Sabtu, 11 Oktober 2014

Galileo: the causes of the failure of the Fregat become clearer

Galileo: the causes of the failure of the Fregat become clearer

On October 7, Arianespace will release the report on the failure of the orbit of two Galileo satellites. Its contents, however, already leaked in the press. It's a hardware problem in the Fregat stage which is the cause of a bad path.

The Fregat upper stage is behind the failure of the orbit of the two Galileo satellites. Involved, some of the fuel that would have frozen in midair.
This week that must be made ??public the report of the independent commission of inquiry set up after the last post missed the first two satellites of the operational phase of Galileo (FOC). On August 22, a pitcher Russian Soyuz lifted off from its launch pad from the spaceport with carrying two Galileo satellites. Due to a problem in the Fregat upper stage, the two satellites have not been placed on the orbit circular referred to some 23,200 km from the Earth .

They are now on an elliptical orbit of 25,900 km of height and 13,700 km of perigee . Moreover, they are not on the right orbital plane: 49.68 instead of 56. That said, while these satellites now operate in an orbit unusable for the operation of the constellation, he will be much more useful than you think.

A design flaw in the Fregat
This report has now been already leaked to the press. And if initially a first explanation for the failure of launcher reported a flaw in the software that controls the Fregat upper stage, it seems that the cause is more serious. Indeed, according to the newspaper Le Monde, citing sources close to the investigation, "it's not human error, but a lack of precision in the Fregat scheme design that makes the fuel froze in mid-air ". According to our own sources, the information is quite plausible.
This material dysfunction is much more problematic than a software fault that corrects a simple rewrite of source code. In addition, the investigators found that other floors under construction Fregat had this same defect. Now return to flight is conditioned on the results of this investigation. If it turns out that this is a design problem, this stage could remain grounded for much longer than expected, which will have a negative impact on the launch schedule "of Arianespace, which operates the Soyuz and this floor from the CSG.
However, before imagining all the possible consequences, it is prudent to await the final conclusions of this inquiry.

Nobel Prize in Physics 2014: Led lighting rewarded

Nobel Prize in Physics 2014: Led lighting rewarded

Members of the Royal Academy of Sciences of Sweden against all odds by awarding the Nobel Prize in Physics in 2014 for the Japanese and American physicists behind the technology of blue LEDs. Deserved reward already used in mobile phones and Blu-ray, the blue LED will become ubiquitous in the future of lighting.

The blue LED is poised to change the future of humanity in the same way that the light bulb Edison did in the last century.  Their discovery deserved a Nobel Prize.

The choice of the winner of Nobel Prize in Physics in 2014 are probably surprised many. Among the frontrunners were Wojciech Zurek and Vera Rubin. One for his work on decoherence in quantum physics and the second for his work on dark matter . But it is ultimately for contributions apparently much less spectacular than the members of the Royal Swedish Academy of Sciences has decided to award the prize famous of Alfred Nobel Japanese physicists Isamu Akasaki , Hiroshi Amano and American physicist of Japanese Shuji Nakamura .
In the early 1990s, these three scientists have indeed managed to get through perseverance diodes emitting blue. Many had failed before them for nearly 30 years despite sustained efforts. Simply a matter of color ? No. In doing so, they initiated a technological revolution which all the consequences have not yet been felt, but that could be for the XXI th century that the bulb 's Edison was to the XX th century.

The light-emitting diode (English: Light - Emitting Diode , LED ) existed long before the work of three researchers. One of its major advantages is its low power consumption. Unlike lamps bulbs , which produce a lot of heat, the use of semiconductors in LED features an almost direct conversion of electricity into light . One could imagine, for example, replace the lighting of cities by Led. But this required to produce white light. But for a long time did not allow the LED to produce than red or green light. A solution to obtain white light was of course obvious: together using red, green and blue LEDs. Easier said than done. The development of these blue LED's cooperation was indeed very difficult. Akasaki, Amano and Nakamura finally succeeded using indium gallium nitride.

The LED, the lighting of the future world

Today, the blue LED are almost everywhere since they are found in the flashes of mobile phones and the screens backlight LCD . They are also involved in the operation of lasers fitted blue drives optical disc Blu-ray . But at a time when humanity is consuming more and more energy and resources as fuels fossils are depleted or threaten the climate of the Earth , the global replacement of incandescent lamps with LED will certainly win. 20 to 30% of global electricity is used for lighting effect. However, as technology continues to grow, lighting Led currently reaches up to 300 lumens per watt as incandescent lamps are 16 lumens per watt.

