* 22 entries including: power grid infrastructure, UN Secretary General Ban Ki-Moon, future cellphones, RFID tagging luggage, Chinese sweatshop practices, Boeing versus Airbus, ethanol in Latin America, Bigelow commercial space stations, cheating with online scoring systems, using the internet in Baghdad, improved geothermal energy technology, modular home construction, the art of bribery, space pen myth.
* INFRASTRUCTURE -- THE POWER GRID (8): There are a number of other interesting details to be observed at a power substation:
All the gear in a substation is heavily grounded, since if it weren't a worker touching a transformer case might end up being the connection to ground instead. Even the fencing is heavily grounded, and the chain-link fence around the site may be strung through with wires to keep it from building up an induced charge from the strong electric fields permeating the site.
Other items worthy of comment at substations may be plastic plates or baskets over the lines coming into or going out of the substation. Squirrels like to walk on power lines, and if they get into the substation it may be bad for their health and for the operation of the substation. There may be sets of fiberglass poles or "hot sticks" stacked inside the substation: they're used by service workers to clear debris from or otherwise interact with "hot" gear in the substation. [TO BE CONTINUED]START | PREV | NEXT
* FUTURE PHONES: Cellphones have evolved in ways that would have been hard to predict decades ago, demonstrating that the prediction game is dodgy. However, as reported in THE ECONOMIST ("The Phone Of The Future", 2 December 2006), considerable effort has been put into imagining where the cellphone will be decades from now.
Even in the present, the cellphone is no longer strictly a tool for voice communications. Cellphones often incorporate digital cameras and digital music players. Games and video entertainment are catching on a bit, as are location systems, and in the Far East cellphones with short-range RF interfaces are starting to be used as "electronic wallets" for performing small purchases. Digital messaging and networked transaction systems are making inroads as well. Where will it end? According to Bruce Sterling, a science-fiction writer turned "futurist", the phone will become the "remote control for life."
Cellphone processing power and memory are increasing rapidly, and the capabilities of the cellphone of tomorrow will likely match or even exceed that of the laptop computers of today. It is also very plausible that the cellphone of tomorrow won't look like a cellphone. Cellphone manufacturers have come to the conclusion that building a cellphone to do absolutely everything leads to an clunky and overly expensive product -- "flexibility is the key to uselessness", as the old saying goes -- and it may be attractive to modularly break up the functionality. We already have bluetooth sets that fit into the ear; displays in the form of glasses are being developed, and research is under way on schemes to read the vibrations of the larynx to provide a form of voice input.
There is no obstacle but investment to turn the cellphone of today into an enhanced networking tool that would allow a user to control a home. With increasing use of RFID in products, a cellphone could be even used to find some object, eyeglasses maybe, misplaced in the house. Of course, predictions of the future are always dodgy, particularly in terms of the social changes, both good and bad, they can lead to. Technological visionaries aren't the only ones considering the implications of new technology. So are crooks -- and they are very quick to exploit new opportunities.BACK_TO_TOP
* LUGGAGE RFID: According to an article from WIRED.com ("Never Lose Luggage Again" by Dave Demerjian), RFID systems promise to make lost luggage from an airplane trip a rarity instead of a common complaint -- if the cash-strapped airlines can be persuaded to use them.
These days, the normal scheme for tracking luggage is a barcoded luggage tag with a 10-digit identifier, which is read by laser scanners connected to a central database as the luggage is shunted along conveyors. Unfortunately, the tags get crushed, dirty, or lost, and so even new barcode scanners don't read the tags correctly more than 90% of the time. As the scanners age, the ratio of good reads drops. In 2005, there were 3.5 million lost-baggage complaints, and the number for 2006 is expected to be bigger. The costs of tracking down lost luggage run to several billion USD a year.
Luggage tags with disposable passive electronic RFID systems would be a much better technical solution than barcodes. RFID doesn't need a clear line of sight to the tag, and dirt does little to degrade reading of the tag. RFID tags are not much damaged by weather, and adapting the baggage-handling system to RFID readers should be straightforward. Best of all, RFID scanners have a successful read rate of better than 99%. This would reduce the problem of lost luggage to a fraction of what it is now.
The problem is that while a barcode tag might costs about 2 cents, an RFID tag might cost up to 20 cents. With a large airline like Delta handling over a hundred million bags a year, that cost adds up, and airlines are reluctant to take the plunge. However, McCarran International Airport in Las Vegas now has an RFID-based baggage handling system. With 70,000 bags going through the airport each day, a 90% read rate means 7,000 lost bags a day. A read rate of better than 99% means a much more manageable situation. The McCarran system includes 300 readers set up at check-in stations and another 70 readers distributed along the internal baggage distribution system. Passenger data is entered into a database at check-in time, with the baggage handling system referencing the RFID tags to the database to make sure the luggage is correctly routed. Right now, barcode tags are used along with the RFID tags, but soon combination tags will be available. The use of both systems means that the scheme will work even if not all airports and airlines used RFID luggage tags, allowing the scheme to be introduced gradually.
Hong Kong International Airport also has an RFID baggage handling system, which has the additional interesting security measure of flagging any luggage stowed on an aircraft for removal if the owner hasn't boarded. There were some problems with the system at first, since RFID tags couldn't be read if they were lying on a metal surface, but that was fixed with some minor changes to the conveyor system. The readers also sometimes picked up the wrong tags, but this problem was addressed by reducing the reader power and range.
Several airlines are committing to RFID schemes. The International Air Transportation Association (IATA) has come up with a global RFID tag specification to ensure that a tag attached at one airport can be read at another. Compared to the costs of lost baggage, going RFID would seem to be a no-brainer, but not all the airlines are convinced they'll come out ahead -- the Hong Kong International system cost $50 million USD, which was not pocket change. It's by no means certain that RFID will be universal in baggage handling systems any time soon
Still, some advocates are convinced that RFID is the way of the future for the airlines, with tags also tracking luggage bins, catering trolleys, and even passengers. Says an enthusiast: "Embed a tag in their boarding pass or give them a bracelet, and it would be quite easy to locate passengers who were late boarding their flights." Those who have suggested that RFID is literally the work of the devil might not like the idea of being tagged like a wild bear -- but given how paranoid airports are, it's not an implausible vision of the future by any means.BACK_TO_TOP
* SWEATSHOP SLEIGHT OF HAND: These days, global corporations like Nike and Walmart are very careful about dealing with subcontractors in countries like China where protection of worker's rights are weak. No big company wants to be accused of supporting worker exploitation, and so the companies have guidelines for their subcontractors, performing audits on the subcontractors to ensure compliance.
As reported by BUSINESS WEEK, a Chinese supplier of pens, mechanical pencils, and highlighters was under the gun from Walmart, having flunked three audits for paying under minimum wage and violating overtime rules. The company was faced with a fourth audit that would be the last if things hadn't changed -- when the management got a cold-call from an official named Lai Mingwei with a firm with the seemingly innocent name of the Shanghai Corporate Responsibility Management & Consulting Company. Lai promised them that, for a fee, he could make sure they passed the audit. They hired him.
Lai's angle on "corporate responsibility management" was focused on "management" at the cost of "corporate responsibility". He showed the client company how to cook up a set of fake books to give to the auditors, how to spot troublemaking workers and send them home for the day of the audit, and briefed managers on what to say to the auditors. It all worked perfectly, the company passing the audit easily -- without having otherwise changed their business practices in the slightest. Ex-workers from various Chinese companies have been blowing the whistle on such games. BUSINESS WEEK reporters talked with Lai's clients, who deny wrongdoing; Lai was willing to talk with reporters, saying his consulting activities were perfectly legitimate, focused on rectifying problems and not just covering them up.
There does seem to a lot of cheating on the system, and it's all but inevitable. Chinese labor laws and enforcement of such laws as do exist are weak, and suppliers are under relentless price pressure from clients such as Walmart. Even as the suppliers are being squeezed on prices, they are being held to compliance on work rules that make it more difficult to stay in business. In other words, the system is arranged to give strong incentives to cheat, and also tends to implicitly shift part of the blame on the corporations, not just the subcontractors. One corporate compliance manager believes that only about 20% of Chinese subcontractors comply with wage rules, while only 5% comply with overtime rules. An owner of a Hong Kong factory flatly says: "These goals are a fantasy. Maybe in two or three decades we can meet them." Even some workers are inclined to cheat the rules: faced with the choice of working extra hours for the same pay when the alternative is no extra pay at all, they choose the extra pay.
To compound the difficulty, the auditing industry is a big business, not only involving large auditing operations inside major corporations, but bringing in global auditing agencies such Cal Safety Compliance, SGS of Switzerland, and Bureau Veritas of France. A single subcontractor may have several clients who are insisting on different sets of rules, with auditors visiting almost daily. Auret van Heerden, head of the Fair Labor Association, a compliance group of 20 corporations including Nike, Adidas, and Nordstrom, admits to the chaos: "McDonald's, Walt Disney, and Walmart are doing thousands of audits a year that are not harmonized." Given such a torrent of inspection, even factory managers who want to be conscientious start to fall prey to "audit fatigue".
Some corporations, such as Nike, are becoming more involved in the operations of subcontractors, helping them to streamline their processes to raise their profit margins without having to break the rules. Other corporations have tried to establish better communications with suppliers, listening to them when they say they are having troubles complying with the rules, instead of simply making demands and driving the problems underground. Corporations have also established a "Fair Factories Clearinghouse" to allow them to compare notes on suppliers and also set more consistent rules. However, getting the system to work, particularly in the face of China's lax labor laws, promises to be an uphill struggle for a long time to come.BACK_TO_TOP
* MISTER BAN'S NEW JOB (3): The issue of peacekeeping operations deserves a closer look. Since 1998, the number of UN peacekeepers has multiplied several times, with 100,000 personnel now in the field -- including about 74,000 soldiers -- conducting 18 separate operations. NATO, the European Union (EU), and African Union (AU) have about the same number of troops involved in peacekeeping. Lump onto this the 160,000 Yanks and Tommies in Iraq and that adds up to a lot of soldiers trying, with various levels of success, to keep the peace.
