Thursday 31 December 2015

Solstice Sun at Lulworth Cove

more »
A southern exposure and striking symmetry made Lulworth Cove, along the Jurassic Coast of England, planet Earth a beautiful setting during this December's Solstice. Five frames in this dramatic composite view follow the lowest arc of the Sun, from sunrise to sunset, during the shortest day of the year. The solstice arc spans about 103 degrees at this northern latitude. Of course, erosion by wave action has produced the cove's remarkable shape in the coastal limestone layers. The cove's narrow entrance is responsible, creating a circular wave diffraction pattern made clearer by a low sun angle.

Zazzle Space Gifts for young and old

Tuesday 29 December 2015

Dust of the Orion Nebula

more »



Zazzle Space Gifts for young and old

Graphene for catalysis

more »

Catalysis plays a major role in today’s society, impacting an estimated 90% of all commercially produced chemical products. Generating about a trillion USD in products worldwide, catalysis is used in energy processing (petroleum refining, steam reforming, automotive catalytic conversion, fuel cells), bulk and fine chemical manufacturing, food processing, and environmental protection.

Catalysis is a process in which an added catalyst enhances the rate of reaction by lowering its reaction energy threshold. Most catalytic processes employ heterogeneous catalysis, where the catalyst is solid whereas the reactant fuel is in the liquid phase. Carbon plays a diverse role in heterogeneous catalysis, most prominently featured as a solid support for metal catalysts, for example on fuel cell electrodes. In some processes, carbon itself acts as a catalyst.

Graphene, as a form of carbon with a high electron mobility and specific surface area, arises as a natural candidate as a catalytic support. In the most common catalytic reaction, a noble metal catalyst is anchored to a support that acts not only as mechanical support, but also provides charge transfer that assists the reaction. In its purest form, graphene is a chemically inert surface, because there are no free chemical bonds. However, the addition of strain, defects, or functional groups radically changes the chemical properties of graphene and makes it suitable as catalytic support.

A desirable method for the immobilization of metal complexes is the formation of a covalent bond between the solid support and a ligand binder. In the case of graphene this general method has two important drawbacks. First arising from the need of an additional functionalization of the metal complex and the graphene solid surface (which, in turn implies an increase in the catalyst preparation cost) and second, arising from the possible changes in chemical reactivity and therefore in catalytic activity, derived from the formation of the covalent bond.

As an alternative, non-covalent interactions are emerging as a powerful tool that gives rise to supported catalysts without chemical modification of the homogeneous catalyst or the graphene. The most common non-covalent interactions are hydrogen bonding, van der Waals forces and π-stacking. The relative energy of a single non-covalent interaction is much lower than a typical covalent bond but on account of their multiplicity, the overall influence should not be negligible on the anchoring of the metal complex on the surface of graphene.

The main advantage of immobilizating a homogeneous catalyst by non-covalent interactions is the simplicity of catalyst design and availability. Further modifications to achieve high selectivity and stability are easily obtained by tuning the electronic and steric properties. The well defined supported molecular complexes for catalytic applications should facilitate precise characterization of the hybrid materials and the study of the reaction mechanisms. The reaction mechanism could be studied in solution at the molecular level with the well-defined homogeneous organometallic techniques. The support may play a role during the catalytic process, not acting as a simple platform for anchoring the molecular complex, but also enhancing the catalytic activity by avoiding aggregation and facilitating the interaction between the substrates and the catalytic active species.

Non-covalent interactions by means of π-stacking are a particularly attractive method for immobilization of metal complexes onto graphene, because the number of functional groups in this material is limited. Moreover, non-covalent interactions between the catalyst and the support are arising as promising alternatives to the more widely used covalent interactions because they also avoid the functionalization of both, the catalyst and the surface, which may turn in the modification of the inherent properties of the catalyst and the graphene.

Graphene catalysis

Image: Graphene as catalytic support (courtesy of Prof. Jose A. Mata Martínez, Departamento de Química Inorgánica y Orgánica, Universitat Jaume I, Castellon)

Metal complexes of Pd and Ru have been anchored on the surface of graphene by non covalent interactions under mild reaction conditions. The results reveal that the metal complexes are strongly anchored on the surface of graphene. The catalytic properties of the hybrid material reveal that the catalytic activity is increased when the metal complex is immobilized on the surface of graphene. The system is stable and can be reused without any decrease in activity.

To conclude, graphene is an excellent candidate for use as catalytic support, especially in the emerging technology of non-covalently bonded supports, which offer simpler fuel cells at a reduced cost compared to current technology. The most useful form of graphene for catalysis so far is reduced graphene oxide, rGO, which is one of our most popular products. This form of graphene is low-cost and easily integrated into matrices.


via Graphenea

Saturday 26 December 2015

Southern Craters and Galaxies

more »
The Henbury craters in the Northern Territory, Australia, planet Earth, are the scars of an impact over 4,000 years old. When an ancient meteorite fragmented into dozens of pieces, the largest made the 180 meter diameter crater whose weathered walls and floor are lit in the foreground of this southern hemisphere nightscape. The vertical panoramic view follows our magnificent Milky Way galaxy stretching above horizon, its rich central starfields cut by obscuring dust clouds. A glance along the galactic plane also reveals Alpha and Beta Centauri and the stars of the Southern Cross. Captured in the region's spectacular, dark skies, the Small Magellanic Cloud, satellite of the Milky Way, is the bright galaxy to the left. Not the lights of a nearby town, the visible glow on the horizon below it is the Large Magellanic Cloud rising.

