Instrumentation for sub-millisecond time-resolved small-angle neutron scattering measurements at NIST is described and applied to the reorientation dynamics of elongated hematite nanoparticles.

A fast and exact algorithm to calculate the powder pair distribution function (PDF) for the case of periodic structures is presented. The algorithm especially improves X-ray and electron PDF calculations, and the handling of instrumental resolution functions.

The sasPDF method, an extension of the atomic pair distribution function (PDF) analysis to the small-angle scattering (SAS) regime, is presented. The method is applied to characterize the structure of nanoparticle assemblies with different levels of structural order.

SVAT4 is a computer program for interactive visualization of three-dimensional crystal structures. A wide range of functions are available for structural analysis.

Exact and approximate formulas for equatorial aberration of a continuous-scan Si strip detector are compared.

A portable small-angle X-ray scattering instrument with geometrical dimensions suitable for installation at the D22 instrument was designed and constructed for simultaneous small-angle X-ray and neutron scattering experiments at ILL.

Dynamical X-ray diffraction simulations of very asymmetric diffraction from single crystals of silicon were made to accompany an experimental rocking-curve topography study reported in a seperate paper. Effects on rocking curves were found and are reported. The development of Uragami [(1969), J. Phys. Soc. Jpn, 27, 147–154] for Takagi–Taupin simulations was followed and applied to the case of both convex and concave surface undulations.

Very asymmetric crystal diffraction was obtained from a finely polished silicon crystal set to reflect in Bragg diffraction at grazing incidence for the (333) reflection. The angle of incidence to achieve Bragg diffraction was varied between 1.08° and 0.33° by changing the X-ray energy from 8.100 to 8.200 keV. Topographic images obtained as the crystal was rocked were used to identify the effects of surface undulations, and the results are compared with dynamical X-ray diffraction calculations made with the Takagi–Taupin equations specialized to a surface having convex or concave features, as reported in an accompanying paper.

The diffraction response of a single crystal to electric field measured by X-ray diffraction by angles close to π. Such schemes allow one to determine with high (~ 10–5–10–6) accuracy the relative changes in the lattice constant.

An algorithm, based on the matching of q-vectors pairs, is combined with three-dimensional pattern matching using a nearest-neighbors approach to index Laue and monochromatic serial crystallography data recorded on small unit cell samples.

The principles of using the Laue-analyzer as an X-ray optical element for separating two characteristic lines of an X-ray tube are presented.

A software package for Grazing Incident Wide Angle X-ray Scattering (GIWAXS) geared toward weakly ordered materials, including: scattering intensity normalization/uncertainty, scattering pattern indexing, and refractive shift correction.

Neutron crystal structure analysis of hen egg-white lysozyme hydrogen/deuterium exchanged before crystallization were performed by the joint X-ray and neutron refinement. The differences in hydrogen/deuterium exchange behavior between this study and previous ones were observed.

EDDIDAT is a program that provides a graphical user interface (GUI) for the evaluation of energy-dispersive X-ray diffraction data with the focus on the depth-resolved residual stress analysis.

A detailed theoretical and experimental comparison of dark-field electron holography (DFEH) and high-resolution X-ray diffraction (HRXRD) is performed. Both techniques are being applied to measure elastic strain in an array of transistors and the role of the geometric phase is emphasized.

Describing his project of counting bears, bobcats and other predatory mammals along the Appalachian Trail, National Zoological Park wildlife ecologist William McShea looks to American literature for a comparison.

The post Appalachian Trail survey aims hidden cameras at large predators appeared first on Smithsonian Insider.

For those who think that global warming is a 21st-century phenomenon, Scott Wing, a scientist at the Smithsonian’s National Museum of Natural History, has news about the past.

The post Fossils Show Prehistoric Global Warming appeared first on Smithsonian Insider.

Each year thousands of vacationers enjoy the scenery along Virginia’s Skyline Drive, little knowing that for a few brief moments they are passing through the territory of an endangered […]

The post Study aims to give endangered Shenandoah salamander better odds at survival appeared first on Smithsonian Insider.

A recent study of dog bones excavated from archaeological sites on the Channel Islands of California has cast new light on the past ecology of the islands and the impact that domestic dogs--brought to the islands by Native Americans more than 6,000 years ago—may have once had on the islands’ animals and ecosystems.

The post Dog bones reveal ecological history of California’s Channel Islands appeared first on Smithsonian Insider.

New measurements show that the Milky Way is bigger and more massive than previous data suggested, putting us on equal footing with our neighbor. Specifically, the Milky Way is 15 percent larger in size and contains 50 percent more mass. That is the cosmic equivalent of a 5-foot-5, 140-pound man suddenly bulking up to the size of a 6-foot-3, 210-pound NFL linebacker.

The post New research reveals our galaxy is much larger than we thought appeared first on Smithsonian Insider.