One reason for this military hyperactivity is the "war on terror", but the UN undersecretary for peacekeeping, Jean-Marie Guehenno, says there is actually a silver lining in the boom market for peacekeeping: it means that a lot of wars have come to a halt and it's time for cleanup. This is true for the three biggest UN peacekeeping operations -- in the Congo, southern Sudan, and Liberia -- but elsewhere -- Lebanon and Cote de Ivoire -- the most peacekeepers are doing is holding a no-man's land between sides effectively still at war.
Africa is the main target of UN peacekeeping operations. The AU has been trying to police their own continent, but lacks resources. The UN has taken over the AU peacekeeping mission in Burundi, and now a combined UN-AU peacekeeping mission for Darfur is poised to take over from an ineffective AU operation. The Sudanese government has long fought any UN intervention in the Darfur region, calling it Western imperialism in disguise, but intense pressure forced the government to concede.
Guehenno is cautious about what he thinks can be achieved there. Darfur is a vast region with a harsh environment and poor infrastructure, and it will be expensive to support a military force big enough to do the job -- presuming the troops can be found. The spirit of voluntarism can be high for some peacekeeping operations, with European countries quick to send troops to Lebanon in the aftermath of last summer's war, but that is not always the case. Kofi Annan once observed that the UN is the only fire brigade that must go out and buy a fire engine before it can respond to an emergency. The Security Council must authorize the operation and set up a budget; then the secretariat must wheedle the troops from member states and manage the operation. The big countries pay for the missions, sometimes providing logistical support such as air transport, while poorer countries -- India, Pakistan, Bangladesh, Nepal, Jordan -- supply the soldiers and do the grunt work. The UN payments for the troops help support the armed forces, and the armed forces get field training.
From the start, there have been pushes to set up a dedicated UN force, but the idea has always foundered on the reluctance of member states to hand too much power over to the UN, as well as the simple logistical and financial difficulty of supporting such a force. Given the failures of the UN in the Balkans and Rwanda, there are those who argue that the peacekeeping job should be done by those equipped to do it. NATO forces put a stop to the warfighting in Kosovo in 1999, while Australian troops ended conflict in East Timor the same year. In 2000, the UN peacekeeping force in Sierra Leone was close to collapse in the face of rebel attacks when the intervention of a mere brigade -- a thousand men -- of professional British Army troops quickly crushed the rebels.
However, in 2000 a panel under UN envoy Lakdhar Brahimi conducted a study that recommended changes in the way the UN performed peacekeeping operations. The panel did say that the UN "does not wage war" but that UN blue-helmet forces could "project credible force" and distinguish between victims and aggressors. The panel's core recommendation that forces be set up among member states in pre-preparation for rapid deployment to trouble spots hasn't advanced smoothly, but other recommendations have been implemented. A more powerful headquarters organization has been set up; equipment has been stockpiled; the UN now has lists of military officers, police, and other experts who are more or less "on call" for emergencies; and much more thought has been put into meshing peacekeeping operations with ordinary policing, government reform, and economic development. The weak peacekeeping mandates of the past are being discarded; peacekeeping operations are now expected to use "all necessary means" to carry out their mission -- though to no surprise there are now worries that the use of force may be taken to the other extreme.
The UN is even taking a page from the book of the US military and thinking about hiring private security companies for peacekeeping operations. That is a big and controversial step, not likely to happen any time soon, but it is a sign that the UN is increasingly willing to think out of the box to accomplish the peacekeeping mission more effectively. [END OF SERIES]START | PREV
* INFRASTRUCTURE -- THE POWER GRID (7): Towns always have power substations where the high-voltage trunks terminate and the electricity is distributed for local use. A substation is a fenced-off site cluttered with mysterious equipment, with a high-voltage line coming in and low-voltage lines going out. The site is crisscrossed with sets of "bus bars", usually long aluminum tubes, to shuffle the electricity around. The bars are held up by a scaffolding system, of course connected through porcelain insulator strings to prevent them from shorting out. Longer bus bars may be interrupted and jumped by a metal braid to compensate for thermal expansion.
The biggest objects in the substation are the transformers, which look like boxes with electrical connections coming in on one side and out on the other, filled with big transformer coils. For a triple-phase line, there will be a set of three transformers, possibly with all three in the same box. The high-voltage input generally has heftier "bushings" -- they look like insulating strings but conduct electricity down the center -- than the output or outputs. Although transformers are efficient, they still dissipate a bit of power, and so there are fins and banks of fans on them to get rid of the heat.
Oil circulates inside the transformer box to transport the heat from the interior. There may be an oil tank or tanks on top of the transformer to make sure there's adequate oil. Sensor systems built into the transformer check the state of the oil, checking for hydrogen bubbles that could indicate shorting inside the coils. A substation site is usually laid out with a barrier around the perimeter to ensure that oil will not drain off and contaminate the soil if a transformer springs a leak or blows out.
The amount of voltage pulled off the output side of a transformer can be varied simply by moving the "tap" connection off the output coil. This needs to be done at times to make sure the output voltage remains constant. The "tap-changer" on the side of the transformer housing used to have a hefty manual lever on it, but these days it's all done by remote control and there's nothing to see but a closed box on the side of the transformer. Very often the transformer has to be shut down before the tap can be changed.
* Shutting down the flow of electricity means a switch, but not too surprisingly the switches at a power substation are more formidable than those in your house. A typical high-voltage switch looks like a box or cylinder with two bushings on top to connect to inputs and outputs. The switch is full of oil, same stuff as inside the transformer box; when the switch contacts are opened, they tend to arc across (as described earlier) and the vaporized oil helps to shut down or "quench" the arc quickly.
A switch can look like a transformer, but there are clear differences. In the first place, a switch doesn't dissipate power whether its open or closed, and so a switch has no cooling fins or fans. In the second place, a transformer has a circuit in and a circuit out, meaning at least two insulator strings on each side. A switch is in line with a circuit, meaning that they may have one insulator string in and one insulator string out. For three-phase power, three switches are ganged together.
There are variations on switch technology. "Air-blast" switches, as their name implies, use a blast of high-pressure air to quench the arc. They lack the big tank of oil switches and may have a tee-shaped structure. The advantage of an air-blast switch is that there's no oil to deal with. The disadvantage is that they make a loud BANG when they're actuated, and they are not well suited for use in areas where neighbors can complain. In Europe, "metalclad" switches use sulfur hexafluoride, which is a heavy gas that its very efficient at quenching arcs. It is also very expensive.
Switches can be actuated manually -- at least in the sense of someone pressing a button, though a switch actually gets the command by remote control -- or by automated systems that determine network faults, in which case the switch acts as a "circuit breaker", conceptually similar to those in a home. Since network faults tend to be transients, a circuit breaker thrown open will automatically reclose after a second or two; if the fault persists after a number of retries, the breaker stays open and service workers have to deal with the problem.
A substation has to designed carefully as a component of the complete network to ensure reliability. There is generally a degree of redundancy to make sure that power gets to the end users even when part of the system goes down. [TO BE CONTINUED]START | PREV | NEXT
* GIMMICKS & GADGETS: BUSINESS WEEK reported on an interesting wind-power gimmick proposed by an American designer, Mark Obserholzer. His idea is to put vertical wind turbines in the barrier between the lanes of a freeway, with the turbines driven by traffic roaring past. One further concept would be to run an electric light rail down the midline, running on the power generated by the turbines.
* Britain is sometimes regarded as the world homeland for security cameras, a notion reinforced by a test exercise in Plymouth in which 250 police officers are wearing helmets fitted with a small color video camera. The cameras document an officer's actions and record details of incidents. Initial results of the trial show a 40% increase in the number of crimes being detected and a 20% increase in the conversion of a violent incident into an official crime.
* According to CNET.com, researchers at Purdue University have developed a "tactical biorefinery" for the US Army -- a portable generator that extracts energy from trash. The biorefinery is about the size of a small moving van and can process a range of trash, including paper, plastic, styrofoam, cardboard, woodchips and food waste.
Two different processes are used: food material is dumped into a bioreactor to be fermented by yeasts into ethanol, while the other materials -- paper cups, plastic forks, and so on -- are crushed into pellets and then burned to produce a mixed hydrocarbon-hydrogen gas. The ethanol and the gas are used to drive a diesel / multifuel electric generator to drive the biorefinery and provide external power. The generator can be run on conventional diesel fuel until its conversion processes are up to speed. The Army is interested in the system not merely because of the service's public mandate for environmental responsibility, but because it reduces the level of trash needed to be handled in field operations.
* Users of the latest Microsoft Internet Explorer 7 (IE7) may have noticed an interesting feature: get into a site like Paypal and the URL bar of the browser turns green. The feature, intended to defeat "phishing" online scams, is based on an "extended validation (EV) certificate" associated with Paypal or other properly registered sites. Security certification are not new, being associated with the "https" or "secure http" pages often used to ask for credit card information and the like, but the EV certificate is much more robust and harder to fake. That makes it more expensive, with a cost of hundreds instead of tens of dollars, and small businesses complain it is burdensome for their needs -- though it is the big operators like Paypal that are the primary focus of scams. Other browser makers are considering implementing the scheme.BACK_TO_TOP
* THE WOLF BITES BACK: In the business world, there are some sets of competitors whose relationship goes beyond even intense rivalry to bitter hatred. The acid relationship between Microsoft and its rivals, particularly Apple, seems subdued these days, but the enmity between world's two biggest jetliner manufacturers, Boeing of the USA and Airbus Industries of Europe, continues in full force.
