The best hope for bringing the hydrogen-fueled automobile to the American roadway may be a technology that is invisible to the naked eye.The technology is in the form of tiny graphite structures that together act as a sponge to absorb and store hydrogen in the fuel system of the automobile. Onboard storage of hydrogen gas is the major obstacle impeding the progress and wide-scale commercial production of the hydrogen-powered vehicle, which many view as the next generation in energy-efficient and environmentally friendly road transportation.The graphite structures are a product of the burgeoning field of nanotechnology. Engineers design the structures at the molecular level, working in scales as small as millimeters and nanometers. The engineers stack the fibrous platelets one atop the other, leaving the optimum gap between the wafers; then they arrange the chemistry so that hydrogen molecules are absorbed in the graphite.The nanostructures are extremely porous, like a sponge, allowing them to absorb large capacities of hydrogen until fully saturated. Experiments demonstrate that the hydrogen storage in graphite nanofibers is safe.Another method of hydrogen storage derived from nanotechnology involves carbon nano-tubes. With carbon nanotubes, engineers arrange carbon platelets in different configurations. Research has shown the carbon nanotubes to display strong hydrogen storage capabilities.The contribution of nanotechnology to hydrogen storage is timely, as automobile companies work to advance fuel cell technology amid growing public sentiments to develop alternative forms of energy. Despite the promise of nanotechnology in automobile fuel cells, additional research is required to refine graphite nanofibers and carbon nanotubes and to develop cost-effective means to manufacture the advanced structures.The Nanotechnology Institute at the American Society of Mechanical Engineers (ASME) strongly supports research in nanotechnology and is dedicated to narrowing the gap between theoretical science and real-world applications. Among other programs, the institute organizes forums that bring together the technical community and general public to review developments in the field.
Has your family started to cram into the old sedan like a pack of sardines? Have members of the neighborhood car pool begun to look suspiciously at your battered station wagon? Perhaps its time to retire the old family car and move up to a bigger vehicle. Often, the choice for a more spacious family vehicle is a toss-up between a sport utility vehicle (SUV) and a minivan. Both offer flexible passenger and cargo areas, comfortable seating for five to eight persons, and rear-seat entertainment systems. Although the SUV has a slightly higher risk for rollovers than minivans do, both are equipped with similar safety features, such as air bags and anti-lock brake systems. So, which one deserves to park in your family garage? To come up with the right choice, you need to look at how the vehicles styling, fuel economy, passenger and cargo space, towing capacity, and safety will suit your familys needs and lifestyle.StylingMore than a matter of need, a vehicles styling is a matter of personal preference. The SUV usually wins out over the minivan when it comes to appearance. With its rugged, sporty styling, an SUV oozes urban cool, unlike the minivan, which is perpetually associated with soccer moms and suburban neighborhood carpools. Most men would recoil at the thought of driving a minivan, so if your husband would be sharing driving duties, you might have to talk it out with him. Likewise, many teenagers wouldnt be caught dead stepping out of a minivan, so if youd be using the vehicle mainly to drop off and pick up your adolescent children from school, youd have to consider their preferences, too.Fuel economyMinivans give better mileage than SUVs, which have a reputation for being gas guzzlers. If you want to squeeze more miles out of the gasoline tank, then a minivan would make a more economic choice than an SUV. Other ownership costs, such as maintenance and insurance, also tend to be higher for SUVs than minivans. Unless youre willing to pay the price for being cool and stylish, the practical minivan is the way to go.Passenger and cargo spaceSport utility vehicles and minivans have comparable passenger and cargo space, but the roomy interiors of a minivan can be a delight to young kids. Unlike SUVs, minivans also have a low step-in height, so theyre easier for kids to climb into. Minivans large picture windows afford young passengers a better view of the passing scenery, therefore keeping your impatient young ones amused for a good part of the ride.Towing capacityIf you own a boat and like to take the entire brood for weekend sailing retreats, then an SUV would make an appropriate choice. SUVs have superior towing capacities, enabling them to pull practically anything between a trailer and a small boat. Otherwise, if youre only schlepping groceries and your kids soccer team, then theres no reason to overlook the minivan.SafetyAlthough both have comparable safety features, SUVs have a higher rollover risk than minivans. SUV devotees counter this by pointing out that rollovers account for only three percent of all traffic accidents and claiming that SUVs offer excellent passenger protection in two-car collisions. It remains to be seen whether this supposed collision safety factor outweighs the risk of rollovers. If the threat of rollover accidents keeps you awake at night, then a minivan could give you a little peace of mind.