Nearly 1.5 billion people in developing countries could benefit in the near future a cheap and environmentally friendly lighting through LED powered by solar electricity . This is a good illustration of the thesis of Peter Diamandis exposed in his book Abundance: The Future Is Better Than You Think . The CEO of the X Prize Foundation will maintains that technological advances make it possible to abundant resources that are initially rare.

Given the impact on the well-being of mankind has led and will continue to lead the development of blue LED and given the spirit in which Alfred Nobel established its prices, it seems clear that awarded in physics for 2014 is particularly well justified.

Nobel Prize for Medicine in 2014 for the "GPS of the brain"

Nobel Prize for Medicine in 2014 for the "GPS of the brain"

The Nobel Prize in Medicine in 2014 belongs to John O'Keefe, on the one hand, and May-Britt Moser and Edvard other, for their work on brain cells that form a kind of "internal GPS".

Where am I, where am I going? How do I get from point A to point B and easily find my way? These questions have been a number of responses by the winners of the Nobel Prize in Medicine 2014: three physiologists discovered the cellular basis of a system of geolocation house located in the brain .
In 1971, John O'Keefe, a researcher from University College London, discovered the first cells involved in this kind of GPS internally. He recorded signals nerve cells in a part of the brain, the hippocampus in rats that were moving freely in a room. He then found that some cells were activated when the animal was in a certain place in the environment. These cells "positioning" (" Place cells ") were building a map of the environment. He concluded that the hippocampus generates many cards. Thus the memory of an environment would be stored in the form of a combination of activities cell positioning in the hippocampus.

More than 30 years later, in 2005, two Norwegian researchers, May-Britt and Edvard Moser have discovered other associated geolocation system cells of the brain : the "grid cells" ("grid cells") that allow positioning accurate. By constructing a map of the connections of the hippocampus in rats moved into a room, the two researchers found activity in a part of the brain near the hippocampus: the cortex entorhinal.

A GPS disrupted in Alzheimer's disease
The grids cells constitute a system that allows navigation in space. With other cells of the entorhinal cortex which recognize the direction of the head and the boundaries of the room, they form circuits with the positioning of cells in the hippocampus. Researchers have described how cell positioning and grids cells work together to allow the brain to know where it is and how to lead a movement.

Recent research using the brain imaging as well as observations on patients undergoing surgery of the brain, have provided evidence of the existence of these cells in humans.
Moreover, in patients suffering from Alzheimer disease, the hippocampus and entorhinal cortex are often affected at an early stage; Sometimes these patients tend to lose their way or not to recognize their environment. This work could lead to a better understanding of the mechanism of loss of spatial memory in patients by the Alzheimer's disease.

Autonomous car is looming on the horizon

Autonomous car is looming on the horizon

At the Paris Motor Show, showcases is made electronics and various and varied accessories. This is probably a foretaste of future developments of the car, as many predict independently, as evidenced by several specialists.

Will there be another driver in the car in 2030 ? The car , already increasingly connected and automated, should soon lead alone, according to manufacturers working on this promising new technological frontier. But before becoming a part of everyday life, time savings and safety to the key, the autonomous car still faces technical, legal and especially psychological challenges.
Most of a certain level of luxury cars already offer driving aids: lane departure warning, windshield wipers and automatic headlights, radar and backup cameras. High-end, some models perform niche for themselves. Mercedes-Benz on its flagship S which often gives the "the" equipment with five to ten years ahead of the least expensive cars class, already offers a system of quasi-automatic driving in traffic and a regulator of rate which maintains the distance to other cars on the highway.

In the wake of automation increasingly important, "we believe that the autonomous vehicle will be a reality from 2020, but believe that the most significant deployment will take place after 2030," said Josselin Chabert, automotive expert consultancy PWC." The technology is there, "adds Thierry Hay, director of innovations and embedded systems with PSA Peugeot-Citroen, noting that manufacturers " all work "to develop such facilities.

The Ford Fusion Hybrid prototype serves as a laboratory to develop the constructor functions of autonomous driving.  On the roof, five Lidar sensors use a laser pulse to analyze the surroundings in three dimensions.

