Nanotecnología Revolución Mircoscópica

Este es un articulo publicado por el periódico Reforma el día lunes 22 de agosto.

Nano tecnología. Revolución microscópica

El diseño de materiales, máquinas y sistemas diminutos ya está impulsando numerosos campos del conocimiento

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• Uso amplio en los cosméticos 2011-08-22

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Lunes 22 de agosto de 2011Guillermo Cárdenas Guzmán | El Universalguicardenas@hotmail.com
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A bordo del submarino Proteus, un equipo médico-militar se dispone a viajar a través del torrente sanguíneo del científico Jan Benes —quien permanece en estado de coma tras sufrir un atentado mortal— para destruir un coágulo alojado en su cerebro.

El submarino y sus tripulantes necesitan reducir su tamaño al de una célula para desplazarse por las arterias del sabio agonizante, depositario de un gran secreto. ¿Demasiado futurista? ¿Más ficción que ciencia? Tal vez esto encierre el clásico filme Viaje fantástico, estelarizado en 1966 por Stephen Boyd y Rachel Welch.

Es imposible miniaturizar seres humanos sin afectar las propiedades de sus cuerpos. En cambio, el diseño y manipulación de robots, dispositivos, estructuras y sistemas a escalas microscópicas, al nivel molecular e incluso atómico, poco a poco deja de ser ficción gracias al desarrollo de las nanociencias y sus aplicaciones.

“Algunas nanoestructuras podrían ser hasta un millón de veces más resistentes que el diamante, pero huecas y con el mismo peso que el aire. Esto sin duda es una revolución, tan importante como la introducción de la piedra o los metales”, dice Víctor Manuel Castaño, del Centro de Física Avanzada y Tecnología Aplicada de la UNAM.

Propiedades inusuales

¿Qué tiene de peculiar el estudio, obtención y manipulación de materiales o dispositivos microscópicos, medidos en escalas de 1 a 100 nanómetros (millonésimas de milímetro) y que ha generado gran polémica?

A este nivel los materiales experimentan un gran aumento en su área superficial en comparación con su volumen (como si estuvieran “plegados”), por lo cual adquieren propiedades físicas y químicas inusuales, que jamás podrían verse en el mundo “macro”. Por ejemplo, la transmisión de energía no se da continuamente, sino a través de “paquetes”.

Gracias a estas características se prevé construir microchips realmente “micro” (del tamaño de un grano de arena), nuevas clases de resistores capaces de almacenar datos (memoria), láseres más potentes o cables conductores de electricidad de 10 nanómetros de ancho y 50 veces más largos, capaces de autoensamblarse como el ADN en las células .

Esto reducirá los costos de numerosos componentes electrónicos y aumentará miles de veces la velocidad de procesamiento y capacidad de almacenamiento de las computadoras. Los nanotecnólogos buscan también construir pequeñas máquinas “híbridas” con proteínas, bacterias, virus o ADN integrados para funciones específicas.

En el laboratorio ya se han obtenido nanocristales, nanotubos de carbono y algunos nanocables semiconductores, entre otros materiales. Para ello se usan instrumentos como emisores ópticos, que concentran luz. Ahora los científicos pretenden dar el siguiente paso: encontrar la arquitectura adecuada para que dichas estructuras puedan producirse a nivel masivo y a bajo costo.

Nueva era

El campo de la medicina también se beneficiará ampliamente con el ensamblaje de minúsculas cápsulas o nanorrobots que, como en Viaje fantástico, se internen en el sistema circulatorio humano para detectar enfermedades, reparar glóbulos rojos dañados, destruir virus o células enfermas o administrar fármacos a las dosis exactas requeridas.

Por lo pronto ya hay al menos varias líneas de estudio en tal dirección no sólo en los grandes laboratorios del mundo, sino también en México, donde Tessy López Goerne desarrolla la nanomedicina catalítica en el Instituto Nacional de Neurología. Ella ha empleado nanocápsulas de óxidos de silicio o titanio para tratar cánceres cerebrales.

