The overall project objective was to apply high throughput experimentation and combinatorial methods together with novel syntheses to discover and optimize efficient, practical, and economically sustainable materials for photoelectrochemical production of bulk hydrogen from water. Automated electrochemical synthesis and photoelectrochemical screening systems were designed and constructed and used to study a variety of new photoelectrocatalytic materials. We evaluated photocatalytic performance in the dark and under illumination with or without applied bias in a high-throughput manner and did detailed evaluation on many materials. Significant attention was given to -Fe2O3 based semiconductor materials and thin films with different dopants were synthesized by co-electrodeposition techniques. Approximately 30 dopants including Al, Zn, Cu, Ni, Co, Cr, Mo, Ti, Pt, etc. were investigated. Hematite thin films doped with Al, Ti, Pt, Cr, and Mo exhibited significant improvements in efficiency for photoelectrochemical water splitting compared with undoped hematite. In several cases we collaborated with theorists who used density functional theory to help explain performance trends and suggest new materials. The best materials were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visual spectroscopy (UV-Vis), X-ray photoelectron spectroscopy (XPS). The photoelectrocatalytic performance of the thin films was evaluated and their incident photon

Photosynthesis is the biological process that converts solar energy into chemical energy. Elucidation of the mechanisms of photosynthetic energy conversion at a molecular level is fundamentally important for understanding the biology of photosynthetic organisms, for optimizing biological solar fuels production, and for developing biologically inspired approaches to solar energy conversion. The 2011 Gordon Conference on Photosynthesis will present cutting-edge research focusing on the biochemical aspects of photosynthesis, including: (1) structure, assembly, and function of photosynthetic complexes; (2) the mechanism of water splitting by PSII; (3) light harvesting and quenching; (4) alternative electron transport pathways; (5) biosynthesis of pigments and cofactors; and (6) improvement of photosynthesis for bioenergy and food production. Reflecting the interdisciplinary nature of photosynthesis research, a diverse group of invited speakers will represent a variety of scientific approaches to investigate photosynthesis, such as biochemistry, molecular genetics, structural biology, systems biology, and spectroscopy. Highly interactive poster sessions provide opportunities for graduate students and postdocs to present their work and exchange ideas with leaders in the field. One of the highlights of the Conference is a session featuring short talks by junior investigators selected from the poster presentations. The collegial atmosphere of the Photosynthesis GRC, with programmed discussion sessions as …

The purpose of this document is to establish a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking database tool and are tailored to meet the scope of each specific field campaign.

The goal of this project has been to develop a lossless compression algorithm for message-passing libraries that can accelerate HPC systems by reducing the communication time. Because both compression and decompression have to be performed in software in real time, the algorithm has to be extremely fast while still delivering a good compression ratio. During the first half of this project, they designed a new compression algorithm called FPC for scientific double-precision data, made the source code available on the web, and published two papers describing its operation, the first in the proceedings of the Data Compression Conference and the second in the IEEE Transactions on Computers. At comparable average compression ratios, this algorithm compresses and decompresses 10 to 100 times faster than BZIP2, DFCM, FSD, GZIP, and PLMI on the three architectures tested. With prediction tables that fit into the CPU's L1 data acache, FPC delivers a guaranteed throughput of six gigabits per second on a 1.6 GHz Itanium 2 system. The C source code and documentation of FPC are posted on-line and have already been downloaded hundreds of times. To evaluate FPC, they gathered 13 real-world scientific datasets from around the globe, including satellite data, crash-simulation data, and …

Abstract Fusion welding is used extensively in industries that support the nation's energy supply, defense, infrastructure, and standard of living. Safety and reliability of the welded joints are affected by their geometry, composition and structure. This report provides an account of the significant advances made in quantitative understanding of the geometry, composition and various aspects of the weldment structure with financial support from DOE/BES. In particular, this report provides an account of the research conducted under the grant DE-FG02-84ER45158 in this important area and lists all the publications that document the details of the technical accomplishments that resulted from the work. Investigations of heat transfer, fluid flow and alloying element vaporization during laser welding resulted in a new technique for the determination of the peak temperature in the weld pool and provided a new method to estimate weld metal composition. Studies on the interfacial phenomena in fusion welding resulted in quantitative understanding of the interrelationship between the weld metal composition and geometry and provided new knowledge as to when the surface active elements would affect the weldment geometry and when these elements would have no effect on the geometry. Partitioning of oxygen nitrogen and hydrogen between the welding environment and …

Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a ma jor impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30◦ or 60◦ . We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.