#da monitoring

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On August 23, 2018 the identification and distribution of aerosols in the Earth’s atmosphere is shown in this dramatic, planet-wide visualization. Produced in real time, the Goddard Earth Observing System Forward Processing (GEOS FP) model relies on a combination of Earth-observing satellite and ground-based data to calculate the presence of types of aerosols, tiny solid particles and liquid droplets, as they circulate above the entire planet.

This August 23rd model shows black carbon particles  Remote Diagnostics  in red from combustion processes, like smoke from the fi m2m connectivity  res in the United States and Canada, spreading across large stretches of North America and Africa. Sea salt aerosols are in blue, swirling above threatening typhoons near  industrial IoT Gateway  South Korea and Japan, and the hurricane looming near Hawaii. Dust shown in purple hues is blowing over African and Asian deserts. The location of cities and towns can be found from the concentrations of lights based on satellite image data of the Earth at night.

Credit: NASA Earth Observatory, GEOS FP, Joshua Stevens

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This 7-ion system applied for encoding one logical quantum bit can be used as a building block for much larger quantum systems. The bigger the lattice, the more robust it becomes. (Illustration: IQOQI/Harald Ritsch)

Physicists have experimentally encoded one qubit in entangled states distributed over 7 trapped-ion qubits and demonstrate the capability of the code to detect one bit flip, phase flip or a combined error of both, regardless on which of the qubits they occur.

In a close collaborative effort, Spanish and Austrian physicists have experimentally encoded one quantum bit (qubit) in entangled states distributed over several particles and for the first time carried out simple computations on it. The 7-qubit quantum register could be used as the main building block for a quantum computer that corrects any type of error. The researchers’ results have now been published in Science.

Even computers are error-prone. The slightest disturbances may alter saved information and falsify the results of calculations. To overcome these problems, computers use specific routines to continuously detect and correct errors. This also holds true for a future quantum computer, which will require procedures for error correction as well: “Quantum phenomena are extremely fragile and error-prone. Errors can spread rapidly and severely disturb the computer,” says Thomas Monz, member of Rainer Blatt’s research group at the Institute for Experimental Physics at the University of Innsbruck. Together with Markus Müller and Miguel Angel Martin-Delgado from the Department for Theoretical Physics at the Complutense University in Madrid, the physicists in Innsbruck developed a new quantum error-correcting method and tested it experimentally. “A quantum bit is extremely complex and cannot be simply copied. Mo m2m connectivity  reover, errors in the microscopic quantum world are more manifold and harder to correct than in conventional computers,” underlines Monz. “To detect and correct general errors in a quantum computer, we need highly sophisticated so-called quantum error-correcting codes.” The topological code used for this current experiment was proposed by Martin-Delgado’s research group in Madrid. It arranges the qubits on a two-dimensional lattice, where they can interact with the neighboring particles.

A quantum bit encoded in seven ions

For th Android Industrial Computer  e experiment at the University of Innsbruck the physicists confined seven calcium atoms in an ion trap, which allows them to cool these atoms to almost absolute zero temperature and precisely control them by laser beams. The researchers encoded the fragile quantum states of one logical qubit in entangled states of these particles. The quantum error-correcting code provided the program for this process. “Encoding the logical qubit in the seven physical qubits was a real experimental challenge,” relates Daniel Nigg, a member of Rainer Blatt’s research group. The physicists achieved this in three steps, where in each step complex sequences of laser pulses were used to create entanglement between four neighboring qubits. “For the first time we have been able to encode a single quantum bit by distributing its information over seven atoms in a controlled way,” says an excited Markus Müller, who in 2011 moved from Innsbruck to the Complutense University in Madrid. “When we entangle atoms in this specific way, they provide enough information for subsequent error correction and possible computations.”

Error-free operations

In another step the physicists tested the code’s capability to detect and correct different types of errors. “We have demonstrated that in this type of quantum system we are able to independently detect and correct every possible error for each particle,” says Daniel Nigg. “To do this we only need information about the correlations between the particles and don’t have to perform measurements of the single particles,” explains Daniel Nigg’s colleague Esteban Martinez. In addition to reliably detecting single errors, the physicists were for the first time able to apply single or even repetitive operations on a logical encoded qubit. Once the obstacle of the complex encoding process is overcome, only simple single-qubit gate operations are necessary for each gate operation. “With this quantum code we can implement basic quantum operations and simultaneously correct all possible errors,” explains Thomas Monz this crucial milestone on the route towards a reliable and fault tolerant quantum computer.

