Tag Archives: Technology

Views from the Solar System (222)


The U.S. Gulf Coast at Night

NASA – ISS040-E-090540 (9 Aug. 2014) — One of the Expedition 40 crew members aboard the International Space Station photographed this nighttime image showing city lights in at least half a dozen southern states from some 225 miles above the home planet. Lights from areas in the Gulf Coast states of Texas, Louisiana, Mississippi and Alabama, as well as some of the states that border them on the north, are visible.

Monitoring of singlet oxygen in individual cells with InGaAs camera


R&D – Singlet oxygen, the first excited state of molecular oxygen, is a highly reactive species that plays an important role in a wide range of biological processes, including cell signaling, immune response, macromolecule degradation, and elimination of neoplastic tissue during photodynamic therapy. Often, a photosensitizing process is employed to produce singlet oxygen from ground state oxygen.

The researchers at Charles Univ. utilized two detection channels (VIS and NIR) to perform real-time imaging of the very weak near-infrared phosphorescence of singlet oxygen and photosensitizer simultaneously with visible fluorescence of the photosensitizer. Their new experimental setup enables acquisition of spectral images based on singlet oxygen and photosensitizer luminescence from individual cells. more> http://tinyurl.com/kuhbuzc

Galactic Views (134)



SPACE WATCH

Supernova SN 2014J Explodes

NASA – New data from NASA’s Chandra X-ray Observatory has provided stringent constraints on the environment around one of the closest supernovas discovered in decades. The Chandra results provide insight into possible cause of the explosion, as described in our press release.

On January 21, 2014, astronomers witnessed a supernova soon after it exploded in the Messier 82, or M82, galaxy. Telescopes across the globe and in space turned their attention to study this newly exploded star, including Chandra.  Astronomers determined that this supernova, dubbed SN 2014J, belongs to a class of explosions called “Type Ia” supernovas. These supernovas are used as cosmic distance-markers and played a key role in the discovery of the Universe’s accelerated expansion, which has been attributed to the effects of dark energy.  Scientists think that all Type Ia supernovas involve the detonation of a white dwarf. One important question is whether the fuse on the explosion is lit when the white dwarf pulls too much material from a companion star like the Sun, or when two white dwarf stars merge.

This image contains Chandra data, where low, medium, and high-energy X-rays are red, green, and blue respectively. The boxes in the bottom of the image show close-up views of the region around the supernova in data taken prior to the explosion (left), as well as data gathered on February 3, 2014, after the supernova went off (right).  The lack  of the detection of X-rays detected by Chandra is an important clue for astronomers looking for the exact mechanism of how this star exploded.

The non-detection of X-rays reveals that the region around the site of the supernova explosion is relatively devoid of material. This finding is a critical clue to the origin of the explosion. Astronomers expect that if a white dwarf exploded because it had been steadily collecting matter from a companion star prior to exploding, the mass transfer process would not be 100% efficient, and the white dwarf would be immersed in a cloud of gas.

If a significant amount of material were surrounding the doomed star, the blast wave generated by the supernova would have struck it by the time of the Chandra observation, producing a bright X-ray source. Since they do not detect any X-rays, the researchers determined that the region around SN 2014J is exceptionally clean.

A viable candidate for the cause of SN 2014J must explain the relatively gas-free environment around the star prior to the explosion.  One possibility is the merger of two white dwarf stars, in which case there might have been little mass transfer and pollution of the environment before the explosion. Another is that several smaller eruptions on the surface of the white dwarf cleared the region prior to the supernova.  Further observations a few hundred days after the explosion could shed light on the amount of gas in a larger volume, and help decide between these and other scenarios.

A paper describing these results was published in the July 20 issue of The Astrophysical Journal and is available online. The first author is Raffaella Margutti from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, MA, and the co-authors are Jerod Parrent (CfA), Atish Kamble (CfA), Alicia Soderberg (CfA), Ryan Foley (University of Illinois at Urbana-Champaign), Dan Milisavljevic (CfA), Maria Drout (CfA), and Robert Kirshner (CfA).

Image Credit: NASA/CXC/SAO/R.Margutti et al

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› Chandra on Flickr

Updates from SIEMENS


Modeling the truck as a whole: Scania uses LMS Imagine.Lab Amesim for testing approach
SIEMENS – Just how do you design a truck?

And especially a truck that needs to haul loads of timber out of snowy Scandinavian forests or coal out of dusty, unpredictable Indonesian mines?

Or, simply be able to run dependably 24 hours a day, seven days a week on the highway?

Precision is the answer for Scania. Obtaining this precision equals the right type of design early in the process. This is just one of the reasons why this global truck manufacturer uses LMS Imagine.Lab™ software. The engineering team counts on this tool to simulate the entire vehicle dynamics, including the hydraulics and the driveline, and to couple various systems such as electronics to create a “virtual” truck.

A leader in the truck and bus market, the Swedish multinational was founded in 1891. Since then, the company has produced and delivered more than 1,400,000 trucks and buses for heavy transportation. You can imagine that a lot has changed since Gustaf Eriksson designed a usable petrol engine in 1902, the year the company manufactured its first truck. more> http://tinyurl.com/l3er3qc

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How Verizon lets its copper network decay to force phone customers onto fiber


By Jon Brodkin – Not everyone wants fiber, because, when it comes to voice calls, the newer technology doesn’t have all the benefits of the old copper phone network.

In particular, fiber doesn’t conduct electricity, where copper does. That means when your power goes out, copper landlines might keep working for days or weeks by drawing electricity over the lines, while a phone that relies on fiber will only last as long as its battery. That’s up to eight hours for Verizon’s most widely available backup system.

“Verizon’s efforts to force people off copper in my area of Rhode Island rise to the level of harassment,” Verizon customer Karen Anne Kolling of North Kingstown, Rhode Island, told Ars. more> http://tinyurl.com/o5jvv5n

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