On August 6, 2014, after a decade-long journey chasing its target, the European Space Agency's Rosetta probe, carrying three NASA instruments, became the first spacecraft to rendezvous with a comet, 67P/Churyumov-Gerasimenko.
"After 10 years, five months and four days travelling towards our destination, looping around the sun five times and clocking up 6.4 billion kilometers, we are delighted to announce finally we are here," said Jean-Jacques Dordain, ESA's director General.
Comet 67P/Churyumov-Gerasimenko and Rosetta are 252 million miles (405 million kilometers) from Earth, about halfway between the orbits of Jupiter and Mars. The comet is in an elliptical, 6.5-year orbit that takes it from beyond Jupiter at its farthest point, to between the orbits of Mars and Earth at its closest to the sun. Rosetta will accompany the com- et for over a year as it swings around the sun and back out towards Jupiter again.
Rosetta is 62 miles (100 kilometers) from the comet's surface. Over the next six weeks, it will fly two triangular-shaped trajectories in front of the comet, first at the 62-mile (100-kilometer) altitude and then down at 31 miles (50 kilometers). At the
Rosetta Arrives at Target Comet
Graphene is viewed as a kind of
"miracle solution": It is thin, trans- parent and has a tensile strength greater than that of steel. In addi- tion, it conducts electricity better than copper. Since it comprises only a single layer of carbon atoms it is considered two-dimensional.
In 2010 the scientists Andre Geim and Konstantin Novoselov were awarded the Nobel Prize for their ground-breaking work on this
material.
In October 2013, the
"Graphene" project was selected alongside the "Human Brain Project" as a Flagship Project of the EU FET Initiative (Future and Emerging Technologies).
Under the supervision of Chalmers University of Technol- ogy in Sweden, it bundles the research activities and will be funded with one billion euro
over ten years. In July 2014 the program took on 66 new part- ners, including the Technical Univ. of Munich.
Optical prostheses for blind people
Because of its unusual properties, graphene holds great potential for applications, especially in the field of medical technology. A team of researchers led by Dr. Jose A.
Garrido at ...Read More….
Artificial retina: Physicists develop an interface to the optical nerve
Department of Physics—United Arab Emirates University
August 09, 2014 Volume 4, Issue 32Graphene electronics can be prepared on flexible substrates. Only the gold metal leads are visible in the transparent graphene sensor. Image: Natalia Hutanu/TUM
Weekly news from around the world compiled by Dr. Ilias Fernini
Astronomy & Physics News
Rosetta Arrives at Target Comet 1
Artificial retina: Physicists devel- op an interface to the optical nerve 1 Synthesis of structurally pure carbon nanotubes using molecular seeds
2
MESSENGER Team Cele- brates 10th Anniversary of Launch
2
Learning from origami to design
new materials 2
Planet-like object may have spent its youth as hot as a star 3 High-energy particle collisions reveal the unexpected 3 X-rays in five seconds 3 Boosting microelectronics with a little liquid logic
4
Scientists use lasers and carbon nanotubes to look inside living brains
4 Inside this issue:
same time, the spacecraft's suite of instruments will provide a detailed scientific study of the comet, scanning the surface to identify a target site for its comet lander, Philae. Eventually, Rosetta will attempt a close, near-circular orbit at 19 miles (30 kilometers) and, depending on the activity of the comet, may come even closer.
"Over the next few months, in addition to char- acterizing the comet nucleus ...Read More….
Comet 67P/Churyumov-Gerasimenko by Rosetta’s OSIRIS narrow-angle camera on August 3, 2014, from a distance of 177 miles (285 kilometers). Credits:
ESA/Rosetta/MPS for OSIRIS Team
For the first time, researchers at Empa and the Max Planck Institute for Solid State Re- search have succeeded in "growing" single- wall carbon nanotubes (CNT) with a single predefined structure—and hence with identi- cal electronic properties. And here is how they pulled it off: the CNTs "assembled them- selves", as it were, out of tailor-made organic precursor molecules on a platinum surface, as reported by the researchers in the latest issue of the journal Nature. In future, CNTs of this kind may be used in ultra-sensitive light detec- tors and ultra-small transistors.