Basis for future innovations

This new approach developed by the Spanish and Austrian physicists constitutes a promising basis for future innovations. “This 7-ion system applied for encoding one lo 3g modem  gical quantum bit can be used as a building block for much larger quantum systems,” says theoretical physicist Müller. “The bigger the lattice, the more robust it becomes. The result might be a quantum computer that could perform any number of operations without being impeded by errors.” The current experiment not only opens new routes for technological innovations: “Here, completely new questions come up, for example which methods can be used in the first place to characterize such large logical quantum bits,” says Rainer Blatt with a view into the future. “Moreover, we would also like to collaboratively develop the used quantum codes further to optimize them for even more extensive operations,” adds Martin-Delgado.

The researchers are financially supported by the Spanish Ministry of Science, the Austrian Science Fund, the U.S. Government, the European Commission and the Federation of Austrian Industries Tyrol.

Publication: Daniel Nigg, et al., “Quantum Computations on a Topologically Encoded Qubit,” Science Express, 2014; DOI:10.1126/science.1253742

PDF Copy of the Study: Experimental Quantum Computations on a Topologically Encoded Qubit

Image: IQOQI/Harald Ritsch

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Graphene remains the strongest material ever measured and, as Professor Hone once put it, so strong that “it would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.” Illustration by Andrew Shea for Columbia Engineering

A new study from Columbia Engineering researchers reports on the strength of large-area graphene films grown using chemical vapor deposition (CVD), correcting the mistaken consensus that grain boundaries of graphene are weak.

In a new study, published in Science May 31, 2013, Columbia Engineering researchers demonstrate that graphene, even if stitched together from many small crystalline grains, is almost as strong as graphene in its perfect crystalline form. This work resolves a contradiction between theoretical simulations, which predicted that grain boundaries can be strong, and earlier experiments, which indicated that they were much weaker than the perfect lattice.

Graphene consists of a single atomic layer of carbon, arranged in a honeycomb lattice. “Our first Science paper, in 2008, studied the strength graphene can achieve if it has no defects—its intrinsic strength,” says James Hone, professor of mechanical engineering, who led the study with Jeffrey Kysar, professor of mechanical engineering. “But defect-free, pristine graphene exists only in very small areas. Large-area sheets required for applications must contain many small grains connected at grain boundaries, and it was unclear how strong those gra m2m connectivity  in boundaries were. This, our second Science paper, reports on the strength of large-area graphene films grown using chemical vapor deposition (CVD), and we’re excited to say that graphene is back and stronger than ever.”

The study verifies that commonly used methods for post-processing CVD-grown graphene weaken grain boundaries, resulting in the extremely low strength seen in previous studies. The Columbia Engineering team developed a new process that prevents any damage of graphene during transfer. “We substituted a different etchant and were able to create test samples without harming the graphene,” notes the paper’s lead author, Gwan-Hyoung Lee, a postdoctoral fellow in the Hone lab. “Our findings clearly correct the mistaken consensus that grain boundaries of graphene are weak. This is great news because graphene offers such a plethora of opportunities both for fundamental scientific research and industrial applications.”

In its perfect crystalline form, graphene (a one-atom-thick carbon layer) is the strongest material ever measured, as the Columbia Engineering team reported in Science in 2008—so strong that, as Hone observed, “it would take an elephant, balanced on a pencil, to break through a sheet of graphene the thickness of Saran Wrap.” For the first study, the team obtained small, structurally perfect flakes of graphene by mechanical exfoliation, or mechanical peeling, from a crystal of graphite. But exfoliation is a time-consuming process that will never be practical for any of the many potential applications of graphene that require industrial mass production.

Currently, scientists can grow sheets of graphene as large as a television s cloud vms  creen by using chemical vapor deposition (CVD), in which single layers of graphene are grown on copper substrates in a high-temperature furnace. One of the first applications of graphene may be as a conducting layer in flexible displays.

