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A description of a single VLSI chip for computing syndromes in the (255, 223) Reed-Solomon decoder is presented. The architecture that leads to this single VLSI chip design makes use of the dual basis multiplication algorithm. The same architecture can be applied to design VLSI chips to compute various kinds of number theoretic transforms.
The aerodynamic influence coefficients calculated using an existing linear theory program were used to modify the pressures calculated using impact theory. Application of the combined approach to several wing-alone configurations shows that the combined approach gives improved predictions of the local pressure and loadings over either linear theory alone or impact theory alone. The approach not only removes most of the short-comings of the individual methods, as applied in the Mach 4 to 8 range, but also provides the basis for an inverse design procedure applicable to high speed configurations.
During the past decade, the US Department of Energy (DOE)/National Nuclear Security Administration (NNSA) Nuclear Criticality Safety Program (NCSP) has been coordinating nuclear criticality safety (NCS) courses to provide training and qualification to new staff, supervisors, managers, regulators, and other professionals involved with NCS. To address the growing need for more NCS training possibilities, a subcritical assembly was designed at Oak Ridge National Laboratory (ORNL). The Oak Ridge Subcritical Assembly (ORSA), operated at ORNL, could be used in a new course for fissile material handlers/operators or as a backup training facility for currently existing NCSP hands-on NCS training. This paper describes some of the design steps necessary for obtaining a final ORSA design, beginning with a successful feasibility study performed in 2020. Numerous parameters within each main element of the assembly were considered, such as the reflector used, the type of fuel coating or plating used, and the number of fuel plates used. The design choices related to each parametric study described in this paper are detailed and justified at the end of each subsection. An overview of the current final design characteristics of ORSA and the experiments’ possibilities is also provided. ORSA will be built with fuel plates from legacy Aerojet General Nucleonics (AGN)-201M research reactors currently stored at the Y-12 National Security Complex (Y-12). The cylindrical fuel plates comprise UO 2 particles embedded in polyethylene and have a nominal enrichment of 19.5 ± 0.5 wt % 235 U. The basis for the final design was the feasibility study from 2020. In the feasibility study, ORSA achieved k eff = 0.95, corresponding to a multiplication factor of 20, with approximately 620 g of 235 U (four 4 cm plates, three 2 cm plates, and two 1 cm plates) and an 8.5 cm thick graphite reflector radially and on top of the assembly. The bottom of the assembly has a graphite thickness of 5 cm, and the chosen graphite density was 2.3 g/cm 3 . All design calculations were performed using SCALE 6.2.4 KENO-VI and with the ENDF/B VII.1 Continuous Energy cross-section library.
PNNL staff are currently working to conduct analyses, integrate experimental data, and develop the technical basis for extended long term storage and subsequent transportation of used nuclear fuel. Analyses will serve to augment the experimental work by addressing degradation phenomena not readily obtainable through experimentation, such as low temperature creep over very long periods of time. Analyses can also address issues such as concrete degradation that may not require a comprehensive R&D program to resolve, as well as evaluation of engineering design solutions that can be implemented to mitigate the amount and extent of experimental data needed. Most importantly, analyses are necessary to determine how much degradation any structure, system, or component can experience and still maintain its ability to meet its safety functions. This paper focuses on various structural modeling issues that are affected by material degradation in extended long term storage scenarios. Typical storage cask and transportation package designs have a safety basis that includes a number of structural static or dynamic finite element analysis (FEA) models. Some of the features of these standard models need to be reconsidered when the fuel is in an extended long term storage state. In this paper, a number of standard safety basis FEA models are discussed and evaluated for their applicability to long term storage scenarios. A vertical handling drop analysis is used to illustrate a case where additional modeling is needed to define the loads and loading history needed to properly evaluate material degradation in long term storage scenarios.
