June 20, 2009

Genetically Engineered mice Copy Bacteria Turn Fat to CO2 and not Sugar : High Fat Diet Induced Obesity Resistance

Mice that were engineered with a fat-burning pathway borrowed from bacteria (top) remained thin compared with normal mice (bottom) when both were fed a high-fat diet.
Credit: Jason Dean, University of California, Los Angeles

This is transgenic metabolism transfer. They take the metabolism of bacteria and plants and transferred [maybe re-activated dormant genes] it to mice. The changed genes were introduced into the liver and instead of converting fat to sugar, fat was converted to carbon dioxide. Cholesterol levels were also lower.

Someday, it may be possible to actually introduce these bacterial genes or proteins into humans, although Pei points out that such a feat poses many challenges, including a potential immune response to foreign genes. Another possibility would be to search for drugs that could mimic the effects of these enzymes. Furthermore, earlier studies reported glyoxylate shunt activity in chickens and rats, suggesting that higher organisms might retain the genes for this pathway but don't use them; it might be possible to activate dormant genes.

Liao says that the study borrows strategies from synthetic biology, a field that has for the most part focused on engineering new functions into bacteria and other lower organisms. The study suggests that the same concepts could be applied to mammals: just as we create bacteria that produce biofuels, we could introduce new abilities into the bodies of humans and other animals.

Researchers at the University of California, Los Angeles (UCLA), who transplanted a fat-burning pathway used by bacteria and plants into mice. The genetic alterations enabled the animals to convert fat into carbon dioxide and remain lean while eating the equivalent of a fast-food diet.

"Resistance to Diet-Induced Obesity in Mice with Synthetic Glyoxylate Shunt" in Cell Metabolism Journal

Given the success in engineering synthetic phenotypes in microbes and mammalian cells, constructing non-native pathways in mammals has become increasingly attractive for understanding and identifying potential targets for treating metabolic disorders. Here, we introduced the glyoxylate shunt into mouse liver to investigate mammalian fatty acid metabolism. Mice expressing the shunt showed resistance to diet-induced obesity on a high-fat diet despite similar food consumption. This was accompanied by a decrease in total fat mass, circulating leptin levels, plasma triglyceride concentration, and a signaling metabolite in liver, malonyl-CoA, that inhibits fatty acid degradation. Contrary to plants and bacteria, in which the glyoxylate shunt prevents the complete oxidation of fatty acids, this pathway when introduced in mice increases fatty acid oxidation such that resistance to diet-induced obesity develops. This work suggests that using non-native pathways in higher organisms to explore and modulate metabolism may be a useful approach.

The UCLA press release on the research

To investigate the effects of the glyoxylate shunt on fatty acid metabolism in mammals, Liao's team cloned bacteria genes from Escherichia coli that would enable the shunt, then introduced the cloned E. coli genes into the mitochondria of liver cells in mice; mitochondria are where fatty acids are burned in cells.

The researchers found that the glyoxylate shunt cut the energy-generating pathway of the cell in half, allowing the cell to digest the fatty acid much faster than normal. They also found that by cutting through this pathway, they created an additional pathway for converting fatty acid into carbon dioxide. This new cycle allowed the cell to digest fatty acid more effectively.

"The significance of this is great. It is a unique approach to understanding metabolism. Perturbing metabolic pathways, such as introducing the glyoxylate shunt and seeing how it affects overall metabolism, is a novel way to understand the control of metabolism," Dipple said.

The team also found that the new pathway decreased the regulatory signal malonyl-CoA. When malonyl-CoA levels are high, a signal is released that tells the body it is too full and that it needs to stop using fat and begin making it. Malonyl-CoA is high after eating a meal, blocking fatty acid metabolism. The new pathway, however, allowed for fat degradation even when the body was full.

Ultimately, the research team found that mice with the glyoxylate shunt that were fed the same high-fat diet — 60 percent of calories from fat — for six weeks remained skinny, compared with mice without the shunt.

"One exciting aspect of this study is that it provides a proof-of-principle for how engineering a specific metabolic pathway in the liver can affect the whole body adiposity and response to a high-fat diet," said Karen Reue, a UCLA professor of human genetics and an author of the study. "This could have relevance in understanding, and potentially treating, human obesity and associated diseases, such as diabetes and heart disease

To create the fat-burning mice, the researchers focused on a metabolic strategy used by some bacteria and plants called the glyoxylate shunt. James Liao, a biomolecular-engineering professor at UCLA and a senior author of the study, says, "This pathway is essential for the cell to convert fat to sugar" and is used when sugar is not readily available or to convert the fat stored in plant seeds into usable energy. Liao also says that it's not known why mammals lack this particular strategy, although it may be because our bodies are designed to store fat rather than burn it.

The glyoxylate shunt is composed of just two enzymes. The researchers first introduced genes for these enzymes from E. coli bacteria into cultured human cells and found that they increased the metabolism of fats in the cells. But surprisingly, rather than converting the fat into sugar as bacteria do, the cells burned the fat completely into carbon dioxide. The scientists analyzed gene expression in the cells and found that the new pathway promoted cellular responses that led the cells to metabolize fats rather than sugar.

The researchers then introduced the genes into the livers of mice. While normal mice gain weight when put on a high-fat diet, Liao says that the engineered mice "remained skinny despite the fact that they ate about the same and produced the same waste" and were as active as their normal counterparts. They also had lower fat levels in the liver and lower cholesterol levels. As in the cultured cells, the engineered mice did not convert the fat into sugar, which could have the dangerous side effect of promoting high blood sugar and diabetes. Instead, the scientists found a measured increase in their carbon dioxide output; the excess fat was literally released into thin air. The mice exhibited no visible side effects, although more detailed studies are necessary to verify that.

Supplemental information 36 page pdf

Retrofitting Fat Metabolism is discussed in this other article in Cell Metabolism.

Cancer Breakthrough: Ipilimumab a Monoclonal antibody drug and hormone therapy converts Inoperable Prostate Cancer Tumors into Operable

Two patients with inoperable prostate cancer have made dramatic recoveries after receiving one dose of an experimental drug that is creating excitement among cancer specialists.

The results were so startling that researchers decided to release details of the two cases before the drug trial – in which the patients took part – was complete. Doctors said their progress had exceeded all expectations. The men were treated at the Mayo Clinic in Minnesota in the US, one of the top medical centres in the world.

Dr Eugene Kwon, the urologist who was in charge of their treatment, compared the results to the first pilot breaking the sound barrier.

"This is one of the Holy Grails of prostate cancer research. We have been looking for this for years," he said.

Ipilimumab is one of a class of drugs called monoclonal antibodies, which stimulate the body's own immune system to fight disease. The experimental treatment is being developed by Bristol-Myers Squibb and Medarex, a US biotech company. The drug is being trialled on malignant melanoma, the most serious form of skin cancer, Hodgkin's disease, lung cancer and prostate cancer. Studies are most advanced in melanoma, where it has been shown to prolong survival in patients with advanced forms of the disease. In the Mayo Clinic study of prostate cancer, researchers say that standard hormone treatment ignited the immune response, and adding ipilimumab was like "pouring gasoline on the pilot light".

Prostate cancer is the most common cancer in men – 34,000 new cases and more than 10,000 deaths are reported each year in Britain, where rates of its occurrence have tripled in the past 30 years, mainly due to improved detection. The US has the highest incidence of the disease.