One day, the car will park only

Creating a pipeline of autonomous cars is part of industrial projects launched by the French government, a pulse that has not expected Akka, a consulting and engineering working for Daimler (Mercedes) office, which is Now in its third generation of autonomous vehicle, says the CEO of this company from the Lyon region, Maurice Ricci. For him, the current main technical challenge is to allow the vehicle to react in real time to a changing environment: other cars, pedestrians or animals crossing the road, not to mention the occasional work that prevent rely solely on data GPS . " We consider that the vehicle must be able to create his model digital and move in , "he says. For now, " it detects only 30 kg of organic mass, so we have progress to make , "says Maurice Ricci. Bristling with sensors, the car Link & Go Akka throne on the stand of the Department of Ecology at the Paris Motor Show.
The French supplier Valeo has demonstrated its amazing system that replaces the carrier side: you leave your car in front of a restaurant, and she goes on her own to find a parking place, preventing you from multimedia phone when it is parked. But he'll have the law evolves to allow circulation of autonomous cars , says Mr. Hay. The Vienna Convention on Road Traffic (1968), ratified by most European countries including France, provides that " any vehicle in motion or series of vehicles shall have a driver . "

Home of the Google Car , California, after Nevada (western United States), has to adapt its legislation to permit experiments autonomous vehicles on public roads . The French authorities have planned to do the same from 2015 Once the technical aspects solved, remain outstanding the issue of liability in the heart of the insurance system. In case of accident, " are we going to give more credit to a vehicle driven by a computer , or Man? "asks Josselin Chabert, PWC. As for the psychological blow for drivers not destined to become passengers Thierry Hay says that customers surveys " show that people imagine very well and think it's a natural evolution. " The benefits of autonomous cars are potentially huge: reducing congestion, consumption, and 90% fewer accidents in the future, emphasizes Josselin Chabert. Besides the free time. " No one is particularly excited by the prospect of spending half an hour in traffic morning and evening and welcome the opportunity to do something else during that half hour then, "said Thierry Hay.

The loss of smell would signal an increased risk of death within 5 years

The loss of smell would signal an increased risk of death within 5 years

Unable to identify the mere odor elderly are at increased risk of dying within five years of risk, according to research recently published in the journal Plos One .

The scent of flowers is the mixing of some of their compounds, chemists can analyze assembly for a single scent.  When you no longer feel this perfume is not only a shame but, perhaps, a bad sign!
Researchers who conducted a study on the sense of smell in older people found that 39% of subjects 57 to 85 years unable to recognize simple smells like the pink , orange, of fish , of mint and leather died within a period of five years, against 19% of participants with moderate loss of smell and 10% for those that may feel normal.

Olfactory dysfunction was found to be a better predictor of mortality than a diagnosis of heart failure, cancer or lung disease, according to the scientists at the University of Chicago, whose work has just been published in the journal Plos One . Only pathologies severe liver are a strong indicator of the probability of dying within five years, say the authors of this research.
The study, which is part of the National Social Life, Health and Aging Project that was conducted among 3,000 men and representative of the American elderly women. Nearly 78% of those tested were classified as having a smell normal, identifying four or five odors on five, which is the data on the population.

The sign of a decline in the overall capacity for regeneration?

Approximately 20% of participants were classified as hyposmiques, recognizing only two to three odors, the remaining 3.5% as anosmic, that is to say, deprived of smell almost. They could not recognize one of the five test odors and none for 1.1% of the group. Age makes a big difference: 64% of younger (57 years old) were able to recognize all the smells against only 25% of older (85 years).

This team of researchers that included psychologists, physicians, sociologists and statisticians put forward several hypotheses to explain this phenomenon. One of them from the fact that the olfactory system contains stem cells capable of regenerating. A reduced sense of smell may signal a decline in the overall capacity of regeneration of the body with age, which would increase all-cause mortality, these scientists argue.
"We believe that the loss of smell, it's like a canary in a mine coal", said Dr. Jayant Pinto, a lead author of the study and assistant professor of surgery specializing in genetics and the treatment of olfactory disorders. "This is not a direct cause of death but a harbinger that something is more wrong with the body", he has said. He said the results of this research "could help develop useful and inexpensive clinical test capable of rapidly identifying current greater mortality risk persons".

The dogfish shark made personal choices

The dogfish shark made personal choices

Small bats, these common sharks in the Atlantic and Mediterranean, each with their character, at least in terms of social interaction. As this behavior affects the chances of survival, these individual variations may surprise.

