Class 8 tractor-trailers are responsible for 11-12% of the total US consumption of petroleum. Overcoming aero drag represents 65% of energy expenditure at highway speeds. Most of the drag results from pressure differences and reducing highway speeds is very effective. The goal is to reduce aerodynamic drag by 25% which would translate to 12% improved fuel economy or 4,200 million gal/year. Objectives are: (1) In support of DOE's mission, provide guidance to industry in the reduction of aerodynamic drag; (2) To shorten and improve design process, establish a database of experimental, computational, and conceptual design information; (3) Demonstrate new drag-reduction techniques; and (4) Get devices on the road. Some accomplishments are: (1) Concepts developed/tested that exceeded 25% drag reduction goal; (2) Insight and guidelines for drag reduction provided to industry through computations and experiments; (3) Joined with industry in getting devices on the road and providing design concepts through virtual modeling and testing; and (4) International recognition achieved through open documentation and database.
Proposed for publication in Physical Review Letters.
We propose a method for controlling a class of low temperature chemical reactions. Specifically, we show the hydrogen abstraction channel in the reaction of formaldehyde (H{sub 2}CO) and the hydroxyl radical (OH) can be controlled through either the molecular state or an external electric field. We also outline experiments for investigating and demonstrating control over this important reaction. To this end, we report the first Stark deceleration of H{sub 2}CO. We have decelerated a molecular beam of H{sub 2}CO essentially to rest, producing molecules at 100 mK with a density of {approx} 10{sup 6} cm{sup -3}.
Security system analytical performance analysis is generally based on the probability of system effectiveness. The probability of effectiveness is a function of the probabilities of interruption and neutralization. Interruption occurs if the response forces are notified in sufficient time to engage the adversary. Neutralization occurs if the adversary attack is defeated after the security forces have actively engaged the adversary. Both depend upon communications of data. This paper explores details of embedded communications functions that are often assumed to be inconsequential. It is the intent of the authors to bring focus to an issue in security system modeling that, if not well understood, has the potential to be a deciding factor in the overall system failure or effectiveness.
Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.
In the discharge of a capacitor the current was measured with a current viewing transformer (CVT). In addition to measuring the current flowing through the CVT primary, a 51 MHz noise signal was added to the primary current. When the CVT was covered with a gold shield, the noise was eliminated. Analysis of the measured results indicate that the gold layer reflected the electromagnetic that was generated by current flowing in the primary and that the capacitance between the shield and the CVT secondary had no measurable effect on the CVT output.
A computational fluid dynamics (CFD) analysis is conducted for internal natural convection heat transfer using the low Mach number code Fuego. The flow conditions under investigation are primarily laminar, transitional, or low-intensity level turbulent flows. In the case of turbulent boundary layers at low-level turbulence or transitional Reynolds numbers, the use of standard wall functions no longer applies, in general, for wall-bounded flows. One must integrate all the way to the wall in order to account for gradients in the dependent variables in the viscous sublayer. Fuego provides two turbulence models in which resolution of the near-wall region is appropriate. These models are the v2-f turbulence model and a Launder-Sharma, low-Reynolds number turbulence model. Two standard geometries are considered: the annulus formed between horizontal concentric cylinders and a square enclosure. Each geometry emphasizes wall shear flow and complexities associated with turbulent or near turbulent boundary layers in contact with a motionless core fluid. Overall, the Fuego simulations for both laminar and turbulent flows compared well to measured data, for both geometries under investigation, and to a widely accepted commercial CFD code (FLUENT).
Polymer degradation has been explored on the basis of synergistic infectious and inhibitive interaction between separate materials. A dual stage chemiluminescence detection system with individually controlled hot stages was applied to probe for interaction effects during polymer degradation in an oxidizing environment. Experimental confirmation was obtained that volatile antioxidants can be transferred over a relatively large distance. The thermal degradation of a polypropylene (PP) sample receiving traces of inhibitive antioxidants from a remote source is delayed. Similarly, volatiles from two stabilized elastomers were also capable of retarding a degradation process remotely. This observation demonstrates inhibitive cross-talk as a novel interactive phenomenon between different polymers and is consequential for understanding general polymer interactions, fundamental degradation processes and long-term aging effects of multiple materials in a single environment.
Proposed for publication in the Journal of Coatings Technology.
Advances in technology have resulted in the need for electronic devices to continue functioning even when placed in harsh environments. Widespread use of cell phones, laptop computers, and other personal electronic devices, the increased number of electronic controls in home appliances, and the ever more extensive utilization of digital technology in the automotive industry have led to a growing demand for printed circuit boards (PCBs) that can perform under difficult conditions. Conformal coatings provide a protective barrier that enables the PCBs to function in these demanding environments. This growth in demand comes despite the cost and numerous difficulties associated with the application of these coatings. Many conformal coatings manufacturers are investing in the development of new technologies that minimize these difficulties. Others are involved in developing disruptive technologies that will serve as alternatives to traditional conformal coatings processes.
Given pre-existing Groundwater Modeling System (GMS) models of the Horonobe Underground Research Laboratory (URL) at both the regional and site scales, this work performs an example uncertainty analysis for performance assessment (PA) applications. After a general overview of uncertainty and sensitivity analysis techniques, the existing GMS site-scale model is converted to a PA model of the steady-state conditions expected after URL closure. This is done to examine the impact of uncertainty in site-specific data in conjunction with conceptual model uncertainty regarding the location of the Oomagari Fault. A heterogeneous stochastic model is developed and corresponding flow fields and particle tracks are calculated. In addition, a quantitative analysis of the ratio of dispersive to advective forces, the F-ratio, is performed for stochastic realizations of each conceptual model. Finally, a one-dimensional transport abstraction is modeled based on the particle path lengths and the materials through which each particle passes to yield breakthrough curves at the model boundary. All analyses indicate that accurate characterization of the Oomagari Fault with respect to both location and hydraulic conductivity is critical to PA calculations. This work defines and outlines typical uncertainty and sensitivity analysis procedures and demonstrates them with example PA calculations relevant to the Horonobe URL. Acknowledgement: This project was funded by Japan Nuclear Cycle Development Institute (JNC). This work was conducted jointly between Sandia National Laboratories (SNL) and JNC under a joint JNC/U.S. Department of Energy (DOE) work agreement. Performance assessment calculations were conducted and analyzed at SNL based on a preliminary model by Kashima, Quintessa, and JNC and include significant input from JNC to make sure the results are relevant for the Japanese nuclear waste program.
Solution stamping nanolithography (SSNL) was used to print patterns of metallic copper and high-temperature-superconducting YBa{sub 2}Cu{sub 3}O{sub 7}. SSNL combines soft lithography and chemical-solution deposition to achieve direct printing of inorganic materials. The size of the printed patterns is determined by both the stamp feature size and the wetting properties of the solution.