Hyderabad International Airport facilitated the first arrival evacuation flight from Kuwait on Saturday.This is the first flight to Hyderabad and is p

In chemistry, stereochemically active lone pairs are typically described as an important non-bonding effect, and recent interest has centred on understanding the derived effect of lone pair expression on physical properties such as thermal conductivity. To manipulate such properties, it is essential to understand the conditions that lead to lone pair expression and provide a quantitative chemical description of their identity to allow comparison between systems. Here, density functional theory calculations are used first to establish the presence of stereochemically active lone pairs on antimony in the archetypical chalcogenide MnSb2O4. The lone pairs are formed through a similar mechanism to those in binary post-transition metal compounds in an oxidation state of two less than their main group number [e.g. Pb(II) and Sb(III)], where the degree of orbital interaction (covalency) determines the expression of the lone pair. In MnSb2O4 the Sb lone pairs interact through a void space in the crystal structure, and their their mutual repulsion is minimized by introducing a deflection angle. This angle increases significantly with decreasing Sb—Sb distance introduced by simulating high pressure, thus showing the highly destabilizing nature of the lone pair interactions. Analysis of the chemical bonding in MnSb2O4 shows that it is dominated by polar covalent interactions with significant contributions both from charge accumulation in the bonding regions and from charge transfer. A database search of related ternary chalcogenide structures shows that, for structures with a lone pair (SbX3 units), the degree of lone pair expression is largely determined by whether the antimony–chalcogen units are connected or not, suggesting a cooperative effect. Isolated SbX3 units have larger X—Sb—X bond angles and therefore weaker lone pair expression than connected units. Since increased lone pair expression is equivalent to an increased orbital interaction (covalent bonding), which typically leads to increased heat conduction, this can explain the previously established correlation between larger bond angles and lower thermal conductivity. Thus, it appears that for these chalcogenides, lone pair expression and thermal conductivity may be related through the degree of covalency of the system.

The room-temperature experiment has been revisited for macromolecular crystallography. Despite being limited by radiation damage, such experiments reveal structural differences depending on temperature, and it is expected that they will be able to probe structures that are physiologically alive. For such experiments, the humid-air and glue-coating (HAG) method for humidity-controlled experiments is proposed. The HAG method improves the stability of most crystals in capillary-free experiments and is applicable at both cryogenic and ambient temperatures. To expand the thermal versatility of the HAG method, a new humidifier and a protein-crystal-handling workbench have been developed. The devices provide temperatures down to 4°C and successfully maintain growth at that temperature of bovine cytochrome c oxidase crystals, which are highly sensitive to temperature variation. Hence, the humidifier and protein-crystal-handling workbench have proved useful for temperature-sensitive samples and will help reveal temperature-dependent variations in protein structures.

The residual strain distribution has been measured as a function of depth in both top coat and bond coat in as-received and heat-treated air plasma sprayed thermal barrier coating samples. High-energy synchrotron X-ray beams were used in transmission to produce full Debye–Scherrer rings whose non-circular aspect ratio gave the in-plane and out-of-plane strains far more efficiently than the sin2ψ method. The residual strain in the bond coat is found to be tensile and the strain in the β phase of the as-received sample was measured. The residual strains observed in the top coat were generally compressive (increasing towards the interface), with two kinds of nonlinear trend. These was a `jump' feature near the interface, and in some cases there was another `jump' feature near the surface. It is shown how these trend differences can be correlated to cracks in the coating.

Molybdenum oxides and sulfides on various low-cost high-surface-area supports are excellent catalysts for several industrially relevant reactions. The surface layer structure of these materials is, however, difficult to characterize due to small and disordered MoOx domains. Here, it is shown how X-ray total scattering can be applied to gain insights into the structure through differential pair distribution function (d-PDF) analysis, where the scattering signal from the support material is subtracted to obtain structural information on the supported structure. MoOx catalysts supported on alumina nanoparticles and on zeolites are investigated, and it is shown that the structure of the hydrated molybdenum oxide layer is closely related to that of disordered and polydisperse polyoxometalates. By analysing the PDFs with a large number of automatically generated cluster structures, which are constructed in an iterative manner from known polyoxometalate clusters, information is derived on the structural motifs in supported MoOx.