Boeing had dominated the world jetliner market and was contemptuously dismissive of upstart Airbus at first, Boeing officials publicly stating that Airbus was just another European boondoggle that would sell a handful of aircraft and then be forgotten. When Airbus finally landed a US deal using what might be tactfully called "imaginative financing", Boeing's reaction was loud and angry, leading a senior Airbus official to sneer that "the Big Bad Wolf is screaming because Little Red Riding Hood has bitten him in the ass."
Only a few years back, Airbus could finally boast of a year of orders that exceeded those of Boeing, and was moving full speed ahead on the new A380 "super jumbo" airliner. Boeing seemed to be stalled, unwilling to accept the challenge, and then the company was hit with scandals that led to the successive resignations of two CEOs, as well as the imposition of US government penalties. It didn't take a mind reader to sense the satisfaction that Airbus took in the distress of its rival.
Now, as discussed in an article in BUSINESS WEEK ("The Secret Weapon At Boeing" by Stanley Holmes, 8 January 2007), the shoe is on the other foot. When Boeing announced the advanced twinjet 787 Dreamliner, Airbus officials were quick to criticize its "excessive" reliance on composite construction, but this was merely a classic exercise in spreading "fear, uncertainty, and doubt (FUD)" among potential customers that fizzled. The 787 was the right product at the right time: airlines were looking to replace aging air fleets, and with high fuel prices the fuel-economical 787 was exactly what they wanted. Airbus gave up the FUD campaign and responded with a competing "A350" design, which even at best would not be delivered to customers until several years after the 787 was in service. Design waffling in the face of customer inputs put it even further behind.
Airbus hoped the A380 would not only be a market leader as a passenger liner, but it would also be able to take on Boeing's continued domination of the air freightliner market, mostly through to freighter versions of the classic Boeing 747 jumbo jet. Unfortunately for Airbus, the A380 has run into technical problems with its vast wiring system and has been delayed. Boeing is working to release an improved 777 freightliner in 2008, and then the "747-8" freightliner in 2009. The 747-8 is the latest incarnation of the 747; it will be stretched for more capacity and range; feature new, highly efficient engines and wings; and have advanced avionics leveraged from the 787 program -- hence the "-8" suffix.
The air freight business is booming, particularly as trade from Asia increases. Boeing's traditional proportion of freightliner sales to total business is about 10%; for the moment it's up to 17%. Overall orders have zoomed back ahead of Airbus. Even when Airbus gets the A380 flying right, the 747-8 will be highly competitive in terms of capability and operating economy -- and with the dollar being weak at this time, relatively cheap to buy as well. Customers who had planned to buy A380 freighters are now canceling orders and lining up to get the 747-8, to such an extent that industry observers are suggesting that the A380 freightliner may be canceled. Airbus is now restructuring and performing layoffs.
The delay in the A380 program also helps Boeing in other ways. It means that more old 747 jetliners are being kept in service, instead of being converted to freightliners, and so there is a better new-buy market for freightliners. It also opens a window of opportunity for Boeing to sell 747-8 passenger liners. Airbus had mocked the announcement of 747-8 passenger liner versions, calling the 747 design in effect "old news", but with the A380 program delayed the 747-8 passenger liner just keeps looking better and better. Boeing can respond in all truth to the "old news" jab that, unlike the A380, the 747 is a well-proven and trustworthy design, and that with the latest improvements the 747-8 is a match for the A380 as far as cost-effectiveness is concerned.
Boeing has not demonstrated much inclination to publicly gloat over the distress of Airbus; Boeing's own recent troubles ensured that company officials aren't in a comfortable position to crow, and the message seems to have soaked in that the customers and the aerospace industry in general are sick of listening to the petty-minded sniping between the two companies. However, once again it hardly takes a mind-reader to suspect that there's a lot of gloating going on in private.BACK_TO_TOP
* LATIN ETHANOL: US President George W. Bush recently conducted a Latin American tour in hopes of mending tattered fences, and as it turned out one of the big items on the agenda was biofuel production. According to an article in THE ECONOMIST ("Fuel For Friendship", 3 March 2007), the matter is an important one to Bush, who has stated that the US will become increasingly reliant on biofuels in the near future, and to his first host on the tour, Brazilian President Luiz Inacio Lula da Silva.
Biofuels have been a bit of a sore point between the US and Brazil. The US has been pushing corn-based ethanol, with corn regarded as an expensive feedstock and the ethanol produced from it suffering from a number of drawbacks; Brazil uses sugar cane as a feedstock, still not perfect but grown in great quantity and, best of all, more easily converted into ethanol than corn: cornstarch has to be broken down into sugars first, sugar cane is mostly sugar to begin with. That means that Brazilian ethanol is about 75% the price of American ethanol -- and in today's oil market, cost-competitive even without subsidies. To keep American farmers happy, the US government has slapped import duties of 54 cents per US gallon (14.25 cents per liter) on most foreign ethanol.
This trade protectionism runs head-on into Brazil's biofuel ambitions. New ethanol production is coming online at a fast clip, with projections that Brazil will have 412 distilleries pouring out 36 billion liters (9.5 billion US gallons) of ethanol. Brazil would like trade barriers with the US (and with Europe, which similarly shuts out Brazilian ethanol) to fall, with projections showing that a fair trade regime would boost the country's current exports of 3 billion liters (790 million US gallons) per year to 200 billion liters (53 billion US gallons) by 2025. To put that in perspective, that would replace 10% of the world's gasoline consumption. That's not just an economic opportunity -- it's a bid for global power.
Other Latin American nations are jumping on the biofuel bandwagon as well, with their interest partly boosted by the fact that sugar cane is a common crop throughout the region. Colombia is building a number of plants, with government regulations ensuring there will be a market: by 2009, filling stations will be required to sell a 10% ethanol / 90% gasoline mix, with the proportion of ethanol rising to 25% in time. Costa Rica has implemented much the same policy, and Panama is considering it. Studies have encouraged Mexico to come on board, and a number of Caribbean nations see ethanol as a tempting way to boost their lagging sugar industry.
What these countries would like is access to the US market. Some of the smaller players in the game, such as Peru, already have it, the import duty having been waivered by trade concessions. A pipeline is being built in Peru to pump the ethanol to tankers for seaborne delivery to the USA and elsewhere. The Peruvians see exports of 120 million liters (32 million US gallons) by 2010 -- a drop in the bucket compared to what Brazil is capable of, but a substantial sum in itself.
The US has many good reasons to promote the biofuel industry in Latin America. For one, there is no way that the US can meet the targets for biofuel use stated by the Bush II Administration on its own. Imports from Latin America wouldn't constitute "energy independence", but ethanol from "friendlies" like Brazil and Colombia is much preferable to oil from "hostiles" like Iran and Venezuela. Buying Latin American ethanol would also help economic development in the region, reduce the flow of illegal immigrants, and polish America's somewhat tarnished reputation south of the border.
Outgoing Florida Governor Jeb Bush, the president's brother, set up an "InterAmerican Ethanol Commission" to promote a hemispheric biofuel effort and wrote the White House to suggest that the Federal government similarly devise "a comprehensive ethanol strategy" involving the USA and America's neighbors. On his Brazil stop, Presidents Bush and Lula da Silva signed a cooperative agreement on biofuels that was played up in the news media. The tariff still remains in effect, however, at least until it lapses in 2009.BACK_TO_TOP
* MISTER BAN'S NEW JOB (2): Ban Ki-moon's appointment to head the UN was, as noted, loaded with booby-traps, particularly given the fractious nature of the relationship between the UN and the Bush II Administration. Worse, though he flatly says he needs American help to run the UN, he can't be seen as a tool of the US either, since it would destroy his credibility with the assertive group of members from developing countries known as the "G77". It was established in 1964, with 77 members as the name indicates, and for a long time it amounted to little, with no agreement among its members except for more aid and trade concessions. Now it has 131 members, plus China, and is far from unassertive.
Not everyone disagreed with John Bolton's agenda at the UN, but very few liked the ham-fisted and abrasive way he tried to push it, and his detractors claim that his most significant accomplishment in the 16 months he was ambassador was to rally the G77 into a dedicated anti-American bloc. The polarization now cuts across all issues: UN management reform is denounced by G77 members as an attempt by the rich powers to reinforce control over the secretariat, while attempts to deal with genocides are seen as a pretext by which the rich nations assume a right to meddle in the affairs of the poor.
Ban is trying to court the G77, affirming his commitment to the "Millennium Development Goals (MDG)" established under Annan in 2000 as the centerpiece of his secretariat. The MDG's objectives are to commit world leaders to halving poverty, slashing mortality and illiteracy rates, and raising aid to 0.7% of GDP by 2015. As proud as Annan was of the MDG, he admitted as he went out the door the job was "far from done": although the UN had made significant progress on HIV-AIDS and debt relief, he said other efforts were "not on track".
Other work begun under Annan remains unfinished. Reform of the Security Council and UN management has stalled; the new Human Rights Council is just as feeble as its predecessor, with members including many barely-apologetic human-rights violators; the UN has wrung its hands over the atrocities in the unsettled Darfur region of Sudan, but proven unable to stop them. However, few seriously point a finger at Annan for this state of affairs. As John Bolton put it, taking a conciliatory tone as he himself went out the door: "While it is easy to blame the UN as an institution for some of the problems we confront today, we must recognize that ultimately it is the member states that must take action and therefore bear the responsibility."
Indeed, Kofi Annan can take pride in major accomplishments under his watch. He directed a reorganization of the UN's Department of Humanitarian Affairs and tightened links with humanitarian nongovernmental organizations (NGOs). The result is that the UN's humanitarian relief operations, once regarded as bad examples, are now seen as models of how to conduct such operations. Currently, about 30 million citizens in 50-odd countries depend on the UN for day-to-day survival. A new $500 million USD central emergency relief fund was recently established to allow UN relief workers to get the pipeline open to aid recipients in hours, not weeks. Another fund, running to $250 million USD, has been set up for use by the UN's new intergovernmental Peacekeeping Commission to finance reconstruction in countries recovering from war. Sierra Leone and Burundi are the first two candidates; they will have to meet certain standards of governmental competence to get the assistance.