June 19, 2009

Supercritical CO2 Recompression Cycle for Nuclear Reactors

Three direct cycle designs [steam indirect cycle, helium direct, supercritical CO2]were selected for further investigation: the basic design with turbine inlet temperature of 550P o PC, an advanced design with turbine inlet temperature of 650P o PC and a high-performance design with turbine inlet temperature of 700P o PC, all with the compressor outlet pressure set at 20 MPa. The basic design achieves 45.3 % thermal efficiency and reduces the cost of the power plant by ~ 18% compared to a conventional Rankine steam cycle. The capital cost of the basic design compared to a helium Brayton cycle is about the same, but the supercritical COB2B cycle operates at significantly lower temperature. The thermal efficiency of the advanced design is close to 50% and the reactor system with the direct supercritical COB2B cycle is ~ 24% less expensive than the steam indirect cycle and 7% less expensive than a helium direct Brayton cycle. It is expected in the future that high temperature materials will become available and a high performance design with turbine inlet temperatures of 700P o PC will be possible. This high performance design achieves a thermal efficiency approaching 53%, which yields additional cost savings. [Current nuclear reactors are at about 35% thermal efficiency, and some newer designs will have 40-45%]

The turbomachinery is highly compact and achieves efficiencies of more than 90%. For the 600 MWBthB/246 MWBeB power plant the turbine body is 1.2 m in diameter and
0.55 m long, which translates into an extremely high power density of 395 MWBeB/mP
3P. The compressors are even more compact as they operate close to the critical point where the density of the fluid is higher than in the turbine. The power conversion unit that houses these components and the generator is 18 m tall and 7.6 m in diameter. Its power density (MWBeB/mP 3 P) is about ~ 46% higher than that of the helium GT-MHR (Gas Turbine Modular Helium Reactor).

The supercritical CO2 turbines are tiny

Information from a 2004 MIT study that is 6.6 megabytes and 326 pages.

H/T Kirk Sorenson at thoriumenergy for his article "Supercritical CO2 is dense like water".

Information on supercritical carbon dioxide at wikipedia

Intel Using 193-nm Immersion Lithography Making Lines and Spaces down to 15 nm and Intel Research Highlights

EETimes reports Intel Corp. claims that it has pushed 193-nm immersion lithography down to 15-nm--at least in the lab.

The disclosure is further evidence that 193-nm immersion -- with some form of a double-patterning technique -- can scale much further than previously thought. It also means that extreme ultraviolet (EUV) lithography could get pushed out--again.

There are various double-patterning schemes vying for dominance in the market. The major types include litho-etch-litho-etch, litho-freeze-litho-etch, and the sidewall spacer approach, also called SADP.

Intel may -- or may not -- use multiple double-patterning technologies. ''It depends on the layer,'' Mayberry said.

He said that Intel has pushed 193-nm immersion with double-patterning down to 15-nm. This is still in the R&D phase; the scanners have only been able to print lines and spaces--and not actual chip features.

Instead of 193-nm immersion, Intel would rather use EUV for the 16-nm node. At this point, EUV is still not ready for prime time, as the alpha tools can only print lines and spaces ''down to 24-nm,'' he said. As previously reported, EUV suffers from the lack of power sources, resists and defect free masks.

Intel Research Highlights

Intel Research Day Highlights

1. Confrontational computing. Intel and the University of California at Berkeley have rolled out The Dispute Finder, a technology that highlights disputed claims on Web pages you browse and shows you evidence for alternative points of view.
''Use this Web interface to tell Dispute Finder what snippets to highlight and what evidence to present for alternative viewpoints. You can create a new disputed claim, mark new instances of a claim on the Web, and add evidence that supports or opposes a claim,'' according to the site. That site can be found here.

2. Intel and the University of Illinois at Urbana-Champaign are working on tele-immersive 3-D multi-camera room environments. These environments allow people to engage in distributed physical activities such as physical therapy, sport activities, and entertainment. In one demo, Intel showed ''virtual light saber dueling'' between people in various locations--in 3-D. That site can be found here.

3. Intel also showed ScienceSim.com, a 3-D Internet technology. ''The 3D Internet refers to a currently disparate but rapidly converging set of 3D technologies used for visualizing 3D information on the Web,'' according to that site. It site can be found here.

4. Platform power management (PPM), a research effort in Intel Labs, has helped enable up to a 50x reduction [most of the time 50-90% reduction] in platform idle power for Moorestown over today's Atom-based platform, which translates to much longer battery life.

A review of next generation lithography from March 2009 at EETimes

Precise Semiconductor Nanowire Placement Through Dielectrophoresis

University of California, San Diego researchers demonstrated the ability to precisely control the alignment and placement of large numbers of InAs nanowires from solution onto very narrow, prepatterned electrodes using dielectrophoresis.
An understanding of dielectrophoretic behavior associated with such electrode geometries is essential to development of approaches for assembly of intricate nanowire systems. The influence of signal frequency and electrode design on nanowire manipulation and placement is examined. Signal frequencies in the range of 10 MHz are found to yield high percentages of aligned nanowires on electrodes with dimensions similar to that of the nanowire. Strategies for further improvement of nanowire alignment are suggested and analyzed.

Dielectrophoresis at wikipedia.

Dielectrophoresis (or DEP) is a phenomenon in which a force is exerted on a dielectric particle when it is subjected to a non-uniform electric field. This force does not require the particle to be charged. All particles exhibit dielectrophoretic activity in the presence of electric fields. However, the strength of the force depends strongly on the medium and particles' electrical properties, on the particles' shape and size, as well as on the frequency of the electric field. Consequently, fields of a particular frequency can manipulate particles with great selectivity. This has allowed, for example, the separation of cells or the orientation and manipulation of nanoparticles and nanowires. Dielectrophoresis can be used to manipulate, transport, separate and sort different types of particles. Since biological cells have dielectric properties Dielectrophoresis is used in medicine. Prototypes that separate cancer cells from healthy cells are already made.

Nanowerk has extensive coverage.

Optical microscope images of electrode arrays after DEP alignment. The top and bottom rows show images of chips with 100 alignment sites and 50 alignment sites, respectively. Sites with perfect alignment are indicated by a rectangle while unaligned wires are indicated by a line. Each image is 500 x 500 µm. (Reprinted with permission from American Chemical Society)

This technique can also be used to integrate III-V nanowires with existing silicon based circuitry to act as light sources and detectors for on chip optical interconnects. Furthermore, because nanowires devices are placed and positioned on a host substrate after fabrication it is possible to create high quality devices and then place them on exotic substrates allowing for the possibility of stretchable or flexible electronics.

Yu points out that there are many challenges facing nanowire based circuits and systems. "It is still necessary to improve the quality of individual devices and the yield associated with them. While integration schemes are improving, further refinement is still necessary. As a field we must not only show that we are able to construct nanowire based devices and complex systems based on nanowire components – but that there is a significant advantage to using nanowire based systems given the different complexities and costs associated with such systems."

Yu and Raychaudhuri also note that, with further development, there are certain applications for which nanowires and related nanostructures are likely to provide either improved performance or new functionality that cannot be realized using more conventional material or fabrication technologies. In particular, nanowire-based systems are likely to be particularly well suited to those applications that require the harnessing different inherent material properties into a single system – such as CMOS circuitry with on chip optical interconnects, or applications involving unconventional substrates – such as flexible sensor arrays, displays, or energy harvesting systems.

