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Turning garbage into gas

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Why burn or bury garbage when you can vaporize them and turn garbage into electricity? This is the solution for landfill.

Feb 3rd 2011, Economist
Atomising trash eliminates the need to dump it, and generates useful power too

DISPOSING of household rubbish is not, at first glance, a task that looks amenable to high-tech solutions. But Hilburn Hillestad of Geoplasma, a firm based in Atlanta, Georgia, begs to differ. Burying trash—the usual way of disposing of the stuff—is old-fashioned and polluting. Instead, Geoplasma, part of a conglomerate called the Jacoby Group, proposes to tear it into its constituent atoms with electricity. It is clean. It is modern. And, what is more, it might even be profitable.

For years, some particularly toxic types of waste, such as the sludge from oil refineries, have been destroyed with artificial lightning from electric plasma torches—devices that heat matter to a temperature higher than that of the sun’s surface. Until recently this has been an expensive process, costing as much as $2,000 per tonne of waste, according to SRL Plasma, an Australian firm that has manufactured torches for 13 of the roughly two dozen plants around the world that work this way.

Now, though, costs are coming down. Moreover, it has occurred to people such as Dr Hillestad that the process could be used to generate power as well as consuming it. Appropriately tweaked, the destruction of organic materials (including paper and plastics) by plasma torches produces a mixture of carbon monoxide and hydrogen called syngas. That, in turn, can be burned to generate electricity. Add in the value of the tipping fees that do not have to be paid if rubbish is simply vaporised, plus the fact that energy prices in general are rising, and plasma torches start to look like a plausible alternative to burial.
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The technology has got better, too. The core of a plasma torch is a pair of electrodes, usually made from a nickel-based alloy. A current arcs between them and turns the surrounding air into a plasma by stripping electrons from their parent atoms. Waste (chopped up into small pieces if it is solid) is fed into this plasma. The heat and electric charges of the plasma break the chemical bonds in the waste, vaporising it. Then, if the mix of waste is correct, the carbon and oxygen atoms involved recombine to form carbon monoxide and the hydrogen atoms link up into diatomic hydrogen molecules. Both of these are fuels (they burn in air to form carbon dioxide and water, respectively). Metals and other inorganic materials that do not turn into gas fall to the bottom of the chamber as molten slag. Once it has cooled, this slag can be used to make bricks or to pave roads.

Electric arcs are a harsh environment to operate in, and early plasma torches were not noted for reliability. These days, though, the quality of the nickel alloys has improved so that the torches work continuously. On top of that, developments in a field called computational fluid dynamics allow the rubbish going into the process to be mixed in a way that produces the most syngas for the least input of electricity.

The first rubbish-to-syngas plants were built almost a decade ago, in Japan—where land scarcity means tipping fees are particularly high. Now the idea is moving elsewhere. This year Geoplasma plans to start constructing a plant costing $120m in St Lucie County, Florida. It will be fed with waste from local households and should create enough syngas to make electricity for more than 20,000 homes. The company reckons it can make enough money from the project to service the debt incurred in constructing the plant and still provide a profit from the beginning.

Nor is Geoplasma alone. More than three dozen other American firms are proposing plasma-torch syngas plants, according to Gershman, Brickner & Bratton, a waste consultancy based in Fairfax, Virginia. Demand is so great that the Westinghouse Plasma Corporation, an American manufacturer of plasma torches, is able to hire out its test facility in Madison, Pennsylvania, for $150,000 a day.

Syngas can also be converted into other things. The “syn” is short for “synthesis” and syngas was once an important industrial raw material. The rise of the petrochemical industry has rather eclipsed it, but it may become important again. One novel proposal, by Coskata, a firm based in Warrenville, Illinois, is to ferment it into ethanol, for use as vehicle fuel. At the moment Coskata uses a plasma torch to make syngas from waste wood and wood-pulp, but modifying the apparatus to take household waste should not be too hard.

