Desalinización más barata

Drops to drink


SINGAPORE’S average annual rainfall is more than double that of notoriously soggy Britain, so the casual observer might be surprised to learn that the place has a shortage of drinking water. Yet with around 7,000 people per square kilometre, Singapore is the third most densely populated country in the world. Its land mass is not large enough to supply its 5m inhabitants with water.

One answer is to desalinate seawater. That, though, is expensive, so the Singaporean government is keen to find cheaper ways of doing it. And, in collaboration with Siemens, a German engineering conglomerate, it may have done so, for Siemens says its demonstration electrochemical desalination plant on the island can turn seawater into drinking water using less than half the energy required by the most efficient previous method.

To make seawater fit for human consumption its salt content of approximately 3.5% must be cut to 0.5% or less. Existing desalination plants do this in one of two ways. Some employ distillation, which needs about 10 kilowatt-hours (kWh) of energy per cubic metre of seawater processed. Brine is heated, and the resulting water vapour is condensed. Other plants employ reverse osmosis. This uses molecular sieves that pass water molecules while holding back the ions, such as sodium and chloride, that make water salty. Generating the pressure needed to do this sieving consumes about 4kWh per cubic metre. The Siemens system, by contrast, consumes 1.8kWh per cubic metre, and the firm hopes to get that down to 1.5kWh.

It works using a process called electrodialysis, in which the seawater is pumped into a series of channels walled by membranes that have slightly different properties from those used in reverse osmosis. Instead of passing water molecules, these membranes pass ions. Moreover, the membranes employed in electrodialysis are of two types. One passes positively charged ions and the other passes negatively charged ones. The two types alternate, so that each channel has one wall of each type. Two electrodes flanking the system of channels then create a voltage that pulls positively charged ions such as sodium in one direction and negatively charged ions such as chloride in the other.

The result is that the ions concentrate in half of the channels, creating a strong brine, while fresher water accumulates in the other half. As the brine emerges, it is thrown away. The fresher water is put through the same process twice more and eventually has its salt concentration reduced to 1%. That is not bad, but is still double what is potable. There is therefore one further step. This is to employ an ion-exchange resin in addition to the membranes. Such resins increase the electrical conductivity of the system and allow one more passage, bringing the salt concentration below 0.5%.

A demonstration plant has been operating since December, and a full-scale pilot plant should be completed by 2013. If all goes well, then, Singapore’s inhabitants will soon no longer feel like Coleridge’s ancient mariner—that there is water, water, everywhere, nor any drop to drink.

Felipe Cubillos

Columna de Felipe Cubillos: “Soy un indignado”

Publicado el: Martes 30 de Ago de 2011
En la Categoría: En la Prensa, Novedades, destacado home
134 Comentarios



Pertenezco a ese grupo de chilenos que después del terremoto y tsunami del 27 de febrero de 2010 nos hemos dedicado a ayudar a levantar escuelas, jardines infantiles, botes de pescadores y comercios que fueron destruidos por la fuerza de la naturaleza. Hemos sido miles los que hemos dedicado nuestro mejor esfuerzo, nuestra pasión y nuestro compromiso en ayudar a volver a levantar a Chile. Lo hicimos desde la alegría y desde nuestra libertad.

Muchos lo hicimos donando a Teletón, Desafío Levantemos Chile, al Techo para Chile y a muchas organizaciones de la sociedad civil. Miles de jóvenes se volcaron a ayudar a miles de familias chilenas, y nos conmovimos con el sufrimiento, pero sobre todo nos cautivamos con el compromiso de tantos por reconstruir nuestra sociedad. Sabemos que todavía nos queda mucho por hacer.

Soy un indignado, porque trabajamos sin descanso para que ningún niño chileno perdiera su año escolar en 2010 y, junto a mucha gente, lo logramos. Pero, un año después, vemos que miles de nuestros jóvenes están a punto de perderlo.

Soy un indignado, porque logramos levantar escuelas caídas para que nuestros niños pudieran estudiar, pero, un año después, otros las queman.

Soy un indignado, porque trabajamos sin descanso para levantar los pequeños comercios devastados por el terremoto y tsunami para que los emprendedores se volvieran a levantar; pero, un año después, veo a cientos de comerciantes como ellos que sufren los destrozos de sus locales cada vez que hay una protesta callejera.