Purpose: For a given bowtie filter design, both the selection of material and the physical design control the energy fluence, and consequently the dose distribution, in the object. Using three previously described bowtie filter designs, the goal of this work is to demonstrate the effect that different materials have on the bowtie filter performance measures. Methods: Three bowtie filter designs that compensate for one or more aspects of the beam-modifying effects due to the differences in path length in a projection have been designed. The nature of the designs allows for their realization using a variety of materials. The designs were based on a phantom, 14 cm in diameter, composed of 40% fibroglandular and 60% adipose tissue. Bowtie design #1 is based on single material spectral matching and produces nearly uniform spectral shape for radiation incident upon the detector. Bowtie design #2 uses the idea of basis-material decomposition to produce the same spectral shape and intensity at the detector, using two different materials. With bowtie design #3, it is possible to eliminate the beam hardening effect in the reconstructed image by adjusting the bowtie filter thickness so that the effective attenuation coefficient for every ray is the same. Seven different materials were chosen to represent a range of chemical compositions and densities. After calculation of construction parameters for each bowtie filter design, a bowtie filter was created using each of these materials (assuming reasonable construction parameters were obtained), resulting in a total of 26 bowtie filters modeled analytically and in the PENELOPE Monte Carlo simulation environment. Using the analytical model of each bowtie filter, design profiles were obtained and energy fluence as a function of fan-angle was calculated. Projection images with and without each bowtie filter design were also generated using PENELOPE and reconstructed using FBP. Parameters such as dose distribution, noise uniformity, and scatter were investigated. Results: Analytical calculations with and without each bowtie filter show that some materials for a given design produce bowtie filters that are too large for implementation in breast CT scanners or too small to accurately manufacture. Results also demonstrate the ability to manipulate the energy fluence distribution (dynamic range) by using different materials, or different combinations of materials, for a given bowtie filter design. This feature is especially advantageous when using photon counting detector technology. Monte Carlo simulation results from PENELOPE show that all studied material choices for bowtie design #2 achieve nearly uniform dose distribution, noise uniformity index less than 5%, and nearly uniform scatter-to-primary ratio. These same features can also be obtained using certain materials with bowtie designs #1 and #3. Conclusions: With the three bowtie filter designs used in this work, the selection of material is an important design consideration. An appropriate material choice can improve image quality, dose uniformity, and dynamic range.
In July 2010, Stark State College (SSC), received Grant DE-EE0003229 from the U.S. Department of Energy (DOE), Golden Field Office, for the development of the electrical and control systems, and mechanical commissioning of a unique 20kW scale high-pressure, high temperature, natural gas fueled Stack Block Test System (SBTS). SSC worked closely with subcontractor, Rolls-Royce Fuel Cell Systems (US) Inc. (RRFCS) over a 13 month period to successfully complete the project activities. This system will be utilized by RRFCS for pre-commercial technology development and training of SSC student interns. In the longer term, when RRFCS is producing commercial products, SSC will utilize the equipment for workforce training. In addition to DOE Hydrogen, Fuel Cells, and Infrastructure Technologies program funding, RRFCS internal funds, funds from the state of Ohio, and funding from the DOE Solid State Energy Conversion Alliance (SECA) program have been utilized to design, develop and commission this equipment. Construction of the SBTS (mechanical components) was performed under a Grant from the State of Ohio through Ohio's Third Frontier program (Grant TECH 08-053). This Ohio program supported development of a system that uses natural gas as a fuel. Funding was provided under the Department of Energy (DOE) Solid-state Energy Conversion Alliance (SECA) program for modifications required to test on coal synthesis gas. The subject DOE program provided funding for the electrical build, control system development and mechanical commissioning. Performance testing, which includes electrical commissioning, was subsequently performed under the DOE SECA program. Rolls-Royce Fuel Cell Systems is developing a megawatt-scale solid oxide fuel cell (SOFC) stationary power generation system. This system, based on RRFCS proprietary technology, is fueled with natural gas, and operates at elevated pressure. A critical success factor for development of the full scale system is the capability to test fuel cell components at a scale and under conditions that can be accurately extrapolated to full system performance. This requires specially designed equipment that replicates the pressure (up to 6.5 bara), temperature (about 910 C), anode and cathode gas compositions, flows and power generation density of the full scale design. The SBTS fuel cell anode gas is produced through the reaction of pipeline natural gas with a mixture of steam, CO2, and O2 in a catalytic partial oxidation (CPOX) reactor. Production of the fuel cell anode gas in this manner provides the capability to test a fuel cell with varying anode gas compositions ranging from traditional reformed natural gas to a coal-syngas surrogate fuel. Stark State College and RRFCS have a history of collaboration. This is based upon SSCAs commitment to provide students with skills for advanced energy industries, and RRFCS need for a workforce that is skilled in high temperature fuel cell development and testing. A key to this approach is the access of students to unique SOFC test and evaluation equipment. This equipment is designed and developed by RRFCS, with the participation of SSC interns. In the near-term, the equipment will be used by RRFCS for technology development. When this stage is completed, and RRFCS has moved to commercial products, SSC will utilize this equipment for workforce training. The RRFCS fuel cell design is based upon a unique ceramic substrate architecture in which a porous, flat substrate (tube) provides the support structure for a network of solid oxide fuel cells that are electrically connected in series. These tubes are grouped into a {approx}350-tube repeat configuration, called a stack/block. Stack/block testing, performed at system conditions, provides data that can be confidently scaled to full scale performance. This is the basis for the specially designed and developed test equipment that is required for advancing and accelerating the RRFCS SOFC power system development program. All contract DE-EE0003229 objectives were achieved and deliverables completed during the period from March 1, 2010 through March 31, 2011. As a result of program completion, the Stack Block Test System was ready to support installation and electrical operation of a RRFCS solid oxide fuel cell (SOFC) stack block in the second quarter of 2011.