Even if efforts to convert such waste into syngas fail, existing plants that use plasma torches to destroy more hazardous material could be modified to take advantage of the idea. The Beijing Victex Environmental Science and Technology Development Company, for example, uses the torches to destroy sludge from Chinese oil refineries. According to Fiona Qian, the firm’s deputy manager, the high cost of doing this means some refineries are still dumping toxic waste in landfills. Stopping that sort of thing by bringing the price down would be a good thing by itself.

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IP Integration : What is the difference between stitching and weaving?

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I should write a article on: What is the difference between reusing and salvaging…

by David Murray, 12/15/2010, Design and Reuse

As a hardware design engineer, I was never comfortable when someone talked about IP integration as ‘stitching a chip together’. First of all, it sounded like a painful process involving sharp needles, usually preceded by a painful accident. I happened to be the recipient of said stitches when, at 8 years of age, I contested a stairs post with my forehead, and sorely lost. I have to say, luckily, I have been quite adept at avoiding the needle and thread ever since. That was of course until once when, an hour before that important customer presentation, my top-shirt button, due to an over enthusiastic yawn, pinged across my hotel room floor like a nano-UFO. A panicked retrieval of the renegade button was followed quickly with a successful hunt for an elusive emergency sewing-kit. The crisis quickly dissipated as I stitched back the button in a random-but-directed type of methodology. Needle-less to say stitching, whilst sometimes necessary, makes me uncomfortable.

Stitching, according to Wikipedia, is “.. the fastening of cloth, leather, furs, bark, or other flexible materials, using needle and thread. Its use is nearly universal among human populations and dates back to Paleolithic times (30,000 BCE).” It also states that stitching predates the weaving of cloth. So, 32,000 years later, in these hi-tech times we are still stitching things together. It’s not fur this time, but ‘ports’. Stitching a chip together involves connecting ports together with wires. (Note the terminology also where, if you don’t use certain ports you ’tie’ them off).

Weaving is a different game altogether. One definition simplifies weaving as ‘creating fabric’. Thus a key differentiator between stitching and weaving is that stitching may refer to fixing/mending things whilst weaving is used to create. Stitching is an emergency, an ah-hoc approach (please refer to my stitched button above) whilst weaving is more structured, more planned. Stitching invokes the image of being bent over, eyes squinted, immersed in the tiniest of detail. Weaving is more graceful and productive. In IC design flow terms, I equate stitching with scripting. It is task that is useful to join pieces of the flow together. Weaving creates something. It transforms thread to cloth, and therefore equates more to synthesis. Weaving is a process.

So when it came to developing and naming a tool used to effectively integrate IP and create a chip hierarchy, in a structured manner, we didn’t consider consider ‘STITCHER’ – It had to be ‘WEAVER’.

Stitching is important to fix things, and is necessary in emergency situations, however it has its limitations and as if used as a core creation process, it may come undone. So as I ranted on during that vital presentation, as I got to the cusp of the value-add, I curbed my enthusiasm, keep it slightly in check just in case those button stitches came undone and resulted in a serious eye injury of an altogether innocent customer. What then, of those poor stitched chips? What if those threads start to unravel and your chip integration is running very late. You may have to resort to different type of Weaving, when dealing with your management, customers or partners.

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Which MBA? Think twice

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According to Economist, studying MBA is not a good investment. So I should be glad that MBA school rejected my application.

2 Feb 2011, Economist
Set your heart on an MBA? Philip Delves Broughton suggests a radical alternative: don’t bother

Business schools have long sold the promise that, like an F1 driver zipping into the pits for fresh tyres, it just takes a short hiatus on an MBA programme and you will come roaring back into the career race primed to win. After all, it signals to companies that you were good enough to be accepted by a decent business school (so must be good enough for them); it plugs you into a network of fellow MBAs; and, to a much lesser extent, there’s the actual classroom education. Why not just pay the bill, sign here and reap the rewards?

