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What is Storage?

storage-device-computer

 

In a computer, storage is the place where data is held in an electromagnetic or optical form for access by a computer processor. There are two general usages.

  1. Storage is frequently used to mean the devices and data connected to the computer through input/output operations – that is, hard disk and tape systems and other forms of storage that don’t include computer memory and other in-computer storage. For the enterprise, the options for this kind of storage are of much greater variety and expense than that related to memory. This meaning is probably more common in the IT industry than meaning 2 (the following).
  2. In a more formal usage, storage has been divided into:
    1. Primary storage, which holds data in memory (sometimes called random access memory or RAM) and other “built-in” devices such as the processor’s L1 cache, and
    2. Ssecondary storage, which holds data on hard disks, tapes, and other devices requiring input/output operations.

Primary storage is much faster to access than secondary storage because of the proximity of the storage to the processor or because of the nature of the storage devices. On the other hand, secondary storage can hold much more data than primary storage.

In addition to RAM, primary storage includes read-only memory (ROM) and L1 and L2 cache memory. In addition to hard disks, secondary storage includes a range of device types and technologies, including diskettes, Zip drives, redundant array of independent disks (RAID) systems, and holographic storage. Devices that hold storage are collectively known as storage media.

A somewhat antiquated term for primary storage is main storage and a somewhat antiquated term for secondary storage is auxiliary storage. Note that, to add to the confusion, there is an additional meaning for primary storage that distinguishes actively used storage from backup storage.

Nobel Prize in Physics for 2015

Illustration of the Sudbury Neutrino Observatory. Credit: Copyright Johan Jarnestad/The Royal Swedish Academy of Sciences
Illustration of the Sudbury Neutrino Observatory.
Credit: Copyright Johan Jarnestad/The Royal Swedish Academy of Sciences

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2015 to Takaaki Kajita Super-Kamiokande Collaboration University of Tokyo, Kashiwa, Japan and Arthur B. McDonald Sudbury Neutrino Observatory Collaboration Queen’s University, Kingston, Canada “for the discovery of neutrino oscillations, which shows that neutrinos have mass.”

Metamorphosis in the particle world

The Nobel Prize in Physics 2015 recognises Takaaki Kajita in Japan and Arthur B. McDonald in Canada, for their key contributions to the experiments which demonstrated that neutrinos change identities. This metamorphosis requires that neutrinos have mass. The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe.

Around the turn of the millennium, Takaaki Kajita presented the discovery that neutrinos from the atmosphere switch between two identities on their way to the Super-Kamiokande detector in Japan.

Meanwhile, the research group in Canada led by Arthur B. McDonald could demonstrate that the neutrinos from the Sun were not disappearing on their way to Earth. Instead they were captured with a different identity when arriving to the Sudbury Neutrino Observatory.

A neutrino puzzle that physicists had wrestled with for decades had been resolved. Compared to theoretical calculations of the number of neutrinos, up to two thirds of the neutrinos were missing in measurements performed on Earth. Now, the two experiments discovered that the neutrinos had changed identities.

The discovery led to the far-reaching conclusion that neutrinos, which for a long time were considered massless, must have some mass, however small.

For particle physics this was a historic discovery. Its Standard Model of the innermost workings of matter had been incredibly successful, having resisted all experimental challenges for more than twenty years. However, as it requires neutrinos to be massless, the new observations had clearly showed that the Standard Model cannot be the complete theory of the fundamental constituents of the universe.

The discovery rewarded with this year’s Nobel Prize in Physics have yielded crucial insights into the all but hidden world of neutrinos. After photons, the particles of light, neutrinos are the most numerous in the entire cosmos. Earth is constantly bombarded by them.

Many neutrinos are created in reactions between cosmic radiation and Earth’s atmosphere. Others are produced in nuclear reactions inside the Sun. Thousands of billions of neutrinos are streaming through our bodies each second. Hardly anything can stop them passing; neutrinos are nature’s most elusive elementary particles.

Now the experiments continue and intense activity is underway worldwide in order to capture neutrinos and examine their properties. New discoveries about their deepest secrets are expected to change our current understanding of the history, structure and future fate of the universe.