En lugar de aplicar quimioterapia (que no es selectiva y destruye por igual células malignas y sanas) o administrar medicamentos por vía oral (sólo el 5% llega hasta el cerebro, debido a la barrera hematoencefálica) la científica y sus colegas han empleado esas nanocápsulas como vehículos de la sustancia anticancerosa.

Los resultados (inhibición de tumores cancerosos hasta más de 90%) han sido alentadores en perros y ratas de laboratorio y ahora los investigadores tratarán de experimentar con seres humanos. Más adelante buscarán terapias con esta base para combatir otros trastornos neurológicos como Parkinson o Alzheimer.

El México de la inmoralidad

Terrible es siempre la muerte. De una persona o de 62, como ocurrió ayer en Monterrey. Tal vez varios de los fallecidos no eran apostadores compulsivos, sino curiosos ocasionales que tuvieron la mala fortuna -irónico en un lugar en donde se acude en busca de mejorar la suerte- de estar en el lugar equivocado, el día y la hora erróneas.

Un análisis frío de lo ocurrido en el Casino Royal de Monterrey:

a) era un lugar de apuestas que, aunque en zona elegante y pudiente, tenía una situación ilegal;

b) dentro de esa ilegalidad, el gobierno estatal y municipal solaparon su funcionamiento;

c) en México, cualquiera de estos giros negros sirve para lavar dinero, venta de drogas, trata de personas;

d) en el lugar habían menores de edad;

e) corrupción, ilegalidad, piratería, tráfico de estrupefacientes, la mezcla del desastre.

Repito, lamentable lo que ocurrió, pero mientras todos los ingredientes que mencioné continuen en varias partes de nuestro país, seguiremos viendo este tipo de hechos de sangre. Y los encontramos en numerososo sitios: en empresas (públicas y privadas), en sindicatos (de maestros, de petroleros, de electricistas, de trabajadores de la salud, de obreros y campesinos, de todo), en universidades (públicas y privadas), en moteles de paso y en "salones de baile" (mejor conocidos como Table Dances, Men's Clubs), en sitios de apuestas (legalizados en la época de Santiago Creel cuando secretario de gobernación, y hoy convertidos en lavaderos de dinero ilegal -narco, trata de personas, desvío de impuestos, venta de armas...-).

Que el Presidente Calderón el día de hoy apunte con el dedo flamígero hacia Estados Unidos y les acuse de no estar atacando el origen de todo el problema (el consumo de drogas en su población y la venta irrestricta e ilegal de armas que terminan en manos de los ejercitos del narco), aunque valeroso -pero tardío- no es suficiente. El problema es cultural, muy de fondo, casi idiosincrático. Nos encanta encontrar en el gobierno la causa de todos nuestros males, y su ineficiencia total no ayuda a verlo de otra forma. Pero también nosotros somos culpables. Somos culpables al tolerar, premiar, realizar aunque sea los más mínimos actos de impunidad, corrupción e ilegalidad. Hasta los más mínimos. Tan inmoral es un servidor público embolsándose hasta las ligas con dinero que compra conciencias y contratos de obras, como lo es el peatón que atraviesa por la mitad una calle, o el automovilista rebasando por la derecha, estacionándose en doble fila o en sitio reservado o que da vuelta en zona prohibida o se pasa un alto. Inmoral es el que tira la colilla del cigarrillo en la acera, o la bolsa de papas en la coladera. Inmoral es el que acusa al gobierno de ineficiente en la lucha contra el narco, pero acepta que su hermano, amiga o conocido consuma marihuana, pues es "una droga social, inócua". Inmoral el empresario que ahorra gastos retirando contratos justos a sus trabajadores, dando bonos en vez de salarios apropiados para ahorrarse impuestos, que hace reingeniería de la planta laboral para maximizar las ganancias. Inmoral el líder sindical que negocia con el jefe o el gobierno en perjuicio (y hasta en beneficio) de sus agremiados, que se enriquece con las cuotas y promete/regala apoyos a cambio de prebendas políticas. Inmoral la maestra o maestro que, careciendo de amor y vocación por la enseñanza, se mueve entre las jerarquias educativas en busca del bono extra, el mínimo esfuerzo. Inmoral el jefe que, abusando del poder y la confianza, crea redes para perpetuarse beneficios, expulsa a sus opositores, aplasta cualquier indicio de pensamiento independiente y recto. Inmoral, inmoral, inmoral.