June 18, 2009

General Fusion was Awarded C$13.9 million

Sustainable Development Technology Canada, recently awarded General Fusion a $13.9 million (Canadian) grant toward a four-year project aimed at showing the acoustic pulse system works as claimed. The first phase will focus on making the plasma and building pistons, after which the full-scale system – capable initially of firing its pistons every half-hour – will be constructed.

UPDATE: General Fusion has raised US$9 million in additional funding.

In Dec, 2008 General Fusion had raised $7 million out of a needed $10 million for the second round. However, with the agency funding they probably did not have trouble getting a significant private matching of funds.

The last technical update on this site on General fusion was in March, 2009 with many pictures and video

The amount of money from SDTC is unprecedented, given the agency's average deal size is around $3 million. The funds, however, are conditional on the company's ability to raise another $33 million from private investors. It's part of the way there. The hope is that enough money can be raised by the end of [April, 2009] to begin the first two-year phase, says Richardson.

Being a Canadian company doesn't help. "Canada does not have a fusion program, so it's very challenging. There's nobody you can talk to, there's no process in place, nobody who can say yes or no," says Richardson.

This has required outside consultation. For example, Chrysalix helped get five experts at aerospace titan Boeing Co. to conduct a technical review of General Fusion's reactor design. The team's 14-page report was encouraging. "They said they didn't see any reason why it wouldn't work, and that the plan is the right plan," says Brown.

The company has also linked up research efforts with the Los Alamos National Laboratory in New Mexico. It's one of the few, and most advanced, facilities in the world actively researching Laberge's brand of fusion.

But Glen Wurden, manager of the fusion energy program at Los Alamos, doesn't sugar coat the challenges that lie ahead for General Fusion.

"They have a lot of work to do before they are able to show net energy gain," Wurden wrote in an email dispatch from his lab. He called the idea of pulsing the system every second a unique approach. "But this is the third, or even fourth step in learning how to walk. The first step is still to be demonstrated."

Brown, who over his 40 years as a venture capitalist has seen many ideas and companies come and go, is the first guy in the room to tell you that delivering a test fusion reactor for $50 million is a tall order that most write off as unlikely, if not impossible.

"We've got lots and lots of work to do, and there are lots of uncertainties here," he says.

"But Laberge – he's just unbelievable. And between him and Richardson these are very, very smart guys."

In 10 years, if all goes as planned, the entire world will know exactly how smart.

General Fusion is using the MTF (Magnetized Target Fusion) approach but with a new, patent pending and cost-effective compression system to collapse the plasma. They describe the injectors at the top and bottom of the above image in the new research paper. The goal is to build small fusion reactors that can produce around 100 megawatts of power. The company claims plants would cost around US$50 million, allowing them to generate electricity at about four cents per kilowatt hour.

If there are no funding delays, then in 2010-2011 for completion of the tests and work for an almost full scale version (2 meters instead of 3 meter diameter).

The third phase for General Fusion is to raise $50 million for a net energy gain device with a target date of 2013 if the second/third phase are roughly on schedule. [The canadian government funding and private funding could take General Fusion all the way through the third phase]

If they get $300-500 million for commercialization, the first commercial scale unit could be 2016-2018.

The fifth project funded on this media release page is General Fusion.

5. Lead organization: General Fusion Inc., Burnaby, British Columbia

Project Title: Acoustically Driven Magnetized Target Fusion

Environmental Benefit: Climate Change / Clean Air

Economic Sector: Power Generation

Consortium members:
General Fusion Inc.
Los Alamos National Laboratory
Powertech Labs Inc.

Project Description:
To date, attempts at fusion reactions with the objective of producing power have been extremely complex and expensive. General Fusion Inc. is developing fusion technology which uses acoustic waves to create a fusion reaction, thereby generating inexpensive and plentiful electricity without greenhouse gas emissions, pollution, or long lived radioactive waste streams. General Fusion is embarking on the second phase of its technology development which involves the construction of the core components and the assembly of a full scale engine to demonstrate attractive conversion efficiencies. The project will verify the technical and economic viability of General Fusion’s Acoustically Driven Magnetized Target Fusion technology. General Fusion’s engine, when commercialized, has the potential to displace traditional fossil fuel energy sources, greatly reducing greenhouse gas emissions. General Fusion’s demonstration will produce 600MJ of thermal energy per cycle.

Tyler Hamilton wrote the Toronto Star Article and mentions more about General Fusion on his blog.

Walmart prices for Nuclear reactor modules

There is a discussion of the cost advantages of large versus small reactors at thoriumenergy and Left-atomics.

Mainly they are focusing on the traditional discussion of whether the economies of scale of large reactors can be matched by the economies of scale of many duplicate smaller modules. The smaller modules can one control center to avoid unnecessary duplication.

I have covered small modular reactors frequently and looked at the latest large reactors as well.

The main cost advantage of factory produced reactors would be that they could be built in factories in China, Russia or other places like that.

Nuclear reactors built in China cost about $1565/kw.

Russia is also planning for sub-$1500/kw reactors.

The plus or minus 20% of large versus many smaller modules is less than the 300-600% cost differential of a reactor built in the United States or Europe versus a China or Russian built reactor. Small modular reactors allow the cost advantage of China and Russia to be obtained for nuclear reactors, just like the cost advantage of things we buy from Walmart.

The cost of shipping or transporting by rail would be a nominal part. China's reactors are pricing out at $1500/kw, which is about three times or more less than US reactors. The pebble bed HTR-PM reactor that China is making could be 10-20% less or it might initially start out a bit more expensive versus Chinese construction of a LWR/PWR [traditional large reactors]. Russia's smaller lead breeder reactors and other reactors are also supposed to be in the $1500/kw or less range. These new reactors have inherently safer designs. The pebble beds have walk away meltdown resistant designs. These small reactors are also heading towards 2-3 year construction times. Short and predictable construction times reduces the interest and financing charges, which are the majority of the cost of large projects. Smaller modules means that the total debt that must be obtained is less. A utility can buy one reactor module for $50-500 million and then start operating it to get some cashflow going and then build another module. The amount of debt could be controlled to not exceed $50-500 million. For large reactors, a utility might need to arrange for $5-10 billion of debt. China and Russia will likely take the first two dozen of the modular reactors domestically. Eventually the US can certify them and benefit from the lower costs.

So it is a matter of getting the new modular reactors developed and then having them certified for use and installation in the United States.

Some other alternatives are to have floating reactors (Russia is building floating reactors) off the coast and having long power cables into the United States or installing reactors in Mexico and running power across the border.

Sound Technology Roundup: Sonar Cloaking, Sound laser, Black hole for Sound

1. A new invisibility cloak for sound could help doctors find tiny tumors or hide submarines from enemy sonar.

"Our focus is not about dampening noise, but to guide sound waves around structures," said Nicholas Fang, a professor a the University of Illinois at Urbana Champaign and coauthor, along with Shu Zhang and Leilei Yin, on a paper that appears in the journal Physical Review Letters.

Sound waves are larger than electromagnetic/optical waves. To manipulate either wave requires structures many times smaller than the size of the wave. Because the properties of the material are determined by their physical structure and not their chemical make-up, as they traditionally are, they are called metamaterials.

"If you need to build an ultrasonic metamaterial, the dimension of the physical structure is tens or hundreds of microns," said Fang. "Compare that with optical metamaterials, and you are talking about hundreds of nanometers. That makes it a lot more amenable for research."

The sonic metamaterial uses cubes and octagons to create holes that can then bend the wave around the structure. The most obvious application would be as a coating for submarines that want to avoid detection from enemy sonar.