Takaaki Kajita, Japanese citizen. Born 1959 in Higashimatsuyama, Japan. Ph.D. 1986 from University of Tokyo, Japan. Director of Institute for Cosmic Ray Research and Professor at University of Tokyo, Kashiwa, Japan. www.icrr.u-tokyo.ac.jp/about/greeting_eng.html

Arthur B. McDonald, Canadian citizen. Born 1943 in Sydney, Canada. Ph.D. 1969 from Californa Institute of Technology, Pasadena, CA, USA. Professor Emeritus at Queen’s University, Kingston, Canada. www.queensu.ca/physics/arthur-mcdonald

Prize amount: SEK 8 million, to be shared equally between the Laureates.


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The above post is reprinted from materials provided by Nobel Foundation. Note: Materials may be edited for content and length.

Interview Question : What is Hard Disk?

what-is-hard-disk-drive-hdd

A hard disk is part of a unit, often called a “disk drive,” “hard drive,” or “hard disk drive (HDD),” that stores and provides relatively quick access to large amounts of data on an electromagnetically charged surface or set of surfaces. Today’s computers typically come with a hard disk that contains several billion bytes (gigabytes) of storage.

A Hard disk can also be defined as:

  1. a rigid (“hard”) non-removable magnetic disk with a large data storage capacity.
  2. a data storage device used for storing and retrieving digital information using one or more rigid (“hard”) rapidly rotating disks (platters) coated with magnetic material.
  3. A magnetic disk on which you can store computer data. The term hard is used to distinguish it from a soft, or floppy disk. Hard disks hold more data and are faster than floppy disks.

Extra Information

A hard disk is really a set of stacked “disks,” each of which, like phonograph records, has data recorded electromagnetically in concentric circles or “tracks” on the disk. A “head” (something like a phonograph arm but in a relatively fixed position) records (writes) or reads the information on the tracks. Two heads, one on each side of a disk, read or write the data as the disk spins. Each read or write operation requires that data be located, which is an operation called a “seek.” (Data already in a disk cache, however, will be located more quickly.)

A hard disk/drive unit comes with a set rotation speed varying from 4500 to 7200 rpm. Disk access time is measured in milliseconds. Although the physical location can be identified with cylinder, track, and sector locations, these are actually mapped to a logical block address (LBA) that works with the larger address range on today’s hard disks.

To know more regarding the terms follow the post about Difference between Disc and Disk click here.

 

Life History of a Dinosaur: Maiasaura

Research published in the journal Paleobiology is showing more about the life history of Maiasaura peeblesorum than any other known dinosaur. Credit: Courtesy Holly Woodward
Research published in the journal Paleobiology is showing more about the life history of Maiasaura peeblesorum than any other known dinosaur.
Credit: Courtesy Holly Woodward

Decades of research on Montana’s state fossil — the “good mother lizard” Maiasaura peeblesorum — has resulted in the most detailed life history of any dinosaur known and created a model to which all other dinosaurs can be compared, according to new research published recently in the journal Paleobiology.

Researchers from Oklahoma State University, Montana State University and Indiana Purdue University used fossils collected from a huge bonebed in western Montana for their study.

“This is one of the most important pieces of paleontology involving MSU in the past 20 years,” said Jack Horner, curator of the Museum of the Rockies at MSU. “This is a dramatic step forward from studying fossilized creatures as single individuals to understanding their life cycle. We are moving away from the novelty of a single instance to looking at a population of dinosaurs in the same way we look at populations of animals today.”

The study was led by Holly Woodward, who did the research as her doctoral thesis in paleontology at MSU. Woodward is now professor of anatomy at Oklahoma State University Center for Health Sciences.

The Paleobiology study examined the fossil bone microstructure, or histology, of 50 Maiasaura tibiae (shin bones). Bone histology reveals aspects of growth that cannot be obtained by simply looking at the shape of the bone, including information about growth rate, metabolism, age at death, sexual maturity, skeletal maturity and how long a species took to reach adult size.

“Histology is the key to understanding the growth dynamics of extinct animals,” Woodward said. “You can only learn so much from a bone by looking at its shape. But the entire growth history of the animal is recorded within the bone.”

A sample of 50 might not sound like much, but for dinosaur paleontologists dealing with an often sparse fossil record, the Maiasaura fossils are a treasure trove.

“No other histological study of a single dinosaur species approaches our sample size,” Woodward said.

With it, the researchers discovered a wealth of new information about how Maiasaura grew up: it had bird-level growth rates throughout most of its life, and its bone tissue most closely resembled that of modern day warm-blooded large mammals such as elk.

Major life events are recorded in the growth of the bones and the rates at which different-aged animals died.