“But CVD graphene is ‘stitched’ together from many small crystalline grains—like a quilt—at grain boundaries that contain defects in the atomic structure,” Kysar explains. “These grain boundaries can severely limit the strength of large-area graphene if they break much more easily than the perfect crystal lattice, and so there has been intense interest in understanding how strong they can be.”

The Columbia Engineering team wanted to discover what was making CVD graphene so weak. In studying the processing techniques used to create their samples for testing, they found that the chemical most commonly used to remove the copper substrate also causes damage to the graphene, severely degrading its strength.

Their experiments demonstrated that CVD graphene with large grains remote secure networking   is exactly as strong as exfoliated graphene, showing that its crystal lattice is just as perfect. And, more surprisingly, their experiments also showed that CVD graphene with small grains, even when tested right at a grain boundary, is about 90% as strong as the ideal crystal.

“This is an exciting result for the future of graphene, because it provides experimental evidence that the exceptional strength it possesses at the atomic scale can persist all the way up to samples inches or more in size,” says Hone. “This strength will be invaluable as scientists continue to develop new flexible electronics and ultrastrong composite materials.”

Strong, large-area graphene can be used for a wide variety of applications such as flexible electronics and strengthening components—potentially, a television screen that rolls up like a poster or ultrastrong composites that could replace carbon fiber. Or, the researchers speculate, a science fiction idea of a space elevator that could connect an orbiting satellite to Earth by a long cord that might consist of sheets of CVD graphene, since graphene (and its cousin material, carbon nanotubes) is the only material with the high strength-to-weight ratio required for this kind of hypothetical application.

The team is also excited about studying 2D materials like graphene. “Very little is known about the effects of grain boundaries in 2D materials,” Kysar adds. “Our work shows that grain boundaries in 2D materials can be much more sensitive to processing than in 3D materials. This is due to all the atoms in graphene being surface atoms, so surface damage that would normally not degrade the strength of 3D materials can completely destroy the strength of 2D materials. However with appropriate processing that avoids surface damage, grain boundaries in 2D materials, especially graphene, can be nearly as strong as the perfect, defect-free structure.”

The study was supported by grants from the Air Force Office of Scientific Research and the National Science Foundation.

Publication: Gwan-Hyoung Lee, et al., “High-Strength Chemical-Vapor–Deposited Graphene and Grain Boundaries,” Science 31 May 2013: Vol. 340 no. 6136 pp. 1073-1076; DOI: 10.1126/science.1235126

Image: Illustration by Andrew Shea for Columbia Engineering

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Composite aerial photograph of Area A, showing Building 101. (Photographs by Sky-View and Griffin Aerial Imaging; dividing lines not marked.)

Over the last 25 years many scholars have questioned the existence of the kingdom of David and Solomon, which was supposed to have existed in the 10th century BCE. This was based to a large extent on the lack of evidence of royal construction at the heart of the region in which the kingdom supposedly existed. As a result, it was assumed that the rulers at the time were just local chiefs who ruled only over Jerusalem and its immediate surroundings.

Now researchers from Bar-Ilan University in Israel have uncovered new evidence that supports the existence of Israel’s united monarchy and indicate that the Kingdom extended beyond Jerusalem’s vicinity. The findings were recently published by Pr Vending Telemetry  of. Avraham Faust and Dr. Yair Sapir in the journal Radiocarbon.

Over the past decade Prof. Avi Faust, of the Martin (Szusz) Department of Land of Israel Studies and Archaeology at Bar-Ilan University, excavated a large residence of the type, known as a “four-room house,” which was destroyed in massive conflagration in the 8th century BCE, during one of the Assyrian campaigns. The residence is located at Tel ‘Eton in the Shephelah (20 km. southeast of the city of Qiryat Gat). This large building had at least two stories and its ground floor extended over some 225 sq. m. Large, high quality ashlar stones were placed in the building’s corners and entrances. The structure was built on the highest part of the mound, on top of deep foundations, using high quality building materials and according to a meticulous plan. Hundreds of vessels and additional finds were discovered within the conflagration. “Surprisingly, radiocarbon dates from within the floor make-up and from within a foundation deposit that was placed MV smart grid sensorbelow the floor indicate that the building had already been erected in the 10th century BCE, between the late 11th century and the third quarter of the 10th century BCE. This date is in line with other finds related to the construction, like the foundation deposit itself,” says Prof. Faust. Faust and Sapir say that construction of such a large residence on the top of the mound, visible from a great distance, along with the significant growth of the size of the city at the same time, was an important event in the history of Tel ‘Eton.

