iPhones are the best
Trying to surf the Web on a mobile phone used to be an exercise in futility. Although smart phones have included Web browsing for quite a few years now, it is only recently that mobile Internet speeds and interfaces have improved to the point where accessing the Internet on a mobile phone is practical and enjoyable.
The introduction of the Apple iPhone set a new standard in mobile phone Web browsing, and a new study from M:Metrics reinforces the commonly held assumption that, given a good mobile Internet browser, users will take full advantage of Internet services on their phones.
The study, which followed the phone habits of over 10,000 adults for a period of six months following the iPhone’s release in the US, found that a full 85% of iPhone users access news and other Web content on a regular basis. The study found that users of other smartphones used the mobile Internet considerably less — only 58% surfed the Web regularly from their phone.
The numbers get even worse for users of regular mobile phones, with only 13% regularly surfing the web from their cell phone.
Mobile Internet experts attribute this to the iPhone’s groundbreaking touchscreen interface and intuitive Web browser. And although many new smartphones have attempted to emulate the intuitive iPhone interface, so far none have succeeded in creating a more user-friendly mobile Web surfing experience.
The study by M:Metrics confirms information released by Google in February, indicating that the Google search engine received 50 times as many search requests from Apple iPhones as from any other competing smart phone.
Another contributing factor may be Apple’s partnership with AT&T. The company offers an unlimited data plan, which thousands of iPhone users have taken advantage of. If they’re not paying anything extra for surfing the web heavily on their phone, it stands to reason that users will take advantage of Web content and services more often.
But experts agree that what really separates the iPhone from its competition is the uniqueness of its Web interface, and the simplicity of the phone’s touchscreen. This allows iPhone users to maneuver their way around the web intuitively, and even provides possibilities unheard-of with a desktop PC.
For example, by touching and “pinching” the screen, iPhone users can manipulate web sites in ways a regular desktop or notebook PC cannot. This allows for a slightly different web surfing experience, but one that is not so different that it requires any additional thought. In other words, the iPhone has managed to strike a careful balance between uniqueness and familiarity — something we all want in any new technology.
Monday 31 March 2008
Sunday 30 March 2008
Nanoparticle Catalyst For More Efficient Hydrogen Fuel-Cell Vehicles
University of Wisconsin-Madison and University of Maryland (UM) team has developed a new nanotechnology-driven chemical catalyst that paves the way for more efficient hydrogen fuel-cell vehicles.
Writing in this week's Advance Online Publication of Nature Materials, UW-Madison chemical and biological engineering Professor Manos Mavrikakis and UM chemistry and biochemistry Professor Bryan Eichhorn describe a new type of catalyst created by surrounding a nanoparticle of ruthenium (Ru) with one to two layers of platinum (Pt) atoms. The result is a robust room-temperature catalyst that dramatically improves a key hydrogen purification reaction and leaves more hydrogen available to make energy in the fuel cell.
One day, it could be common for fuel cells to create electricity by consuming hydrogen generated from renewable resources. For now, most of the world's hydrogen supply is derived from fossil fuels in a process called reforming.
An important step in this multistage process, called preferential oxidation of CO in the presence of hydrogen (PROX), uses a catalyst to purge hydrogen of carbon monoxide (CO) before it enters the fuel cell. CO presents a major obstacle to the practical application of fuel cells because it poisons the expensive platinum catalyst that runs the fuel cell reaction.
Attractive for transportation applications and as a battery replacement, proton exchange membrane fuel cells generate electricity using porous carbon electrodes containing a platinum catalyst separated by a solid polymer. Hydrogen fuel enters one side of the cell and oxygen enters on the opposite side. Platinum facilitates the production of protons from molecular hydrogen, and these protons cross the membrane to react with oxygen on the other side. The result is electricity with water and heat as byproducts.
A conventionally constructed catalyst combining ruthenium and platinum must be heated to 70 degrees Celsius or 158 degrees Fahrenheit in order to drive the PROX reaction, but the same elements combined as core-shell nanoparticles operate at room temperature. The lower the temperature at which catalyst activates the reactants and makes the products, the more energy is saved.
"We understand why it works," Mavrikakis says. "We know now the reason behind this marvelous behavior. The first reason is the core-cell nanostructure. This polymer-based method developed by my colleagues in Maryland allows the exact amount of an element, in this case platinum, to be placed exactly where you want it to be on specific seeds of ruthenium."
This very specific nano-architecture and composition can sustain significantly less CO on its surface than pure Pt would. Because the binding is weaker, Mavrikakis says fewer sites on the core-cell nanostructure are available to bind with CO than would occur with Pt alone. That leaves empty sites for oxygen to come in and react.