“By studying the clues in the bone histology, and looking at patterns in the death assemblage, we found multiple pieces of evidence all supporting the same timing of sexual and skeletal maturity,” said Elizabeth Freedman Fowler, curator of paleontology at the Great Plains Dinosaur Museum in Malta and adjunct professor at MSU, who performed the mathematical analyses for the study.

Sexual maturity occurred within the third year of life, and Maiasaura reached an average adult mass of 2.3 tonnes in eight years. Life was especially hard for the very young and the old. The average mortality rate for those less than a year of age was 89.9 percent, and 44.4 percent for individuals 8 years and older.

If Maiasaura individuals could survive through their second year, they enjoyed a six-year window of peak physical and reproductive fitness, when the average mortality rate was just 12.7 percent.

“By looking within the bones, and by synthesizing what previous studies revealed, we now know more about the life history of Maiasaura than any other dinosaur and have the sample size to back up our conclusions,” Woodward said. “Our study makes Maiasaura a model organism to which other dinosaur population biology studies will be compared.”

The 50 tibiae also highlighted the extent of individual size variation within a dinosaur species. Previous dinosaur studies histologically examined a small subset of dinosaur bones and assigned ages to the entire sample based on the lengths of the few histologically aged bones.

“Our results suggest you can’t just measure the length of a dinosaur bone and assume it represents an animal of a certain age,” Woodward said. “Within our sample, there is a lot of variability in the length of the tibia in each age group. It would be like trying to assign an age to a person based on their height because you know the height and age of someone else. Histology is the only way to quantify age in dinosaurs.”

Horner, a coauthor on the research and curator of the Museum of the Rockies at MSU where the Maiasaura fossils are reposited, discovered and named Maiasaura in 1979. He made headlines by announcing the world’s first discovery of fossil dinosaur embryos and eggs. Based on the immature development of the baby dinosaur fossils found in nests, Horner hypothesized that they were helpless upon hatching and had to be cared for by parents, so naming the dinosaur Maiasaura, Latin for “good mother lizard.”

Studies that followed revealed aspects of Maiasaura biology including that they were social and nested in colonies; Maiasaura walked on two legs when young and shifted to walking on all four as they got bigger; their preferred foods included rotting wood; and that their environment was warm and semi-arid, with a long dry season prone to drought.

The tibiae included in the Paleobiology study came from a single bonebed in western Montana covering at least two square kilometers. More than 30 years of excavation and thousands of fossils later, the bonebed shows no signs of running dry. Woodward plans to lead annual summer excavations of the Maiasaura bonebed to collect more data.

“Our study kicks off The Maiasaura Life History Project, which seeks to learn as much as possible about Maiasaura and its environment 76 million years ago by continuing to collect and histologically examine fossils from the bonebed, adding statistical strength to the sample,” she said.

“We plan to examine other skeletal elements to make a histological ‘map’ of Maiasaura, seeing if the different bones in its body grew at different rates, which would allow us to study more aspects of its biology and behavior. We also want to better understand the environment in which Maiasaura lived, including the life histories of other animals in the ecosystem,” she added.

The Maiasaura Life History Project will also provide opportunities for college-aged students accompanying Woodward in her excavations to learn about the fields of ecology, biology and geology, thereby encouraging younger generations to pursue careers in science.

In addition to Woodward, Horner and Freedman Fowler, James Farlow, professor emeritus of Geology at Indiana Purdue University, contributed to the Paleobiology paper.


Story Source:

The above post is reprinted from materials provided by Montana State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Holly N. Woodward, Elizabeth A. Freedman Fowler, James O. Farlow, John R. Horner. Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship. Paleobiology, 2015; 1 DOI: 10.1017/pab.2015.19

Virtual reality for mice teaches scientists about navigation

A mouse is ready to enter a virtual-reality system where its brain can be imaged while it thinks it’s running through a maze.
A mouse is ready to enter a virtual-reality system where its brain can be imaged while it thinks it’s running through a maze.

 

Scientists can now observe the brains of lab animals in microscopic detail as the animals go about some action. A technique called two-photon imaging, in particular, allows neuroscientists to watch thousands of neurons working in concert to encode information.

The trouble is, two-photon imaging requires the animal’s head to stay fixed in place. That would seem to preclude watching the brain as the animal does anything of much interest.

One creative solution is virtual reality—a computer-generated environment experienced through a headset. A few years ago neuroscientists started designing tiny virtual-reality systems to fool mice into thinking they were navigating a maze when they were really running on the top of a large ball, their heads fixed in position.