For 20 years, carbon nanotubes (CNTs) have been the subject of intensive fundamental as well as applied research. With their extraordi- nary mechanical, thermal and electronic prop-
erties, these tiny tubes with their graphitic honeycomb lattice have become the paragon of nanomaterials.
They could help to create next-generation electronic and electro-optical components that are smaller than ever before, and thus to achieve even faster switching times.
As uniform as possible
With a diameter of roughly one nanometre, single- wall CNTs (or SWCNTs) need to be considered as quantum structures; the slightest structural changes, such as differences in diameter or in the alignment of the atomic lattice, may result in dramatic changes to the electronic properties: one SWCNT may be metal- lic, whilst another one with a slightly different struc- ture is a semiconductor. Hence, there is a great deal of interest in reliable methods of making SWCNTs as structurally uniform as possible. ...Read More….
folding methods for "tuning" the fundamental physical properties of any type of thin sheet, which may eventually lead to development of molecular-scale machines that could snap into place and perform mechan- ical tasks. Results are reported today in an early online edition of Science.
At a physics meeting a couple of years ago, Santangelo mentioned the unusual properties of a special type of origami fold called Miura-ori to fellow physicist Jesse Silverberg of Cornell, a long-time origami enthusi- ast. Miura-ori, named after the astro- A challenge increasingly important to
physicists and materials scientists in recent years has been how to design controllable new materials that exhib- it desired physical properties rather than relying on those properties to emerge naturally, says University of Massachusetts Amherst physicist Christian Santangelo.
Now he and physicist Arthur Evans and polymer scientist Ryan Hayward at UMass Amherst, with others at Cornell and Western New England University, are using origami-based
physicist who invented the tech- nique, is a series folded parallelo- grams that change the stiffness of a sheet of paper based only on the crease pattern.
Also known as tessellation, this special folding, which occurs naturally in some leaves and tissues, arranges a flat surface using a repeated pattern of alternating mountain-and- valley zigzag folds. Objects folded this way contract when squeezed, a bit like an accordi- on, so they can ...Read
Synthesis of structurally pure carbon nanotubes using molecular seeds
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Mission Operations Manager Andy Callo- way, of the Johns Hopkins University Ap- plied Physics Laboratory (APL).
"The MESSENGER spacecraft operates in one of the most challenging and demanding space environments in our Solar System, and we have met that challenge directly through innovation and hard work, as exemplified by the stunning discoveries and data return achievements. Our only regret is that we have insufficient propellant to operate anoth- er 10 years, but we look forward to the in- credible science returns planned for the final eight months of the mission."
MESSENGER is only the second spacecraft sent to Mercury. Mariner 10 ...Read More...
Learning from origami to design new materials MESSENGER Team Celebrates 10th Anniversary of Launch
Ten years ago, on August 3, 2004, NASA's MESSENGER spacecraft blasted off from Cape Canaveral, Florida, for a risky mission that would take the small satellite dangerously close to Mercury's surface, paving the way for an ambitious study of the planet closest to the Sun.
The spacecraft traveled 4.9 billion miles (7.9 billion kilometers) -- a journey that included 15 trips around the Sun and flybys of Earth once, Venus twice, and Mercury three times -- before it was inserted into orbit around its target planet in 2011.
"We have operated successfully in orbit for more than three Earth years and more than 14 Mercury years as we celebrate this amazing 10th anniversary milestone," said MESSENGER
Physicists and materials scientists are using origa- mi-based folding methods, or tessellation, for 'tuning' the fundamental physical properties of thin sheets, which could help develop molecular-scale machines that snap into place and perform mechan- ical tasks. Credit: Jesse Silverberg, Cornell Univer- sity
Scanning tunneling microscopy images the precur- sor, the “folded” end cap, and the resulting carbon nanotube, together with the corresponding struc- tural models. Image: Empa / Juan Ramon Sanchez Valencia
File Image.