The problem is that these days it doesn’t work like that. Rather, more and more students are finding the promise of business schools to be hollow. The return on investment on an MBA has gone the way of Greek public debt. If you have a decent job in your mid- to late- 20s, unless you have the backing of a corporate sponsor, leaving it to get an MBA is a higher risk than ever. If you are getting good business experience already, the best strategy is to keep on getting it, thereby making yourself ever more useful rather than groping for the evanescent brass rings of business school.

Business schools argue that a recession is the best time to invest in oneself. What they won’t say is that they also need your money. There are business academics right now panting for your cheque. They need it to pad their sinecures and fund their threadbare research. There is surely no more oxymoronic profession than the tenured business-school professor, and yet these job-squatting apostles of the free market are rife and desperate. Potential students should take note: if taking a professional risk were as marvellous as they say, why do these role models so assiduously avoid it?

Harvard Business School recently chose a new dean, Nitin Nohria, an expert in ethics and leadership. He was asked by Bloomberg Businessweek if he had watched the Congressional hearings on Goldman Sachs. He replied: “The events in the financial sector are something that we have watched closely at Harvard Business School. We teach by the case method, and one of the things we’ll do through this experience is study these cases deeply as information is revealed over time so we can understand what happened at all these financial firms. I’m sure that at some point we’ll write cases about Goldman Sachs because that’s how we learn.” He could have stood up for Goldman or criticised it. Instead he punted on one of the singular business issues of our time. It is indicative of the cringing attitude of business schools before the business world they purport to study.

When you look at today’s most evolved business organisms, it is obvious that an MBA is not required for business success. Apple, which recently usurped Microsoft as the world’s largest technology firm (by market capitalisation), has hardly any MBAs among its top ranks. Most of the world’s top hedge funds prefer seasoned traders, engineers and mathematicians, people with insight and programming skills, to MBAs brandishing spreadsheets, the latest two-by-twos and the guilt induced by some watery ethics course.

In the BRIC economies, one sees fortunes being made in the robust manner of the 19th-century American robber barons, with scarcely a nod to the niceties of MBA programmes. The cute stratagems and frameworks taught at business schools become quickly redundant in the hurly-burly of economic change. I’ve often wondered what Li Ka-Shing of Hong Kong or Stanely Ho of Macao, or Rupert Murdoch, for that matter, would make of an MBA programme. They would probably see it for what it is: a business opportunity. And as such, they would focus on the value of investing in it.

They would look at the high cost, and note the tables which show that financial rewards are not evenly distributed among MBAs but tilt heavily to those from the very top programmes who tend to go into finance and consulting. Successful entrepreneurs are as rare among MBAs as they are in the general population.

They would think to themselves that business is fundamentally about two things, innovating and selling, and that most MBA programmes teach neither. They might wonder about the realities of the MBA network. There is no point acquiring a global network of randomly assembled business students if you just want to work in your home town. Also, they will recall that the most effective way to build a network is not to go to school, but to be successful. That way you will have all the MBA friends you could ever want.

They might even meet a few business academics and wonder. Then they would take their application and do with it what most potential applicants should: toss it away.

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The power of posture

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According to this research, how your posture affect your projection of power and how other people perceive it. It is interesting to note the powerful sitting posture is regard as bad sitting manner in traditional Chinese culture. Another evidence for my theory that manners are simply rules set by the authority to make people easier to rule.

How you hold yourself affects how you view yourself
Jan 13th 2011, Economist

“STAND up straight!” “Chest out!” “Shoulders back!” These are the perennial cries of sergeant majors and fussy parents throughout the ages. Posture certainly matters. Big is dominant and in species after species, humans included, postures that enhance the posturer’s apparent size cause others to treat him as if he were more powerful.