Soy un indignado, porque un joven inocente ha perdido su vida tan sólo por haber estado en el lugar y momento equivocados (mientras escribo esta columna nos acabamos de enterar de que la bala que mató al joven Manuel Gutiérrez salió del arma de un carabinero; ojalá tengamos la mesura para condenar un hecho puntual y no a una institución completa, pues si es así escalemos también hasta los organizadores de las protestas).

Soy un indignado, porque vimos cómo nuestros carabineros evitaban los saqueos en los días posteriores al terremoto, y ahora vemos cómo delincuentes, escondidos entre los estudiantes, los atacan sin piedad en cada protesta.

Soy un indignado porque, pese a todos los problemas que tenemos como sociedad, hemos tenido avances notables en las últimas décadas, y hoy nadie se atreve a reconocer su paternidad o maternidad.

Soy un indignado por esos pseudoempresarios que engañan a la gente, sobre todo a los más pobres, renegociándoles sus condiciones sin ni siquiera preguntarles.

Soy un indignado, porque conozco a muchos emprendedores de la educación subvencionada que, precisamente por hacerlo mejor que los colegios estatales (sí, los municipales, también son estatales), hoy día corren el riesgo de tener que cerrar sus colegios.

Soy un indignado, porque muchos de los parlamentarios de nuestro país han renunciado al liderazgo y responsabilidad que les otorgamos en las urnas.

Soy un indignado cuando veo al presidente del Colegio de Profesores defendiendo una supuesta calidad de la educación, cuando el gremio que preside se niega a evaluarse.

Soy un indignado, porque no estamos discutiendo las verdaderas y profundas razones de la pésima y desigual educación que les estamos entregando a nuestros jóvenes, quizás porque llevamos años usando a la educación como caballito de batalla de la política de turno.

Soy un indignado porque, salvo honrosas excepciones, hemos caído en la política de las encuestas y el Twitter, y hemos renunciado a defender las convicciones. ¿Qué tal si los políticos apagaran por unos días sus computadores y se dedicaran a defender sus convicciones?

Hoy día hablo por mí, y sólo por mí, porque además creo que no somos muchos los que en estos tiempos creemos en la libertad; sí, esa libertad para emprender, para equivocarse, para educar, para enseñar y para aprender.

Soy un convencido de que la derrota de la libertad no se debe a la fuerza de sus enemigos, sino que a la debilidad de sus defensores.

The Halt and the Lame (Krugman)