En el país de la inmoralidad, la mediocridad y el cangrejismo, hechos violentos y de terror como el de ayer en Monterrey, no tienen otro destino y futuro mas que su multiplicación. Y la justicia, sumergida en el oceano de la impunidad y el servilismo, probablemente naufragará en la búsqueda de su aplicación.

Pobre México.

"Dry water" could be the next storage medium for dangerous chemicals

Despite the oxymoronic name, 'dry water' is very real. This bone-dry water-silica compound could provide a way to transport dangerous liquids and gases safely - inside trillions of water-drop sized packages.

'Dry water' is comprised of 95% water, with a thin layer of silica coating each droplet, essentially turning it into a dry powder. When it's mixed with certain liquids or gasses, they combine with the water - which then traps them in a silica cage. Hence, they become non-reactive, and are easily transported without worrying about accidental detonation and the like.

'Dry water' was first discovered in the late 60s, and was immediately snatched up by cosmetic companies, eager to make use of its unique properties. It resurfaced in 2006, and researchers at the University of Liverpool have been working on new applications for the hydrate.

This substance gleefully combines with both liquids and gasses - and this feature makes it very useful. The primary application would be carbon dioxide sequestering. The 'dry water' can absorb three times the mass of CO2 as its constituent ingredients could.

The research also indicates the substance could be used a number of other ways: for storing and transporting methane (from natural deposits, or as fuel); as a way of speeding up the reaction between hydrogen gas and maleic acid to produce succinic acid, which is used to make drugs, food ingredients, and consumer products; or, to aid in transporting emulsions.

What about getting the stored materials out again, once they've been sequestered? Dr. Ben Carter, a researcher on the product, says it's quite straightforward to separate:

A dry liquid (either pure water or a solution of something dissolved in water) can be separated back to liquid + silica by either of two methods. You can centrifuge it at high speed to force the two apart, or you can add an alcoholic solvent like methanol or ethanol. This reduces the water surface tension as the alcohol penetrates the water droplets, causing the dry liquid to fall apart.

If you've stored a gas in DW as a gas hydrate, all you have to do to release it is warm up the material to melt the hydrate (hydrates normally form at 0 degrees C under pressure, and can be stored at -20 degrees C without the need to be kept under further pressure).

The dry water itself is easy enough to manufacture. The hydrophobic silica and water are blended together at 19,000 rpm for 90 seconds, which coats the water droplets completely.

El futuro del tabaco en baterias de litio.

The tobacco mosaic virus is a destructive beast infecting over a hundred different species of plants, including tomatoes. But it may have a weird eco benefit: Incorporated into lithium batteries, it can increase storage capacity up to ten times.

Scientists in the U.S. had already worked out how to coat the tiny rod-like cells of the virus with conductive materials. But the recent breakthrough has seen the nanorods incorporated into battery technology, with astonishingly beneficial results. The tobacco mosaic virus is a perfect candidate because it's the right size and shape to aid construction of battery electrodes, and it's self-replicating and self-assembling and can bind to metal.

The idea is that TMV nanorods are bound to the electrodes in a lithium cell--without the need for any bonding agent--and automagically increase the surface area of the electrode. This is a critical matter in battery design, since it affects how much electrical energy the battery can hold, and TMV's benefits mean a similar cell can hold up to ten times more charge than a more conventional one.