Zazzle Space Gifts for young and old

Friday 25 December 2015

Timothy Peake, British Astronaut, Dials Wrong Number From Space

more »
Mr. Peake, aboard the International Space Station, took his flub to Twitter, apologizing to “the lady I just called by mistake saying ‘Hello, is this planet Earth?’”










via New York Times

To Scale: The Solar System

more »
Want to build a scale model Solar System? A blue marble 1.4 centimeters (about half an inch) across would be a good choice for a scale model Earth. Since the Sun is 109 times the diameter of Earth, a 1.5 meter diameter balloon could represent the Sun. But the distance between the Earth and Sun, 150 million kilometers, would translate to just under 180 meters (590 feet) at the same scale. That would mean the completed project, including the orbits of the outer planets, is probably not going to fit in your backyard. Still, you might find enough room on a dry lakebed. Check out this video for an inspirational road trip through the Solar System to scale.

Zazzle Space Gifts for young and old

Thursday 24 December 2015

Star Colors and Pinyon Pine

more »
Beautiful, luminous decorations on this pinyon pine tree are actually bright stars in the constellation Scorpius and the faint glow of the central Milky Way. Captured in June from the north rim of the Grand Canyon of planet Earth, the shallow, close focus image has rendered pine needles on the tree branch sharp, but blurred the distant stars, their light smeared into remarkably colorful disks. Of course, temperature determines the color of a star. Most of the out-of-focus bright stars of Scorpius show a predominately blue hue, their surface temperatures much hotter than the Sun's. Cooler and larger than the Sun, and noticably redder on the scene, is giant star Antares at the heart of the scorpion. In focused, telescopic views the whitish disk at the upper right would be immediately recognizable though, reflecting the Sun's light as ringed gas giant Saturn.

Zazzle Space Gifts for young and old

Gullies on Mars sculpted by dry ice rather than liquid water

more »
Mars's gullies may be formed by dry ice processes rather than flowing liquid water, as previously thought. Scientists show that, during late winter and spring, underneath the seasonal CO2 ice layer heated by the sun, intense gas fluxes can destabilize the regolith material and induce gas-lubricated debris flows which look like water-sculpted gullies on Earth. Since 2000, the cameras in orbit around Mars have transmitted numerous images of small valleys cut into slopes, similar in shape to gullies formed by flowing water on Earth. The gullies seem less than a few million years old-and sometimes less than a few years old.
via Science Daily
Zazzle Space Exploration market place

Wednesday 23 December 2015

Geminid Meteors over Xinglong Observatory

more »



Zazzle Space Gifts for young and old

U.S. demonstrates production of fuel for missions to the solar system and beyond

more »
The first U.S. production in nearly 30 years of a specialized fuel to power future deep space missions has been completed by researchers at the Department of Energy's Oak Ridge National Laboratory (ORNL) in Tennessee.
via Science Daily
Zazzle Space Exploration market place

NASA suspends 2016 launch of InSight mission to Mars

more »
After thorough examination, NASA managers have decided to suspend the planned March 2016 launch of the Interior Exploration using Seismic Investigations Geodesy and Heat Transport (InSight) mission. The decision follows unsuccessful attempts to repair a leak in a section of the prime instrument in the science payload.
via Science Daily
Zazzle Space Exploration market place

Leaks in Instrument Force NASA to Delay Mars Mission Until 2018

more »
The Mars InSight mission will miss its March 2016 launch date, and will remain earthbound for at least two years.










via New York Times

Tuesday 22 December 2015

Mixing modern materials? Math app helps you manage your mashup

more »
Polymers play a vast number of roles in daily life, but they lack many properties that would make them even more useful. As in cooking, a way around these limitations is to mix in other ingredients that have the right properties. Scientists have just made recipe development a more palatable job.
via Science Daily

Move aside carbon: Boron nitride-reinforced materials are even stronger

more »
When mixed with lightweight polymers, tiny carbon tubes reinforce the material, promising lightweight and strong materials for airplanes, spaceships, cars and even sports equipment. While such carbon nanotube-polymer nanocomposites have attracted enormous interest from the materials research community, a group of scientists now has evidence that a different nanotube -- made from boron nitride -- could offer even more strength per unit of weight.
via Science Daily

Cassini completes final close Enceladus flyby

more »
NASA's Cassini spacecraft has begun transmitting data and images from the mission's final close flyby of Saturn's active moon Enceladus. Cassini passed Enceladus at a distance of 3,106 miles (4,999 kilometers) on Saturday, Dec. 19, at 9:49 a.m. PST (12:49 p.m. EST).
via Science Daily
Zazzle Space Exploration market place

Lowdown on Ceres: Images from Dawn's closest orbit

more »
NASA's Dawn spacecraft, cruising in its lowest and final orbit at dwarf planet Ceres, has delivered the first images from its best-ever viewpoint. The new images showcase details of the cratered and fractured surface. 3-D versions of two of these views are also available.
via Science Daily
Zazzle Space Exploration market place

Giant comets could pose danger to life on Earth

more »
The discovery of hundreds of giant comets in the outer planetary system over the last two decades means that these objects pose a much greater hazard to life than asteroids, a team of astronomers reports.
via Science Daily
Zazzle Space Exploration market place

Solstice Illuminated: A Year of Sky

more »



Zazzle Space Gifts for young and old

SpaceX Successfully Lands Rocket After Launch of Satellites Into Orbit

more »
The launch and then landing could become a familiar sight in spaceflight, allowing rockets to be refurbished and reused.










via New York Times