According to a news release on Wednesday by the Rice University, the foam is highly porous and its properties can be tuned for use in air filters and as gas absorption materials.
Materials scientist Pulickel Ajayan and his team discovered freeze-drying h-BN turned it into a macro-scale foam that disintegrates in liquids. But adding a bit of polyvinyl alcohol (PVA) into the mix transformed it into a far more robust and useful material.
The polyvinyl alcohol serves as a glue. Mixed into a solution with flakes of h-BN, it binds the junctions as the microscopic sheets arrange themselves into a lattice when freeze-dried. The one-step process is scalable, the researchers said.
In molecular dynamics simulations, the foam adsorbed 340 percent of its own weight in carbon dioxide. The greenhouse gas can be evaporated out of the material , which can be reused repeatedly. Compression tests showed the foam got stiffer through 2,000 cycles as well.
And when coated with PDMS, another polymer, the foam becomes an effective shield from lasers that could be used in biomedical, electronics and other applications.
Ultimately , the researchers want to gain control over the size of the material's pores for specific applications, like separating oil from water.
Their work appears in the American Chemical Society journal ACS Nano. Rice graduate student Peter Owuor is lead author of the paper.
SAN FRANCISCO, Aug. 15 (Xinhua) -- Uber Technologies, Inc. has agreed to implement a privacy program and obtain independent audits in the next 20 years to settle Federal Trade Commission (FTC) charges that it failed to protect consumer and driver data.
As an independent agency of the U.S. federal government, the FTC announced the settlement Tuesday in Washington , D.C.
One of FTC charges was that due to the San Francisco-based company's failure to provide ride-hailing services, an intruder accessed personal information about Uber drivers in May 2014, including more than 100,000 names and drivers' license numbers that Uber stored in a datastore operated by Amazon Web Services.
In addition, following media reports alleging Uber employees were improperly accessing consumer data , the company stated in November 2014 that it had a "strict policy prohibiting" employees from accessing rider and driver data, except for a limited set of legitimate business purposes, and that employee access would be closely monitored.
However, the FTC found that Uber developed an automated system for monitoring employee access to consumer personal information in December 2014, but the company stopped using the system less than a year after it was put in place; and that for more than nine months afterwards , the company rarely monitored internal access to personal information about users and drivers.
The FTC alleged that Uber did not require engineers and programmers to use distinct access keys to access personal information stored in the cloud. Instead, it allowed them to use a single key that gave them full administrative access to all the data, and did not require multi-factor authentication for accessing the data. And, it stored sensitive consumer information, including geolocation information , in plain readable text in database back-ups stored in the cloud.
"Uber failed consumers in two key ways: First by misrepresenting the extent to which it monitored its employees' access to personal information about users and drivers, and second by misrepresenting that it took reasonable steps to secure that data," FTC Acting Chairman Maureen Ohlhausen was quoted as saying in a news release. "This case shows that, even if you're a fast growing company, you can't leave consumers behind: you must honor your privacy and security promises."
To settle with the FTC , Uber agreed not to misrepresent its monitoring of internal access to consumers' personal information and its protection of such data; agreed to implement a program that addresses privacy risks related to new and existing products and services and protects the privacy and confidentiality of personal information; and agreed to obtain every two years for the next 20 years, independent, third-party audits certifying that it has a privacy program in place that meets or exceeds the requirements of the FTC order.
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HO CHI MINH CITY, April 23 (Xinhua) -- Hanoi topped the country's National Archery Championships 2017, which wrapped up on Sunday in southern Vinh Long province.
Hanoi grabbed 16 golds , seven silvers and nine bronze, followed by Vinh Long with nine golds, six silvers and six bronzes.
Over 150 archers from 16 cities and provinces attended the tournament.
Outstanding archers will either be added to the national team for intensive training, or compete at big regional tournaments. The most prominent archers will compete at the 2017 Southeast Asian Games in Malaysia.
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