Héroes, 21 de abril: Antonio Velasco Benito



El 21 de abril de 1984 la banda terrorista ETA asesina en Bilbao al guardia civil ANTONIO VELASCO BENITO. Formaba parte del retén que aquel sábado prestaba servicio de vigilancia en la Audiencia Territorial de Bilbao, y se encontraba en una de las puertas del edificio, en pleno centro de la ciudad. Eran aproximadamente las 17:30 horas y, en ese momento, Antonio era el único agente que se encontraba en el exterior del edificio.
Fue tiroteado con armas automáticas desde un coche en marcha en el que iban tres terroristas, dos hombres y una mujer. Antonio fue alcanzado en la cabeza y en una pierna. Trasladado al Hospital Civil de Basurto, murió una hora después.
Los etarras ocupaban un vehículo Renault 14 blanco, robado previamente a punta de pistola. Sin llegar a detener el mismo, dispararon al menos seis disparos contra Antonio. En el lugar de los hechos se encontraron dos casquillos del calibre 9 milímetros parabellum marca FN. Los terroristas se dieron a la fuga en el mismo vehículo desde el que habían disparado, en dirección al casco antiguo de la ciudad.
El coche fue localizado poco después cerca del lugar del atentado. Artificieros de la Policía Nacional registraron el automóvil con sumas precauciones, en previsión de que en su interior hubiera sido colocada una bomba-trampa similar a la que, el 13 de abril, asesinó a Tomás Palacín Pellejero y Juan José Visiedo Calero en Pamplona.
Antonio Velasco Benito, de 39 años, era de Pedrosilla del Ralo (Salamanca). Estaba casado y tenía un niño de 7 años. Fue enterrado en su localidad natal, en un acto presidido por el ministro de Interior.

Hormigón Armado y Pretensado

Concreto reforzado y preesforzado. 2007. Enrique Hernández Montes y Luisa María Gil Martín. [Descargar en PDF, 16.8 Mb].

Incluyo este libro en mi recopilación sobre Estructuras.


Estimado amigo: 

El libro que te presentamos, con el título “Hormigón Armado y Pretensado –Concreto Reforzado y Preesforzado-“ corresponde al libro de texto de la asignatura del mismo nombre en la Escuela de Ingenieros de Caminos, Canales y Puertos de la Universidad de Granada, España. Si bien ha sido enriquecido tratando de responder a las dudas que nos han surgido durante nuestros años docentes. Este libro pretende ser un tratado general de cálculo de estructuras de hormigón armado y pretensado, por eso se han obviado temas como soluciones constructivas y detalles, que se pueden consultar en otros volúmenes existentes en el mercado y en proyectos constructivos.

Hoy día, debido a la facilidad de cálculo asociada con el desarrollo de la informática, el uso de tablas y reglas simplificadas está en desuso. De hecho, actualmente es inconcebible abordar el cálculo de una estructura sin la ayuda de un programa de ordenador adecuado. En este contexto, este libro pretende aumentar el conocimiento teórico del ingeniero y del alumno de ingenieríateniendo como base una importante carga teórica y conceptual.

Aunque generalmente se utiliza la normativa española (EHE) y la europea (Eurocódigo-2), en general el texto no se ciñe a una norma específica, haciéndose mención, por su interés práctico en casos concretos, a otras normas como la americana ACI-318 o la suiza SIA-165 -entre otras-.

Nuestro agradecimiento a los profesores que en mayor o menor medida han colaborado en la edición de este libro, especialmente a: Mark Aschheim de la Universidad de Santa Clara (California), Luis Albajar Molera de la UPM, Rafael Gallego Sevilla y Miguel Losada Rodríguez, ambos de la UGR, a Stravoula Pantazopoulous de la Universidad de Tracia y a Daniel Kuchma de la Universidad de Illinois U-C.

Especial agradecimiento a las empresas y asociaciones que han colaborado y sin cuya financiación no hubiésemos extendido este trabajo a todas la Escuelas de Ingenieros de Caminos de España, para cuyos alumnos de la signatura de hormigón armado, este volumen será gratuito los próximos dos años. Además está disponible en red para cualquier persona que lo desee. Estas empresas son:

SACYR, JOCA, AZVI, PROINTEC, HOLCIM, DETECSA, ORTIZ Construcciones, BRUES Y FERNÁNDEZ, GARASA, IECA y CHM.

Los autores.

Granada, Diciembre de 2007

War Is Good for the Economy - Isn't It?



Antiwar.com, March 6, 2006
A common theme that has emerged in critiques of my "Wartime Economist" columns on Antiwar.com is that war is good for an economy. One respondent wrote:

"Why did [Franklin D.] Roosevelt want the war [World War II] so badly? He wanted it for the same reason every American president since that time has wanted a war, and that is to prevent the US economy from slipping deeper and deeper into economic depression. Counting the Cold War, the United States has been in a continual state of war for the past 60 years, and there is no end in sight. Without war, I do not believe our economy can survive."