Acoustic shield

2. UK and Ukrainian physicists have built the first "saser", or sound laser, able to generate terahertz-frequency sounds.

The saser produces a highly focused beam that is similar to the way a laser pointer produces a red spot when it hits a wall (Image: Tony Kent and American Physics Society)

The new saser is a semiconductor stack, made from thin, alternating layers of gallium arsenide and aluminium arsenide.

To fire the device, the upper part of the sandwich is exposed to an intense light beam. That excites electrons in the material, which then release sound waves, or phonons.

Those reach the lower part of the sandwich where they bounce off the interfaces between different layers. The spacing of the layers has been carefully chosen so that the weak echoes combine into stronger sounds in which all of the phonons are synchronised.

Those strong phonons reflect back into the upper sandwich where they interact with the light-excited electrons – causing them to release further phonons and amplify the signal.

The result is the formation of an intense series of synchronised phonons inside the stack, which leaves the device as a narrow saser beam of high-frequency ultrasound.

Although light is currently used to "pump" the saser, it should be possible to achieve the same effect electrically too, says Kent.

Saser beams that operate at much lower frequencies, in which the phonons oscillate a billion times per second (gigahertz) rather than a trillion times per second (terahertz), have been made before.

However, they have had little impact because there are other methods of generating sound at such frequencies, says Kent. "The saser could have a much bigger impact at terahertz frequencies, where other methods of generating coherent sound waves are not as well developed."

3. A sonic black hole in a density-inverted Bose-Einstein condensate.

We have created the analogue of a black hole in a Bose-Einstein condensate. In this sonic black hole, sound waves, rather than light waves, cannot escape the event horizon. The black hole is realized via a counterintuitive density inversion, in which an attractive potential repels the atoms. This allows for measured flow speeds which cross and exceed the speed of sound by an order of magnitude. The Landau critical velocity is therefore surpassed. The point where the flow speed equals the speed of sound is the event horizon. The effective gravity is determined from the profiles of the velocity and speed of sound

17 page pdf paper on the sonic black hole.

In conclusion, a sonic black hole/white hole pair has been realized in a Bose-Einstein condensate. The supersonic flow field results from the repulsion of the condensate by an attractive potential. The Landau critical velocity is exceeded by an order of magnitude. The effective surface gravity is extracted from the in-situ velocity and sound speed profiles. The flow field contains regions of negative and positive phonon energies. This property, combined with increased velocity gradients, could be used in a study of Hawking radiation.

Fewer Nanotech Blogs ? Disillusionment ?

IEEE Spectrum has an article"The shrinking nanotechnology blog universe", which tries to connect some turnover in nanotechnology blogs with disillusionment with the pace of progress or work towards molecular manufacturing.

This is wrong on several levels.

The non-focus on molecular manufacturing has existed for over twelve years. So any disillusionment would have been several years ago. There has been more recent progress towards funding and work on the path to molecular manufacturing than in the past. The connection to where nanotechnology is headed assumes that molecular manufacturing is not happening.

* DNA nanotechnology is going 3D.
* There are adjustable DNA glueing of nanoparticles.
* Self assembly is becoming more elaborate and useful.
* Moriarty was funded to experimentally investigate the diamondoid molecular manufacturing simulations of Freitas and Merkle.
* Zyvex and its group were funded to make more elaborate atomic layer expitaxy.
* There is aerojet printing of carbon nanotubes.
* E-beams, EUV and massively parallel ion beams and other methods are getting to higher throughput 1-10 nanometer patterning.
* Single molecule quantum dots.
* molecular electronics is making interesting advances through several paths
* More and more interesting activity is happening with molecular manufacturing and advanced nanotechnology.
* Advanced accelerating technology is happening in spite of government waste mis-spending.

The turnover of blogs is a natural aspect of blogs. Within blogs on a particular subject there is turnover.

- NY Times and mainstream newspapers and media are adjusting staff and sections because of overall pressure on the newspapers
- Some bloggers have employment or personal time and health issues.
- if blogs are written by one person then any number of factors could cause that person to blog less or stop blogging

I will also note that IEEE Spectrum no longer has Dexter Johnson's nanotechnology tech talk blog in its own sub-category. It is now mixed in under semiconductor/devices. So it is now part of part of a sub-category and there are now more categories and sub-categories. Dexter's posting frequency on nanotechnology seems to average less than once per month.

$257 billion spent each year on Space Industry by Governments and Businesses

Most of the money ($257 billion) is spent on
- satellite TV ($70 billion)
- maintaining ground stations ($74 billion)
- $17 billion fixed satellite services
- $26 billion Department of Defence (military satellites and the spending around it)
- $17 billion NASA
- $10 billion national reconnaissance office (spy satellites and spending around it)
- $8.9 billion missile defense agency

The foreign government spending looks undercounted. It does not look like the foreign military or spy spending has been taken into account.

$5.6 billion on commercial satellite building
$2 billion on commercial launch systems

IEEE Spectrum has more information on the business of space.

IEEE Spectrum has the latest update of a Mars plan from Robert Zubrin.

Milking Diatoms for Sustainable Energy: Biochemical Engineering versus Gasoline-Secreting Diatom Solar Panels

Canadian researchers propose ways of harvesting oil from diatoms, using biochemical engineering and also a new solar panel approach that utilizes genomically modifiable aspects of diatom biology, offering the prospect of “milking” diatoms for sustainable energy by altering them to actively secrete oil products. Secretion by and milking of diatoms may provide a way around the puzzle of how to make algae that both grow quickly and have a very high oil content.

They review a simple line of reasoning: (a) geologists claim that much crude oil comes from diatoms; (b) diatoms do indeed make oil; (c) agriculturists claim that diatoms could make 10−200 times as much oil per hectare as oil seeds; and (d) therefore, sustainable energy could be made from diatoms.

The transparent diatom silica shell consists of a pair of frustules and a varying number of girdle bands that both protect and constrain the size of the oil droplets within, and capture the light needed for their biosynthesis. We propose three methods: (a) biochemical engineering, to extract oil from diatoms and process it into gasoline; (b) a multiscale nanostructured leaf-like panel, using live diatoms genetically engineered to secrete oil (as accomplished by mammalian milk ducts), which is then processed into gasoline; and (c) the use of such a panel with diatoms that produce gasoline directly.

NOTE: This is a specific proposal of something that seems promising, but for which there is a lot of research to prove and then more research to scale up and to make work. The research might proceed well, but it has not happened yet.

Greencarcongress has more details.

With more than 200,000 species from which to choose, and all the combinatorics of nutrient and genome manipulation, finding or creating the “best” diatom for sustainable gasoline will be challenging, the authors offer some guidelines for starting species:

Choose planktonic diatoms with positive buoyancy or at least neutral buoyancy.

Choose diatoms that harbor symbiotic nitrogen-fixing cyanobacteria, which should reduce nutrient requirements.

Choose diatoms that have high efficiency of photon use, perhaps from those that function at low light levels.

Choose diatoms that are thermophilic, especially for solar panels subject to solar heating.

Consider those genera that have been demonstrated by paleogenetics to have contributed to fossil organics.

For motile or sessile pennate diatoms that adhere to surfaces, buoyancy may be much less important than survival from desiccation, which seems to induce oil production. Therefore, the reaction of these diatoms to drying is a place to start. The reaction of oceanic planktonic species to drying has not been investigated, although one would anticipate that they have no special mechanisms for addressing this (for them) unusual situation.

