The Marangoni effect (sometimes called “tears of wine” ) occurs when drops of a relatively strong alcohol (ethanol) solution on a wine glass slowly begin to crawl up the side of the glass due to the differential evaporation of the ethanol.
Explain this effect from a surface chemical perspective. Would this effect still occur if a less well-made glass were used such that it was significantly rougher than the original glass? What about if a smooth plastic “glass” were used?
The link below has a video of this formation:
http://rapidshare.com/files/82604143/spherical_glass_10ml_300_times.mpg
Wine, is a water-alcohol mixture, and is drawn up the sides of a wine glass as a thin film due to interfacial tensions between the glass and the water alcohol mixture. As the film climbs up the glass, the opposing force of gravity causes the film to thin out at the top, with a greater surface to volume ratio, higher up the glass. This increased surface exposure results in an increase in the evaporation of alcohol from the water-alcohol mixture with a local depletion in alcohol and an increased concentration of water. This local increase in water concentration results in a increase in surface tension (Surface tension for water @ 20°C is 72.8 mJ/m2 and the surface tension of ethanol @ 20°C is 22.3 mJ/m2) Chemical/physical system are always driven to their lowest possible energy state. This increased surface tension and higher energy state is alleviated by the transfer of more wine, containing a higher concentration of alcohol, to the alcohol depleted location at the top of the film. This reduces the surface tension and reduces the energy state. This lifting of wine continues until the forces driving the wine up are outweighed by the forces of gravity pulling the wine down. At this stage the watery wine depleted in alcohol at the top minimises its surface tension by beading until it becomes too heavy and gravity wins as witnessed by the flow of "tears" from the visible ring back down to the wine as it does so. A glass of pure water will see some water drawn up the sides of the glass because of the interfacial tensions, but only to a limited degree, forming a meniscus. Similarly, a meniscus will form with a glass of pure ethanol.
If a less well-made glass were used such that it was significantly rougher than the original glass, it increases the surface tension, increases the wetting ability.
1) Tim Berners Lee -- Founder of the World Wide Web
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2) Picture taken when microsoft was started
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3) Steve Woznaik(sitting) and Steve Jobs of APPLE Computers.
He was three months late in filing a name for the business because he didn't get any better name for his new company.
So one day he told to the staff: " If I'll not get better name by 5 o'clcok today, our company's name will be anything he likes..."
so at 5 o'clcok nobody cameup with better name, and he was eating APPLE that time...
so he kept the name of the company 'Apple Computers'
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4) Bill Hewlett(L) and Dave Packard® of HP.
Behind them in the picture is the famous HP Garage.
Bill Hewlett and Dave Packard tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett.
And the winner was NOT Bill... the winner was Dave.
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5) Ken Thompson (L)and Dennis Ritchie® ,creators of UNIX.
Dennis Ritchie improved on the B programming language and called it 'New B'.
B was created by Ken Thompson as a revision of the Bon programming language (named after his wife Bonnie)
He later called it C.
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6) Larry Page(L) and Sergey Brin®, founders of Google.
Google was originally named 'Googol'.
After founders (Stanford graduates) Sergey Brin and Larry Page presented their project to an angel investor...
they received a cheque made out to 'Google' !...
So they kept name as GOOGLE
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7) Gordon Moore(L) and Bob Noyce® ,founders of Intel.
Bob Noyce and Gordon Moore wanted to name their new company 'Moore Noyce'.
But that was already trademarked by a hotel chain...
So they had to settle for an acronym of INTegrated ELectronics... INTEL
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8 Andreas Bechtolsheim , Bill Joy, Scott Mc Nealy and Vinod Khosla of SUN(StanfordUniversity Network) MicroSystems.
Founded by four StanfordUniversity buddies.
Andreas Bechtolsheim built a microcomputer;
Vinod Khosla recruited him;
Scott McNealy to manufacture computers based on it;
and Bill Joy to develop a UNIX-based OS for the computer...
SUN is the acronym for Stanford University Network .
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9) Linus Torvalds of Linux Operating System Linus Torvalds originally used the Minix OS on his system which he replaced by his OS.
Hence the working name was Linux (Linus' Minix).
He thought the name to be too egotistical and planned to name it Freax (free + freak + x).