Spike Lee is one of the most influential and provocative American moviemakers. Recently, he celebrated the 20 year anniversary for the release of his remarkable debut film Shes Gotta Have It. His films are groundbreaking in their controversial approach towards social and political issues and offer different perspective on race, class and gender issues in contemporary America. "Spike Lee" was born as Shelton Jackson Lee in 1957 in Atlanta, Georgia to a jazz musician and an art teacher. When Lee was a young child, the family relocated to Brooklyn, which was used as a background for many of Spike Lee's movies. Lee's talent was recognized while he was still a film student in NYU. His thesis film Joes Bed Stuy Barbershop: We Cut Heads won 1983 Student Academy Award for best director. Spike Lee's debut movie "Shes Gotta Have It" was released in 1986. The movie was shot in 12 days in a budget of 175,000 dollars. The film was written, produced and directed by Spike Lee. Shes Gotta Have It tells the story of Nora Darling, a young, independent African American graphic designer who cannot commit to any of her three lovers. Tracy Camilla Jones played the role of Nora Darling. Tommy Redmond Hicks and John Canada Terrell along with Lee himself played the three men in Noras life. Shes Gotta Have It was a landmark film in its presentation of African American characters in an American movie and part of the explosion of 80s independent movie industry. The African American community embraced the movie, which displayed a non stereotypical group of young, intelligent black American people. The film won the Prix de Jeuness at the Cannes film festival for the best new film by a newcomer. The 1992 biographic epic Malcolm X is considered by many as Lee's best film. The 195 minutes movie depicts the story of the African American activist "Malcolm X" , from his early childhood to his assassination. Lee uses the Malcolm X story to confront the audience with the racial discrimination and violence that black people went through during the 1950s and 1960s in America. Spike Lee's name was associated with many controversies. He was often accused of anti Semitism and racism for portraying Jews and Italians in his films a stereotypical manner. His 2001 television miniseries about one of the Black Panthers founders, Huey P. Newton, stirred another controversy, which helped establish Lee's image as a provocative and radical figures in the American film industry. Lee's latest project is the documentary When the Levees Broke: A Requiem in Four Acts, which tells the story of New Orleans post and pre hurricane Katrina. The four hours documentary is about the New Orleans culture, the damage caused by hurricane Katrina and the recovery efforts. Lee does not spare his critic on the government inadequate reaction to the destruction. 5 Top Movies Directed by Spike LeeDo The Right Thing: this 1989 comic drama shows what happens in Brookline when the interracial tension heats up during the hottest day of the year. Starring: Spike Lee, Danny Aiello, John TurturroMo Better Blues: Denzel Washington as a jazz trumpeter who makes all the wrong decisions regarding his musical career and relationships.Jungle Fever tells a pessimistic interracial love story between an African American man and an Italian American woman.Girl 6 looks at the life of a young black actress who prefers working as a phone girl than being abused by movie directors25th Hour is dedicated to the last 24 hours in the life of a New York drug dealer before his jail term begins.