Planet-like object may have spent its youth as hot as a star
Astronomers have discovered an extremely cool object that could have a particularly diverse history- although it is now as cool as a planet, it may have spent much of its youth as hot as a star.
The current temperature of the object is 200 to 300 degrees Fahr- enheit (100 to 150 degrees Celsi- us), which is intermediate between that of the Earth and of Venus.
However, the object shows evi- dence of a possible ancient origin, implying that a large change in temperature has taken place. In the past this object would have been as hot as a star for many millions of years.
Called WISE J0304-2705, the object is a member of the recently established "Y dwarf" class-the coolest stellar temperature class yet defined, following the other classes O, B, A, F, G, K, M, L, and T.
Although the temperature is simi- lar to that of the planets, the ob- ject is dissimilar to the rocky Earth -like planets, and instead is a giant ball of gas like Jupiter.
The international discovery team, led by David Pinfield from the University of Hertfordshire and including Carnegie's Yuri Beletsky, identified the Y dwarf using the
WISE observatory-a NASA space telescope that has imaged the entire sky in the mid-infrared.
The team also measured the spectrum of light emitted by the Y dwarf, which allowed them to determine its current temperature and better under- stand its history. Their work is published by Monthly Notices of the Royal Astronomical Society.
Only 20 other Y dwarfs have been discovered to-date, and amongst these WISE J0304- 2705 is defined as "peculiar"
due to unusual features in its emitted light spectrum...Read More...
is consistent with a theory known as geometric scaling over an unexpectedly wide range of con- ditions.
A hypothesis arising from recent particle physics theory is that at extremely high energies, gluons could reach densities high enough to form an intermediate and exotic state of matter called a color glass condensate (Fig. 1), which is a precur- sor to other exotic states known as glasma and quark–gluon plasma. At high energies and densi- ties, the color glass condensate also exhibits a property called geometric scaling, where physical quantities such as the rate of ...Read More...
The nucleus of an atom is composed of protons and neutrons, which are themselves made up of elementary particles called quarks and gluons.
Observing these elementary particles is difficult and typically involves smashing atoms together at close to the speed of light to observe emis- sions from high-energy collisions.
Larry McLerran from the RIKEN–BNL Re- search Center and Christian Klein-Boesing from the University of Münster in Germany have now shown that the production of photons in heavy- ion collisions at the Relativistic Heavy Ion Col- lider (RHIC) and Large Hadron Collider (LHC)
kidney stones or tumors.
The difference with this new equipment is that it replaces the radiographic film for a radiation detector, which will provide elec- trical signals proportional to the levels of radiation received. The digital detectors cointain a device called a cesium iodide scintillator, that converts X-rays into light, which in turn is converted into digital signals through a layer of amorphous silicon photodiodes that are processed to obtain a picture.
A digital image allows a more Wanting to replace the medical
equipment for taking X-rays, the Mexican Society of Radiology (CMR) created a system of digital x-ray imaging, which replaces the traditional plaque by a solid detec- tor, which delivers results in five seconds. Analog equipment take six minutes to develop the tradi- tional film.
Engineer Nashelli Cuaranta Mon- roy, CMR researcher, explained that the system called ARiX RAD obtains X-ray images that aid in the diagnosis of various diseases, like identifying bone fractures,
accurate assessment by using soft- ware tools that enable enhancement and post-processing of the radio- graph that unfolds in conventional monitors. In addition, control and virtual management facilitates distri- bution through the internet, ena- bling processes like teleradiology and remote diagnostics.
The ARiX RAD system is integrated by a computer that performs three functions: first it selects the radio- graphic technique for the study;
then it converts electrical sig- nals from the radiation detector into a digital image, and ...Read More...