Genetic engineering of diatoms to enhance oil production has been attempted, but it has not yet been successful.

Generally, cell proliferation seems to be counterproductive to oil production on a per-cell basis, which is a problem that has been expressed as an unsolved Catch-22. However, this balance may shift in our favor when we start milking diatoms for oil instead of grinding them.

Nonstick and Laser-safe Gold Ten Times Better for Trapping of Biomolecules

The gold posts in this colorized micrograph, averaging 450 nanometers in diameter, are used to anchor individual biomolecules such as DNA for studies of their mechanical properties. The background surface is glass coated with a protein to prevent unwanted sticking. Credit: D.H. Paik/JILA

Successful use of gold in optical-trapping experiments, reported in Nano Letters, could lead to a 10-fold increase in numbers of single molecules studied in certain assays, from roughly five to 50 per day, according to group leader Tom Perkins of NIST. The ability to carry out more experiments with greater precision will lead to new insights, such as uncovering diversity in seemingly identical molecules, and enhance NIST’s ability to carry out mission work, such as reproducing and verifying piconewton-scale force measurements using DNA, Perkins says.

Perkins and other biophysicists use laser beams to precisely manipulate, track and measure molecules like DNA, which typically have one end bonded to a surface and the other end attached to a micron-sized bead that acts as a “handle” for the laser. Until now, creating the platform for such experiments has generally involved nonspecifically absorbing fragile molecules onto a sticky glass surface, producing random spacing and sometimes destroying biological activity. “It’s like dropping a car onto a road from 100 feet up and hoping it will land tires down. If the molecule lands in the wrong orientation, it won’t be active or, worse, it will only partially work,” Perkins says.

Ideally, scientists want to attach biomolecules in an optimal pattern on an otherwise nonstick surface. Gold posts are easy to lay down in desired patterns at the nanometer scale. Perkins’ group attached the DNA to the gold with sulfur-based chemical units called thiols (widely used in nanotechnology), an approach that is mechanically stronger than the protein-based bonding techniques typically used in biology. The JILA scientists used six thiol bonds instead of just one between the DNA and the gold posts. These bonds were mechanically strong enough to withstand high-force laser trapping and chemically robust enough to allow the JILA team to coat the unreacted gold on each nanopost with a polymer cushion, which eliminated undesired sticking. “Now you can anchor DNA to gold and keep the rest of the gold very nonstick,” Perkins says.

Moreover, the gold nanoposts were small enough—with diameters of 100 to 500 nanometers and a height of 20 nanometers—that the scientists could avoid hitting the posts directly with lasers. “Like oil and water, traditionally laser tweezers and gold don’t mix. By making very small islands of gold, we positioned individual molecules where we wanted them, and with a mechanical strength that enables more precise and additional types of studies,” Perkins says.

NIST Discovers How Strain at Grain Boundaries Suppresses High-Temperature Superconductivity

Electron microscope image of two superconducting thin films that meet at a 6 degree tilt boundary (the dark line running through the image). The numerous smaller lines that intersect the grain boundary at 90 degrees are the individual crystalline layers. The connection between the two films shows distortions in the superconducting layers, which severely limits current flow in these materials. Color added for clarity. Credit: F.J. Baca, U.S. Air Force Research Lab

Researchers at the National Institute of Standards and Technology (NIST) have discovered that a reduction in mechanical strain at the boundaries of crystal grains can significantly improve the performance of high-temperature superconductors (HTS). Their results could lead to lower cost and significantly improved performance of superconductors in a wide variety of applications, such as power transmission, power grid reliability and advanced physics research.

Although it is well known that dislocations cause part of the grain boundary crosssection to become non-superconducting, the effect of strain—which extends from the dislocations into the remaining superconducting bridges over the grain boundary—was previously unknown. NIST’s Danko van der Laan and his collaborators have found that this strain plays a key role in reducing current flow over grain boundaries in YBCO. Furthermore, when the strain was removed by applying compression to the grain boundaries, the superconducting properties improved dramatically.

The new understanding of the effects of strain on current flow in thin-film superconductors could significantly advance the development of these materials for practical applications and could lower their cost. Some of the most promising uses are in more efficient electrical transmission lines, which already have been successfully demonstrated by U.S. power companies, and increased electric power grid reliability. NIST has research programs in both these areas. Improved HTS thin-film conductors could also enable more powerful high-field particle accelerators and advanced cancer treatment facilities

June 17, 2009

Nuclear DC-X : Recent Nuclear Thermal Rocket Proposals

103 page pdf, advanced propulsion study for the US Air Force made in 2004 prepared by Eric Davis of Warp Drive Metrics. Eric W Davis is an advisor to the Lifeboat Foundation. On pages 48-57, the recent nuclear thermal rocket variants are described. They are estimated to require 5 years of technological development and could have launch costs of $85-150/kg for a single stage to orbit vehicle.

The ETO performance capability of Nuclear DC-X (Paul March, 2001
March, P. (2001), “LANTR VTOL-SSTO Reusable Heavy Cargo Lifter Launch
Vehicle,” Briefing to the Advanced Deep Space Transport Group-Propulsion and Power
Subgroup, and Private Communications, Lockheed-Martin Co., Houston, TX):
* VTOL-SSTO Heavy Cargo Lifter
* Nuclear DC-X propulsion system: 5,000 MWt class LANTR engine
* Utilize Air Force Timber Wind PeBR (see below for discussion of Timber Wind) or Russian Zrhydride heterogeneous reactor design with ternary-carbide fuels, operating at power densities ≈ 20 – 40 MWt/liter with reactor temperature of 3,000 K
* LANTR segmented aerospike exhaust nozzle with variable thrust control on each engine for attitude and flight trajectory control (no gimballing): 5-throttled LANTR engines per vehicle [LANTR is LOX-Augmented Nuclear Thermal Rocket]
* Canard stabilator flight control surfaces
* Landing struts (5) perform multiple functions: provide vehicle support, aerodynamic control, heat rejection, and landing shock absorption
* X-33 type Metallic Reentry Thermal Protection System on the bottom of the vehicle, plus carboncarbon leading edges on all landing struts/stabilators
* The LANTR engines are tilted inboard to place neutron shadow-shield between ground observers and the engines after lift-off – rely on the Conda-effect for flow turning on the aerospike exhaust nozzle
* Neutron shields: graphite-Al walled tanks filled with H2O loaded with 10B
* LANTR engine Oxidizer/Fuel = 4:1
* LANTR engine run time = 200 seconds, total boost time = 500 seconds
* Nuclear DC-X is VTOL from any prepared concrete pad
* 40% GTOW can be carried to LEO (at 400 km altitude and 51° inclination) from a 45° latitude launch
* Dry vehicle mass fraction is 30%, thus giving a payload fraction of 10%, or a payload mass of 10^5 kg to orbit on each flight
* Launch cost estimate: $150/kg of payload, if commercially developed and operated
* Launch cost estimate: $85/kg of payload, if developed and operated by the U.S. government

LANTR : LOX-Augmented Nuclear Thermal Rocket benefits

Summary of LANTR performance improvements over conventional NTR’s (ISNPS, 2003):
LANTR couples a reverse scramjet LOX-afterburner nozzle to a conventional LH2-cooled NTR to
achieve the following benefits:
• LANTR engines are smaller, cheaper NTR’s with “big engine” performance
• Smaller, cheaper facilities for contained ground testing
• Variable thrust and Isp capability from constant power NTR
• Shortened burn times and extended engine life
• Reduced LH2 propellant tank size, mass, and boil-off
• Reduced stage size allowing smaller launch vehicles
• Increased operational range – ability to utilize extraterrestrial sources of O2 and H2