This has all sorts of implications for mobile technology. Imagine every lithium battery in every mobile device you own lasting up to ten times longer. That would mean Apple's new MacBook Airs could hang on in standby mode for 10 months, and Amazon's Kindles may only require charging once every year. Smartphones could have useful call times extending up to a week, and as well as changing how we think about our tech this could have an eco upshot--you'd probably not leave your charger plugged in, sucking down vampire power as much as it does right now.

Alternatively, batteries could be made with the same capacity that they have now, only ten times smaller--freeing up designers to create all sorts of practically useful gadgets that would be impossible at the moment. Micro-batteries are also possible, meaning rechargeable batteries could replace disposable ones in devices like hearing aids.

If the scientists at the University of Maryland driving this research find a way to scale up the invention to a commercial scale, then tobacco growers around the world may find themselves contributing something more positive to society, and the way we think about mobile technology may change radically.

link : www.fastcompany.com/1708167/how-to-make-lithium-batteries-last-ten-times-longer-incorporate-a-plant-virus

Simbolos de la Alquimia

Solo por diversión y a quien le interese ver esta pagina con muchos símbolos usados para la alquimia aquí les dejo algunos y el link de la misma

http://www.iridius.info/current/info/a.html

		air
		air
		alcohol
		alcohol
		alkali
		alum
		alum
		alum
		aluminium
		amalgam
		amalgam
		amalgamation
		ammonia
		anneal
		antimony
		antimony
		aqua
		aqua fortis
		aqua fortis
		aqua regia
		aqua vitae
		aqua vitae
		arsenic

El "Olor metalico " es meramente olor corporal.

¿Por que el metal tiene olor ?

Probablemente la mayoría de las personas alguna vez en su vida hayan experimentado un olor al entrar en contacto con metales como el hierro o el cobre . Al agarrar un pasamanos de hierro o algún pedazo de metal aparentemente la mano queda impregnada de este olor metálico. Sin embargo Dietmar Glindermann y sus compañeros de la universidad alemana de Leipzig dicen que realmente el metal no es que tiene olor si no que mas bien este reacciona con algunos compuestos de la piel y genera este peculiar olor asociado al metal. Lean la nota completa(esta en inglés ) .

Why does metal smell? Chemists have found a surprising answer: it doesn't.

After you've grasped an iron railing, a door handle or a piece of steel cutlery, your hand often gives off what seems to be a metallic odour. But Dietmar Glindemann of the University of Leipzig, Germany, and his co-workers say that you're not smelling the metal at all.

They have found that the musty odour comes from chemical compounds in your skin, which are transformed in an instant by the touch of iron. They report the results in the international edition of Angewandte Chemie.

Copper has a similar effect, accounting for the metallic smell created by handling coins made of copper alloys. "When a shopkeeper hands you a coin," says Glindemann, "you're smelling his body odour."

The smelly reactions induced by these metals create "the sensory illusion that it is the 'metal in itself' that we smell right after touching it", the researchers say. In other words, a 'metallic' smell is only deemed to be so by association.

Sweaty palms

“When a shopkeeper hands you a coin, you're smelling his body odour.” Dietmar Glindemann, University of Leipzig

Glindemann began studying this question years ago when he became curious about the garlic-tinged metallic aroma of iron after it has been touched by a sweaty palm. He found that acids naturally present in sweat induce reactions between carbon and phosphorus impurities typically present in iron, generating smelly, volatile molecules called organophosphines.

But the 'metallic' smell left on your hands after you handle iron or copper was different from the scent of metals touched by acid in the lab. "This problem tortured me for five or six years," Glindemann says.

The breakthrough came when he teamed up with environmental chemist Andrea Dietrich at Virginia Polytechnic Institute and State University in Blacksburg. She was trying to understand why people often complain of a metallic taste in drinking water.