A new temperature-controllable humidifier for X-ray diffraction has been developed. It is shown that the humidifier can successfully maintain protein crystal growth at a temperature lower than room temperature.

Ba excess in LaBaGaO4 triggers ionic conductivity together with structural disorder. A direct correlation is found between the density functional theory model energy and the pair distribution function fit residual.

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.

The crystal structure of the organic pigment 2-monomethyl-quinacridone (Pigment Red 192, C21H14N2O2) was solved from X-ray powder diffraction data. The resulting average structure is described in space group Poverline 1, Z = 1 with the molecule on the inversion centre. The molecules are arranged in chains. The molecules, which have no inversion symmetry, show orientational head-to-tail disorder. In the average structure, the methyl group is disordered and found on both ends of the molecule with an occupancy of 0.5 each. The disorder and the local structure were investigated using various ordered structural models. All models were analysed by three approaches: Rietveld refinement, structure refinement to the pair distribution function (PDF) and lattice-energy minimization. All refinements converged well. The Rietveld refinement provided the average structure and gave no indication of a long-range ordering. The refinement to the PDF turned out to be very sensitive to small structural details, giving insight into the local structure. The lattice-energy minimizations revealed a significantly preferred local ordering of neighbouring molecules along the [0ar 11] direction. In conclusion, all methods indicate a statistical orientational disorder with a preferred parallel orientation of molecules in one direction. Additionally, electron diffraction revealed twinning and faint diffuse scattering.

The crystal structure of the nanocrystalline pigment mono­methyl-quinacridone was solved from X-ray powder data. The orientational disorder was investigated using Rietveld refinements, structure refinement to the pair-distribution function, and lattice-energy minimizations of various ordered structural models.

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.

Kiwis come to National Zoo. The Smithsonian’s National Zoo will be using a new kiwi pair donated by the New Zealand Embassy to establish a breeding science center. […]

The post New Zealand Embassy donates kiwi pair to National Zoo Breeding Science Center appeared first on Smithsonian Insider.

The words “box jelly” may bring to mind something sweet and tasty, but the banded box jelly of Bonaire is a highly venomous jellyfish with […]

The post “Ohboya!” It’s the Bonaire banded box jellyfish, a new species appeared first on Smithsonian Insider.

Discovery, the longest-serving orbiter in the space shuttle fleet, will be accepted into the Smithsonian’s National Air and Space Museum collection. The space shuttle has been the icon for American spaceflight for a generation, and Discovery has flown every type of mission during its 27-year career.

The post Space shuttle Discovery to be added to National Air and Space Museum collection appeared first on Smithsonian Insider.

The National Zoo has received a breeding pair of Asian small-clawed otters at Asia Trail for the first time. Mac, a three-year-old male from the Point Defiance Zoo in Tacoma, Wash., and Smidge, a five-year-old female from the Columbus Zoo in Ohio, arrived in April and are now in their exhibit.

The post Keepers are optimistic about Zoo’s new breeding pair of Asian small-clawed otters appeared first on Smithsonian Insider.

A new video to help aviators identify the cause of bird strikes has been posted on YouTube by the U.S. Department of Agriculture's Wildlife Services Airport Wildlife Hazard Program and the Smithsonian's National Museum of Natural History.

The post Aircraft bird-strike reports can save lives. New video shows how to report, collect and ship evidence appeared first on Smithsonian Insider.

The Smithsonian Astrophysical Observatory has been awarded a NASA project to build the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument. TEMPO will measure North American air pollution, from Mexico City to the Canadian tar/oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution.

The post NASA funds Smithsonian Astrophysical Observatory instrument to track North American air pollution appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum announced that it will receive a $6 million donation from the Thomas W. Haas Foundation to establish an […]

The post Air and Space Museum receives $6 million donation for Public Observatory Program appeared first on Smithsonian Insider.