Variants: Pebble Bed, LANTR and Fission Fragment

1. Pellet Bed Reactor (PeBR) NTR (Nuclear Thermal Rocket)
a) Performance in pure NTR mode:
* Isp ≈ 1,000 seconds
* Thrust = 1,112 kN/engine
* Thrust/Weight > 12
* vex (exhaust velocity) = 9.8 km/sec
b) Performance in LANTR mode:
* Isp ≈ 600 seconds
* Thrust = 3,336 kN/engine
* Thrust/Weight > 38
* vex = 5.9 km/sec

2. Thin-Film Fission Fragment Heated NTR
• A high-performance NTR formulated by C. Rubbia
• Reactor core consists of thin-walled porous propellant flow passages coated with a thin layer of Americium-242m
• Propellant is injected radially into the flow passages and heated directly by fission fragments from the Am-242m liner
• This approach allow for much higher bulk temperatures in the propellant than in a
conventional NTR while keeping the propellant in contact with the walls (within the
material temperature limits)
• Theoretical Isp = 2,000 – 4,000 seconds
• Thrust is comparable to a conventional NTR
• Fission Fragment LANTR mode performance is comparable to the PeBR LANTR mode

The PeBR NTR in item 1 above has nuclear fuel that is in the form of a particulate bed (fluidized-bed, dust-bed, or rotating-bed) through which the propellant is pumped (El-Genk et al., 1990; Ludewig, 1990; Horman et al., 1991; ISNPS, 2003). This permits NTR operation at a higher temperature than solid-core NTR’s by reducing the fuel strength requirements. This results in the increased engine performance noted above. The core of the reactor is rotated about its longitudinal axis at approximately 3,000 rpm so that the fuel bed is centrifuged against the inner surface of a cylindrical wall through which H2 gas is injected.
This rotating bed reactor has the advantage that the radioactive particle core can be dumped at the end of an operational cycle and recharged prior to a subsequent burn, thus eliminating the need for decay heat removal, minimizing shielding requirements, and simplifying maintenance and refurbishment operations.
Thin-film fission fragment propulsion involves allowing the energetic fragments produced in the nuclear fission process to directly escape the reactor. Thus, the fission fragments, moving at several percent of the speed of light, can be directly used as the propellant (Chapline, 1988; Wright, 1990; Ronen et al., 2000a, b). However, March (2001) prefers to use Carlo Rubbia’s modification of this concept in which the fragments are used to directly heat a conventional NTR propellant (H2) for propulsion, as described in item 2 above (Rubbia, 1999, 2000; Ronen et al., 2000a, b). In order for the fragments to escape from the nuclear fuel and reactor, a low-mass density critical reactor must be constructed. In order to design such a reactor, highly fissionable nuclear fuels such as Americium (Am) or Curium (Cm) must be used. These fairly rare fuels are produced from reprocessed spent nuclear fuel (via the extraction of Pu-241 and Am-241), which is a very expensive multistep process. However, small amounts of Am- 242m are already available. Ronen et al. (2000a, b) demonstrate that Am-242m can maintain sustained nuclear fission as an extremely thin metallic film, less than 1/1000th of a millimeter thick. Am-242m requires only 1% of the mass of U-235 or Pu-239 to reach its critical state. It should be noted that obtaining fission fragments is not possible with U-235 and Pu-239 nuclear fuels because they both require large fuel rods, which absorb their fission products. The fission fragment propulsion concept is near-term technology, however it requires the development of new technology and technology risk reduction.

Blast Wave Accelerator: Space Launch System

103 page pdf, advanced propulsion study for the US Air Force made in 2004 On pages 25-27, the blast wave accelerator is described. It is something that could be made with current technology and would have launch costs of $200-2000/kg.

Explosive or blast-wave accelerators are a member of the class of chemical catapult (artillery gun type) launch systems. In explosive accelerators, a projectile is accelerated either by a high explosive or by hydrogen gas that is compressed by an explosive (Wenzel and Gehring, 1965; Wenzel, 1987). Explosives such as Composition B, Octol, RDX, HMX9404, LX-10 and PBX 9010 are used for their high detonation velocities of 7 – 9 km/s. Examples of this concept include the air cavity launcher, the shaped-charge detonation launcher, the Voitenko implosion gun, and the blast-wave accelerator. The air cavity launcher uses a high explosive to accelerate a small projectile to 5.5 km/s (Clark et al., 1960; Kineke, 1960). The shaped-charge detonation launcher uses a high explosive to implode a conical metal liner, whereby the implosion fuses the liner into a thin liquid jet that accelerates a projectile to 16.5 km/s (Wenzel and Gehring, 1965). And the Voitenko implosion gun uses a high explosive to accelerate hydrogen gas, which in turn accelerates a thin disk to 40 km/s (Voitenko, 1964; Sawle, 1969).

The blast-wave accelerator is chosen as a recommended advanced propulsion concept because of its simplicity and very low system cost. Projectiles are accelerated by a series of hollow explosive rings that are detonated in rapid sequence causing a near-constant pressure to form at the base of the projectile, thereby generating a near-constant and large acceleration (Moore et al., 1965; Rodenberger, 1969; Rodenberger et al., 1970; Bakirov and Mitrofanov, 1976; Voitenko, 1990; Tarzhanov, 1991; Kryukov, 1995; Carrier et al., 1995; Tan et al., 1996; Takayama and Sasoh, 1998; Wilson and Tan, 2001). The gun can have a barrel (launch tube) or explosive rings that are supported by a top beam via inertial confinement (see Figures 4 and 5). The gun’s structure is simple since the principal change required to reload the gun is the replacement of the explosive rings and rudimentary structure. Plastic foam is used in steel launch tube designs to protect the tube from the explosion, and hydrogen gas flows near the tube axis. There are disposable designs that forgo the plastic foam in order to achieve higher hydrogen gas pressure. The projectile accelerations produced by a blast-wave accelerator are moderate compared to the other explosive accelerators. Payloads can have an apogee kick motor attached to circularize their trajectory and enter orbit. The overall system has nominal-to-low cost operation.

The salient features of the blast-wave accelerator (Bekey, 2003):
• This system is a one-stage gun launcher, which can directly place payloads into orbit
• This is a lower-cost launch system that can orbit small dense payloads or multiple modules designed to be assembled in orbit
• This system can launch commodities and small spacecraft with electronics
• This system can ballistically deliver a warhead (oriented projectiles or explosives, undersea homing torpedoes, etc.) or payload anywhere on the globe:
* it can be used as a precision strike weapon with global reach
* it can achieve strike precision at near-orbital speed
* it has artillery-like operations, complexity and cost
* it can be based anywhere
* it possesses excellent stealth (i.e., it has no exhaust plume)
* it has affordability, ferocity, and quick reaction time
• The Blast-Wave Accelerator:
* is of Russian origin
* is a concept that has been verified by NASA studies
* is state-of-the-art technology
• Estimated launch cost: $200 – 2,000/kg of payload, depending on construction and refurbishment options
• 15 m barrel generates 300,000 g acceleration
• 40 m barrel generates 100,000 g acceleration
• Longer barrel generates lower launch acceleration
• Russian experiments indicate that Mach 27 projectile/payload velocity is achievable
• Payload mass fraction is 70 - 95%
It should be noted that experiments have demonstrated that electronic circuits and components (including vacuum tube electronics) can withstand accelerations up to and above 100,000 g and continue to function.

