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(USC News) Diamonds are forever - or, at least, the effects of this diamond on quantum computing may be. A team that includes scientists from USC has built a quantum computer in a diamond, the first of its kind to include protection against “decoherence” - noise that prevents the computer from functioning properly. Like all diamonds, the diamond used by the researchers has impurities - things other than carbon. The more impurities in a diamond, the less attractive it is as a piece of jewelry because it makes the crystal appear cloudy. The team, however, utilized the impurities themselves. A rogue nitrogen nucleus became the first qubit. In a second flaw sat an electron, which became the second qubit. (Though put more accurately, the “spin” of each of these subatomic particles was used as the qubit.)
(Detroit News) US manufacturers are now more than 40 percent dependent on imports of many commodity and rare earth metals.For example, import reliance on gallium is at 94 percent, cobalt and titanium 81 percent, chromium 56 percent, silicon 44 percent and nickel 43 percent. These minerals are critical for defense and energy technologies and many high-tech consumer products. Consider nickel, which is needed in the manufacture of stainless steel and electricity storage batteries, among other things. Oregon has the only US mine producing nickel. Almost all of the domestic nickel comes from recycling alloys containing nickel. Now, thanks to a $100-million-plus investment by Rio Tinto, the Eagle nickel mine in Michigan’s Upper Peninsula is expected to open in 2014, producing 16,000 tons of nickel and 10,000 tons of copper.
(PNAS) Here we demonstrate a scalable method for creating extremely small structures in graphene with atomic precision. It consists of inducing defect nucleation centers with energetic ions, followed by edge-selective electron recoil sputtering. As a first application, we create graphene nanopores with radii as small as 3 Å, which corresponds to 10 atoms removed. We observe carbon atom removal from the nanopore edge in situ using an aberration-corrected electron microscope, measure the cross-section for the process, and obtain a mean edge atom displacement energy of 14.1 ± 0.1 eV. This approach does not require focused beams and allows scalable production of single nanopores and arrays of monodisperse nanopores for atomic-scale selectively permeable membranes.
(Science) Some physicists argue that phonons must still play a key indirect role in high-temperature superconductors. And experiments have shown that the phonons and electrons do interact in the compounds. Now, Claudio Giannetti of the Catholic University of the Sacred Heart in Brescia, Italy, and a dozen colleagues report data that, they say, show that electrons alone tell the whole story. They shined pulses of laser light onto a high-temperature superconductor called bismuth strontium calcium yttrium copper oxide (BSCCO) to study how the material reflects light at various wavelengths,
(PNAS) We show that in the stoichiometry CaH6 a body-centered cubic structure with hydrogen that forms unusual “sodalite” cages containing enclathrated Ca stabilizes above pressure 150 GPa. The stability of this structure is derived from the acceptance by two H2 of electrons donated by Ca forming an “H4” unit as the building block in the construction of the three-dimensional sodalite cage. This unique structure has a partial occupation of the degenerated orbitals at the zone center. The resultant dynamic Jahn-Teller effect helps to enhance electron-phonon coupling and leads to superconductivity of CaH6. A superconducting critical temperature (Tc) of 220-235 K at 150 GPa obtained from the solution of the Eliashberg equations is the highest among all hydrides studied thus far.
(MIT Technology Review) If Germany is to meet its ambitious goals of getting a third of its electricity from renewable energy by 2020 and 80 percent by 2050, it must find a way to store huge quantities of electricity in order to make up for the intermittency of renewable energy. Siemens says it has just the technology: electrolyzer plants, each the size of a large warehouse, that split water to make hydrogen gas. The hydrogen could be used when the wind isn’t blowing to generate electricity in gas-fired power plants, or it could be used to fuel cars. Unlike conventional industrial electrolyzers, which need a fairly steady supply of power to efficiently split water, Siemens’s new design is flexible enough to run on intermittent power from wind turbines.
The first full day of the Materials Challenges in Alternative and Renewable Energy was dedicated to a range of plenary talks that covered the gamut of potential sources and, of course, the materials challenges each one faced. The sessions were MC’d by conference cochairs George Wicks and Jack Simon.