The Smithsonian Tropical Research Institute in Panama was recently given a collection of more than 25,000 different pollen grains and spores, each mounted on a microscope slide and labeled according to the plant that produced it. “The collection is worldwide in coverage with an emphasis on plants of the Americas,” explains collection donor Alan Graham, professor emeritus at Kent State University and curator at the Missouri Botanical Garden.

The post Research collection of pollen grains given to Smithsonian Tropical Research Institute appeared first on Smithsonian Insider.

Scientists at the Smithsonian Institution examined the feather remains from the Jan. 15, 2009, US Airways Flight 1549 bird strike to determine not only the species, but also that the Canada geese involved were from a migratory, rather than resident, population. This knowledge is essential for wildlife professionals to develop policies and techniques that will reduce the risk of future collisions. The team’s findings were published in the journal “Frontiers in Ecology and the Environment” in June.

The post Scientists Determine Geese Involved in Hudson River Plane Crash Were Migratory appeared first on Smithsonian Insider.

It was an exciting and busy 24 hours at the National Zoo’s Conservation and Research Center in Front Royal, Va., last week as three births took place just hours apart. On the evening of July 9, a clouded leopard cub was born, followed by a Przewalski’s horse foal and a red panda cub.

The post Baby Boom of Endangered Species at Smithsonian’s National Zoo’s Conservation and Research Center appeared first on Smithsonian Insider.

In southeastern Greenland, two rivers of ice named Helheim and Kangerdlugssuaq flow in spurts and starts toward the coast. They are much like any other […]

The post Astrophysical Observatory scientists are monitoring the mysterious movements of glaciers appeared first on Smithsonian Insider.

The fossil teeth of a 15- to 18-million-year-old three-toed browsing horse, Anchitherium clarencei, were recently discovered by scientists from the Smithsonian Tropical Research Institute and the […]

The post Fossil teeth of 15-million-year-old browsing horse found in Panama Canal excavations. appeared first on Smithsonian Insider.

When songwriter Oscar Hammerstein penned the lyrics “fish gotta swim, birds gotta fly,” he clearly did not have the ratites in mind. Large flightless birds, the ratites include ostriches, emus, rheas and cassowaries, along with kiwis and several extinct species.

The post DNA evidence is rearranging the branches of the avian family tree appeared first on Smithsonian Insider.

While studying bats recently at the Academy of Natural Sciences in Philadelphia, Smithsonian mammalogist Kristofer Helgen discovered a new species of flying fox bat from […]

The post Smithsonian Scientist Discovers Two New Bat Species Hiding in Museum Collections for More Than 150 Years appeared first on Smithsonian Insider.

A new Smithsonian study that examines 10 million years of the evolution of tiny coral-like organisms called cupuladriid bryzoans has revealed that some species of this organism lingered on earth for more than one million years after the event that ultimately caused their extinction: the rising of the Isthmus of Panama.

The post Fossils of tiny cupuladriid colonies reveal extinction can lag more than one million years after its cause appeared first on Smithsonian Insider.

Already under siege from overfishing, disease and poor water quality, the oyster population in the Chesapeake Bay today stands at 2 percent of what it was in colonial times. Now, new data show that rising acidity in the Bay will have a negative impact on oyster shells.

The post Rising acidification of estuary waters spells trouble for Chesapeake Bay oysters appeared first on Smithsonian Insider.

Today the Smithsonian Institution announced Eva J. Pell, Senior Vice President for Research and Dean of the Graduate School at Pennsylvania State University, will be the new Under Secretary for Science at the Institution.

The post Smithsonian Names Eva Pell as Under Secretary for Science appeared first on Smithsonian Insider.

New observations by the Smithsonian’s Submillimeter Array, a radio telescope atop Mauna Kea in Hawaii, are shedding light on planet formation. The array provides sharp views by combining eight antennas into the equivalent of a single, large telescope. It can resolve details as small as a dime seen from seven miles away.

The post Cosmic “baby photos” of distant solar systems lend insight as to how planets form appeared first on Smithsonian Insider.

Successes in animal health care presents many new challenges for veterinarians. Longer life spans in captivity mean zoo animals are now experiencing age-related health problems that their zoo predecessors never lived long enough to develop—like diabetes in cheetahs, arthritis in big cats and dental issues for coatis.

The post Golden years at the Zoo: Veterinarians work to help animals live longer, stay healthy appeared first on Smithsonian Insider.

A recent survey of the bottom-dwelling animals of the Chesapeake has revealed that communities of even these relatively hardy organisms are under stress. Many regions of the bay are becoming inhospitable to bottom-dwelling animals because of a lack of oxygen—a condition known as “hypoxia.”

The post Bottom-dwelling creatures in the Chesapeake Bay need more oxygen, study finds. appeared first on Smithsonian Insider.

A Smithsonian Institution biologist, working with the Natural History Unit of the British Broadcasting Corp., has discovered a new species of giant rat on a film-making expedition to a remote rainforest in New Guinea.

The post New species of giant rat discovered in crater of volcano in Papua New Guinea appeared first on Smithsonian Insider.