This is an overlooked, promising near-term concept. It does not require the development of new technology or technology risk reduction. This concept has not been in development for reasons involving politics, agenda, legacy, or simple resistance to different ways of doing things. This concept possesses substantial unrealized benefits and it can be implemented right now to meet most unmanned mission requirements.

RAM Accelerators and Hydrogen core ram accelerators and the blast wave accelerator are part of the traverse gun family of launchers. Need about 10,000 tons of mass to launch 1 ton.


Synthesis of a fullerene-based one-dimensional nanopolymer
through topochemical transformation of the parent nanowire (30 page pdf)

Large-scale practical applications of fullerene (C60) in nanodevices could be significantly facilitated if the commercially-available micrometer-scale raw C60 powder were further processed into a one-dimensional (1D) nanowire-related polymer displaying covalent bonding as molecular interlinks and resembling traditional important conjugated polymers. However, there has been little study thus far in this area despite the abundant literature on fullerene. Here we report the synthesis and characterization of such a C60-based nanowire polymer, (-C60TMB-)n, where TMB=1,2,4-trimethylbenzene, which displays a well-defined crystalline structure, exceptionally large length-to-width ratio and excellent thermal stability. The material is prepared by first growing the corresponding nanowire through a solution phase of C60 followed by a topochemical polymerization reaction in the solid state. Gas chromatography, mass spectrometry and 13C nuclear magnetic resonance evidence is provided for the nature of the covalent bonding mode adopted by the polymeric chains. Theoretical analysis based on detailed calculations of the reaction energetics and structural analysis provides an in-depth understanding of the polymerization pathway. The nanopolymer promises important applications in biological fields and in the development of optical, electrical, and magnetic nanodevices.

From MIT Technology Review Blog:

The exciting thing about this breakthrough is the potential to grow buckywires on an industrial scale from buckyballs dissolved in a vat of bubbling oil. Since the buckywires are insoluble, they precipitate out, forming crystals. (Here it ought to be said that various other groups are said to have made buckywires of one kind or another, but none seem to have nailed it from an industrial perspective.)

So what might buckywires be good for? First up is photovoltaics: these buckywires look as if they could be hugely efficient light harvesters because of their great surface area and the way that they can conduct photon-liberated electrons. Then there are various electronic applications in wiring up molecular circuit boards.

But perhaps the area of greatest interest is drug delivery. Geng and co suggest that buckywires ought to be safer than carbon nanotubes because the production method is entirely metal-free.

We have demonstrated for the first time an approach to the synthesis of a C60-based nanowire polymer and established the chemical bonding mode involved in the polymeric chains based on both experimental measurements and theoretical calculations. Importantly, the material adopts a crystalline 1D nanostructure which resembles carbon nanotubes in shape and other important conjugated polymers in structure. Since the material does not contain any metal but is simply composed almost entirely of carbon (while it contains hydrogen, the content is only 1.4 wt %), it suggests biological compatibility and it is, perhaps, even more attractive than carbon nanotubes for bio-applications. In addition, the material has further important potential for applications in photo-electrical devices because of the intrinsically large magnitude of the nonlinear optical response of C60 and the excellence of its photoinduced charge transfer properties. Considering all these, we believe that this work represents a step toward true applications of C60 in nanotechnology by the ability of processing commercially available raw C60 powder into a one-dimensional, crystalline, and covalently-bonded fullerene nanopolymer.

We consider that applications of the reported nanopolymer may be facilitated by a wet chemical approach through surface modification of the material using the rich chemistry of fullerene developed over the last 20 years. Since the nanopolymer is insoluble in common solvents, such surface modification or functionalization should be possible to achieve in either an aqueous or an organic solution without destructing its solid-state structure. Such a wet approach would benefit from low-cost processing, the need for only simple apparatus and the possibility of scaling-up to the industrial level. Moreover, the nanopolymer itself not only provides an example of phase transition of the parent nanowire driven by forming and breaking covalent bonds, but also illustrates the enduring significance of the original fullerene concept and its versatility as applied to new fullerene-related nanostructures. Finally, the host (C60) and guest (1,2,4-TMB) nature of the polymerization suggests a general host-guest route to the synthesis of new types of fullerene-based nanopolymers constructed by different organic monomers and fullerenes

IEC Fusion WB7, WB8, and WB9 Information

Talk Polywell and IECFusiontech have uncovered details of the WB-8 contract [pdf]. Those details can give us some insight into how WB-7 has gone.

The WB8 design shall use circular coils around each main face cusp axis. The device shall use emitter electron gun arrays and an ion beam drive. The machine will be operated in magnetic fields with pulsed currents. WB8 shall be operated at a magnetic field strength of approximately 0.8 Tesla, which represents an increase of 8 times the magnetic field strength of previous WB machines. Improvements over previous WB machines in WB confinement, ion energy and fusion reactivity are expected as a result of these changes to WB machine design.

AS M Simon explains
An increase of field strength by a factor of 8 means - if the scaling laws hold a factor of about 4,000 increase in power out. If WB-7 was similar to WB-6 it means an increase from 3 neutrons a shot to 12,000. A real countable number i.e the error bars will be much lower. A count of 3 can actually be considered a count of 3 +/-2. That is a big error bar. For 12,000 the error bar is on the order of +/-100 about 1%. That makes improvements or degradations of 5% easily detectable. Where as in the first situation (WB-6/7) changes that doubled or halved the output rate would be hard to detect.

WB 8.1 : Testing Aneutronic proton/boron 11

Enhanced Ion Drive with PB11 (proton/boron 11): Based on the results of WB8 testing, and the availability of government funds the contractor shall develop a WB machine (WB8.1) which incorporates the knowledge and improvements gained in WB8. It is expected that higher ion drive capabilities will be added, and that a “PB11” reaction will be demonstrated. The contractor shall investigate and validate the plasma scaling laws with respect to B-field, voltage and reactor size. The contractor shall investigate the feasibility of a neutron-free fusion power reaction using a polywell WB machine. It is anticipated that improvements in WB confinement, ion energy, and fusion reactivity will be demonstrated in WB8.1. Improvements over the WB8 predictive, computational model are expected, which should yield a better understanding of the WB fusion reaction thus allowing optimization of the WB machine.

The contractor shall deliver a report detailing the results of the experimental testing of WB8.1. The report shall address the conceptual requirements for a polywell fusion reactor capable of generating approximately 100 milliwatts.

From M Simon:
At 100 milliwatts for a follow on reactor they are starting to get into the power range. If they can get that kind of power with .3 m diameter. coils and .8 T fields, then a reactor with 3 m coils and 10 T fields should produce about 2.5 Mega Watts if the scaling laws hold.

WB-9 Follow-Up Discussion
The contractor shall deliver a conceptual design for a follow-on fusion demonstration device, WB-9. Conceptual studies will focus on the feasibility of extending the WB-8 results to this device and determining the suitability of this concept as a fusion reactor.

AGEE refers to Advanced Gaseous Electrostatic Energy (AGEE).

Talk Polywell discussion on these documents

June 16, 2009

Nvidia Tegra Chip Line Uses less than One Watt

Nvidia projects that in just a few years Tegra, its embedded system on a chip (SoC), will account for more than half of income.