En los ltimos aos la mucha gente se ha dado cuenta de la importancia de una dieta apropiada y acompaada de ejercicio fsico. En los pasados 20 aos sin duda ha habido un cambio en cuanto al estado de salud de muchas sociedades, que ha determinado una mejor calidad de vida. Sin embargo, esto no ha trado salud mental que es tan importante como la salud fsica.Hoy en da, la mayora de la gente hace de 4 a 6 horas de ejercicio por da, y se asegura de que todo lo que ingiere, no tiene azucares o preservantes, pero no prestan atencin a su salud mental. Es decir, mucha gente no toma las vacaciones necesarias, ni siquiera en los fines de semana largos. La gente trabaja 60 horas por semana, llevndose a las casas los problemas del trabajo y trabajando los fines de semana tambin. Todo esto con esperanzas de mejorar la calidad de vida material. Pero, de que sirve todo el esfuerzo cuando el cerebro esta abundado y sientes explotar en la oficina?Al final, la salud fsica puede sufrir no importa que bien comas y hagas ejercicio. Probablemente tengas alta presin, estrs y tensin lo cual pondr en alto riesgo tu salud.Para ayudarte a evitar llegar a alguna de las anteriores situaciones, aqu te presento algunos consejos para mejorar tu condicin mental.Si disfrutas la adrenalina, te recomiendo que pruebes deportes como kite surfing, bunge jumping, y dems. Si disfrutas andar en motocicleta es muy bueno andar en contra del viento como terapia para relajarse y disfrutar un buen viaje.Buscar actividades que te desconecten de la rutina diaria (la cual a veces puede ser estresante) es la clave principal. Por ejemplo, si disfrutas leer, un buen libro de ciencia ficcin como "Harry Potter", "Lord of the Rings" u otros pueden ser perfectos para ti. Si disfrutas en cambio mirar pelculas, entonces comienza con hacerte socio de una tienda de DVDs y veras que bien te har.Actividades como paseos fuera de la ciudad, visitar viedos, campos, parques y dems son esenciales a la hora de relajarse. Si disfrutas las montaas, todava puedes ir a visitar la nieve, esquiar y aflojar tu mente. Las vacaciones, por ms pequeas que sean te llenaran el alma con memorias alegres y positivas.Si disfrutas andar en bicicleta, o en patines esas son actividades que te destaparan y ayudaran a sentirte mejor. Siempre es divertido hacerlo con amigos que estn dispuestos a un poco de aventura. Organizar un grupo grande de gente que quiera hacerlo es una buena idea, que los puede llevar a conocer lugares que nunca creas que ibas a encontrar. Ros abandonados, pasajes que estn cerrados para la gente, bosques y dems lugares increbles para conocer.En fin, hay un sin fin de actividades para llevar a cabo si buscas caminos diferentes para mejorar tu salud mental y relajarte naturalmente. No olvides que la salud mental es tan importante como la fsica y que para tener una hay que tener la otra!
Helmet is a French derivative of the word helm from 15th century. Although helmets are available in countless designs for different utilities, they all serve just one purpose, which is head protection. The earlier helmets used to be manufactured in leather till the 10th century AD when metals with inner cloth lining for cushioning and comfort of wearing on the head became the norm. Helmet wearing is mandatory in northern America, barring a few states, for all bikers, whereas Sikhs are demanding a waiver from this mandate.Functional Utility and SymbolismTill the early 20th century, helmets were basically the protective head gears of soldiers and used to be a part of combat uniform. With industrialization, helmets reinvented themselves and undergone a lot of changes, both in terms of strengths and weights and became a must wear for certain industrial workers in sectors such as mining, construction and manufacturing etc. Surely, the popularity of helmets shot-up, thanks to the symbolic protection they offered.Typical ClassificationHelmets can be classified based on their utility and construction. The simplest for of helmets worn by construction workers and bicycle riders are nothing more than hard hats as they are required to protect blunt impacts, whereas a soldiers helmets are designed for ballistic impact protection. These are made by Kevlar, which has excellent bullet proofing qualities and fragmentation powers.Helmets match particular needs also. Military helmets identify the ranks of the wearers with symbolic visors and bars therein, whereas hard hats of bicycle riders sport large ventilation slots.Quality StandardsBikers and parents of small children are in dilemma concerning the sudden fall in childrens helmet prices. One must keep in mind that price is not a good quality indicator. In the US, the Consumer Product Safety Commission (CPSC) requires all helmets be certified. The certification is issued after stringent quality tests are carried out. There is another quality standard for helmets, too. Snell Memorial Foundation standards or Snells as they are known are a bit extra stringent, albeit not compulsory by all types of helmet manufacturers to conform to. This fact should try to put at rest the apprehensions of consumers when they dont see Snells label on helmets.It is hard to think of a modern and adventurous sport without helmets being mandatory. Although helmets arent absolutely safe, you cant think of cross country biking without them, especially if the riders are your little ones, helmets are a must!