Unlocking the mysteries of animal migration through precise, near real-time tracking can solve major conservation challenges and transform wildlife science worldwide. For the past year, […]

The post New project to unlock migration mysteries from air appeared first on Smithsonian Insider.

Santa Claus and his sleigh full of gifts has been upstaged early this holiday season by news of autonomous drones possibly delivering packages to your […]

The post Package-delivering drones? Q&A with Roger Connor of the National Air and Space Museum appeared first on Smithsonian Insider.

Humanity is on the threshold of being able to detect signs of alien life on other worlds. By studying exoplanet atmospheres, we can look for […]

The post Finding ET by searching for alien air pollution appeared first on Smithsonian Insider.

How did the earliest birds take wing? Did they fall from trees and learn to flap their forelimbs to avoid crashing? Or did they run […]

The post Baby bird study proves innate ability for midair maneuvers appeared first on Smithsonian Insider.

A new study by Florida State University and Smithsonian Institution biologists shows that bleaching events brought on by rising sea temperatures are having a detrimental […]

The post Study: Bleaching events impair long-term coral reproduction appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum has acquired a large collection from the Sir Arthur C. Clarke Trust. The collection consists of 87 cubic […]

The post Arthur C. Clarke papers come to Air and Space Museum Archives appeared first on Smithsonian Insider.

Only the Wing is a new book by Russell Lee that recounts Horten's epic quest to stabalize and control the all-wing aircraft.

The post New Book: “Only the Wing: Reimar Horten’s Epic Quest to Stabilize and Control the All-Wing Aircraft” appeared first on Smithsonian Insider.

“My recurring theme is the transformation of the ordinary…,” explains National Air and Space Museum photographer Carolyn Russo in reference to her new book, Art […]

The post Book: Airport Towers as Abstract Art appeared first on Smithsonian Insider.

Isabella Guardamagna, Elisabetta Bassi, Monica Savio, Paola Perucca, Ornella Cazzalini, Ennio Prosperi, and Lucia A. Stivala

Assessing DNA repair is an important endpoint to study the DNA damage response for investigating the biochemical mechanisms of this process and the efficacy of chemotherapy, which often uses DNA damaging compounds. Numerous in vitro methods to biochemically characterize DNA repair mechanisms have been developed so far. However, they show some limitations mainly due to the lack of chromatin organization. Here we describe a functional cell-free system to study DNA repair synthesis in vitro, using G1-phase nuclei isolated from human cells treated with different genotoxic agents. Upon incubation in the correspondent damage-activated cytosolic extracts, containing biotin-16-dUTP, nuclei are able to initiate DNA repair synthesis. The use of specific DNA synthesis inhibitors markedly decreased biotinylated dUTP incorporation, indicating the specificity of the repair response. Exogenously added human recombinant PCNA protein, but not the sensors of UV-DNA damage DDB2 or DDB1, stimulated UVC induced dUTP incorporation. In contrast, a DDB2^PCNA- mutant protein, unable to associate with PCNA, interfered with DNA repair synthesis. Given its responsiveness to different type of DNA lesions, this system offers an additional tool to study DNA repair mechanisms.

Admired from afar by the ancient Romans, the moon was once deified as a goddess, Luna. Today, two-thousand years later, geologists who scrutinize the moon’s […]

The post Orbiting Camera Unveils New Moon in Air and Space Museum Exhibition appeared first on Smithsonian Insider.

Monday, Aug. 21 was an unusual day across North America. Early in the morning, families, colleagues and tourists were searching for special solar glasses with […]

The post Crowds gather at Air and Space Museum to view solar eclipse appeared first on Smithsonian Insider.

A novel approach for finding and evaluating structural models of small metallic nanoparticles is presented. Rather than fitting a single model with many degrees of freedom, libraries of clusters from multiple structural motifs are built algorithmically and individually refined against experimental pair distribution functions. Each cluster fit is highly constrained. The approach, called cluster-mining, returns all candidate structure models that are consistent with the data as measured by a goodness of fit. It is highly automated, easy to use, and yields models that are more physically realistic and result in better agreement to the data than models based on cubic close-packed crystallographic cores, often reported in the literature for metallic nanoparticles.

