laboratory (INL) for the Off-Site Source Recovery Project (OSRP), is designed to help international partners meet the unique challenges of end-of-life radioactive material management. The MHC will provide a critical resource for countries that require assistance securing and disposing of Disused Sealed Radioactive Sources (DSRS) and orphaned sources in challenging environments, allowing these sources to be secured against misuse and nefarious activities. The MHC is a rapidly deployable system for conditioning and preparing end-of-life radioactive sources for transportation or storage. It is designed to handle sources of up to 1,000 Ci Co-60 equivalent while maintaining full radiological and biological containment. It will be deployable within 48 hours of an alert, making it ideal for emergency situations. The MHC features an operational suite for control, support racks for electronics, pneumatics, and welding systems, and a modular robust steel structure providing radiological shielding and internal robotic support. This design allows configurations for multiple device types to be conditioned and the ability to safely manage routine issues such as leaking or damaged sources. The MHC has been designed with the transportation challenges of rapid deployment to difficult environments in mind. The system weighs approximately 150,000 pounds, with individual systems breaking down into pieces not exceeding 20,000 pounds. Components are to be transportable on standard 20ft ISO containers, with shielding shells on 20ft flat racks. It is estimated that a total of eight containers and flat racks will be required. The use of 20ft containers, as opposed to 40ft containers, minimizes the impact on less developed road infrastructures, enabling the MHC to be positioned in constrained environments such as hospital parking lots. The system’s modularity also allows for deployment using smaller equipment, such as a 10-ton boom truck or forklift, which is crucial given the potential logistical challenges in different countries. This transportation strategy, evaluated in collaboration with Utah State University, ensures the MHC can be deployed via ground, rail, sea, or air, addressing the primary concern of international transport logistics.
Considering the current booming interest for the large-scale deployment of bifacial photovoltaic modules, the solar industry now requires accurate estimates of broadband surface albedo at high spatial resolution. In this context, the present study evaluates the adequacy and performance over North America of two Moderate Resolution Imaging Spectroradiometer (MODIS) white-sky albedo products (at 500-m and 1-km resolution) and the National Solar Radiation Database (NSRDB) product at 4-km resolution. Two variations of the 500-m MODIS product are also considered: black-sky albedo and all-sky albedo. Albedo observations from 36 radiometric stations during 2011–2015 are analyzed while considering the apparent homogeneity of the surface characteristics over the 4x4 km NSRDB pixel in which they are located. Even at sites where the albedo around the station has been found “homogeneous” in the literature, marked differences are found between the daily observations and the gridded estimates at any spatial resolution. Furthermore, differences in seasonal behavior and between the three different albedo types also impact the accuracy of the albedo estimates, with overtones caused by local specificities and inhomogeneities. All this precludes the desirable evaluation of the local albedo at a specific site of relatively small size compared to its corresponding 4x4-km pixel if only the mean albedo over that pixel is known. Significant discrepancies are also found at snow-impacted sites, most importantly in the case of the NSRDB albedo estimates, which are typically much too high.