The stand-up-straight brigade, however, often make a further claim: that posture affects the way the posturer treats himself, as well as how others treat him. To test the truth of this, Li Huang and Adam Galinsky, at Northwestern University in Illinois, have compared posture’s effects on self-esteem with those of a more conventional ego-booster, management responsibility. In a paper just published in Psychological Science they conclude, surprisingly, that posture may matter more.

The two researchers’ experimental animals—77 undergraduate students—first filled out questionnaires, ostensibly to assess their leadership capacity. Half were then given feedback forms which indicated that, on the basis of the questionnaires, they were to be assigned to be managers in a forthcoming experiment. The other half were told they would be subordinates. While the participants waited for this feedback, they were asked to help with a marketing test on ergonomic chairs. This required them to sit in a computer chair in a specific posture for between three and five minutes. Half the participants sat in constricted postures, with their hands under their thighs, legs together or shoulders hunched. The other half sat in expansive postures with their legs spread wide or their arms reaching outward.

In fact, neither of these tests was what it seemed. The questionnaires were irrelevant. Volunteers were assigned to be managers or subordinates at random. The test of posture had nothing to do with ergonomics. And, crucially, each version of the posture test included equal numbers of those who would become “managers” and “subordinates”.

Once the posture test was over the participants received their new statuses and the researchers measured their implicit sense of power by asking them to engage in a word-completion task. Participants were instructed to complete a number of fragments (for example, “l_ad”) with the first word that came to mind. Seven of the fragments could be interpreted as words related to power (“power”, “direct”, “lead”, “authority”, “control”, “command” and “rich”). For each of these that was filled out as a power word (“lead”, say, instead of “load”) the participant was secretly given a score of one point.

Although previous studies suggested a mere title is enough to produce a detectable increase in an individual’s sense of power, Dr Huang and Dr Galinsky found no difference in the word-completion scores of those told they would be managers and those told they would be subordinates. The posture experiment, however, did make a difference. Those who had sat in an expansive pose, regardless of whether they thought of themselves as managers or subordinates, scored an average of 3.44. Those who had sat in constricted postures scored an average of 2.78.

Having established the principle, Dr Huang and Dr Galinsky went on to test the effect of posture on other power-related decisions: whether to speak first in a debate, whether to leave the site of a plane crash to find help and whether to join a movement to free a prisoner who was wrongfully locked up. In all three cases those who had sat in expansive postures chose the active option (to speak first, to search for help, to fight for justice) more often than those who had sat crouched.

The upshot, then, is that father (or the sergeant major) was right. Those who walk around with their heads held high not only get the respect of others, they seem also to respect themselves.

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To Really Learn, Quit Studying and Take a Test

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That’s why the most effective way to learn is taking a course with the home work assignments and exams that force you to learn.

By Pam, Belluck, New York Times, January 20, 2011

Taking a test is not just a passive mechanism for assessing how much people know, according to new research. It actually helps people learn, and it works better than a number of other studying techniques.

The research, published online Thursday in the journal Science, found that students who read a passage, then took a test asking them to recall what they had read, retained about 50 percent more of the information a week later than students who used two other methods.

One of those methods — repeatedly studying the material — is familiar to legions of students who cram before exams. The other — having students draw detailed diagrams documenting what they are learning — is prized by many teachers because it forces students to make connections among facts.

These other methods not only are popular, the researchers reported; they also seem to give students the illusion that they know material better than they do.

In the experiments, the students were asked to predict how much they would remember a week after using one of the methods to learn the material. Those who took the test after reading the passage predicted they would remember less than the other students predicted — but the results were just the opposite.

“I think that learning is all about retrieving, all about reconstructing our knowledge,” said the lead author, Jeffrey Karpicke, an assistant professor of psychology at Purdue University. “I think that we’re tapping into something fundamental about how the mind works when we talk about retrieval.”

Several cognitive scientists and education experts said the results were striking.

The students who took the recall tests may “recognize some gaps in their knowledge,” said Marcia Linn, an education professor at the University of California, Berkeley, “and they might revisit the ideas in the back of their mind or the front of their mind.”

