Archive for septiembre, 2007

A solar refrigerator for developing world

septiembre 17, 2007


Posted by Michael Kanellos
The Solar Turbine Group is trying to bring refrigeration to emerging nations by harnessing the power of the sun.

The organization, which consists largely of MIT alumni, has devised a solar thermal generator that can be brought to market for $12,000 or less. A typical system can generate 600 watts of electricity or 20 kilowatts of energy for heating and cooling, according to Sam White, director for STG. The same system can also produce both at the same time, albeit less of each.

Parabolic mirror for capturing the sun

(Credit: Solar Turbine Group)
Like other solar thermal systems, STG uses mirrors. Mirrors concentrate heat from the sun onto a tube filled with a liquid (in this case glycol). The heat from the liquid can then be used in two ways. One, the heat can be transferred to another liquid. The second liquid gets vaporized and ultimately gets used to turn a turbine to create electricity.

Two, heat from the glycol can be used to boil refrigerant.

Although many villages in emerging nations don’t have electricity, a lack of refrigeration is perhaps a more dire problem. Without refrigeration, food-borne diseases spread more rapidly. Farmers also can’t store their crops in hopes of getting a better price, noted White. Thus, something like this could help improve health and local economies.

One reason the Northern Hemisphere (in my mind) moved ahead of the Southern Hemisphere is that the people there had to only figure out heating, a relatively straightforward process, rather than cooling. (I came up with that idea one day in Malaysia after walking into an air-conditioned Burger King after four hours in the midday sun.)

Hawaii’s Sopogy is marketing similar devices in developed countries.

The company has installed a few prototypes in Lesotho and wants to put some in India. What has the group learned? That they have to show locals applications where and how the generator can be used. Locals just don’t come up with the ideas on their own at first. “That was probably the most useful insight,” he said.

The low cost comes in part because many of the parts required to build one of its solar generators are actually old car parts, White said. There’s another problem solved: putting salvage to good use.

Fuente: CnetNews


Boinayel, el pluvioso

septiembre 7, 2007

Recordé esta experiencia al leer recientemente los resultados de una encuesta, donde, al preguntárseles a los dominicanos sobre el color de su piel, el 70% contestó que éramos indios.

Por Bernardo Vega


Durante mis 19 años de funcionario público, pasé por muchas experiencias, pero entre ellas descuella, por lo inusual, el caso de Boinayel, el pluvioso.

Fui director del Museo del Hombre Dominicano por cinco años y me esmeré en promover exhibiciones temporales. Gracias a gestiones del personal diplomático de nuestra embajada en Londres, logré que la Càmara de los Lores autorizara el envío temporal a nuestro país de la fabulosa colección del Museum of Mankind londinense de unas ocho piezas taínas de madera.

A diferencia de los aztecas y los incas, cuyas piezas de madera son muy escasas y de baja calidad, las mejores de los taínos son precisamente las de madera.

Primero llegó un inglés, para ver si llenábamos las condiciones mínimas de seguridad. No sólo habló con el representante local de INTERPOL, sino que, de madrugada, se le vio rondando el museo. Al irse me informó que nuestro país era demasiado “atrasado” como para que la gente robara o vandalizara piezas de museo.

Un par de años después leí un artículo donde se le citaba con relación a la destrucción de un cuadro muy valioso por parte de un espectador en un afamado museo inglés.

Entre las piezas taínas que nos prestaron estaba la representación de Boinayel, el cemí taíno auspiciador de la lluvia, evidenciado por las lágrimas que surcan de sus ojos. Para una sociedad que dependía de la yuca, ese dios era de los más importantes.

Para promover la exhibición declaré a la prensa que Boinayel era el equivalente taíno a Tlaloc, el dios azteca de la lluvia y cité que cuando se trajo a la ciudad de México su enorme estatua, que había sido encontrada en el interior, para colocarla permanentemente en el Museo Antropológico, las muy fuertes lluvias no cesaron. Rafael Herrera editorializó sobre ese símil.

La noche inaugural de la exhibición temporal se caracterizó por fuertes lluvias, las cuales no cesaron durante varios días. Cientos de personas fueron al museo a ver al responsable de los aguaceros. Entonces recibí una llamada de parte del presidente Antonio Guzmán.

El intermediario explicó que el presidente no creía en esas cosas, pero que el obispo de Barahona lo había llamado para advertirle que allí los campesinos se habían amotinado culpando a Boinayel por las inundaciones y otras consecuencias funestas de las lluvias. Me solicitó, cortés, pero firmemente, que devolviera la pieza a Londres.

El dilema era serio, pues el contrato con el museo inglés no permitía devolver una pieza sin que estuviera presente en el país un funcionario de esa institución. A medianoche, con gran discreción, movimos la pieza unos 10 metros, hasta colocarla dentro de un closet, el cual cerramos herméticamente. Al día siguiente mentimos al informar a Palacio que la pieza había sido devuelta a Inglaterra.

El sol resplandecía contra un cielo totalmente azul. Sería tan sólo un mes después cuando Boinayel retornaría muy confidencialmente, junto con las otras piezas, al pluvioso Londres.

Recordé esta experiencia al leer recientemente los resultados de una encuesta, donde, al preguntárseles a los dominicanos sobre el color de su piel, el 70% contestó que éramos indios.