Exploring the issue of metallic taste led her to think about metallic smell. That took her to Glindemann, and they cracked the problem together.

The researchers captured the vapours emitted from the skin of people who had handled iron objects, and studied their chemical composition. The gases contained several compounds called aldehydes and ketones, which often have strong and distinctive smells. The odour of preserving fluid, or formaldehyde, makes for the characteristic reek of old anatomy labs, for example, while the ketone acetone makes the distinctive solvent whiff of nail-varnish remover.

These compounds are produced by rapid reactions between iron or copper and oils on our skin.

New device from CU physicist tests uncertainty principle to unprecedented level -- and shows that looks can cool

In the submicroscopic world -- the domain of elementary particles and individual atoms -- things behave in the strange, counter-intuitive fashion governed by the principles of quantum mechanics. Nothing (or so it seems) like our macroscopic world -- or even the microscopic world of cells or bacteria or dust particles -- where Newton's much more reasonable laws keep things sensibly ordered.

Provided

A scanning electron microscope image of an aluminum and silicon nitride resonator coupled to a superconducting single electron transistor (SSET). Researchers watched the resonator move through a phenomenon known as quantum back-action.

The problem comes in finding the dividing line between the two worlds -- or even in establishing that such a line exists. To that end, Keith Schwab, associate professor of physics who moved to Cornell Univeristy this year from the National Security Agency, and colleagues have created a device that approaches this quantum mechanical limit at the largest length-scale to date.

And surprisingly, the research also has shown how researchers can lower the temperature of an object -- just by watching it.

The results, which could have applications in quantum computing, cooling engineering and more, appear in the Sept. 14 issue of the journal Nature.

The device is actually a tiny (8.7 microns, or millionths of a meter, long; 200 nanometers, or billionths of a meter, wide) sliver of aluminum on silicon nitride, pinned down at both ends and allowed to vibrate in the middle. Nearby, Schwab positioned a superconducting single electron transistor (SSET) to detect minuscule changes in the sliver's position.

According to the Heisenberg uncertainty principle, the precision of simultaneous measurements of position and velocity of a particle is limited by a quantifiable amount. Schwab and his colleagues were able to get closer than ever to that theoretical limit with their measurements, demonstrating as well a phenomenon called back-action, by which the act of observing something actually gives it a nudge of momentum.

"We made measurements of position that are so intense -- so strongly coupled -- that by looking at it we can make it move," said Schwab. "Quantum mechanics requires that you cannot make a measurement of something and not perturb it. We're doing measurements that are very close to the uncertainty principle; and we can couple so strongly that by measuring the position we can see the thing move."

The device, while undeniably small, is -- at about ten thousand billion atoms -- vastly bigger than the typical quantum world of elementary particles.

Still, while that result was unprecedented, it had been predicted by theory. But the second observation was a surprise: By applying certain voltages to the transistor, the researchers saw the system's temperature decrease.

"By looking at it you cannot only make it move; you can pull energy out of it," said Schwab. "And the numbers suggest, if we were to keep going on with this work, we would be able to cool this thing very cold. Much colder than we could if we just had this big refrigerator."

The mechanism behind the cooling is analogous to a process called optical or Doppler cooling, which allows atomic physicists to cool atomic vapor with a red laser. This is the first time the phenomenon has been observed in a condensed matter context.

Schwab hasn't decided if he'll pursue the cooling project. More interesting, he says, is the task of figuring out the bigger problem of quantum mechanics: whether it holds true in the macroscopic world; and if not, where the system breaks down.

For that he's focusing on another principle of quantum mechanics -- the superposition principle -- which holds that a particle can simultaneously be in two places.

"We're trying to make a mechanical device be in two places at one time. What's really neat is it looks like we should be able to do it," he said. "The hope, the dream, the fantasy is that we get that superposition and start making bigger devices and find the breakdown."

www.news.cornell.edu/stories/Sept06/schwab.quantum.html