United States' economy Over-regulated America The home of laissez-faire is being suffocated by excessive and badly written regulation Feb 18th 2012 | from the print edition The Economist AMERICANS love to laugh at ridiculous regulations. A Florida law requires vending-machine labels to urge the public to file a report if the label is not there. The Federal Railroad Administration insists that all trains must be painted with an “F” at the front, so you can tell which end is which. Bureaucratic busybodies in Bethesda, Maryland, have shut down children’s lemonade stands because the enterprising young moppets did not have trading licences. The list goes hilariously on. But red tape in America is no laughing matter. The problem is not the rules that are self-evidently absurd. It is the ones that sound reasonable on their own but impose a huge burden collectively. America is meant to be the home of laissez-faire. Unlike Europeans, whose lives have long been circumscribed by meddling governments and diktats from Brussels, Americans are supposed to be free to choose, for better or for worse. Yet for some time America has been straying from this ideal. Consider the Dodd-Frank law of 2010. Its aim was noble: to prevent another financial crisis. Its strategy was sensible, too: improve transparency, stop banks from taking excessive risks, prevent abusive financial practices and end “too big to fail” by authorising regulators to seize any big, tottering financial firm and wind it down. This newspaper supported these goals at the time, and we still do. But Dodd-Frank is far too complex, and becoming more so. At 848 pages, it is 23 times longer than Glass-Steagall, the reform that followed the Wall Street crash of 1929. Worse, every other page demands that regulators fill in further detail. Some of these clarifications are hundreds of pages long. Just one bit, the “Volcker rule”, which aims to curb risky proprietary trading by banks, includes 383 questions that break down into 1,420 subquestions. Hardly anyone has actually read Dodd-Frank, besides the Chinese government and our correspondent in New York (see article). Those who have struggle to make sense of it, not least because so much detail has yet to be filled in: of the 400 rules it mandates, only 93 have been finalised. So financial firms in America must prepare to comply with a law that is partly unintelligible and partly unknowable. Flaming water-skis Dodd-Frank is part of a wider trend. Governments of both parties keep adding stacks of rules, few of which are ever rescinded. Republicans write rules to thwart terrorists, which make flying in America an ordeal and prompt legions of brainy migrants to move to Canada instead. Democrats write rules to expand the welfare state. Barack Obama’s health-care reform of 2010 had many virtues, especially its attempt to make health insurance universal. But it does little to reduce the system’s staggering and increasing complexity. Every hour spent treating a patient in America creates at least 30 minutes of paperwork, and often a whole hour. Next year the number of federally mandated categories of illness and injury for which hospitals may claim reimbursement will rise from 18,000 to 140,000. There are nine codes relating to injuries caused by parrots, and three relating to burns from flaming water-skis. Two forces make American laws too complex. One is hubris. Many lawmakers seem to believe that they can lay down rules to govern every eventuality. Examples range from the merely annoying (eg, a proposed code for nurseries in Colorado that specifies how many crayons each box must contain) to the delusional (eg, the conceit of Dodd-Frank that you can anticipate and ban every nasty trick financiers will dream up in the future). Far from preventing abuses, complexity creates loopholes that the shrewd can abuse with impunity. The other force that makes American laws complex is lobbying. The government’s drive to micromanage so many activities creates a huge incentive for interest groups to push for special favours. When a bill is hundreds of pages long, it is not hard for congressmen to slip in clauses that benefit their chums and campaign donors. The health-care bill included tons of favours for the pushy. Congress’s last, failed attempt to regulate greenhouse gases was even worse. Complexity costs money. Sarbanes-Oxley, a law aimed at preventing Enron-style frauds, has made it so difficult to list shares on an American stockmarket that firms increasingly look elsewhere or stay private. America’s share of initial public offerings fell from 67% in 2002 (when Sarbox passed) to 16% last year, despite some benign tweaks to the law. A study for the Small Business Administration, a government body, found that regulations in general add $10,585 in costs per employee. It’s a wonder the jobless rate isn’t even higher than it is. A plea for simplicity Democrats pay lip service to the need to slim the rulebook—Mr Obama’s regulations tsar is supposed to ensure that new rules are cost-effective. But the administration has a bias towards overstating benefits and underestimating costs (see article). Republicans bluster that they will repeal Obamacare and Dodd-Frank and abolish whole government agencies, but give only a sketchy idea of what should replace them. America needs a smarter approach to regulation. First, all important rules should be subjected to cost-benefit analysis by an independent watchdog. The results should be made public before the rule is enacted. All big regulations should also come with sunset clauses, so that they expire after, say, ten years unless Congress explicitly re-authorises them. More important, rules need to be much simpler. When regulators try to write an all-purpose instruction manual, the truly important dos and don’ts are lost in an ocean of verbiage. Far better to lay down broad goals and prescribe only what is strictly necessary to achieve them. Legislators should pass simple rules, and leave regulators to enforce them. Would this hand too much power to unelected bureaucrats? Not if they are made more accountable. Unreasonable judgments should be subject to swift appeal. Regulators who make bad decisions should be easily sackable. None of this will resolve the inevitable difficulties of regulating a complex modern society. But it would mitigate a real danger: that regulation may crush the life out of America’s economy.

Ecología

Canada’s environment
Boreal blues

OTTAWA
In the frigid north tension grows between conservation and development

CANADA’S vast boreal zone contains the world’s largest intact old-growth forest and has more fresh water than the Amazon. Its flora help to slow climate change and it is a breeding ground for 3 billion migratory songbirds. Only 12% of the region is now formally protected, well below the 50% scientists say is necessary to save its ecosystem. On May 9th Quebec unveiled the Plan Nord, a C$2.1 billion ($2.2 billion) proposal that seeks both to develop its northern region and to safeguard its environment. But whether those two objectives are actually compatible remains open for debate.
For a party closely tied to the oil industry, the Conservatives—who won a majority on May 2nd after five years of minority government—have been surprisingly progressive in protecting boreal land. They have set aside 12% of the area’s 552m hectares (1.36 billion acres), including the Mealy Mountains national park in Labrador announced last year (see map). Some provinces have also taken the lead. In 2010 Ontario passed a law shielding half of its far north from development, and Manitoba recently protected 4m hectares of forest. Quebec’s Plan Nord would ban industrial activity in half of its north and make 12% a nature reserve, and offers tax credits for eco-friendly projects.