Of course, peacekeeping is the highest-profile UN activity, even though the original UN charter doesn't mention it. It is a troublesome matter even in concept. The UN has no troops or military facilities of its own, being entirely dependent on member states for such resources, and when conflicts began to burn all over the world in the aftermath of the end of the Cold War the UN was hard-pressed to respond. Troops were generally obtained from undeveloped countries and often proved poorly trained and equipped; their peacekeeping mandates were restrictive and badly thought out. The UN still bears the stigma of failing to stop the Srebrenica massacre and the Rwandan genocide.
However, since the beginning of the century UN peacekeeping efforts have improved markedly in professionalism and effectiveness. A 2005 study by the US Rand Corporation that contrasted UN and American peacekeeping efforts showed the UN efforts to be cheaper, not to mention to no surprise far less controversial on the international stage. A Canadian study claims that the dramatic decline in global violence over the past few years owes much to UN efforts. Kofi Annan was instrumental in this process, having been a head of peacekeeping before he moved up to the secretary-general's office.
* Ban's critics point out that he has no comparable experience, and see him as bland, smiling, ever agreeable -- not the kind of leader the UN needs, they say, with some suspecting that the US backed him because the White House wanted a weak secretary-general. On the other hand, he is honest, conscientious, and a workaholic, and he has himself pointed out the truth well-recognized in Asian cultures that a smiling face can hide an inner strength. Certainly his experience in diplomacy with the wildly volatile North Koreans suggests he can grasp the nettle. His advocates have their hopes in him, and certainly given the inherent, unavoidable weaknesses of the UN, it may be the case that a quiet but energetic secretary-general who will seek a consensus among the UN's quarreling factions might be exactly the man to carry out "Mission Impossible." [TO BE CONTINUED]START | PREV | NEXT
* INFRASTRUCTURE -- THE POWER GRID (6): A high voltage line has such an intense electric field around it that it can ionize the air molecules in its vicinity. The ionization and recombination of the molecules results in a faint sizzling sound, a faint glow visible on dark nights, and radio noise -- which is why AM radios tend to be lost in noise when a car drives under a power line. This is "corona", mentioned in an earlier installment.
Corona is not particularly noticeable in lines running at 100 kV or less, but at 345 kV or above it can waste a lot of power. Its radio emissions are subject to regulations as well, and the ionization can produce ozone and nitrous oxides, both air pollutants. As a result, power companies try to minimize it. One way is to control the geometry of electrical gear: a pointed element concentrates charge and increases electric field strength, while a flat element provides the minimal electric field. High voltage electrical gear features gentle curves, rounded corners, and smooth surfaces. Corona is harder to deal with in wet weather, but not as might be supposed because the air is more conductive: the reason is that water droplets on the line form into little spikes that produce lots of corona.
Increasing the diameter of a conductor reduces corona. "Expanded" conductors are steel-core conductors with a sheath of nonconductive fibers between the core and the current-carrying aluminum strands. The "bundled" conductor schemes mentioned earlier -- two, three, or four conductors held in parallel by spacers -- produce an effect in which the electric fields of the multiple conductors merge to make the bundle look like one big fat conductor. Corona tends to be nasty at the connection from a conductor to an insulator, so this connection often features a ring called a "corona ring" or "corona shield" that distributes the electric field, reducing corona.
Incidentally, in principle small birds can land on a high voltage line and not get electrocuted, since there's no connection to ground and no current can flow. However, they can feel the corona and stay away.
* Power line insulators are usually stacks or "strings" of glass or porcelain, clamped to a conductor on one end and pivoting freely from the power tower on the other. Little or no current will flow through the insulator itself, but it can leak over the exterior of the insulator, a phenomenon known as "surface creep". It gets worse when the insulator is wet or dirty. The insulator is made slick to shed contaminants, and the disks have ridges or the like to increase the length of the creep path, increasing the resistance and reducing the losses. The problem is worse in polluted areas; in such places, insulators may be greased, or hosed off every now and then.
While the simplest hookup arrangement is a single insulator string from the tower to the conductor, "vee" arrangements of two insulator strings linked from the power pylon to a single conductor are sometimes used to reduce swaying. Arrangements of insulators can become even more complicated. Insulator disks used to be brown or black, with porcelain disks sometimes a pretty dark red color. These days they're usually an unobtrusive neutral gray.
* Lightning is a hazard to power lines. The towers usually have a hefty ground strap connected to a rod pounded into the ground, giving the lightning bolt a path to drain off into the earth. The conductors can't be grounded, of course, so to protect them, "aerial wires" strung at the top of the line assembly, above the power conductors. The aerial wires are electrically connected to the power towers, giving the lightning a way to drain off to ground. Incidentally, birds will perch on the aerial wires.
Lightning can still hit the power conductors, so the power system has defenses at its terminal ends -- circuit breakers and the like, more on this later. With lines operating at 500 kilovolts or more, circuit breakers have to be specially designed, not just to handle the higher voltages but to open more slowly. As mentioned, break the circuit to an inductor and the voltages will skyrocket, sparking across the open circuit gap. Abruptly throw open a very high voltage line, which has a degree of inductance, and the results can be disastrous.
* There have been concerns that people living near or under high-voltage lines are prone to cancers and other ailments. However, the increase in vulnerability is marginal and there are suspicions the seeming increase is just statistical noise -- all the more so because the incidence of such afflictions doesn't seem to change with level of exposure to electric fields, which makes no sense from a biomedical point of view. The electric field is certainly perceptible, however. Try going under a high voltage line at night with a fluorescent light tube; it may well flicker and glow. Just don't take a long tube and don't wave it overhead.
* As a final footnote to high-voltage lines, consider the issue of maintaining them. It's difficult to shut them down, so generally maintenance has to be performing by linemen working on hot lines. The surprising part is that they do it bare-handed, more or less. A lineman is brought up to the line on an insulated cherry-picker and neutralizes the difference in potential with a pole. He has to wear a conductive suit to prevent from being zapped by the simple gradient in electric field. It is said that up next to the line, one hears a buzzing sound like being in a hive of bees. [TO BE CONTINUED]START | PREV | NEXT
* The notion of "commercial space" has been around for decades; it has been largely marked by strings of failures, but there are still those willing to dare. As reported by an article in IEEE SPECTRUM ("Putting up the Ritz" by James Oberg, February 2007), for the last few years Robert T. Bigelow, a real-estate tycoon from Las Vegas, Nevada, has been pushing a new commercial space project: a commercial space station. Bigelow is not trying to tap into the "space tourism" market, which really doesn't exist just yet; he plans to lease or sell his orbital facility to the world's official space programs. What sets Bigelow's idea apart from most commercial space ventures is that he's got hardware in orbit. That in itself would attract attention; the fact that his technology is a departure from traditional space station schemes also excites interest.
The "Genesis I" prototype space station is now orbiting the Earth at an altitude of 560 kilometers (360 miles), having been put into space by a Russian Dnepr booster on 12 July 2006. An engineering mockup of Genesis I sits in the Bigelow plant in the desert outside of Las Vegas. The mockup is a gray fabric-covered cylinder about 4.4 meters (13 feet 5 inches) long and 2.5 meters (8 feet 2 inches), with an internal volume of 11.5 cubic meters (406 cubic feet). The fabric is not just an outer layer over a metal frame: it provides the outer structure of the station and is kept in shape by air pressure. The fabric is hardly some cheap cloth like that used to make clothes, of course: it's a multilayer construct, several centimeters thick, that not only provides structure but also thermal control.
Bigelow believes that an "inflatable" space station could cut procurement and launch costs by 25% to 50% compared to existing space station technology. An inflatable station is cheaper to build, and is lighter and more compact, permitting it to be launched on a cheaper booster. Genesis I is strictly a technology testbed, carrying only instruments and cameras, inflated to about a half an atmosphere pressure.
The Bigelow station has its roots in work performed by the US National Aeronautics & Space Administration (NASA) on a "TransHab" inflatable space station in the 1990s, which was envisioned as an orbital module with a volume of 340 cubic meters (12,000 cubic feet) and a mass of 13.2 tonnes (14.5 tons). This gave a volume to mass ratio of 25:1; in comparison, a typical International Space Station (ISS) module has a ratio of 9:1. The big worry was that a micrometeorite would puncture the TransHab, causing it to disastrously deflate. The solution was to design the fabric to be extremely strong, four times stronger than required to deal with any stress it might normally be expected to endure. The skin consisted of several layers, described from the inside out:
TransHab's skin was 41 centimeters (16 inches) thick and had 60 separate layers. The multiple layers were able to tolerate impacts of aluminum projectiles 1.7 centimeters (two-thirds of an inch) in diameter slammed into it at 25,200 KPH (15,650 MPH). Even if punctured, the hefty inflatable structure would collapse very slowly, giving the occupants plenty of time to apply a patch, or evacuate if it came to that.
NASA axed the effort in 2002. Bigelow had heard about the project and was intrigued; he bought up the patents and hired the NASA TransHab project leader, William Schneider, as a consultant. The design wasn't quite ready for flight at the time: one serious omission was windows, which proved so tricky to fit into the TransHab that NASA had simply not bothered with them. Bigelow felt that windows would be an absolute necessity for his purposes. Tests to destruction were performed on prototype window installations, some resulting in loud bangs that led to complaints from neighbors. The final window design is 40 centimeters (16 inches) thick.
The production Genesis modules also needed power, control, communications, and other flight systems. Bigelow was able to obtain most of these off-the-shelf from aerospace manufacturers. System reliability was enhanced by "dissimilar redundancy" -- not merely using dual systems, but implementing each of the the two systems differently so they wouldn't fail in the same way. One of the functions of the orbiting Genesis I module was to evaluate systems for later flights. Incidentally, the Genesis I had dual communications systems, one at each end; since it didn't have attitude control, that ensured that communications would not be lost.