Tegra has 42 total design wins, announced at the recent Computex show, including 18 smart phones and 18 customers for mobile Internet devices (MIDs).

nVidia has an aggressive roadmap for Tegra; instead of the usual two or three years for a refresh, it plans to release new products annually. The second generation Tegra is due by next year and will feature four times the performance in the same power envelope, which is under one watt. The third generation, one year after that, will have 10 times the performance as generation one, in the same power envelope.

NVIDIA HD AVP (High Definition Audio Video Processor) with NVIDIA® PureVideo® technology
* Up to 1080p HD video playback
* Unprecedented picture quality and ultra-smooth, vivid movie playback with low CPU use and power consumption

Superior Imaging
* Take sharp and steady pictures with a 12 MP camera with a built-in image-stabilization algorithm
* Integrated image signal processor (ISP) with proprietary algorithms that enables image and video stabilization, face tracking, and advanced trick modes.

ULP (Ultra Low Power) NVIDIA Graphics Processing Unit (GPU)
* NVIDIA graphics technology architected for low-power applications
* Superior 3D user interface capabilities based on a unique compositing framework that delivers seamless web browsing

NVDIA nPower™ technology
* Low-power design delivers over 100 hours audio and10 hours HD video playback
Optimizes system power use

The NVIDIA® Tegra™ 600 Series products are the smallest, most advanced, and most highly integrated visual computers-on-a-chip. Featuring unprecedented multimedia functionality—including HD 1080p video and advanced 3D technology—and delivering 10× the power efficiency of competition, Tegra 600 Series products deliver the ultimate visual experience on a broad range of connected devices.

The Tegra line uses ARM chips and ULP (ultra low power) NVidia GPUs

Bismuth telluride could revolutionize electronics : Electrons travel without energy loss across surface at room temperature

Surface electron band structure of bismuth telluride. (Image courtesy of Yulin Chen and Z. X. Shen.)

Physicists at the Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University have confirmed the existence of a type of material (bismuth Telluride) that could one day provide dramatically faster, more efficient computer chips.

Bismuth Telluride allows electrons on its surface to travel with no loss of energy at room temperatures and can be fabricated using existing semiconductor technologies. Such material could provide a leap in microchip speeds, and even become the bedrock of an entirely new kind of computing industry based on spintronics, the next evolution of electronics.

The experimenters examined bismuth telluride samples using X-rays from the Stanford Synchrotron Radiation Lightsource at SLAC and the Advanced Light Source at Lawrence Berkeley National Laboratory. When Chen and his colleagues investigated the electrons' behavior, they saw the clear signature of a topological insulator. Not only that, the group discovered that the reality of bismuth telluride was even better than theory.

"The theorists were very close," Chen said, "but there was a quantitative difference." The experiments showed that bismuth telluride could tolerate even higher temperatures than theorists had predicted. "This means that the material is closer to application than we thought," Chen said.

This magic is possible thanks to surprisingly well-behaved electrons. The quantum spin of each electron is aligned with the electron's motion—a phenomenon called the quantum spin Hall effect. This alignment is a key component in creating spintronics devices, new kinds of devices that go beyond standard electronics. "When you hit something, there's usually scattering, some possibility of bouncing back," explained theorist Xiaoliang Qi. "But the quantum spin Hall effect means that you can't reflect to exactly the reverse path." As a dramatic consequence, electrons flow without resistance. Put a voltage on a topological insulator, and this special spin current will flow without heating the material or dissipating.

Topological insulators aren't conventional superconductors nor fodder for super-efficient power lines, as they can only carry small currents, but they could pave the way for a paradigm shift in microchip development. "This could lead to new applications of spintronics, or using the electron spin to carry information," Qi said. "Whether or not it can build better wires, I'm optimistic it can lead to new devices, transistors, and spintronics devices."

Fortunately for real-world applications, bismuth telluride is fairly simple to grow and work with. Chen said, "It's a three-dimensional material, so it's easy to fabricate with the current mature semiconductor technology. It's also easy to dope—you can tune the properties relatively easily."

Experimental Realization of a Three-Dimensional Topological Insulator, Bi2Te3

Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 with angle resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole-doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi2Te3 also points to great potential for possible high-temperature spintronics applications.

10 page pdf with supporting material.

Designer Magnetic Superatoms Could Be Ideal for Molecular Electronics

A team of Virginia Commonwealth University scientists has discovered a ‘magnetic superatom’ – a stable cluster of atoms that can mimic different elements of the periodic table – that one day may be used to create molecular electronic devices for the next generation of faster computers with larger memory storage.

New magnetic superatoms' assemblies could be ideal for molecular electronic devices, as the coupling could be altered by charging or weak fields.

The quantum states in metal clusters are grouped into bunches of close-lying eigenvalues, termed electronic shells, similar to those of atoms. Filling of the electronic shells with paired electrons results in local minima in energy to give stable species called magic clusters. This led to the realization that selected clusters mimic chemical properties of elemental atoms on the periodic table and can be classified as superatoms. So far the work on superatoms has focused on non-magnetic species. Here we propose a framework for magnetic superatoms by invoking systems that have both localized and delocalized electronic states, in which localized electrons stabilize magnetic moments and filled nearly-free electron shells lead to stable species. An isolated VCs8 and a ligated MnAu24(SH)18 are shown to be such magnetic superatoms. The magnetic superatoms' assemblies could be ideal for molecular electronic devices, as the coupling could be altered by charging or weak fields.

Through an elaborate series of theoretical studies, Shiv N. Khanna, Ph.D., professor in the VCU Department of Physics, together with VCU postdoctoral associates J. Ulises Reveles, A.C. Reber, and graduate student P. Clayborne, and collaborators at the Naval Research Laboratory in D.C., and the Harish-Chandra Research Institute in Allahabad, India, examined the electronic and magnetic properties of clusters having one vanadium atom surrounded by multiple cesium atoms.

They found that when the cluster had eight cesium atoms it acquired extra stability due to a filled electronic state. An atom is in a stable configuration when its outermost shell is full. Consequently, when an atom combines with other atoms, it tends to lose or gain valence electrons to acquire a stable configuration.

According to Khanna, the new cluster had a magnetic moment of five Bohr magnetons, which is more than twice the value for an iron atom in a solid iron magnet. A magnetic moment is a measure of the internal magnetism of the cluster. A manganese atom also has a similar magnetic moment and a closed electronic shell of more tightly bound electrons, and Khanna said that the new cluster could be regarded as a mimic of a manganese atom.

“An important objective of the discovery was to find what combination of atoms will lead to a species that is stable as we put multiple units together. The combination of magnetic and conducting attributes was also desirable. Cesium is a good conductor of electricity and hence the superatom combines the benefit of magnetic character along with ease of conduction through its outer skin,” Khanna said.

“A combination such as the one we have created here can lead to significant developments in the area of “molecular electronics,” a field where researchers study electric currents through small molecules. These molecular devices are expected to help make non-volatile data storage, denser integrated devices, higher data processing and other benefits,” he said.

Khanna and his team are conducting preliminary studies on molecules composed of two such superatoms and have made some promising observations that may have applications in spintronics. Spintronics is a process using electron spin to synthesize new devices for memory and data processing.

The researchers have also proposed that by combining gold and manganese, one can make other superatoms that have magnetic moment, but will not conduct electricity. These superatoms may have potential biomedical applications such as sensing, imaging and drug delivery.

8 pages of supplemental information.

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