A new approach is presented to obtain candidate structures from atomic pair distribution function (PDF) data in a highly automated way. It fetches, from web-based structural databases, all the structures meeting the experimenter's search criteria and performs structure refinements on them without human intervention. It supports both X-ray and neutron PDFs. Tests on various material systems show the effectiveness and robustness of the algorithm in finding the correct atomic crystal structure. It works on crystalline and nanocrystalline materials including complex oxide nanoparticles and nanowires, low-symmetry and locally distorted structures, and complicated doped and magnetic materials. This approach could greatly reduce the traditional structure searching work and enable the possibility of high-throughput real-time auto-analysis PDF experiments in the future.

This new PBS Newshour video takes a look at a new exhibit at the Air and Space Museum celebrating NASA's space art program.

The post PBS Newshour takes a look at the new National Air and Space Museum exhibition “NASA | ART: 50 Years of Exploration” appeared first on Smithsonian Insider.

Tom Crouch, Senior curator in the National Air and Space Museum's Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance during the Civil War. This presentation was recorded on May 11, 2011 on the National Mall.

The post Tom Crouch, Senior curator in the National Air and Space Museum’s Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance appeared first on Smithsonian Insider.

Silent black & white archival film clip from "Japan: Promotional and Theatrical Footage, ca. 1927". The full film, which is 17 minutes long, includes segments from what are believed to be a theatrical film, a promotional film and, possibly, amateur film - all of unknown origin.

The post Geisha Hairstyling, ca. 1927, a silent black & white archival film clip from the Smithsonian’s Human Studies Film Archives appeared first on Smithsonian Insider.

One of Italy’s greatest treasures, Leonardo da Vinci’s Codex on the Flight of Birds, will be exhibited at the National Air and Space Museum from […]

The post da Vinci’s “Codex on the Flight of Birds” will be on view at Air and Space Museum, Sept. 13-Oct. 22. appeared first on Smithsonian Insider.

Get a look behind the scenes as we installed “Outside the Spacecraft: 50 Years of Extra-vehicular Activity,” a new exhibition on view at the Museum […]

The post “Outside the Spacecraft,” a new exhibition at the Air and Space Museum appeared first on Smithsonian Insider.

NASA’s Kepler mission is responsible for history’s first detection of Earth-sized planets orbiting other suns in their temperate “habitable zones.” The team in charge of […]

The post NASA’s Kepler mission receives National Air and Space Museum’s highest group honor appeared first on Smithsonian Insider.

The National Air and Space Museum will reopen the “Boeing Milestones of Flight Hall” July 1 in conjunction with the museum’s 40th anniversary. The two-year […]

The post Air and Space Museum’s “Boeing Milestones of Flight Hall” Reopens July 1! appeared first on Smithsonian Insider.

National Air and Space Museum Curator John Anderson describes major flight innovations made possible by the Full Scale Tunnel, built in 1931 at the National […]

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Happy Holidays from the Smithsonian’s National Air and Space Museum!

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The Emeco Alfi Chair is on view as part of ‘Making | Breaking New Arrivals,’ at Cooper Hewitt, Smithsonian Design Museum May–October, 2017. To learn […]

The post Cooper Hewitt: Emeco Alfi Chair Production Process slideshow appeared first on Smithsonian Insider.

The storage and flux of terrestrial carbon (C) is one of the most uncertain components of the global C budget and detailed quantification of forest […]

The post Remote sensing of a Smithsonian forest with airborne LiDAR appeared first on Smithsonian Insider.

Monday, April 30 marks planetary geologist Dr. Ellen Stofan’s first day as the new John and Adrienne Mars Director of the National Air and Space […]

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Police say TSA agent Gerardo Hernandez was shot and killed last Friday at the base of the escalators of LAX Terminal 3, and not at the checkpoint gates.  Paul Ciancia is accused of killing Hernandez and wounding several others.  Ciancia remains hospitalized in critical condition.

Steve Julian: Business analyst Mark Lacter, how did the airlines respond to shooting and its aftermath?