Up to this point, ultrasonic inspection-based condition data has only been available for double-shell tank (DST) sidewalls because direct inspection access to the primary tank bottom is limited to vent duct channels in an insulating refractory pad that the primary tank rests on. Probe access through the air slot would provide the opportunity to get information about the condition of the bottom of the primary tank, but it is a challenge to deploy a crawling robot that is capable of performing nondestructive ultrasonic and visual inspection through confined air slots. As such, a conceptual prototype of a deployable inspection robot system to enable ultrasonic and visual inspection for DST base through ventilation ducts was designed and fabricated. This prototype dual robot system consisting of the AnnulusBot and the MouseBot can be integrated with nondestructive evaluation (NDE) sensors to inspect and examine the physical properties of the underside of DSTs to enable status assessment. The AnnulusBot was designed to carry the MouseBot and to be deployed to the annulus space through a riser. To deploy the MouseBot to every ventilation channel in the annulus, the arm consisting of a boom and a forearm was used to place the MouseBot on the underside of the tank. The AnnulusBot used segmented wheels enable to traverse pipes and other potential obstacles. The cable management system utilized motorized wheels to feed the cable into the ventilation channel. This would reduce the amount of work that the MouseBot would have to do during inspection. This feeding mechanism would also be used to retrieve the MouseBot at the end of its inspection. Additionally, if the MouseBot fails, this mechanism would be used for retrieval. Once deployed, the MouseBot navigates to the center of the tank via the air ventilation channel beneath the inner shell (the primary tank) while inspecting the space. The MouseBot is then retrieved from the channel by a combination of its own drive power and the AnnulusBot retracting the attached umbilical cord. Compare with the AnnulusBot, the physical dimensional limitations of the MouseBot were a greater challenge. As the surface state of the concrete of the air channels could have variable texture, and may contain debris, it was decided not to travel along this surface. The ceiling of these channels is carbon steel and can be utilized throughout the channel. To use this travel surface, magnetic wheels were employed. A foreseeable problem with the use of magnets on this surface, is that they would preclude the use of eddy currents sensors. However, other technologies like ultrasonic technology sensors should be unaffected. Laboratory scale test was performed on a mock-up single wedge of the refractory pad to evaluate maneuverability of the MouseBot. The electronic components for the prototype would work in the ranges of 150-185 deg. F (65.6-85 deg. C). Both the AnnulusBot and MouseBot will be subject to constant radiation. All major printed circuit board (PCB) microcontroller components were designed to be situated outside of the annulus space and inside the main control panel to avoid radiation-induced failure. As future work, electronic components including the Arduinos that used Atmel commercial microcontrollers will be replaced with the high temperature rated Atmel microcontrollers so that the robots can be operated reliably at ambient temperatures up to 200 deg. F (93.3 deg. C). In addition, the robots will be service life tested to evaluate performance at elevated temperature and under gamma irradiation. (authors)
The National Rural Electric Cooperative Association (NRECA) is the national association representing 833 distribution and 62 generation and transmission (G&T) cooperatives. From booming suburbs to remote rural farming communities, America’s electric cooperatives are energy providers and engines of economic development and way of life for more than 19 million American homes, businesses, farms, and schools in 47 states across the U.S. Member owned and responsive, generally smaller than investor-owned and municipal utilities, often more nimble in services for members, co-ops provide the U.S. Department of Energy (DOE) with a strong partner for testing and accelerating utility-scale solar design, pricing, and delivery models.
This dataset contains sonic anemometer data deployed on tethered balloon system at AWAKEN site G. The sonic data include time stamp, wind speed, wind direction, turbulence, and boom attitude and motion. Z02 refers to the second height position of the sonic anemometers mounted on the tethered balloon.
This dataset contains sonic anemometer data deployed on tethered balloon system at AWAKEN site G. The sonic data include time stamp, wind speed, wind direction, turbulence, and boom attitude and motion. Z01 refers to the first height position of the sonic anemometers mounted on the tethered balloon.
This dataset contains sonic anemometer data deployed on tethered balloon system at AWAKEN site A1. The sonic data include time stamp, wind speed, wind direction, turbulence, and boom attitude and motion.
Irrigation modernisation is booming globally because of the increasing demand on water and food. However, irrigation infrastructures can injure fish or entrain them into irrigation water. Screening is an effective method to mitigate fish entrainment. In this study, two autonomous sensor devices, developed and manufactured at Pacific Northwest National Laboratory (Sensor Fish and its miniaturised version, Sensor Fish Mini) were deployed to evaluate the physical and fish passage conditions of a unique horizontal, flat-plate fish and debris screen (known as the Farmers Screen) that was installed in Oregon, USA. Only 1 of the 27 Sensor Fish Mini releases had a severe acceleration event, whereas 0 of the 37 Sensor Fish releases had severe events. The rates of severe events and amplitudes of accelerations at the Farmers Screen were significantly lower than those at other hydraulic structures, including a fish-friendly surface weir that recorded nearly 100% fish survival. Overall, the results indicated that the Farmers Screens can provide safe downstream passage for fish at irrigation diversions. This study also demonstrated that the Sensor Fish technology, including Sensor Fish Mini, is a suitable technology for evaluating irrigation structures and providing important information for the development of sustainable irrigation.