Bigelow handles mission control of the flights. Interestingly, the company obtains tracking more or less for free, since the US Department of Defense tracks space objects and publishes the data, and the company uses orbital prediction software to determine when Genesis I is within a line of sight to one of the two company ground stations -- one in Las Vegas and the other in Arlington, Virginia. Two more ground stations are being brought online, one in Alaska and the other in Hawaii. Genesis I is in an orbit with a lifetime of 7 to 13 years, giving the company plenty of observations of how it functions in orbit.
Bigelow hopes to launch the "Genesis II" test module in 2007. It will be the same size as the Genesis I but will have improved subsystems. It is to be followed in late 2008 by a half-scale "Galaxy" module, and then a "Sundancer" small station with a crew of three. The Sundancer will have dimensions of 8.69 by 6.28 meters (28 feet 7 inches by 20 feet 7 inches) and a volume of 180 cubic meters (6,351 cubic feet). It will have a propulsion module, a Soyuz-type docking port at one end, and a new lightweight NASA "Low Impact Docking System" at the other end.
Bigelow's goal is to perform two test flights a year up to the launch of the production man-rated station. Bigelow envisions an operational station based on two "BA330" modules, each with an internal volume of 330 cubic meters (11,645 cubic feet) and space for six crew, mated together by a central node module. The node module will also be fitted with a propulsion module, and will have docking ports for Soyuz or Shenzhou space capsules. The plan is to have a fully operational station in orbit by 2015.
Bigelow seems on track to obtain a functional space module. The question remains as to whether there will be enough demand for the product to make it pay off. Bigelow is optimistic, he wouldn't be moving forward so aggressively if he wasn't, but he is perfectly aware that he is trying to buck the notoriously poor record of past space commercialization efforts.BACK_TO_TOP
* WHO CAN YOU TRUST? Anybody who has ever used online reviews quickly realizes that they are often exploited by people with a vested interest in praising their own products or in low-balling a competitor. According to an article from WIRED.com ("Herding The Mob" by Annalee Newitz), the same sort of trickery is now being applied to online feedback scores.
Those who use eBay or Amazon peer-to-peer sales know the scheme: buy something from somebody, then score them on how well they follow through with the transaction. Now scammers, spammers, and thieves are trying to "crowdhack" scoring systems in order to boost sales, increase website traffic, or simply steal.
The eBay ratings scheme was a pioneer scoring system, with the firm initially offering the scheme in 1996. Under the rules, only those involved in a transaction can rate the transaction, and there's no way to change the scores or remarks once posted. It became the model for online scoring systems. It might seem fairly hard to cheat given the rules, but that would be underestimating the resourcefulness of cheats.
A typical eBay scam is simple: the scammer sells a lot of small items to build up a positive profile -- then moves up to big-ticket items, sells them off in a burst, and leaves town with the money. Arizona police say that in 2003 a woman named Nancy Drexler sold a stream of CDs and DVDs, acquired a good rating, and then sold off $100,000 USD worth of expensive items that didn't exist, ripping off about 500 buyers. Arizona authorities haven't pressed fraud charges against her yet, but the state of Nevada has in a separate case.
John Morgan, a professor at the Haas School of Business of the University of California at Berkeley, has researched eBay fraud and says it is not only common, it is also blatant. The usual game is to set up networks of "buyers" and "sellers" that perform dummy purchases from one another, the usual price of a sale being a penny or so, to build up positive profiles. One of the "hot" items in this trade was a booklet explaining the scam, with the booklet to be resold by the purchaser to keep the scam rolling. Says Morgan: "We saw a number of sellers who used sham transactions to build reputation, laid low for a period of time, and then re-entered high-value markets as apparently 'reputable' sellers."
The scams are not being ignored by eBay. A company spokesman says that the online system includes software to spot patterns of dubious transactions. The details are secret to prevent scammers from getting wise. However, other commerce sites don't have such protection. Yahoo Shopping, for example, lets anyone post a review, allowing the same people to log in using multiple email addresses and post glowing reviews over and over again. This tactic has long been known on internet forums, with individuals pretending to be multiple people to "gang up" on opponents, the game being called a "sock puppet show". A Brooklyn-based company named PriceRitePhoto got superb Yahoo ratings despite many negative reports. Those who posted criticisms were harassed by the shop's owner. Yahoo threw PriceRitePhoto off the system, but it came back a few months later as Barclays-Photo. It got thrown off again after a series of complaints, but it's still operating on eBay -- with suspiciously high ratings.
* The "crowdhacking" phenomenon is also penetrating link-community sites like Digg. These sites bring together networks of users who tip off each other to interesting links on the web, with statistics kept and the most popular links listed on the site's front page. This potentially means a lot of traffic to sites that reach the top of the list.
The method of choice for manipulating Digg is called a "Sybil attack", after the tale of the woman who claimed she had 16 different personalities. It's another "sock puppet show" trick, with one person opening multiple accounts and recommending the same link with all the accounts. There are other ways to cheat on votes: one enterprising soul set up a site named "User/Submitter" to promote websites on Digg for a fee; once paid off, User/Submitter paid Digg users 50 cents if they voted for three articles promoted by User/Submitter. Some companies also contact top Digg users and pay them to promote specified sites. Then there is "Spike the Vote", which is something like a pyramid scheme in which Digg users vote up each other's pet links. Like eBay, Digg has software to spot bogus voting patterns. For example, the software will sound an alarm if a number of accounts are created in a short period of time and all vote for the same links, or if people vote for a link without checking out the link first.
The arms race continues. Some are optimistic that the white hats will win, simply because scoring systems will be destroyed if nobody can trust the tallies, and those who own the systems have a vested long-term interest in making sure the game is honest. However, there are plenty of black hats with a short-term interest in making a killing, the long run be hanged -- and they can be very ingenious.BACK_TO_TOP
* STAYING ALIVE IN BAGHDAD: Intelligence is always a necessity in war. According to an article from BBC.com ("Iraqis Use Internet To Survive War" by Andrew North), Iraqi civilians have been finding the internet a valuable tool to enhance their chances for survival. The popular Iraq League site, for example, suggests that people download satellite images of their neighborhoods to determine where death squads might enter the area, and to identify escape routes. Of course, the death squads are sure to be using them as well to plan their attacks.
The Iraq League site, which is actually hosted in the UK, is in principle nonpartisan, but is more of a reference for Sunnis than Shiites. It offers grim advice. Don't let the police arrest you, for example, since they are likely to torture and kill you. "If they tell you we just have a few questions and you will be back in an hour, don't believe them. You will be dead in an hour or disappear for months."
The site adds that everyone needs to be trained and vigilant, quick to call in local guard forces if intruders arrive. People should vary their routes from day to day, and Iraqis with names common among Sunnis -- like Abu Bakr or Omar -- should get new ID cards with less dangerous names. Devout Sunnis often have long beards; Shias wear short beards, and so it's safer to keep beards trimmed. Other websites suggest that Sunni shopkeepers hang up pictures of Shiite Grand Ayatollah Ali Sistani, or Imam Hussein, grandson of the Prophet and the great martyr of Shiite faith.
The Iraq League also maintains a section containing messages from people, both Sunnis and Shiites, trying to find missing family members and friends. The messages make the tragedies of war painfully apparent: "Please help me to find my husband who was kidnapped traveling from Baghdad to Amman. Gunmen seized him because he is a Shia, but they left my brother and his family because they are Sunni. Please help me." The message is months old and unanswered.
Sometimes the results are less discouraging. Help was offered to a girl who suffered an eye injury during a mortar attack on her school early in the year: "We can provide medical treatment outside Iraq." The fact that people are still willing to try to help each other is encouraging, but for the time being the real objective is just to stay alive.BACK_TO_TOP
* MISTER BAN'S NEW JOB (1): As discussed by an article in THE ECONOMIST ("Mission Impossible?", 6 January 2007), at the beginning of 2007, the United Nations (UN) acquired a new secretary-general, a South Korean named Ban Ki-moon who had been that country's foreign minister. He replaced outgoing secretary Kofi Annan of Ghana, who had completed a ten-year stint at the helm. Ban is quiet, pleasant, unassertive, a Christian, and the first Asian to hold the secretary-general's position in 35 years, the last being U Thant of Burma. Ban gets a good salary, a nice apartment in Manhattan, and global superstar prestige, but he's got his work cut out for him. He has to deal with war fires raging in the Mideast; an ongoing humanitarian disaster in Darfur; worries about climate change, weapons of mass destruction, the HIV-AIDS pandemic -- and, last but not least, the process of UN organizational reform begun by his predecessor, Kofi Annan. Ban, in his usual mildly humorous way, said he hoped that his job wouldn't turn into "Mission Impossible".
The difficulties with the UN go back to its foundation in 1945. The organization was set up by the victors of World War II -- the US, the USSR, Britain, France, and China -- and so allocated 5 permanent seats on the 11-seat Security Council to themselves, with the permanent members known as the "P5". The P5 had veto powers; the other six seats were allocated to other members, to be elected by the UN General Assembly for two-year, non-renewable terms -- without veto powers.
Nobody, not even in 1945, would have described this arrangement as particularly even-handed. Since then the number of UN member nations has gone from 51 to 192, with two-thirds of these countries from the developing world. The only really noticeable change in the UN's top-level organizational structure has been the addition of four more non-permanent seats, and that was in 1965. A prominent scholar, Paul Kennedy, has called the matter "outrageous".
However, the UN wasn't set up to be even-handed. The prewar League of Nations had proven ineffectual and eventually dissolved; the only realistic goal in the establishment of the UN was something that worked, however imperfectly. To be sure, there were those who were more idealistic, but when pressed by realities even they had to admit that something was better than nothing. The great powers, meaning essentially the US and the USSR at the outset, were not going to accept an arrangement that worked against their interests. Any of the P5 can block any motion contrary to national interests; if the UN doesn't do the job for them, they are perfectly free to go it alone. Kennedy asserts that the status quo, while imperfect, does work more or less as per design.