The people who write me to this effect seem to hate that "fact." They would prefer that war not be a plus for an economy – but, nevertheless, they think it is. This belief has led many of these people to feel hopeless because they think that, on top of all the other difficulties of opposing war, they are opposing something that makes Americans better off. If I thought that, I would feel hopeless too. Fortunately, it's not true. The actual fact is that any war, even a war that is justified, has substantial costs.

Imagine an economy whose government spends 2 percent of its GDP on its military. (On average, the world's governments spend just under 2 percent of their countries' GDP on the military, and the U.S. government spends about 4 percent.) Then, imagine that the government suddenly gets into a war and raises military spending to 7 percent of national income. How does that affect people in that country? Whether the government finances the war effort with taxes or debt or by printing money is not very important. What matters much more is that the government now takes an additional 5 percent of the real output of that economy to wage its war. The government buys tanks, trucks, fuel, clothing, parachutes, bullets, guns, airplanes, and all the other paraphernalia of war. In addition, the government hires laborers away from other uses, or it drafts them. All of the capital and labor that go to produce the "outputs" of war is capital and labor that cannot be used in their previous uses. Thus, there is a cost of all these resources used in war – what economists call the "opportunity cost." "Opportunity cost" means the value of the highest-valued opportunity foregone. The opportunity cost of resources spent on war is the value of these resources in what they would have been used for had the government not gone to war.

Take World War II. The government spent a good deal more than 7 percent of GDP on the war, and, in fact, in 1944, the peak of the U.S. government's World War II spending (as a percent of gross national product), the government spent about 45 percent of gross national product on the war. (Gross national product, not gross domestic product, was the widely used measure back then. For the U.S. economy, the difference between the two measures is close to rounding error.) Where did the resources come from to make the hundreds of thousands of trucks and jeeps and the tens of thousands of tanks and airplanes? Much of the capital and labor would have been producing cars and trucks for the domestic economy. In fact, the assembly lines in Detroit, which had churned out 3.6 million cars in 1941, were retooled to produce the vehicles of war. By 1942, auto production was down to under 1 million. For the years 1943 to 1945, auto production was so low that Wikipedia does not even report it. During the period from late 1942 to the 1945, in other words, almost the whole of U.S. participation in the war, production of civilian cars was essentially shut down.

Consider fuel. Because the government wanted to buy fuel at an artificially low price, it imposed price controls on gasoline and put itself first in line. Then it issued ration cards to Americans, dramatically reducing the amount that normal Americans could buy at the controlled prices. In his autobiography, the late David Brinkley tells how he was unable to continue a serious romance during World War II because he couldn't legally buy gasoline to drive to the city where his lady friend lived. Even railroad seats were rationed, writes Brinkley, with priority given to military personnel. In the government's eyes, letting congressmen and other high-level government officials have all the gasoline they wanted, with the rare "X" stickers, was so important to the war effort that the amount available to them was not rationed at all. A young congressman named Lyndon B. Johnson took advantage of this, driving home to his district in Texas from Washington almost every weekend.

In short, the resources used for the war effort were not available to the typical American and his or her previous normal pursuits.

So imagine that somehow the United States had avoided entering World War II. I don't want to talk about the consequences for the world – that is controversial and, more important, completely separable from the issue of the war's effect on the U.S. economy. Millions of cars would have been produced; people would have been able to travel much more widely; and there would have been no rationing of meat, tires, nylons, eggs, butter, and sugar. In short, by the standard measures of prosperity, Americans would have been much more prosperous. And David Brinkley would have been able to pursue his true love. I mention this last consequence not to emphasize the trivia, but, in fact, to do the opposite – to emphasize one of millions of stories of the large human cost that befell even Americans whom the U.S. government did not put at risk of dying.

But I certainly shouldn't leave the issue of human cost without mentioning the ultimate cost – the 407,000 Americans who lost their lives because of the war. As one of my students, a U.S. military officer, put it in a classroom discussion, the war was not good for their economy, to put it mildly.

To many of you, what I wrote above may sound strange. Isn't World War II, in fact, the big counterexample to all that I'm saying? Didn't World War II bring us out of the Great Depression, as the vast majority of Americans and a simple majority of economists, appear to believe? If we go merely with labels and definitions and forget what they're supposed to stand for, then yes. The Great Depression is typically defined as the period from 1929 to 1941, and America entered the war in 1941. But if we go with the idea that depressions are supposed to measure something about the real amount of goods and services available to people, then no. A complete exposition of this is the topic of my next column on Antiwar.com. Stay tuned.

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Espeluznante reporte de una doctora mexicana que visita a Cuba

En Cuba es más fácil abortar que conseguir un condón”, afirma la sexóloga mexicana Claudia Rampazzo luego de una visita de ocho días a La Habana, en la cual la “increíble realidad cotidiana” la superó de tal manera que regresó deprimida. Relata la especialista que una colega cubana que conoció pasando un curso de superación en su país, actualmente tiene entre sus "obligaciones profesionales” limpiar los baños (servicios sanitarios) del Instituto Médico en el cual trabaja bajo la dirección de Mariela Castro.