In this study, a high-tonnage harvesting system designed specifically to operate efficiently in the expected stand types of a bioenergy scenario was built, deployed, and evaluated in a production setting. Stands on which the system was evaluated exhibited the heavy stocking levels (> 600 stems per acre) and tree size distributions with significant volume in small stems (down to 2” DBH) that were expected in the modified energy plantation silvicultural approach. The harvest system also was designed to be functional in the traditional plantation stands dominating the commercial forestry landscape in the region. The Tigercat 845D feller buncher, which was a prototype machine designed for the high tonnage harvest system, used a boom-mounted prototype DT1802 shear felling head and incorporated a number of options intended to maximize its small-stem productivity, including: a high-speed shear severing system that was cheaper to operate than a saw; a large-pocket felling head that allowed larger accumulations of small stems to be built before expending the time to drop them for the skidder; efficient, low ground pressure, tracked carrier system to decrease the amount of maneuvering, saving time and minimizing soil disturbance; and various energy-saving devices to lower fuel costs and minimize air quality impacts. Overall, the feller buncher represented a quantum advance in small-stem harvesting technology. Extensive testing showed the machine’s production rate to be relatively insensitive to piece size, much less so than comparable traditional equipment. In plantation stands, the feller buncher was able to produce approximately 100 green tons of biomass per productive machine hour (PMH), and in natural stands, it produced nearly 120 green tons per PMH. The ability of the high tonnage feller buncher to maintain high productivity in stands with smaller diameter stems is something that has not been achieved in previous feller buncher designs. The Tigercat 845D feller buncher is now a production machine for Tigercat and is being sold in their current product line. The high-speed felling system was paired with a Tigercat 630D skidder and high-capacity grapple; one that could match the felling productivity when pulling small stems. The harvesting system minimized hourly costs using a single, high-capacity skidder (with a single operator), rather than two smaller ones, which is the traditional practice. The skidder itself can be considered a mid-range size and had an engine no larger than other machines in its class, but it incorporated a very large capacity 25 ft2 grapple. The large grapple is well suited to grabbing and hauling a large bunch of small-diameter trees, as produced by the high tonnage feller buncher. The grapple worked effectively in larger stems as well, but its ability to carry large numbers of small stems meant the average payload did not drop as stand DBH decreased. Tests with the machine indicated its travel speeds were nearly the same as, or perhaps slightly better than, conventionally equipped skidders, but grapple capacity was 75% larger. Productivity and cost per ton of the new skidder were better than conventional skidders for average skid distances of any length greater than 100 feet. Measured skidder productivity was as high as 143 gt/PMH. Its productivity exceeded that of the high-capacity feller buncher for skid distances out to nearly 700 feet, so system productivity could be expected to remain high for stands of a size typical in the southern U.S. The Tigercat 630D skidder is a production machine for Tigercat and the large grapple can now be ordered by customers using it for small diameter trees. When the feller buncher and skidder are analyzed as a two-machine system, overall productivity is fixed at the level of the least productive machine. Results from a set of side-by-side tests in the same density stand with conventional feller bunchers and skidders showed that the high tonnage system produced 97 gt/PMH versus 68 gt/PMH for a comparable conventional system. Machine rate costs for felling and skidding were $2.31/gt and $3.72/gt for the high tonnage, and conventional systems, respectively. However, the most significant result of the project is that the high tonnage system was shown to be relatively insensitive to tree size. This ability to maintain felling and skidding productivity and cost as tree size decreases is a breakthrough in harvesting systems for southern pine plantations. The concept of transpirational drying of woody biomass was tested at an industrial scale at multiple locations during this project. Felled trees were allowed to dry in two scenarios: 1) in bunches where they were felled, and 2) in roadside piles. Although the wood piled in large piles at roadside did experience drying, the wood left in bunches experienced a greater moisture reduction. Drying times of 72 days in the late summer resulted in mean wood moisture content of 26% for skidder bunches and 39% for the large pile at roadside as compared to moisture contents of 55% to 58% for freshly cut trees. An existing whole-tree chipper, Precision 2675, was modified to allow production of chips smaller than the traditional pulp size chip (i.e. “microchips”). Feed rates and knife placements were retained in the new design, while additional pockets were incorporated in the chipper disk to allow the attachment of either four knives for pulp chips or eight knives for microchips. This design facilitated switching between the energy and pulp chip product options at relatively low