Mark Lacter: Generally pretty well, Steve, considering that the airport was effectively closed for several hours on Friday, and most of Terminal 3 was out of commission until Saturday afternoon.  You know, there's always this precarious balance in operating airlines and airports, even in the best of circumstances.  Just so many flights coming in and going out, and so many thousands people using the facility at any given time - and it really doesn't take much to upset the balance.  So, when you have something horrific take place and you see all those travelers stranded outside the terminals, the ripple effects are enormous - not just at LAX but all over the country.

Julian: More than a thousand flights were either canceled or delayed on Friday.

Lacter: And, there was a further complication because the airlines flying out of Terminal 3 are not the legacy carriers like United, American, and Delta that have all kinds of resources, but smaller operations with less flexibility.  It's not like there's an empty aircraft just sitting in a hangar waiting to take passengers wherever they want to go.  Actually, the airlines have gotten better at arranging re-bookings when there's a snowstorm or some other emergency that gives them advance warning.  But obviously, there was no advance warning last Friday, so the carriers needed to improvise in handling passengers whose flights were cancelled.

Julian: What did they do?

Lacter: One step was waiving the fees normally charged to re-book flights (and that's gotten to be a pretty penny).  Another was waiving the difference in the price of the original ticket and the re-booked ticket.  But, the policies varied according to the airline, and we heard about travelers not receiving hotel or food vouchers, or having to buy a brand new ticket on another airline if they wanted to avoid the wait - and that can be expensive.  Which raises another issue: planes tend to be completely full these days because airlines have been cutting back on the number of flights.  And that can be a problem if you're taking a route that doesn't have too many flights in the first place.  So, it gets really complicated.

Julian: Why do you think we haven't we heard more horror stories from passengers?

Lacter: Well, look at the cities that the airlines in Terminal 3 fly to - New York, San Francisco, Seattle, Dallas.  They're all served by several other carriers.  L.A. to New York, in particular, is one of the busiest routes in the world, which means that it's also one of the most competitive.  So, even if your flight was cancelled, there's a good chance you'd be able to find space by Saturday (which is normally a slower day for air travel).  This is a big reason, in general, why people like LAX.

Julian: Why don't other local airports handle more of the load?

Lacter: You might remember a few years ago local officials were promoting something called "regionalization" - the idea was that as LAX maxed out on the number of passengers it was allowed to handle each year, then other airports would make up the difference - places like Ontario, Bob Hope in Burbank, and John Wayne in Orange County.

Julian: Right, and they talked about easing traffic congestion by spreading around the flights.

Lacter: Well, regionalization never happened because, first of all, passenger levels at L.A. International didn't come close to maxing out.  But, more importantly, because the airlines decided that using LAX was more efficient for everything from handling baggage to arranging international connections.  So, through the first nine months of the year, passenger traffic at LAX is up 4.2 percent from a year earlier, while at Ontario traffic was down 9.3 percent.  And, we've seen that John Wayne, Bob Hope, and Long Beach are all struggling.  Of course, the challenge at a busy place like LAX is making it as safe as possible, and that will no doubt become a priority in the weeks ahead.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

Studies at two remote Smithsonian Institution Global Earth Observatory sites in Panama and Thailand show the first evidence of long-term effects of nitrogen pollution in tropical trees.

The post Air pollution is fertilizing tropical forests appeared first on Smithsonian Insider.

“When you can’t breathe, nothing else matters,” once a tagline of the American Lung Association, today it might easily describe what is happening in many […]

The post Gasping for air: nutrients, warming trigger ocean oxygen deficit appeared first on Smithsonian Insider.

It is shown how to reconstruct the stacking sequence from the pairwise correlation functions between layers in close-packed structures. First, of theoretical interest, the analytical formulation and solution of the problem are presented when the exact pairwise correlation counts are known. In the second part, the practical problem is approached. A simulated annealing procedure is developed to solve the problem using as initial guess approximate solutions from previous treatments. The robustness of the procedure is tested with synthetic data, followed by an experimental example. The developed approach performs robustly over different synthetic and experimental data, comparing favorably with the reported methods.