 La entrevista fue realizada por Carlos Cataño para su programa “De regreso a casa” que transmite Radio Caracol de lunes a viernes de 4 a 7 p.m.

Audio.

All Alone in the Night - Time-lapse footage of the Earth as seen from the ISS


The third industrial revolution

The digitisation of manufacturing will transform the way goods are made—and change the politics of jobs too.



The first industrial revolution began in Britain in the late 18th century, with the mechanisation of the textile industry. Tasks previously done laboriously by hand in hundreds of weavers’ cottages were brought together in a single cotton mill, and the factory was born. The second industrial revolution came in the early 20th century, when Henry Ford mastered the moving assembly line and ushered in the age of mass production. The first two industrial revolutions made people richer and more urban. Now a third revolution is under way. Manufacturing is going digital. As this week’s special report argues, this could change not just business, but much else besides.
A number of remarkable technologies are converging: clever software, novel materials, more dexterous robots, new processes (notably three-dimensional printing) and a whole range of web-based services. The factory of the past was based on cranking out zillions of identical products: Ford famously said that car-buyers could have any colour they liked, as long as it was black. But the cost of producing much smaller batches of a wider variety, with each product tailored precisely to each customer’s whims, is falling. The factory of the future will focus on mass customisation—and may look more like those weavers’ cottages than Ford’s assembly line.
Towards a third dimension.


The old way of making things involved taking lots of parts and screwing or welding them together. Now a product can be designed on a computer and “printed” on a 3D printer, which creates a solid object by building up successive layers of material. The digital design can be tweaked with a few mouseclicks. The 3D printer can run unattended, and can make many things which are too complex for a traditional factory to handle. In time, these amazing machines may be able to make almost anything, anywhere—from your garage to an African village.
The applications of 3D printing are especially mind-boggling. Already, hearing aids and high-tech parts of military jets are being printed in customised shapes. The geography of supply chains will change. An engineer working in the middle of a desert who finds he lacks a certain tool no longer has to have it delivered from the nearest city. He can simply download the design and print it. The days when projects ground to a halt for want of a piece of kit, or when customers complained that they could no longer find spare parts for things they had bought, will one day seem quaint.
Other changes are nearly as momentous. New materials are lighter, stronger and more durable than the old ones. Carbon fibre is replacing steel and aluminium in products ranging from aeroplanes to mountain bikes. New techniques let engineers shape objects at a tiny scale. Nanotechnology is giving products enhanced features, such as bandages that help heal cuts, engines that run more efficiently and crockery that cleans more easily. Genetically engineered viruses are being developed to make items such as batteries. And with the internet allowing ever more designers to collaborate on new products, the barriers to entry are falling. Ford needed heaps of capital to build his colossal River Rouge factory; his modern equivalent can start with little besides a laptop and a hunger to invent.
Like all revolutions, this one will be disruptive. Digital technology has already rocked the media and retailing industries, just as cotton mills crushed hand looms and the Model T put farriers out of work. Many people will look at the factories of the future and shudder. They will not be full of grimy machines manned by men in oily overalls. Many will be squeaky clean—and almost deserted. Some carmakers already produce twice as many vehicles per employee as they did only a decade or so ago. Most jobs will not be on the factory floor but in the offices nearby, which will be full of designers, engineers, IT specialists, logistics experts, marketing staff and other professionals. The manufacturing jobs of the future will require more skills. Many dull, repetitive tasks will become obsolete: you no longer need riveters when a product has no rivets.
The revolution will affect not only how things are made, but where. Factories used to move to low-wage countries to curb labour costs. But labour costs are growing less and less important: a $499 first-generation iPad included only about $33 of manufacturing labour, of which the final assembly in China accounted for just $8. Offshore production is increasingly moving back to rich countries not because Chinese wages are rising, but because companies now want to be closer to their customers so that they can respond more quickly to changes in demand. And some products are so sophisticated that it helps to have the people who design them and the people who make them in the same place. The Boston Consulting Group reckons that in areas such as transport, computers, fabricated metals and machinery, 10-30% of the goods that America now imports from China could be made at home by 2020, boosting American output by $20 billion-55 billion a year.
The shock of the new
Consumers will have little difficulty adapting to the new age of better products, swiftly delivered. Governments, however, may find it harder. Their instinct is to protect industries and companies that already exist, not the upstarts that would destroy them. They shower old factories with subsidies and bully bosses who want to move production abroad. They spend billions backing the new technologies which they, in their wisdom, think will prevail. And they cling to a romantic belief that manufacturing is superior to services, let alone finance.
None of this makes sense. The lines between manufacturing and services are blurring. Rolls-Royce no longer sells jet engines; it sells the hours that each engine is actually thrusting an aeroplane through the sky. Governments have always been lousy at picking winners, and they are likely to become more so, as legions of entrepreneurs and tinkerers swap designs online, turn them into products at home and market them globally from a garage. As the revolution rages, governments should stick to the basics: better schools for a skilled workforce, clear rules and a level playing field for enterprises of all kinds. Leave the rest to the revolutionaries.