expense (about ½ day downtime). Chipping of whole-trees into pulp chips and microchips with the Precision 2675 disk chipper resulted in average productivities of 79.5 gt/PMH and 70.7 gt/PMH, respectively. Production rates of the chipper were lower when producing microchips by about 10% relative to producing pulp chips, but rates were similar to those achievable when making clean pulp chips. Particle size analysis for clean pine microchips revealed 26.6% retention on a 13 mm (slightly less than 3/8-inch) round hole screen and 25.9% retention for whole-tree pine microchips. For comparison, clean pine pulp chips had 52.2% retained. Ash content (% dry basis) was 0.54% for clean pine microchips and 0.62% for whole-tree pine microchips. Ash content for clean pine pulp chips was 0.39%. For transpirationally-dried material there was 38.1% retention for whole-tree microchips on a 13mm screen compared to 70.1% for dried clean pulp chips. Ash content was 0.78% and 0.44% respectively for these two chip types. Clean pine microchips stored at roadside had 25.2% retention on a 13 mm screen and 0.50% ash content. For mixed species (pine and hardwood), whole-tree microchips had 25.1% retention on a 13 mm screen compared to 50.6% for whole-tree pulp chips. Ash content was 2.12% and 2.74% respectively for these two chip types. Clean hardwood microchips stored at roadside had 35.0% retention on a 13 mm screen and an ash content of 1.24%. There are two significant advantages to using transpirational drying: reduced transportation costs, and reduced drying costs (capital and operating costs) for the biorefinery. This project evaluated the potential to reduce transportation costs through transpirational drying, and it included a component that tested higher capacity chip trailers (23% larger volume) to be able to transport dry wood with a lower bulk density. For transpirationally-dried chips at 35% MC, the high-capacity trailers achieved loads with a mean payload of 24 tons with maximum payloads of 29 tons. The typical legal payload on this trailer is 28.5 tons. Therefore, the project demonstrated that it is possible to achieve maximum legal payloads on chip trailers with transpirationally dried wood. Assuming that the truck is loaded to the legal payload limit, the transportation costs of chips can be reduced from $15.91/dry ton (dt) for 56% MC wood to $10.77/dt for transpirationally dried wood at 35% MC (for an example 50-mile haul distance at $0.14 per one-way ton-mile). For longer haul distances, these savings in trucking costs become even more significant. These results have demonstrated how significant savings in transportation costs can be achieved through transpirational drying. Also, these results show that it may be possible to increase the procurement radius for a biorefinery by using transpirational drying. Further cost reductions can be realized by the biorefinery when drying costs are reduced. The goal of this study was development of a timber harvesting system as productive in stands optimized for biomass production as it was in stands grown for roundwood markets. If that goal is achieved, a logger can invest in a single suite of equipment and operate efficiently in any future silvicultural regime that might include energy feedstocks as an output. It was the premise of the study that a future biomass market would shift the age distribution and stem size in stands grown for energy downward, and the key strategy in developing a harvest system for that scenario would be creating one with logging costs relatively insensitive to tree size. Our vision for such a system included a felling machine with a large capacity head to minimize time spent building bunches, plus a skidder capable of moving large volumes of small trees. The study proposed building the system and testing it against existing equipment in stands similar to those envisioned as resulting from biomass-optimized silviculture. As stated previously, the new feller buncher and skidder evaluated on their own merits showed their designs were clearly a step in the right direction - their productivity was indeed high and less sensitive to reductions in stem size. Cost projections based on extensive time and production studies of the high tonnage and benchmark operations showed modest advantages in FOB costs of the new system in both ‘average’ and simulated ‘energy’ stands (7.7% and 9.5%, respectively). But it was clear, when coupled into a traditional logging system, the in-woods productivity advantage of the modified equipment was easily overwhelmed by inefficiencies in chipping or trucking. Some additional savings can be achieved by spreading the cost of the feller buncher over multiple chipping operations (another 7.5%), but generally, in stands with average DBH above 6 inches, the in-woods equipment was not limiting productivity, and costs were driven by chipping and transport. Our results were a positive step in lowering delivered cost of trees grown for energy purposes, but they also argue strongly for a more comprehensive approach in solving this issue. The procurement system in its entirety has to be optimized to take full advantage of the productivity gains achieved with the machines and transpirational drying techniques developed in this project. We have to understand the true costs of all logistical options, particularly those of the choice in chipping strategy and in truck allocation, both of which seemed, in this study, to be the greatest source of variability in cost, and often the most expensive operations as well.