But who initiated the change? The researchers say that the evidence hints at the identity of the builders. The mere fact that the residence was built as a classical four-room house, a style that was very dominant in Israelite sites and missing or rare at Canaanite and Philistine sites, seems to send a clear message regarding the identity of the builders – the emerging Israelite polity in the highlands.

Interestingly, however, the site was not destroyed during the changes, and new construction and development were apparently not a result of a conquest and the arrival of new population. Thus, while the transformations were inspired by the highland kingdom, the development was done in cooperation with the local population. This is also indicated by the combination of the highland, Israelite-inspired architectural style, along with the use of the Canaanite tradition of placing foundation deposits below the floors.

The finds are indicative of impressive public construction underway already in the 10th century BCE, and even on the use of ashlar stones in the region of Judah at this early stage. When the finds from Tel ‘Eton are combined with those at other sites in the region, the process in which the highland polity took over the Shephelah, and gradually colonized it, can be reconstructed.

Faust and Sapir stress that “the association with David is not based on direct archaeological evidence, but solely on circumstantial grounds”. The source of the changes at Tel ‘Eton (i. Vending PC  e,. the erection of the four-room residency and the growth in size of the site) appears to be in the highlands, and since these changes took place at the time when David was supposed to have existed in the highland, the link is plausible.” They add that “if someone thinks that there was no king by the name of David, we should find another name to call the highland king in whose time the region was incorporated into the highland kingdom.”

Beyond the identification of social complexity in Judah already in the 10th century BCE, the study has broader implications for archaeology. “The finds from Tel ‘Eton indicate that structures can exist for centuries, but the finds reflect their last period of usage. From their long lives – sometimes centuries – very little will be found, and even less will be reported,” says Faust. One of the negative implications of this, he says, is that a series of destructive events following a long period of peace will lead to extensive information on the time of the destruction, but very little on the era that preceded it. “Archaeologists should therefore be careful when they conclude that the rarity of finds from these eras indicates that society was poor, and lacked social complexity.”

Publication: Avraham Faust and Yair Sapir, “The “Governor’s Residency” at Tel ‘Eton, The United Monarchy, and the Impact of the Old-House Effect on Large-Scale Archaeological Reconstructions,” Radiocarbon, 2018; doi:10.1017/RDC.2018.10

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Image: Lynn Betts/USDA NRSC

Hog farms might be nauseating, but a new study indicates that a hog farm emissions, which include dust, irritants, allergens, hydrogen sulfides, ammonia, and other volatile compounds, could have an impact on the health of the people living nearby. Neighbors of such farms experience a rise in blood pressure when the odor of the farm is strong.

The scientists published their findings in the journal Environmental Health Perspectives. Concentrated animal feeding operations (CAFOs) have a number of measurable impacts on the environment, mostly from the massive quantities of manure that they produce. That waste contains microbes that can make humans sick, and it’s usually collected in open pits or sprayed on fields as fertilizer, risking the contamination of air, water and soil.

The smell is the also problematic, as the staggering stench has shown negative effects on stress and moods. Steve Wing, epidemiologist at the University of North Carolina, Chapel Hill, sought to figure out if there was a link between the odors from CAFOs and some of these symptoms.

Using mobile monitoring equipment, the researchers measured the air quality of neighborhoods adjacent to hog CAFOs in North Carolina. Participating residents sat outside their houses for two 10-minute periods each day, reporting on the strength of the swine odor on a graded scale. Their blood pressure was also taken with an automated device.

