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OSTIblog Articles in the In the OSTI Collections Topic

The Kondo Effect Phenomena

by Kathy Chambers 22 Mar, 2016 in
Brookhaven National Laboratory (BNL) researcher Ignace Jarrige shown with the sample used in the magnetic refrigeration experiment. Courtesy BNLBrookhaven National Laboratory (BNL) researcher Ignace Jarrige shown with the sample used in the magnetic refrigeration experiment. Courtesy BNL

For more than 50 years, scientists around the world have attempted to understand the intriguing phenomena of the Kondo effect.  When magnetic impurities are added to non-magnetic host materials, their properties display unexpected, anomalous behavior as a result of the Kondo effect.  These dilute magnetic alloys, and their unusual behaviors are important tools for scientific research in topics such as ferromagnetism, superconductivity, and other solid-state phenomena.  The Kondo effect provides insight into the electronic properties of a wide variety of materials and opens doors to new discoveries. 

Dutch physicist and mathematician Wander Johannes de Haas and fellow researchers observed an unexpected rise in the resistivity of some gold samples at low temperatures in 1933.  This was unusual because metals were expected to show a residual resistivity as their temperatures were reduced.  Some thirty years later, American physicist Phil Anderson developed a microscopic model of how local magnetic moments form in metals with magnetic impurities.  Then in 1964, Japanese theorist Jun Kondo finally was able to explain the scattering of electrons from a localized magnetic impurity.  Kondo's key concept...

Related Topics: alloy, In the OSTI Collections, Kondo Effect, magnetic, temperatures


Shape-Memory Materials Magic

by Kathy Chambers 23 Feb, 2016 in
Hubble Space Telescope Courtesy of NASAHubble Space Telescope Courtesy of NASA

Just like magic, shape-memory materials have the ability to be transformed into another shape and then return to their original shape—or in some cases even metamorphose into a third shape before returning to their original shape.  This transformation is possible because the crystalline structure of shape-memory alloys allows them to sense and respond to their environment.  Shape-memory transformation behavior can now be created by thermal, light, or chemical environments. Shape-memory alloys have been used by the research community for well over a decade to accomplish tasks that were not possible otherwise.   

Visit OSTI's Catalogue of Collections to learn about the magic happening with shape-memory technology by DOE researchers and U.S. federal agencies.

SciTech Connect is DOE's premier full-text source for research and development results in the OSTI Collections.  A myriad of DOE's research projects have utilized shape-memory materials such as endovascular therapiesenergy-efficient cooling systems that use an elastic shape-memory metal alloy as a refrigerant, and the discovery of shape-...

Related Topics: fiber, In the OSTI Collections, plastic, Shape-Memory, solar


The Legendary Richard Feynman

Richard Feynman visits National Accelerator Laboratory (Fermilab) December 1972. Fermilab photo 72-0910-04.Richard Feynman visits National Accelerator Laboratory (Fermilab) December 1972. Fermilab photo 72-0910-04.Richard Phillips Feynman was one of the world’s great quantum physicists. He was best known for his research in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of superfluidity of supercooled liquid helium, and in particle physics for which he proposed the parton model.  Many of his theories and inventions, such as the Feynman diagrams and microelectromechanical systems (MEMS), have evolved into techniques scientists use todayFeynman was able to think visually and invent problem-solving tools that forever altered the direction of theoretical physics.  His extraordinary genius along with his blunt, mischievous, and eccentric personality made him a legend.

Many of Feynman’s brilliant ideas were not readily accepted.  In the 1940s, Feynman introduced a graphical interpretation called Feynman diagrams to make sense of...

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High-Altitude Water Cherenkov Gamma-Ray Observatory

Image credit: HAWCImage credit: HAWCCheers of celebration erupted in March 2015 as the High-Altitude Water Cherenkov (HAWC) Gamma- Ray Observatory was formally inaugurated on the slopes of the Sierra Negra volcano in the State of Puebla, Mexico.  The inaugural ceremony marked the completion of HAWC, the latest tool for mapping the northern sky and studying the universe’s violent explosions of supernovae, which are neutron star collisions and active galactic nuclei that produce high-energy gamma rays and cosmic rays that travel large distances, making it possible to see objects and events far outside our galaxy.  

This extraordinary observatory uses a unique detection technique that differs from the classical astronomical design of mirrors, lenses, and antennae.  From its perch on top of the highest accessible peak in Mexico, HAWC observes TeV gamma rays and cosmic rays with an instantaneous aperture that covers more than 15% of the sky.  The detector is exposed to two-thirds of the sky during a 24-hour period.  The observatory's ability to operate continuously and its location at 14,000 feet above sea level allow HAWC to observe the highest energy gamma rays arriving anywhere within its field of view.