We are presenting the layout and the optics of a beam line to be used as a medical gantry in radiation therapy. The optical properties of the gantry's beam line are such as to make the beam line achromatic and uncoupled. These two properties make the beam spot size, which is delivered and focused by the gantry, on the tumor of the patient, independent of the angular orientation of the gantry. In this paper we present the layout of the magnetic elements of the gantry, and also present the theoretical basis for the optics design of such a gantry. A medical gantry, as it is used in the radiation treatment of cancer patients, is the last part of the beam optical system, of the accelerator complex, which delivers and focuses the beam on the tumor. The curved line shown in figure 1 is a schematic diagram of a gantry which can rotate about a horizontal axis. The particle beam (green arrow in fig. 1) enters the gantry, and is guided by the gantry on the tumor (red spot in fig. 1). As the gantry rotates about the axis shown in figure 1, the beam exiting the gantry always lies on a plane normal to the rotation axis at the point of the icocenter. Thus the gantry facilitates the ability of the beam delivery system, to deliver the beam at the tumor, which is placed at the icocenter, from any angle on this vertical plane, which is normal to the rotation angle of the gantry as stated earlier. The gantry consists of dipoles and quadrupoles elements whose median symmetry plane lies on a plane which contains the rotation axis of the gantry. In this paper we define this plane as the 'plane of the gantry'. As the beam is transported along the axis of rotation of the gantry and before it enters the gantry, it is focused by 'normal' quadrupoles and experiences no linear beam coupling. Subsequently the beam enters the gantry, and is transported by the gantry to the delivery point which is the tumor. The transported beam at the tumor is still linearly uncoupled as long as the plane of the gantry lies either, on the horizontal, or the vertical plane. In these two orientations of the gantry the dipoles and the quadrupoles are 'normal' therefore the linear R-transport-matrix appears linearly uncoupled. As the gantry rotates about this horizontal axis, to irradiate the tumor at a different angle, the linear beam coupling is unavoidable since the coordinate system of the gantry's quadrupoles is rotated with respect to the coordinate system of the quadrupoles at the entrance of the gantry which are located along the axis of rotation. As a result, in this rotated coordinate system, the beam will be linearly coupled as it is transported by the gantry to the tumor and the beam size at the location of the tumor will vary in size depending on the orientation of the gantry. In this paper we present a method which makes the beam transport R-matrix linearly uncoupled, achromatic and independent of the orientation angle of the gantry as is proven in the following section.
A computer program for aircraft synthesis using a numerical optimizer was developed to study the application of the joined-wing configuration to transport aircraft. The structural design algorithm included the effects of secondary bending moments to investigate the possibility of tail buckling and to design joined wings resistant to buckling. The structural weight computed using this method was combined with a statistically-based method to obtain realistic estimates of total lifting surface weight and aircraft empty weight. A variety of 'optimum' joined-wing and conventional aircraft designs were compared on the basis of direct operating cost, gross weight, and cruise drag. The most promising joined-wing designs were found to have a joint location at about 70 percent of the wing semispan. The optimum joined-wing transport is shown to save 1.7 percent in direct operating cost and 11 percent in drag for a 2000 nautical mile transport mission.
The Advanced Integrated Life Support System Program (AILSS) is an advanced development effort to integrate the life support and protection requirements using the U.S. Navy's fighter/attack mission as a starting point. The goal of AILSS is to optimally mate protection from altitude, acceleration, chemical/biological agent, thermal environment (hot, cold, and cold water immersion) stress as well as mission enhancement through improved restraint, night vision, and head-mounted reticules and displays to ensure mission capability. The primary emphasis to date has been to establish garment design requirements and tradeoffs for protection. Here the garment and the human interface are treated as a system. Twelve state-off-the-art concepts from government and industry were evaluated for design versus performance. On the basis of a combination of centrifuge, thermal manikin data, thermal modeling, and mobility studies, some key design parameters have been determined. Future efforts will concentrate on the integration of protection through garment design and the use of a single layer, multiple function concept to streamline the garment system.