Stronger odors and higher measured hydrogen sulfide concentrations correlate Global Leader in Industrial IoTd to higher blood pressure in residents. The most dramatic effects were nearly a 2 mmHg rise in diastolic blood pressure when the odor was rated 8/8 compared to cloud VMS   no odor. This also gave a 3mmHg rise in systolic blood pressure when hydrogen sulfide concentrations reached 10 parts per billion compared to no detectable levels.Grid Fault Detection

Wing suspects that the residents’ lack of control over the odor might account for the rise in blood pressure. There is no way of avoiding the smell wafting from a giant hog farm.

[via ScienceNOW]

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These are geothermal heat flux predictions for Greenland. Direct GHF measurements from the coastal rock cores, inferences from ice cores, and additional Gaussian-fit GHF data around ice core sites are used as training samples. Predictions are shown for three different values. The white dashed region roughly shows the extent of elevated heat flux and a possible trajectory of Greenland’s movement over the Icelandic plume. KU News Service

A paper appearing in Geophysical Research Letters uses machine learning to craft an improved model for understanding geothermal heat flux — heat emanating from the Earth’s interior — below the Greenland Ice Sheet. It’s a research approachmedium voltage smart grid sensor new to glaciology that could lead to more accurate predictions for ice-mass loss and global sea-level rise.

Among the key findings:

Greenland has an anomalously high heat flux in a relatively large northern region spreading from the interior to the east and west. Southern Greenland has relatively low geothermal heat flux, corresponding with the extent of the North Atlantic Craton, a stable portion of one of the oldest extant continental crusts on the planet. The research model predicts slightly elevated heat flux upstream of several fast-flowing glaciers in Greenland, including Jakobshavn Isbræ in the central-west, the fastest moving glacier on Earth.

“Heat that comes up from the interior of the Earth contributes to the amount of melt on the bottom of the ice sheet — so it’s extremely important to understand the pattern of that heat and how it’s distributed at the bottom of the ice sheet,” said Soroush Rezvanbehbahani,  remote maintenance  a doctoral student in geology at the University of Kansas who spearheaded the research. “When we walk on a slope that’s wet, we’re more likely to slip. It’s the same idea with ice — when it isn’t frozen, it’s more likely to slide into the ocean. But we don’t have an easy way to measure geothermal heat flux except for extremely expensive field campaigns that drill through the ice sheet. Instead of expensive field surveys, we try to do this through statistical methods.”

Rezvanbehbahani and his colleagues have adopted machine learning — a type of artificial intelligence using statistical techniques and computer algorithms — to predict heat flux values that would be daunting to obtain in the same detail via conventional ice cores.

Using all available geologic, tectonic and geothermal heat flux data for Greenland — along with geothermal heat flux data from around the globe — the team deployed a machine learning approach that predicts geothermal heat flux values under the ice sheet throughout Greenland based on 22 geologic variables such as bedrock topography, crustal thickness, magnetic anomalies, rock types and proximity to features like trenches, ridges, young rifts, volcanoes and hot spots.

“We have a lot of data points from around the Earth — we know in certain parts of the world the crust is a certain thickness, composed of a specific kind of rock and located a known distance from a volcano — and we take those relationships and apply them to what we know about Greenland,” said co-author Leigh Stearns, associate professor of geology at KU.

The researchers said their new predictive model is a “definite improvement” over current models of geothermal heat flux that don’t incorporate as many variables. Indeed, many numerical ice sheet models of Greenland assume that a uniform value of geothermal heat flux exists everywhere across Greenland.

“Most other models really only honor one particular data set,” Stearns said. “They look at geothermal heat flux through seismic signals or magnetic data in Greenland, but not crustal thickness or rock type or distance from a hot spot. But we know those are related to geothermal heat flux. We try to incorporate as many geologic data sets as we can rather than assuming one is the most important.”

In addition to Rezvanbehbahani and Stearns, the research team behind the new paper includes KU’s J. Doug Walker and C.J. van der Veen, as well as Amir Kadivar of McGill University. Rezvanbehbahani and Stearns also are affiliated with the Center for the Remote Sensing of Ice Sheets, headquartered at KU.

The authors found the five most important geologic featur cellular router  es in predicting geothermal flux values are topography, distance to young rifts, distance to trench, depth of lithosphere-asthenosphere boundary (layers of the Earth’s mantle) and depth to Mohoroviči? discontinuity (the boundary between the crust and the mantle in the Earth). The researchers said their geothermal heat flux map of Greenland is expected to be within about 15 percent of true values.