Until now, however, mice didn’t run on the ball until they’d had weeks of training. Jeremy Freeman, working with colleague Nicholas Sofroniew and others at the HHMI Janelia Research Campus in Virginia, created a virtual maze the mice seem to understand right away: they navigate through virtual corridors without training. It’s designed to exploit the way mice navigate in nature, Freeman says. Instead of relying primarily on their eyes, mice rely heavily on their whiskers to feel their way through the world.

In the whisker-oriented virtual reality, the walls move to give the mouse the illusion that it is running down winding corridors, he says. But the whole time, the rodent’s head is stationary.

This approach doesn’t translate neatly to the human world. Mice rely heavily on their whiskers to get around, and the neural imaging requires genetically altering mice to produce fluorescent proteins. However, this mouse-sized VR could still shed plenty of light on autism and other conditions that affect decisions, learning and the senses.


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The above post is reprinted from materials provided by MIT Technology Review. Note: Materials may be edited for content and length.

NASA shows off Pluto’s largest moon

pluto-moon-Horizon-mission
This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by NASA’s New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon’s polar red terrain and Pluto’s equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their true separation is not to scale. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC). Credits: NASA/JHUAPL/SwRI

 

NASA’s New Horizons spacecraft has returned the best color and the highest resolution images yet of Pluto’s largest moon, Charon – and these pictures show a surprisingly complex and violent history.

At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they’re finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.

NASA has posted some new high-res enhanced color pictures of Pluto’s largest moon, Charon (shown above in the upper left corner). Other than a reddish polar region, the images also reveal a surprisingly detailed landscape with canyons, mountains and more. A video composite of images (embedded after the break) takes us flying over a canyon NASA says is four times as long as the Grand Canyon, and twice as deep. NASA says even better pictures are on the way, although with the spacecraft 3.1 billion miles away and still going, we’ll be waiting a year to get everything.

charon-neutral-bright
Charon in Enhanced Color NASA’s New Horizons captured this high-resolution enhanced color view of Charon just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon. Charon’s color palette is not as diverse as Pluto’s; most striking is the reddish north (top) polar region, informally named Mordor Macula. Charon is 754 miles (1,214 kilometers) across; this image resolves details as small as 1.8 miles (2.9 kilometers). Credits: NASA/JHUAPL/SwRI

 

Making batteries with portabella mushrooms

Diagram showing how mushrooms are turned into a material for battery anodes. Credit: Image courtesy of University of California - Riverside
Diagram showing how mushrooms are turned into a material for battery anodes.
Credit: Image courtesy of University of California – Riverside

Can portabella stop cell phone batteries from degrading over time?

Researchers at the University of California, Riverside Bourns College of Engineering think so.

They have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce. The current industry standard for rechargeable lithium-ion battery anodes is synthetic graphite, which comes with a high cost of manufacturing because it requires tedious purification and preparation processes that are also harmful to the environment.

With the anticipated increase in batteries needed for electric vehicles and electronics, a cheaper and sustainable source to replace graphite is needed. Using biomass, a biological material from living or recently living organisms, as a replacement for graphite, has drawn recent attention because of its high carbon content, low cost and environmental friendliness.

UC Riverside engineers were drawn to using mushrooms as a form of biomass because past research has established they are highly porous, meaning they have a lot of small spaces for liquid or air to pass through. That porosity is important for batteries because it creates more space for the storage and transfer of energy, a critical component to improving battery performance.

In addition, the high potassium salt concentration in mushrooms allows for increased electrolyte-active material over time by activating more pores, gradually increasing its capacity.

A conventional anode allows lithium to fully access most of the material during the first few cycles and capacity fades from electrode damage occurs from that point on. The mushroom carbon anode technology could, with optimization, replace graphite anodes. It also provides a binderless and current-collector free approach to anode fabrication.

“With battery materials like this, future cell phones may see an increase in run time after many uses, rather than a decrease, due to apparent activation of blind pores within the carbon architectures as the cell charges and discharges over time,” said Brennan Campbell, a graduate student in the Materials Science and Engineering program at UC Riverside.

The research findings were outlined in a paper, “Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries,” published in the journal Scientific Reports. It was authored by Cengiz Ozkan and Mihri Ozkan, both professors in the Bourns College of Engineering, and three of their current or former graduate students: Campbell, Robert Ionescu and Zachary Favors.