Testing caterpillars’ taste buds is no simple task. Just like your local salad bar, plants in the wild come in different shapes, textures and flavors. Herbivores rely on each of these cues to tell them what to eat. Deciphering this code is Lind’s task. He’s examining 40 different plant species – half invasive, half native.

The post Salad science: Coaxing caterpillars to reveal the secrets of their leafy desires appeared first on Smithsonian Insider.

The Smithsonian Center for Education and Museum Studies is hosting “Climate Change,” a three-day, free, education online conference Tuesday, Sept. 29 through Thursday, Oct. 1. This […]

The post Smithsonian to host online Climate Change conference Sept. 29-Oct. 1 appeared first on Smithsonian Insider.

The giant squid was collected during a 60-day scientific study in which NOAA scientists were studying the availability and diversity of sperm whale prey. The squid was caught in a trawl net pulled behind a research vessel at a depth of more than 1,500 feet.

The post Smithsonian receives giant squid caught in the Gulf of Mexico appeared first on Smithsonian Insider.

Determining the locations of future highways and roads in countries with tropical rainforests will be the greatest single factor in influencing future forest loss, fragmentation and degradation. In broad terms, roads can be thought of as the enemies of rainforests. By spreading people out across the forest, roads inherently promote rapid and widespread deforestation.

The post Roads kill rainforests. Stop them now, say Smithsonian biologists appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum has opened a new Public Observatory that contains a 16-inch, 3,000-pound Boller and Chivens telescope, on loan from the Smithsonian Astrophysical Observatory. Through this powerful telescope, museum visitors can now observe the sun (with a special filter), the moon and the brighter stars and planets, such as Venus, Jupiter and Saturn, during daylight hours. Funding for the project was provided by the National Science Foundation.

The post The Smithsonian’s National Air and Space Museum opens new Public Observatory on the Mall in Washington, D.C. appeared first on Smithsonian Insider.

A new census of tropical sulfur butterflies (Aphrissa statira) migrating across the Panama Canal has revealed the central role that weather plays in determining why populations of these lemon-yellow insects vary from year to year.

The post A dry spring in Panama means more sulfur butterflies, study reveals appeared first on Smithsonian Insider.

Scientists from the Smithsonian Migratory Bird Center at the National Zoo have taken blood samples from thousands of birds and mosquitoes in an effort to track the progress of the West Nile Virus in the eastern United States. Come along in this video as Smithsonian scientists net birds living in downtown Washington, D.C., extract small amounts of blood, and then release them back into the "wild."

The post Video: Common birds in Washington, D.C. are helping Smithsonian scientists track intensity of the West Nile Virus appeared first on Smithsonian Insider.

The spread of Africanized honey bees across Central America has had a much smaller impact on native tropical bee species than scientists previously predicted...

The post Native bees prove resilient in competition with invasive African honey bees appeared first on Smithsonian Insider.

A major new exhibition hall dedicated to the discovery and understanding of human origins will open next year at the Smithsonian's National Museum of Natural History: The David H. Koch Hall of Human Origins

The post Hall of Human Origins to open at Smithsonian’s Natural History Museum, March 17, 2010 appeared first on Smithsonian Insider.

The John Marshall Ju/'hoan Bushman Film and Video Collection, 1950-2000, was among 35 documentary heritage items of exceptional value added to UNESCO’s Memory of the World Register in 2009.

The post John Marshall Ju/’hoan Bushman Film and Video Collection added to UNESCO register appeared first on Smithsonian Insider.

Native to Africa and Madagascar, females of the species have a body length of 1.5 inches and a leg span of 4 to 5 inches. Males are tiny in comparison.

The post Females are giants in newly discovered species of golden orb weaver spider appeared first on Smithsonian Insider.

The National Zoo has been awarded a grant from the U.S. Fish and Wildlife Service to establish a captive population of the Virginia big-eared bat at the National Zoo’s Conservation & Research Center near Front Royal, Va. Only 15,000 Virginia big-eared bats remain living in caves in West Virginia, Virginia, Kentucky and North Carolina, and these are threatened by the white-nose syndrome.

The post In face of crisis, National Zoo to start captive population of Virginia big-eared bats appeared first on Smithsonian Insider.

Invasive species, contaminants, excessive nutrient's and sediment are just some of the many factors threatening sensitive wetlands and seagrass beds.

The post Smithsonian to lead study on degradation of nearshore coastal habitats of the Chesapeake appeared first on Smithsonian Insider.

Nearly 100 years ago, scientists detected the first signs of cosmic rays—subatomic particles (mostly protons) that zip through space at nearly the speed of light. […]

The post Telescope array finds new evidence that exploding stars are sources of cosmic rays appeared first on Smithsonian Insider.

The way that massive stars form remains mysterious, in part, because massive stars are rare and tend to spend their youth shrouded by dust and gas and hidden from view.

The post Radio telescopes give astronomers rare glimpse at a young protostar’s formation appeared first on Smithsonian Insider.