Small bats live on the seabed in shallow water, and are camouflaged by burrowing.  When they are young, these sharks can isolate or prefer to approach conspecifics already installed.
Small dogfish, Scyliorhinus canicula , have varying personalities, some are likely to approach their peers while others prefer to stay alone on a warm background: this is what the British zoologists observed Now in captivity ten groups of these selachians in three types of environments, the MBA Plymouth ( Marine Biological Association ).

Bearing multiple names (catfish, or cow, or rock salmon at the fish), small foxes are common along the coasts of the Atlantic and the Mediterranean. These sharks 80cm live on soft bottoms (gravel, sand or mud) and may form loose groups. David Jacoby and colleagues have placed in several basins of juveniles in amounts larger or smaller and observed their social behavior, individual by individual. Sociability, here, is limited to settle on the bottom, close to or at a remote location.

Is it better to hide alone or in groups?

The findings, published in the journal Behavioral Ecology and Sociobiology , show that young bats rather retain their social or asocial rather whatever the size of the group and for the three types of environmental character. The researchers' conclusion is that these behavioral differences are not dependent on anything other than the individual himself.
The observation is rather surprising because the choice of where dogfish settles on the bottom is key to effective camouflage. When they are young, these fish are indeed beautiful prey when stationary in the sand, mud or gravel. So there would be two different strategies among individuals, with some preferring established groups and other deserted places. But this is only a hypothesis. Dogfish still retains his secret inclinations.

The terrible anger of a young turbulent star

The terrible anger of a young turbulent star

On April 23, a series of eruptions produced a dazzling line 60 light years red dwarf surprised astronomers. The Swift satellite that issued the alert and scrutinized the phenomenon several days, noted that the most intense event was 10,000 times more powerful than the most violent eruptions recorded on the surface of our sun. How such small stars can they be the scene of such a strong and sudden activity?

Illustration torque red dwarf DG or DG Canum Venaticorum CVn, located about 60 light years from the Solar System.  One of them had several eruptions, the most important was 10,000 times more powerful than the most intense solar flare known, recorded in November 2003 Its brightness in X-rays exceeded that of two stars in all lengths wave.
Mood swings, the sun knows a lot. More or less intense. It depends on the period of its activity cycle which lasts 11 years on average. The dark spots, active regions, the source of flares are more numerous when peaking effect caused by the inversion of the magnetic field . The current cycle 24 is however below the previous (Cycle 23 peaked between 2001 and 2003), so that solar physicists believe that our star is going through a "mini max." Admittedly, the term suggests a mini activity down, but do not exclude that solar supertempĂȘtes can manifest as was the case July 23, 2012 (without hitting our magnetosphere ).

The solar flares are created by the twists of an intense magnetic field that, in the active regions, store energy and release it suddenly after a magnetic reconnection . They are classified into three categories (or classes) according to the intensity of X-rays: A, B and C for the lowest, M for Moderate and X for the most powerful. They emit in all wavelengths. The most powerful of Cycle 24 occurred August 9, 2011 and was classified X6.9. But the one that beats them all deployed energy since we are able to observe the surface of our star dated November 4, 2003 . She was then classified X28 and X45 to review.

Series of super eruptions stellar 60 light years

Although these tantrums are impressive, they seem pretty ridiculous compared to what astronomers have caught April 23, 2014 from a pair of red dwarf named DG Canum Venaticorum (abbreviated as DG CVn). Although a less massive than a third yellow dwarf like the Sun, one of the two star located about 60 light years from the solar system was the site of a 10,000 times more powerful than the eruption in November 2003 (in the case of the Sun). The two stars are separated only three astronomical units (three times the Earth-Sun distance), it is difficult since the orbit Earth to determine which of the two is at the origin. It is the instrument BAT ( Burst Alert Telescope ) satellite Swift dedicated to the detection of the most violent radiation in the Universe (X and gamma) that gave the alert. Moments later, several observatories were informed and the telescope spatial began a more extensive observational campaign.
"Three minutes after the BAT, the X-rays of this super eruption was above the brightness of the two stars combined in all wavelengths under normal conditions, " recalls Adam Kowalski GSFC ( Goddard Space Flight Center ), which studied the phenomenon, adding that "eruptions of this magnitude are extremely rare for red dwarfs" . Moreover, "the system (...) was not on our watch list of stars that could produce large eruptions, confesses Rachel Osten ( Space Telescope Science Institute in Baltimore). We had no idea that DG CVn was in it " . Indeed, the radiation was multiplied by 10 in the visible and 100 in the ultraviolet as pointed instruments. Measurements indicate that at the height of the event, the temperature was about 200 million degrees Celsius , or more than 12 times that which prevails in the center of the Sun!