Although things have changed very much since 1945, one reality remains as true for the UN as it was in the past, maybe more so: keeping the United States on board, since the Americans provide the biggest chunk of money for the organization by far, and carry the biggest global economic and military clout. Ban says that one of his top priorities is to strengthen the link between the UN and the US government.
* The relationship has not been good in recent years. Right-wing American nationalists have long despised the UN. During the Clinton Administration, stories circulated among the extreme Right that the UN and Clinton were conspiring to set up a secret force of "black helicopters" that would swoop down on all the patriots to haul them off to camps ringed with barbed wire and guard towers. More recently, the US National Rifle Association furiously denounced Annan for implementing a weapons buy-back scheme in the war-torn Congo, asserting that the UN was planning to disarm Americans as well.
Such tales make for amusing reading, but there were other issues that couldn't be laughed off. The Bush II Administration came into office in 2001 with a generally low opinion of the UN, part of what appeared to be a distaste for diplomacy in general. The relationship started to go downhill badly in 2003 during the run-up to the US-led invasion of Iraq, when the UN refused to back the operation. It wasn't really Kofi Annan's fault, the resistance being led by the French, but the US was scathingly criticized all over the globe for then going it alone -- this was doubly irritating because there was nothing new about member states doing so, and the French had a long custom of unilateral military interventions themselves. However, there was plenty of irritation left over in the White House for Annan.
Then came the particularly shocking and undeniable revelations about major corruption in the Iraq oil-for-food program, followed by the lesser embarrassments of UN peacekeeping troops in Haiti trying to hustle teenaged girls. The UN seemed ineffectual overall, and the loud American criticisms were no longer coming from the fringe, instead being voiced in the US press and the Congress. Although the second term of the Bush II Administration has featured a much softer line on diplomacy, the White House still appointed a UN ambassador, John Bolton, who hardly disguised his hostility to the organization.
Annan reciprocated the hostility, letting his annoyance with the American attitude show in speeches delivered as he made his way to the exit. He stressed the importance of American support and leadership for the UN, but denounced the Bush II Administration's inclination towards unilateral action, saying that no nation, however powerful, could go it alone in the face of the world's problems. In his soft-spoken manner he scathingly blasted the US, asserting that no nation "could make itself secure by seeking supremacy over all others", and chastised the Americans for their inclination to push to the edges of international law or beyond in pursuit of the war on terror, saying the US should "remain true to its principles".
Ban has now stepped into this unpleasant dispute. He was by no means unaware of it. Asked for comment on Annan's views, Ban replied that they represented Annan's "personal assessment and insight." South Koreans might have had good reasons to be amused at this response: Ban is famous in his own land for his smooth way of amiably dodging thorny questions, being known as the "slippery eel". He may need all the slipperiness he is capable of to be effective. Although he did much to win the secretary-general position on his own efforts, he couldn't have done it without prominent backing by the US and China, which makes him beholden to two patrons who disagree on a fair list of issues. [TO BE CONTINUED]NEXT
* INFRASTRUCTURE -- THE POWER GRID (5): The previous installment in this series mentioned power-line conductors, but basically took them for granted. They are actually an interesting subject in themselves.
Silver is the most highly conductive metal, but due to the obvious expense it is rarely used in electrical systems. Copper is next-best and gets plenty of use, but aluminum, the third-best, is cheap and light, so it is the conductor metal of choice in power lines: it works as well as copper if the conductor is made thicker.
The conductor wire in a power cable for, say, a vacuum cleaner is maybe about as big around as a pencil lead. The heavy-duty cable used with a clothes dryer has maybe the diameter of a crayon. The cable used in a high-power line can have a diameter up to about that of a baseball bat. It's not a solid length of aluminum, of course, which would make it somewhat hard to coil up, instead being a bundle of small, flexible strands. Oddly, aluminum cable configurations are named after flowers: the common 61-strand cable, capable of handling 1,100 amperes, is a "narcissus", with others named "snapdragon", "lupine", and "bluebonnet" -- the last being the heftiest standard cable, with a capacity of more than 2,000 amperes.
Some conductors have aluminum strands wrapped around a steel core. Steel is a middling conductor, but it adds strength. Such conductors are named after birds -- for example, a "starling" has 26 aluminum strands braided around seven finer steel strands. Conductors can be so strong that there are cases when they pulled down towers after ice storms -- not the desired effect, since it's much easier to fix a broken conductor than a tower. As mentioned earlier, high voltage lines will have bundles of two conductors, with the really high voltage lines having three or four, the conductors being separated by spacers.
Conductors are delivered on big wooden spools. Once the conductor from one spool has been strung up, it has to be spliced to a conductor from another. The splice is performed with an aluminum sleeve, with the two conductors inserted and the sleeve then compressed to snug them together. The splicing procedure is performed by either a hydraulic ram unit or, believe it or not, shaped explosive charges. Of course, the splicing is performed on the ground and the spliced cable then strung up.
Although residential line conductors are wrapped in insulation, high voltage line conductors are not. Insulation simply doesn't work: the voltages are so high that they would zap right through it.
Conductors often have puzzling elements attached to them, for example little dumbbells. They are vibration dampers, intended to prevent the conductor from vibrating and weakening itself. The dumbbells are called "Stockbridge dampers", for George Stockbridge, an American engineer who invented them in the 1920s. Other dampers included spirals of heavy wiring wrapped around the conductor. Extra strands of wire are also wrapped around a conductor where it is clamped through an insulator to a power pole, with such "armor bars" reducing the potential for damage from vibration.
Conductors may be strung with brightly colored balls to make them more visible where they could be a hazard to navigation, near airports or when they're strung across rivers. In Europe, lights are hung from conductors to ensure that they are visible at night; the lights don't have a power supply, they get all the juice they need from the electric field around the conductor. In the US West, large raptors such as eagles and ospreys will often try to build nests on the top of power pylons, and the birds are big enough to short out the lines if they touch two conductors while flying down to roost. Shooing the birds off isn't practical, so platforms are built well above the original top of the tower to allow the birds to nest safely. It also wins the power company fair points on wildlife conservation. [TO BE CONTINUED]START | PREV | NEXT
* IMPROVING GEOTHERMAL: Geothermal power -- the idea of tapping steam from the Earth to drive electrical power turbines -- is not a new concept. In fact, it wasn't all that new an idea when it was promoted as an alternative power source during the 1970s energy crisis, and it hasn't been promoted much during the current energy crisis, partly because the 1970s hype about geothermal proved overblown. In the first place, it can only be used in locales that have geothermal activity, and in the second place it's a tricky engineering problem, with geothermal sources tending to be inconstant and plant gear suffering from fouling and corrosion.
One of the issues is the temperature of the steam obtained from the Earth. If the steam is much cooler than about 150 degrees Celsius, it will condense before it can be driven through a turbine; if it's hotter than 400 degrees Celsius, it's hard to handle. However, work is being performed to extend geothermal power outside these limits.
The waters at Chena hot springs in Alaska are pleasantly warm for bathers, but even the 74 degree Celsius temperature of the water down in the wells of the hot spring is on the cool side for power generation. It can still be done: a closed-loop system pumps a refrigerant known as R134A down into the well, where it is vaporized and comes back up to drive a turbine. The R134A is cooled down to liquid again by a local river, and sent back down the wells.
This isn't basically all that new an idea, either, the problem with it being that traditionally the cost of the system was prohibitive. The builders of the system at Chena have been able to reduce costs by using off-the-shelf air-conditioning components, and claim that their technology is cost-effective for any site where there is a difference in temperature of at least 50 degrees Celsius between the heat source and the cold sink. Some oil wells achieve that much and could be used to generate power.
Iceland is the world center for geothermal power; existing geothermal sites are well developed, and so there is an urge there to drill deeper to reach new, more potent geothermal sources. The "Iceland Deep Drilling Project" intends to extend the reach of current geothermal wells from about two kilometers (about 6,600 feet) to twice that depth or more, where the steam temperatures will run about 600 degrees Celsius. There's no one magic trick to handling such hot steam, it's just a question of engineering to handle the higher temperatures and pressures.
A deep-well geothermal power plant might cost three times as much as an shallow-well plant -- but it will produce ten times as much power. Industries are already locating to Iceland to take advantage of cheap electrical power, and deep-well plants will only enhance the country's industrial game plan. Icelanders are also exporting their technology to countries where active volcanic systems are common.BACK_TO_TOP
* PLUG-TOGETHER HOUSE: Prefabricated housing is nothing new, being represented in the US by the "factory homes" plugged into trailer parks, but they represent the low end of the housing market and aren't all that convenient in many ways, with a fixed configuration and still requiring a fair amount of fussing to get into operation.
According to an article in POPULAR SCIENCE ("Building Blocks" by Don Stover, November 2006), Kent Larson, a professor of architecture at the Massachusetts Institute of Technology (MIT), thinks that prefab homes are the way of the future, that the traditional approach to housebuilding is archaic and inefficient: "Every product except homes has become more sophisticated, with higher quality at lower cost. Homes are just the opposite." Very few people can afford a custom home built to their specifications, but even homes built to a standard are effectively custom in construction, put together piece-by-piece just as are the true custom homes. In his earlier life as a commercial architect in New York City, he was appalled by the indifferent and piecework way houses were built, and when he went to MIT in 1996 he began work on a scheme to change things.
Larson envisions a modular approach to building a house, with components built in a factory that are easy to update or replace. Buyers should be able to configure a design online to precisely fit their needs. His concept involves a rugged central "chassis" that could last for centuries, which would be fitted or refitted with a roof, walls, siding, and electronics as desired. Larson calls the concept the "open source building".
