The publication is a compilation of various feature stories published on NREL's public website, nrel.gov, throughout Calendar Year 2013.

Laser interactions have traditionall been at thec center of nanomaterials science, providing highly nonequilibrium growth conditions to enable the syn- thesis of novel new nanoparticles, nanotubes, and nanowires with metastable phases. Simultaneously, lasers provide unique opportunities for the remote char- acterization of nanomaterial size, structure, and composition through tunable laser spectroscopy, scattering, and imaging. Pulsed lasers offer the opportunity, there- fore, to supply the required energy and excitation to both control and understand the growth processes of nanomaterials, providing valuable views of the typically nonequilibrium growth kinetics and intermediates involved. Here we illustrate the key challenges and progress in laser interactions for the synthesis and in situ diagnostics of nanomaterials through recent examples involving primarily carbon nanomaterials, including the pulsed growth of carbon nanotubes and graphene.

The Mars Hopper is an exploratory vehicle designed to fly on Mars using carbon dioxide from the Martian atmosphere as a rocket propellant. The propellent gasses are thermally heated while traversing a radioisotope ther- mal rocket (RTR) engine’s core. This core is comprised of a radioisotope surrounded by a heat capacitive material interspersed with tubes for the propellant to travel through. These tubes, or flow channels, can be manu- factured in various cross-sectional shapes such as a special four-point star or the traditional circle. Analytical heat transfer and computational fluid dynamics (CFD) anal- yses were performed using flow channels with either a circle or a star cross- sectional shape. The nominal total inlet pressure was specified at 2,805,000 Pa; and the outlet pressure was set to 2,785,000 Pa. The CO2 inlet tem- perature was 300 K; and the channel wall was 1200 K. The steady-state CFD simulations computed the smooth-walled star shape’s outlet temper- ature to be 959 K on the finest mesh. The smooth-walled circle’s outlet temperature was 902 K. A circle with a surface roughness specification at 0.01 mm gave 946 K and at 0.1 mm yielded 989 K. The The effects of a slightly varied inlet pressure …

Today's cyberspace is a powerful, virtual environment enabled by our global digital infrastructure that provides a bright landscape for commerce, science, education, communication, and government. The future of America's prosperity hinges on rebalancing cyberspace to mitigate threats and maximize benefits, ensuring security and privacy in a constantly changing adversarial environment. Recognizing this great need, we requested original paper submissions in four general areas derived from the Federal Cybersecurity R&D program thrusts: Designed-In-Security (DIS) Builds the capability to design, develop, and evolve high-assurance, software-intensive systems predictably and reliably while effectively managing risk, cost, schedule, quality, and complexity. Tailored Trustworthy Spaces (TTS) Provides flexible, adaptive, distributed trust environments that can support functional and policy requirements arising from a wide spectrum of activities in the face of an evolving range of threats--recognizing the user's context and evolves as the context evolves. Moving Target (MT) Enables us to create, analyze, evaluate, and deploy mechanisms and strategies that are diverse and that continually shift and change over time to increase complexity and cost for attackers, limit the exposure of vulnerabilities and opportunities for attack, and increase system resiliency. Cyber Economic Incentives (CEI) Develops effective incentives to make cybersecurity ubiquitous, including incentives affecting individuals and organizations.

Inter-Vehicle Communication (IVC) could be an important component of next-generation Intelligent Transportation System (ITS). It provides wireless connectivity among traveling vehicles to exchange real-time road condition and traffic information to support safe driving and traffic management. IVC system can be considered as a special form of mobile ad-hoc network (MANET). The MANET and IVC are both hot issues for researches. However, there are few domestic literatures combining the two topics. Most of them are discussed separately. Thus, the studies on architecture and protocols of mobile ad-hoc network have great value for establishing vehicular networks. The simulating method is an available way to assess the performance of networks. This paper has a specific description about the network simulator NS-2 . Under the basic of simulating practices, the design method and procedure for MANET simulation are summarized in detail. In this report, two simple IVC scenarios are implemented on NS-2. The quantitative metrics like network throughput, delay and packet-loss are used to assess the performance of MANET for IVC under different vehicular speeds, transport layer protocols and routing protocols. The results indicate that MANET can be used for IVC well. The different speeds and protocols should be chosen based on specific IVC …