Put succinctly, each technology is “materials hungry,” and whether it’s solar, hydrogen, wind, hydro or nuclear, the materials mantra is: less, lighter, stronger and more efficient. And, by the way, the materials advances also need to lead to improved processing and manufacturing.
In most cases, speakers, such as Dow Corning Solar Solution’s Eric Peeters, spoke of having clear goals and roadmaps. For solar, the target is $1 per Watt (installed) by decade’s end, which would bring it close to $0.12-0.13 per kWh (comparable to natural gas).
For some, the features of the roadmap are clearer than for others. Peeters spoke of plans to use thinner wafers and glass, plus silicone-sealed frameless panels that use conductive adhesives. DOE hydrogen guru Ned Stetson discussed the short-range challenges of storing and transporting H2 in its pure form (via materials that will permit stronger, lighter cylinders), but that chemical hydrogen storage systems—e.g., metal hydrides—can deliver higher H storage capacity (measured by weight percent) than anything involving just H2.
GM Global R&D manager Bob Powell outlined the evolutionary steps of moving from electrical assist and hybrid technologies, through the “bridge” technologies of extended range electric vehicles, to, ultimately, fuel cell transportation (and auxiliary power generation). He says some of the challenges for the bridge materials are battery performance degradation, shrinkage–expansion and ability to withstand 5000 charge-discharge cycles.
Megan McCluer and Jim Ahlgrimm of DOE’s Wind & Hydropower Technology programs spoke widely about several traditional and novel wind and hydro (including ocean-based) technologies, but they reported that much of it—especially the strong, stable and better sited offshore wind capacity—is largely untapped. The analogy they use is, “What Saudi Arabia is to oil, the US is to wind energy and power.” But, offshore wind assets bring a new set of challenges: corrosion and biofouling, plus larger-scale blades, drivetrains and generators.
McCluer and Ahlgrimm noted their DOE programs cover a huge variety of wind and hydro generation approaches, so much of their work is based on establishing hypothetical production scenarios (e.g., supplying the US with 15 percent of power from water sources and 20 percent from wind), and then working backwards to figure out what advancements would be needed from each technology stream to meet the goals. Lab-academia-industry collaborations have been set up to address the next generation of blades, bearings/gearings and generators (including, ultimately, light-weight full superconductive generators).
Bhakta Rath from the Naval Research Lab took (friendly) issue with the suggestion that Saudi Arabia is the leader in oil and hydrocarbon-based energy reserves. What makes the US the leader, he says, are the largely untapped shale oil deposits in the Green River region of Western United States, plus rich methane hydrate deposits. Rath also mentioned the progress being made in understanding the potential of power generation based on exploiting ocean thermal energy gradients.
Is nuclear power an alternative or renewable form of energy? Savannah River National Lab’s Tom Sanders thinks there is an argument to be made. He says, in essence, whether solar is classified as alternative or renewable, remember that it is the product of fusion. Sanders, however, thinks along more practical lines than philosophical ones: He says small modular nuclear reactors are going to be manufactured, if not by the US, then by other nations. He says they can be made to deliver nuclear fuel efficiency, safety and security. In addition, their 100-300 MW size corresponds to the emerging sweet spot for modular size that existing electric utilities have found works well for new gas-fired turbines. SMNRs would also allow developing nations to leapfrog many grid infrastructure investments, similar to the way cell phones have eliminated the need for “last-mile” telecommunications wiring investments. Finally, Sanders says SMNRs can aid nonproliferation of nuclear weapons by allowing the U.S. to leverage nuclear fuel supplies at the front and back end of the generation cycles.
Each of the plenary speakers have kindly allowed ACerS to put their Powerpoint Presentations (typically converted to a pdf format) on the Society’s website, via the MCARE Plenary Speakers page. Just click on the title of each presentation.
How do our engineers and scientists find the lighter, stronger, more efficient and easier-to-use materials? Ah—that’s the topic for the next three days of symposia. Stay tuned.
And, here are some of the photos from MCARE on Monday.
Check ‘em out:
The Fisher-Barton Group has opened a new $2-million, state-of-the-art materials research laboratory in Watertown, Wis. The lab’s capabilities include scanning electron microscopy with energy dispersive spectrometry for high-magnification imaging, and elemental and chemical characterization; X-ray fluorescence and diffraction for analyzing complex, unknown bulk samples, and identifying the elements and crystallographic structure of the sample, and; drop-weight impact testing that produces a highly-sensitive time history of applied force and deformation during a test.