His friend Ari Lemmk encouraged Linus to upload it to a network so it could be easily downloaded.
Ari gave Linus a directory called linux on his FTP server, as he did not like the name Freax.
Linus like that directory name and he kept the name of his new OS to LINUX...
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10) Yahoo! began as a student hobby and evolved into a global brand that has changed the way people communicate with each other, find and access information and purchase things. The two founders of Yahoo!, David Filo and Jerry Yang, Ph.D. candidates in Electrical Engineering at Stanford University, started their guide in a campus trailer in February 1994 as a way to keep track of their personal interests on the Internet. Before long they were spending more time on their home-brewed lists of favorite links than on their doctoral dissertations. Eventually, Jerry and David's lists became too long and unwieldy, and they broke them out into categories. When the categories became too full, they developed subcategories ... and the core concept behind Yahoo! was born.
The Web site started out as "Jerry and David's Guide to the World Wide Web" but eventually received a new moniker with the help of a dictionary. The name Yahoo! is an acronym for "Yet Another Hierarchical Officious Oracle," but Filo and Yang insist they selected the name because they liked the general definition of a yahoo: "rude, unsophisticated, uncouth." Yahoo! itself first resided on Yang's student workstation, "Akebono," while the software was lodged on Filo's computer, "Konishiki" - both named after legendary sumo wrestlers.
"Freedom of the Seas"
M/S Freedom of the Seas is a Royal Caribbean International cruise ship. The world's largest passenger vessel, she can accommodate over 4,300 passengers on her fifteen passenger decks, served by over 1300 crew.
She is about 229 ft. longer, about 108,000 gross tons larger, and can accommodate 2,147 more passengers than RMS Titanic. Her operating costs are $1 million per day. Rooms for the maiden voyage were priced from $1,900 to $22,000 for the week. As routine service continues, starting room rates are expected to descend as low as $700 for cruises scheduled in the autumn of 2007. The ship consumes approximately 28,000 gallons of fuel per hour.
Facilities:
The ship features three swimming areas; an interactive water park, a dedicated adult pool and the main pool. There are 2 whirlpools cantilevered out from the ship's sides. The Royal Promenade sports a coffee shop, Sorrento's Pizzeria, a Ben and Jerry's ice-cream shop, Vintage's winery, the Bull and Bear Irish pub, and many Duty-free shops. The 13th deck features a sports area with amenities such as a rock climbing wall, the FlowRider (an onboard wave generator for surfing), a miniature golf course and a full size basketball court. Other items include an ice skating rink, a casino, a Johnny Rockets, Wi-Fi capabilities throughout the ship, flat panel televisions in all staterooms, and cell phone connectivity.
Darpa says a soldier's brain can be monitored in real time, with an EEG picking up "neural signatures" that indicate target detection.U.S. Special Forces may soon have a strange and powerful new weapon in their arsenal: a pair of high-tech binoculars 10 times more powerful than anything available today, augmented by an alerting system that literally taps the wearer's prefrontal cortex to warn of furtive threats detected by the soldier's subconscious.In a new effort dubbed "Luke's Binoculars" -- after the high-tech binoculars Luke Skywalker uses in Star Wars -- the Defense Advanced Research Projects Agency is setting out to create its own version of this science-fiction hardware. And while the Pentagon's R&D arm often focuses on technologies 20 years out, this new effort is dramatically different -- Darpa says it expects to have prototypes in the hands of soldiers in three years.The agency claims no scientific breakthrough is needed on the project -- formally called the Cognitive Technology Threat Warning System. Instead, Darpa hopes to integrate technologies that have been simmering in laboratories for years, ranging from flat-field, wide-angle optics, to the use of advanced electroencephalograms, or EEGs, to rapidly recognize brainwave signatures.In March, Darpa held a meeting in Arlington, Virginia, for scientists and defense contractors who might participate in the project. According to the presentations from the meeting, the agency wants the binoculars to have a range of 1,000 to 10,000 meters, compared to the current generation, which can see out only 300 to 1,000 meters. Darpa also wants the binoculars to provide a 120-degree field of view and be able to spot moving vehicles as far as 10 kilometers away.The most far-reaching component of the binocs has nothing to do with the optics: it's Darpa's aspirations to integrate EEG electrodes that monitor the wearer's neural signals, cueing soldiers to recognize targets faster than the unaided brain could on its own. The idea is that EEG can spot "neural