Dive deeper into Sizing gems

Notwithstanding a large number of semiconductors for executing calculations, the scientists’ new chip incorporates every one of the parts fundamental for optical correspondence: modulators; waveguides, which steer light across the chip; resonators, what separate out various frequencies of light, every one of which can convey various information; and photodetectors, which decipher approaching light signals once more into electrical signs.

Silicon — which is the premise of most current central processors — should be created on top of a layer of glass to yield helpful optical parts. The contrast between the refractive records of the silicon and the glass — the degrees to which the materials twist light — is the thing that limits light to the silicon optical parts. Hanya di barefootfoundation.com tempat main judi secara online 24jam, situs judi online terpercaya di jamin pasti bayar dan bisa deposit menggunakan pulsa

The previous work on incorporated photonics, which was additionally driven by Ram, Stojanovic, and Popovic, involved a cycle called wafer holding, in which a solitary, enormous gem of silicon is melded to a layer of glass saved on a different chip. The new work, in empowering the immediate testimony of silicon — with differing thickness — on top of glass, should manage with supposed polysilicon, which comprises of numerous little gems of silicon.

Single-precious stone silicon is helpful for the two optics and gadgets, however in polysilicon, there’s a tradeoff among optical and electrical effectiveness. Enormous gem polysilicon is productive at directing power, however the huge precious stones will quite often dissipate light, bringing down the optical effectiveness. Little gem polysilicon dissipates light less, however it’s not as great a conductor.

Utilizing the assembling offices at SUNY-Albany’s Colleges for Nanoscale Sciences and Engineering, the scientists evaluated a progression of plans for polysilicon statement, differing the kind of crude silicon utilized, handling temperatures and times, until they observed one to be that offered a decent tradeoff among electronic and optical properties.

“I figure we probably gone through in excess of 50 silicon wafers prior to observing a material that was perfect,” Atabaki says.

New Study Suggests Wind, Not Water, Formed Mount Sharp on Mars

A roughly 3.5-mile high Martian mound that scientists suspect preserves evidence of a massive lake might actually have formed as a result of the Red Planet’s famously dusty atmosphere, an analysis of the mound’s features suggests. If correct, the research could dilute expectations that the mound holds evidence of a large body of water, which would have important implications for understanding Mars’ past habitability.

Researchers based at Princeton University and the California Institute of Technology suggest that the mound, known as Mount Sharp, most likely emerged as strong winds carried dust and sand into the 96-mile-wide crater in which the mound sits. They report in the journal Geology that air likely rises out of the massive Gale Crater when the Martian surface warms during the day, then sweeps back down its steep walls at night. Though strong along the Gale Crater walls, these “slope winds” would have died down at the crater’s center where the fine dust in the air settled and accumulated to eventually form Mount Sharp, which is close in size to Alaska’s Mt. McKinley.

This dynamic counters the prevailing theory that Mount Sharp formed from layers of lakebed silt — and could mean that the mound contains less evidence of a past, Earth-like Martian climate than most scientists currently expect. Evidence that Gale Crater once contained a lake in part determined the landing site for the NASA Mars rover Curiosity. The rover touched down near Mount Sharp in August with the purpose of uncovering evidence of a habitable environment, and in December Curiosity found traces of clay, water molecules and organic compounds. Determining the origin of these elements and how they relate to Mount Sharp will be a focus for Curiosity in the coming months.

But the mound itself was likely never under water, though a body of water could have existed in the moat around the base of Mount Sharp, said study co-author Kevin Lewis, a Princeton associate research scholar in geosciences and a participating scientist on the Curiosity rover mission, Mars Science Laboratory. The quest to determine whether Mars could have at one time supported life might be better directed elsewhere, he said.

“Our work doesn’t preclude the existence of lakes in Gale Crater, but suggests that the bulk of the material in Mount Sharp was deposited largely by the wind,” said Lewis, who worked with first author Edwin Kite, a planetary science postdoctoral scholar at Caltech; Michael Lamb, an assistant professor of geology at Caltech; and Claire Newman and Mark Richardson of California-based research company Ashima Research.