Luce que Boinayel quiso evidenciar sus poderes en el único lugar del mundo donde la gente todavía cree que desciende de los taínos, de aquellos que alegremente cambiaron oro de aluvión por cascabeles de latón, en esta isla al reves, a la cual por poco le agregamos el cascabel de una isla artificial.

Fuente: Clave Digital

‘The Redevelopment of a City is an Art’

septiembre 2, 2007

Charles Landry, 58, is considered one of the world’s leading urban researchers and is the author of “The Creative City.” He talks to SPIEGEL about how cities can harness their inhabitants’ skills so they show up on the international radar and the German tendency to make cities too neat and tidy.

SPIEGEL: What does a city need to have for you to feel good in it?
Landry: Contradictions, most of all, a balance between chaos and order. It needs neighborhoods vibrating with energy just as much as cozy little corners and parks; well-tended, middle-class sections as well as an alternative scene; technology centers for innovative youth and social facilities for older people. In other words, it needs creativity to retain the high performers who have lived there for years as well as to attract new, interesting residents.

SPIEGEL: Can this creativity be regulated?

Landry: Not really, but it can be encouraged. The redevelopment or revitalization of a city is an art. It depends on the individual strengths of a place and the will of the leadership to bring about change. The goal is to establish a cultural infrastructure. Creativity is also needed in the administration. There is no magic formula, no 10-point plan where you can check off items and suddenly be successful.

SPIEGEL: What in particular do city officials have to take into account, and what should they focus on?

Landry: First, they must be conscious of the international competitive situation dictated by globalization. As industries migrate toward the Far East, the future of many Western cities will no longer lie in manufacturing products but ideas and patents. Young, mobile elites can choose where they want to live, and they can easily move, which means that cities are involved in a heated competition for the best people. Only the most attractive cities can benefit from this development.

SPIEGEL: But some cities just happen to be more attractive than others, perhaps because they’re on the coast or in the mountains, or their history creates a certain atmosphere.

Landry: That’s true, of course. Some remain great cities, but they shouldn’t stand still. They should move in the direction of a knowledge-oriented society. Most cities have to do something to draw attention to themselves and make their particular assets visible on the international radar. I’m not talking about developing countries, but about the United States and Europe.

SPIEGEL: Surely it’s a tall order to attract creative people when your city has a high crime rate, collapsed infrastructure and slums?

Landry: Like Detroit, an urban hell. But even in this city of the dying auto industry, there is reason to hope, if they manage to combine the creative forces of designers and other intellectual “suppliers” in other ways. All cities have one key resource: the special abilities of the people who live in them. You just have to find out what they are. In the Australian city of Adelaide, for example, which is overshadowed by Sydney and Melbourne, I discovered a number of experts in the penal system. I advised them to work with these special skills.

SPIEGEL: Which European city is the best at utilizing its particular human resources?

Landry: I like what Barcelona is doing. This city almost perfectly combines its natural advantages with cultural attractions, IT parks and first-rate educational opportunities. The same applies for Dublin, which manages to achieve a blend of complexity, tolerance and artistry and makes a point of not devoting every part of the city to the tourism industry. Sometimes creativity also means forgoing short-term profits and simply saying no.

SPIEGEL: Is multiculturalism an advantage or a drawback?

Landry: It can be both. In a city like London, the fact that cultures live together and cross-fertilize is a beautiful and natural thing. The many cultures in Amsterdam contribute to the city’s high level of craziness — something which every interesting city should offer. But sometimes immigrants can live in parallel worlds which can exclude others and not be very attractive. As far as population size goes, big is no longer important, and it can even be a drawback. In fact, the future belongs more to second-tier cities. Any place can become a world-class center today by finding an area in which it outperforms others, by thinking for the long term, by expanding its competitive abilities and by operating globally.

SPIEGEL: What do you think of German cities?

Landry: Hamburg is getting a new symbol with its new Elbe Philharmonic concert hall. Such an architecturally impressive building is built somewhere in the world maybe once every five years, if you’re lucky. Hamburg will have a new and important attraction with which it can distinguish itself from other cities. But the important thing is that activities should not just be limited to the building, but that the concert hall should symbolize a general mood of creative rejuvenation. Another thing I like about German cities — and it’s an advantage which they haven’t sufficiently exploited yet — is that they are pioneers when it comes to environmental technologies. And green solutions are becoming more and more important.

SPIEGEL: Are there things about Germany which you don’t like?
Landry: The Germans are often too bureaucratic, too fixated on rules and not risk-oriented enough. And some of their officials have the feeling that they need to make everything in the cityscape look nice and pretty as quickly as possible. That was particularly apparent in the former East Germany after reunification. Then cities sometimes get a bit too neat and tidy.

SPIEGEL: Where do you live when you’re not on the road?

Landry: I travel a lot and my job means that I’m almost always in big cities. I sometimes stay in one city for a few months for my consulting work, as I did recently in the Australian city of Perth.

SPIEGEL: But don’t you need a place that you can call home?

Landry: Yes, of course. I live not too far from London, in the countryside in Gloucestershire — in a village with just 20 houses.

Interview conducted by Erich Follath.