Nanocarbon architectures derived from biological materials such as mushrooms can be considered a green and sustainable alternative to graphite-based anodes, said Cengiz Ozkan, a professor of mechanical engineering and materials science and engineering.

The nano-ribbon-like architectures transform upon heat treatment into an interconnected porous network architecture which is important for battery electrodes because such architectures possess a very large surface area for the storage of energy, a critical component to improving battery performance.

One of the problems with conventional carbons, such as graphite, is that they are typically prepared with chemicals such as acids and activated by bases that are not environmentally friendly, said Mihri Ozkan, a professor of electrical and computer engineering. Therefore, the UC Riverside team is focused on naturally-derived carbons, such as the skin of the caps of portabella mushrooms, for making batteries.

It is expected that nearly 900,000 tons of natural raw graphite would be needed for anode fabrication for nearly six million electric vehicle forecast to be built by 2020. This requires that the graphite be treated with harsh chemicals, including hydrofluoric and sulfuric acids, a process that creates large quantities of hazardous waste. The European Union projects this process will be unsustainable in the future.

The Ozkan’s research is supported by the University of California, Riverside.

This paper involving mushrooms is published just over a year after the Ozkan’s labs developed a lithium-ion battery anode based on nanosilicon via beach sand as the natural raw material. Ozkan’s team is currently working on the development of pouch prototype batteries based on nanosilicon anodes.

The UCR Office of Technology Commercialization has filed patents for the inventions above.


Story Source:

The above post is reprinted from materials provided by University of California – Riverside. The original item was written by Sean Nealon. Note: Materials may be edited for content and length.


Journal Reference:

  1. Brennan Campbell, Robert Ionescu, Zachary Favors, Cengiz S. Ozkan, Mihrimah Ozkan. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries. Scientific Reports, 2015; 5: 14575 DOI: 10.1038/srep14575

Sleep may strengthen long-term memories in the immune system

The immune system "remembers" an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. Credit: © Sabphoto / Fotolia
The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond.
Credit: © Sabphoto / Fotolia

More than a century ago, scientists demonstrated that sleep supports the retention of memories of facts and events. Later studies have shown that slow-wave sleep, often referred to as deep sleep, is important for transforming fragile, recently formed memories into stable, long-term memories. Now, in an Opinion article published September 29 inTrends in Neurosciences, part of a special issue on Neuroimmunology, researchers propose that deep sleep may also strengthen immunological memories of previously encountered pathogens.

“While it has been known for a long time that sleep supports long-term memory formation in the psychological domain, the idea that long-term memory formation is a function of sleep effective in all organismic systems is in our view entirely new,” says senior author Jan Born of the University of Tuebingen. “We consider our approach toward a unifying concept of biological long-term memory formation, in which sleep plays a critical role, a new development in sleep research and memory research.”

The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. These memory T cells appear to abstract “gist information” about the pathogens, as only T cells that store information about the tiniest fragments ever elicit a response. The selection of gist information allows memory T cells to detect new pathogens that are similar, but not identical, to previously encountered bacteria or viruses.

Studies in humans have shown that long-term increases in memory T cells are associated with deep slow-wave sleep on the nights after vaccination. Taken together, the findings support the view that slow-wave sleep contributes to the formation of long-term memories of abstract, generalized information, which leads to adaptive behavioral and immunological responses. The obvious implication is that sleep deprivation could put your body at risk.

“If we didn’t sleep, then the immune system might focus on the wrong parts of the pathogen,” Born says. “For example, many viruses can easily mutate some parts of their proteins to escape from immune responses. If too few antigen-recognizing cells [the cells that present the fragments to T cells] are available, then they might all be needed to fight off the pathogen. In addition to this, there is evidence that the hormones released during sleep benefit the crosstalk between antigen-presenting and antigen-recognizing cells, and some of these important hormones could be lacking without sleep.”

Born says that future research should examine what information is selected during sleep for storage in long-term memory, and how this selection is achieved. In the end, this research could have important clinical implications.

“In order to design effective vaccines against HIV, malaria, and tuberculosis, which are based on immunological memory, the correct memory model must be available,” Born says. “It is our hope that by comparing the concepts of neuronal and immunological memory, a model of immunological memory can be developed which integrates the available experimental data and serves as a helpful basis for vaccine development.”