signatures" for target detection before the conscious mind becomes aware of a potential threat or target.Darpa's ambitions are grounded in solid research, says Dennis McBride, president of the Potomac Institute and an expert in the field. "This is all about target recognition and pattern recognition," says McBride, who previously worked for the Navy as an experimental psychologist and has consulted for Darpa. "It turns out that humans in particular have evolved over these many millions of years with a prominent prefrontal cortex."That prefrontal cortex, he explains, allows the brain to pick up patterns quickly, but it also exercises a powerful impulse control, inhibiting false alarms. EEG would essentially allow the binoculars to bypass this inhibitory reaction and signal the wearer to a potential threat. In other words, like Spiderman's "spider sense," a soldier could be alerted to danger that his or her brain had sensed, but not yet had time to process.That said, researchers are circumspect about plans to deploy the technology. One participant in last month's Darpa workshop, John Murray, a scientist at SRI International, says he thought the technology was feasible "in a demonstration environment," but fielding it is another matter."In recent years the ability to measure neural signals and to analyze them quickly has advanced significantly," says Murray, whose own work focuses on human effectiveness. "Typically in these situations, there are a whole lot of other issues (involved) in building and deploying, beyond the research."It's unclear what the final system will look like. The agency's presentations show soldiers operating with EEG sensors attached helmet-style to their heads. Although the electrodes might initially seem ungainly, McBride says that the EEG technology is becoming smaller and less obtrusive. "It's easier and easier," he says.But getting the system down to a target weight of less than five pounds will be a challenge, and Darpa's presentations make it clear that size and power are also issues. But even if EEG doesn't make it into the initial binoculars, researchers involved in other areas say there are plenty of improvements to existing technology that can be fielded.For example, another key aspect of the binoculars will detect threats using neuromorphic engineering, the science of using hardware and software to mimic biological systems. Paul Hasler, a Georgia Institute of Technology professor who specializes in this area and attended the Darpa workshop, describes, for example, an effort to use neural computation to "emulate the brain's visual cortex" -- creating sensors that, like the brain, can scan across a wide field of view and "figure out what's interesting to look at."While some engineers are mimicking the brain, others are going after the eye. Vladimir Brojavic, a former Carnegie Mellon University professor, specializes in a technology that replicates the function of the human retina to allow cameras to see in shadows and poor illumination. He attended last month's workshop, but he said he was unsure whether his company, Intrigue Technologies, would bid for work on the project. "I'm hesitant to pick it up, in case it would distract us from our product development," he says.According to the Darpa presentations, the first prototypes of Luke's Binoculars could be in soldiers' hands within three years. That's an ambitious schedule, and an unusual one for Darpa, note several workshop attendees, who also say they expect fierce competition over the project. The list of attendees at the meeting ranged from university professors to major contractors. Spokespeople for Lockheed Martin and Raytheon both confirmed interest in the program, but declined to say whether they would bid on it.Once fielded, Darpa indicates the measure of success lies with the military. According to information the agency provided to industry, initial prototypes would go to Special Forces. If the military asks to keep the binoculars after the trials, "that's exactly what you want here," Darpa wrote. "That's success."Why all the rush? "I have to wonder if they aren't under pressure from Congress to make a contribution (to the war on terrorism), or if DOD is really leaning on them to come up with some stuff," suggests Jonathan Moreno, a professor of ethics at the University of Pennsylvania, whose recent book, Mind Wars, looks at the Pentagon's burgeoning interest in neuroscience. Darpa did not respond to press inquiries about the program.Despite the fast schedule, McBride, of the Potomac Institute, thinks the idea is doable. "It's a risky venture, but that's what Darpa does," he says. "It's absolutely feasible."A Look at Darpa's Mind-Melding Binoculars
It's not just EEG and neuromorphic engineering that would make these binoculars powerful; Darpa also plans to integrate advanced optics and digital processing.
Combining neural signals, neuromimetic algorithms and neuromorphic processing, Darpa wants "Luke's Binoculars" to take advantage of the latest developments in neuroscience research and applications