The problem is one of specifications and standards. A personal computer is reconfigurable because of the standard interfaces it supports, and Larson's reconfigurable house will need comparable standards to make sure the parts all work together. Larson is now working with a New Hampshire builder named Tedd Benson to construct four prototype houses, the first of which will be completed in the summer of 2007. The project is a pilot for MIT's Open Source Building Alliance (OSBA), a group of manufacturers with an interest in the concept. Larson wants to make sure industry is definitely on board the concept, since he knows it will have no chance of working if it's just passed down from on high from an academic institution.
Tedd Benson did not need to be converted to the vision, in fact he was maybe a bit ahead of Larson in the concept. His construction firm, Bensonwood Homes, had been putting together modular assemblies for the homes built by the firm, but they still needed considerable work to put together on the building site. Like Larson, Benson found the whole scheme absurdly backward and inefficient. Unlike most home builders, Benson had a scholarly bent, and in the early 1990s he discovered the writings of Dutch architect N. John Habraken, who proposed that a building's support structure should be separate from its "infill" -- interior elements such as partitions, wiring, plumbing, and cabinets. Habraken was a pioneer in the concept of "open building", which would evolve into Larson's "open source building". Habraken had been working at MIT and Benson invited him to New Hampshire to talk with the staff of Bensonwood Homes.
Then Benson discovered a book published in 1994 by Stewart Brand, best known for his WHOLE EARTH CATALOG series, titled HOW BUILDINGS LEARN. Brand's book divided buildings into six systems or "layers", each with a different lifespan: site, structure, skin, space plan, services, and "stuff":
In response to these ideas, Benson developed a modular scheme he calls "Open-Built", which involves modules attached to a timber-frame skeleton. However, he was still trapped by the "entanglement" problem, the need to wire and route systems on site. That's when he and Larson joined forces.
The pilot house is named "Open_1" and is part of a rehabilitation facility for brain injury patients in Greenfield, New Hampshire. It is a three-story timber-frame house, built in 40 prefab sections, including an elevator system, that were put into place with a crane. The sections were all completely finished, and the building was assembled in less than a month. The total amount of trash resulting from the construction filled up about two barrels.
The electrical links between sections were established using snap-together connectors. Wiring that might need to be updated was run through easily accessible raceways. The ceilings are made of removeable panels that allow easy access to light fixtures. The next prototype will have moveable interior walls. Larson, Benson, and others involved in the project believe that the open source building scheme will revolutionize construction, not only reducing costs but providing more flexibility and even improved quality.
* ED: I live next to a trailer park and factory homes seem like a fairly decent thing, nothing special but a clear step up from the tinny trailers they are gradually replacing, and seemingly cozy once various accessories like a porch and a garage are attached. I had elderly uncle and aunt who had been living in a "developed community" house, which like many such structures had two floors; when they got too old to handle the stairs, they moved to a double-wide factory home, which was much more convenient because it was all on a single level.
Still, factory homes are nothing more than setpiece boxes, and the open source building concept is light-years beyond such structures. What is particularly interesting about open source building is that there are contractors who are pushing the idea. I grew up in a construction family and the idea that guys with saws and hammers could even be interested in academic notions is a real surprise: they are not at all as a rule bookish people. I have a feeling that if open source building can be made to work, traditional house builders are going to have real problems adjusting to technologies that will blow their doors off in cost, quality, and customer appeal.
* In related news, WIRED Online had a short article on a "high style" factory home, the "Glassic Soho", designed by San Francisco architect and designer Christopher Deam, which is along the lines of a sleek, modern glass-fronted summer home. It has 37.2 square meters (400 feet) of floor space. The Glassic is manufactured by the Breckenridge company. Base price is only $59,000 USD, not counting installation. Three floor plans are available: one-bedroom, two-bedroom (no kitchen), or studio.BACK_TO_TOP
* THE ART OF BRIBERY: Utopian social schemes have a nasty tendency to founder on certain aspects of human cussedness, one of the more prominent being corruption. Although much worse in some places than in others, it exists everywhere, and no culture has been ever able to stamp it out completely. An article in THE ECONOMIST ("How To Grease A Palm", 23 December 2006), took a close-up of the phenomenon of bribery. In Uganda, bribes account for 8% of the cost of running a business. Hospital supplies in Buenos Aires, Argentina, are 15% more expensive than they need to be, due to the overhead of paying bribes. Bribery is an obvious and generally unproductive drain on a country's economy, and World Bank boss Paul Wolfowitz is pushing an effort to fight corruption. For most of the people who have to deal with bribery on a daily basis, however, the concern is much less for the drain on GDP than for the nuisance and humiliation of having to make payoffs all the time.
There is actually a fairly elaborate set of rituals for bribery that are surprisingly constant all over the world. It is rare, crass, and clumsy for someone to simply come out and demand money; the process is almost always disguised as a proper sort of transaction. This is not done merely to avoid prosecution for a crime, since there are places where nobody is ever punished for taking bribes; the indirection also allows bribe-takers to at least tell themselves they're not doing anything wrong, and reduce if not eliminate the humiliation to the bribe-giver.
Petty officials in nations where corruption is common, for example, are fond of coming up with elaborate regulations that seem to change with the wind and time of day, which may require "fees", or lead to "fines" when they are, of course, violated. Border officials are fond of asking for "expediting fees", which is actually not all that much of a euphemism, the message being that people in a hurry can pay the fee and pass through with little hassle -- or put up with all the inspections and bureaucracy that can be exercised. In India, government inspectors can be given "speed money" to ensure that business permits are issued more quickly. In Eastern Europe, setting up and running a privatize company usually means hiring a "consultant" for a large "fee", who then makes sure that all the proper officials are paid off while taking his own cut -- a scheme that has the advantage of making the connection between bribe-givers and bribe-takers less obvious.
In many cases, the camouflage is a fiction that the bribe-taker is just asking for a little favor. In North Africa, they ask for "une petit cadeau" or "a little gift". Mexican police will ask for a "refresco", or soft drink; in Angola and Mozambique petty officials make the same request, though they use the Portuguese term, "gazoso". Corruption is blatant in Iraq, but officials will still ask for "good coffee"; in Kenya, the term "chai" conveniently means both "tea" and "bribe". Of course, the Middle-Eastern term "baksheesh" is widely understood, though surprisingly it's of Persian, not Arabic, origin; the literal translation is more along the likes of a "tip" or "alms".
Along with the evasive language comes an inclination towards evasive ways of making payouts. Once again the habit persists even in places where bribery is regarded as normal, and few fear any punishment for it. A bribe to a border guard may be hidden inside a passport. In many countries, bribes are simply called "envelopes", since envelopes are a common way to pass over money in a concealed fashion.
* The daily hassles over bribery in corrupt countries are aggravating to the locals, but they at least understand that a policeman who's getting little or sometimes no pay is just trying to survive. It is the big-time corruption of the people at the top that is really infuriating. Visitors, on the other hand, are usually not as aware of the high-end corruption as of the petty bribery, and in fact tend to get it worse than the locals. Foreigners don't know the rules, and they're often assumed to be rich anyway. Journalists are particular targets, since they are generally trying to make their way into offices not generally open to the public. Of course, journalists are often given bribes as well. In Nigeria, they are given hundreds of dollars -- in discreet brown envelopes -- to attend press conferences and dutifully report the official line.
Although Nigeria is notoriously corrupt, as anyone getting email from Nigerian email scammers might imagine, even in the USA journalists end up getting their palms greased, though the means are subtler. One conservative columnist and talk-show host was found to have taken $240,000 USD from the US Department of Education to say nice things about an education-reform bill. This example suggests that bribery is not always a clearly-defined concept. A New York businessman may not have to pay bribes as a matter of course as does a businessman in Africa or suchlike, but he won't think twice about bribing his way into a fancy restaurant without a reservation using a fifty-dollar bill.
Indeed, ordinary practices of the US Congress verge on the corrupt. Lobbyists make large campaign contributions and get preferential treatment in return. As long as there's no legally identifiable link between the cause and effect, it's within the law, and it's very hard to prove any such link. Lobbyists generally know better than to make a pitch and then hand over money, or even mention it; the money's handed off discreetly at some other time and under an appropriate guise -- generally a contribution to a campaign fund, which is legal in itself. Going over the line into blatant bribery can be asking for trouble, the most entertaining recent case being Congressman Randy Cunningham, a Vietnam-era jet ace who got a Rolls-Royce from defense contractors, along with other impressively sparkly goodies.
* Still, the US and Western Europe are much cleaner than elsewhere. Very few citizens encounter bribery on even an occasional basis there. Even orderly, industrious Japan is much more corrupt, at least at the higher level -- Japanese cops generally don't take bribes, but ministers of parliament and government bureaucrats will.
However, for really serious corruption, one must go to the poorer countries. Poverty and bribery generally go together. Bribery is not only correlated with poverty and illiteracy, but also linked to the level of state control over the media and the amount of government red tape it takes to get things done. Socialist and recently socialist countries, with high levels of red tape, tend to be more corrupt than others. The more bottlenecks in a society, the more opportunities police and petty officials have to abuse their power. Authoritarian states, despite their heavy-handed concepts of law along with inclination towards rough policing and harsh punishments, seem particularly prone to corruption -- authoritarianism being closely linked with a lack of accountability.
It is characteristic of bureaucracies to keep piling up rules to make sure things are done right, but in the end the result may be to have so many rules that nobody can do anything without breaking some of them. As a result, the laws are no longer taken very seriously. Too much of the rule of law, it seems, tends to lead to a land where the law no longer rules.BACK_TO_TOP
* A SHORT HISTORY OF WHEAT (2): Norman Borlaug wasn't the only one working on improved wheat strains in the postwar period. From wheat's origins and through much of its history, humans had been tweaking with wheat strains by finding unusual mutations and through crossbreeding, but in 1956 scientists at Britain's Atomic Energy Research Establishment used neutron bombardment to create an "artificial mutant" variant of barley that had shorter, stiffer stalks, but otherwise produced perfectly palatable barley. Such "mutation breeding" techniques -- using neutron radiation, X-rays, or carcinogenic chemicals -- were quickly applied to other cereals, including wheat. Most of the common wheat strains available today were produced by this brute-force approach.