Related Topics: HAWC; LANL; Los Alamos National Laboratory


Graphene’s Humble Creation and Promising Future

by Kathy Chambers 05 Jan, 2015 in

Sometimes the ordinary things we use every day can lead to extraordinary discoveries.  This was truly the case when physicists Andre Geim and Konstantin Novoselov used the humble adhesive tape to extract single layers of graphene from graphite. 

Although graphene had been theorized years before, it was thought to be impossible to isolate such thin crystalline materials in a laboratory.  Geim and Novoselov not only exfoliated their thin sheets of graphene, they transferred them to a silicon substrate, the standard working material in the semiconductor industry and did electrical characterization on the graphite layers.  Their discovery was published in 2004 and in 2010 they were awarded the Nobel Prize in Physics for successfully producing, isolating, identifying and characterizing graphene.  Their adhesive tape, dispenser, chuck of graphite and a graphene transistor (shown above) were donated to the Nobel Museum in Stockholm. 

Graphene is a single layer of carbon packed in a hexagonal (honeycomb) lattice and the first in a new class of two-dimensional crystalline materials with remarkable mechanical and electrical properties.  Graphene is the strongest known substance, 200 times stronger than steel, so dense that the smallest gas atom helium cannot pass through it.  It is an unmatched thermal and electrical conductor, stable, stretchable, transparent and impermeable.

Graphene holds much promise.  Since the 2003 discovery, graphene research has increased substantially in many areas, including the development of solar cells, composite materials, lithium-ion batteries, biological and chemical sensors, transistors, inkjet printing of next generation electronics, telecommunications, novel coatings and lubricants.  Department of Energy...

Related Topics: adhesive tape, Andre Geim, graphene, In the OSTI Collections, Konstantin Novoselov


ACME - Perfecting Earth System Models

by Kathy Chambers 29 Oct, 2014 in

Earth system modeling as we know it and how it benefits climate change research is about to transform with the newly launched Accelerated Climate Modeling for Energy (ACME) project sponsored by the Earth System Modeling program within the Department of Energy’s (DOE) Office of Biological and Environmental Research.  ACME is an unprecedented collaboration among eight national laboratories, the National Center for Atmospheric Research, four academic institutions, and one private-sector company to develop and apply the most complete, leading-edge climate and earth system models to the most challenging and demanding climate-change issues.  They collectively represent a unique combination of scientific and engineering expertise as well as advanced computing and information technologies required to construct, maintain, and advance an earth system modeling capability that will help us better understand and address climate change.

The core of the ACME project is model development.  This element connects the scientific and energy mission needs with computing power provided by the DOE Office of Science.  The models created will be used to simulate changes in the hydrological cycle, with a specific focus on precipitation and surface water in orographically complex regions such as the western United States and the headwaters of the Amazon.  They will address biogeochemistry by examining how more complete treatments of nutrient cycles affect carbon-climate feedbacks, with a focus on tropical systems;...

Related Topics: Accelerated Climate Modeling for Energy, ACME, Advanced Scientific Computing Research, ASCR, climate change, earth systems modeling, High-performance computing, HPC, In the OSTI Collections, Supercomputers



by Kathy Chambers 20 Jun, 2014 in

Image: N. Watson, L. Thompson, MITImage: N. Watson, L. Thompson, MITGenomes of individual organisms and systems of organisms contain the information and operating capabilities that determine structure and function across multiple scales of biological organization. These complex systems hold the secrets of life. Because we do not yet have a full understanding of how a living system works, and how these organisms interact with and modify their environments, the Department of Energy’s (DOE) Genomic Science Program is working to achieve a predictive, system-level understanding of plants, microbes, and biological communities. This program is providing the foundational knowledge underlying biological approaches to producing biofuels, sequestering carbon in terrestrial ecosystems, and cleaning up contaminated environments.

An example of the progress being made with genomic research is the work being done by Sally W. (Penny) Chisholm, a U.S. biological oceanographer and faculty member at the Massachusetts Institute of Technology (MIT). According to MIT, Chisholm’s studies of dominant photosynthetic organisms of the sea have revolutionized our understanding of life in the world’s oceans. Chisholm was awarded the National Medal of Science in 2013 for her outstanding contribution to science.   

Chisholm led a team that discovered the ocean phytoplankton Prochlorococcus – the world’s smallest and most abundant photosynthetic organism. She and her team also utilized flow cytometry...

Related Topics: genomics, In the OSTI Collections, MIT, Prochlorococcus, Sally W. Chisholm