“The most interesting finding is the sharp contrast between the south and the north of Greenland,” said Rezvanbehbahani. “We had little information in the south, but we had three or four more cores in the northern part of the ice sheet. Based on the southern core we thought this was a localized low heat-flux region — but our model shows that a much larger part of the southern ice sheet has low heat flux. By contrast, in the northern regions, we found large areas with high geothermal heat flux. This isn’t as surprising because we have one ice core with a very high reading. But the spatial pattern and how the heat flux is distributed, that a was a new finding. That’s not just one northern location with high heat flux, but a wide region.”

The investigators said their model would be made even more accurate as more information on Greenland is compiled in the research community.

“We give the slight disclaimer that this is just another model — it’s our best statistical model — but we have not reproduced reality,” said Stearns. “In Earth science and glaciology, we’re seeing an explosion of publicly available data. Machine learning technology that synthesizes this data and helps us learn from the whole range of data sensors is becoming increasingly important. It’s exciting to be at the forefront.”

Publication: Soroush Rezvanbehbahani, et al., “Predicting the Geothermal Heat Flux in Greenland: A Machine Learning Approach,” Geophysical Research Letters, 2017; DOI: 10.1002/2017GL075661

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Silicon chip with porous surface next to the special furnace where it was coated with graphene to create a supercapacitor electrode. Credit: Joe Howell / Vanderbilt

Using porous silicon coated with graphene, material scientists at Vanderbilt University have developed the first supercapacitor that is made out of silicon.

Solar cells that produce electricity 24/7, not just when the sun is shining. Mobile phones with built-in power cells that recharge in seconds and work for weeks between charges.

These are just two of the possibilities raised by a novel supercapacitor design invented by material scientists at Vanderbilt University that is described in a paper published in the October 22 issue of the journal Scientific Reports.

It is the first supercapacitor that is made out of silicon so it can be built into a silicon chip along with the microelectronic circuitry that it powers. In fact, it should be possible to construct these power cells out of the excess silicon that exists in the current generation of solar cells, sensors, mobile phones and a variety of other electromechanical devices, providing a considerable cost savings.

“If you ask experts about making a supercapacitor out of silicon, they will tell you it is a crazy idea,” said Cary Pint, the assistant professor of mechanical engineering who headed the development. “But we’ve found an easy way to do it.”

Instead of storing energy in chemical reactions the way batteries do, “supercaps” store electricity by assembling ions on the surface of a porous material. As a result, they tend to charge and discharge in minutes, instead of hours, and operate for a few million cycles, instead of a few thousand cycles like batteries.

These properties have alloweindustrial cellular vpn routerd commercial supercapacitors, which are made out of activated carbon, to capture a few niche markets, such as storing energy captured by regenerative braking systems on buses and electric vehicles and to provide the bursts of power required to adjust of the blades of giant wind turbines to changing wind conditions. Supercapacitors still lag behind the electrical energy storage capability of lithium-ion batteries, so they are too bulky to power most consumer devices. However, they have been catching up rapidly.

Graph displays the power density (watts per kilogram) and energy density (watt-hours per kilogram) of capacitors made from porous silicon (P-Si), graphene-coated porous silicon and carbon-based commercial capacitors. (Cary Pint / Vanderbilt)

Research to improve the energy density of supercapacitors has focused on carbon-based nanomaterials like graphene and nanotubes. Because these devices store electrical charge on the surface of their electrodes, the way to increase their energy density is to increase the electrodes’ surface area, which means making surfaces filled with nanoscale ridges and pores.

“The big challenge for this approach is assembling the materials,” said Pint. “Constructing high-performance, functional devices out of nanoscale building blocks with any level of control has proven to be quite challenging, and when it is achieved it is difficult to repeat.”

So Pint and his research team – graduate students Landon Oakes, Andrew Westover and post-doctoral fellow Shahana Chatterjee – decided to take a radically different approach: using porous silicon, a material with a controllable and well-defined nanostructure made by electrochemically etching the surface of a silicon wafer.