Story Source:

The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Westermann et al. System Consolidation during Sleep–A Common Principle Underlying Psychological and Immunological Memory Formation. Trends in Neurosciences, September 2015 DOI:10.1016/j.tins.2015.07.007

Liquid water flows on today’s Mars: NASA confirms evidence

Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. Credit: NASA/JPL-Caltech/Univ. of Arizona
Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field.
Credit: NASA/JPL-Caltech/Univ. of Arizona

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

“We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,” said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO’s High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

The spectrometer observations show signatures of hydrated salts at multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren’t as extensive, they detected no hydrated salt.

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

Perchlorates have previously been seen on Mars. NASA’s Phoenix lander and Curiosity rover both found them in the planet’s soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit.

MRO has been examining Mars since 2006 with its six science instruments.

“The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are,” said Rich Zurek, MRO project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL.”

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”


Story Source:

The above post is reprinted from materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lujendra Ojha, Mary Beth Wilhelm, Scott L. Murchie, Alfred S. McEwen, James J. Wray, Jennifer Hanley, Marion Massé & Matt Chojnacki. Spectral evidence for hydrated salts in recurring slope lineae on Mars AOP. Nature Geoscience, 2015; DOI: 10.1038/ngeo2546

Small-scale nuclear fusion may be a new energy source

[dropcap]Fusion energy [/dropcap]may soon be used in small-scale power stations. This means producing environmentally friendly heating and electricity at a low cost from fuel found in water. Both heating generators and generators for electricity could be developed within a few years, according to research that has primarily been conducted at the University of Gothenburg.

Nuclear fusion is a process whereby atomic nuclei melt together and release energy. Because of the low binding energy of the tiny atomic nuclei, energy can be released by combining two small nuclei with a heavier one. A collaboration between researchers at the University of Gothenburg and the University of Iceland has been to study a new type of nuclear fusion process. This produces almost no neutrons but instead fast, heavy electrons (muons), since it is based on nuclear reactions in ultra-dense heavy hydrogen (deuterium).

“This is a considerable advantage compared to other nuclear fusion processes which are under development at other research facilities, since the neutrons produced by such processes can cause dangerous flash burns,” says Leif Holmlid, Professor Emeritus at the University of Gothenburg.

No radiation The new fusion process can take place in relatively small laser-fired fusion reactors fueled by heavy hydrogen (deuterium). It has already been shown to produce more energy than that needed to start it. Heavy hydrogen is found in large quantities in ordinary water and is easy to extract. The dangerous handling of radioactive heavy hydrogen (tritium) which would most likely be needed for operating large-scale fusion reactors with a magnetic enclosure in the future is therefore unnecessary.

Rendering of an atom. Nuclear fusion is a process whereby atomic nuclei melt together and release energy. Credit: © Sergey Nivens / Fotolia
Rendering of an atom. Nuclear fusion is a process whereby atomic nuclei melt together and release energy.
Credit: © Sergey Nivens / Fotolia

 

” A considerable advantage of the fast heavy electrons produced by the new process is that these are charged and can therefore produce electrical energy instantly. The energy in the neutrons which accumulate in large quantities in other types of nuclear fusion is difficult to handle because the neutrons are not charged. These neutrons are high-energy and very damaging to living organisms, whereas the fast, heavy electrons are considerably less dangerous.”

Neutrons are difficult to slow down or stop and require reactor enclosures that are several meters thick. Muons — fast, heavy electrons — decay very quickly into ordinary electrons and similar particles.

Research shows that far smaller and simpler fusion reactors can be built. The next step is to create a generator that produces instant electrical energy.

The research done in this area has been supported by GU Ventures AB, the holding company linked to the University of Gothenburg. The results have recently been published in three international scientific journals.


Story Source:

The above post is reprinted from materials provided by University of Gothenburg. The original item was written by Carina Eliasson. Note: Materials may be edited for content and length.


Journal References:

  1. Leif Holmlid, Sveinn Olafsson. Spontaneous ejection of high-energy particles from ultra-dense deuterium D(0). International Journal of Hydrogen Energy, 2015; 40 (33): 10559 DOI: 10.1016/j.ijhydene.2015.06.116
  2. Leif Holmlid, Sveinn Olafsson. Muon detection studied by pulse-height energy analysis: Novel converter arrangements. Review of Scientific Instruments, 2015; 86 (8): 083306 DOI: 10.1063/1.4928109
  3. Leif Holmlid. Heat generation above break-even from laser-induced fusion in ultra-dense deuterium. AIP Advances, 2015; 5 (8): 087129 DOI: 10.1063/1.4928572