“Every day and night you have these strong winds that flow up and down the steep topographic slopes. It turns out that a mound like this would be a natural thing to form in a crater like Gale,” Lewis said. “Contrary to our expectations, Mount Sharp could have essentially formed as a free-standing pile of sediment that never filled the crater.”

Even if Mount Sharp were born of wind, it and similar mounds likely overflow with a valuable geological — if not biological — history of Mars that can help unravel the climate history of Mars and guide future missions, Lewis said.

“These sedimentary mounds could still record millions of years of Martian climate history,” Lewis said. “This is how we learn about Earth’s history, by finding the most complete sedimentary records we can and going through layer by layer. One way or another, we’re going to get an incredible history book of all the events going on while that sediment was being deposited. I think Mount Sharp will still provide an incredible story to read. It just might not have been a lake.”

Curiosity Rover Uses Autonomous Navigation for the First Time

This latest addition to Curiosity’s array of capabilities will help the rover cover the remaining ground en route to Mount Sharp, where geological layers hold information about environmental changes on ancient Mars. The capability uses software that engineers adapted to this larger and more complex vehicle from a similar capability used by NASA’s Mars Exploration Rover Opportunity, which is also currently active on Mars.

Using autonomous navigation, or autonav, Curiosity can analyze images it takes during a drive to calculate a safe driving path. This enables it to proceed safely even beyond the area that the human rover drivers on Earth can evaluate ahead of time.

On Tuesday, Aug. 27, Curiosity successfully used autonomous navigation to drive onto ground that could not be confirmed safe before the start of the drive. This was a first for Curiosity. In a preparatory test last week, Curiosity plotted part of a drive for itself, but kept within an area that operators had identified in advance as safe.

“Curiosity takes several sets of stereo pairs of images, and the rover’s computer processes that information to map any geometric hazard or rough terrain,” said Mark Maimone, rover mobility engineer and rover driver at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “The rover considers all the paths it could take to get to the designated endpoint for the drive and chooses the best one.”

The drive on Tuesday, the mission’s 376th Martian day, or “sol,” took Curiosity across a depression where ground-surface details had not been visible from the location where the previous drive ended. The drive included about 33 feet (10 meters) of autonomous navigation across hidden ground as part of a day’s total drive of about 141 feet (43 meters).

“We could see the area before the dip, and we told the rover where to drive on that part. We could see the ground on the other side, where we designated a point for the rover to end the drive, but Curiosity figured out for herself how to drive the uncharted part in between,” said JPL’s John Wright, a rover driver.

Curiosity is nearly two months into a multi-month trek from the “Glenelg” area, where it worked for the first half of 2013, to an entry point for the mission’s major destination: the lower layers of a 3-mile-tall (5-kilometer-tall) mound called Mount Sharp.

The latest drive brought the distance traveled since leaving Glenelg to 0.86 mile (1.39 kilometers). The remaining distance to the Mount Sharp entry point is about 4.46 miles (7.18 kilometers) along a “rapid transit route.” That route was plotted on the basis of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. The actual driving route, which will be based on images from Curiosity’s own cameras, could be longer or shorter.

Curiosity’s science team has picked a few waypoints along the rapid transit route to Mount Sharp where driving may be suspended for a few days for science. The rover has about 0.31 mile (500 meters) left to go before reaching the first of these waypoints, which appears from orbiter images to offer exposed bedrock for inspection.

“Each waypoint represents an opportunity for Curiosity to pause during its long journey to Mount Sharp and study features of local interest,” said Curiosity Project Scientist John Grotzinger of the California Institute of Technology, Pasadena. “These features are geologically interesting, based on HiRISE images, and they lie very close to the path that provides the most expeditious route to the base of Mount Sharp. We’ll study each for several sols, perhaps selecting one for drilling if it looks sufficiently interesting.”

After landing inside Gale Crater in August 2012, Curiosity drove eastward to the Glenelg area, where it accomplished the mission’s major science objective of finding evidence for an ancient wet environment that had conditions favorable for microbial life. The rover’s route is now southwestward. At Mount Sharp, in the middle of Gale Crater, scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.