Yet provincial governments are also pushing to tap the region’s rich resources. Ontario has registered 30,000 mining claims in an area west of James Bay nicknamed the “Ring of Fire”, where chromite (used for stainless steel) was found in 2006. And Quebec’s Plan Nord will open an area twice as big as France to mining, energy development and forestry. Meanwhile Alberta has few limits on boreal oil exploration. In April its government released the details of a plan to protect 20% of the region’s land and faced a backlash from energy firms. The federal government has little power to make the provinces become greener.
Aboriginal groups, who hold treaty rights in the north, have also tussled with environmentalists, whom they blame for disrupting their fur trade and seal hunt. They hope that miners will provide much-needed jobs. Ontario’s Nishnawbe Aski Nation and the Quebec and Labrador arm of the Assembly of First Nations say they were not adequately consulted before their provinces’ conservation laws were drafted, and now oppose the legislation. Indigenous peoples may not be as anti-green as oil companies, but they are no tree-huggers either.
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¿Puede ser rentable el periodismo digital?

http://www.puroperiodismo.cl/?p=13082

El capitalismo y los mineros

http://j.mp/dlo08D

Artículo de mi hijo Pablo en El Mostrador

PABLO LARRAÍN

Economista, MSc en Finanzas.

http://twitter.com/pdvn

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Todos entendemos la euforia general que se ha desatado con el inminente rescate de los mineros. Salvo algunos pocos que mantuvieron la esperanza en todo momento, la mayoría flaqueamos y estábamos preparados para que no hubiera sobrevivientes. Pocos días antes de ser encontrados, El Mercurio en primera página del suplemento Reportajes señalaba citando la opinión de expertos una probabilidad de 2% que estuvieran con vida. En otras palabras, estaban muertos.

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Pasar de la desazón y de la idea de convertir a la mina en un santuario tal como se había hecho en Méjico, a estar a días que los treinta y tres puedan retomar sus vidas junto a sus familias explica con largueza el interés y apasionamiento con que el país ha seguido cada uno de los detalles del proceso. A esto se suma el hecho que el rescate ha pasado a ser una noticia global y sabemos cuánto nos importa lo que opinen de nosotros. Estuvimos y estaremos en todas las portadas de diarios y noticieros de todo el mundo por un hecho que combina el trabajo bien hecho y el temple de un grupo de chilenos, bálsamo para nuestros inseguros ojos y oídos.
Sin embargo, debemos estar conscientes que esta historia no termina el día que salen a la superficie. Hay toda una vida por delante para los mineros rescatados y como sociedad podemos ayudar a que esa vida sea mejor o peor. ¿Será mucho pedir sobriedad en lo que viene post rescate? Sí, esa misma sobriedad que han mostrado Golborne, Sougarret y los múltiples profesionales y técnicos que han trabajado silenciosa e incansablemente.

La imagen del Presidente agitando una bandera y coreando interminables ceacheís no le suma nada a él ni tampoco a los mineros y la incierta nueva vida que les viene por delante. No es fácil la contención en este caso, pero creo que vale largamente la pena, pues va a sentar en parte el tono del resto de la sociedad.

Nuestra epopeya bicentenaria será mucho mejor si los mineros no son parte del jurado de ningún festival, si la muchacha con silicona de turno no se enamora perdida y súbitamente de uno de los rescatados, si los programas de televisión tratan con respeto a sus familias y no los transforman en íconos desechables que lloran y reciben regalos de canal en canal, si las grandes marcas deciden no utilizarlos como rostros de la próxima campaña. Es natural que haya múltiples reconocimientos a los mineros pero varios sabemos distinguir la sana valoración de un circo comercial.

En este proceso el gobierno también puede ayudar y de paso ayudarse. El haberse expuesto, invertido recursos sin medir gastos, organizado eficientemente un proceso de alta complejidad y el haber dispuesto recursos humanos de primer nivel, legítimamente le da derecho a cosechar el éxito del rescate. Pero como todo en la vida, hay límites. Nada sería peor para el gobierno que aparecer haciendo aprovechamiento político de los mineros rescatados. Si hay algo seguro es que la oposición lo va a acusar de ello por lo que debe ser especialmente delicado y sobrio en su actuar.

Si el Presidente está de gira en Europa, cuando se concrete el rescate, qué mejor para él y su prestigio internacional. Esté donde esté, nadie va a dudar que este ha sido un desafío en que se ha involucrado en forma personal. Lo único que puede mermar su éxito en este tema es la sobre exposición; la imagen del Presidente agitando una bandera y coreando interminables ceacheís no le suma nada a él ni tampoco a los mineros y la incierta nueva vida que les viene por delante. No es fácil la contención en este caso, pero creo que vale largamente la pena, pues va a sentar en parte el tono del resto de la sociedad.