The purpose of this paper is to give a detailed description of the design, activation, and operation of the J2-X Subscale Simulator (JSS) installed in Cell 1 of the E3 test facility at Stennis Space Center, MS (SSC). The primary purpose of the JSS is to simulate the installation of the J2-X engine in the A3 Subscale Rocket Altitude Test Facility at SSC. The JSS is designed to give aerodynamically and thermodynamically similar plume properties as the J2-X engine currently under development for use as the upper stage engine on the ARES I and ARES V spacecraft. The JSS is a scale pressure fed, LOX/GH fueled rocket that is geometrically similar to the J2-X from the throat to the nozzle exit plane (NEP) and is operated at the same oxidizer to fuel ratios and chamber pressures. This paper describes the heritage hardware used as the basis of the JSS design, the newly designed rocket hardware, igniter systems used, and the activation and operation of the JSS.
An analysis of upper air winds was performed to define the wind environment at potential operating altitudes for high altitude powered platform concepts. Wind conditions of the continental United States, Pacific area (Alaska to Sea of Japan), and European area (Norwegian and Mediterranean Sea) were obtained using a representative network of sites selected based upon adequate high altitude sampling, geographic dispersion, and observed upper wind patterns. A data base of twenty plus years of rawinsonde gathered wind information was used in the analysis. Annual variations from surface to 10 mb pressure altitude were investigated to encompass the practical operating range for the platform concepts. Parametric analysis for the United States and foreign areas was performed to provide a basis for vehicle system design tradeoffs. This analysis of wind magnitudes indicates the feasibility of annual operation at a majority of sites and more selective seasonal operation for the extreme conditions between the pressure altitudes of 100 to 25 mb based upon the assumed design speeds.
An analysis of upper air winds was performed to define the wind environment at potential operating altitudes for high-altitude powered platform concepts. Expected wind conditions of the contiguous United States, Pacific area (Alaska to Sea of Japan), and European area (Norwegian and Mediterranean Seas) were obtained using a representative network of sites selected based upon adequate high-altitude sampling, geographic dispersion, and observed upper wind patterns. A data base of twenty plus years of rawinsonde gathered wind information was used in the analysis. Annual variations from surface to 10 mb (approximately 31 km) pressure altitude were investigated to encompass the practical operating range for the platform concepts. Parametric analysis for the United States and foreign areas was performed to provide a basis for vehicle system design tradeoffs. This analysis of wind magnitudes indicates the feasibility of annual operation at a majority of sites and more selective seasonal operation for the extreme conditions between the pressure altitudes of 100 to 25 mb based upon the assumed design speeds.
GEM-FLO (A Generic Simulation Environment for Modeling Future Launch Operations) is a computer program that facilitates creation of discrete-event simulation models of ground processes in which reusable or expendable launch vehicles (RLVs) are prepared for flight. GEM-FLO includes a component, developed in Visual Basic, that generates a graphical user interface (GUI) and a component, developed in the Arena simulation language, that creates a generic discrete-event simulation model. Through the GUI, GEM-FLO elicits RLV design information from the user. The design information can include information on flight hardware elements, resources, and ground processes. GEM-FLO translates the user s responses into mathematical variables and expressions that populate the generic simulation model. The variables and expressions can represent processing times, resource capacities, status variables, and other process parameters needed to configure a simulation model that reflects the ground processing flow and requirements of a specific RLV. Upon execution of the model, GEMFLO puts out data on many measures of performance, including the flight rate, turnaround time, and utilization of resources. This information can serve as the basis for determining whether design goals can be met, and for comparing characteristics of competing RLV designs
One of the key objectives of the SFR R&D program is to develop and demonstrate innovative cost reduction and performance enhancing technologies for SFRs. The supercritical carbon dioxide (S-CO 2 ) Brayton cycle power converter system has been identified as one such innovation that could contribute to meeting this objective. One appealing feature of this system is the small footprint that the hardware requires, which is in part due to the use of Printed Circuit Heat Exchangers (PCHEs) as the secondary (Na-to-CO 2 ) heat exchanger as well as the recuperator and cooler modules. Although PCHEs have a high degree of structural integrity, the potential for leak(s) to develop between the sodium and CO2 coolant channels in the secondary heat exchanger cannot be ruled out, leading to discharge of high pressure CO 2 into the secondary coolant circuit. Due to the robustness of the PCHE design, catastrophic failure leading to gas jet blowdown into the secondary sodium loop is not deemed to be a likely scenario. Rather, small crack(s) (or micro-leaks) may develop in which CO 2 will bleed into the secondary system at a relatively low rate and chemically react with the sodium. The primary focus of the current work is to develop an experiment capability to investigate reaction characteristics under micro-leak conditions. This report summarizes the progress that was made towards meeting this objective this fiscal year. In particular, the facility scaling rationale was developed, and on that basis, the detailed facility design and operating procedures were completed. Based on the design work, fabrication drawings for the three primary system components (i.e., test vessel, dump tank, and separator/vapor trap) were generated and submitted to an outside vendor (i.e., Ability Engineering Technology in South Holland, IL) for fabrication. Fabrication of these components was also completed this year. Plans are to have the facility assembled by the midpoint of FY11 and to begin shakedown testing at that time.