Being able to create mutants at will instead of waiting for them to happen by accident was a step ahead. The next step ahead, which began in the 1980s, was to actually design mutants with specific desired features using "genetic engineering" techniques. However, by the time "genetically modified (GM)" crops were ready for the big time in the 1990s, they had attracted stiff opposition from environmental groups who blasted them as "frankenfoods".
There were certainly valid reasons for concern over the impact of introducing new strains of crops, but GM advocates found the opposition exaggerated and exasperating. Most food crops had long been genetically altered by crossbreeding, in some cases (wheat, corn, and bananas for examples) to the point where the plants could no longer propagate on their own; and mutation breeding had been going on for decades with no major concerns, oversight, or problems. GM, to be sure, introduced the unsettling notion of adding traits from entirely different organisms, but there was little "natural" about most existing crops in the first place. How could people protest so loudly over theoretical hazards, while dismissing the fact that GM crops could do a lot to alleviate hunger in poor countries? Some have irritably suggested that GM foods have become a cause to the Left that parallels the way fluoridation of water supplies has long been a preoccupation with the Right.
* Although GM has proven controversial, about 810,000 square kilometers of GM crops were planted in 2004, providing improved yields at lower cost, particularly through reduction of use of environmentally-unfriendly pesticides -- one of the genes that has been introduced allows crop plants to produce their own pesticide.
Wheat has been something of a laggard in GM. The issue is that ancient hybridizations that produced wheat as we know it resulted in a genetic train wreck. Most organisms, including ourselves, are "diploid", having dual sets of chromosomes, but wheat is "hexaploid", with six sets of chromosomes. Wheat's genetic code is five times longer than that of a human, six times longer than that of corn, and forty times longer than that of rice. This makes genetic tinkering with wheat more difficult, though one of the first GM wheats -- a strain that will grow if simply scattered on the ground, not even tilled into the soil -- has been cleared for distribution.
Advocates believe that more use of GM crops will be needed to fight what may well be the last bout of the Malthusian battle. Although there were fears in the 1960s that human population would continue to soar until a ghastly crash was inevitable, at the time the rate of growth had peaked, to begin slowing down in the mid-1970s. By the late 1980s, the absolute numbers of humans added each year began to fall. Given current demographics, world population itself will begin to fall not long after 2050.
It will, however, peak at almost ten billion souls. That implies increasing food production by 35%, which very much implies improving crop yields. Wheat is no longer the primary cereal crop. Although the most land is devoted to raising wheat, in recent decades corn and then rice overtook it in terms of tonnage of foodstuffs produced. Wheat still remains an important crop, and it will play an important part in the "ultimate battle" against hunger. [END OF SERIES]PREV
* INFRASTRUCTURE -- THE POWER GRID (4): The electrical power system for the US and Canada is in the form of a "grid" consisting of multipoint networks that ensure power continues to flow even if a plant goes down. The grid is divided into two primary "zones" or "interconnections", with the dividing line between the two zones running roughly along the eastern side of the Rockies. There are also two secondary zones, one for Quebec, one for Texas, except for most of the Texas Panhandle. Within each zone, the AC power generation is kept precisely in lockstep: if it weren't, phase changes between different plants would result in wildly varying voltages over the power lines. Power transferred between zones is converted to DC and then back to AC to prevent phase mismatches.
The "feeder" lines of the grid of course feature power towers, and as a general rule the bigger the tower, the higher the voltage, and the longer the feeder line, with the longer lines carrying more power to supply the shorter lines fed by them. Short-haul lines, running maybe 80 kilometers (50 miles) operate at 115 or 138 kilovolts. Longer feeder lines use higher voltages, though the voltages vary by region. Along the West Coast, in the mid-Atlantic States, and the Southeast, most long feeder lines use 230 or 500 kilovolts. In New England, New York, and the Midwest, most run at 345 kilovolts -- with a few high-capacity lines running at 735 or 765 kilovolts.
Since higher voltages translate to higher efficiencies, it's not surprising that the voltages get higher as the length of the line and the power being carried increases. The question, then, is why not build all feeders to operate at the highest voltages? In fact, why not run them at megavolts? The answer was basically given above: the higher the voltage, the more robust and expensive the power towers and distribution system. Since resistive losses in the wiring -- the "conductors" -- increase with distance, high voltages are absolutely needed for the long-distance lines, but the losses are acceptable over shorter lines and so there's no need to spend so much money. In addition, higher voltages mean greater losses through a leakage process known as "corona", of which more is said later.
It's difficult to tell what kind of voltages are being sent over a particular powerline just by looking at a power tower, but it is possible to get some clues. The spacing between conductors on a 735 or 765 kilovolt line will be 15 meters (50 feet) or more, with the spacing on a 345 kilovolt line running about half that. The spacing for lines running at 200 kilovolts or less will be maybe 5 meters (15 feet) or so. In addition, instead of three separate conductors, high voltage lines will have three loose "bundles" of conductors, with two, three, or four individual conductors linked together in each bundle using spacers. The bundle scheme is related to corona -- again, more on that later.
The best-known form of a powerline tower is a metal truss latticework. This scheme is sturdy, lightweight, not much disturbed by wind, and can be easily transported in sections to be assembled on site. Single-pylon designs, like street lamp-posts but with multiple arms or "boughs" to carry the cables, are also common. They are harder to set up and require a more robust foundation than a latticework tower; in addition, the conductors have to be strung vertically on the boughs, and since regulations demand minimum heights and spacing of powerlines, that means a taller tower. However, pylon towers have a smaller footprint, making them better suited to urban areas.
A twin-pylon arrangement, usually with wooden pylons, allows the three conductors to be strung horizontally. X-shaped and Y-shaped towers are also used. The power substation into Disney World in Florida has a tower in the shape of Mickey Mouse's head. Towers set up where the line changes direction are always more robust than the rest, because they have to handle unbalanced forces; large towers may also be needed to span a river or canyon.
Two feeder lines are often run on the same line of towers, with six conductors run from tower to tower, reducing costs; separate multiple feeder lines from primary power stations may follow the same right-of-way for the same reason, at least until they branch off to their ultimate destinations.
There are a number of factors to consider in the design of a power line. One is that the length of the conductors will change with the weather, expanding in the summer and contracting in the winter. A longer conductor has greater resistance, so the limit of power that can be transferred is greater in the summer. Another factor is that there is a subtle electromagnetic interaction between the three conductors, resulting in the middle conductor in a three-phase triplet having slightly different electrical properties than the two on the sides. Over long distances, this difference will "unbalance" the line, so every here and there the power line has a special tower that swaps the conductors around.
* By the way, after all the handwaving about why DC is no good for long-range power transmission, it must be added that there are many long-distance DC power lines, running at 500 kilovolts or so. It doesn't contradict what was said before, it just involves a layer of trickery. AC power is stepped up through transformers to a high voltage as before -- to then be converted to DC for transmission over the line. At the remote end, the DC is converted back into AC and then run through a stepdown transformer. From the endpoints, it still looks like an AC line.
Why bother? Mainly because it reduces the number of conductors from three to two, which means a cost saving over long distance -- two-thirds the wiring and lighter towers. Another advantage is that there's no need to ensure phase synchronization between the source of the power and the end users, with the back-conversion system ensuring the phase match. DC lines are often used to transfer power between zones.
The AC/DC conversion is performed by a set of high-power switches. When DC long-distance lines were introduced, back in the 1960s, the switches were "mercury-arc" valves, like an old vacuum tube except that they were filled with mercury vapor, were as long as one's arm, and had to be water-cooled. Modern converters use a solid-state switch called a "thyristor": it's also pretty hefty, though not in the same league as the old mercury-arc valves, and demands aggressive cooling. [TO BE CONTINUED]START | PREV | NEXT
* SPACE PEN MYTH: SCIENTIFICAMERICAN.com recently had an interesting little article about a technology "urban legend" involving "space pens". According to the legend, the US National Aeronautics & Space Administration spent millions to design a pen whose ink would flow in space -- while the sensible Soviets simply used pencils.
As the article explains, like many urban legends, there's enough truth in the story to see how it got started, but it's still bogus in the end. In the early days of manned space flight, both NASA and the Soviets used pencils, but they left something to be desired: the graphite leads could break and float around, becoming a nuisance and possibly even a hazard -- suppose a fragment got into the seal of a pressure suit? NASA also got into a fiasco in 1965 when it became public that the agency had ordered 34 mechanical pencils from an engineering firm that cost well over $100 USD each. Apparently the pencils had to meet special specs, and since they were built in such low volume they ended up being very expensive. A different solution was required.
Paul C. Fisher and his company, the Fisher Pen Company, invested their own funds to design a better solution, the "space pen". Fisher patented this device in 1965; it could write upside-down and keep on writing in arctic or roasting conditions -- or even underwater. It achieved this feat with ink that was driven to a tungsten carbide ballpoint by pressurized nitrogen gas. The ink was in the form of a gel, with the rotation of the ballpoint turning it into a liquid.
The space pen was a marvel of technology. NASA was cautious at first, having been burned on the mechanical pencils, but investigated the device and became enthusiastic, ordering 400 in early 1968. The next year, the USSR ordered 100 for their own space program. Both only paid $2.39 per pen -- expensive for a ballpoint pen, particularly in those days, but these were no ordinary ballpoint pens. They worked very well, and in fact the Apollo 11 astronauts used a space pen to fix a broken switch.
Fisher is still in the space pen business, continuing to sell improved models to NASA and Russia. Fisher will sell the pens to anyone who wants to buy them, no questions asked. It's not like they're secret weapons -- but most people don't want to pay $100 USD for a ballpoint pen, even one that's vastly superior to any ballpoint pen they could get at a supermarket.BACK_TO_TOP