In this chapter, we review the physiology of switchgrass from seed dormancy till the effects of water and nutrients stress on grown plants. These characteristics are presented and discussed mainly at the canopy and whole-plant level with emphasis on the agro-physiology of the species in view of the possible contribution of crop physiology to agricultural development. Switchgrass is noted for the variable degrees of seed dormancy regulated by endogenous and exogenous factors that determine the successful seedling establishment. Plant growth rates are determined by temperature while the reproductive phase is controlled mainly by photoperiod. There is also evidence that some physiological attributes, such as photosynthesis, transpiration, and water use efficiency differ between tetraploid, hexaploid and octaploid ecotypes. But despite these differences, in general switchgrass combines important attributes of efficient use of nutrients and water with high yields thanks to its ability to acquire resources from extended soil volumes, especially at deep layers. Moreover at canopy level, resources capture and conservation are determined by morpho-physiological characteristics (C{sub 4} photosynthetic pathway, stomatal control of transpiration, high leaf area index, low light extinction coefficient) that enhance radiation use efficiency and reduce carbon losses. However, specific information on switchgrass physiology is still missing, in …

As HPC systems and applications get bigger and more complex, we are approaching an era in which resiliency and run-time elasticity concerns become paramount. We offer a building block for an alternative resiliency approach in which computations will be able to make progress while components fail, in addition to enabling a dynamic set of nodes throughout a computation lifetime. The core of our solution is a hierarchical scalable membership service providing eventual consistency semantics. An attribute replication service is used for hierarchy organization, and is exposed to external applications. Our solution is based on P2P technologies and provides resiliency and elastic runtime support at ultra large scales. Resulting middleware is general purpose while exploiting HPC platform unique features and architecture. We have implemented and tested this system on BlueGene/P with Linux, and using worst-case analysis, evaluated the service scalability as effective for up to 1M nodes.

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Modeling relationships between land-management practices and resulting changes in carbon, nitrogen, albedo, and other factors is complex. Even so, such modeling can be used to integrate scientific knowledge and provide a bridge between scientific understanding and policy. Yet, too often decision makers have a poor understanding of the underlying models and thus may misinterpret the implications. More often, decision makers diminish model results as fictitious, for they do not recognize the validity or extent of the underlying science. Decision makers should understand that the modeling process (1) involves formalizing hypotheses concerning relationships among components of human, biophysical, and ecological systems and (2) fosters exploration of implications of those hypotheses. To be most helpful for decision making, developing a model requires documentation of the model components and implications including all assumptions, input and output variables, and methods used to calibrate and validate the model as well as to identify sensitivities and uncertainties. There is no one modeling approach that meets the diverse needs of decision makers regarding land and carbon issues. As with all scientific explorations, new learning typically results in improved understanding, new questions, and revised hypotheses about the way the system works. Decision makers need to realize that models …

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This book is focused on the pretreatment of biomass, a necessary step for efficient conversion of the plant cell wall materials to fuels and other products. Pretreatment is required because it is difficult to access, separate, and release the monomeric sugars comprising the biopolymers within the biomass that can be further upgraded to products through chemical processes such as aqueous phase reforming or biological routes such as fermentation of the sugars to ethanol This resistance to degradation or difficulty to release the monomers (mostly sugars) is commonly referred to as recalcitrance. There are many methods to overcome plant recalcitrance, but the underlying cause of the recalcitrance lies in the complex combination of chemical and structural features of the plant cell walls.

Plant based sources of hydrocarbons are being considered as alternatives to petrochemicals because of the need to conserve petroleum resources for reasons of national security and climate change. Changes in fuel formulations to include ethanol from corn sugar and methyl esters from soybean oil are examples of this policy in the United States and elsewhere. Replacements for commodity chemicals are also being considered, as this value stream represents much of the profit for the oil industry and one that would be affected by shortages in oil or other fossil fuels. While the discovery of large amounts of natural gas associated with oil shale deposits has abated this concern, research into bio-based feedstock materials continues. In particular, this chapter reviews a literature on the conversion of bio-based extracts to hydrocarbons for fuels and for building block commodity chemicals, with a focus on soybean derived products. Conversion of methyl esters from soybean triglycerides for replacement of diesel fuel is an active area of research; however, the focus of this chapter will not reside with esterification or transesterification, except has a means to provide materials for the production of hydrocarbons for fuels or chemical feedstocks. Methyl ester content in vehicle fuel is limited …

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A pad is disclosed for use in a weighing system for weighing a load. The pad includes a weighing platform, load cells, and foot members. Improvements to the pad reduce or substantially eliminate rotation of one or more of the corner foot members. A flexible foot strap disposed between the corner foot members reduces rotation of the respective foot members about vertical axes through the corner foot members and couples the corner foot members such that rotation of one corner foot member results in substantially the same amount of rotation of the other comer foot member. In a strapless variant one or more fasteners prevents substantially all rotation of a foot member. In a diagonal variant, a foot strap extends between a corner foot member and the weighing platform to reduce rotation of the foot member about a vertical axis through the comer foot member.

Sensor modules including accelerometers are placed on a physical structure and tri-axial accelerometer data is converted to mechanical power (P) data which then processed to provide a forewarning of a critical event concerning the physical structure. The forewarning is based on a number of occurrences of a composite measure of dissimilarity (Ci) exceeding a forewarning threshold over a defined sampling time; and a forewarning signal is provided to a human observer through a visual, audible or tangible s1gnal. A forewarning of a structural failure can also be provided based on a number of occurrences of (Ci) above a failure value threshold.