GigaOm’s Ucilia Wang reports about the Solar Power International conference in Dallas last week, where a panel of utility executives served up some telling views about their interest and misgivings about investing in solar. She provides five takeaway opinion points from the session.
A budding new Japanese graduate school backed by the likes of Nobel laureates Sydney Brenner, Susumu Tonegawa, Jerome Friedman and others has cleared the last hurdle required to start teaching. Japan’s cabinet officially approved the law formally recognizing the Okinawa Institute of Science and Technology (OIST) Graduate University. Proposed in 2001, OIST started operations as a research institute in 2005 with a handful of scientists working in borrowed space, with Brenner serving as president and a board of governors stacked with scientific luminaries, including five Nobel laureates. OIST supporters, including domestic politicians and scientists, want to shake up Japan’s universities by creating a new academic model emphasizing interdisciplinary research. It is also attempting to attract non-Japanese faculty members by using English for teaching and administrative affairs.
Materials with very high hydrogen density have attracted considerable interest due to a range of motivations, including the search for chemically precompressed metallic hydrogen and hydrogen storage applications. As reported on in PNAS, a team using high-pressure synchrotron X-ray diffraction technique and theoretical calculations have discovered a new rhodium dihydride with high volumetric hydrogen density (163.7 g/L). Compressing rhodium in fluid hydrogen at ambient temperature, the fcc rhodium metal absorbs hydrogen and expands unit-cell volume by two discrete steps to form NaCl-typed fcc rhodium monohydride at 4 GPa and fluorite-typed fcc RhH2 at 8 GPa. RhH2 is the first dihydride discovered in the platinum group metals under high pressure. Their low-temperature experiments show that RhH2 is recoverable after releasing pressure cryogenically to one bar and is capable of retaining hydrogen up to 150 K for minutes and 77 K for an indefinite length of time.
Engineering Ceramics in Europe and the USA: A Market and Strategic Study to the Year 2016, a 300-page market report that analyses the European and North American markets for engineering ceramics (also known as advanced ceramics), discusses the demand for various materials and products, and highlights new commercial opportunities. In the recent past, the possibilities offered by engineering ceramics have become recognised across a wide range of industrial applications, where their outstanding properties allow cost savings due to extended component lifespans in duties where metals and other materials may fail.
Do you ever get tired of the simplicity and sensitivity of your smart phone’s touchscreen, or the elegance and intuitiveness of the now-standard pinch zoom? Do you want a way of interacting with your phone that requires two hands, and an element of brute force? If so, then this Nokia concept—a “kinetic device” that receives input by being bent or twisted—might be for you.
Two separate groups have announced what sounds like somewhat similar magnesium hydride-based nanotechnology approaches to hydrogen storage.
One group, at the Lawrence Berkeley National Lab, has designed a new composite material for hydrogen storage consisting of nanoparticles of magnesium metal sprinkled through a matrix of poly(methyl methacrylate) (think Plexiglas). The group says the nanocomposite has several features, including selective gas permeability, blocking oxygen and water.
Researchers in the group say that with this design, the composite can quickly absorb hydrogen (up to 6 wt% of Mg, 4 wt% for the composite in less than 30 minutes at 200°C) to form magnesium hydride. They say it also can quickly reverse the process and release hydrogen, and the polymer barrier prevents the oxidation of the metal. In addition, these investigators say the material is pliable.
The group, whose work is being conducted as part of the DOE’s Hydrogen Storage Program, hopes that with this combination of properties, the storage material could be a major breakthrough in materials design for hydrogen storage, batteries and fuel cells.
Details of this work can be found in the paper (doi:10.1038/nmat2978), published in Nature Materials.
The other group is composed of chemists at the University of Glasgow working with the European Aeronautic Defense and Space Innovation Works group. The group is using nanotechnology to develop plans to improve the design and material composition of a special storage tank with the aim of making it so efficient that it will be feasible to use solid-state hydrogen in airplanes and cars.