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High-energy particle collisions reveal the unexpected
High-energy collisions between nuclei (white arrows) produce a cloud of elementary particles including quarks (red) and gluons (yellow). When gluons form an expansion front, they can produce a wall of matter called a color glass condensate, which eventually dissipates as the expansion continues. Credit:
© 2014 Larry McLerran, RIKEN–BNL Research Center
X-rays in five seconds
This is a four-stage sequence (left to right) show- ing the possible extreme temperature evolution for WISE J0304-2705. For about 20 million years, the object was as hot as a star, shining with a temperature of at least 5,100 degrees Fahren- heit (2800 degrees Celsius). After about 100 million years it had cooled to about 2,700 degrees Fahrenheit (1500 degrees Celsius), and by a billion years its temperature was about 1,800 degrees Fahrenheit (1000 degrees Celsius). The final stage is billions of years later, when WISE J0304-2705 has cooled to its current planetary temperature of 100-150 C.
College of Science - United Arab Emirates University POB 15551
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United Arab Emirates
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view of activity at the cellular level. But the trauma can alter the function or activity of the brain or even stimulate an immune re- sponse. Meanwhile, non-invasive techniques such as CT scans or MRI visualize function best at the whole-organ level; they cannot visualize individual vessels or groups of neu- rons.
The first step of the new technique, called near infrared-IIa imaging, or NIR-IIa, calls for in- jecting water-soluble carbon nanotubes into a live mouse's bloodstream. The researchers then shine a near-infrared laser over the rodent's skull.
The light causes the specially designed nano- tubes to fluoresce at wavelengths of 1,300- 1,400 nanometers; this range represents a sweet spot for optimal penetration with very little light scattering. The fluorescing nano- tubes can then be detected to visualize the blood vessels' structure.
A team of Stanford scientists has developed an entirely non-invasive technique that pro- vides a view of blood flow in the brain. The tool could provide powerful insights into strokes and possibly Alzheimer's disease.
Some of the most damaging brain diseases can be traced to irregular blood delivery in the brain. Now, Stanford chemists have em- ployed lasers and carbon nanotubes to capture an unprecedented look at blood flowing through a living brain.
The technique was developed for mice but could one day be applied to humans, poten- tially providing vital information in the study of stroke and migraines, and perhaps even Alzheimer's and Parkinson's diseases. The work is described in the journal Nature Pho- tonics.
Current procedures for exploring the brain in living animals face significant tradeoffs. Surgi- cally removing part of the skull offers a clear
Amazingly, the technique allows scientists to view about three millimeters underneath the scalp and is fine enough to visualize blood coursing through single capillaries only a few microns across, said senior author Hongjie Dai, a professor of chemistry at Stanford. Further- more, it does not appear to have any adverse affect on innate brain functions….Read More...
Scientists use lasers and carbon nanotubes to look inside living brains
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Physics Department
Boosting microelectronics with a little liquid logic
Certain titanium-based metal oxides can form a crystal structure known as perovskite that results in a subtle internal imbalance of electric charges. This imbalance gives the material the ability to flip between two 'ferroelectric' states in response to an electric field—a promising recipe for fast, ultra-low-energy storage of digital data.
Masashi Kawasaki and colleagues from the RIKEN Center for Emergent Matter Sci- ence, in collaboration with Yusuke Kozuka and co-workers from the University of Tokyo, have now discovered a way to sweep away the stray charges that typically de- grade the performance of ferroelectric materials by using an ionic liquid.
Silicon-based field-effect transistors are the basis of modern electronics. In these devic- es, current flow through the transistor junction is controlled by altering the electronic state of a semiconducting 'gate' between the input 'source' and output '...Read More...
This illustration shows how carbon nanotubes, once injected into the subject, can be fluoresced using near- infrared light in order to visualize the brain vasculature and track cerebral blood flow. Credit: Dai Lab Schematic of an electric double-layer transistor featuring a ferroelectric barium titanate (BaTiO3) channel and an ionic liquid ‘gate’ that removes impurities for improved device performance. Credit: © 2014 Masashi Kawasaki, RIKEN Center for Emer- gent Matter Science