H- volume sources and especially caesiated H- volume sources are important ion sources for generating high intensity proton beams, which then in turn generate large quantities of other particles. This paper discusses the physics and technology of the volume production and the caesium enhanced (surface) production of H- ions. Starting with Bacal s discovery of the H- volume production, the paper briefly recounts the development of some H- sources, which capitalized on this process to significantly increase the production of H- beams. Another significant increase was achieved in the 1990s by adding cesiated surfaces to supplement the volume produced ions with surface produced ions as illustrated with other H- sources. Finally the focus turns to some of the experience gained when such a source was successfully ramped up in H- output as well as in duty factor to support the generation of 1 MW proton beams for the Spallation Neutron Source.

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Both drug addiction and obesity can be defined as disorders in which the saliency value of one type of reward (drugs and food, respectively) becomes abnormally enhanced relative to, and at the expense of others. This model is consistent with the fact that both drugs and food have powerful reinforcing effects - partly mediated by dopamine increases in the limbic system - that, under certain circumstances or in vulnerable individuals, could overwhelm the brain's homeostatic control mechanisms. Such parallels have generated significant interest in understanding the shared vulnerabilities and trajectories between addiction and obesity. Now, brain imaging discoveries have started to uncover common features between these two conditions and to delineate some of the overlapping brain circuits whose dysfunctions may explain stereotypic and related behavioral deficits in human subjects. These results suggest that both obese and drug addicted individuals suffer from impairments in dopaminergic pathways that regulate neuronal systems associated not only with reward sensitivity and incentive motivation, but also with conditioning (memory/learning), impulse control (behavioral inhibition), stress reactivity and interoceptive awareness. Here, we integrate findings predominantly derived from positron emission tomography that investigate the role of dopamine in drug addiction and in obesity and propose an updated working model …

The main immobilization technologies that are available commercially and have been demonstrated to be viable are cementation, bituminization, and vitrification. Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either alkali borosilicate glass or alkali aluminophosphate glass. The exact compositions of nuclear waste glasses are tailored for easy preparation and melting, avoidance of glass-in-glass phase separation, avoidance of uncontrolled crystallization, and acceptable chemical durability, e.g., leach resistance. Glass has also been used to stabilize a variety of low level wastes (LLW) and mixed (radioactive and hazardous) low level wastes (MLLW) from other sources such as fuel rod cladding/decladding processes, chemical separations, radioactive sources, radioactive mill tailings, contaminated soils, medical research applications, and other commercial processes. The sources of radioactive waste generation are captured in other chapters in this book regarding the individual practices in various countries (legacy wastes, currently generated wastes, and future waste generation). Future waste generation is primarily driven by interest in sources of clean energy and this has led to an increased interest in advanced nuclear power production. The development of advanced wasteforms is a …

Radiochemical analyses of surface water samples, in the framework of Environmental Monitoring, have associated uncertainties for the radioisotopic results reported. These uncertainty analyses pertain to the tritium results from surface water samples collected at five locations on the Savannah River near the U.S. Department of Energy's Savannah River Site (SRS). Uncertainties can result from the field-sampling routine, can be incurred during transport due to the physical properties of the sample, from equipment limitations, and from the measurement instrumentation used. The uncertainty reported by the SRS in their Annual Site Environmental Report currently considers only the counting uncertainty in the measurements, which is the standard reporting protocol for radioanalytical chemistry results. The focus of this work is to provide an overview of all uncertainty components associated with SRS tritium measurements, estimate the total uncertainty according to ISO 17025, and to propose additional experiments to verify some of the estimated uncertainties. The main uncertainty components discovered and investigated in this paper are tritium absorption or desorption in the sample container, HTO/H{sub 2}O isotopic effect during distillation, pipette volume, and tritium standard uncertainty. The goal is to quantify these uncertainties and to establish a combined uncertainty in order to increase the scientific depth …

This book chapter presents an overview of research conducted in our laboratory on preparation, optical and physico-chemical properties of metallic and nanohybrid materials. Metallic nanoparticles, particularly gold, silver, platinum or a combination of those are the main focus of this review manuscript. These metallic nanoparticles were further functionalized and used as templates for creation of complex and ordered nanomaterials with tailored and tunable structural, optical, catalytic and surface properties. Controlling the surface chemistry on/off metallic nanoparticles allows production of advanced nanoarchitectures. This includes coupled or encapsulated core-shell geometries, nano-peapods, solid or hollow, monometallic/bimetallic, hybrid nanoparticles. Rational assemblies of these nanostructures into one-, two- and tridimensional nano-architectures is described and analyzed. Their sensing, environmental and energy related applications are reviewed.