(Press-News.org) By adding an incredibly thin coating of alumina to a metal surface, researchers at the Georgia Institute of Technology have doubled the rate that heat travels from a solid surface – such as a pot on a stove – into the liquid in the pot. The results are published in the American Institute of Physics' journal Applied Physics Letters.
Pool boiling is the most common and familiar method of heating a container's contents, and is a remarkably efficient heat transfer method. The transfer of heat in this case is referred to as the "heat flux." There exists, however, a critical point at which a solid surface gets too hot and pool-boiling efficiency is lost.
"Delaying the critical flux could play an important role in advancing thermal management of electronics as well as improving the efficiency of a number of energy systems," says Bo Feng, Ph.D., the Georgia Tech researcher leading this project.
In boiling, bubbles carry away large amounts of heat from solid surfaces, but the bubbles also act as an insulator, preventing the liquid from rewetting the surface and thereby interrupting heat transfer. The alumina coating – only a few hundreds of atoms thick (1/1,000 the thickness of a human hair) – has a high affinity to water and, as a result, facilitates the rapid rewetting of the solid surface.
"This is the primary reason for the enhancement of heat transfer," says Feng. An atomic layer deposition technique was used to control the thickness. By achieving such a thin coating, the additional layer of alumina did not appreciably increase thermal resistance, but it did increase the overall heat transfer.
"The potential contribution of this investigation lies in tailoring the wettability of surfaces at the nanometer scale, thereby greatly increasing the heat transfer during pool boiling," adds G.P. "Bud" Peterson, Ph.D., director of Georgia Tech's Two-Phase Heat Transfer Lab. "This is especially promising for applications where the implementation of nanotube or nanowire arrays are possible."
Nanotube and nanowire arrays are another effective way to enhance pool boiling heat transfer. Combining these two techniques – nanotube and/or nanowire arrays and nano-coating by atomic layer deposition – may increase pool-boiling efficiency even further.
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Article: "Enhancement of Critical Heat Flux in Pool Boiling Using Atomic Layer Deposition of Alumina" is published in Applied Physics Letters.
Authors: Bo Feng (1), Keith Weaver (1), and G. P. Peterson (1).
(1) George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Ga.
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Atlanta tree services company Yellow Ribbon Tree Experts wants everyone to remember that Arbor Day comes much earlier in Georgia than the Nation's Arbor Day. Arbor Day in Georgia is the third Friday in February, the 17th this year, to align with optimal tree planting season in Georgia, which is between November and mid-March. Arbor Day is observed nationally on the third Friday in April.
Arbor Day is a reminder to take a moment and reflect on the important role that trees play in the great state of Georgia and across the nation. Arbor Day should be about the future and ...
Cyclone Giovanna crossed over the island of Madagascar leaving flooding and damages in its wake and has now entered the Mozambique Channel. NASA's Aqua satellite captured an image that showed a ragged eye still exists, and the storm is regaining strength in the warm Channel waters.
Once Giovanna traversed the island nation of Madagascar and entered the Mozambique Channel, the body of water between Madagascar and Mozambique on the African mainland, NASA's Aqua satellite passed overhead and captured a visible image with the Moderate Resolution Imaging Spectroradiometer ...
With more than 900,000 people travelling with British Airways this February half-term, the airline is giving travellers a light-hearted helping hand with their top travel and baggage tips collected from their staff all over the airline.
The videos, which are located on YouTube, can be found at: http://bit.ly/y0jiLN (Travel) and http://bit.ly/xNZFgE (Baggage).
The videos include tips pertaining to travelling with small children, remaining comfortable when travelling between different climates, how to remember passports and other essentials, and practical packing and ...
A UCLA study has found that a new parent-training program is effective in reducing the risk of low-income, preschool-age Latino children being overweight.
Researchers found that after one year, there was a 9 percent reduction in overweight and obese children in the parent-training intervention group, while a control group that did not receive the parent training had a 16 percent increase in overweight and obese children.
"This is the first pilot intervention study that reversed the weight gain seen in preschool Latino children living in low-income families," said ...
The Radisson Blu Hotel & Spa Sligo has revealed that Dublin based couple, Delia Teahan and Neil O'Donnell have won the wedding of their dreams with the hotel.
The competition was announced in the Sligo Champion, with hundreds of entries from couples longing to win a perfect wedding from the Rosses Point hotel. Ten deserving couples were chosen for the final and had to come face to face in the annual 'Wedding Olympics' competition which was held in the hotel.
There were several rounds in the Wedding Olympics, including going against the clock dressing their partner ...
Vancouver, B.C. — February 15, 2012 — We are on the cusp of a new information revolution — a quantum leap in technology — and the Institute for Quantum Computing (IQC) at the University of Waterloo is leading the way. With the world's largest concentration of researchers working to harness the forces of quantum mechanics, the institute stands to transform computing, communications and other technologies.
"We are learning to speak the language of the quantum realm — of atoms and electrons and molecules," says IQC Executive Director Raymond Laflamme. "By controlling nature's ...
SALT LAKE CITY -- Climate change spells trouble for many tropical birds – especially those living in mountains, coastal forests and relatively small areas – and the damage will be compounded by other threats like habitat loss, disease and competition among species.
That is among the conclusions of a review of nearly 200 scientific studies relevant to the topic. The review was scheduled for online publication this week in the journal Biological Conservation by Çağan Şekercioğlu (pronounced Cha-awn Shay-care-gee-oh-loo), an assistant professor of biology ...
Next are excited to launch their SS12 Lipsy shoe collection! From peeptoe heels to patent courts, the collection of fashionable footwear look great with Lipsy dresses, playsuits and pleated trousers alike.
The collection has pretty party platforms in hot pinks, electric blues and sorbet tones as well as classic black suede heels and shoe boots. Fashion favourites include the beautiful Tilly Criss Cross Wedges, with a flattering design of chunky wedges mixed with delicate dainty straps as well as the Tara courts in pink or animal print. Other new arrivals from Lipsy London ...
Boating industry innovator Teleflex Marine has launched Optimus 360 by SeaStar, a revolutionary joystick steering/shift/throttle control system engineered for powerboats with mechanically-controlled twin outboards. With Optimus 360 by SeaStar, those boat owners can now upgrade their control systems and enjoy easy, precise, intuitive control of their vessel.
Years in development and testing, Optimus 360 by SeaStar uses state-of-the-art electronics to provide easy 360-degree maneuvering capabilities when docking, negotiating crowded areas or loading a vessel onto a trailer. ...
Philadelphia, PA -- The trefoil factor 3 (TFF3) protein protects and maintains the integrity of the epithelial surface in the normal breast. New research has found that while TFF3 protein expression is higher in well-differentiated low grade tumors and therefore associated with features of a good prognosis, it has a more sinister role in breast cancer invasion and metastasis. The report is published in the March issue of the American Journal of Pathology.
"Our findings suggest that TFF3 is regulated by estrogen and has beneficial properties in breast epithelia," says ...