Data-intensive research in seismology is experiencing a recent boom, driven in part by large volumes of available data and advances in the growing field of data science. However, there are significant barriers to processing large data volumes, such as long retrieval times from data repositories, complex data management, and limited computational resources. New tools and platforms have reduced the barriers to entry for scientific cluster computing, including the maturation of the commercial cloud as an accessible instrument for research. Here, we build a customized research cluster in the cloud to test a new workflow for large-scale seismic analysis, in which data are processed as a stream (retrieved on-the-fly and acted upon without storing), with data from the Incorporated Research Institutions for Seismology Data Management Center. We use this workflow to deploy a spectral peak detection algorithm over 5.6 TB of compressed continuous seismic data from 2074 stations of the USArray Transportable Array EarthScope network. Using a 50-node cluster in the cloud, we completed the noise survey in 80 hr, with an average data throughput of 1.7 GB per minute. By varying cluster sizes, we find the scaling of our analysis to be sublinear, due to a combination of algorithmic limitations and data center response times. The cloud-based streaming workflow represents an order-of-magnitude increase in acquisition and processing speed compared to a traditional download-store-process workflow, and offers the additional benefits of employing a flexible, accessible, and widely used computing architecture. It is limited, however, due to its reliance on Internet transfer speeds and data center service capacity, and may not work well for repeated analyses or those for which even higher data throughputs are needed. These research applications will require a new class of cloud-native approaches in which both data and analysis are in the cloud.
Per regulatory agreement and facility closure design, U.S. Department of Energy Hanford Site nuclear fuel cycle structures and materials require in situ isolation in perpetuity and/or interim physicochemical stabilization as a part of final disposal or interim waste removal, respectively. To this end, grout materials are being used to encase facilities structures or are being incorporated within structures containing hazardous and radioactive contaminants. Facilities where grout materials have been recently used for isolation and stabilization include: (1) spent fuel separations, (2) uranium trioxide calcining, (3) reactor fuel storage basin, (4) reactor fuel cooling basin transport rail tanker cars and casks, (5) cold vacuum drying and reactor fuel load-out, and (6) plutonium fuel metal finishing. Grout components primarily include: (1) portland cement, (2) fly ash, (3) aggregate, and (4) chemical admixtures. Mix designs for these typically include aggregate and non aggregate slurries and bulk powders. Placement equipment includes: (1) concrete piston line pump or boom pump truck for grout slurry, (2) progressive cavity and shearing vortex pump systems, and (3) extendable boom fork lift for bulk powder dry grout mix. Grout slurries placed within the interior of facilities were typically conveyed utilizing large diameter slick line and the equivalent diameter flexible high pressure concrete conveyance hose. Other facilities requirements dictated use of much smaller diameter flexible grout conveyance hose. Placement required direct operator location within facilities structures in most cases, whereas due to radiological dose concerns, placement has also been completed remotely with significant standoff distances. Grout performance during placement and subsequent to placement often required unique design. For example, grout placed in fuel basin structures to serve as interim stabilization materials required sufficient bearing i.e., unconfined compressive strength, to sustain heavy equipment yet, low breakout force to permit efficient removal by track hoe bucket or equivalent construction equipment. Further, flow of slurries through small orifice geometries of moderate head pressures was another typical design requirement. Phase separation of less than 1 percent was a typical design requirement for slurries. On the order of 30,000 cubic meters of cementitious grout have recently been placed in the above noted U.S. Department of Energy Hanford Site facilities or structures. Each has presented a unique challenge in mix design, equipment, grout injection or placement, and ultimate facility or structure performance. Unconfined compressive and shear strength, flow, density, mass attenuation coefficient, phase separation, air content, wash-out, parameters and others, unique to each facility or structure, dictate the grout mix design for each. Each mix design was tested under laboratory and scaled field conditions as a precursor to field deployment. Further, after injection or placement of each grout formulation, the material was field inspected either by standard laboratory testing protocols, direct physical evaluation, or both. (authors)