Rising public concern over the safety of synthetic preservatives in personal care products, such as sunscreens, is pressuring stores and manufacturers to turn to naturally derived alternatives. But an article in Chemical & Engineering News (C&EN), the weekly news magazine of the American Chemical Society, notes that a recent recall of a naturally preserved product that nonetheless became contaminated with microbes shows the issue of synthetic versus natural is not cut-and-dried. Marc S. Reisch, a C&EN senior correspondent, explains that preservatives, regardless of where they come from, keep potentially harmful microbes from growing in bottled products. Preservatives are low-cost, low-concentration additives that give these products their long shelf life. But research within the past decade suggests that common synthetic preservatives, such as parabens and formaldehyde, carry their own health risks. Defenders of these compounds counter that the concentrations of the preservatives are so low that they pose little, if any, danger. But some environmental health experts and consumers aren’t buying that argument. In response, some manufacturers are turning to alternatives, including naturally derived compounds. However, last year, a maker of natural personal care products found that some tubes of its children’s sunscreen lotion were contaminated with potentially troublesome microbes, despite containing a plant-based preservative,
The post The fight over preservatives in personal care products has been published on Technology Org.
SpaceX mostly grabs attention for its resupply flights to the International Space Station and for its plans to carry humans to orbit some day soon. But the reason NASA is interested in the company is because it provides a cheap ride to space. And, for that reason, SpaceX has also attracted the interest of commercial satellite providers.
Today, SpaceX hopes to send to orbit some commercial communication satellites from Orbcomm. The hardware, called OG2, will eventually form a 17-satellite mesh that provides constant global coverage. The hardware is compact and light enough that SpaceX's Falcon 9 will be able to carry six to orbit in a single launch.
Right now, weather conditions suggest there's better than even odds that the launch will have to be scrubbed. Should it go ahead, the scheduled departure time is just after 6pm, US Eastern time. SpaceX is livestreaming the launch for those who would like to tune in.
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Principle behind the proposed quantum cryptography protocol. The final single bit value is calculated from many bits through a pair of numbers {i,j} announced by the receiver, Bob. The upper panel corresponds to the actual scheme, in which Bob measures the wave-like nature of the received light sent by Alice to learn the final bit value. Notice that the value of {i,j} might be controlled by an eavesdropper (Eve) through the signal (II) fed to Bob’s measurement process M, so looking at this panel alone, the security is ambiguous. If Bob now measures the particle-like nature of the received light, he no longer learns the final bit but can still exactly produce the same pair {i,j} Lower panel: Here it is seen that {i,j} is directly randomized by the random number generator. Therefore, the possibility that Bob could have measured the particle-like nature of the received light ensures that the randomness of {i,j} is not rigged by Eve. Credit: Toshihiko Sasaki Cryptography – the art and science of providing secure communications – typically employs three methods to authenticate users and prevent data theft: secret key (symmetric) cryptography, which uses a single key for both encryption and decryption; public key (asymmetric) cryptography which uses different
The post Eavesdroppers begone: New quantum key distribution technique is impervious to noise has been published on Technology Org.
esearchers and industry representatives in the refrigeration and air conditioning field will converge in Des Moines later this month to discuss and promote the cause of magnetic refrigeration at the 3rd International Conference on Magnetic Refrigeration at Room Temperature – known in the business as Thermag III. The focus of the four-day event will be on an energy efficient form of refrigeration that replaces gas compressors and ozone-depleting refrigerants with a system that uses special alloys and a magnetic field to provide the cooling and environmentally benign coolants to circulate that cooling power through the refrigeration loop. “Modern compression/expansion refrigeration cycle cooling is a high-energy-demand industry that annually consumes as much as 15 percent of the total electrical energy produced,” said conference organizer Karl Gschneidner, a senior metallurgist at the U.S. Department of Energy’s Ames Laboratory. Gschneidner is an Anson Marston Distinguished Professor at Iowa State University, a pioneer in magnetic refrigeration and a world-renowned expert in the rare-earth metals used in the technology. “Magnetic cooling and refrigeration is 20 to 30 percent more energy efficient than conventional vapor-compression refrigeration,” Gschneidner said, “The magnetic refrigerants are solids, so the hazardous, ozone-depleting and greenhouse chemicals are completely eliminated, making magnetic refrigeration
The post Magnetic cooling enables efficient, ‘green’ refrigeration has been published on Technology Org.
Monitoring a patient’s vital signs and other physiological parameters is a standard part of medical care, but, increasingly, health and fitness-minded individuals are looking for ways to easily keep their own tabs on these measurements. Enter the biometric watch. In a pair of papers published in The Optical Society’s (OSA) open-access journal Biomedical Optics Express, groups of researchers from the Netherlands and Israel describe two new wearable devices that use changing patterns of scattered light to monitor biometrics: one tracks glucose concentration and dehydration levels, and the other monitors pulse. The glucose sensor is the first wearable device that can measure glucose concentration directly but noninvasively, the authors say. And while other wearable devices have been made to monitor pulse, the authors claim their new design would be less sensitive to errors when the wearer is in motion, for example while walking or playing sports Both of the watches described in the two papers make use of the so-called “speckle” effect, the grainy interference patterns that are produced on images when laser light reflects from an uneven surface or scatters from an opaque material. When the material that is scattering the light is moving—say, in the case of blood flowing through the circulatory
The post New biometric watches use light to non-invasively monitor glucose, dehydration, pulse has been published on Technology Org.