This allowed them to create surfaces with optimal nanostructures for supercapacitor electrodes, but it left them with a major problem. Silicon is generally considered unsuitable for use in supercapacitors because it reacts readily with some of chemicals in the electrolytes that pr remote connectivity  ovide the ions that store the electrical charge.

With experience in growing carbon nanostructures, Pint’s group decided to try to coat the porous silicon surface with carbon. “We had no idea what would happen,” said Pint. “Typically, researchers grow graphene from silicon-carbide materials at temperatures in excess of 1400 degrees Celsius. But at lower temperatures – 600 to 700 degrees Celsius – we certainly didn’t expect graphene-like material growth.”

When the researchers pulled the porous silicon out of the furnace, they found that it had turned from orange to purple or black. When they inspected it under a powerful scanning electron microscope they found that it looked nearly identical to the original material but it was coated by a layer of graphene a few nanometers thick.

When the researchers tested the coated material they found that it had chemically stabilized the silicon surface. When they used it to make supercapacitors, they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors.

The graphene layer acts as an atomically thin protective coating. Pint and his group argue that this approach isn’t limited to graphene. “The ability to engineer surfaces with atomically thin layers of materials combined with the control achieved in designing porous materials opens opportunities for a number of different applications beyond energy storage,” he said.

“Despite the excellent device performance we achieved, our goal wasn’t to create devices with record performance,” said Pint. “It was to develop a road map for integrated energy storage. Silicon is an ideal material to focus on beca cellular router  use it is the basis of so much of our modern technology and applications. In addition, most of the silicon in existing devices remains unused since it is very expensive and wasteful to produce thin silicon wafers.”

Pint’s group is currently using this approach to develop energy storage that can be formed in the excess materials or on the unused back sides of solar cells and sensors. The supercapacitors would store excess the electricity that the cells generate at midday and release it when the demand peaks in the afternoon.

“All the things that define us in a modern environment require electricity,” said Pint. “The more that we can integrate power storage into existing materials and devices, the more compact and efficient they will become.”

Research associate Jeremy Mares, graduate student William Erwin, Assistant Professor of Chemical and Biomolecular Engineering Rizia Bardhan and Associate Professor of Electrical Engineering and Computer Science Sharon Weiss also contributed to the research, which was funded by National Science Foundation grants CMMI 1334269 and EPS 1004083 and Army Research Office grant W911BF-09-1-0101.

Publication: Landon Oakes, et al., “Surface engineered porous silicon for stable, high performance electrochemical supercapacitors,” Scientific Reports 3, Article number: 3020; doi:10.1038/srep03020

Image: Joe Howell / Vanderbilt; Cary Pint / Vanderbilt

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The primitive ancestors of modern day fleas were built to drain the blood of dinosaurs, more than 150 million years ago, during the Jurassic period. This potential host-parasite relationship was recently uncovered thanks to a set of preserved fossils found in China.

Fleas, insects from theSiphonaptera order, infest all types of mammals and birds, but little is known about their origins. The fossil record consists mostly of modern-looking fleas from the past 65 million years, and possible fleas from the Cretaceous period, though this has been debated by experts. Michael Engel, a paleoentomologist, from the University of Kansas in Lawrence, and his colleagues have extended the history of these parasites by at least 60 million years. Their findings smart grid  were published last week in the journal Nature secure web based scada  .

Engel et al. studied nine flea specimens from two sites. One of them is the 165-million-year-old Jurassic site in Daohugou and the other is the 125-million year old Cretaceous strata at Huangbanjigou in China. These prehistoric flea species were between 8 and 21 mm in length, while todays fleas range between 1 and 10 mm.

The Jurassic and Cretaceous fleas lacked the spring-legged, jumping specializations of their more modern cousins, but their mouthparts were armored, studded with saw like protuberances, unlike the smooth jaws of modern fleas.

These traits may indicate that prehistoric fleas wercellular modem ethernete ambush specialists, catching meals by hiding in the periphery and scrambling onto their hosts for a quick meal, before bolting off again. The mouthparts were specialized for working into heavy hides, such as the ones found on dinosaurs.

The only way to confirm this is to find fossilized fleas caught in the act of feeding on dinosaurs.

[via Nature]