Not many details are available, and it appears that this approach is still more conceptual than the Berkeley Lab group, but they say they plan on using a magnesium hydride, which has been modified at the nanoscale, to allow it to receive and release the hydrogen at fast rate.
This latter group, led by Duncan Gregory, professor of Inorganic Materials at the School of Chemistry at the University of Glasgow, has been working on finding a new material for a special storage tank for fuel cell applications under development by Hydrogen Horizons, a company about which there is little public information, but is described in these announcements as a start-up company. Reportedly, prototypes of the HH tank have used a lanthanum/nickel (LaNi5) alloy (for some discussion of LaNi5 storage, see this paper (pdf) about some ideas GM was working on several years ago).
Gregory says in a news release, “Using new active nanomaterials in combination with novel storage tank design principles presents a hugely exciting opportunity to address the considerable challenges of introducing hydrogen as a fuel for aviation. This collaboration between engineers and chemists and between industry and academia provides the pathway to achieve this.”
Previously, Gregory has done research on nitridic hydrogen storage materials. Currently, however, he seems to be focusing on a magnesium hydride material that he says will extend its longevity and release the hydrogen at a rate that could feed a fuel cell at energy densities that could power an airplane. Unfortunately, he doesn’t offer any hints about how his group is planning to combat the oxidation of the metal.
So, while the details are slim, the plans are bold: With a new tank structure, EADS hopes to fly an unmanned hydrogen-powered test plane in 2014 with a longer term view of introducing commercial airplanes powered by hydrogen.
Duncan and EADS IW have some funding from the Materials Knowledge Transfer Network — part of the U.K. Technology Strategy Board — and the Engineering and Physical Sciences Research Council. This will allow a student to carry out a four year Ph.D. project.
The University of Glascow’s website reports, ”Once the technology has been proven in a small-scale demonstration, Prof. Gregory, Hydrogen Horizons and the EADS IW team intend to build a larger collaborative team with academic and industrial partners to seek large-scale funding from the U.K. and the European Union.”
EADS is comprised of Airbus, Astrium, Eurocopter and Cassidian.
A group of researchers from the Jawaharlal Nehru Center for Advanced Scientific Research in Bangalore, India say they have come across a new approach for using graphene for hydrogen storage. They say in a paper published in the Proceedings of the National Academy of Sciences they have been able to create samples containing up to 5 wt percent hydrogen, which they say can be completely released through heating or by irradiating with a laser or UV light source. For comparison purposes, the maximum amount of hydrogen that can be contained in graphene is 7.7 wt percent.
This isn’t the first time researchers have looked at graphene. Much of this work has been done in the context of trying to find some sort of suitable solid body for hydrogen storage. Previously, some investigators began thinking about carbon nanotubes. Some storage effects were achieved, but overall the results have been disappointing.
Other research also has been done at Columbia University using single-layer graphene showing that hydrogenation can occur and be reversed through a photothermal heating process, but apparently the amount of hydrogen that is stored in the single layer was not measured (the work was focused on methods to manipulate the charge transport properties of the graphene).
The JNCASR group, led by C.N.R. Rao, looked at additional research that suggested that hydrogen loading might be better accomplished through the use of multiple layers of graphene, and decided to do some detailed studies in this area.
In brief, the group used two methods to form few-layer graphene samples: exfoliation of graphite oxide (forming 6–7 layers) and arc evaporation of graphite under hydrogen (forming 2–3 layers). The researchers hydrogenated both samples (using Birch reduction), and both samples displayed a hydrogen content of approximately 5 wt percent.
They found that the hydrogen-containing graphene is stable at room temperature “and can be stored over long periods.”
When the samples are heated, the hydrogen begins to be released around 200°C and is totally released at 500°C. As mentioned above, they also used laser and UV irradiation to break the C–H bonds and free the hydrogen.
The group feels this storage system may have potential applications, and that a better storage system may be achievable. The authors note, “Although Birch reduction enabled us to incorporate 5 wt percent of hydrogen in few-layer graphenes, it may be possible to carry out hydrogenation more effectively by other methods.” They also report they have achieved 3 wt percent storage using graphene nanoribbons, which also fully releases its hydrogen at 500°C.