"The second reason is that there is a completely new reaction mechanism that makes this work so well," he says. "We call it hydrogen-assisted CO oxidation. It uses atomic hydrogen to attack molecular oxygen and make a hydroperoxy intermediate, which in turn, easily produces atomic oxygen. Then, atomic oxygen selectively attacks CO to produce CO2, leaving much more molecular hydrogen free to be fed to the fuel cell than pure Pt does."
While the breakthrough is important to the development of fuel-cell technology, the researchers say it's even more significant to catalysis in general.
First, the team, including graduate students Anand Nilekar of UW-Madison and Selim Alayoglu of Maryland, used theory rather than an experimental approach to zero in on ruthenium/platinum as the ideal core shell system.
Second, the nanoscale fabrication of ruthenium and platinum resulted in a different nano-architecture than when ruthenium and platinum are combined in bulk. For the field of catalysis, the pairing of these approaches could bridge the gap between surface science and catalysis opening new paths to novel and more energy-efficient materials discovery for a variety of industrially important chemical processes.
Writing in this week's Advance Online Publication of Nature Materials, UW-Madison chemical and biological engineering Professor Manos Mavrikakis and UM chemistry and biochemistry Professor Bryan Eichhorn describe a new type of catalyst created by surrounding a nanoparticle of ruthenium (Ru) with one to two layers of platinum (Pt) atoms. The result is a robust room-temperature catalyst that dramatically improves a key hydrogen purification reaction and leaves more hydrogen available to make energy in the fuel cell.
One day, it could be common for fuel cells to create electricity by consuming hydrogen generated from renewable resources. For now, most of the world's hydrogen supply is derived from fossil fuels in a process called reforming.
An important step in this multistage process, called preferential oxidation of CO in the presence of hydrogen (PROX), uses a catalyst to purge hydrogen of carbon monoxide (CO) before it enters the fuel cell. CO presents a major obstacle to the practical application of fuel cells because it poisons the expensive platinum catalyst that runs the fuel cell reaction.
Attractive for transportation applications and as a battery replacement, proton exchange membrane fuel cells generate electricity using porous carbon electrodes containing a platinum catalyst separated by a solid polymer. Hydrogen fuel enters one side of the cell and oxygen enters on the opposite side. Platinum facilitates the production of protons from molecular hydrogen, and these protons cross the membrane to react with oxygen on the other side. The result is electricity with water and heat as byproducts.
A conventionally constructed catalyst combining ruthenium and platinum must be heated to 70 degrees Celsius or 158 degrees Fahrenheit in order to drive the PROX reaction, but the same elements combined as core-shell nanoparticles operate at room temperature. The lower the temperature at which catalyst activates the reactants and makes the products, the more energy is saved.
"We understand why it works," Mavrikakis says. "We know now the reason behind this marvelous behavior. The first reason is the core-cell nanostructure. This polymer-based method developed by my colleagues in Maryland allows the exact amount of an element, in this case platinum, to be placed exactly where you want it to be on specific seeds of ruthenium."
This very specific nano-architecture and composition can sustain significantly less CO on its surface than pure Pt would. Because the binding is weaker, Mavrikakis says fewer sites on the core-cell nanostructure are available to bind with CO than would occur with Pt alone. That leaves empty sites for oxygen to come in and react.
"The second reason is that there is a completely new reaction mechanism that makes this work so well," he says. "We call it hydrogen-assisted CO oxidation. It uses atomic hydrogen to attack molecular oxygen and make a hydroperoxy intermediate, which in turn, easily produces atomic oxygen. Then, atomic oxygen selectively attacks CO to produce CO2, leaving much more molecular hydrogen free to be fed to the fuel cell than pure Pt does."
While the breakthrough is important to the development of fuel-cell technology, the researchers say it's even more significant to catalysis in general.
First, the team, including graduate students Anand Nilekar of UW-Madison and Selim Alayoglu of Maryland, used theory rather than an experimental approach to zero in on ruthenium/platinum as the ideal core shell system.
Second, the nanoscale fabrication of ruthenium and platinum resulted in a different nano-architecture than when ruthenium and platinum are combined in bulk. For the field of catalysis, the pairing of these approaches could bridge the gap between surface science and catalysis opening new paths to novel and more energy-efficient materials discovery for a variety of industrially important chemical processes.
Tuesday 18 March 2008
Coursework stress
The week has come for coursework submission...
I'm beginging to feel the stress related to coursework; i'm off for two weeks for mid term break, but it isn't a break at all, so much work to do. Heading to Lanzarote tomorrow, dont think ill be able to enjoy it, knowing ive all this work to do :(
I'm beginging to feel the stress related to coursework; i'm off for two weeks for mid term break, but it isn't a break at all, so much work to do. Heading to Lanzarote tomorrow, dont think ill be able to enjoy it, knowing ive all this work to do :(
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