Previously, many thought, as Stephen Drake, an astrophysicist at GSFC who introduced last August, the results of this study to the meetings of the High Energy Division of the American Astronomical Society ( American Astronomical Society ), that "the major eruptions on the surface red dwarfs can not exceed one day " . But Swift showed it occurred in at least seven in the space of two weeks! "It was a very complex event. " About three hours after the first eruption, a second was evident with almost as much intensity. The following eleven days, the satellite has observed many more, but increasingly weak. Researchers found that everything was back to normal after 20 days. Rachel Osten compares the phenomenon to replicas after an earthquake of a magnitude significant.

Turbulent youth

For researchers, these sudden exhalations power from such a small star are due to his youth. Or rather his childhood as DG CVn has only 30 million years, only 0.7% of the age of our Sun. These stars toddlers are about a thousand within 100 light years. In just out of the cradle, the two red dwarfs still turn on themselves very quickly, in just one day (on average 30 times faster than the Sun). Also the effect dynamo created by the differential rotation, which generates the magnetic field, is it amplified. The situation refers to the one could have known at an early stage our star. It is important to keep an eye on these stars because they show the stellar youth and interactions with their surroundings.

Very common throughout the Milky Way and probably surrounded, for the most part, gas planets and rocky, the red dwarfs , however, are often disqualified by astronomers and exobiologistes looking for potentially habitable planets . Involved, in addition to the violence of some eruptions in their youth, the erosion of magnetic fields and atmospheres of these worlds by stellar winds.

Exomain gives a sense of touch to virtual reality

Exomain gives a sense of touch to virtual reality

North American society Dexta Robotics has developed a hand exoskeleton that generates a sensation of touching a virtual prototype environment. The system is currently still very rudimentary but promising.
On the left, the exomain Dexmo Classic manufactured by Dexta Robotics.  It can animate and control a virtual hand.  On the right, the Dexmo F2 and feedback system which gives effect the sense of touch model.  Both boxes located at the thumb and index finger generate mechanical strength when the avatar of the hand encounters a virtual object.  The system is limited for now to "on-off" mode, explain its designers, which means that it does not perceive nuances depending on the type of virtual object hit.

Whether playful or scientists, applications of virtual reality continue to demonstrate their full potential, with sometimes surprising examples:  make palpable a virtual object , observe their own brain activity or help archaeologists to save a site. The acquisition in March the company Oculus Rift by Facebook for 2 billion is another important signal for the development of a mass market. Remember that this sapling California markets since 2012 a prototype virtual reality helmet reserved for the moment, to developers.
She has also just introduced a new version of its device called Crescent Bay which is accompanied by a series of applications. " We believe that one day, this type of augmented reality immersive will be part of everyday life for billions of people , "said at redemption Mark Zuckerberg, co-founder and CEO of Facebook. While great strides have been made ??in the visual and auditory immersion, a crucial sensory barrier remains. This is the touch which is currently crudely rendered by vibrations or sounds. But a North American company, Dexta Robotics offers a more attractive option.
The exomain Dexmo F2 here in action. With boxes placed on the thumb and forefinger, the user feels a resistance when manipulating virtual objects. In this demonstration, it allows him to precisely control two robotic arms perceiving an effect back when the clamps grab something.

The Dexmo are still rudimentary but affordable

This company has developed an exoskeleton hand that is able to provide feedback effect to the user manipulates a virtual object. The Dexmo F2 is a derivative of a first model named exomain Dexmo Classic prototype. Five grandchildren and motorized articulated arms are attached to the ends of the fingers and pick up all the movements of the hands (11 degrees of freedom). With a kit software , developers can control a virtual hand with loyalty with exomain. In this technology, the Dexmo F2 adds a feedback system effect to produce a sensation of touch. These two housings containing a brake system miniaturized disc.
When the avatar that you control enters or touches a virtual object, the exomain generates resistance in the thumb or index finger, as it would with a real object. Admittedly, the system is fairly rudimentary as it does not feel the hardness of an object or material. In addition, the effect return applies only two fingers. But this exomain has the advantage of being inexpensive since Dexta Robotics account the market via a KickStarter campaign for less than 200 dollars (158 euros at current prices). This solution is certainly still far from what can be done in a few years, but it could be quickly improved as long as Dexta Robotics plays the opening with the community of virtual reality applications developers.