Size reduction systems used in biomass processing break biomass into smaller pieces by utilizing the kinetic energy from the sharp rotating blades. Abrasive and/or erosive wear caused by biomass comminution results in blade wear of the sharp edged cutters, deteriorating the process efficiency. Here, this study aims to optimize the blade design and improve the system efficiency by attempting to understand the interactions between the blades and biomass particles. Since real-time monitoring of these interactions is impractical during operation, mechanical simulations offer a viable alternative for investigating the shredding process. Yet, the irregular geometry and complex mechanical properties of biomass—such as the anisotropic nature of woodchips and their nonlinear fracture behavior—pose significant challenges for accurately simulating contact pressure. In this work an anisotropic yield material model, along with a damage initiation and evolution function, is applied to the woodchip particle to study the contact pressure on shredder blade, offering a scientific basis for improved blade design and process efficiency. This approach can be extended to other biomass processing systems with similar anisotropic feedstocks, making it a valuable tool for advancing sustainable biomass utilization.
The design of high voltage and medium voltage AC and DC standoff insulators, and, in general, of insulation systems where surface and interface properties are predominant factors, is based on specifications and standards that rely upon long-term experiences and lab testing. Surface insulating properties depend on electrical and thermal stresses, besides environmental factors, and the inception of extrinsic ageing phenomena, such as partial discharges, can be already a cause of reduced reliability and premature failure (for organic insulating materials). An innovative approach, based on field simulation, discharge modelling, and partial discharge inception measurements is presented by the authors, which can establish a solid basis to optimise insulation design for any type of supply voltage waveform. This method, the three-leg approach, is applied here to a cable system under AC sinusoidal voltage, but it can work for any type of insulation system, such as bushings, switch gears, transformers, rotating machines, and power electronics boards.
Chapter 3 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report. The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.
Current light-duty vehicles provide passenger thermal comfort primarily through the use of a centralized HVAC (Heating, Ventilation, and Air Conditioning) unit that distributes conditioned air to vent locations throughout the vehicle. A substantial portion of the air energy content is spent conditioning various elements of the vehicle's interior structures. This is not an overwhelming issue in today’s vehicles, but as pressure builds to improve powertrain efficiency, the energy available to provide occupant comfort will decrease. Thermoelectric devices were identified by the US Department of Energy as one method to potentially reduce HVAC-related energy consumption in vehicles. The objective of the Ford Thermoelectric HVAC Project was to identify a technical and business approach to accelerate research and development of light-duty automotive thermoelectric HVAC technology. A zonal HVAC system was developed to provide thermal comfort to each occupant, with the objective of reducing the overall power consumed by the HVAC system compared with a baseline system. The system was designed to provide a basis for a down-sized central HVAC unit, while providing equivalent comfort and equivalent heating/cooling time-to-comfort at startup, and reduce the energy consumed to provide these functions. Project success was evaluated using occupant comfort and energy consumption metrics, based on a novel thermal comfort-modeling approach, and empirical testing. The ability to produce and market the thermoelectric devices developed in this program was assessed by a business analysis that outlined key steps required for thermoelectric HVAC devices to come to market. Key hardware and controls attribute requirements were identified to determine how they contribute to the commercialization potential of the technology. Final testing and analysis showed that use of thermal comfort and zonal design criteria reduced the energy consumption of the climate control system in both heating and cooling tests, and were significantly better in low vehicle occupancy cases where zonal strategies could be employed. Thermoelectric devices were utilized in the vehicle design to support achieving the technical performance goals of the project. It was found that these devices need additional development in order to address commercial issues, due to their cost and performance limitations.