Spin-dependent transport in molecular tunnel junctions

We present measurements of magnetic tunnel junctions made using a self-assembled-monolayer molecular barrier. Ni/octanethiol/Ni samples were fabricated in a nanopore geometry. The devices exhibit significant changes in resistance as the angle between the magnetic moments in the two electrodes is varied, demonstrating that low-energy electrons can traverse the molecular barrier while maintaining spin coherence. An analysis of the voltage and temperature dependence of the data suggests that the spin-coherent transport signals can be degraded by localized states in the molecular barriers.Comment: 4 pages, 5 color figure

Controlling the stereochemistry and regularity of butanethiol self-assembled monolayers on Au(111)

© 2014 American Chemical Society. The rich stereochemistry of the self-assembled monolayers (SAMs) of four butanethiols on Au(111) is described, the SAMs containing up to 12 individual C, S, or Au chiral centers per surface unit cell. This is facilitated by synthesis of enantiomerically pure 2-butanethiol (the smallest unsubstituted chiral alkanethiol), followed by in situ scanning tunneling microscopy (STM) imaging combined with density functional theory molecular dynamics STM image simulations. Even though butanethiol SAMs manifest strong headgroup interactions, steric interactions are shown to dominate SAM structure and chirality. Indeed, steric interactions are shown to dictate the nature of the headgroup itself, whether it takes on the adatom-bound motif RS•Au(0)S•R or involves direct binding of RS• to face-centered-cubic or hexagonal-close-packed sites. Binding as RS• produces large, organizationally chiral domains even when R is achiral, while adatom binding leads to rectangular plane groups that suppress long-range expression of chirality. Binding as RS• also inhibits the pitting intrinsically associated with adatom binding, desirably producing more regularly structured SAMs

Our energy future: where is reality. [Northwest USA]

The energy future will be affected by decisions made in the next few years. The author speaks on the reality of the future, specifically for electric power generation in the Northwest United States. His four main thoughts are: decisions made today will stand for ten years or more and are irreversible; only coal and nuclear are options available in the Northwest; coal and nuclear must be utilized to alleviate power outages leading to rationing and allocation measures; and conservation of electricity will benefit all. After summing up all issues involved with these thoughts, the author told the teachers at the conference that they were obligated to prepare youth to participate knowledgeably in this decision process. (MCW

CosmoCaixa PRINT3D: Reimprimir la realidad

"PRINT3D" is an exhibition that invites us to travel into the future through 3D printing. To what extent will it transform our day to day life and what will that mean for the current production system? A tour through this exhibition will help us discover the versatility of this technology. In it, we will find multiple practical applications in which 3D printing is already being used, in fields as diverse as medicine, construction or art. We will navigate through time thanks to 3D printing, discovering how it allows us to recreate extinct species or archaeological relics in great detail. But not only will we be able to travel to the past, but we will also imagine our future, making use of this type of impression in space and on other planets. In these settings where resources are very limited, the versatility of this technology is unmatched. How far will 3D printing take us

International nuclear waste management fact book

The International Nuclear Waste Management Fact Book has been compiled to provide current data on fuel cycle and waste management facilities, R and D programs, and key personnel in 24 countries, including the US; four multinational agencies; and 20 nuclear societies. This document, which is in its second year of publication supersedes the previously issued International Nuclear Fuel Cycle Fact Book (PNL-3594), which appeared annually for 12 years. The content has been updated to reflect current information. The Fact Book is organized as follows: National summaries--a section for each country that summarizes nuclear policy, describes organizational relationships, and provides addresses and names of key personnel and information on facilities. International agencies--a section for each of the international agencies that has significant fuel cycle involvement and a list of nuclear societies. Glossary--a list of abbreviations/acronyms of organizations, facilities, and technical and other terms. The national summaries, in addition to the data described above, feature a small map for each country and some general information that is presented from the perspective of the Fact Book user in the US

Hanford technology integration: A success story

This paper describes recent activities of the Richland Northwest Laboratory in the area of technology transfer. A major thrust within major DOE laboratories has been the implementation of technology transfer activities which transfer scientific knowledge, transfer technologies developed to deal with the production or conservation of energy, and transfer spinoff technologies into the private sector. Several activities which are in process or have been implemented are described in this paper

Atomic Energy Commission Reports

Report describing a 300-Mw(e) Supercritical Pressure Power Reactor's facilities, physics, economics, and problems encountered during its development. Appendix begins on page 103