When they are later asked what they have learned, she went on, they can more easily “retrieve it and organize the knowledge that they have in a way that makes sense to them.”

The researchers engaged 200 college students in two experiments, assigning them to read several paragraphs about a scientific subject — how the digestive system works, for example, or the different types of vertebrate muscle tissue.

In the first experiment, the students were divided into four groups. One did nothing more than read the text for five minutes. Another studied the passage in four consecutive five-minute sessions.

A third group engaged in “concept mapping,” in which, with the passage in front of them, they arranged information from the passage into a kind of diagram, writing details and ideas in hand-drawn bubbles and linking the bubbles in an organized way.

The final group took a “retrieval practice” test. Without the passage in front of them, they wrote what they remembered in a free-form essay for 10 minutes. Then they reread the passage and took another retrieval practice test.

A week later all four groups were given a short-answer test that assessed their ability to recall facts and draw logical conclusions based on the facts.

The second experiment focused only on concept mapping and retrieval practice testing, with each student doing an exercise using each method. In this initial phase, researchers reported, students who made diagrams while consulting the passage included more detail than students asked to recall what they had just read in an essay.

But when they were evaluated a week later, the students in the testing group did much better than the concept mappers. They even did better when they were evaluated not with a short-answer test but with a test requiring them to draw a concept map from memory.

Why retrieval testing helps is still unknown. Perhaps it is because by remembering information we are organizing it and creating cues and connections that our brains later recognize.

“When you’re retrieving something out of a computer’s memory, you don’t change anything — it’s simple playback,” said Robert Bjork, a psychologist at the University of California, Los Angeles, who was not involved with the study.

But “when we use our memories by retrieving things, we change our access” to that information, Dr. Bjork said. “What we recall becomes more recallable in the future. In a sense you are practicing what you are going to need to do later.”

It may also be that the struggle involved in recalling something helps reinforce it in our brains.

Maybe that is also why students who took retrieval practice tests were less confident about how they would perform a week later.

“The struggle helps you learn, but it makes you feel like you’re not learning,” said Nate Kornell, a psychologist at Williams College. “You feel like: ‘I don’t know it that well. This is hard and I’m having trouble coming up with this information.’ ”

By contrast, he said, when rereading texts and possibly even drawing diagrams, “you say: ‘Oh, this is easier. I read this already.’ ”

The Purdue study supports findings of a recent spate of research showing learning benefits from testing, including benefits when students get questions wrong. But by comparing testing with other methods, the study goes further.

“It really bumps it up a level of importance by contrasting it with concept mapping, which many educators think of as sort of the gold standard,” said Daniel Willingham, a psychology professor at the University of Virginia. Although “it’s not totally obvious that this is shovel-ready — put it in the classroom and it’s good to go — for educators this ought to be a big deal.”

Howard Gardner, an education professor at Harvard who advocates constructivism — the idea that children should discover their own approach to learning, emphasizing reasoning over memorization — said in an e-mail that the results “throw down the gauntlet to those progressive educators, myself included.”

“Educators who embrace seemingly more active approaches, like concept mapping,” he continued, “are challenged to devise outcome measures that can demonstrate the superiority of such constructivist approaches.”

Testing, of course, is a highly charged issue in education, drawing criticism that too much promotes rote learning, swallows valuable time for learning new things and causes excessive student anxiety.

“More testing isn’t necessarily better,” said Dr. Linn, who said her work with California school districts had found that asking students to explain what they did in a science experiment rather than having them simply conduct the hands-on experiment — a version of retrieval practice testing — was beneficial. “Some tests are just not learning opportunities. We need a different kind of testing than we currently have.”

Dr. Kornell said that “even though in the short term it may seem like a waste of time,” retrieval practice appears to “make things stick in a way that may not be used in the classroom.

“It’s going to last for the rest of their schooling, and potentially for the rest of their lives.”